/* * 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: src/sys/kern/kern_exit.c,v 1.92.2.11 2003/01/13 22:51:16 dillon Exp $ * $DragonFly: src/sys/kern/kern_exit.c,v 1.23 2003/08/26 21:09:02 rob Exp $ */ #include "opt_compat.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for acct_process() function prototype */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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 (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. * * SYS_EXIT_ARGS(int rval) */ void sys_exit(struct sys_exit_args *uap) { exit1(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(int rv) { struct proc *p = curproc; struct proc *q, *nq; struct vmspace *vm; struct vnode *vtmp; 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? */ 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 */ kill(&killArgs); nq = q; q = q->p_peers; } while (p->p_peers) tsleep((caddr_t)p, 0, "exit1", 0); } #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->p_thread); if (p->p_flag & P_PROFIL) 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. */ p->p_flag &= ~(P_TRACED | P_PPWAIT); p->p_flag |= P_WEXIT; SIGEMPTYSET(p->p_siglist); if (timevalisset(&p->p_realtimer.it_value)) untimeout(realitexpire, (caddr_t)p, p->p_ithandle); /* * 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); 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); } /* * 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. * * Processes sharing the same vmspace may exit in one order, and * get cleaned up by vmspace_exit() in a different order. The * last exiting process to reach this point releases as much of * the environment as it can, and the last process cleaned up * by vmspace_exit() (which decrements exitingcnt) cleans up the * remainder. */ ++vm->vm_exitingcnt; if (--vm->vm_refcnt == 0) { shmexit(vm); 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); } if (SESS_LEADER(p)) { 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 && (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; } 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 ((vtmp = p->p_tracep) != NULL) { p->p_tracep = NULL; vrele(vtmp); } #endif /* * Release reference to text vnode */ if ((vtmp = p->p_textvp) != NULL) { p->p_textvp = NULL; vrele(vtmp); } /* * Once we set SZOMB the process can get reaped. The wait1 code * will also wait for TDF_RUNNING to be cleared in the thread's flags, * indicating that it has been completely switched out. */ /* * Remove proc from allproc queue and pidhash chain. * Place onto zombproc. Unlink from parent's child list. */ LIST_REMOVE(p, p_list); LIST_INSERT_HEAD(&zombproc, p, p_list); p->p_stat = SZOMB; LIST_REMOVE(p, p_hash); q = LIST_FIRST(&p->p_children); if (q) /* only need this if any child is S_ZOMB */ wakeup((caddr_t) initproc); for (; q != 0; q = nq) { nq = LIST_NEXT(q, p_sibling); LIST_REMOVE(q, p_sibling); LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); q->p_pptr = 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); } } /* * 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 interested parties of our demise. */ 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); } if (p->p_sigparent && p->p_pptr != initproc) { psignal(p->p_pptr, p->p_sigparent); } else { psignal(p->p_pptr, SIGCHLD); } wakeup((caddr_t)p->p_pptr); #if defined(tahoe) /* move this to cpu_exit */ p->p_thread->td_pcb->pcb_saveacc.faddr = (float *)NULL; #endif /* * cpu_exit is responsible for clearing curproc, since * it is heavily integrated with the thread/switching sequence. * * Other substructures are freed from wait(). */ if (--p->p_limit->p_refcnt == 0) { FREE(p->p_limit, M_SUBPROC); p->p_limit = NULL; } /* * Release the P_CURPROC designation on the process so the userland * scheduler can work in someone else. */ release_curproc(p); /* * 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_proc_exit(); } #ifdef COMPAT_43 /* * owait() * * owait_args(int dummy) */ int owait(struct owait_args *uap) { struct wait_args w; w.options = 0; w.rusage = NULL; w.pid = WAIT_ANY; w.status = NULL; return (wait1(&w, 1)); } #endif /* COMPAT_43 */ int wait4(struct wait_args *uap) { return (wait1(uap, 0)); } /* * wait1() * * wait_args(int pid, int *status, int options, struct rusage *rusage) */ static int wait1(struct wait_args *uap, int compat) { struct proc *q = curproc; struct proc *p, *t; int status, nfound, error; if (uap->pid == 0) uap->pid = -q->p_pgid; if (uap->options &~ (WUNTRACED|WNOHANG|WLINUXCLONE)) return (EINVAL); loop: nfound = 0; 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. */ if ((p->p_sigparent != SIGCHLD) ^ ((uap->options & WLINUXCLONE) != 0)) continue; nfound++; if (p->p_stat == SZOMB) { /* * The process's thread may still be in the middle * of switching away, we can't rip its stack out from * under it until TDF_RUNNING clears! * * YYY no wakeup occurs so we depend on the timeout. */ if ((p->p_thread->td_flags & TDF_RUNNING) != 0) { tsleep(p->p_thread, 0, "reap", 1); goto loop; } /* * Other kernel threads may be in the middle of * accessing the proc. For example, kern/kern_proc.c * could be blocked writing proc data to a sysctl. * At the moment, if this occurs, we are not woken * up and rely on a one-second retry. */ if (p->p_lock) { printf("Diagnostic: waiting for p_lock\n"); while (p->p_lock) tsleep(p, 0, "reap2", hz); } lwkt_wait_free(p->p_thread); /* charge childs scheduling cpu usage to parent */ if (curproc->p_pid != 1) { curproc->p_estcpu = ESTCPULIM(curproc->p_estcpu + p->p_estcpu); } uap->sysmsg_fds[0] = p->p_pid; #ifdef COMPAT_43 if (compat) uap->sysmsg_fds[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); p->p_ru = NULL; /* * Decrement the count of procs running with this uid. */ (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); /* * Free up credentials. */ crfree(p->p_ucred); p->p_ucred = NULL; /* * Remove unused arguments */ if (p->p_args && --p->p_args->ar_ref == 0) FREE(p->p_args, M_PARGS); /* * Finally finished with old proc entry. * Unlink it from its process group and free it. */ leavepgrp(p); LIST_REMOVE(p, p_list); /* off zombproc */ LIST_REMOVE(p, p_sibling); 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; } vm_waitproc(p); 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)) { p->p_flag |= P_WAITED; uap->sysmsg_fds[0] = p->p_pid; #ifdef COMPAT_43 if (compat) { uap->sysmsg_fds[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) { uap->sysmsg_fds[0] = 0; return (0); } if ((error = tsleep((caddr_t)q, PCATCH, "wait", 0))) return (error); goto loop; } /* * make process 'parent' the new parent of process 'child'. */ void proc_reparent(child, parent) struct proc *child; struct proc *parent; { 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; 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); } }