/* * 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 * $Id: kern_exit.c,v 1.66 1998/04/06 08:26:03 phk Exp $ */ #include "opt_compat.h" #include "opt_ktrace.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/sysproto.h> #include <sys/malloc.h> #include <sys/proc.h> #include <sys/pioctl.h> #include <sys/tty.h> #include <sys/wait.h> #include <sys/vnode.h> #include <sys/resourcevar.h> #include <sys/signalvar.h> #include <sys/ptrace.h> #include <sys/acct.h> /* for acct_process() function prototype */ #include <sys/filedesc.h> #include <sys/shm.h> #include <sys/sem.h> #include <sys/aio.h> #ifdef COMPAT_43 #include <machine/reg.h> #include <machine/psl.h> #endif #include <machine/limits.h> /* for UCHAR_MAX = typeof(p_priority)_MAX */ #include <vm/vm.h> #include <vm/vm_param.h> #include <sys/lock.h> #include <vm/pmap.h> #include <vm/vm_map.h> #include <vm/vm_zone.h> static MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); static int wait1 __P((struct proc *, struct wait_args *, int)); /* * callout list for things to do at exit time */ typedef struct exit_list_element { struct exit_list_element *next; exitlist_fn function; } *ele_p; static ele_p exit_list; /* * exit -- * Death of process. */ void exit(p, uap) struct proc *p; struct rexit_args /* { int rval; } */ *uap; { 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. */ void exit1(p, rv) register struct proc *p; int rv; { register struct proc *q, *nq; register struct vmspace *vm; ele_p ep = exit_list; 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(p, &killArgs); nq = q; q = q->p_peers; /* * orphan the threads so we don't mess up * when they call exit */ nq->p_peers = 0; nq->p_leader = nq; } /* otherwise are we a peer? */ } else if(p->p_peers) { q = p->p_leader; while(q->p_peers != p) q = q->p_peers; q->p_peers = p->p_peers; } #ifdef PGINPROF vmsizmon(); #endif STOPEVENT(p, S_EXIT, rv); /* * Check if any LKMs need anything done at process exit. * e.g. SYSV IPC stuff * XXX what if one of these generates an error? */ while (ep) { (*ep->function)(p); ep = ep->next; } 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; p->p_sigignore = ~0; p->p_siglist = 0; if (timevalisset(&p->p_realtimer.it_value)) untimeout(realitexpire, (caddr_t)p, p->p_ithandle); /* * Close open files and release open-file table. * This may block! */ fdfree(p); /* * 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. */ if (vm->vm_refcnt == 1) { if (vm->vm_shm) shmexit(p); pmap_remove_pages(&vm->vm_pmap, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS); (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 && (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 (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. */ LIST_REMOVE(p, p_list); LIST_INSERT_HEAD(&zombproc, p, p_list); p->p_stat = SZOMB; LIST_REMOVE(p, p_hash); q = p->p_children.lh_first; if (q) /* only need this if any child is S_ZOMB */ wakeup((caddr_t) initproc); for (; q != 0; q = nq) { nq = q->p_sibling.le_next; LIST_REMOVE(q, p_sibling); LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling); q->p_pptr = initproc; /* * 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 parent that we're gone. If parent has the P_NOCLDWAIT * flag set, notify process 1 instead (and hope it will handle * this situation). */ if (p->p_pptr->p_flag & P_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); } 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); p->p_limit = NULL; } /* * 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_exit(p); } #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 int owait(p, uap) struct proc *p; register struct owait_args /* { int dummy; } */ *uap; { struct wait_args w; #ifdef PSL_ALLCC if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) { w.options = 0; w.rusage = NULL; } else { w.options = p->p_md.md_regs[R0]; w.rusage = (struct rusage *)p->p_md.md_regs[R1]; } #else w.options = 0; w.rusage = NULL; #endif w.pid = WAIT_ANY; w.status = NULL; return (wait1(p, &w, 1)); } #endif /* COMPAT_43 */ int wait4(p, uap) struct proc *p; struct wait_args *uap; { return (wait1(p, uap, 0)); } static int wait1(q, uap, compat) register struct proc *q; register struct wait_args /* { int pid; int *status; int options; struct rusage *rusage; } */ *uap; int compat; { register int nfound; register struct proc *p, *t; int status, error; if (uap->pid == 0) uap->pid = -q->p_pgid; if (uap->options &~ (WUNTRACED|WNOHANG)) return (EINVAL); loop: nfound = 0; for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { if (uap->pid != WAIT_ANY && p->p_pid != uap->pid && p->p_pgid != -uap->pid) continue; nfound++; if (p->p_stat == SZOMB) { /* charge childs scheduling cpu usage to parent */ if (curproc->p_pid != 1) { curproc->p_estcpu = min(curproc->p_estcpu + p->p_estcpu, UCHAR_MAX); } q->p_retval[0] = p->p_pid; #ifdef COMPAT_43 if (compat) q->p_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); p->p_ru = NULL; /* * Decrement the count of procs running with this uid. */ (void)chgproccnt(p->p_cred->p_ruid, -1); /* * Release reference to text vnode */ if (p->p_textvp) vrele(p->p_textvp); /* * Free up credentials. */ if (--p->p_cred->p_refcnt == 0) { crfree(p->p_cred->pc_ucred); FREE(p->p_cred, M_SUBPROC); p->p_cred = NULL; } /* * 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); /* * Give machine-dependent layer a chance * to free anything that cpu_exit couldn't * release while still running in process context. */ cpu_wait(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; q->p_retval[0] = p->p_pid; #ifdef COMPAT_43 if (compat) { q->p_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) { q->p_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; { 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; { ele_p ep; /* Be noisy if the programmer has lost track of things */ if (rm_at_exit(function)) printf("exit callout entry already present\n"); ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT); if (ep == NULL) return (ENOMEM); ep->next = exit_list; ep->function = function; exit_list = ep; return (0); } /* * Scan the exit callout list for the given items and remove them. * Returns the number of items removed. * Logically this can only be 0 or 1. */ int rm_at_exit(function) exitlist_fn function; { ele_p *epp, ep; int count; count = 0; epp = &exit_list; ep = *epp; while (ep) { if (ep->function == function) { *epp = ep->next; free(ep, M_TEMP); count++; } else { epp = &ep->next; } ep = *epp; } return (count); }