freebsd-src/sys/kern/kern_proc.c
Robert Watson b1fc0ec1a7 o Merge contents of struct pcred into struct ucred. Specifically, add the
real uid, saved uid, real gid, and saved gid to ucred, as well as the
  pcred->pc_uidinfo, which was associated with the real uid, only rename
  it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
  corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
  original macro that pointed.
  p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
  p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
  cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
  cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
  we figure out locking and optimizations; generally speaking, this
  means moving to a structure like this:
        newcred = crdup(oldcred);
        ...
        p->p_ucred = newcred;
        crfree(oldcred);
  It's not race-free, but better than nothing.  There are also races
  in sys_process.c, all inter-process authorization, fork, exec, and
  exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
  remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
  use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
  pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
  allocation.
o Clean up ktrcanset() to take into account changes, and move to using
  suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
  calls to better document current behavior.  In a couple of places,
  current behavior is a little questionable and we need to check
  POSIX.1 to make sure it's "right".  More commenting work still
  remains to be done.
o Update credential management calls, such as crfree(), to take into
  account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
      change_euid()
      change_egid()
      change_ruid()
      change_rgid()
      change_svuid()
      change_svgid()
  In each case, the call now acts on a credential not a process, and as
  such no longer requires more complicated process locking/etc.  They
  now assume the caller will do any necessary allocation of an
  exclusive credential reference.  Each is commented to document its
  reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
  and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
  questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
  processes and pcreds.  Note that this authorization, as well as
  CANSIGIO(), needs to be updated to use the p_cansignal() and
  p_cansched() centralized authorization routines, as they currently
  do not take into account some desirable restrictions that are handled
  by the centralized routines, as well as being inconsistent with other
  similar authorization instances.
o Update libkvm to take these changes into account.

Obtained from:	TrustedBSD Project
Reviewed by:	green, bde, jhb, freebsd-arch, freebsd-audit
2001-05-25 16:59:11 +00:00

756 lines
18 KiB
C

/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* @(#)kern_proc.c 8.7 (Berkeley) 2/14/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/filedesc.h>
#include <sys/tty.h>
#include <sys/signalvar.h>
#include <sys/sx.h>
#include <sys/user.h>
#include <sys/jail.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_zone.h>
static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
MALLOC_DEFINE(M_SESSION, "session", "session header");
static MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
int ps_showallprocs = 1;
SYSCTL_INT(_kern, OID_AUTO, ps_showallprocs, CTLFLAG_RW,
&ps_showallprocs, 0, "");
static void pgdelete __P((struct pgrp *));
static void orphanpg __P((struct pgrp *pg));
/*
* Other process lists
*/
struct pidhashhead *pidhashtbl;
u_long pidhash;
struct pgrphashhead *pgrphashtbl;
u_long pgrphash;
struct proclist allproc;
struct proclist zombproc;
struct sx allproc_lock;
struct sx proctree_lock;
vm_zone_t proc_zone;
vm_zone_t ithread_zone;
/*
* Initialize global process hashing structures.
*/
void
procinit()
{
int i, j;
sx_init(&allproc_lock, "allproc");
sx_init(&proctree_lock, "proctree");
LIST_INIT(&allproc);
LIST_INIT(&zombproc);
pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
uihashinit();
/*
* This should really be a compile time warning, but I do
* not know of any way to do that...
*/
if (sizeof(struct kinfo_proc) != KINFO_PROC_SIZE) {
printf("This message will repeat for the next 20 seconds\n");
for (i = 0; i < 20; i++) {
printf("WARNING: size of kinfo_proc (%ld) should be %d!!!\n",
(long)sizeof(struct kinfo_proc), KINFO_PROC_SIZE);
printf("The kinfo_proc structure was changed ");
printf("incorrectly in <sys/user.h>\n");
for (j = 0; j < 0x7ffffff; j++);
}
}
}
/*
* Is p an inferior of the current process?
*/
int
inferior(p)
register struct proc *p;
{
int rval;
PROC_LOCK_ASSERT(p, MA_OWNED);
if (p == curproc)
return (1);
if (p->p_pid == 0)
return (0);
PROC_LOCK(p->p_pptr);
rval = inferior(p->p_pptr);
PROC_UNLOCK(p->p_pptr);
return (rval);
}
/*
* Locate a process by number
*/
struct proc *
pfind(pid)
register pid_t pid;
{
register struct proc *p;
sx_slock(&allproc_lock);
LIST_FOREACH(p, PIDHASH(pid), p_hash)
if (p->p_pid == pid) {
PROC_LOCK(p);
break;
}
sx_sunlock(&allproc_lock);
return (p);
}
/*
* Locate a process group by number
*/
struct pgrp *
pgfind(pgid)
register pid_t pgid;
{
register struct pgrp *pgrp;
LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
if (pgrp->pg_id == pgid)
return (pgrp);
return (NULL);
}
/*
* Move p to a new or existing process group (and session)
*/
int
enterpgrp(p, pgid, mksess)
register struct proc *p;
pid_t pgid;
int mksess;
{
register struct pgrp *pgrp = pgfind(pgid);
struct pgrp *savegrp;
KASSERT(pgrp == NULL || !mksess,
("enterpgrp: setsid into non-empty pgrp"));
KASSERT(!SESS_LEADER(p),
("enterpgrp: session leader attempted setpgrp"));
if (pgrp == NULL) {
pid_t savepid = p->p_pid;
struct proc *np;
/*
* new process group
*/
KASSERT(p->p_pid == pgid,
("enterpgrp: new pgrp and pid != pgid"));
if ((np = pfind(savepid)) == NULL || np != p) {
if (np != NULL)
PROC_UNLOCK(np);
return (ESRCH);
}
PROC_UNLOCK(np);
MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
M_WAITOK);
if (mksess) {
register struct session *sess;
/*
* new session
*/
MALLOC(sess, struct session *, sizeof(struct session),
M_SESSION, M_WAITOK);
sess->s_leader = p;
sess->s_sid = p->p_pid;
sess->s_count = 1;
sess->s_ttyvp = NULL;
sess->s_ttyp = NULL;
bcopy(p->p_session->s_login, sess->s_login,
sizeof(sess->s_login));
PROC_LOCK(p);
p->p_flag &= ~P_CONTROLT;
PROC_UNLOCK(p);
pgrp->pg_session = sess;
KASSERT(p == curproc,
("enterpgrp: mksession and p != curproc"));
} else {
pgrp->pg_session = p->p_session;
pgrp->pg_session->s_count++;
}
pgrp->pg_id = pgid;
LIST_INIT(&pgrp->pg_members);
LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
pgrp->pg_jobc = 0;
SLIST_INIT(&pgrp->pg_sigiolst);
} else if (pgrp == p->p_pgrp)
return (0);
/*
* Adjust eligibility of affected pgrps to participate in job control.
* Increment eligibility counts before decrementing, otherwise we
* could reach 0 spuriously during the first call.
*/
fixjobc(p, pgrp, 1);
fixjobc(p, p->p_pgrp, 0);
PROC_LOCK(p);
LIST_REMOVE(p, p_pglist);
savegrp = p->p_pgrp;
p->p_pgrp = pgrp;
LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
PROC_UNLOCK(p);
if (LIST_EMPTY(&savegrp->pg_members))
pgdelete(savegrp);
return (0);
}
/*
* remove process from process group
*/
int
leavepgrp(p)
register struct proc *p;
{
struct pgrp *savegrp;
PROC_LOCK(p);
LIST_REMOVE(p, p_pglist);
savegrp = p->p_pgrp;
p->p_pgrp = NULL;
PROC_UNLOCK(p);
if (LIST_EMPTY(&savegrp->pg_members))
pgdelete(savegrp);
return (0);
}
/*
* delete a process group
*/
static void
pgdelete(pgrp)
register struct pgrp *pgrp;
{
/*
* Reset any sigio structures pointing to us as a result of
* F_SETOWN with our pgid.
*/
funsetownlst(&pgrp->pg_sigiolst);
if (pgrp->pg_session->s_ttyp != NULL &&
pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
pgrp->pg_session->s_ttyp->t_pgrp = NULL;
LIST_REMOVE(pgrp, pg_hash);
if (--pgrp->pg_session->s_count == 0)
FREE(pgrp->pg_session, M_SESSION);
FREE(pgrp, M_PGRP);
}
/*
* Adjust pgrp jobc counters when specified process changes process group.
* We count the number of processes in each process group that "qualify"
* the group for terminal job control (those with a parent in a different
* process group of the same session). If that count reaches zero, the
* process group becomes orphaned. Check both the specified process'
* process group and that of its children.
* entering == 0 => p is leaving specified group.
* entering == 1 => p is entering specified group.
*/
void
fixjobc(p, pgrp, entering)
register struct proc *p;
register struct pgrp *pgrp;
int entering;
{
register struct pgrp *hispgrp;
register struct session *mysession = pgrp->pg_session;
/*
* Check p's parent to see whether p qualifies its own process
* group; if so, adjust count for p's process group.
*/
sx_slock(&proctree_lock);
if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession) {
if (entering)
pgrp->pg_jobc++;
else if (--pgrp->pg_jobc == 0)
orphanpg(pgrp);
}
/*
* Check this process' children to see whether they qualify
* their process groups; if so, adjust counts for children's
* process groups.
*/
LIST_FOREACH(p, &p->p_children, p_sibling)
if ((hispgrp = p->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession &&
p->p_stat != SZOMB) {
if (entering)
hispgrp->pg_jobc++;
else if (--hispgrp->pg_jobc == 0)
orphanpg(hispgrp);
}
sx_sunlock(&proctree_lock);
}
/*
* A process group has become orphaned;
* if there are any stopped processes in the group,
* hang-up all process in that group.
*/
static void
orphanpg(pg)
struct pgrp *pg;
{
register struct proc *p;
mtx_lock_spin(&sched_lock);
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
if (p->p_stat == SSTOP) {
mtx_unlock_spin(&sched_lock);
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
psignal(p, SIGHUP);
psignal(p, SIGCONT);
PROC_UNLOCK(p);
}
return;
}
}
mtx_unlock_spin(&sched_lock);
}
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
DB_SHOW_COMMAND(pgrpdump, pgrpdump)
{
register struct pgrp *pgrp;
register struct proc *p;
register int i;
for (i = 0; i <= pgrphash; i++) {
if (!LIST_EMPTY(&pgrphashtbl[i])) {
printf("\tindx %d\n", i);
LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
printf(
"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
(void *)pgrp, (long)pgrp->pg_id,
(void *)pgrp->pg_session,
pgrp->pg_session->s_count,
(void *)LIST_FIRST(&pgrp->pg_members));
LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
printf("\t\tpid %ld addr %p pgrp %p\n",
(long)p->p_pid, (void *)p,
(void *)p->p_pgrp);
}
}
}
}
}
#endif /* DDB */
/*
* Fill in an kinfo_proc structure for the specified process.
*/
void
fill_kinfo_proc(p, kp)
struct proc *p;
struct kinfo_proc *kp;
{
struct tty *tp;
struct session *sp;
bzero(kp, sizeof(*kp));
kp->ki_structsize = sizeof(*kp);
kp->ki_paddr = p;
PROC_LOCK(p);
kp->ki_addr = p->p_addr;
kp->ki_args = p->p_args;
kp->ki_tracep = p->p_tracep;
kp->ki_textvp = p->p_textvp;
kp->ki_fd = p->p_fd;
kp->ki_vmspace = p->p_vmspace;
if (p->p_ucred) {
kp->ki_uid = p->p_ucred->cr_uid;
kp->ki_ruid = p->p_ucred->cr_ruid;
kp->ki_svuid = p->p_ucred->cr_svuid;
kp->ki_ngroups = p->p_ucred->cr_ngroups;
bcopy(p->p_ucred->cr_groups, kp->ki_groups,
NGROUPS * sizeof(gid_t));
kp->ki_rgid = p->p_ucred->cr_rgid;
kp->ki_svgid = p->p_ucred->cr_svgid;
}
if (p->p_procsig) {
kp->ki_sigignore = p->p_procsig->ps_sigignore;
kp->ki_sigcatch = p->p_procsig->ps_sigcatch;
}
mtx_lock_spin(&sched_lock);
if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
struct vmspace *vm = p->p_vmspace;
kp->ki_size = vm->vm_map.size;
kp->ki_rssize = vmspace_resident_count(vm); /*XXX*/
kp->ki_swrss = vm->vm_swrss;
kp->ki_tsize = vm->vm_tsize;
kp->ki_dsize = vm->vm_dsize;
kp->ki_ssize = vm->vm_ssize;
}
if ((p->p_sflag & PS_INMEM) && p->p_stats) {
kp->ki_start = p->p_stats->p_start;
kp->ki_rusage = p->p_stats->p_ru;
kp->ki_childtime.tv_sec = p->p_stats->p_cru.ru_utime.tv_sec +
p->p_stats->p_cru.ru_stime.tv_sec;
kp->ki_childtime.tv_usec = p->p_stats->p_cru.ru_utime.tv_usec +
p->p_stats->p_cru.ru_stime.tv_usec;
}
if (p->p_wmesg) {
strncpy(kp->ki_wmesg, p->p_wmesg, WMESGLEN);
kp->ki_wmesg[WMESGLEN] = 0;
}
if (p->p_stat == SMTX) {
kp->ki_kiflag |= KI_MTXBLOCK;
strncpy(kp->ki_mtxname, p->p_mtxname, MTXNAMELEN);
kp->ki_mtxname[MTXNAMELEN] = 0;
}
kp->ki_stat = p->p_stat;
kp->ki_sflag = p->p_sflag;
kp->ki_pctcpu = p->p_pctcpu;
kp->ki_estcpu = p->p_estcpu;
kp->ki_slptime = p->p_slptime;
kp->ki_swtime = p->p_swtime;
kp->ki_wchan = p->p_wchan;
kp->ki_traceflag = p->p_traceflag;
kp->ki_pri = p->p_pri;
kp->ki_nice = p->p_nice;
kp->ki_runtime = p->p_runtime;
kp->ki_pid = p->p_pid;
kp->ki_rqindex = p->p_rqindex;
kp->ki_oncpu = p->p_oncpu;
kp->ki_lastcpu = p->p_lastcpu;
mtx_unlock_spin(&sched_lock);
sp = NULL;
if (p->p_pgrp) {
kp->ki_pgid = p->p_pgrp->pg_id;
kp->ki_jobc = p->p_pgrp->pg_jobc;
sp = p->p_pgrp->pg_session;
if (sp != NULL) {
kp->ki_sid = sp->s_sid;
bcopy(sp->s_login, kp->ki_login, sizeof(kp->ki_login));
if (sp->s_ttyvp)
kp->ki_kiflag = KI_CTTY;
if (SESS_LEADER(p))
kp->ki_kiflag |= KI_SLEADER;
}
}
if ((p->p_flag & P_CONTROLT) && sp && ((tp = sp->s_ttyp) != NULL)) {
kp->ki_tdev = dev2udev(tp->t_dev);
kp->ki_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
if (tp->t_session)
kp->ki_tsid = tp->t_session->s_sid;
} else
kp->ki_tdev = NOUDEV;
if (p->p_comm[0] != 0) {
strncpy(kp->ki_comm, p->p_comm, MAXCOMLEN);
kp->ki_comm[MAXCOMLEN] = 0;
}
kp->ki_siglist = p->p_siglist;
kp->ki_sigmask = p->p_sigmask;
kp->ki_xstat = p->p_xstat;
kp->ki_acflag = p->p_acflag;
kp->ki_flag = p->p_flag;
/* If jailed(p->p_ucred), emulate the old P_JAILED flag. */
if (jailed(p->p_ucred))
kp->ki_flag |= P_JAILED;
kp->ki_lock = p->p_lock;
if (p->p_pptr)
kp->ki_ppid = p->p_pptr->p_pid;
PROC_UNLOCK(p);
}
/*
* Locate a zombie process by number
*/
struct proc *
zpfind(pid_t pid)
{
struct proc *p;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &zombproc, p_list)
if (p->p_pid == pid) {
PROC_LOCK(p);
break;
}
sx_sunlock(&allproc_lock);
return (p);
}
static int
sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
{
struct kinfo_proc kinfo_proc;
int error;
struct proc *np;
pid_t pid = p->p_pid;
fill_kinfo_proc(p, &kinfo_proc);
error = SYSCTL_OUT(req, (caddr_t)&kinfo_proc, sizeof(kinfo_proc));
if (error)
return (error);
if (doingzomb)
np = zpfind(pid);
else {
if (pid == 0)
return (0);
np = pfind(pid);
}
if (np == NULL)
return EAGAIN;
if (np != p) {
PROC_UNLOCK(np);
return EAGAIN;
}
PROC_UNLOCK(np);
return (0);
}
static int
sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
{
int *name = (int*) arg1;
u_int namelen = arg2;
struct proc *p;
int doingzomb;
int error = 0;
if (oidp->oid_number == KERN_PROC_PID) {
if (namelen != 1)
return (EINVAL);
p = pfind((pid_t)name[0]);
if (!p)
return (0);
if (p_can(curproc, p, P_CAN_SEE, NULL)) {
PROC_UNLOCK(p);
return (0);
}
PROC_UNLOCK(p);
error = sysctl_out_proc(p, req, 0);
return (error);
}
if (oidp->oid_number == KERN_PROC_ALL && !namelen)
;
else if (oidp->oid_number != KERN_PROC_ALL && namelen == 1)
;
else
return (EINVAL);
if (!req->oldptr) {
/* overestimate by 5 procs */
error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
if (error)
return (error);
}
sx_slock(&allproc_lock);
for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
if (!doingzomb)
p = LIST_FIRST(&allproc);
else
p = LIST_FIRST(&zombproc);
for (; p != 0; p = LIST_NEXT(p, p_list)) {
/*
* Show a user only appropriate processes.
*/
if (p_can(curproc, p, P_CAN_SEE, NULL))
continue;
/*
* Skip embryonic processes.
*/
if (p->p_stat == SIDL)
continue;
/*
* TODO - make more efficient (see notes below).
* do by session.
*/
switch (oidp->oid_number) {
case KERN_PROC_PGRP:
/* could do this by traversing pgrp */
if (p->p_pgrp == NULL ||
p->p_pgrp->pg_id != (pid_t)name[0])
continue;
break;
case KERN_PROC_TTY:
if ((p->p_flag & P_CONTROLT) == 0 ||
p->p_session == NULL ||
p->p_session->s_ttyp == NULL ||
dev2udev(p->p_session->s_ttyp->t_dev) !=
(udev_t)name[0])
continue;
break;
case KERN_PROC_UID:
if (p->p_ucred == NULL ||
p->p_ucred->cr_uid != (uid_t)name[0])
continue;
break;
case KERN_PROC_RUID:
if (p->p_ucred == NULL ||
p->p_ucred->cr_ruid != (uid_t)name[0])
continue;
break;
}
if (p_can(curproc, p, P_CAN_SEE, NULL))
continue;
error = sysctl_out_proc(p, req, doingzomb);
if (error) {
sx_sunlock(&allproc_lock);
return (error);
}
}
}
sx_sunlock(&allproc_lock);
return (0);
}
/*
* This sysctl allows a process to retrieve the argument list or process
* title for another process without groping around in the address space
* of the other process. It also allow a process to set its own "process
* title to a string of its own choice.
*/
static int
sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
{
int *name = (int*) arg1;
u_int namelen = arg2;
struct proc *p;
struct pargs *pa;
int error = 0;
if (namelen != 1)
return (EINVAL);
p = pfind((pid_t)name[0]);
if (!p)
return (0);
if ((!ps_argsopen) && p_can(curproc, p, P_CAN_SEE, NULL)) {
PROC_UNLOCK(p);
return (0);
}
PROC_UNLOCK(p);
if (req->newptr && curproc != p)
return (EPERM);
if (req->oldptr && p->p_args != NULL)
error = SYSCTL_OUT(req, p->p_args->ar_args, p->p_args->ar_length);
if (req->newptr == NULL)
return (error);
PROC_LOCK(p);
if (p->p_args && --p->p_args->ar_ref == 0)
FREE(p->p_args, M_PARGS);
p->p_args = NULL;
PROC_UNLOCK(p);
if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
return (error);
MALLOC(pa, struct pargs *, sizeof(struct pargs) + req->newlen,
M_PARGS, M_WAITOK);
pa->ar_ref = 1;
pa->ar_length = req->newlen;
error = SYSCTL_IN(req, pa->ar_args, req->newlen);
if (!error) {
PROC_LOCK(p);
p->p_args = pa;
PROC_UNLOCK(p);
} else
FREE(pa, M_PARGS);
return (error);
}
SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table");
SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY,
sysctl_kern_proc_args, "Process argument list");