4.4BSD/usr/src/sys/kern/kern_exit.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_exit.c 8.1 (Berkeley) 6/14/93
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/map.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/resourcevar.h>
#include <sys/ptrace.h>
#include <machine/cpu.h>
#ifdef COMPAT_43
#include <machine/reg.h>
#include <machine/psl.h>
#endif
#include <vm/vm.h>
#include <vm/vm_kern.h>
__dead void cpu_exit __P((struct proc *));
__dead void exit1 __P((struct proc *, int));
/*
* exit --
* Death of process.
*/
struct rexit_args {
int rval;
};
__dead void
exit(p, uap, retval)
struct proc *p;
struct rexit_args *uap;
int *retval;
{
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.
*/
__dead void
exit1(p, rv)
register struct proc *p;
int rv;
{
register struct proc *q, *nq;
register struct proc **pp;
register struct vmspace *vm;
int s;
if (p->p_pid == 1)
panic("init died (signal %d, exit %d)",
WTERMSIG(rv), WEXITSTATUS(rv));
#ifdef PGINPROF
vmsizmon();
#endif
if (p->p_flag & SPROFIL)
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,
* SPPWAIT is set; we will wakeup the parent below.
*/
p->p_flag &= ~(STRC|SPPWAIT);
p->p_flag |= SWEXIT;
p->p_sigignore = ~0;
p->p_sig = 0;
untimeout(realitexpire, (caddr_t)p);
/*
* Close open files and release open-file table.
* This may block!
*/
fdfree(p);
/* The next two chunks should probably be moved to vmspace_exit. */
vm = p->p_vmspace;
#ifdef SYSVSHM
if (vm->vm_shm)
shmexit(p);
#endif
/*
* 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)
(void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
VM_MAXUSER_ADDRESS);
if (SESS_LEADER(p)) {
register struct session *sp = p->p_session;
if (sp->s_ttyvp) {
/*
* Controlling process.
* Signal foreground pgrp,
* drain controlling terminal
* and revoke access to controlling terminal.
*/
if (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);
vgoneall(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;
}
fixjobc(p, p->p_pgrp, 0);
p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
(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.
*/
if (*p->p_prev = p->p_nxt)
p->p_nxt->p_prev = p->p_prev;
if (p->p_nxt = zombproc)
p->p_nxt->p_prev = &p->p_nxt;
p->p_prev = &zombproc;
zombproc = p;
p->p_stat = SZOMB;
for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash)
if (*pp == p) {
*pp = p->p_hash;
goto done;
}
panic("exit");
done:
if (p->p_cptr) /* only need this if any child is S_ZOMB */
wakeup((caddr_t) initproc);
for (q = p->p_cptr; q != NULL; q = nq) {
nq = q->p_osptr;
if (nq != NULL)
nq->p_ysptr = NULL;
if (initproc->p_cptr)
initproc->p_cptr->p_ysptr = q;
q->p_osptr = initproc->p_cptr;
q->p_ysptr = NULL;
initproc->p_cptr = q;
q->p_pptr = initproc;
/*
* Traced processes are killed
* since their existence means someone is screwing up.
*/
if (q->p_flag&STRC) {
q->p_flag &= ~STRC;
psignal(q, SIGKILL);
}
}
p->p_cptr = NULL;
/*
* 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;
calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
ruadd(p->p_ru, &p->p_stats->p_cru);
/*
* Notify parent that we're gone.
*/
psignal(p->p_pptr, SIGCHLD);
wakeup((caddr_t)p->p_pptr);
#if defined(tahoe)
/* move this to cpu_exit */
p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
#endif
/*
* 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().
*/
curproc = NULL;
if (--p->p_limit->p_refcnt == 0)
FREE(p->p_limit, M_SUBPROC);
/*
* 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_swtch(), finishing
* our execution (pun intended).
*/
cpu_exit(p);
}
struct wait_args {
int pid;
int *status;
int options;
struct rusage *rusage;
#ifdef COMPAT_43
int compat; /* pseudo */
#endif
};
#ifdef COMPAT_43
#if defined(hp300) || defined(luna68k)
#include <machine/frame.h>
#define GETPS(rp) ((struct frame *)(rp))->f_sr
#else
#define GETPS(rp) (rp)[PS]
#endif
owait(p, uap, retval)
struct proc *p;
register struct wait_args *uap;
int *retval;
{
#ifdef PSL_ALLCC
if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) {
uap->options = 0;
uap->rusage = NULL;
} else {
uap->options = p->p_md.md_regs[R0];
uap->rusage = (struct rusage *)p->p_md.md_regs[R1];
}
#else
uap->options = 0;
uap->rusage = NULL;
#endif
uap->pid = WAIT_ANY;
uap->status = NULL;
uap->compat = 1;
return (wait1(p, uap, retval));
}
wait4(p, uap, retval)
struct proc *p;
struct wait_args *uap;
int *retval;
{
uap->compat = 0;
return (wait1(p, uap, retval));
}
#else
#define wait1 wait4
#endif
/*
* Wait: check child processes to see if any have exited,
* stopped under trace, or (optionally) stopped by a signal.
* Pass back status and deallocate exited child's proc structure.
*/
wait1(q, uap, retval)
register struct proc *q;
register struct wait_args *uap;
int retval[];
{
register int nfound;
register struct proc *p, *t;
int status, error;
if (uap->pid == 0)
uap->pid = -q->p_pgid;
#ifdef notyet
if (uap->options &~ (WUNTRACED|WNOHANG))
return (EINVAL);
#endif
loop:
nfound = 0;
for (p = q->p_cptr; p; p = p->p_osptr) {
if (uap->pid != WAIT_ANY &&
p->p_pid != uap->pid && p->p_pgid != -uap->pid)
continue;
nfound++;
if (p->p_stat == SZOMB) {
retval[0] = p->p_pid;
#ifdef COMPAT_43
if (uap->compat)
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.
*/
if (p->p_oppid && (t = pfind(p->p_oppid))) {
p->p_oppid = 0;
proc_reparent(p, t);
psignal(t, SIGCHLD);
wakeup((caddr_t)t);
return (0);
}
p->p_xstat = 0;
ruadd(&q->p_stats->p_cru, p->p_ru);
FREE(p->p_ru, M_ZOMBIE);
/*
* Decrement the count of procs running with this uid.
*/
(void)chgproccnt(p->p_cred->p_ruid, -1);
/*
* Free up credentials.
*/
if (--p->p_cred->p_refcnt == 0) {
crfree(p->p_cred->pc_ucred);
FREE(p->p_cred, M_SUBPROC);
}
/*
* Finally finished with old proc entry.
* Unlink it from its process group and free it.
*/
leavepgrp(p);
if (*p->p_prev = p->p_nxt) /* off zombproc */
p->p_nxt->p_prev = p->p_prev;
if (q = p->p_ysptr)
q->p_osptr = p->p_osptr;
if (q = p->p_osptr)
q->p_ysptr = p->p_ysptr;
if ((q = p->p_pptr)->p_cptr == p)
q->p_cptr = p->p_osptr;
/*
* Give machine-dependent layer a chance
* to free anything that cpu_exit couldn't
* release while still running in process context.
*/
cpu_wait(p);
FREE(p, M_PROC);
nprocs--;
return (0);
}
if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
(p->p_flag & STRC || uap->options & WUNTRACED)) {
p->p_flag |= SWTED;
retval[0] = p->p_pid;
#ifdef COMPAT_43
if (uap->compat) {
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);
}
}
if (nfound == 0)
return (ECHILD);
if (uap->options & WNOHANG) {
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'.
*/
void
proc_reparent(child, parent)
register struct proc *child;
register struct proc *parent;
{
register struct proc *o;
register struct proc *y;
if (child->p_pptr == parent)
return;
/* fix up the child linkage for the old parent */
o = child->p_osptr;
y = child->p_ysptr;
if (y)
y->p_osptr = o;
if (o)
o->p_ysptr = y;
if (child->p_pptr->p_cptr == child)
child->p_pptr->p_cptr = o;
/* fix up child linkage for new parent */
o = parent->p_cptr;
if (o)
o->p_ysptr = child;
child->p_osptr = o;
child->p_ysptr = NULL;
parent->p_cptr = child;
child->p_pptr = parent;
}