BSD 4_3 release

[unix-history] / usr / src / sys / sys / kern_exit.c

/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)kern_exit.c 7.1 (Berkeley) 6/5/86
*/

#include "../machine/reg.h"
#include "../machine/psl.h"

#include "param.h"
#include "systm.h"
#include "map.h"
#include "dir.h"
#include "user.h"
#include "kernel.h"
#include "proc.h"
#include "buf.h"
#include "wait.h"
#include "vm.h"
#include "file.h"
#include "mbuf.h"
#include "inode.h"
#include "syslog.h"

/*
* Exit system call: pass back caller's arg
*/
rexit()
{
       register struct a {
               int     rval;
       } *uap;

       uap = (struct a *)u.u_ap;
       exit((uap->rval & 0377) << 8);
}

/*
* Release resources.
* Save u. area for parent to look at.
* Enter zombie state.
* Wake up parent and init processes,
* and dispose of children.
*/
exit(rv)
       int rv;
{
       register int i;
       register struct proc *p, *q, *nq;
       register int x;
       struct mbuf *m = m_getclr(M_WAIT, MT_ZOMBIE);

#ifdef PGINPROF
       vmsizmon();
#endif
       p = u.u_procp;
       p->p_flag &= ~(STRC|SULOCK);
       p->p_flag |= SWEXIT;
       p->p_sigignore = ~0;
       p->p_cpticks = 0;
       p->p_pctcpu = 0;
       for (i = 0; i < NSIG; i++)
               u.u_signal[i] = SIG_IGN;
       untimeout(realitexpire, (caddr_t)p);
       /*
        * Release virtual memory.  If we resulted from
        * a vfork(), instead give the resources back to
        * the parent.
        */
       if ((p->p_flag & SVFORK) == 0)
               vrelvm();
       else {
               p->p_flag &= ~SVFORK;
               wakeup((caddr_t)p);
               while ((p->p_flag & SVFDONE) == 0)
                       sleep((caddr_t)p, PZERO - 1);
               p->p_flag &= ~SVFDONE;
       }
       for (i = 0; i <= u.u_lastfile; i++) {
               struct file *f;

               f = u.u_ofile[i];
               if (f) {
                       u.u_ofile[i] = NULL;
                       u.u_pofile[i] = 0;
                       closef(f);
               }
       }
       ilock(u.u_cdir);
       iput(u.u_cdir);
       if (u.u_rdir) {
               ilock(u.u_rdir);
               iput(u.u_rdir);
       }
       u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
       acct();
#ifdef QUOTA
       qclean();
#endif
       /*
        * Freeing the user structure and kernel stack
        * for the current process: have to run a bit longer
        * using the pages which are about to be freed...
        * vrelu will block memory allocation by raising ipl.
        */
       vrelu(u.u_procp, 0);
       vrelpt(u.u_procp);
       if (*p->p_prev = p->p_nxt)              /* off allproc queue */
               p->p_nxt->p_prev = p->p_prev;
       if (p->p_nxt = zombproc)                /* onto zombproc */
               p->p_nxt->p_prev = &p->p_nxt;
       p->p_prev = &zombproc;
       zombproc = p;
       multprog--;
       p->p_stat = SZOMB;
       noproc = 1;
       i = PIDHASH(p->p_pid);
       x = p - proc;
       if (pidhash[i] == x)
               pidhash[i] = p->p_idhash;
       else {
               for (i = pidhash[i]; i != 0; i = proc[i].p_idhash)
                       if (proc[i].p_idhash == x) {
                               proc[i].p_idhash = p->p_idhash;
                               goto done;
                       }
               panic("exit");
       }
       if (p->p_pid == 1) {
               if (p->p_dsize == 0) {
                       printf("Can't exec /etc/init\n");
                       for (;;)
                               ;
               } else
                       panic("init died");
       }
done:
       p->p_xstat = rv;
       p->p_ru = mtod(m, struct rusage *);
       *p->p_ru = u.u_ru;
       ruadd(p->p_ru, &u.u_cru);
       if (p->p_cptr)          /* only need this if any child is S_ZOMB */
               wakeup((caddr_t)&proc[1]);
       for (q = p->p_cptr; q != NULL; q = nq) {
               nq = q->p_osptr;
               if (nq != NULL)
                       nq->p_ysptr = NULL;
               if (proc[1].p_cptr)
                       proc[1].p_cptr->p_ysptr = q;
               q->p_osptr = proc[1].p_cptr;
               q->p_ysptr = NULL;
               proc[1].p_cptr = q;

               q->p_pptr = &proc[1];
               q->p_ppid = 1;
               /*
                * Traced processes are killed
                * since their existence means someone is screwing up.
                * Stopped processes are sent a hangup and a continue.
                * This is designed to be ``safe'' for setuid
                * processes since they must be willing to tolerate
                * hangups anyways.
                */
               if (q->p_flag&STRC) {
                       q->p_flag &= ~STRC;
                       psignal(q, SIGKILL);
               } else if (q->p_stat == SSTOP) {
                       psignal(q, SIGHUP);
                       psignal(q, SIGCONT);
               }
               /*
                * Protect this process from future
                * tty signals, clear TSTP/TTIN/TTOU if pending.
                */
               (void) spgrp(q);
       }
       p->p_cptr = NULL;
       psignal(p->p_pptr, SIGCHLD);
       wakeup((caddr_t)p->p_pptr);
       swtch();
}

wait()
{
       struct rusage ru, *rup;

       if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
               u.u_error = wait1(0, (struct rusage *)0);
               return;
       }
       rup = (struct rusage *)u.u_ar0[R1];
       u.u_error = wait1(u.u_ar0[R0], &ru);
       if (u.u_error)
               return;
       if (rup != (struct rusage *)0)
               u.u_error = copyout((caddr_t)&ru, (caddr_t)rup,
                   sizeof (struct rusage));
}

/*
* Wait system call.
* Search for a terminated (zombie) child,
* finally lay it to rest, and collect its status.
* Look also for stopped (traced) children,
* and pass back status from them.
*/
wait1(options, ru)
       register int options;
       struct rusage *ru;
{
       register f;
       register struct proc *p, *q;

       f = 0;
loop:
       q = u.u_procp;
       for (p = q->p_cptr; p; p = p->p_osptr) {
               f++;
               if (p->p_stat == SZOMB) {
                       u.u_r.r_val1 = p->p_pid;
                       u.u_r.r_val2 = p->p_xstat;
                       p->p_xstat = 0;
                       if (ru && p->p_ru)
                               *ru = *p->p_ru;
                       if (p->p_ru) {
                               ruadd(&u.u_cru, p->p_ru);
                               (void) m_free(dtom(p->p_ru));
                               p->p_ru = 0;
                       }
                       p->p_stat = NULL;
                       p->p_pid = 0;
                       p->p_ppid = 0;
                       if (*p->p_prev = p->p_nxt)      /* off zombproc */
                               p->p_nxt->p_prev = p->p_prev;
                       p->p_nxt = freeproc;            /* onto freeproc */
                       freeproc = p;
                       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;
                       p->p_pptr = 0;
                       p->p_ysptr = 0;
                       p->p_osptr = 0;
                       p->p_cptr = 0;
                       p->p_sig = 0;
                       p->p_sigcatch = 0;
                       p->p_sigignore = 0;
                       p->p_sigmask = 0;
                       p->p_pgrp = 0;
                       p->p_flag = 0;
                       p->p_wchan = 0;
                       p->p_cursig = 0;
                       return (0);
               }
               if (p->p_stat == SSTOP && (p->p_flag&SWTED)==0 &&
                   (p->p_flag&STRC || options&WUNTRACED)) {
                       p->p_flag |= SWTED;
                       u.u_r.r_val1 = p->p_pid;
                       u.u_r.r_val2 = (p->p_cursig<<8) | WSTOPPED;
                       return (0);
               }
       }
       if (f == 0)
               return (ECHILD);
       if (options&WNOHANG) {
               u.u_r.r_val1 = 0;
               return (0);
       }
       if (setjmp(&u.u_qsave)) {
               p = u.u_procp;
               if ((u.u_sigintr & sigmask(p->p_cursig)) != 0)
                       return(EINTR);
               u.u_eosys = RESTARTSYS;
               return (0);
       }
       sleep((caddr_t)u.u_procp, PWAIT);
       goto loop;
}