/* $NetBSD: kern_exit.c,v 1.200 2008/03/21 21:55:00 ad Exp $ */ /*- * Copyright (c) 1998, 1999, 2006, 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center, and by Andrew Doran. * * 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 NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * 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. 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 8.10 (Berkeley) 2/23/95 */ #include __KERNEL_RCSID(0, "$NetBSD: kern_exit.c,v 1.200 2008/03/21 21:55:00 ad Exp $"); #include "opt_ktrace.h" #include "opt_perfctrs.h" #include "opt_sysv.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(PERFCTRS) #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEBUG_EXIT #ifdef DEBUG_EXIT int debug_exit = 0; #define DPRINTF(x) if (debug_exit) printf x #else #define DPRINTF(x) #endif static int find_stopped_child(struct proc *, pid_t, int, struct proc **, int *); static void proc_free(struct proc *, struct rusage *); /* * Fill in the appropriate signal information, and signal the parent. */ static void exit_psignal(struct proc *p, struct proc *pp, ksiginfo_t *ksi) { KSI_INIT(ksi); if ((ksi->ksi_signo = P_EXITSIG(p)) == SIGCHLD) { if (WIFSIGNALED(p->p_xstat)) { if (WCOREDUMP(p->p_xstat)) ksi->ksi_code = CLD_DUMPED; else ksi->ksi_code = CLD_KILLED; } else { ksi->ksi_code = CLD_EXITED; } } /* * We fill those in, even for non-SIGCHLD. * It's safe to access p->p_cred unlocked here. */ ksi->ksi_pid = p->p_pid; ksi->ksi_uid = kauth_cred_geteuid(p->p_cred); ksi->ksi_status = p->p_xstat; /* XXX: is this still valid? */ ksi->ksi_utime = p->p_stats->p_ru.ru_utime.tv_sec; ksi->ksi_stime = p->p_stats->p_ru.ru_stime.tv_sec; } /* * exit -- * Death of process. */ int sys_exit(struct lwp *l, const struct sys_exit_args *uap, register_t *retval) { /* { syscallarg(int) rval; } */ struct proc *p = l->l_proc; /* Don't call exit1() multiple times in the same process. */ KERNEL_LOCK(1, NULL); mutex_enter(&p->p_smutex); if (p->p_sflag & PS_WEXIT) { mutex_exit(&p->p_smutex); lwp_exit(l); } /* exit1() will release the mutex. */ exit1(l, W_EXITCODE(SCARG(uap, rval), 0)); /* NOTREACHED */ return (0); } /* * 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. * * Must be called with p->p_smutex held. Does not return. */ void exit1(struct lwp *l, int rv) { struct proc *p, *q, *nq; ksiginfo_t ksi; ksiginfoq_t kq; int wakeinit; p = l->l_proc; KASSERT(mutex_owned(&p->p_smutex)); if (__predict_false(p == initproc)) panic("init died (signal %d, exit %d)", WTERMSIG(rv), WEXITSTATUS(rv)); p->p_sflag |= PS_WEXIT; /* * Force all other LWPs to exit before we do. Only then can we * begin to tear down the rest of the process state. */ if (p->p_nlwps > 1) exit_lwps(l); ksiginfo_queue_init(&kq); /* * If we have been asked to stop on exit, do so now. */ if (p->p_sflag & PS_STOPEXIT) { KERNEL_UNLOCK_ALL(l, &l->l_biglocks); sigclearall(p, &contsigmask, &kq); p->p_waited = 0; membar_producer(); p->p_stat = SSTOP; lwp_lock(l); p->p_nrlwps--; l->l_stat = LSSTOP; mutex_exit(&p->p_smutex); mi_switch(l); KERNEL_LOCK(l->l_biglocks, l); } else mutex_exit(&p->p_smutex); /* Destroy any lwpctl info. */ if (p->p_lwpctl != NULL) lwp_ctl_exit(); /* Destroy all AIO works */ aio_exit(p, p->p_aio); /* * Drain all remaining references that procfs, ptrace and others may * have on the process. */ rw_enter(&p->p_reflock, RW_WRITER); /* * Bin any remaining signals and mark the process as dying so it will * not be found for, e.g. signals. */ mutex_enter(&p->p_smutex); sigfillset(&p->p_sigctx.ps_sigignore); sigclearall(p, NULL, &kq); p->p_stat = SDYING; mutex_exit(&p->p_smutex); ksiginfo_queue_drain(&kq); DPRINTF(("exit1: %d.%d exiting.\n", p->p_pid, l->l_lid)); #ifdef PGINPROF vmsizmon(); #endif timers_free(p, TIMERS_ALL); #if defined(__HAVE_RAS) ras_purgeall(); #endif /* * Close open files, release open-file table and free signal * actions. This may block! */ fd_free(); cwdfree(p->p_cwdi); p->p_cwdi = NULL; doexithooks(p); sigactsfree(p->p_sigacts); /* * Write out accounting data. */ (void)acct_process(l); #ifdef KTRACE /* * Release trace file. */ if (p->p_tracep != NULL) { mutex_enter(&ktrace_lock); ktrderef(p); mutex_exit(&ktrace_lock); } #endif /* * If emulation has process exit hook, call it now. * Set the exit status now so that the exit hook has * an opportunity to tweak it (COMPAT_LINUX requires * this for thread group emulation) */ p->p_xstat = rv; if (p->p_emul->e_proc_exit) (*p->p_emul->e_proc_exit)(p); /* * Free the VM resources we're still holding on to. * We must do this from a valid thread because doing * so may block. This frees vmspace, which we don't * need anymore. The only remaining lwp is the one * we run at this moment, nothing runs in userland * anymore. */ uvm_proc_exit(p); /* * While we can still block, and mark the LWP as unswappable to * prevent conflicts with the with the swapper. We also shouldn't * be swapped out, because we are about to exit and will release * memory. */ uvm_lwp_hold(l); /* * Stop profiling. */ if ((p->p_stflag & PST_PROFIL) != 0) { mutex_spin_enter(&p->p_stmutex); stopprofclock(p); mutex_spin_exit(&p->p_stmutex); } /* * If parent is waiting for us to exit or exec, P_PPWAIT is set; we * wake up the parent early to avoid deadlock. We can do this once * the VM resources are released. */ mutex_enter(&proclist_lock); mutex_enter(&p->p_smutex); if (p->p_sflag & PS_PPWAIT) { p->p_sflag &= ~PS_PPWAIT; cv_broadcast(&p->p_pptr->p_waitcv); } mutex_exit(&p->p_smutex); if (SESS_LEADER(p)) { struct vnode *vprele = NULL, *vprevoke = NULL; struct session *sp = p->p_session; struct tty *tp; if (sp->s_ttyvp) { /* * Controlling process. * Signal foreground pgrp, * drain controlling terminal * and revoke access to controlling terminal. */ tp = sp->s_ttyp; mutex_spin_enter(&tty_lock); if (tp->t_session == sp) { if (tp->t_pgrp) { mutex_enter(&proclist_mutex); pgsignal(tp->t_pgrp, SIGHUP, 1); mutex_exit(&proclist_mutex); } /* we can't guarantee the revoke will do this */ tp->t_pgrp = NULL; tp->t_session = NULL; mutex_spin_exit(&tty_lock); mutex_exit(&proclist_lock); (void) ttywait(tp); mutex_enter(&proclist_lock); /* The tty could have been revoked. */ vprevoke = sp->s_ttyvp; } else mutex_spin_exit(&tty_lock); vprele = 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; if (vprevoke != NULL || vprele != NULL) { if (vprevoke != NULL) { SESSRELE(sp); mutex_exit(&proclist_lock); VOP_REVOKE(vprevoke, REVOKEALL); } else mutex_exit(&proclist_lock); if (vprele != NULL) vrele(vprele); mutex_enter(&proclist_lock); } } mutex_enter(&proclist_mutex); fixjobc(p, p->p_pgrp, 0); mutex_exit(&proclist_mutex); /* * Finalize the last LWP's specificdata, as well as the * specificdata for the proc itself. */ lwp_finispecific(l); proc_finispecific(p); /* * Notify interested parties of our demise. */ KNOTE(&p->p_klist, NOTE_EXIT); #if PERFCTRS /* * Save final PMC information in parent process & clean up. */ if (PMC_ENABLED(p)) { pmc_save_context(p); pmc_accumulate(p->p_pptr, p); pmc_process_exit(p); } #endif /* * Reset p_opptr pointer of all former children which got * traced by another process and were reparented. We reset * it to NULL here; the trace detach code then reparents * the child to initproc. We only check allproc list, since * eventual former children on zombproc list won't reference * p_opptr anymore. */ if (p->p_slflag & PSL_CHTRACED) { PROCLIST_FOREACH(q, &allproc) { if (q->p_opptr == p) q->p_opptr = NULL; } } /* * Give orphaned children to init(8). */ q = LIST_FIRST(&p->p_children); wakeinit = (q != NULL); for (; q != NULL; q = nq) { nq = LIST_NEXT(q, p_sibling); /* * Traced processes are killed since their existence * means someone is screwing up. Since we reset the * trace flags, the logic in sys_wait4() would not be * triggered to reparent the process to its * original parent, so we must do this here. */ if (q->p_slflag & PSL_TRACED) { mutex_enter(&p->p_smutex); q->p_slflag &= ~(PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL); mutex_exit(&p->p_smutex); if (q->p_opptr != q->p_pptr) { struct proc *t = q->p_opptr; proc_reparent(q, t ? t : initproc); q->p_opptr = NULL; } else proc_reparent(q, initproc); killproc(q, "orphaned traced process"); } else proc_reparent(q, initproc); } /* * Move proc from allproc to zombproc, it's now nearly ready to be * collected by parent. */ mutex_enter(&proclist_mutex); LIST_REMOVE(l, l_list); LIST_REMOVE(p, p_list); LIST_INSERT_HEAD(&zombproc, p, p_list); /* * Mark the process as dead. We must do this before we signal * the parent. */ p->p_stat = SDEAD; /* Put in front of parent's sibling list for parent to collect it */ q = p->p_pptr; q->p_nstopchild++; if (LIST_FIRST(&q->p_children) != p) { /* Put child where it can be found quickly */ LIST_REMOVE(p, p_sibling); LIST_INSERT_HEAD(&q->p_children, p, p_sibling); } mutex_exit(&proclist_mutex); /* * Notify parent that we're gone. If parent has the P_NOCLDWAIT * flag set, notify init instead (and hope it will handle * this situation). */ mutex_enter(&q->p_mutex); if (q->p_flag & (PK_NOCLDWAIT|PK_CLDSIGIGN)) { proc_reparent(p, initproc); wakeinit = 1; /* * If this was the last child of our parent, notify * parent, so in case he was wait(2)ing, he will * continue. */ if (LIST_FIRST(&q->p_children) == NULL) cv_broadcast(&q->p_waitcv); } mutex_exit(&q->p_mutex); /* Reload parent pointer, since p may have been reparented above */ q = p->p_pptr; if ((p->p_slflag & PSL_FSTRACE) == 0 && p->p_exitsig != 0) { exit_psignal(p, q, &ksi); mutex_enter(&proclist_mutex); kpsignal(q, &ksi, NULL); mutex_exit(&proclist_mutex); } /* Calculate the final rusage info. */ calcru(p, &p->p_stats->p_ru.ru_utime, &p->p_stats->p_ru.ru_stime, NULL, NULL); if (wakeinit) cv_broadcast(&initproc->p_waitcv); callout_destroy(&l->l_timeout_ch); /* * Remaining lwp resources will be freed in lwp_exit2() once we've * switch to idle context; at that point, we will be marked as a * full blown zombie. * * XXXSMP disable preemption. */ mutex_enter(&p->p_smutex); lwp_drainrefs(l); lwp_lock(l); l->l_prflag &= ~LPR_DETACHED; l->l_stat = LSZOMB; lwp_unlock(l); KASSERT(curlwp == l); KASSERT(p->p_nrlwps == 1); KASSERT(p->p_nlwps == 1); p->p_stat = SZOMB; p->p_nrlwps--; p->p_nzlwps++; p->p_ndlwps = 0; mutex_exit(&p->p_smutex); /* * Signal the parent to collect us, and drop the proclist lock. * Drop debugger/procfs lock; no new references can be gained. */ cv_broadcast(&p->p_pptr->p_waitcv); mutex_exit(&proclist_lock); rw_exit(&p->p_reflock); /* Verify that we hold no locks other than the kernel lock. */ #ifdef MULTIPROCESSOR LOCKDEBUG_BARRIER(&kernel_lock, 0); #else LOCKDEBUG_BARRIER(NULL, 0); #endif /* * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP! */ /* * Give machine-dependent code a chance to free any MD LWP * resources. This must be done before uvm_lwp_exit(), in * case these resources are in the PCB. */ #ifndef __NO_CPU_LWP_FREE cpu_lwp_free(l, 1); #endif pmap_deactivate(l); /* This process no longer needs to hold the kernel lock. */ #ifdef notyet /* XXXSMP hold in lwp_userret() */ KERNEL_UNLOCK_LAST(l); #else KERNEL_UNLOCK_ALL(l, NULL); #endif lwp_exit_switchaway(l); } void exit_lwps(struct lwp *l) { struct proc *p; struct lwp *l2; int error; lwpid_t waited; #if defined(MULTIPROCESSOR) int nlocks; #endif KERNEL_UNLOCK_ALL(l, &nlocks); p = l->l_proc; KASSERT(mutex_owned(&p->p_smutex)); retry: /* * Interrupt LWPs in interruptable sleep, unsuspend suspended * LWPs and then wait for everyone else to finish. */ LIST_FOREACH(l2, &p->p_lwps, l_sibling) { if (l2 == l) continue; lwp_lock(l2); l2->l_flag |= LW_WEXIT; if ((l2->l_stat == LSSLEEP && (l2->l_flag & LW_SINTR)) || l2->l_stat == LSSUSPENDED || l2->l_stat == LSSTOP) { /* setrunnable() will release the lock. */ setrunnable(l2); DPRINTF(("exit_lwps: Made %d.%d runnable\n", p->p_pid, l2->l_lid)); continue; } lwp_unlock(l2); } while (p->p_nlwps > 1) { DPRINTF(("exit_lwps: waiting for %d LWPs (%d zombies)\n", p->p_nlwps, p->p_nzlwps)); error = lwp_wait1(l, 0, &waited, LWPWAIT_EXITCONTROL); if (p->p_nlwps == 1) break; if (error == EDEADLK) { /* * LWPs can get suspended/slept behind us. * (eg. sa_setwoken) * kick them again and retry. */ goto retry; } if (error) panic("exit_lwps: lwp_wait1 failed with error %d", error); DPRINTF(("exit_lwps: Got LWP %d from lwp_wait1()\n", waited)); } #if defined(MULTIPROCESSOR) if (nlocks > 0) { mutex_exit(&p->p_smutex); KERNEL_LOCK(nlocks, l); mutex_enter(&p->p_smutex); } #endif /* defined(MULTIPROCESSOR) */ KASSERT(p->p_nlwps == 1); } int do_sys_wait(struct lwp *l, int *pid, int *status, int options, struct rusage *ru, int *was_zombie) { struct proc *child; int error; KERNEL_LOCK(1, NULL); /* XXXSMP */ mutex_enter(&proclist_lock); error = find_stopped_child(l->l_proc, *pid, options, &child, status); KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ if (child == NULL) { mutex_exit(&proclist_lock); *pid = 0; return error; } *pid = child->p_pid; if (child->p_stat == SZOMB) { /* proc_free() will release the proclist_lock. */ *was_zombie = 1; if (options & WNOWAIT) mutex_exit(&proclist_lock); else { proc_free(child, ru); } } else { /* Child state must have been SSTOP. */ *was_zombie = 0; mutex_exit(&proclist_lock); *status = W_STOPCODE(*status); } return 0; } int sys_wait4(struct lwp *l, const struct sys_wait4_args *uap, register_t *retval) { /* { syscallarg(int) pid; syscallarg(int *) status; syscallarg(int) options; syscallarg(struct rusage *) rusage; } */ int status, error; int was_zombie; struct rusage ru; int pid = SCARG(uap, pid); error = do_sys_wait(l, &pid, &status, SCARG(uap, options), SCARG(uap, rusage) != NULL ? &ru : NULL, &was_zombie); retval[0] = pid; if (pid == 0) return error; if (SCARG(uap, rusage)) error = copyout(&ru, SCARG(uap, rusage), sizeof(ru)); if (error == 0 && SCARG(uap, status)) error = copyout(&status, SCARG(uap, status), sizeof(status)); return error; } /* * Scan list of child processes for a child process that has stopped or * exited. Used by sys_wait4 and 'compat' equivalents. * * Must be called with the proclist_lock held, and may release * while waiting. */ static int find_stopped_child(struct proc *parent, pid_t pid, int options, struct proc **child_p, int *status_p) { struct proc *child, *dead; int error; KASSERT(mutex_owned(&proclist_lock)); if (options & ~(WUNTRACED|WNOHANG|WALTSIG|WALLSIG) && !(options & WOPTSCHECKED)) { *child_p = NULL; return EINVAL; } if (pid == 0 && !(options & WOPTSCHECKED)) pid = -parent->p_pgid; for (;;) { error = ECHILD; dead = NULL; mutex_enter(&proclist_mutex); LIST_FOREACH(child, &parent->p_children, p_sibling) { if (pid >= 0) { if (child->p_pid != pid) { child = p_find(pid, PFIND_ZOMBIE | PFIND_LOCKED); if (child == NULL || child->p_pptr != parent) { child = NULL; break; } } } else if (pid != WAIT_ANY && child->p_pgid != -pid) { /* Child not in correct pgrp */ continue; } /* * Wait for processes with p_exitsig != SIGCHLD * processes only if WALTSIG is set; wait for * processes with p_exitsig == SIGCHLD only * if WALTSIG is clear. */ if (((options & WALLSIG) == 0) && (options & WALTSIG ? child->p_exitsig == SIGCHLD : P_EXITSIG(child) != SIGCHLD)){ if (child->p_pid == pid) { child = NULL; break; } continue; } error = 0; if ((options & WNOZOMBIE) == 0) { if (child->p_stat == SZOMB) break; if (child->p_stat == SDEAD) { /* * We may occasionally arrive here * after receiving a signal, but * immediatley before the child * process is zombified. The wait * will be short, so avoid returning * to userspace. */ dead = child; } } if (child->p_stat == SSTOP && child->p_waited == 0 && (child->p_slflag & PSL_TRACED || options & WUNTRACED)) { if ((options & WNOWAIT) == 0) { child->p_waited = 1; parent->p_nstopchild--; } break; } if (parent->p_nstopchild == 0 || child->p_pid == pid) { child = NULL; break; } } if (child != NULL || error != 0 || ((options & WNOHANG) != 0 && dead == NULL)) { if (child != NULL) { *status_p = child->p_xstat; } mutex_exit(&proclist_mutex); *child_p = child; return error; } /* * Wait for another child process to stop. */ mutex_exit(&proclist_lock); error = cv_wait_sig(&parent->p_waitcv, &proclist_mutex); mutex_exit(&proclist_mutex); mutex_enter(&proclist_lock); if (error != 0) { *child_p = NULL; return error; } } } /* * Free a process after parent has taken all the state info. Must be called * with the proclist lock held, and will release before returning. * * *ru is returned to the caller, and must be freed by the caller. */ static void proc_free(struct proc *p, struct rusage *ru) { struct proc *parent; struct lwp *l; ksiginfo_t ksi; kauth_cred_t cred1, cred2; uid_t uid; KASSERT(mutex_owned(&proclist_lock)); KASSERT(p->p_nlwps == 1); KASSERT(p->p_nzlwps == 1); KASSERT(p->p_nrlwps == 0); KASSERT(p->p_stat == SZOMB); /* * If we got the child via ptrace(2) or procfs, and * the parent is different (meaning the process was * attached, rather than run as a child), then we need * to give it back to the old parent, and send the * parent the exit signal. The rest of the cleanup * will be done when the old parent waits on the child. */ if ((p->p_slflag & PSL_TRACED) != 0) { parent = p->p_pptr; if (p->p_opptr != parent){ mutex_enter(&p->p_smutex); p->p_slflag &= ~(PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL); mutex_exit(&p->p_smutex); parent = p->p_opptr; if (parent == NULL) parent = initproc; proc_reparent(p, parent); p->p_opptr = NULL; if (p->p_exitsig != 0) { exit_psignal(p, parent, &ksi); mutex_enter(&proclist_mutex); kpsignal(parent, &ksi, NULL); mutex_exit(&proclist_mutex); } KERNEL_LOCK(1, NULL); /* XXXSMP */ cv_broadcast(&parent->p_waitcv); KERNEL_UNLOCK_ONE(NULL); /* XXXSMP */ mutex_exit(&proclist_lock); return; } } /* * Finally finished with old proc entry. Unlink it from its process * group. */ leavepgrp(p); parent = p->p_pptr; sched_proc_exit(parent, p); /* * Add child times of exiting process onto its own times. * This cannot be done any earlier else it might get done twice. */ ruadd(&p->p_stats->p_ru, &p->p_stats->p_cru); ruadd(&parent->p_stats->p_cru, &p->p_stats->p_ru); if (ru != NULL) *ru = p->p_stats->p_ru; p->p_xstat = 0; /* * At this point we are going to start freeing the final resources. * If anyone tries to access the proc structure after here they will * get a shock - bits are missing. Attempt to make it hard! We * don't bother with any further locking past this point. */ mutex_enter(&proclist_mutex); p->p_stat = SIDL; /* not even a zombie any more */ LIST_REMOVE(p, p_list); /* off zombproc */ parent = p->p_pptr; p->p_pptr->p_nstopchild--; mutex_exit(&proclist_mutex); LIST_REMOVE(p, p_sibling); /* * Let pid be reallocated. */ proc_free_pid(p); mutex_exit(&proclist_lock); l = LIST_FIRST(&p->p_lwps); /* * Delay release until after lwp_free. */ cred2 = l->l_cred; /* * Free the last LWP's resources. * * lwp_free ensures the LWP is no longer running on another CPU. */ lwp_free(l, false, true); /* * Now no one except us can reach the process p. */ /* * Decrement the count of procs running with this uid. */ cred1 = p->p_cred; uid = kauth_cred_getuid(cred1); (void)chgproccnt(uid, -1); /* * Release substructures. */ limfree(p->p_limit); pstatsfree(p->p_stats); kauth_cred_free(cred1); kauth_cred_free(cred2); /* * Release reference to text vnode */ if (p->p_textvp) vrele(p->p_textvp); mutex_destroy(&p->p_auxlock); mutex_destroy(&p->p_mutex); mutex_destroy(&p->p_stmutex); mutex_destroy(&p->p_smutex); cv_destroy(&p->p_waitcv); cv_destroy(&p->p_lwpcv); rw_destroy(&p->p_reflock); proc_free_mem(p); } /* * make process 'parent' the new parent of process 'child'. * * Must be called with proclist_lock lock held. */ void proc_reparent(struct proc *child, struct proc *parent) { KASSERT(mutex_owned(&proclist_lock)); if (child->p_pptr == parent) return; mutex_enter(&proclist_mutex); if (child->p_stat == SZOMB || (child->p_stat == SSTOP && !child->p_waited)) { child->p_pptr->p_nstopchild--; parent->p_nstopchild++; } mutex_exit(&proclist_mutex); if (parent == initproc) child->p_exitsig = SIGCHLD; LIST_REMOVE(child, p_sibling); LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); child->p_pptr = parent; }