2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
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9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
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13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
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33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
42 #include "opt_ktrace.h"
44 #include <sys/param.h>
45 #include <sys/ctype.h>
46 #include <sys/systm.h>
47 #include <sys/signalvar.h>
48 #include <sys/vnode.h>
50 #include <sys/capsicum.h>
51 #include <sys/compressor.h>
52 #include <sys/condvar.h>
53 #include <sys/devctl.h>
54 #include <sys/event.h>
55 #include <sys/fcntl.h>
56 #include <sys/imgact.h>
57 #include <sys/kernel.h>
59 #include <sys/ktrace.h>
60 #include <sys/limits.h>
62 #include <sys/malloc.h>
63 #include <sys/mutex.h>
64 #include <sys/refcount.h>
65 #include <sys/namei.h>
67 #include <sys/procdesc.h>
68 #include <sys/ptrace.h>
69 #include <sys/posix4.h>
70 #include <sys/racct.h>
71 #include <sys/resourcevar.h>
74 #include <sys/sleepqueue.h>
78 #include <sys/syscallsubr.h>
79 #include <sys/sysctl.h>
80 #include <sys/sysent.h>
81 #include <sys/syslog.h>
82 #include <sys/sysproto.h>
83 #include <sys/timers.h>
84 #include <sys/unistd.h>
87 #include <vm/vm_extern.h>
92 #include <machine/cpu.h>
94 #include <security/audit/audit.h>
96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
98 SDT_PROVIDER_DECLARE(proc);
99 SDT_PROBE_DEFINE3(proc, , , signal__send,
100 "struct thread *", "struct proc *", "int");
101 SDT_PROBE_DEFINE2(proc, , , signal__clear,
102 "int", "ksiginfo_t *");
103 SDT_PROBE_DEFINE3(proc, , , signal__discard,
104 "struct thread *", "struct proc *", "int");
106 static int coredump(struct thread *);
107 static int killpg1(struct thread *td, int sig, int pgid, int all,
109 static int issignal(struct thread *td);
110 static void reschedule_signals(struct proc *p, sigset_t block, int flags);
111 static int sigprop(int sig);
112 static void tdsigwakeup(struct thread *, int, sig_t, int);
113 static int sig_suspend_threads(struct thread *, struct proc *, int);
114 static int filt_sigattach(struct knote *kn);
115 static void filt_sigdetach(struct knote *kn);
116 static int filt_signal(struct knote *kn, long hint);
117 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock);
118 static void sigqueue_start(void);
120 static uma_zone_t ksiginfo_zone = NULL;
121 struct filterops sig_filtops = {
123 .f_attach = filt_sigattach,
124 .f_detach = filt_sigdetach,
125 .f_event = filt_signal,
128 static int kern_logsigexit = 1;
129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
131 "Log processes quitting on abnormal signals to syslog(3)");
133 static int kern_forcesigexit = 1;
134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW,
135 &kern_forcesigexit, 0, "Force trap signal to be handled");
137 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
138 "POSIX real time signal");
140 static int max_pending_per_proc = 128;
141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW,
142 &max_pending_per_proc, 0, "Max pending signals per proc");
144 static int preallocate_siginfo = 1024;
145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN,
146 &preallocate_siginfo, 0, "Preallocated signal memory size");
148 static int signal_overflow = 0;
149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD,
150 &signal_overflow, 0, "Number of signals overflew");
152 static int signal_alloc_fail = 0;
153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD,
154 &signal_alloc_fail, 0, "signals failed to be allocated");
156 static int kern_lognosys = 0;
157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0,
158 "Log invalid syscalls");
160 __read_frequently bool sigfastblock_fetch_always = false;
161 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN,
162 &sigfastblock_fetch_always, 0,
163 "Fetch sigfastblock word on each syscall entry for proper "
164 "blocking semantic");
166 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
169 * Policy -- Can ucred cr1 send SIGIO to process cr2?
170 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
171 * in the right situations.
173 #define CANSIGIO(cr1, cr2) \
174 ((cr1)->cr_uid == 0 || \
175 (cr1)->cr_ruid == (cr2)->cr_ruid || \
176 (cr1)->cr_uid == (cr2)->cr_ruid || \
177 (cr1)->cr_ruid == (cr2)->cr_uid || \
178 (cr1)->cr_uid == (cr2)->cr_uid)
180 static int sugid_coredump;
181 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN,
182 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core");
184 static int capmode_coredump;
185 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN,
186 &capmode_coredump, 0, "Allow processes in capability mode to dump core");
188 static int do_coredump = 1;
189 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
190 &do_coredump, 0, "Enable/Disable coredumps");
192 static int set_core_nodump_flag = 0;
193 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag,
194 0, "Enable setting the NODUMP flag on coredump files");
196 static int coredump_devctl = 0;
197 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl,
198 0, "Generate a devctl notification when processes coredump");
201 * Signal properties and actions.
202 * The array below categorizes the signals and their default actions
203 * according to the following properties:
205 #define SIGPROP_KILL 0x01 /* terminates process by default */
206 #define SIGPROP_CORE 0x02 /* ditto and coredumps */
207 #define SIGPROP_STOP 0x04 /* suspend process */
208 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */
209 #define SIGPROP_IGNORE 0x10 /* ignore by default */
210 #define SIGPROP_CONT 0x20 /* continue if suspended */
211 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */
213 static int sigproptbl[NSIG] = {
214 [SIGHUP] = SIGPROP_KILL,
215 [SIGINT] = SIGPROP_KILL,
216 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE,
217 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE,
218 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE,
219 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE,
220 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE,
221 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE,
222 [SIGKILL] = SIGPROP_KILL,
223 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE,
224 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE,
225 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE,
226 [SIGPIPE] = SIGPROP_KILL,
227 [SIGALRM] = SIGPROP_KILL,
228 [SIGTERM] = SIGPROP_KILL,
229 [SIGURG] = SIGPROP_IGNORE,
230 [SIGSTOP] = SIGPROP_STOP,
231 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP,
232 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT,
233 [SIGCHLD] = SIGPROP_IGNORE,
234 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP,
235 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP,
236 [SIGIO] = SIGPROP_IGNORE,
237 [SIGXCPU] = SIGPROP_KILL,
238 [SIGXFSZ] = SIGPROP_KILL,
239 [SIGVTALRM] = SIGPROP_KILL,
240 [SIGPROF] = SIGPROP_KILL,
241 [SIGWINCH] = SIGPROP_IGNORE,
242 [SIGINFO] = SIGPROP_IGNORE,
243 [SIGUSR1] = SIGPROP_KILL,
244 [SIGUSR2] = SIGPROP_KILL,
247 sigset_t fastblock_mask;
252 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t),
253 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
254 uma_prealloc(ksiginfo_zone, preallocate_siginfo);
255 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS);
256 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1);
257 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc);
258 SIGFILLSET(fastblock_mask);
259 SIG_CANTMASK(fastblock_mask);
263 ksiginfo_alloc(int wait)
270 if (ksiginfo_zone != NULL)
271 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags));
276 ksiginfo_free(ksiginfo_t *ksi)
278 uma_zfree(ksiginfo_zone, ksi);
282 ksiginfo_tryfree(ksiginfo_t *ksi)
284 if (!(ksi->ksi_flags & KSI_EXT)) {
285 uma_zfree(ksiginfo_zone, ksi);
292 sigqueue_init(sigqueue_t *list, struct proc *p)
294 SIGEMPTYSET(list->sq_signals);
295 SIGEMPTYSET(list->sq_kill);
296 SIGEMPTYSET(list->sq_ptrace);
297 TAILQ_INIT(&list->sq_list);
299 list->sq_flags = SQ_INIT;
303 * Get a signal's ksiginfo.
305 * 0 - signal not found
306 * others - signal number
309 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si)
311 struct proc *p = sq->sq_proc;
312 struct ksiginfo *ksi, *next;
315 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
317 if (!SIGISMEMBER(sq->sq_signals, signo))
320 if (SIGISMEMBER(sq->sq_ptrace, signo)) {
322 SIGDELSET(sq->sq_ptrace, signo);
323 si->ksi_flags |= KSI_PTRACE;
325 if (SIGISMEMBER(sq->sq_kill, signo)) {
328 SIGDELSET(sq->sq_kill, signo);
331 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
332 if (ksi->ksi_signo == signo) {
334 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
335 ksi->ksi_sigq = NULL;
336 ksiginfo_copy(ksi, si);
337 if (ksiginfo_tryfree(ksi) && p != NULL)
346 SIGDELSET(sq->sq_signals, signo);
347 si->ksi_signo = signo;
352 sigqueue_take(ksiginfo_t *ksi)
358 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL)
362 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
363 ksi->ksi_sigq = NULL;
364 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL)
367 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL;
368 kp = TAILQ_NEXT(kp, ksi_link)) {
369 if (kp->ksi_signo == ksi->ksi_signo)
372 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) &&
373 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo))
374 SIGDELSET(sq->sq_signals, ksi->ksi_signo);
378 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si)
380 struct proc *p = sq->sq_proc;
381 struct ksiginfo *ksi;
384 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
387 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path
390 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) {
391 SIGADDSET(sq->sq_kill, signo);
395 /* directly insert the ksi, don't copy it */
396 if (si->ksi_flags & KSI_INS) {
397 if (si->ksi_flags & KSI_HEAD)
398 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link);
400 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link);
405 if (__predict_false(ksiginfo_zone == NULL)) {
406 SIGADDSET(sq->sq_kill, signo);
410 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) {
413 } else if ((ksi = ksiginfo_alloc(0)) == NULL) {
419 ksiginfo_copy(si, ksi);
420 ksi->ksi_signo = signo;
421 if (si->ksi_flags & KSI_HEAD)
422 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link);
424 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link);
429 if ((si->ksi_flags & KSI_PTRACE) != 0) {
430 SIGADDSET(sq->sq_ptrace, signo);
433 } else if ((si->ksi_flags & KSI_TRAP) != 0 ||
434 (si->ksi_flags & KSI_SIGQ) == 0) {
435 SIGADDSET(sq->sq_kill, signo);
443 SIGADDSET(sq->sq_signals, signo);
448 sigqueue_flush(sigqueue_t *sq)
450 struct proc *p = sq->sq_proc;
453 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited"));
456 PROC_LOCK_ASSERT(p, MA_OWNED);
458 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) {
459 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
460 ksi->ksi_sigq = NULL;
461 if (ksiginfo_tryfree(ksi) && p != NULL)
465 SIGEMPTYSET(sq->sq_signals);
466 SIGEMPTYSET(sq->sq_kill);
467 SIGEMPTYSET(sq->sq_ptrace);
471 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set)
474 struct proc *p1, *p2;
475 ksiginfo_t *ksi, *next;
477 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited"));
478 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited"));
481 /* Move siginfo to target list */
482 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) {
483 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
484 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link);
487 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link);
494 /* Move pending bits to target list */
496 SIGSETAND(tmp, *set);
497 SIGSETOR(dst->sq_kill, tmp);
498 SIGSETNAND(src->sq_kill, tmp);
500 tmp = src->sq_ptrace;
501 SIGSETAND(tmp, *set);
502 SIGSETOR(dst->sq_ptrace, tmp);
503 SIGSETNAND(src->sq_ptrace, tmp);
505 tmp = src->sq_signals;
506 SIGSETAND(tmp, *set);
507 SIGSETOR(dst->sq_signals, tmp);
508 SIGSETNAND(src->sq_signals, tmp);
513 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo)
518 SIGADDSET(set, signo);
519 sigqueue_move_set(src, dst, &set);
524 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set)
526 struct proc *p = sq->sq_proc;
527 ksiginfo_t *ksi, *next;
529 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited"));
531 /* Remove siginfo queue */
532 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) {
533 if (SIGISMEMBER(*set, ksi->ksi_signo)) {
534 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link);
535 ksi->ksi_sigq = NULL;
536 if (ksiginfo_tryfree(ksi) && p != NULL)
540 SIGSETNAND(sq->sq_kill, *set);
541 SIGSETNAND(sq->sq_ptrace, *set);
542 SIGSETNAND(sq->sq_signals, *set);
546 sigqueue_delete(sigqueue_t *sq, int signo)
551 SIGADDSET(set, signo);
552 sigqueue_delete_set(sq, &set);
555 /* Remove a set of signals for a process */
557 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set)
562 PROC_LOCK_ASSERT(p, MA_OWNED);
564 sigqueue_init(&worklist, NULL);
565 sigqueue_move_set(&p->p_sigqueue, &worklist, set);
567 FOREACH_THREAD_IN_PROC(p, td0)
568 sigqueue_move_set(&td0->td_sigqueue, &worklist, set);
570 sigqueue_flush(&worklist);
574 sigqueue_delete_proc(struct proc *p, int signo)
579 SIGADDSET(set, signo);
580 sigqueue_delete_set_proc(p, &set);
584 sigqueue_delete_stopmask_proc(struct proc *p)
589 SIGADDSET(set, SIGSTOP);
590 SIGADDSET(set, SIGTSTP);
591 SIGADDSET(set, SIGTTIN);
592 SIGADDSET(set, SIGTTOU);
593 sigqueue_delete_set_proc(p, &set);
597 * Determine signal that should be delivered to thread td, the current
598 * thread, 0 if none. If there is a pending stop signal with default
599 * action, the process stops in issignal().
602 cursig(struct thread *td)
604 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
605 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
606 THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
607 return (SIGPENDING(td) ? issignal(td) : 0);
611 * Arrange for ast() to handle unmasked pending signals on return to user
612 * mode. This must be called whenever a signal is added to td_sigqueue or
613 * unmasked in td_sigmask.
616 signotify(struct thread *td)
619 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
621 if (SIGPENDING(td)) {
623 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
629 * Returns 1 (true) if altstack is configured for the thread, and the
630 * passed stack bottom address falls into the altstack range. Handles
631 * the 43 compat special case where the alt stack size is zero.
634 sigonstack(size_t sp)
639 if ((td->td_pflags & TDP_ALTSTACK) == 0)
641 #if defined(COMPAT_43)
642 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0)
643 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0);
645 return (sp >= (size_t)td->td_sigstk.ss_sp &&
646 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp);
653 if (sig > 0 && sig < nitems(sigproptbl))
654 return (sigproptbl[sig]);
659 sig_ffs(sigset_t *set)
663 for (i = 0; i < _SIG_WORDS; i++)
665 return (ffs(set->__bits[i]) + (i * 32));
670 sigact_flag_test(const struct sigaction *act, int flag)
674 * SA_SIGINFO is reset when signal disposition is set to
675 * ignore or default. Other flags are kept according to user
678 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO ||
679 ((__sighandler_t *)act->sa_sigaction != SIG_IGN &&
680 (__sighandler_t *)act->sa_sigaction != SIG_DFL)));
690 kern_sigaction(struct thread *td, int sig, const struct sigaction *act,
691 struct sigaction *oact, int flags)
694 struct proc *p = td->td_proc;
696 if (!_SIG_VALID(sig))
698 if (act != NULL && act->sa_handler != SIG_DFL &&
699 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK |
700 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER |
701 SA_NOCLDWAIT | SA_SIGINFO)) != 0)
706 mtx_lock(&ps->ps_mtx);
708 memset(oact, 0, sizeof(*oact));
709 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
710 if (SIGISMEMBER(ps->ps_sigonstack, sig))
711 oact->sa_flags |= SA_ONSTACK;
712 if (!SIGISMEMBER(ps->ps_sigintr, sig))
713 oact->sa_flags |= SA_RESTART;
714 if (SIGISMEMBER(ps->ps_sigreset, sig))
715 oact->sa_flags |= SA_RESETHAND;
716 if (SIGISMEMBER(ps->ps_signodefer, sig))
717 oact->sa_flags |= SA_NODEFER;
718 if (SIGISMEMBER(ps->ps_siginfo, sig)) {
719 oact->sa_flags |= SA_SIGINFO;
721 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)];
723 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
724 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
725 oact->sa_flags |= SA_NOCLDSTOP;
726 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
727 oact->sa_flags |= SA_NOCLDWAIT;
730 if ((sig == SIGKILL || sig == SIGSTOP) &&
731 act->sa_handler != SIG_DFL) {
732 mtx_unlock(&ps->ps_mtx);
738 * Change setting atomically.
741 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
742 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
743 if (sigact_flag_test(act, SA_SIGINFO)) {
744 ps->ps_sigact[_SIG_IDX(sig)] =
745 (__sighandler_t *)act->sa_sigaction;
746 SIGADDSET(ps->ps_siginfo, sig);
748 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
749 SIGDELSET(ps->ps_siginfo, sig);
751 if (!sigact_flag_test(act, SA_RESTART))
752 SIGADDSET(ps->ps_sigintr, sig);
754 SIGDELSET(ps->ps_sigintr, sig);
755 if (sigact_flag_test(act, SA_ONSTACK))
756 SIGADDSET(ps->ps_sigonstack, sig);
758 SIGDELSET(ps->ps_sigonstack, sig);
759 if (sigact_flag_test(act, SA_RESETHAND))
760 SIGADDSET(ps->ps_sigreset, sig);
762 SIGDELSET(ps->ps_sigreset, sig);
763 if (sigact_flag_test(act, SA_NODEFER))
764 SIGADDSET(ps->ps_signodefer, sig);
766 SIGDELSET(ps->ps_signodefer, sig);
767 if (sig == SIGCHLD) {
768 if (act->sa_flags & SA_NOCLDSTOP)
769 ps->ps_flag |= PS_NOCLDSTOP;
771 ps->ps_flag &= ~PS_NOCLDSTOP;
772 if (act->sa_flags & SA_NOCLDWAIT) {
774 * Paranoia: since SA_NOCLDWAIT is implemented
775 * by reparenting the dying child to PID 1 (and
776 * trust it to reap the zombie), PID 1 itself
777 * is forbidden to set SA_NOCLDWAIT.
780 ps->ps_flag &= ~PS_NOCLDWAIT;
782 ps->ps_flag |= PS_NOCLDWAIT;
784 ps->ps_flag &= ~PS_NOCLDWAIT;
785 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
786 ps->ps_flag |= PS_CLDSIGIGN;
788 ps->ps_flag &= ~PS_CLDSIGIGN;
791 * Set bit in ps_sigignore for signals that are set to SIG_IGN,
792 * and for signals set to SIG_DFL where the default is to
793 * ignore. However, don't put SIGCONT in ps_sigignore, as we
794 * have to restart the process.
796 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
797 (sigprop(sig) & SIGPROP_IGNORE &&
798 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
799 /* never to be seen again */
800 sigqueue_delete_proc(p, sig);
802 /* easier in psignal */
803 SIGADDSET(ps->ps_sigignore, sig);
804 SIGDELSET(ps->ps_sigcatch, sig);
806 SIGDELSET(ps->ps_sigignore, sig);
807 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
808 SIGDELSET(ps->ps_sigcatch, sig);
810 SIGADDSET(ps->ps_sigcatch, sig);
812 #ifdef COMPAT_FREEBSD4
813 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
814 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
815 (flags & KSA_FREEBSD4) == 0)
816 SIGDELSET(ps->ps_freebsd4, sig);
818 SIGADDSET(ps->ps_freebsd4, sig);
821 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
822 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
823 (flags & KSA_OSIGSET) == 0)
824 SIGDELSET(ps->ps_osigset, sig);
826 SIGADDSET(ps->ps_osigset, sig);
829 mtx_unlock(&ps->ps_mtx);
834 #ifndef _SYS_SYSPROTO_H_
835 struct sigaction_args {
837 struct sigaction *act;
838 struct sigaction *oact;
842 sys_sigaction(struct thread *td, struct sigaction_args *uap)
844 struct sigaction act, oact;
845 struct sigaction *actp, *oactp;
848 actp = (uap->act != NULL) ? &act : NULL;
849 oactp = (uap->oact != NULL) ? &oact : NULL;
851 error = copyin(uap->act, actp, sizeof(act));
855 error = kern_sigaction(td, uap->sig, actp, oactp, 0);
857 error = copyout(oactp, uap->oact, sizeof(oact));
861 #ifdef COMPAT_FREEBSD4
862 #ifndef _SYS_SYSPROTO_H_
863 struct freebsd4_sigaction_args {
865 struct sigaction *act;
866 struct sigaction *oact;
870 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap)
872 struct sigaction act, oact;
873 struct sigaction *actp, *oactp;
876 actp = (uap->act != NULL) ? &act : NULL;
877 oactp = (uap->oact != NULL) ? &oact : NULL;
879 error = copyin(uap->act, actp, sizeof(act));
883 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
885 error = copyout(oactp, uap->oact, sizeof(oact));
888 #endif /* COMAPT_FREEBSD4 */
890 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
891 #ifndef _SYS_SYSPROTO_H_
892 struct osigaction_args {
894 struct osigaction *nsa;
895 struct osigaction *osa;
899 osigaction(struct thread *td, struct osigaction_args *uap)
901 struct osigaction sa;
902 struct sigaction nsa, osa;
903 struct sigaction *nsap, *osap;
906 if (uap->signum <= 0 || uap->signum >= ONSIG)
909 nsap = (uap->nsa != NULL) ? &nsa : NULL;
910 osap = (uap->osa != NULL) ? &osa : NULL;
913 error = copyin(uap->nsa, &sa, sizeof(sa));
916 nsap->sa_handler = sa.sa_handler;
917 nsap->sa_flags = sa.sa_flags;
918 OSIG2SIG(sa.sa_mask, nsap->sa_mask);
920 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
921 if (osap && !error) {
922 sa.sa_handler = osap->sa_handler;
923 sa.sa_flags = osap->sa_flags;
924 SIG2OSIG(osap->sa_mask, sa.sa_mask);
925 error = copyout(&sa, uap->osa, sizeof(sa));
930 #if !defined(__i386__)
931 /* Avoid replicating the same stub everywhere */
933 osigreturn(struct thread *td, struct osigreturn_args *uap)
936 return (nosys(td, (struct nosys_args *)uap));
939 #endif /* COMPAT_43 */
942 * Initialize signal state for process 0;
943 * set to ignore signals that are ignored by default.
946 siginit(struct proc *p)
953 mtx_lock(&ps->ps_mtx);
954 for (i = 1; i <= NSIG; i++) {
955 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) {
956 SIGADDSET(ps->ps_sigignore, i);
959 mtx_unlock(&ps->ps_mtx);
964 * Reset specified signal to the default disposition.
967 sigdflt(struct sigacts *ps, int sig)
970 mtx_assert(&ps->ps_mtx, MA_OWNED);
971 SIGDELSET(ps->ps_sigcatch, sig);
972 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT)
973 SIGADDSET(ps->ps_sigignore, sig);
974 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
975 SIGDELSET(ps->ps_siginfo, sig);
979 * Reset signals for an exec of the specified process.
982 execsigs(struct proc *p)
990 * Reset caught signals. Held signals remain held
991 * through td_sigmask (unless they were caught,
992 * and are now ignored by default).
994 PROC_LOCK_ASSERT(p, MA_OWNED);
996 mtx_lock(&ps->ps_mtx);
1000 * As CloudABI processes cannot modify signal handlers, fully
1001 * reset all signals to their default behavior. Do ignore
1002 * SIGPIPE, as it would otherwise be impossible to recover from
1003 * writes to broken pipes and sockets.
1005 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) {
1006 osigignore = ps->ps_sigignore;
1007 while (SIGNOTEMPTY(osigignore)) {
1008 sig = sig_ffs(&osigignore);
1009 SIGDELSET(osigignore, sig);
1013 SIGADDSET(ps->ps_sigignore, SIGPIPE);
1017 * Reset stack state to the user stack.
1018 * Clear set of signals caught on the signal stack.
1021 MPASS(td->td_proc == p);
1022 td->td_sigstk.ss_flags = SS_DISABLE;
1023 td->td_sigstk.ss_size = 0;
1024 td->td_sigstk.ss_sp = 0;
1025 td->td_pflags &= ~TDP_ALTSTACK;
1027 * Reset no zombies if child dies flag as Solaris does.
1029 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
1030 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
1031 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
1032 mtx_unlock(&ps->ps_mtx);
1036 * kern_sigprocmask()
1038 * Manipulate signal mask.
1041 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset,
1044 sigset_t new_block, oset1;
1049 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0)
1050 PROC_LOCK_ASSERT(p, MA_OWNED);
1053 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0
1054 ? MA_OWNED : MA_NOTOWNED);
1056 *oset = td->td_sigmask;
1063 oset1 = td->td_sigmask;
1064 SIGSETOR(td->td_sigmask, *set);
1065 new_block = td->td_sigmask;
1066 SIGSETNAND(new_block, oset1);
1069 SIGSETNAND(td->td_sigmask, *set);
1074 oset1 = td->td_sigmask;
1075 if (flags & SIGPROCMASK_OLD)
1076 SIGSETLO(td->td_sigmask, *set);
1078 td->td_sigmask = *set;
1079 new_block = td->td_sigmask;
1080 SIGSETNAND(new_block, oset1);
1089 * The new_block set contains signals that were not previously
1090 * blocked, but are blocked now.
1092 * In case we block any signal that was not previously blocked
1093 * for td, and process has the signal pending, try to schedule
1094 * signal delivery to some thread that does not block the
1095 * signal, possibly waking it up.
1097 if (p->p_numthreads != 1)
1098 reschedule_signals(p, new_block, flags);
1102 if (!(flags & SIGPROCMASK_PROC_LOCKED))
1107 #ifndef _SYS_SYSPROTO_H_
1108 struct sigprocmask_args {
1110 const sigset_t *set;
1115 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap)
1118 sigset_t *setp, *osetp;
1121 setp = (uap->set != NULL) ? &set : NULL;
1122 osetp = (uap->oset != NULL) ? &oset : NULL;
1124 error = copyin(uap->set, setp, sizeof(set));
1128 error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
1129 if (osetp && !error) {
1130 error = copyout(osetp, uap->oset, sizeof(oset));
1135 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1136 #ifndef _SYS_SYSPROTO_H_
1137 struct osigprocmask_args {
1143 osigprocmask(struct thread *td, struct osigprocmask_args *uap)
1148 OSIG2SIG(uap->mask, set);
1149 error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
1150 SIG2OSIG(oset, td->td_retval[0]);
1153 #endif /* COMPAT_43 */
1156 sys_sigwait(struct thread *td, struct sigwait_args *uap)
1162 error = copyin(uap->set, &set, sizeof(set));
1164 td->td_retval[0] = error;
1168 error = kern_sigtimedwait(td, set, &ksi, NULL);
1170 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT)
1172 if (error == ERESTART)
1174 td->td_retval[0] = error;
1178 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo));
1179 td->td_retval[0] = error;
1184 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
1187 struct timespec *timeout;
1193 error = copyin(uap->timeout, &ts, sizeof(ts));
1201 error = copyin(uap->set, &set, sizeof(set));
1205 error = kern_sigtimedwait(td, set, &ksi, timeout);
1210 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1213 td->td_retval[0] = ksi.ksi_signo;
1218 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
1224 error = copyin(uap->set, &set, sizeof(set));
1228 error = kern_sigtimedwait(td, set, &ksi, NULL);
1233 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t));
1236 td->td_retval[0] = ksi.ksi_signo;
1241 proc_td_siginfo_capture(struct thread *td, siginfo_t *si)
1245 FOREACH_THREAD_IN_PROC(td->td_proc, thr) {
1249 thr->td_si.si_signo = 0;
1254 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi,
1255 struct timespec *timeout)
1258 sigset_t saved_mask, new_block;
1260 int error, sig, timo, timevalid = 0;
1261 struct timespec rts, ets, ts;
1271 if (timeout != NULL) {
1272 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) {
1274 getnanouptime(&rts);
1275 timespecadd(&rts, timeout, &ets);
1279 /* Some signals can not be waited for. */
1280 SIG_CANTMASK(waitset);
1283 saved_mask = td->td_sigmask;
1284 SIGSETNAND(td->td_sigmask, waitset);
1286 mtx_lock(&ps->ps_mtx);
1288 mtx_unlock(&ps->ps_mtx);
1289 KASSERT(sig >= 0, ("sig %d", sig));
1290 if (sig != 0 && SIGISMEMBER(waitset, sig)) {
1291 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 ||
1292 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) {
1302 * POSIX says this must be checked after looking for pending
1305 if (timeout != NULL) {
1310 getnanouptime(&rts);
1311 if (timespeccmp(&rts, &ets, >=)) {
1315 timespecsub(&ets, &rts, &ts);
1316 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1327 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
1329 if (timeout != NULL) {
1330 if (error == ERESTART) {
1331 /* Timeout can not be restarted. */
1333 } else if (error == EAGAIN) {
1334 /* We will calculate timeout by ourself. */
1340 * If PTRACE_SCE or PTRACE_SCX were set after
1341 * userspace entered the syscall, return spurious
1342 * EINTR after wait was done. Only do this as last
1343 * resort after rechecking for possible queued signals
1344 * and expired timeouts.
1346 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0)
1350 new_block = saved_mask;
1351 SIGSETNAND(new_block, td->td_sigmask);
1352 td->td_sigmask = saved_mask;
1354 * Fewer signals can be delivered to us, reschedule signal
1357 if (p->p_numthreads != 1)
1358 reschedule_signals(p, new_block, 0);
1361 SDT_PROBE2(proc, , , signal__clear, sig, ksi);
1363 if (ksi->ksi_code == SI_TIMER)
1364 itimer_accept(p, ksi->ksi_timerid, ksi);
1367 if (KTRPOINT(td, KTR_PSIG)) {
1370 mtx_lock(&ps->ps_mtx);
1371 action = ps->ps_sigact[_SIG_IDX(sig)];
1372 mtx_unlock(&ps->ps_mtx);
1373 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code);
1376 if (sig == SIGKILL) {
1377 proc_td_siginfo_capture(td, &ksi->ksi_info);
1385 #ifndef _SYS_SYSPROTO_H_
1386 struct sigpending_args {
1391 sys_sigpending(struct thread *td, struct sigpending_args *uap)
1393 struct proc *p = td->td_proc;
1397 pending = p->p_sigqueue.sq_signals;
1398 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1400 return (copyout(&pending, uap->set, sizeof(sigset_t)));
1403 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1404 #ifndef _SYS_SYSPROTO_H_
1405 struct osigpending_args {
1410 osigpending(struct thread *td, struct osigpending_args *uap)
1412 struct proc *p = td->td_proc;
1416 pending = p->p_sigqueue.sq_signals;
1417 SIGSETOR(pending, td->td_sigqueue.sq_signals);
1419 SIG2OSIG(pending, td->td_retval[0]);
1422 #endif /* COMPAT_43 */
1424 #if defined(COMPAT_43)
1426 * Generalized interface signal handler, 4.3-compatible.
1428 #ifndef _SYS_SYSPROTO_H_
1429 struct osigvec_args {
1437 osigvec(struct thread *td, struct osigvec_args *uap)
1440 struct sigaction nsa, osa;
1441 struct sigaction *nsap, *osap;
1444 if (uap->signum <= 0 || uap->signum >= ONSIG)
1446 nsap = (uap->nsv != NULL) ? &nsa : NULL;
1447 osap = (uap->osv != NULL) ? &osa : NULL;
1449 error = copyin(uap->nsv, &vec, sizeof(vec));
1452 nsap->sa_handler = vec.sv_handler;
1453 OSIG2SIG(vec.sv_mask, nsap->sa_mask);
1454 nsap->sa_flags = vec.sv_flags;
1455 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
1457 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
1458 if (osap && !error) {
1459 vec.sv_handler = osap->sa_handler;
1460 SIG2OSIG(osap->sa_mask, vec.sv_mask);
1461 vec.sv_flags = osap->sa_flags;
1462 vec.sv_flags &= ~SA_NOCLDWAIT;
1463 vec.sv_flags ^= SA_RESTART;
1464 error = copyout(&vec, uap->osv, sizeof(vec));
1469 #ifndef _SYS_SYSPROTO_H_
1470 struct osigblock_args {
1475 osigblock(struct thread *td, struct osigblock_args *uap)
1479 OSIG2SIG(uap->mask, set);
1480 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0);
1481 SIG2OSIG(oset, td->td_retval[0]);
1485 #ifndef _SYS_SYSPROTO_H_
1486 struct osigsetmask_args {
1491 osigsetmask(struct thread *td, struct osigsetmask_args *uap)
1495 OSIG2SIG(uap->mask, set);
1496 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0);
1497 SIG2OSIG(oset, td->td_retval[0]);
1500 #endif /* COMPAT_43 */
1503 * Suspend calling thread until signal, providing mask to be set in the
1506 #ifndef _SYS_SYSPROTO_H_
1507 struct sigsuspend_args {
1508 const sigset_t *sigmask;
1513 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap)
1518 error = copyin(uap->sigmask, &mask, sizeof(mask));
1521 return (kern_sigsuspend(td, mask));
1525 kern_sigsuspend(struct thread *td, sigset_t mask)
1527 struct proc *p = td->td_proc;
1531 * When returning from sigsuspend, we want
1532 * the old mask to be restored after the
1533 * signal handler has finished. Thus, we
1534 * save it here and mark the sigacts structure
1538 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask,
1539 SIGPROCMASK_PROC_LOCKED);
1540 td->td_pflags |= TDP_OLDMASK;
1543 * Process signals now. Otherwise, we can get spurious wakeup
1544 * due to signal entered process queue, but delivered to other
1545 * thread. But sigsuspend should return only on signal
1548 (p->p_sysent->sv_set_syscall_retval)(td, EINTR);
1549 for (has_sig = 0; !has_sig;) {
1550 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause",
1553 thread_suspend_check(0);
1554 mtx_lock(&p->p_sigacts->ps_mtx);
1555 while ((sig = cursig(td)) != 0) {
1556 KASSERT(sig >= 0, ("sig %d", sig));
1557 has_sig += postsig(sig);
1559 mtx_unlock(&p->p_sigacts->ps_mtx);
1562 * If PTRACE_SCE or PTRACE_SCX were set after
1563 * userspace entered the syscall, return spurious
1566 if ((p->p_ptevents & PTRACE_SYSCALL) != 0)
1570 td->td_errno = EINTR;
1571 td->td_pflags |= TDP_NERRNO;
1572 return (EJUSTRETURN);
1575 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
1577 * Compatibility sigsuspend call for old binaries. Note nonstandard calling
1578 * convention: libc stub passes mask, not pointer, to save a copyin.
1580 #ifndef _SYS_SYSPROTO_H_
1581 struct osigsuspend_args {
1587 osigsuspend(struct thread *td, struct osigsuspend_args *uap)
1591 OSIG2SIG(uap->mask, mask);
1592 return (kern_sigsuspend(td, mask));
1594 #endif /* COMPAT_43 */
1596 #if defined(COMPAT_43)
1597 #ifndef _SYS_SYSPROTO_H_
1598 struct osigstack_args {
1599 struct sigstack *nss;
1600 struct sigstack *oss;
1605 osigstack(struct thread *td, struct osigstack_args *uap)
1607 struct sigstack nss, oss;
1610 if (uap->nss != NULL) {
1611 error = copyin(uap->nss, &nss, sizeof(nss));
1615 oss.ss_sp = td->td_sigstk.ss_sp;
1616 oss.ss_onstack = sigonstack(cpu_getstack(td));
1617 if (uap->nss != NULL) {
1618 td->td_sigstk.ss_sp = nss.ss_sp;
1619 td->td_sigstk.ss_size = 0;
1620 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
1621 td->td_pflags |= TDP_ALTSTACK;
1623 if (uap->oss != NULL)
1624 error = copyout(&oss, uap->oss, sizeof(oss));
1628 #endif /* COMPAT_43 */
1630 #ifndef _SYS_SYSPROTO_H_
1631 struct sigaltstack_args {
1638 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap)
1643 if (uap->ss != NULL) {
1644 error = copyin(uap->ss, &ss, sizeof(ss));
1648 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
1649 (uap->oss != NULL) ? &oss : NULL);
1652 if (uap->oss != NULL)
1653 error = copyout(&oss, uap->oss, sizeof(stack_t));
1658 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1660 struct proc *p = td->td_proc;
1663 oonstack = sigonstack(cpu_getstack(td));
1666 *oss = td->td_sigstk;
1667 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
1668 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
1674 if ((ss->ss_flags & ~SS_DISABLE) != 0)
1676 if (!(ss->ss_flags & SS_DISABLE)) {
1677 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
1680 td->td_sigstk = *ss;
1681 td->td_pflags |= TDP_ALTSTACK;
1683 td->td_pflags &= ~TDP_ALTSTACK;
1689 struct killpg1_ctx {
1699 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg)
1703 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 ||
1704 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW)
1707 err = p_cansignal(arg->td, p, arg->sig);
1708 if (err == 0 && arg->sig != 0)
1709 pksignal(p, arg->sig, arg->ksi);
1715 else if (arg->ret == 0 && err != ESRCH && err != EPERM)
1720 * Common code for kill process group/broadcast kill.
1721 * cp is calling process.
1724 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi)
1728 struct killpg1_ctx arg;
1740 sx_slock(&allproc_lock);
1741 FOREACH_PROC_IN_SYSTEM(p) {
1742 killpg1_sendsig(p, true, &arg);
1744 sx_sunlock(&allproc_lock);
1746 sx_slock(&proctree_lock);
1749 * zero pgid means send to my process group.
1751 pgrp = td->td_proc->p_pgrp;
1754 pgrp = pgfind(pgid);
1756 sx_sunlock(&proctree_lock);
1760 sx_sunlock(&proctree_lock);
1761 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1762 killpg1_sendsig(p, false, &arg);
1766 MPASS(arg.ret != 0 || arg.found || !arg.sent);
1767 if (arg.ret == 0 && !arg.sent)
1768 arg.ret = arg.found ? EPERM : ESRCH;
1772 #ifndef _SYS_SYSPROTO_H_
1780 sys_kill(struct thread *td, struct kill_args *uap)
1783 return (kern_kill(td, uap->pid, uap->signum));
1787 kern_kill(struct thread *td, pid_t pid, int signum)
1794 * A process in capability mode can send signals only to himself.
1795 * The main rationale behind this is that abort(3) is implemented as
1796 * kill(getpid(), SIGABRT).
1798 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid)
1801 AUDIT_ARG_SIGNUM(signum);
1803 if ((u_int)signum > _SIG_MAXSIG)
1806 ksiginfo_init(&ksi);
1807 ksi.ksi_signo = signum;
1808 ksi.ksi_code = SI_USER;
1809 ksi.ksi_pid = td->td_proc->p_pid;
1810 ksi.ksi_uid = td->td_ucred->cr_ruid;
1813 /* kill single process */
1814 if ((p = pfind_any(pid)) == NULL)
1816 AUDIT_ARG_PROCESS(p);
1817 error = p_cansignal(td, p, signum);
1818 if (error == 0 && signum)
1819 pksignal(p, signum, &ksi);
1824 case -1: /* broadcast signal */
1825 return (killpg1(td, signum, 0, 1, &ksi));
1826 case 0: /* signal own process group */
1827 return (killpg1(td, signum, 0, 0, &ksi));
1828 default: /* negative explicit process group */
1829 return (killpg1(td, signum, -pid, 0, &ksi));
1835 sys_pdkill(struct thread *td, struct pdkill_args *uap)
1840 AUDIT_ARG_SIGNUM(uap->signum);
1841 AUDIT_ARG_FD(uap->fd);
1842 if ((u_int)uap->signum > _SIG_MAXSIG)
1845 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p);
1848 AUDIT_ARG_PROCESS(p);
1849 error = p_cansignal(td, p, uap->signum);
1850 if (error == 0 && uap->signum)
1851 kern_psignal(p, uap->signum);
1856 #if defined(COMPAT_43)
1857 #ifndef _SYS_SYSPROTO_H_
1858 struct okillpg_args {
1865 okillpg(struct thread *td, struct okillpg_args *uap)
1869 AUDIT_ARG_SIGNUM(uap->signum);
1870 AUDIT_ARG_PID(uap->pgid);
1871 if ((u_int)uap->signum > _SIG_MAXSIG)
1874 ksiginfo_init(&ksi);
1875 ksi.ksi_signo = uap->signum;
1876 ksi.ksi_code = SI_USER;
1877 ksi.ksi_pid = td->td_proc->p_pid;
1878 ksi.ksi_uid = td->td_ucred->cr_ruid;
1879 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi));
1881 #endif /* COMPAT_43 */
1883 #ifndef _SYS_SYSPROTO_H_
1884 struct sigqueue_args {
1887 /* union sigval */ void *value;
1891 sys_sigqueue(struct thread *td, struct sigqueue_args *uap)
1895 sv.sival_ptr = uap->value;
1897 return (kern_sigqueue(td, uap->pid, uap->signum, &sv));
1901 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value)
1907 if ((u_int)signum > _SIG_MAXSIG)
1911 * Specification says sigqueue can only send signal to
1917 if ((p = pfind_any(pid)) == NULL)
1919 error = p_cansignal(td, p, signum);
1920 if (error == 0 && signum != 0) {
1921 ksiginfo_init(&ksi);
1922 ksi.ksi_flags = KSI_SIGQ;
1923 ksi.ksi_signo = signum;
1924 ksi.ksi_code = SI_QUEUE;
1925 ksi.ksi_pid = td->td_proc->p_pid;
1926 ksi.ksi_uid = td->td_ucred->cr_ruid;
1927 ksi.ksi_value = *value;
1928 error = pksignal(p, ksi.ksi_signo, &ksi);
1935 * Send a signal to a process group.
1938 gsignal(int pgid, int sig, ksiginfo_t *ksi)
1943 sx_slock(&proctree_lock);
1944 pgrp = pgfind(pgid);
1945 sx_sunlock(&proctree_lock);
1947 pgsignal(pgrp, sig, 0, ksi);
1954 * Send a signal to a process group. If checktty is 1,
1955 * limit to members which have a controlling terminal.
1958 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi)
1963 PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
1964 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1966 if (p->p_state == PRS_NORMAL &&
1967 (checkctty == 0 || p->p_flag & P_CONTROLT))
1968 pksignal(p, sig, ksi);
1975 * Recalculate the signal mask and reset the signal disposition after
1976 * usermode frame for delivery is formed. Should be called after
1977 * mach-specific routine, because sysent->sv_sendsig() needs correct
1978 * ps_siginfo and signal mask.
1981 postsig_done(int sig, struct thread *td, struct sigacts *ps)
1985 mtx_assert(&ps->ps_mtx, MA_OWNED);
1986 td->td_ru.ru_nsignals++;
1987 mask = ps->ps_catchmask[_SIG_IDX(sig)];
1988 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1989 SIGADDSET(mask, sig);
1990 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL,
1991 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED);
1992 if (SIGISMEMBER(ps->ps_sigreset, sig))
1997 * Send a signal caused by a trap to the current thread. If it will be
1998 * caught immediately, deliver it with correct code. Otherwise, post it
2002 trapsignal(struct thread *td, ksiginfo_t *ksi)
2010 sig = ksi->ksi_signo;
2011 code = ksi->ksi_code;
2012 KASSERT(_SIG_VALID(sig), ("invalid signal"));
2014 sigfastblock_fetch(td);
2017 mtx_lock(&ps->ps_mtx);
2018 sigmask = td->td_sigmask;
2019 if (td->td_sigblock_val != 0)
2020 SIGSETOR(sigmask, fastblock_mask);
2021 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
2022 !SIGISMEMBER(sigmask, sig)) {
2024 if (KTRPOINT(curthread, KTR_PSIG))
2025 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
2026 &td->td_sigmask, code);
2028 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)],
2029 ksi, &td->td_sigmask);
2030 postsig_done(sig, td, ps);
2031 mtx_unlock(&ps->ps_mtx);
2034 * Avoid a possible infinite loop if the thread
2035 * masking the signal or process is ignoring the
2038 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) ||
2039 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) {
2040 SIGDELSET(td->td_sigmask, sig);
2041 SIGDELSET(ps->ps_sigcatch, sig);
2042 SIGDELSET(ps->ps_sigignore, sig);
2043 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2044 td->td_pflags &= ~TDP_SIGFASTBLOCK;
2045 td->td_sigblock_val = 0;
2047 mtx_unlock(&ps->ps_mtx);
2048 p->p_sig = sig; /* XXX to verify code */
2049 tdsendsignal(p, td, sig, ksi);
2054 static struct thread *
2055 sigtd(struct proc *p, int sig, bool fast_sigblock)
2057 struct thread *td, *signal_td;
2059 PROC_LOCK_ASSERT(p, MA_OWNED);
2060 MPASS(!fast_sigblock || p == curproc);
2063 * Check if current thread can handle the signal without
2064 * switching context to another thread.
2066 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) &&
2067 (!fast_sigblock || curthread->td_sigblock_val == 0))
2070 FOREACH_THREAD_IN_PROC(p, td) {
2071 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock ||
2072 td != curthread || td->td_sigblock_val == 0)) {
2077 if (signal_td == NULL)
2078 signal_td = FIRST_THREAD_IN_PROC(p);
2083 * Send the signal to the process. If the signal has an action, the action
2084 * is usually performed by the target process rather than the caller; we add
2085 * the signal to the set of pending signals for the process.
2088 * o When a stop signal is sent to a sleeping process that takes the
2089 * default action, the process is stopped without awakening it.
2090 * o SIGCONT restarts stopped processes (or puts them back to sleep)
2091 * regardless of the signal action (eg, blocked or ignored).
2093 * Other ignored signals are discarded immediately.
2095 * NB: This function may be entered from the debugger via the "kill" DDB
2096 * command. There is little that can be done to mitigate the possibly messy
2097 * side effects of this unwise possibility.
2100 kern_psignal(struct proc *p, int sig)
2104 ksiginfo_init(&ksi);
2105 ksi.ksi_signo = sig;
2106 ksi.ksi_code = SI_KERNEL;
2107 (void) tdsendsignal(p, NULL, sig, &ksi);
2111 pksignal(struct proc *p, int sig, ksiginfo_t *ksi)
2114 return (tdsendsignal(p, NULL, sig, ksi));
2117 /* Utility function for finding a thread to send signal event to. */
2119 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd)
2123 if (sigev->sigev_notify == SIGEV_THREAD_ID) {
2124 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid);
2136 tdsignal(struct thread *td, int sig)
2140 ksiginfo_init(&ksi);
2141 ksi.ksi_signo = sig;
2142 ksi.ksi_code = SI_KERNEL;
2143 (void) tdsendsignal(td->td_proc, td, sig, &ksi);
2147 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi)
2150 (void) tdsendsignal(td->td_proc, td, sig, ksi);
2154 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi)
2157 sigqueue_t *sigqueue;
2164 MPASS(td == NULL || p == td->td_proc);
2165 PROC_LOCK_ASSERT(p, MA_OWNED);
2167 if (!_SIG_VALID(sig))
2168 panic("%s(): invalid signal %d", __func__, sig);
2170 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__));
2173 * IEEE Std 1003.1-2001: return success when killing a zombie.
2175 if (p->p_state == PRS_ZOMBIE) {
2176 if (ksi && (ksi->ksi_flags & KSI_INS))
2177 ksiginfo_tryfree(ksi);
2182 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig);
2183 prop = sigprop(sig);
2186 td = sigtd(p, sig, false);
2187 sigqueue = &p->p_sigqueue;
2189 sigqueue = &td->td_sigqueue;
2191 SDT_PROBE3(proc, , , signal__send, td, p, sig);
2194 * If the signal is being ignored,
2195 * then we forget about it immediately.
2196 * (Note: we don't set SIGCONT in ps_sigignore,
2197 * and if it is set to SIG_IGN,
2198 * action will be SIG_DFL here.)
2200 mtx_lock(&ps->ps_mtx);
2201 if (SIGISMEMBER(ps->ps_sigignore, sig)) {
2202 SDT_PROBE3(proc, , , signal__discard, td, p, sig);
2204 mtx_unlock(&ps->ps_mtx);
2205 if (ksi && (ksi->ksi_flags & KSI_INS))
2206 ksiginfo_tryfree(ksi);
2209 if (SIGISMEMBER(td->td_sigmask, sig))
2211 else if (SIGISMEMBER(ps->ps_sigcatch, sig))
2215 if (SIGISMEMBER(ps->ps_sigintr, sig))
2219 mtx_unlock(&ps->ps_mtx);
2221 if (prop & SIGPROP_CONT)
2222 sigqueue_delete_stopmask_proc(p);
2223 else if (prop & SIGPROP_STOP) {
2225 * If sending a tty stop signal to a member of an orphaned
2226 * process group, discard the signal here if the action
2227 * is default; don't stop the process below if sleeping,
2228 * and don't clear any pending SIGCONT.
2230 if ((prop & SIGPROP_TTYSTOP) &&
2231 (p->p_pgrp->pg_jobc == 0) &&
2232 (action == SIG_DFL)) {
2233 if (ksi && (ksi->ksi_flags & KSI_INS))
2234 ksiginfo_tryfree(ksi);
2237 sigqueue_delete_proc(p, SIGCONT);
2238 if (p->p_flag & P_CONTINUED) {
2239 p->p_flag &= ~P_CONTINUED;
2240 PROC_LOCK(p->p_pptr);
2241 sigqueue_take(p->p_ksi);
2242 PROC_UNLOCK(p->p_pptr);
2246 ret = sigqueue_add(sigqueue, sig, ksi);
2251 * Defer further processing for signals which are held,
2252 * except that stopped processes must be continued by SIGCONT.
2254 if (action == SIG_HOLD &&
2255 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG)))
2261 * Some signals have a process-wide effect and a per-thread
2262 * component. Most processing occurs when the process next
2263 * tries to cross the user boundary, however there are some
2264 * times when processing needs to be done immediately, such as
2265 * waking up threads so that they can cross the user boundary.
2266 * We try to do the per-process part here.
2268 if (P_SHOULDSTOP(p)) {
2269 KASSERT(!(p->p_flag & P_WEXIT),
2270 ("signal to stopped but exiting process"));
2271 if (sig == SIGKILL) {
2273 * If traced process is already stopped,
2274 * then no further action is necessary.
2276 if (p->p_flag & P_TRACED)
2279 * SIGKILL sets process running.
2280 * It will die elsewhere.
2281 * All threads must be restarted.
2283 p->p_flag &= ~P_STOPPED_SIG;
2287 if (prop & SIGPROP_CONT) {
2289 * If traced process is already stopped,
2290 * then no further action is necessary.
2292 if (p->p_flag & P_TRACED)
2295 * If SIGCONT is default (or ignored), we continue the
2296 * process but don't leave the signal in sigqueue as
2297 * it has no further action. If SIGCONT is held, we
2298 * continue the process and leave the signal in
2299 * sigqueue. If the process catches SIGCONT, let it
2300 * handle the signal itself. If it isn't waiting on
2301 * an event, it goes back to run state.
2302 * Otherwise, process goes back to sleep state.
2304 p->p_flag &= ~P_STOPPED_SIG;
2306 if (p->p_numthreads == p->p_suspcount) {
2308 p->p_flag |= P_CONTINUED;
2309 p->p_xsig = SIGCONT;
2310 PROC_LOCK(p->p_pptr);
2311 childproc_continued(p);
2312 PROC_UNLOCK(p->p_pptr);
2315 if (action == SIG_DFL) {
2316 thread_unsuspend(p);
2318 sigqueue_delete(sigqueue, sig);
2321 if (action == SIG_CATCH) {
2323 * The process wants to catch it so it needs
2324 * to run at least one thread, but which one?
2330 * The signal is not ignored or caught.
2332 thread_unsuspend(p);
2337 if (prop & SIGPROP_STOP) {
2339 * If traced process is already stopped,
2340 * then no further action is necessary.
2342 if (p->p_flag & P_TRACED)
2345 * Already stopped, don't need to stop again
2346 * (If we did the shell could get confused).
2347 * Just make sure the signal STOP bit set.
2349 p->p_flag |= P_STOPPED_SIG;
2350 sigqueue_delete(sigqueue, sig);
2355 * All other kinds of signals:
2356 * If a thread is sleeping interruptibly, simulate a
2357 * wakeup so that when it is continued it will be made
2358 * runnable and can look at the signal. However, don't make
2359 * the PROCESS runnable, leave it stopped.
2360 * It may run a bit until it hits a thread_suspend_check().
2364 if (TD_CAN_ABORT(td))
2365 wakeup_swapper = sleepq_abort(td, intrval);
2371 * Mutexes are short lived. Threads waiting on them will
2372 * hit thread_suspend_check() soon.
2374 } else if (p->p_state == PRS_NORMAL) {
2375 if (p->p_flag & P_TRACED || action == SIG_CATCH) {
2376 tdsigwakeup(td, sig, action, intrval);
2380 MPASS(action == SIG_DFL);
2382 if (prop & SIGPROP_STOP) {
2383 if (p->p_flag & (P_PPWAIT|P_WEXIT))
2385 p->p_flag |= P_STOPPED_SIG;
2388 wakeup_swapper = sig_suspend_threads(td, p, 1);
2389 if (p->p_numthreads == p->p_suspcount) {
2391 * only thread sending signal to another
2392 * process can reach here, if thread is sending
2393 * signal to its process, because thread does
2394 * not suspend itself here, p_numthreads
2395 * should never be equal to p_suspcount.
2399 sigqueue_delete_proc(p, p->p_xsig);
2405 /* Not in "NORMAL" state. discard the signal. */
2406 sigqueue_delete(sigqueue, sig);
2411 * The process is not stopped so we need to apply the signal to all the
2415 tdsigwakeup(td, sig, action, intrval);
2417 thread_unsuspend(p);
2420 /* If we jump here, proc slock should not be owned. */
2421 PROC_SLOCK_ASSERT(p, MA_NOTOWNED);
2429 * The force of a signal has been directed against a single
2430 * thread. We need to see what we can do about knocking it
2431 * out of any sleep it may be in etc.
2434 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
2436 struct proc *p = td->td_proc;
2437 int prop, wakeup_swapper;
2439 PROC_LOCK_ASSERT(p, MA_OWNED);
2440 prop = sigprop(sig);
2445 * Bring the priority of a thread up if we want it to get
2446 * killed in this lifetime. Be careful to avoid bumping the
2447 * priority of the idle thread, since we still allow to signal
2450 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 &&
2451 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
2452 sched_prio(td, PUSER);
2453 if (TD_ON_SLEEPQ(td)) {
2455 * If thread is sleeping uninterruptibly
2456 * we can't interrupt the sleep... the signal will
2457 * be noticed when the process returns through
2458 * trap() or syscall().
2460 if ((td->td_flags & TDF_SINTR) == 0)
2463 * If SIGCONT is default (or ignored) and process is
2464 * asleep, we are finished; the process should not
2467 if ((prop & SIGPROP_CONT) && action == SIG_DFL) {
2470 sigqueue_delete(&p->p_sigqueue, sig);
2472 * It may be on either list in this state.
2473 * Remove from both for now.
2475 sigqueue_delete(&td->td_sigqueue, sig);
2480 * Don't awaken a sleeping thread for SIGSTOP if the
2481 * STOP signal is deferred.
2483 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY |
2484 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY)
2488 * Give low priority threads a better chance to run.
2490 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td))
2491 sched_prio(td, PUSER);
2493 wakeup_swapper = sleepq_abort(td, intrval);
2501 * Other states do nothing with the signal immediately,
2502 * other than kicking ourselves if we are running.
2503 * It will either never be noticed, or noticed very soon.
2506 if (TD_IS_RUNNING(td) && td != curthread)
2516 sig_suspend_threads(struct thread *td, struct proc *p, int sending)
2521 PROC_LOCK_ASSERT(p, MA_OWNED);
2522 PROC_SLOCK_ASSERT(p, MA_OWNED);
2523 MPASS(sending || td == curthread);
2526 FOREACH_THREAD_IN_PROC(p, td2) {
2528 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
2529 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
2530 (td2->td_flags & TDF_SINTR)) {
2531 if (td2->td_flags & TDF_SBDRY) {
2533 * Once a thread is asleep with
2534 * TDF_SBDRY and without TDF_SERESTART
2535 * or TDF_SEINTR set, it should never
2536 * become suspended due to this check.
2538 KASSERT(!TD_IS_SUSPENDED(td2),
2539 ("thread with deferred stops suspended"));
2540 if (TD_SBDRY_INTR(td2)) {
2541 wakeup_swapper |= sleepq_abort(td2,
2542 TD_SBDRY_ERRNO(td2));
2545 } else if (!TD_IS_SUSPENDED(td2))
2546 thread_suspend_one(td2);
2547 } else if (!TD_IS_SUSPENDED(td2)) {
2548 if (sending || td != td2)
2549 td2->td_flags |= TDF_ASTPENDING;
2551 if (TD_IS_RUNNING(td2) && td2 != td)
2552 forward_signal(td2);
2557 return (wakeup_swapper);
2561 * Stop the process for an event deemed interesting to the debugger. If si is
2562 * non-NULL, this is a signal exchange; the new signal requested by the
2563 * debugger will be returned for handling. If si is NULL, this is some other
2564 * type of interesting event. The debugger may request a signal be delivered in
2565 * that case as well, however it will be deferred until it can be handled.
2568 ptracestop(struct thread *td, int sig, ksiginfo_t *si)
2570 struct proc *p = td->td_proc;
2574 PROC_LOCK_ASSERT(p, MA_OWNED);
2575 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process"));
2576 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2577 &p->p_mtx.lock_object, "Stopping for traced signal");
2581 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) {
2582 td->td_dbgflags |= TDB_XSIG;
2583 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d",
2584 td->td_tid, p->p_pid, td->td_dbgflags, sig);
2586 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
2589 * Ensure that, if we've been PT_KILLed, the
2590 * exit status reflects that. Another thread
2591 * may also be in ptracestop(), having just
2592 * received the SIGKILL, but this thread was
2593 * unsuspended first.
2595 td->td_dbgflags &= ~TDB_XSIG;
2596 td->td_xsig = SIGKILL;
2600 if (p->p_flag & P_SINGLE_EXIT &&
2601 !(td->td_dbgflags & TDB_EXIT)) {
2603 * Ignore ptrace stops except for thread exit
2604 * events when the process exits.
2606 td->td_dbgflags &= ~TDB_XSIG;
2612 * Make wait(2) work. Ensure that right after the
2613 * attach, the thread which was decided to become the
2614 * leader of attach gets reported to the waiter.
2615 * Otherwise, just avoid overwriting another thread's
2616 * assignment to p_xthread. If another thread has
2617 * already set p_xthread, the current thread will get
2618 * a chance to report itself upon the next iteration.
2620 if ((td->td_dbgflags & TDB_FSTP) != 0 ||
2621 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 &&
2622 p->p_xthread == NULL)) {
2627 * If we are on sleepqueue already,
2628 * let sleepqueue code decide if it
2629 * needs to go sleep after attach.
2631 if (td->td_wchan == NULL)
2632 td->td_dbgflags &= ~TDB_FSTP;
2634 p->p_flag2 &= ~P2_PTRACE_FSTP;
2635 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE;
2636 sig_suspend_threads(td, p, 0);
2638 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) {
2639 td->td_dbgflags &= ~TDB_STOPATFORK;
2642 thread_suspend_switch(td, p);
2643 if (p->p_xthread == td)
2644 p->p_xthread = NULL;
2645 if (!(p->p_flag & P_TRACED))
2647 if (td->td_dbgflags & TDB_SUSPEND) {
2648 if (p->p_flag & P_SINGLE_EXIT)
2656 if (si != NULL && sig == td->td_xsig) {
2657 /* Parent wants us to take the original signal unchanged. */
2658 si->ksi_flags |= KSI_HEAD;
2659 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0)
2661 } else if (td->td_xsig != 0) {
2663 * If parent wants us to take a new signal, then it will leave
2664 * it in td->td_xsig; otherwise we just look for signals again.
2666 ksiginfo_init(&ksi);
2667 ksi.ksi_signo = td->td_xsig;
2668 ksi.ksi_flags |= KSI_PTRACE;
2669 td2 = sigtd(p, td->td_xsig, false);
2670 tdsendsignal(p, td2, td->td_xsig, &ksi);
2675 return (td->td_xsig);
2679 reschedule_signals(struct proc *p, sigset_t block, int flags)
2684 bool fastblk, pslocked;
2686 PROC_LOCK_ASSERT(p, MA_OWNED);
2688 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0;
2689 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED);
2690 if (SIGISEMPTY(p->p_siglist))
2692 SIGSETAND(block, p->p_siglist);
2693 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0;
2694 while ((sig = sig_ffs(&block)) != 0) {
2695 SIGDELSET(block, sig);
2696 td = sigtd(p, sig, fastblk);
2699 * If sigtd() selected us despite sigfastblock is
2700 * blocking, do not activate AST or wake us, to avoid
2701 * loop in AST handler.
2703 if (fastblk && td == curthread)
2708 mtx_lock(&ps->ps_mtx);
2709 if (p->p_flag & P_TRACED ||
2710 (SIGISMEMBER(ps->ps_sigcatch, sig) &&
2711 !SIGISMEMBER(td->td_sigmask, sig))) {
2712 tdsigwakeup(td, sig, SIG_CATCH,
2713 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR :
2717 mtx_unlock(&ps->ps_mtx);
2722 tdsigcleanup(struct thread *td)
2728 PROC_LOCK_ASSERT(p, MA_OWNED);
2730 sigqueue_flush(&td->td_sigqueue);
2731 if (p->p_numthreads == 1)
2735 * Since we cannot handle signals, notify signal post code
2736 * about this by filling the sigmask.
2738 * Also, if needed, wake up thread(s) that do not block the
2739 * same signals as the exiting thread, since the thread might
2740 * have been selected for delivery and woken up.
2742 SIGFILLSET(unblocked);
2743 SIGSETNAND(unblocked, td->td_sigmask);
2744 SIGFILLSET(td->td_sigmask);
2745 reschedule_signals(p, unblocked, 0);
2750 sigdeferstop_curr_flags(int cflags)
2753 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 ||
2754 (cflags & TDF_SBDRY) != 0);
2755 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART));
2759 * Defer the delivery of SIGSTOP for the current thread, according to
2760 * the requested mode. Returns previous flags, which must be restored
2761 * by sigallowstop().
2763 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and
2764 * cleared by the current thread, which allow the lock-less read-only
2768 sigdeferstop_impl(int mode)
2774 cflags = sigdeferstop_curr_flags(td->td_flags);
2776 case SIGDEFERSTOP_NOP:
2779 case SIGDEFERSTOP_OFF:
2782 case SIGDEFERSTOP_SILENT:
2783 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART);
2785 case SIGDEFERSTOP_EINTR:
2786 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART;
2788 case SIGDEFERSTOP_ERESTART:
2789 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR;
2792 panic("sigdeferstop: invalid mode %x", mode);
2795 if (cflags == nflags)
2796 return (SIGDEFERSTOP_VAL_NCHG);
2798 td->td_flags = (td->td_flags & ~cflags) | nflags;
2804 * Restores the STOP handling mode, typically permitting the delivery
2805 * of SIGSTOP for the current thread. This does not immediately
2806 * suspend if a stop was posted. Instead, the thread will suspend
2807 * either via ast() or a subsequent interruptible sleep.
2810 sigallowstop_impl(int prev)
2815 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop"));
2816 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0,
2817 ("sigallowstop: incorrect previous mode %x", prev));
2819 cflags = sigdeferstop_curr_flags(td->td_flags);
2820 if (cflags != prev) {
2822 td->td_flags = (td->td_flags & ~cflags) | prev;
2828 * If the current process has received a signal (should be caught or cause
2829 * termination, should interrupt current syscall), return the signal number.
2830 * Stop signals with default action are processed immediately, then cleared;
2831 * they aren't returned. This is checked after each entry to the system for
2832 * a syscall or trap (though this can usually be done without calling issignal
2833 * by checking the pending signal masks in cursig.) The normal call
2836 * while (sig = cursig(curthread))
2840 issignal(struct thread *td)
2844 struct sigqueue *queue;
2845 sigset_t sigpending;
2851 mtx_assert(&ps->ps_mtx, MA_OWNED);
2852 PROC_LOCK_ASSERT(p, MA_OWNED);
2854 sigpending = td->td_sigqueue.sq_signals;
2855 SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
2856 SIGSETNAND(sigpending, td->td_sigmask);
2858 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags &
2859 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY)
2860 SIG_STOPSIGMASK(sigpending);
2861 if (SIGISEMPTY(sigpending)) /* no signal to send */
2865 * Do fast sigblock if requested by usermode. Since
2866 * we do know that there was a signal pending at this
2867 * point, set the FAST_SIGBLOCK_PEND as indicator for
2868 * usermode to perform a dummy call to
2869 * FAST_SIGBLOCK_UNBLOCK, which causes immediate
2870 * delivery of postponed pending signal.
2872 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) {
2873 if (td->td_sigblock_val != 0)
2874 SIGSETNAND(sigpending, fastblock_mask);
2875 if (SIGISEMPTY(sigpending)) {
2876 td->td_pflags |= TDP_SIGFASTPENDING;
2881 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED &&
2882 (p->p_flag2 & P2_PTRACE_FSTP) != 0 &&
2883 SIGISMEMBER(sigpending, SIGSTOP)) {
2885 * If debugger just attached, always consume
2886 * SIGSTOP from ptrace(PT_ATTACH) first, to
2887 * execute the debugger attach ritual in
2891 td->td_dbgflags |= TDB_FSTP;
2893 sig = sig_ffs(&sigpending);
2897 * We should see pending but ignored signals
2898 * only if P_TRACED was on when they were posted.
2900 if (SIGISMEMBER(ps->ps_sigignore, sig) &&
2901 (p->p_flag & P_TRACED) == 0) {
2902 sigqueue_delete(&td->td_sigqueue, sig);
2903 sigqueue_delete(&p->p_sigqueue, sig);
2906 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) {
2908 * If traced, always stop.
2909 * Remove old signal from queue before the stop.
2910 * XXX shrug off debugger, it causes siginfo to
2913 queue = &td->td_sigqueue;
2914 ksiginfo_init(&ksi);
2915 if (sigqueue_get(queue, sig, &ksi) == 0) {
2916 queue = &p->p_sigqueue;
2917 sigqueue_get(queue, sig, &ksi);
2919 td->td_si = ksi.ksi_info;
2921 mtx_unlock(&ps->ps_mtx);
2922 sig = ptracestop(td, sig, &ksi);
2923 mtx_lock(&ps->ps_mtx);
2925 td->td_si.si_signo = 0;
2928 * Keep looking if the debugger discarded or
2929 * replaced the signal.
2935 * If the signal became masked, re-queue it.
2937 if (SIGISMEMBER(td->td_sigmask, sig)) {
2938 ksi.ksi_flags |= KSI_HEAD;
2939 sigqueue_add(&p->p_sigqueue, sig, &ksi);
2944 * If the traced bit got turned off, requeue
2945 * the signal and go back up to the top to
2946 * rescan signals. This ensures that p_sig*
2947 * and p_sigact are consistent.
2949 if ((p->p_flag & P_TRACED) == 0) {
2950 ksi.ksi_flags |= KSI_HEAD;
2951 sigqueue_add(queue, sig, &ksi);
2956 prop = sigprop(sig);
2959 * Decide whether the signal should be returned.
2960 * Return the signal's number, or fall through
2961 * to clear it from the pending mask.
2963 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
2964 case (intptr_t)SIG_DFL:
2966 * Don't take default actions on system processes.
2968 if (p->p_pid <= 1) {
2971 * Are you sure you want to ignore SIGSEGV
2974 printf("Process (pid %lu) got signal %d\n",
2975 (u_long)p->p_pid, sig);
2977 break; /* == ignore */
2980 * If there is a pending stop signal to process with
2981 * default action, stop here, then clear the signal.
2982 * Traced or exiting processes should ignore stops.
2983 * Additionally, a member of an orphaned process group
2984 * should ignore tty stops.
2986 if (prop & SIGPROP_STOP) {
2988 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) ||
2989 (p->p_pgrp->pg_jobc == 0 &&
2990 prop & SIGPROP_TTYSTOP))
2991 break; /* == ignore */
2992 if (TD_SBDRY_INTR(td)) {
2993 KASSERT((td->td_flags & TDF_SBDRY) != 0,
2994 ("lost TDF_SBDRY"));
2997 mtx_unlock(&ps->ps_mtx);
2998 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
2999 &p->p_mtx.lock_object, "Catching SIGSTOP");
3000 sigqueue_delete(&td->td_sigqueue, sig);
3001 sigqueue_delete(&p->p_sigqueue, sig);
3002 p->p_flag |= P_STOPPED_SIG;
3005 sig_suspend_threads(td, p, 0);
3006 thread_suspend_switch(td, p);
3008 mtx_lock(&ps->ps_mtx);
3010 } else if (prop & SIGPROP_IGNORE) {
3012 * Except for SIGCONT, shouldn't get here.
3013 * Default action is to ignore; drop it.
3015 break; /* == ignore */
3020 case (intptr_t)SIG_IGN:
3022 * Masking above should prevent us ever trying
3023 * to take action on an ignored signal other
3024 * than SIGCONT, unless process is traced.
3026 if ((prop & SIGPROP_CONT) == 0 &&
3027 (p->p_flag & P_TRACED) == 0)
3028 printf("issignal\n");
3029 break; /* == ignore */
3033 * This signal has an action, let
3034 * postsig() process it.
3038 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */
3039 sigqueue_delete(&p->p_sigqueue, sig);
3046 thread_stopped(struct proc *p)
3050 PROC_LOCK_ASSERT(p, MA_OWNED);
3051 PROC_SLOCK_ASSERT(p, MA_OWNED);
3055 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
3057 p->p_flag &= ~P_WAITED;
3058 PROC_LOCK(p->p_pptr);
3059 childproc_stopped(p, (p->p_flag & P_TRACED) ?
3060 CLD_TRAPPED : CLD_STOPPED);
3061 PROC_UNLOCK(p->p_pptr);
3067 * Take the action for the specified signal
3068 * from the current set of pending signals.
3078 sigset_t returnmask;
3080 KASSERT(sig != 0, ("postsig"));
3084 PROC_LOCK_ASSERT(p, MA_OWNED);
3086 mtx_assert(&ps->ps_mtx, MA_OWNED);
3087 ksiginfo_init(&ksi);
3088 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 &&
3089 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0)
3091 ksi.ksi_signo = sig;
3092 if (ksi.ksi_code == SI_TIMER)
3093 itimer_accept(p, ksi.ksi_timerid, &ksi);
3094 action = ps->ps_sigact[_SIG_IDX(sig)];
3096 if (KTRPOINT(td, KTR_PSIG))
3097 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
3098 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code);
3101 if (action == SIG_DFL) {
3103 * Default action, where the default is to kill
3104 * the process. (Other cases were ignored above.)
3106 mtx_unlock(&ps->ps_mtx);
3107 proc_td_siginfo_capture(td, &ksi.ksi_info);
3112 * If we get here, the signal must be caught.
3114 KASSERT(action != SIG_IGN, ("postsig action %p", action));
3115 KASSERT(!SIGISMEMBER(td->td_sigmask, sig),
3116 ("postsig action: blocked sig %d", sig));
3119 * Set the new mask value and also defer further
3120 * occurrences of this signal.
3122 * Special case: user has done a sigsuspend. Here the
3123 * current mask is not of interest, but rather the
3124 * mask from before the sigsuspend is what we want
3125 * restored after the signal processing is completed.
3127 if (td->td_pflags & TDP_OLDMASK) {
3128 returnmask = td->td_oldsigmask;
3129 td->td_pflags &= ~TDP_OLDMASK;
3131 returnmask = td->td_sigmask;
3133 if (p->p_sig == sig) {
3136 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask);
3137 postsig_done(sig, td, ps);
3143 sig_ast_checksusp(struct thread *td)
3149 PROC_LOCK_ASSERT(p, MA_OWNED);
3151 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0)
3154 ret = thread_suspend_check(1);
3155 MPASS(ret == 0 || ret == EINTR || ret == ERESTART);
3160 sig_ast_needsigchk(struct thread *td)
3167 PROC_LOCK_ASSERT(p, MA_OWNED);
3169 if ((td->td_flags & TDF_NEEDSIGCHK) == 0)
3173 mtx_lock(&ps->ps_mtx);
3176 mtx_unlock(&ps->ps_mtx);
3177 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY"));
3178 KASSERT(TD_SBDRY_INTR(td),
3179 ("lost TDF_SERESTART of TDF_SEINTR"));
3180 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) !=
3181 (TDF_SEINTR | TDF_SERESTART),
3182 ("both TDF_SEINTR and TDF_SERESTART"));
3183 ret = TD_SBDRY_ERRNO(td);
3184 } else if (sig != 0) {
3185 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART;
3186 mtx_unlock(&ps->ps_mtx);
3188 mtx_unlock(&ps->ps_mtx);
3193 * Do not go into sleep if this thread was the ptrace(2)
3194 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH,
3195 * but we usually act on the signal by interrupting sleep, and
3196 * should do that here as well.
3198 if ((td->td_dbgflags & TDB_FSTP) != 0) {
3201 td->td_dbgflags &= ~TDB_FSTP;
3215 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0)
3221 ret = sig_ast_checksusp(td);
3223 ret = sig_ast_needsigchk(td);
3229 proc_wkilled(struct proc *p)
3232 PROC_LOCK_ASSERT(p, MA_OWNED);
3233 if ((p->p_flag & P_WKILLED) == 0) {
3234 p->p_flag |= P_WKILLED;
3236 * Notify swapper that there is a process to swap in.
3237 * The notification is racy, at worst it would take 10
3238 * seconds for the swapper process to notice.
3240 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0)
3246 * Kill the current process for stated reason.
3249 killproc(struct proc *p, const char *why)
3252 PROC_LOCK_ASSERT(p, MA_OWNED);
3253 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid,
3255 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n",
3256 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id,
3257 p->p_ucred->cr_uid, why);
3259 kern_psignal(p, SIGKILL);
3263 * Force the current process to exit with the specified signal, dumping core
3264 * if appropriate. We bypass the normal tests for masked and caught signals,
3265 * allowing unrecoverable failures to terminate the process without changing
3266 * signal state. Mark the accounting record with the signal termination.
3267 * If dumping core, save the signal number for the debugger. Calls exit and
3271 sigexit(struct thread *td, int sig)
3273 struct proc *p = td->td_proc;
3275 PROC_LOCK_ASSERT(p, MA_OWNED);
3276 p->p_acflag |= AXSIG;
3278 * We must be single-threading to generate a core dump. This
3279 * ensures that the registers in the core file are up-to-date.
3280 * Also, the ELF dump handler assumes that the thread list doesn't
3281 * change out from under it.
3283 * XXX If another thread attempts to single-thread before us
3284 * (e.g. via fork()), we won't get a dump at all.
3286 if ((sigprop(sig) & SIGPROP_CORE) &&
3287 thread_single(p, SINGLE_NO_EXIT) == 0) {
3290 * Log signals which would cause core dumps
3291 * (Log as LOG_INFO to appease those who don't want
3293 * XXX : Todo, as well as euid, write out ruid too
3294 * Note that coredump() drops proc lock.
3296 if (coredump(td) == 0)
3298 if (kern_logsigexit)
3300 "pid %d (%s), jid %d, uid %d: exited on "
3301 "signal %d%s\n", p->p_pid, p->p_comm,
3302 p->p_ucred->cr_prison->pr_id,
3303 td->td_ucred->cr_uid,
3305 sig & WCOREFLAG ? " (core dumped)" : "");
3313 * Send queued SIGCHLD to parent when child process's state
3317 sigparent(struct proc *p, int reason, int status)
3319 PROC_LOCK_ASSERT(p, MA_OWNED);
3320 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
3322 if (p->p_ksi != NULL) {
3323 p->p_ksi->ksi_signo = SIGCHLD;
3324 p->p_ksi->ksi_code = reason;
3325 p->p_ksi->ksi_status = status;
3326 p->p_ksi->ksi_pid = p->p_pid;
3327 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid;
3328 if (KSI_ONQ(p->p_ksi))
3331 pksignal(p->p_pptr, SIGCHLD, p->p_ksi);
3335 childproc_jobstate(struct proc *p, int reason, int sig)
3339 PROC_LOCK_ASSERT(p, MA_OWNED);
3340 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED);
3343 * Wake up parent sleeping in kern_wait(), also send
3344 * SIGCHLD to parent, but SIGCHLD does not guarantee
3345 * that parent will awake, because parent may masked
3348 p->p_pptr->p_flag |= P_STATCHILD;
3351 ps = p->p_pptr->p_sigacts;
3352 mtx_lock(&ps->ps_mtx);
3353 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
3354 mtx_unlock(&ps->ps_mtx);
3355 sigparent(p, reason, sig);
3357 mtx_unlock(&ps->ps_mtx);
3361 childproc_stopped(struct proc *p, int reason)
3364 childproc_jobstate(p, reason, p->p_xsig);
3368 childproc_continued(struct proc *p)
3370 childproc_jobstate(p, CLD_CONTINUED, SIGCONT);
3374 childproc_exited(struct proc *p)
3378 if (WCOREDUMP(p->p_xsig)) {
3379 reason = CLD_DUMPED;
3380 status = WTERMSIG(p->p_xsig);
3381 } else if (WIFSIGNALED(p->p_xsig)) {
3382 reason = CLD_KILLED;
3383 status = WTERMSIG(p->p_xsig);
3385 reason = CLD_EXITED;
3386 status = p->p_xexit;
3389 * XXX avoid calling wakeup(p->p_pptr), the work is
3392 sigparent(p, reason, status);
3395 #define MAX_NUM_CORE_FILES 100000
3396 #ifndef NUM_CORE_FILES
3397 #define NUM_CORE_FILES 5
3399 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES);
3400 static int num_cores = NUM_CORE_FILES;
3403 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS)
3408 new_val = num_cores;
3409 error = sysctl_handle_int(oidp, &new_val, 0, req);
3410 if (error != 0 || req->newptr == NULL)
3412 if (new_val > MAX_NUM_CORE_FILES)
3413 new_val = MAX_NUM_CORE_FILES;
3416 num_cores = new_val;
3419 SYSCTL_PROC(_debug, OID_AUTO, ncores,
3420 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int),
3421 sysctl_debug_num_cores_check, "I",
3422 "Maximum number of generated process corefiles while using index format");
3424 #define GZIP_SUFFIX ".gz"
3425 #define ZSTD_SUFFIX ".zst"
3427 int compress_user_cores = 0;
3430 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS)
3434 val = compress_user_cores;
3435 error = sysctl_handle_int(oidp, &val, 0, req);
3436 if (error != 0 || req->newptr == NULL)
3438 if (val != 0 && !compressor_avail(val))
3440 compress_user_cores = val;
3443 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores,
3444 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int),
3445 sysctl_compress_user_cores, "I",
3446 "Enable compression of user corefiles ("
3447 __XSTRING(COMPRESS_GZIP) " = gzip, "
3448 __XSTRING(COMPRESS_ZSTD) " = zstd)");
3450 int compress_user_cores_level = 6;
3451 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN,
3452 &compress_user_cores_level, 0,
3453 "Corefile compression level");
3456 * Protect the access to corefilename[] by allproc_lock.
3458 #define corefilename_lock allproc_lock
3460 static char corefilename[MAXPATHLEN] = {"%N.core"};
3461 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename));
3464 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS)
3468 sx_xlock(&corefilename_lock);
3469 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename),
3471 sx_xunlock(&corefilename_lock);
3475 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW |
3476 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A",
3477 "Process corefile name format string");
3480 vnode_close_locked(struct thread *td, struct vnode *vp)
3484 vn_close(vp, FWRITE, td->td_ucred, td);
3488 * If the core format has a %I in it, then we need to check
3489 * for existing corefiles before defining a name.
3490 * To do this we iterate over 0..ncores to find a
3491 * non-existing core file name to use. If all core files are
3492 * already used we choose the oldest one.
3495 corefile_open_last(struct thread *td, char *name, int indexpos,
3496 int indexlen, int ncores, struct vnode **vpp)
3498 struct vnode *oldvp, *nextvp, *vp;
3500 struct nameidata nd;
3501 int error, i, flags, oflags, cmode;
3503 struct timespec lasttime;
3505 nextvp = oldvp = NULL;
3506 cmode = S_IRUSR | S_IWUSR;
3507 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE |
3508 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
3510 for (i = 0; i < ncores; i++) {
3511 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3513 ch = name[indexpos + indexlen];
3514 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen,
3516 name[indexpos + indexlen] = ch;
3518 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3519 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred,
3525 NDFREE(&nd, NDF_ONLY_PNBUF);
3526 if ((flags & O_CREAT) == O_CREAT) {
3531 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
3533 vnode_close_locked(td, vp);
3537 if (oldvp == NULL ||
3538 lasttime.tv_sec > vattr.va_mtime.tv_sec ||
3539 (lasttime.tv_sec == vattr.va_mtime.tv_sec &&
3540 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) {
3542 vn_close(oldvp, FWRITE, td->td_ucred, td);
3545 lasttime = vattr.va_mtime;
3547 vnode_close_locked(td, vp);
3551 if (oldvp != NULL) {
3552 if (nextvp == NULL) {
3553 if ((td->td_proc->p_flag & P_SUGID) != 0) {
3555 vn_close(oldvp, FWRITE, td->td_ucred, td);
3558 error = vn_lock(nextvp, LK_EXCLUSIVE);
3560 vn_close(nextvp, FWRITE, td->td_ucred,
3566 vn_close(oldvp, FWRITE, td->td_ucred, td);
3571 vnode_close_locked(td, oldvp);
3580 * corefile_open(comm, uid, pid, td, compress, vpp, namep)
3581 * Expand the name described in corefilename, using name, uid, and pid
3582 * and open/create core file.
3583 * corefilename is a printf-like string, with three format specifiers:
3584 * %N name of process ("name")
3585 * %P process id (pid)
3587 * For example, "%N.core" is the default; they can be disabled completely
3588 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
3589 * This is controlled by the sysctl variable kern.corefile (see above).
3592 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td,
3593 int compress, int signum, struct vnode **vpp, char **namep)
3596 struct nameidata nd;
3598 char *hostname, *name;
3599 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores;
3602 format = corefilename;
3603 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO);
3607 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN);
3608 sx_slock(&corefilename_lock);
3609 for (i = 0; format[i] != '\0'; i++) {
3610 switch (format[i]) {
3611 case '%': /* Format character */
3613 switch (format[i]) {
3615 sbuf_putc(&sb, '%');
3617 case 'H': /* hostname */
3618 if (hostname == NULL) {
3619 hostname = malloc(MAXHOSTNAMELEN,
3622 getcredhostname(td->td_ucred, hostname,
3624 sbuf_printf(&sb, "%s", hostname);
3626 case 'I': /* autoincrementing index */
3627 if (indexpos != -1) {
3628 sbuf_printf(&sb, "%%I");
3632 indexpos = sbuf_len(&sb);
3633 sbuf_printf(&sb, "%u", ncores - 1);
3634 indexlen = sbuf_len(&sb) - indexpos;
3636 case 'N': /* process name */
3637 sbuf_printf(&sb, "%s", comm);
3639 case 'P': /* process id */
3640 sbuf_printf(&sb, "%u", pid);
3642 case 'S': /* signal number */
3643 sbuf_printf(&sb, "%i", signum);
3645 case 'U': /* user id */
3646 sbuf_printf(&sb, "%u", uid);
3650 "Unknown format character %c in "
3651 "corename `%s'\n", format[i], format);
3656 sbuf_putc(&sb, format[i]);
3660 sx_sunlock(&corefilename_lock);
3661 free(hostname, M_TEMP);
3662 if (compress == COMPRESS_GZIP)
3663 sbuf_printf(&sb, GZIP_SUFFIX);
3664 else if (compress == COMPRESS_ZSTD)
3665 sbuf_printf(&sb, ZSTD_SUFFIX);
3666 if (sbuf_error(&sb) != 0) {
3667 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too "
3668 "long\n", (long)pid, comm, (u_long)uid);
3676 if (indexpos != -1) {
3677 error = corefile_open_last(td, name, indexpos, indexlen, ncores,
3681 "pid %d (%s), uid (%u): Path `%s' failed "
3682 "on initial open test, error = %d\n",
3683 pid, comm, uid, name, error);
3686 cmode = S_IRUSR | S_IWUSR;
3687 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE |
3688 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0);
3689 flags = O_CREAT | FWRITE | O_NOFOLLOW;
3690 if ((td->td_proc->p_flag & P_SUGID) != 0)
3693 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td);
3694 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred,
3698 NDFREE(&nd, NDF_ONLY_PNBUF);
3704 audit_proc_coredump(td, name, error);
3714 * Dump a process' core. The main routine does some
3715 * policy checking, and creates the name of the coredump;
3716 * then it passes on a vnode and a size limit to the process-specific
3717 * coredump routine if there is one; if there _is not_ one, it returns
3718 * ENOSYS; otherwise it returns the error from the process-specific routine.
3722 coredump(struct thread *td)
3724 struct proc *p = td->td_proc;
3725 struct ucred *cred = td->td_ucred;
3729 size_t fullpathsize;
3730 int error, error1, locked;
3731 char *name; /* name of corefile */
3734 char *fullpath, *freepath = NULL;
3737 PROC_LOCK_ASSERT(p, MA_OWNED);
3738 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td);
3740 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) ||
3741 (p->p_flag2 & P2_NOTRACE) != 0) {
3747 * Note that the bulk of limit checking is done after
3748 * the corefile is created. The exception is if the limit
3749 * for corefiles is 0, in which case we don't bother
3750 * creating the corefile at all. This layout means that
3751 * a corefile is truncated instead of not being created,
3752 * if it is larger than the limit.
3754 limit = (off_t)lim_cur(td, RLIMIT_CORE);
3755 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) {
3761 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td,
3762 compress_user_cores, p->p_sig, &vp, &name);
3767 * Don't dump to non-regular files or files with links.
3768 * Do not dump into system files. Effective user must own the corefile.
3770 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 ||
3771 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 ||
3772 vattr.va_uid != cred->cr_uid) {
3780 /* Postpone other writers, including core dumps of other processes. */
3781 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3783 lf.l_whence = SEEK_SET;
3786 lf.l_type = F_WRLCK;
3787 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
3791 if (set_core_nodump_flag)
3792 vattr.va_flags = UF_NODUMP;
3793 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3794 VOP_SETATTR(vp, &vattr, cred);
3797 p->p_acflag |= ACORE;
3800 if (p->p_sysent->sv_coredump != NULL) {
3801 error = p->p_sysent->sv_coredump(td, vp, limit, 0);
3807 lf.l_type = F_UNLCK;
3808 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
3810 vn_rangelock_unlock(vp, rl_cookie);
3813 * Notify the userland helper that a process triggered a core dump.
3814 * This allows the helper to run an automated debugging session.
3816 if (error != 0 || coredump_devctl == 0)
3818 sb = sbuf_new_auto();
3819 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0)
3821 sbuf_printf(sb, "comm=\"");
3822 devctl_safe_quote_sb(sb, fullpath);
3823 free(freepath, M_TEMP);
3824 sbuf_printf(sb, "\" core=\"");
3827 * We can't lookup core file vp directly. When we're replacing a core, and
3828 * other random times, we flush the name cache, so it will fail. Instead,
3829 * if the path of the core is relative, add the current dir in front if it.
3831 if (name[0] != '/') {
3832 fullpathsize = MAXPATHLEN;
3833 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK);
3834 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) {
3835 free(freepath, M_TEMP);
3838 devctl_safe_quote_sb(sb, fullpath);
3839 free(freepath, M_TEMP);
3842 devctl_safe_quote_sb(sb, name);
3843 sbuf_printf(sb, "\"");
3844 if (sbuf_finish(sb) == 0)
3845 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb));
3849 error1 = vn_close(vp, FWRITE, cred, td);
3853 audit_proc_coredump(td, name, error);
3860 * Nonexistent system call-- signal process (may want to handle it). Flag
3861 * error in case process won't see signal immediately (blocked or ignored).
3863 #ifndef _SYS_SYSPROTO_H_
3870 nosys(struct thread *td, struct nosys_args *args)
3877 tdsignal(td, SIGSYS);
3879 if (kern_lognosys == 1 || kern_lognosys == 3) {
3880 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm,
3883 if (kern_lognosys == 2 || kern_lognosys == 3 ||
3884 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) {
3885 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm,
3892 * Send a SIGIO or SIGURG signal to a process or process group using stored
3893 * credentials rather than those of the current process.
3896 pgsigio(struct sigio **sigiop, int sig, int checkctty)
3899 struct sigio *sigio;
3901 ksiginfo_init(&ksi);
3902 ksi.ksi_signo = sig;
3903 ksi.ksi_code = SI_KERNEL;
3907 if (sigio == NULL) {
3911 if (sigio->sio_pgid > 0) {
3912 PROC_LOCK(sigio->sio_proc);
3913 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
3914 kern_psignal(sigio->sio_proc, sig);
3915 PROC_UNLOCK(sigio->sio_proc);
3916 } else if (sigio->sio_pgid < 0) {
3919 PGRP_LOCK(sigio->sio_pgrp);
3920 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
3922 if (p->p_state == PRS_NORMAL &&
3923 CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
3924 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
3925 kern_psignal(p, sig);
3928 PGRP_UNLOCK(sigio->sio_pgrp);
3934 filt_sigattach(struct knote *kn)
3936 struct proc *p = curproc;
3938 kn->kn_ptr.p_proc = p;
3939 kn->kn_flags |= EV_CLEAR; /* automatically set */
3941 knlist_add(p->p_klist, kn, 0);
3947 filt_sigdetach(struct knote *kn)
3949 struct proc *p = kn->kn_ptr.p_proc;
3951 knlist_remove(p->p_klist, kn, 0);
3955 * signal knotes are shared with proc knotes, so we apply a mask to
3956 * the hint in order to differentiate them from process hints. This
3957 * could be avoided by using a signal-specific knote list, but probably
3958 * isn't worth the trouble.
3961 filt_signal(struct knote *kn, long hint)
3964 if (hint & NOTE_SIGNAL) {
3965 hint &= ~NOTE_SIGNAL;
3967 if (kn->kn_id == hint)
3970 return (kn->kn_data != 0);
3978 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
3979 refcount_init(&ps->ps_refcnt, 1);
3980 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
3985 sigacts_free(struct sigacts *ps)
3988 if (refcount_release(&ps->ps_refcnt) == 0)
3990 mtx_destroy(&ps->ps_mtx);
3991 free(ps, M_SUBPROC);
3995 sigacts_hold(struct sigacts *ps)
3998 refcount_acquire(&ps->ps_refcnt);
4003 sigacts_copy(struct sigacts *dest, struct sigacts *src)
4006 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
4007 mtx_lock(&src->ps_mtx);
4008 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
4009 mtx_unlock(&src->ps_mtx);
4013 sigacts_shared(struct sigacts *ps)
4016 return (ps->ps_refcnt > 1);
4020 sig_drop_caught(struct proc *p)
4026 PROC_LOCK_ASSERT(p, MA_OWNED);
4027 mtx_assert(&ps->ps_mtx, MA_OWNED);
4028 while (SIGNOTEMPTY(ps->ps_sigcatch)) {
4029 sig = sig_ffs(&ps->ps_sigcatch);
4031 if ((sigprop(sig) & SIGPROP_IGNORE) != 0)
4032 sigqueue_delete_proc(p, sig);
4037 sigfastblock_failed(struct thread *td, bool sendsig, bool write)
4042 * Prevent further fetches and SIGSEGVs, allowing thread to
4043 * issue syscalls despite corruption.
4045 sigfastblock_clear(td);
4049 ksiginfo_init_trap(&ksi);
4050 ksi.ksi_signo = SIGSEGV;
4051 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR;
4052 ksi.ksi_addr = td->td_sigblock_ptr;
4053 trapsignal(td, &ksi);
4057 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp)
4061 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0)
4063 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) {
4064 sigfastblock_failed(td, sendsig, false);
4068 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS;
4073 sigfastblock_resched(struct thread *td, bool resched)
4080 reschedule_signals(p, td->td_sigmask, 0);
4084 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK;
4089 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap)
4098 case SIGFASTBLOCK_SETPTR:
4099 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) {
4103 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) {
4107 td->td_pflags |= TDP_SIGFASTBLOCK;
4108 td->td_sigblock_ptr = uap->ptr;
4111 case SIGFASTBLOCK_UNBLOCK:
4112 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) {
4118 res = casueword32(td->td_sigblock_ptr,
4119 SIGFASTBLOCK_PEND, &oldval, 0);
4122 sigfastblock_failed(td, false, true);
4128 if (oldval != SIGFASTBLOCK_PEND) {
4132 error = thread_check_susp(td, false);
4140 * td_sigblock_val is cleared there, but not on a
4141 * syscall exit. The end effect is that a single
4142 * interruptible sleep, while user sigblock word is
4143 * set, might return EINTR or ERESTART to usermode
4144 * without delivering signal. All further sleeps,
4145 * until userspace clears the word and does
4146 * sigfastblock(UNBLOCK), observe current word and no
4147 * longer get interrupted. It is slight
4148 * non-conformance, with alternative to have read the
4149 * sigblock word on each syscall entry.
4151 td->td_sigblock_val = 0;
4154 * Rely on normal ast mechanism to deliver pending
4155 * signals to current thread. But notify others about
4158 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1);
4162 case SIGFASTBLOCK_UNSETPTR:
4163 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) {
4167 if (!sigfastblock_fetch_sig(td, false, &oldval)) {
4171 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) {
4175 sigfastblock_clear(td);
4186 sigfastblock_clear(struct thread *td)
4190 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0)
4192 td->td_sigblock_val = 0;
4193 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 ||
4195 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING);
4196 sigfastblock_resched(td, resched);
4200 sigfastblock_fetch(struct thread *td)
4204 (void)sigfastblock_fetch_sig(td, true, &val);
4208 sigfastblock_setpend1(struct thread *td)
4213 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0)
4215 res = fueword32((void *)td->td_sigblock_ptr, &oldval);
4217 sigfastblock_failed(td, true, false);
4221 res = casueword32(td->td_sigblock_ptr, oldval, &oldval,
4222 oldval | SIGFASTBLOCK_PEND);
4224 sigfastblock_failed(td, true, true);
4228 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS;
4229 td->td_pflags &= ~TDP_SIGFASTPENDING;
4233 if (thread_check_susp(td, false) != 0)
4239 sigfastblock_setpend(struct thread *td, bool resched)
4243 sigfastblock_setpend1(td);
4247 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK);