freebsd-dev/sys/fs/procfs/procfs_status.c
Konstantin Belousov 5c7bebf961 The process spin lock currently has the following distinct uses:
- Threads lifetime cycle, in particular, counting of the threads in
  the process, and interlocking with process mutex and thread lock.
  The main reason of this is that turnstile locks are after thread
  locks, so you e.g. cannot unlock blockable mutex (think process
  mutex) while owning thread lock.

- Virtual and profiling itimers, since the timers activation is done
  from the clock interrupt context.  Replace the p_slock by p_itimmtx
  and PROC_ITIMLOCK().

- Profiling code (profil(2)), for similar reason.  Replace the p_slock
  by p_profmtx and PROC_PROFLOCK().

- Resource usage accounting.  Need for the spinlock there is subtle,
  my understanding is that spinlock blocks context switching for the
  current thread, which prevents td_runtime and similar fields from
  changing (updates are done at the mi_switch()).  Replace the p_slock
  by p_statmtx and PROC_STATLOCK().

The split is done mostly for code clarity, and should not affect
scalability.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-11-26 14:10:00 +00:00

198 lines
5.2 KiB
C

/*-
* Copyright (c) 1993 Jan-Simon Pendry
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* 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.
* 4. 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.
*
* @(#)procfs_status.c 8.4 (Berkeley) 6/15/94
*
* From:
* $Id: procfs_status.c,v 3.1 1993/12/15 09:40:17 jsp Exp $
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/jail.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sbuf.h>
#include <sys/sysent.h>
#include <sys/tty.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_param.h>
#include <fs/pseudofs/pseudofs.h>
#include <fs/procfs/procfs.h>
int
procfs_doprocstatus(PFS_FILL_ARGS)
{
struct session *sess;
struct thread *tdfirst;
struct tty *tp;
struct ucred *cr;
const char *wmesg;
char *pc;
char *sep;
int pid, ppid, pgid, sid;
int i;
pid = p->p_pid;
PROC_LOCK(p);
ppid = p->p_pptr ? p->p_pptr->p_pid : 0;
pgid = p->p_pgrp->pg_id;
sess = p->p_pgrp->pg_session;
SESS_LOCK(sess);
sid = sess->s_leader ? sess->s_leader->p_pid : 0;
/* comm pid ppid pgid sid tty ctty,sldr start ut st wmsg
euid ruid rgid,egid,groups[1 .. ngroups]
*/
pc = p->p_comm;
do {
if (*pc < 33 || *pc > 126 || *pc == '\\')
sbuf_printf(sb, "\\%03o", *pc);
else
sbuf_putc(sb, *pc);
} while (*++pc);
sbuf_printf(sb, " %d %d %d %d ", pid, ppid, pgid, sid);
if ((p->p_flag & P_CONTROLT) && (tp = sess->s_ttyp))
sbuf_printf(sb, "%s ", devtoname(tp->t_dev));
else
sbuf_printf(sb, "- ");
sep = "";
if (sess->s_ttyvp) {
sbuf_printf(sb, "%sctty", sep);
sep = ",";
}
if (SESS_LEADER(p)) {
sbuf_printf(sb, "%ssldr", sep);
sep = ",";
}
SESS_UNLOCK(sess);
if (*sep != ',') {
sbuf_printf(sb, "noflags");
}
tdfirst = FIRST_THREAD_IN_PROC(p);
thread_lock(tdfirst);
if (tdfirst->td_wchan != NULL) {
KASSERT(tdfirst->td_wmesg != NULL,
("wchan %p has no wmesg", tdfirst->td_wchan));
wmesg = tdfirst->td_wmesg;
} else
wmesg = "nochan";
thread_unlock(tdfirst);
if (p->p_flag & P_INMEM) {
struct timeval start, ut, st;
PROC_STATLOCK(p);
calcru(p, &ut, &st);
PROC_STATUNLOCK(p);
start = p->p_stats->p_start;
timevaladd(&start, &boottime);
sbuf_printf(sb, " %jd,%ld %jd,%ld %jd,%ld",
(intmax_t)start.tv_sec, start.tv_usec,
(intmax_t)ut.tv_sec, ut.tv_usec,
(intmax_t)st.tv_sec, st.tv_usec);
} else
sbuf_printf(sb, " -1,-1 -1,-1 -1,-1");
sbuf_printf(sb, " %s", wmesg);
cr = p->p_ucred;
sbuf_printf(sb, " %lu %lu %lu",
(u_long)cr->cr_uid,
(u_long)cr->cr_ruid,
(u_long)cr->cr_rgid);
/* egid (cr->cr_svgid) is equal to cr_ngroups[0]
see also getegid(2) in /sys/kern/kern_prot.c */
for (i = 0; i < cr->cr_ngroups; i++) {
sbuf_printf(sb, ",%lu", (u_long)cr->cr_groups[i]);
}
if (jailed(cr)) {
mtx_lock(&cr->cr_prison->pr_mtx);
sbuf_printf(sb, " %s",
prison_name(td->td_ucred->cr_prison, cr->cr_prison));
mtx_unlock(&cr->cr_prison->pr_mtx);
} else {
sbuf_printf(sb, " -");
}
PROC_UNLOCK(p);
sbuf_printf(sb, "\n");
return (0);
}
int
procfs_doproccmdline(PFS_FILL_ARGS)
{
/*
* If we are using the ps/cmdline caching, use that. Otherwise
* read argv from the process space.
* Note that if the argv is no longer available, we deliberately
* don't fall back on p->p_comm or return an error: the authentic
* Linux behaviour is to return zero-length in this case.
*/
PROC_LOCK(p);
if (p->p_args && p_cansee(td, p) == 0) {
sbuf_bcpy(sb, p->p_args->ar_args, p->p_args->ar_length);
PROC_UNLOCK(p);
return (0);
}
if ((p->p_flag & P_SYSTEM) != 0) {
PROC_UNLOCK(p);
return (0);
}
PROC_UNLOCK(p);
return (proc_getargv(td, p, sb));
}