/*- * 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. * 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_sig.c 8.7 (Berkeley) 4/18/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_compat.h" #include "opt_ktrace.h" #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 #include #include #include #include #include #include #include #include #include #include #include #include #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ static int coredump(struct thread *); static char *expand_name(const char *, uid_t, pid_t); static int killpg1(struct thread *td, int sig, int pgid, int all); static int issignal(struct thread *p); static int sigprop(int sig); static void tdsigwakeup(struct thread *, int, sig_t, int); static void sig_suspend_threads(struct thread *, struct proc *, int); static int filt_sigattach(struct knote *kn); static void filt_sigdetach(struct knote *kn); static int filt_signal(struct knote *kn, long hint); static struct thread *sigtd(struct proc *p, int sig, int prop); static int do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *); static void sigqueue_start(void); static uma_zone_t ksiginfo_zone = NULL; struct filterops sig_filtops = { 0, filt_sigattach, filt_sigdetach, filt_signal }; static int kern_logsigexit = 1; SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, &kern_logsigexit, 0, "Log processes quitting on abnormal signals to syslog(3)"); static int kern_forcesigexit = 1; SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, &kern_forcesigexit, 0, "Force trap signal to be handled"); SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); static int max_pending_per_proc = 128; SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, &max_pending_per_proc, 0, "Max pending signals per proc"); static int preallocate_siginfo = 1024; TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, &preallocate_siginfo, 0, "Preallocated signal memory size"); static int signal_overflow = 0; SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, &signal_overflow, 0, "Number of signals overflew"); static int signal_alloc_fail = 0; SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, &signal_alloc_fail, 0, "signals failed to be allocated"); SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); /* * Policy -- Can ucred cr1 send SIGIO to process cr2? * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG * in the right situations. */ #define CANSIGIO(cr1, cr2) \ ((cr1)->cr_uid == 0 || \ (cr1)->cr_ruid == (cr2)->cr_ruid || \ (cr1)->cr_uid == (cr2)->cr_ruid || \ (cr1)->cr_ruid == (cr2)->cr_uid || \ (cr1)->cr_uid == (cr2)->cr_uid) int sugid_coredump; SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); static int do_coredump = 1; SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, &do_coredump, 0, "Enable/Disable coredumps"); static int set_core_nodump_flag = 0; SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 0, "Enable setting the NODUMP flag on coredump files"); /* * Signal properties and actions. * The array below categorizes the signals and their default actions * according to the following properties: */ #define SA_KILL 0x01 /* terminates process by default */ #define SA_CORE 0x02 /* ditto and coredumps */ #define SA_STOP 0x04 /* suspend process */ #define SA_TTYSTOP 0x08 /* ditto, from tty */ #define SA_IGNORE 0x10 /* ignore by default */ #define SA_CONT 0x20 /* continue if suspended */ #define SA_CANTMASK 0x40 /* non-maskable, catchable */ #define SA_PROC 0x80 /* deliverable to any thread */ static int sigproptbl[NSIG] = { SA_KILL|SA_PROC, /* SIGHUP */ SA_KILL|SA_PROC, /* SIGINT */ SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ SA_KILL|SA_CORE, /* SIGILL */ SA_KILL|SA_CORE, /* SIGTRAP */ SA_KILL|SA_CORE, /* SIGABRT */ SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ SA_KILL|SA_CORE, /* SIGFPE */ SA_KILL|SA_PROC, /* SIGKILL */ SA_KILL|SA_CORE, /* SIGBUS */ SA_KILL|SA_CORE, /* SIGSEGV */ SA_KILL|SA_CORE, /* SIGSYS */ SA_KILL|SA_PROC, /* SIGPIPE */ SA_KILL|SA_PROC, /* SIGALRM */ SA_KILL|SA_PROC, /* SIGTERM */ SA_IGNORE|SA_PROC, /* SIGURG */ SA_STOP|SA_PROC, /* SIGSTOP */ SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ SA_IGNORE|SA_PROC, /* SIGCHLD */ SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ SA_IGNORE|SA_PROC, /* SIGIO */ SA_KILL, /* SIGXCPU */ SA_KILL, /* SIGXFSZ */ SA_KILL|SA_PROC, /* SIGVTALRM */ SA_KILL|SA_PROC, /* SIGPROF */ SA_IGNORE|SA_PROC, /* SIGWINCH */ SA_IGNORE|SA_PROC, /* SIGINFO */ SA_KILL|SA_PROC, /* SIGUSR1 */ SA_KILL|SA_PROC, /* SIGUSR2 */ }; static void sigqueue_start(void) { ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); uma_prealloc(ksiginfo_zone, preallocate_siginfo); p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); } ksiginfo_t * ksiginfo_alloc(int wait) { int flags; flags = M_ZERO; if (! wait) flags |= M_NOWAIT; if (ksiginfo_zone != NULL) return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); return (NULL); } void ksiginfo_free(ksiginfo_t *ksi) { uma_zfree(ksiginfo_zone, ksi); } static __inline int ksiginfo_tryfree(ksiginfo_t *ksi) { if (!(ksi->ksi_flags & KSI_EXT)) { uma_zfree(ksiginfo_zone, ksi); return (1); } return (0); } void sigqueue_init(sigqueue_t *list, struct proc *p) { SIGEMPTYSET(list->sq_signals); SIGEMPTYSET(list->sq_kill); TAILQ_INIT(&list->sq_list); list->sq_proc = p; list->sq_flags = SQ_INIT; } /* * Get a signal's ksiginfo. * Return: * 0 - signal not found * others - signal number */ int sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) { struct proc *p = sq->sq_proc; struct ksiginfo *ksi, *next; int count = 0; KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); if (!SIGISMEMBER(sq->sq_signals, signo)) return (0); if (SIGISMEMBER(sq->sq_kill, signo)) { count++; SIGDELSET(sq->sq_kill, signo); } for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { next = TAILQ_NEXT(ksi, ksi_link); if (ksi->ksi_signo == signo) { if (count == 0) { TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); ksi->ksi_sigq = NULL; ksiginfo_copy(ksi, si); if (ksiginfo_tryfree(ksi) && p != NULL) p->p_pendingcnt--; } count++; } } if (count <= 1) SIGDELSET(sq->sq_signals, signo); si->ksi_signo = signo; return (signo); } void sigqueue_take(ksiginfo_t *ksi) { struct ksiginfo *kp; struct proc *p; sigqueue_t *sq; if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) return; p = sq->sq_proc; TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); ksi->ksi_sigq = NULL; if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) p->p_pendingcnt--; for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; kp = TAILQ_NEXT(kp, ksi_link)) { if (kp->ksi_signo == ksi->ksi_signo) break; } if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) SIGDELSET(sq->sq_signals, ksi->ksi_signo); } int sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) { struct proc *p = sq->sq_proc; struct ksiginfo *ksi; int ret = 0; KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { SIGADDSET(sq->sq_kill, signo); goto out_set_bit; } /* directly insert the ksi, don't copy it */ if (si->ksi_flags & KSI_INS) { TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); si->ksi_sigq = sq; goto out_set_bit; } if (__predict_false(ksiginfo_zone == NULL)) { SIGADDSET(sq->sq_kill, signo); goto out_set_bit; } if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { signal_overflow++; ret = EAGAIN; } else if ((ksi = ksiginfo_alloc(0)) == NULL) { signal_alloc_fail++; ret = EAGAIN; } else { if (p != NULL) p->p_pendingcnt++; ksiginfo_copy(si, ksi); ksi->ksi_signo = signo; TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); ksi->ksi_sigq = sq; } if ((si->ksi_flags & KSI_TRAP) != 0) { if (ret != 0) SIGADDSET(sq->sq_kill, signo); ret = 0; goto out_set_bit; } if (ret != 0) return (ret); out_set_bit: SIGADDSET(sq->sq_signals, signo); return (ret); } void sigqueue_flush(sigqueue_t *sq) { struct proc *p = sq->sq_proc; ksiginfo_t *ksi; KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); if (p != NULL) PROC_LOCK_ASSERT(p, MA_OWNED); while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); ksi->ksi_sigq = NULL; if (ksiginfo_tryfree(ksi) && p != NULL) p->p_pendingcnt--; } SIGEMPTYSET(sq->sq_signals); SIGEMPTYSET(sq->sq_kill); } void sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) { ksiginfo_t *ksi; KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) SIGADDSET(*set, ksi->ksi_signo); SIGSETOR(*set, sq->sq_kill); } void sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) { sigset_t tmp, set; struct proc *p1, *p2; ksiginfo_t *ksi, *next; KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); /* * make a copy, this allows setp to point to src or dst * sq_signals without trouble. */ set = *setp; p1 = src->sq_proc; p2 = dst->sq_proc; /* Move siginfo to target list */ for (ksi = TAILQ_FIRST(&src->sq_list); ksi != NULL; ksi = next) { next = TAILQ_NEXT(ksi, ksi_link); if (SIGISMEMBER(set, ksi->ksi_signo)) { TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); if (p1 != NULL) p1->p_pendingcnt--; TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); ksi->ksi_sigq = dst; if (p2 != NULL) p2->p_pendingcnt++; } } /* Move pending bits to target list */ tmp = src->sq_kill; SIGSETAND(tmp, set); SIGSETOR(dst->sq_kill, tmp); SIGSETNAND(src->sq_kill, tmp); tmp = src->sq_signals; SIGSETAND(tmp, set); SIGSETOR(dst->sq_signals, tmp); SIGSETNAND(src->sq_signals, tmp); /* Finally, rescan src queue and set pending bits for it */ sigqueue_collect_set(src, &src->sq_signals); } void sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) { sigset_t set; SIGEMPTYSET(set); SIGADDSET(set, signo); sigqueue_move_set(src, dst, &set); } void sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) { struct proc *p = sq->sq_proc; ksiginfo_t *ksi, *next; KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); /* Remove siginfo queue */ for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { next = TAILQ_NEXT(ksi, ksi_link); if (SIGISMEMBER(*set, ksi->ksi_signo)) { TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); ksi->ksi_sigq = NULL; if (ksiginfo_tryfree(ksi) && p != NULL) p->p_pendingcnt--; } } SIGSETNAND(sq->sq_kill, *set); SIGSETNAND(sq->sq_signals, *set); /* Finally, rescan queue and set pending bits for it */ sigqueue_collect_set(sq, &sq->sq_signals); } void sigqueue_delete(sigqueue_t *sq, int signo) { sigset_t set; SIGEMPTYSET(set); SIGADDSET(set, signo); sigqueue_delete_set(sq, &set); } /* Remove a set of signals for a process */ void sigqueue_delete_set_proc(struct proc *p, sigset_t *set) { sigqueue_t worklist; struct thread *td0; PROC_LOCK_ASSERT(p, MA_OWNED); sigqueue_init(&worklist, NULL); sigqueue_move_set(&p->p_sigqueue, &worklist, set); mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td0) sigqueue_move_set(&td0->td_sigqueue, &worklist, set); mtx_unlock_spin(&sched_lock); sigqueue_flush(&worklist); } void sigqueue_delete_proc(struct proc *p, int signo) { sigset_t set; SIGEMPTYSET(set); SIGADDSET(set, signo); sigqueue_delete_set_proc(p, &set); } void sigqueue_delete_stopmask_proc(struct proc *p) { sigset_t set; SIGEMPTYSET(set); SIGADDSET(set, SIGSTOP); SIGADDSET(set, SIGTSTP); SIGADDSET(set, SIGTTIN); SIGADDSET(set, SIGTTOU); sigqueue_delete_set_proc(p, &set); } /* * Determine signal that should be delivered to process p, the current * process, 0 if none. If there is a pending stop signal with default * action, the process stops in issignal(). * * MP SAFE. */ int cursig(struct thread *td) { PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); mtx_assert(&sched_lock, MA_NOTOWNED); return (SIGPENDING(td) ? issignal(td) : 0); } /* * Arrange for ast() to handle unmasked pending signals on return to user * mode. This must be called whenever a signal is added to td_sigqueue or * unmasked in td_sigmask. */ void signotify(struct thread *td) { struct proc *p; sigset_t set, saved; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); /* * If our mask changed we may have to move signal that were * previously masked by all threads to our sigqueue. */ set = p->p_sigqueue.sq_signals; if (p->p_flag & P_SA) saved = p->p_sigqueue.sq_signals; SIGSETNAND(set, td->td_sigmask); if (! SIGISEMPTY(set)) sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set); if (SIGPENDING(td)) { mtx_lock_spin(&sched_lock); td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; mtx_unlock_spin(&sched_lock); } if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { /* pending set changed */ p->p_flag |= P_SIGEVENT; wakeup(&p->p_siglist); } } } int sigonstack(size_t sp) { struct thread *td = curthread; return ((td->td_pflags & TDP_ALTSTACK) ? #if defined(COMPAT_43) ((td->td_sigstk.ss_size == 0) ? (td->td_sigstk.ss_flags & SS_ONSTACK) : ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) #else ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) #endif : 0); } static __inline int sigprop(int sig) { if (sig > 0 && sig < NSIG) return (sigproptbl[_SIG_IDX(sig)]); return (0); } int sig_ffs(sigset_t *set) { int i; for (i = 0; i < _SIG_WORDS; i++) if (set->__bits[i]) return (ffs(set->__bits[i]) + (i * 32)); return (0); } /* * kern_sigaction * sigaction * freebsd4_sigaction * osigaction * * MPSAFE */ int kern_sigaction(td, sig, act, oact, flags) struct thread *td; register int sig; struct sigaction *act, *oact; int flags; { struct sigacts *ps; struct proc *p = td->td_proc; if (!_SIG_VALID(sig)) return (EINVAL); PROC_LOCK(p); ps = p->p_sigacts; mtx_lock(&ps->ps_mtx); if (oact) { oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; oact->sa_flags = 0; if (SIGISMEMBER(ps->ps_sigonstack, sig)) oact->sa_flags |= SA_ONSTACK; if (!SIGISMEMBER(ps->ps_sigintr, sig)) oact->sa_flags |= SA_RESTART; if (SIGISMEMBER(ps->ps_sigreset, sig)) oact->sa_flags |= SA_RESETHAND; if (SIGISMEMBER(ps->ps_signodefer, sig)) oact->sa_flags |= SA_NODEFER; if (SIGISMEMBER(ps->ps_siginfo, sig)) oact->sa_flags |= SA_SIGINFO; if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) oact->sa_flags |= SA_NOCLDSTOP; if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) oact->sa_flags |= SA_NOCLDWAIT; } if (act) { if ((sig == SIGKILL || sig == SIGSTOP) && act->sa_handler != SIG_DFL) { mtx_unlock(&ps->ps_mtx); PROC_UNLOCK(p); return (EINVAL); } /* * Change setting atomically. */ ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); if (act->sa_flags & SA_SIGINFO) { ps->ps_sigact[_SIG_IDX(sig)] = (__sighandler_t *)act->sa_sigaction; SIGADDSET(ps->ps_siginfo, sig); } else { ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; SIGDELSET(ps->ps_siginfo, sig); } if (!(act->sa_flags & SA_RESTART)) SIGADDSET(ps->ps_sigintr, sig); else SIGDELSET(ps->ps_sigintr, sig); if (act->sa_flags & SA_ONSTACK) SIGADDSET(ps->ps_sigonstack, sig); else SIGDELSET(ps->ps_sigonstack, sig); if (act->sa_flags & SA_RESETHAND) SIGADDSET(ps->ps_sigreset, sig); else SIGDELSET(ps->ps_sigreset, sig); if (act->sa_flags & SA_NODEFER) SIGADDSET(ps->ps_signodefer, sig); else SIGDELSET(ps->ps_signodefer, sig); if (sig == SIGCHLD) { if (act->sa_flags & SA_NOCLDSTOP) ps->ps_flag |= PS_NOCLDSTOP; else ps->ps_flag &= ~PS_NOCLDSTOP; if (act->sa_flags & SA_NOCLDWAIT) { /* * Paranoia: since SA_NOCLDWAIT is implemented * by reparenting the dying child to PID 1 (and * trust it to reap the zombie), PID 1 itself * is forbidden to set SA_NOCLDWAIT. */ if (p->p_pid == 1) ps->ps_flag &= ~PS_NOCLDWAIT; else ps->ps_flag |= PS_NOCLDWAIT; } else ps->ps_flag &= ~PS_NOCLDWAIT; if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) ps->ps_flag |= PS_CLDSIGIGN; else ps->ps_flag &= ~PS_CLDSIGIGN; } /* * 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 (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || (sigprop(sig) & SA_IGNORE && ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { if ((p->p_flag & P_SA) && SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) { p->p_flag |= P_SIGEVENT; wakeup(&p->p_siglist); } /* never to be seen again */ sigqueue_delete_proc(p, sig); if (sig != SIGCONT) /* easier in psignal */ SIGADDSET(ps->ps_sigignore, sig); SIGDELSET(ps->ps_sigcatch, sig); } else { SIGDELSET(ps->ps_sigignore, sig); if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) SIGDELSET(ps->ps_sigcatch, sig); else SIGADDSET(ps->ps_sigcatch, sig); } #ifdef COMPAT_FREEBSD4 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || (flags & KSA_FREEBSD4) == 0) SIGDELSET(ps->ps_freebsd4, sig); else SIGADDSET(ps->ps_freebsd4, sig); #endif #ifdef COMPAT_43 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || (flags & KSA_OSIGSET) == 0) SIGDELSET(ps->ps_osigset, sig); else SIGADDSET(ps->ps_osigset, sig); #endif } mtx_unlock(&ps->ps_mtx); PROC_UNLOCK(p); return (0); } #ifndef _SYS_SYSPROTO_H_ struct sigaction_args { int sig; struct sigaction *act; struct sigaction *oact; }; #endif /* * MPSAFE */ int sigaction(td, uap) struct thread *td; register struct sigaction_args *uap; { struct sigaction act, oact; register struct sigaction *actp, *oactp; int error; actp = (uap->act != NULL) ? &act : NULL; oactp = (uap->oact != NULL) ? &oact : NULL; if (actp) { error = copyin(uap->act, actp, sizeof(act)); if (error) return (error); } error = kern_sigaction(td, uap->sig, actp, oactp, 0); if (oactp && !error) error = copyout(oactp, uap->oact, sizeof(oact)); return (error); } #ifdef COMPAT_FREEBSD4 #ifndef _SYS_SYSPROTO_H_ struct freebsd4_sigaction_args { int sig; struct sigaction *act; struct sigaction *oact; }; #endif /* * MPSAFE */ int freebsd4_sigaction(td, uap) struct thread *td; register struct freebsd4_sigaction_args *uap; { struct sigaction act, oact; register struct sigaction *actp, *oactp; int error; actp = (uap->act != NULL) ? &act : NULL; oactp = (uap->oact != NULL) ? &oact : NULL; if (actp) { error = copyin(uap->act, actp, sizeof(act)); if (error) return (error); } error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); if (oactp && !error) error = copyout(oactp, uap->oact, sizeof(oact)); return (error); } #endif /* COMAPT_FREEBSD4 */ #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ #ifndef _SYS_SYSPROTO_H_ struct osigaction_args { int signum; struct osigaction *nsa; struct osigaction *osa; }; #endif /* * MPSAFE */ int osigaction(td, uap) struct thread *td; register struct osigaction_args *uap; { struct osigaction sa; struct sigaction nsa, osa; register struct sigaction *nsap, *osap; int error; if (uap->signum <= 0 || uap->signum >= ONSIG) return (EINVAL); nsap = (uap->nsa != NULL) ? &nsa : NULL; osap = (uap->osa != NULL) ? &osa : NULL; if (nsap) { error = copyin(uap->nsa, &sa, sizeof(sa)); if (error) return (error); nsap->sa_handler = sa.sa_handler; nsap->sa_flags = sa.sa_flags; OSIG2SIG(sa.sa_mask, nsap->sa_mask); } error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); if (osap && !error) { sa.sa_handler = osap->sa_handler; sa.sa_flags = osap->sa_flags; SIG2OSIG(osap->sa_mask, sa.sa_mask); error = copyout(&sa, uap->osa, sizeof(sa)); } return (error); } #if !defined(__i386__) /* Avoid replicating the same stub everywhere */ int osigreturn(td, uap) struct thread *td; struct osigreturn_args *uap; { return (nosys(td, (struct nosys_args *)uap)); } #endif #endif /* COMPAT_43 */ /* * Initialize signal state for process 0; * set to ignore signals that are ignored by default. */ void siginit(p) struct proc *p; { register int i; struct sigacts *ps; PROC_LOCK(p); ps = p->p_sigacts; mtx_lock(&ps->ps_mtx); for (i = 1; i <= NSIG; i++) if (sigprop(i) & SA_IGNORE && i != SIGCONT) SIGADDSET(ps->ps_sigignore, i); mtx_unlock(&ps->ps_mtx); PROC_UNLOCK(p); } /* * Reset signals for an exec of the specified process. */ void execsigs(struct proc *p) { struct sigacts *ps; int sig; struct thread *td; /* * Reset caught signals. Held signals remain held * through td_sigmask (unless they were caught, * and are now ignored by default). */ PROC_LOCK_ASSERT(p, MA_OWNED); td = FIRST_THREAD_IN_PROC(p); ps = p->p_sigacts; mtx_lock(&ps->ps_mtx); while (SIGNOTEMPTY(ps->ps_sigcatch)) { sig = sig_ffs(&ps->ps_sigcatch); SIGDELSET(ps->ps_sigcatch, sig); if (sigprop(sig) & SA_IGNORE) { if (sig != SIGCONT) SIGADDSET(ps->ps_sigignore, sig); sigqueue_delete_proc(p, sig); } ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } /* * Reset stack state to the user stack. * Clear set of signals caught on the signal stack. */ td->td_sigstk.ss_flags = SS_DISABLE; td->td_sigstk.ss_size = 0; td->td_sigstk.ss_sp = 0; td->td_pflags &= ~TDP_ALTSTACK; /* * Reset no zombies if child dies flag as Solaris does. */ ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; mtx_unlock(&ps->ps_mtx); } /* * kern_sigprocmask() * * Manipulate signal mask. */ int kern_sigprocmask(td, how, set, oset, old) struct thread *td; int how; sigset_t *set, *oset; int old; { int error; PROC_LOCK(td->td_proc); if (oset != NULL) *oset = td->td_sigmask; error = 0; if (set != NULL) { switch (how) { case SIG_BLOCK: SIG_CANTMASK(*set); SIGSETOR(td->td_sigmask, *set); break; case SIG_UNBLOCK: SIGSETNAND(td->td_sigmask, *set); signotify(td); break; case SIG_SETMASK: SIG_CANTMASK(*set); if (old) SIGSETLO(td->td_sigmask, *set); else td->td_sigmask = *set; signotify(td); break; default: error = EINVAL; break; } } PROC_UNLOCK(td->td_proc); return (error); } /* * sigprocmask() - MP SAFE */ #ifndef _SYS_SYSPROTO_H_ struct sigprocmask_args { int how; const sigset_t *set; sigset_t *oset; }; #endif int sigprocmask(td, uap) register struct thread *td; struct sigprocmask_args *uap; { sigset_t set, oset; sigset_t *setp, *osetp; int error; setp = (uap->set != NULL) ? &set : NULL; osetp = (uap->oset != NULL) ? &oset : NULL; if (setp) { error = copyin(uap->set, setp, sizeof(set)); if (error) return (error); } error = kern_sigprocmask(td, uap->how, setp, osetp, 0); if (osetp && !error) { error = copyout(osetp, uap->oset, sizeof(oset)); } return (error); } #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ /* * osigprocmask() - MP SAFE */ #ifndef _SYS_SYSPROTO_H_ struct osigprocmask_args { int how; osigset_t mask; }; #endif int osigprocmask(td, uap) register struct thread *td; struct osigprocmask_args *uap; { sigset_t set, oset; int error; OSIG2SIG(uap->mask, set); error = kern_sigprocmask(td, uap->how, &set, &oset, 1); SIG2OSIG(oset, td->td_retval[0]); return (error); } #endif /* COMPAT_43 */ /* * MPSAFE */ int sigwait(struct thread *td, struct sigwait_args *uap) { ksiginfo_t ksi; sigset_t set; int error; error = copyin(uap->set, &set, sizeof(set)); if (error) { td->td_retval[0] = error; return (0); } error = kern_sigtimedwait(td, set, &ksi, NULL); if (error) { if (error == ERESTART) return (error); td->td_retval[0] = error; return (0); } error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); td->td_retval[0] = error; return (0); } /* * MPSAFE */ int sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) { struct timespec ts; struct timespec *timeout; sigset_t set; ksiginfo_t ksi; int error; if (uap->timeout) { error = copyin(uap->timeout, &ts, sizeof(ts)); if (error) return (error); timeout = &ts; } else timeout = NULL; error = copyin(uap->set, &set, sizeof(set)); if (error) return (error); error = kern_sigtimedwait(td, set, &ksi, timeout); if (error) return (error); if (uap->info) error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); if (error == 0) td->td_retval[0] = ksi.ksi_signo; return (error); } /* * MPSAFE */ int sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) { ksiginfo_t ksi; sigset_t set; int error; error = copyin(uap->set, &set, sizeof(set)); if (error) return (error); error = kern_sigtimedwait(td, set, &ksi, NULL); if (error) return (error); if (uap->info) error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); if (error == 0) td->td_retval[0] = ksi.ksi_signo; return (error); } int kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, struct timespec *timeout) { struct sigacts *ps; sigset_t savedmask; struct proc *p; int error, sig, hz, i, timevalid = 0; struct timespec rts, ets, ts; struct timeval tv; p = td->td_proc; error = 0; sig = 0; SIG_CANTMASK(waitset); PROC_LOCK(p); ps = p->p_sigacts; savedmask = td->td_sigmask; if (timeout) { if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { timevalid = 1; getnanouptime(&rts); ets = rts; timespecadd(&ets, timeout); } } restart: for (i = 1; i <= _SIG_MAXSIG; ++i) { if (!SIGISMEMBER(waitset, i)) continue; if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { if (p->p_flag & P_SA) { p->p_flag |= P_SIGEVENT; wakeup(&p->p_siglist); } sigqueue_move(&p->p_sigqueue, &td->td_sigqueue, i); } else continue; } SIGFILLSET(td->td_sigmask); SIG_CANTMASK(td->td_sigmask); SIGDELSET(td->td_sigmask, i); mtx_lock(&ps->ps_mtx); sig = cursig(td); mtx_unlock(&ps->ps_mtx); if (sig) goto out; else { /* * Because cursig() may have stopped current thread, * after it is resumed, things may have already been * changed, it should rescan any pending signals. */ goto restart; } } if (error) goto out; /* * POSIX says this must be checked after looking for pending * signals. */ if (timeout) { if (!timevalid) { error = EINVAL; goto out; } getnanouptime(&rts); if (timespeccmp(&rts, &ets, >=)) { error = EAGAIN; goto out; } ts = ets; timespecsub(&ts, &rts); TIMESPEC_TO_TIMEVAL(&tv, &ts); hz = tvtohz(&tv); } else hz = 0; td->td_sigmask = savedmask; SIGSETNAND(td->td_sigmask, waitset); signotify(td); error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); if (timeout) { if (error == ERESTART) { /* timeout can not be restarted. */ error = EINTR; } else if (error == EAGAIN) { /* will calculate timeout by ourself. */ error = 0; } } goto restart; out: td->td_sigmask = savedmask; signotify(td); if (sig) { ksiginfo_init(ksi); sigqueue_get(&td->td_sigqueue, sig, ksi); ksi->ksi_signo = sig; if (ksi->ksi_code == SI_TIMER) itimer_accept(p, ksi->ksi_timerid, ksi); error = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_PSIG)) { sig_t action; mtx_lock(&ps->ps_mtx); action = ps->ps_sigact[_SIG_IDX(sig)]; mtx_unlock(&ps->ps_mtx); ktrpsig(sig, action, &td->td_sigmask, 0); } #endif if (sig == SIGKILL) sigexit(td, sig); } PROC_UNLOCK(p); return (error); } #ifndef _SYS_SYSPROTO_H_ struct sigpending_args { sigset_t *set; }; #endif /* * MPSAFE */ int sigpending(td, uap) struct thread *td; struct sigpending_args *uap; { struct proc *p = td->td_proc; sigset_t pending; PROC_LOCK(p); pending = p->p_sigqueue.sq_signals; SIGSETOR(pending, td->td_sigqueue.sq_signals); PROC_UNLOCK(p); return (copyout(&pending, uap->set, sizeof(sigset_t))); } #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ #ifndef _SYS_SYSPROTO_H_ struct osigpending_args { int dummy; }; #endif /* * MPSAFE */ int osigpending(td, uap) struct thread *td; struct osigpending_args *uap; { struct proc *p = td->td_proc; sigset_t pending; PROC_LOCK(p); pending = p->p_sigqueue.sq_signals; SIGSETOR(pending, td->td_sigqueue.sq_signals); PROC_UNLOCK(p); SIG2OSIG(pending, td->td_retval[0]); return (0); } #endif /* COMPAT_43 */ #if defined(COMPAT_43) /* * Generalized interface signal handler, 4.3-compatible. */ #ifndef _SYS_SYSPROTO_H_ struct osigvec_args { int signum; struct sigvec *nsv; struct sigvec *osv; }; #endif /* * MPSAFE */ /* ARGSUSED */ int osigvec(td, uap) struct thread *td; register struct osigvec_args *uap; { struct sigvec vec; struct sigaction nsa, osa; register struct sigaction *nsap, *osap; int error; if (uap->signum <= 0 || uap->signum >= ONSIG) return (EINVAL); nsap = (uap->nsv != NULL) ? &nsa : NULL; osap = (uap->osv != NULL) ? &osa : NULL; if (nsap) { error = copyin(uap->nsv, &vec, sizeof(vec)); if (error) return (error); nsap->sa_handler = vec.sv_handler; OSIG2SIG(vec.sv_mask, nsap->sa_mask); nsap->sa_flags = vec.sv_flags; nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ } error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); if (osap && !error) { vec.sv_handler = osap->sa_handler; SIG2OSIG(osap->sa_mask, vec.sv_mask); vec.sv_flags = osap->sa_flags; vec.sv_flags &= ~SA_NOCLDWAIT; vec.sv_flags ^= SA_RESTART; error = copyout(&vec, uap->osv, sizeof(vec)); } return (error); } #ifndef _SYS_SYSPROTO_H_ struct osigblock_args { int mask; }; #endif /* * MPSAFE */ int osigblock(td, uap) register struct thread *td; struct osigblock_args *uap; { struct proc *p = td->td_proc; sigset_t set; OSIG2SIG(uap->mask, set); SIG_CANTMASK(set); PROC_LOCK(p); SIG2OSIG(td->td_sigmask, td->td_retval[0]); SIGSETOR(td->td_sigmask, set); PROC_UNLOCK(p); return (0); } #ifndef _SYS_SYSPROTO_H_ struct osigsetmask_args { int mask; }; #endif /* * MPSAFE */ int osigsetmask(td, uap) struct thread *td; struct osigsetmask_args *uap; { struct proc *p = td->td_proc; sigset_t set; OSIG2SIG(uap->mask, set); SIG_CANTMASK(set); PROC_LOCK(p); SIG2OSIG(td->td_sigmask, td->td_retval[0]); SIGSETLO(td->td_sigmask, set); signotify(td); PROC_UNLOCK(p); return (0); } #endif /* COMPAT_43 */ /* * Suspend calling thread until signal, providing mask to be set * in the meantime. */ #ifndef _SYS_SYSPROTO_H_ struct sigsuspend_args { const sigset_t *sigmask; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sigsuspend(td, uap) struct thread *td; struct sigsuspend_args *uap; { sigset_t mask; int error; error = copyin(uap->sigmask, &mask, sizeof(mask)); if (error) return (error); return (kern_sigsuspend(td, mask)); } int kern_sigsuspend(struct thread *td, sigset_t mask) { struct proc *p = td->td_proc; /* * When returning from sigsuspend, 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. */ PROC_LOCK(p); td->td_oldsigmask = td->td_sigmask; td->td_pflags |= TDP_OLDMASK; SIG_CANTMASK(mask); td->td_sigmask = mask; signotify(td); while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) /* void */; PROC_UNLOCK(p); /* always return EINTR rather than ERESTART... */ return (EINTR); } #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ /* * Compatibility sigsuspend call for old binaries. Note nonstandard calling * convention: libc stub passes mask, not pointer, to save a copyin. */ #ifndef _SYS_SYSPROTO_H_ struct osigsuspend_args { osigset_t mask; }; #endif /* * MPSAFE */ /* ARGSUSED */ int osigsuspend(td, uap) struct thread *td; struct osigsuspend_args *uap; { struct proc *p = td->td_proc; sigset_t mask; PROC_LOCK(p); td->td_oldsigmask = td->td_sigmask; td->td_pflags |= TDP_OLDMASK; OSIG2SIG(uap->mask, mask); SIG_CANTMASK(mask); SIGSETLO(td->td_sigmask, mask); signotify(td); while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) /* void */; PROC_UNLOCK(p); /* always return EINTR rather than ERESTART... */ return (EINTR); } #endif /* COMPAT_43 */ #if defined(COMPAT_43) #ifndef _SYS_SYSPROTO_H_ struct osigstack_args { struct sigstack *nss; struct sigstack *oss; }; #endif /* * MPSAFE */ /* ARGSUSED */ int osigstack(td, uap) struct thread *td; register struct osigstack_args *uap; { struct sigstack nss, oss; int error = 0; if (uap->nss != NULL) { error = copyin(uap->nss, &nss, sizeof(nss)); if (error) return (error); } oss.ss_sp = td->td_sigstk.ss_sp; oss.ss_onstack = sigonstack(cpu_getstack(td)); if (uap->nss != NULL) { td->td_sigstk.ss_sp = nss.ss_sp; td->td_sigstk.ss_size = 0; td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; td->td_pflags |= TDP_ALTSTACK; } if (uap->oss != NULL) error = copyout(&oss, uap->oss, sizeof(oss)); return (error); } #endif /* COMPAT_43 */ #ifndef _SYS_SYSPROTO_H_ struct sigaltstack_args { stack_t *ss; stack_t *oss; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sigaltstack(td, uap) struct thread *td; register struct sigaltstack_args *uap; { stack_t ss, oss; int error; if (uap->ss != NULL) { error = copyin(uap->ss, &ss, sizeof(ss)); if (error) return (error); } error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, (uap->oss != NULL) ? &oss : NULL); if (error) return (error); if (uap->oss != NULL) error = copyout(&oss, uap->oss, sizeof(stack_t)); return (error); } int kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) { struct proc *p = td->td_proc; int oonstack; oonstack = sigonstack(cpu_getstack(td)); if (oss != NULL) { *oss = td->td_sigstk; oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; } if (ss != NULL) { if (oonstack) return (EPERM); if ((ss->ss_flags & ~SS_DISABLE) != 0) return (EINVAL); if (!(ss->ss_flags & SS_DISABLE)) { if (ss->ss_size < p->p_sysent->sv_minsigstksz) return (ENOMEM); td->td_sigstk = *ss; td->td_pflags |= TDP_ALTSTACK; } else { td->td_pflags &= ~TDP_ALTSTACK; } } return (0); } /* * Common code for kill process group/broadcast kill. * cp is calling process. */ static int killpg1(td, sig, pgid, all) register struct thread *td; int sig, pgid, all; { register struct proc *p; struct pgrp *pgrp; int nfound = 0; if (all) { /* * broadcast */ sx_slock(&allproc_lock); LIST_FOREACH(p, &allproc, p_list) { PROC_LOCK(p); if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || p == td->td_proc || p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } if (p_cansignal(td, p, sig) == 0) { nfound++; if (sig) psignal(p, sig); } PROC_UNLOCK(p); } sx_sunlock(&allproc_lock); } else { sx_slock(&proctree_lock); if (pgid == 0) { /* * zero pgid means send to my process group. */ pgrp = td->td_proc->p_pgrp; PGRP_LOCK(pgrp); } else { pgrp = pgfind(pgid); if (pgrp == NULL) { sx_sunlock(&proctree_lock); return (ESRCH); } } sx_sunlock(&proctree_lock); LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { PROC_LOCK(p); if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || p->p_state == PRS_NEW ) { PROC_UNLOCK(p); continue; } if (p_cansignal(td, p, sig) == 0) { nfound++; if (sig) psignal(p, sig); } PROC_UNLOCK(p); } PGRP_UNLOCK(pgrp); } return (nfound ? 0 : ESRCH); } #ifndef _SYS_SYSPROTO_H_ struct kill_args { int pid; int signum; }; #endif /* * MPSAFE */ /* ARGSUSED */ int kill(td, uap) register struct thread *td; register struct kill_args *uap; { register struct proc *p; int error; AUDIT_ARG(signum, uap->signum); if ((u_int)uap->signum > _SIG_MAXSIG) return (EINVAL); if (uap->pid > 0) { /* kill single process */ if ((p = pfind(uap->pid)) == NULL) { if ((p = zpfind(uap->pid)) == NULL) return (ESRCH); } AUDIT_ARG(process, p); error = p_cansignal(td, p, uap->signum); if (error == 0 && uap->signum) psignal(p, uap->signum); PROC_UNLOCK(p); return (error); } AUDIT_ARG(pid, uap->pid); switch (uap->pid) { case -1: /* broadcast signal */ return (killpg1(td, uap->signum, 0, 1)); case 0: /* signal own process group */ return (killpg1(td, uap->signum, 0, 0)); default: /* negative explicit process group */ return (killpg1(td, uap->signum, -uap->pid, 0)); } /* NOTREACHED */ } #if defined(COMPAT_43) #ifndef _SYS_SYSPROTO_H_ struct okillpg_args { int pgid; int signum; }; #endif /* * MPSAFE */ /* ARGSUSED */ int okillpg(td, uap) struct thread *td; register struct okillpg_args *uap; { AUDIT_ARG(signum, uap->signum); AUDIT_ARG(pid, uap->pgid); if ((u_int)uap->signum > _SIG_MAXSIG) return (EINVAL); return (killpg1(td, uap->signum, uap->pgid, 0)); } #endif /* COMPAT_43 */ #ifndef _SYS_SYSPROTO_H_ struct sigqueue_args { pid_t pid; int signum; /* union sigval */ void *value; }; #endif int sigqueue(struct thread *td, struct sigqueue_args *uap) { ksiginfo_t ksi; struct proc *p; int error; if ((u_int)uap->signum > _SIG_MAXSIG) return (EINVAL); /* * Specification says sigqueue can only send signal to * single process. */ if (uap->pid <= 0) return (EINVAL); if ((p = pfind(uap->pid)) == NULL) { if ((p = zpfind(uap->pid)) == NULL) return (ESRCH); } error = p_cansignal(td, p, uap->signum); if (error == 0 && uap->signum != 0) { ksiginfo_init(&ksi); ksi.ksi_signo = uap->signum; ksi.ksi_code = SI_QUEUE; ksi.ksi_pid = td->td_proc->p_pid; ksi.ksi_uid = td->td_ucred->cr_ruid; ksi.ksi_value.sival_ptr = uap->value; error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); } PROC_UNLOCK(p); return (error); } /* * Send a signal to a process group. */ void gsignal(pgid, sig) int pgid, sig; { struct pgrp *pgrp; if (pgid != 0) { sx_slock(&proctree_lock); pgrp = pgfind(pgid); sx_sunlock(&proctree_lock); if (pgrp != NULL) { pgsignal(pgrp, sig, 0); PGRP_UNLOCK(pgrp); } } } /* * Send a signal to a process group. If checktty is 1, * limit to members which have a controlling terminal. */ void pgsignal(pgrp, sig, checkctty) struct pgrp *pgrp; int sig, checkctty; { register struct proc *p; if (pgrp) { PGRP_LOCK_ASSERT(pgrp, MA_OWNED); LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { PROC_LOCK(p); if (checkctty == 0 || p->p_flag & P_CONTROLT) psignal(p, sig); PROC_UNLOCK(p); } } } /* * Send a signal caused by a trap to the current thread. * If it will be caught immediately, deliver it with correct code. * Otherwise, post it normally. * * MPSAFE */ void trapsignal(struct thread *td, ksiginfo_t *ksi) { struct sigacts *ps; struct proc *p; int error; int sig; int code; p = td->td_proc; sig = ksi->ksi_signo; code = ksi->ksi_code; KASSERT(_SIG_VALID(sig), ("invalid signal")); if (td->td_pflags & TDP_SA) { if (td->td_mailbox == NULL) thread_user_enter(td); PROC_LOCK(p); SIGDELSET(td->td_sigmask, sig); mtx_lock_spin(&sched_lock); /* * Force scheduling an upcall, so UTS has chance to * process the signal before thread runs again in * userland. */ if (td->td_upcall) td->td_upcall->ku_flags |= KUF_DOUPCALL; mtx_unlock_spin(&sched_lock); } else { PROC_LOCK(p); } ps = p->p_sigacts; mtx_lock(&ps->ps_mtx); if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && !SIGISMEMBER(td->td_sigmask, sig)) { p->p_stats->p_ru.ru_nsignals++; #ifdef KTRACE if (KTRPOINT(curthread, KTR_PSIG)) ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], &td->td_sigmask, code); #endif if (!(td->td_pflags & TDP_SA)) (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], ksi, &td->td_sigmask); else if (td->td_mailbox == NULL) { mtx_unlock(&ps->ps_mtx); /* UTS caused a sync signal */ p->p_code = code; /* XXX for core dump/debugger */ p->p_sig = sig; /* XXX to verify code */ sigexit(td, sig); } else { mtx_unlock(&ps->ps_mtx); SIGADDSET(td->td_sigmask, sig); PROC_UNLOCK(p); error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig, sizeof(siginfo_t)); PROC_LOCK(p); /* UTS memory corrupted */ if (error) sigexit(td, SIGSEGV); mtx_lock(&ps->ps_mtx); } SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); if (!SIGISMEMBER(ps->ps_signodefer, sig)) SIGADDSET(td->td_sigmask, sig); if (SIGISMEMBER(ps->ps_sigreset, sig)) { /* * See kern_sigaction() for origin of this code. */ SIGDELSET(ps->ps_sigcatch, sig); if (sig != SIGCONT && sigprop(sig) & SA_IGNORE) SIGADDSET(ps->ps_sigignore, sig); ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } mtx_unlock(&ps->ps_mtx); } else { /* * Avoid a possible infinite loop if the thread * masking the signal or process is ignoring the * signal. */ if (kern_forcesigexit && (SIGISMEMBER(td->td_sigmask, sig) || ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { SIGDELSET(td->td_sigmask, sig); SIGDELSET(ps->ps_sigcatch, sig); SIGDELSET(ps->ps_sigignore, sig); ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } mtx_unlock(&ps->ps_mtx); p->p_code = code; /* XXX for core dump/debugger */ p->p_sig = sig; /* XXX to verify code */ tdsignal(p, td, sig, ksi); } PROC_UNLOCK(p); } static struct thread * sigtd(struct proc *p, int sig, int prop) { struct thread *td, *signal_td; PROC_LOCK_ASSERT(p, MA_OWNED); /* * Check if current thread can handle the signal without * switching conetxt to another thread. */ if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) return (curthread); signal_td = NULL; mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td) { if (!SIGISMEMBER(td->td_sigmask, sig)) { signal_td = td; break; } } if (signal_td == NULL) signal_td = FIRST_THREAD_IN_PROC(p); mtx_unlock_spin(&sched_lock); return (signal_td); } /* * 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. * * MPSAFE */ void psignal(struct proc *p, int sig) { (void) tdsignal(p, NULL, sig, NULL); } int psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) { struct thread *td = NULL; PROC_LOCK_ASSERT(p, MA_OWNED); KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); /* * ksi_code and other fields should be set before * calling this function. */ ksi->ksi_signo = sigev->sigev_signo; ksi->ksi_value = sigev->sigev_value; if (sigev->sigev_notify == SIGEV_THREAD_ID) { td = thread_find(p, sigev->sigev_notify_thread_id); if (td == NULL) return (ESRCH); } return (tdsignal(p, td, ksi->ksi_signo, ksi)); } /* * MPSAFE */ int tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) { sigset_t saved; int ret; if (p->p_flag & P_SA) saved = p->p_sigqueue.sq_signals; ret = do_tdsignal(p, td, sig, ksi); if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { /* pending set changed */ p->p_flag |= P_SIGEVENT; wakeup(&p->p_siglist); } } return (ret); } static int do_tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) { sig_t action; sigqueue_t *sigqueue; int prop; struct sigacts *ps; int intrval; int ret = 0; PROC_LOCK_ASSERT(p, MA_OWNED); if (!_SIG_VALID(sig)) panic("do_tdsignal(): invalid signal"); KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue")); /* * IEEE Std 1003.1-2001: return success when killing a zombie. */ if (p->p_state == PRS_ZOMBIE) { if (ksi && (ksi->ksi_flags & KSI_INS)) ksiginfo_tryfree(ksi); return (ret); } ps = p->p_sigacts; KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); prop = sigprop(sig); /* * If the signal is blocked and not destined for this thread, then * assign it to the process so that we can find it later in the first * thread that unblocks it. Otherwise, assign it to this thread now. */ if (td == NULL) { td = sigtd(p, sig, prop); if (SIGISMEMBER(td->td_sigmask, sig)) sigqueue = &p->p_sigqueue; else sigqueue = &td->td_sigqueue; } else { KASSERT(td->td_proc == p, ("invalid thread")); sigqueue = &td->td_sigqueue; } /* * If the signal is being ignored, * or process is exiting or thread is exiting, * 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.) */ mtx_lock(&ps->ps_mtx); if (SIGISMEMBER(ps->ps_sigignore, sig) || (p->p_flag & P_WEXIT)) { mtx_unlock(&ps->ps_mtx); if (ksi && (ksi->ksi_flags & KSI_INS)) ksiginfo_tryfree(ksi); return (ret); } if (SIGISMEMBER(td->td_sigmask, sig)) action = SIG_HOLD; else if (SIGISMEMBER(ps->ps_sigcatch, sig)) action = SIG_CATCH; else action = SIG_DFL; if (SIGISMEMBER(ps->ps_sigintr, sig)) intrval = EINTR; else intrval = ERESTART; mtx_unlock(&ps->ps_mtx); if (prop & SA_CONT) sigqueue_delete_stopmask_proc(p); else if (prop & SA_STOP) { /* * 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) && (p->p_pgrp->pg_jobc == 0) && (action == SIG_DFL)) { if (ksi && (ksi->ksi_flags & KSI_INS)) ksiginfo_tryfree(ksi); return (ret); } sigqueue_delete_proc(p, SIGCONT); if (p->p_flag & P_CONTINUED) { p->p_flag &= ~P_CONTINUED; PROC_LOCK(p->p_pptr); sigqueue_take(p->p_ksi); PROC_UNLOCK(p->p_pptr); } } ret = sigqueue_add(sigqueue, sig, ksi); if (ret != 0) return (ret); signotify(td); /* * Defer further processing for signals which are held, * except that stopped processes must be continued by SIGCONT. */ if (action == SIG_HOLD && !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) return (ret); /* * SIGKILL: Remove procfs STOPEVENTs. */ if (sig == SIGKILL) { /* from procfs_ioctl.c: PIOCBIC */ p->p_stops = 0; /* from procfs_ioctl.c: PIOCCONT */ p->p_step = 0; wakeup(&p->p_step); } /* * Some signals have a process-wide effect and a per-thread * component. Most processing occurs when the process next * tries to cross the user boundary, however there are some * times when processing needs to be done immediatly, such as * waking up threads so that they can cross the user boundary. * We try do the per-process part here. */ if (P_SHOULDSTOP(p)) { /* * The process is in stopped mode. All the threads should be * either winding down or already on the suspended queue. */ if (p->p_flag & P_TRACED) { /* * The traced process is already stopped, * so no further action is necessary. * No signal can restart us. */ goto out; } if (sig == SIGKILL) { /* * SIGKILL sets process running. * It will die elsewhere. * All threads must be restarted. */ p->p_flag &= ~P_STOPPED_SIG; goto runfast; } if (prop & SA_CONT) { /* * If SIGCONT is default (or ignored), we continue the * process but don't leave the signal in sigqueue as * it has no further action. If SIGCONT is held, we * continue the process and leave the signal in * sigqueue. If the process catches SIGCONT, let it * handle the signal itself. If it isn't waiting on * an event, it goes back to run state. * Otherwise, process goes back to sleep state. */ p->p_flag &= ~P_STOPPED_SIG; if (p->p_numthreads == p->p_suspcount) { p->p_flag |= P_CONTINUED; p->p_xstat = SIGCONT; PROC_LOCK(p->p_pptr); childproc_continued(p); PROC_UNLOCK(p->p_pptr); } if (action == SIG_DFL) { sigqueue_delete(sigqueue, sig); } else if (action == SIG_CATCH) { /* * The process wants to catch it so it needs * to run at least one thread, but which one? * It would seem that the answer would be to * run an upcall in the next KSE to run, and * deliver the signal that way. In a NON KSE * process, we need to make sure that the * single thread is runnable asap. * XXXKSE for now however, make them all run. */ goto runfast; } /* * The signal is not ignored or caught. */ mtx_lock_spin(&sched_lock); thread_unsuspend(p); mtx_unlock_spin(&sched_lock); goto out; } if (prop & SA_STOP) { /* * Already stopped, don't need to stop again * (If we did the shell could get confused). * Just make sure the signal STOP bit set. */ p->p_flag |= P_STOPPED_SIG; sigqueue_delete(sigqueue, sig); goto out; } /* * All other kinds of signals: * If a thread is sleeping interruptibly, simulate a * wakeup so that when it is continued it will be made * runnable and can look at the signal. However, don't make * the PROCESS runnable, leave it stopped. * It may run a bit until it hits a thread_suspend_check(). */ mtx_lock_spin(&sched_lock); if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) sleepq_abort(td, intrval); mtx_unlock_spin(&sched_lock); goto out; /* * Mutexes are short lived. Threads waiting on them will * hit thread_suspend_check() soon. */ } else if (p->p_state == PRS_NORMAL) { if (p->p_flag & P_TRACED || action == SIG_CATCH) { mtx_lock_spin(&sched_lock); tdsigwakeup(td, sig, action, intrval); mtx_unlock_spin(&sched_lock); goto out; } MPASS(action == SIG_DFL); if (prop & SA_STOP) { if (p->p_flag & P_PPWAIT) goto out; p->p_flag |= P_STOPPED_SIG; p->p_xstat = sig; mtx_lock_spin(&sched_lock); sig_suspend_threads(td, p, 1); if (p->p_numthreads == p->p_suspcount) { /* * only thread sending signal to another * process can reach here, if thread is sending * signal to its process, because thread does * not suspend itself here, p_numthreads * should never be equal to p_suspcount. */ thread_stopped(p); mtx_unlock_spin(&sched_lock); sigqueue_delete_proc(p, p->p_xstat); } else mtx_unlock_spin(&sched_lock); goto out; } else goto runfast; /* NOTREACHED */ } else { /* Not in "NORMAL" state. discard the signal. */ sigqueue_delete(sigqueue, sig); goto out; } /* * The process is not stopped so we need to apply the signal to all the * running threads. */ runfast: mtx_lock_spin(&sched_lock); tdsigwakeup(td, sig, action, intrval); thread_unsuspend(p); mtx_unlock_spin(&sched_lock); out: /* If we jump here, sched_lock should not be owned. */ mtx_assert(&sched_lock, MA_NOTOWNED); return (ret); } /* * The force of a signal has been directed against a single * thread. We need to see what we can do about knocking it * out of any sleep it may be in etc. */ static void tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) { struct proc *p = td->td_proc; register int prop; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_assert(&sched_lock, MA_OWNED); prop = sigprop(sig); /* * Bring the priority of a thread up if we want it to get * killed in this lifetime. */ if (action == SIG_DFL && (prop & SA_KILL)) { if (p->p_nice > 0) sched_nice(td->td_proc, 0); if (td->td_priority > PUSER) sched_prio(td, PUSER); } if (TD_ON_SLEEPQ(td)) { /* * If thread is sleeping uninterruptibly * we can't interrupt the sleep... the signal will * be noticed when the process returns through * trap() or syscall(). */ if ((td->td_flags & TDF_SINTR) == 0) return; /* * 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) { mtx_unlock_spin(&sched_lock); sigqueue_delete(&p->p_sigqueue, sig); /* * It may be on either list in this state. * Remove from both for now. */ sigqueue_delete(&td->td_sigqueue, sig); mtx_lock_spin(&sched_lock); return; } /* * Give low priority threads a better chance to run. */ if (td->td_priority > PUSER) sched_prio(td, PUSER); sleepq_abort(td, intrval); } else { /* * Other states do nothing with the signal immediately, * other than kicking ourselves if we are running. * It will either never be noticed, or noticed very soon. */ #ifdef SMP if (TD_IS_RUNNING(td) && td != curthread) forward_signal(td); #endif } } static void sig_suspend_threads(struct thread *td, struct proc *p, int sending) { struct thread *td2; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_assert(&sched_lock, MA_OWNED); FOREACH_THREAD_IN_PROC(p, td2) { if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && (td2->td_flags & TDF_SINTR) && !TD_IS_SUSPENDED(td2)) { thread_suspend_one(td2); } else { if (sending || td != td2) td2->td_flags |= TDF_ASTPENDING; #ifdef SMP if (TD_IS_RUNNING(td2) && td2 != td) forward_signal(td2); #endif } } } int ptracestop(struct thread *td, int sig) { struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, &p->p_mtx.mtx_object, "Stopping for traced signal"); mtx_lock_spin(&sched_lock); td->td_flags |= TDF_XSIG; mtx_unlock_spin(&sched_lock); td->td_xsig = sig; while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { if (p->p_flag & P_SINGLE_EXIT) { mtx_lock_spin(&sched_lock); td->td_flags &= ~TDF_XSIG; mtx_unlock_spin(&sched_lock); return (sig); } /* * Just make wait() to work, the last stopped thread * will win. */ p->p_xstat = sig; p->p_xthread = td; p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); mtx_lock_spin(&sched_lock); sig_suspend_threads(td, p, 0); stopme: thread_stopped(p); thread_suspend_one(td); PROC_UNLOCK(p); DROP_GIANT(); mi_switch(SW_VOL, NULL); mtx_unlock_spin(&sched_lock); PICKUP_GIANT(); PROC_LOCK(p); if (!(p->p_flag & P_TRACED)) break; if (td->td_flags & TDF_DBSUSPEND) { if (p->p_flag & P_SINGLE_EXIT) break; mtx_lock_spin(&sched_lock); goto stopme; } } return (td->td_xsig); } /* * 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 cursig.) The normal call * sequence is * * while (sig = cursig(curthread)) * postsig(sig); */ static int issignal(td) struct thread *td; { struct proc *p; struct sigacts *ps; sigset_t sigpending; int sig, prop, newsig; p = td->td_proc; ps = p->p_sigacts; mtx_assert(&ps->ps_mtx, MA_OWNED); PROC_LOCK_ASSERT(p, MA_OWNED); for (;;) { int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); sigpending = td->td_sigqueue.sq_signals; SIGSETNAND(sigpending, td->td_sigmask); if (p->p_flag & P_PPWAIT) SIG_STOPSIGMASK(sigpending); if (SIGISEMPTY(sigpending)) /* no signal to send */ return (0); sig = sig_ffs(&sigpending); if (p->p_stops & S_SIG) { mtx_unlock(&ps->ps_mtx); stopevent(p, S_SIG, sig); mtx_lock(&ps->ps_mtx); } /* * We should see pending but ignored signals * only if P_TRACED was on when they were posted. */ if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { sigqueue_delete(&td->td_sigqueue, sig); if (td->td_pflags & TDP_SA) SIGADDSET(td->td_sigmask, sig); continue; } if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { /* * If traced, always stop. */ mtx_unlock(&ps->ps_mtx); newsig = ptracestop(td, sig); mtx_lock(&ps->ps_mtx); if (td->td_pflags & TDP_SA) SIGADDSET(td->td_sigmask, sig); if (sig != newsig) { ksiginfo_t ksi; /* * clear old signal. * XXX shrug off debugger, it causes siginfo to * be thrown away. */ sigqueue_get(&td->td_sigqueue, sig, &ksi); /* * If parent wants us to take the signal, * then it will leave it in p->p_xstat; * otherwise we just look for signals again. */ if (newsig == 0) continue; sig = newsig; /* * Put the new signal into td_sigqueue. If the * signal is being masked, look for other signals. */ SIGADDSET(td->td_sigqueue.sq_signals, sig); if (td->td_pflags & TDP_SA) SIGDELSET(td->td_sigmask, sig); if (SIGISMEMBER(td->td_sigmask, sig)) continue; signotify(td); } /* * If the traced bit got turned off, go back up * to the top to rescan signals. This ensures * that p_sig* and p_sigact are consistent. */ if ((p->p_flag & P_TRACED) == 0) continue; } prop = sigprop(sig); /* * Decide whether the signal should be returned. * Return the signal's number, or fall through * to clear it from the pending mask. */ switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { case (intptr_t)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 %lu) got signal %d\n", (u_long)p->p_pid, sig); #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 (p->p_flag & P_TRACED || (p->p_pgrp->pg_jobc == 0 && prop & SA_TTYSTOP)) break; /* == ignore */ mtx_unlock(&ps->ps_mtx); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, &p->p_mtx.mtx_object, "Catching SIGSTOP"); p->p_flag |= P_STOPPED_SIG; p->p_xstat = sig; mtx_lock_spin(&sched_lock); sig_suspend_threads(td, p, 0); thread_stopped(p); thread_suspend_one(td); PROC_UNLOCK(p); DROP_GIANT(); mi_switch(SW_INVOL, NULL); mtx_unlock_spin(&sched_lock); PICKUP_GIANT(); PROC_LOCK(p); mtx_lock(&ps->ps_mtx); break; } else if (prop & SA_IGNORE) { /* * Except for SIGCONT, shouldn't get here. * Default action is to ignore; drop it. */ break; /* == ignore */ } else return (sig); /*NOTREACHED*/ case (intptr_t)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 && (p->p_flag & P_TRACED) == 0) printf("issignal\n"); break; /* == ignore */ default: /* * This signal has an action, let * postsig() process it. */ return (sig); } sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ } /* NOTREACHED */ } /* * MPSAFE */ void thread_stopped(struct proc *p) { int n; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_assert(&sched_lock, MA_OWNED); n = p->p_suspcount; if (p == curproc) n++; if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { mtx_unlock_spin(&sched_lock); p->p_flag &= ~P_WAITED; PROC_LOCK(p->p_pptr); childproc_stopped(p, (p->p_flag & P_TRACED) ? CLD_TRAPPED : CLD_STOPPED); PROC_UNLOCK(p->p_pptr); mtx_lock_spin(&sched_lock); } } /* * Take the action for the specified signal * from the current set of pending signals. */ void postsig(sig) register int sig; { struct thread *td = curthread; register struct proc *p = td->td_proc; struct sigacts *ps; sig_t action; ksiginfo_t ksi; sigset_t returnmask; int code; KASSERT(sig != 0, ("postsig")); PROC_LOCK_ASSERT(p, MA_OWNED); ps = p->p_sigacts; mtx_assert(&ps->ps_mtx, MA_OWNED); ksiginfo_init(&ksi); sigqueue_get(&td->td_sigqueue, sig, &ksi); ksi.ksi_signo = sig; if (ksi.ksi_code == SI_TIMER) itimer_accept(p, ksi.ksi_timerid, &ksi); action = ps->ps_sigact[_SIG_IDX(sig)]; #ifdef KTRACE if (KTRPOINT(td, KTR_PSIG)) ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? &td->td_oldsigmask : &td->td_sigmask, 0); #endif if (p->p_stops & S_SIG) { mtx_unlock(&ps->ps_mtx); stopevent(p, S_SIG, sig); mtx_lock(&ps->ps_mtx); } if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { /* * Default action, where the default is to kill * the process. (Other cases were ignored above.) */ mtx_unlock(&ps->ps_mtx); sigexit(td, sig); /* NOTREACHED */ } else { if (td->td_pflags & TDP_SA) { if (sig == SIGKILL) { mtx_unlock(&ps->ps_mtx); sigexit(td, sig); } } /* * If we get here, the signal must be caught. */ KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), ("postsig action")); /* * Set the new mask value and also defer further * occurrences of this signal. * * Special case: user has done a sigsuspend. Here the * current mask is not of interest, but rather the * mask from before the sigsuspend is what we want * restored after the signal processing is completed. */ if (td->td_pflags & TDP_OLDMASK) { returnmask = td->td_oldsigmask; td->td_pflags &= ~TDP_OLDMASK; } else returnmask = td->td_sigmask; SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); if (!SIGISMEMBER(ps->ps_signodefer, sig)) SIGADDSET(td->td_sigmask, sig); if (SIGISMEMBER(ps->ps_sigreset, sig)) { /* * See kern_sigaction() for origin of this code. */ SIGDELSET(ps->ps_sigcatch, sig); if (sig != SIGCONT && sigprop(sig) & SA_IGNORE) SIGADDSET(ps->ps_sigignore, sig); ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } p->p_stats->p_ru.ru_nsignals++; if (p->p_sig != sig) { code = 0; } else { code = p->p_code; p->p_code = 0; p->p_sig = 0; } if (td->td_pflags & TDP_SA) thread_signal_add(curthread, &ksi); else (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); } } /* * Kill the current process for stated reason. */ void killproc(p, why) struct proc *p; char *why; { PROC_LOCK_ASSERT(p, MA_OWNED); CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, p->p_comm); log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); psignal(p, SIGKILL); } /* * 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. * * MPSAFE */ void sigexit(td, sig) struct thread *td; int sig; { struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); p->p_acflag |= AXSIG; /* * We must be single-threading to generate a core dump. This * ensures that the registers in the core file are up-to-date. * Also, the ELF dump handler assumes that the thread list doesn't * change out from under it. * * XXX If another thread attempts to single-thread before us * (e.g. via fork()), we won't get a dump at all. */ if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { p->p_sig = sig; /* * Log signals which would cause core dumps * (Log as LOG_INFO to appease those who don't want * these messages.) * XXX : Todo, as well as euid, write out ruid too * Note that coredump() drops proc lock. */ if (coredump(td) == 0) sig |= WCOREFLAG; if (kern_logsigexit) log(LOG_INFO, "pid %d (%s), uid %d: exited on signal %d%s\n", p->p_pid, p->p_comm, td->td_ucred ? td->td_ucred->cr_uid : -1, sig &~ WCOREFLAG, sig & WCOREFLAG ? " (core dumped)" : ""); } else PROC_UNLOCK(p); exit1(td, W_EXITCODE(0, sig)); /* NOTREACHED */ } /* * Send queued SIGCHLD to parent when child process's state * is changed. */ static void sigparent(struct proc *p, int reason, int status) { PROC_LOCK_ASSERT(p, MA_OWNED); PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); if (p->p_ksi != NULL) { p->p_ksi->ksi_signo = SIGCHLD; p->p_ksi->ksi_code = reason; p->p_ksi->ksi_status = status; p->p_ksi->ksi_pid = p->p_pid; p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; if (KSI_ONQ(p->p_ksi)) return; } tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); } static void childproc_jobstate(struct proc *p, int reason, int status) { struct sigacts *ps; PROC_LOCK_ASSERT(p, MA_OWNED); PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); /* * Wake up parent sleeping in kern_wait(), also send * SIGCHLD to parent, but SIGCHLD does not guarantee * that parent will awake, because parent may masked * the signal. */ p->p_pptr->p_flag |= P_STATCHILD; wakeup(p->p_pptr); ps = p->p_pptr->p_sigacts; mtx_lock(&ps->ps_mtx); if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { mtx_unlock(&ps->ps_mtx); sigparent(p, reason, status); } else mtx_unlock(&ps->ps_mtx); } void childproc_stopped(struct proc *p, int reason) { childproc_jobstate(p, reason, p->p_xstat); } void childproc_continued(struct proc *p) { childproc_jobstate(p, CLD_CONTINUED, SIGCONT); } void childproc_exited(struct proc *p) { int reason; int status = p->p_xstat; /* convert to int */ reason = CLD_EXITED; if (WCOREDUMP(status)) reason = CLD_DUMPED; else if (WIFSIGNALED(status)) reason = CLD_KILLED; /* * XXX avoid calling wakeup(p->p_pptr), the work is * done in exit1(). */ sigparent(p, reason, status); } static char corefilename[MAXPATHLEN] = {"%N.core"}; SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, sizeof(corefilename), "process corefile name format string"); /* * expand_name(name, uid, pid) * Expand the name described in corefilename, using name, uid, and pid. * corefilename is a printf-like string, with three format specifiers: * %N name of process ("name") * %P process id (pid) * %U user id (uid) * For example, "%N.core" is the default; they can be disabled completely * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". * This is controlled by the sysctl variable kern.corefile (see above). */ static char * expand_name(name, uid, pid) const char *name; uid_t uid; pid_t pid; { const char *format, *appendstr; char *temp; char buf[11]; /* Buffer for pid/uid -- max 4B */ size_t i, l, n; format = corefilename; temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); if (temp == NULL) return (NULL); for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { switch (format[i]) { case '%': /* Format character */ i++; switch (format[i]) { case '%': appendstr = "%"; break; case 'N': /* process name */ appendstr = name; break; case 'P': /* process id */ sprintf(buf, "%u", pid); appendstr = buf; break; case 'U': /* user id */ sprintf(buf, "%u", uid); appendstr = buf; break; default: appendstr = ""; log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); } l = strlen(appendstr); if ((n + l) >= MAXPATHLEN) goto toolong; memcpy(temp + n, appendstr, l); n += l; break; default: temp[n++] = format[i]; } } if (format[i] != '\0') goto toolong; return (temp); toolong: log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", (long)pid, name, (u_long)uid); free(temp, M_TEMP); return (NULL); } /* * Dump a process' core. The main routine does some * policy checking, and creates the name of the coredump; * then it passes on a vnode and a size limit to the process-specific * coredump routine if there is one; if there _is not_ one, it returns * ENOSYS; otherwise it returns the error from the process-specific routine. */ static int coredump(struct thread *td) { struct proc *p = td->td_proc; register struct vnode *vp; register struct ucred *cred = td->td_ucred; struct flock lf; struct nameidata nd; struct vattr vattr; int error, error1, flags, locked; struct mount *mp; char *name; /* name of corefile */ off_t limit; int vfslocked; PROC_LOCK_ASSERT(p, MA_OWNED); MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); _STOPEVENT(p, S_CORE, 0); if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { PROC_UNLOCK(p); return (EFAULT); } /* * Note that the bulk of limit checking is done after * the corefile is created. The exception is if the limit * for corefiles is 0, in which case we don't bother * creating the corefile at all. This layout means that * a corefile is truncated instead of not being created, * if it is larger than the limit. */ limit = (off_t)lim_cur(p, RLIMIT_CORE); PROC_UNLOCK(p); if (limit == 0) return (EFBIG); restart: name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); if (name == NULL) return (EINVAL); NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); flags = O_CREAT | FWRITE | O_NOFOLLOW; error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); free(name, M_TEMP); if (error) return (error); vfslocked = NDHASGIANT(&nd); NDFREE(&nd, NDF_ONLY_PNBUF); vp = nd.ni_vp; /* Don't dump to non-regular files or files with links. */ if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { VOP_UNLOCK(vp, 0, td); error = EFAULT; goto close; } VOP_UNLOCK(vp, 0, td); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_WRLCK; locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { lf.l_type = F_UNLCK; if (locked) VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); if ((error = vn_close(vp, FWRITE, cred, td)) != 0) goto out; if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) goto out; VFS_UNLOCK_GIANT(vfslocked); goto restart; } VATTR_NULL(&vattr); vattr.va_size = 0; if (set_core_nodump_flag) vattr.va_flags = UF_NODUMP; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); VOP_LEASE(vp, td, cred, LEASE_WRITE); VOP_SETATTR(vp, &vattr, cred, td); VOP_UNLOCK(vp, 0, td); vn_finished_write(mp); PROC_LOCK(p); p->p_acflag |= ACORE; PROC_UNLOCK(p); error = p->p_sysent->sv_coredump ? p->p_sysent->sv_coredump(td, vp, limit) : ENOSYS; if (locked) { lf.l_type = F_UNLCK; VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); } close: error1 = vn_close(vp, FWRITE, cred, td); if (error == 0) error = error1; out: VFS_UNLOCK_GIANT(vfslocked); return (error); } /* * Nonexistent system call-- signal process (may want to handle it). * Flag error in case process won't see signal immediately (blocked or ignored). */ #ifndef _SYS_SYSPROTO_H_ struct nosys_args { int dummy; }; #endif /* * MPSAFE */ /* ARGSUSED */ int nosys(td, args) struct thread *td; struct nosys_args *args; { struct proc *p = td->td_proc; PROC_LOCK(p); psignal(p, SIGSYS); PROC_UNLOCK(p); return (ENOSYS); } /* * Send a SIGIO or SIGURG signal to a process or process group using * stored credentials rather than those of the current process. */ void pgsigio(sigiop, sig, checkctty) struct sigio **sigiop; int sig, checkctty; { struct sigio *sigio; SIGIO_LOCK(); sigio = *sigiop; if (sigio == NULL) { SIGIO_UNLOCK(); return; } if (sigio->sio_pgid > 0) { PROC_LOCK(sigio->sio_proc); if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) psignal(sigio->sio_proc, sig); PROC_UNLOCK(sigio->sio_proc); } else if (sigio->sio_pgid < 0) { struct proc *p; PGRP_LOCK(sigio->sio_pgrp); LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { PROC_LOCK(p); if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && (checkctty == 0 || (p->p_flag & P_CONTROLT))) psignal(p, sig); PROC_UNLOCK(p); } PGRP_UNLOCK(sigio->sio_pgrp); } SIGIO_UNLOCK(); } static int filt_sigattach(struct knote *kn) { struct proc *p = curproc; kn->kn_ptr.p_proc = p; kn->kn_flags |= EV_CLEAR; /* automatically set */ knlist_add(&p->p_klist, kn, 0); return (0); } static void filt_sigdetach(struct knote *kn) { struct proc *p = kn->kn_ptr.p_proc; knlist_remove(&p->p_klist, kn, 0); } /* * 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. */ static 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); } struct sigacts * sigacts_alloc(void) { struct sigacts *ps; ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); ps->ps_refcnt = 1; mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); return (ps); } void sigacts_free(struct sigacts *ps) { mtx_lock(&ps->ps_mtx); ps->ps_refcnt--; if (ps->ps_refcnt == 0) { mtx_destroy(&ps->ps_mtx); free(ps, M_SUBPROC); } else mtx_unlock(&ps->ps_mtx); } struct sigacts * sigacts_hold(struct sigacts *ps) { mtx_lock(&ps->ps_mtx); ps->ps_refcnt++; mtx_unlock(&ps->ps_mtx); return (ps); } void sigacts_copy(struct sigacts *dest, struct sigacts *src) { KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); mtx_lock(&src->ps_mtx); bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); mtx_unlock(&src->ps_mtx); } int sigacts_shared(struct sigacts *ps) { int shared; mtx_lock(&ps->ps_mtx); shared = ps->ps_refcnt > 1; mtx_unlock(&ps->ps_mtx); return (shared); }