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38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
42 #include "opt_compat.h"
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
51 #include <sys/pioctl.h>
54 #include <sys/vnode.h>
55 #include <sys/resourcevar.h>
56 #include <sys/signalvar.h>
57 #include <sys/ptrace.h>
58 #include <sys/acct.h> /* for acct_process() function prototype */
59 #include <sys/filedesc.h>
66 #include <vm/vm_param.h>
69 #include <vm/vm_map.h>
70 #include <vm/vm_zone.h>
73 /* Required to be non-static for SysVR4 emulator */
74 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
76 static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
78 static int wait1 __P((struct proc *, struct wait_args *, int));
81 * callout list for things to do at exit time
85 TAILQ_ENTRY(exitlist) next;
88 TAILQ_HEAD(exit_list_head, exitlist);
89 static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
98 struct rexit_args /* {
103 exit1(p, W_EXITCODE(uap->rval, 0));
108 * Exit: deallocate address space and other resources, change proc state
109 * to zombie, and unlink proc from allproc and parent's lists. Save exit
110 * status and rusage for wait(). Check for child processes and orphan them.
114 register struct proc *p;
117 register struct proc *q, *nq;
118 register struct vmspace *vm;
122 printf("init died (signal %d, exit %d)\n",
123 WTERMSIG(rv), WEXITSTATUS(rv));
124 panic("Going nowhere without my init!");
129 /* are we a task leader? */
130 if(p == p->p_leader) {
131 struct kill_args killArgs;
132 killArgs.signum = SIGKILL;
135 killArgs.pid = q->p_pid;
137 * The interface for kill is better
138 * than the internal signal
145 tsleep((caddr_t)p, PWAIT, "exit1", 0);
151 STOPEVENT(p, S_EXIT, rv);
152 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
155 * Check if any loadable modules need anything done at process exit.
156 * e.g. SYSV IPC stuff
157 * XXX what if one of these generates an error?
159 TAILQ_FOREACH(ep, &exit_list, next)
162 if (p->p_flag & P_PROFIL)
164 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
167 * If parent is waiting for us to exit or exec,
168 * P_PPWAIT is set; we will wakeup the parent below.
170 p->p_flag &= ~(P_TRACED | P_PPWAIT);
171 p->p_flag |= P_WEXIT;
172 SIGEMPTYSET(p->p_siglist);
173 if (timevalisset(&p->p_realtimer.it_value))
174 untimeout(realitexpire, (caddr_t)p, p->p_ithandle);
177 * Reset any sigio structures pointing to us as a result of
178 * F_SETOWN with our pid.
180 funsetownlst(&p->p_sigiolst);
183 * Close open files and release open-file table.
188 if(p->p_leader->p_peers) {
190 while(q->p_peers != p)
192 q->p_peers = p->p_peers;
193 wakeup((caddr_t)p->p_leader);
197 * XXX Shutdown SYSV semaphores
201 /* The next two chunks should probably be moved to vmspace_exit. */
204 * Release user portion of address space.
205 * This releases references to vnodes,
206 * which could cause I/O if the file has been unlinked.
207 * Need to do this early enough that we can still sleep.
208 * Can't free the entire vmspace as the kernel stack
209 * may be mapped within that space also.
211 if (vm->vm_refcnt == 1) {
214 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_ADDRESS,
216 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
220 if (SESS_LEADER(p)) {
221 register struct session *sp = p->p_session;
225 * Controlling process.
226 * Signal foreground pgrp,
227 * drain controlling terminal
228 * and revoke access to controlling terminal.
230 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
231 if (sp->s_ttyp->t_pgrp)
232 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
233 (void) ttywait(sp->s_ttyp);
235 * The tty could have been revoked
239 VOP_REVOKE(sp->s_ttyvp, REVOKEALL);
245 * s_ttyp is not zero'd; we use this to indicate
246 * that the session once had a controlling terminal.
247 * (for logging and informational purposes)
252 fixjobc(p, p->p_pgrp, 0);
253 (void)acct_process(p);
258 p->p_traceflag = 0; /* don't trace the vrele() */
263 * Remove proc from allproc queue and pidhash chain.
264 * Place onto zombproc. Unlink from parent's child list.
266 LIST_REMOVE(p, p_list);
267 LIST_INSERT_HEAD(&zombproc, p, p_list);
270 LIST_REMOVE(p, p_hash);
272 q = LIST_FIRST(&p->p_children);
273 if (q) /* only need this if any child is S_ZOMB */
274 wakeup((caddr_t) initproc);
275 for (; q != 0; q = nq) {
276 nq = LIST_NEXT(q, p_sibling);
277 LIST_REMOVE(q, p_sibling);
278 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling);
279 q->p_pptr = initproc;
280 q->p_sigparent = SIGCHLD;
282 * Traced processes are killed
283 * since their existence means someone is screwing up.
285 if (q->p_flag & P_TRACED) {
286 q->p_flag &= ~P_TRACED;
292 * Save exit status and final rusage info, adding in child rusage
293 * info and self times.
296 *p->p_ru = p->p_stats->p_ru;
297 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
298 ruadd(p->p_ru, &p->p_stats->p_cru);
301 * Pretend that an mi_switch() to the next process occurs now. We
302 * must set `switchtime' directly since we will call cpu_switch()
303 * directly. Set it now so that the rest of the exit time gets
304 * counted somewhere if possible.
306 microuptime(&switchtime);
310 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
311 * flag set, notify process 1 instead (and hope it will handle
314 if (p->p_pptr->p_procsig->ps_flag & PS_NOCLDWAIT) {
315 struct proc *pp = p->p_pptr;
316 proc_reparent(p, initproc);
318 * If this was the last child of our parent, notify
319 * parent, so in case he was wait(2)ing, he will
322 if (LIST_EMPTY(&pp->p_children))
326 if (p->p_sigparent && p->p_pptr != initproc) {
327 psignal(p->p_pptr, p->p_sigparent);
329 psignal(p->p_pptr, SIGCHLD);
332 wakeup((caddr_t)p->p_pptr);
334 /* move this to cpu_exit */
335 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
338 * Clear curproc after we've done all operations
339 * that could block, and before tearing down the rest
340 * of the process state that might be used from clock, etc.
341 * Also, can't clear curproc while we're still runnable,
342 * as we're not on a run queue (we are current, just not
343 * a proper proc any longer!).
345 * Other substructures are freed from wait().
348 if (--p->p_limit->p_refcnt == 0) {
349 FREE(p->p_limit, M_SUBPROC);
354 * Finally, call machine-dependent code to release the remaining
355 * resources including address space, the kernel stack and pcb.
356 * The address space is released by "vmspace_free(p->p_vmspace)";
357 * This is machine-dependent, as we may have to change stacks
358 * or ensure that the current one isn't reallocated before we
359 * finish. cpu_exit will end with a call to cpu_switch(), finishing
360 * our execution (pun intended).
369 register struct owait_args /* {
379 return (wait1(p, &w, 1));
381 #endif /* COMPAT_43 */
386 struct wait_args *uap;
389 return (wait1(p, uap, 0));
393 wait1(q, uap, compat)
394 register struct proc *q;
395 register struct wait_args /* {
399 struct rusage *rusage;
404 register struct proc *p, *t;
408 uap->pid = -q->p_pgid;
409 if (uap->options &~ (WUNTRACED|WNOHANG|WLINUXCLONE))
413 LIST_FOREACH(p, &q->p_children, p_sibling) {
414 if (uap->pid != WAIT_ANY &&
415 p->p_pid != uap->pid && p->p_pgid != -uap->pid)
418 /* This special case handles a kthread spawned by linux_clone
419 * (see linux_misc.c). The linux_wait4 and linux_waitpid functions
420 * need to be able to distinguish between waiting on a process and
421 * waiting on a thread. It is a thread if p_sigparent is not SIGCHLD,
422 * and the WLINUXCLONE option signifies we want to wait for threads
425 if ((p->p_sigparent != SIGCHLD) ^ ((uap->options & WLINUXCLONE) != 0))
429 if (p->p_stat == SZOMB) {
430 /* charge childs scheduling cpu usage to parent */
431 if (curproc->p_pid != 1) {
433 ESTCPULIM(curproc->p_estcpu + p->p_estcpu);
436 q->p_retval[0] = p->p_pid;
439 q->p_retval[1] = p->p_xstat;
443 status = p->p_xstat; /* convert to int */
444 if ((error = copyout((caddr_t)&status,
445 (caddr_t)uap->status, sizeof(status))))
448 if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
449 (caddr_t)uap->rusage, sizeof (struct rusage))))
452 * If we got the child via a ptrace 'attach',
453 * we need to give it back to the old parent.
455 if (p->p_oppid && (t = pfind(p->p_oppid))) {
463 ruadd(&q->p_stats->p_cru, p->p_ru);
464 FREE(p->p_ru, M_ZOMBIE);
468 * Decrement the count of procs running with this uid.
470 (void)chgproccnt(p->p_cred->p_ruid, -1);
473 * Release reference to text vnode
479 * Free up credentials.
481 if (--p->p_cred->p_refcnt == 0) {
483 FREE(p->p_cred, M_SUBPROC);
488 * Destroy empty prisons
490 if (p->p_prison && !--p->p_prison->pr_ref) {
491 if (p->p_prison->pr_linux != NULL)
492 FREE(p->p_prison->pr_linux, M_PRISON);
493 FREE(p->p_prison, M_PRISON);
497 * Remove unused arguments
499 if (p->p_args && --p->p_args->ar_ref == 0)
500 FREE(p->p_args, M_PARGS);
503 * Finally finished with old proc entry.
504 * Unlink it from its process group and free it.
507 LIST_REMOVE(p, p_list); /* off zombproc */
508 LIST_REMOVE(p, p_sibling);
510 if (--p->p_procsig->ps_refcnt == 0) {
511 if (p->p_sigacts != &p->p_addr->u_sigacts)
512 FREE(p->p_sigacts, M_SUBPROC);
513 FREE(p->p_procsig, M_SUBPROC);
518 * Give machine-dependent layer a chance
519 * to free anything that cpu_exit couldn't
520 * release while still running in process context.
527 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
528 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
529 p->p_flag |= P_WAITED;
530 q->p_retval[0] = p->p_pid;
533 q->p_retval[1] = W_STOPCODE(p->p_xstat);
538 status = W_STOPCODE(p->p_xstat);
539 error = copyout((caddr_t)&status,
540 (caddr_t)uap->status, sizeof(status));
548 if (uap->options & WNOHANG) {
552 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)))
558 * make process 'parent' the new parent of process 'child'.
561 proc_reparent(child, parent)
562 register struct proc *child;
563 register struct proc *parent;
566 if (child->p_pptr == parent)
569 LIST_REMOVE(child, p_sibling);
570 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
571 child->p_pptr = parent;
575 * The next two functions are to handle adding/deleting items on the
579 * Take the arguments given and put them onto the exit callout list,
580 * However first make sure that it's not already there.
581 * returns 0 on success.
586 exitlist_fn function;
591 /* Be noisy if the programmer has lost track of things */
592 if (rm_at_exit(function))
593 printf("WARNING: exit callout entry (%p) already present\n",
596 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
599 ep->function = function;
600 TAILQ_INSERT_TAIL(&exit_list, ep, next);
605 * Scan the exit callout list for the given item and remove it.
606 * Returns the number of items removed (0 or 1)
610 exitlist_fn function;
614 TAILQ_FOREACH(ep, &exit_list, next) {
615 if (ep->function == function) {
616 TAILQ_REMOVE(&exit_list, ep, next);
624 void check_sigacts (void)
626 struct proc *p = curproc;
630 if (p->p_procsig->ps_refcnt == 1 &&
631 p->p_sigacts != &p->p_addr->u_sigacts) {
634 p->p_addr->u_sigacts = *pss;
635 p->p_sigacts = &p->p_addr->u_sigacts;
637 FREE(pss, M_SUBPROC);