/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2013 Gleb Smirnoff <glebius@FreeBSD.org>
* Copyright (c) 2010 Juniper Networks, Inc.
* Copyright (c) 2009 Robert N. M. Watson
* Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org>
* Copyright (c) 2008 Yahoo!, Inc.
* All rights reserved.
*
* Written by: John Baldwin <jhb@FreeBSD.org>
*
* This software was developed by Robert N. M. Watson under contract
* to Juniper Networks, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/pcpu.h>
#include <sys/sysctl.h>
#include <kvm.h>
#include <limits.h>
#include <stdlib.h>
#include "kvm_private.h"
#ifdef __amd64__
#define __OFFSET_BY_PCPU
#endif
static struct nlist kvm_pcpu_nl[] = {
{ .n_name = "_cpuid_to_pcpu" },
{ .n_name = "_mp_maxcpus" },
{ .n_name = "_mp_ncpus" },
#ifdef __OFFSET_BY_PCPU
{ .n_name = "___pcpu" },
#endif
{ .n_name = NULL },
};
#define NL_CPUID_TO_PCPU 0
#define NL_MP_MAXCPUS 1
#define NL_MP_NCPUS 2
#define NL___PCPU 3
/*
* Kernel per-CPU data state. We cache this stuff on the first
* access.
*
* XXXRW: Possibly, this (and kvmpcpu_nl) should be per-kvm_t, in case the
* consumer has multiple handles in flight to differently configured
* kernels/crashdumps.
*/
static void **pcpu_data;
static int maxcpu;
static int mp_ncpus;
#ifdef __OFFSET_BY_PCPU
static unsigned long __pcpu;
#endif
static int
_kvm_pcpu_init(kvm_t *kd)
{
size_t len;
int max;
void *data;
if (kvm_nlist(kd, kvm_pcpu_nl) < 0)
return (-1);
if (kvm_pcpu_nl[NL_CPUID_TO_PCPU].n_value == 0) {
_kvm_err(kd, kd->program, "unable to find cpuid_to_pcpu");
return (-1);
}
if (kvm_pcpu_nl[NL_MP_MAXCPUS].n_value == 0) {
_kvm_err(kd, kd->program, "unable to find mp_maxcpus");
return (-1);
}
if (kvm_read(kd, kvm_pcpu_nl[NL_MP_MAXCPUS].n_value, &max,
sizeof(max)) != sizeof(max)) {
_kvm_err(kd, kd->program, "cannot read mp_maxcpus");
return (-1);
}
if (kvm_pcpu_nl[NL_MP_NCPUS].n_value == 0) {
_kvm_err(kd, kd->program, "unable to find mp_ncpus");
return (-1);
}
if (kvm_read(kd, kvm_pcpu_nl[NL_MP_NCPUS].n_value, &mp_ncpus,
sizeof(mp_ncpus)) != sizeof(mp_ncpus)) {
_kvm_err(kd, kd->program, "cannot read mp_ncpus");
return (-1);
}
#ifdef __OFFSET_BY_PCPU
if (kvm_pcpu_nl[NL___PCPU].n_value == 0) {
_kvm_err(kd, kd->program, "unable to find __pcpu");
return (-1);
}
if (kvm_read(kd, kvm_pcpu_nl[NL___PCPU].n_value, &__pcpu,
sizeof(__pcpu)) != sizeof(__pcpu)) {
_kvm_err(kd, kd->program, "cannot read __pcpu");
return (-1);
}
#endif
len = max * sizeof(void *);
data = malloc(len);
if (data == NULL) {
_kvm_err(kd, kd->program, "out of memory");
return (-1);
}
if (kvm_read(kd, kvm_pcpu_nl[NL_CPUID_TO_PCPU].n_value, data, len) !=
(ssize_t)len) {
_kvm_err(kd, kd->program, "cannot read cpuid_to_pcpu array");
free(data);
return (-1);
}
pcpu_data = data;
maxcpu = max;
return (0);
}
static void
_kvm_pcpu_clear(void)
{
maxcpu = 0;
free(pcpu_data);
pcpu_data = NULL;
}
void *
kvm_getpcpu(kvm_t *kd, int cpu)
{
char *buf;
if (kd == NULL) {
_kvm_pcpu_clear();
return (NULL);
}
if (maxcpu == 0)
if (_kvm_pcpu_init(kd) < 0)
return ((void *)-1);
if (cpu >= maxcpu || pcpu_data[cpu] == NULL)
return (NULL);
buf = malloc(sizeof(struct pcpu));
if (buf == NULL) {
_kvm_err(kd, kd->program, "out of memory");
return ((void *)-1);
}
if (kvm_read(kd, (uintptr_t)pcpu_data[cpu], buf,
sizeof(struct pcpu)) != sizeof(struct pcpu)) {
_kvm_err(kd, kd->program, "unable to read per-CPU data");
free(buf);
return ((void *)-1);
}
return (buf);
}
int
kvm_getmaxcpu(kvm_t *kd)
{
if (kd == NULL) {
_kvm_pcpu_clear();
return (0);
}
if (maxcpu == 0)
if (_kvm_pcpu_init(kd) < 0)
return (-1);
return (maxcpu);
}
int
kvm_getncpus(kvm_t *kd)
{
if (mp_ncpus == 0)
if (_kvm_pcpu_init(kd) < 0)
return (-1);
return (mp_ncpus);
}
static int
_kvm_dpcpu_setcpu(kvm_t *kd, u_int cpu, int report_error)
{
if (!kd->dpcpu_initialized) {
if (report_error)
_kvm_err(kd, kd->program, "%s: not initialized",
__func__);
return (-1);
}
if (cpu >= kd->dpcpu_maxcpus) {
if (report_error)
_kvm_err(kd, kd->program, "%s: CPU %u too big",
__func__, cpu);
return (-1);
}
if (kd->dpcpu_off[cpu] == 0) {
if (report_error)
_kvm_err(kd, kd->program, "%s: CPU %u not found",
__func__, cpu);
return (-1);
}
kd->dpcpu_curcpu = cpu;
kd->dpcpu_curoff = kd->dpcpu_off[cpu];
return (0);
}
/*
* Set up libkvm to handle dynamic per-CPU memory.
*/
static int
_kvm_dpcpu_init(kvm_t *kd)
{
struct kvm_nlist nl[] = {
#define NLIST_START_SET_PCPU 0
{ .n_name = "___start_" DPCPU_SETNAME },
#define NLIST_STOP_SET_PCPU 1
{ .n_name = "___stop_" DPCPU_SETNAME },
#define NLIST_DPCPU_OFF 2
{ .n_name = "_dpcpu_off" },
#define NLIST_MP_MAXCPUS 3
{ .n_name = "_mp_maxcpus" },
{ .n_name = NULL },
};
uintptr_t *dpcpu_off_buf;
size_t len;
u_int dpcpu_maxcpus;
/*
* XXX: This only works for native kernels for now.
*/
if (!kvm_native(kd))
return (-1);
/*
* Locate and cache locations of important symbols using the internal
* version of _kvm_nlist, turning off initialization to avoid
* recursion in case of unresolveable symbols.
*/
if (_kvm_nlist(kd, nl, 0) != 0)
return (-1);
if (kvm_read(kd, nl[NLIST_MP_MAXCPUS].n_value, &dpcpu_maxcpus,
sizeof(dpcpu_maxcpus)) != sizeof(dpcpu_maxcpus))
return (-1);
len = dpcpu_maxcpus * sizeof(*dpcpu_off_buf);
dpcpu_off_buf = malloc(len);
if (dpcpu_off_buf == NULL)
return (-1);
if (kvm_read(kd, nl[NLIST_DPCPU_OFF].n_value, dpcpu_off_buf, len) !=
(ssize_t)len) {
free(dpcpu_off_buf);
return (-1);
}
kd->dpcpu_start = nl[NLIST_START_SET_PCPU].n_value;
kd->dpcpu_stop = nl[NLIST_STOP_SET_PCPU].n_value;
kd->dpcpu_maxcpus = dpcpu_maxcpus;
kd->dpcpu_off = dpcpu_off_buf;
kd->dpcpu_initialized = 1;
(void)_kvm_dpcpu_setcpu(kd, 0, 0);
return (0);
}
/*
* Check whether the dpcpu module has been initialized successfully or not,
* initialize it if permitted.
*/
int
_kvm_dpcpu_initialized(kvm_t *kd, int intialize)
{
if (kd->dpcpu_initialized || !intialize)
return (kd->dpcpu_initialized);
(void)_kvm_dpcpu_init(kd);
return (kd->dpcpu_initialized);
}
/*
* Check whether the value is within the dpcpu symbol range and only if so
* adjust the offset relative to the current offset.
*/
kvaddr_t
_kvm_dpcpu_validaddr(kvm_t *kd, kvaddr_t value)
{
if (value == 0)
return (value);
if (!kd->dpcpu_initialized)
return (value);
if (value < kd->dpcpu_start || value >= kd->dpcpu_stop)
return (value);
return (kd->dpcpu_curoff + value);
}
int
kvm_dpcpu_setcpu(kvm_t *kd, u_int cpu)
{
int ret;
if (!kd->dpcpu_initialized) {
ret = _kvm_dpcpu_init(kd);
if (ret != 0) {
_kvm_err(kd, kd->program, "%s: init failed",
__func__);
return (ret);
}
}
return (_kvm_dpcpu_setcpu(kd, cpu, 1));
}
/*
* Obtain a per-CPU copy for given cpu from UMA_ZONE_PCPU allocation.
*/
ssize_t
kvm_read_zpcpu(kvm_t *kd, u_long base, void *buf, size_t size, int cpu)
{
if (!kvm_native(kd))
return (-1);
if (mp_ncpus == 0)
if (_kvm_pcpu_init(kd) < 0)
return (0);
#ifdef __OFFSET_BY_PCPU
base += __pcpu;
#endif
return (kvm_read(kd, (uintptr_t)(base + sizeof(struct pcpu) * cpu),
buf, size));
}
/*
* Fetch value of a counter(9).
*/
uint64_t
kvm_counter_u64_fetch(kvm_t *kd, u_long base)
{
uint64_t r, c;
if (mp_ncpus == 0)
if (_kvm_pcpu_init(kd) < 0)
return (0);
r = 0;
for (int i = 0; i < mp_ncpus; i++) {
if (kvm_read_zpcpu(kd, base, &c, sizeof(c), i) != sizeof(c))
return (0);
r += c;
}
return (r);
}
