/*
* Copyright (c) 1982, 1986, 1989, 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.
*
* 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_exit.c 8.7 (Berkeley) 2/12/94
* $FreeBSD$
*/
#include "opt_compat.h"
#include "opt_ktrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/pioctl.h>
#include <sys/tty.h>
#include <sys/wait.h>
#include <sys/vnode.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/sx.h>
#include <sys/ptrace.h>
#include <sys/acct.h> /* for acct_process() function prototype */
#include <sys/filedesc.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/aio.h>
#include <sys/jail.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_zone.h>
#include <sys/user.h>
/* Required to be non-static for SysVR4 emulator */
MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
static int wait1 __P((struct proc *, struct wait_args *, int));
/*
* callout list for things to do at exit time
*/
struct exitlist {
exitlist_fn function;
TAILQ_ENTRY(exitlist) next;
};
TAILQ_HEAD(exit_list_head, exitlist);
static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
/*
* exit --
* Death of process.
*/
void
sys_exit(p, uap)
struct proc *p;
struct sys_exit_args /* {
int rval;
} */ *uap;
{
exit1(p, W_EXITCODE(uap->rval, 0));
/* NOTREACHED */
}
/*
* Exit: deallocate address space and other resources, change proc state
* to zombie, and unlink proc from allproc and parent's lists. Save exit
* status and rusage for wait(). Check for child processes and orphan them.
*/
void
exit1(p, rv)
register struct proc *p;
int rv;
{
register struct proc *q, *nq;
register struct vmspace *vm;
struct exitlist *ep;
if (p->p_pid == 1) {
printf("init died (signal %d, exit %d)\n",
WTERMSIG(rv), WEXITSTATUS(rv));
panic("Going nowhere without my init!");
}
aio_proc_rundown(p);
/* are we a task leader? */
PROC_LOCK(p);
if(p == p->p_leader) {
struct kill_args killArgs;
killArgs.signum = SIGKILL;
q = p->p_peers;
while(q) {
killArgs.pid = q->p_pid;
/*
* The interface for kill is better
* than the internal signal
*/
PROC_UNLOCK(p);
kill(p, &killArgs);
PROC_LOCK(p);
nq = q;
q = q->p_peers;
}
while (p->p_peers)
msleep((caddr_t)p, &p->p_mtx, PWAIT, "exit1", 0);
}
PROC_UNLOCK(p);
#ifdef PGINPROF
vmsizmon();
#endif
STOPEVENT(p, S_EXIT, rv);
wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
/*
* Check if any loadable modules need anything done at process exit.
* e.g. SYSV IPC stuff
* XXX what if one of these generates an error?
*/
TAILQ_FOREACH(ep, &exit_list, next)
(*ep->function)(p);
stopprofclock(p);
MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
M_ZOMBIE, M_WAITOK);
/*
* If parent is waiting for us to exit or exec,
* P_PPWAIT is set; we will wakeup the parent below.
*/
PROC_LOCK(p);
p->p_flag &= ~(P_TRACED | P_PPWAIT);
p->p_flag |= P_WEXIT;
SIGEMPTYSET(p->p_siglist);
PROC_UNLOCK(p);
if (timevalisset(&p->p_realtimer.it_value))
callout_stop(&p->p_itcallout);
/*
* Reset any sigio structures pointing to us as a result of
* F_SETOWN with our pid.
*/
funsetownlst(&p->p_sigiolst);
/*
* Close open files and release open-file table.
* This may block!
*/
fdfree(p);
/*
* Remove ourself from our leader's peer list and wake our leader.
*/
PROC_LOCK(p);
if(p->p_leader->p_peers) {
q = p->p_leader;
while(q->p_peers != p)
q = q->p_peers;
q->p_peers = p->p_peers;
wakeup((caddr_t)p->p_leader);
}
PROC_UNLOCK(p);
/*
* XXX Shutdown SYSV semaphores
*/
semexit(p);
/* The next two chunks should probably be moved to vmspace_exit. */
vm = p->p_vmspace;
/*
* Release user portion of address space.
* This releases references to vnodes,
* which could cause I/O if the file has been unlinked.
* Need to do this early enough that we can still sleep.
* Can't free the entire vmspace as the kernel stack
* may be mapped within that space also.
*/
if (vm->vm_refcnt == 1) {
if (vm->vm_shm)
shmexit(p);
pmap_remove_pages(vmspace_pmap(vm), VM_MIN_ADDRESS,
VM_MAXUSER_ADDRESS);
(void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
VM_MAXUSER_ADDRESS);
}
PROC_LOCK(p);
if (SESS_LEADER(p)) {
register struct session *sp = p->p_session;
PROC_UNLOCK(p);
if (sp->s_ttyvp) {
/*
* Controlling process.
* Signal foreground pgrp,
* drain controlling terminal
* and revoke access to controlling terminal.
*/
if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
if (sp->s_ttyp->t_pgrp)
pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
(void) ttywait(sp->s_ttyp);
/*
* The tty could have been revoked
* if we blocked.
*/
if (sp->s_ttyvp)
VOP_REVOKE(sp->s_ttyvp, REVOKEALL);
}
if (sp->s_ttyvp)
vrele(sp->s_ttyvp);
sp->s_ttyvp = NULL;
/*
* s_ttyp is not zero'd; we use this to indicate
* that the session once had a controlling terminal.
* (for logging and informational purposes)
*/
}
sp->s_leader = NULL;
} else
PROC_UNLOCK(p);
fixjobc(p, p->p_pgrp, 0);
(void)acct_process(p);
#ifdef KTRACE
/*
* release trace file
*/
p->p_traceflag = 0; /* don't trace the vrele() */
if (p->p_tracep)
vrele(p->p_tracep);
#endif
/*
* Remove proc from allproc queue and pidhash chain.
* Place onto zombproc. Unlink from parent's child list.
*/
sx_xlock(&allproc_lock);
LIST_REMOVE(p, p_list);
LIST_INSERT_HEAD(&zombproc, p, p_list);
LIST_REMOVE(p, p_hash);
sx_xunlock(&allproc_lock);
sx_xlock(&proctree_lock);
q = LIST_FIRST(&p->p_children);
if (q != NULL) /* only need this if any child is S_ZOMB */
wakeup((caddr_t) initproc);
for (; q != NULL; q = nq) {
nq = LIST_NEXT(q, p_sibling);
PROC_LOCK(q);
proc_reparent(q, initproc);
q->p_sigparent = SIGCHLD;
/*
* Traced processes are killed
* since their existence means someone is screwing up.
*/
if (q->p_flag & P_TRACED) {
q->p_flag &= ~P_TRACED;
psignal(q, SIGKILL);
}
PROC_UNLOCK(q);
}
/*
* Save exit status and final rusage info, adding in child rusage
* info and self times.
*/
p->p_xstat = rv;
*p->p_ru = p->p_stats->p_ru;
mtx_lock_spin(&sched_lock);
calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
mtx_unlock_spin(&sched_lock);
ruadd(p->p_ru, &p->p_stats->p_cru);
/*
* Pretend that an mi_switch() to the next process occurs now. We
* must set `switchtime' directly since we will call cpu_switch()
* directly. Set it now so that the rest of the exit time gets
* counted somewhere if possible.
*/
mtx_lock_spin(&sched_lock);
microuptime(PCPU_PTR(switchtime));
PCPU_SET(switchticks, ticks);
mtx_unlock_spin(&sched_lock);
/*
* notify interested parties of our demise.
*/
PROC_LOCK(p);
KNOTE(&p->p_klist, NOTE_EXIT);
/*
* Notify parent that we're gone. If parent has the PS_NOCLDWAIT
* flag set, notify process 1 instead (and hope it will handle
* this situation).
*/
if (p->p_pptr->p_procsig->ps_flag & PS_NOCLDWAIT) {
struct proc *pp = p->p_pptr;
proc_reparent(p, initproc);
/*
* If this was the last child of our parent, notify
* parent, so in case he was wait(2)ing, he will
* continue.
*/
if (LIST_EMPTY(&pp->p_children))
wakeup((caddr_t)pp);
}
PROC_LOCK(p->p_pptr);
if (p->p_sigparent && p->p_pptr != initproc)
psignal(p->p_pptr, p->p_sigparent);
else
psignal(p->p_pptr, SIGCHLD);
PROC_UNLOCK(p->p_pptr);
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
/*
* Clear curproc after we've done all operations
* that could block, and before tearing down the rest
* of the process state that might be used from clock, etc.
* Also, can't clear curproc while we're still runnable,
* as we're not on a run queue (we are current, just not
* a proper proc any longer!).
*
* Other substructures are freed from wait().
*/
mtx_assert(&Giant, MA_OWNED);
if (--p->p_limit->p_refcnt == 0) {
FREE(p->p_limit, M_SUBPROC);
p->p_limit = NULL;
}
/*
* Finally, call machine-dependent code to release the remaining
* resources including address space, the kernel stack and pcb.
* The address space is released by "vmspace_free(p->p_vmspace)";
* This is machine-dependent, as we may have to change stacks
* or ensure that the current one isn't reallocated before we
* finish. cpu_exit will end with a call to cpu_switch(), finishing
* our execution (pun intended).
*/
cpu_exit(p);
}
#ifdef COMPAT_43
int
owait(p, uap)
struct proc *p;
register struct owait_args /* {
int dummy;
} */ *uap;
{
struct wait_args w;
w.options = 0;
w.rusage = NULL;
w.pid = WAIT_ANY;
w.status = NULL;
return (wait1(p, &w, 1));
}
#endif /* COMPAT_43 */
int
wait4(p, uap)
struct proc *p;
struct wait_args *uap;
{
return (wait1(p, uap, 0));
}
static int
wait1(q, uap, compat)
register struct proc *q;
register struct wait_args /* {
int pid;
int *status;
int options;
struct rusage *rusage;
} */ *uap;
int compat;
{
register int nfound;
register struct proc *p, *t;
int status, error;
if (uap->pid == 0)
uap->pid = -q->p_pgid;
if (uap->options &~ (WUNTRACED|WNOHANG|WLINUXCLONE))
return (EINVAL);
loop:
nfound = 0;
sx_slock(&proctree_lock);
LIST_FOREACH(p, &q->p_children, p_sibling) {
if (uap->pid != WAIT_ANY &&
p->p_pid != uap->pid && p->p_pgid != -uap->pid)
continue;
/*
* This special case handles a kthread spawned by linux_clone
* (see linux_misc.c). The linux_wait4 and linux_waitpid
* functions need to be able to distinguish between waiting
* on a process and waiting on a thread. It is a thread if
* p_sigparent is not SIGCHLD, and the WLINUXCLONE option
* signifies we want to wait for threads and not processes.
*/
PROC_LOCK(p);
if ((p->p_sigparent != SIGCHLD) ^
((uap->options & WLINUXCLONE) != 0)) {
PROC_UNLOCK(p);
continue;
}
nfound++;
mtx_lock_spin(&sched_lock);
if (p->p_stat == SZOMB) {
/* charge childs scheduling cpu usage to parent */
if (curproc->p_pid != 1) {
curproc->p_estcpu =
ESTCPULIM(curproc->p_estcpu + p->p_estcpu);
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
sx_sunlock(&proctree_lock);
q->p_retval[0] = p->p_pid;
#ifdef COMPAT_43
if (compat)
q->p_retval[1] = p->p_xstat;
else
#endif
if (uap->status) {
status = p->p_xstat; /* convert to int */
if ((error = copyout((caddr_t)&status,
(caddr_t)uap->status, sizeof(status))))
return (error);
}
if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
(caddr_t)uap->rusage, sizeof (struct rusage))))
return (error);
/*
* If we got the child via a ptrace 'attach',
* we need to give it back to the old parent.
*/
sx_xlock(&proctree_lock);
if (p->p_oppid) {
if ((t = pfind(p->p_oppid)) != NULL) {
PROC_LOCK(p);
p->p_oppid = 0;
proc_reparent(p, t);
PROC_UNLOCK(p);
PROC_LOCK(t);
psignal(t, SIGCHLD);
PROC_UNLOCK(t);
sx_xunlock(&proctree_lock);
wakeup((caddr_t)t);
return (0);
}
}
sx_xunlock(&proctree_lock);
PROC_LOCK(p);
p->p_xstat = 0;
PROC_UNLOCK(p);
ruadd(&q->p_stats->p_cru, p->p_ru);
FREE(p->p_ru, M_ZOMBIE);
p->p_ru = NULL;
/*
* Decrement the count of procs running with this uid.
*/
(void)chgproccnt(p->p_cred->p_uidinfo, -1, 0);
/*
* Release reference to text vnode
*/
if (p->p_textvp)
vrele(p->p_textvp);
/*
* Free up credentials.
*/
PROC_LOCK(p);
if (--p->p_cred->p_refcnt == 0) {
crfree(p->p_ucred);
uifree(p->p_cred->p_uidinfo);
FREE(p->p_cred, M_SUBPROC);
p->p_cred = NULL;
}
/*
* Remove unused arguments
*/
if (p->p_args && --p->p_args->ar_ref == 0)
FREE(p->p_args, M_PARGS);
PROC_UNLOCK(p);
/*
* Finally finished with old proc entry.
* Unlink it from its process group and free it.
*/
leavepgrp(p);
sx_xlock(&allproc_lock);
LIST_REMOVE(p, p_list); /* off zombproc */
sx_xunlock(&allproc_lock);
sx_xlock(&proctree_lock);
LIST_REMOVE(p, p_sibling);
sx_xunlock(&proctree_lock);
PROC_LOCK(p);
if (--p->p_procsig->ps_refcnt == 0) {
if (p->p_sigacts != &p->p_addr->u_sigacts)
FREE(p->p_sigacts, M_SUBPROC);
FREE(p->p_procsig, M_SUBPROC);
p->p_procsig = NULL;
}
PROC_UNLOCK(p);
/*
* Give machine-dependent layer a chance
* to free anything that cpu_exit couldn't
* release while still running in process context.
*/
cpu_wait(p);
mtx_destroy(&p->p_mtx);
zfree(proc_zone, p);
nprocs--;
return (0);
}
if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
(p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
mtx_unlock_spin(&sched_lock);
p->p_flag |= P_WAITED;
PROC_UNLOCK(p);
sx_sunlock(&proctree_lock);
q->p_retval[0] = p->p_pid;
#ifdef COMPAT_43
if (compat) {
q->p_retval[1] = W_STOPCODE(p->p_xstat);
error = 0;
} else
#endif
if (uap->status) {
status = W_STOPCODE(p->p_xstat);
error = copyout((caddr_t)&status,
(caddr_t)uap->status, sizeof(status));
} else
error = 0;
return (error);
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
}
sx_sunlock(&proctree_lock);
if (nfound == 0)
return (ECHILD);
if (uap->options & WNOHANG) {
q->p_retval[0] = 0;
return (0);
}
if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)))
return (error);
goto loop;
}
/*
* Make process 'parent' the new parent of process 'child'.
* Must be called with an exclusive hold of proctree lock.
*/
void
proc_reparent(child, parent)
register struct proc *child;
register struct proc *parent;
{
SX_ASSERT_XLOCKED(&proctree_lock);
PROC_LOCK_ASSERT(child, MA_OWNED);
if (child->p_pptr == parent)
return;
LIST_REMOVE(child, p_sibling);
LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
child->p_pptr = parent;
}
/*
* The next two functions are to handle adding/deleting items on the
* exit callout list
*
* at_exit():
* Take the arguments given and put them onto the exit callout list,
* However first make sure that it's not already there.
* returns 0 on success.
*/
int
at_exit(function)
exitlist_fn function;
{
struct exitlist *ep;
#ifdef INVARIANTS
/* Be noisy if the programmer has lost track of things */
if (rm_at_exit(function))
printf("WARNING: exit callout entry (%p) already present\n",
function);
#endif
ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
if (ep == NULL)
return (ENOMEM);
ep->function = function;
TAILQ_INSERT_TAIL(&exit_list, ep, next);
return (0);
}
/*
* Scan the exit callout list for the given item and remove it.
* Returns the number of items removed (0 or 1)
*/
int
rm_at_exit(function)
exitlist_fn function;
{
struct exitlist *ep;
TAILQ_FOREACH(ep, &exit_list, next) {
if (ep->function == function) {
TAILQ_REMOVE(&exit_list, ep, next);
free(ep, M_ATEXIT);
return(1);
}
}
return (0);
}
void check_sigacts (void)
{
struct proc *p = curproc;
struct sigacts *pss;
int s;
PROC_LOCK(p);
if (p->p_procsig->ps_refcnt == 1 &&
p->p_sigacts != &p->p_addr->u_sigacts) {
pss = p->p_sigacts;
s = splhigh();
p->p_addr->u_sigacts = *pss;
p->p_sigacts = &p->p_addr->u_sigacts;
splx(s);
FREE(pss, M_SUBPROC);
}
PROC_UNLOCK(p);
}
