/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Copyright (c) 2002 Networks Associates Technologies, Inc.
* All rights reserved.
*
* Portions of this software were developed for the FreeBSD Project by
* ThinkSec AS and NAI Labs, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* 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 University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 "opt_stack.h"
#include <sys/param.h>
#include <sys/cons.h>
#include <sys/kdb.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/stack.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
/*
* Returns 1 if p2 is "better" than p1
*
* The algorithm for picking the "interesting" process is thus:
*
* 1) Only foreground processes are eligible - implied.
* 2) Runnable processes are favored over anything else. The runner
* with the highest cpu utilization is picked (p_estcpu). Ties are
* broken by picking the highest pid.
* 3) The sleeper with the shortest sleep time is next. With ties,
* we pick out just "short-term" sleepers (P_SINTR == 0).
* 4) Further ties are broken by picking the highest pid.
*/
#define TESTAB(a, b) ((a)<<1 | (b))
#define ONLYA 2
#define ONLYB 1
#define BOTH 3
static int
proc_sum(struct proc *p, fixpt_t *estcpup)
{
struct thread *td;
int estcpu;
int val;
val = 0;
estcpu = 0;
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
if (TD_ON_RUNQ(td) ||
TD_IS_RUNNING(td))
val = 1;
estcpu += sched_pctcpu(td);
thread_unlock(td);
}
*estcpup = estcpu;
return (val);
}
static int
thread_compare(struct thread *td, struct thread *td2)
{
int runa, runb;
int slpa, slpb;
fixpt_t esta, estb;
if (td == NULL)
return (1);
/*
* Fetch running stats, pctcpu usage, and interruptable flag.
*/
thread_lock(td);
runa = TD_IS_RUNNING(td) | TD_ON_RUNQ(td);
slpa = td->td_flags & TDF_SINTR;
esta = sched_pctcpu(td);
thread_unlock(td);
thread_lock(td2);
runb = TD_IS_RUNNING(td2) | TD_ON_RUNQ(td2);
estb = sched_pctcpu(td2);
slpb = td2->td_flags & TDF_SINTR;
thread_unlock(td2);
/*
* see if at least one of them is runnable
*/
switch (TESTAB(runa, runb)) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
break;
}
/*
* favor one with highest recent cpu utilization
*/
if (estb > esta)
return (1);
if (esta > estb)
return (0);
/*
* favor one sleeping in a non-interruptible sleep
*/
switch (TESTAB(slpa, slpb)) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
break;
}
return (td < td2);
}
static int
proc_compare(struct proc *p1, struct proc *p2)
{
int runa, runb;
fixpt_t esta, estb;
if (p1 == NULL)
return (1);
/*
* Fetch various stats about these processes. After we drop the
* lock the information could be stale but the race is unimportant.
*/
PROC_LOCK(p1);
runa = proc_sum(p1, &esta);
PROC_UNLOCK(p1);
PROC_LOCK(p2);
runb = proc_sum(p2, &estb);
PROC_UNLOCK(p2);
/*
* see if at least one of them is runnable
*/
switch (TESTAB(runa, runb)) {
case ONLYA:
return (0);
case ONLYB:
return (1);
case BOTH:
break;
}
/*
* favor one with highest recent cpu utilization
*/
if (estb > esta)
return (1);
if (esta > estb)
return (0);
/*
* weed out zombies
*/
switch (TESTAB(p1->p_state == PRS_ZOMBIE, p2->p_state == PRS_ZOMBIE)) {
case ONLYA:
return (1);
case ONLYB:
return (0);
case BOTH:
break;
}
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
static int
sbuf_tty_drain(void *a, const char *d, int len)
{
struct tty *tp;
int rc;
tp = a;
if (kdb_active) {
cnputsn(d, len);
return (len);
}
if (tp != NULL && !KERNEL_PANICKED()) {
rc = tty_putstrn(tp, d, len);
if (rc != 0)
return (-ENXIO);
return (len);
}
return (-ENXIO);
}
#ifdef STACK
static int tty_info_kstacks = STACK_SBUF_FMT_COMPACT;
static int
sysctl_tty_info_kstacks(SYSCTL_HANDLER_ARGS)
{
enum stack_sbuf_fmt val;
int error;
val = tty_info_kstacks;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
switch (val) {
case STACK_SBUF_FMT_NONE:
case STACK_SBUF_FMT_LONG:
case STACK_SBUF_FMT_COMPACT:
tty_info_kstacks = val;
break;
default:
error = EINVAL;
}
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, tty_info_kstacks,
CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_INT, NULL, 0,
sysctl_tty_info_kstacks, "I",
"Adjust format of kernel stack(9) traces on ^T (tty info): "
"0 - disabled; 1 - long; 2 - compact");
#endif
/*
* Report on state of foreground process group.
*/
void
tty_info(struct tty *tp)
{
struct timeval rtime, utime, stime;
#ifdef STACK
struct stack stack;
int sterr, kstacks_val;
bool print_kstacks;
#endif
struct proc *p, *ppick;
struct thread *td, *tdpick;
const char *stateprefix, *state;
struct sbuf sb;
long rss;
int load, pctcpu;
pid_t pid;
char comm[MAXCOMLEN + 1];
struct rusage ru;
tty_assert_locked(tp);
if (tty_checkoutq(tp) == 0)
return;
(void)sbuf_new(&sb, tp->t_prbuf, tp->t_prbufsz, SBUF_FIXEDLEN);
sbuf_set_drain(&sb, sbuf_tty_drain, tp);
/* Print load average. */
load = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
sbuf_printf(&sb, "%sload: %d.%02d ", tp->t_column == 0 ? "" : "\n",
load / 100, load % 100);
if (tp->t_session == NULL) {
sbuf_printf(&sb, "not a controlling terminal\n");
goto out;
}
if (tp->t_pgrp == NULL) {
sbuf_printf(&sb, "no foreground process group\n");
goto out;
}
PGRP_LOCK(tp->t_pgrp);
if (LIST_EMPTY(&tp->t_pgrp->pg_members)) {
PGRP_UNLOCK(tp->t_pgrp);
sbuf_printf(&sb, "empty foreground process group\n");
goto out;
}
/*
* Pick the most interesting process and copy some of its
* state for printing later. This operation could rely on stale
* data as we can't hold the proc slock or thread locks over the
* whole list. However, we're guaranteed not to reference an exited
* thread or proc since we hold the tty locked.
*/
p = NULL;
LIST_FOREACH(ppick, &tp->t_pgrp->pg_members, p_pglist)
if (proc_compare(p, ppick))
p = ppick;
PROC_LOCK(p);
PGRP_UNLOCK(tp->t_pgrp);
td = NULL;
FOREACH_THREAD_IN_PROC(p, tdpick)
if (thread_compare(td, tdpick))
td = tdpick;
stateprefix = "";
thread_lock(td);
if (TD_IS_RUNNING(td))
state = "running";
else if (TD_ON_RUNQ(td) || TD_CAN_RUN(td))
state = "runnable";
else if (TD_IS_SLEEPING(td)) {
/* XXX: If we're sleeping, are we ever not in a queue? */
if (TD_ON_SLEEPQ(td))
state = td->td_wmesg;
else
state = "sleeping without queue";
} else if (TD_ON_LOCK(td)) {
state = td->td_lockname;
stateprefix = "*";
} else if (TD_IS_SUSPENDED(td))
state = "suspended";
else if (TD_AWAITING_INTR(td))
state = "intrwait";
else if (p->p_state == PRS_ZOMBIE)
state = "zombie";
else
state = "unknown";
pctcpu = (sched_pctcpu(td) * 10000 + FSCALE / 2) >> FSHIFT;
#ifdef STACK
kstacks_val = atomic_load_int(&tty_info_kstacks);
print_kstacks = (kstacks_val != STACK_SBUF_FMT_NONE);
if (print_kstacks) {
if (TD_IS_SWAPPED(td))
sterr = ENOENT;
else
sterr = stack_save_td(&stack, td);
}
#endif
thread_unlock(td);
if (p->p_state == PRS_NEW || p->p_state == PRS_ZOMBIE)
rss = 0;
else
rss = pgtok(vmspace_resident_count(p->p_vmspace));
microuptime(&rtime);
timevalsub(&rtime, &p->p_stats->p_start);
rufetchcalc(p, &ru, &utime, &stime);
pid = p->p_pid;
strlcpy(comm, p->p_comm, sizeof comm);
PROC_UNLOCK(p);
/* Print command, pid, state, rtime, utime, stime, %cpu, and rss. */
sbuf_printf(&sb,
" cmd: %s %d [%s%s] %ld.%02ldr %ld.%02ldu %ld.%02lds %d%% %ldk\n",
comm, pid, stateprefix, state,
(long)rtime.tv_sec, rtime.tv_usec / 10000,
(long)utime.tv_sec, utime.tv_usec / 10000,
(long)stime.tv_sec, stime.tv_usec / 10000,
pctcpu / 100, rss);
#ifdef STACK
if (print_kstacks && sterr == 0)
stack_sbuf_print_flags(&sb, &stack, M_NOWAIT, kstacks_val);
#endif
out:
sbuf_finish(&sb);
sbuf_delete(&sb);
}
