/* $OpenBSD: kern_sig.c,v 1.151 2013/04/29 17:06:20 matthew Exp $ */ /* $NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $ */ /* * Copyright (c) 1997 Theo de Raadt. All rights reserved. * 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_sig.c 8.7 (Berkeley) 4/18/94 */ #define SIGPROP /* include signal properties table */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int filt_sigattach(struct knote *kn); void filt_sigdetach(struct knote *kn); int filt_signal(struct knote *kn, long hint); struct filterops sig_filtops = { 0, filt_sigattach, filt_sigdetach, filt_signal }; void proc_stop(struct proc *p, int); void proc_stop_sweep(void *); struct timeout proc_stop_to; int cansignal(struct proc *, struct pcred *, struct proc *, int); struct pool sigacts_pool; /* memory pool for sigacts structures */ /* * Can process p, with pcred pc, send the signal signum to process q? */ int cansignal(struct proc *p, struct pcred *pc, struct proc *q, int signum) { if (pc->pc_ucred->cr_uid == 0) return (1); /* root can always signal */ if (p == q) return (1); /* process can always signal itself */ if (signum == SIGCONT && q->p_p->ps_session == p->p_p->ps_session) return (1); /* SIGCONT in session */ /* * Using kill(), only certain signals can be sent to setugid * child processes */ if (q->p_p->ps_flags & PS_SUGID) { switch (signum) { case 0: case SIGKILL: case SIGINT: case SIGTERM: case SIGALRM: case SIGSTOP: case SIGTTIN: case SIGTTOU: case SIGTSTP: case SIGHUP: case SIGUSR1: case SIGUSR2: if (pc->p_ruid == q->p_cred->p_ruid || pc->pc_ucred->cr_uid == q->p_cred->p_ruid) return (1); } return (0); } if (pc->p_ruid == q->p_cred->p_ruid || pc->p_ruid == q->p_cred->p_svuid || pc->pc_ucred->cr_uid == q->p_cred->p_ruid || pc->pc_ucred->cr_uid == q->p_cred->p_svuid) return (1); return (0); } /* * Initialize signal-related data structures. */ void signal_init(void) { timeout_set(&proc_stop_to, proc_stop_sweep, NULL); pool_init(&sigacts_pool, sizeof(struct sigacts), 0, 0, 0, "sigapl", &pool_allocator_nointr); } /* * Create an initial sigacts structure, using the same signal state * as p. */ struct sigacts * sigactsinit(struct proc *p) { struct sigacts *ps; ps = pool_get(&sigacts_pool, PR_WAITOK); memcpy(ps, p->p_sigacts, sizeof(struct sigacts)); ps->ps_refcnt = 1; return (ps); } /* * Share a sigacts structure. */ struct sigacts * sigactsshare(struct proc *p) { p->p_sigacts->ps_refcnt++; return p->p_sigacts; } /* * Initialize a new sigaltstack structure. */ void sigstkinit(struct sigaltstack *ss) { ss->ss_flags = SS_DISABLE; ss->ss_size = 0; ss->ss_sp = 0; } /* * Make this process not share its sigacts, maintaining all * signal state. */ void sigactsunshare(struct proc *p) { struct sigacts *newps; if (p->p_sigacts->ps_refcnt == 1) return; newps = sigactsinit(p); sigactsfree(p); p->p_sigacts = newps; } /* * Release a sigacts structure. */ void sigactsfree(struct proc *p) { struct sigacts *ps = p->p_sigacts; if (--ps->ps_refcnt > 0) return; p->p_sigacts = NULL; pool_put(&sigacts_pool, ps); } /* ARGSUSED */ int sys_sigaction(struct proc *p, void *v, register_t *retval) { struct sys_sigaction_args /* { syscallarg(int) signum; syscallarg(const struct sigaction *) nsa; syscallarg(struct sigaction *) osa; } */ *uap = v; struct sigaction vec; #ifdef KTRACE struct sigaction ovec; #endif struct sigaction *sa; const struct sigaction *nsa; struct sigaction *osa; struct sigacts *ps = p->p_sigacts; int signum; int bit, error; signum = SCARG(uap, signum); nsa = SCARG(uap, nsa); osa = SCARG(uap, osa); if (signum <= 0 || signum >= NSIG || (nsa && (signum == SIGKILL || signum == SIGSTOP))) return (EINVAL); sa = &vec; if (osa) { sa->sa_handler = ps->ps_sigact[signum]; sa->sa_mask = ps->ps_catchmask[signum]; bit = sigmask(signum); sa->sa_flags = 0; if ((ps->ps_sigonstack & bit) != 0) sa->sa_flags |= SA_ONSTACK; if ((ps->ps_sigintr & bit) == 0) sa->sa_flags |= SA_RESTART; if ((ps->ps_sigreset & bit) != 0) sa->sa_flags |= SA_RESETHAND; if ((ps->ps_siginfo & bit) != 0) sa->sa_flags |= SA_SIGINFO; if (signum == SIGCHLD) { if ((ps->ps_flags & SAS_NOCLDSTOP) != 0) sa->sa_flags |= SA_NOCLDSTOP; if ((ps->ps_flags & SAS_NOCLDWAIT) != 0) sa->sa_flags |= SA_NOCLDWAIT; } if ((sa->sa_mask & bit) == 0) sa->sa_flags |= SA_NODEFER; sa->sa_mask &= ~bit; error = copyout(sa, osa, sizeof (vec)); if (error) return (error); #ifdef KTRACE if (KTRPOINT(p, KTR_STRUCT)) ovec = vec; #endif } if (nsa) { error = copyin(nsa, sa, sizeof (vec)); if (error) return (error); #ifdef KTRACE if (KTRPOINT(p, KTR_STRUCT)) ktrsigaction(p, sa); #endif setsigvec(p, signum, sa); } #ifdef KTRACE if (osa && KTRPOINT(p, KTR_STRUCT)) ktrsigaction(p, &ovec); #endif return (0); } void setsigvec(struct proc *p, int signum, struct sigaction *sa) { struct sigacts *ps = p->p_sigacts; int bit; int s; bit = sigmask(signum); /* * Change setting atomically. */ s = splhigh(); ps->ps_sigact[signum] = sa->sa_handler; if ((sa->sa_flags & SA_NODEFER) == 0) sa->sa_mask |= sigmask(signum); ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask; if (signum == SIGCHLD) { if (sa->sa_flags & SA_NOCLDSTOP) atomic_setbits_int(&ps->ps_flags, SAS_NOCLDSTOP); else atomic_clearbits_int(&ps->ps_flags, SAS_NOCLDSTOP); /* * If the SA_NOCLDWAIT flag is set or the handler * is SIG_IGN we reparent the dying child to PID 1 * (init) which will reap the zombie. Because we use * init to do our dirty work we never set SAS_NOCLDWAIT * for PID 1. */ if (initproc->p_sigacts != ps && ((sa->sa_flags & SA_NOCLDWAIT) || sa->sa_handler == SIG_IGN)) atomic_setbits_int(&ps->ps_flags, SAS_NOCLDWAIT); else atomic_clearbits_int(&ps->ps_flags, SAS_NOCLDWAIT); } if ((sa->sa_flags & SA_RESETHAND) != 0) ps->ps_sigreset |= bit; else ps->ps_sigreset &= ~bit; if ((sa->sa_flags & SA_SIGINFO) != 0) ps->ps_siginfo |= bit; else ps->ps_siginfo &= ~bit; if ((sa->sa_flags & SA_RESTART) == 0) ps->ps_sigintr |= bit; else ps->ps_sigintr &= ~bit; if ((sa->sa_flags & SA_ONSTACK) != 0) ps->ps_sigonstack |= bit; else ps->ps_sigonstack &= ~bit; /* * Set bit in ps_sigignore for signals that are set to SIG_IGN, * and for signals set to SIG_DFL where the default is to ignore. * However, don't put SIGCONT in ps_sigignore, * as we have to restart the process. */ if (sa->sa_handler == SIG_IGN || (sigprop[signum] & SA_IGNORE && sa->sa_handler == SIG_DFL)) { atomic_clearbits_int(&p->p_siglist, bit); if (signum != SIGCONT) ps->ps_sigignore |= bit; /* easier in psignal */ ps->ps_sigcatch &= ~bit; } else { ps->ps_sigignore &= ~bit; if (sa->sa_handler == SIG_DFL) ps->ps_sigcatch &= ~bit; else ps->ps_sigcatch |= bit; } splx(s); } /* * Initialize signal state for process 0; * set to ignore signals that are ignored by default. */ void siginit(struct proc *p) { struct sigacts *ps = p->p_sigacts; int i; for (i = 0; i < NSIG; i++) if (sigprop[i] & SA_IGNORE && i != SIGCONT) ps->ps_sigignore |= sigmask(i); ps->ps_flags = SAS_NOCLDWAIT | SAS_NOCLDSTOP; } /* * Reset signals for an exec of the specified process. */ void execsigs(struct proc *p) { struct sigacts *ps; int nc, mask; sigactsunshare(p); ps = p->p_sigacts; /* * Reset caught signals. Held signals remain held * through p_sigmask (unless they were caught, * and are now ignored by default). */ while (ps->ps_sigcatch) { nc = ffs((long)ps->ps_sigcatch); mask = sigmask(nc); ps->ps_sigcatch &= ~mask; if (sigprop[nc] & SA_IGNORE) { if (nc != SIGCONT) ps->ps_sigignore |= mask; atomic_clearbits_int(&p->p_siglist, mask); } ps->ps_sigact[nc] = SIG_DFL; } /* * Reset stack state to the user stack. * Clear set of signals caught on the signal stack. */ sigstkinit(&p->p_sigstk); ps->ps_flags &= ~SAS_NOCLDWAIT; if (ps->ps_sigact[SIGCHLD] == SIG_IGN) ps->ps_sigact[SIGCHLD] = SIG_DFL; } /* * Manipulate signal mask. * Note that we receive new mask, not pointer, * and return old mask as return value; * the library stub does the rest. */ int sys_sigprocmask(struct proc *p, void *v, register_t *retval) { struct sys_sigprocmask_args /* { syscallarg(int) how; syscallarg(sigset_t) mask; } */ *uap = v; int error = 0; int s; sigset_t mask; *retval = p->p_sigmask; mask = SCARG(uap, mask); s = splhigh(); switch (SCARG(uap, how)) { case SIG_BLOCK: p->p_sigmask |= mask &~ sigcantmask; break; case SIG_UNBLOCK: p->p_sigmask &= ~mask; break; case SIG_SETMASK: p->p_sigmask = mask &~ sigcantmask; break; default: error = EINVAL; break; } splx(s); return (error); } /* ARGSUSED */ int sys_sigpending(struct proc *p, void *v, register_t *retval) { *retval = p->p_siglist; return (0); } /* * Suspend process until signal, providing mask to be set * in the meantime. Note nonstandard calling convention: * libc stub passes mask, not pointer, to save a copyin. */ /* ARGSUSED */ int sys_sigsuspend(struct proc *p, void *v, register_t *retval) { struct sys_sigsuspend_args /* { syscallarg(int) mask; } */ *uap = v; struct sigacts *ps = p->p_sigacts; /* * When returning from sigpause, we want * the old mask to be restored after the * signal handler has finished. Thus, we * save it here and mark the sigacts structure * to indicate this. */ p->p_oldmask = p->p_sigmask; atomic_setbits_int(&p->p_flag, P_SIGSUSPEND); p->p_sigmask = SCARG(uap, mask) &~ sigcantmask; while (tsleep(ps, PPAUSE|PCATCH, "pause", 0) == 0) /* void */; /* always return EINTR rather than ERESTART... */ return (EINTR); } int sigonstack(size_t stack) { const struct sigaltstack *ss = &curproc->p_sigstk; return (ss->ss_flags & SS_DISABLE ? 0 : (stack - (size_t)ss->ss_sp < ss->ss_size)); } int sys_sigaltstack(struct proc *p, void *v, register_t *retval) { struct sys_sigaltstack_args /* { syscallarg(const struct sigaltstack *) nss; syscallarg(struct sigaltstack *) oss; } */ *uap = v; struct sigaltstack ss; const struct sigaltstack *nss; struct sigaltstack *oss; int onstack = sigonstack(PROC_STACK(p)); int error; nss = SCARG(uap, nss); oss = SCARG(uap, oss); if (oss != NULL) { ss = p->p_sigstk; if (onstack) ss.ss_flags |= SS_ONSTACK; if ((error = copyout(&ss, oss, sizeof(ss)))) return (error); } if (nss == NULL) return (0); error = copyin(nss, &ss, sizeof(ss)); if (error) return (error); if (onstack) return (EPERM); if (ss.ss_flags & ~SS_DISABLE) return (EINVAL); if (ss.ss_flags & SS_DISABLE) { p->p_sigstk.ss_flags = ss.ss_flags; return (0); } if (ss.ss_size < MINSIGSTKSZ) return (ENOMEM); p->p_sigstk = ss; return (0); } /* ARGSUSED */ int sys_kill(struct proc *cp, void *v, register_t *retval) { struct sys_kill_args /* { syscallarg(int) pid; syscallarg(int) signum; } */ *uap = v; struct proc *p; struct pcred *pc = cp->p_cred; int pid = SCARG(uap, pid); int signum = SCARG(uap, signum); if (((u_int)signum) >= NSIG) return (EINVAL); if (pid > 0) { enum signal_type type = SPROCESS; /* * If the target pid is > THREAD_PID_OFFSET then this * must be a kill of another thread in the same process. * Otherwise, this is a process kill and the target must * be a main thread. */ if (pid > THREAD_PID_OFFSET) { if ((p = pfind(pid - THREAD_PID_OFFSET)) == NULL) return (ESRCH); if (p->p_p != cp->p_p) return (ESRCH); type = STHREAD; } else { if ((p = pfind(pid)) == NULL) return (ESRCH); if (p->p_flag & P_THREAD) return (ESRCH); if (!cansignal(cp, pc, p, signum)) return (EPERM); } /* kill single process or thread */ if (signum) ptsignal(p, signum, type); return (0); } switch (pid) { case -1: /* broadcast signal */ return (killpg1(cp, signum, 0, 1)); case 0: /* signal own process group */ return (killpg1(cp, signum, 0, 0)); default: /* negative explicit process group */ return (killpg1(cp, signum, -pid, 0)); } /* NOTREACHED */ } /* * Common code for kill process group/broadcast kill. * cp is calling process. */ int killpg1(struct proc *cp, int signum, int pgid, int all) { struct proc *p; struct process *pr; struct pcred *pc = cp->p_cred; struct pgrp *pgrp; int nfound = 0; if (all) /* * broadcast */ LIST_FOREACH(p, &allproc, p_list) { if (p->p_pid <= 1 || p->p_flag & (P_SYSTEM|P_THREAD) || p == cp || !cansignal(cp, pc, p, signum)) continue; nfound++; if (signum) psignal(p, signum); } else { if (pgid == 0) /* * zero pgid means send to my process group. */ pgrp = cp->p_p->ps_pgrp; else { pgrp = pgfind(pgid); if (pgrp == NULL) return (ESRCH); } LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) { p = pr->ps_mainproc; if (p->p_pid <= 1 || p->p_flag & (P_SYSTEM|P_THREAD) || !cansignal(cp, pc, p, signum)) continue; nfound++; if (signum && P_ZOMBIE(p) == 0) psignal(p, signum); } } return (nfound ? 0 : ESRCH); } #define CANDELIVER(uid, euid, pr) \ (euid == 0 || \ (uid) == (pr)->ps_cred->p_ruid || \ (uid) == (pr)->ps_cred->p_svuid || \ (uid) == (pr)->ps_cred->pc_ucred->cr_uid || \ (euid) == (pr)->ps_cred->p_ruid || \ (euid) == (pr)->ps_cred->p_svuid || \ (euid) == (pr)->ps_cred->pc_ucred->cr_uid) /* * Deliver signum to pgid, but first check uid/euid against each * process and see if it is permitted. */ void csignal(pid_t pgid, int signum, uid_t uid, uid_t euid) { struct pgrp *pgrp; struct process *pr; if (pgid == 0) return; if (pgid < 0) { pgid = -pgid; if ((pgrp = pgfind(pgid)) == NULL) return; LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) if (CANDELIVER(uid, euid, pr)) prsignal(pr, signum); } else { if ((pr = prfind(pgid)) == NULL) return; if (CANDELIVER(uid, euid, pr)) prsignal(pr, signum); } } /* * Send a signal to a process group. */ void gsignal(int pgid, int signum) { struct pgrp *pgrp; if (pgid && (pgrp = pgfind(pgid))) pgsignal(pgrp, signum, 0); } /* * Send a signal to a process group. If checktty is 1, * limit to members which have a controlling terminal. */ void pgsignal(struct pgrp *pgrp, int signum, int checkctty) { struct process *pr; if (pgrp) LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) if (checkctty == 0 || pr->ps_flags & PS_CONTROLT) prsignal(pr, signum); } /* * Send a signal caused by a trap to the current process. * If it will be caught immediately, deliver it with correct code. * Otherwise, post it normally. */ void trapsignal(struct proc *p, int signum, u_long trapno, int code, union sigval sigval) { struct sigacts *ps = p->p_sigacts; int mask; mask = sigmask(signum); if ((p->p_p->ps_flags & PS_TRACED) == 0 && (ps->ps_sigcatch & mask) != 0 && (p->p_sigmask & mask) == 0) { #ifdef KTRACE if (KTRPOINT(p, KTR_PSIG)) { siginfo_t si; initsiginfo(&si, signum, trapno, code, sigval); ktrpsig(p, signum, ps->ps_sigact[signum], p->p_sigmask, code, &si); } #endif p->p_ru.ru_nsignals++; (*p->p_emul->e_sendsig)(ps->ps_sigact[signum], signum, p->p_sigmask, trapno, code, sigval); p->p_sigmask |= ps->ps_catchmask[signum]; if ((ps->ps_sigreset & mask) != 0) { ps->ps_sigcatch &= ~mask; if (signum != SIGCONT && sigprop[signum] & SA_IGNORE) ps->ps_sigignore |= mask; ps->ps_sigact[signum] = SIG_DFL; } } else { p->p_sisig = signum; p->p_sitrapno = trapno; /* XXX for core dump/debugger */ p->p_sicode = code; p->p_sigval = sigval; ptsignal(p, signum, STHREAD); } } /* * Send the signal to the process. If the signal has an action, the action * is usually performed by the target process rather than the caller; we add * the signal to the set of pending signals for the process. * * Exceptions: * o When a stop signal is sent to a sleeping process that takes the * default action, the process is stopped without awakening it. * o SIGCONT restarts stopped processes (or puts them back to sleep) * regardless of the signal action (eg, blocked or ignored). * * Other ignored signals are discarded immediately. */ void psignal(struct proc *p, int signum) { ptsignal(p, signum, SPROCESS); } /* * type = SPROCESS process signal, can be diverted (sigwait()) * XXX if blocked in all threads, mark as pending in struct process * type = STHREAD thread signal, but should be propagated if unhandled * type = SPROPAGATED propagated to this thread, so don't propagate again */ void ptsignal(struct proc *p, int signum, enum signal_type type) { int s, prop; sig_t action; int mask; struct process *pr = p->p_p; struct proc *q; int wakeparent = 0; #ifdef DIAGNOSTIC if ((u_int)signum >= NSIG || signum == 0) panic("psignal signal number"); #endif /* Ignore signal if we are exiting */ if (pr->ps_flags & PS_EXITING) return; mask = sigmask(signum); if (type == SPROCESS) { /* Accept SIGKILL to coredumping processes */ if (pr->ps_flags & PS_COREDUMP && signum == SIGKILL) { if (pr->ps_single != NULL) p = pr->ps_single; atomic_setbits_int(&p->p_siglist, mask); return; } /* * A process-wide signal can be diverted to a different * thread that's in sigwait() for this signal. If there * isn't such a thread, then pick a thread that doesn't * have it blocked so that the stop/kill consideration * isn't delayed. Otherwise, mark it pending on the * main thread. */ TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { /* ignore exiting threads */ if (q->p_flag & P_WEXIT) continue; /* sigwait: definitely go to this thread */ if (q->p_sigdivert & mask) { p = q; break; } /* unblocked: possibly go to this thread */ if ((q->p_sigmask & mask) == 0) p = q; } } if (type != SPROPAGATED) KNOTE(&pr->ps_klist, NOTE_SIGNAL | signum); prop = sigprop[signum]; /* * If proc is traced, always give parent a chance. * XXX give sigwait() priority until it's fixed to do this * XXX from issignal/postsig */ if (p->p_sigdivert & mask) { p->p_sigwait = signum; atomic_clearbits_int(&p->p_sigdivert, ~0); action = SIG_CATCH; wakeup(&p->p_sigdivert); } else if (pr->ps_flags & PS_TRACED) { action = SIG_DFL; atomic_setbits_int(&p->p_siglist, mask); } else { /* * If the signal is being ignored, * then we forget about it immediately. * (Note: we don't set SIGCONT in ps_sigignore, * and if it is set to SIG_IGN, * action will be SIG_DFL here.) */ if (p->p_sigacts->ps_sigignore & mask) return; if (p->p_sigmask & mask) action = SIG_HOLD; else if (p->p_sigacts->ps_sigcatch & mask) action = SIG_CATCH; else { action = SIG_DFL; if (prop & SA_KILL && pr->ps_nice > NZERO) pr->ps_nice = NZERO; /* * If sending a tty stop signal to a member of an * orphaned process group, discard the signal here if * the action is default; don't stop the process below * if sleeping, and don't clear any pending SIGCONT. */ if (prop & SA_TTYSTOP && pr->ps_pgrp->pg_jobc == 0) return; } atomic_setbits_int(&p->p_siglist, mask); } if (prop & SA_CONT) { atomic_clearbits_int(&p->p_siglist, stopsigmask); } if (prop & SA_STOP) { atomic_clearbits_int(&p->p_siglist, contsigmask); atomic_clearbits_int(&p->p_flag, P_CONTINUED); } /* * XXX delay processing of SA_STOP signals unless action == SIG_DFL? */ if (prop & (SA_CONT | SA_STOP) && type != SPROPAGATED) { TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { if (q != p) ptsignal(q, signum, SPROPAGATED); } } /* * Defer further processing for signals which are held, * except that stopped processes must be continued by SIGCONT. */ if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) return; SCHED_LOCK(s); switch (p->p_stat) { case SSLEEP: /* * If process is sleeping uninterruptibly * we can't interrupt the sleep... the signal will * be noticed when the process returns through * trap() or syscall(). */ if ((p->p_flag & P_SINTR) == 0) goto out; /* * Process is sleeping and traced... make it runnable * so it can discover the signal in issignal() and stop * for the parent. */ if (pr->ps_flags & PS_TRACED) goto run; /* * If SIGCONT is default (or ignored) and process is * asleep, we are finished; the process should not * be awakened. */ if ((prop & SA_CONT) && action == SIG_DFL) { atomic_clearbits_int(&p->p_siglist, mask); goto out; } /* * When a sleeping process receives a stop * signal, process immediately if possible. */ if ((prop & SA_STOP) && action == SIG_DFL) { /* * If a child holding parent blocked, * stopping could cause deadlock. */ if (pr->ps_flags & PS_PPWAIT) goto out; atomic_clearbits_int(&p->p_siglist, mask); p->p_xstat = signum; proc_stop(p, 0); goto out; } /* * All other (caught or default) signals * cause the process to run. */ goto runfast; /*NOTREACHED*/ case SSTOP: /* * If traced process is already stopped, * then no further action is necessary. */ if (pr->ps_flags & PS_TRACED) goto out; /* * Kill signal always sets processes running. */ if (signum == SIGKILL) { atomic_clearbits_int(&p->p_flag, P_SUSPSIG); goto runfast; } if (prop & SA_CONT) { /* * If SIGCONT is default (or ignored), we continue the * process but don't leave the signal in p_siglist, as * it has no further action. If SIGCONT is held, we * continue the process and leave the signal in * p_siglist. If the process catches SIGCONT, let it * handle the signal itself. If it isn't waiting on * an event, then it goes back to run state. * Otherwise, process goes back to sleep state. */ atomic_setbits_int(&p->p_flag, P_CONTINUED); atomic_clearbits_int(&p->p_flag, P_SUSPSIG); wakeparent = 1; if (action == SIG_DFL) atomic_clearbits_int(&p->p_siglist, mask); if (action == SIG_CATCH) goto runfast; if (p->p_wchan == 0) goto run; p->p_stat = SSLEEP; goto out; } if (prop & SA_STOP) { /* * Already stopped, don't need to stop again. * (If we did the shell could get confused.) */ atomic_clearbits_int(&p->p_siglist, mask); goto out; } /* * If process is sleeping interruptibly, then simulate a * wakeup so that when it is continued, it will be made * runnable and can look at the signal. But don't make * the process runnable, leave it stopped. */ if (p->p_wchan && p->p_flag & P_SINTR) unsleep(p); goto out; case SONPROC: signotify(p); /* FALLTHROUGH */ default: /* * SRUN, SIDL, SZOMB do nothing with the signal, * other than kicking ourselves if we are running. * It will either never be noticed, or noticed very soon. */ goto out; } /*NOTREACHED*/ runfast: /* * Raise priority to at least PUSER. */ if (p->p_priority > PUSER) p->p_priority = PUSER; run: setrunnable(p); out: SCHED_UNLOCK(s); if (wakeparent) wakeup(pr->ps_pptr); } /* * If the current process has received a signal (should be caught or cause * termination, should interrupt current syscall), return the signal number. * Stop signals with default action are processed immediately, then cleared; * they aren't returned. This is checked after each entry to the system for * a syscall or trap (though this can usually be done without calling issignal * by checking the pending signal masks in the CURSIG macro.) The normal call * sequence is * * while (signum = CURSIG(curproc)) * postsig(signum); */ int issignal(struct proc *p) { struct process *pr = p->p_p; int signum, mask, prop; int dolock = (p->p_flag & P_SINTR) == 0; int s; for (;;) { mask = p->p_siglist & ~p->p_sigmask; if (pr->ps_flags & PS_PPWAIT) mask &= ~stopsigmask; if (mask == 0) /* no signal to send */ return (0); signum = ffs((long)mask); mask = sigmask(signum); atomic_clearbits_int(&p->p_siglist, mask); /* * We should see pending but ignored signals * only if P_TRACED was on when they were posted. */ if (mask & p->p_sigacts->ps_sigignore && (pr->ps_flags & PS_TRACED) == 0) continue; if ((pr->ps_flags & (PS_TRACED | PS_PPWAIT)) == PS_TRACED) { /* * If traced, always stop, and stay * stopped until released by the debugger. */ p->p_xstat = signum; KERNEL_LOCK(); single_thread_set(p, SINGLE_SUSPEND, 0); KERNEL_UNLOCK(); if (dolock) SCHED_LOCK(s); proc_stop(p, 1); if (dolock) SCHED_UNLOCK(s); KERNEL_LOCK(); single_thread_clear(p, 0); KERNEL_UNLOCK(); /* * If we are no longer being traced, or the parent * didn't give us a signal, look for more signals. */ if ((pr->ps_flags & PS_TRACED) == 0 || p->p_xstat == 0) continue; /* * If the new signal is being masked, look for other * signals. */ signum = p->p_xstat; mask = sigmask(signum); if ((p->p_sigmask & mask) != 0) continue; /* take the signal! */ atomic_clearbits_int(&p->p_siglist, mask); } prop = sigprop[signum]; /* * Decide whether the signal should be returned. * Return the signal's number, or fall through * to clear it from the pending mask. */ switch ((long)p->p_sigacts->ps_sigact[signum]) { case (long)SIG_DFL: /* * Don't take default actions on system processes. */ if (p->p_pid <= 1) { #ifdef DIAGNOSTIC /* * Are you sure you want to ignore SIGSEGV * in init? XXX */ printf("Process (pid %d) got signal %d\n", p->p_pid, signum); #endif break; /* == ignore */ } /* * If there is a pending stop signal to process * with default action, stop here, * then clear the signal. However, * if process is member of an orphaned * process group, ignore tty stop signals. */ if (prop & SA_STOP) { if (pr->ps_flags & PS_TRACED || (pr->ps_pgrp->pg_jobc == 0 && prop & SA_TTYSTOP)) break; /* == ignore */ p->p_xstat = signum; if (dolock) SCHED_LOCK(s); proc_stop(p, 1); if (dolock) SCHED_UNLOCK(s); break; } else if (prop & SA_IGNORE) { /* * Except for SIGCONT, shouldn't get here. * Default action is to ignore; drop it. */ break; /* == ignore */ } else goto keep; /*NOTREACHED*/ case (long)SIG_IGN: /* * Masking above should prevent us ever trying * to take action on an ignored signal other * than SIGCONT, unless process is traced. */ if ((prop & SA_CONT) == 0 && (pr->ps_flags & PS_TRACED) == 0) printf("issignal\n"); break; /* == ignore */ default: /* * This signal has an action, let * postsig() process it. */ goto keep; } } /* NOTREACHED */ keep: atomic_setbits_int(&p->p_siglist, mask); /*leave the signal for later */ return (signum); } /* * Put the argument process into the stopped state and notify the parent * via wakeup. Signals are handled elsewhere. The process must not be * on the run queue. */ void proc_stop(struct proc *p, int sw) { extern void *softclock_si; #ifdef MULTIPROCESSOR SCHED_ASSERT_LOCKED(); #endif p->p_stat = SSTOP; atomic_clearbits_int(&p->p_p->ps_flags, PS_WAITED); atomic_setbits_int(&p->p_flag, P_STOPPED|P_SUSPSIG); if (!timeout_pending(&proc_stop_to)) { timeout_add(&proc_stop_to, 0); /* * We need this soft interrupt to be handled fast. * Extra calls to softclock don't hurt. */ softintr_schedule(softclock_si); } if (sw) mi_switch(); } /* * Called from a timeout to send signals to the parents of stopped processes. * We can't do this in proc_stop because it's called with nasty locks held * and we would need recursive scheduler lock to deal with that. */ void proc_stop_sweep(void *v) { struct proc *p; LIST_FOREACH(p, &allproc, p_list) { if ((p->p_flag & P_STOPPED) == 0) continue; atomic_clearbits_int(&p->p_flag, P_STOPPED); if ((p->p_p->ps_pptr->ps_mainproc->p_sigacts->ps_flags & SAS_NOCLDSTOP) == 0) prsignal(p->p_p->ps_pptr, SIGCHLD); wakeup(p->p_p->ps_pptr); } } /* * Take the action for the specified signal * from the current set of pending signals. */ void postsig(int signum) { struct proc *p = curproc; struct sigacts *ps = p->p_sigacts; sig_t action; u_long trapno; int mask, returnmask; union sigval sigval; int s, code; #ifdef DIAGNOSTIC if (signum == 0) panic("postsig"); #endif KERNEL_LOCK(); mask = sigmask(signum); atomic_clearbits_int(&p->p_siglist, mask); action = ps->ps_sigact[signum]; sigval.sival_ptr = 0; if (p->p_sisig != signum) { trapno = 0; code = SI_USER; sigval.sival_ptr = 0; } else { trapno = p->p_sitrapno; code = p->p_sicode; sigval = p->p_sigval; } #ifdef KTRACE if (KTRPOINT(p, KTR_PSIG)) { siginfo_t si; initsiginfo(&si, signum, trapno, code, sigval); ktrpsig(p, signum, action, p->p_flag & P_SIGSUSPEND ? p->p_oldmask : p->p_sigmask, code, &si); } #endif if (action == SIG_DFL) { /* * Default action, where the default is to kill * the process. (Other cases were ignored above.) */ sigexit(p, signum); /* NOTREACHED */ } else { /* * If we get here, the signal must be caught. */ #ifdef DIAGNOSTIC if (action == SIG_IGN || (p->p_sigmask & mask)) panic("postsig action"); #endif /* * Set the new mask value and also defer further * occurrences of this signal. * * Special case: user has done a sigpause. Here the * current mask is not of interest, but rather the * mask from before the sigpause is what we want * restored after the signal processing is completed. */ #ifdef MULTIPROCESSOR s = splsched(); #else s = splhigh(); #endif if (p->p_flag & P_SIGSUSPEND) { atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); returnmask = p->p_oldmask; } else returnmask = p->p_sigmask; p->p_sigmask |= ps->ps_catchmask[signum]; if ((ps->ps_sigreset & mask) != 0) { ps->ps_sigcatch &= ~mask; if (signum != SIGCONT && sigprop[signum] & SA_IGNORE) ps->ps_sigignore |= mask; ps->ps_sigact[signum] = SIG_DFL; } splx(s); p->p_ru.ru_nsignals++; if (p->p_sisig == signum) { p->p_sisig = 0; p->p_sitrapno = 0; p->p_sicode = SI_USER; p->p_sigval.sival_ptr = NULL; } (*p->p_emul->e_sendsig)(action, signum, returnmask, trapno, code, sigval); } KERNEL_UNLOCK(); } /* * Force the current process to exit with the specified signal, dumping core * if appropriate. We bypass the normal tests for masked and caught signals, * allowing unrecoverable failures to terminate the process without changing * signal state. Mark the accounting record with the signal termination. * If dumping core, save the signal number for the debugger. Calls exit and * does not return. */ void sigexit(struct proc *p, int signum) { /* Mark process as going away */ atomic_setbits_int(&p->p_flag, P_WEXIT); p->p_p->ps_acflag |= AXSIG; if (sigprop[signum] & SA_CORE) { p->p_sisig = signum; /* if there are other threads, pause them */ if (TAILQ_FIRST(&p->p_p->ps_threads) != p || TAILQ_NEXT(p, p_thr_link) != NULL) single_thread_set(p, SINGLE_SUSPEND, 0); if (coredump(p) == 0) signum |= WCOREFLAG; } exit1(p, W_EXITCODE(0, signum), EXIT_NORMAL); /* NOTREACHED */ } int nosuidcoredump = 1; struct coredump_iostate { struct proc *io_proc; struct vnode *io_vp; struct ucred *io_cred; off_t io_offset; }; /* * Dump core, into a file named "progname.core", unless the process was * setuid/setgid. */ int coredump(struct proc *p) { #ifdef SMALL_KERNEL return EPERM; #else struct vnode *vp; struct ucred *cred = p->p_ucred; struct vmspace *vm = p->p_vmspace; struct nameidata nd; struct vattr vattr; struct coredump_iostate io; int error, len; char name[sizeof("/var/crash/") + MAXCOMLEN + sizeof(".core")]; char *dir = ""; p->p_p->ps_flags |= PS_COREDUMP; /* * Don't dump if not root and the process has used set user or * group privileges, unless the nosuidcoredump sysctl is set to 2, * in which case dumps are put into /var/crash/. */ if (((p->p_p->ps_flags & PS_SUGID) && (error = suser(p, 0))) || ((p->p_p->ps_flags & PS_SUGID) && nosuidcoredump)) { if (nosuidcoredump == 2) dir = "/var/crash/"; else return (EPERM); } /* Don't dump if will exceed file size limit. */ if (USPACE + ptoa(vm->vm_dsize + vm->vm_ssize) >= p->p_rlimit[RLIMIT_CORE].rlim_cur) return (EFBIG); len = snprintf(name, sizeof(name), "%s%s.core", dir, p->p_comm); if (len >= sizeof(name)) return (EACCES); /* * ... but actually write it as UID */ cred = crdup(cred); cred->cr_uid = p->p_cred->p_ruid; cred->cr_gid = p->p_cred->p_rgid; NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p); error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); if (error) goto out; /* * Don't dump to non-regular files, files with links, or files * owned by someone else. */ vp = nd.ni_vp; if ((error = VOP_GETATTR(vp, &vattr, cred, p)) != 0) { VOP_UNLOCK(vp, 0, p); vn_close(vp, FWRITE, cred, p); goto out; } if (vp->v_type != VREG || vattr.va_nlink != 1 || vattr.va_mode & ((VREAD | VWRITE) >> 3 | (VREAD | VWRITE) >> 6) || vattr.va_uid != cred->cr_uid) { error = EACCES; VOP_UNLOCK(vp, 0, p); vn_close(vp, FWRITE, cred, p); goto out; } VATTR_NULL(&vattr); vattr.va_size = 0; VOP_SETATTR(vp, &vattr, cred, p); p->p_p->ps_acflag |= ACORE; io.io_proc = p; io.io_vp = vp; io.io_cred = cred; io.io_offset = 0; VOP_UNLOCK(vp, 0, p); vref(vp); error = vn_close(vp, FWRITE, cred, p); if (error == 0) error = (*p->p_emul->e_coredump)(p, &io); vrele(vp); out: crfree(cred); return (error); #endif } int coredump_trad(struct proc *p, void *cookie) { #ifdef SMALL_KERNEL return EPERM; #else struct coredump_iostate *io = cookie; struct vmspace *vm = io->io_proc->p_vmspace; struct vnode *vp = io->io_vp; struct ucred *cred = io->io_cred; struct core core; int error; core.c_midmag = 0; strlcpy(core.c_name, p->p_comm, sizeof(core.c_name)); core.c_nseg = 0; core.c_signo = p->p_sisig; core.c_ucode = p->p_sitrapno; core.c_cpusize = 0; core.c_tsize = (u_long)ptoa(vm->vm_tsize); core.c_dsize = (u_long)ptoa(vm->vm_dsize); core.c_ssize = (u_long)round_page(ptoa(vm->vm_ssize)); error = cpu_coredump(p, vp, cred, &core); if (error) return (error); /* * uvm_coredump() spits out all appropriate segments. * All that's left to do is to write the core header. */ error = uvm_coredump(p, vp, cred, &core); if (error) return (error); error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&core, (int)core.c_hdrsize, (off_t)0, UIO_SYSSPACE, IO_UNIT, cred, NULL, p); return (error); #endif } #ifndef SMALL_KERNEL int coredump_write(void *cookie, enum uio_seg segflg, const void *data, size_t len) { struct coredump_iostate *io = cookie; off_t coffset = 0; size_t csize; int chunk, error; csize = len; do { if (io->io_proc->p_siglist & sigmask(SIGKILL)) return (EINTR); /* Rest of the loop sleeps with lock held, so... */ yield(); chunk = MIN(csize, MAXPHYS); error = vn_rdwr(UIO_WRITE, io->io_vp, (caddr_t)data + coffset, chunk, io->io_offset + coffset, segflg, IO_UNIT, io->io_cred, NULL, io->io_proc); if (error) { printf("pid %d (%s): %s write of %lu@%p" " at %lld failed: %d\n", io->io_proc->p_pid, io->io_proc->p_comm, segflg == UIO_USERSPACE ? "user" : "system", len, data, (long long) io->io_offset, error); return (error); } coffset += chunk; csize -= chunk; } while (csize > 0); io->io_offset += len; return (0); } void coredump_unmap(void *cookie, vaddr_t start, vaddr_t end) { struct coredump_iostate *io = cookie; uvm_unmap(&io->io_proc->p_vmspace->vm_map, start, end); } #endif /* !SMALL_KERNEL */ /* * Nonexistent system call-- signal process (may want to handle it). * Flag error in case process won't see signal immediately (blocked or ignored). */ /* ARGSUSED */ int sys_nosys(struct proc *p, void *v, register_t *retval) { ptsignal(p, SIGSYS, STHREAD); return (ENOSYS); } int sys___thrsigdivert(struct proc *p, void *v, register_t *retval) { struct sys___thrsigdivert_args /* { syscallarg(sigset_t) sigmask; syscallarg(siginfo_t *) info; syscallarg(const struct timespec *) timeout; } */ *uap = v; sigset_t mask; sigset_t *m; long long to_ticks = 0; int error; m = NULL; mask = SCARG(uap, sigmask) &~ sigcantmask; /* pending signal for this thread? */ if (p->p_siglist & mask) m = &p->p_siglist; else if (p->p_p->ps_mainproc->p_siglist & mask) m = &p->p_p->ps_mainproc->p_siglist; if (m != NULL) { int sig = ffs((long)(*m & mask)); atomic_clearbits_int(m, sigmask(sig)); *retval = sig; return (0); } if (SCARG(uap, timeout) != NULL) { struct timespec ts; if ((error = copyin(SCARG(uap, timeout), &ts, sizeof(ts))) != 0) return (error); #ifdef KTRACE if (KTRPOINT(p, KTR_STRUCT)) ktrreltimespec(p, &ts); #endif to_ticks = (long long)hz * ts.tv_sec + ts.tv_nsec / (tick * 1000); if (to_ticks > INT_MAX) to_ticks = INT_MAX; } p->p_sigwait = 0; atomic_setbits_int(&p->p_sigdivert, mask); error = tsleep(&p->p_sigdivert, PPAUSE|PCATCH, "sigwait", (int)to_ticks); if (p->p_sigdivert) { /* interrupted */ KASSERT(error != 0); atomic_clearbits_int(&p->p_sigdivert, ~0); if (error == EINTR) error = ERESTART; else if (error == ETIMEDOUT) error = EAGAIN; return (error); } KASSERT(p->p_sigwait != 0); *retval = p->p_sigwait; if (SCARG(uap, info) == NULL) { error = 0; } else { siginfo_t si; bzero(&si, sizeof si); si.si_signo = p->p_sigwait; error = copyout(&si, SCARG(uap, info), sizeof(si)); } return (error); } void initsiginfo(siginfo_t *si, int sig, u_long trapno, int code, union sigval val) { bzero(si, sizeof *si); si->si_signo = sig; si->si_code = code; if (code == SI_USER) { si->si_value = val; } else { switch (sig) { case SIGSEGV: case SIGILL: case SIGBUS: case SIGFPE: si->si_addr = val.sival_ptr; si->si_trapno = trapno; break; case SIGXFSZ: break; } } } int filt_sigattach(struct knote *kn) { struct process *pr = curproc->p_p; kn->kn_ptr.p_process = pr; kn->kn_flags |= EV_CLEAR; /* automatically set */ /* XXX lock the proc here while adding to the list? */ SLIST_INSERT_HEAD(&pr->ps_klist, kn, kn_selnext); return (0); } void filt_sigdetach(struct knote *kn) { struct process *pr = kn->kn_ptr.p_process; SLIST_REMOVE(&pr->ps_klist, kn, knote, kn_selnext); } /* * signal knotes are shared with proc knotes, so we apply a mask to * the hint in order to differentiate them from process hints. This * could be avoided by using a signal-specific knote list, but probably * isn't worth the trouble. */ int filt_signal(struct knote *kn, long hint) { if (hint & NOTE_SIGNAL) { hint &= ~NOTE_SIGNAL; if (kn->kn_id == hint) kn->kn_data++; } return (kn->kn_data != 0); } void userret(struct proc *p) { int sig; while ((sig = CURSIG(p)) != 0) postsig(sig); /* * If P_SIGSUSPEND is still set here, then we still need to restore * the original sigmask before returning to userspace. Also, this * might unmask some pending signals, so we need to check a second * time for signals to post. */ if (p->p_flag & P_SIGSUSPEND) { atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); p->p_sigmask = p->p_oldmask; while ((sig = CURSIG(p)) != 0) postsig(sig); } if (p->p_flag & P_SUSPSINGLE) { KERNEL_LOCK(); single_thread_check(p, 0); KERNEL_UNLOCK(); } p->p_cpu->ci_schedstate.spc_curpriority = p->p_priority = p->p_usrpri; } int single_thread_check(struct proc *p, int deep) { struct process *pr = p->p_p; if (pr->ps_single != NULL && pr->ps_single != p) { do { int s; /* if we're in deep, we need to unwind to the edge */ if (deep) { if (pr->ps_flags & PS_SINGLEUNWIND) return (ERESTART); if (pr->ps_flags & PS_SINGLEEXIT) return (EINTR); } if (--pr->ps_singlecount == 0) wakeup(&pr->ps_singlecount); if (pr->ps_flags & PS_SINGLEEXIT) exit1(p, 0, EXIT_THREAD_NOCHECK); /* not exiting and don't need to unwind, so suspend */ SCHED_LOCK(s); p->p_stat = SSTOP; mi_switch(); SCHED_UNLOCK(s); } while (pr->ps_single != NULL); } return (0); } /* * Stop other threads in the process. The mode controls how and * where the other threads should stop: * - SINGLE_SUSPEND: stop wherever they are, will later either be told to exit * (by setting to SINGLE_EXIT) or be released (via single_thread_clear()) * - SINGLE_UNWIND: just unwind to kernel boundary, will be told to exit * or released as with SINGLE_SUSPEND * - SINGLE_EXIT: unwind to kernel boundary and exit */ int single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) { struct process *pr = p->p_p; struct proc *q; int error; if ((error = single_thread_check(p, deep))) return error; switch (mode) { case SINGLE_SUSPEND: break; case SINGLE_UNWIND: atomic_setbits_int(&pr->ps_flags, PS_SINGLEUNWIND); break; case SINGLE_EXIT: atomic_setbits_int(&pr->ps_flags, PS_SINGLEEXIT); atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND); break; #ifdef DIAGNOSTIC default: panic("single_thread_mode = %d", mode); #endif } pr->ps_single = p; pr->ps_singlecount = 0; TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { int s; if (q == p) continue; if (q->p_flag & P_WEXIT) { if (mode == SINGLE_EXIT) { SCHED_LOCK(s); if (q->p_stat == SSTOP) { setrunnable(q); pr->ps_singlecount++; } SCHED_UNLOCK(s); } continue; } SCHED_LOCK(s); atomic_setbits_int(&q->p_flag, P_SUSPSINGLE); switch (q->p_stat) { case SIDL: case SRUN: pr->ps_singlecount++; break; case SSLEEP: /* if it's not interruptible, then just have to wait */ if (q->p_flag & P_SINTR) { /* merely need to suspend? just stop it */ if (mode == SINGLE_SUSPEND) { q->p_stat = SSTOP; break; } /* need to unwind or exit, so wake it */ setrunnable(q); } pr->ps_singlecount++; break; case SSTOP: if (mode == SINGLE_EXIT) { setrunnable(q); pr->ps_singlecount++; } break; case SZOMB: case SDEAD: break; case SONPROC: pr->ps_singlecount++; signotify(q); break; } SCHED_UNLOCK(s); } /* wait until they're all suspended */ while (pr->ps_singlecount > 0) tsleep(&pr->ps_singlecount, PUSER, "suspend", 0); return 0; } void single_thread_clear(struct proc *p, int flag) { struct process *pr = p->p_p; struct proc *q; KASSERT(pr->ps_single == p); pr->ps_single = NULL; atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND | PS_SINGLEEXIT); TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { int s; if (q == p || (q->p_flag & P_SUSPSINGLE) == 0) continue; atomic_clearbits_int(&q->p_flag, P_SUSPSINGLE); /* * if the thread was only stopped for single threading * then clearing that either makes it runnable or puts * it back into some sleep queue */ SCHED_LOCK(s); if (q->p_stat == SSTOP && (q->p_flag & flag) == 0) { if (q->p_wchan == 0) setrunnable(q); else q->p_stat = SSLEEP; } SCHED_UNLOCK(s); } }