/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
* $FreeBSD$
*/
/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2016, Joyent, Inc. All rights reserved.
* Copyright (c) 2012, 2014 by Delphix. All rights reserved.
*/
/*
* DTrace - Dynamic Tracing for Solaris
*
* This is the implementation of the Solaris Dynamic Tracing framework
* (DTrace). The user-visible interface to DTrace is described at length in
* the "Solaris Dynamic Tracing Guide". The interfaces between the libdtrace
* library, the in-kernel DTrace framework, and the DTrace providers are
* described in the block comments in the <sys/dtrace.h> header file. The
* internal architecture of DTrace is described in the block comments in the
* <sys/dtrace_impl.h> header file. The comments contained within the DTrace
* implementation very much assume mastery of all of these sources; if one has
* an unanswered question about the implementation, one should consult them
* first.
*
* The functions here are ordered roughly as follows:
*
* - Probe context functions
* - Probe hashing functions
* - Non-probe context utility functions
* - Matching functions
* - Provider-to-Framework API functions
* - Probe management functions
* - DIF object functions
* - Format functions
* - Predicate functions
* - ECB functions
* - Buffer functions
* - Enabling functions
* - DOF functions
* - Anonymous enabling functions
* - Consumer state functions
* - Helper functions
* - Hook functions
* - Driver cookbook functions
*
* Each group of functions begins with a block comment labelled the "DTrace
* [Group] Functions", allowing one to find each block by searching forward
* on capital-f functions.
*/
#include <sys/errno.h>
#ifndef illumos
#include <sys/time.h>
#endif
#include <sys/stat.h>
#include <sys/modctl.h>
#include <sys/conf.h>
#include <sys/systm.h>
#ifdef illumos
#include <sys/ddi.h>
#include <sys/sunddi.h>
#endif
#include <sys/cpuvar.h>
#include <sys/kmem.h>
#ifdef illumos
#include <sys/strsubr.h>
#endif
#include <sys/sysmacros.h>
#include <sys/dtrace_impl.h>
#include <sys/atomic.h>
#include <sys/cmn_err.h>
#ifdef illumos
#include <sys/mutex_impl.h>
#include <sys/rwlock_impl.h>
#endif
#include <sys/ctf_api.h>
#ifdef illumos
#include <sys/panic.h>
#include <sys/priv_impl.h>
#endif
#include <sys/policy.h>
#ifdef illumos
#include <sys/cred_impl.h>
#include <sys/procfs_isa.h>
#endif
#include <sys/taskq.h>
#ifdef illumos
#include <sys/mkdev.h>
#include <sys/kdi.h>
#endif
#include <sys/zone.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "strtolctype.h"
/* FreeBSD includes: */
#ifndef illumos
#include <sys/callout.h>
#include <sys/ctype.h>
#include <sys/eventhandler.h>
#include <sys/limits.h>
#include <sys/linker.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/ptrace.h>
#include <sys/rwlock.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/dtrace_bsd.h>
#include <netinet/in.h>
#include "dtrace_cddl.h"
#include "dtrace_debug.c"
#endif
/*
* DTrace Tunable Variables
*
* The following variables may be tuned by adding a line to /etc/system that
* includes both the name of the DTrace module ("dtrace") and the name of the
* variable. For example:
*
* set dtrace:dtrace_destructive_disallow = 1
*
* In general, the only variables that one should be tuning this way are those
* that affect system-wide DTrace behavior, and for which the default behavior
* is undesirable. Most of these variables are tunable on a per-consumer
* basis using DTrace options, and need not be tuned on a system-wide basis.
* When tuning these variables, avoid pathological values; while some attempt
* is made to verify the integrity of these variables, they are not considered
* part of the supported interface to DTrace, and they are therefore not
* checked comprehensively. Further, these variables should not be tuned
* dynamically via "mdb -kw" or other means; they should only be tuned via
* /etc/system.
*/
int dtrace_destructive_disallow = 0;
#ifndef illumos
/* Positive logic version of dtrace_destructive_disallow for loader tunable */
int dtrace_allow_destructive = 1;
#endif
dtrace_optval_t dtrace_nonroot_maxsize = (16 * 1024 * 1024);
size_t dtrace_difo_maxsize = (256 * 1024);
dtrace_optval_t dtrace_dof_maxsize = (8 * 1024 * 1024);
size_t dtrace_statvar_maxsize = (16 * 1024);
size_t dtrace_actions_max = (16 * 1024);
size_t dtrace_retain_max = 1024;
dtrace_optval_t dtrace_helper_actions_max = 128;
dtrace_optval_t dtrace_helper_providers_max = 32;
dtrace_optval_t dtrace_dstate_defsize = (1 * 1024 * 1024);
size_t dtrace_strsize_default = 256;
dtrace_optval_t dtrace_cleanrate_default = 9900990; /* 101 hz */
dtrace_optval_t dtrace_cleanrate_min = 200000; /* 5000 hz */
dtrace_optval_t dtrace_cleanrate_max = (uint64_t)60 * NANOSEC; /* 1/minute */
dtrace_optval_t dtrace_aggrate_default = NANOSEC; /* 1 hz */
dtrace_optval_t dtrace_statusrate_default = NANOSEC; /* 1 hz */
dtrace_optval_t dtrace_statusrate_max = (hrtime_t)10 * NANOSEC; /* 6/minute */
dtrace_optval_t dtrace_switchrate_default = NANOSEC; /* 1 hz */
dtrace_optval_t dtrace_nspec_default = 1;
dtrace_optval_t dtrace_specsize_default = 32 * 1024;
dtrace_optval_t dtrace_stackframes_default = 20;
dtrace_optval_t dtrace_ustackframes_default = 20;
dtrace_optval_t dtrace_jstackframes_default = 50;
dtrace_optval_t dtrace_jstackstrsize_default = 512;
int dtrace_msgdsize_max = 128;
hrtime_t dtrace_chill_max = MSEC2NSEC(500); /* 500 ms */
hrtime_t dtrace_chill_interval = NANOSEC; /* 1000 ms */
int dtrace_devdepth_max = 32;
int dtrace_err_verbose;
hrtime_t dtrace_deadman_interval = NANOSEC;
hrtime_t dtrace_deadman_timeout = (hrtime_t)10 * NANOSEC;
hrtime_t dtrace_deadman_user = (hrtime_t)30 * NANOSEC;
hrtime_t dtrace_unregister_defunct_reap = (hrtime_t)60 * NANOSEC;
#ifndef illumos
int dtrace_memstr_max = 4096;
#endif
/*
* DTrace External Variables
*
* As dtrace(7D) is a kernel module, any DTrace variables are obviously
* available to DTrace consumers via the backtick (`) syntax. One of these,
* dtrace_zero, is made deliberately so: it is provided as a source of
* well-known, zero-filled memory. While this variable is not documented,
* it is used by some translators as an implementation detail.
*/
const char dtrace_zero[256] = { 0 }; /* zero-filled memory */
/*
* DTrace Internal Variables
*/
#ifdef illumos
static dev_info_t *dtrace_devi; /* device info */
#endif
#ifdef illumos
static vmem_t *dtrace_arena; /* probe ID arena */
static vmem_t *dtrace_minor; /* minor number arena */
#else
static taskq_t *dtrace_taskq; /* task queue */
static struct unrhdr *dtrace_arena; /* Probe ID number. */
#endif
static dtrace_probe_t **dtrace_probes; /* array of all probes */
static int dtrace_nprobes; /* number of probes */
static dtrace_provider_t *dtrace_provider; /* provider list */
static dtrace_meta_t *dtrace_meta_pid; /* user-land meta provider */
static int dtrace_opens; /* number of opens */
static int dtrace_helpers; /* number of helpers */
static int dtrace_getf; /* number of unpriv getf()s */
#ifdef illumos
static void *dtrace_softstate; /* softstate pointer */
#endif
static dtrace_hash_t *dtrace_bymod; /* probes hashed by module */
static dtrace_hash_t *dtrace_byfunc; /* probes hashed by function */
static dtrace_hash_t *dtrace_byname; /* probes hashed by name */
static dtrace_toxrange_t *dtrace_toxrange; /* toxic range array */
static int dtrace_toxranges; /* number of toxic ranges */
static int dtrace_toxranges_max; /* size of toxic range array */
static dtrace_anon_t dtrace_anon; /* anonymous enabling */
static kmem_cache_t *dtrace_state_cache; /* cache for dynamic state */
static uint64_t dtrace_vtime_references; /* number of vtimestamp refs */
static kthread_t *dtrace_panicked; /* panicking thread */
static dtrace_ecb_t *dtrace_ecb_create_cache; /* cached created ECB */
static dtrace_genid_t dtrace_probegen; /* current probe generation */
static dtrace_helpers_t *dtrace_deferred_pid; /* deferred helper list */
static dtrace_enabling_t *dtrace_retained; /* list of retained enablings */
static dtrace_genid_t dtrace_retained_gen; /* current retained enab gen */
static dtrace_dynvar_t dtrace_dynhash_sink; /* end of dynamic hash chains */
static int dtrace_dynvar_failclean; /* dynvars failed to clean */
#ifndef illumos
static struct mtx dtrace_unr_mtx;
MTX_SYSINIT(dtrace_unr_mtx, &dtrace_unr_mtx, "Unique resource identifier", MTX_DEF);
static eventhandler_tag dtrace_kld_load_tag;
static eventhandler_tag dtrace_kld_unload_try_tag;
#endif
/*
* DTrace Locking
* DTrace is protected by three (relatively coarse-grained) locks:
*
* (1) dtrace_lock is required to manipulate essentially any DTrace state,
* including enabling state, probes, ECBs, consumer state, helper state,
* etc. Importantly, dtrace_lock is _not_ required when in probe context;
* probe context is lock-free -- synchronization is handled via the
* dtrace_sync() cross call mechanism.
*
* (2) dtrace_provider_lock is required when manipulating provider state, or
* when provider state must be held constant.
*
* (3) dtrace_meta_lock is required when manipulating meta provider state, or
* when meta provider state must be held constant.
*
* The lock ordering between these three locks is dtrace_meta_lock before
* dtrace_provider_lock before dtrace_lock. (In particular, there are
* several places where dtrace_provider_lock is held by the framework as it
* calls into the providers -- which then call back into the framework,
* grabbing dtrace_lock.)
*
* There are two other locks in the mix: mod_lock and cpu_lock. With respect
* to dtrace_provider_lock and dtrace_lock, cpu_lock continues its historical
* role as a coarse-grained lock; it is acquired before both of these locks.
* With respect to dtrace_meta_lock, its behavior is stranger: cpu_lock must
* be acquired _between_ dtrace_meta_lock and any other DTrace locks.
* mod_lock is similar with respect to dtrace_provider_lock in that it must be
* acquired _between_ dtrace_provider_lock and dtrace_lock.
*/
static kmutex_t dtrace_lock; /* probe state lock */
static kmutex_t dtrace_provider_lock; /* provider state lock */
static kmutex_t dtrace_meta_lock; /* meta-provider state lock */
#ifndef illumos
/* XXX FreeBSD hacks. */
#define cr_suid cr_svuid
#define cr_sgid cr_svgid
#define ipaddr_t in_addr_t
#define mod_modname pathname
#define vuprintf vprintf
#define ttoproc(_a) ((_a)->td_proc)
#define crgetzoneid(_a) 0
#define NCPU MAXCPU
#define SNOCD 0
#define CPU_ON_INTR(_a) 0
#define PRIV_EFFECTIVE (1 << 0)
#define PRIV_DTRACE_KERNEL (1 << 1)
#define PRIV_DTRACE_PROC (1 << 2)
#define PRIV_DTRACE_USER (1 << 3)
#define PRIV_PROC_OWNER (1 << 4)
#define PRIV_PROC_ZONE (1 << 5)
#define PRIV_ALL ~0
SYSCTL_DECL(_debug_dtrace);
SYSCTL_DECL(_kern_dtrace);
#endif
#ifdef illumos
#define curcpu CPU->cpu_id
#endif
/*
* DTrace Provider Variables
*
* These are the variables relating to DTrace as a provider (that is, the
* provider of the BEGIN, END, and ERROR probes).
*/
static dtrace_pattr_t dtrace_provider_attr = {
{ DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
{ DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
{ DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
};
static void
dtrace_nullop(void)
{}
static dtrace_pops_t dtrace_provider_ops = {
(void (*)(void *, dtrace_probedesc_t *))dtrace_nullop,
(void (*)(void *, modctl_t *))dtrace_nullop,
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
NULL,
NULL,
NULL,
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop
};
static dtrace_id_t dtrace_probeid_begin; /* special BEGIN probe */
static dtrace_id_t dtrace_probeid_end; /* special END probe */
dtrace_id_t dtrace_probeid_error; /* special ERROR probe */
/*
* DTrace Helper Tracing Variables
*
* These variables should be set dynamically to enable helper tracing. The
* only variables that should be set are dtrace_helptrace_enable (which should
* be set to a non-zero value to allocate helper tracing buffers on the next
* open of /dev/dtrace) and dtrace_helptrace_disable (which should be set to a
* non-zero value to deallocate helper tracing buffers on the next close of
* /dev/dtrace). When (and only when) helper tracing is disabled, the
* buffer size may also be set via dtrace_helptrace_bufsize.
*/
int dtrace_helptrace_enable = 0;
int dtrace_helptrace_disable = 0;
int dtrace_helptrace_bufsize = 16 * 1024 * 1024;
uint32_t dtrace_helptrace_nlocals;
static dtrace_helptrace_t *dtrace_helptrace_buffer;
static uint32_t dtrace_helptrace_next = 0;
static int dtrace_helptrace_wrapped = 0;
/*
* DTrace Error Hashing
*
* On DEBUG kernels, DTrace will track the errors that has seen in a hash
* table. This is very useful for checking coverage of tests that are
* expected to induce DIF or DOF processing errors, and may be useful for
* debugging problems in the DIF code generator or in DOF generation . The
* error hash may be examined with the ::dtrace_errhash MDB dcmd.
*/
#ifdef DEBUG
static dtrace_errhash_t dtrace_errhash[DTRACE_ERRHASHSZ];
static const char *dtrace_errlast;
static kthread_t *dtrace_errthread;
static kmutex_t dtrace_errlock;
#endif
/*
* DTrace Macros and Constants
*
* These are various macros that are useful in various spots in the
* implementation, along with a few random constants that have no meaning
* outside of the implementation. There is no real structure to this cpp
* mishmash -- but is there ever?
*/
#define DTRACE_HASHSTR(hash, probe) \
dtrace_hash_str(*((char **)((uintptr_t)(probe) + (hash)->dth_stroffs)))
#define DTRACE_HASHNEXT(hash, probe) \
(dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_nextoffs)
#define DTRACE_HASHPREV(hash, probe) \
(dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_prevoffs)
#define DTRACE_HASHEQ(hash, lhs, rhs) \
(strcmp(*((char **)((uintptr_t)(lhs) + (hash)->dth_stroffs)), \
*((char **)((uintptr_t)(rhs) + (hash)->dth_stroffs))) == 0)
#define DTRACE_AGGHASHSIZE_SLEW 17
#define DTRACE_V4MAPPED_OFFSET (sizeof (uint32_t) * 3)
/*
* The key for a thread-local variable consists of the lower 61 bits of the
* t_did, plus the 3 bits of the highest active interrupt above LOCK_LEVEL.
* We add DIF_VARIABLE_MAX to t_did to assure that the thread key is never
* equal to a variable identifier. This is necessary (but not sufficient) to
* assure that global associative arrays never collide with thread-local
* variables. To guarantee that they cannot collide, we must also define the
* order for keying dynamic variables. That order is:
*
* [ key0 ] ... [ keyn ] [ variable-key ] [ tls-key ]
*
* Because the variable-key and the tls-key are in orthogonal spaces, there is
* no way for a global variable key signature to match a thread-local key
* signature.
*/
#ifdef illumos
#define DTRACE_TLS_THRKEY(where) { \
uint_t intr = 0; \
uint_t actv = CPU->cpu_intr_actv >> (LOCK_LEVEL + 1); \
for (; actv; actv >>= 1) \
intr++; \
ASSERT(intr < (1 << 3)); \
(where) = ((curthread->t_did + DIF_VARIABLE_MAX) & \
(((uint64_t)1 << 61) - 1)) | ((uint64_t)intr << 61); \
}
#else
#define DTRACE_TLS_THRKEY(where) { \
solaris_cpu_t *_c = &solaris_cpu[curcpu]; \
uint_t intr = 0; \
uint_t actv = _c->cpu_intr_actv; \
for (; actv; actv >>= 1) \
intr++; \
ASSERT(intr < (1 << 3)); \
(where) = ((curthread->td_tid + DIF_VARIABLE_MAX) & \
(((uint64_t)1 << 61) - 1)) | ((uint64_t)intr << 61); \
}
#endif
#define DT_BSWAP_8(x) ((x) & 0xff)
#define DT_BSWAP_16(x) ((DT_BSWAP_8(x) << 8) | DT_BSWAP_8((x) >> 8))
#define DT_BSWAP_32(x) ((DT_BSWAP_16(x) << 16) | DT_BSWAP_16((x) >> 16))
#define DT_BSWAP_64(x) ((DT_BSWAP_32(x) << 32) | DT_BSWAP_32((x) >> 32))
#define DT_MASK_LO 0x00000000FFFFFFFFULL
#define DTRACE_STORE(type, tomax, offset, what) \
*((type *)((uintptr_t)(tomax) + (uintptr_t)offset)) = (type)(what);
#ifndef __x86
#define DTRACE_ALIGNCHECK(addr, size, flags) \
if (addr & (size - 1)) { \
*flags |= CPU_DTRACE_BADALIGN; \
cpu_core[curcpu].cpuc_dtrace_illval = addr; \
return (0); \
}
#else
#define DTRACE_ALIGNCHECK(addr, size, flags)
#endif
/*
* Test whether a range of memory starting at testaddr of size testsz falls
* within the range of memory described by addr, sz. We take care to avoid
* problems with overflow and underflow of the unsigned quantities, and
* disallow all negative sizes. Ranges of size 0 are allowed.
*/
#define DTRACE_INRANGE(testaddr, testsz, baseaddr, basesz) \
((testaddr) - (uintptr_t)(baseaddr) < (basesz) && \
(testaddr) + (testsz) - (uintptr_t)(baseaddr) <= (basesz) && \
(testaddr) + (testsz) >= (testaddr))
#define DTRACE_RANGE_REMAIN(remp, addr, baseaddr, basesz) \
do { \
if ((remp) != NULL) { \
*(remp) = (uintptr_t)(baseaddr) + (basesz) - (addr); \
} \
_NOTE(CONSTCOND) } while (0)
/*
* Test whether alloc_sz bytes will fit in the scratch region. We isolate
* alloc_sz on the righthand side of the comparison in order to avoid overflow
* or underflow in the comparison with it. This is simpler than the INRANGE
* check above, because we know that the dtms_scratch_ptr is valid in the
* range. Allocations of size zero are allowed.
*/
#define DTRACE_INSCRATCH(mstate, alloc_sz) \
((mstate)->dtms_scratch_base + (mstate)->dtms_scratch_size - \
(mstate)->dtms_scratch_ptr >= (alloc_sz))
#define DTRACE_LOADFUNC(bits) \
/*CSTYLED*/ \
uint##bits##_t \
dtrace_load##bits(uintptr_t addr) \
{ \
size_t size = bits / NBBY; \
/*CSTYLED*/ \
uint##bits##_t rval; \
int i; \
volatile uint16_t *flags = (volatile uint16_t *) \
&cpu_core[curcpu].cpuc_dtrace_flags; \
\
DTRACE_ALIGNCHECK(addr, size, flags); \
\
for (i = 0; i < dtrace_toxranges; i++) { \
if (addr >= dtrace_toxrange[i].dtt_limit) \
continue; \
\
if (addr + size <= dtrace_toxrange[i].dtt_base) \
continue; \
\
/* \
* This address falls within a toxic region; return 0. \
*/ \
*flags |= CPU_DTRACE_BADADDR; \
cpu_core[curcpu].cpuc_dtrace_illval = addr; \
return (0); \
} \
\
*flags |= CPU_DTRACE_NOFAULT; \
/*CSTYLED*/ \
rval = *((volatile uint##bits##_t *)addr); \
*flags &= ~CPU_DTRACE_NOFAULT; \
\
return (!(*flags & CPU_DTRACE_FAULT) ? rval : 0); \
}
#ifdef _LP64
#define dtrace_loadptr dtrace_load64
#else
#define dtrace_loadptr dtrace_load32
#endif
#define DTRACE_DYNHASH_FREE 0
#define DTRACE_DYNHASH_SINK 1
#define DTRACE_DYNHASH_VALID 2
#define DTRACE_MATCH_NEXT 0
#define DTRACE_MATCH_DONE 1
#define DTRACE_ANCHORED(probe) ((probe)->dtpr_func[0] != '\0')
#define DTRACE_STATE_ALIGN 64
#define DTRACE_FLAGS2FLT(flags) \
(((flags) & CPU_DTRACE_BADADDR) ? DTRACEFLT_BADADDR : \
((flags) & CPU_DTRACE_ILLOP) ? DTRACEFLT_ILLOP : \
((flags) & CPU_DTRACE_DIVZERO) ? DTRACEFLT_DIVZERO : \
((flags) & CPU_DTRACE_KPRIV) ? DTRACEFLT_KPRIV : \
((flags) & CPU_DTRACE_UPRIV) ? DTRACEFLT_UPRIV : \
((flags) & CPU_DTRACE_TUPOFLOW) ? DTRACEFLT_TUPOFLOW : \
((flags) & CPU_DTRACE_BADALIGN) ? DTRACEFLT_BADALIGN : \
((flags) & CPU_DTRACE_NOSCRATCH) ? DTRACEFLT_NOSCRATCH : \
((flags) & CPU_DTRACE_BADSTACK) ? DTRACEFLT_BADSTACK : \
DTRACEFLT_UNKNOWN)
#define DTRACEACT_ISSTRING(act) \
((act)->dta_kind == DTRACEACT_DIFEXPR && \
(act)->dta_difo->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING)
/* Function prototype definitions: */
static size_t dtrace_strlen(const char *, size_t);
static dtrace_probe_t *dtrace_probe_lookup_id(dtrace_id_t id);
static void dtrace_enabling_provide(dtrace_provider_t *);
static int dtrace_enabling_match(dtrace_enabling_t *, int *);
static void dtrace_enabling_matchall(void);
static void dtrace_enabling_reap(void);
static dtrace_state_t *dtrace_anon_grab(void);
static uint64_t dtrace_helper(int, dtrace_mstate_t *,
dtrace_state_t *, uint64_t, uint64_t);
static dtrace_helpers_t *dtrace_helpers_create(proc_t *);
static void dtrace_buffer_drop(dtrace_buffer_t *);
static int dtrace_buffer_consumed(dtrace_buffer_t *, hrtime_t when);
static intptr_t dtrace_buffer_reserve(dtrace_buffer_t *, size_t, size_t,
dtrace_state_t *, dtrace_mstate_t *);
static int dtrace_state_option(dtrace_state_t *, dtrace_optid_t,
dtrace_optval_t);
static int dtrace_ecb_create_enable(dtrace_probe_t *, void *);
static void dtrace_helper_provider_destroy(dtrace_helper_provider_t *);
uint16_t dtrace_load16(uintptr_t);
uint32_t dtrace_load32(uintptr_t);
uint64_t dtrace_load64(uintptr_t);
uint8_t dtrace_load8(uintptr_t);
void dtrace_dynvar_clean(dtrace_dstate_t *);
dtrace_dynvar_t *dtrace_dynvar(dtrace_dstate_t *, uint_t, dtrace_key_t *,
size_t, dtrace_dynvar_op_t, dtrace_mstate_t *, dtrace_vstate_t *);
uintptr_t dtrace_dif_varstr(uintptr_t, dtrace_state_t *, dtrace_mstate_t *);
static int dtrace_priv_proc(dtrace_state_t *);
static void dtrace_getf_barrier(void);
static int dtrace_canload_remains(uint64_t, size_t, size_t *,
dtrace_mstate_t *, dtrace_vstate_t *);
static int dtrace_canstore_remains(uint64_t, size_t, size_t *,
dtrace_mstate_t *, dtrace_vstate_t *);
/*
* DTrace Probe Context Functions
*
* These functions are called from probe context. Because probe context is
* any context in which C may be called, arbitrarily locks may be held,
* interrupts may be disabled, we may be in arbitrary dispatched state, etc.
* As a result, functions called from probe context may only call other DTrace
* support functions -- they may not interact at all with the system at large.
* (Note that the ASSERT macro is made probe-context safe by redefining it in
* terms of dtrace_assfail(), a probe-context safe function.) If arbitrary
* loads are to be performed from probe context, they _must_ be in terms of
* the safe dtrace_load*() variants.
*
* Some functions in this block are not actually called from probe context;
* for these functions, there will be a comment above the function reading
* "Note: not called from probe context."
*/
void
dtrace_panic(const char *format, ...)
{
va_list alist;
va_start(alist, format);
#ifdef __FreeBSD__
vpanic(format, alist);
#else
dtrace_vpanic(format, alist);
#endif
va_end(alist);
}
int
dtrace_assfail(const char *a, const char *f, int l)
{
dtrace_panic("assertion failed: %s, file: %s, line: %d", a, f, l);
/*
* We just need something here that even the most clever compiler
* cannot optimize away.
*/
return (a[(uintptr_t)f]);
}
/*
* Atomically increment a specified error counter from probe context.
*/
static void
dtrace_error(uint32_t *counter)
{
/*
* Most counters stored to in probe context are per-CPU counters.
* However, there are some error conditions that are sufficiently
* arcane that they don't merit per-CPU storage. If these counters
* are incremented concurrently on different CPUs, scalability will be
* adversely affected -- but we don't expect them to be white-hot in a
* correctly constructed enabling...
*/
uint32_t oval, nval;
do {
oval = *counter;
if ((nval = oval + 1) == 0) {
/*
* If the counter would wrap, set it to 1 -- assuring
* that the counter is never zero when we have seen
* errors. (The counter must be 32-bits because we
* aren't guaranteed a 64-bit compare&swap operation.)
* To save this code both the infamy of being fingered
* by a priggish news story and the indignity of being
* the target of a neo-puritan witch trial, we're
* carefully avoiding any colorful description of the
* likelihood of this condition -- but suffice it to
* say that it is only slightly more likely than the
* overflow of predicate cache IDs, as discussed in
* dtrace_predicate_create().
*/
nval = 1;
}
} while (dtrace_cas32(counter, oval, nval) != oval);
}
/*
* Use the DTRACE_LOADFUNC macro to define functions for each of loading a
* uint8_t, a uint16_t, a uint32_t and a uint64_t.
*/
/* BEGIN CSTYLED */
DTRACE_LOADFUNC(8)
DTRACE_LOADFUNC(16)
DTRACE_LOADFUNC(32)
DTRACE_LOADFUNC(64)
/* END CSTYLED */
static int
dtrace_inscratch(uintptr_t dest, size_t size, dtrace_mstate_t *mstate)
{
if (dest < mstate->dtms_scratch_base)
return (0);
if (dest + size < dest)
return (0);
if (dest + size > mstate->dtms_scratch_ptr)
return (0);
return (1);
}
static int
dtrace_canstore_statvar(uint64_t addr, size_t sz, size_t *remain,
dtrace_statvar_t **svars, int nsvars)
{
int i;
size_t maxglobalsize, maxlocalsize;
if (nsvars == 0)
return (0);
maxglobalsize = dtrace_statvar_maxsize + sizeof (uint64_t);
maxlocalsize = maxglobalsize * NCPU;
for (i = 0; i < nsvars; i++) {
dtrace_statvar_t *svar = svars[i];
uint8_t scope;
size_t size;
if (svar == NULL || (size = svar->dtsv_size) == 0)
continue;
scope = svar->dtsv_var.dtdv_scope;
/*
* We verify that our size is valid in the spirit of providing
* defense in depth: we want to prevent attackers from using
* DTrace to escalate an orthogonal kernel heap corruption bug
* into the ability to store to arbitrary locations in memory.
*/
VERIFY((scope == DIFV_SCOPE_GLOBAL && size <= maxglobalsize) ||
(scope == DIFV_SCOPE_LOCAL && size <= maxlocalsize));
if (DTRACE_INRANGE(addr, sz, svar->dtsv_data,
svar->dtsv_size)) {
DTRACE_RANGE_REMAIN(remain, addr, svar->dtsv_data,
svar->dtsv_size);
return (1);
}
}
return (0);
}
/*
* Check to see if the address is within a memory region to which a store may
* be issued. This includes the DTrace scratch areas, and any DTrace variable
* region. The caller of dtrace_canstore() is responsible for performing any
* alignment checks that are needed before stores are actually executed.
*/
static int
dtrace_canstore(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
dtrace_vstate_t *vstate)
{
return (dtrace_canstore_remains(addr, sz, NULL, mstate, vstate));
}
/*
* Implementation of dtrace_canstore which communicates the upper bound of the
* allowed memory region.
*/
static int
dtrace_canstore_remains(uint64_t addr, size_t sz, size_t *remain,
dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
{
/*
* First, check to see if the address is in scratch space...
*/
if (DTRACE_INRANGE(addr, sz, mstate->dtms_scratch_base,
mstate->dtms_scratch_size)) {
DTRACE_RANGE_REMAIN(remain, addr, mstate->dtms_scratch_base,
mstate->dtms_scratch_size);
return (1);
}
/*
* Now check to see if it's a dynamic variable. This check will pick
* up both thread-local variables and any global dynamically-allocated
* variables.
*/
if (DTRACE_INRANGE(addr, sz, vstate->dtvs_dynvars.dtds_base,
vstate->dtvs_dynvars.dtds_size)) {
dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
uintptr_t base = (uintptr_t)dstate->dtds_base +
(dstate->dtds_hashsize * sizeof (dtrace_dynhash_t));
uintptr_t chunkoffs;
dtrace_dynvar_t *dvar;
/*
* Before we assume that we can store here, we need to make
* sure that it isn't in our metadata -- storing to our
* dynamic variable metadata would corrupt our state. For
* the range to not include any dynamic variable metadata,
* it must:
*
* (1) Start above the hash table that is at the base of
* the dynamic variable space
*
* (2) Have a starting chunk offset that is beyond the
* dtrace_dynvar_t that is at the base of every chunk
*
* (3) Not span a chunk boundary
*
* (4) Not be in the tuple space of a dynamic variable
*
*/
if (addr < base)
return (0);
chunkoffs = (addr - base) % dstate->dtds_chunksize;
if (chunkoffs < sizeof (dtrace_dynvar_t))
return (0);
if (chunkoffs + sz > dstate->dtds_chunksize)
return (0);
dvar = (dtrace_dynvar_t *)((uintptr_t)addr - chunkoffs);
if (dvar->dtdv_hashval == DTRACE_DYNHASH_FREE)
return (0);
if (chunkoffs < sizeof (dtrace_dynvar_t) +
((dvar->dtdv_tuple.dtt_nkeys - 1) * sizeof (dtrace_key_t)))
return (0);
DTRACE_RANGE_REMAIN(remain, addr, dvar, dstate->dtds_chunksize);
return (1);
}
/*
* Finally, check the static local and global variables. These checks
* take the longest, so we perform them last.
*/
if (dtrace_canstore_statvar(addr, sz, remain,
vstate->dtvs_locals, vstate->dtvs_nlocals))
return (1);
if (dtrace_canstore_statvar(addr, sz, remain,
vstate->dtvs_globals, vstate->dtvs_nglobals))
return (1);
return (0);
}
/*
* Convenience routine to check to see if the address is within a memory
* region in which a load may be issued given the user's privilege level;
* if not, it sets the appropriate error flags and loads 'addr' into the
* illegal value slot.
*
* DTrace subroutines (DIF_SUBR_*) should use this helper to implement
* appropriate memory access protection.
*/
static int
dtrace_canload(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
dtrace_vstate_t *vstate)
{
return (dtrace_canload_remains(addr, sz, NULL, mstate, vstate));
}
/*
* Implementation of dtrace_canload which communicates the uppoer bound of the
* allowed memory region.
*/
static int
dtrace_canload_remains(uint64_t addr, size_t sz, size_t *remain,
dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
{
volatile uintptr_t *illval = &cpu_core[curcpu].cpuc_dtrace_illval;
file_t *fp;
/*
* If we hold the privilege to read from kernel memory, then
* everything is readable.
*/
if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0) {
DTRACE_RANGE_REMAIN(remain, addr, addr, sz);
return (1);
}
/*
* You can obviously read that which you can store.
*/
if (dtrace_canstore_remains(addr, sz, remain, mstate, vstate))
return (1);
/*
* We're allowed to read from our own string table.
*/
if (DTRACE_INRANGE(addr, sz, mstate->dtms_difo->dtdo_strtab,
mstate->dtms_difo->dtdo_strlen)) {
DTRACE_RANGE_REMAIN(remain, addr,
mstate->dtms_difo->dtdo_strtab,
mstate->dtms_difo->dtdo_strlen);
return (1);
}
if (vstate->dtvs_state != NULL &&
dtrace_priv_proc(vstate->dtvs_state)) {
proc_t *p;
/*
* When we have privileges to the current process, there are
* several context-related kernel structures that are safe to
* read, even absent the privilege to read from kernel memory.
* These reads are safe because these structures contain only
* state that (1) we're permitted to read, (2) is harmless or
* (3) contains pointers to additional kernel state that we're
* not permitted to read (and as such, do not present an
* opportunity for privilege escalation). Finally (and
* critically), because of the nature of their relation with
* the current thread context, the memory associated with these
* structures cannot change over the duration of probe context,
* and it is therefore impossible for this memory to be
* deallocated and reallocated as something else while it's
* being operated upon.
*/
if (DTRACE_INRANGE(addr, sz, curthread, sizeof (kthread_t))) {
DTRACE_RANGE_REMAIN(remain, addr, curthread,
sizeof (kthread_t));
return (1);
}
if ((p = curthread->t_procp) != NULL && DTRACE_INRANGE(addr,
sz, curthread->t_procp, sizeof (proc_t))) {
DTRACE_RANGE_REMAIN(remain, addr, curthread->t_procp,
sizeof (proc_t));
return (1);
}
if (curthread->t_cred != NULL && DTRACE_INRANGE(addr, sz,
curthread->t_cred, sizeof (cred_t))) {
DTRACE_RANGE_REMAIN(remain, addr, curthread->t_cred,
sizeof (cred_t));
return (1);
}
#ifdef illumos
if (p != NULL && p->p_pidp != NULL && DTRACE_INRANGE(addr, sz,
&(p->p_pidp->pid_id), sizeof (pid_t))) {
DTRACE_RANGE_REMAIN(remain, addr, &(p->p_pidp->pid_id),
sizeof (pid_t));
return (1);
}
if (curthread->t_cpu != NULL && DTRACE_INRANGE(addr, sz,
curthread->t_cpu, offsetof(cpu_t, cpu_pause_thread))) {
DTRACE_RANGE_REMAIN(remain, addr, curthread->t_cpu,
offsetof(cpu_t, cpu_pause_thread));
return (1);
}
#endif
}
if ((fp = mstate->dtms_getf) != NULL) {
uintptr_t psz = sizeof (void *);
vnode_t *vp;
vnodeops_t *op;
/*
* When getf() returns a file_t, the enabling is implicitly
* granted the (transient) right to read the returned file_t
* as well as the v_path and v_op->vnop_name of the underlying
* vnode. These accesses are allowed after a successful
* getf() because the members that they refer to cannot change
* once set -- and the barrier logic in the kernel's closef()
* path assures that the file_t and its referenced vode_t
* cannot themselves be stale (that is, it impossible for
* either dtms_getf itself or its f_vnode member to reference
* freed memory).
*/
if (DTRACE_INRANGE(addr, sz, fp, sizeof (file_t))) {
DTRACE_RANGE_REMAIN(remain, addr, fp, sizeof (file_t));
return (1);
}
if ((vp = fp->f_vnode) != NULL) {
size_t slen;
#ifdef illumos
if (DTRACE_INRANGE(addr, sz, &vp->v_path, psz)) {
DTRACE_RANGE_REMAIN(remain, addr, &vp->v_path,
psz);
return (1);
}
slen = strlen(vp->v_path) + 1;
if (DTRACE_INRANGE(addr, sz, vp->v_path, slen)) {
DTRACE_RANGE_REMAIN(remain, addr, vp->v_path,
slen);
return (1);
}
#endif
if (DTRACE_INRANGE(addr, sz, &vp->v_op, psz)) {
DTRACE_RANGE_REMAIN(remain, addr, &vp->v_op,
psz);
return (1);
}
#ifdef illumos
if ((op = vp->v_op) != NULL &&
DTRACE_INRANGE(addr, sz, &op->vnop_name, psz)) {
DTRACE_RANGE_REMAIN(remain, addr,
&op->vnop_name, psz);
return (1);
}
if (op != NULL && op->vnop_name != NULL &&
DTRACE_INRANGE(addr, sz, op->vnop_name,
(slen = strlen(op->vnop_name) + 1))) {
DTRACE_RANGE_REMAIN(remain, addr,
op->vnop_name, slen);
return (1);
}
#endif
}
}
DTRACE_CPUFLAG_SET(CPU_DTRACE_KPRIV);
*illval = addr;
return (0);
}
/*
* Convenience routine to check to see if a given string is within a memory
* region in which a load may be issued given the user's privilege level;
* this exists so that we don't need to issue unnecessary dtrace_strlen()
* calls in the event that the user has all privileges.
*/
static int
dtrace_strcanload(uint64_t addr, size_t sz, size_t *remain,
dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
{
size_t rsize;
/*
* If we hold the privilege to read from kernel memory, then
* everything is readable.
*/
if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0) {
DTRACE_RANGE_REMAIN(remain, addr, addr, sz);
return (1);
}
/*
* Even if the caller is uninterested in querying the remaining valid
* range, it is required to ensure that the access is allowed.
*/
if (remain == NULL) {
remain = &rsize;
}
if (dtrace_canload_remains(addr, 0, remain, mstate, vstate)) {
size_t strsz;
/*
* Perform the strlen after determining the length of the
* memory region which is accessible. This prevents timing
* information from being used to find NULs in memory which is
* not accessible to the caller.
*/
strsz = 1 + dtrace_strlen((char *)(uintptr_t)addr,
MIN(sz, *remain));
if (strsz <= *remain) {
return (1);
}
}
return (0);
}
/*
* Convenience routine to check to see if a given variable is within a memory
* region in which a load may be issued given the user's privilege level.
*/
static int
dtrace_vcanload(void *src, dtrace_diftype_t *type, size_t *remain,
dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
{
size_t sz;
ASSERT(type->dtdt_flags & DIF_TF_BYREF);
/*
* Calculate the max size before performing any checks since even
* DTRACE_ACCESS_KERNEL-credentialed callers expect that this function
* return the max length via 'remain'.
*/
if (type->dtdt_kind == DIF_TYPE_STRING) {
dtrace_state_t *state = vstate->dtvs_state;
if (state != NULL) {
sz = state->dts_options[DTRACEOPT_STRSIZE];
} else {
/*
* In helper context, we have a NULL state; fall back
* to using the system-wide default for the string size
* in this case.
*/
sz = dtrace_strsize_default;
}
} else {
sz = type->dtdt_size;
}
/*
* If we hold the privilege to read from kernel memory, then
* everything is readable.
*/
if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0) {
DTRACE_RANGE_REMAIN(remain, (uintptr_t)src, src, sz);
return (1);
}
if (type->dtdt_kind == DIF_TYPE_STRING) {
return (dtrace_strcanload((uintptr_t)src, sz, remain, mstate,
vstate));
}
return (dtrace_canload_remains((uintptr_t)src, sz, remain, mstate,
vstate));
}
/*
* Convert a string to a signed integer using safe loads.
*
* NOTE: This function uses various macros from strtolctype.h to manipulate
* digit values, etc -- these have all been checked to ensure they make
* no additional function calls.
*/
static int64_t
dtrace_strtoll(char *input, int base, size_t limit)
{
uintptr_t pos = (uintptr_t)input;
int64_t val = 0;
int x;
boolean_t neg = B_FALSE;
char c, cc, ccc;
uintptr_t end = pos + limit;
/*
* Consume any whitespace preceding digits.
*/
while ((c = dtrace_load8(pos)) == ' ' || c == '\t')
pos++;
/*
* Handle an explicit sign if one is present.
*/
if (c == '-' || c == '+') {
if (c == '-')
neg = B_TRUE;
c = dtrace_load8(++pos);
}
/*
* Check for an explicit hexadecimal prefix ("0x" or "0X") and skip it
* if present.
*/
if (base == 16 && c == '0' && ((cc = dtrace_load8(pos + 1)) == 'x' ||
cc == 'X') && isxdigit(ccc = dtrace_load8(pos + 2))) {
pos += 2;
c = ccc;
}
/*
* Read in contiguous digits until the first non-digit character.
*/
for (; pos < end && c != '\0' && lisalnum(c) && (x = DIGIT(c)) < base;
c = dtrace_load8(++pos))
val = val * base + x;
return (neg ? -val : val);
}
/*
* Compare two strings using safe loads.
*/
static int
dtrace_strncmp(char *s1, char *s2, size_t limit)
{
uint8_t c1, c2;
volatile uint16_t *flags;
if (s1 == s2 || limit == 0)
return (0);
flags = (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
do {
if (s1 == NULL) {
c1 = '\0';
} else {
c1 = dtrace_load8((uintptr_t)s1++);
}
if (s2 == NULL) {
c2 = '\0';
} else {
c2 = dtrace_load8((uintptr_t)s2++);
}
if (c1 != c2)
return (c1 - c2);
} while (--limit && c1 != '\0' && !(*flags & CPU_DTRACE_FAULT));
return (0);
}
/*
* Compute strlen(s) for a string using safe memory accesses. The additional
* len parameter is used to specify a maximum length to ensure completion.
*/
static size_t
dtrace_strlen(const char *s, size_t lim)
{
uint_t len;
for (len = 0; len != lim; len++) {
if (dtrace_load8((uintptr_t)s++) == '\0')
break;
}
return (len);
}
/*
* Check if an address falls within a toxic region.
*/
static int
dtrace_istoxic(uintptr_t kaddr, size_t size)
{
uintptr_t taddr, tsize;
int i;
for (i = 0; i < dtrace_toxranges; i++) {
taddr = dtrace_toxrange[i].dtt_base;
tsize = dtrace_toxrange[i].dtt_limit - taddr;
if (kaddr - taddr < tsize) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
cpu_core[curcpu].cpuc_dtrace_illval = kaddr;
return (1);
}
if (taddr - kaddr < size) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
cpu_core[curcpu].cpuc_dtrace_illval = taddr;
return (1);
}
}
return (0);
}
/*
* Copy src to dst using safe memory accesses. The src is assumed to be unsafe
* memory specified by the DIF program. The dst is assumed to be safe memory
* that we can store to directly because it is managed by DTrace. As with
* standard bcopy, overlapping copies are handled properly.
*/
static void
dtrace_bcopy(const void *src, void *dst, size_t len)
{
if (len != 0) {
uint8_t *s1 = dst;
const uint8_t *s2 = src;
if (s1 <= s2) {
do {
*s1++ = dtrace_load8((uintptr_t)s2++);
} while (--len != 0);
} else {
s2 += len;
s1 += len;
do {
*--s1 = dtrace_load8((uintptr_t)--s2);
} while (--len != 0);
}
}
}
/*
* Copy src to dst using safe memory accesses, up to either the specified
* length, or the point that a nul byte is encountered. The src is assumed to
* be unsafe memory specified by the DIF program. The dst is assumed to be
* safe memory that we can store to directly because it is managed by DTrace.
* Unlike dtrace_bcopy(), overlapping regions are not handled.
*/
static void
dtrace_strcpy(const void *src, void *dst, size_t len)
{
if (len != 0) {
uint8_t *s1 = dst, c;
const uint8_t *s2 = src;
do {
*s1++ = c = dtrace_load8((uintptr_t)s2++);
} while (--len != 0 && c != '\0');
}
}
/*
* Copy src to dst, deriving the size and type from the specified (BYREF)
* variable type. The src is assumed to be unsafe memory specified by the DIF
* program. The dst is assumed to be DTrace variable memory that is of the
* specified type; we assume that we can store to directly.
*/
static void
dtrace_vcopy(void *src, void *dst, dtrace_diftype_t *type, size_t limit)
{
ASSERT(type->dtdt_flags & DIF_TF_BYREF);
if (type->dtdt_kind == DIF_TYPE_STRING) {
dtrace_strcpy(src, dst, MIN(type->dtdt_size, limit));
} else {
dtrace_bcopy(src, dst, MIN(type->dtdt_size, limit));
}
}
/*
* Compare s1 to s2 using safe memory accesses. The s1 data is assumed to be
* unsafe memory specified by the DIF program. The s2 data is assumed to be
* safe memory that we can access directly because it is managed by DTrace.
*/
static int
dtrace_bcmp(const void *s1, const void *s2, size_t len)
{
volatile uint16_t *flags;
flags = (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
if (s1 == s2)
return (0);
if (s1 == NULL || s2 == NULL)
return (1);
if (s1 != s2 && len != 0) {
const uint8_t *ps1 = s1;
const uint8_t *ps2 = s2;
do {
if (dtrace_load8((uintptr_t)ps1++) != *ps2++)
return (1);
} while (--len != 0 && !(*flags & CPU_DTRACE_FAULT));
}
return (0);
}
/*
* Zero the specified region using a simple byte-by-byte loop. Note that this
* is for safe DTrace-managed memory only.
*/
static void
dtrace_bzero(void *dst, size_t len)
{
uchar_t *cp;
for (cp = dst; len != 0; len--)
*cp++ = 0;
}
static void
dtrace_add_128(uint64_t *addend1, uint64_t *addend2, uint64_t *sum)
{
uint64_t result[2];
result[0] = addend1[0] + addend2[0];
result[1] = addend1[1] + addend2[1] +
(result[0] < addend1[0] || result[0] < addend2[0] ? 1 : 0);
sum[0] = result[0];
sum[1] = result[1];
}
/*
* Shift the 128-bit value in a by b. If b is positive, shift left.
* If b is negative, shift right.
*/
static void
dtrace_shift_128(uint64_t *a, int b)
{
uint64_t mask;
if (b == 0)
return;
if (b < 0) {
b = -b;
if (b >= 64) {
a[0] = a[1] >> (b - 64);
a[1] = 0;
} else {
a[0] >>= b;
mask = 1LL << (64 - b);
mask -= 1;
a[0] |= ((a[1] & mask) << (64 - b));
a[1] >>= b;
}
} else {
if (b >= 64) {
a[1] = a[0] << (b - 64);
a[0] = 0;
} else {
a[1] <<= b;
mask = a[0] >> (64 - b);
a[1] |= mask;
a[0] <<= b;
}
}
}
/*
* The basic idea is to break the 2 64-bit values into 4 32-bit values,
* use native multiplication on those, and then re-combine into the
* resulting 128-bit value.
*
* (hi1 << 32 + lo1) * (hi2 << 32 + lo2) =
* hi1 * hi2 << 64 +
* hi1 * lo2 << 32 +
* hi2 * lo1 << 32 +
* lo1 * lo2
*/
static void
dtrace_multiply_128(uint64_t factor1, uint64_t factor2, uint64_t *product)
{
uint64_t hi1, hi2, lo1, lo2;
uint64_t tmp[2];
hi1 = factor1 >> 32;
hi2 = factor2 >> 32;
lo1 = factor1 & DT_MASK_LO;
lo2 = factor2 & DT_MASK_LO;
product[0] = lo1 * lo2;
product[1] = hi1 * hi2;
tmp[0] = hi1 * lo2;
tmp[1] = 0;
dtrace_shift_128(tmp, 32);
dtrace_add_128(product, tmp, product);
tmp[0] = hi2 * lo1;
tmp[1] = 0;
dtrace_shift_128(tmp, 32);
dtrace_add_128(product, tmp, product);
}
/*
* This privilege check should be used by actions and subroutines to
* verify that the user credentials of the process that enabled the
* invoking ECB match the target credentials
*/
static int
dtrace_priv_proc_common_user(dtrace_state_t *state)
{
cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
/*
* We should always have a non-NULL state cred here, since if cred
* is null (anonymous tracing), we fast-path bypass this routine.
*/
ASSERT(s_cr != NULL);
if ((cr = CRED()) != NULL &&
s_cr->cr_uid == cr->cr_uid &&
s_cr->cr_uid == cr->cr_ruid &&
s_cr->cr_uid == cr->cr_suid &&
s_cr->cr_gid == cr->cr_gid &&
s_cr->cr_gid == cr->cr_rgid &&
s_cr->cr_gid == cr->cr_sgid)
return (1);
return (0);
}
/*
* This privilege check should be used by actions and subroutines to
* verify that the zone of the process that enabled the invoking ECB
* matches the target credentials
*/
static int
dtrace_priv_proc_common_zone(dtrace_state_t *state)
{
#ifdef illumos
cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
/*
* We should always have a non-NULL state cred here, since if cred
* is null (anonymous tracing), we fast-path bypass this routine.
*/
ASSERT(s_cr != NULL);
if ((cr = CRED()) != NULL && s_cr->cr_zone == cr->cr_zone)
return (1);
return (0);
#else
return (1);
#endif
}
/*
* This privilege check should be used by actions and subroutines to
* verify that the process has not setuid or changed credentials.
*/
static int
dtrace_priv_proc_common_nocd(void)
{
proc_t *proc;
if ((proc = ttoproc(curthread)) != NULL &&
!(proc->p_flag & SNOCD))
return (1);
return (0);
}
static int
dtrace_priv_proc_destructive(dtrace_state_t *state)
{
int action = state->dts_cred.dcr_action;
if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE) == 0) &&
dtrace_priv_proc_common_zone(state) == 0)
goto bad;
if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER) == 0) &&
dtrace_priv_proc_common_user(state) == 0)
goto bad;
if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG) == 0) &&
dtrace_priv_proc_common_nocd() == 0)
goto bad;
return (1);
bad:
cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
return (0);
}
static int
dtrace_priv_proc_control(dtrace_state_t *state)
{
if (state->dts_cred.dcr_action & DTRACE_CRA_PROC_CONTROL)
return (1);
if (dtrace_priv_proc_common_zone(state) &&
dtrace_priv_proc_common_user(state) &&
dtrace_priv_proc_common_nocd())
return (1);
cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
return (0);
}
static int
dtrace_priv_proc(dtrace_state_t *state)
{
if (state->dts_cred.dcr_action & DTRACE_CRA_PROC)
return (1);
cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
return (0);
}
static int
dtrace_priv_kernel(dtrace_state_t *state)
{
if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL)
return (1);
cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
return (0);
}
static int
dtrace_priv_kernel_destructive(dtrace_state_t *state)
{
if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL_DESTRUCTIVE)
return (1);
cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
return (0);
}
/*
* Determine if the dte_cond of the specified ECB allows for processing of
* the current probe to continue. Note that this routine may allow continued
* processing, but with access(es) stripped from the mstate's dtms_access
* field.
*/
static int
dtrace_priv_probe(dtrace_state_t *state, dtrace_mstate_t *mstate,
dtrace_ecb_t *ecb)
{
dtrace_probe_t *probe = ecb->dte_probe;
dtrace_provider_t *prov = probe->dtpr_provider;
dtrace_pops_t *pops = &prov->dtpv_pops;
int mode = DTRACE_MODE_NOPRIV_DROP;
ASSERT(ecb->dte_cond);
#ifdef illumos
if (pops->dtps_mode != NULL) {
mode = pops->dtps_mode(prov->dtpv_arg,
probe->dtpr_id, probe->dtpr_arg);
ASSERT((mode & DTRACE_MODE_USER) ||
(mode & DTRACE_MODE_KERNEL));
ASSERT((mode & DTRACE_MODE_NOPRIV_RESTRICT) ||
(mode & DTRACE_MODE_NOPRIV_DROP));
}
/*
* If the dte_cond bits indicate that this consumer is only allowed to
* see user-mode firings of this probe, call the provider's dtps_mode()
* entry point to check that the probe was fired while in a user
* context. If that's not the case, use the policy specified by the
* provider to determine if we drop the probe or merely restrict
* operation.
*/
if (ecb->dte_cond & DTRACE_COND_USERMODE) {
ASSERT(mode != DTRACE_MODE_NOPRIV_DROP);
if (!(mode & DTRACE_MODE_USER)) {
if (mode & DTRACE_MODE_NOPRIV_DROP)
return (0);
mstate->dtms_access &= ~DTRACE_ACCESS_ARGS;
}
}
#endif
/*
* This is more subtle than it looks. We have to be absolutely certain
* that CRED() isn't going to change out from under us so it's only
* legit to examine that structure if we're in constrained situations.
* Currently, the only times we'll this check is if a non-super-user
* has enabled the profile or syscall providers -- providers that
* allow visibility of all processes. For the profile case, the check
* above will ensure that we're examining a user context.
*/
if (ecb->dte_cond & DTRACE_COND_OWNER) {
cred_t *cr;
cred_t *s_cr = state->dts_cred.dcr_cred;
proc_t *proc;
ASSERT(s_cr != NULL);
if ((cr = CRED()) == NULL ||
s_cr->cr_uid != cr->cr_uid ||
s_cr->cr_uid != cr->cr_ruid ||
s_cr->cr_uid != cr->cr_suid ||
s_cr->cr_gid != cr->cr_gid ||
s_cr->cr_gid != cr->cr_rgid ||
s_cr->cr_gid != cr->cr_sgid ||
(proc = ttoproc(curthread)) == NULL ||
(proc->p_flag & SNOCD)) {
if (mode & DTRACE_MODE_NOPRIV_DROP)
return (0);
#ifdef illumos
mstate->dtms_access &= ~DTRACE_ACCESS_PROC;
#endif
}
}
#ifdef illumos
/*
* If our dte_cond is set to DTRACE_COND_ZONEOWNER and we are not
* in our zone, check to see if our mode policy is to restrict rather
* than to drop; if to restrict, strip away both DTRACE_ACCESS_PROC
* and DTRACE_ACCESS_ARGS
*/
if (ecb->dte_cond & DTRACE_COND_ZONEOWNER) {
cred_t *cr;
cred_t *s_cr = state->dts_cred.dcr_cred;
ASSERT(s_cr != NULL);
if ((cr = CRED()) == NULL ||
s_cr->cr_zone->zone_id != cr->cr_zone->zone_id) {
if (mode & DTRACE_MODE_NOPRIV_DROP)
return (0);
mstate->dtms_access &=
~(DTRACE_ACCESS_PROC | DTRACE_ACCESS_ARGS);
}
}
#endif
return (1);
}
/*
* Note: not called from probe context. This function is called
* asynchronously (and at a regular interval) from outside of probe context to
* clean the dirty dynamic variable lists on all CPUs. Dynamic variable
* cleaning is explained in detail in <sys/dtrace_impl.h>.
*/
void
dtrace_dynvar_clean(dtrace_dstate_t *dstate)
{
dtrace_dynvar_t *dirty;
dtrace_dstate_percpu_t *dcpu;
dtrace_dynvar_t **rinsep;
int i, j, work = 0;
for (i = 0; i < NCPU; i++) {
dcpu = &dstate->dtds_percpu[i];
rinsep = &dcpu->dtdsc_rinsing;
/*
* If the dirty list is NULL, there is no dirty work to do.
*/
if (dcpu->dtdsc_dirty == NULL)
continue;
if (dcpu->dtdsc_rinsing != NULL) {
/*
* If the rinsing list is non-NULL, then it is because
* this CPU was selected to accept another CPU's
* dirty list -- and since that time, dirty buffers
* have accumulated. This is a highly unlikely
* condition, but we choose to ignore the dirty
* buffers -- they'll be picked up a future cleanse.
*/
continue;
}
if (dcpu->dtdsc_clean != NULL) {
/*
* If the clean list is non-NULL, then we're in a
* situation where a CPU has done deallocations (we
* have a non-NULL dirty list) but no allocations (we
* also have a non-NULL clean list). We can't simply
* move the dirty list into the clean list on this
* CPU, yet we also don't want to allow this condition
* to persist, lest a short clean list prevent a
* massive dirty list from being cleaned (which in
* turn could lead to otherwise avoidable dynamic
* drops). To deal with this, we look for some CPU
* with a NULL clean list, NULL dirty list, and NULL
* rinsing list -- and then we borrow this CPU to
* rinse our dirty list.
*/
for (j = 0; j < NCPU; j++) {
dtrace_dstate_percpu_t *rinser;
rinser = &dstate->dtds_percpu[j];
if (rinser->dtdsc_rinsing != NULL)
continue;
if (rinser->dtdsc_dirty != NULL)
continue;
if (rinser->dtdsc_clean != NULL)
continue;
rinsep = &rinser->dtdsc_rinsing;
break;
}
if (j == NCPU) {
/*
* We were unable to find another CPU that
* could accept this dirty list -- we are
* therefore unable to clean it now.
*/
dtrace_dynvar_failclean++;
continue;
}
}
work = 1;
/*
* Atomically move the dirty list aside.
*/
do {
dirty = dcpu->dtdsc_dirty;
/*
* Before we zap the dirty list, set the rinsing list.
* (This allows for a potential assertion in
* dtrace_dynvar(): if a free dynamic variable appears
* on a hash chain, either the dirty list or the
* rinsing list for some CPU must be non-NULL.)
*/
*rinsep = dirty;
dtrace_membar_producer();
} while (dtrace_casptr(&dcpu->dtdsc_dirty,
dirty, NULL) != dirty);
}
if (!work) {
/*
* We have no work to do; we can simply return.
*/
return;
}
dtrace_sync();
for (i = 0; i < NCPU; i++) {
dcpu = &dstate->dtds_percpu[i];
if (dcpu->dtdsc_rinsing == NULL)
continue;
/*
* We are now guaranteed that no hash chain contains a pointer
* into this dirty list; we can make it clean.
*/
ASSERT(dcpu->dtdsc_clean == NULL);
dcpu->dtdsc_clean = dcpu->dtdsc_rinsing;
dcpu->dtdsc_rinsing = NULL;
}
/*
* Before we actually set the state to be DTRACE_DSTATE_CLEAN, make
* sure that all CPUs have seen all of the dtdsc_clean pointers.
* This prevents a race whereby a CPU incorrectly decides that
* the state should be something other than DTRACE_DSTATE_CLEAN
* after dtrace_dynvar_clean() has completed.
*/
dtrace_sync();
dstate->dtds_state = DTRACE_DSTATE_CLEAN;
}
/*
* Depending on the value of the op parameter, this function looks-up,
* allocates or deallocates an arbitrarily-keyed dynamic variable. If an
* allocation is requested, this function will return a pointer to a
* dtrace_dynvar_t corresponding to the allocated variable -- or NULL if no
* variable can be allocated. If NULL is returned, the appropriate counter
* will be incremented.
*/
dtrace_dynvar_t *
dtrace_dynvar(dtrace_dstate_t *dstate, uint_t nkeys,
dtrace_key_t *key, size_t dsize, dtrace_dynvar_op_t op,
dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
{
uint64_t hashval = DTRACE_DYNHASH_VALID;
dtrace_dynhash_t *hash = dstate->dtds_hash;
dtrace_dynvar_t *free, *new_free, *next, *dvar, *start, *prev = NULL;
processorid_t me = curcpu, cpu = me;
dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[me];
size_t bucket, ksize;
size_t chunksize = dstate->dtds_chunksize;
uintptr_t kdata, lock, nstate;
uint_t i;
ASSERT(nkeys != 0);
/*
* Hash the key. As with aggregations, we use Jenkins' "One-at-a-time"
* algorithm. For the by-value portions, we perform the algorithm in
* 16-bit chunks (as opposed to 8-bit chunks). This speeds things up a
* bit, and seems to have only a minute effect on distribution. For
* the by-reference data, we perform "One-at-a-time" iterating (safely)
* over each referenced byte. It's painful to do this, but it's much
* better than pathological hash distribution. The efficacy of the
* hashing algorithm (and a comparison with other algorithms) may be
* found by running the ::dtrace_dynstat MDB dcmd.
*/
for (i = 0; i < nkeys; i++) {
if (key[i].dttk_size == 0) {
uint64_t val = key[i].dttk_value;
hashval += (val >> 48) & 0xffff;
hashval += (hashval << 10);
hashval ^= (hashval >> 6);
hashval += (val >> 32) & 0xffff;
hashval += (hashval << 10);
hashval ^= (hashval >> 6);
hashval += (val >> 16) & 0xffff;
hashval += (hashval << 10);
hashval ^= (hashval >> 6);
hashval += val & 0xffff;
hashval += (hashval << 10);
hashval ^= (hashval >> 6);
} else {
/*
* This is incredibly painful, but it beats the hell
* out of the alternative.
*/
uint64_t j, size = key[i].dttk_size;
uintptr_t base = (uintptr_t)key[i].dttk_value;
if (!dtrace_canload(base, size, mstate, vstate))
break;
for (j = 0; j < size; j++) {
hashval += dtrace_load8(base + j);
hashval += (hashval << 10);
hashval ^= (hashval >> 6);
}
}
}
if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
return (NULL);
hashval += (hashval << 3);
hashval ^= (hashval >> 11);
hashval += (hashval << 15);
/*
* There is a remote chance (ideally, 1 in 2^31) that our hashval
* comes out to be one of our two sentinel hash values. If this
* actually happens, we set the hashval to be a value known to be a
* non-sentinel value.
*/
if (hashval == DTRACE_DYNHASH_FREE || hashval == DTRACE_DYNHASH_SINK)
hashval = DTRACE_DYNHASH_VALID;
/*
* Yes, it's painful to do a divide here. If the cycle count becomes
* important here, tricks can be pulled to reduce it. (However, it's
* critical that hash collisions be kept to an absolute minimum;
* they're much more painful than a divide.) It's better to have a
* solution that generates few collisions and still keeps things
* relatively simple.
*/
bucket = hashval % dstate->dtds_hashsize;
if (op == DTRACE_DYNVAR_DEALLOC) {
volatile uintptr_t *lockp = &hash[bucket].dtdh_lock;
for (;;) {
while ((lock = *lockp) & 1)
continue;
if (dtrace_casptr((volatile void *)lockp,
(volatile void *)lock, (volatile void *)(lock + 1)) == (void *)lock)
break;
}
dtrace_membar_producer();
}
top:
prev = NULL;
lock = hash[bucket].dtdh_lock;
dtrace_membar_consumer();
start = hash[bucket].dtdh_chain;
ASSERT(start != NULL && (start->dtdv_hashval == DTRACE_DYNHASH_SINK ||
start->dtdv_hashval != DTRACE_DYNHASH_FREE ||
op != DTRACE_DYNVAR_DEALLOC));
for (dvar = start; dvar != NULL; dvar = dvar->dtdv_next) {
dtrace_tuple_t *dtuple = &dvar->dtdv_tuple;
dtrace_key_t *dkey = &dtuple->dtt_key[0];
if (dvar->dtdv_hashval != hashval) {
if (dvar->dtdv_hashval == DTRACE_DYNHASH_SINK) {
/*
* We've reached the sink, and therefore the
* end of the hash chain; we can kick out of
* the loop knowing that we have seen a valid
* snapshot of state.
*/
ASSERT(dvar->dtdv_next == NULL);
ASSERT(dvar == &dtrace_dynhash_sink);
break;
}
if (dvar->dtdv_hashval == DTRACE_DYNHASH_FREE) {
/*
* We've gone off the rails: somewhere along
* the line, one of the members of this hash
* chain was deleted. Note that we could also
* detect this by simply letting this loop run
* to completion, as we would eventually hit
* the end of the dirty list. However, we
* want to avoid running the length of the
* dirty list unnecessarily (it might be quite
* long), so we catch this as early as
* possible by detecting the hash marker. In
* this case, we simply set dvar to NULL and
* break; the conditional after the loop will
* send us back to top.
*/
dvar = NULL;
break;
}
goto next;
}
if (dtuple->dtt_nkeys != nkeys)
goto next;
for (i = 0; i < nkeys; i++, dkey++) {
if (dkey->dttk_size != key[i].dttk_size)
goto next; /* size or type mismatch */
if (dkey->dttk_size != 0) {
if (dtrace_bcmp(
(void *)(uintptr_t)key[i].dttk_value,
(void *)(uintptr_t)dkey->dttk_value,
dkey->dttk_size))
goto next;
} else {
if (dkey->dttk_value != key[i].dttk_value)
goto next;
}
}
if (op != DTRACE_DYNVAR_DEALLOC)
return (dvar);
ASSERT(dvar->dtdv_next == NULL ||
dvar->dtdv_next->dtdv_hashval != DTRACE_DYNHASH_FREE);
if (prev != NULL) {
ASSERT(hash[bucket].dtdh_chain != dvar);
ASSERT(start != dvar);
ASSERT(prev->dtdv_next == dvar);
prev->dtdv_next = dvar->dtdv_next;
} else {
if (dtrace_casptr(&hash[bucket].dtdh_chain,
start, dvar->dtdv_next) != start) {
/*
* We have failed to atomically swing the
* hash table head pointer, presumably because
* of a conflicting allocation on another CPU.
* We need to reread the hash chain and try
* again.
*/
goto top;
}
}
dtrace_membar_producer();
/*
* Now set the hash value to indicate that it's free.
*/
ASSERT(hash[bucket].dtdh_chain != dvar);
dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
dtrace_membar_producer();
/*
* Set the next pointer to point at the dirty list, and
* atomically swing the dirty pointer to the newly freed dvar.
*/
do {
next = dcpu->dtdsc_dirty;
dvar->dtdv_next = next;
} while (dtrace_casptr(&dcpu->dtdsc_dirty, next, dvar) != next);
/*
* Finally, unlock this hash bucket.
*/
ASSERT(hash[bucket].dtdh_lock == lock);
ASSERT(lock & 1);
hash[bucket].dtdh_lock++;
return (NULL);
next:
prev = dvar;
continue;
}
if (dvar == NULL) {
/*
* If dvar is NULL, it is because we went off the rails:
* one of the elements that we traversed in the hash chain
* was deleted while we were traversing it. In this case,
* we assert that we aren't doing a dealloc (deallocs lock
* the hash bucket to prevent themselves from racing with
* one another), and retry the hash chain traversal.
*/
ASSERT(op != DTRACE_DYNVAR_DEALLOC);
goto top;
}
if (op != DTRACE_DYNVAR_ALLOC) {
/*
* If we are not to allocate a new variable, we want to
* return NULL now. Before we return, check that the value
* of the lock word hasn't changed. If it has, we may have
* seen an inconsistent snapshot.
*/
if (op == DTRACE_DYNVAR_NOALLOC) {
if (hash[bucket].dtdh_lock != lock)
goto top;
} else {
ASSERT(op == DTRACE_DYNVAR_DEALLOC);
ASSERT(hash[bucket].dtdh_lock == lock);
ASSERT(lock & 1);
hash[bucket].dtdh_lock++;
}
return (NULL);
}
/*
* We need to allocate a new dynamic variable. The size we need is the
* size of dtrace_dynvar plus the size of nkeys dtrace_key_t's plus the
* size of any auxiliary key data (rounded up to 8-byte alignment) plus
* the size of any referred-to data (dsize). We then round the final
* size up to the chunksize for allocation.
*/
for (ksize = 0, i = 0; i < nkeys; i++)
ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
/*
* This should be pretty much impossible, but could happen if, say,
* strange DIF specified the tuple. Ideally, this should be an
* assertion and not an error condition -- but that requires that the
* chunksize calculation in dtrace_difo_chunksize() be absolutely
* bullet-proof. (That is, it must not be able to be fooled by
* malicious DIF.) Given the lack of backwards branches in DIF,
* solving this would presumably not amount to solving the Halting
* Problem -- but it still seems awfully hard.
*/
if (sizeof (dtrace_dynvar_t) + sizeof (dtrace_key_t) * (nkeys - 1) +
ksize + dsize > chunksize) {
dcpu->dtdsc_drops++;
return (NULL);
}
nstate = DTRACE_DSTATE_EMPTY;
do {
retry:
free = dcpu->dtdsc_free;
if (free == NULL) {
dtrace_dynvar_t *clean = dcpu->dtdsc_clean;
void *rval;
if (clean == NULL) {
/*
* We're out of dynamic variable space on
* this CPU. Unless we have tried all CPUs,
* we'll try to allocate from a different
* CPU.
*/
switch (dstate->dtds_state) {
case DTRACE_DSTATE_CLEAN: {
void *sp = &dstate->dtds_state;
if (++cpu >= NCPU)
cpu = 0;
if (dcpu->dtdsc_dirty != NULL &&
nstate == DTRACE_DSTATE_EMPTY)
nstate = DTRACE_DSTATE_DIRTY;
if (dcpu->dtdsc_rinsing != NULL)
nstate = DTRACE_DSTATE_RINSING;
dcpu = &dstate->dtds_percpu[cpu];
if (cpu != me)
goto retry;
(void) dtrace_cas32(sp,
DTRACE_DSTATE_CLEAN, nstate);
/*
* To increment the correct bean
* counter, take another lap.
*/
goto retry;
}
case DTRACE_DSTATE_DIRTY:
dcpu->dtdsc_dirty_drops++;
break;
case DTRACE_DSTATE_RINSING:
dcpu->dtdsc_rinsing_drops++;
break;
case DTRACE_DSTATE_EMPTY:
dcpu->dtdsc_drops++;
break;
}
DTRACE_CPUFLAG_SET(CPU_DTRACE_DROP);
return (NULL);
}
/*
* The clean list appears to be non-empty. We want to
* move the clean list to the free list; we start by
* moving the clean pointer aside.
*/
if (dtrace_casptr(&dcpu->dtdsc_clean,
clean, NULL) != clean) {
/*
* We are in one of two situations:
*
* (a) The clean list was switched to the
* free list by another CPU.
*
* (b) The clean list was added to by the
* cleansing cyclic.
*
* In either of these situations, we can
* just reattempt the free list allocation.
*/
goto retry;
}
ASSERT(clean->dtdv_hashval == DTRACE_DYNHASH_FREE);
/*
* Now we'll move the clean list to our free list.
* It's impossible for this to fail: the only way
* the free list can be updated is through this
* code path, and only one CPU can own the clean list.
* Thus, it would only be possible for this to fail if
* this code were racing with dtrace_dynvar_clean().
* (That is, if dtrace_dynvar_clean() updated the clean
* list, and we ended up racing to update the free
* list.) This race is prevented by the dtrace_sync()
* in dtrace_dynvar_clean() -- which flushes the
* owners of the clean lists out before resetting
* the clean lists.
*/
dcpu = &dstate->dtds_percpu[me];
rval = dtrace_casptr(&dcpu->dtdsc_free, NULL, clean);
ASSERT(rval == NULL);
goto retry;
}
dvar = free;
new_free = dvar->dtdv_next;
} while (dtrace_casptr(&dcpu->dtdsc_free, free, new_free) != free);
/*
* We have now allocated a new chunk. We copy the tuple keys into the
* tuple array and copy any referenced key data into the data space
* following the tuple array. As we do this, we relocate dttk_value
* in the final tuple to point to the key data address in the chunk.
*/
kdata = (uintptr_t)&dvar->dtdv_tuple.dtt_key[nkeys];
dvar->dtdv_data = (void *)(kdata + ksize);
dvar->dtdv_tuple.dtt_nkeys = nkeys;
for (i = 0; i < nkeys; i++) {
dtrace_key_t *dkey = &dvar->dtdv_tuple.dtt_key[i];
size_t kesize = key[i].dttk_size;
if (kesize != 0) {
dtrace_bcopy(
(const void *)(uintptr_t)key[i].dttk_value,
(void *)kdata, kesize);
dkey->dttk_value = kdata;
kdata += P2ROUNDUP(kesize, sizeof (uint64_t));
} else {
dkey->dttk_value = key[i].dttk_value;
}
dkey->dttk_size = kesize;
}
ASSERT(dvar->dtdv_hashval == DTRACE_DYNHASH_FREE);
dvar->dtdv_hashval = hashval;
dvar->dtdv_next = start;
if (dtrace_casptr(&hash[bucket].dtdh_chain, start, dvar) == start)
return (dvar);
/*
* The cas has failed. Either another CPU is adding an element to
* this hash chain, or another CPU is deleting an element from this
* hash chain. The simplest way to deal with both of these cases
* (though not necessarily the most efficient) is to free our
* allocated block and re-attempt it all. Note that the free is
* to the dirty list and _not_ to the free list. This is to prevent
* races with allocators, above.
*/
dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
dtrace_membar_producer();
do {
free = dcpu->dtdsc_dirty;
dvar->dtdv_next = free;
} while (dtrace_casptr(&dcpu->dtdsc_dirty, free, dvar) != free);
goto top;
}
/*ARGSUSED*/
static void
dtrace_aggregate_min(uint64_t *oval, uint64_t nval, uint64_t arg)
{
if ((int64_t)nval < (int64_t)*oval)
*oval = nval;
}
/*ARGSUSED*/
static void
dtrace_aggregate_max(uint64_t *oval, uint64_t nval, uint64_t arg)
{
if ((int64_t)nval > (int64_t)*oval)
*oval = nval;
}
static void
dtrace_aggregate_quantize(uint64_t *quanta, uint64_t nval, uint64_t incr)
{
int i, zero = DTRACE_QUANTIZE_ZEROBUCKET;
int64_t val = (int64_t)nval;
if (val < 0) {
for (i = 0; i < zero; i++) {
if (val <= DTRACE_QUANTIZE_BUCKETVAL(i)) {
quanta[i] += incr;
return;
}
}
} else {
for (i = zero + 1; i < DTRACE_QUANTIZE_NBUCKETS; i++) {
if (val < DTRACE_QUANTIZE_BUCKETVAL(i)) {
quanta[i - 1] += incr;
return;
}
}
quanta[DTRACE_QUANTIZE_NBUCKETS - 1] += incr;
return;
}
ASSERT(0);
}
static void
dtrace_aggregate_lquantize(uint64_t *lquanta, uint64_t nval, uint64_t incr)
{
uint64_t arg = *lquanta++;
int32_t base = DTRACE_LQUANTIZE_BASE(arg);
uint16_t step = DTRACE_LQUANTIZE_STEP(arg);
uint16_t levels = DTRACE_LQUANTIZE_LEVELS(arg);
int32_t val = (int32_t)nval, level;
ASSERT(step != 0);
ASSERT(levels != 0);
if (val < base) {
/*
* This is an underflow.
*/
lquanta[0] += incr;
return;
}
level = (val - base) / step;
if (level < levels) {
lquanta[level + 1] += incr;
return;
}
/*
* This is an overflow.
*/
lquanta[levels + 1] += incr;
}
static int
dtrace_aggregate_llquantize_bucket(uint16_t factor, uint16_t low,
uint16_t high, uint16_t nsteps, int64_t value)
{
int64_t this = 1, last, next;
int base = 1, order;
ASSERT(factor <= nsteps);
ASSERT(nsteps % factor == 0);
for (order = 0; order < low; order++)
this *= factor;
/*
* If our value is less than our factor taken to the power of the
* low order of magnitude, it goes into the zeroth bucket.
*/
if (value < (last = this))
return (0);
for (this *= factor; order <= high; order++) {
int nbuckets = this > nsteps ? nsteps : this;
if ((next = this * factor) < this) {
/*
* We should not generally get log/linear quantizations
* with a high magnitude that allows 64-bits to
* overflow, but we nonetheless protect against this
* by explicitly checking for overflow, and clamping
* our value accordingly.
*/
value = this - 1;
}
if (value < this) {
/*
* If our value lies within this order of magnitude,
* determine its position by taking the offset within
* the order of magnitude, dividing by the bucket
* width, and adding to our (accumulated) base.
*/
return (base + (value - last) / (this / nbuckets));
}
base += nbuckets - (nbuckets / factor);
last = this;
this = next;
}
/*
* Our value is greater than or equal to our factor taken to the
* power of one plus the high magnitude -- return the top bucket.
*/
return (base);
}
static void
dtrace_aggregate_llquantize(uint64_t *llquanta, uint64_t nval, uint64_t incr)
{
uint64_t arg = *llquanta++;
uint16_t factor = DTRACE_LLQUANTIZE_FACTOR(arg);
uint16_t low = DTRACE_LLQUANTIZE_LOW(arg);
uint16_t high = DTRACE_LLQUANTIZE_HIGH(arg);
uint16_t nsteps = DTRACE_LLQUANTIZE_NSTEP(arg);
llquanta[dtrace_aggregate_llquantize_bucket(factor,
low, high, nsteps, nval)] += incr;
}
/*ARGSUSED*/
static void
dtrace_aggregate_avg(uint64_t *data, uint64_t nval, uint64_t arg)
{
data[0]++;
data[1] += nval;
}
/*ARGSUSED*/
static void
dtrace_aggregate_stddev(uint64_t *data, uint64_t nval, uint64_t arg)
{
int64_t snval = (int64_t)nval;
uint64_t tmp[2];
data[0]++;
data[1] += nval;
/*
* What we want to say here is:
*
* data[2] += nval * nval;
*
* But given that nval is 64-bit, we could easily overflow, so
* we do this as 128-bit arithmetic.
*/
if (snval < 0)
snval = -snval;
dtrace_multiply_128((uint64_t)snval, (uint64_t)snval, tmp);
dtrace_add_128(data + 2, tmp, data + 2);
}
/*ARGSUSED*/
static void
dtrace_aggregate_count(uint64_t *oval, uint64_t nval, uint64_t arg)
{
*oval = *oval + 1;
}
/*ARGSUSED*/
static void
dtrace_aggregate_sum(uint64_t *oval, uint64_t nval, uint64_t arg)
{
*oval += nval;
}
/*
* Aggregate given the tuple in the principal data buffer, and the aggregating
* action denoted by the specified dtrace_aggregation_t. The aggregation
* buffer is specified as the buf parameter. This routine does not return
* failure; if there is no space in the aggregation buffer, the data will be
* dropped, and a corresponding counter incremented.
*/
static void
dtrace_aggregate(dtrace_aggregation_t *agg, dtrace_buffer_t *dbuf,
intptr_t offset, dtrace_buffer_t *buf, uint64_t expr, uint64_t arg)
{
dtrace_recdesc_t *rec = &agg->dtag_action.dta_rec;
uint32_t i, ndx, size, fsize;
uint32_t align = sizeof (uint64_t) - 1;
dtrace_aggbuffer_t *agb;
dtrace_aggkey_t *key;
uint32_t hashval = 0, limit, isstr;
caddr_t tomax, data, kdata;
dtrace_actkind_t action;
dtrace_action_t *act;
uintptr_t offs;
if (buf == NULL)
return;
if (!agg->dtag_hasarg) {
/*
* Currently, only quantize() and lquantize() take additional
* arguments, and they have the same semantics: an increment
* value that defaults to 1 when not present. If additional
* aggregating actions take arguments, the setting of the
* default argument value will presumably have to become more
* sophisticated...
*/
arg = 1;
}
action = agg->dtag_action.dta_kind - DTRACEACT_AGGREGATION;
size = rec->dtrd_offset - agg->dtag_base;
fsize = size + rec->dtrd_size;
ASSERT(dbuf->dtb_tomax != NULL);
data = dbuf->dtb_tomax + offset + agg->dtag_base;
if ((tomax = buf->dtb_tomax) == NULL) {
dtrace_buffer_drop(buf);
return;
}
/*
* The metastructure is always at the bottom of the buffer.
*/
agb = (dtrace_aggbuffer_t *)(tomax + buf->dtb_size -
sizeof (dtrace_aggbuffer_t));
if (buf->dtb_offset == 0) {
/*
* We just kludge up approximately 1/8th of the size to be
* buckets. If this guess ends up being routinely
* off-the-mark, we may need to dynamically readjust this
* based on past performance.
*/
uintptr_t hashsize = (buf->dtb_size >> 3) / sizeof (uintptr_t);
if ((uintptr_t)agb - hashsize * sizeof (dtrace_aggkey_t *) <
(uintptr_t)tomax || hashsize == 0) {
/*
* We've been given a ludicrously small buffer;
* increment our drop count and leave.
*/
dtrace_buffer_drop(buf);
return;
}
/*
* And now, a pathetic attempt to try to get a an odd (or
* perchance, a prime) hash size for better hash distribution.
*/
if (hashsize > (DTRACE_AGGHASHSIZE_SLEW << 3))
hashsize -= DTRACE_AGGHASHSIZE_SLEW;
agb->dtagb_hashsize = hashsize;
agb->dtagb_hash = (dtrace_aggkey_t **)((uintptr_t)agb -
agb->dtagb_hashsize * sizeof (dtrace_aggkey_t *));
agb->dtagb_free = (uintptr_t)agb->dtagb_hash;
for (i = 0; i < agb->dtagb_hashsize; i++)
agb->dtagb_hash[i] = NULL;
}
ASSERT(agg->dtag_first != NULL);
ASSERT(agg->dtag_first->dta_intuple);
/*
* Calculate the hash value based on the key. Note that we _don't_
* include the aggid in the hashing (but we will store it as part of
* the key). The hashing algorithm is Bob Jenkins' "One-at-a-time"
* algorithm: a simple, quick algorithm that has no known funnels, and
* gets good distribution in practice. The efficacy of the hashing
* algorithm (and a comparison with other algorithms) may be found by
* running the ::dtrace_aggstat MDB dcmd.
*/
for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
i = act->dta_rec.dtrd_offset - agg->dtag_base;
limit = i + act->dta_rec.dtrd_size;
ASSERT(limit <= size);
isstr = DTRACEACT_ISSTRING(act);
for (; i < limit; i++) {
hashval += data[i];
hashval += (hashval << 10);
hashval ^= (hashval >> 6);
if (isstr && data[i] == '\0')
break;
}
}
hashval += (hashval << 3);
hashval ^= (hashval >> 11);
hashval += (hashval << 15);
/*
* Yes, the divide here is expensive -- but it's generally the least
* of the performance issues given the amount of data that we iterate
* over to compute hash values, compare data, etc.
*/
ndx = hashval % agb->dtagb_hashsize;
for (key = agb->dtagb_hash[ndx]; key != NULL; key = key->dtak_next) {
ASSERT((caddr_t)key >= tomax);
ASSERT((caddr_t)key < tomax + buf->dtb_size);
if (hashval != key->dtak_hashval || key->dtak_size != size)
continue;
kdata = key->dtak_data;
ASSERT(kdata >= tomax && kdata < tomax + buf->dtb_size);
for (act = agg->dtag_first; act->dta_intuple;
act = act->dta_next) {
i = act->dta_rec.dtrd_offset - agg->dtag_base;
limit = i + act->dta_rec.dtrd_size;
ASSERT(limit <= size);
isstr = DTRACEACT_ISSTRING(act);
for (; i < limit; i++) {
if (kdata[i] != data[i])
goto next;
if (isstr && data[i] == '\0')
break;
}
}
if (action != key->dtak_action) {
/*
* We are aggregating on the same value in the same
* aggregation with two different aggregating actions.
* (This should have been picked up in the compiler,
* so we may be dealing with errant or devious DIF.)
* This is an error condition; we indicate as much,
* and return.
*/
DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
return;
}
/*
* This is a hit: we need to apply the aggregator to
* the value at this key.
*/
agg->dtag_aggregate((uint64_t *)(kdata + size), expr, arg);
return;
next:
continue;
}
/*
* We didn't find it. We need to allocate some zero-filled space,
* link it into the hash table appropriately, and apply the aggregator
* to the (zero-filled) value.
*/
offs = buf->dtb_offset;
while (offs & (align - 1))
offs += sizeof (uint32_t);
/*
* If we don't have enough room to both allocate a new key _and_
* its associated data, increment the drop count and return.
*/
if ((uintptr_t)tomax + offs + fsize >
agb->dtagb_free - sizeof (dtrace_aggkey_t)) {
dtrace_buffer_drop(buf);
return;
}
/*CONSTCOND*/
ASSERT(!(sizeof (dtrace_aggkey_t) & (sizeof (uintptr_t) - 1)));
key = (dtrace_aggkey_t *)(agb->dtagb_free - sizeof (dtrace_aggkey_t));
agb->dtagb_free -= sizeof (dtrace_aggkey_t);
key->dtak_data = kdata = tomax + offs;
buf->dtb_offset = offs + fsize;
/*
* Now copy the data across.
*/
*((dtrace_aggid_t *)kdata) = agg->dtag_id;
for (i = sizeof (dtrace_aggid_t); i < size; i++)
kdata[i] = data[i];
/*
* Because strings are not zeroed out by default, we need to iterate
* looking for actions that store strings, and we need to explicitly
* pad these strings out with zeroes.
*/
for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
int nul;
if (!DTRACEACT_ISSTRING(act))
continue;
i = act->dta_rec.dtrd_offset - agg->dtag_base;
limit = i + act->dta_rec.dtrd_size;
ASSERT(limit <= size);
for (nul = 0; i < limit; i++) {
if (nul) {
kdata[i] = '\0';
continue;
}
if (data[i] != '\0')
continue;
nul = 1;
}
}
for (i = size; i < fsize; i++)
kdata[i] = 0;
key->dtak_hashval = hashval;
key->dtak_size = size;
key->dtak_action = action;
key->dtak_next = agb->dtagb_hash[ndx];
agb->dtagb_hash[ndx] = key;
/*
* Finally, apply the aggregator.
*/
*((uint64_t *)(key->dtak_data + size)) = agg->dtag_initial;
agg->dtag_aggregate((uint64_t *)(key->dtak_data + size), expr, arg);
}
/*
* Given consumer state, this routine finds a speculation in the INACTIVE
* state and transitions it into the ACTIVE state. If there is no speculation
* in the INACTIVE state, 0 is returned. In this case, no error counter is
* incremented -- it is up to the caller to take appropriate action.
*/
static int
dtrace_speculation(dtrace_state_t *state)
{
int i = 0;
dtrace_speculation_state_t current;
uint32_t *stat = &state->dts_speculations_unavail, count;
while (i < state->dts_nspeculations) {
dtrace_speculation_t *spec = &state->dts_speculations[i];
current = spec->dtsp_state;
if (current != DTRACESPEC_INACTIVE) {
if (current == DTRACESPEC_COMMITTINGMANY ||
current == DTRACESPEC_COMMITTING ||
current == DTRACESPEC_DISCARDING)
stat = &state->dts_speculations_busy;
i++;
continue;
}
if (dtrace_cas32((uint32_t *)&spec->dtsp_state,
current, DTRACESPEC_ACTIVE) == current)
return (i + 1);
}
/*
* We couldn't find a speculation. If we found as much as a single
* busy speculation buffer, we'll attribute this failure as "busy"
* instead of "unavail".
*/
do {
count = *stat;
} while (dtrace_cas32(stat, count, count + 1) != count);
return (0);
}
/*
* This routine commits an active speculation. If the specified speculation
* is not in a valid state to perform a commit(), this routine will silently do
* nothing. The state of the specified speculation is transitioned according
* to the state transition diagram outlined in <sys/dtrace_impl.h>
*/
static void
dtrace_speculation_commit(dtrace_state_t *state, processorid_t cpu,
dtrace_specid_t which)
{
dtrace_speculation_t *spec;
dtrace_buffer_t *src, *dest;
uintptr_t daddr, saddr, dlimit, slimit;
dtrace_speculation_state_t current, new = 0;
intptr_t offs;
uint64_t timestamp;
if (which == 0)
return;
if (which > state->dts_nspeculations) {
cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
return;
}
spec = &state->dts_speculations[which - 1];
src = &spec->dtsp_buffer[cpu];
dest = &state->dts_buffer[cpu];
do {
current = spec->dtsp_state;
if (current == DTRACESPEC_COMMITTINGMANY)
break;
switch (current) {
case DTRACESPEC_INACTIVE:
case DTRACESPEC_DISCARDING:
return;
case DTRACESPEC_COMMITTING:
/*
* This is only possible if we are (a) commit()'ing
* without having done a prior speculate() on this CPU
* and (b) racing with another commit() on a different
* CPU. There's nothing to do -- we just assert that
* our offset is 0.
*/
ASSERT(src->dtb_offset == 0);
return;
case DTRACESPEC_ACTIVE:
new = DTRACESPEC_COMMITTING;
break;
case DTRACESPEC_ACTIVEONE:
/*
* This speculation is active on one CPU. If our
* buffer offset is non-zero, we know that the one CPU
* must be us. Otherwise, we are committing on a
* different CPU from the speculate(), and we must
* rely on being asynchronously cleaned.
*/
if (src->dtb_offset != 0) {
new = DTRACESPEC_COMMITTING;
break;
}
/*FALLTHROUGH*/
case DTRACESPEC_ACTIVEMANY:
new = DTRACESPEC_COMMITTINGMANY;
break;
default:
ASSERT(0);
}
} while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
current, new) != current);
/*
* We have set the state to indicate that we are committing this
* speculation. Now reserve the necessary space in the destination
* buffer.
*/
if ((offs = dtrace_buffer_reserve(dest, src->dtb_offset,
sizeof (uint64_t), state, NULL)) < 0) {
dtrace_buffer_drop(dest);
goto out;
}
/*
* We have sufficient space to copy the speculative buffer into the
* primary buffer. First, modify the speculative buffer, filling
* in the timestamp of all entries with the current time. The data
* must have the commit() time rather than the time it was traced,
* so that all entries in the primary buffer are in timestamp order.
*/
timestamp = dtrace_gethrtime();
saddr = (uintptr_t)src->dtb_tomax;
slimit = saddr + src->dtb_offset;
while (saddr < slimit) {
size_t size;
dtrace_rechdr_t *dtrh = (dtrace_rechdr_t *)saddr;
if (dtrh->dtrh_epid == DTRACE_EPIDNONE) {
saddr += sizeof (dtrace_epid_t);
continue;
}
ASSERT3U(dtrh->dtrh_epid, <=, state->dts_necbs);
size = state->dts_ecbs[dtrh->dtrh_epid - 1]->dte_size;
ASSERT3U(saddr + size, <=, slimit);
ASSERT3U(size, >=, sizeof (dtrace_rechdr_t));
ASSERT3U(DTRACE_RECORD_LOAD_TIMESTAMP(dtrh), ==, UINT64_MAX);
DTRACE_RECORD_STORE_TIMESTAMP(dtrh, timestamp);
saddr += size;
}
/*
* Copy the buffer across. (Note that this is a
* highly subobtimal bcopy(); in the unlikely event that this becomes
* a serious performance issue, a high-performance DTrace-specific
* bcopy() should obviously be invented.)
*/
daddr = (uintptr_t)dest->dtb_tomax + offs;
dlimit = daddr + src->dtb_offset;
saddr = (uintptr_t)src->dtb_tomax;
/*
* First, the aligned portion.
*/
while (dlimit - daddr >= sizeof (uint64_t)) {
*((uint64_t *)daddr) = *((uint64_t *)saddr);
daddr += sizeof (uint64_t);
saddr += sizeof (uint64_t);
}
/*
* Now any left-over bit...
*/
while (dlimit - daddr)
*((uint8_t *)daddr++) = *((uint8_t *)saddr++);
/*
* Finally, commit the reserved space in the destination buffer.
*/
dest->dtb_offset = offs + src->dtb_offset;
out:
/*
* If we're lucky enough to be the only active CPU on this speculation
* buffer, we can just set the state back to DTRACESPEC_INACTIVE.
*/
if (current == DTRACESPEC_ACTIVE ||
(current == DTRACESPEC_ACTIVEONE && new == DTRACESPEC_COMMITTING)) {
uint32_t rval = dtrace_cas32((uint32_t *)&spec->dtsp_state,
DTRACESPEC_COMMITTING, DTRACESPEC_INACTIVE);
ASSERT(rval == DTRACESPEC_COMMITTING);
}
src->dtb_offset = 0;
src->dtb_xamot_drops += src->dtb_drops;
src->dtb_drops = 0;
}
/*
* This routine discards an active speculation. If the specified speculation
* is not in a valid state to perform a discard(), this routine will silently
* do nothing. The state of the specified speculation is transitioned
* according to the state transition diagram outlined in <sys/dtrace_impl.h>
*/
static void
dtrace_speculation_discard(dtrace_state_t *state, processorid_t cpu,
dtrace_specid_t which)
{
dtrace_speculation_t *spec;
dtrace_speculation_state_t current, new = 0;
dtrace_buffer_t *buf;
if (which == 0)
return;
if (which > state->dts_nspeculations) {
cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
return;
}
spec = &state->dts_speculations[which - 1];
buf = &spec->dtsp_buffer[cpu];
do {
current = spec->dtsp_state;
switch (current) {
case DTRACESPEC_INACTIVE:
case DTRACESPEC_COMMITTINGMANY:
case DTRACESPEC_COMMITTING:
case DTRACESPEC_DISCARDING:
return;
case DTRACESPEC_ACTIVE:
case DTRACESPEC_ACTIVEMANY:
new = DTRACESPEC_DISCARDING;
break;
case DTRACESPEC_ACTIVEONE:
if (buf->dtb_offset != 0) {
new = DTRACESPEC_INACTIVE;
} else {
new = DTRACESPEC_DISCARDING;
}
break;
default:
ASSERT(0);
}
} while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
current, new) != current);
buf->dtb_offset = 0;
buf->dtb_drops = 0;
}
/*
* Note: not called from probe context. This function is called
* asynchronously from cross call context to clean any speculations that are
* in the COMMITTINGMANY or DISCARDING states. These speculations may not be
* transitioned back to the INACTIVE state until all CPUs have cleaned the
* speculation.
*/
static void
dtrace_speculation_clean_here(dtrace_state_t *state)
{
dtrace_icookie_t cookie;
processorid_t cpu = curcpu;
dtrace_buffer_t *dest = &state->dts_buffer[cpu];
dtrace_specid_t i;
cookie = dtrace_interrupt_disable();
if (dest->dtb_tomax == NULL) {
dtrace_interrupt_enable(cookie);
return;
}
for (i = 0; i < state->dts_nspeculations; i++) {
dtrace_speculation_t *spec = &state->dts_speculations[i];
dtrace_buffer_t *src = &spec->dtsp_buffer[cpu];
if (src->dtb_tomax == NULL)
continue;
if (spec->dtsp_state == DTRACESPEC_DISCARDING) {
src->dtb_offset = 0;
continue;
}
if (spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
continue;
if (src->dtb_offset == 0)
continue;
dtrace_speculation_commit(state, cpu, i + 1);
}
dtrace_interrupt_enable(cookie);
}
/*
* Note: not called from probe context. This function is called
* asynchronously (and at a regular interval) to clean any speculations that
* are in the COMMITTINGMANY or DISCARDING states. If it discovers that there
* is work to be done, it cross calls all CPUs to perform that work;
* COMMITMANY and DISCARDING speculations may not be transitioned back to the
* INACTIVE state until they have been cleaned by all CPUs.
*/
static void
dtrace_speculation_clean(dtrace_state_t *state)
{
int work = 0, rv;
dtrace_specid_t i;
for (i = 0; i < state->dts_nspeculations; i++) {
dtrace_speculation_t *spec = &state->dts_speculations[i];
ASSERT(!spec->dtsp_cleaning);
if (spec->dtsp_state != DTRACESPEC_DISCARDING &&
spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
continue;
work++;
spec->dtsp_cleaning = 1;
}
if (!work)
return;
dtrace_xcall(DTRACE_CPUALL,
(dtrace_xcall_t)dtrace_speculation_clean_here, state);
/*
* We now know that all CPUs have committed or discarded their
* speculation buffers, as appropriate. We can now set the state
* to inactive.
*/
for (i = 0; i < state->dts_nspeculations; i++) {
dtrace_speculation_t *spec = &state->dts_speculations[i];
dtrace_speculation_state_t current, new;
if (!spec->dtsp_cleaning)
continue;
current = spec->dtsp_state;
ASSERT(current == DTRACESPEC_DISCARDING ||
current == DTRACESPEC_COMMITTINGMANY);
new = DTRACESPEC_INACTIVE;
rv = dtrace_cas32((uint32_t *)&spec->dtsp_state, current, new);
ASSERT(rv == current);
spec->dtsp_cleaning = 0;
}
}
/*
* Called as part of a speculate() to get the speculative buffer associated
* with a given speculation. Returns NULL if the specified speculation is not
* in an ACTIVE state. If the speculation is in the ACTIVEONE state -- and
* the active CPU is not the specified CPU -- the speculation will be
* atomically transitioned into the ACTIVEMANY state.
*/
static dtrace_buffer_t *
dtrace_speculation_buffer(dtrace_state_t *state, processorid_t cpuid,
dtrace_specid_t which)
{
dtrace_speculation_t *spec;
dtrace_speculation_state_t current, new = 0;
dtrace_buffer_t *buf;
if (which == 0)
return (NULL);
if (which > state->dts_nspeculations) {
cpu_core[cpuid].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
return (NULL);
}
spec = &state->dts_speculations[which - 1];
buf = &spec->dtsp_buffer[cpuid];
do {
current = spec->dtsp_state;
switch (current) {
case DTRACESPEC_INACTIVE:
case DTRACESPEC_COMMITTINGMANY:
case DTRACESPEC_DISCARDING:
return (NULL);
case DTRACESPEC_COMMITTING:
ASSERT(buf->dtb_offset == 0);
return (NULL);
case DTRACESPEC_ACTIVEONE:
/*
* This speculation is currently active on one CPU.
* Check the offset in the buffer; if it's non-zero,
* that CPU must be us (and we leave the state alone).
* If it's zero, assume that we're starting on a new
* CPU -- and change the state to indicate that the
* speculation is active on more than one CPU.
*/
if (buf->dtb_offset != 0)
return (buf);
new = DTRACESPEC_ACTIVEMANY;
break;
case DTRACESPEC_ACTIVEMANY:
return (buf);
case DTRACESPEC_ACTIVE:
new = DTRACESPEC_ACTIVEONE;
break;
default:
ASSERT(0);
}
} while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
current, new) != current);
ASSERT(new == DTRACESPEC_ACTIVEONE || new == DTRACESPEC_ACTIVEMANY);
return (buf);
}
/*
* Return a string. In the event that the user lacks the privilege to access
* arbitrary kernel memory, we copy the string out to scratch memory so that we
* don't fail access checking.
*
* dtrace_dif_variable() uses this routine as a helper for various
* builtin values such as 'execname' and 'probefunc.'
*/
uintptr_t
dtrace_dif_varstr(uintptr_t addr, dtrace_state_t *state,
dtrace_mstate_t *mstate)
{
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t ret;
size_t strsz;
/*
* The easy case: this probe is allowed to read all of memory, so
* we can just return this as a vanilla pointer.
*/
if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
return (addr);
/*
* This is the tougher case: we copy the string in question from
* kernel memory into scratch memory and return it that way: this
* ensures that we won't trip up when access checking tests the
* BYREF return value.
*/
strsz = dtrace_strlen((char *)addr, size) + 1;
if (mstate->dtms_scratch_ptr + strsz >
mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
return (0);
}
dtrace_strcpy((const void *)addr, (void *)mstate->dtms_scratch_ptr,
strsz);
ret = mstate->dtms_scratch_ptr;
mstate->dtms_scratch_ptr += strsz;
return (ret);
}
/*
* Return a string from a memoy address which is known to have one or
* more concatenated, individually zero terminated, sub-strings.
* In the event that the user lacks the privilege to access
* arbitrary kernel memory, we copy the string out to scratch memory so that we
* don't fail access checking.
*
* dtrace_dif_variable() uses this routine as a helper for various
* builtin values such as 'execargs'.
*/
static uintptr_t
dtrace_dif_varstrz(uintptr_t addr, size_t strsz, dtrace_state_t *state,
dtrace_mstate_t *mstate)
{
char *p;
size_t i;
uintptr_t ret;
if (mstate->dtms_scratch_ptr + strsz >
mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
return (0);
}
dtrace_bcopy((const void *)addr, (void *)mstate->dtms_scratch_ptr,
strsz);
/* Replace sub-string termination characters with a space. */
for (p = (char *) mstate->dtms_scratch_ptr, i = 0; i < strsz - 1;
p++, i++)
if (*p == '\0')
*p = ' ';
ret = mstate->dtms_scratch_ptr;
mstate->dtms_scratch_ptr += strsz;
return (ret);
}
/*
* This function implements the DIF emulator's variable lookups. The emulator
* passes a reserved variable identifier and optional built-in array index.
*/
static uint64_t
dtrace_dif_variable(dtrace_mstate_t *mstate, dtrace_state_t *state, uint64_t v,
uint64_t ndx)
{
/*
* If we're accessing one of the uncached arguments, we'll turn this
* into a reference in the args array.
*/
if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9) {
ndx = v - DIF_VAR_ARG0;
v = DIF_VAR_ARGS;
}
switch (v) {
case DIF_VAR_ARGS:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_ARGS);
if (ndx >= sizeof (mstate->dtms_arg) /
sizeof (mstate->dtms_arg[0])) {
int aframes = mstate->dtms_probe->dtpr_aframes + 2;
dtrace_provider_t *pv;
uint64_t val;
pv = mstate->dtms_probe->dtpr_provider;
if (pv->dtpv_pops.dtps_getargval != NULL)
val = pv->dtpv_pops.dtps_getargval(pv->dtpv_arg,
mstate->dtms_probe->dtpr_id,
mstate->dtms_probe->dtpr_arg, ndx, aframes);
else
val = dtrace_getarg(ndx, aframes);
/*
* This is regrettably required to keep the compiler
* from tail-optimizing the call to dtrace_getarg().
* The condition always evaluates to true, but the
* compiler has no way of figuring that out a priori.
* (None of this would be necessary if the compiler
* could be relied upon to _always_ tail-optimize
* the call to dtrace_getarg() -- but it can't.)
*/
if (mstate->dtms_probe != NULL)
return (val);
ASSERT(0);
}
return (mstate->dtms_arg[ndx]);
#ifdef illumos
case DIF_VAR_UREGS: {
klwp_t *lwp;
if (!dtrace_priv_proc(state))
return (0);
if ((lwp = curthread->t_lwp) == NULL) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
cpu_core[curcpu].cpuc_dtrace_illval = NULL;
return (0);
}
return (dtrace_getreg(lwp->lwp_regs, ndx));
return (0);
}
#else
case DIF_VAR_UREGS: {
struct trapframe *tframe;
if (!dtrace_priv_proc(state))
return (0);
if ((tframe = curthread->td_frame) == NULL) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
cpu_core[curcpu].cpuc_dtrace_illval = 0;
return (0);
}
return (dtrace_getreg(tframe, ndx));
}
#endif
case DIF_VAR_CURTHREAD:
if (!dtrace_priv_proc(state))
return (0);
return ((uint64_t)(uintptr_t)curthread);
case DIF_VAR_TIMESTAMP:
if (!(mstate->dtms_present & DTRACE_MSTATE_TIMESTAMP)) {
mstate->dtms_timestamp = dtrace_gethrtime();
mstate->dtms_present |= DTRACE_MSTATE_TIMESTAMP;
}
return (mstate->dtms_timestamp);
case DIF_VAR_VTIMESTAMP:
ASSERT(dtrace_vtime_references != 0);
return (curthread->t_dtrace_vtime);
case DIF_VAR_WALLTIMESTAMP:
if (!(mstate->dtms_present & DTRACE_MSTATE_WALLTIMESTAMP)) {
mstate->dtms_walltimestamp = dtrace_gethrestime();
mstate->dtms_present |= DTRACE_MSTATE_WALLTIMESTAMP;
}
return (mstate->dtms_walltimestamp);
#ifdef illumos
case DIF_VAR_IPL:
if (!dtrace_priv_kernel(state))
return (0);
if (!(mstate->dtms_present & DTRACE_MSTATE_IPL)) {
mstate->dtms_ipl = dtrace_getipl();
mstate->dtms_present |= DTRACE_MSTATE_IPL;
}
return (mstate->dtms_ipl);
#endif
case DIF_VAR_EPID:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_EPID);
return (mstate->dtms_epid);
case DIF_VAR_ID:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
return (mstate->dtms_probe->dtpr_id);
case DIF_VAR_STACKDEPTH:
if (!dtrace_priv_kernel(state))
return (0);
if (!(mstate->dtms_present & DTRACE_MSTATE_STACKDEPTH)) {
int aframes = mstate->dtms_probe->dtpr_aframes + 2;
mstate->dtms_stackdepth = dtrace_getstackdepth(aframes);
mstate->dtms_present |= DTRACE_MSTATE_STACKDEPTH;
}
return (mstate->dtms_stackdepth);
case DIF_VAR_USTACKDEPTH:
if (!dtrace_priv_proc(state))
return (0);
if (!(mstate->dtms_present & DTRACE_MSTATE_USTACKDEPTH)) {
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) &&
CPU_ON_INTR(CPU)) {
mstate->dtms_ustackdepth = 0;
} else {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
mstate->dtms_ustackdepth =
dtrace_getustackdepth();
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
}
mstate->dtms_present |= DTRACE_MSTATE_USTACKDEPTH;
}
return (mstate->dtms_ustackdepth);
case DIF_VAR_CALLER:
if (!dtrace_priv_kernel(state))
return (0);
if (!(mstate->dtms_present & DTRACE_MSTATE_CALLER)) {
int aframes = mstate->dtms_probe->dtpr_aframes + 2;
if (!DTRACE_ANCHORED(mstate->dtms_probe)) {
/*
* If this is an unanchored probe, we are
* required to go through the slow path:
* dtrace_caller() only guarantees correct
* results for anchored probes.
*/
pc_t caller[2] = {0, 0};
dtrace_getpcstack(caller, 2, aframes,
(uint32_t *)(uintptr_t)mstate->dtms_arg[0]);
mstate->dtms_caller = caller[1];
} else if ((mstate->dtms_caller =
dtrace_caller(aframes)) == -1) {
/*
* We have failed to do this the quick way;
* we must resort to the slower approach of
* calling dtrace_getpcstack().
*/
pc_t caller = 0;
dtrace_getpcstack(&caller, 1, aframes, NULL);
mstate->dtms_caller = caller;
}
mstate->dtms_present |= DTRACE_MSTATE_CALLER;
}
return (mstate->dtms_caller);
case DIF_VAR_UCALLER:
if (!dtrace_priv_proc(state))
return (0);
if (!(mstate->dtms_present & DTRACE_MSTATE_UCALLER)) {
uint64_t ustack[3];
/*
* dtrace_getupcstack() fills in the first uint64_t
* with the current PID. The second uint64_t will
* be the program counter at user-level. The third
* uint64_t will contain the caller, which is what
* we're after.
*/
ustack[2] = 0;
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_getupcstack(ustack, 3);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
mstate->dtms_ucaller = ustack[2];
mstate->dtms_present |= DTRACE_MSTATE_UCALLER;
}
return (mstate->dtms_ucaller);
case DIF_VAR_PROBEPROV:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
return (dtrace_dif_varstr(
(uintptr_t)mstate->dtms_probe->dtpr_provider->dtpv_name,
state, mstate));
case DIF_VAR_PROBEMOD:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
return (dtrace_dif_varstr(
(uintptr_t)mstate->dtms_probe->dtpr_mod,
state, mstate));
case DIF_VAR_PROBEFUNC:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
return (dtrace_dif_varstr(
(uintptr_t)mstate->dtms_probe->dtpr_func,
state, mstate));
case DIF_VAR_PROBENAME:
ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
return (dtrace_dif_varstr(
(uintptr_t)mstate->dtms_probe->dtpr_name,
state, mstate));
case DIF_VAR_PID:
if (!dtrace_priv_proc(state))
return (0);
#ifdef illumos
/*
* Note that we are assuming that an unanchored probe is
* always due to a high-level interrupt. (And we're assuming
* that there is only a single high level interrupt.)
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return (pid0.pid_id);
/*
* It is always safe to dereference one's own t_procp pointer:
* it always points to a valid, allocated proc structure.
* Further, it is always safe to dereference the p_pidp member
* of one's own proc structure. (These are truisms becuase
* threads and processes don't clean up their own state --
* they leave that task to whomever reaps them.)
*/
return ((uint64_t)curthread->t_procp->p_pidp->pid_id);
#else
return ((uint64_t)curproc->p_pid);
#endif
case DIF_VAR_PPID:
if (!dtrace_priv_proc(state))
return (0);
#ifdef illumos
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return (pid0.pid_id);
/*
* It is always safe to dereference one's own t_procp pointer:
* it always points to a valid, allocated proc structure.
* (This is true because threads don't clean up their own
* state -- they leave that task to whomever reaps them.)
*/
return ((uint64_t)curthread->t_procp->p_ppid);
#else
if (curproc->p_pid == proc0.p_pid)
return (curproc->p_pid);
else
return (curproc->p_pptr->p_pid);
#endif
case DIF_VAR_TID:
#ifdef illumos
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return (0);
#endif
return ((uint64_t)curthread->t_tid);
case DIF_VAR_EXECARGS: {
struct pargs *p_args = curthread->td_proc->p_args;
if (p_args == NULL)
return(0);
return (dtrace_dif_varstrz(
(uintptr_t) p_args->ar_args, p_args->ar_length, state, mstate));
}
case DIF_VAR_EXECNAME:
#ifdef illumos
if (!dtrace_priv_proc(state))
return (0);
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return ((uint64_t)(uintptr_t)p0.p_user.u_comm);
/*
* It is always safe to dereference one's own t_procp pointer:
* it always points to a valid, allocated proc structure.
* (This is true because threads don't clean up their own
* state -- they leave that task to whomever reaps them.)
*/
return (dtrace_dif_varstr(
(uintptr_t)curthread->t_procp->p_user.u_comm,
state, mstate));
#else
return (dtrace_dif_varstr(
(uintptr_t) curthread->td_proc->p_comm, state, mstate));
#endif
case DIF_VAR_ZONENAME:
#ifdef illumos
if (!dtrace_priv_proc(state))
return (0);
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return ((uint64_t)(uintptr_t)p0.p_zone->zone_name);
/*
* It is always safe to dereference one's own t_procp pointer:
* it always points to a valid, allocated proc structure.
* (This is true because threads don't clean up their own
* state -- they leave that task to whomever reaps them.)
*/
return (dtrace_dif_varstr(
(uintptr_t)curthread->t_procp->p_zone->zone_name,
state, mstate));
#else
return (0);
#endif
case DIF_VAR_UID:
if (!dtrace_priv_proc(state))
return (0);
#ifdef illumos
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return ((uint64_t)p0.p_cred->cr_uid);
/*
* It is always safe to dereference one's own t_procp pointer:
* it always points to a valid, allocated proc structure.
* (This is true because threads don't clean up their own
* state -- they leave that task to whomever reaps them.)
*
* Additionally, it is safe to dereference one's own process
* credential, since this is never NULL after process birth.
*/
return ((uint64_t)curthread->t_procp->p_cred->cr_uid);
#else
return ((uint64_t)curthread->td_ucred->cr_uid);
#endif
case DIF_VAR_GID:
if (!dtrace_priv_proc(state))
return (0);
#ifdef illumos
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return ((uint64_t)p0.p_cred->cr_gid);
/*
* It is always safe to dereference one's own t_procp pointer:
* it always points to a valid, allocated proc structure.
* (This is true because threads don't clean up their own
* state -- they leave that task to whomever reaps them.)
*
* Additionally, it is safe to dereference one's own process
* credential, since this is never NULL after process birth.
*/
return ((uint64_t)curthread->t_procp->p_cred->cr_gid);
#else
return ((uint64_t)curthread->td_ucred->cr_gid);
#endif
case DIF_VAR_ERRNO: {
#ifdef illumos
klwp_t *lwp;
if (!dtrace_priv_proc(state))
return (0);
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
return (0);
/*
* It is always safe to dereference one's own t_lwp pointer in
* the event that this pointer is non-NULL. (This is true
* because threads and lwps don't clean up their own state --
* they leave that task to whomever reaps them.)
*/
if ((lwp = curthread->t_lwp) == NULL)
return (0);
return ((uint64_t)lwp->lwp_errno);
#else
return (curthread->td_errno);
#endif
}
#ifndef illumos
case DIF_VAR_CPU: {
return curcpu;
}
#endif
default:
DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
return (0);
}
}
typedef enum dtrace_json_state {
DTRACE_JSON_REST = 1,
DTRACE_JSON_OBJECT,
DTRACE_JSON_STRING,
DTRACE_JSON_STRING_ESCAPE,
DTRACE_JSON_STRING_ESCAPE_UNICODE,
DTRACE_JSON_COLON,
DTRACE_JSON_COMMA,
DTRACE_JSON_VALUE,
DTRACE_JSON_IDENTIFIER,
DTRACE_JSON_NUMBER,
DTRACE_JSON_NUMBER_FRAC,
DTRACE_JSON_NUMBER_EXP,
DTRACE_JSON_COLLECT_OBJECT
} dtrace_json_state_t;
/*
* This function possesses just enough knowledge about JSON to extract a single
* value from a JSON string and store it in the scratch buffer. It is able
* to extract nested object values, and members of arrays by index.
*
* elemlist is a list of JSON keys, stored as packed NUL-terminated strings, to
* be looked up as we descend into the object tree. e.g.
*
* foo[0].bar.baz[32] --> "foo" NUL "0" NUL "bar" NUL "baz" NUL "32" NUL
* with nelems = 5.
*
* The run time of this function must be bounded above by strsize to limit the
* amount of work done in probe context. As such, it is implemented as a
* simple state machine, reading one character at a time using safe loads
* until we find the requested element, hit a parsing error or run off the
* end of the object or string.
*
* As there is no way for a subroutine to return an error without interrupting
* clause execution, we simply return NULL in the event of a missing key or any
* other error condition. Each NULL return in this function is commented with
* the error condition it represents -- parsing or otherwise.
*
* The set of states for the state machine closely matches the JSON
* specification (http://json.org/). Briefly:
*
* DTRACE_JSON_REST:
* Skip whitespace until we find either a top-level Object, moving
* to DTRACE_JSON_OBJECT; or an Array, moving to DTRACE_JSON_VALUE.
*
* DTRACE_JSON_OBJECT:
* Locate the next key String in an Object. Sets a flag to denote
* the next String as a key string and moves to DTRACE_JSON_STRING.
*
* DTRACE_JSON_COLON:
* Skip whitespace until we find the colon that separates key Strings
* from their values. Once found, move to DTRACE_JSON_VALUE.
*
* DTRACE_JSON_VALUE:
* Detects the type of the next value (String, Number, Identifier, Object
* or Array) and routes to the states that process that type. Here we also
* deal with the element selector list if we are requested to traverse down
* into the object tree.
*
* DTRACE_JSON_COMMA:
* Skip whitespace until we find the comma that separates key-value pairs
* in Objects (returning to DTRACE_JSON_OBJECT) or values in Arrays
* (similarly DTRACE_JSON_VALUE). All following literal value processing
* states return to this state at the end of their value, unless otherwise
* noted.
*
* DTRACE_JSON_NUMBER, DTRACE_JSON_NUMBER_FRAC, DTRACE_JSON_NUMBER_EXP:
* Processes a Number literal from the JSON, including any exponent
* component that may be present. Numbers are returned as strings, which
* may be passed to strtoll() if an integer is required.
*
* DTRACE_JSON_IDENTIFIER:
* Processes a "true", "false" or "null" literal in the JSON.
*
* DTRACE_JSON_STRING, DTRACE_JSON_STRING_ESCAPE,
* DTRACE_JSON_STRING_ESCAPE_UNICODE:
* Processes a String literal from the JSON, whether the String denotes
* a key, a value or part of a larger Object. Handles all escape sequences
* present in the specification, including four-digit unicode characters,
* but merely includes the escape sequence without converting it to the
* actual escaped character. If the String is flagged as a key, we
* move to DTRACE_JSON_COLON rather than DTRACE_JSON_COMMA.
*
* DTRACE_JSON_COLLECT_OBJECT:
* This state collects an entire Object (or Array), correctly handling
* embedded strings. If the full element selector list matches this nested
* object, we return the Object in full as a string. If not, we use this
* state to skip to the next value at this level and continue processing.
*
* NOTE: This function uses various macros from strtolctype.h to manipulate
* digit values, etc -- these have all been checked to ensure they make
* no additional function calls.
*/
static char *
dtrace_json(uint64_t size, uintptr_t json, char *elemlist, int nelems,
char *dest)
{
dtrace_json_state_t state = DTRACE_JSON_REST;
int64_t array_elem = INT64_MIN;
int64_t array_pos = 0;
uint8_t escape_unicount = 0;
boolean_t string_is_key = B_FALSE;
boolean_t collect_object = B_FALSE;
boolean_t found_key = B_FALSE;
boolean_t in_array = B_FALSE;
uint32_t braces = 0, brackets = 0;
char *elem = elemlist;
char *dd = dest;
uintptr_t cur;
for (cur = json; cur < json + size; cur++) {
char cc = dtrace_load8(cur);
if (cc == '\0')
return (NULL);
switch (state) {
case DTRACE_JSON_REST:
if (isspace(cc))
break;
if (cc == '{') {
state = DTRACE_JSON_OBJECT;
break;
}
if (cc == '[') {
in_array = B_TRUE;
array_pos = 0;
array_elem = dtrace_strtoll(elem, 10, size);
found_key = array_elem == 0 ? B_TRUE : B_FALSE;
state = DTRACE_JSON_VALUE;
break;
}
/*
* ERROR: expected to find a top-level object or array.
*/
return (NULL);
case DTRACE_JSON_OBJECT:
if (isspace(cc))
break;
if (cc == '"') {
state = DTRACE_JSON_STRING;
string_is_key = B_TRUE;
break;
}
/*
* ERROR: either the object did not start with a key
* string, or we've run off the end of the object
* without finding the requested key.
*/
return (NULL);
case DTRACE_JSON_STRING:
if (cc == '\\') {
*dd++ = '\\';
state = DTRACE_JSON_STRING_ESCAPE;
break;
}
if (cc == '"') {
if (collect_object) {
/*
* We don't reset the dest here, as
* the string is part of a larger
* object being collected.
*/
*dd++ = cc;
collect_object = B_FALSE;
state = DTRACE_JSON_COLLECT_OBJECT;
break;
}
*dd = '\0';
dd = dest; /* reset string buffer */
if (string_is_key) {
if (dtrace_strncmp(dest, elem,
size) == 0)
found_key = B_TRUE;
} else if (found_key) {
if (nelems > 1) {
/*
* We expected an object, not
* this string.
*/
return (NULL);
}
return (dest);
}
state = string_is_key ? DTRACE_JSON_COLON :
DTRACE_JSON_COMMA;
string_is_key = B_FALSE;
break;
}
*dd++ = cc;
break;
case DTRACE_JSON_STRING_ESCAPE:
*dd++ = cc;
if (cc == 'u') {
escape_unicount = 0;
state = DTRACE_JSON_STRING_ESCAPE_UNICODE;
} else {
state = DTRACE_JSON_STRING;
}
break;
case DTRACE_JSON_STRING_ESCAPE_UNICODE:
if (!isxdigit(cc)) {
/*
* ERROR: invalid unicode escape, expected
* four valid hexidecimal digits.
*/
return (NULL);
}
*dd++ = cc;
if (++escape_unicount == 4)
state = DTRACE_JSON_STRING;
break;
case DTRACE_JSON_COLON:
if (isspace(cc))
break;
if (cc == ':') {
state = DTRACE_JSON_VALUE;
break;
}
/*
* ERROR: expected a colon.
*/
return (NULL);
case DTRACE_JSON_COMMA:
if (isspace(cc))
break;
if (cc == ',') {
if (in_array) {
state = DTRACE_JSON_VALUE;
if (++array_pos == array_elem)
found_key = B_TRUE;
} else {
state = DTRACE_JSON_OBJECT;
}
break;
}
/*
* ERROR: either we hit an unexpected character, or
* we reached the end of the object or array without
* finding the requested key.
*/
return (NULL);
case DTRACE_JSON_IDENTIFIER:
if (islower(cc)) {
*dd++ = cc;
break;
}
*dd = '\0';
dd = dest; /* reset string buffer */
if (dtrace_strncmp(dest, "true", 5) == 0 ||
dtrace_strncmp(dest, "false", 6) == 0 ||
dtrace_strncmp(dest, "null", 5) == 0) {
if (found_key) {
if (nelems > 1) {
/*
* ERROR: We expected an object,
* not this identifier.
*/
return (NULL);
}
return (dest);
} else {
cur--;
state = DTRACE_JSON_COMMA;
break;
}
}
/*
* ERROR: we did not recognise the identifier as one
* of those in the JSON specification.
*/
return (NULL);
case DTRACE_JSON_NUMBER:
if (cc == '.') {
*dd++ = cc;
state = DTRACE_JSON_NUMBER_FRAC;
break;
}
if (cc == 'x' || cc == 'X') {
/*
* ERROR: specification explicitly excludes
* hexidecimal or octal numbers.
*/
return (NULL);
}
/* FALLTHRU */
case DTRACE_JSON_NUMBER_FRAC:
if (cc == 'e' || cc == 'E') {
*dd++ = cc;
state = DTRACE_JSON_NUMBER_EXP;
break;
}
if (cc == '+' || cc == '-') {
/*
* ERROR: expect sign as part of exponent only.
*/
return (NULL);
}
/* FALLTHRU */
case DTRACE_JSON_NUMBER_EXP:
if (isdigit(cc) || cc == '+' || cc == '-') {
*dd++ = cc;
break;
}
*dd = '\0';
dd = dest; /* reset string buffer */
if (found_key) {
if (nelems > 1) {
/*
* ERROR: We expected an object, not
* this number.
*/
return (NULL);
}
return (dest);
}
cur--;
state = DTRACE_JSON_COMMA;
break;
case DTRACE_JSON_VALUE:
if (isspace(cc))
break;
if (cc == '{' || cc == '[') {
if (nelems > 1 && found_key) {
in_array = cc == '[' ? B_TRUE : B_FALSE;
/*
* If our element selector directs us
* to descend into this nested object,
* then move to the next selector
* element in the list and restart the
* state machine.
*/
while (*elem != '\0')
elem++;
elem++; /* skip the inter-element NUL */
nelems--;
dd = dest;
if (in_array) {
state = DTRACE_JSON_VALUE;
array_pos = 0;
array_elem = dtrace_strtoll(
elem, 10, size);
found_key = array_elem == 0 ?
B_TRUE : B_FALSE;
} else {
found_key = B_FALSE;
state = DTRACE_JSON_OBJECT;
}
break;
}
/*
* Otherwise, we wish to either skip this
* nested object or return it in full.
*/
if (cc == '[')
brackets = 1;
else
braces = 1;
*dd++ = cc;
state = DTRACE_JSON_COLLECT_OBJECT;
break;
}
if (cc == '"') {
state = DTRACE_JSON_STRING;
break;
}
if (islower(cc)) {
/*
* Here we deal with true, false and null.
*/
*dd++ = cc;
state = DTRACE_JSON_IDENTIFIER;
break;
}
if (cc == '-' || isdigit(cc)) {
*dd++ = cc;
state = DTRACE_JSON_NUMBER;
break;
}
/*
* ERROR: unexpected character at start of value.
*/
return (NULL);
case DTRACE_JSON_COLLECT_OBJECT:
if (cc == '\0')
/*
* ERROR: unexpected end of input.
*/
return (NULL);
*dd++ = cc;
if (cc == '"') {
collect_object = B_TRUE;
state = DTRACE_JSON_STRING;
break;
}
if (cc == ']') {
if (brackets-- == 0) {
/*
* ERROR: unbalanced brackets.
*/
return (NULL);
}
} else if (cc == '}') {
if (braces-- == 0) {
/*
* ERROR: unbalanced braces.
*/
return (NULL);
}
} else if (cc == '{') {
braces++;
} else if (cc == '[') {
brackets++;
}
if (brackets == 0 && braces == 0) {
if (found_key) {
*dd = '\0';
return (dest);
}
dd = dest; /* reset string buffer */
state = DTRACE_JSON_COMMA;
}
break;
}
}
return (NULL);
}
/*
* Emulate the execution of DTrace ID subroutines invoked by the call opcode.
* Notice that we don't bother validating the proper number of arguments or
* their types in the tuple stack. This isn't needed because all argument
* interpretation is safe because of our load safety -- the worst that can
* happen is that a bogus program can obtain bogus results.
*/
static void
dtrace_dif_subr(uint_t subr, uint_t rd, uint64_t *regs,
dtrace_key_t *tupregs, int nargs,
dtrace_mstate_t *mstate, dtrace_state_t *state)
{
volatile uint16_t *flags = &cpu_core[curcpu].cpuc_dtrace_flags;
volatile uintptr_t *illval = &cpu_core[curcpu].cpuc_dtrace_illval;
dtrace_vstate_t *vstate = &state->dts_vstate;
#ifdef illumos
union {
mutex_impl_t mi;
uint64_t mx;
} m;
union {
krwlock_t ri;
uintptr_t rw;
} r;
#else
struct thread *lowner;
union {
struct lock_object *li;
uintptr_t lx;
} l;
#endif
switch (subr) {
case DIF_SUBR_RAND:
regs[rd] = (dtrace_gethrtime() * 2416 + 374441) % 1771875;
break;
#ifdef illumos
case DIF_SUBR_MUTEX_OWNED:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
m.mx = dtrace_load64(tupregs[0].dttk_value);
if (MUTEX_TYPE_ADAPTIVE(&m.mi))
regs[rd] = MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER;
else
regs[rd] = LOCK_HELD(&m.mi.m_spin.m_spinlock);
break;
case DIF_SUBR_MUTEX_OWNER:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
m.mx = dtrace_load64(tupregs[0].dttk_value);
if (MUTEX_TYPE_ADAPTIVE(&m.mi) &&
MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER)
regs[rd] = (uintptr_t)MUTEX_OWNER(&m.mi);
else
regs[rd] = 0;
break;
case DIF_SUBR_MUTEX_TYPE_ADAPTIVE:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
m.mx = dtrace_load64(tupregs[0].dttk_value);
regs[rd] = MUTEX_TYPE_ADAPTIVE(&m.mi);
break;
case DIF_SUBR_MUTEX_TYPE_SPIN:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
m.mx = dtrace_load64(tupregs[0].dttk_value);
regs[rd] = MUTEX_TYPE_SPIN(&m.mi);
break;
case DIF_SUBR_RW_READ_HELD: {
uintptr_t tmp;
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (uintptr_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
r.rw = dtrace_loadptr(tupregs[0].dttk_value);
regs[rd] = _RW_READ_HELD(&r.ri, tmp);
break;
}
case DIF_SUBR_RW_WRITE_HELD:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (krwlock_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
r.rw = dtrace_loadptr(tupregs[0].dttk_value);
regs[rd] = _RW_WRITE_HELD(&r.ri);
break;
case DIF_SUBR_RW_ISWRITER:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (krwlock_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
r.rw = dtrace_loadptr(tupregs[0].dttk_value);
regs[rd] = _RW_ISWRITER(&r.ri);
break;
#else /* !illumos */
case DIF_SUBR_MUTEX_OWNED:
if (!dtrace_canload(tupregs[0].dttk_value,
sizeof (struct lock_object), mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr((uintptr_t)&tupregs[0].dttk_value);
regs[rd] = LOCK_CLASS(l.li)->lc_owner(l.li, &lowner);
break;
case DIF_SUBR_MUTEX_OWNER:
if (!dtrace_canload(tupregs[0].dttk_value,
sizeof (struct lock_object), mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr((uintptr_t)&tupregs[0].dttk_value);
LOCK_CLASS(l.li)->lc_owner(l.li, &lowner);
regs[rd] = (uintptr_t)lowner;
break;
case DIF_SUBR_MUTEX_TYPE_ADAPTIVE:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (struct mtx),
mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr((uintptr_t)&tupregs[0].dttk_value);
/* XXX - should be only LC_SLEEPABLE? */
regs[rd] = (LOCK_CLASS(l.li)->lc_flags &
(LC_SLEEPLOCK | LC_SLEEPABLE)) != 0;
break;
case DIF_SUBR_MUTEX_TYPE_SPIN:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (struct mtx),
mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr((uintptr_t)&tupregs[0].dttk_value);
regs[rd] = (LOCK_CLASS(l.li)->lc_flags & LC_SPINLOCK) != 0;
break;
case DIF_SUBR_RW_READ_HELD:
case DIF_SUBR_SX_SHARED_HELD:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (uintptr_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr((uintptr_t)&tupregs[0].dttk_value);
regs[rd] = LOCK_CLASS(l.li)->lc_owner(l.li, &lowner) &&
lowner == NULL;
break;
case DIF_SUBR_RW_WRITE_HELD:
case DIF_SUBR_SX_EXCLUSIVE_HELD:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (uintptr_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr(tupregs[0].dttk_value);
LOCK_CLASS(l.li)->lc_owner(l.li, &lowner);
regs[rd] = (lowner == curthread);
break;
case DIF_SUBR_RW_ISWRITER:
case DIF_SUBR_SX_ISEXCLUSIVE:
if (!dtrace_canload(tupregs[0].dttk_value, sizeof (uintptr_t),
mstate, vstate)) {
regs[rd] = 0;
break;
}
l.lx = dtrace_loadptr(tupregs[0].dttk_value);
regs[rd] = LOCK_CLASS(l.li)->lc_owner(l.li, &lowner) &&
lowner != NULL;
break;
#endif /* illumos */
case DIF_SUBR_BCOPY: {
/*
* We need to be sure that the destination is in the scratch
* region -- no other region is allowed.
*/
uintptr_t src = tupregs[0].dttk_value;
uintptr_t dest = tupregs[1].dttk_value;
size_t size = tupregs[2].dttk_value;
if (!dtrace_inscratch(dest, size, mstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
if (!dtrace_canload(src, size, mstate, vstate)) {
regs[rd] = 0;
break;
}
dtrace_bcopy((void *)src, (void *)dest, size);
break;
}
case DIF_SUBR_ALLOCA:
case DIF_SUBR_COPYIN: {
uintptr_t dest = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
uint64_t size =
tupregs[subr == DIF_SUBR_ALLOCA ? 0 : 1].dttk_value;
size_t scratch_size = (dest - mstate->dtms_scratch_ptr) + size;
/*
* This action doesn't require any credential checks since
* probes will not activate in user contexts to which the
* enabling user does not have permissions.
*/
/*
* Rounding up the user allocation size could have overflowed
* a large, bogus allocation (like -1ULL) to 0.
*/
if (scratch_size < size ||
!DTRACE_INSCRATCH(mstate, scratch_size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
if (subr == DIF_SUBR_COPYIN) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_copyin(tupregs[0].dttk_value, dest, size, flags);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
}
mstate->dtms_scratch_ptr += scratch_size;
regs[rd] = dest;
break;
}
case DIF_SUBR_COPYINTO: {
uint64_t size = tupregs[1].dttk_value;
uintptr_t dest = tupregs[2].dttk_value;
/*
* This action doesn't require any credential checks since
* probes will not activate in user contexts to which the
* enabling user does not have permissions.
*/
if (!dtrace_inscratch(dest, size, mstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_copyin(tupregs[0].dttk_value, dest, size, flags);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
}
case DIF_SUBR_COPYINSTR: {
uintptr_t dest = mstate->dtms_scratch_ptr;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
if (nargs > 1 && tupregs[1].dttk_value < size)
size = tupregs[1].dttk_value + 1;
/*
* This action doesn't require any credential checks since
* probes will not activate in user contexts to which the
* enabling user does not have permissions.
*/
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_copyinstr(tupregs[0].dttk_value, dest, size, flags);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
((char *)dest)[size - 1] = '\0';
mstate->dtms_scratch_ptr += size;
regs[rd] = dest;
break;
}
#ifdef illumos
case DIF_SUBR_MSGSIZE:
case DIF_SUBR_MSGDSIZE: {
uintptr_t baddr = tupregs[0].dttk_value, daddr;
uintptr_t wptr, rptr;
size_t count = 0;
int cont = 0;
while (baddr != 0 && !(*flags & CPU_DTRACE_FAULT)) {
if (!dtrace_canload(baddr, sizeof (mblk_t), mstate,
vstate)) {
regs[rd] = 0;
break;
}
wptr = dtrace_loadptr(baddr +
offsetof(mblk_t, b_wptr));
rptr = dtrace_loadptr(baddr +
offsetof(mblk_t, b_rptr));
if (wptr < rptr) {
*flags |= CPU_DTRACE_BADADDR;
*illval = tupregs[0].dttk_value;
break;
}
daddr = dtrace_loadptr(baddr +
offsetof(mblk_t, b_datap));
baddr = dtrace_loadptr(baddr +
offsetof(mblk_t, b_cont));
/*
* We want to prevent against denial-of-service here,
* so we're only going to search the list for
* dtrace_msgdsize_max mblks.
*/
if (cont++ > dtrace_msgdsize_max) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
if (subr == DIF_SUBR_MSGDSIZE) {
if (dtrace_load8(daddr +
offsetof(dblk_t, db_type)) != M_DATA)
continue;
}
count += wptr - rptr;
}
if (!(*flags & CPU_DTRACE_FAULT))
regs[rd] = count;
break;
}
#endif
case DIF_SUBR_PROGENYOF: {
pid_t pid = tupregs[0].dttk_value;
proc_t *p;
int rval = 0;
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
for (p = curthread->t_procp; p != NULL; p = p->p_parent) {
#ifdef illumos
if (p->p_pidp->pid_id == pid) {
#else
if (p->p_pid == pid) {
#endif
rval = 1;
break;
}
}
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
regs[rd] = rval;
break;
}
case DIF_SUBR_SPECULATION:
regs[rd] = dtrace_speculation(state);
break;
case DIF_SUBR_COPYOUT: {
uintptr_t kaddr = tupregs[0].dttk_value;
uintptr_t uaddr = tupregs[1].dttk_value;
uint64_t size = tupregs[2].dttk_value;
if (!dtrace_destructive_disallow &&
dtrace_priv_proc_control(state) &&
!dtrace_istoxic(kaddr, size) &&
dtrace_canload(kaddr, size, mstate, vstate)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_copyout(kaddr, uaddr, size, flags);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
}
break;
}
case DIF_SUBR_COPYOUTSTR: {
uintptr_t kaddr = tupregs[0].dttk_value;
uintptr_t uaddr = tupregs[1].dttk_value;
uint64_t size = tupregs[2].dttk_value;
size_t lim;
if (!dtrace_destructive_disallow &&
dtrace_priv_proc_control(state) &&
!dtrace_istoxic(kaddr, size) &&
dtrace_strcanload(kaddr, size, &lim, mstate, vstate)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_copyoutstr(kaddr, uaddr, lim, flags);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
}
break;
}
case DIF_SUBR_STRLEN: {
size_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t addr = (uintptr_t)tupregs[0].dttk_value;
size_t lim;
if (!dtrace_strcanload(addr, size, &lim, mstate, vstate)) {
regs[rd] = 0;
break;
}
regs[rd] = dtrace_strlen((char *)addr, lim);
break;
}
case DIF_SUBR_STRCHR:
case DIF_SUBR_STRRCHR: {
/*
* We're going to iterate over the string looking for the
* specified character. We will iterate until we have reached
* the string length or we have found the character. If this
* is DIF_SUBR_STRRCHR, we will look for the last occurrence
* of the specified character instead of the first.
*/
uintptr_t addr = tupregs[0].dttk_value;
uintptr_t addr_limit;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
size_t lim;
char c, target = (char)tupregs[1].dttk_value;
if (!dtrace_strcanload(addr, size, &lim, mstate, vstate)) {
regs[rd] = 0;
break;
}
addr_limit = addr + lim;
for (regs[rd] = 0; addr < addr_limit; addr++) {
if ((c = dtrace_load8(addr)) == target) {
regs[rd] = addr;
if (subr == DIF_SUBR_STRCHR)
break;
}
if (c == '\0')
break;
}
break;
}
case DIF_SUBR_STRSTR:
case DIF_SUBR_INDEX:
case DIF_SUBR_RINDEX: {
/*
* We're going to iterate over the string looking for the
* specified string. We will iterate until we have reached
* the string length or we have found the string. (Yes, this
* is done in the most naive way possible -- but considering
* that the string we're searching for is likely to be
* relatively short, the complexity of Rabin-Karp or similar
* hardly seems merited.)
*/
char *addr = (char *)(uintptr_t)tupregs[0].dttk_value;
char *substr = (char *)(uintptr_t)tupregs[1].dttk_value;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
size_t len = dtrace_strlen(addr, size);
size_t sublen = dtrace_strlen(substr, size);
char *limit = addr + len, *orig = addr;
int notfound = subr == DIF_SUBR_STRSTR ? 0 : -1;
int inc = 1;
regs[rd] = notfound;
if (!dtrace_canload((uintptr_t)addr, len + 1, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!dtrace_canload((uintptr_t)substr, sublen + 1, mstate,
vstate)) {
regs[rd] = 0;
break;
}
/*
* strstr() and index()/rindex() have similar semantics if
* both strings are the empty string: strstr() returns a
* pointer to the (empty) string, and index() and rindex()
* both return index 0 (regardless of any position argument).
*/
if (sublen == 0 && len == 0) {
if (subr == DIF_SUBR_STRSTR)
regs[rd] = (uintptr_t)addr;
else
regs[rd] = 0;
break;
}
if (subr != DIF_SUBR_STRSTR) {
if (subr == DIF_SUBR_RINDEX) {
limit = orig - 1;
addr += len;
inc = -1;
}
/*
* Both index() and rindex() take an optional position
* argument that denotes the starting position.
*/
if (nargs == 3) {
int64_t pos = (int64_t)tupregs[2].dttk_value;
/*
* If the position argument to index() is
* negative, Perl implicitly clamps it at
* zero. This semantic is a little surprising
* given the special meaning of negative
* positions to similar Perl functions like
* substr(), but it appears to reflect a
* notion that index() can start from a
* negative index and increment its way up to
* the string. Given this notion, Perl's
* rindex() is at least self-consistent in
* that it implicitly clamps positions greater
* than the string length to be the string
* length. Where Perl completely loses
* coherence, however, is when the specified
* substring is the empty string (""). In
* this case, even if the position is
* negative, rindex() returns 0 -- and even if
* the position is greater than the length,
* index() returns the string length. These
* semantics violate the notion that index()
* should never return a value less than the
* specified position and that rindex() should
* never return a value greater than the
* specified position. (One assumes that
* these semantics are artifacts of Perl's
* implementation and not the results of
* deliberate design -- it beggars belief that
* even Larry Wall could desire such oddness.)
* While in the abstract one would wish for
* consistent position semantics across
* substr(), index() and rindex() -- or at the
* very least self-consistent position
* semantics for index() and rindex() -- we
* instead opt to keep with the extant Perl
* semantics, in all their broken glory. (Do
* we have more desire to maintain Perl's
* semantics than Perl does? Probably.)
*/
if (subr == DIF_SUBR_RINDEX) {
if (pos < 0) {
if (sublen == 0)
regs[rd] = 0;
break;
}
if (pos > len)
pos = len;
} else {
if (pos < 0)
pos = 0;
if (pos >= len) {
if (sublen == 0)
regs[rd] = len;
break;
}
}
addr = orig + pos;
}
}
for (regs[rd] = notfound; addr != limit; addr += inc) {
if (dtrace_strncmp(addr, substr, sublen) == 0) {
if (subr != DIF_SUBR_STRSTR) {
/*
* As D index() and rindex() are
* modeled on Perl (and not on awk),
* we return a zero-based (and not a
* one-based) index. (For you Perl
* weenies: no, we're not going to add
* $[ -- and shouldn't you be at a con
* or something?)
*/
regs[rd] = (uintptr_t)(addr - orig);
break;
}
ASSERT(subr == DIF_SUBR_STRSTR);
regs[rd] = (uintptr_t)addr;
break;
}
}
break;
}
case DIF_SUBR_STRTOK: {
uintptr_t addr = tupregs[0].dttk_value;
uintptr_t tokaddr = tupregs[1].dttk_value;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t limit, toklimit;
size_t clim;
uint8_t c = 0, tokmap[32]; /* 256 / 8 */
char *dest = (char *)mstate->dtms_scratch_ptr;
int i;
/*
* Check both the token buffer and (later) the input buffer,
* since both could be non-scratch addresses.
*/
if (!dtrace_strcanload(tokaddr, size, &clim, mstate, vstate)) {
regs[rd] = 0;
break;
}
toklimit = tokaddr + clim;
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
if (addr == 0) {
/*
* If the address specified is NULL, we use our saved
* strtok pointer from the mstate. Note that this
* means that the saved strtok pointer is _only_
* valid within multiple enablings of the same probe --
* it behaves like an implicit clause-local variable.
*/
addr = mstate->dtms_strtok;
limit = mstate->dtms_strtok_limit;
} else {
/*
* If the user-specified address is non-NULL we must
* access check it. This is the only time we have
* a chance to do so, since this address may reside
* in the string table of this clause-- future calls
* (when we fetch addr from mstate->dtms_strtok)
* would fail this access check.
*/
if (!dtrace_strcanload(addr, size, &clim, mstate,
vstate)) {
regs[rd] = 0;
break;
}
limit = addr + clim;
}
/*
* First, zero the token map, and then process the token
* string -- setting a bit in the map for every character
* found in the token string.
*/
for (i = 0; i < sizeof (tokmap); i++)
tokmap[i] = 0;
for (; tokaddr < toklimit; tokaddr++) {
if ((c = dtrace_load8(tokaddr)) == '\0')
break;
ASSERT((c >> 3) < sizeof (tokmap));
tokmap[c >> 3] |= (1 << (c & 0x7));
}
for (; addr < limit; addr++) {
/*
* We're looking for a character that is _not_
* contained in the token string.
*/
if ((c = dtrace_load8(addr)) == '\0')
break;
if (!(tokmap[c >> 3] & (1 << (c & 0x7))))
break;
}
if (c == '\0') {
/*
* We reached the end of the string without finding
* any character that was not in the token string.
* We return NULL in this case, and we set the saved
* address to NULL as well.
*/
regs[rd] = 0;
mstate->dtms_strtok = 0;
mstate->dtms_strtok_limit = 0;
break;
}
/*
* From here on, we're copying into the destination string.
*/
for (i = 0; addr < limit && i < size - 1; addr++) {
if ((c = dtrace_load8(addr)) == '\0')
break;
if (tokmap[c >> 3] & (1 << (c & 0x7)))
break;
ASSERT(i < size);
dest[i++] = c;
}
ASSERT(i < size);
dest[i] = '\0';
regs[rd] = (uintptr_t)dest;
mstate->dtms_scratch_ptr += size;
mstate->dtms_strtok = addr;
mstate->dtms_strtok_limit = limit;
break;
}
case DIF_SUBR_SUBSTR: {
uintptr_t s = tupregs[0].dttk_value;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
char *d = (char *)mstate->dtms_scratch_ptr;
int64_t index = (int64_t)tupregs[1].dttk_value;
int64_t remaining = (int64_t)tupregs[2].dttk_value;
size_t len = dtrace_strlen((char *)s, size);
int64_t i;
if (!dtrace_canload(s, len + 1, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
if (nargs <= 2)
remaining = (int64_t)size;
if (index < 0) {
index += len;
if (index < 0 && index + remaining > 0) {
remaining += index;
index = 0;
}
}
if (index >= len || index < 0) {
remaining = 0;
} else if (remaining < 0) {
remaining += len - index;
} else if (index + remaining > size) {
remaining = size - index;
}
for (i = 0; i < remaining; i++) {
if ((d[i] = dtrace_load8(s + index + i)) == '\0')
break;
}
d[i] = '\0';
mstate->dtms_scratch_ptr += size;
regs[rd] = (uintptr_t)d;
break;
}
case DIF_SUBR_JSON: {
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t json = tupregs[0].dttk_value;
size_t jsonlen = dtrace_strlen((char *)json, size);
uintptr_t elem = tupregs[1].dttk_value;
size_t elemlen = dtrace_strlen((char *)elem, size);
char *dest = (char *)mstate->dtms_scratch_ptr;
char *elemlist = (char *)mstate->dtms_scratch_ptr + jsonlen + 1;
char *ee = elemlist;
int nelems = 1;
uintptr_t cur;
if (!dtrace_canload(json, jsonlen + 1, mstate, vstate) ||
!dtrace_canload(elem, elemlen + 1, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!DTRACE_INSCRATCH(mstate, jsonlen + 1 + elemlen + 1)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
/*
* Read the element selector and split it up into a packed list
* of strings.
*/
for (cur = elem; cur < elem + elemlen; cur++) {
char cc = dtrace_load8(cur);
if (cur == elem && cc == '[') {
/*
* If the first element selector key is
* actually an array index then ignore the
* bracket.
*/
continue;
}
if (cc == ']')
continue;
if (cc == '.' || cc == '[') {
nelems++;
cc = '\0';
}
*ee++ = cc;
}
*ee++ = '\0';
if ((regs[rd] = (uintptr_t)dtrace_json(size, json, elemlist,
nelems, dest)) != 0)
mstate->dtms_scratch_ptr += jsonlen + 1;
break;
}
case DIF_SUBR_TOUPPER:
case DIF_SUBR_TOLOWER: {
uintptr_t s = tupregs[0].dttk_value;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
char *dest = (char *)mstate->dtms_scratch_ptr, c;
size_t len = dtrace_strlen((char *)s, size);
char lower, upper, convert;
int64_t i;
if (subr == DIF_SUBR_TOUPPER) {
lower = 'a';
upper = 'z';
convert = 'A';
} else {
lower = 'A';
upper = 'Z';
convert = 'a';
}
if (!dtrace_canload(s, len + 1, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
for (i = 0; i < size - 1; i++) {
if ((c = dtrace_load8(s + i)) == '\0')
break;
if (c >= lower && c <= upper)
c = convert + (c - lower);
dest[i] = c;
}
ASSERT(i < size);
dest[i] = '\0';
regs[rd] = (uintptr_t)dest;
mstate->dtms_scratch_ptr += size;
break;
}
#ifdef illumos
case DIF_SUBR_GETMAJOR:
#ifdef _LP64
regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR64) & MAXMAJ64;
#else
regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR) & MAXMAJ;
#endif
break;
case DIF_SUBR_GETMINOR:
#ifdef _LP64
regs[rd] = tupregs[0].dttk_value & MAXMIN64;
#else
regs[rd] = tupregs[0].dttk_value & MAXMIN;
#endif
break;
case DIF_SUBR_DDI_PATHNAME: {
/*
* This one is a galactic mess. We are going to roughly
* emulate ddi_pathname(), but it's made more complicated
* by the fact that we (a) want to include the minor name and
* (b) must proceed iteratively instead of recursively.
*/
uintptr_t dest = mstate->dtms_scratch_ptr;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
char *start = (char *)dest, *end = start + size - 1;
uintptr_t daddr = tupregs[0].dttk_value;
int64_t minor = (int64_t)tupregs[1].dttk_value;
char *s;
int i, len, depth = 0;
/*
* Due to all the pointer jumping we do and context we must
* rely upon, we just mandate that the user must have kernel
* read privileges to use this routine.
*/
if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) == 0) {
*flags |= CPU_DTRACE_KPRIV;
*illval = daddr;
regs[rd] = 0;
}
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
*end = '\0';
/*
* We want to have a name for the minor. In order to do this,
* we need to walk the minor list from the devinfo. We want
* to be sure that we don't infinitely walk a circular list,
* so we check for circularity by sending a scout pointer
* ahead two elements for every element that we iterate over;
* if the list is circular, these will ultimately point to the
* same element. You may recognize this little trick as the
* answer to a stupid interview question -- one that always
* seems to be asked by those who had to have it laboriously
* explained to them, and who can't even concisely describe
* the conditions under which one would be forced to resort to
* this technique. Needless to say, those conditions are
* found here -- and probably only here. Is this the only use
* of this infamous trick in shipping, production code? If it
* isn't, it probably should be...
*/
if (minor != -1) {
uintptr_t maddr = dtrace_loadptr(daddr +
offsetof(struct dev_info, devi_minor));
uintptr_t next = offsetof(struct ddi_minor_data, next);
uintptr_t name = offsetof(struct ddi_minor_data,
d_minor) + offsetof(struct ddi_minor, name);
uintptr_t dev = offsetof(struct ddi_minor_data,
d_minor) + offsetof(struct ddi_minor, dev);
uintptr_t scout;
if (maddr != NULL)
scout = dtrace_loadptr(maddr + next);
while (maddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
uint64_t m;
#ifdef _LP64
m = dtrace_load64(maddr + dev) & MAXMIN64;
#else
m = dtrace_load32(maddr + dev) & MAXMIN;
#endif
if (m != minor) {
maddr = dtrace_loadptr(maddr + next);
if (scout == NULL)
continue;
scout = dtrace_loadptr(scout + next);
if (scout == NULL)
continue;
scout = dtrace_loadptr(scout + next);
if (scout == NULL)
continue;
if (scout == maddr) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
continue;
}
/*
* We have the minor data. Now we need to
* copy the minor's name into the end of the
* pathname.
*/
s = (char *)dtrace_loadptr(maddr + name);
len = dtrace_strlen(s, size);
if (*flags & CPU_DTRACE_FAULT)
break;
if (len != 0) {
if ((end -= (len + 1)) < start)
break;
*end = ':';
}
for (i = 1; i <= len; i++)
end[i] = dtrace_load8((uintptr_t)s++);
break;
}
}
while (daddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
ddi_node_state_t devi_state;
devi_state = dtrace_load32(daddr +
offsetof(struct dev_info, devi_node_state));
if (*flags & CPU_DTRACE_FAULT)
break;
if (devi_state >= DS_INITIALIZED) {
s = (char *)dtrace_loadptr(daddr +
offsetof(struct dev_info, devi_addr));
len = dtrace_strlen(s, size);
if (*flags & CPU_DTRACE_FAULT)
break;
if (len != 0) {
if ((end -= (len + 1)) < start)
break;
*end = '@';
}
for (i = 1; i <= len; i++)
end[i] = dtrace_load8((uintptr_t)s++);
}
/*
* Now for the node name...
*/
s = (char *)dtrace_loadptr(daddr +
offsetof(struct dev_info, devi_node_name));
daddr = dtrace_loadptr(daddr +
offsetof(struct dev_info, devi_parent));
/*
* If our parent is NULL (that is, if we're the root
* node), we're going to use the special path
* "devices".
*/
if (daddr == 0)
s = "devices";
len = dtrace_strlen(s, size);
if (*flags & CPU_DTRACE_FAULT)
break;
if ((end -= (len + 1)) < start)
break;
for (i = 1; i <= len; i++)
end[i] = dtrace_load8((uintptr_t)s++);
*end = '/';
if (depth++ > dtrace_devdepth_max) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
}
if (end < start)
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
if (daddr == 0) {
regs[rd] = (uintptr_t)end;
mstate->dtms_scratch_ptr += size;
}
break;
}
#endif
case DIF_SUBR_STRJOIN: {
char *d = (char *)mstate->dtms_scratch_ptr;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t s1 = tupregs[0].dttk_value;
uintptr_t s2 = tupregs[1].dttk_value;
int i = 0, j = 0;
size_t lim1, lim2;
char c;
if (!dtrace_strcanload(s1, size, &lim1, mstate, vstate) ||
!dtrace_strcanload(s2, size, &lim2, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
for (;;) {
if (i >= size) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
c = (i >= lim1) ? '\0' : dtrace_load8(s1++);
if ((d[i++] = c) == '\0') {
i--;
break;
}
}
for (;;) {
if (i >= size) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
c = (j++ >= lim2) ? '\0' : dtrace_load8(s2++);
if ((d[i++] = c) == '\0')
break;
}
if (i < size) {
mstate->dtms_scratch_ptr += i;
regs[rd] = (uintptr_t)d;
}
break;
}
case DIF_SUBR_STRTOLL: {
uintptr_t s = tupregs[0].dttk_value;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
size_t lim;
int base = 10;
if (nargs > 1) {
if ((base = tupregs[1].dttk_value) <= 1 ||
base > ('z' - 'a' + 1) + ('9' - '0' + 1)) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
}
if (!dtrace_strcanload(s, size, &lim, mstate, vstate)) {
regs[rd] = INT64_MIN;
break;
}
regs[rd] = dtrace_strtoll((char *)s, base, lim);
break;
}
case DIF_SUBR_LLTOSTR: {
int64_t i = (int64_t)tupregs[0].dttk_value;
uint64_t val, digit;
uint64_t size = 65; /* enough room for 2^64 in binary */
char *end = (char *)mstate->dtms_scratch_ptr + size - 1;
int base = 10;
if (nargs > 1) {
if ((base = tupregs[1].dttk_value) <= 1 ||
base > ('z' - 'a' + 1) + ('9' - '0' + 1)) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
}
val = (base == 10 && i < 0) ? i * -1 : i;
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
for (*end-- = '\0'; val; val /= base) {
if ((digit = val % base) <= '9' - '0') {
*end-- = '0' + digit;
} else {
*end-- = 'a' + (digit - ('9' - '0') - 1);
}
}
if (i == 0 && base == 16)
*end-- = '0';
if (base == 16)
*end-- = 'x';
if (i == 0 || base == 8 || base == 16)
*end-- = '0';
if (i < 0 && base == 10)
*end-- = '-';
regs[rd] = (uintptr_t)end + 1;
mstate->dtms_scratch_ptr += size;
break;
}
case DIF_SUBR_HTONS:
case DIF_SUBR_NTOHS:
#if BYTE_ORDER == BIG_ENDIAN
regs[rd] = (uint16_t)tupregs[0].dttk_value;
#else
regs[rd] = DT_BSWAP_16((uint16_t)tupregs[0].dttk_value);
#endif
break;
case DIF_SUBR_HTONL:
case DIF_SUBR_NTOHL:
#if BYTE_ORDER == BIG_ENDIAN
regs[rd] = (uint32_t)tupregs[0].dttk_value;
#else
regs[rd] = DT_BSWAP_32((uint32_t)tupregs[0].dttk_value);
#endif
break;
case DIF_SUBR_HTONLL:
case DIF_SUBR_NTOHLL:
#if BYTE_ORDER == BIG_ENDIAN
regs[rd] = (uint64_t)tupregs[0].dttk_value;
#else
regs[rd] = DT_BSWAP_64((uint64_t)tupregs[0].dttk_value);
#endif
break;
case DIF_SUBR_DIRNAME:
case DIF_SUBR_BASENAME: {
char *dest = (char *)mstate->dtms_scratch_ptr;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t src = tupregs[0].dttk_value;
int i, j, len = dtrace_strlen((char *)src, size);
int lastbase = -1, firstbase = -1, lastdir = -1;
int start, end;
if (!dtrace_canload(src, len + 1, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
/*
* The basename and dirname for a zero-length string is
* defined to be "."
*/
if (len == 0) {
len = 1;
src = (uintptr_t)".";
}
/*
* Start from the back of the string, moving back toward the
* front until we see a character that isn't a slash. That
* character is the last character in the basename.
*/
for (i = len - 1; i >= 0; i--) {
if (dtrace_load8(src + i) != '/')
break;
}
if (i >= 0)
lastbase = i;
/*
* Starting from the last character in the basename, move
* towards the front until we find a slash. The character
* that we processed immediately before that is the first
* character in the basename.
*/
for (; i >= 0; i--) {
if (dtrace_load8(src + i) == '/')
break;
}
if (i >= 0)
firstbase = i + 1;
/*
* Now keep going until we find a non-slash character. That
* character is the last character in the dirname.
*/
for (; i >= 0; i--) {
if (dtrace_load8(src + i) != '/')
break;
}
if (i >= 0)
lastdir = i;
ASSERT(!(lastbase == -1 && firstbase != -1));
ASSERT(!(firstbase == -1 && lastdir != -1));
if (lastbase == -1) {
/*
* We didn't find a non-slash character. We know that
* the length is non-zero, so the whole string must be
* slashes. In either the dirname or the basename
* case, we return '/'.
*/
ASSERT(firstbase == -1);
firstbase = lastbase = lastdir = 0;
}
if (firstbase == -1) {
/*
* The entire string consists only of a basename
* component. If we're looking for dirname, we need
* to change our string to be just "."; if we're
* looking for a basename, we'll just set the first
* character of the basename to be 0.
*/
if (subr == DIF_SUBR_DIRNAME) {
ASSERT(lastdir == -1);
src = (uintptr_t)".";
lastdir = 0;
} else {
firstbase = 0;
}
}
if (subr == DIF_SUBR_DIRNAME) {
if (lastdir == -1) {
/*
* We know that we have a slash in the name --
* or lastdir would be set to 0, above. And
* because lastdir is -1, we know that this
* slash must be the first character. (That
* is, the full string must be of the form
* "/basename".) In this case, the last
* character of the directory name is 0.
*/
lastdir = 0;
}
start = 0;
end = lastdir;
} else {
ASSERT(subr == DIF_SUBR_BASENAME);
ASSERT(firstbase != -1 && lastbase != -1);
start = firstbase;
end = lastbase;
}
for (i = start, j = 0; i <= end && j < size - 1; i++, j++)
dest[j] = dtrace_load8(src + i);
dest[j] = '\0';
regs[rd] = (uintptr_t)dest;
mstate->dtms_scratch_ptr += size;
break;
}
case DIF_SUBR_GETF: {
uintptr_t fd = tupregs[0].dttk_value;
struct filedesc *fdp;
file_t *fp;
if (!dtrace_priv_proc(state)) {
regs[rd] = 0;
break;
}
fdp = curproc->p_fd;
FILEDESC_SLOCK(fdp);
fp = fget_locked(fdp, fd);
mstate->dtms_getf = fp;
regs[rd] = (uintptr_t)fp;
FILEDESC_SUNLOCK(fdp);
break;
}
case DIF_SUBR_CLEANPATH: {
char *dest = (char *)mstate->dtms_scratch_ptr, c;
uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t src = tupregs[0].dttk_value;
size_t lim;
int i = 0, j = 0;
#ifdef illumos
zone_t *z;
#endif
if (!dtrace_strcanload(src, size, &lim, mstate, vstate)) {
regs[rd] = 0;
break;
}
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
/*
* Move forward, loading each character.
*/
do {
c = (i >= lim) ? '\0' : dtrace_load8(src + i++);
next:
if (j + 5 >= size) /* 5 = strlen("/..c\0") */
break;
if (c != '/') {
dest[j++] = c;
continue;
}
c = (i >= lim) ? '\0' : dtrace_load8(src + i++);
if (c == '/') {
/*
* We have two slashes -- we can just advance
* to the next character.
*/
goto next;
}
if (c != '.') {
/*
* This is not "." and it's not ".." -- we can
* just store the "/" and this character and
* drive on.
*/
dest[j++] = '/';
dest[j++] = c;
continue;
}
c = (i >= lim) ? '\0' : dtrace_load8(src + i++);
if (c == '/') {
/*
* This is a "/./" component. We're not going
* to store anything in the destination buffer;
* we're just going to go to the next component.
*/
goto next;
}
if (c != '.') {
/*
* This is not ".." -- we can just store the
* "/." and this character and continue
* processing.
*/
dest[j++] = '/';
dest[j++] = '.';
dest[j++] = c;
continue;
}
c = (i >= lim) ? '\0' : dtrace_load8(src + i++);
if (c != '/' && c != '\0') {
/*
* This is not ".." -- it's "..[mumble]".
* We'll store the "/.." and this character
* and continue processing.
*/
dest[j++] = '/';
dest[j++] = '.';
dest[j++] = '.';
dest[j++] = c;
continue;
}
/*
* This is "/../" or "/..\0". We need to back up
* our destination pointer until we find a "/".
*/
i--;
while (j != 0 && dest[--j] != '/')
continue;
if (c == '\0')
dest[++j] = '/';
} while (c != '\0');
dest[j] = '\0';
#ifdef illumos
if (mstate->dtms_getf != NULL &&
!(mstate->dtms_access & DTRACE_ACCESS_KERNEL) &&
(z = state->dts_cred.dcr_cred->cr_zone) != kcred->cr_zone) {
/*
* If we've done a getf() as a part of this ECB and we
* don't have kernel access (and we're not in the global
* zone), check if the path we cleaned up begins with
* the zone's root path, and trim it off if so. Note
* that this is an output cleanliness issue, not a
* security issue: knowing one's zone root path does
* not enable privilege escalation.
*/
if (strstr(dest, z->zone_rootpath) == dest)
dest += strlen(z->zone_rootpath) - 1;
}
#endif
regs[rd] = (uintptr_t)dest;
mstate->dtms_scratch_ptr += size;
break;
}
case DIF_SUBR_INET_NTOA:
case DIF_SUBR_INET_NTOA6:
case DIF_SUBR_INET_NTOP: {
size_t size;
int af, argi, i;
char *base, *end;
if (subr == DIF_SUBR_INET_NTOP) {
af = (int)tupregs[0].dttk_value;
argi = 1;
} else {
af = subr == DIF_SUBR_INET_NTOA ? AF_INET: AF_INET6;
argi = 0;
}
if (af == AF_INET) {
ipaddr_t ip4;
uint8_t *ptr8, val;
if (!dtrace_canload(tupregs[argi].dttk_value,
sizeof (ipaddr_t), mstate, vstate)) {
regs[rd] = 0;
break;
}
/*
* Safely load the IPv4 address.
*/
ip4 = dtrace_load32(tupregs[argi].dttk_value);
/*
* Check an IPv4 string will fit in scratch.
*/
size = INET_ADDRSTRLEN;
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
base = (char *)mstate->dtms_scratch_ptr;
end = (char *)mstate->dtms_scratch_ptr + size - 1;
/*
* Stringify as a dotted decimal quad.
*/
*end-- = '\0';
ptr8 = (uint8_t *)&ip4;
for (i = 3; i >= 0; i--) {
val = ptr8[i];
if (val == 0) {
*end-- = '0';
} else {
for (; val; val /= 10) {
*end-- = '0' + (val % 10);
}
}
if (i > 0)
*end-- = '.';
}
ASSERT(end + 1 >= base);
} else if (af == AF_INET6) {
struct in6_addr ip6;
int firstzero, tryzero, numzero, v6end;
uint16_t val;
const char digits[] = "0123456789abcdef";
/*
* Stringify using RFC 1884 convention 2 - 16 bit
* hexadecimal values with a zero-run compression.
* Lower case hexadecimal digits are used.
* eg, fe80::214:4fff:fe0b:76c8.
* The IPv4 embedded form is returned for inet_ntop,
* just the IPv4 string is returned for inet_ntoa6.
*/
if (!dtrace_canload(tupregs[argi].dttk_value,
sizeof (struct in6_addr), mstate, vstate)) {
regs[rd] = 0;
break;
}
/*
* Safely load the IPv6 address.
*/
dtrace_bcopy(
(void *)(uintptr_t)tupregs[argi].dttk_value,
(void *)(uintptr_t)&ip6, sizeof (struct in6_addr));
/*
* Check an IPv6 string will fit in scratch.
*/
size = INET6_ADDRSTRLEN;
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
base = (char *)mstate->dtms_scratch_ptr;
end = (char *)mstate->dtms_scratch_ptr + size - 1;
*end-- = '\0';
/*
* Find the longest run of 16 bit zero values
* for the single allowed zero compression - "::".
*/
firstzero = -1;
tryzero = -1;
numzero = 1;
for (i = 0; i < sizeof (struct in6_addr); i++) {
#ifdef illumos
if (ip6._S6_un._S6_u8[i] == 0 &&
#else
if (ip6.__u6_addr.__u6_addr8[i] == 0 &&
#endif
tryzero == -1 && i % 2 == 0) {
tryzero = i;
continue;
}
if (tryzero != -1 &&
#ifdef illumos
(ip6._S6_un._S6_u8[i] != 0 ||
#else
(ip6.__u6_addr.__u6_addr8[i] != 0 ||
#endif
i == sizeof (struct in6_addr) - 1)) {
if (i - tryzero <= numzero) {
tryzero = -1;
continue;
}
firstzero = tryzero;
numzero = i - i % 2 - tryzero;
tryzero = -1;
#ifdef illumos
if (ip6._S6_un._S6_u8[i] == 0 &&
#else
if (ip6.__u6_addr.__u6_addr8[i] == 0 &&
#endif
i == sizeof (struct in6_addr) - 1)
numzero += 2;
}
}
ASSERT(firstzero + numzero <= sizeof (struct in6_addr));
/*
* Check for an IPv4 embedded address.
*/
v6end = sizeof (struct in6_addr) - 2;
if (IN6_IS_ADDR_V4MAPPED(&ip6) ||
IN6_IS_ADDR_V4COMPAT(&ip6)) {
for (i = sizeof (struct in6_addr) - 1;
i >= DTRACE_V4MAPPED_OFFSET; i--) {
ASSERT(end >= base);
#ifdef illumos
val = ip6._S6_un._S6_u8[i];
#else
val = ip6.__u6_addr.__u6_addr8[i];
#endif
if (val == 0) {
*end-- = '0';
} else {
for (; val; val /= 10) {
*end-- = '0' + val % 10;
}
}
if (i > DTRACE_V4MAPPED_OFFSET)
*end-- = '.';
}
if (subr == DIF_SUBR_INET_NTOA6)
goto inetout;
/*
* Set v6end to skip the IPv4 address that
* we have already stringified.
*/
v6end = 10;
}
/*
* Build the IPv6 string by working through the
* address in reverse.
*/
for (i = v6end; i >= 0; i -= 2) {
ASSERT(end >= base);
if (i == firstzero + numzero - 2) {
*end-- = ':';
*end-- = ':';
i -= numzero - 2;
continue;
}
if (i < 14 && i != firstzero - 2)
*end-- = ':';
#ifdef illumos
val = (ip6._S6_un._S6_u8[i] << 8) +
ip6._S6_un._S6_u8[i + 1];
#else
val = (ip6.__u6_addr.__u6_addr8[i] << 8) +
ip6.__u6_addr.__u6_addr8[i + 1];
#endif
if (val == 0) {
*end-- = '0';
} else {
for (; val; val /= 16) {
*end-- = digits[val % 16];
}
}
}
ASSERT(end + 1 >= base);
} else {
/*
* The user didn't use AH_INET or AH_INET6.
*/
DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
regs[rd] = 0;
break;
}
inetout: regs[rd] = (uintptr_t)end + 1;
mstate->dtms_scratch_ptr += size;
break;
}
case DIF_SUBR_MEMREF: {
uintptr_t size = 2 * sizeof(uintptr_t);
uintptr_t *memref = (uintptr_t *) P2ROUNDUP(mstate->dtms_scratch_ptr, sizeof(uintptr_t));
size_t scratch_size = ((uintptr_t) memref - mstate->dtms_scratch_ptr) + size;
/* address and length */
memref[0] = tupregs[0].dttk_value;
memref[1] = tupregs[1].dttk_value;
regs[rd] = (uintptr_t) memref;
mstate->dtms_scratch_ptr += scratch_size;
break;
}
#ifndef illumos
case DIF_SUBR_MEMSTR: {
char *str = (char *)mstate->dtms_scratch_ptr;
uintptr_t mem = tupregs[0].dttk_value;
char c = tupregs[1].dttk_value;
size_t size = tupregs[2].dttk_value;
uint8_t n;
int i;
regs[rd] = 0;
if (size == 0)
break;
if (!dtrace_canload(mem, size - 1, mstate, vstate))
break;
if (!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
break;
}
if (dtrace_memstr_max != 0 && size > dtrace_memstr_max) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
for (i = 0; i < size - 1; i++) {
n = dtrace_load8(mem++);
str[i] = (n == 0) ? c : n;
}
str[size - 1] = 0;
regs[rd] = (uintptr_t)str;
mstate->dtms_scratch_ptr += size;
break;
}
#endif
}
}
/*
* Emulate the execution of DTrace IR instructions specified by the given
* DIF object. This function is deliberately void of assertions as all of
* the necessary checks are handled by a call to dtrace_difo_validate().
*/
static uint64_t
dtrace_dif_emulate(dtrace_difo_t *difo, dtrace_mstate_t *mstate,
dtrace_vstate_t *vstate, dtrace_state_t *state)
{
const dif_instr_t *text = difo->dtdo_buf;
const uint_t textlen = difo->dtdo_len;
const char *strtab = difo->dtdo_strtab;
const uint64_t *inttab = difo->dtdo_inttab;
uint64_t rval = 0;
dtrace_statvar_t *svar;
dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
dtrace_difv_t *v;
volatile uint16_t *flags = &cpu_core[curcpu].cpuc_dtrace_flags;
volatile uintptr_t *illval = &cpu_core[curcpu].cpuc_dtrace_illval;
dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
uint64_t regs[DIF_DIR_NREGS];
uint64_t *tmp;
uint8_t cc_n = 0, cc_z = 0, cc_v = 0, cc_c = 0;
int64_t cc_r;
uint_t pc = 0, id, opc = 0;
uint8_t ttop = 0;
dif_instr_t instr;
uint_t r1, r2, rd;
/*
* We stash the current DIF object into the machine state: we need it
* for subsequent access checking.
*/
mstate->dtms_difo = difo;
regs[DIF_REG_R0] = 0; /* %r0 is fixed at zero */
while (pc < textlen && !(*flags & CPU_DTRACE_FAULT)) {
opc = pc;
instr = text[pc++];
r1 = DIF_INSTR_R1(instr);
r2 = DIF_INSTR_R2(instr);
rd = DIF_INSTR_RD(instr);
switch (DIF_INSTR_OP(instr)) {
case DIF_OP_OR:
regs[rd] = regs[r1] | regs[r2];
break;
case DIF_OP_XOR:
regs[rd] = regs[r1] ^ regs[r2];
break;
case DIF_OP_AND:
regs[rd] = regs[r1] & regs[r2];
break;
case DIF_OP_SLL:
regs[rd] = regs[r1] << regs[r2];
break;
case DIF_OP_SRL:
regs[rd] = regs[r1] >> regs[r2];
break;
case DIF_OP_SUB:
regs[rd] = regs[r1] - regs[r2];
break;
case DIF_OP_ADD:
regs[rd] = regs[r1] + regs[r2];
break;
case DIF_OP_MUL:
regs[rd] = regs[r1] * regs[r2];
break;
case DIF_OP_SDIV:
if (regs[r2] == 0) {
regs[rd] = 0;
*flags |= CPU_DTRACE_DIVZERO;
} else {
regs[rd] = (int64_t)regs[r1] /
(int64_t)regs[r2];
}
break;
case DIF_OP_UDIV:
if (regs[r2] == 0) {
regs[rd] = 0;
*flags |= CPU_DTRACE_DIVZERO;
} else {
regs[rd] = regs[r1] / regs[r2];
}
break;
case DIF_OP_SREM:
if (regs[r2] == 0) {
regs[rd] = 0;
*flags |= CPU_DTRACE_DIVZERO;
} else {
regs[rd] = (int64_t)regs[r1] %
(int64_t)regs[r2];
}
break;
case DIF_OP_UREM:
if (regs[r2] == 0) {
regs[rd] = 0;
*flags |= CPU_DTRACE_DIVZERO;
} else {
regs[rd] = regs[r1] % regs[r2];
}
break;
case DIF_OP_NOT:
regs[rd] = ~regs[r1];
break;
case DIF_OP_MOV:
regs[rd] = regs[r1];
break;
case DIF_OP_CMP:
cc_r = regs[r1] - regs[r2];
cc_n = cc_r < 0;
cc_z = cc_r == 0;
cc_v = 0;
cc_c = regs[r1] < regs[r2];
break;
case DIF_OP_TST:
cc_n = cc_v = cc_c = 0;
cc_z = regs[r1] == 0;
break;
case DIF_OP_BA:
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BE:
if (cc_z)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BNE:
if (cc_z == 0)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BG:
if ((cc_z | (cc_n ^ cc_v)) == 0)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BGU:
if ((cc_c | cc_z) == 0)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BGE:
if ((cc_n ^ cc_v) == 0)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BGEU:
if (cc_c == 0)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BL:
if (cc_n ^ cc_v)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BLU:
if (cc_c)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BLE:
if (cc_z | (cc_n ^ cc_v))
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_BLEU:
if (cc_c | cc_z)
pc = DIF_INSTR_LABEL(instr);
break;
case DIF_OP_RLDSB:
if (!dtrace_canload(regs[r1], 1, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDSB:
regs[rd] = (int8_t)dtrace_load8(regs[r1]);
break;
case DIF_OP_RLDSH:
if (!dtrace_canload(regs[r1], 2, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDSH:
regs[rd] = (int16_t)dtrace_load16(regs[r1]);
break;
case DIF_OP_RLDSW:
if (!dtrace_canload(regs[r1], 4, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDSW:
regs[rd] = (int32_t)dtrace_load32(regs[r1]);
break;
case DIF_OP_RLDUB:
if (!dtrace_canload(regs[r1], 1, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDUB:
regs[rd] = dtrace_load8(regs[r1]);
break;
case DIF_OP_RLDUH:
if (!dtrace_canload(regs[r1], 2, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDUH:
regs[rd] = dtrace_load16(regs[r1]);
break;
case DIF_OP_RLDUW:
if (!dtrace_canload(regs[r1], 4, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDUW:
regs[rd] = dtrace_load32(regs[r1]);
break;
case DIF_OP_RLDX:
if (!dtrace_canload(regs[r1], 8, mstate, vstate))
break;
/*FALLTHROUGH*/
case DIF_OP_LDX:
regs[rd] = dtrace_load64(regs[r1]);
break;
case DIF_OP_ULDSB:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] = (int8_t)
dtrace_fuword8((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_ULDSH:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] = (int16_t)
dtrace_fuword16((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_ULDSW:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] = (int32_t)
dtrace_fuword32((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_ULDUB:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] =
dtrace_fuword8((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_ULDUH:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] =
dtrace_fuword16((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_ULDUW:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] =
dtrace_fuword32((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_ULDX:
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
regs[rd] =
dtrace_fuword64((void *)(uintptr_t)regs[r1]);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
break;
case DIF_OP_RET:
rval = regs[rd];
pc = textlen;
break;
case DIF_OP_NOP:
break;
case DIF_OP_SETX:
regs[rd] = inttab[DIF_INSTR_INTEGER(instr)];
break;
case DIF_OP_SETS:
regs[rd] = (uint64_t)(uintptr_t)
(strtab + DIF_INSTR_STRING(instr));
break;
case DIF_OP_SCMP: {
size_t sz = state->dts_options[DTRACEOPT_STRSIZE];
uintptr_t s1 = regs[r1];
uintptr_t s2 = regs[r2];
size_t lim1, lim2;
if (s1 != 0 &&
!dtrace_strcanload(s1, sz, &lim1, mstate, vstate))
break;
if (s2 != 0 &&
!dtrace_strcanload(s2, sz, &lim2, mstate, vstate))
break;
cc_r = dtrace_strncmp((char *)s1, (char *)s2,
MIN(lim1, lim2));
cc_n = cc_r < 0;
cc_z = cc_r == 0;
cc_v = cc_c = 0;
break;
}
case DIF_OP_LDGA:
regs[rd] = dtrace_dif_variable(mstate, state,
r1, regs[r2]);
break;
case DIF_OP_LDGS:
id = DIF_INSTR_VAR(instr);
if (id >= DIF_VAR_OTHER_UBASE) {
uintptr_t a;
id -= DIF_VAR_OTHER_UBASE;
svar = vstate->dtvs_globals[id];
ASSERT(svar != NULL);
v = &svar->dtsv_var;
if (!(v->dtdv_type.dtdt_flags & DIF_TF_BYREF)) {
regs[rd] = svar->dtsv_data;
break;
}
a = (uintptr_t)svar->dtsv_data;
if (*(uint8_t *)a == UINT8_MAX) {
/*
* If the 0th byte is set to UINT8_MAX
* then this is to be treated as a
* reference to a NULL variable.
*/
regs[rd] = 0;
} else {
regs[rd] = a + sizeof (uint64_t);
}
break;
}
regs[rd] = dtrace_dif_variable(mstate, state, id, 0);
break;
case DIF_OP_STGS:
id = DIF_INSTR_VAR(instr);
ASSERT(id >= DIF_VAR_OTHER_UBASE);
id -= DIF_VAR_OTHER_UBASE;
VERIFY(id < vstate->dtvs_nglobals);
svar = vstate->dtvs_globals[id];
ASSERT(svar != NULL);
v = &svar->dtsv_var;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
uintptr_t a = (uintptr_t)svar->dtsv_data;
size_t lim;
ASSERT(a != 0);
ASSERT(svar->dtsv_size != 0);
if (regs[rd] == 0) {
*(uint8_t *)a = UINT8_MAX;
break;
} else {
*(uint8_t *)a = 0;
a += sizeof (uint64_t);
}
if (!dtrace_vcanload(
(void *)(uintptr_t)regs[rd], &v->dtdv_type,
&lim, mstate, vstate))
break;
dtrace_vcopy((void *)(uintptr_t)regs[rd],
(void *)a, &v->dtdv_type, lim);
break;
}
svar->dtsv_data = regs[rd];
break;
case DIF_OP_LDTA:
/*
* There are no DTrace built-in thread-local arrays at
* present. This opcode is saved for future work.
*/
*flags |= CPU_DTRACE_ILLOP;
regs[rd] = 0;
break;
case DIF_OP_LDLS:
id = DIF_INSTR_VAR(instr);
if (id < DIF_VAR_OTHER_UBASE) {
/*
* For now, this has no meaning.
*/
regs[rd] = 0;
break;
}
id -= DIF_VAR_OTHER_UBASE;
ASSERT(id < vstate->dtvs_nlocals);
ASSERT(vstate->dtvs_locals != NULL);
svar = vstate->dtvs_locals[id];
ASSERT(svar != NULL);
v = &svar->dtsv_var;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
uintptr_t a = (uintptr_t)svar->dtsv_data;
size_t sz = v->dtdv_type.dtdt_size;
size_t lim;
sz += sizeof (uint64_t);
ASSERT(svar->dtsv_size == NCPU * sz);
a += curcpu * sz;
if (*(uint8_t *)a == UINT8_MAX) {
/*
* If the 0th byte is set to UINT8_MAX
* then this is to be treated as a
* reference to a NULL variable.
*/
regs[rd] = 0;
} else {
regs[rd] = a + sizeof (uint64_t);
}
break;
}
ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
regs[rd] = tmp[curcpu];
break;
case DIF_OP_STLS:
id = DIF_INSTR_VAR(instr);
ASSERT(id >= DIF_VAR_OTHER_UBASE);
id -= DIF_VAR_OTHER_UBASE;
VERIFY(id < vstate->dtvs_nlocals);
ASSERT(vstate->dtvs_locals != NULL);
svar = vstate->dtvs_locals[id];
ASSERT(svar != NULL);
v = &svar->dtsv_var;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
uintptr_t a = (uintptr_t)svar->dtsv_data;
size_t sz = v->dtdv_type.dtdt_size;
size_t lim;
sz += sizeof (uint64_t);
ASSERT(svar->dtsv_size == NCPU * sz);
a += curcpu * sz;
if (regs[rd] == 0) {
*(uint8_t *)a = UINT8_MAX;
break;
} else {
*(uint8_t *)a = 0;
a += sizeof (uint64_t);
}
if (!dtrace_vcanload(
(void *)(uintptr_t)regs[rd], &v->dtdv_type,
&lim, mstate, vstate))
break;
dtrace_vcopy((void *)(uintptr_t)regs[rd],
(void *)a, &v->dtdv_type, lim);
break;
}
ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
tmp[curcpu] = regs[rd];
break;
case DIF_OP_LDTS: {
dtrace_dynvar_t *dvar;
dtrace_key_t *key;
id = DIF_INSTR_VAR(instr);
ASSERT(id >= DIF_VAR_OTHER_UBASE);
id -= DIF_VAR_OTHER_UBASE;
v = &vstate->dtvs_tlocals[id];
key = &tupregs[DIF_DTR_NREGS];
key[0].dttk_value = (uint64_t)id;
key[0].dttk_size = 0;
DTRACE_TLS_THRKEY(key[1].dttk_value);
key[1].dttk_size = 0;
dvar = dtrace_dynvar(dstate, 2, key,
sizeof (uint64_t), DTRACE_DYNVAR_NOALLOC,
mstate, vstate);
if (dvar == NULL) {
regs[rd] = 0;
break;
}
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
} else {
regs[rd] = *((uint64_t *)dvar->dtdv_data);
}
break;
}
case DIF_OP_STTS: {
dtrace_dynvar_t *dvar;
dtrace_key_t *key;
id = DIF_INSTR_VAR(instr);
ASSERT(id >= DIF_VAR_OTHER_UBASE);
id -= DIF_VAR_OTHER_UBASE;
VERIFY(id < vstate->dtvs_ntlocals);
key = &tupregs[DIF_DTR_NREGS];
key[0].dttk_value = (uint64_t)id;
key[0].dttk_size = 0;
DTRACE_TLS_THRKEY(key[1].dttk_value);
key[1].dttk_size = 0;
v = &vstate->dtvs_tlocals[id];
dvar = dtrace_dynvar(dstate, 2, key,
v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
v->dtdv_type.dtdt_size : sizeof (uint64_t),
regs[rd] ? DTRACE_DYNVAR_ALLOC :
DTRACE_DYNVAR_DEALLOC, mstate, vstate);
/*
* Given that we're storing to thread-local data,
* we need to flush our predicate cache.
*/
curthread->t_predcache = 0;
if (dvar == NULL)
break;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
size_t lim;
if (!dtrace_vcanload(
(void *)(uintptr_t)regs[rd],
&v->dtdv_type, &lim, mstate, vstate))
break;
dtrace_vcopy((void *)(uintptr_t)regs[rd],
dvar->dtdv_data, &v->dtdv_type, lim);
} else {
*((uint64_t *)dvar->dtdv_data) = regs[rd];
}
break;
}
case DIF_OP_SRA:
regs[rd] = (int64_t)regs[r1] >> regs[r2];
break;
case DIF_OP_CALL:
dtrace_dif_subr(DIF_INSTR_SUBR(instr), rd,
regs, tupregs, ttop, mstate, state);
break;
case DIF_OP_PUSHTR:
if (ttop == DIF_DTR_NREGS) {
*flags |= CPU_DTRACE_TUPOFLOW;
break;
}
if (r1 == DIF_TYPE_STRING) {
/*
* If this is a string type and the size is 0,
* we'll use the system-wide default string
* size. Note that we are _not_ looking at
* the value of the DTRACEOPT_STRSIZE option;
* had this been set, we would expect to have
* a non-zero size value in the "pushtr".
*/
tupregs[ttop].dttk_size =
dtrace_strlen((char *)(uintptr_t)regs[rd],
regs[r2] ? regs[r2] :
dtrace_strsize_default) + 1;
} else {
if (regs[r2] > LONG_MAX) {
*flags |= CPU_DTRACE_ILLOP;
break;
}
tupregs[ttop].dttk_size = regs[r2];
}
tupregs[ttop++].dttk_value = regs[rd];
break;
case DIF_OP_PUSHTV:
if (ttop == DIF_DTR_NREGS) {
*flags |= CPU_DTRACE_TUPOFLOW;
break;
}
tupregs[ttop].dttk_value = regs[rd];
tupregs[ttop++].dttk_size = 0;
break;
case DIF_OP_POPTS:
if (ttop != 0)
ttop--;
break;
case DIF_OP_FLUSHTS:
ttop = 0;
break;
case DIF_OP_LDGAA:
case DIF_OP_LDTAA: {
dtrace_dynvar_t *dvar;
dtrace_key_t *key = tupregs;
uint_t nkeys = ttop;
id = DIF_INSTR_VAR(instr);
ASSERT(id >= DIF_VAR_OTHER_UBASE);
id -= DIF_VAR_OTHER_UBASE;
key[nkeys].dttk_value = (uint64_t)id;
key[nkeys++].dttk_size = 0;
if (DIF_INSTR_OP(instr) == DIF_OP_LDTAA) {
DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
key[nkeys++].dttk_size = 0;
VERIFY(id < vstate->dtvs_ntlocals);
v = &vstate->dtvs_tlocals[id];
} else {
VERIFY(id < vstate->dtvs_nglobals);
v = &vstate->dtvs_globals[id]->dtsv_var;
}
dvar = dtrace_dynvar(dstate, nkeys, key,
v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
v->dtdv_type.dtdt_size : sizeof (uint64_t),
DTRACE_DYNVAR_NOALLOC, mstate, vstate);
if (dvar == NULL) {
regs[rd] = 0;
break;
}
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
} else {
regs[rd] = *((uint64_t *)dvar->dtdv_data);
}
break;
}
case DIF_OP_STGAA:
case DIF_OP_STTAA: {
dtrace_dynvar_t *dvar;
dtrace_key_t *key = tupregs;
uint_t nkeys = ttop;
id = DIF_INSTR_VAR(instr);
ASSERT(id >= DIF_VAR_OTHER_UBASE);
id -= DIF_VAR_OTHER_UBASE;
key[nkeys].dttk_value = (uint64_t)id;
key[nkeys++].dttk_size = 0;
if (DIF_INSTR_OP(instr) == DIF_OP_STTAA) {
DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
key[nkeys++].dttk_size = 0;
VERIFY(id < vstate->dtvs_ntlocals);
v = &vstate->dtvs_tlocals[id];
} else {
VERIFY(id < vstate->dtvs_nglobals);
v = &vstate->dtvs_globals[id]->dtsv_var;
}
dvar = dtrace_dynvar(dstate, nkeys, key,
v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
v->dtdv_type.dtdt_size : sizeof (uint64_t),
regs[rd] ? DTRACE_DYNVAR_ALLOC :
DTRACE_DYNVAR_DEALLOC, mstate, vstate);
if (dvar == NULL)
break;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
size_t lim;
if (!dtrace_vcanload(
(void *)(uintptr_t)regs[rd], &v->dtdv_type,
&lim, mstate, vstate))
break;
dtrace_vcopy((void *)(uintptr_t)regs[rd],
dvar->dtdv_data, &v->dtdv_type, lim);
} else {
*((uint64_t *)dvar->dtdv_data) = regs[rd];
}
break;
}
case DIF_OP_ALLOCS: {
uintptr_t ptr = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
size_t size = ptr - mstate->dtms_scratch_ptr + regs[r1];
/*
* Rounding up the user allocation size could have
* overflowed large, bogus allocations (like -1ULL) to
* 0.
*/
if (size < regs[r1] ||
!DTRACE_INSCRATCH(mstate, size)) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
regs[rd] = 0;
break;
}
dtrace_bzero((void *) mstate->dtms_scratch_ptr, size);
mstate->dtms_scratch_ptr += size;
regs[rd] = ptr;
break;
}
case DIF_OP_COPYS:
if (!dtrace_canstore(regs[rd], regs[r2],
mstate, vstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
if (!dtrace_canload(regs[r1], regs[r2], mstate, vstate))
break;
dtrace_bcopy((void *)(uintptr_t)regs[r1],
(void *)(uintptr_t)regs[rd], (size_t)regs[r2]);
break;
case DIF_OP_STB:
if (!dtrace_canstore(regs[rd], 1, mstate, vstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
*((uint8_t *)(uintptr_t)regs[rd]) = (uint8_t)regs[r1];
break;
case DIF_OP_STH:
if (!dtrace_canstore(regs[rd], 2, mstate, vstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
if (regs[rd] & 1) {
*flags |= CPU_DTRACE_BADALIGN;
*illval = regs[rd];
break;
}
*((uint16_t *)(uintptr_t)regs[rd]) = (uint16_t)regs[r1];
break;
case DIF_OP_STW:
if (!dtrace_canstore(regs[rd], 4, mstate, vstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
if (regs[rd] & 3) {
*flags |= CPU_DTRACE_BADALIGN;
*illval = regs[rd];
break;
}
*((uint32_t *)(uintptr_t)regs[rd]) = (uint32_t)regs[r1];
break;
case DIF_OP_STX:
if (!dtrace_canstore(regs[rd], 8, mstate, vstate)) {
*flags |= CPU_DTRACE_BADADDR;
*illval = regs[rd];
break;
}
if (regs[rd] & 7) {
*flags |= CPU_DTRACE_BADALIGN;
*illval = regs[rd];
break;
}
*((uint64_t *)(uintptr_t)regs[rd]) = regs[r1];
break;
}
}
if (!(*flags & CPU_DTRACE_FAULT))
return (rval);
mstate->dtms_fltoffs = opc * sizeof (dif_instr_t);
mstate->dtms_present |= DTRACE_MSTATE_FLTOFFS;
return (0);
}
static void
dtrace_action_breakpoint(dtrace_ecb_t *ecb)
{
dtrace_probe_t *probe = ecb->dte_probe;
dtrace_provider_t *prov = probe->dtpr_provider;
char c[DTRACE_FULLNAMELEN + 80], *str;
char *msg = "dtrace: breakpoint action at probe ";
char *ecbmsg = " (ecb ";
uintptr_t mask = (0xf << (sizeof (uintptr_t) * NBBY / 4));
uintptr_t val = (uintptr_t)ecb;
int shift = (sizeof (uintptr_t) * NBBY) - 4, i = 0;
if (dtrace_destructive_disallow)
return;
/*
* It's impossible to be taking action on the NULL probe.
*/
ASSERT(probe != NULL);
/*
* This is a poor man's (destitute man's?) sprintf(): we want to
* print the provider name, module name, function name and name of
* the probe, along with the hex address of the ECB with the breakpoint
* action -- all of which we must place in the character buffer by
* hand.
*/
while (*msg != '\0')
c[i++] = *msg++;
for (str = prov->dtpv_name; *str != '\0'; str++)
c[i++] = *str;
c[i++] = ':';
for (str = probe->dtpr_mod; *str != '\0'; str++)
c[i++] = *str;
c[i++] = ':';
for (str = probe->dtpr_func; *str != '\0'; str++)
c[i++] = *str;
c[i++] = ':';
for (str = probe->dtpr_name; *str != '\0'; str++)
c[i++] = *str;
while (*ecbmsg != '\0')
c[i++] = *ecbmsg++;
while (shift >= 0) {
mask = (uintptr_t)0xf << shift;
if (val >= ((uintptr_t)1 << shift))
c[i++] = "0123456789abcdef"[(val & mask) >> shift];
shift -= 4;
}
c[i++] = ')';
c[i] = '\0';
#ifdef illumos
debug_enter(c);
#else
kdb_enter(KDB_WHY_DTRACE, "breakpoint action");
#endif
}
static void
dtrace_action_panic(dtrace_ecb_t *ecb)
{
dtrace_probe_t *probe = ecb->dte_probe;
/*
* It's impossible to be taking action on the NULL probe.
*/
ASSERT(probe != NULL);
if (dtrace_destructive_disallow)
return;
if (dtrace_panicked != NULL)
return;
if (dtrace_casptr(&dtrace_panicked, NULL, curthread) != NULL)
return;
/*
* We won the right to panic. (We want to be sure that only one
* thread calls panic() from dtrace_probe(), and that panic() is
* called exactly once.)
*/
dtrace_panic("dtrace: panic action at probe %s:%s:%s:%s (ecb %p)",
probe->dtpr_provider->dtpv_name, probe->dtpr_mod,
probe->dtpr_func, probe->dtpr_name, (void *)ecb);
}
static void
dtrace_action_raise(uint64_t sig)
{
if (dtrace_destructive_disallow)
return;
if (sig >= NSIG) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
return;
}
#ifdef illumos
/*
* raise() has a queue depth of 1 -- we ignore all subsequent
* invocations of the raise() action.
*/
if (curthread->t_dtrace_sig == 0)
curthread->t_dtrace_sig = (uint8_t)sig;
curthread->t_sig_check = 1;
aston(curthread);
#else
struct proc *p = curproc;
PROC_LOCK(p);
kern_psignal(p, sig);
PROC_UNLOCK(p);
#endif
}
static void
dtrace_action_stop(void)
{
if (dtrace_destructive_disallow)
return;
#ifdef illumos
if (!curthread->t_dtrace_stop) {
curthread->t_dtrace_stop = 1;
curthread->t_sig_check = 1;
aston(curthread);
}
#else
struct proc *p = curproc;
PROC_LOCK(p);
kern_psignal(p, SIGSTOP);
PROC_UNLOCK(p);
#endif
}
static void
dtrace_action_chill(dtrace_mstate_t *mstate, hrtime_t val)
{
hrtime_t now;
volatile uint16_t *flags;
#ifdef illumos
cpu_t *cpu = CPU;
#else
cpu_t *cpu = &solaris_cpu[curcpu];
#endif
if (dtrace_destructive_disallow)
return;
flags = (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
now = dtrace_gethrtime();
if (now - cpu->cpu_dtrace_chillmark > dtrace_chill_interval) {
/*
* We need to advance the mark to the current time.
*/
cpu->cpu_dtrace_chillmark = now;
cpu->cpu_dtrace_chilled = 0;
}
/*
* Now check to see if the requested chill time would take us over
* the maximum amount of time allowed in the chill interval. (Or
* worse, if the calculation itself induces overflow.)
*/
if (cpu->cpu_dtrace_chilled + val > dtrace_chill_max ||
cpu->cpu_dtrace_chilled + val < cpu->cpu_dtrace_chilled) {
*flags |= CPU_DTRACE_ILLOP;
return;
}
while (dtrace_gethrtime() - now < val)
continue;
/*
* Normally, we assure that the value of the variable "timestamp" does
* not change within an ECB. The presence of chill() represents an
* exception to this rule, however.
*/
mstate->dtms_present &= ~DTRACE_MSTATE_TIMESTAMP;
cpu->cpu_dtrace_chilled += val;
}
static void
dtrace_action_ustack(dtrace_mstate_t *mstate, dtrace_state_t *state,
uint64_t *buf, uint64_t arg)
{
int nframes = DTRACE_USTACK_NFRAMES(arg);
int strsize = DTRACE_USTACK_STRSIZE(arg);
uint64_t *pcs = &buf[1], *fps;
char *str = (char *)&pcs[nframes];
int size, offs = 0, i, j;
size_t rem;
uintptr_t old = mstate->dtms_scratch_ptr, saved;
uint16_t *flags = &cpu_core[curcpu].cpuc_dtrace_flags;
char *sym;
/*
* Should be taking a faster path if string space has not been
* allocated.
*/
ASSERT(strsize != 0);
/*
* We will first allocate some temporary space for the frame pointers.
*/
fps = (uint64_t *)P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
size = (uintptr_t)fps - mstate->dtms_scratch_ptr +
(nframes * sizeof (uint64_t));
if (!DTRACE_INSCRATCH(mstate, size)) {
/*
* Not enough room for our frame pointers -- need to indicate
* that we ran out of scratch space.
*/
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
return;
}
mstate->dtms_scratch_ptr += size;
saved = mstate->dtms_scratch_ptr;
/*
* Now get a stack with both program counters and frame pointers.
*/
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_getufpstack(buf, fps, nframes + 1);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
/*
* If that faulted, we're cooked.
*/
if (*flags & CPU_DTRACE_FAULT)
goto out;
/*
* Now we want to walk up the stack, calling the USTACK helper. For
* each iteration, we restore the scratch pointer.
*/
for (i = 0; i < nframes; i++) {
mstate->dtms_scratch_ptr = saved;
if (offs >= strsize)
break;
sym = (char *)(uintptr_t)dtrace_helper(
DTRACE_HELPER_ACTION_USTACK,
mstate, state, pcs[i], fps[i]);
/*
* If we faulted while running the helper, we're going to
* clear the fault and null out the corresponding string.
*/
if (*flags & CPU_DTRACE_FAULT) {
*flags &= ~CPU_DTRACE_FAULT;
str[offs++] = '\0';
continue;
}
if (sym == NULL) {
str[offs++] = '\0';
continue;
}
if (!dtrace_strcanload((uintptr_t)sym, strsize, &rem, mstate,
&(state->dts_vstate))) {
str[offs++] = '\0';
continue;
}
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
/*
* Now copy in the string that the helper returned to us.
*/
for (j = 0; offs + j < strsize && j < rem; j++) {
if ((str[offs + j] = sym[j]) == '\0')
break;
}
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
offs += j + 1;
}
if (offs >= strsize) {
/*
* If we didn't have room for all of the strings, we don't
* abort processing -- this needn't be a fatal error -- but we
* still want to increment a counter (dts_stkstroverflows) to
* allow this condition to be warned about. (If this is from
* a jstack() action, it is easily tuned via jstackstrsize.)
*/
dtrace_error(&state->dts_stkstroverflows);
}
while (offs < strsize)
str[offs++] = '\0';
out:
mstate->dtms_scratch_ptr = old;
}
static void
dtrace_store_by_ref(dtrace_difo_t *dp, caddr_t tomax, size_t size,
size_t *valoffsp, uint64_t *valp, uint64_t end, int intuple, int dtkind)
{
volatile uint16_t *flags;
uint64_t val = *valp;
size_t valoffs = *valoffsp;
flags = (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags;
ASSERT(dtkind == DIF_TF_BYREF || dtkind == DIF_TF_BYUREF);
/*
* If this is a string, we're going to only load until we find the zero
* byte -- after which we'll store zero bytes.
*/
if (dp->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING) {
char c = '\0' + 1;
size_t s;
for (s = 0; s < size; s++) {
if (c != '\0' && dtkind == DIF_TF_BYREF) {
c = dtrace_load8(val++);
} else if (c != '\0' && dtkind == DIF_TF_BYUREF) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
c = dtrace_fuword8((void *)(uintptr_t)val++);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
if (*flags & CPU_DTRACE_FAULT)
break;
}
DTRACE_STORE(uint8_t, tomax, valoffs++, c);
if (c == '\0' && intuple)
break;
}
} else {
uint8_t c;
while (valoffs < end) {
if (dtkind == DIF_TF_BYREF) {
c = dtrace_load8(val++);
} else if (dtkind == DIF_TF_BYUREF) {
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
c = dtrace_fuword8((void *)(uintptr_t)val++);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
if (*flags & CPU_DTRACE_FAULT)
break;
}
DTRACE_STORE(uint8_t, tomax,
valoffs++, c);
}
}
*valp = val;
*valoffsp = valoffs;
}
/*
* If you're looking for the epicenter of DTrace, you just found it. This
* is the function called by the provider to fire a probe -- from which all
* subsequent probe-context DTrace activity emanates.
*/
void
dtrace_probe(dtrace_id_t id, uintptr_t arg0, uintptr_t arg1,
uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
{
processorid_t cpuid;
dtrace_icookie_t cookie;
dtrace_probe_t *probe;
dtrace_mstate_t mstate;
dtrace_ecb_t *ecb;
dtrace_action_t *act;
intptr_t offs;
size_t size;
int vtime, onintr;
volatile uint16_t *flags;
hrtime_t now;
if (panicstr != NULL)
return;
#ifdef illumos
/*
* Kick out immediately if this CPU is still being born (in which case
* curthread will be set to -1) or the current thread can't allow
* probes in its current context.
*/
if (((uintptr_t)curthread & 1) || (curthread->t_flag & T_DONTDTRACE))
return;
#endif
cookie = dtrace_interrupt_disable();
probe = dtrace_probes[id - 1];
cpuid = curcpu;
onintr = CPU_ON_INTR(CPU);
if (!onintr && probe->dtpr_predcache != DTRACE_CACHEIDNONE &&
probe->dtpr_predcache == curthread->t_predcache) {
/*
* We have hit in the predicate cache; we know that
* this predicate would evaluate to be false.
*/
dtrace_interrupt_enable(cookie);
return;
}
#ifdef illumos
if (panic_quiesce) {
#else
if (panicstr != NULL) {
#endif
/*
* We don't trace anything if we're panicking.
*/
dtrace_interrupt_enable(cookie);
return;
}
now = mstate.dtms_timestamp = dtrace_gethrtime();
mstate.dtms_present |= DTRACE_MSTATE_TIMESTAMP;
vtime = dtrace_vtime_references != 0;
if (vtime && curthread->t_dtrace_start)
curthread->t_dtrace_vtime += now - curthread->t_dtrace_start;
mstate.dtms_difo = NULL;
mstate.dtms_probe = probe;
mstate.dtms_strtok = 0;
mstate.dtms_arg[0] = arg0;
mstate.dtms_arg[1] = arg1;
mstate.dtms_arg[2] = arg2;
mstate.dtms_arg[3] = arg3;
mstate.dtms_arg[4] = arg4;
flags = (volatile uint16_t *)&cpu_core[cpuid].cpuc_dtrace_flags;
for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
dtrace_predicate_t *pred = ecb->dte_predicate;
dtrace_state_t *state = ecb->dte_state;
dtrace_buffer_t *buf = &state->dts_buffer[cpuid];
dtrace_buffer_t *aggbuf = &state->dts_aggbuffer[cpuid];
dtrace_vstate_t *vstate = &state->dts_vstate;
dtrace_provider_t *prov = probe->dtpr_provider;
uint64_t tracememsize = 0;
int committed = 0;
caddr_t tomax;
/*
* A little subtlety with the following (seemingly innocuous)
* declaration of the automatic 'val': by looking at the
* code, you might think that it could be declared in the
* action processing loop, below. (That is, it's only used in
* the action processing loop.) However, it must be declared
* out of that scope because in the case of DIF expression
* arguments to aggregating actions, one iteration of the
* action loop will use the last iteration's value.
*/
uint64_t val = 0;
mstate.dtms_present = DTRACE_MSTATE_ARGS | DTRACE_MSTATE_PROBE;
mstate.dtms_getf = NULL;
*flags &= ~CPU_DTRACE_ERROR;
if (prov == dtrace_provider) {
/*
* If dtrace itself is the provider of this probe,
* we're only going to continue processing the ECB if
* arg0 (the dtrace_state_t) is equal to the ECB's
* creating state. (This prevents disjoint consumers
* from seeing one another's metaprobes.)
*/
if (arg0 != (uint64_t)(uintptr_t)state)
continue;
}
if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE) {
/*
* We're not currently active. If our provider isn't
* the dtrace pseudo provider, we're not interested.
*/
if (prov != dtrace_provider)
continue;
/*
* Now we must further check if we are in the BEGIN
* probe. If we are, we will only continue processing
* if we're still in WARMUP -- if one BEGIN enabling
* has invoked the exit() action, we don't want to
* evaluate subsequent BEGIN enablings.
*/
if (probe->dtpr_id == dtrace_probeid_begin &&
state->dts_activity != DTRACE_ACTIVITY_WARMUP) {
ASSERT(state->dts_activity ==
DTRACE_ACTIVITY_DRAINING);
continue;
}
}
if (ecb->dte_cond) {
/*
* If the dte_cond bits indicate that this
* consumer is only allowed to see user-mode firings
* of this probe, call the provider's dtps_usermode()
* entry point to check that the probe was fired
* while in a user context. Skip this ECB if that's
* not the case.
*/
if ((ecb->dte_cond & DTRACE_COND_USERMODE) &&
prov->dtpv_pops.dtps_usermode(prov->dtpv_arg,
probe->dtpr_id, probe->dtpr_arg) == 0)
continue;
#ifdef illumos
/*
* This is more subtle than it looks. We have to be
* absolutely certain that CRED() isn't going to
* change out from under us so it's only legit to
* examine that structure if we're in constrained
* situations. Currently, the only times we'll this
* check is if a non-super-user has enabled the
* profile or syscall providers -- providers that
* allow visibility of all processes. For the
* profile case, the check above will ensure that
* we're examining a user context.
*/
if (ecb->dte_cond & DTRACE_COND_OWNER) {
cred_t *cr;
cred_t *s_cr =
ecb->dte_state->dts_cred.dcr_cred;
proc_t *proc;
ASSERT(s_cr != NULL);
if ((cr = CRED()) == NULL ||
s_cr->cr_uid != cr->cr_uid ||
s_cr->cr_uid != cr->cr_ruid ||
s_cr->cr_uid != cr->cr_suid ||
s_cr->cr_gid != cr->cr_gid ||
s_cr->cr_gid != cr->cr_rgid ||
s_cr->cr_gid != cr->cr_sgid ||
(proc = ttoproc(curthread)) == NULL ||
(proc->p_flag & SNOCD))
continue;
}
if (ecb->dte_cond & DTRACE_COND_ZONEOWNER) {
cred_t *cr;
cred_t *s_cr =
ecb->dte_state->dts_cred.dcr_cred;
ASSERT(s_cr != NULL);
if ((cr = CRED()) == NULL ||
s_cr->cr_zone->zone_id !=
cr->cr_zone->zone_id)
continue;
}
#endif
}
if (now - state->dts_alive > dtrace_deadman_timeout) {
/*
* We seem to be dead. Unless we (a) have kernel
* destructive permissions (b) have explicitly enabled
* destructive actions and (c) destructive actions have
* not been disabled, we're going to transition into
* the KILLED state, from which no further processing
* on this state will be performed.
*/
if (!dtrace_priv_kernel_destructive(state) ||
!state->dts_cred.dcr_destructive ||
dtrace_destructive_disallow) {
void *activity = &state->dts_activity;
dtrace_activity_t current;
do {
current = state->dts_activity;
} while (dtrace_cas32(activity, current,
DTRACE_ACTIVITY_KILLED) != current);
continue;
}
}
if ((offs = dtrace_buffer_reserve(buf, ecb->dte_needed,
ecb->dte_alignment, state, &mstate)) < 0)
continue;
tomax = buf->dtb_tomax;
ASSERT(tomax != NULL);
if (ecb->dte_size != 0) {
dtrace_rechdr_t dtrh;
if (!(mstate.dtms_present & DTRACE_MSTATE_TIMESTAMP)) {
mstate.dtms_timestamp = dtrace_gethrtime();
mstate.dtms_present |= DTRACE_MSTATE_TIMESTAMP;
}
ASSERT3U(ecb->dte_size, >=, sizeof (dtrace_rechdr_t));
dtrh.dtrh_epid = ecb->dte_epid;
DTRACE_RECORD_STORE_TIMESTAMP(&dtrh,
mstate.dtms_timestamp);
*((dtrace_rechdr_t *)(tomax + offs)) = dtrh;
}
mstate.dtms_epid = ecb->dte_epid;
mstate.dtms_present |= DTRACE_MSTATE_EPID;
if (state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)
mstate.dtms_access = DTRACE_ACCESS_KERNEL;
else
mstate.dtms_access = 0;
if (pred != NULL) {
dtrace_difo_t *dp = pred->dtp_difo;
uint64_t rval;
rval = dtrace_dif_emulate(dp, &mstate, vstate, state);
if (!(*flags & CPU_DTRACE_ERROR) && !rval) {
dtrace_cacheid_t cid = probe->dtpr_predcache;
if (cid != DTRACE_CACHEIDNONE && !onintr) {
/*
* Update the predicate cache...
*/
ASSERT(cid == pred->dtp_cacheid);
curthread->t_predcache = cid;
}
continue;
}
}
for (act = ecb->dte_action; !(*flags & CPU_DTRACE_ERROR) &&
act != NULL; act = act->dta_next) {
size_t valoffs;
dtrace_difo_t *dp;
dtrace_recdesc_t *rec = &act->dta_rec;
size = rec->dtrd_size;
valoffs = offs + rec->dtrd_offset;
if (DTRACEACT_ISAGG(act->dta_kind)) {
uint64_t v = 0xbad;
dtrace_aggregation_t *agg;
agg = (dtrace_aggregation_t *)act;
if ((dp = act->dta_difo) != NULL)
v = dtrace_dif_emulate(dp,
&mstate, vstate, state);
if (*flags & CPU_DTRACE_ERROR)
continue;
/*
* Note that we always pass the expression
* value from the previous iteration of the
* action loop. This value will only be used
* if there is an expression argument to the
* aggregating action, denoted by the
* dtag_hasarg field.
*/
dtrace_aggregate(agg, buf,
offs, aggbuf, v, val);
continue;
}
switch (act->dta_kind) {
case DTRACEACT_STOP:
if (dtrace_priv_proc_destructive(state))
dtrace_action_stop();
continue;
case DTRACEACT_BREAKPOINT:
if (dtrace_priv_kernel_destructive(state))
dtrace_action_breakpoint(ecb);
continue;
case DTRACEACT_PANIC:
if (dtrace_priv_kernel_destructive(state))
dtrace_action_panic(ecb);
continue;
case DTRACEACT_STACK:
if (!dtrace_priv_kernel(state))
continue;
dtrace_getpcstack((pc_t *)(tomax + valoffs),
size / sizeof (pc_t), probe->dtpr_aframes,
DTRACE_ANCHORED(probe) ? NULL :
(uint32_t *)arg0);
continue;
case DTRACEACT_JSTACK:
case DTRACEACT_USTACK:
if (!dtrace_priv_proc(state))
continue;
/*
* See comment in DIF_VAR_PID.
*/
if (DTRACE_ANCHORED(mstate.dtms_probe) &&
CPU_ON_INTR(CPU)) {
int depth = DTRACE_USTACK_NFRAMES(
rec->dtrd_arg) + 1;
dtrace_bzero((void *)(tomax + valoffs),
DTRACE_USTACK_STRSIZE(rec->dtrd_arg)
+ depth * sizeof (uint64_t));
continue;
}
if (DTRACE_USTACK_STRSIZE(rec->dtrd_arg) != 0 &&
curproc->p_dtrace_helpers != NULL) {
/*
* This is the slow path -- we have
* allocated string space, and we're
* getting the stack of a process that
* has helpers. Call into a separate
* routine to perform this processing.
*/
dtrace_action_ustack(&mstate, state,
(uint64_t *)(tomax + valoffs),
rec->dtrd_arg);
continue;
}
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
dtrace_getupcstack((uint64_t *)
(tomax + valoffs),
DTRACE_USTACK_NFRAMES(rec->dtrd_arg) + 1);
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
continue;
default:
break;
}
dp = act->dta_difo;
ASSERT(dp != NULL);
val = dtrace_dif_emulate(dp, &mstate, vstate, state);
if (*flags & CPU_DTRACE_ERROR)
continue;
switch (act->dta_kind) {
case DTRACEACT_SPECULATE: {
dtrace_rechdr_t *dtrh;
ASSERT(buf == &state->dts_buffer[cpuid]);
buf = dtrace_speculation_buffer(state,
cpuid, val);
if (buf == NULL) {
*flags |= CPU_DTRACE_DROP;
continue;
}
offs = dtrace_buffer_reserve(buf,
ecb->dte_needed, ecb->dte_alignment,
state, NULL);
if (offs < 0) {
*flags |= CPU_DTRACE_DROP;
continue;
}
tomax = buf->dtb_tomax;
ASSERT(tomax != NULL);
if (ecb->dte_size == 0)
continue;
ASSERT3U(ecb->dte_size, >=,
sizeof (dtrace_rechdr_t));
dtrh = ((void *)(tomax + offs));
dtrh->dtrh_epid = ecb->dte_epid;
/*
* When the speculation is committed, all of
* the records in the speculative buffer will
* have their timestamps set to the commit
* time. Until then, it is set to a sentinel
* value, for debugability.
*/
DTRACE_RECORD_STORE_TIMESTAMP(dtrh, UINT64_MAX);
continue;
}
case DTRACEACT_PRINTM: {
/* The DIF returns a 'memref'. */
uintptr_t *memref = (uintptr_t *)(uintptr_t) val;
/* Get the size from the memref. */
size = memref[1];
/*
* Check if the size exceeds the allocated
* buffer size.
*/
if (size + sizeof(uintptr_t) > dp->dtdo_rtype.dtdt_size) {
/* Flag a drop! */
*flags |= CPU_DTRACE_DROP;
continue;
}
/* Store the size in the buffer first. */
DTRACE_STORE(uintptr_t, tomax,
valoffs, size);
/*
* Offset the buffer address to the start
* of the data.
*/
valoffs += sizeof(uintptr_t);
/*
* Reset to the memory address rather than
* the memref array, then let the BYREF
* code below do the work to store the
* memory data in the buffer.
*/
val = memref[0];
break;
}
case DTRACEACT_CHILL:
if (dtrace_priv_kernel_destructive(state))
dtrace_action_chill(&mstate, val);
continue;
case DTRACEACT_RAISE:
if (dtrace_priv_proc_destructive(state))
dtrace_action_raise(val);
continue;
case DTRACEACT_COMMIT:
ASSERT(!committed);
/*
* We need to commit our buffer state.
*/
if (ecb->dte_size)
buf->dtb_offset = offs + ecb->dte_size;
buf = &state->dts_buffer[cpuid];
dtrace_speculation_commit(state, cpuid, val);
committed = 1;
continue;
case DTRACEACT_DISCARD:
dtrace_speculation_discard(state, cpuid, val);
continue;
case DTRACEACT_DIFEXPR:
case DTRACEACT_LIBACT:
case DTRACEACT_PRINTF:
case DTRACEACT_PRINTA:
case DTRACEACT_SYSTEM:
case DTRACEACT_FREOPEN:
case DTRACEACT_TRACEMEM:
break;
case DTRACEACT_TRACEMEM_DYNSIZE:
tracememsize = val;
break;
case DTRACEACT_SYM:
case DTRACEACT_MOD:
if (!dtrace_priv_kernel(state))
continue;
break;
case DTRACEACT_USYM:
case DTRACEACT_UMOD:
case DTRACEACT_UADDR: {
#ifdef illumos
struct pid *pid = curthread->t_procp->p_pidp;
#endif
if (!dtrace_priv_proc(state))
continue;
DTRACE_STORE(uint64_t, tomax,
#ifdef illumos
valoffs, (uint64_t)pid->pid_id);
#else
valoffs, (uint64_t) curproc->p_pid);
#endif
DTRACE_STORE(uint64_t, tomax,
valoffs + sizeof (uint64_t), val);
continue;
}
case DTRACEACT_EXIT: {
/*
* For the exit action, we are going to attempt
* to atomically set our activity to be
* draining. If this fails (either because
* another CPU has beat us to the exit action,
* or because our current activity is something
* other than ACTIVE or WARMUP), we will
* continue. This assures that the exit action
* can be successfully recorded at most once
* when we're in the ACTIVE state. If we're
* encountering the exit() action while in
* COOLDOWN, however, we want to honor the new
* status code. (We know that we're the only
* thread in COOLDOWN, so there is no race.)
*/
void *activity = &state->dts_activity;
dtrace_activity_t current = state->dts_activity;
if (current == DTRACE_ACTIVITY_COOLDOWN)
break;
if (current != DTRACE_ACTIVITY_WARMUP)
current = DTRACE_ACTIVITY_ACTIVE;
if (dtrace_cas32(activity, current,
DTRACE_ACTIVITY_DRAINING) != current) {
*flags |= CPU_DTRACE_DROP;
continue;
}
break;
}
default:
ASSERT(0);
}
if (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF ||
dp->dtdo_rtype.dtdt_flags & DIF_TF_BYUREF) {
uintptr_t end = valoffs + size;
if (tracememsize != 0 &&
valoffs + tracememsize < end) {
end = valoffs + tracememsize;
tracememsize = 0;
}
if (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF &&
!dtrace_vcanload((void *)(uintptr_t)val,
&dp->dtdo_rtype, NULL, &mstate, vstate))
continue;
dtrace_store_by_ref(dp, tomax, size, &valoffs,
&val, end, act->dta_intuple,
dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF ?
DIF_TF_BYREF: DIF_TF_BYUREF);
continue;
}
switch (size) {
case 0:
break;
case sizeof (uint8_t):
DTRACE_STORE(uint8_t, tomax, valoffs, val);
break;
case sizeof (uint16_t):
DTRACE_STORE(uint16_t, tomax, valoffs, val);
break;
case sizeof (uint32_t):
DTRACE_STORE(uint32_t, tomax, valoffs, val);
break;
case sizeof (uint64_t):
DTRACE_STORE(uint64_t, tomax, valoffs, val);
break;
default:
/*
* Any other size should have been returned by
* reference, not by value.
*/
ASSERT(0);
break;
}
}
if (*flags & CPU_DTRACE_DROP)
continue;
if (*flags & CPU_DTRACE_FAULT) {
int ndx;
dtrace_action_t *err;
buf->dtb_errors++;
if (probe->dtpr_id == dtrace_probeid_error) {
/*
* There's nothing we can do -- we had an
* error on the error probe. We bump an
* error counter to at least indicate that
* this condition happened.
*/
dtrace_error(&state->dts_dblerrors);
continue;
}
if (vtime) {
/*
* Before recursing on dtrace_probe(), we
* need to explicitly clear out our start
* time to prevent it from being accumulated
* into t_dtrace_vtime.
*/
curthread->t_dtrace_start = 0;
}
/*
* Iterate over the actions to figure out which action
* we were processing when we experienced the error.
* Note that act points _past_ the faulting action; if
* act is ecb->dte_action, the fault was in the
* predicate, if it's ecb->dte_action->dta_next it's
* in action #1, and so on.
*/
for (err = ecb->dte_action, ndx = 0;
err != act; err = err->dta_next, ndx++)
continue;
dtrace_probe_error(state, ecb->dte_epid, ndx,
(mstate.dtms_present & DTRACE_MSTATE_FLTOFFS) ?
mstate.dtms_fltoffs : -1, DTRACE_FLAGS2FLT(*flags),
cpu_core[cpuid].cpuc_dtrace_illval);
continue;
}
if (!committed)
buf->dtb_offset = offs + ecb->dte_size;
}
if (vtime)
curthread->t_dtrace_start = dtrace_gethrtime();
dtrace_interrupt_enable(cookie);
}
/*
* DTrace Probe Hashing Functions
*
* The functions in this section (and indeed, the functions in remaining
* sections) are not _called_ from probe context. (Any exceptions to this are
* marked with a "Note:".) Rather, they are called from elsewhere in the
* DTrace framework to look-up probes in, add probes to and remove probes from
* the DTrace probe hashes. (Each probe is hashed by each element of the
* probe tuple -- allowing for fast lookups, regardless of what was
* specified.)
*/
static uint_t
dtrace_hash_str(const char *p)
{
unsigned int g;
uint_t hval = 0;
while (*p) {
hval = (hval << 4) + *p++;
if ((g = (hval & 0xf0000000)) != 0)
hval ^= g >> 24;
hval &= ~g;
}
return (hval);
}
static dtrace_hash_t *
dtrace_hash_create(uintptr_t stroffs, uintptr_t nextoffs, uintptr_t prevoffs)
{
dtrace_hash_t *hash = kmem_zalloc(sizeof (dtrace_hash_t), KM_SLEEP);
hash->dth_stroffs = stroffs;
hash->dth_nextoffs = nextoffs;
hash->dth_prevoffs = prevoffs;
hash->dth_size = 1;
hash->dth_mask = hash->dth_size - 1;
hash->dth_tab = kmem_zalloc(hash->dth_size *
sizeof (dtrace_hashbucket_t *), KM_SLEEP);
return (hash);
}
static void
dtrace_hash_destroy(dtrace_hash_t *hash)
{
#ifdef DEBUG
int i;
for (i = 0; i < hash->dth_size; i++)
ASSERT(hash->dth_tab[i] == NULL);
#endif
kmem_free(hash->dth_tab,
hash->dth_size * sizeof (dtrace_hashbucket_t *));
kmem_free(hash, sizeof (dtrace_hash_t));
}
static void
dtrace_hash_resize(dtrace_hash_t *hash)
{
int size = hash->dth_size, i, ndx;
int new_size = hash->dth_size << 1;
int new_mask = new_size - 1;
dtrace_hashbucket_t **new_tab, *bucket, *next;
ASSERT((new_size & new_mask) == 0);
new_tab = kmem_zalloc(new_size * sizeof (void *), KM_SLEEP);
for (i = 0; i < size; i++) {
for (bucket = hash->dth_tab[i]; bucket != NULL; bucket = next) {
dtrace_probe_t *probe = bucket->dthb_chain;
ASSERT(probe != NULL);
ndx = DTRACE_HASHSTR(hash, probe) & new_mask;
next = bucket->dthb_next;
bucket->dthb_next = new_tab[ndx];
new_tab[ndx] = bucket;
}
}
kmem_free(hash->dth_tab, hash->dth_size * sizeof (void *));
hash->dth_tab = new_tab;
hash->dth_size = new_size;
hash->dth_mask = new_mask;
}
static void
dtrace_hash_add(dtrace_hash_t *hash, dtrace_probe_t *new)
{
int hashval = DTRACE_HASHSTR(hash, new);
int ndx = hashval & hash->dth_mask;
dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
dtrace_probe_t **nextp, **prevp;
for (; bucket != NULL; bucket = bucket->dthb_next) {
if (DTRACE_HASHEQ(hash, bucket->dthb_chain, new))
goto add;
}
if ((hash->dth_nbuckets >> 1) > hash->dth_size) {
dtrace_hash_resize(hash);
dtrace_hash_add(hash, new);
return;
}
bucket = kmem_zalloc(sizeof (dtrace_hashbucket_t), KM_SLEEP);
bucket->dthb_next = hash->dth_tab[ndx];
hash->dth_tab[ndx] = bucket;
hash->dth_nbuckets++;
add:
nextp = DTRACE_HASHNEXT(hash, new);
ASSERT(*nextp == NULL && *(DTRACE_HASHPREV(hash, new)) == NULL);
*nextp = bucket->dthb_chain;
if (bucket->dthb_chain != NULL) {
prevp = DTRACE_HASHPREV(hash, bucket->dthb_chain);
ASSERT(*prevp == NULL);
*prevp = new;
}
bucket->dthb_chain = new;
bucket->dthb_len++;
}
static dtrace_probe_t *
dtrace_hash_lookup(dtrace_hash_t *hash, dtrace_probe_t *template)
{
int hashval = DTRACE_HASHSTR(hash, template);
int ndx = hashval & hash->dth_mask;
dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
for (; bucket != NULL; bucket = bucket->dthb_next) {
if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
return (bucket->dthb_chain);
}
return (NULL);
}
static int
dtrace_hash_collisions(dtrace_hash_t *hash, dtrace_probe_t *template)
{
int hashval = DTRACE_HASHSTR(hash, template);
int ndx = hashval & hash->dth_mask;
dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
for (; bucket != NULL; bucket = bucket->dthb_next) {
if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
return (bucket->dthb_len);
}
return (0);
}
static void
dtrace_hash_remove(dtrace_hash_t *hash, dtrace_probe_t *probe)
{
int ndx = DTRACE_HASHSTR(hash, probe) & hash->dth_mask;
dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
dtrace_probe_t **prevp = DTRACE_HASHPREV(hash, probe);
dtrace_probe_t **nextp = DTRACE_HASHNEXT(hash, probe);
/*
* Find the bucket that we're removing this probe from.
*/
for (; bucket != NULL; bucket = bucket->dthb_next) {
if (DTRACE_HASHEQ(hash, bucket->dthb_chain, probe))
break;
}
ASSERT(bucket != NULL);
if (*prevp == NULL) {
if (*nextp == NULL) {
/*
* The removed probe was the only probe on this
* bucket; we need to remove the bucket.
*/
dtrace_hashbucket_t *b = hash->dth_tab[ndx];
ASSERT(bucket->dthb_chain == probe);
ASSERT(b != NULL);
if (b == bucket) {
hash->dth_tab[ndx] = bucket->dthb_next;
} else {
while (b->dthb_next != bucket)
b = b->dthb_next;
b->dthb_next = bucket->dthb_next;
}
ASSERT(hash->dth_nbuckets > 0);
hash->dth_nbuckets--;
kmem_free(bucket, sizeof (dtrace_hashbucket_t));
return;
}
bucket->dthb_chain = *nextp;
} else {
*(DTRACE_HASHNEXT(hash, *prevp)) = *nextp;
}
if (*nextp != NULL)
*(DTRACE_HASHPREV(hash, *nextp)) = *prevp;
}
/*
* DTrace Utility Functions
*
* These are random utility functions that are _not_ called from probe context.
*/
static int
dtrace_badattr(const dtrace_attribute_t *a)
{
return (a->dtat_name > DTRACE_STABILITY_MAX ||
a->dtat_data > DTRACE_STABILITY_MAX ||
a->dtat_class > DTRACE_CLASS_MAX);
}
/*
* Return a duplicate copy of a string. If the specified string is NULL,
* this function returns a zero-length string.
*/
static char *
dtrace_strdup(const char *str)
{
char *new = kmem_zalloc((str != NULL ? strlen(str) : 0) + 1, KM_SLEEP);
if (str != NULL)
(void) strcpy(new, str);
return (new);
}
#define DTRACE_ISALPHA(c) \
(((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
static int
dtrace_badname(const char *s)
{
char c;
if (s == NULL || (c = *s++) == '\0')
return (0);
if (!DTRACE_ISALPHA(c) && c != '-' && c != '_' && c != '.')
return (1);
while ((c = *s++) != '\0') {
if (!DTRACE_ISALPHA(c) && (c < '0' || c > '9') &&
c != '-' && c != '_' && c != '.' && c != '`')
return (1);
}
return (0);
}
static void
dtrace_cred2priv(cred_t *cr, uint32_t *privp, uid_t *uidp, zoneid_t *zoneidp)
{
uint32_t priv;
#ifdef illumos
if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
/*
* For DTRACE_PRIV_ALL, the uid and zoneid don't matter.
*/
priv = DTRACE_PRIV_ALL;
} else {
*uidp = crgetuid(cr);
*zoneidp = crgetzoneid(cr);
priv = 0;
if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE))
priv |= DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER;
else if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE))
priv |= DTRACE_PRIV_USER;
if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE))
priv |= DTRACE_PRIV_PROC;
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
priv |= DTRACE_PRIV_OWNER;
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
priv |= DTRACE_PRIV_ZONEOWNER;
}
#else
priv = DTRACE_PRIV_ALL;
#endif
*privp = priv;
}
#ifdef DTRACE_ERRDEBUG
static void
dtrace_errdebug(const char *str)
{
int hval = dtrace_hash_str(str) % DTRACE_ERRHASHSZ;
int occupied = 0;
mutex_enter(&dtrace_errlock);
dtrace_errlast = str;
dtrace_errthread = curthread;
while (occupied++ < DTRACE_ERRHASHSZ) {
if (dtrace_errhash[hval].dter_msg == str) {
dtrace_errhash[hval].dter_count++;
goto out;
}
if (dtrace_errhash[hval].dter_msg != NULL) {
hval = (hval + 1) % DTRACE_ERRHASHSZ;
continue;
}
dtrace_errhash[hval].dter_msg = str;
dtrace_errhash[hval].dter_count = 1;
goto out;
}
panic("dtrace: undersized error hash");
out:
mutex_exit(&dtrace_errlock);
}
#endif
/*
* DTrace Matching Functions
*
* These functions are used to match groups of probes, given some elements of
* a probe tuple, or some globbed expressions for elements of a probe tuple.
*/
static int
dtrace_match_priv(const dtrace_probe_t *prp, uint32_t priv, uid_t uid,
zoneid_t zoneid)
{
if (priv != DTRACE_PRIV_ALL) {
uint32_t ppriv = prp->dtpr_provider->dtpv_priv.dtpp_flags;
uint32_t match = priv & ppriv;
/*
* No PRIV_DTRACE_* privileges...
*/
if ((priv & (DTRACE_PRIV_PROC | DTRACE_PRIV_USER |
DTRACE_PRIV_KERNEL)) == 0)
return (0);
/*
* No matching bits, but there were bits to match...
*/
if (match == 0 && ppriv != 0)
return (0);
/*
* Need to have permissions to the process, but don't...
*/
if (((ppriv & ~match) & DTRACE_PRIV_OWNER) != 0 &&
uid != prp->dtpr_provider->dtpv_priv.dtpp_uid) {
return (0);
}
/*
* Need to be in the same zone unless we possess the
* privilege to examine all zones.
*/
if (((ppriv & ~match) & DTRACE_PRIV_ZONEOWNER) != 0 &&
zoneid != prp->dtpr_provider->dtpv_priv.dtpp_zoneid) {
return (0);
}
}
return (1);
}
/*
* dtrace_match_probe compares a dtrace_probe_t to a pre-compiled key, which
* consists of input pattern strings and an ops-vector to evaluate them.
* This function returns >0 for match, 0 for no match, and <0 for error.
*/
static int
dtrace_match_probe(const dtrace_probe_t *prp, const dtrace_probekey_t *pkp,
uint32_t priv, uid_t uid, zoneid_t zoneid)
{
dtrace_provider_t *pvp = prp->dtpr_provider;
int rv;
if (pvp->dtpv_defunct)
return (0);
if ((rv = pkp->dtpk_pmatch(pvp->dtpv_name, pkp->dtpk_prov, 0)) <= 0)
return (rv);
if ((rv = pkp->dtpk_mmatch(prp->dtpr_mod, pkp->dtpk_mod, 0)) <= 0)
return (rv);
if ((rv = pkp->dtpk_fmatch(prp->dtpr_func, pkp->dtpk_func, 0)) <= 0)
return (rv);
if ((rv = pkp->dtpk_nmatch(prp->dtpr_name, pkp->dtpk_name, 0)) <= 0)
return (rv);
if (dtrace_match_priv(prp, priv, uid, zoneid) == 0)
return (0);
return (rv);
}
/*
* dtrace_match_glob() is a safe kernel implementation of the gmatch(3GEN)
* interface for matching a glob pattern 'p' to an input string 's'. Unlike
* libc's version, the kernel version only applies to 8-bit ASCII strings.
* In addition, all of the recursion cases except for '*' matching have been
* unwound. For '*', we still implement recursive evaluation, but a depth
* counter is maintained and matching is aborted if we recurse too deep.
* The function returns 0 if no match, >0 if match, and <0 if recursion error.
*/
static int
dtrace_match_glob(const char *s, const char *p, int depth)
{
const char *olds;
char s1, c;
int gs;
if (depth > DTRACE_PROBEKEY_MAXDEPTH)
return (-1);
if (s == NULL)
s = ""; /* treat NULL as empty string */
top:
olds = s;
s1 = *s++;
if (p == NULL)
return (0);
if ((c = *p++) == '\0')
return (s1 == '\0');
switch (c) {
case '[': {
int ok = 0, notflag = 0;
char lc = '\0';
if (s1 == '\0')
return (0);
if (*p == '!') {
notflag = 1;
p++;
}
if ((c = *p++) == '\0')
return (0);
do {
if (c == '-' && lc != '\0' && *p != ']') {
if ((c = *p++) == '\0')
return (0);
if (c == '\\' && (c = *p++) == '\0')
return (0);
if (notflag) {
if (s1 < lc || s1 > c)
ok++;
else
return (0);
} else if (lc <= s1 && s1 <= c)
ok++;
} else if (c == '\\' && (c = *p++) == '\0')
return (0);
lc = c; /* save left-hand 'c' for next iteration */
if (notflag) {
if (s1 != c)
ok++;
else
return (0);
} else if (s1 == c)
ok++;
if ((c = *p++) == '\0')
return (0);
} while (c != ']');
if (ok)
goto top;
return (0);
}
case '\\':
if ((c = *p++) == '\0')
return (0);
/*FALLTHRU*/
default:
if (c != s1)
return (0);
/*FALLTHRU*/
case '?':
if (s1 != '\0')
goto top;
return (0);
case '*':
while (*p == '*')
p++; /* consecutive *'s are identical to a single one */
if (*p == '\0')
return (1);
for (s = olds; *s != '\0'; s++) {
if ((gs = dtrace_match_glob(s, p, depth + 1)) != 0)
return (gs);
}
return (0);
}
}
/*ARGSUSED*/
static int
dtrace_match_string(const char *s, const char *p, int depth)
{
return (s != NULL && strcmp(s, p) == 0);
}
/*ARGSUSED*/
static int
dtrace_match_nul(const char *s, const char *p, int depth)
{
return (1); /* always match the empty pattern */
}
/*ARGSUSED*/
static int
dtrace_match_nonzero(const char *s, const char *p, int depth)
{
return (s != NULL && s[0] != '\0');
}
static int
dtrace_match(const dtrace_probekey_t *pkp, uint32_t priv, uid_t uid,
zoneid_t zoneid, int (*matched)(dtrace_probe_t *, void *), void *arg)
{
dtrace_probe_t template, *probe;
dtrace_hash_t *hash = NULL;
int len, best = INT_MAX, nmatched = 0;
dtrace_id_t i;
ASSERT(MUTEX_HELD(&dtrace_lock));
/*
* If the probe ID is specified in the key, just lookup by ID and
* invoke the match callback once if a matching probe is found.
*/
if (pkp->dtpk_id != DTRACE_IDNONE) {
if ((probe = dtrace_probe_lookup_id(pkp->dtpk_id)) != NULL &&
dtrace_match_probe(probe, pkp, priv, uid, zoneid) > 0) {
(void) (*matched)(probe, arg);
nmatched++;
}
return (nmatched);
}
template.dtpr_mod = (char *)pkp->dtpk_mod;
template.dtpr_func = (char *)pkp->dtpk_func;
template.dtpr_name = (char *)pkp->dtpk_name;
/*
* We want to find the most distinct of the module name, function
* name, and name. So for each one that is not a glob pattern or
* empty string, we perform a lookup in the corresponding hash and
* use the hash table with the fewest collisions to do our search.
*/
if (pkp->dtpk_mmatch == &dtrace_match_string &&
(len = dtrace_hash_collisions(dtrace_bymod, &template)) < best) {
best = len;
hash = dtrace_bymod;
}
if (pkp->dtpk_fmatch == &dtrace_match_string &&
(len = dtrace_hash_collisions(dtrace_byfunc, &template)) < best) {
best = len;
hash = dtrace_byfunc;
}
if (pkp->dtpk_nmatch == &dtrace_match_string &&
(len = dtrace_hash_collisions(dtrace_byname, &template)) < best) {
best = len;
hash = dtrace_byname;
}
/*
* If we did not select a hash table, iterate over every probe and
* invoke our callback for each one that matches our input probe key.
*/
if (hash == NULL) {
for (i = 0; i < dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i]) == NULL ||
dtrace_match_probe(probe, pkp, priv, uid,
zoneid) <= 0)
continue;
nmatched++;
if ((*matched)(probe, arg) != DTRACE_MATCH_NEXT)
break;
}
return (nmatched);
}
/*
* If we selected a hash table, iterate over each probe of the same key
* name and invoke the callback for every probe that matches the other
* attributes of our input probe key.
*/
for (probe = dtrace_hash_lookup(hash, &template); probe != NULL;
probe = *(DTRACE_HASHNEXT(hash, probe))) {
if (dtrace_match_probe(probe, pkp, priv, uid, zoneid) <= 0)
continue;
nmatched++;
if ((*matched)(probe, arg) != DTRACE_MATCH_NEXT)
break;
}
return (nmatched);
}
/*
* Return the function pointer dtrace_probecmp() should use to compare the
* specified pattern with a string. For NULL or empty patterns, we select
* dtrace_match_nul(). For glob pattern strings, we use dtrace_match_glob().
* For non-empty non-glob strings, we use dtrace_match_string().
*/
static dtrace_probekey_f *
dtrace_probekey_func(const char *p)
{
char c;
if (p == NULL || *p == '\0')
return (&dtrace_match_nul);
while ((c = *p++) != '\0') {
if (c == '[' || c == '?' || c == '*' || c == '\\')
return (&dtrace_match_glob);
}
return (&dtrace_match_string);
}
/*
* Build a probe comparison key for use with dtrace_match_probe() from the
* given probe description. By convention, a null key only matches anchored
* probes: if each field is the empty string, reset dtpk_fmatch to
* dtrace_match_nonzero().
*/
static void
dtrace_probekey(dtrace_probedesc_t *pdp, dtrace_probekey_t *pkp)
{
pkp->dtpk_prov = pdp->dtpd_provider;
pkp->dtpk_pmatch = dtrace_probekey_func(pdp->dtpd_provider);
pkp->dtpk_mod = pdp->dtpd_mod;
pkp->dtpk_mmatch = dtrace_probekey_func(pdp->dtpd_mod);
pkp->dtpk_func = pdp->dtpd_func;
pkp->dtpk_fmatch = dtrace_probekey_func(pdp->dtpd_func);
pkp->dtpk_name = pdp->dtpd_name;
pkp->dtpk_nmatch = dtrace_probekey_func(pdp->dtpd_name);
pkp->dtpk_id = pdp->dtpd_id;
if (pkp->dtpk_id == DTRACE_IDNONE &&
pkp->dtpk_pmatch == &dtrace_match_nul &&
pkp->dtpk_mmatch == &dtrace_match_nul &&
pkp->dtpk_fmatch == &dtrace_match_nul &&
pkp->dtpk_nmatch == &dtrace_match_nul)
pkp->dtpk_fmatch = &dtrace_match_nonzero;
}
/*
* DTrace Provider-to-Framework API Functions
*
* These functions implement much of the Provider-to-Framework API, as
* described in <sys/dtrace.h>. The parts of the API not in this section are
* the functions in the API for probe management (found below), and
* dtrace_probe() itself (found above).
*/
/*
* Register the calling provider with the DTrace framework. This should
* generally be called by DTrace providers in their attach(9E) entry point.
*/
int
dtrace_register(const char *name, const dtrace_pattr_t *pap, uint32_t priv,
cred_t *cr, const dtrace_pops_t *pops, void *arg, dtrace_provider_id_t *idp)
{
dtrace_provider_t *provider;
if (name == NULL || pap == NULL || pops == NULL || idp == NULL) {
cmn_err(CE_WARN, "failed to register provider '%s': invalid "
"arguments", name ? name : "<NULL>");
return (EINVAL);
}
if (name[0] == '\0' || dtrace_badname(name)) {
cmn_err(CE_WARN, "failed to register provider '%s': invalid "
"provider name", name);
return (EINVAL);
}
if ((pops->dtps_provide == NULL && pops->dtps_provide_module == NULL) ||
pops->dtps_enable == NULL || pops->dtps_disable == NULL ||
pops->dtps_destroy == NULL ||
((pops->dtps_resume == NULL) != (pops->dtps_suspend == NULL))) {
cmn_err(CE_WARN, "failed to register provider '%s': invalid "
"provider ops", name);
return (EINVAL);
}
if (dtrace_badattr(&pap->dtpa_provider) ||
dtrace_badattr(&pap->dtpa_mod) ||
dtrace_badattr(&pap->dtpa_func) ||
dtrace_badattr(&pap->dtpa_name) ||
dtrace_badattr(&pap->dtpa_args)) {
cmn_err(CE_WARN, "failed to register provider '%s': invalid "
"provider attributes", name);
return (EINVAL);
}
if (priv & ~DTRACE_PRIV_ALL) {
cmn_err(CE_WARN, "failed to register provider '%s': invalid "
"privilege attributes", name);
return (EINVAL);
}
if ((priv & DTRACE_PRIV_KERNEL) &&
(priv & (DTRACE_PRIV_USER | DTRACE_PRIV_OWNER)) &&
pops->dtps_usermode == NULL) {
cmn_err(CE_WARN, "failed to register provider '%s': need "
"dtps_usermode() op for given privilege attributes", name);
return (EINVAL);
}
provider = kmem_zalloc(sizeof (dtrace_provider_t), KM_SLEEP);
provider->dtpv_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
(void) strcpy(provider->dtpv_name, name);
provider->dtpv_attr = *pap;
provider->dtpv_priv.dtpp_flags = priv;
if (cr != NULL) {
provider->dtpv_priv.dtpp_uid = crgetuid(cr);
provider->dtpv_priv.dtpp_zoneid = crgetzoneid(cr);
}
provider->dtpv_pops = *pops;
if (pops->dtps_provide == NULL) {
ASSERT(pops->dtps_provide_module != NULL);
provider->dtpv_pops.dtps_provide =
(void (*)(void *, dtrace_probedesc_t *))dtrace_nullop;
}
if (pops->dtps_provide_module == NULL) {
ASSERT(pops->dtps_provide != NULL);
provider->dtpv_pops.dtps_provide_module =
(void (*)(void *, modctl_t *))dtrace_nullop;
}
if (pops->dtps_suspend == NULL) {
ASSERT(pops->dtps_resume == NULL);
provider->dtpv_pops.dtps_suspend =
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
provider->dtpv_pops.dtps_resume =
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
}
provider->dtpv_arg = arg;
*idp = (dtrace_provider_id_t)provider;
if (pops == &dtrace_provider_ops) {
ASSERT(MUTEX_HELD(&dtrace_provider_lock));
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dtrace_anon.dta_enabling == NULL);
/*
* We make sure that the DTrace provider is at the head of
* the provider chain.
*/
provider->dtpv_next = dtrace_provider;
dtrace_provider = provider;
return (0);
}
mutex_enter(&dtrace_provider_lock);
mutex_enter(&dtrace_lock);
/*
* If there is at least one provider registered, we'll add this
* provider after the first provider.
*/
if (dtrace_provider != NULL) {
provider->dtpv_next = dtrace_provider->dtpv_next;
dtrace_provider->dtpv_next = provider;
} else {
dtrace_provider = provider;
}
if (dtrace_retained != NULL) {
dtrace_enabling_provide(provider);
/*
* Now we need to call dtrace_enabling_matchall() -- which
* will acquire cpu_lock and dtrace_lock. We therefore need
* to drop all of our locks before calling into it...
*/
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
dtrace_enabling_matchall();
return (0);
}
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
return (0);
}
/*
* Unregister the specified provider from the DTrace framework. This should
* generally be called by DTrace providers in their detach(9E) entry point.
*/
int
dtrace_unregister(dtrace_provider_id_t id)
{
dtrace_provider_t *old = (dtrace_provider_t *)id;
dtrace_provider_t *prev = NULL;
int i, self = 0, noreap = 0;
dtrace_probe_t *probe, *first = NULL;
if (old->dtpv_pops.dtps_enable ==
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop) {
/*
* If DTrace itself is the provider, we're called with locks
* already held.
*/
ASSERT(old == dtrace_provider);
#ifdef illumos
ASSERT(dtrace_devi != NULL);
#endif
ASSERT(MUTEX_HELD(&dtrace_provider_lock));
ASSERT(MUTEX_HELD(&dtrace_lock));
self = 1;
if (dtrace_provider->dtpv_next != NULL) {
/*
* There's another provider here; return failure.
*/
return (EBUSY);
}
} else {
mutex_enter(&dtrace_provider_lock);
#ifdef illumos
mutex_enter(&mod_lock);
#endif
mutex_enter(&dtrace_lock);
}
/*
* If anyone has /dev/dtrace open, or if there are anonymous enabled
* probes, we refuse to let providers slither away, unless this
* provider has already been explicitly invalidated.
*/
if (!old->dtpv_defunct &&
(dtrace_opens || (dtrace_anon.dta_state != NULL &&
dtrace_anon.dta_state->dts_necbs > 0))) {
if (!self) {
mutex_exit(&dtrace_lock);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_provider_lock);
}
return (EBUSY);
}
/*
* Attempt to destroy the probes associated with this provider.
*/
for (i = 0; i < dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i]) == NULL)
continue;
if (probe->dtpr_provider != old)
continue;
if (probe->dtpr_ecb == NULL)
continue;
/*
* If we are trying to unregister a defunct provider, and the
* provider was made defunct within the interval dictated by
* dtrace_unregister_defunct_reap, we'll (asynchronously)
* attempt to reap our enablings. To denote that the provider
* should reattempt to unregister itself at some point in the
* future, we will return a differentiable error code (EAGAIN
* instead of EBUSY) in this case.
*/
if (dtrace_gethrtime() - old->dtpv_defunct >
dtrace_unregister_defunct_reap)
noreap = 1;
if (!self) {
mutex_exit(&dtrace_lock);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_provider_lock);
}
if (noreap)
return (EBUSY);
(void) taskq_dispatch(dtrace_taskq,
(task_func_t *)dtrace_enabling_reap, NULL, TQ_SLEEP);
return (EAGAIN);
}
/*
* All of the probes for this provider are disabled; we can safely
* remove all of them from their hash chains and from the probe array.
*/
for (i = 0; i < dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i]) == NULL)
continue;
if (probe->dtpr_provider != old)
continue;
dtrace_probes[i] = NULL;
dtrace_hash_remove(dtrace_bymod, probe);
dtrace_hash_remove(dtrace_byfunc, probe);
dtrace_hash_remove(dtrace_byname, probe);
if (first == NULL) {
first = probe;
probe->dtpr_nextmod = NULL;
} else {
probe->dtpr_nextmod = first;
first = probe;
}
}
/*
* The provider's probes have been removed from the hash chains and
* from the probe array. Now issue a dtrace_sync() to be sure that
* everyone has cleared out from any probe array processing.
*/
dtrace_sync();
for (probe = first; probe != NULL; probe = first) {
first = probe->dtpr_nextmod;
old->dtpv_pops.dtps_destroy(old->dtpv_arg, probe->dtpr_id,
probe->dtpr_arg);
kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
#ifdef illumos
vmem_free(dtrace_arena, (void *)(uintptr_t)(probe->dtpr_id), 1);
#else
free_unr(dtrace_arena, probe->dtpr_id);
#endif
kmem_free(probe, sizeof (dtrace_probe_t));
}
if ((prev = dtrace_provider) == old) {
#ifdef illumos
ASSERT(self || dtrace_devi == NULL);
ASSERT(old->dtpv_next == NULL || dtrace_devi == NULL);
#endif
dtrace_provider = old->dtpv_next;
} else {
while (prev != NULL && prev->dtpv_next != old)
prev = prev->dtpv_next;
if (prev == NULL) {
panic("attempt to unregister non-existent "
"dtrace provider %p\n", (void *)id);
}
prev->dtpv_next = old->dtpv_next;
}
if (!self) {
mutex_exit(&dtrace_lock);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_provider_lock);
}
kmem_free(old->dtpv_name, strlen(old->dtpv_name) + 1);
kmem_free(old, sizeof (dtrace_provider_t));
return (0);
}
/*
* Invalidate the specified provider. All subsequent probe lookups for the
* specified provider will fail, but its probes will not be removed.
*/
void
dtrace_invalidate(dtrace_provider_id_t id)
{
dtrace_provider_t *pvp = (dtrace_provider_t *)id;
ASSERT(pvp->dtpv_pops.dtps_enable !=
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop);
mutex_enter(&dtrace_provider_lock);
mutex_enter(&dtrace_lock);
pvp->dtpv_defunct = dtrace_gethrtime();
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
}
/*
* Indicate whether or not DTrace has attached.
*/
int
dtrace_attached(void)
{
/*
* dtrace_provider will be non-NULL iff the DTrace driver has
* attached. (It's non-NULL because DTrace is always itself a
* provider.)
*/
return (dtrace_provider != NULL);
}
/*
* Remove all the unenabled probes for the given provider. This function is
* not unlike dtrace_unregister(), except that it doesn't remove the provider
* -- just as many of its associated probes as it can.
*/
int
dtrace_condense(dtrace_provider_id_t id)
{
dtrace_provider_t *prov = (dtrace_provider_t *)id;
int i;
dtrace_probe_t *probe;
/*
* Make sure this isn't the dtrace provider itself.
*/
ASSERT(prov->dtpv_pops.dtps_enable !=
(void (*)(void *, dtrace_id_t, void *))dtrace_nullop);
mutex_enter(&dtrace_provider_lock);
mutex_enter(&dtrace_lock);
/*
* Attempt to destroy the probes associated with this provider.
*/
for (i = 0; i < dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i]) == NULL)
continue;
if (probe->dtpr_provider != prov)
continue;
if (probe->dtpr_ecb != NULL)
continue;
dtrace_probes[i] = NULL;
dtrace_hash_remove(dtrace_bymod, probe);
dtrace_hash_remove(dtrace_byfunc, probe);
dtrace_hash_remove(dtrace_byname, probe);
prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, i + 1,
probe->dtpr_arg);
kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
kmem_free(probe, sizeof (dtrace_probe_t));
#ifdef illumos
vmem_free(dtrace_arena, (void *)((uintptr_t)i + 1), 1);
#else
free_unr(dtrace_arena, i + 1);
#endif
}
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
return (0);
}
/*
* DTrace Probe Management Functions
*
* The functions in this section perform the DTrace probe management,
* including functions to create probes, look-up probes, and call into the
* providers to request that probes be provided. Some of these functions are
* in the Provider-to-Framework API; these functions can be identified by the
* fact that they are not declared "static".
*/
/*
* Create a probe with the specified module name, function name, and name.
*/
dtrace_id_t
dtrace_probe_create(dtrace_provider_id_t prov, const char *mod,
const char *func, const char *name, int aframes, void *arg)
{
dtrace_probe_t *probe, **probes;
dtrace_provider_t *provider = (dtrace_provider_t *)prov;
dtrace_id_t id;
if (provider == dtrace_provider) {
ASSERT(MUTEX_HELD(&dtrace_lock));
} else {
mutex_enter(&dtrace_lock);
}
#ifdef illumos
id = (dtrace_id_t)(uintptr_t)vmem_alloc(dtrace_arena, 1,
VM_BESTFIT | VM_SLEEP);
#else
id = alloc_unr(dtrace_arena);
#endif
probe = kmem_zalloc(sizeof (dtrace_probe_t), KM_SLEEP);
probe->dtpr_id = id;
probe->dtpr_gen = dtrace_probegen++;
probe->dtpr_mod = dtrace_strdup(mod);
probe->dtpr_func = dtrace_strdup(func);
probe->dtpr_name = dtrace_strdup(name);
probe->dtpr_arg = arg;
probe->dtpr_aframes = aframes;
probe->dtpr_provider = provider;
dtrace_hash_add(dtrace_bymod, probe);
dtrace_hash_add(dtrace_byfunc, probe);
dtrace_hash_add(dtrace_byname, probe);
if (id - 1 >= dtrace_nprobes) {
size_t osize = dtrace_nprobes * sizeof (dtrace_probe_t *);
size_t nsize = osize << 1;
if (nsize == 0) {
ASSERT(osize == 0);
ASSERT(dtrace_probes == NULL);
nsize = sizeof (dtrace_probe_t *);
}
probes = kmem_zalloc(nsize, KM_SLEEP);
if (dtrace_probes == NULL) {
ASSERT(osize == 0);
dtrace_probes = probes;
dtrace_nprobes = 1;
} else {
dtrace_probe_t **oprobes = dtrace_probes;
bcopy(oprobes, probes, osize);
dtrace_membar_producer();
dtrace_probes = probes;
dtrace_sync();
/*
* All CPUs are now seeing the new probes array; we can
* safely free the old array.
*/
kmem_free(oprobes, osize);
dtrace_nprobes <<= 1;
}
ASSERT(id - 1 < dtrace_nprobes);
}
ASSERT(dtrace_probes[id - 1] == NULL);
dtrace_probes[id - 1] = probe;
if (provider != dtrace_provider)
mutex_exit(&dtrace_lock);
return (id);
}
static dtrace_probe_t *
dtrace_probe_lookup_id(dtrace_id_t id)
{
ASSERT(MUTEX_HELD(&dtrace_lock));
if (id == 0 || id > dtrace_nprobes)
return (NULL);
return (dtrace_probes[id - 1]);
}
static int
dtrace_probe_lookup_match(dtrace_probe_t *probe, void *arg)
{
*((dtrace_id_t *)arg) = probe->dtpr_id;
return (DTRACE_MATCH_DONE);
}
/*
* Look up a probe based on provider and one or more of module name, function
* name and probe name.
*/
dtrace_id_t
dtrace_probe_lookup(dtrace_provider_id_t prid, char *mod,
char *func, char *name)
{
dtrace_probekey_t pkey;
dtrace_id_t id;
int match;
pkey.dtpk_prov = ((dtrace_provider_t *)prid)->dtpv_name;
pkey.dtpk_pmatch = &dtrace_match_string;
pkey.dtpk_mod = mod;
pkey.dtpk_mmatch = mod ? &dtrace_match_string : &dtrace_match_nul;
pkey.dtpk_func = func;
pkey.dtpk_fmatch = func ? &dtrace_match_string : &dtrace_match_nul;
pkey.dtpk_name = name;
pkey.dtpk_nmatch = name ? &dtrace_match_string : &dtrace_match_nul;
pkey.dtpk_id = DTRACE_IDNONE;
mutex_enter(&dtrace_lock);
match = dtrace_match(&pkey, DTRACE_PRIV_ALL, 0, 0,
dtrace_probe_lookup_match, &id);
mutex_exit(&dtrace_lock);
ASSERT(match == 1 || match == 0);
return (match ? id : 0);
}
/*
* Returns the probe argument associated with the specified probe.
*/
void *
dtrace_probe_arg(dtrace_provider_id_t id, dtrace_id_t pid)
{
dtrace_probe_t *probe;
void *rval = NULL;
mutex_enter(&dtrace_lock);
if ((probe = dtrace_probe_lookup_id(pid)) != NULL &&
probe->dtpr_provider == (dtrace_provider_t *)id)
rval = probe->dtpr_arg;
mutex_exit(&dtrace_lock);
return (rval);
}
/*
* Copy a probe into a probe description.
*/
static void
dtrace_probe_description(const dtrace_probe_t *prp, dtrace_probedesc_t *pdp)
{
bzero(pdp, sizeof (dtrace_probedesc_t));
pdp->dtpd_id = prp->dtpr_id;
(void) strncpy(pdp->dtpd_provider,
prp->dtpr_provider->dtpv_name, DTRACE_PROVNAMELEN - 1);
(void) strncpy(pdp->dtpd_mod, prp->dtpr_mod, DTRACE_MODNAMELEN - 1);
(void) strncpy(pdp->dtpd_func, prp->dtpr_func, DTRACE_FUNCNAMELEN - 1);
(void) strncpy(pdp->dtpd_name, prp->dtpr_name, DTRACE_NAMELEN - 1);
}
/*
* Called to indicate that a probe -- or probes -- should be provided by a
* specfied provider. If the specified description is NULL, the provider will
* be told to provide all of its probes. (This is done whenever a new
* consumer comes along, or whenever a retained enabling is to be matched.) If
* the specified description is non-NULL, the provider is given the
* opportunity to dynamically provide the specified probe, allowing providers
* to support the creation of probes on-the-fly. (So-called _autocreated_
* probes.) If the provider is NULL, the operations will be applied to all
* providers; if the provider is non-NULL the operations will only be applied
* to the specified provider. The dtrace_provider_lock must be held, and the
* dtrace_lock must _not_ be held -- the provider's dtps_provide() operation
* will need to grab the dtrace_lock when it reenters the framework through
* dtrace_probe_lookup(), dtrace_probe_create(), etc.
*/
static void
dtrace_probe_provide(dtrace_probedesc_t *desc, dtrace_provider_t *prv)
{
#ifdef illumos
modctl_t *ctl;
#endif
int all = 0;
ASSERT(MUTEX_HELD(&dtrace_provider_lock));
if (prv == NULL) {
all = 1;
prv = dtrace_provider;
}
do {
/*
* First, call the blanket provide operation.
*/
prv->dtpv_pops.dtps_provide(prv->dtpv_arg, desc);
#ifdef illumos
/*
* Now call the per-module provide operation. We will grab
* mod_lock to prevent the list from being modified. Note
* that this also prevents the mod_busy bits from changing.
* (mod_busy can only be changed with mod_lock held.)
*/
mutex_enter(&mod_lock);
ctl = &modules;
do {
if (ctl->mod_busy || ctl->mod_mp == NULL)
continue;
prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
} while ((ctl = ctl->mod_next) != &modules);
mutex_exit(&mod_lock);
#endif
} while (all && (prv = prv->dtpv_next) != NULL);
}
#ifdef illumos
/*
* Iterate over each probe, and call the Framework-to-Provider API function
* denoted by offs.
*/
static void
dtrace_probe_foreach(uintptr_t offs)
{
dtrace_provider_t *prov;
void (*func)(void *, dtrace_id_t, void *);
dtrace_probe_t *probe;
dtrace_icookie_t cookie;
int i;
/*
* We disable interrupts to walk through the probe array. This is
* safe -- the dtrace_sync() in dtrace_unregister() assures that we
* won't see stale data.
*/
cookie = dtrace_interrupt_disable();
for (i = 0; i < dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i]) == NULL)
continue;
if (probe->dtpr_ecb == NULL) {
/*
* This probe isn't enabled -- don't call the function.
*/
continue;
}
prov = probe->dtpr_provider;
func = *((void(**)(void *, dtrace_id_t, void *))
((uintptr_t)&prov->dtpv_pops + offs));
func(prov->dtpv_arg, i + 1, probe->dtpr_arg);
}
dtrace_interrupt_enable(cookie);
}
#endif
static int
dtrace_probe_enable(dtrace_probedesc_t *desc, dtrace_enabling_t *enab)
{
dtrace_probekey_t pkey;
uint32_t priv;
uid_t uid;
zoneid_t zoneid;
ASSERT(MUTEX_HELD(&dtrace_lock));
dtrace_ecb_create_cache = NULL;
if (desc == NULL) {
/*
* If we're passed a NULL description, we're being asked to
* create an ECB with a NULL probe.
*/
(void) dtrace_ecb_create_enable(NULL, enab);
return (0);
}
dtrace_probekey(desc, &pkey);
dtrace_cred2priv(enab->dten_vstate->dtvs_state->dts_cred.dcr_cred,
&priv, &uid, &zoneid);
return (dtrace_match(&pkey, priv, uid, zoneid, dtrace_ecb_create_enable,
enab));
}
/*
* DTrace Helper Provider Functions
*/
static void
dtrace_dofattr2attr(dtrace_attribute_t *attr, const dof_attr_t dofattr)
{
attr->dtat_name = DOF_ATTR_NAME(dofattr);
attr->dtat_data = DOF_ATTR_DATA(dofattr);
attr->dtat_class = DOF_ATTR_CLASS(dofattr);
}
static void
dtrace_dofprov2hprov(dtrace_helper_provdesc_t *hprov,
const dof_provider_t *dofprov, char *strtab)
{
hprov->dthpv_provname = strtab + dofprov->dofpv_name;
dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_provider,
dofprov->dofpv_provattr);
dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_mod,
dofprov->dofpv_modattr);
dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_func,
dofprov->dofpv_funcattr);
dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_name,
dofprov->dofpv_nameattr);
dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_args,
dofprov->dofpv_argsattr);
}
static void
dtrace_helper_provide_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
{
uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
dof_hdr_t *dof = (dof_hdr_t *)daddr;
dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
dof_provider_t *provider;
dof_probe_t *probe;
uint32_t *off, *enoff;
uint8_t *arg;
char *strtab;
uint_t i, nprobes;
dtrace_helper_provdesc_t dhpv;
dtrace_helper_probedesc_t dhpb;
dtrace_meta_t *meta = dtrace_meta_pid;
dtrace_mops_t *mops = &meta->dtm_mops;
void *parg;
provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
provider->dofpv_strtab * dof->dofh_secsize);
prb_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
provider->dofpv_probes * dof->dofh_secsize);
arg_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
provider->dofpv_prargs * dof->dofh_secsize);
off_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
provider->dofpv_proffs * dof->dofh_secsize);
strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
off = (uint32_t *)(uintptr_t)(daddr + off_sec->dofs_offset);
arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
enoff = NULL;
/*
* See dtrace_helper_provider_validate().
*/
if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
provider->dofpv_prenoffs != DOF_SECT_NONE) {
enoff_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
provider->dofpv_prenoffs * dof->dofh_secsize);
enoff = (uint32_t *)(uintptr_t)(daddr + enoff_sec->dofs_offset);
}
nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
/*
* Create the provider.
*/
dtrace_dofprov2hprov(&dhpv, provider, strtab);
if ((parg = mops->dtms_provide_pid(meta->dtm_arg, &dhpv, pid)) == NULL)
return;
meta->dtm_count++;
/*
* Create the probes.
*/
for (i = 0; i < nprobes; i++) {
probe = (dof_probe_t *)(uintptr_t)(daddr +
prb_sec->dofs_offset + i * prb_sec->dofs_entsize);
/* See the check in dtrace_helper_provider_validate(). */
if (strlen(strtab + probe->dofpr_func) >= DTRACE_FUNCNAMELEN)
continue;
dhpb.dthpb_mod = dhp->dofhp_mod;
dhpb.dthpb_func = strtab + probe->dofpr_func;
dhpb.dthpb_name = strtab + probe->dofpr_name;
dhpb.dthpb_base = probe->dofpr_addr;
dhpb.dthpb_offs = off + probe->dofpr_offidx;
dhpb.dthpb_noffs = probe->dofpr_noffs;
if (enoff != NULL) {
dhpb.dthpb_enoffs = enoff + probe->dofpr_enoffidx;
dhpb.dthpb_nenoffs = probe->dofpr_nenoffs;
} else {
dhpb.dthpb_enoffs = NULL;
dhpb.dthpb_nenoffs = 0;
}
dhpb.dthpb_args = arg + probe->dofpr_argidx;
dhpb.dthpb_nargc = probe->dofpr_nargc;
dhpb.dthpb_xargc = probe->dofpr_xargc;
dhpb.dthpb_ntypes = strtab + probe->dofpr_nargv;
dhpb.dthpb_xtypes = strtab + probe->dofpr_xargv;
mops->dtms_create_probe(meta->dtm_arg, parg, &dhpb);
}
}
static void
dtrace_helper_provide(dof_helper_t *dhp, pid_t pid)
{
uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
dof_hdr_t *dof = (dof_hdr_t *)daddr;
int i;
ASSERT(MUTEX_HELD(&dtrace_meta_lock));
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
dof->dofh_secoff + i * dof->dofh_secsize);
if (sec->dofs_type != DOF_SECT_PROVIDER)
continue;
dtrace_helper_provide_one(dhp, sec, pid);
}
/*
* We may have just created probes, so we must now rematch against
* any retained enablings. Note that this call will acquire both
* cpu_lock and dtrace_lock; the fact that we are holding
* dtrace_meta_lock now is what defines the ordering with respect to
* these three locks.
*/
dtrace_enabling_matchall();
}
static void
dtrace_helper_provider_remove_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
{
uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
dof_hdr_t *dof = (dof_hdr_t *)daddr;
dof_sec_t *str_sec;
dof_provider_t *provider;
char *strtab;
dtrace_helper_provdesc_t dhpv;
dtrace_meta_t *meta = dtrace_meta_pid;
dtrace_mops_t *mops = &meta->dtm_mops;
provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
provider->dofpv_strtab * dof->dofh_secsize);
strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
/*
* Create the provider.
*/
dtrace_dofprov2hprov(&dhpv, provider, strtab);
mops->dtms_remove_pid(meta->dtm_arg, &dhpv, pid);
meta->dtm_count--;
}
static void
dtrace_helper_provider_remove(dof_helper_t *dhp, pid_t pid)
{
uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
dof_hdr_t *dof = (dof_hdr_t *)daddr;
int i;
ASSERT(MUTEX_HELD(&dtrace_meta_lock));
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
dof->dofh_secoff + i * dof->dofh_secsize);
if (sec->dofs_type != DOF_SECT_PROVIDER)
continue;
dtrace_helper_provider_remove_one(dhp, sec, pid);
}
}
/*
* DTrace Meta Provider-to-Framework API Functions
*
* These functions implement the Meta Provider-to-Framework API, as described
* in <sys/dtrace.h>.
*/
int
dtrace_meta_register(const char *name, const dtrace_mops_t *mops, void *arg,
dtrace_meta_provider_id_t *idp)
{
dtrace_meta_t *meta;
dtrace_helpers_t *help, *next;
int i;
*idp = DTRACE_METAPROVNONE;
/*
* We strictly don't need the name, but we hold onto it for
* debuggability. All hail error queues!
*/
if (name == NULL) {
cmn_err(CE_WARN, "failed to register meta-provider: "
"invalid name");
return (EINVAL);
}
if (mops == NULL ||
mops->dtms_create_probe == NULL ||
mops->dtms_provide_pid == NULL ||
mops->dtms_remove_pid == NULL) {
cmn_err(CE_WARN, "failed to register meta-register %s: "
"invalid ops", name);
return (EINVAL);
}
meta = kmem_zalloc(sizeof (dtrace_meta_t), KM_SLEEP);
meta->dtm_mops = *mops;
meta->dtm_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
(void) strcpy(meta->dtm_name, name);
meta->dtm_arg = arg;
mutex_enter(&dtrace_meta_lock);
mutex_enter(&dtrace_lock);
if (dtrace_meta_pid != NULL) {
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_meta_lock);
cmn_err(CE_WARN, "failed to register meta-register %s: "
"user-land meta-provider exists", name);
kmem_free(meta->dtm_name, strlen(meta->dtm_name) + 1);
kmem_free(meta, sizeof (dtrace_meta_t));
return (EINVAL);
}
dtrace_meta_pid = meta;
*idp = (dtrace_meta_provider_id_t)meta;
/*
* If there are providers and probes ready to go, pass them
* off to the new meta provider now.
*/
help = dtrace_deferred_pid;
dtrace_deferred_pid = NULL;
mutex_exit(&dtrace_lock);
while (help != NULL) {
for (i = 0; i < help->dthps_nprovs; i++) {
dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
help->dthps_pid);
}
next = help->dthps_next;
help->dthps_next = NULL;
help->dthps_prev = NULL;
help->dthps_deferred = 0;
help = next;
}
mutex_exit(&dtrace_meta_lock);
return (0);
}
int
dtrace_meta_unregister(dtrace_meta_provider_id_t id)
{
dtrace_meta_t **pp, *old = (dtrace_meta_t *)id;
mutex_enter(&dtrace_meta_lock);
mutex_enter(&dtrace_lock);
if (old == dtrace_meta_pid) {
pp = &dtrace_meta_pid;
} else {
panic("attempt to unregister non-existent "
"dtrace meta-provider %p\n", (void *)old);
}
if (old->dtm_count != 0) {
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_meta_lock);
return (EBUSY);
}
*pp = NULL;
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_meta_lock);
kmem_free(old->dtm_name, strlen(old->dtm_name) + 1);
kmem_free(old, sizeof (dtrace_meta_t));
return (0);
}
/*
* DTrace DIF Object Functions
*/
static int
dtrace_difo_err(uint_t pc, const char *format, ...)
{
if (dtrace_err_verbose) {
va_list alist;
(void) uprintf("dtrace DIF object error: [%u]: ", pc);
va_start(alist, format);
(void) vuprintf(format, alist);
va_end(alist);
}
#ifdef DTRACE_ERRDEBUG
dtrace_errdebug(format);
#endif
return (1);
}
/*
* Validate a DTrace DIF object by checking the IR instructions. The following
* rules are currently enforced by dtrace_difo_validate():
*
* 1. Each instruction must have a valid opcode
* 2. Each register, string, variable, or subroutine reference must be valid
* 3. No instruction can modify register %r0 (must be zero)
* 4. All instruction reserved bits must be set to zero
* 5. The last instruction must be a "ret" instruction
* 6. All branch targets must reference a valid instruction _after_ the branch
*/
static int
dtrace_difo_validate(dtrace_difo_t *dp, dtrace_vstate_t *vstate, uint_t nregs,
cred_t *cr)
{
int err = 0, i;
int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
int kcheckload;
uint_t pc;
int maxglobal = -1, maxlocal = -1, maxtlocal = -1;
kcheckload = cr == NULL ||
(vstate->dtvs_state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) == 0;
dp->dtdo_destructive = 0;
for (pc = 0; pc < dp->dtdo_len && err == 0; pc++) {
dif_instr_t instr = dp->dtdo_buf[pc];
uint_t r1 = DIF_INSTR_R1(instr);
uint_t r2 = DIF_INSTR_R2(instr);
uint_t rd = DIF_INSTR_RD(instr);
uint_t rs = DIF_INSTR_RS(instr);
uint_t label = DIF_INSTR_LABEL(instr);
uint_t v = DIF_INSTR_VAR(instr);
uint_t subr = DIF_INSTR_SUBR(instr);
uint_t type = DIF_INSTR_TYPE(instr);
uint_t op = DIF_INSTR_OP(instr);
switch (op) {
case DIF_OP_OR:
case DIF_OP_XOR:
case DIF_OP_AND:
case DIF_OP_SLL:
case DIF_OP_SRL:
case DIF_OP_SRA:
case DIF_OP_SUB:
case DIF_OP_ADD:
case DIF_OP_MUL:
case DIF_OP_SDIV:
case DIF_OP_UDIV:
case DIF_OP_SREM:
case DIF_OP_UREM:
case DIF_OP_COPYS:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 >= nregs)
err += efunc(pc, "invalid register %u\n", r2);
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_NOT:
case DIF_OP_MOV:
case DIF_OP_ALLOCS:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 != 0)
err += efunc(pc, "non-zero reserved bits\n");
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_LDSB:
case DIF_OP_LDSH:
case DIF_OP_LDSW:
case DIF_OP_LDUB:
case DIF_OP_LDUH:
case DIF_OP_LDUW:
case DIF_OP_LDX:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 != 0)
err += efunc(pc, "non-zero reserved bits\n");
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
if (kcheckload)
dp->dtdo_buf[pc] = DIF_INSTR_LOAD(op +
DIF_OP_RLDSB - DIF_OP_LDSB, r1, rd);
break;
case DIF_OP_RLDSB:
case DIF_OP_RLDSH:
case DIF_OP_RLDSW:
case DIF_OP_RLDUB:
case DIF_OP_RLDUH:
case DIF_OP_RLDUW:
case DIF_OP_RLDX:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 != 0)
err += efunc(pc, "non-zero reserved bits\n");
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_ULDSB:
case DIF_OP_ULDSH:
case DIF_OP_ULDSW:
case DIF_OP_ULDUB:
case DIF_OP_ULDUH:
case DIF_OP_ULDUW:
case DIF_OP_ULDX:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 != 0)
err += efunc(pc, "non-zero reserved bits\n");
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_STB:
case DIF_OP_STH:
case DIF_OP_STW:
case DIF_OP_STX:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 != 0)
err += efunc(pc, "non-zero reserved bits\n");
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to 0 address\n");
break;
case DIF_OP_CMP:
case DIF_OP_SCMP:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 >= nregs)
err += efunc(pc, "invalid register %u\n", r2);
if (rd != 0)
err += efunc(pc, "non-zero reserved bits\n");
break;
case DIF_OP_TST:
if (r1 >= nregs)
err += efunc(pc, "invalid register %u\n", r1);
if (r2 != 0 || rd != 0)
err += efunc(pc, "non-zero reserved bits\n");
break;
case DIF_OP_BA:
case DIF_OP_BE:
case DIF_OP_BNE:
case DIF_OP_BG:
case DIF_OP_BGU:
case DIF_OP_BGE:
case DIF_OP_BGEU:
case DIF_OP_BL:
case DIF_OP_BLU:
case DIF_OP_BLE:
case DIF_OP_BLEU:
if (label >= dp->dtdo_len) {
err += efunc(pc, "invalid branch target %u\n",
label);
}
if (label <= pc) {
err += efunc(pc, "backward branch to %u\n",
label);
}
break;
case DIF_OP_RET:
if (r1 != 0 || r2 != 0)
err += efunc(pc, "non-zero reserved bits\n");
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
break;
case DIF_OP_NOP:
case DIF_OP_POPTS:
case DIF_OP_FLUSHTS:
if (r1 != 0 || r2 != 0 || rd != 0)
err += efunc(pc, "non-zero reserved bits\n");
break;
case DIF_OP_SETX:
if (DIF_INSTR_INTEGER(instr) >= dp->dtdo_intlen) {
err += efunc(pc, "invalid integer ref %u\n",
DIF_INSTR_INTEGER(instr));
}
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_SETS:
if (DIF_INSTR_STRING(instr) >= dp->dtdo_strlen) {
err += efunc(pc, "invalid string ref %u\n",
DIF_INSTR_STRING(instr));
}
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_LDGA:
case DIF_OP_LDTA:
if (r1 > DIF_VAR_ARRAY_MAX)
err += efunc(pc, "invalid array %u\n", r1);
if (r2 >= nregs)
err += efunc(pc, "invalid register %u\n", r2);
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_LDGS:
case DIF_OP_LDTS:
case DIF_OP_LDLS:
case DIF_OP_LDGAA:
case DIF_OP_LDTAA:
if (v < DIF_VAR_OTHER_MIN || v > DIF_VAR_OTHER_MAX)
err += efunc(pc, "invalid variable %u\n", v);
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
break;
case DIF_OP_STGS:
case DIF_OP_STTS:
case DIF_OP_STLS:
case DIF_OP_STGAA:
case DIF_OP_STTAA:
if (v < DIF_VAR_OTHER_UBASE || v > DIF_VAR_OTHER_MAX)
err += efunc(pc, "invalid variable %u\n", v);
if (rs >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
break;
case DIF_OP_CALL:
if (subr > DIF_SUBR_MAX)
err += efunc(pc, "invalid subr %u\n", subr);
if (rd >= nregs)
err += efunc(pc, "invalid register %u\n", rd);
if (rd == 0)
err += efunc(pc, "cannot write to %r0\n");
if (subr == DIF_SUBR_COPYOUT ||
subr == DIF_SUBR_COPYOUTSTR) {
dp->dtdo_destructive = 1;
}
if (subr == DIF_SUBR_GETF) {
/*
* If we have a getf() we need to record that
* in our state. Note that our state can be
* NULL if this is a helper -- but in that
* case, the call to getf() is itself illegal,
* and will be caught (slightly later) when
* the helper is validated.
*/
if (vstate->dtvs_state != NULL)
vstate->dtvs_state->dts_getf++;
}
break;
case DIF_OP_PUSHTR:
if (type != DIF_TYPE_STRING && type != DIF_TYPE_CTF)
err += efunc(pc, "invalid ref type %u\n", type);
if (r2 >= nregs)
err += efunc(pc, "invalid register %u\n", r2);
if (rs >= nregs)
err += efunc(pc, "invalid register %u\n", rs);
break;
case DIF_OP_PUSHTV:
if (type != DIF_TYPE_CTF)
err += efunc(pc, "invalid val type %u\n", type);
if (r2 >= nregs)
err += efunc(pc, "invalid register %u\n", r2);
if (rs >= nregs)
err += efunc(pc, "invalid register %u\n", rs);
break;
default:
err += efunc(pc, "invalid opcode %u\n",
DIF_INSTR_OP(instr));
}
}
if (dp->dtdo_len != 0 &&
DIF_INSTR_OP(dp->dtdo_buf[dp->dtdo_len - 1]) != DIF_OP_RET) {
err += efunc(dp->dtdo_len - 1,
"expected 'ret' as last DIF instruction\n");
}
if (!(dp->dtdo_rtype.dtdt_flags & (DIF_TF_BYREF | DIF_TF_BYUREF))) {
/*
* If we're not returning by reference, the size must be either
* 0 or the size of one of the base types.
*/
switch (dp->dtdo_rtype.dtdt_size) {
case 0:
case sizeof (uint8_t):
case sizeof (uint16_t):
case sizeof (uint32_t):
case sizeof (uint64_t):
break;
default:
err += efunc(dp->dtdo_len - 1, "bad return size\n");
}
}
for (i = 0; i < dp->dtdo_varlen && err == 0; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i], *existing = NULL;
dtrace_diftype_t *vt, *et;
uint_t id, ndx;
if (v->dtdv_scope != DIFV_SCOPE_GLOBAL &&
v->dtdv_scope != DIFV_SCOPE_THREAD &&
v->dtdv_scope != DIFV_SCOPE_LOCAL) {
err += efunc(i, "unrecognized variable scope %d\n",
v->dtdv_scope);
break;
}
if (v->dtdv_kind != DIFV_KIND_ARRAY &&
v->dtdv_kind != DIFV_KIND_SCALAR) {
err += efunc(i, "unrecognized variable type %d\n",
v->dtdv_kind);
break;
}
if ((id = v->dtdv_id) > DIF_VARIABLE_MAX) {
err += efunc(i, "%d exceeds variable id limit\n", id);
break;
}
if (id < DIF_VAR_OTHER_UBASE)
continue;
/*
* For user-defined variables, we need to check that this
* definition is identical to any previous definition that we
* encountered.
*/
ndx = id - DIF_VAR_OTHER_UBASE;
switch (v->dtdv_scope) {
case DIFV_SCOPE_GLOBAL:
if (maxglobal == -1 || ndx > maxglobal)
maxglobal = ndx;
if (ndx < vstate->dtvs_nglobals) {
dtrace_statvar_t *svar;
if ((svar = vstate->dtvs_globals[ndx]) != NULL)
existing = &svar->dtsv_var;
}
break;
case DIFV_SCOPE_THREAD:
if (maxtlocal == -1 || ndx > maxtlocal)
maxtlocal = ndx;
if (ndx < vstate->dtvs_ntlocals)
existing = &vstate->dtvs_tlocals[ndx];
break;
case DIFV_SCOPE_LOCAL:
if (maxlocal == -1 || ndx > maxlocal)
maxlocal = ndx;
if (ndx < vstate->dtvs_nlocals) {
dtrace_statvar_t *svar;
if ((svar = vstate->dtvs_locals[ndx]) != NULL)
existing = &svar->dtsv_var;
}
break;
}
vt = &v->dtdv_type;
if (vt->dtdt_flags & DIF_TF_BYREF) {
if (vt->dtdt_size == 0) {
err += efunc(i, "zero-sized variable\n");
break;
}
if ((v->dtdv_scope == DIFV_SCOPE_GLOBAL ||
v->dtdv_scope == DIFV_SCOPE_LOCAL) &&
vt->dtdt_size > dtrace_statvar_maxsize) {
err += efunc(i, "oversized by-ref static\n");
break;
}
}
if (existing == NULL || existing->dtdv_id == 0)
continue;
ASSERT(existing->dtdv_id == v->dtdv_id);
ASSERT(existing->dtdv_scope == v->dtdv_scope);
if (existing->dtdv_kind != v->dtdv_kind)
err += efunc(i, "%d changed variable kind\n", id);
et = &existing->dtdv_type;
if (vt->dtdt_flags != et->dtdt_flags) {
err += efunc(i, "%d changed variable type flags\n", id);
break;
}
if (vt->dtdt_size != 0 && vt->dtdt_size != et->dtdt_size) {
err += efunc(i, "%d changed variable type size\n", id);
break;
}
}
for (pc = 0; pc < dp->dtdo_len && err == 0; pc++) {
dif_instr_t instr = dp->dtdo_buf[pc];
uint_t v = DIF_INSTR_VAR(instr);
uint_t op = DIF_INSTR_OP(instr);
switch (op) {
case DIF_OP_LDGS:
case DIF_OP_LDGAA:
case DIF_OP_STGS:
case DIF_OP_STGAA:
if (v > DIF_VAR_OTHER_UBASE + maxglobal)
err += efunc(pc, "invalid variable %u\n", v);
break;
case DIF_OP_LDTS:
case DIF_OP_LDTAA:
case DIF_OP_STTS:
case DIF_OP_STTAA:
if (v > DIF_VAR_OTHER_UBASE + maxtlocal)
err += efunc(pc, "invalid variable %u\n", v);
break;
case DIF_OP_LDLS:
case DIF_OP_STLS:
if (v > DIF_VAR_OTHER_UBASE + maxlocal)
err += efunc(pc, "invalid variable %u\n", v);
break;
default:
break;
}
}
return (err);
}
/*
* Validate a DTrace DIF object that it is to be used as a helper. Helpers
* are much more constrained than normal DIFOs. Specifically, they may
* not:
*
* 1. Make calls to subroutines other than copyin(), copyinstr() or
* miscellaneous string routines
* 2. Access DTrace variables other than the args[] array, and the
* curthread, pid, ppid, tid, execname, zonename, uid and gid variables.
* 3. Have thread-local variables.
* 4. Have dynamic variables.
*/
static int
dtrace_difo_validate_helper(dtrace_difo_t *dp)
{
int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
int err = 0;
uint_t pc;
for (pc = 0; pc < dp->dtdo_len; pc++) {
dif_instr_t instr = dp->dtdo_buf[pc];
uint_t v = DIF_INSTR_VAR(instr);
uint_t subr = DIF_INSTR_SUBR(instr);
uint_t op = DIF_INSTR_OP(instr);
switch (op) {
case DIF_OP_OR:
case DIF_OP_XOR:
case DIF_OP_AND:
case DIF_OP_SLL:
case DIF_OP_SRL:
case DIF_OP_SRA:
case DIF_OP_SUB:
case DIF_OP_ADD:
case DIF_OP_MUL:
case DIF_OP_SDIV:
case DIF_OP_UDIV:
case DIF_OP_SREM:
case DIF_OP_UREM:
case DIF_OP_COPYS:
case DIF_OP_NOT:
case DIF_OP_MOV:
case DIF_OP_RLDSB:
case DIF_OP_RLDSH:
case DIF_OP_RLDSW:
case DIF_OP_RLDUB:
case DIF_OP_RLDUH:
case DIF_OP_RLDUW:
case DIF_OP_RLDX:
case DIF_OP_ULDSB:
case DIF_OP_ULDSH:
case DIF_OP_ULDSW:
case DIF_OP_ULDUB:
case DIF_OP_ULDUH:
case DIF_OP_ULDUW:
case DIF_OP_ULDX:
case DIF_OP_STB:
case DIF_OP_STH:
case DIF_OP_STW:
case DIF_OP_STX:
case DIF_OP_ALLOCS:
case DIF_OP_CMP:
case DIF_OP_SCMP:
case DIF_OP_TST:
case DIF_OP_BA:
case DIF_OP_BE:
case DIF_OP_BNE:
case DIF_OP_BG:
case DIF_OP_BGU:
case DIF_OP_BGE:
case DIF_OP_BGEU:
case DIF_OP_BL:
case DIF_OP_BLU:
case DIF_OP_BLE:
case DIF_OP_BLEU:
case DIF_OP_RET:
case DIF_OP_NOP:
case DIF_OP_POPTS:
case DIF_OP_FLUSHTS:
case DIF_OP_SETX:
case DIF_OP_SETS:
case DIF_OP_LDGA:
case DIF_OP_LDLS:
case DIF_OP_STGS:
case DIF_OP_STLS:
case DIF_OP_PUSHTR:
case DIF_OP_PUSHTV:
break;
case DIF_OP_LDGS:
if (v >= DIF_VAR_OTHER_UBASE)
break;
if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9)
break;
if (v == DIF_VAR_CURTHREAD || v == DIF_VAR_PID ||
v == DIF_VAR_PPID || v == DIF_VAR_TID ||
v == DIF_VAR_EXECARGS ||
v == DIF_VAR_EXECNAME || v == DIF_VAR_ZONENAME ||
v == DIF_VAR_UID || v == DIF_VAR_GID)
break;
err += efunc(pc, "illegal variable %u\n", v);
break;
case DIF_OP_LDTA:
case DIF_OP_LDTS:
case DIF_OP_LDGAA:
case DIF_OP_LDTAA:
err += efunc(pc, "illegal dynamic variable load\n");
break;
case DIF_OP_STTS:
case DIF_OP_STGAA:
case DIF_OP_STTAA:
err += efunc(pc, "illegal dynamic variable store\n");
break;
case DIF_OP_CALL:
if (subr == DIF_SUBR_ALLOCA ||
subr == DIF_SUBR_BCOPY ||
subr == DIF_SUBR_COPYIN ||
subr == DIF_SUBR_COPYINTO ||
subr == DIF_SUBR_COPYINSTR ||
subr == DIF_SUBR_INDEX ||
subr == DIF_SUBR_INET_NTOA ||
subr == DIF_SUBR_INET_NTOA6 ||
subr == DIF_SUBR_INET_NTOP ||
subr == DIF_SUBR_JSON ||
subr == DIF_SUBR_LLTOSTR ||
subr == DIF_SUBR_STRTOLL ||
subr == DIF_SUBR_RINDEX ||
subr == DIF_SUBR_STRCHR ||
subr == DIF_SUBR_STRJOIN ||
subr == DIF_SUBR_STRRCHR ||
subr == DIF_SUBR_STRSTR ||
subr == DIF_SUBR_HTONS ||
subr == DIF_SUBR_HTONL ||
subr == DIF_SUBR_HTONLL ||
subr == DIF_SUBR_NTOHS ||
subr == DIF_SUBR_NTOHL ||
subr == DIF_SUBR_NTOHLL ||
subr == DIF_SUBR_MEMREF)
break;
#ifdef __FreeBSD__
if (subr == DIF_SUBR_MEMSTR)
break;
#endif
err += efunc(pc, "invalid subr %u\n", subr);
break;
default:
err += efunc(pc, "invalid opcode %u\n",
DIF_INSTR_OP(instr));
}
}
return (err);
}
/*
* Returns 1 if the expression in the DIF object can be cached on a per-thread
* basis; 0 if not.
*/
static int
dtrace_difo_cacheable(dtrace_difo_t *dp)
{
int i;
if (dp == NULL)
return (0);
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
if (v->dtdv_scope != DIFV_SCOPE_GLOBAL)
continue;
switch (v->dtdv_id) {
case DIF_VAR_CURTHREAD:
case DIF_VAR_PID:
case DIF_VAR_TID:
case DIF_VAR_EXECARGS:
case DIF_VAR_EXECNAME:
case DIF_VAR_ZONENAME:
break;
default:
return (0);
}
}
/*
* This DIF object may be cacheable. Now we need to look for any
* array loading instructions, any memory loading instructions, or
* any stores to thread-local variables.
*/
for (i = 0; i < dp->dtdo_len; i++) {
uint_t op = DIF_INSTR_OP(dp->dtdo_buf[i]);
if ((op >= DIF_OP_LDSB && op <= DIF_OP_LDX) ||
(op >= DIF_OP_ULDSB && op <= DIF_OP_ULDX) ||
(op >= DIF_OP_RLDSB && op <= DIF_OP_RLDX) ||
op == DIF_OP_LDGA || op == DIF_OP_STTS)
return (0);
}
return (1);
}
static void
dtrace_difo_hold(dtrace_difo_t *dp)
{
int i;
ASSERT(MUTEX_HELD(&dtrace_lock));
dp->dtdo_refcnt++;
ASSERT(dp->dtdo_refcnt != 0);
/*
* We need to check this DIF object for references to the variable
* DIF_VAR_VTIMESTAMP.
*/
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
continue;
if (dtrace_vtime_references++ == 0)
dtrace_vtime_enable();
}
}
/*
* This routine calculates the dynamic variable chunksize for a given DIF
* object. The calculation is not fool-proof, and can probably be tricked by
* malicious DIF -- but it works for all compiler-generated DIF. Because this
* calculation is likely imperfect, dtrace_dynvar() is able to gracefully fail
* if a dynamic variable size exceeds the chunksize.
*/
static void
dtrace_difo_chunksize(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
{
uint64_t sval = 0;
dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
const dif_instr_t *text = dp->dtdo_buf;
uint_t pc, srd = 0;
uint_t ttop = 0;
size_t size, ksize;
uint_t id, i;
for (pc = 0; pc < dp->dtdo_len; pc++) {
dif_instr_t instr = text[pc];
uint_t op = DIF_INSTR_OP(instr);
uint_t rd = DIF_INSTR_RD(instr);
uint_t r1 = DIF_INSTR_R1(instr);
uint_t nkeys = 0;
uchar_t scope = 0;
dtrace_key_t *key = tupregs;
switch (op) {
case DIF_OP_SETX:
sval = dp->dtdo_inttab[DIF_INSTR_INTEGER(instr)];
srd = rd;
continue;
case DIF_OP_STTS:
key = &tupregs[DIF_DTR_NREGS];
key[0].dttk_size = 0;
key[1].dttk_size = 0;
nkeys = 2;
scope = DIFV_SCOPE_THREAD;
break;
case DIF_OP_STGAA:
case DIF_OP_STTAA:
nkeys = ttop;
if (DIF_INSTR_OP(instr) == DIF_OP_STTAA)
key[nkeys++].dttk_size = 0;
key[nkeys++].dttk_size = 0;
if (op == DIF_OP_STTAA) {
scope = DIFV_SCOPE_THREAD;
} else {
scope = DIFV_SCOPE_GLOBAL;
}
break;
case DIF_OP_PUSHTR:
if (ttop == DIF_DTR_NREGS)
return;
if ((srd == 0 || sval == 0) && r1 == DIF_TYPE_STRING) {
/*
* If the register for the size of the "pushtr"
* is %r0 (or the value is 0) and the type is
* a string, we'll use the system-wide default
* string size.
*/
tupregs[ttop++].dttk_size =
dtrace_strsize_default;
} else {
if (srd == 0)
return;
if (sval > LONG_MAX)
return;
tupregs[ttop++].dttk_size = sval;
}
break;
case DIF_OP_PUSHTV:
if (ttop == DIF_DTR_NREGS)
return;
tupregs[ttop++].dttk_size = 0;
break;
case DIF_OP_FLUSHTS:
ttop = 0;
break;
case DIF_OP_POPTS:
if (ttop != 0)
ttop--;
break;
}
sval = 0;
srd = 0;
if (nkeys == 0)
continue;
/*
* We have a dynamic variable allocation; calculate its size.
*/
for (ksize = 0, i = 0; i < nkeys; i++)
ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
size = sizeof (dtrace_dynvar_t);
size += sizeof (dtrace_key_t) * (nkeys - 1);
size += ksize;
/*
* Now we need to determine the size of the stored data.
*/
id = DIF_INSTR_VAR(instr);
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
if (v->dtdv_id == id && v->dtdv_scope == scope) {
size += v->dtdv_type.dtdt_size;
break;
}
}
if (i == dp->dtdo_varlen)
return;
/*
* We have the size. If this is larger than the chunk size
* for our dynamic variable state, reset the chunk size.
*/
size = P2ROUNDUP(size, sizeof (uint64_t));
/*
* Before setting the chunk size, check that we're not going
* to set it to a negative value...
*/
if (size > LONG_MAX)
return;
/*
* ...and make certain that we didn't badly overflow.
*/
if (size < ksize || size < sizeof (dtrace_dynvar_t))
return;
if (size > vstate->dtvs_dynvars.dtds_chunksize)
vstate->dtvs_dynvars.dtds_chunksize = size;
}
}
static void
dtrace_difo_init(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
{
int i, oldsvars, osz, nsz, otlocals, ntlocals;
uint_t id;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dp->dtdo_buf != NULL && dp->dtdo_len != 0);
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
dtrace_statvar_t *svar, ***svarp = NULL;
size_t dsize = 0;
uint8_t scope = v->dtdv_scope;
int *np = NULL;
if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
continue;
id -= DIF_VAR_OTHER_UBASE;
switch (scope) {
case DIFV_SCOPE_THREAD:
while (id >= (otlocals = vstate->dtvs_ntlocals)) {
dtrace_difv_t *tlocals;
if ((ntlocals = (otlocals << 1)) == 0)
ntlocals = 1;
osz = otlocals * sizeof (dtrace_difv_t);
nsz = ntlocals * sizeof (dtrace_difv_t);
tlocals = kmem_zalloc(nsz, KM_SLEEP);
if (osz != 0) {
bcopy(vstate->dtvs_tlocals,
tlocals, osz);
kmem_free(vstate->dtvs_tlocals, osz);
}
vstate->dtvs_tlocals = tlocals;
vstate->dtvs_ntlocals = ntlocals;
}
vstate->dtvs_tlocals[id] = *v;
continue;
case DIFV_SCOPE_LOCAL:
np = &vstate->dtvs_nlocals;
svarp = &vstate->dtvs_locals;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
dsize = NCPU * (v->dtdv_type.dtdt_size +
sizeof (uint64_t));
else
dsize = NCPU * sizeof (uint64_t);
break;
case DIFV_SCOPE_GLOBAL:
np = &vstate->dtvs_nglobals;
svarp = &vstate->dtvs_globals;
if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
dsize = v->dtdv_type.dtdt_size +
sizeof (uint64_t);
break;
default:
ASSERT(0);
}
while (id >= (oldsvars = *np)) {
dtrace_statvar_t **statics;
int newsvars, oldsize, newsize;
if ((newsvars = (oldsvars << 1)) == 0)
newsvars = 1;
oldsize = oldsvars * sizeof (dtrace_statvar_t *);
newsize = newsvars * sizeof (dtrace_statvar_t *);
statics = kmem_zalloc(newsize, KM_SLEEP);
if (oldsize != 0) {
bcopy(*svarp, statics, oldsize);
kmem_free(*svarp, oldsize);
}
*svarp = statics;
*np = newsvars;
}
if ((svar = (*svarp)[id]) == NULL) {
svar = kmem_zalloc(sizeof (dtrace_statvar_t), KM_SLEEP);
svar->dtsv_var = *v;
if ((svar->dtsv_size = dsize) != 0) {
svar->dtsv_data = (uint64_t)(uintptr_t)
kmem_zalloc(dsize, KM_SLEEP);
}
(*svarp)[id] = svar;
}
svar->dtsv_refcnt++;
}
dtrace_difo_chunksize(dp, vstate);
dtrace_difo_hold(dp);
}
static dtrace_difo_t *
dtrace_difo_duplicate(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
{
dtrace_difo_t *new;
size_t sz;
ASSERT(dp->dtdo_buf != NULL);
ASSERT(dp->dtdo_refcnt != 0);
new = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
ASSERT(dp->dtdo_buf != NULL);
sz = dp->dtdo_len * sizeof (dif_instr_t);
new->dtdo_buf = kmem_alloc(sz, KM_SLEEP);
bcopy(dp->dtdo_buf, new->dtdo_buf, sz);
new->dtdo_len = dp->dtdo_len;
if (dp->dtdo_strtab != NULL) {
ASSERT(dp->dtdo_strlen != 0);
new->dtdo_strtab = kmem_alloc(dp->dtdo_strlen, KM_SLEEP);
bcopy(dp->dtdo_strtab, new->dtdo_strtab, dp->dtdo_strlen);
new->dtdo_strlen = dp->dtdo_strlen;
}
if (dp->dtdo_inttab != NULL) {
ASSERT(dp->dtdo_intlen != 0);
sz = dp->dtdo_intlen * sizeof (uint64_t);
new->dtdo_inttab = kmem_alloc(sz, KM_SLEEP);
bcopy(dp->dtdo_inttab, new->dtdo_inttab, sz);
new->dtdo_intlen = dp->dtdo_intlen;
}
if (dp->dtdo_vartab != NULL) {
ASSERT(dp->dtdo_varlen != 0);
sz = dp->dtdo_varlen * sizeof (dtrace_difv_t);
new->dtdo_vartab = kmem_alloc(sz, KM_SLEEP);
bcopy(dp->dtdo_vartab, new->dtdo_vartab, sz);
new->dtdo_varlen = dp->dtdo_varlen;
}
dtrace_difo_init(new, vstate);
return (new);
}
static void
dtrace_difo_destroy(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
{
int i;
ASSERT(dp->dtdo_refcnt == 0);
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
dtrace_statvar_t *svar, **svarp = NULL;
uint_t id;
uint8_t scope = v->dtdv_scope;
int *np = NULL;
switch (scope) {
case DIFV_SCOPE_THREAD:
continue;
case DIFV_SCOPE_LOCAL:
np = &vstate->dtvs_nlocals;
svarp = vstate->dtvs_locals;
break;
case DIFV_SCOPE_GLOBAL:
np = &vstate->dtvs_nglobals;
svarp = vstate->dtvs_globals;
break;
default:
ASSERT(0);
}
if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
continue;
id -= DIF_VAR_OTHER_UBASE;
ASSERT(id < *np);
svar = svarp[id];
ASSERT(svar != NULL);
ASSERT(svar->dtsv_refcnt > 0);
if (--svar->dtsv_refcnt > 0)
continue;
if (svar->dtsv_size != 0) {
ASSERT(svar->dtsv_data != 0);
kmem_free((void *)(uintptr_t)svar->dtsv_data,
svar->dtsv_size);
}
kmem_free(svar, sizeof (dtrace_statvar_t));
svarp[id] = NULL;
}
if (dp->dtdo_buf != NULL)
kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
if (dp->dtdo_inttab != NULL)
kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
if (dp->dtdo_strtab != NULL)
kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
if (dp->dtdo_vartab != NULL)
kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
kmem_free(dp, sizeof (dtrace_difo_t));
}
static void
dtrace_difo_release(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
{
int i;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dp->dtdo_refcnt != 0);
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
continue;
ASSERT(dtrace_vtime_references > 0);
if (--dtrace_vtime_references == 0)
dtrace_vtime_disable();
}
if (--dp->dtdo_refcnt == 0)
dtrace_difo_destroy(dp, vstate);
}
/*
* DTrace Format Functions
*/
static uint16_t
dtrace_format_add(dtrace_state_t *state, char *str)
{
char *fmt, **new;
uint16_t ndx, len = strlen(str) + 1;
fmt = kmem_zalloc(len, KM_SLEEP);
bcopy(str, fmt, len);
for (ndx = 0; ndx < state->dts_nformats; ndx++) {
if (state->dts_formats[ndx] == NULL) {
state->dts_formats[ndx] = fmt;
return (ndx + 1);
}
}
if (state->dts_nformats == USHRT_MAX) {
/*
* This is only likely if a denial-of-service attack is being
* attempted. As such, it's okay to fail silently here.
*/
kmem_free(fmt, len);
return (0);
}
/*
* For simplicity, we always resize the formats array to be exactly the
* number of formats.
*/
ndx = state->dts_nformats++;
new = kmem_alloc((ndx + 1) * sizeof (char *), KM_SLEEP);
if (state->dts_formats != NULL) {
ASSERT(ndx != 0);
bcopy(state->dts_formats, new, ndx * sizeof (char *));
kmem_free(state->dts_formats, ndx * sizeof (char *));
}
state->dts_formats = new;
state->dts_formats[ndx] = fmt;
return (ndx + 1);
}
static void
dtrace_format_remove(dtrace_state_t *state, uint16_t format)
{
char *fmt;
ASSERT(state->dts_formats != NULL);
ASSERT(format <= state->dts_nformats);
ASSERT(state->dts_formats[format - 1] != NULL);
fmt = state->dts_formats[format - 1];
kmem_free(fmt, strlen(fmt) + 1);
state->dts_formats[format - 1] = NULL;
}
static void
dtrace_format_destroy(dtrace_state_t *state)
{
int i;
if (state->dts_nformats == 0) {
ASSERT(state->dts_formats == NULL);
return;
}
ASSERT(state->dts_formats != NULL);
for (i = 0; i < state->dts_nformats; i++) {
char *fmt = state->dts_formats[i];
if (fmt == NULL)
continue;
kmem_free(fmt, strlen(fmt) + 1);
}
kmem_free(state->dts_formats, state->dts_nformats * sizeof (char *));
state->dts_nformats = 0;
state->dts_formats = NULL;
}
/*
* DTrace Predicate Functions
*/
static dtrace_predicate_t *
dtrace_predicate_create(dtrace_difo_t *dp)
{
dtrace_predicate_t *pred;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dp->dtdo_refcnt != 0);
pred = kmem_zalloc(sizeof (dtrace_predicate_t), KM_SLEEP);
pred->dtp_difo = dp;
pred->dtp_refcnt = 1;
if (!dtrace_difo_cacheable(dp))
return (pred);
if (dtrace_predcache_id == DTRACE_CACHEIDNONE) {
/*
* This is only theoretically possible -- we have had 2^32
* cacheable predicates on this machine. We cannot allow any
* more predicates to become cacheable: as unlikely as it is,
* there may be a thread caching a (now stale) predicate cache
* ID. (N.B.: the temptation is being successfully resisted to
* have this cmn_err() "Holy shit -- we executed this code!")
*/
return (pred);
}
pred->dtp_cacheid = dtrace_predcache_id++;
return (pred);
}
static void
dtrace_predicate_hold(dtrace_predicate_t *pred)
{
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(pred->dtp_difo != NULL && pred->dtp_difo->dtdo_refcnt != 0);
ASSERT(pred->dtp_refcnt > 0);
pred->dtp_refcnt++;
}
static void
dtrace_predicate_release(dtrace_predicate_t *pred, dtrace_vstate_t *vstate)
{
dtrace_difo_t *dp = pred->dtp_difo;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dp != NULL && dp->dtdo_refcnt != 0);
ASSERT(pred->dtp_refcnt > 0);
if (--pred->dtp_refcnt == 0) {
dtrace_difo_release(pred->dtp_difo, vstate);
kmem_free(pred, sizeof (dtrace_predicate_t));
}
}
/*
* DTrace Action Description Functions
*/
static dtrace_actdesc_t *
dtrace_actdesc_create(dtrace_actkind_t kind, uint32_t ntuple,
uint64_t uarg, uint64_t arg)
{
dtrace_actdesc_t *act;
#ifdef illumos
ASSERT(!DTRACEACT_ISPRINTFLIKE(kind) || (arg != NULL &&
arg >= KERNELBASE) || (arg == NULL && kind == DTRACEACT_PRINTA));
#endif
act = kmem_zalloc(sizeof (dtrace_actdesc_t), KM_SLEEP);
act->dtad_kind = kind;
act->dtad_ntuple = ntuple;
act->dtad_uarg = uarg;
act->dtad_arg = arg;
act->dtad_refcnt = 1;
return (act);
}
static void
dtrace_actdesc_hold(dtrace_actdesc_t *act)
{
ASSERT(act->dtad_refcnt >= 1);
act->dtad_refcnt++;
}
static void
dtrace_actdesc_release(dtrace_actdesc_t *act, dtrace_vstate_t *vstate)
{
dtrace_actkind_t kind = act->dtad_kind;
dtrace_difo_t *dp;
ASSERT(act->dtad_refcnt >= 1);
if (--act->dtad_refcnt != 0)
return;
if ((dp = act->dtad_difo) != NULL)
dtrace_difo_release(dp, vstate);
if (DTRACEACT_ISPRINTFLIKE(kind)) {
char *str = (char *)(uintptr_t)act->dtad_arg;
#ifdef illumos
ASSERT((str != NULL && (uintptr_t)str >= KERNELBASE) ||
(str == NULL && act->dtad_kind == DTRACEACT_PRINTA));
#endif
if (str != NULL)
kmem_free(str, strlen(str) + 1);
}
kmem_free(act, sizeof (dtrace_actdesc_t));
}
/*
* DTrace ECB Functions
*/
static dtrace_ecb_t *
dtrace_ecb_add(dtrace_state_t *state, dtrace_probe_t *probe)
{
dtrace_ecb_t *ecb;
dtrace_epid_t epid;
ASSERT(MUTEX_HELD(&dtrace_lock));
ecb = kmem_zalloc(sizeof (dtrace_ecb_t), KM_SLEEP);
ecb->dte_predicate = NULL;
ecb->dte_probe = probe;
/*
* The default size is the size of the default action: recording
* the header.
*/
ecb->dte_size = ecb->dte_needed = sizeof (dtrace_rechdr_t);
ecb->dte_alignment = sizeof (dtrace_epid_t);
epid = state->dts_epid++;
if (epid - 1 >= state->dts_necbs) {
dtrace_ecb_t **oecbs = state->dts_ecbs, **ecbs;
int necbs = state->dts_necbs << 1;
ASSERT(epid == state->dts_necbs + 1);
if (necbs == 0) {
ASSERT(oecbs == NULL);
necbs = 1;
}
ecbs = kmem_zalloc(necbs * sizeof (*ecbs), KM_SLEEP);
if (oecbs != NULL)
bcopy(oecbs, ecbs, state->dts_necbs * sizeof (*ecbs));
dtrace_membar_producer();
state->dts_ecbs = ecbs;
if (oecbs != NULL) {
/*
* If this state is active, we must dtrace_sync()
* before we can free the old dts_ecbs array: we're
* coming in hot, and there may be active ring
* buffer processing (which indexes into the dts_ecbs
* array) on another CPU.
*/
if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
dtrace_sync();
kmem_free(oecbs, state->dts_necbs * sizeof (*ecbs));
}
dtrace_membar_producer();
state->dts_necbs = necbs;
}
ecb->dte_state = state;
ASSERT(state->dts_ecbs[epid - 1] == NULL);
dtrace_membar_producer();
state->dts_ecbs[(ecb->dte_epid = epid) - 1] = ecb;
return (ecb);
}
static void
dtrace_ecb_enable(dtrace_ecb_t *ecb)
{
dtrace_probe_t *probe = ecb->dte_probe;
ASSERT(MUTEX_HELD(&cpu_lock));
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(ecb->dte_next == NULL);
if (probe == NULL) {
/*
* This is the NULL probe -- there's nothing to do.
*/
return;
}
if (probe->dtpr_ecb == NULL) {
dtrace_provider_t *prov = probe->dtpr_provider;
/*
* We're the first ECB on this probe.
*/
probe->dtpr_ecb = probe->dtpr_ecb_last = ecb;
if (ecb->dte_predicate != NULL)
probe->dtpr_predcache = ecb->dte_predicate->dtp_cacheid;
prov->dtpv_pops.dtps_enable(prov->dtpv_arg,
probe->dtpr_id, probe->dtpr_arg);
} else {
/*
* This probe is already active. Swing the last pointer to
* point to the new ECB, and issue a dtrace_sync() to assure
* that all CPUs have seen the change.
*/
ASSERT(probe->dtpr_ecb_last != NULL);
probe->dtpr_ecb_last->dte_next = ecb;
probe->dtpr_ecb_last = ecb;
probe->dtpr_predcache = 0;
dtrace_sync();
}
}
static int
dtrace_ecb_resize(dtrace_ecb_t *ecb)
{
dtrace_action_t *act;
uint32_t curneeded = UINT32_MAX;
uint32_t aggbase = UINT32_MAX;
/*
* If we record anything, we always record the dtrace_rechdr_t. (And
* we always record it first.)
*/
ecb->dte_size = sizeof (dtrace_rechdr_t);
ecb->dte_alignment = sizeof (dtrace_epid_t);
for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
dtrace_recdesc_t *rec = &act->dta_rec;
ASSERT(rec->dtrd_size > 0 || rec->dtrd_alignment == 1);
ecb->dte_alignment = MAX(ecb->dte_alignment,
rec->dtrd_alignment);
if (DTRACEACT_ISAGG(act->dta_kind)) {
dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
ASSERT(rec->dtrd_size != 0);
ASSERT(agg->dtag_first != NULL);
ASSERT(act->dta_prev->dta_intuple);
ASSERT(aggbase != UINT32_MAX);
ASSERT(curneeded != UINT32_MAX);
agg->dtag_base = aggbase;
curneeded = P2ROUNDUP(curneeded, rec->dtrd_alignment);
rec->dtrd_offset = curneeded;
if (curneeded + rec->dtrd_size < curneeded)
return (EINVAL);
curneeded += rec->dtrd_size;
ecb->dte_needed = MAX(ecb->dte_needed, curneeded);
aggbase = UINT32_MAX;
curneeded = UINT32_MAX;
} else if (act->dta_intuple) {
if (curneeded == UINT32_MAX) {
/*
* This is the first record in a tuple. Align
* curneeded to be at offset 4 in an 8-byte
* aligned block.
*/
ASSERT(act->dta_prev == NULL ||
!act->dta_prev->dta_intuple);
ASSERT3U(aggbase, ==, UINT32_MAX);
curneeded = P2PHASEUP(ecb->dte_size,
sizeof (uint64_t), sizeof (dtrace_aggid_t));
aggbase = curneeded - sizeof (dtrace_aggid_t);
ASSERT(IS_P2ALIGNED(aggbase,
sizeof (uint64_t)));
}
curneeded = P2ROUNDUP(curneeded, rec->dtrd_alignment);
rec->dtrd_offset = curneeded;
if (curneeded + rec->dtrd_size < curneeded)
return (EINVAL);
curneeded += rec->dtrd_size;
} else {
/* tuples must be followed by an aggregation */
ASSERT(act->dta_prev == NULL ||
!act->dta_prev->dta_intuple);
ecb->dte_size = P2ROUNDUP(ecb->dte_size,
rec->dtrd_alignment);
rec->dtrd_offset = ecb->dte_size;
if (ecb->dte_size + rec->dtrd_size < ecb->dte_size)
return (EINVAL);
ecb->dte_size += rec->dtrd_size;
ecb->dte_needed = MAX(ecb->dte_needed, ecb->dte_size);
}
}
if ((act = ecb->dte_action) != NULL &&
!(act->dta_kind == DTRACEACT_SPECULATE && act->dta_next == NULL) &&
ecb->dte_size == sizeof (dtrace_rechdr_t)) {
/*
* If the size is still sizeof (dtrace_rechdr_t), then all
* actions store no data; set the size to 0.
*/
ecb->dte_size = 0;
}
ecb->dte_size = P2ROUNDUP(ecb->dte_size, sizeof (dtrace_epid_t));
ecb->dte_needed = P2ROUNDUP(ecb->dte_needed, (sizeof (dtrace_epid_t)));
ecb->dte_state->dts_needed = MAX(ecb->dte_state->dts_needed,
ecb->dte_needed);
return (0);
}
static dtrace_action_t *
dtrace_ecb_aggregation_create(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
{
dtrace_aggregation_t *agg;
size_t size = sizeof (uint64_t);
int ntuple = desc->dtad_ntuple;
dtrace_action_t *act;
dtrace_recdesc_t *frec;
dtrace_aggid_t aggid;
dtrace_state_t *state = ecb->dte_state;
agg = kmem_zalloc(sizeof (dtrace_aggregation_t), KM_SLEEP);
agg->dtag_ecb = ecb;
ASSERT(DTRACEACT_ISAGG(desc->dtad_kind));
switch (desc->dtad_kind) {
case DTRACEAGG_MIN:
agg->dtag_initial = INT64_MAX;
agg->dtag_aggregate = dtrace_aggregate_min;
break;
case DTRACEAGG_MAX:
agg->dtag_initial = INT64_MIN;
agg->dtag_aggregate = dtrace_aggregate_max;
break;
case DTRACEAGG_COUNT:
agg->dtag_aggregate = dtrace_aggregate_count;
break;
case DTRACEAGG_QUANTIZE:
agg->dtag_aggregate = dtrace_aggregate_quantize;
size = (((sizeof (uint64_t) * NBBY) - 1) * 2 + 1) *
sizeof (uint64_t);
break;
case DTRACEAGG_LQUANTIZE: {
uint16_t step = DTRACE_LQUANTIZE_STEP(desc->dtad_arg);
uint16_t levels = DTRACE_LQUANTIZE_LEVELS(desc->dtad_arg);
agg->dtag_initial = desc->dtad_arg;
agg->dtag_aggregate = dtrace_aggregate_lquantize;
if (step == 0 || levels == 0)
goto err;
size = levels * sizeof (uint64_t) + 3 * sizeof (uint64_t);
break;
}
case DTRACEAGG_LLQUANTIZE: {
uint16_t factor = DTRACE_LLQUANTIZE_FACTOR(desc->dtad_arg);
uint16_t low = DTRACE_LLQUANTIZE_LOW(desc->dtad_arg);
uint16_t high = DTRACE_LLQUANTIZE_HIGH(desc->dtad_arg);
uint16_t nsteps = DTRACE_LLQUANTIZE_NSTEP(desc->dtad_arg);
int64_t v;
agg->dtag_initial = desc->dtad_arg;
agg->dtag_aggregate = dtrace_aggregate_llquantize;
if (factor < 2 || low >= high || nsteps < factor)
goto err;
/*
* Now check that the number of steps evenly divides a power
* of the factor. (This assures both integer bucket size and
* linearity within each magnitude.)
*/
for (v = factor; v < nsteps; v *= factor)
continue;
if ((v % nsteps) || (nsteps % factor))
goto err;
size = (dtrace_aggregate_llquantize_bucket(factor,
low, high, nsteps, INT64_MAX) + 2) * sizeof (uint64_t);
break;
}
case DTRACEAGG_AVG:
agg->dtag_aggregate = dtrace_aggregate_avg;
size = sizeof (uint64_t) * 2;
break;
case DTRACEAGG_STDDEV:
agg->dtag_aggregate = dtrace_aggregate_stddev;
size = sizeof (uint64_t) * 4;
break;
case DTRACEAGG_SUM:
agg->dtag_aggregate = dtrace_aggregate_sum;
break;
default:
goto err;
}
agg->dtag_action.dta_rec.dtrd_size = size;
if (ntuple == 0)
goto err;
/*
* We must make sure that we have enough actions for the n-tuple.
*/
for (act = ecb->dte_action_last; act != NULL; act = act->dta_prev) {
if (DTRACEACT_ISAGG(act->dta_kind))
break;
if (--ntuple == 0) {
/*
* This is the action with which our n-tuple begins.
*/
agg->dtag_first = act;
goto success;
}
}
/*
* This n-tuple is short by ntuple elements. Return failure.
*/
ASSERT(ntuple != 0);
err:
kmem_free(agg, sizeof (dtrace_aggregation_t));
return (NULL);
success:
/*
* If the last action in the tuple has a size of zero, it's actually
* an expression argument for the aggregating action.
*/
ASSERT(ecb->dte_action_last != NULL);
act = ecb->dte_action_last;
if (act->dta_kind == DTRACEACT_DIFEXPR) {
ASSERT(act->dta_difo != NULL);
if (act->dta_difo->dtdo_rtype.dtdt_size == 0)
agg->dtag_hasarg = 1;
}
/*
* We need to allocate an id for this aggregation.
*/
#ifdef illumos
aggid = (dtrace_aggid_t)(uintptr_t)vmem_alloc(state->dts_aggid_arena, 1,
VM_BESTFIT | VM_SLEEP);
#else
aggid = alloc_unr(state->dts_aggid_arena);
#endif
if (aggid - 1 >= state->dts_naggregations) {
dtrace_aggregation_t **oaggs = state->dts_aggregations;
dtrace_aggregation_t **aggs;
int naggs = state->dts_naggregations << 1;
int onaggs = state->dts_naggregations;
ASSERT(aggid == state->dts_naggregations + 1);
if (naggs == 0) {
ASSERT(oaggs == NULL);
naggs = 1;
}
aggs = kmem_zalloc(naggs * sizeof (*aggs), KM_SLEEP);
if (oaggs != NULL) {
bcopy(oaggs, aggs, onaggs * sizeof (*aggs));
kmem_free(oaggs, onaggs * sizeof (*aggs));
}
state->dts_aggregations = aggs;
state->dts_naggregations = naggs;
}
ASSERT(state->dts_aggregations[aggid - 1] == NULL);
state->dts_aggregations[(agg->dtag_id = aggid) - 1] = agg;
frec = &agg->dtag_first->dta_rec;
if (frec->dtrd_alignment < sizeof (dtrace_aggid_t))
frec->dtrd_alignment = sizeof (dtrace_aggid_t);
for (act = agg->dtag_first; act != NULL; act = act->dta_next) {
ASSERT(!act->dta_intuple);
act->dta_intuple = 1;
}
return (&agg->dtag_action);
}
static void
dtrace_ecb_aggregation_destroy(dtrace_ecb_t *ecb, dtrace_action_t *act)
{
dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
dtrace_state_t *state = ecb->dte_state;
dtrace_aggid_t aggid = agg->dtag_id;
ASSERT(DTRACEACT_ISAGG(act->dta_kind));
#ifdef illumos
vmem_free(state->dts_aggid_arena, (void *)(uintptr_t)aggid, 1);
#else
free_unr(state->dts_aggid_arena, aggid);
#endif
ASSERT(state->dts_aggregations[aggid - 1] == agg);
state->dts_aggregations[aggid - 1] = NULL;
kmem_free(agg, sizeof (dtrace_aggregation_t));
}
static int
dtrace_ecb_action_add(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
{
dtrace_action_t *action, *last;
dtrace_difo_t *dp = desc->dtad_difo;
uint32_t size = 0, align = sizeof (uint8_t), mask;
uint16_t format = 0;
dtrace_recdesc_t *rec;
dtrace_state_t *state = ecb->dte_state;
dtrace_optval_t *opt = state->dts_options, nframes = 0, strsize;
uint64_t arg = desc->dtad_arg;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(ecb->dte_action == NULL || ecb->dte_action->dta_refcnt == 1);
if (DTRACEACT_ISAGG(desc->dtad_kind)) {
/*
* If this is an aggregating action, there must be neither
* a speculate nor a commit on the action chain.
*/
dtrace_action_t *act;
for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
if (act->dta_kind == DTRACEACT_COMMIT)
return (EINVAL);
if (act->dta_kind == DTRACEACT_SPECULATE)
return (EINVAL);
}
action = dtrace_ecb_aggregation_create(ecb, desc);
if (action == NULL)
return (EINVAL);
} else {
if (DTRACEACT_ISDESTRUCTIVE(desc->dtad_kind) ||
(desc->dtad_kind == DTRACEACT_DIFEXPR &&
dp != NULL && dp->dtdo_destructive)) {
state->dts_destructive = 1;
}
switch (desc->dtad_kind) {
case DTRACEACT_PRINTF:
case DTRACEACT_PRINTA:
case DTRACEACT_SYSTEM:
case DTRACEACT_FREOPEN:
case DTRACEACT_DIFEXPR:
/*
* We know that our arg is a string -- turn it into a
* format.
*/
if (arg == 0) {
ASSERT(desc->dtad_kind == DTRACEACT_PRINTA ||
desc->dtad_kind == DTRACEACT_DIFEXPR);
format = 0;
} else {
ASSERT(arg != 0);
#ifdef illumos
ASSERT(arg > KERNELBASE);
#endif
format = dtrace_format_add(state,
(char *)(uintptr_t)arg);
}
/*FALLTHROUGH*/
case DTRACEACT_LIBACT:
case DTRACEACT_TRACEMEM:
case DTRACEACT_TRACEMEM_DYNSIZE:
if (dp == NULL)
return (EINVAL);
if ((size = dp->dtdo_rtype.dtdt_size) != 0)
break;
if (dp->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING) {
if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
return (EINVAL);
size = opt[DTRACEOPT_STRSIZE];
}
break;
case DTRACEACT_STACK:
if ((nframes = arg) == 0) {
nframes = opt[DTRACEOPT_STACKFRAMES];
ASSERT(nframes > 0);
arg = nframes;
}
size = nframes * sizeof (pc_t);
break;
case DTRACEACT_JSTACK:
if ((strsize = DTRACE_USTACK_STRSIZE(arg)) == 0)
strsize = opt[DTRACEOPT_JSTACKSTRSIZE];
if ((nframes = DTRACE_USTACK_NFRAMES(arg)) == 0)
nframes = opt[DTRACEOPT_JSTACKFRAMES];
arg = DTRACE_USTACK_ARG(nframes, strsize);
/*FALLTHROUGH*/
case DTRACEACT_USTACK:
if (desc->dtad_kind != DTRACEACT_JSTACK &&
(nframes = DTRACE_USTACK_NFRAMES(arg)) == 0) {
strsize = DTRACE_USTACK_STRSIZE(arg);
nframes = opt[DTRACEOPT_USTACKFRAMES];
ASSERT(nframes > 0);
arg = DTRACE_USTACK_ARG(nframes, strsize);
}
/*
* Save a slot for the pid.
*/
size = (nframes + 1) * sizeof (uint64_t);
size += DTRACE_USTACK_STRSIZE(arg);
size = P2ROUNDUP(size, (uint32_t)(sizeof (uintptr_t)));
break;
case DTRACEACT_SYM:
case DTRACEACT_MOD:
if (dp == NULL || ((size = dp->dtdo_rtype.dtdt_size) !=
sizeof (uint64_t)) ||
(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
return (EINVAL);
break;
case DTRACEACT_USYM:
case DTRACEACT_UMOD:
case DTRACEACT_UADDR:
if (dp == NULL ||
(dp->dtdo_rtype.dtdt_size != sizeof (uint64_t)) ||
(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
return (EINVAL);
/*
* We have a slot for the pid, plus a slot for the
* argument. To keep things simple (aligned with
* bitness-neutral sizing), we store each as a 64-bit
* quantity.
*/
size = 2 * sizeof (uint64_t);
break;
case DTRACEACT_STOP:
case DTRACEACT_BREAKPOINT:
case DTRACEACT_PANIC:
break;
case DTRACEACT_CHILL:
case DTRACEACT_DISCARD:
case DTRACEACT_RAISE:
if (dp == NULL)
return (EINVAL);
break;
case DTRACEACT_EXIT:
if (dp == NULL ||
(size = dp->dtdo_rtype.dtdt_size) != sizeof (int) ||
(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
return (EINVAL);
break;
case DTRACEACT_SPECULATE:
if (ecb->dte_size > sizeof (dtrace_rechdr_t))
return (EINVAL);
if (dp == NULL)
return (EINVAL);
state->dts_speculates = 1;
break;
case DTRACEACT_PRINTM:
size = dp->dtdo_rtype.dtdt_size;
break;
case DTRACEACT_COMMIT: {
dtrace_action_t *act = ecb->dte_action;
for (; act != NULL; act = act->dta_next) {
if (act->dta_kind == DTRACEACT_COMMIT)
return (EINVAL);
}
if (dp == NULL)
return (EINVAL);
break;
}
default:
return (EINVAL);
}
if (size != 0 || desc->dtad_kind == DTRACEACT_SPECULATE) {
/*
* If this is a data-storing action or a speculate,
* we must be sure that there isn't a commit on the
* action chain.
*/
dtrace_action_t *act = ecb->dte_action;
for (; act != NULL; act = act->dta_next) {
if (act->dta_kind == DTRACEACT_COMMIT)
return (EINVAL);
}
}
action = kmem_zalloc(sizeof (dtrace_action_t), KM_SLEEP);
action->dta_rec.dtrd_size = size;
}
action->dta_refcnt = 1;
rec = &action->dta_rec;
size = rec->dtrd_size;
for (mask = sizeof (uint64_t) - 1; size != 0 && mask > 0; mask >>= 1) {
if (!(size & mask)) {
align = mask + 1;
break;
}
}
action->dta_kind = desc->dtad_kind;
if ((action->dta_difo = dp) != NULL)
dtrace_difo_hold(dp);
rec->dtrd_action = action->dta_kind;
rec->dtrd_arg = arg;
rec->dtrd_uarg = desc->dtad_uarg;
rec->dtrd_alignment = (uint16_t)align;
rec->dtrd_format = format;
if ((last = ecb->dte_action_last) != NULL) {
ASSERT(ecb->dte_action != NULL);
action->dta_prev = last;
last->dta_next = action;
} else {
ASSERT(ecb->dte_action == NULL);
ecb->dte_action = action;
}
ecb->dte_action_last = action;
return (0);
}
static void
dtrace_ecb_action_remove(dtrace_ecb_t *ecb)
{
dtrace_action_t *act = ecb->dte_action, *next;
dtrace_vstate_t *vstate = &ecb->dte_state->dts_vstate;
dtrace_difo_t *dp;
uint16_t format;
if (act != NULL && act->dta_refcnt > 1) {
ASSERT(act->dta_next == NULL || act->dta_next->dta_refcnt == 1);
act->dta_refcnt--;
} else {
for (; act != NULL; act = next) {
next = act->dta_next;
ASSERT(next != NULL || act == ecb->dte_action_last);
ASSERT(act->dta_refcnt == 1);
if ((format = act->dta_rec.dtrd_format) != 0)
dtrace_format_remove(ecb->dte_state, format);
if ((dp = act->dta_difo) != NULL)
dtrace_difo_release(dp, vstate);
if (DTRACEACT_ISAGG(act->dta_kind)) {
dtrace_ecb_aggregation_destroy(ecb, act);
} else {
kmem_free(act, sizeof (dtrace_action_t));
}
}
}
ecb->dte_action = NULL;
ecb->dte_action_last = NULL;
ecb->dte_size = 0;
}
static void
dtrace_ecb_disable(dtrace_ecb_t *ecb)
{
/*
* We disable the ECB by removing it from its probe.
*/
dtrace_ecb_t *pecb, *prev = NULL;
dtrace_probe_t *probe = ecb->dte_probe;
ASSERT(MUTEX_HELD(&dtrace_lock));
if (probe == NULL) {
/*
* This is the NULL probe; there is nothing to disable.
*/
return;
}
for (pecb = probe->dtpr_ecb; pecb != NULL; pecb = pecb->dte_next) {
if (pecb == ecb)
break;
prev = pecb;
}
ASSERT(pecb != NULL);
if (prev == NULL) {
probe->dtpr_ecb = ecb->dte_next;
} else {
prev->dte_next = ecb->dte_next;
}
if (ecb == probe->dtpr_ecb_last) {
ASSERT(ecb->dte_next == NULL);
probe->dtpr_ecb_last = prev;
}
/*
* The ECB has been disconnected from the probe; now sync to assure
* that all CPUs have seen the change before returning.
*/
dtrace_sync();
if (probe->dtpr_ecb == NULL) {
/*
* That was the last ECB on the probe; clear the predicate
* cache ID for the probe, disable it and sync one more time
* to assure that we'll never hit it again.
*/
dtrace_provider_t *prov = probe->dtpr_provider;
ASSERT(ecb->dte_next == NULL);
ASSERT(probe->dtpr_ecb_last == NULL);
probe->dtpr_predcache = DTRACE_CACHEIDNONE;
prov->dtpv_pops.dtps_disable(prov->dtpv_arg,
probe->dtpr_id, probe->dtpr_arg);
dtrace_sync();
} else {
/*
* There is at least one ECB remaining on the probe. If there
* is _exactly_ one, set the probe's predicate cache ID to be
* the predicate cache ID of the remaining ECB.
*/
ASSERT(probe->dtpr_ecb_last != NULL);
ASSERT(probe->dtpr_predcache == DTRACE_CACHEIDNONE);
if (probe->dtpr_ecb == probe->dtpr_ecb_last) {
dtrace_predicate_t *p = probe->dtpr_ecb->dte_predicate;
ASSERT(probe->dtpr_ecb->dte_next == NULL);
if (p != NULL)
probe->dtpr_predcache = p->dtp_cacheid;
}
ecb->dte_next = NULL;
}
}
static void
dtrace_ecb_destroy(dtrace_ecb_t *ecb)
{
dtrace_state_t *state = ecb->dte_state;
dtrace_vstate_t *vstate = &state->dts_vstate;
dtrace_predicate_t *pred;
dtrace_epid_t epid = ecb->dte_epid;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(ecb->dte_next == NULL);
ASSERT(ecb->dte_probe == NULL || ecb->dte_probe->dtpr_ecb != ecb);
if ((pred = ecb->dte_predicate) != NULL)
dtrace_predicate_release(pred, vstate);
dtrace_ecb_action_remove(ecb);
ASSERT(state->dts_ecbs[epid - 1] == ecb);
state->dts_ecbs[epid - 1] = NULL;
kmem_free(ecb, sizeof (dtrace_ecb_t));
}
static dtrace_ecb_t *
dtrace_ecb_create(dtrace_state_t *state, dtrace_probe_t *probe,
dtrace_enabling_t *enab)
{
dtrace_ecb_t *ecb;
dtrace_predicate_t *pred;
dtrace_actdesc_t *act;
dtrace_provider_t *prov;
dtrace_ecbdesc_t *desc = enab->dten_current;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(state != NULL);
ecb = dtrace_ecb_add(state, probe);
ecb->dte_uarg = desc->dted_uarg;
if ((pred = desc->dted_pred.dtpdd_predicate) != NULL) {
dtrace_predicate_hold(pred);
ecb->dte_predicate = pred;
}
if (probe != NULL) {
/*
* If the provider shows more leg than the consumer is old
* enough to see, we need to enable the appropriate implicit
* predicate bits to prevent the ecb from activating at
* revealing times.
*
* Providers specifying DTRACE_PRIV_USER at register time
* are stating that they need the /proc-style privilege
* model to be enforced, and this is what DTRACE_COND_OWNER
* and DTRACE_COND_ZONEOWNER will then do at probe time.
*/
prov = probe->dtpr_provider;
if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLPROC) &&
(prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
ecb->dte_cond |= DTRACE_COND_OWNER;
if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLZONE) &&
(prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
ecb->dte_cond |= DTRACE_COND_ZONEOWNER;
/*
* If the provider shows us kernel innards and the user
* is lacking sufficient privilege, enable the
* DTRACE_COND_USERMODE implicit predicate.
*/
if (!(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) &&
(prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_KERNEL))
ecb->dte_cond |= DTRACE_COND_USERMODE;
}
if (dtrace_ecb_create_cache != NULL) {
/*
* If we have a cached ecb, we'll use its action list instead
* of creating our own (saving both time and space).
*/
dtrace_ecb_t *cached = dtrace_ecb_create_cache;
dtrace_action_t *act = cached->dte_action;
if (act != NULL) {
ASSERT(act->dta_refcnt > 0);
act->dta_refcnt++;
ecb->dte_action = act;
ecb->dte_action_last = cached->dte_action_last;
ecb->dte_needed = cached->dte_needed;
ecb->dte_size = cached->dte_size;
ecb->dte_alignment = cached->dte_alignment;
}
return (ecb);
}
for (act = desc->dted_action; act != NULL; act = act->dtad_next) {
if ((enab->dten_error = dtrace_ecb_action_add(ecb, act)) != 0) {
dtrace_ecb_destroy(ecb);
return (NULL);
}
}
if ((enab->dten_error = dtrace_ecb_resize(ecb)) != 0) {
dtrace_ecb_destroy(ecb);
return (NULL);
}
return (dtrace_ecb_create_cache = ecb);
}
static int
dtrace_ecb_create_enable(dtrace_probe_t *probe, void *arg)
{
dtrace_ecb_t *ecb;
dtrace_enabling_t *enab = arg;
dtrace_state_t *state = enab->dten_vstate->dtvs_state;
ASSERT(state != NULL);
if (probe != NULL && probe->dtpr_gen < enab->dten_probegen) {
/*
* This probe was created in a generation for which this
* enabling has previously created ECBs; we don't want to
* enable it again, so just kick out.
*/
return (DTRACE_MATCH_NEXT);
}
if ((ecb = dtrace_ecb_create(state, probe, enab)) == NULL)
return (DTRACE_MATCH_DONE);
dtrace_ecb_enable(ecb);
return (DTRACE_MATCH_NEXT);
}
static dtrace_ecb_t *
dtrace_epid2ecb(dtrace_state_t *state, dtrace_epid_t id)
{
dtrace_ecb_t *ecb;
ASSERT(MUTEX_HELD(&dtrace_lock));
if (id == 0 || id > state->dts_necbs)
return (NULL);
ASSERT(state->dts_necbs > 0 && state->dts_ecbs != NULL);
ASSERT((ecb = state->dts_ecbs[id - 1]) == NULL || ecb->dte_epid == id);
return (state->dts_ecbs[id - 1]);
}
static dtrace_aggregation_t *
dtrace_aggid2agg(dtrace_state_t *state, dtrace_aggid_t id)
{
dtrace_aggregation_t *agg;
ASSERT(MUTEX_HELD(&dtrace_lock));
if (id == 0 || id > state->dts_naggregations)
return (NULL);
ASSERT(state->dts_naggregations > 0 && state->dts_aggregations != NULL);
ASSERT((agg = state->dts_aggregations[id - 1]) == NULL ||
agg->dtag_id == id);
return (state->dts_aggregations[id - 1]);
}
/*
* DTrace Buffer Functions
*
* The following functions manipulate DTrace buffers. Most of these functions
* are called in the context of establishing or processing consumer state;
* exceptions are explicitly noted.
*/
/*
* Note: called from cross call context. This function switches the two
* buffers on a given CPU. The atomicity of this operation is assured by
* disabling interrupts while the actual switch takes place; the disabling of
* interrupts serializes the execution with any execution of dtrace_probe() on
* the same CPU.
*/
static void
dtrace_buffer_switch(dtrace_buffer_t *buf)
{
caddr_t tomax = buf->dtb_tomax;
caddr_t xamot = buf->dtb_xamot;
dtrace_icookie_t cookie;
hrtime_t now;
ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
ASSERT(!(buf->dtb_flags & DTRACEBUF_RING));
cookie = dtrace_interrupt_disable();
now = dtrace_gethrtime();
buf->dtb_tomax = xamot;
buf->dtb_xamot = tomax;
buf->dtb_xamot_drops = buf->dtb_drops;
buf->dtb_xamot_offset = buf->dtb_offset;
buf->dtb_xamot_errors = buf->dtb_errors;
buf->dtb_xamot_flags = buf->dtb_flags;
buf->dtb_offset = 0;
buf->dtb_drops = 0;
buf->dtb_errors = 0;
buf->dtb_flags &= ~(DTRACEBUF_ERROR | DTRACEBUF_DROPPED);
buf->dtb_interval = now - buf->dtb_switched;
buf->dtb_switched = now;
dtrace_interrupt_enable(cookie);
}
/*
* Note: called from cross call context. This function activates a buffer
* on a CPU. As with dtrace_buffer_switch(), the atomicity of the operation
* is guaranteed by the disabling of interrupts.
*/
static void
dtrace_buffer_activate(dtrace_state_t *state)
{
dtrace_buffer_t *buf;
dtrace_icookie_t cookie = dtrace_interrupt_disable();
buf = &state->dts_buffer[curcpu];
if (buf->dtb_tomax != NULL) {
/*
* We might like to assert that the buffer is marked inactive,
* but this isn't necessarily true: the buffer for the CPU
* that processes the BEGIN probe has its buffer activated
* manually. In this case, we take the (harmless) action
* re-clearing the bit INACTIVE bit.
*/
buf->dtb_flags &= ~DTRACEBUF_INACTIVE;
}
dtrace_interrupt_enable(cookie);
}
#ifdef __FreeBSD__
/*
* Activate the specified per-CPU buffer. This is used instead of
* dtrace_buffer_activate() when APs have not yet started, i.e. when
* activating anonymous state.
*/
static void
dtrace_buffer_activate_cpu(dtrace_state_t *state, int cpu)
{
if (state->dts_buffer[cpu].dtb_tomax != NULL)
state->dts_buffer[cpu].dtb_flags &= ~DTRACEBUF_INACTIVE;
}
#endif
static int
dtrace_buffer_alloc(dtrace_buffer_t *bufs, size_t size, int flags,
processorid_t cpu, int *factor)
{
#ifdef illumos
cpu_t *cp;
#endif
dtrace_buffer_t *buf;
int allocated = 0, desired = 0;
#ifdef illumos
ASSERT(MUTEX_HELD(&cpu_lock));
ASSERT(MUTEX_HELD(&dtrace_lock));
*factor = 1;
if (size > dtrace_nonroot_maxsize &&
!PRIV_POLICY_CHOICE(CRED(), PRIV_ALL, B_FALSE))
return (EFBIG);
cp = cpu_list;
do {
if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
continue;
buf = &bufs[cp->cpu_id];
/*
* If there is already a buffer allocated for this CPU, it
* is only possible that this is a DR event. In this case,
*/
if (buf->dtb_tomax != NULL) {
ASSERT(buf->dtb_size == size);
continue;
}
ASSERT(buf->dtb_xamot == NULL);
if ((buf->dtb_tomax = kmem_zalloc(size,
KM_NOSLEEP | KM_NORMALPRI)) == NULL)
goto err;
buf->dtb_size = size;
buf->dtb_flags = flags;
buf->dtb_offset = 0;
buf->dtb_drops = 0;
if (flags & DTRACEBUF_NOSWITCH)
continue;
if ((buf->dtb_xamot = kmem_zalloc(size,
KM_NOSLEEP | KM_NORMALPRI)) == NULL)
goto err;
} while ((cp = cp->cpu_next) != cpu_list);
return (0);
err:
cp = cpu_list;
do {
if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
continue;
buf = &bufs[cp->cpu_id];
desired += 2;
if (buf->dtb_xamot != NULL) {
ASSERT(buf->dtb_tomax != NULL);
ASSERT(buf->dtb_size == size);
kmem_free(buf->dtb_xamot, size);
allocated++;
}
if (buf->dtb_tomax != NULL) {
ASSERT(buf->dtb_size == size);
kmem_free(buf->dtb_tomax, size);
allocated++;
}
buf->dtb_tomax = NULL;
buf->dtb_xamot = NULL;
buf->dtb_size = 0;
} while ((cp = cp->cpu_next) != cpu_list);
#else
int i;
*factor = 1;
#if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
defined(__mips__) || defined(__powerpc__) || defined(__riscv__)
/*
* FreeBSD isn't good at limiting the amount of memory we
* ask to malloc, so let's place a limit here before trying
* to do something that might well end in tears at bedtime.
*/
if (size > physmem * PAGE_SIZE / (128 * (mp_maxid + 1)))
return (ENOMEM);
#endif
ASSERT(MUTEX_HELD(&dtrace_lock));
CPU_FOREACH(i) {
if (cpu != DTRACE_CPUALL && cpu != i)
continue;
buf = &bufs[i];
/*
* If there is already a buffer allocated for this CPU, it
* is only possible that this is a DR event. In this case,
* the buffer size must match our specified size.
*/
if (buf->dtb_tomax != NULL) {
ASSERT(buf->dtb_size == size);
continue;
}
ASSERT(buf->dtb_xamot == NULL);
if ((buf->dtb_tomax = kmem_zalloc(size,
KM_NOSLEEP | KM_NORMALPRI)) == NULL)
goto err;
buf->dtb_size = size;
buf->dtb_flags = flags;
buf->dtb_offset = 0;
buf->dtb_drops = 0;
if (flags & DTRACEBUF_NOSWITCH)
continue;
if ((buf->dtb_xamot = kmem_zalloc(size,
KM_NOSLEEP | KM_NORMALPRI)) == NULL)
goto err;
}
return (0);
err:
/*
* Error allocating memory, so free the buffers that were
* allocated before the failed allocation.
*/
CPU_FOREACH(i) {
if (cpu != DTRACE_CPUALL && cpu != i)
continue;
buf = &bufs[i];
desired += 2;
if (buf->dtb_xamot != NULL) {
ASSERT(buf->dtb_tomax != NULL);
ASSERT(buf->dtb_size == size);
kmem_free(buf->dtb_xamot, size);
allocated++;
}
if (buf->dtb_tomax != NULL) {
ASSERT(buf->dtb_size == size);
kmem_free(buf->dtb_tomax, size);
allocated++;
}
buf->dtb_tomax = NULL;
buf->dtb_xamot = NULL;
buf->dtb_size = 0;
}
#endif
*factor = desired / (allocated > 0 ? allocated : 1);
return (ENOMEM);
}
/*
* Note: called from probe context. This function just increments the drop
* count on a buffer. It has been made a function to allow for the
* possibility of understanding the source of mysterious drop counts. (A
* problem for which one may be particularly disappointed that DTrace cannot
* be used to understand DTrace.)
*/
static void
dtrace_buffer_drop(dtrace_buffer_t *buf)
{
buf->dtb_drops++;
}
/*
* Note: called from probe context. This function is called to reserve space
* in a buffer. If mstate is non-NULL, sets the scratch base and size in the
* mstate. Returns the new offset in the buffer, or a negative value if an
* error has occurred.
*/
static intptr_t
dtrace_buffer_reserve(dtrace_buffer_t *buf, size_t needed, size_t align,
dtrace_state_t *state, dtrace_mstate_t *mstate)
{
intptr_t offs = buf->dtb_offset, soffs;
intptr_t woffs;
caddr_t tomax;
size_t total;
if (buf->dtb_flags & DTRACEBUF_INACTIVE)
return (-1);
if ((tomax = buf->dtb_tomax) == NULL) {
dtrace_buffer_drop(buf);
return (-1);
}
if (!(buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL))) {
while (offs & (align - 1)) {
/*
* Assert that our alignment is off by a number which
* is itself sizeof (uint32_t) aligned.
*/
ASSERT(!((align - (offs & (align - 1))) &
(sizeof (uint32_t) - 1)));
DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
offs += sizeof (uint32_t);
}
if ((soffs = offs + needed) > buf->dtb_size) {
dtrace_buffer_drop(buf);
return (-1);
}
if (mstate == NULL)
return (offs);
mstate->dtms_scratch_base = (uintptr_t)tomax + soffs;
mstate->dtms_scratch_size = buf->dtb_size - soffs;
mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
return (offs);
}
if (buf->dtb_flags & DTRACEBUF_FILL) {
if (state->dts_activity != DTRACE_ACTIVITY_COOLDOWN &&
(buf->dtb_flags & DTRACEBUF_FULL))
return (-1);
goto out;
}
total = needed + (offs & (align - 1));
/*
* For a ring buffer, life is quite a bit more complicated. Before
* we can store any padding, we need to adjust our wrapping offset.
* (If we've never before wrapped or we're not about to, no adjustment
* is required.)
*/
if ((buf->dtb_flags & DTRACEBUF_WRAPPED) ||
offs + total > buf->dtb_size) {
woffs = buf->dtb_xamot_offset;
if (offs + total > buf->dtb_size) {
/*
* We can't fit in the end of the buffer. First, a
* sanity check that we can fit in the buffer at all.
*/
if (total > buf->dtb_size) {
dtrace_buffer_drop(buf);
return (-1);
}
/*
* We're going to be storing at the top of the buffer,
* so now we need to deal with the wrapped offset. We
* only reset our wrapped offset to 0 if it is
* currently greater than the current offset. If it
* is less than the current offset, it is because a
* previous allocation induced a wrap -- but the
* allocation didn't subsequently take the space due
* to an error or false predicate evaluation. In this
* case, we'll just leave the wrapped offset alone: if
* the wrapped offset hasn't been advanced far enough
* for this allocation, it will be adjusted in the
* lower loop.
*/
if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
if (woffs >= offs)
woffs = 0;
} else {
woffs = 0;
}
/*
* Now we know that we're going to be storing to the
* top of the buffer and that there is room for us
* there. We need to clear the buffer from the current
* offset to the end (there may be old gunk there).
*/
while (offs < buf->dtb_size)
tomax[offs++] = 0;
/*
* We need to set our offset to zero. And because we
* are wrapping, we need to set the bit indicating as
* much. We can also adjust our needed space back
* down to the space required by the ECB -- we know
* that the top of the buffer is aligned.
*/
offs = 0;
total = needed;
buf->dtb_flags |= DTRACEBUF_WRAPPED;
} else {
/*
* There is room for us in the buffer, so we simply
* need to check the wrapped offset.
*/
if (woffs < offs) {
/*
* The wrapped offset is less than the offset.
* This can happen if we allocated buffer space
* that induced a wrap, but then we didn't
* subsequently take the space due to an error
* or false predicate evaluation. This is
* okay; we know that _this_ allocation isn't
* going to induce a wrap. We still can't
* reset the wrapped offset to be zero,
* however: the space may have been trashed in
* the previous failed probe attempt. But at
* least the wrapped offset doesn't need to
* be adjusted at all...
*/
goto out;
}
}
while (offs + total > woffs) {
dtrace_epid_t epid = *(uint32_t *)(tomax + woffs);
size_t size;
if (epid == DTRACE_EPIDNONE) {
size = sizeof (uint32_t);
} else {
ASSERT3U(epid, <=, state->dts_necbs);
ASSERT(state->dts_ecbs[epid - 1] != NULL);
size = state->dts_ecbs[epid - 1]->dte_size;
}
ASSERT(woffs + size <= buf->dtb_size);
ASSERT(size != 0);
if (woffs + size == buf->dtb_size) {
/*
* We've reached the end of the buffer; we want
* to set the wrapped offset to 0 and break
* out. However, if the offs is 0, then we're
* in a strange edge-condition: the amount of
* space that we want to reserve plus the size
* of the record that we're overwriting is
* greater than the size of the buffer. This
* is problematic because if we reserve the
* space but subsequently don't consume it (due
* to a failed predicate or error) the wrapped
* offset will be 0 -- yet the EPID at offset 0
* will not be committed. This situation is
* relatively easy to deal with: if we're in
* this case, the buffer is indistinguishable
* from one that hasn't wrapped; we need only
* finish the job by clearing the wrapped bit,
* explicitly setting the offset to be 0, and
* zero'ing out the old data in the buffer.
*/
if (offs == 0) {
buf->dtb_flags &= ~DTRACEBUF_WRAPPED;
buf->dtb_offset = 0;
woffs = total;
while (woffs < buf->dtb_size)
tomax[woffs++] = 0;
}
woffs = 0;
break;
}
woffs += size;
}
/*
* We have a wrapped offset. It may be that the wrapped offset
* has become zero -- that's okay.
*/
buf->dtb_xamot_offset = woffs;
}
out:
/*
* Now we can plow the buffer with any necessary padding.
*/
while (offs & (align - 1)) {
/*
* Assert that our alignment is off by a number which
* is itself sizeof (uint32_t) aligned.
*/
ASSERT(!((align - (offs & (align - 1))) &
(sizeof (uint32_t) - 1)));
DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
offs += sizeof (uint32_t);
}
if (buf->dtb_flags & DTRACEBUF_FILL) {
if (offs + needed > buf->dtb_size - state->dts_reserve) {
buf->dtb_flags |= DTRACEBUF_FULL;
return (-1);
}
}
if (mstate == NULL)
return (offs);
/*
* For ring buffers and fill buffers, the scratch space is always
* the inactive buffer.
*/
mstate->dtms_scratch_base = (uintptr_t)buf->dtb_xamot;
mstate->dtms_scratch_size = buf->dtb_size;
mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
return (offs);
}
static void
dtrace_buffer_polish(dtrace_buffer_t *buf)
{
ASSERT(buf->dtb_flags & DTRACEBUF_RING);
ASSERT(MUTEX_HELD(&dtrace_lock));
if (!(buf->dtb_flags & DTRACEBUF_WRAPPED))
return;
/*
* We need to polish the ring buffer. There are three cases:
*
* - The first (and presumably most common) is that there is no gap
* between the buffer offset and the wrapped offset. In this case,
* there is nothing in the buffer that isn't valid data; we can
* mark the buffer as polished and return.
*
* - The second (less common than the first but still more common
* than the third) is that there is a gap between the buffer offset
* and the wrapped offset, and the wrapped offset is larger than the
* buffer offset. This can happen because of an alignment issue, or
* can happen because of a call to dtrace_buffer_reserve() that
* didn't subsequently consume the buffer space. In this case,
* we need to zero the data from the buffer offset to the wrapped
* offset.
*
* - The third (and least common) is that there is a gap between the
* buffer offset and the wrapped offset, but the wrapped offset is
* _less_ than the buffer offset. This can only happen because a
* call to dtrace_buffer_reserve() induced a wrap, but the space
* was not subsequently consumed. In this case, we need to zero the
* space from the offset to the end of the buffer _and_ from the
* top of the buffer to the wrapped offset.
*/
if (buf->dtb_offset < buf->dtb_xamot_offset) {
bzero(buf->dtb_tomax + buf->dtb_offset,
buf->dtb_xamot_offset - buf->dtb_offset);
}
if (buf->dtb_offset > buf->dtb_xamot_offset) {
bzero(buf->dtb_tomax + buf->dtb_offset,
buf->dtb_size - buf->dtb_offset);
bzero(buf->dtb_tomax, buf->dtb_xamot_offset);
}
}
/*
* This routine determines if data generated at the specified time has likely
* been entirely consumed at user-level. This routine is called to determine
* if an ECB on a defunct probe (but for an active enabling) can be safely
* disabled and destroyed.
*/
static int
dtrace_buffer_consumed(dtrace_buffer_t *bufs, hrtime_t when)
{
int i;
for (i = 0; i < NCPU; i++) {
dtrace_buffer_t *buf = &bufs[i];
if (buf->dtb_size == 0)
continue;
if (buf->dtb_flags & DTRACEBUF_RING)
return (0);
if (!buf->dtb_switched && buf->dtb_offset != 0)
return (0);
if (buf->dtb_switched - buf->dtb_interval < when)
return (0);
}
return (1);
}
static void
dtrace_buffer_free(dtrace_buffer_t *bufs)
{
int i;
for (i = 0; i < NCPU; i++) {
dtrace_buffer_t *buf = &bufs[i];
if (buf->dtb_tomax == NULL) {
ASSERT(buf->dtb_xamot == NULL);
ASSERT(buf->dtb_size == 0);
continue;
}
if (buf->dtb_xamot != NULL) {
ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
kmem_free(buf->dtb_xamot, buf->dtb_size);
}
kmem_free(buf->dtb_tomax, buf->dtb_size);
buf->dtb_size = 0;
buf->dtb_tomax = NULL;
buf->dtb_xamot = NULL;
}
}
/*
* DTrace Enabling Functions
*/
static dtrace_enabling_t *
dtrace_enabling_create(dtrace_vstate_t *vstate)
{
dtrace_enabling_t *enab;
enab = kmem_zalloc(sizeof (dtrace_enabling_t), KM_SLEEP);
enab->dten_vstate = vstate;
return (enab);
}
static void
dtrace_enabling_add(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb)
{
dtrace_ecbdesc_t **ndesc;
size_t osize, nsize;
/*
* We can't add to enablings after we've enabled them, or after we've
* retained them.
*/
ASSERT(enab->dten_probegen == 0);
ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
if (enab->dten_ndesc < enab->dten_maxdesc) {
enab->dten_desc[enab->dten_ndesc++] = ecb;
return;
}
osize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
if (enab->dten_maxdesc == 0) {
enab->dten_maxdesc = 1;
} else {
enab->dten_maxdesc <<= 1;
}
ASSERT(enab->dten_ndesc < enab->dten_maxdesc);
nsize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
ndesc = kmem_zalloc(nsize, KM_SLEEP);
bcopy(enab->dten_desc, ndesc, osize);
if (enab->dten_desc != NULL)
kmem_free(enab->dten_desc, osize);
enab->dten_desc = ndesc;
enab->dten_desc[enab->dten_ndesc++] = ecb;
}
static void
dtrace_enabling_addlike(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb,
dtrace_probedesc_t *pd)
{
dtrace_ecbdesc_t *new;
dtrace_predicate_t *pred;
dtrace_actdesc_t *act;
/*
* We're going to create a new ECB description that matches the
* specified ECB in every way, but has the specified probe description.
*/
new = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
if ((pred = ecb->dted_pred.dtpdd_predicate) != NULL)
dtrace_predicate_hold(pred);
for (act = ecb->dted_action; act != NULL; act = act->dtad_next)
dtrace_actdesc_hold(act);
new->dted_action = ecb->dted_action;
new->dted_pred = ecb->dted_pred;
new->dted_probe = *pd;
new->dted_uarg = ecb->dted_uarg;
dtrace_enabling_add(enab, new);
}
static void
dtrace_enabling_dump(dtrace_enabling_t *enab)
{
int i;
for (i = 0; i < enab->dten_ndesc; i++) {
dtrace_probedesc_t *desc = &enab->dten_desc[i]->dted_probe;
#ifdef __FreeBSD__
printf("dtrace: enabling probe %d (%s:%s:%s:%s)\n", i,
desc->dtpd_provider, desc->dtpd_mod,
desc->dtpd_func, desc->dtpd_name);
#else
cmn_err(CE_NOTE, "enabling probe %d (%s:%s:%s:%s)", i,
desc->dtpd_provider, desc->dtpd_mod,
desc->dtpd_func, desc->dtpd_name);
#endif
}
}
static void
dtrace_enabling_destroy(dtrace_enabling_t *enab)
{
int i;
dtrace_ecbdesc_t *ep;
dtrace_vstate_t *vstate = enab->dten_vstate;
ASSERT(MUTEX_HELD(&dtrace_lock));
for (i = 0; i < enab->dten_ndesc; i++) {
dtrace_actdesc_t *act, *next;
dtrace_predicate_t *pred;
ep = enab->dten_desc[i];
if ((pred = ep->dted_pred.dtpdd_predicate) != NULL)
dtrace_predicate_release(pred, vstate);
for (act = ep->dted_action; act != NULL; act = next) {
next = act->dtad_next;
dtrace_actdesc_release(act, vstate);
}
kmem_free(ep, sizeof (dtrace_ecbdesc_t));
}
if (enab->dten_desc != NULL)
kmem_free(enab->dten_desc,
enab->dten_maxdesc * sizeof (dtrace_enabling_t *));
/*
* If this was a retained enabling, decrement the dts_nretained count
* and take it off of the dtrace_retained list.
*/
if (enab->dten_prev != NULL || enab->dten_next != NULL ||
dtrace_retained == enab) {
ASSERT(enab->dten_vstate->dtvs_state != NULL);
ASSERT(enab->dten_vstate->dtvs_state->dts_nretained > 0);
enab->dten_vstate->dtvs_state->dts_nretained--;
dtrace_retained_gen++;
}
if (enab->dten_prev == NULL) {
if (dtrace_retained == enab) {
dtrace_retained = enab->dten_next;
if (dtrace_retained != NULL)
dtrace_retained->dten_prev = NULL;
}
} else {
ASSERT(enab != dtrace_retained);
ASSERT(dtrace_retained != NULL);
enab->dten_prev->dten_next = enab->dten_next;
}
if (enab->dten_next != NULL) {
ASSERT(dtrace_retained != NULL);
enab->dten_next->dten_prev = enab->dten_prev;
}
kmem_free(enab, sizeof (dtrace_enabling_t));
}
static int
dtrace_enabling_retain(dtrace_enabling_t *enab)
{
dtrace_state_t *state;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
ASSERT(enab->dten_vstate != NULL);
state = enab->dten_vstate->dtvs_state;
ASSERT(state != NULL);
/*
* We only allow each state to retain dtrace_retain_max enablings.
*/
if (state->dts_nretained >= dtrace_retain_max)
return (ENOSPC);
state->dts_nretained++;
dtrace_retained_gen++;
if (dtrace_retained == NULL) {
dtrace_retained = enab;
return (0);
}
enab->dten_next = dtrace_retained;
dtrace_retained->dten_prev = enab;
dtrace_retained = enab;
return (0);
}
static int
dtrace_enabling_replicate(dtrace_state_t *state, dtrace_probedesc_t *match,
dtrace_probedesc_t *create)
{
dtrace_enabling_t *new, *enab;
int found = 0, err = ENOENT;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(strlen(match->dtpd_provider) < DTRACE_PROVNAMELEN);
ASSERT(strlen(match->dtpd_mod) < DTRACE_MODNAMELEN);
ASSERT(strlen(match->dtpd_func) < DTRACE_FUNCNAMELEN);
ASSERT(strlen(match->dtpd_name) < DTRACE_NAMELEN);
new = dtrace_enabling_create(&state->dts_vstate);
/*
* Iterate over all retained enablings, looking for enablings that
* match the specified state.
*/
for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
int i;
/*
* dtvs_state can only be NULL for helper enablings -- and
* helper enablings can't be retained.
*/
ASSERT(enab->dten_vstate->dtvs_state != NULL);
if (enab->dten_vstate->dtvs_state != state)
continue;
/*
* Now iterate over each probe description; we're looking for
* an exact match to the specified probe description.
*/
for (i = 0; i < enab->dten_ndesc; i++) {
dtrace_ecbdesc_t *ep = enab->dten_desc[i];
dtrace_probedesc_t *pd = &ep->dted_probe;
if (strcmp(pd->dtpd_provider, match->dtpd_provider))
continue;
if (strcmp(pd->dtpd_mod, match->dtpd_mod))
continue;
if (strcmp(pd->dtpd_func, match->dtpd_func))
continue;
if (strcmp(pd->dtpd_name, match->dtpd_name))
continue;
/*
* We have a winning probe! Add it to our growing
* enabling.
*/
found = 1;
dtrace_enabling_addlike(new, ep, create);
}
}
if (!found || (err = dtrace_enabling_retain(new)) != 0) {
dtrace_enabling_destroy(new);
return (err);
}
return (0);
}
static void
dtrace_enabling_retract(dtrace_state_t *state)
{
dtrace_enabling_t *enab, *next;
ASSERT(MUTEX_HELD(&dtrace_lock));
/*
* Iterate over all retained enablings, destroy the enablings retained
* for the specified state.
*/
for (enab = dtrace_retained; enab != NULL; enab = next) {
next = enab->dten_next;
/*
* dtvs_state can only be NULL for helper enablings -- and
* helper enablings can't be retained.
*/
ASSERT(enab->dten_vstate->dtvs_state != NULL);
if (enab->dten_vstate->dtvs_state == state) {
ASSERT(state->dts_nretained > 0);
dtrace_enabling_destroy(enab);
}
}
ASSERT(state->dts_nretained == 0);
}
static int
dtrace_enabling_match(dtrace_enabling_t *enab, int *nmatched)
{
int i = 0;
int matched = 0;
ASSERT(MUTEX_HELD(&cpu_lock));
ASSERT(MUTEX_HELD(&dtrace_lock));
for (i = 0; i < enab->dten_ndesc; i++) {
dtrace_ecbdesc_t *ep = enab->dten_desc[i];
enab->dten_current = ep;
enab->dten_error = 0;
matched += dtrace_probe_enable(&ep->dted_probe, enab);
if (enab->dten_error != 0) {
/*
* If we get an error half-way through enabling the
* probes, we kick out -- perhaps with some number of
* them enabled. Leaving enabled probes enabled may
* be slightly confusing for user-level, but we expect
* that no one will attempt to actually drive on in
* the face of such errors. If this is an anonymous
* enabling (indicated with a NULL nmatched pointer),
* we cmn_err() a message. We aren't expecting to
* get such an error -- such as it can exist at all,
* it would be a result of corrupted DOF in the driver
* properties.
*/
if (nmatched == NULL) {
cmn_err(CE_WARN, "dtrace_enabling_match() "
"error on %p: %d", (void *)ep,
enab->dten_error);
}
return (enab->dten_error);
}
}
enab->dten_probegen = dtrace_probegen;
if (nmatched != NULL)
*nmatched = matched;
return (0);
}
static void
dtrace_enabling_matchall(void)
{
dtrace_enabling_t *enab;
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_lock);
/*
* Iterate over all retained enablings to see if any probes match
* against them. We only perform this operation on enablings for which
* we have sufficient permissions by virtue of being in the global zone
* or in the same zone as the DTrace client. Because we can be called
* after dtrace_detach() has been called, we cannot assert that there
* are retained enablings. We can safely load from dtrace_retained,
* however: the taskq_destroy() at the end of dtrace_detach() will
* block pending our completion.
*/
for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
#ifdef illumos
cred_t *cr = enab->dten_vstate->dtvs_state->dts_cred.dcr_cred;
if (INGLOBALZONE(curproc) ||
cr != NULL && getzoneid() == crgetzoneid(cr))
#endif
(void) dtrace_enabling_match(enab, NULL);
}
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
}
/*
* If an enabling is to be enabled without having matched probes (that is, if
* dtrace_state_go() is to be called on the underlying dtrace_state_t), the
* enabling must be _primed_ by creating an ECB for every ECB description.
* This must be done to assure that we know the number of speculations, the
* number of aggregations, the minimum buffer size needed, etc. before we
* transition out of DTRACE_ACTIVITY_INACTIVE. To do this without actually
* enabling any probes, we create ECBs for every ECB decription, but with a
* NULL probe -- which is exactly what this function does.
*/
static void
dtrace_enabling_prime(dtrace_state_t *state)
{
dtrace_enabling_t *enab;
int i;
for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
ASSERT(enab->dten_vstate->dtvs_state != NULL);
if (enab->dten_vstate->dtvs_state != state)
continue;
/*
* We don't want to prime an enabling more than once, lest
* we allow a malicious user to induce resource exhaustion.
* (The ECBs that result from priming an enabling aren't
* leaked -- but they also aren't deallocated until the
* consumer state is destroyed.)
*/
if (enab->dten_primed)
continue;
for (i = 0; i < enab->dten_ndesc; i++) {
enab->dten_current = enab->dten_desc[i];
(void) dtrace_probe_enable(NULL, enab);
}
enab->dten_primed = 1;
}
}
/*
* Called to indicate that probes should be provided due to retained
* enablings. This is implemented in terms of dtrace_probe_provide(), but it
* must take an initial lap through the enabling calling the dtps_provide()
* entry point explicitly to allow for autocreated probes.
*/
static void
dtrace_enabling_provide(dtrace_provider_t *prv)
{
int i, all = 0;
dtrace_probedesc_t desc;
dtrace_genid_t gen;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(MUTEX_HELD(&dtrace_provider_lock));
if (prv == NULL) {
all = 1;
prv = dtrace_provider;
}
do {
dtrace_enabling_t *enab;
void *parg = prv->dtpv_arg;
retry:
gen = dtrace_retained_gen;
for (enab = dtrace_retained; enab != NULL;
enab = enab->dten_next) {
for (i = 0; i < enab->dten_ndesc; i++) {
desc = enab->dten_desc[i]->dted_probe;
mutex_exit(&dtrace_lock);
prv->dtpv_pops.dtps_provide(parg, &desc);
mutex_enter(&dtrace_lock);
/*
* Process the retained enablings again if
* they have changed while we weren't holding
* dtrace_lock.
*/
if (gen != dtrace_retained_gen)
goto retry;
}
}
} while (all && (prv = prv->dtpv_next) != NULL);
mutex_exit(&dtrace_lock);
dtrace_probe_provide(NULL, all ? NULL : prv);
mutex_enter(&dtrace_lock);
}
/*
* Called to reap ECBs that are attached to probes from defunct providers.
*/
static void
dtrace_enabling_reap(void)
{
dtrace_provider_t *prov;
dtrace_probe_t *probe;
dtrace_ecb_t *ecb;
hrtime_t when;
int i;
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_lock);
for (i = 0; i < dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i]) == NULL)
continue;
if (probe->dtpr_ecb == NULL)
continue;
prov = probe->dtpr_provider;
if ((when = prov->dtpv_defunct) == 0)
continue;
/*
* We have ECBs on a defunct provider: we want to reap these
* ECBs to allow the provider to unregister. The destruction
* of these ECBs must be done carefully: if we destroy the ECB
* and the consumer later wishes to consume an EPID that
* corresponds to the destroyed ECB (and if the EPID metadata
* has not been previously consumed), the consumer will abort
* processing on the unknown EPID. To reduce (but not, sadly,
* eliminate) the possibility of this, we will only destroy an
* ECB for a defunct provider if, for the state that
* corresponds to the ECB:
*
* (a) There is no speculative tracing (which can effectively
* cache an EPID for an arbitrary amount of time).
*
* (b) The principal buffers have been switched twice since the
* provider became defunct.
*
* (c) The aggregation buffers are of zero size or have been
* switched twice since the provider became defunct.
*
* We use dts_speculates to determine (a) and call a function
* (dtrace_buffer_consumed()) to determine (b) and (c). Note
* that as soon as we've been unable to destroy one of the ECBs
* associated with the probe, we quit trying -- reaping is only
* fruitful in as much as we can destroy all ECBs associated
* with the defunct provider's probes.
*/
while ((ecb = probe->dtpr_ecb) != NULL) {
dtrace_state_t *state = ecb->dte_state;
dtrace_buffer_t *buf = state->dts_buffer;
dtrace_buffer_t *aggbuf = state->dts_aggbuffer;
if (state->dts_speculates)
break;
if (!dtrace_buffer_consumed(buf, when))
break;
if (!dtrace_buffer_consumed(aggbuf, when))
break;
dtrace_ecb_disable(ecb);
ASSERT(probe->dtpr_ecb != ecb);
dtrace_ecb_destroy(ecb);
}
}
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
}
/*
* DTrace DOF Functions
*/
/*ARGSUSED*/
static void
dtrace_dof_error(dof_hdr_t *dof, const char *str)
{
if (dtrace_err_verbose)
cmn_err(CE_WARN, "failed to process DOF: %s", str);
#ifdef DTRACE_ERRDEBUG
dtrace_errdebug(str);
#endif
}
/*
* Create DOF out of a currently enabled state. Right now, we only create
* DOF containing the run-time options -- but this could be expanded to create
* complete DOF representing the enabled state.
*/
static dof_hdr_t *
dtrace_dof_create(dtrace_state_t *state)
{
dof_hdr_t *dof;
dof_sec_t *sec;
dof_optdesc_t *opt;
int i, len = sizeof (dof_hdr_t) +
roundup(sizeof (dof_sec_t), sizeof (uint64_t)) +
sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
ASSERT(MUTEX_HELD(&dtrace_lock));
dof = kmem_zalloc(len, KM_SLEEP);
dof->dofh_ident[DOF_ID_MAG0] = DOF_MAG_MAG0;
dof->dofh_ident[DOF_ID_MAG1] = DOF_MAG_MAG1;
dof->dofh_ident[DOF_ID_MAG2] = DOF_MAG_MAG2;
dof->dofh_ident[DOF_ID_MAG3] = DOF_MAG_MAG3;
dof->dofh_ident[DOF_ID_MODEL] = DOF_MODEL_NATIVE;
dof->dofh_ident[DOF_ID_ENCODING] = DOF_ENCODE_NATIVE;
dof->dofh_ident[DOF_ID_VERSION] = DOF_VERSION;
dof->dofh_ident[DOF_ID_DIFVERS] = DIF_VERSION;
dof->dofh_ident[DOF_ID_DIFIREG] = DIF_DIR_NREGS;
dof->dofh_ident[DOF_ID_DIFTREG] = DIF_DTR_NREGS;
dof->dofh_flags = 0;
dof->dofh_hdrsize = sizeof (dof_hdr_t);
dof->dofh_secsize = sizeof (dof_sec_t);
dof->dofh_secnum = 1; /* only DOF_SECT_OPTDESC */
dof->dofh_secoff = sizeof (dof_hdr_t);
dof->dofh_loadsz = len;
dof->dofh_filesz = len;
dof->dofh_pad = 0;
/*
* Fill in the option section header...
*/
sec = (dof_sec_t *)((uintptr_t)dof + sizeof (dof_hdr_t));
sec->dofs_type = DOF_SECT_OPTDESC;
sec->dofs_align = sizeof (uint64_t);
sec->dofs_flags = DOF_SECF_LOAD;
sec->dofs_entsize = sizeof (dof_optdesc_t);
opt = (dof_optdesc_t *)((uintptr_t)sec +
roundup(sizeof (dof_sec_t), sizeof (uint64_t)));
sec->dofs_offset = (uintptr_t)opt - (uintptr_t)dof;
sec->dofs_size = sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
for (i = 0; i < DTRACEOPT_MAX; i++) {
opt[i].dofo_option = i;
opt[i].dofo_strtab = DOF_SECIDX_NONE;
opt[i].dofo_value = state->dts_options[i];
}
return (dof);
}
static dof_hdr_t *
dtrace_dof_copyin(uintptr_t uarg, int *errp)
{
dof_hdr_t hdr, *dof;
ASSERT(!MUTEX_HELD(&dtrace_lock));
/*
* First, we're going to copyin() the sizeof (dof_hdr_t).
*/
if (copyin((void *)uarg, &hdr, sizeof (hdr)) != 0) {
dtrace_dof_error(NULL, "failed to copyin DOF header");
*errp = EFAULT;
return (NULL);
}
/*
* Now we'll allocate the entire DOF and copy it in -- provided
* that the length isn't outrageous.
*/
if (hdr.dofh_loadsz >= dtrace_dof_maxsize) {
dtrace_dof_error(&hdr, "load size exceeds maximum");
*errp = E2BIG;
return (NULL);
}
if (hdr.dofh_loadsz < sizeof (hdr)) {
dtrace_dof_error(&hdr, "invalid load size");
*errp = EINVAL;
return (NULL);
}
dof = kmem_alloc(hdr.dofh_loadsz, KM_SLEEP);
if (copyin((void *)uarg, dof, hdr.dofh_loadsz) != 0 ||
dof->dofh_loadsz != hdr.dofh_loadsz) {
kmem_free(dof, hdr.dofh_loadsz);
*errp = EFAULT;
return (NULL);
}
return (dof);
}
#ifdef __FreeBSD__
static dof_hdr_t *
dtrace_dof_copyin_proc(struct proc *p, uintptr_t uarg, int *errp)
{
dof_hdr_t hdr, *dof;
struct thread *td;
size_t loadsz;
ASSERT(!MUTEX_HELD(&dtrace_lock));
td = curthread;
/*
* First, we're going to copyin() the sizeof (dof_hdr_t).
*/
if (proc_readmem(td, p, uarg, &hdr, sizeof(hdr)) != sizeof(hdr)) {
dtrace_dof_error(NULL, "failed to copyin DOF header");
*errp = EFAULT;
return (NULL);
}
/*
* Now we'll allocate the entire DOF and copy it in -- provided
* that the length isn't outrageous.
*/
if (hdr.dofh_loadsz >= dtrace_dof_maxsize) {
dtrace_dof_error(&hdr, "load size exceeds maximum");
*errp = E2BIG;
return (NULL);
}
loadsz = (size_t)hdr.dofh_loadsz;
if (loadsz < sizeof (hdr)) {
dtrace_dof_error(&hdr, "invalid load size");
*errp = EINVAL;
return (NULL);
}
dof = kmem_alloc(loadsz, KM_SLEEP);
if (proc_readmem(td, p, uarg, dof, loadsz) != loadsz ||
dof->dofh_loadsz != loadsz) {
kmem_free(dof, hdr.dofh_loadsz);
*errp = EFAULT;
return (NULL);
}
return (dof);
}
static __inline uchar_t
dtrace_dof_char(char c)
{
switch (c) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return (c - '0');
case 'A':
case 'B':
case 'C':
case 'D':
case 'E':
case 'F':
return (c - 'A' + 10);
case 'a':
case 'b':
case 'c':
case 'd':
case 'e':
case 'f':
return (c - 'a' + 10);
}
/* Should not reach here. */
return (UCHAR_MAX);
}
#endif /* __FreeBSD__ */
static dof_hdr_t *
dtrace_dof_property(const char *name)
{
#ifdef __FreeBSD__
uint8_t *dofbuf;
u_char *data, *eol;
caddr_t doffile;
size_t bytes, len, i;
dof_hdr_t *dof;
u_char c1, c2;
dof = NULL;
doffile = preload_search_by_type("dtrace_dof");
if (doffile == NULL)
return (NULL);
data = preload_fetch_addr(doffile);
len = preload_fetch_size(doffile);
for (;;) {
/* Look for the end of the line. All lines end in a newline. */
eol = memchr(data, '\n', len);
if (eol == NULL)
return (NULL);
if (strncmp(name, data, strlen(name)) == 0)
break;
eol++; /* skip past the newline */
len -= eol - data;
data = eol;
}
/* We've found the data corresponding to the specified key. */
data += strlen(name) + 1; /* skip past the '=' */
len = eol - data;
bytes = len / 2;
if (bytes < sizeof(dof_hdr_t)) {
dtrace_dof_error(NULL, "truncated header");
goto doferr;
}
/*
* Each byte is represented by the two ASCII characters in its hex
* representation.
*/
dofbuf = malloc(bytes, M_SOLARIS, M_WAITOK);
for (i = 0; i < bytes; i++) {
c1 = dtrace_dof_char(data[i * 2]);
c2 = dtrace_dof_char(data[i * 2 + 1]);
if (c1 == UCHAR_MAX || c2 == UCHAR_MAX) {
dtrace_dof_error(NULL, "invalid hex char in DOF");
goto doferr;
}
dofbuf[i] = c1 * 16 + c2;
}
dof = (dof_hdr_t *)dofbuf;
if (bytes < dof->dofh_loadsz) {
dtrace_dof_error(NULL, "truncated DOF");
goto doferr;
}
if (dof->dofh_loadsz >= dtrace_dof_maxsize) {
dtrace_dof_error(NULL, "oversized DOF");
goto doferr;
}
return (dof);
doferr:
free(dof, M_SOLARIS);
return (NULL);
#else /* __FreeBSD__ */
uchar_t *buf;
uint64_t loadsz;
unsigned int len, i;
dof_hdr_t *dof;
/*
* Unfortunately, array of values in .conf files are always (and
* only) interpreted to be integer arrays. We must read our DOF
* as an integer array, and then squeeze it into a byte array.
*/
if (ddi_prop_lookup_int_array(DDI_DEV_T_ANY, dtrace_devi, 0,
(char *)name, (int **)&buf, &len) != DDI_PROP_SUCCESS)
return (NULL);
for (i = 0; i < len; i++)
buf[i] = (uchar_t)(((int *)buf)[i]);
if (len < sizeof (dof_hdr_t)) {
ddi_prop_free(buf);
dtrace_dof_error(NULL, "truncated header");
return (NULL);
}
if (len < (loadsz = ((dof_hdr_t *)buf)->dofh_loadsz)) {
ddi_prop_free(buf);
dtrace_dof_error(NULL, "truncated DOF");
return (NULL);
}
if (loadsz >= dtrace_dof_maxsize) {
ddi_prop_free(buf);
dtrace_dof_error(NULL, "oversized DOF");
return (NULL);
}
dof = kmem_alloc(loadsz, KM_SLEEP);
bcopy(buf, dof, loadsz);
ddi_prop_free(buf);
return (dof);
#endif /* !__FreeBSD__ */
}
static void
dtrace_dof_destroy(dof_hdr_t *dof)
{
kmem_free(dof, dof->dofh_loadsz);
}
/*
* Return the dof_sec_t pointer corresponding to a given section index. If the
* index is not valid, dtrace_dof_error() is called and NULL is returned. If
* a type other than DOF_SECT_NONE is specified, the header is checked against
* this type and NULL is returned if the types do not match.
*/
static dof_sec_t *
dtrace_dof_sect(dof_hdr_t *dof, uint32_t type, dof_secidx_t i)
{
dof_sec_t *sec = (dof_sec_t *)(uintptr_t)
((uintptr_t)dof + dof->dofh_secoff + i * dof->dofh_secsize);
if (i >= dof->dofh_secnum) {
dtrace_dof_error(dof, "referenced section index is invalid");
return (NULL);
}
if (!(sec->dofs_flags & DOF_SECF_LOAD)) {
dtrace_dof_error(dof, "referenced section is not loadable");
return (NULL);
}
if (type != DOF_SECT_NONE && type != sec->dofs_type) {
dtrace_dof_error(dof, "referenced section is the wrong type");
return (NULL);
}
return (sec);
}
static dtrace_probedesc_t *
dtrace_dof_probedesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_probedesc_t *desc)
{
dof_probedesc_t *probe;
dof_sec_t *strtab;
uintptr_t daddr = (uintptr_t)dof;
uintptr_t str;
size_t size;
if (sec->dofs_type != DOF_SECT_PROBEDESC) {
dtrace_dof_error(dof, "invalid probe section");
return (NULL);
}
if (sec->dofs_align != sizeof (dof_secidx_t)) {
dtrace_dof_error(dof, "bad alignment in probe description");
return (NULL);
}
if (sec->dofs_offset + sizeof (dof_probedesc_t) > dof->dofh_loadsz) {
dtrace_dof_error(dof, "truncated probe description");
return (NULL);
}
probe = (dof_probedesc_t *)(uintptr_t)(daddr + sec->dofs_offset);
strtab = dtrace_dof_sect(dof, DOF_SECT_STRTAB, probe->dofp_strtab);
if (strtab == NULL)
return (NULL);
str = daddr + strtab->dofs_offset;
size = strtab->dofs_size;
if (probe->dofp_provider >= strtab->dofs_size) {
dtrace_dof_error(dof, "corrupt probe provider");
return (NULL);
}
(void) strncpy(desc->dtpd_provider,
(char *)(str + probe->dofp_provider),
MIN(DTRACE_PROVNAMELEN - 1, size - probe->dofp_provider));
if (probe->dofp_mod >= strtab->dofs_size) {
dtrace_dof_error(dof, "corrupt probe module");
return (NULL);
}
(void) strncpy(desc->dtpd_mod, (char *)(str + probe->dofp_mod),
MIN(DTRACE_MODNAMELEN - 1, size - probe->dofp_mod));
if (probe->dofp_func >= strtab->dofs_size) {
dtrace_dof_error(dof, "corrupt probe function");
return (NULL);
}
(void) strncpy(desc->dtpd_func, (char *)(str + probe->dofp_func),
MIN(DTRACE_FUNCNAMELEN - 1, size - probe->dofp_func));
if (probe->dofp_name >= strtab->dofs_size) {
dtrace_dof_error(dof, "corrupt probe name");
return (NULL);
}
(void) strncpy(desc->dtpd_name, (char *)(str + probe->dofp_name),
MIN(DTRACE_NAMELEN - 1, size - probe->dofp_name));
return (desc);
}
static dtrace_difo_t *
dtrace_dof_difo(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
cred_t *cr)
{
dtrace_difo_t *dp;
size_t ttl = 0;
dof_difohdr_t *dofd;
uintptr_t daddr = (uintptr_t)dof;
size_t max = dtrace_difo_maxsize;
int i, l, n;
static const struct {
int section;
int bufoffs;
int lenoffs;
int entsize;
int align;
const char *msg;
} difo[] = {
{ DOF_SECT_DIF, offsetof(dtrace_difo_t, dtdo_buf),
offsetof(dtrace_difo_t, dtdo_len), sizeof (dif_instr_t),
sizeof (dif_instr_t), "multiple DIF sections" },
{ DOF_SECT_INTTAB, offsetof(dtrace_difo_t, dtdo_inttab),
offsetof(dtrace_difo_t, dtdo_intlen), sizeof (uint64_t),
sizeof (uint64_t), "multiple integer tables" },
{ DOF_SECT_STRTAB, offsetof(dtrace_difo_t, dtdo_strtab),
offsetof(dtrace_difo_t, dtdo_strlen), 0,
sizeof (char), "multiple string tables" },
{ DOF_SECT_VARTAB, offsetof(dtrace_difo_t, dtdo_vartab),
offsetof(dtrace_difo_t, dtdo_varlen), sizeof (dtrace_difv_t),
sizeof (uint_t), "multiple variable tables" },
{ DOF_SECT_NONE, 0, 0, 0, 0, NULL }
};
if (sec->dofs_type != DOF_SECT_DIFOHDR) {
dtrace_dof_error(dof, "invalid DIFO header section");
return (NULL);
}
if (sec->dofs_align != sizeof (dof_secidx_t)) {
dtrace_dof_error(dof, "bad alignment in DIFO header");
return (NULL);
}
if (sec->dofs_size < sizeof (dof_difohdr_t) ||
sec->dofs_size % sizeof (dof_secidx_t)) {
dtrace_dof_error(dof, "bad size in DIFO header");
return (NULL);
}
dofd = (dof_difohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
n = (sec->dofs_size - sizeof (*dofd)) / sizeof (dof_secidx_t) + 1;
dp = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
dp->dtdo_rtype = dofd->dofd_rtype;
for (l = 0; l < n; l++) {
dof_sec_t *subsec;
void **bufp;
uint32_t *lenp;
if ((subsec = dtrace_dof_sect(dof, DOF_SECT_NONE,
dofd->dofd_links[l])) == NULL)
goto err; /* invalid section link */
if (ttl + subsec->dofs_size > max) {
dtrace_dof_error(dof, "exceeds maximum size");
goto err;
}
ttl += subsec->dofs_size;
for (i = 0; difo[i].section != DOF_SECT_NONE; i++) {
if (subsec->dofs_type != difo[i].section)
continue;
if (!(subsec->dofs_flags & DOF_SECF_LOAD)) {
dtrace_dof_error(dof, "section not loaded");
goto err;
}
if (subsec->dofs_align != difo[i].align) {
dtrace_dof_error(dof, "bad alignment");
goto err;
}
bufp = (void **)((uintptr_t)dp + difo[i].bufoffs);
lenp = (uint32_t *)((uintptr_t)dp + difo[i].lenoffs);
if (*bufp != NULL) {
dtrace_dof_error(dof, difo[i].msg);
goto err;
}
if (difo[i].entsize != subsec->dofs_entsize) {
dtrace_dof_error(dof, "entry size mismatch");
goto err;
}
if (subsec->dofs_entsize != 0 &&
(subsec->dofs_size % subsec->dofs_entsize) != 0) {
dtrace_dof_error(dof, "corrupt entry size");
goto err;
}
*lenp = subsec->dofs_size;
*bufp = kmem_alloc(subsec->dofs_size, KM_SLEEP);
bcopy((char *)(uintptr_t)(daddr + subsec->dofs_offset),
*bufp, subsec->dofs_size);
if (subsec->dofs_entsize != 0)
*lenp /= subsec->dofs_entsize;
break;
}
/*
* If we encounter a loadable DIFO sub-section that is not
* known to us, assume this is a broken program and fail.
*/
if (difo[i].section == DOF_SECT_NONE &&
(subsec->dofs_flags & DOF_SECF_LOAD)) {
dtrace_dof_error(dof, "unrecognized DIFO subsection");
goto err;
}
}
if (dp->dtdo_buf == NULL) {
/*
* We can't have a DIF object without DIF text.
*/
dtrace_dof_error(dof, "missing DIF text");
goto err;
}
/*
* Before we validate the DIF object, run through the variable table
* looking for the strings -- if any of their size are under, we'll set
* their size to be the system-wide default string size. Note that
* this should _not_ happen if the "strsize" option has been set --
* in this case, the compiler should have set the size to reflect the
* setting of the option.
*/
for (i = 0; i < dp->dtdo_varlen; i++) {
dtrace_difv_t *v = &dp->dtdo_vartab[i];
dtrace_diftype_t *t = &v->dtdv_type;
if (v->dtdv_id < DIF_VAR_OTHER_UBASE)
continue;
if (t->dtdt_kind == DIF_TYPE_STRING && t->dtdt_size == 0)
t->dtdt_size = dtrace_strsize_default;
}
if (dtrace_difo_validate(dp, vstate, DIF_DIR_NREGS, cr) != 0)
goto err;
dtrace_difo_init(dp, vstate);
return (dp);
err:
kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
kmem_free(dp, sizeof (dtrace_difo_t));
return (NULL);
}
static dtrace_predicate_t *
dtrace_dof_predicate(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
cred_t *cr)
{
dtrace_difo_t *dp;
if ((dp = dtrace_dof_difo(dof, sec, vstate, cr)) == NULL)
return (NULL);
return (dtrace_predicate_create(dp));
}
static dtrace_actdesc_t *
dtrace_dof_actdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
cred_t *cr)
{
dtrace_actdesc_t *act, *first = NULL, *last = NULL, *next;
dof_actdesc_t *desc;
dof_sec_t *difosec;
size_t offs;
uintptr_t daddr = (uintptr_t)dof;
uint64_t arg;
dtrace_actkind_t kind;
if (sec->dofs_type != DOF_SECT_ACTDESC) {
dtrace_dof_error(dof, "invalid action section");
return (NULL);
}
if (sec->dofs_offset + sizeof (dof_actdesc_t) > dof->dofh_loadsz) {
dtrace_dof_error(dof, "truncated action description");
return (NULL);
}
if (sec->dofs_align != sizeof (uint64_t)) {
dtrace_dof_error(dof, "bad alignment in action description");
return (NULL);
}
if (sec->dofs_size < sec->dofs_entsize) {
dtrace_dof_error(dof, "section entry size exceeds total size");
return (NULL);
}
if (sec->dofs_entsize != sizeof (dof_actdesc_t)) {
dtrace_dof_error(dof, "bad entry size in action description");
return (NULL);
}
if (sec->dofs_size / sec->dofs_entsize > dtrace_actions_max) {
dtrace_dof_error(dof, "actions exceed dtrace_actions_max");
return (NULL);
}
for (offs = 0; offs < sec->dofs_size; offs += sec->dofs_entsize) {
desc = (dof_actdesc_t *)(daddr +
(uintptr_t)sec->dofs_offset + offs);
kind = (dtrace_actkind_t)desc->dofa_kind;
if ((DTRACEACT_ISPRINTFLIKE(kind) &&
(kind != DTRACEACT_PRINTA ||
desc->dofa_strtab != DOF_SECIDX_NONE)) ||
(kind == DTRACEACT_DIFEXPR &&
desc->dofa_strtab != DOF_SECIDX_NONE)) {
dof_sec_t *strtab;
char *str, *fmt;
uint64_t i;
/*
* The argument to these actions is an index into the
* DOF string table. For printf()-like actions, this
* is the format string. For print(), this is the
* CTF type of the expression result.
*/
if ((strtab = dtrace_dof_sect(dof,
DOF_SECT_STRTAB, desc->dofa_strtab)) == NULL)
goto err;
str = (char *)((uintptr_t)dof +
(uintptr_t)strtab->dofs_offset);
for (i = desc->dofa_arg; i < strtab->dofs_size; i++) {
if (str[i] == '\0')
break;
}
if (i >= strtab->dofs_size) {
dtrace_dof_error(dof, "bogus format string");
goto err;
}
if (i == desc->dofa_arg) {
dtrace_dof_error(dof, "empty format string");
goto err;
}
i -= desc->dofa_arg;
fmt = kmem_alloc(i + 1, KM_SLEEP);
bcopy(&str[desc->dofa_arg], fmt, i + 1);
arg = (uint64_t)(uintptr_t)fmt;
} else {
if (kind == DTRACEACT_PRINTA) {
ASSERT(desc->dofa_strtab == DOF_SECIDX_NONE);
arg = 0;
} else {
arg = desc->dofa_arg;
}
}
act = dtrace_actdesc_create(kind, desc->dofa_ntuple,
desc->dofa_uarg, arg);
if (last != NULL) {
last->dtad_next = act;
} else {
first = act;
}
last = act;
if (desc->dofa_difo == DOF_SECIDX_NONE)
continue;
if ((difosec = dtrace_dof_sect(dof,
DOF_SECT_DIFOHDR, desc->dofa_difo)) == NULL)
goto err;
act->dtad_difo = dtrace_dof_difo(dof, difosec, vstate, cr);
if (act->dtad_difo == NULL)
goto err;
}
ASSERT(first != NULL);
return (first);
err:
for (act = first; act != NULL; act = next) {
next = act->dtad_next;
dtrace_actdesc_release(act, vstate);
}
return (NULL);
}
static dtrace_ecbdesc_t *
dtrace_dof_ecbdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
cred_t *cr)
{
dtrace_ecbdesc_t *ep;
dof_ecbdesc_t *ecb;
dtrace_probedesc_t *desc;
dtrace_predicate_t *pred = NULL;
if (sec->dofs_size < sizeof (dof_ecbdesc_t)) {
dtrace_dof_error(dof, "truncated ECB description");
return (NULL);
}
if (sec->dofs_align != sizeof (uint64_t)) {
dtrace_dof_error(dof, "bad alignment in ECB description");
return (NULL);
}
ecb = (dof_ecbdesc_t *)((uintptr_t)dof + (uintptr_t)sec->dofs_offset);
sec = dtrace_dof_sect(dof, DOF_SECT_PROBEDESC, ecb->dofe_probes);
if (sec == NULL)
return (NULL);
ep = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
ep->dted_uarg = ecb->dofe_uarg;
desc = &ep->dted_probe;
if (dtrace_dof_probedesc(dof, sec, desc) == NULL)
goto err;
if (ecb->dofe_pred != DOF_SECIDX_NONE) {
if ((sec = dtrace_dof_sect(dof,
DOF_SECT_DIFOHDR, ecb->dofe_pred)) == NULL)
goto err;
if ((pred = dtrace_dof_predicate(dof, sec, vstate, cr)) == NULL)
goto err;
ep->dted_pred.dtpdd_predicate = pred;
}
if (ecb->dofe_actions != DOF_SECIDX_NONE) {
if ((sec = dtrace_dof_sect(dof,
DOF_SECT_ACTDESC, ecb->dofe_actions)) == NULL)
goto err;
ep->dted_action = dtrace_dof_actdesc(dof, sec, vstate, cr);
if (ep->dted_action == NULL)
goto err;
}
return (ep);
err:
if (pred != NULL)
dtrace_predicate_release(pred, vstate);
kmem_free(ep, sizeof (dtrace_ecbdesc_t));
return (NULL);
}
/*
* Apply the relocations from the specified 'sec' (a DOF_SECT_URELHDR) to the
* specified DOF. At present, this amounts to simply adding 'ubase' to the
* site of any user SETX relocations to account for load object base address.
* In the future, if we need other relocations, this function can be extended.
*/
static int
dtrace_dof_relocate(dof_hdr_t *dof, dof_sec_t *sec, uint64_t ubase)
{
uintptr_t daddr = (uintptr_t)dof;
dof_relohdr_t *dofr =
(dof_relohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
dof_sec_t *ss, *rs, *ts;
dof_relodesc_t *r;
uint_t i, n;
if (sec->dofs_size < sizeof (dof_relohdr_t) ||
sec->dofs_align != sizeof (dof_secidx_t)) {
dtrace_dof_error(dof, "invalid relocation header");
return (-1);
}
ss = dtrace_dof_sect(dof, DOF_SECT_STRTAB, dofr->dofr_strtab);
rs = dtrace_dof_sect(dof, DOF_SECT_RELTAB, dofr->dofr_relsec);
ts = dtrace_dof_sect(dof, DOF_SECT_NONE, dofr->dofr_tgtsec);
if (ss == NULL || rs == NULL || ts == NULL)
return (-1); /* dtrace_dof_error() has been called already */
if (rs->dofs_entsize < sizeof (dof_relodesc_t) ||
rs->dofs_align != sizeof (uint64_t)) {
dtrace_dof_error(dof, "invalid relocation section");
return (-1);
}
r = (dof_relodesc_t *)(uintptr_t)(daddr + rs->dofs_offset);
n = rs->dofs_size / rs->dofs_entsize;
for (i = 0; i < n; i++) {
uintptr_t taddr = daddr + ts->dofs_offset + r->dofr_offset;
switch (r->dofr_type) {
case DOF_RELO_NONE:
break;
case DOF_RELO_SETX:
if (r->dofr_offset >= ts->dofs_size || r->dofr_offset +
sizeof (uint64_t) > ts->dofs_size) {
dtrace_dof_error(dof, "bad relocation offset");
return (-1);
}
if (!IS_P2ALIGNED(taddr, sizeof (uint64_t))) {
dtrace_dof_error(dof, "misaligned setx relo");
return (-1);
}
*(uint64_t *)taddr += ubase;
break;
default:
dtrace_dof_error(dof, "invalid relocation type");
return (-1);
}
r = (dof_relodesc_t *)((uintptr_t)r + rs->dofs_entsize);
}
return (0);
}
/*
* The dof_hdr_t passed to dtrace_dof_slurp() should be a partially validated
* header: it should be at the front of a memory region that is at least
* sizeof (dof_hdr_t) in size -- and then at least dof_hdr.dofh_loadsz in
* size. It need not be validated in any other way.
*/
static int
dtrace_dof_slurp(dof_hdr_t *dof, dtrace_vstate_t *vstate, cred_t *cr,
dtrace_enabling_t **enabp, uint64_t ubase, int noprobes)
{
uint64_t len = dof->dofh_loadsz, seclen;
uintptr_t daddr = (uintptr_t)dof;
dtrace_ecbdesc_t *ep;
dtrace_enabling_t *enab;
uint_t i;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dof->dofh_loadsz >= sizeof (dof_hdr_t));
/*
* Check the DOF header identification bytes. In addition to checking
* valid settings, we also verify that unused bits/bytes are zeroed so
* we can use them later without fear of regressing existing binaries.
*/
if (bcmp(&dof->dofh_ident[DOF_ID_MAG0],
DOF_MAG_STRING, DOF_MAG_STRLEN) != 0) {
dtrace_dof_error(dof, "DOF magic string mismatch");
return (-1);
}
if (dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_ILP32 &&
dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_LP64) {
dtrace_dof_error(dof, "DOF has invalid data model");
return (-1);
}
if (dof->dofh_ident[DOF_ID_ENCODING] != DOF_ENCODE_NATIVE) {
dtrace_dof_error(dof, "DOF encoding mismatch");
return (-1);
}
if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_2) {
dtrace_dof_error(dof, "DOF version mismatch");
return (-1);
}
if (dof->dofh_ident[DOF_ID_DIFVERS] != DIF_VERSION_2) {
dtrace_dof_error(dof, "DOF uses unsupported instruction set");
return (-1);
}
if (dof->dofh_ident[DOF_ID_DIFIREG] > DIF_DIR_NREGS) {
dtrace_dof_error(dof, "DOF uses too many integer registers");
return (-1);
}
if (dof->dofh_ident[DOF_ID_DIFTREG] > DIF_DTR_NREGS) {
dtrace_dof_error(dof, "DOF uses too many tuple registers");
return (-1);
}
for (i = DOF_ID_PAD; i < DOF_ID_SIZE; i++) {
if (dof->dofh_ident[i] != 0) {
dtrace_dof_error(dof, "DOF has invalid ident byte set");
return (-1);
}
}
if (dof->dofh_flags & ~DOF_FL_VALID) {
dtrace_dof_error(dof, "DOF has invalid flag bits set");
return (-1);
}
if (dof->dofh_secsize == 0) {
dtrace_dof_error(dof, "zero section header size");
return (-1);
}
/*
* Check that the section headers don't exceed the amount of DOF
* data. Note that we cast the section size and number of sections
* to uint64_t's to prevent possible overflow in the multiplication.
*/
seclen = (uint64_t)dof->dofh_secnum * (uint64_t)dof->dofh_secsize;
if (dof->dofh_secoff > len || seclen > len ||
dof->dofh_secoff + seclen > len) {
dtrace_dof_error(dof, "truncated section headers");
return (-1);
}
if (!IS_P2ALIGNED(dof->dofh_secoff, sizeof (uint64_t))) {
dtrace_dof_error(dof, "misaligned section headers");
return (-1);
}
if (!IS_P2ALIGNED(dof->dofh_secsize, sizeof (uint64_t))) {
dtrace_dof_error(dof, "misaligned section size");
return (-1);
}
/*
* Take an initial pass through the section headers to be sure that
* the headers don't have stray offsets. If the 'noprobes' flag is
* set, do not permit sections relating to providers, probes, or args.
*/
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)(daddr +
(uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
if (noprobes) {
switch (sec->dofs_type) {
case DOF_SECT_PROVIDER:
case DOF_SECT_PROBES:
case DOF_SECT_PRARGS:
case DOF_SECT_PROFFS:
dtrace_dof_error(dof, "illegal sections "
"for enabling");
return (-1);
}
}
if (DOF_SEC_ISLOADABLE(sec->dofs_type) &&
!(sec->dofs_flags & DOF_SECF_LOAD)) {
dtrace_dof_error(dof, "loadable section with load "
"flag unset");
return (-1);
}
if (!(sec->dofs_flags & DOF_SECF_LOAD))
continue; /* just ignore non-loadable sections */
if (!ISP2(sec->dofs_align)) {
dtrace_dof_error(dof, "bad section alignment");
return (-1);
}
if (sec->dofs_offset & (sec->dofs_align - 1)) {
dtrace_dof_error(dof, "misaligned section");
return (-1);
}
if (sec->dofs_offset > len || sec->dofs_size > len ||
sec->dofs_offset + sec->dofs_size > len) {
dtrace_dof_error(dof, "corrupt section header");
return (-1);
}
if (sec->dofs_type == DOF_SECT_STRTAB && *((char *)daddr +
sec->dofs_offset + sec->dofs_size - 1) != '\0') {
dtrace_dof_error(dof, "non-terminating string table");
return (-1);
}
}
/*
* Take a second pass through the sections and locate and perform any
* relocations that are present. We do this after the first pass to
* be sure that all sections have had their headers validated.
*/
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)(daddr +
(uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
if (!(sec->dofs_flags & DOF_SECF_LOAD))
continue; /* skip sections that are not loadable */
switch (sec->dofs_type) {
case DOF_SECT_URELHDR:
if (dtrace_dof_relocate(dof, sec, ubase) != 0)
return (-1);
break;
}
}
if ((enab = *enabp) == NULL)
enab = *enabp = dtrace_enabling_create(vstate);
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)(daddr +
(uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
if (sec->dofs_type != DOF_SECT_ECBDESC)
continue;
if ((ep = dtrace_dof_ecbdesc(dof, sec, vstate, cr)) == NULL) {
dtrace_enabling_destroy(enab);
*enabp = NULL;
return (-1);
}
dtrace_enabling_add(enab, ep);
}
return (0);
}
/*
* Process DOF for any options. This routine assumes that the DOF has been
* at least processed by dtrace_dof_slurp().
*/
static int
dtrace_dof_options(dof_hdr_t *dof, dtrace_state_t *state)
{
int i, rval;
uint32_t entsize;
size_t offs;
dof_optdesc_t *desc;
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)((uintptr_t)dof +
(uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
if (sec->dofs_type != DOF_SECT_OPTDESC)
continue;
if (sec->dofs_align != sizeof (uint64_t)) {
dtrace_dof_error(dof, "bad alignment in "
"option description");
return (EINVAL);
}
if ((entsize = sec->dofs_entsize) == 0) {
dtrace_dof_error(dof, "zeroed option entry size");
return (EINVAL);
}
if (entsize < sizeof (dof_optdesc_t)) {
dtrace_dof_error(dof, "bad option entry size");
return (EINVAL);
}
for (offs = 0; offs < sec->dofs_size; offs += entsize) {
desc = (dof_optdesc_t *)((uintptr_t)dof +
(uintptr_t)sec->dofs_offset + offs);
if (desc->dofo_strtab != DOF_SECIDX_NONE) {
dtrace_dof_error(dof, "non-zero option string");
return (EINVAL);
}
if (desc->dofo_value == DTRACEOPT_UNSET) {
dtrace_dof_error(dof, "unset option");
return (EINVAL);
}
if ((rval = dtrace_state_option(state,
desc->dofo_option, desc->dofo_value)) != 0) {
dtrace_dof_error(dof, "rejected option");
return (rval);
}
}
}
return (0);
}
/*
* DTrace Consumer State Functions
*/
static int
dtrace_dstate_init(dtrace_dstate_t *dstate, size_t size)
{
size_t hashsize, maxper, min, chunksize = dstate->dtds_chunksize;
void *base;
uintptr_t limit;
dtrace_dynvar_t *dvar, *next, *start;
int i;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(dstate->dtds_base == NULL && dstate->dtds_percpu == NULL);
bzero(dstate, sizeof (dtrace_dstate_t));
if ((dstate->dtds_chunksize = chunksize) == 0)
dstate->dtds_chunksize = DTRACE_DYNVAR_CHUNKSIZE;
VERIFY(dstate->dtds_chunksize < LONG_MAX);
if (size < (min = dstate->dtds_chunksize + sizeof (dtrace_dynhash_t)))
size = min;
if ((base = kmem_zalloc(size, KM_NOSLEEP | KM_NORMALPRI)) == NULL)
return (ENOMEM);
dstate->dtds_size = size;
dstate->dtds_base = base;
dstate->dtds_percpu = kmem_cache_alloc(dtrace_state_cache, KM_SLEEP);
bzero(dstate->dtds_percpu, NCPU * sizeof (dtrace_dstate_percpu_t));
hashsize = size / (dstate->dtds_chunksize + sizeof (dtrace_dynhash_t));
if (hashsize != 1 && (hashsize & 1))
hashsize--;
dstate->dtds_hashsize = hashsize;
dstate->dtds_hash = dstate->dtds_base;
/*
* Set all of our hash buckets to point to the single sink, and (if
* it hasn't already been set), set the sink's hash value to be the
* sink sentinel value. The sink is needed for dynamic variable
* lookups to know that they have iterated over an entire, valid hash
* chain.
*/
for (i = 0; i < hashsize; i++)
dstate->dtds_hash[i].dtdh_chain = &dtrace_dynhash_sink;
if (dtrace_dynhash_sink.dtdv_hashval != DTRACE_DYNHASH_SINK)
dtrace_dynhash_sink.dtdv_hashval = DTRACE_DYNHASH_SINK;
/*
* Determine number of active CPUs. Divide free list evenly among
* active CPUs.
*/
start = (dtrace_dynvar_t *)
((uintptr_t)base + hashsize * sizeof (dtrace_dynhash_t));
limit = (uintptr_t)base + size;
VERIFY((uintptr_t)start < limit);
VERIFY((uintptr_t)start >= (uintptr_t)base);
maxper = (limit - (uintptr_t)start) / NCPU;
maxper = (maxper / dstate->dtds_chunksize) * dstate->dtds_chunksize;
#ifndef illumos
CPU_FOREACH(i) {
#else
for (i = 0; i < NCPU; i++) {
#endif
dstate->dtds_percpu[i].dtdsc_free = dvar = start;
/*
* If we don't even have enough chunks to make it once through
* NCPUs, we're just going to allocate everything to the first
* CPU. And if we're on the last CPU, we're going to allocate
* whatever is left over. In either case, we set the limit to
* be the limit of the dynamic variable space.
*/
if (maxper == 0 || i == NCPU - 1) {
limit = (uintptr_t)base + size;
start = NULL;
} else {
limit = (uintptr_t)start + maxper;
start = (dtrace_dynvar_t *)limit;
}
VERIFY(limit <= (uintptr_t)base + size);
for (;;) {
next = (dtrace_dynvar_t *)((uintptr_t)dvar +
dstate->dtds_chunksize);
if ((uintptr_t)next + dstate->dtds_chunksize >= limit)
break;
VERIFY((uintptr_t)dvar >= (uintptr_t)base &&
(uintptr_t)dvar <= (uintptr_t)base + size);
dvar->dtdv_next = next;
dvar = next;
}
if (maxper == 0)
break;
}
return (0);
}
static void
dtrace_dstate_fini(dtrace_dstate_t *dstate)
{
ASSERT(MUTEX_HELD(&cpu_lock));
if (dstate->dtds_base == NULL)
return;
kmem_free(dstate->dtds_base, dstate->dtds_size);
kmem_cache_free(dtrace_state_cache, dstate->dtds_percpu);
}
static void
dtrace_vstate_fini(dtrace_vstate_t *vstate)
{
/*
* Logical XOR, where are you?
*/
ASSERT((vstate->dtvs_nglobals == 0) ^ (vstate->dtvs_globals != NULL));
if (vstate->dtvs_nglobals > 0) {
kmem_free(vstate->dtvs_globals, vstate->dtvs_nglobals *
sizeof (dtrace_statvar_t *));
}
if (vstate->dtvs_ntlocals > 0) {
kmem_free(vstate->dtvs_tlocals, vstate->dtvs_ntlocals *
sizeof (dtrace_difv_t));
}
ASSERT((vstate->dtvs_nlocals == 0) ^ (vstate->dtvs_locals != NULL));
if (vstate->dtvs_nlocals > 0) {
kmem_free(vstate->dtvs_locals, vstate->dtvs_nlocals *
sizeof (dtrace_statvar_t *));
}
}
#ifdef illumos
static void
dtrace_state_clean(dtrace_state_t *state)
{
if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE)
return;
dtrace_dynvar_clean(&state->dts_vstate.dtvs_dynvars);
dtrace_speculation_clean(state);
}
static void
dtrace_state_deadman(dtrace_state_t *state)
{
hrtime_t now;
dtrace_sync();
now = dtrace_gethrtime();
if (state != dtrace_anon.dta_state &&
now - state->dts_laststatus >= dtrace_deadman_user)
return;
/*
* We must be sure that dts_alive never appears to be less than the
* value upon entry to dtrace_state_deadman(), and because we lack a
* dtrace_cas64(), we cannot store to it atomically. We thus instead
* store INT64_MAX to it, followed by a memory barrier, followed by
* the new value. This assures that dts_alive never appears to be
* less than its true value, regardless of the order in which the
* stores to the underlying storage are issued.
*/
state->dts_alive = INT64_MAX;
dtrace_membar_producer();
state->dts_alive = now;
}
#else /* !illumos */
static void
dtrace_state_clean(void *arg)
{
dtrace_state_t *state = arg;
dtrace_optval_t *opt = state->dts_options;
if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE)
return;
dtrace_dynvar_clean(&state->dts_vstate.dtvs_dynvars);
dtrace_speculation_clean(state);
callout_reset(&state->dts_cleaner, hz * opt[DTRACEOPT_CLEANRATE] / NANOSEC,
dtrace_state_clean, state);
}
static void
dtrace_state_deadman(void *arg)
{
dtrace_state_t *state = arg;
hrtime_t now;
dtrace_sync();
dtrace_debug_output();
now = dtrace_gethrtime();
if (state != dtrace_anon.dta_state &&
now - state->dts_laststatus >= dtrace_deadman_user)
return;
/*
* We must be sure that dts_alive never appears to be less than the
* value upon entry to dtrace_state_deadman(), and because we lack a
* dtrace_cas64(), we cannot store to it atomically. We thus instead
* store INT64_MAX to it, followed by a memory barrier, followed by
* the new value. This assures that dts_alive never appears to be
* less than its true value, regardless of the order in which the
* stores to the underlying storage are issued.
*/
state->dts_alive = INT64_MAX;
dtrace_membar_producer();
state->dts_alive = now;
callout_reset(&state->dts_deadman, hz * dtrace_deadman_interval / NANOSEC,
dtrace_state_deadman, state);
}
#endif /* illumos */
static dtrace_state_t *
#ifdef illumos
dtrace_state_create(dev_t *devp, cred_t *cr)
#else
dtrace_state_create(struct cdev *dev, struct ucred *cred __unused)
#endif
{
#ifdef illumos
minor_t minor;
major_t major;
#else
cred_t *cr = NULL;
int m = 0;
#endif
char c[30];
dtrace_state_t *state;
dtrace_optval_t *opt;
int bufsize = NCPU * sizeof (dtrace_buffer_t), i;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(MUTEX_HELD(&cpu_lock));
#ifdef illumos
minor = (minor_t)(uintptr_t)vmem_alloc(dtrace_minor, 1,
VM_BESTFIT | VM_SLEEP);
if (ddi_soft_state_zalloc(dtrace_softstate, minor) != DDI_SUCCESS) {
vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
return (NULL);
}
state = ddi_get_soft_state(dtrace_softstate, minor);
#else
if (dev != NULL) {
cr = dev->si_cred;
m = dev2unit(dev);
}
/* Allocate memory for the state. */
state = kmem_zalloc(sizeof(dtrace_state_t), KM_SLEEP);
#endif
state->dts_epid = DTRACE_EPIDNONE + 1;
(void) snprintf(c, sizeof (c), "dtrace_aggid_%d", m);
#ifdef illumos
state->dts_aggid_arena = vmem_create(c, (void *)1, UINT32_MAX, 1,
NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
if (devp != NULL) {
major = getemajor(*devp);
} else {
major = ddi_driver_major(dtrace_devi);
}
state->dts_dev = makedevice(major, minor);
if (devp != NULL)
*devp = state->dts_dev;
#else
state->dts_aggid_arena = new_unrhdr(1, INT_MAX, &dtrace_unr_mtx);
state->dts_dev = dev;
#endif
/*
* We allocate NCPU buffers. On the one hand, this can be quite
* a bit of memory per instance (nearly 36K on a Starcat). On the
* other hand, it saves an additional memory reference in the probe
* path.
*/
state->dts_buffer = kmem_zalloc(bufsize, KM_SLEEP);
state->dts_aggbuffer = kmem_zalloc(bufsize, KM_SLEEP);
#ifdef illumos
state->dts_cleaner = CYCLIC_NONE;
state->dts_deadman = CYCLIC_NONE;
#else
callout_init(&state->dts_cleaner, 1);
callout_init(&state->dts_deadman, 1);
#endif
state->dts_vstate.dtvs_state = state;
for (i = 0; i < DTRACEOPT_MAX; i++)
state->dts_options[i] = DTRACEOPT_UNSET;
/*
* Set the default options.
*/
opt = state->dts_options;
opt[DTRACEOPT_BUFPOLICY] = DTRACEOPT_BUFPOLICY_SWITCH;
opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_AUTO;
opt[DTRACEOPT_NSPEC] = dtrace_nspec_default;
opt[DTRACEOPT_SPECSIZE] = dtrace_specsize_default;
opt[DTRACEOPT_CPU] = (dtrace_optval_t)DTRACE_CPUALL;
opt[DTRACEOPT_STRSIZE] = dtrace_strsize_default;
opt[DTRACEOPT_STACKFRAMES] = dtrace_stackframes_default;
opt[DTRACEOPT_USTACKFRAMES] = dtrace_ustackframes_default;
opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_default;
opt[DTRACEOPT_AGGRATE] = dtrace_aggrate_default;
opt[DTRACEOPT_SWITCHRATE] = dtrace_switchrate_default;
opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_default;
opt[DTRACEOPT_JSTACKFRAMES] = dtrace_jstackframes_default;
opt[DTRACEOPT_JSTACKSTRSIZE] = dtrace_jstackstrsize_default;
state->dts_activity = DTRACE_ACTIVITY_INACTIVE;
/*
* Depending on the user credentials, we set flag bits which alter probe
* visibility or the amount of destructiveness allowed. In the case of
* actual anonymous tracing, or the possession of all privileges, all of
* the normal checks are bypassed.
*/
if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
state->dts_cred.dcr_visible = DTRACE_CRV_ALL;
state->dts_cred.dcr_action = DTRACE_CRA_ALL;
} else {
/*
* Set up the credentials for this instantiation. We take a
* hold on the credential to prevent it from disappearing on
* us; this in turn prevents the zone_t referenced by this
* credential from disappearing. This means that we can
* examine the credential and the zone from probe context.
*/
crhold(cr);
state->dts_cred.dcr_cred = cr;
/*
* CRA_PROC means "we have *some* privilege for dtrace" and
* unlocks the use of variables like pid, zonename, etc.
*/
if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE) ||
PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
state->dts_cred.dcr_action |= DTRACE_CRA_PROC;
}
/*
* dtrace_user allows use of syscall and profile providers.
* If the user also has proc_owner and/or proc_zone, we
* extend the scope to include additional visibility and
* destructive power.
*/
if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE)) {
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE)) {
state->dts_cred.dcr_visible |=
DTRACE_CRV_ALLPROC;
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
}
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE)) {
state->dts_cred.dcr_visible |=
DTRACE_CRV_ALLZONE;
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
}
/*
* If we have all privs in whatever zone this is,
* we can do destructive things to processes which
* have altered credentials.
*/
#ifdef illumos
if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
cr->cr_zone->zone_privset)) {
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
}
#endif
}
/*
* Holding the dtrace_kernel privilege also implies that
* the user has the dtrace_user privilege from a visibility
* perspective. But without further privileges, some
* destructive actions are not available.
*/
if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE)) {
/*
* Make all probes in all zones visible. However,
* this doesn't mean that all actions become available
* to all zones.
*/
state->dts_cred.dcr_visible |= DTRACE_CRV_KERNEL |
DTRACE_CRV_ALLPROC | DTRACE_CRV_ALLZONE;
state->dts_cred.dcr_action |= DTRACE_CRA_KERNEL |
DTRACE_CRA_PROC;
/*
* Holding proc_owner means that destructive actions
* for *this* zone are allowed.
*/
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
/*
* Holding proc_zone means that destructive actions
* for this user/group ID in all zones is allowed.
*/
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
#ifdef illumos
/*
* If we have all privs in whatever zone this is,
* we can do destructive things to processes which
* have altered credentials.
*/
if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
cr->cr_zone->zone_privset)) {
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
}
#endif
}
/*
* Holding the dtrace_proc privilege gives control over fasttrap
* and pid providers. We need to grant wider destructive
* privileges in the event that the user has proc_owner and/or
* proc_zone.
*/
if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
state->dts_cred.dcr_action |=
DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
}
}
return (state);
}
static int
dtrace_state_buffer(dtrace_state_t *state, dtrace_buffer_t *buf, int which)
{
dtrace_optval_t *opt = state->dts_options, size;
processorid_t cpu = 0;;
int flags = 0, rval, factor, divisor = 1;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(MUTEX_HELD(&cpu_lock));
ASSERT(which < DTRACEOPT_MAX);
ASSERT(state->dts_activity == DTRACE_ACTIVITY_INACTIVE ||
(state == dtrace_anon.dta_state &&
state->dts_activity == DTRACE_ACTIVITY_ACTIVE));
if (opt[which] == DTRACEOPT_UNSET || opt[which] == 0)
return (0);
if (opt[DTRACEOPT_CPU] != DTRACEOPT_UNSET)
cpu = opt[DTRACEOPT_CPU];
if (which == DTRACEOPT_SPECSIZE)
flags |= DTRACEBUF_NOSWITCH;
if (which == DTRACEOPT_BUFSIZE) {
if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_RING)
flags |= DTRACEBUF_RING;
if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_FILL)
flags |= DTRACEBUF_FILL;
if (state != dtrace_anon.dta_state ||
state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
flags |= DTRACEBUF_INACTIVE;
}
for (size = opt[which]; size >= sizeof (uint64_t); size /= divisor) {
/*
* The size must be 8-byte aligned. If the size is not 8-byte
* aligned, drop it down by the difference.
*/
if (size & (sizeof (uint64_t) - 1))
size -= size & (sizeof (uint64_t) - 1);
if (size < state->dts_reserve) {
/*
* Buffers always must be large enough to accommodate
* their prereserved space. We return E2BIG instead
* of ENOMEM in this case to allow for user-level
* software to differentiate the cases.
*/
return (E2BIG);
}
rval = dtrace_buffer_alloc(buf, size, flags, cpu, &factor);
if (rval != ENOMEM) {
opt[which] = size;
return (rval);
}
if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
return (rval);
for (divisor = 2; divisor < factor; divisor <<= 1)
continue;
}
return (ENOMEM);
}
static int
dtrace_state_buffers(dtrace_state_t *state)
{
dtrace_speculation_t *spec = state->dts_speculations;
int rval, i;
if ((rval = dtrace_state_buffer(state, state->dts_buffer,
DTRACEOPT_BUFSIZE)) != 0)
return (rval);
if ((rval = dtrace_state_buffer(state, state->dts_aggbuffer,
DTRACEOPT_AGGSIZE)) != 0)
return (rval);
for (i = 0; i < state->dts_nspeculations; i++) {
if ((rval = dtrace_state_buffer(state,
spec[i].dtsp_buffer, DTRACEOPT_SPECSIZE)) != 0)
return (rval);
}
return (0);
}
static void
dtrace_state_prereserve(dtrace_state_t *state)
{
dtrace_ecb_t *ecb;
dtrace_probe_t *probe;
state->dts_reserve = 0;
if (state->dts_options[DTRACEOPT_BUFPOLICY] != DTRACEOPT_BUFPOLICY_FILL)
return;
/*
* If our buffer policy is a "fill" buffer policy, we need to set the
* prereserved space to be the space required by the END probes.
*/
probe = dtrace_probes[dtrace_probeid_end - 1];
ASSERT(probe != NULL);
for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
if (ecb->dte_state != state)
continue;
state->dts_reserve += ecb->dte_needed + ecb->dte_alignment;
}
}
static int
dtrace_state_go(dtrace_state_t *state, processorid_t *cpu)
{
dtrace_optval_t *opt = state->dts_options, sz, nspec;
dtrace_speculation_t *spec;
dtrace_buffer_t *buf;
#ifdef illumos
cyc_handler_t hdlr;
cyc_time_t when;
#endif
int rval = 0, i, bufsize = NCPU * sizeof (dtrace_buffer_t);
dtrace_icookie_t cookie;
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_lock);
if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
rval = EBUSY;
goto out;
}
/*
* Before we can perform any checks, we must prime all of the
* retained enablings that correspond to this state.
*/
dtrace_enabling_prime(state);
if (state->dts_destructive && !state->dts_cred.dcr_destructive) {
rval = EACCES;
goto out;
}
dtrace_state_prereserve(state);
/*
* Now we want to do is try to allocate our speculations.
* We do not automatically resize the number of speculations; if
* this fails, we will fail the operation.
*/
nspec = opt[DTRACEOPT_NSPEC];
ASSERT(nspec != DTRACEOPT_UNSET);
if (nspec > INT_MAX) {
rval = ENOMEM;
goto out;
}
spec = kmem_zalloc(nspec * sizeof (dtrace_speculation_t),
KM_NOSLEEP | KM_NORMALPRI);
if (spec == NULL) {
rval = ENOMEM;
goto out;
}
state->dts_speculations = spec;
state->dts_nspeculations = (int)nspec;
for (i = 0; i < nspec; i++) {
if ((buf = kmem_zalloc(bufsize,
KM_NOSLEEP | KM_NORMALPRI)) == NULL) {
rval = ENOMEM;
goto err;
}
spec[i].dtsp_buffer = buf;
}
if (opt[DTRACEOPT_GRABANON] != DTRACEOPT_UNSET) {
if (dtrace_anon.dta_state == NULL) {
rval = ENOENT;
goto out;
}
if (state->dts_necbs != 0) {
rval = EALREADY;
goto out;
}
state->dts_anon = dtrace_anon_grab();
ASSERT(state->dts_anon != NULL);
state = state->dts_anon;
/*
* We want "grabanon" to be set in the grabbed state, so we'll
* copy that option value from the grabbing state into the
* grabbed state.
*/
state->dts_options[DTRACEOPT_GRABANON] =
opt[DTRACEOPT_GRABANON];
*cpu = dtrace_anon.dta_beganon;
/*
* If the anonymous state is active (as it almost certainly
* is if the anonymous enabling ultimately matched anything),
* we don't allow any further option processing -- but we
* don't return failure.
*/
if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
goto out;
}
if (opt[DTRACEOPT_AGGSIZE] != DTRACEOPT_UNSET &&
opt[DTRACEOPT_AGGSIZE] != 0) {
if (state->dts_aggregations == NULL) {
/*
* We're not going to create an aggregation buffer
* because we don't have any ECBs that contain
* aggregations -- set this option to 0.
*/
opt[DTRACEOPT_AGGSIZE] = 0;
} else {
/*
* If we have an aggregation buffer, we must also have
* a buffer to use as scratch.
*/
if (opt[DTRACEOPT_BUFSIZE] == DTRACEOPT_UNSET ||
opt[DTRACEOPT_BUFSIZE] < state->dts_needed) {
opt[DTRACEOPT_BUFSIZE] = state->dts_needed;
}
}
}
if (opt[DTRACEOPT_SPECSIZE] != DTRACEOPT_UNSET &&
opt[DTRACEOPT_SPECSIZE] != 0) {
if (!state->dts_speculates) {
/*
* We're not going to create speculation buffers
* because we don't have any ECBs that actually
* speculate -- set the speculation size to 0.
*/
opt[DTRACEOPT_SPECSIZE] = 0;
}
}
/*
* The bare minimum size for any buffer that we're actually going to
* do anything to is sizeof (uint64_t).
*/
sz = sizeof (uint64_t);
if ((state->dts_needed != 0 && opt[DTRACEOPT_BUFSIZE] < sz) ||
(state->dts_speculates && opt[DTRACEOPT_SPECSIZE] < sz) ||
(state->dts_aggregations != NULL && opt[DTRACEOPT_AGGSIZE] < sz)) {
/*
* A buffer size has been explicitly set to 0 (or to a size
* that will be adjusted to 0) and we need the space -- we
* need to return failure. We return ENOSPC to differentiate
* it from failing to allocate a buffer due to failure to meet
* the reserve (for which we return E2BIG).
*/
rval = ENOSPC;
goto out;
}
if ((rval = dtrace_state_buffers(state)) != 0)
goto err;
if ((sz = opt[DTRACEOPT_DYNVARSIZE]) == DTRACEOPT_UNSET)
sz = dtrace_dstate_defsize;
do {
rval = dtrace_dstate_init(&state->dts_vstate.dtvs_dynvars, sz);
if (rval == 0)
break;
if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
goto err;
} while (sz >>= 1);
opt[DTRACEOPT_DYNVARSIZE] = sz;
if (rval != 0)
goto err;
if (opt[DTRACEOPT_STATUSRATE] > dtrace_statusrate_max)
opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_max;
if (opt[DTRACEOPT_CLEANRATE] == 0)
opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
if (opt[DTRACEOPT_CLEANRATE] < dtrace_cleanrate_min)
opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_min;
if (opt[DTRACEOPT_CLEANRATE] > dtrace_cleanrate_max)
opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
state->dts_alive = state->dts_laststatus = dtrace_gethrtime();
#ifdef illumos
hdlr.cyh_func = (cyc_func_t)dtrace_state_clean;
hdlr.cyh_arg = state;
hdlr.cyh_level = CY_LOW_LEVEL;
when.cyt_when = 0;
when.cyt_interval = opt[DTRACEOPT_CLEANRATE];
state->dts_cleaner = cyclic_add(&hdlr, &when);
hdlr.cyh_func = (cyc_func_t)dtrace_state_deadman;
hdlr.cyh_arg = state;
hdlr.cyh_level = CY_LOW_LEVEL;
when.cyt_when = 0;
when.cyt_interval = dtrace_deadman_interval;
state->dts_deadman = cyclic_add(&hdlr, &when);
#else
callout_reset(&state->dts_cleaner, hz * opt[DTRACEOPT_CLEANRATE] / NANOSEC,
dtrace_state_clean, state);
callout_reset(&state->dts_deadman, hz * dtrace_deadman_interval / NANOSEC,
dtrace_state_deadman, state);
#endif
state->dts_activity = DTRACE_ACTIVITY_WARMUP;
#ifdef illumos
if (state->dts_getf != 0 &&
!(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)) {
/*
* We don't have kernel privs but we have at least one call
* to getf(); we need to bump our zone's count, and (if
* this is the first enabling to have an unprivileged call
* to getf()) we need to hook into closef().
*/
state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf++;
if (dtrace_getf++ == 0) {
ASSERT(dtrace_closef == NULL);
dtrace_closef = dtrace_getf_barrier;
}
}
#endif
/*
* Now it's time to actually fire the BEGIN probe. We need to disable
* interrupts here both to record the CPU on which we fired the BEGIN
* probe (the data from this CPU will be processed first at user
* level) and to manually activate the buffer for this CPU.
*/
cookie = dtrace_interrupt_disable();
*cpu = curcpu;
ASSERT(state->dts_buffer[*cpu].dtb_flags & DTRACEBUF_INACTIVE);
state->dts_buffer[*cpu].dtb_flags &= ~DTRACEBUF_INACTIVE;
dtrace_probe(dtrace_probeid_begin,
(uint64_t)(uintptr_t)state, 0, 0, 0, 0);
dtrace_interrupt_enable(cookie);
/*
* We may have had an exit action from a BEGIN probe; only change our
* state to ACTIVE if we're still in WARMUP.
*/
ASSERT(state->dts_activity == DTRACE_ACTIVITY_WARMUP ||
state->dts_activity == DTRACE_ACTIVITY_DRAINING);
if (state->dts_activity == DTRACE_ACTIVITY_WARMUP)
state->dts_activity = DTRACE_ACTIVITY_ACTIVE;
#ifdef __FreeBSD__
/*
* We enable anonymous tracing before APs are started, so we must
* activate buffers using the current CPU.
*/
if (state == dtrace_anon.dta_state)
for (int i = 0; i < NCPU; i++)
dtrace_buffer_activate_cpu(state, i);
else
dtrace_xcall(DTRACE_CPUALL,
(dtrace_xcall_t)dtrace_buffer_activate, state);
#else
/*
* Regardless of whether or not now we're in ACTIVE or DRAINING, we
* want each CPU to transition its principal buffer out of the
* INACTIVE state. Doing this assures that no CPU will suddenly begin
* processing an ECB halfway down a probe's ECB chain; all CPUs will
* atomically transition from processing none of a state's ECBs to
* processing all of them.
*/
dtrace_xcall(DTRACE_CPUALL,
(dtrace_xcall_t)dtrace_buffer_activate, state);
#endif
goto out;
err:
dtrace_buffer_free(state->dts_buffer);
dtrace_buffer_free(state->dts_aggbuffer);
if ((nspec = state->dts_nspeculations) == 0) {
ASSERT(state->dts_speculations == NULL);
goto out;
}
spec = state->dts_speculations;
ASSERT(spec != NULL);
for (i = 0; i < state->dts_nspeculations; i++) {
if ((buf = spec[i].dtsp_buffer) == NULL)
break;
dtrace_buffer_free(buf);
kmem_free(buf, bufsize);
}
kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
state->dts_nspeculations = 0;
state->dts_speculations = NULL;
out:
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
return (rval);
}
static int
dtrace_state_stop(dtrace_state_t *state, processorid_t *cpu)
{
dtrace_icookie_t cookie;
ASSERT(MUTEX_HELD(&dtrace_lock));
if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE &&
state->dts_activity != DTRACE_ACTIVITY_DRAINING)
return (EINVAL);
/*
* We'll set the activity to DTRACE_ACTIVITY_DRAINING, and issue a sync
* to be sure that every CPU has seen it. See below for the details
* on why this is done.
*/
state->dts_activity = DTRACE_ACTIVITY_DRAINING;
dtrace_sync();
/*
* By this point, it is impossible for any CPU to be still processing
* with DTRACE_ACTIVITY_ACTIVE. We can thus set our activity to
* DTRACE_ACTIVITY_COOLDOWN and know that we're not racing with any
* other CPU in dtrace_buffer_reserve(). This allows dtrace_probe()
* and callees to know that the activity is DTRACE_ACTIVITY_COOLDOWN
* iff we're in the END probe.
*/
state->dts_activity = DTRACE_ACTIVITY_COOLDOWN;
dtrace_sync();
ASSERT(state->dts_activity == DTRACE_ACTIVITY_COOLDOWN);
/*
* Finally, we can release the reserve and call the END probe. We
* disable interrupts across calling the END probe to allow us to
* return the CPU on which we actually called the END probe. This
* allows user-land to be sure that this CPU's principal buffer is
* processed last.
*/
state->dts_reserve = 0;
cookie = dtrace_interrupt_disable();
*cpu = curcpu;
dtrace_probe(dtrace_probeid_end,
(uint64_t)(uintptr_t)state, 0, 0, 0, 0);
dtrace_interrupt_enable(cookie);
state->dts_activity = DTRACE_ACTIVITY_STOPPED;
dtrace_sync();
#ifdef illumos
if (state->dts_getf != 0 &&
!(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)) {
/*
* We don't have kernel privs but we have at least one call
* to getf(); we need to lower our zone's count, and (if
* this is the last enabling to have an unprivileged call
* to getf()) we need to clear the closef() hook.
*/
ASSERT(state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf > 0);
ASSERT(dtrace_closef == dtrace_getf_barrier);
ASSERT(dtrace_getf > 0);
state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf--;
if (--dtrace_getf == 0)
dtrace_closef = NULL;
}
#endif
return (0);
}
static int
dtrace_state_option(dtrace_state_t *state, dtrace_optid_t option,
dtrace_optval_t val)
{
ASSERT(MUTEX_HELD(&dtrace_lock));
if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
return (EBUSY);
if (option >= DTRACEOPT_MAX)
return (EINVAL);
if (option != DTRACEOPT_CPU && val < 0)
return (EINVAL);
switch (option) {
case DTRACEOPT_DESTRUCTIVE:
if (dtrace_destructive_disallow)
return (EACCES);
state->dts_cred.dcr_destructive = 1;
break;
case DTRACEOPT_BUFSIZE:
case DTRACEOPT_DYNVARSIZE:
case DTRACEOPT_AGGSIZE:
case DTRACEOPT_SPECSIZE:
case DTRACEOPT_STRSIZE:
if (val < 0)
return (EINVAL);
if (val >= LONG_MAX) {
/*
* If this is an otherwise negative value, set it to
* the highest multiple of 128m less than LONG_MAX.
* Technically, we're adjusting the size without
* regard to the buffer resizing policy, but in fact,
* this has no effect -- if we set the buffer size to
* ~LONG_MAX and the buffer policy is ultimately set to
* be "manual", the buffer allocation is guaranteed to
* fail, if only because the allocation requires two
* buffers. (We set the the size to the highest
* multiple of 128m because it ensures that the size
* will remain a multiple of a megabyte when
* repeatedly halved -- all the way down to 15m.)
*/
val = LONG_MAX - (1 << 27) + 1;
}
}
state->dts_options[option] = val;
return (0);
}
static void
dtrace_state_destroy(dtrace_state_t *state)
{
dtrace_ecb_t *ecb;
dtrace_vstate_t *vstate = &state->dts_vstate;
#ifdef illumos
minor_t minor = getminor(state->dts_dev);
#endif
int i, bufsize = NCPU * sizeof (dtrace_buffer_t);
dtrace_speculation_t *spec = state->dts_speculations;
int nspec = state->dts_nspeculations;
uint32_t match;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(MUTEX_HELD(&cpu_lock));
/*
* First, retract any retained enablings for this state.
*/
dtrace_enabling_retract(state);
ASSERT(state->dts_nretained == 0);
if (state->dts_activity == DTRACE_ACTIVITY_ACTIVE ||
state->dts_activity == DTRACE_ACTIVITY_DRAINING) {
/*
* We have managed to come into dtrace_state_destroy() on a
* hot enabling -- almost certainly because of a disorderly
* shutdown of a consumer. (That is, a consumer that is
* exiting without having called dtrace_stop().) In this case,
* we're going to set our activity to be KILLED, and then
* issue a sync to be sure that everyone is out of probe
* context before we start blowing away ECBs.
*/
state->dts_activity = DTRACE_ACTIVITY_KILLED;
dtrace_sync();
}
/*
* Release the credential hold we took in dtrace_state_create().
*/
if (state->dts_cred.dcr_cred != NULL)
crfree(state->dts_cred.dcr_cred);
/*
* Now we can safely disable and destroy any enabled probes. Because
* any DTRACE_PRIV_KERNEL probes may actually be slowing our progress
* (especially if they're all enabled), we take two passes through the
* ECBs: in the first, we disable just DTRACE_PRIV_KERNEL probes, and
* in the second we disable whatever is left over.
*/
for (match = DTRACE_PRIV_KERNEL; ; match = 0) {
for (i = 0; i < state->dts_necbs; i++) {
if ((ecb = state->dts_ecbs[i]) == NULL)
continue;
if (match && ecb->dte_probe != NULL) {
dtrace_probe_t *probe = ecb->dte_probe;
dtrace_provider_t *prov = probe->dtpr_provider;
if (!(prov->dtpv_priv.dtpp_flags & match))
continue;
}
dtrace_ecb_disable(ecb);
dtrace_ecb_destroy(ecb);
}
if (!match)
break;
}
/*
* Before we free the buffers, perform one more sync to assure that
* every CPU is out of probe context.
*/
dtrace_sync();
dtrace_buffer_free(state->dts_buffer);
dtrace_buffer_free(state->dts_aggbuffer);
for (i = 0; i < nspec; i++)
dtrace_buffer_free(spec[i].dtsp_buffer);
#ifdef illumos
if (state->dts_cleaner != CYCLIC_NONE)
cyclic_remove(state->dts_cleaner);
if (state->dts_deadman != CYCLIC_NONE)
cyclic_remove(state->dts_deadman);
#else
callout_stop(&state->dts_cleaner);
callout_drain(&state->dts_cleaner);
callout_stop(&state->dts_deadman);
callout_drain(&state->dts_deadman);
#endif
dtrace_dstate_fini(&vstate->dtvs_dynvars);
dtrace_vstate_fini(vstate);
if (state->dts_ecbs != NULL)
kmem_free(state->dts_ecbs, state->dts_necbs * sizeof (dtrace_ecb_t *));
if (state->dts_aggregations != NULL) {
#ifdef DEBUG
for (i = 0; i < state->dts_naggregations; i++)
ASSERT(state->dts_aggregations[i] == NULL);
#endif
ASSERT(state->dts_naggregations > 0);
kmem_free(state->dts_aggregations,
state->dts_naggregations * sizeof (dtrace_aggregation_t *));
}
kmem_free(state->dts_buffer, bufsize);
kmem_free(state->dts_aggbuffer, bufsize);
for (i = 0; i < nspec; i++)
kmem_free(spec[i].dtsp_buffer, bufsize);
if (spec != NULL)
kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
dtrace_format_destroy(state);
if (state->dts_aggid_arena != NULL) {
#ifdef illumos
vmem_destroy(state->dts_aggid_arena);
#else
delete_unrhdr(state->dts_aggid_arena);
#endif
state->dts_aggid_arena = NULL;
}
#ifdef illumos
ddi_soft_state_free(dtrace_softstate, minor);
vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
#endif
}
/*
* DTrace Anonymous Enabling Functions
*/
static dtrace_state_t *
dtrace_anon_grab(void)
{
dtrace_state_t *state;
ASSERT(MUTEX_HELD(&dtrace_lock));
if ((state = dtrace_anon.dta_state) == NULL) {
ASSERT(dtrace_anon.dta_enabling == NULL);
return (NULL);
}
ASSERT(dtrace_anon.dta_enabling != NULL);
ASSERT(dtrace_retained != NULL);
dtrace_enabling_destroy(dtrace_anon.dta_enabling);
dtrace_anon.dta_enabling = NULL;
dtrace_anon.dta_state = NULL;
return (state);
}
static void
dtrace_anon_property(void)
{
int i, rv;
dtrace_state_t *state;
dof_hdr_t *dof;
char c[32]; /* enough for "dof-data-" + digits */
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(MUTEX_HELD(&cpu_lock));
for (i = 0; ; i++) {
(void) snprintf(c, sizeof (c), "dof-data-%d", i);
dtrace_err_verbose = 1;
if ((dof = dtrace_dof_property(c)) == NULL) {
dtrace_err_verbose = 0;
break;
}
#ifdef illumos
/*
* We want to create anonymous state, so we need to transition
* the kernel debugger to indicate that DTrace is active. If
* this fails (e.g. because the debugger has modified text in
* some way), we won't continue with the processing.
*/
if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
cmn_err(CE_NOTE, "kernel debugger active; anonymous "
"enabling ignored.");
dtrace_dof_destroy(dof);
break;
}
#endif
/*
* If we haven't allocated an anonymous state, we'll do so now.
*/
if ((state = dtrace_anon.dta_state) == NULL) {
state = dtrace_state_create(NULL, NULL);
dtrace_anon.dta_state = state;
if (state == NULL) {
/*
* This basically shouldn't happen: the only
* failure mode from dtrace_state_create() is a
* failure of ddi_soft_state_zalloc() that
* itself should never happen. Still, the
* interface allows for a failure mode, and
* we want to fail as gracefully as possible:
* we'll emit an error message and cease
* processing anonymous state in this case.
*/
cmn_err(CE_WARN, "failed to create "
"anonymous state");
dtrace_dof_destroy(dof);
break;
}
}
rv = dtrace_dof_slurp(dof, &state->dts_vstate, CRED(),
&dtrace_anon.dta_enabling, 0, B_TRUE);
if (rv == 0)
rv = dtrace_dof_options(dof, state);
dtrace_err_verbose = 0;
dtrace_dof_destroy(dof);
if (rv != 0) {
/*
* This is malformed DOF; chuck any anonymous state
* that we created.
*/
ASSERT(dtrace_anon.dta_enabling == NULL);
dtrace_state_destroy(state);
dtrace_anon.dta_state = NULL;
break;
}
ASSERT(dtrace_anon.dta_enabling != NULL);
}
if (dtrace_anon.dta_enabling != NULL) {
int rval;
/*
* dtrace_enabling_retain() can only fail because we are
* trying to retain more enablings than are allowed -- but
* we only have one anonymous enabling, and we are guaranteed
* to be allowed at least one retained enabling; we assert
* that dtrace_enabling_retain() returns success.
*/
rval = dtrace_enabling_retain(dtrace_anon.dta_enabling);
ASSERT(rval == 0);
dtrace_enabling_dump(dtrace_anon.dta_enabling);
}
}
/*
* DTrace Helper Functions
*/
static void
dtrace_helper_trace(dtrace_helper_action_t *helper,
dtrace_mstate_t *mstate, dtrace_vstate_t *vstate, int where)
{
uint32_t size, next, nnext, i;
dtrace_helptrace_t *ent, *buffer;
uint16_t flags = cpu_core[curcpu].cpuc_dtrace_flags;
if ((buffer = dtrace_helptrace_buffer) == NULL)
return;
ASSERT(vstate->dtvs_nlocals <= dtrace_helptrace_nlocals);
/*
* What would a tracing framework be without its own tracing
* framework? (Well, a hell of a lot simpler, for starters...)
*/
size = sizeof (dtrace_helptrace_t) + dtrace_helptrace_nlocals *
sizeof (uint64_t) - sizeof (uint64_t);
/*
* Iterate until we can allocate a slot in the trace buffer.
*/
do {
next = dtrace_helptrace_next;
if (next + size < dtrace_helptrace_bufsize) {
nnext = next + size;
} else {
nnext = size;
}
} while (dtrace_cas32(&dtrace_helptrace_next, next, nnext) != next);
/*
* We have our slot; fill it in.
*/
if (nnext == size) {
dtrace_helptrace_wrapped++;
next = 0;
}
ent = (dtrace_helptrace_t *)((uintptr_t)buffer + next);
ent->dtht_helper = helper;
ent->dtht_where = where;
ent->dtht_nlocals = vstate->dtvs_nlocals;
ent->dtht_fltoffs = (mstate->dtms_present & DTRACE_MSTATE_FLTOFFS) ?
mstate->dtms_fltoffs : -1;
ent->dtht_fault = DTRACE_FLAGS2FLT(flags);
ent->dtht_illval = cpu_core[curcpu].cpuc_dtrace_illval;
for (i = 0; i < vstate->dtvs_nlocals; i++) {
dtrace_statvar_t *svar;
if ((svar = vstate->dtvs_locals[i]) == NULL)
continue;
ASSERT(svar->dtsv_size >= NCPU * sizeof (uint64_t));
ent->dtht_locals[i] =
((uint64_t *)(uintptr_t)svar->dtsv_data)[curcpu];
}
}
static uint64_t
dtrace_helper(int which, dtrace_mstate_t *mstate,
dtrace_state_t *state, uint64_t arg0, uint64_t arg1)
{
uint16_t *flags = &cpu_core[curcpu].cpuc_dtrace_flags;
uint64_t sarg0 = mstate->dtms_arg[0];
uint64_t sarg1 = mstate->dtms_arg[1];
uint64_t rval = 0;
dtrace_helpers_t *helpers = curproc->p_dtrace_helpers;
dtrace_helper_action_t *helper;
dtrace_vstate_t *vstate;
dtrace_difo_t *pred;
int i, trace = dtrace_helptrace_buffer != NULL;
ASSERT(which >= 0 && which < DTRACE_NHELPER_ACTIONS);
if (helpers == NULL)
return (0);
if ((helper = helpers->dthps_actions[which]) == NULL)
return (0);
vstate = &helpers->dthps_vstate;
mstate->dtms_arg[0] = arg0;
mstate->dtms_arg[1] = arg1;
/*
* Now iterate over each helper. If its predicate evaluates to 'true',
* we'll call the corresponding actions. Note that the below calls
* to dtrace_dif_emulate() may set faults in machine state. This is
* okay: our caller (the outer dtrace_dif_emulate()) will simply plow
* the stored DIF offset with its own (which is the desired behavior).
* Also, note the calls to dtrace_dif_emulate() may allocate scratch
* from machine state; this is okay, too.
*/
for (; helper != NULL; helper = helper->dtha_next) {
if ((pred = helper->dtha_predicate) != NULL) {
if (trace)
dtrace_helper_trace(helper, mstate, vstate, 0);
if (!dtrace_dif_emulate(pred, mstate, vstate, state))
goto next;
if (*flags & CPU_DTRACE_FAULT)
goto err;
}
for (i = 0; i < helper->dtha_nactions; i++) {
if (trace)
dtrace_helper_trace(helper,
mstate, vstate, i + 1);
rval = dtrace_dif_emulate(helper->dtha_actions[i],
mstate, vstate, state);
if (*flags & CPU_DTRACE_FAULT)
goto err;
}
next:
if (trace)
dtrace_helper_trace(helper, mstate, vstate,
DTRACE_HELPTRACE_NEXT);
}
if (trace)
dtrace_helper_trace(helper, mstate, vstate,
DTRACE_HELPTRACE_DONE);
/*
* Restore the arg0 that we saved upon entry.
*/
mstate->dtms_arg[0] = sarg0;
mstate->dtms_arg[1] = sarg1;
return (rval);
err:
if (trace)
dtrace_helper_trace(helper, mstate, vstate,
DTRACE_HELPTRACE_ERR);
/*
* Restore the arg0 that we saved upon entry.
*/
mstate->dtms_arg[0] = sarg0;
mstate->dtms_arg[1] = sarg1;
return (0);
}
static void
dtrace_helper_action_destroy(dtrace_helper_action_t *helper,
dtrace_vstate_t *vstate)
{
int i;
if (helper->dtha_predicate != NULL)
dtrace_difo_release(helper->dtha_predicate, vstate);
for (i = 0; i < helper->dtha_nactions; i++) {
ASSERT(helper->dtha_actions[i] != NULL);
dtrace_difo_release(helper->dtha_actions[i], vstate);
}
kmem_free(helper->dtha_actions,
helper->dtha_nactions * sizeof (dtrace_difo_t *));
kmem_free(helper, sizeof (dtrace_helper_action_t));
}
static int
dtrace_helper_destroygen(dtrace_helpers_t *help, int gen)
{
proc_t *p = curproc;
dtrace_vstate_t *vstate;
int i;
if (help == NULL)
help = p->p_dtrace_helpers;
ASSERT(MUTEX_HELD(&dtrace_lock));
if (help == NULL || gen > help->dthps_generation)
return (EINVAL);
vstate = &help->dthps_vstate;
for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
dtrace_helper_action_t *last = NULL, *h, *next;
for (h = help->dthps_actions[i]; h != NULL; h = next) {
next = h->dtha_next;
if (h->dtha_generation == gen) {
if (last != NULL) {
last->dtha_next = next;
} else {
help->dthps_actions[i] = next;
}
dtrace_helper_action_destroy(h, vstate);
} else {
last = h;
}
}
}
/*
* Interate until we've cleared out all helper providers with the
* given generation number.
*/
for (;;) {
dtrace_helper_provider_t *prov;
/*
* Look for a helper provider with the right generation. We
* have to start back at the beginning of the list each time
* because we drop dtrace_lock. It's unlikely that we'll make
* more than two passes.
*/
for (i = 0; i < help->dthps_nprovs; i++) {
prov = help->dthps_provs[i];
if (prov->dthp_generation == gen)
break;
}
/*
* If there were no matches, we're done.
*/
if (i == help->dthps_nprovs)
break;
/*
* Move the last helper provider into this slot.
*/
help->dthps_nprovs--;
help->dthps_provs[i] = help->dthps_provs[help->dthps_nprovs];
help->dthps_provs[help->dthps_nprovs] = NULL;
mutex_exit(&dtrace_lock);
/*
* If we have a meta provider, remove this helper provider.
*/
mutex_enter(&dtrace_meta_lock);
if (dtrace_meta_pid != NULL) {
ASSERT(dtrace_deferred_pid == NULL);
dtrace_helper_provider_remove(&prov->dthp_prov,
p->p_pid);
}
mutex_exit(&dtrace_meta_lock);
dtrace_helper_provider_destroy(prov);
mutex_enter(&dtrace_lock);
}
return (0);
}
static int
dtrace_helper_validate(dtrace_helper_action_t *helper)
{
int err = 0, i;
dtrace_difo_t *dp;
if ((dp = helper->dtha_predicate) != NULL)
err += dtrace_difo_validate_helper(dp);
for (i = 0; i < helper->dtha_nactions; i++)
err += dtrace_difo_validate_helper(helper->dtha_actions[i]);
return (err == 0);
}
static int
dtrace_helper_action_add(int which, dtrace_ecbdesc_t *ep,
dtrace_helpers_t *help)
{
dtrace_helper_action_t *helper, *last;
dtrace_actdesc_t *act;
dtrace_vstate_t *vstate;
dtrace_predicate_t *pred;
int count = 0, nactions = 0, i;
if (which < 0 || which >= DTRACE_NHELPER_ACTIONS)
return (EINVAL);
last = help->dthps_actions[which];
vstate = &help->dthps_vstate;
for (count = 0; last != NULL; last = last->dtha_next) {
count++;
if (last->dtha_next == NULL)
break;
}
/*
* If we already have dtrace_helper_actions_max helper actions for this
* helper action type, we'll refuse to add a new one.
*/
if (count >= dtrace_helper_actions_max)
return (ENOSPC);
helper = kmem_zalloc(sizeof (dtrace_helper_action_t), KM_SLEEP);
helper->dtha_generation = help->dthps_generation;
if ((pred = ep->dted_pred.dtpdd_predicate) != NULL) {
ASSERT(pred->dtp_difo != NULL);
dtrace_difo_hold(pred->dtp_difo);
helper->dtha_predicate = pred->dtp_difo;
}
for (act = ep->dted_action; act != NULL; act = act->dtad_next) {
if (act->dtad_kind != DTRACEACT_DIFEXPR)
goto err;
if (act->dtad_difo == NULL)
goto err;
nactions++;
}
helper->dtha_actions = kmem_zalloc(sizeof (dtrace_difo_t *) *
(helper->dtha_nactions = nactions), KM_SLEEP);
for (act = ep->dted_action, i = 0; act != NULL; act = act->dtad_next) {
dtrace_difo_hold(act->dtad_difo);
helper->dtha_actions[i++] = act->dtad_difo;
}
if (!dtrace_helper_validate(helper))
goto err;
if (last == NULL) {
help->dthps_actions[which] = helper;
} else {
last->dtha_next = helper;
}
if (vstate->dtvs_nlocals > dtrace_helptrace_nlocals) {
dtrace_helptrace_nlocals = vstate->dtvs_nlocals;
dtrace_helptrace_next = 0;
}
return (0);
err:
dtrace_helper_action_destroy(helper, vstate);
return (EINVAL);
}
static void
dtrace_helper_provider_register(proc_t *p, dtrace_helpers_t *help,
dof_helper_t *dofhp)
{
ASSERT(MUTEX_NOT_HELD(&dtrace_lock));
mutex_enter(&dtrace_meta_lock);
mutex_enter(&dtrace_lock);
if (!dtrace_attached() || dtrace_meta_pid == NULL) {
/*
* If the dtrace module is loaded but not attached, or if
* there aren't isn't a meta provider registered to deal with
* these provider descriptions, we need to postpone creating
* the actual providers until later.
*/
if (help->dthps_next == NULL && help->dthps_prev == NULL &&
dtrace_deferred_pid != help) {
help->dthps_deferred = 1;
help->dthps_pid = p->p_pid;
help->dthps_next = dtrace_deferred_pid;
help->dthps_prev = NULL;
if (dtrace_deferred_pid != NULL)
dtrace_deferred_pid->dthps_prev = help;
dtrace_deferred_pid = help;
}
mutex_exit(&dtrace_lock);
} else if (dofhp != NULL) {
/*
* If the dtrace module is loaded and we have a particular
* helper provider description, pass that off to the
* meta provider.
*/
mutex_exit(&dtrace_lock);
dtrace_helper_provide(dofhp, p->p_pid);
} else {
/*
* Otherwise, just pass all the helper provider descriptions
* off to the meta provider.
*/
int i;
mutex_exit(&dtrace_lock);
for (i = 0; i < help->dthps_nprovs; i++) {
dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
p->p_pid);
}
}
mutex_exit(&dtrace_meta_lock);
}
static int
dtrace_helper_provider_add(dof_helper_t *dofhp, dtrace_helpers_t *help, int gen)
{
dtrace_helper_provider_t *hprov, **tmp_provs;
uint_t tmp_maxprovs, i;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(help != NULL);
/*
* If we already have dtrace_helper_providers_max helper providers,
* we're refuse to add a new one.
*/
if (help->dthps_nprovs >= dtrace_helper_providers_max)
return (ENOSPC);
/*
* Check to make sure this isn't a duplicate.
*/
for (i = 0; i < help->dthps_nprovs; i++) {
if (dofhp->dofhp_addr ==
help->dthps_provs[i]->dthp_prov.dofhp_addr)
return (EALREADY);
}
hprov = kmem_zalloc(sizeof (dtrace_helper_provider_t), KM_SLEEP);
hprov->dthp_prov = *dofhp;
hprov->dthp_ref = 1;
hprov->dthp_generation = gen;
/*
* Allocate a bigger table for helper providers if it's already full.
*/
if (help->dthps_maxprovs == help->dthps_nprovs) {
tmp_maxprovs = help->dthps_maxprovs;
tmp_provs = help->dthps_provs;
if (help->dthps_maxprovs == 0)
help->dthps_maxprovs = 2;
else
help->dthps_maxprovs *= 2;
if (help->dthps_maxprovs > dtrace_helper_providers_max)
help->dthps_maxprovs = dtrace_helper_providers_max;
ASSERT(tmp_maxprovs < help->dthps_maxprovs);
help->dthps_provs = kmem_zalloc(help->dthps_maxprovs *
sizeof (dtrace_helper_provider_t *), KM_SLEEP);
if (tmp_provs != NULL) {
bcopy(tmp_provs, help->dthps_provs, tmp_maxprovs *
sizeof (dtrace_helper_provider_t *));
kmem_free(tmp_provs, tmp_maxprovs *
sizeof (dtrace_helper_provider_t *));
}
}
help->dthps_provs[help->dthps_nprovs] = hprov;
help->dthps_nprovs++;
return (0);
}
static void
dtrace_helper_provider_destroy(dtrace_helper_provider_t *hprov)
{
mutex_enter(&dtrace_lock);
if (--hprov->dthp_ref == 0) {
dof_hdr_t *dof;
mutex_exit(&dtrace_lock);
dof = (dof_hdr_t *)(uintptr_t)hprov->dthp_prov.dofhp_dof;
dtrace_dof_destroy(dof);
kmem_free(hprov, sizeof (dtrace_helper_provider_t));
} else {
mutex_exit(&dtrace_lock);
}
}
static int
dtrace_helper_provider_validate(dof_hdr_t *dof, dof_sec_t *sec)
{
uintptr_t daddr = (uintptr_t)dof;
dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
dof_provider_t *provider;
dof_probe_t *probe;
uint8_t *arg;
char *strtab, *typestr;
dof_stridx_t typeidx;
size_t typesz;
uint_t nprobes, j, k;
ASSERT(sec->dofs_type == DOF_SECT_PROVIDER);
if (sec->dofs_offset & (sizeof (uint_t) - 1)) {
dtrace_dof_error(dof, "misaligned section offset");
return (-1);
}
/*
* The section needs to be large enough to contain the DOF provider
* structure appropriate for the given version.
*/
if (sec->dofs_size <
((dof->dofh_ident[DOF_ID_VERSION] == DOF_VERSION_1) ?
offsetof(dof_provider_t, dofpv_prenoffs) :
sizeof (dof_provider_t))) {
dtrace_dof_error(dof, "provider section too small");
return (-1);
}
provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
str_sec = dtrace_dof_sect(dof, DOF_SECT_STRTAB, provider->dofpv_strtab);
prb_sec = dtrace_dof_sect(dof, DOF_SECT_PROBES, provider->dofpv_probes);
arg_sec = dtrace_dof_sect(dof, DOF_SECT_PRARGS, provider->dofpv_prargs);
off_sec = dtrace_dof_sect(dof, DOF_SECT_PROFFS, provider->dofpv_proffs);
if (str_sec == NULL || prb_sec == NULL ||
arg_sec == NULL || off_sec == NULL)
return (-1);
enoff_sec = NULL;
if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
provider->dofpv_prenoffs != DOF_SECT_NONE &&
(enoff_sec = dtrace_dof_sect(dof, DOF_SECT_PRENOFFS,
provider->dofpv_prenoffs)) == NULL)
return (-1);
strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
if (provider->dofpv_name >= str_sec->dofs_size ||
strlen(strtab + provider->dofpv_name) >= DTRACE_PROVNAMELEN) {
dtrace_dof_error(dof, "invalid provider name");
return (-1);
}
if (prb_sec->dofs_entsize == 0 ||
prb_sec->dofs_entsize > prb_sec->dofs_size) {
dtrace_dof_error(dof, "invalid entry size");
return (-1);
}
if (prb_sec->dofs_entsize & (sizeof (uintptr_t) - 1)) {
dtrace_dof_error(dof, "misaligned entry size");
return (-1);
}
if (off_sec->dofs_entsize != sizeof (uint32_t)) {
dtrace_dof_error(dof, "invalid entry size");
return (-1);
}
if (off_sec->dofs_offset & (sizeof (uint32_t) - 1)) {
dtrace_dof_error(dof, "misaligned section offset");
return (-1);
}
if (arg_sec->dofs_entsize != sizeof (uint8_t)) {
dtrace_dof_error(dof, "invalid entry size");
return (-1);
}
arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
/*
* Take a pass through the probes to check for errors.
*/
for (j = 0; j < nprobes; j++) {
probe = (dof_probe_t *)(uintptr_t)(daddr +
prb_sec->dofs_offset + j * prb_sec->dofs_entsize);
if (probe->dofpr_func >= str_sec->dofs_size) {
dtrace_dof_error(dof, "invalid function name");
return (-1);
}
if (strlen(strtab + probe->dofpr_func) >= DTRACE_FUNCNAMELEN) {
dtrace_dof_error(dof, "function name too long");
/*
* Keep going if the function name is too long.
* Unlike provider and probe names, we cannot reasonably
* impose restrictions on function names, since they're
* a property of the code being instrumented. We will
* skip this probe in dtrace_helper_provide_one().
*/
}
if (probe->dofpr_name >= str_sec->dofs_size ||
strlen(strtab + probe->dofpr_name) >= DTRACE_NAMELEN) {
dtrace_dof_error(dof, "invalid probe name");
return (-1);
}
/*
* The offset count must not wrap the index, and the offsets
* must also not overflow the section's data.
*/
if (probe->dofpr_offidx + probe->dofpr_noffs <
probe->dofpr_offidx ||
(probe->dofpr_offidx + probe->dofpr_noffs) *
off_sec->dofs_entsize > off_sec->dofs_size) {
dtrace_dof_error(dof, "invalid probe offset");
return (-1);
}
if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1) {
/*
* If there's no is-enabled offset section, make sure
* there aren't any is-enabled offsets. Otherwise
* perform the same checks as for probe offsets
* (immediately above).
*/
if (enoff_sec == NULL) {
if (probe->dofpr_enoffidx != 0 ||
probe->dofpr_nenoffs != 0) {
dtrace_dof_error(dof, "is-enabled "
"offsets with null section");
return (-1);
}
} else if (probe->dofpr_enoffidx +
probe->dofpr_nenoffs < probe->dofpr_enoffidx ||
(probe->dofpr_enoffidx + probe->dofpr_nenoffs) *
enoff_sec->dofs_entsize > enoff_sec->dofs_size) {
dtrace_dof_error(dof, "invalid is-enabled "
"offset");
return (-1);
}
if (probe->dofpr_noffs + probe->dofpr_nenoffs == 0) {
dtrace_dof_error(dof, "zero probe and "
"is-enabled offsets");
return (-1);
}
} else if (probe->dofpr_noffs == 0) {
dtrace_dof_error(dof, "zero probe offsets");
return (-1);
}
if (probe->dofpr_argidx + probe->dofpr_xargc <
probe->dofpr_argidx ||
(probe->dofpr_argidx + probe->dofpr_xargc) *
arg_sec->dofs_entsize > arg_sec->dofs_size) {
dtrace_dof_error(dof, "invalid args");
return (-1);
}
typeidx = probe->dofpr_nargv;
typestr = strtab + probe->dofpr_nargv;
for (k = 0; k < probe->dofpr_nargc; k++) {
if (typeidx >= str_sec->dofs_size) {
dtrace_dof_error(dof, "bad "
"native argument type");
return (-1);
}
typesz = strlen(typestr) + 1;
if (typesz > DTRACE_ARGTYPELEN) {
dtrace_dof_error(dof, "native "
"argument type too long");
return (-1);
}
typeidx += typesz;
typestr += typesz;
}
typeidx = probe->dofpr_xargv;
typestr = strtab + probe->dofpr_xargv;
for (k = 0; k < probe->dofpr_xargc; k++) {
if (arg[probe->dofpr_argidx + k] > probe->dofpr_nargc) {
dtrace_dof_error(dof, "bad "
"native argument index");
return (-1);
}
if (typeidx >= str_sec->dofs_size) {
dtrace_dof_error(dof, "bad "
"translated argument type");
return (-1);
}
typesz = strlen(typestr) + 1;
if (typesz > DTRACE_ARGTYPELEN) {
dtrace_dof_error(dof, "translated argument "
"type too long");
return (-1);
}
typeidx += typesz;
typestr += typesz;
}
}
return (0);
}
static int
#ifdef __FreeBSD__
dtrace_helper_slurp(dof_hdr_t *dof, dof_helper_t *dhp, struct proc *p)
#else
dtrace_helper_slurp(dof_hdr_t *dof, dof_helper_t *dhp)
#endif
{
dtrace_helpers_t *help;
dtrace_vstate_t *vstate;
dtrace_enabling_t *enab = NULL;
#ifndef __FreeBSD__
proc_t *p = curproc;
#endif
int i, gen, rv, nhelpers = 0, nprovs = 0, destroy = 1;
uintptr_t daddr = (uintptr_t)dof;
ASSERT(MUTEX_HELD(&dtrace_lock));
if ((help = p->p_dtrace_helpers) == NULL)
help = dtrace_helpers_create(p);
vstate = &help->dthps_vstate;
if ((rv = dtrace_dof_slurp(dof, vstate, NULL, &enab,
dhp != NULL ? dhp->dofhp_addr : 0, B_FALSE)) != 0) {
dtrace_dof_destroy(dof);
return (rv);
}
/*
* Look for helper providers and validate their descriptions.
*/
if (dhp != NULL) {
for (i = 0; i < dof->dofh_secnum; i++) {
dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
dof->dofh_secoff + i * dof->dofh_secsize);
if (sec->dofs_type != DOF_SECT_PROVIDER)
continue;
if (dtrace_helper_provider_validate(dof, sec) != 0) {
dtrace_enabling_destroy(enab);
dtrace_dof_destroy(dof);
return (-1);
}
nprovs++;
}
}
/*
* Now we need to walk through the ECB descriptions in the enabling.
*/
for (i = 0; i < enab->dten_ndesc; i++) {
dtrace_ecbdesc_t *ep = enab->dten_desc[i];
dtrace_probedesc_t *desc = &ep->dted_probe;
if (strcmp(desc->dtpd_provider, "dtrace") != 0)
continue;
if (strcmp(desc->dtpd_mod, "helper") != 0)
continue;
if (strcmp(desc->dtpd_func, "ustack") != 0)
continue;
if ((rv = dtrace_helper_action_add(DTRACE_HELPER_ACTION_USTACK,
ep, help)) != 0) {
/*
* Adding this helper action failed -- we are now going
* to rip out the entire generation and return failure.
*/
(void) dtrace_helper_destroygen(help,
help->dthps_generation);
dtrace_enabling_destroy(enab);
dtrace_dof_destroy(dof);
return (-1);
}
nhelpers++;
}
if (nhelpers < enab->dten_ndesc)
dtrace_dof_error(dof, "unmatched helpers");
gen = help->dthps_generation++;
dtrace_enabling_destroy(enab);
if (dhp != NULL && nprovs > 0) {
/*
* Now that this is in-kernel, we change the sense of the
* members: dofhp_dof denotes the in-kernel copy of the DOF
* and dofhp_addr denotes the address at user-level.
*/
dhp->dofhp_addr = dhp->dofhp_dof;
dhp->dofhp_dof = (uint64_t)(uintptr_t)dof;
if (dtrace_helper_provider_add(dhp, help, gen) == 0) {
mutex_exit(&dtrace_lock);
dtrace_helper_provider_register(p, help, dhp);
mutex_enter(&dtrace_lock);
destroy = 0;
}
}
if (destroy)
dtrace_dof_destroy(dof);
return (gen);
}
static dtrace_helpers_t *
dtrace_helpers_create(proc_t *p)
{
dtrace_helpers_t *help;
ASSERT(MUTEX_HELD(&dtrace_lock));
ASSERT(p->p_dtrace_helpers == NULL);
help = kmem_zalloc(sizeof (dtrace_helpers_t), KM_SLEEP);
help->dthps_actions = kmem_zalloc(sizeof (dtrace_helper_action_t *) *
DTRACE_NHELPER_ACTIONS, KM_SLEEP);
p->p_dtrace_helpers = help;
dtrace_helpers++;
return (help);
}
#ifdef illumos
static
#endif
void
dtrace_helpers_destroy(proc_t *p)
{
dtrace_helpers_t *help;
dtrace_vstate_t *vstate;
#ifdef illumos
proc_t *p = curproc;
#endif
int i;
mutex_enter(&dtrace_lock);
ASSERT(p->p_dtrace_helpers != NULL);
ASSERT(dtrace_helpers > 0);
help = p->p_dtrace_helpers;
vstate = &help->dthps_vstate;
/*
* We're now going to lose the help from this process.
*/
p->p_dtrace_helpers = NULL;
dtrace_sync();
/*
* Destory the helper actions.
*/
for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
dtrace_helper_action_t *h, *next;
for (h = help->dthps_actions[i]; h != NULL; h = next) {
next = h->dtha_next;
dtrace_helper_action_destroy(h, vstate);
h = next;
}
}
mutex_exit(&dtrace_lock);
/*
* Destroy the helper providers.
*/
if (help->dthps_maxprovs > 0) {
mutex_enter(&dtrace_meta_lock);
if (dtrace_meta_pid != NULL) {
ASSERT(dtrace_deferred_pid == NULL);
for (i = 0; i < help->dthps_nprovs; i++) {
dtrace_helper_provider_remove(
&help->dthps_provs[i]->dthp_prov, p->p_pid);
}
} else {
mutex_enter(&dtrace_lock);
ASSERT(help->dthps_deferred == 0 ||
help->dthps_next != NULL ||
help->dthps_prev != NULL ||
help == dtrace_deferred_pid);
/*
* Remove the helper from the deferred list.
*/
if (help->dthps_next != NULL)
help->dthps_next->dthps_prev = help->dthps_prev;
if (help->dthps_prev != NULL)
help->dthps_prev->dthps_next = help->dthps_next;
if (dtrace_deferred_pid == help) {
dtrace_deferred_pid = help->dthps_next;
ASSERT(help->dthps_prev == NULL);
}
mutex_exit(&dtrace_lock);
}
mutex_exit(&dtrace_meta_lock);
for (i = 0; i < help->dthps_nprovs; i++) {
dtrace_helper_provider_destroy(help->dthps_provs[i]);
}
kmem_free(help->dthps_provs, help->dthps_maxprovs *
sizeof (dtrace_helper_provider_t *));
}
mutex_enter(&dtrace_lock);
dtrace_vstate_fini(&help->dthps_vstate);
kmem_free(help->dthps_actions,
sizeof (dtrace_helper_action_t *) * DTRACE_NHELPER_ACTIONS);
kmem_free(help, sizeof (dtrace_helpers_t));
--dtrace_helpers;
mutex_exit(&dtrace_lock);
}
#ifdef illumos
static
#endif
void
dtrace_helpers_duplicate(proc_t *from, proc_t *to)
{
dtrace_helpers_t *help, *newhelp;
dtrace_helper_action_t *helper, *new, *last;
dtrace_difo_t *dp;
dtrace_vstate_t *vstate;
int i, j, sz, hasprovs = 0;
mutex_enter(&dtrace_lock);
ASSERT(from->p_dtrace_helpers != NULL);
ASSERT(dtrace_helpers > 0);
help = from->p_dtrace_helpers;
newhelp = dtrace_helpers_create(to);
ASSERT(to->p_dtrace_helpers != NULL);
newhelp->dthps_generation = help->dthps_generation;
vstate = &newhelp->dthps_vstate;
/*
* Duplicate the helper actions.
*/
for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
if ((helper = help->dthps_actions[i]) == NULL)
continue;
for (last = NULL; helper != NULL; helper = helper->dtha_next) {
new = kmem_zalloc(sizeof (dtrace_helper_action_t),
KM_SLEEP);
new->dtha_generation = helper->dtha_generation;
if ((dp = helper->dtha_predicate) != NULL) {
dp = dtrace_difo_duplicate(dp, vstate);
new->dtha_predicate = dp;
}
new->dtha_nactions = helper->dtha_nactions;
sz = sizeof (dtrace_difo_t *) * new->dtha_nactions;
new->dtha_actions = kmem_alloc(sz, KM_SLEEP);
for (j = 0; j < new->dtha_nactions; j++) {
dtrace_difo_t *dp = helper->dtha_actions[j];
ASSERT(dp != NULL);
dp = dtrace_difo_duplicate(dp, vstate);
new->dtha_actions[j] = dp;
}
if (last != NULL) {
last->dtha_next = new;
} else {
newhelp->dthps_actions[i] = new;
}
last = new;
}
}
/*
* Duplicate the helper providers and register them with the
* DTrace framework.
*/
if (help->dthps_nprovs > 0) {
newhelp->dthps_nprovs = help->dthps_nprovs;
newhelp->dthps_maxprovs = help->dthps_nprovs;
newhelp->dthps_provs = kmem_alloc(newhelp->dthps_nprovs *
sizeof (dtrace_helper_provider_t *), KM_SLEEP);
for (i = 0; i < newhelp->dthps_nprovs; i++) {
newhelp->dthps_provs[i] = help->dthps_provs[i];
newhelp->dthps_provs[i]->dthp_ref++;
}
hasprovs = 1;
}
mutex_exit(&dtrace_lock);
if (hasprovs)
dtrace_helper_provider_register(to, newhelp, NULL);
}
/*
* DTrace Hook Functions
*/
static void
dtrace_module_loaded(modctl_t *ctl)
{
dtrace_provider_t *prv;
mutex_enter(&dtrace_provider_lock);
#ifdef illumos
mutex_enter(&mod_lock);
#endif
#ifdef illumos
ASSERT(ctl->mod_busy);
#endif
/*
* We're going to call each providers per-module provide operation
* specifying only this module.
*/
for (prv = dtrace_provider; prv != NULL; prv = prv->dtpv_next)
prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_provider_lock);
/*
* If we have any retained enablings, we need to match against them.
* Enabling probes requires that cpu_lock be held, and we cannot hold
* cpu_lock here -- it is legal for cpu_lock to be held when loading a
* module. (In particular, this happens when loading scheduling
* classes.) So if we have any retained enablings, we need to dispatch
* our task queue to do the match for us.
*/
mutex_enter(&dtrace_lock);
if (dtrace_retained == NULL) {
mutex_exit(&dtrace_lock);
return;
}
(void) taskq_dispatch(dtrace_taskq,
(task_func_t *)dtrace_enabling_matchall, NULL, TQ_SLEEP);
mutex_exit(&dtrace_lock);
/*
* And now, for a little heuristic sleaze: in general, we want to
* match modules as soon as they load. However, we cannot guarantee
* this, because it would lead us to the lock ordering violation
* outlined above. The common case, of course, is that cpu_lock is
* _not_ held -- so we delay here for a clock tick, hoping that that's
* long enough for the task queue to do its work. If it's not, it's
* not a serious problem -- it just means that the module that we
* just loaded may not be immediately instrumentable.
*/
delay(1);
}
static void
#ifdef illumos
dtrace_module_unloaded(modctl_t *ctl)
#else
dtrace_module_unloaded(modctl_t *ctl, int *error)
#endif
{
dtrace_probe_t template, *probe, *first, *next;
dtrace_provider_t *prov;
#ifndef illumos
char modname[DTRACE_MODNAMELEN];
size_t len;
#endif
#ifdef illumos
template.dtpr_mod = ctl->mod_modname;
#else
/* Handle the fact that ctl->filename may end in ".ko". */
strlcpy(modname, ctl->filename, sizeof(modname));
len = strlen(ctl->filename);
if (len > 3 && strcmp(modname + len - 3, ".ko") == 0)
modname[len - 3] = '\0';
template.dtpr_mod = modname;
#endif
mutex_enter(&dtrace_provider_lock);
#ifdef illumos
mutex_enter(&mod_lock);
#endif
mutex_enter(&dtrace_lock);
#ifndef illumos
if (ctl->nenabled > 0) {
/* Don't allow unloads if a probe is enabled. */
mutex_exit(&dtrace_provider_lock);
mutex_exit(&dtrace_lock);
*error = -1;
printf(
"kldunload: attempt to unload module that has DTrace probes enabled\n");
return;
}
#endif
if (dtrace_bymod == NULL) {
/*
* The DTrace module is loaded (obviously) but not attached;
* we don't have any work to do.
*/
mutex_exit(&dtrace_provider_lock);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_lock);
return;
}
for (probe = first = dtrace_hash_lookup(dtrace_bymod, &template);
probe != NULL; probe = probe->dtpr_nextmod) {
if (probe->dtpr_ecb != NULL) {
mutex_exit(&dtrace_provider_lock);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_lock);
/*
* This shouldn't _actually_ be possible -- we're
* unloading a module that has an enabled probe in it.
* (It's normally up to the provider to make sure that
* this can't happen.) However, because dtps_enable()
* doesn't have a failure mode, there can be an
* enable/unload race. Upshot: we don't want to
* assert, but we're not going to disable the
* probe, either.
*/
if (dtrace_err_verbose) {
#ifdef illumos
cmn_err(CE_WARN, "unloaded module '%s' had "
"enabled probes", ctl->mod_modname);
#else
cmn_err(CE_WARN, "unloaded module '%s' had "
"enabled probes", modname);
#endif
}
return;
}
}
probe = first;
for (first = NULL; probe != NULL; probe = next) {
ASSERT(dtrace_probes[probe->dtpr_id - 1] == probe);
dtrace_probes[probe->dtpr_id - 1] = NULL;
next = probe->dtpr_nextmod;
dtrace_hash_remove(dtrace_bymod, probe);
dtrace_hash_remove(dtrace_byfunc, probe);
dtrace_hash_remove(dtrace_byname, probe);
if (first == NULL) {
first = probe;
probe->dtpr_nextmod = NULL;
} else {
probe->dtpr_nextmod = first;
first = probe;
}
}
/*
* We've removed all of the module's probes from the hash chains and
* from the probe array. Now issue a dtrace_sync() to be sure that
* everyone has cleared out from any probe array processing.
*/
dtrace_sync();
for (probe = first; probe != NULL; probe = first) {
first = probe->dtpr_nextmod;
prov = probe->dtpr_provider;
prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, probe->dtpr_id,
probe->dtpr_arg);
kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
#ifdef illumos
vmem_free(dtrace_arena, (void *)(uintptr_t)probe->dtpr_id, 1);
#else
free_unr(dtrace_arena, probe->dtpr_id);
#endif
kmem_free(probe, sizeof (dtrace_probe_t));
}
mutex_exit(&dtrace_lock);
#ifdef illumos
mutex_exit(&mod_lock);
#endif
mutex_exit(&dtrace_provider_lock);
}
#ifndef illumos
static void
dtrace_kld_load(void *arg __unused, linker_file_t lf)
{
dtrace_module_loaded(lf);
}
static void
dtrace_kld_unload_try(void *arg __unused, linker_file_t lf, int *error)
{
if (*error != 0)
/* We already have an error, so don't do anything. */
return;
dtrace_module_unloaded(lf, error);
}
#endif
#ifdef illumos
static void
dtrace_suspend(void)
{
dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_suspend));
}
static void
dtrace_resume(void)
{
dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_resume));
}
#endif
static int
dtrace_cpu_setup(cpu_setup_t what, processorid_t cpu)
{
ASSERT(MUTEX_HELD(&cpu_lock));
mutex_enter(&dtrace_lock);
switch (what) {
case CPU_CONFIG: {
dtrace_state_t *state;
dtrace_optval_t *opt, rs, c;
/*
* For now, we only allocate a new buffer for anonymous state.
*/
if ((state = dtrace_anon.dta_state) == NULL)
break;
if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
break;
opt = state->dts_options;
c = opt[DTRACEOPT_CPU];
if (c != DTRACE_CPUALL && c != DTRACEOPT_UNSET && c != cpu)
break;
/*
* Regardless of what the actual policy is, we're going to
* temporarily set our resize policy to be manual. We're
* also going to temporarily set our CPU option to denote
* the newly configured CPU.
*/
rs = opt[DTRACEOPT_BUFRESIZE];
opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_MANUAL;
opt[DTRACEOPT_CPU] = (dtrace_optval_t)cpu;
(void) dtrace_state_buffers(state);
opt[DTRACEOPT_BUFRESIZE] = rs;
opt[DTRACEOPT_CPU] = c;
break;
}
case CPU_UNCONFIG:
/*
* We don't free the buffer in the CPU_UNCONFIG case. (The
* buffer will be freed when the consumer exits.)
*/
break;
default:
break;
}
mutex_exit(&dtrace_lock);
return (0);
}
#ifdef illumos
static void
dtrace_cpu_setup_initial(processorid_t cpu)
{
(void) dtrace_cpu_setup(CPU_CONFIG, cpu);
}
#endif
static void
dtrace_toxrange_add(uintptr_t base, uintptr_t limit)
{
if (dtrace_toxranges >= dtrace_toxranges_max) {
int osize, nsize;
dtrace_toxrange_t *range;
osize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
if (osize == 0) {
ASSERT(dtrace_toxrange == NULL);
ASSERT(dtrace_toxranges_max == 0);
dtrace_toxranges_max = 1;
} else {
dtrace_toxranges_max <<= 1;
}
nsize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
range = kmem_zalloc(nsize, KM_SLEEP);
if (dtrace_toxrange != NULL) {
ASSERT(osize != 0);
bcopy(dtrace_toxrange, range, osize);
kmem_free(dtrace_toxrange, osize);
}
dtrace_toxrange = range;
}
ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_base == 0);
ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_limit == 0);
dtrace_toxrange[dtrace_toxranges].dtt_base = base;
dtrace_toxrange[dtrace_toxranges].dtt_limit = limit;
dtrace_toxranges++;
}
static void
dtrace_getf_barrier()
{
#ifdef illumos
/*
* When we have unprivileged (that is, non-DTRACE_CRV_KERNEL) enablings
* that contain calls to getf(), this routine will be called on every
* closef() before either the underlying vnode is released or the
* file_t itself is freed. By the time we are here, it is essential
* that the file_t can no longer be accessed from a call to getf()
* in probe context -- that assures that a dtrace_sync() can be used
* to clear out any enablings referring to the old structures.
*/
if (curthread->t_procp->p_zone->zone_dtrace_getf != 0 ||
kcred->cr_zone->zone_dtrace_getf != 0)
dtrace_sync();
#endif
}
/*
* DTrace Driver Cookbook Functions
*/
#ifdef illumos
/*ARGSUSED*/
static int
dtrace_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
dtrace_provider_id_t id;
dtrace_state_t *state = NULL;
dtrace_enabling_t *enab;
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_provider_lock);
mutex_enter(&dtrace_lock);
if (ddi_soft_state_init(&dtrace_softstate,
sizeof (dtrace_state_t), 0) != 0) {
cmn_err(CE_NOTE, "/dev/dtrace failed to initialize soft state");
mutex_exit(&cpu_lock);
mutex_exit(&dtrace_provider_lock);
mutex_exit(&dtrace_lock);
return (DDI_FAILURE);
}
if (ddi_create_minor_node(devi, DTRACEMNR_DTRACE, S_IFCHR,
DTRACEMNRN_DTRACE, DDI_PSEUDO, NULL) == DDI_FAILURE ||
ddi_create_minor_node(devi, DTRACEMNR_HELPER, S_IFCHR,
DTRACEMNRN_HELPER, DDI_PSEUDO, NULL) == DDI_FAILURE) {
cmn_err(CE_NOTE, "/dev/dtrace couldn't create minor nodes");
ddi_remove_minor_node(devi, NULL);
ddi_soft_state_fini(&dtrace_softstate);
mutex_exit(&cpu_lock);
mutex_exit(&dtrace_provider_lock);
mutex_exit(&dtrace_lock);
return (DDI_FAILURE);
}
ddi_report_dev(devi);
dtrace_devi = devi;
dtrace_modload = dtrace_module_loaded;
dtrace_modunload = dtrace_module_unloaded;
dtrace_cpu_init = dtrace_cpu_setup_initial;
dtrace_helpers_cleanup = dtrace_helpers_destroy;
dtrace_helpers_fork = dtrace_helpers_duplicate;
dtrace_cpustart_init = dtrace_suspend;
dtrace_cpustart_fini = dtrace_resume;
dtrace_debugger_init = dtrace_suspend;
dtrace_debugger_fini = dtrace_resume;
register_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
ASSERT(MUTEX_HELD(&cpu_lock));
dtrace_arena = vmem_create("dtrace", (void *)1, UINT32_MAX, 1,
NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
dtrace_minor = vmem_create("dtrace_minor", (void *)DTRACEMNRN_CLONE,
UINT32_MAX - DTRACEMNRN_CLONE, 1, NULL, NULL, NULL, 0,
VM_SLEEP | VMC_IDENTIFIER);
dtrace_taskq = taskq_create("dtrace_taskq", 1, maxclsyspri,
1, INT_MAX, 0);
dtrace_state_cache = kmem_cache_create("dtrace_state_cache",
sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
NULL, NULL, NULL, NULL, NULL, 0);
ASSERT(MUTEX_HELD(&cpu_lock));
dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
offsetof(dtrace_probe_t, dtpr_nextmod),
offsetof(dtrace_probe_t, dtpr_prevmod));
dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
offsetof(dtrace_probe_t, dtpr_nextfunc),
offsetof(dtrace_probe_t, dtpr_prevfunc));
dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
offsetof(dtrace_probe_t, dtpr_nextname),
offsetof(dtrace_probe_t, dtpr_prevname));
if (dtrace_retain_max < 1) {
cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
"setting to 1", dtrace_retain_max);
dtrace_retain_max = 1;
}
/*
* Now discover our toxic ranges.
*/
dtrace_toxic_ranges(dtrace_toxrange_add);
/*
* Before we register ourselves as a provider to our own framework,
* we would like to assert that dtrace_provider is NULL -- but that's
* not true if we were loaded as a dependency of a DTrace provider.
* Once we've registered, we can assert that dtrace_provider is our
* pseudo provider.
*/
(void) dtrace_register("dtrace", &dtrace_provider_attr,
DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
ASSERT(dtrace_provider != NULL);
ASSERT((dtrace_provider_id_t)dtrace_provider == id);
dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
dtrace_provider, NULL, NULL, "END", 0, NULL);
dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
dtrace_anon_property();
mutex_exit(&cpu_lock);
/*
* If there are already providers, we must ask them to provide their
* probes, and then match any anonymous enabling against them. Note
* that there should be no other retained enablings at this time:
* the only retained enablings at this time should be the anonymous
* enabling.
*/
if (dtrace_anon.dta_enabling != NULL) {
ASSERT(dtrace_retained == dtrace_anon.dta_enabling);
dtrace_enabling_provide(NULL);
state = dtrace_anon.dta_state;
/*
* We couldn't hold cpu_lock across the above call to
* dtrace_enabling_provide(), but we must hold it to actually
* enable the probes. We have to drop all of our locks, pick
* up cpu_lock, and regain our locks before matching the
* retained anonymous enabling.
*/
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_provider_lock);
mutex_enter(&dtrace_lock);
if ((enab = dtrace_anon.dta_enabling) != NULL)
(void) dtrace_enabling_match(enab, NULL);
mutex_exit(&cpu_lock);
}
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
if (state != NULL) {
/*
* If we created any anonymous state, set it going now.
*/
(void) dtrace_state_go(state, &dtrace_anon.dta_beganon);
}
return (DDI_SUCCESS);
}
#endif /* illumos */
#ifndef illumos
static void dtrace_dtr(void *);
#endif
/*ARGSUSED*/
static int
#ifdef illumos
dtrace_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
#else
dtrace_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
#endif
{
dtrace_state_t *state;
uint32_t priv;
uid_t uid;
zoneid_t zoneid;
#ifdef illumos
if (getminor(*devp) == DTRACEMNRN_HELPER)
return (0);
/*
* If this wasn't an open with the "helper" minor, then it must be
* the "dtrace" minor.
*/
if (getminor(*devp) == DTRACEMNRN_DTRACE)
return (ENXIO);
#else
cred_t *cred_p = NULL;
cred_p = dev->si_cred;
/*
* If no DTRACE_PRIV_* bits are set in the credential, then the
* caller lacks sufficient permission to do anything with DTrace.
*/
dtrace_cred2priv(cred_p, &priv, &uid, &zoneid);
if (priv == DTRACE_PRIV_NONE) {
#endif
return (EACCES);
}
/*
* Ask all providers to provide all their probes.
*/
mutex_enter(&dtrace_provider_lock);
dtrace_probe_provide(NULL, NULL);
mutex_exit(&dtrace_provider_lock);
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_lock);
dtrace_opens++;
dtrace_membar_producer();
#ifdef illumos
/*
* If the kernel debugger is active (that is, if the kernel debugger
* modified text in some way), we won't allow the open.
*/
if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
dtrace_opens--;
mutex_exit(&cpu_lock);
mutex_exit(&dtrace_lock);
return (EBUSY);
}
if (dtrace_helptrace_enable && dtrace_helptrace_buffer == NULL) {
/*
* If DTrace helper tracing is enabled, we need to allocate the
* trace buffer and initialize the values.
*/
dtrace_helptrace_buffer =
kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
dtrace_helptrace_next = 0;
dtrace_helptrace_wrapped = 0;
dtrace_helptrace_enable = 0;
}
state = dtrace_state_create(devp, cred_p);
#else
state = dtrace_state_create(dev, NULL);
devfs_set_cdevpriv(state, dtrace_dtr);
#endif
mutex_exit(&cpu_lock);
if (state == NULL) {
#ifdef illumos
if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL)
(void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
#else
--dtrace_opens;
#endif
mutex_exit(&dtrace_lock);
return (EAGAIN);
}
mutex_exit(&dtrace_lock);
return (0);
}
/*ARGSUSED*/
#ifdef illumos
static int
dtrace_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
#else
static void
dtrace_dtr(void *data)
#endif
{
#ifdef illumos
minor_t minor = getminor(dev);
dtrace_state_t *state;
#endif
dtrace_helptrace_t *buf = NULL;
#ifdef illumos
if (minor == DTRACEMNRN_HELPER)
return (0);
state = ddi_get_soft_state(dtrace_softstate, minor);
#else
dtrace_state_t *state = data;
#endif
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_lock);
#ifdef illumos
if (state->dts_anon)
#else
if (state != NULL && state->dts_anon)
#endif
{
/*
* There is anonymous state. Destroy that first.
*/
ASSERT(dtrace_anon.dta_state == NULL);
dtrace_state_destroy(state->dts_anon);
}
if (dtrace_helptrace_disable) {
/*
* If we have been told to disable helper tracing, set the
* buffer to NULL before calling into dtrace_state_destroy();
* we take advantage of its dtrace_sync() to know that no
* CPU is in probe context with enabled helper tracing
* after it returns.
*/
buf = dtrace_helptrace_buffer;
dtrace_helptrace_buffer = NULL;
}
#ifdef illumos
dtrace_state_destroy(state);
#else
if (state != NULL) {
dtrace_state_destroy(state);
kmem_free(state, 0);
}
#endif
ASSERT(dtrace_opens > 0);
#ifdef illumos
/*
* Only relinquish control of the kernel debugger interface when there
* are no consumers and no anonymous enablings.
*/
if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL)
(void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
#else
--dtrace_opens;
#endif
if (buf != NULL) {
kmem_free(buf, dtrace_helptrace_bufsize);
dtrace_helptrace_disable = 0;
}
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
#ifdef illumos
return (0);
#endif
}
#ifdef illumos
/*ARGSUSED*/
static int
dtrace_ioctl_helper(int cmd, intptr_t arg, int *rv)
{
int rval;
dof_helper_t help, *dhp = NULL;
switch (cmd) {
case DTRACEHIOC_ADDDOF:
if (copyin((void *)arg, &help, sizeof (help)) != 0) {
dtrace_dof_error(NULL, "failed to copyin DOF helper");
return (EFAULT);
}
dhp = &help;
arg = (intptr_t)help.dofhp_dof;
/*FALLTHROUGH*/
case DTRACEHIOC_ADD: {
dof_hdr_t *dof = dtrace_dof_copyin(arg, &rval);
if (dof == NULL)
return (rval);
mutex_enter(&dtrace_lock);
/*
* dtrace_helper_slurp() takes responsibility for the dof --
* it may free it now or it may save it and free it later.
*/
if ((rval = dtrace_helper_slurp(dof, dhp)) != -1) {
*rv = rval;
rval = 0;
} else {
rval = EINVAL;
}
mutex_exit(&dtrace_lock);
return (rval);
}
case DTRACEHIOC_REMOVE: {
mutex_enter(&dtrace_lock);
rval = dtrace_helper_destroygen(NULL, arg);
mutex_exit(&dtrace_lock);
return (rval);
}
default:
break;
}
return (ENOTTY);
}
/*ARGSUSED*/
static int
dtrace_ioctl(dev_t dev, int cmd, intptr_t arg, int md, cred_t *cr, int *rv)
{
minor_t minor = getminor(dev);
dtrace_state_t *state;
int rval;
if (minor == DTRACEMNRN_HELPER)
return (dtrace_ioctl_helper(cmd, arg, rv));
state = ddi_get_soft_state(dtrace_softstate, minor);
if (state->dts_anon) {
ASSERT(dtrace_anon.dta_state == NULL);
state = state->dts_anon;
}
switch (cmd) {
case DTRACEIOC_PROVIDER: {
dtrace_providerdesc_t pvd;
dtrace_provider_t *pvp;
if (copyin((void *)arg, &pvd, sizeof (pvd)) != 0)
return (EFAULT);
pvd.dtvd_name[DTRACE_PROVNAMELEN - 1] = '\0';
mutex_enter(&dtrace_provider_lock);
for (pvp = dtrace_provider; pvp != NULL; pvp = pvp->dtpv_next) {
if (strcmp(pvp->dtpv_name, pvd.dtvd_name) == 0)
break;
}
mutex_exit(&dtrace_provider_lock);
if (pvp == NULL)
return (ESRCH);
bcopy(&pvp->dtpv_priv, &pvd.dtvd_priv, sizeof (dtrace_ppriv_t));
bcopy(&pvp->dtpv_attr, &pvd.dtvd_attr, sizeof (dtrace_pattr_t));
if (copyout(&pvd, (void *)arg, sizeof (pvd)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_EPROBE: {
dtrace_eprobedesc_t epdesc;
dtrace_ecb_t *ecb;
dtrace_action_t *act;
void *buf;
size_t size;
uintptr_t dest;
int nrecs;
if (copyin((void *)arg, &epdesc, sizeof (epdesc)) != 0)
return (EFAULT);
mutex_enter(&dtrace_lock);
if ((ecb = dtrace_epid2ecb(state, epdesc.dtepd_epid)) == NULL) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
if (ecb->dte_probe == NULL) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
epdesc.dtepd_probeid = ecb->dte_probe->dtpr_id;
epdesc.dtepd_uarg = ecb->dte_uarg;
epdesc.dtepd_size = ecb->dte_size;
nrecs = epdesc.dtepd_nrecs;
epdesc.dtepd_nrecs = 0;
for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
continue;
epdesc.dtepd_nrecs++;
}
/*
* Now that we have the size, we need to allocate a temporary
* buffer in which to store the complete description. We need
* the temporary buffer to be able to drop dtrace_lock()
* across the copyout(), below.
*/
size = sizeof (dtrace_eprobedesc_t) +
(epdesc.dtepd_nrecs * sizeof (dtrace_recdesc_t));
buf = kmem_alloc(size, KM_SLEEP);
dest = (uintptr_t)buf;
bcopy(&epdesc, (void *)dest, sizeof (epdesc));
dest += offsetof(dtrace_eprobedesc_t, dtepd_rec[0]);
for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
continue;
if (nrecs-- == 0)
break;
bcopy(&act->dta_rec, (void *)dest,
sizeof (dtrace_recdesc_t));
dest += sizeof (dtrace_recdesc_t);
}
mutex_exit(&dtrace_lock);
if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
kmem_free(buf, size);
return (EFAULT);
}
kmem_free(buf, size);
return (0);
}
case DTRACEIOC_AGGDESC: {
dtrace_aggdesc_t aggdesc;
dtrace_action_t *act;
dtrace_aggregation_t *agg;
int nrecs;
uint32_t offs;
dtrace_recdesc_t *lrec;
void *buf;
size_t size;
uintptr_t dest;
if (copyin((void *)arg, &aggdesc, sizeof (aggdesc)) != 0)
return (EFAULT);
mutex_enter(&dtrace_lock);
if ((agg = dtrace_aggid2agg(state, aggdesc.dtagd_id)) == NULL) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
aggdesc.dtagd_epid = agg->dtag_ecb->dte_epid;
nrecs = aggdesc.dtagd_nrecs;
aggdesc.dtagd_nrecs = 0;
offs = agg->dtag_base;
lrec = &agg->dtag_action.dta_rec;
aggdesc.dtagd_size = lrec->dtrd_offset + lrec->dtrd_size - offs;
for (act = agg->dtag_first; ; act = act->dta_next) {
ASSERT(act->dta_intuple ||
DTRACEACT_ISAGG(act->dta_kind));
/*
* If this action has a record size of zero, it
* denotes an argument to the aggregating action.
* Because the presence of this record doesn't (or
* shouldn't) affect the way the data is interpreted,
* we don't copy it out to save user-level the
* confusion of dealing with a zero-length record.
*/
if (act->dta_rec.dtrd_size == 0) {
ASSERT(agg->dtag_hasarg);
continue;
}
aggdesc.dtagd_nrecs++;
if (act == &agg->dtag_action)
break;
}
/*
* Now that we have the size, we need to allocate a temporary
* buffer in which to store the complete description. We need
* the temporary buffer to be able to drop dtrace_lock()
* across the copyout(), below.
*/
size = sizeof (dtrace_aggdesc_t) +
(aggdesc.dtagd_nrecs * sizeof (dtrace_recdesc_t));
buf = kmem_alloc(size, KM_SLEEP);
dest = (uintptr_t)buf;
bcopy(&aggdesc, (void *)dest, sizeof (aggdesc));
dest += offsetof(dtrace_aggdesc_t, dtagd_rec[0]);
for (act = agg->dtag_first; ; act = act->dta_next) {
dtrace_recdesc_t rec = act->dta_rec;
/*
* See the comment in the above loop for why we pass
* over zero-length records.
*/
if (rec.dtrd_size == 0) {
ASSERT(agg->dtag_hasarg);
continue;
}
if (nrecs-- == 0)
break;
rec.dtrd_offset -= offs;
bcopy(&rec, (void *)dest, sizeof (rec));
dest += sizeof (dtrace_recdesc_t);
if (act == &agg->dtag_action)
break;
}
mutex_exit(&dtrace_lock);
if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
kmem_free(buf, size);
return (EFAULT);
}
kmem_free(buf, size);
return (0);
}
case DTRACEIOC_ENABLE: {
dof_hdr_t *dof;
dtrace_enabling_t *enab = NULL;
dtrace_vstate_t *vstate;
int err = 0;
*rv = 0;
/*
* If a NULL argument has been passed, we take this as our
* cue to reevaluate our enablings.
*/
if (arg == NULL) {
dtrace_enabling_matchall();
return (0);
}
if ((dof = dtrace_dof_copyin(arg, &rval)) == NULL)
return (rval);
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_lock);
vstate = &state->dts_vstate;
if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
dtrace_dof_destroy(dof);
return (EBUSY);
}
if (dtrace_dof_slurp(dof, vstate, cr, &enab, 0, B_TRUE) != 0) {
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
dtrace_dof_destroy(dof);
return (EINVAL);
}
if ((rval = dtrace_dof_options(dof, state)) != 0) {
dtrace_enabling_destroy(enab);
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
dtrace_dof_destroy(dof);
return (rval);
}
if ((err = dtrace_enabling_match(enab, rv)) == 0) {
err = dtrace_enabling_retain(enab);
} else {
dtrace_enabling_destroy(enab);
}
mutex_exit(&cpu_lock);
mutex_exit(&dtrace_lock);
dtrace_dof_destroy(dof);
return (err);
}
case DTRACEIOC_REPLICATE: {
dtrace_repldesc_t desc;
dtrace_probedesc_t *match = &desc.dtrpd_match;
dtrace_probedesc_t *create = &desc.dtrpd_create;
int err;
if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
return (EFAULT);
match->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
match->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
match->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
match->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
create->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
create->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
create->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
create->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
mutex_enter(&dtrace_lock);
err = dtrace_enabling_replicate(state, match, create);
mutex_exit(&dtrace_lock);
return (err);
}
case DTRACEIOC_PROBEMATCH:
case DTRACEIOC_PROBES: {
dtrace_probe_t *probe = NULL;
dtrace_probedesc_t desc;
dtrace_probekey_t pkey;
dtrace_id_t i;
int m = 0;
uint32_t priv;
uid_t uid;
zoneid_t zoneid;
if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
return (EFAULT);
desc.dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
desc.dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
desc.dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
desc.dtpd_name[DTRACE_NAMELEN - 1] = '\0';
/*
* Before we attempt to match this probe, we want to give
* all providers the opportunity to provide it.
*/
if (desc.dtpd_id == DTRACE_IDNONE) {
mutex_enter(&dtrace_provider_lock);
dtrace_probe_provide(&desc, NULL);
mutex_exit(&dtrace_provider_lock);
desc.dtpd_id++;
}
if (cmd == DTRACEIOC_PROBEMATCH) {
dtrace_probekey(&desc, &pkey);
pkey.dtpk_id = DTRACE_IDNONE;
}
dtrace_cred2priv(cr, &priv, &uid, &zoneid);
mutex_enter(&dtrace_lock);
if (cmd == DTRACEIOC_PROBEMATCH) {
for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i - 1]) != NULL &&
(m = dtrace_match_probe(probe, &pkey,
priv, uid, zoneid)) != 0)
break;
}
if (m < 0) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
} else {
for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
if ((probe = dtrace_probes[i - 1]) != NULL &&
dtrace_match_priv(probe, priv, uid, zoneid))
break;
}
}
if (probe == NULL) {
mutex_exit(&dtrace_lock);
return (ESRCH);
}
dtrace_probe_description(probe, &desc);
mutex_exit(&dtrace_lock);
if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_PROBEARG: {
dtrace_argdesc_t desc;
dtrace_probe_t *probe;
dtrace_provider_t *prov;
if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
return (EFAULT);
if (desc.dtargd_id == DTRACE_IDNONE)
return (EINVAL);
if (desc.dtargd_ndx == DTRACE_ARGNONE)
return (EINVAL);
mutex_enter(&dtrace_provider_lock);
mutex_enter(&mod_lock);
mutex_enter(&dtrace_lock);
if (desc.dtargd_id > dtrace_nprobes) {
mutex_exit(&dtrace_lock);
mutex_exit(&mod_lock);
mutex_exit(&dtrace_provider_lock);
return (EINVAL);
}
if ((probe = dtrace_probes[desc.dtargd_id - 1]) == NULL) {
mutex_exit(&dtrace_lock);
mutex_exit(&mod_lock);
mutex_exit(&dtrace_provider_lock);
return (EINVAL);
}
mutex_exit(&dtrace_lock);
prov = probe->dtpr_provider;
if (prov->dtpv_pops.dtps_getargdesc == NULL) {
/*
* There isn't any typed information for this probe.
* Set the argument number to DTRACE_ARGNONE.
*/
desc.dtargd_ndx = DTRACE_ARGNONE;
} else {
desc.dtargd_native[0] = '\0';
desc.dtargd_xlate[0] = '\0';
desc.dtargd_mapping = desc.dtargd_ndx;
prov->dtpv_pops.dtps_getargdesc(prov->dtpv_arg,
probe->dtpr_id, probe->dtpr_arg, &desc);
}
mutex_exit(&mod_lock);
mutex_exit(&dtrace_provider_lock);
if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_GO: {
processorid_t cpuid;
rval = dtrace_state_go(state, &cpuid);
if (rval != 0)
return (rval);
if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_STOP: {
processorid_t cpuid;
mutex_enter(&dtrace_lock);
rval = dtrace_state_stop(state, &cpuid);
mutex_exit(&dtrace_lock);
if (rval != 0)
return (rval);
if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_DOFGET: {
dof_hdr_t hdr, *dof;
uint64_t len;
if (copyin((void *)arg, &hdr, sizeof (hdr)) != 0)
return (EFAULT);
mutex_enter(&dtrace_lock);
dof = dtrace_dof_create(state);
mutex_exit(&dtrace_lock);
len = MIN(hdr.dofh_loadsz, dof->dofh_loadsz);
rval = copyout(dof, (void *)arg, len);
dtrace_dof_destroy(dof);
return (rval == 0 ? 0 : EFAULT);
}
case DTRACEIOC_AGGSNAP:
case DTRACEIOC_BUFSNAP: {
dtrace_bufdesc_t desc;
caddr_t cached;
dtrace_buffer_t *buf;
if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
return (EFAULT);
if (desc.dtbd_cpu < 0 || desc.dtbd_cpu >= NCPU)
return (EINVAL);
mutex_enter(&dtrace_lock);
if (cmd == DTRACEIOC_BUFSNAP) {
buf = &state->dts_buffer[desc.dtbd_cpu];
} else {
buf = &state->dts_aggbuffer[desc.dtbd_cpu];
}
if (buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL)) {
size_t sz = buf->dtb_offset;
if (state->dts_activity != DTRACE_ACTIVITY_STOPPED) {
mutex_exit(&dtrace_lock);
return (EBUSY);
}
/*
* If this buffer has already been consumed, we're
* going to indicate that there's nothing left here
* to consume.
*/
if (buf->dtb_flags & DTRACEBUF_CONSUMED) {
mutex_exit(&dtrace_lock);
desc.dtbd_size = 0;
desc.dtbd_drops = 0;
desc.dtbd_errors = 0;
desc.dtbd_oldest = 0;
sz = sizeof (desc);
if (copyout(&desc, (void *)arg, sz) != 0)
return (EFAULT);
return (0);
}
/*
* If this is a ring buffer that has wrapped, we want
* to copy the whole thing out.
*/
if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
dtrace_buffer_polish(buf);
sz = buf->dtb_size;
}
if (copyout(buf->dtb_tomax, desc.dtbd_data, sz) != 0) {
mutex_exit(&dtrace_lock);
return (EFAULT);
}
desc.dtbd_size = sz;
desc.dtbd_drops = buf->dtb_drops;
desc.dtbd_errors = buf->dtb_errors;
desc.dtbd_oldest = buf->dtb_xamot_offset;
desc.dtbd_timestamp = dtrace_gethrtime();
mutex_exit(&dtrace_lock);
if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
return (EFAULT);
buf->dtb_flags |= DTRACEBUF_CONSUMED;
return (0);
}
if (buf->dtb_tomax == NULL) {
ASSERT(buf->dtb_xamot == NULL);
mutex_exit(&dtrace_lock);
return (ENOENT);
}
cached = buf->dtb_tomax;
ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
dtrace_xcall(desc.dtbd_cpu,
(dtrace_xcall_t)dtrace_buffer_switch, buf);
state->dts_errors += buf->dtb_xamot_errors;
/*
* If the buffers did not actually switch, then the cross call
* did not take place -- presumably because the given CPU is
* not in the ready set. If this is the case, we'll return
* ENOENT.
*/
if (buf->dtb_tomax == cached) {
ASSERT(buf->dtb_xamot != cached);
mutex_exit(&dtrace_lock);
return (ENOENT);
}
ASSERT(cached == buf->dtb_xamot);
/*
* We have our snapshot; now copy it out.
*/
if (copyout(buf->dtb_xamot, desc.dtbd_data,
buf->dtb_xamot_offset) != 0) {
mutex_exit(&dtrace_lock);
return (EFAULT);
}
desc.dtbd_size = buf->dtb_xamot_offset;
desc.dtbd_drops = buf->dtb_xamot_drops;
desc.dtbd_errors = buf->dtb_xamot_errors;
desc.dtbd_oldest = 0;
desc.dtbd_timestamp = buf->dtb_switched;
mutex_exit(&dtrace_lock);
/*
* Finally, copy out the buffer description.
*/
if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_CONF: {
dtrace_conf_t conf;
bzero(&conf, sizeof (conf));
conf.dtc_difversion = DIF_VERSION;
conf.dtc_difintregs = DIF_DIR_NREGS;
conf.dtc_diftupregs = DIF_DTR_NREGS;
conf.dtc_ctfmodel = CTF_MODEL_NATIVE;
if (copyout(&conf, (void *)arg, sizeof (conf)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_STATUS: {
dtrace_status_t stat;
dtrace_dstate_t *dstate;
int i, j;
uint64_t nerrs;
/*
* See the comment in dtrace_state_deadman() for the reason
* for setting dts_laststatus to INT64_MAX before setting
* it to the correct value.
*/
state->dts_laststatus = INT64_MAX;
dtrace_membar_producer();
state->dts_laststatus = dtrace_gethrtime();
bzero(&stat, sizeof (stat));
mutex_enter(&dtrace_lock);
if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE) {
mutex_exit(&dtrace_lock);
return (ENOENT);
}
if (state->dts_activity == DTRACE_ACTIVITY_DRAINING)
stat.dtst_exiting = 1;
nerrs = state->dts_errors;
dstate = &state->dts_vstate.dtvs_dynvars;
for (i = 0; i < NCPU; i++) {
dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[i];
stat.dtst_dyndrops += dcpu->dtdsc_drops;
stat.dtst_dyndrops_dirty += dcpu->dtdsc_dirty_drops;
stat.dtst_dyndrops_rinsing += dcpu->dtdsc_rinsing_drops;
if (state->dts_buffer[i].dtb_flags & DTRACEBUF_FULL)
stat.dtst_filled++;
nerrs += state->dts_buffer[i].dtb_errors;
for (j = 0; j < state->dts_nspeculations; j++) {
dtrace_speculation_t *spec;
dtrace_buffer_t *buf;
spec = &state->dts_speculations[j];
buf = &spec->dtsp_buffer[i];
stat.dtst_specdrops += buf->dtb_xamot_drops;
}
}
stat.dtst_specdrops_busy = state->dts_speculations_busy;
stat.dtst_specdrops_unavail = state->dts_speculations_unavail;
stat.dtst_stkstroverflows = state->dts_stkstroverflows;
stat.dtst_dblerrors = state->dts_dblerrors;
stat.dtst_killed =
(state->dts_activity == DTRACE_ACTIVITY_KILLED);
stat.dtst_errors = nerrs;
mutex_exit(&dtrace_lock);
if (copyout(&stat, (void *)arg, sizeof (stat)) != 0)
return (EFAULT);
return (0);
}
case DTRACEIOC_FORMAT: {
dtrace_fmtdesc_t fmt;
char *str;
int len;
if (copyin((void *)arg, &fmt, sizeof (fmt)) != 0)
return (EFAULT);
mutex_enter(&dtrace_lock);
if (fmt.dtfd_format == 0 ||
fmt.dtfd_format > state->dts_nformats) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
/*
* Format strings are allocated contiguously and they are
* never freed; if a format index is less than the number
* of formats, we can assert that the format map is non-NULL
* and that the format for the specified index is non-NULL.
*/
ASSERT(state->dts_formats != NULL);
str = state->dts_formats[fmt.dtfd_format - 1];
ASSERT(str != NULL);
len = strlen(str) + 1;
if (len > fmt.dtfd_length) {
fmt.dtfd_length = len;
if (copyout(&fmt, (void *)arg, sizeof (fmt)) != 0) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
} else {
if (copyout(str, fmt.dtfd_string, len) != 0) {
mutex_exit(&dtrace_lock);
return (EINVAL);
}
}
mutex_exit(&dtrace_lock);
return (0);
}
default:
break;
}
return (ENOTTY);
}
/*ARGSUSED*/
static int
dtrace_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
dtrace_state_t *state;
switch (cmd) {
case DDI_DETACH:
break;
case DDI_SUSPEND:
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
mutex_enter(&cpu_lock);
mutex_enter(&dtrace_provider_lock);
mutex_enter(&dtrace_lock);
ASSERT(dtrace_opens == 0);
if (dtrace_helpers > 0) {
mutex_exit(&dtrace_provider_lock);
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
return (DDI_FAILURE);
}
if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
mutex_exit(&dtrace_provider_lock);
mutex_exit(&dtrace_lock);
mutex_exit(&cpu_lock);
return (DDI_FAILURE);
}
dtrace_provider = NULL;
if ((state = dtrace_anon_grab()) != NULL) {
/*
* If there were ECBs on this state, the provider should
* have not been allowed to detach; assert that there is
* none.
*/
ASSERT(state->dts_necbs == 0);
dtrace_state_destroy(state);
/*
* If we're being detached with anonymous state, we need to
* indicate to the kernel debugger that DTrace is now inactive.
*/
(void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
}
bzero(&dtrace_anon, sizeof (dtrace_anon_t));
unregister_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
dtrace_cpu_init = NULL;
dtrace_helpers_cleanup = NULL;
dtrace_helpers_fork = NULL;
dtrace_cpustart_init = NULL;
dtrace_cpustart_fini = NULL;
dtrace_debugger_init = NULL;
dtrace_debugger_fini = NULL;
dtrace_modload = NULL;
dtrace_modunload = NULL;
ASSERT(dtrace_getf == 0);
ASSERT(dtrace_closef == NULL);
mutex_exit(&cpu_lock);
kmem_free(dtrace_probes, dtrace_nprobes * sizeof (dtrace_probe_t *));
dtrace_probes = NULL;
dtrace_nprobes = 0;
dtrace_hash_destroy(dtrace_bymod);
dtrace_hash_destroy(dtrace_byfunc);
dtrace_hash_destroy(dtrace_byname);
dtrace_bymod = NULL;
dtrace_byfunc = NULL;
dtrace_byname = NULL;
kmem_cache_destroy(dtrace_state_cache);
vmem_destroy(dtrace_minor);
vmem_destroy(dtrace_arena);
if (dtrace_toxrange != NULL) {
kmem_free(dtrace_toxrange,
dtrace_toxranges_max * sizeof (dtrace_toxrange_t));
dtrace_toxrange = NULL;
dtrace_toxranges = 0;
dtrace_toxranges_max = 0;
}
ddi_remove_minor_node(dtrace_devi, NULL);
dtrace_devi = NULL;
ddi_soft_state_fini(&dtrace_softstate);
ASSERT(dtrace_vtime_references == 0);
ASSERT(dtrace_opens == 0);
ASSERT(dtrace_retained == NULL);
mutex_exit(&dtrace_lock);
mutex_exit(&dtrace_provider_lock);
/*
* We don't destroy the task queue until after we have dropped our
* locks (taskq_destroy() may block on running tasks). To prevent
* attempting to do work after we have effectively detached but before
* the task queue has been destroyed, all tasks dispatched via the
* task queue must check that DTrace is still attached before
* performing any operation.
*/
taskq_destroy(dtrace_taskq);
dtrace_taskq = NULL;
return (DDI_SUCCESS);
}
#endif
#ifdef illumos
/*ARGSUSED*/
static int
dtrace_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
int error;
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
*result = (void *)dtrace_devi;
error = DDI_SUCCESS;
break;
case DDI_INFO_DEVT2INSTANCE:
*result = (void *)0;
error = DDI_SUCCESS;
break;
default:
error = DDI_FAILURE;
}
return (error);
}
#endif
#ifdef illumos
static struct cb_ops dtrace_cb_ops = {
dtrace_open, /* open */
dtrace_close, /* close */
nulldev, /* strategy */
nulldev, /* print */
nodev, /* dump */
nodev, /* read */
nodev, /* write */
dtrace_ioctl, /* ioctl */
nodev, /* devmap */
nodev, /* mmap */
nodev, /* segmap */
nochpoll, /* poll */
ddi_prop_op, /* cb_prop_op */
0, /* streamtab */
D_NEW | D_MP /* Driver compatibility flag */
};
static struct dev_ops dtrace_ops = {
DEVO_REV, /* devo_rev */
0, /* refcnt */
dtrace_info, /* get_dev_info */
nulldev, /* identify */
nulldev, /* probe */
dtrace_attach, /* attach */
dtrace_detach, /* detach */
nodev, /* reset */
&dtrace_cb_ops, /* driver operations */
NULL, /* bus operations */
nodev /* dev power */
};
static struct modldrv modldrv = {
&mod_driverops, /* module type (this is a pseudo driver) */
"Dynamic Tracing", /* name of module */
&dtrace_ops, /* driver ops */
};
static struct modlinkage modlinkage = {
MODREV_1,
(void *)&modldrv,
NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
int
_fini(void)
{
return (mod_remove(&modlinkage));
}
#else
static d_ioctl_t dtrace_ioctl;
static d_ioctl_t dtrace_ioctl_helper;
static void dtrace_load(void *);
static int dtrace_unload(void);
static struct cdev *dtrace_dev;
static struct cdev *helper_dev;
void dtrace_invop_init(void);
void dtrace_invop_uninit(void);
static struct cdevsw dtrace_cdevsw = {
.d_version = D_VERSION,
.d_ioctl = dtrace_ioctl,
.d_open = dtrace_open,
.d_name = "dtrace",
};
static struct cdevsw helper_cdevsw = {
.d_version = D_VERSION,
.d_ioctl = dtrace_ioctl_helper,
.d_name = "helper",
};
#include <dtrace_anon.c>
#include <dtrace_ioctl.c>
#include <dtrace_load.c>
#include <dtrace_modevent.c>
#include <dtrace_sysctl.c>
#include <dtrace_unload.c>
#include <dtrace_vtime.c>
#include <dtrace_hacks.c>
#include <dtrace_isa.c>
SYSINIT(dtrace_load, SI_SUB_DTRACE, SI_ORDER_FIRST, dtrace_load, NULL);
SYSUNINIT(dtrace_unload, SI_SUB_DTRACE, SI_ORDER_FIRST, dtrace_unload, NULL);
SYSINIT(dtrace_anon_init, SI_SUB_DTRACE_ANON, SI_ORDER_FIRST, dtrace_anon_init, NULL);
DEV_MODULE(dtrace, dtrace_modevent, NULL);
MODULE_VERSION(dtrace, 1);
MODULE_DEPEND(dtrace, opensolaris, 1, 1, 1);
#endif
