4.3BSD - /usr/src/sys/sys/kern_exit.c

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)kern_exit.c	7.1 (Berkeley) 6/5/86
   7:  */
   8: 
   9: #include "../machine/reg.h"
  10: #include "../machine/psl.h"
  11: 
  12: #include "param.h"
  13: #include "systm.h"
  14: #include "map.h"
  15: #include "dir.h"
  16: #include "user.h"
  17: #include "kernel.h"
  18: #include "proc.h"
  19: #include "buf.h"
  20: #include "wait.h"
  21: #include "vm.h"
  22: #include "file.h"
  23: #include "mbuf.h"
  24: #include "inode.h"
  25: #include "syslog.h"
  26: 
  27: /*
  28:  * Exit system call: pass back caller's arg
  29:  */
  30: rexit()
  31: {
  32:     register struct a {
  33:         int rval;
  34:     } *uap;
  35: 
  36:     uap = (struct a *)u.u_ap;
  37:     exit((uap->rval & 0377) << 8);
  38: }
  39: 
  40: /*
  41:  * Release resources.
  42:  * Save u. area for parent to look at.
  43:  * Enter zombie state.
  44:  * Wake up parent and init processes,
  45:  * and dispose of children.
  46:  */
  47: exit(rv)
  48:     int rv;
  49: {
  50:     register int i;
  51:     register struct proc *p, *q, *nq;
  52:     register int x;
  53:     struct mbuf *m = m_getclr(M_WAIT, MT_ZOMBIE);
  54: 
  55: #ifdef PGINPROF
  56:     vmsizmon();
  57: #endif
  58:     p = u.u_procp;
  59:     p->p_flag &= ~(STRC|SULOCK);
  60:     p->p_flag |= SWEXIT;
  61:     p->p_sigignore = ~0;
  62:     p->p_cpticks = 0;
  63:     p->p_pctcpu = 0;
  64:     for (i = 0; i < NSIG; i++)
  65:         u.u_signal[i] = SIG_IGN;
  66:     untimeout(realitexpire, (caddr_t)p);
  67:     /*
  68: 	 * Release virtual memory.  If we resulted from
  69: 	 * a vfork(), instead give the resources back to
  70: 	 * the parent.
  71: 	 */
  72:     if ((p->p_flag & SVFORK) == 0)
  73:         vrelvm();
  74:     else {
  75:         p->p_flag &= ~SVFORK;
  76:         wakeup((caddr_t)p);
  77:         while ((p->p_flag & SVFDONE) == 0)
  78:             sleep((caddr_t)p, PZERO - 1);
  79:         p->p_flag &= ~SVFDONE;
  80:     }
  81:     for (i = 0; i <= u.u_lastfile; i++) {
  82:         struct file *f;
  83: 
  84:         f = u.u_ofile[i];
  85:         if (f) {
  86:             u.u_ofile[i] = NULL;
  87:             u.u_pofile[i] = 0;
  88:             closef(f);
  89:         }
  90:     }
  91:     ilock(u.u_cdir);
  92:     iput(u.u_cdir);
  93:     if (u.u_rdir) {
  94:         ilock(u.u_rdir);
  95:         iput(u.u_rdir);
  96:     }
  97:     u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
  98:     acct();
  99: #ifdef QUOTA
 100:     qclean();
 101: #endif
 102:     /*
 103: 	 * Freeing the user structure and kernel stack
 104: 	 * for the current process: have to run a bit longer
 105: 	 * using the pages which are about to be freed...
 106: 	 * vrelu will block memory allocation by raising ipl.
 107: 	 */
 108:     vrelu(u.u_procp, 0);
 109:     vrelpt(u.u_procp);
 110:     if (*p->p_prev = p->p_nxt)      /* off allproc queue */
 111:         p->p_nxt->p_prev = p->p_prev;
 112:     if (p->p_nxt = zombproc)        /* onto zombproc */
 113:         p->p_nxt->p_prev = &p->p_nxt;
 114:     p->p_prev = &zombproc;
 115:     zombproc = p;
 116:     multprog--;
 117:     p->p_stat = SZOMB;
 118:     noproc = 1;
 119:     i = PIDHASH(p->p_pid);
 120:     x = p - proc;
 121:     if (pidhash[i] == x)
 122:         pidhash[i] = p->p_idhash;
 123:     else {
 124:         for (i = pidhash[i]; i != 0; i = proc[i].p_idhash)
 125:             if (proc[i].p_idhash == x) {
 126:                 proc[i].p_idhash = p->p_idhash;
 127:                 goto done;
 128:             }
 129:         panic("exit");
 130:     }
 131:     if (p->p_pid == 1) {
 132:         if (p->p_dsize == 0) {
 133:             printf("Can't exec /etc/init\n");
 134:             for (;;)
 135:                 ;
 136:         } else
 137:             panic("init died");
 138:     }
 139: done:
 140:     p->p_xstat = rv;
 141:     p->p_ru = mtod(m, struct rusage *);
 142:     *p->p_ru = u.u_ru;
 143:     ruadd(p->p_ru, &u.u_cru);
 144:     if (p->p_cptr)      /* only need this if any child is S_ZOMB */
 145:         wakeup((caddr_t)&proc[1]);
 146:     for (q = p->p_cptr; q != NULL; q = nq) {
 147:         nq = q->p_osptr;
 148:         if (nq != NULL)
 149:             nq->p_ysptr = NULL;
 150:         if (proc[1].p_cptr)
 151:             proc[1].p_cptr->p_ysptr = q;
 152:         q->p_osptr = proc[1].p_cptr;
 153:         q->p_ysptr = NULL;
 154:         proc[1].p_cptr = q;
 155: 
 156:         q->p_pptr = &proc[1];
 157:         q->p_ppid = 1;
 158:         /*
 159: 		 * Traced processes are killed
 160: 		 * since their existence means someone is screwing up.
 161: 		 * Stopped processes are sent a hangup and a continue.
 162: 		 * This is designed to be ``safe'' for setuid
 163: 		 * processes since they must be willing to tolerate
 164: 		 * hangups anyways.
 165: 		 */
 166:         if (q->p_flag&STRC) {
 167:             q->p_flag &= ~STRC;
 168:             psignal(q, SIGKILL);
 169:         } else if (q->p_stat == SSTOP) {
 170:             psignal(q, SIGHUP);
 171:             psignal(q, SIGCONT);
 172:         }
 173:         /*
 174: 		 * Protect this process from future
 175: 		 * tty signals, clear TSTP/TTIN/TTOU if pending.
 176: 		 */
 177:         (void) spgrp(q);
 178:     }
 179:     p->p_cptr = NULL;
 180:     psignal(p->p_pptr, SIGCHLD);
 181:     wakeup((caddr_t)p->p_pptr);
 182:     swtch();
 183: }
 184: 
 185: wait()
 186: {
 187:     struct rusage ru, *rup;
 188: 
 189:     if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
 190:         u.u_error = wait1(0, (struct rusage *)0);
 191:         return;
 192:     }
 193:     rup = (struct rusage *)u.u_ar0[R1];
 194:     u.u_error = wait1(u.u_ar0[R0], &ru);
 195:     if (u.u_error)
 196:         return;
 197:     if (rup != (struct rusage *)0)
 198:         u.u_error = copyout((caddr_t)&ru, (caddr_t)rup,
 199:             sizeof (struct rusage));
 200: }
 201: 
 202: /*
 203:  * Wait system call.
 204:  * Search for a terminated (zombie) child,
 205:  * finally lay it to rest, and collect its status.
 206:  * Look also for stopped (traced) children,
 207:  * and pass back status from them.
 208:  */
 209: wait1(options, ru)
 210:     register int options;
 211:     struct rusage *ru;
 212: {
 213:     register f;
 214:     register struct proc *p, *q;
 215: 
 216:     f = 0;
 217: loop:
 218:     q = u.u_procp;
 219:     for (p = q->p_cptr; p; p = p->p_osptr) {
 220:         f++;
 221:         if (p->p_stat == SZOMB) {
 222:             u.u_r.r_val1 = p->p_pid;
 223:             u.u_r.r_val2 = p->p_xstat;
 224:             p->p_xstat = 0;
 225:             if (ru && p->p_ru)
 226:                 *ru = *p->p_ru;
 227:             if (p->p_ru) {
 228:                 ruadd(&u.u_cru, p->p_ru);
 229:                 (void) m_free(dtom(p->p_ru));
 230:                 p->p_ru = 0;
 231:             }
 232:             p->p_stat = NULL;
 233:             p->p_pid = 0;
 234:             p->p_ppid = 0;
 235:             if (*p->p_prev = p->p_nxt)  /* off zombproc */
 236:                 p->p_nxt->p_prev = p->p_prev;
 237:             p->p_nxt = freeproc;        /* onto freeproc */
 238:             freeproc = p;
 239:             if (q = p->p_ysptr)
 240:                 q->p_osptr = p->p_osptr;
 241:             if (q = p->p_osptr)
 242:                 q->p_ysptr = p->p_ysptr;
 243:             if ((q = p->p_pptr)->p_cptr == p)
 244:                 q->p_cptr = p->p_osptr;
 245:             p->p_pptr = 0;
 246:             p->p_ysptr = 0;
 247:             p->p_osptr = 0;
 248:             p->p_cptr = 0;
 249:             p->p_sig = 0;
 250:             p->p_sigcatch = 0;
 251:             p->p_sigignore = 0;
 252:             p->p_sigmask = 0;
 253:             p->p_pgrp = 0;
 254:             p->p_flag = 0;
 255:             p->p_wchan = 0;
 256:             p->p_cursig = 0;
 257:             return (0);
 258:         }
 259:         if (p->p_stat == SSTOP && (p->p_flag&SWTED)==0 &&
 260:             (p->p_flag&STRC || options&WUNTRACED)) {
 261:             p->p_flag |= SWTED;
 262:             u.u_r.r_val1 = p->p_pid;
 263:             u.u_r.r_val2 = (p->p_cursig<<8) | WSTOPPED;
 264:             return (0);
 265:         }
 266:     }
 267:     if (f == 0)
 268:         return (ECHILD);
 269:     if (options&WNOHANG) {
 270:         u.u_r.r_val1 = 0;
 271:         return (0);
 272:     }
 273:     if (setjmp(&u.u_qsave)) {
 274:         p = u.u_procp;
 275:         if ((u.u_sigintr & sigmask(p->p_cursig)) != 0)
 276:             return(EINTR);
 277:         u.u_eosys = RESTARTSYS;
 278:         return (0);
 279:     }
 280:     sleep((caddr_t)u.u_procp, PWAIT);
 281:     goto loop;
 282: }

Defined functions

Defined struct's