2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
42 #include "opt_ktrace.h"
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/sysproto.h>
48 #include <sys/signalvar.h>
49 #include <sys/resourcevar.h>
50 #include <sys/vnode.h>
51 #include <sys/event.h>
53 #include <sys/nlookup.h>
54 #include <sys/pioctl.h>
56 #include <sys/fcntl.h>
59 #include <sys/ktrace.h>
60 #include <sys/syslog.h>
62 #include <sys/sysent.h>
63 #include <sys/sysctl.h>
64 #include <sys/malloc.h>
65 #include <sys/interrupt.h>
66 #include <sys/unistd.h>
67 #include <sys/kern_syscall.h>
68 #include <sys/vkernel.h>
70 #include <sys/signal2.h>
71 #include <sys/thread2.h>
72 #include <sys/spinlock2.h>
74 #include <machine/cpu.h>
75 #include <machine/smp.h>
77 static int coredump(struct lwp *, int);
78 static char *expand_name(const char *, uid_t, pid_t);
79 static int dokillpg(int sig, int pgid, int all);
80 static int sig_ffs(sigset_t *set);
81 static int sigprop(int sig);
82 static void lwp_signotify(struct lwp *lp);
84 static void lwp_signotify_remote(void *arg);
86 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
87 struct timespec *timeout);
89 static int filt_sigattach(struct knote *kn);
90 static void filt_sigdetach(struct knote *kn);
91 static int filt_signal(struct knote *kn, long hint);
93 struct filterops sig_filtops =
94 { 0, filt_sigattach, filt_sigdetach, filt_signal };
96 static int kern_logsigexit = 1;
97 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
99 "Log processes quitting on abnormal signals to syslog(3)");
102 * Can process p, with pcred pc, send the signal sig to process q?
104 #define CANSIGNAL(q, sig) \
105 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
106 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
109 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
111 #define CANSIGIO(ruid, uc, q) \
112 ((uc)->cr_uid == 0 || \
113 (ruid) == (q)->p_ucred->cr_ruid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
115 (ruid) == (q)->p_ucred->cr_uid || \
116 (uc)->cr_uid == (q)->p_ucred->cr_uid)
119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
122 static int do_coredump = 1;
123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
124 &do_coredump, 0, "Enable/Disable coredumps");
127 * Signal properties and actions.
128 * The array below categorizes the signals and their default actions
129 * according to the following properties:
131 #define SA_KILL 0x01 /* terminates process by default */
132 #define SA_CORE 0x02 /* ditto and coredumps */
133 #define SA_STOP 0x04 /* suspend process */
134 #define SA_TTYSTOP 0x08 /* ditto, from tty */
135 #define SA_IGNORE 0x10 /* ignore by default */
136 #define SA_CONT 0x20 /* continue if suspended */
137 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
138 #define SA_CKPT 0x80 /* checkpoint process */
141 static int sigproptbl[NSIG] = {
142 SA_KILL, /* SIGHUP */
143 SA_KILL, /* SIGINT */
144 SA_KILL|SA_CORE, /* SIGQUIT */
145 SA_KILL|SA_CORE, /* SIGILL */
146 SA_KILL|SA_CORE, /* SIGTRAP */
147 SA_KILL|SA_CORE, /* SIGABRT */
148 SA_KILL|SA_CORE, /* SIGEMT */
149 SA_KILL|SA_CORE, /* SIGFPE */
150 SA_KILL, /* SIGKILL */
151 SA_KILL|SA_CORE, /* SIGBUS */
152 SA_KILL|SA_CORE, /* SIGSEGV */
153 SA_KILL|SA_CORE, /* SIGSYS */
154 SA_KILL, /* SIGPIPE */
155 SA_KILL, /* SIGALRM */
156 SA_KILL, /* SIGTERM */
157 SA_IGNORE, /* SIGURG */
158 SA_STOP, /* SIGSTOP */
159 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
160 SA_IGNORE|SA_CONT, /* SIGCONT */
161 SA_IGNORE, /* SIGCHLD */
162 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
163 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
164 SA_IGNORE, /* SIGIO */
165 SA_KILL, /* SIGXCPU */
166 SA_KILL, /* SIGXFSZ */
167 SA_KILL, /* SIGVTALRM */
168 SA_KILL, /* SIGPROF */
169 SA_IGNORE, /* SIGWINCH */
170 SA_IGNORE, /* SIGINFO */
171 SA_KILL, /* SIGUSR1 */
172 SA_KILL, /* SIGUSR2 */
173 SA_IGNORE, /* SIGTHR */
174 SA_CKPT, /* SIGCKPT */
175 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
213 if (sig > 0 && sig < NSIG)
214 return (sigproptbl[_SIG_IDX(sig)]);
219 sig_ffs(sigset_t *set)
223 for (i = 0; i < _SIG_WORDS; i++)
225 return (ffs(set->__bits[i]) + (i * 32));
233 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
235 struct thread *td = curthread;
236 struct proc *p = td->td_proc;
238 struct sigacts *ps = p->p_sigacts;
240 if (sig <= 0 || sig > _SIG_MAXSIG)
243 lwkt_gettoken(&p->p_token);
246 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
247 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
249 if (SIGISMEMBER(ps->ps_sigonstack, sig))
250 oact->sa_flags |= SA_ONSTACK;
251 if (!SIGISMEMBER(ps->ps_sigintr, sig))
252 oact->sa_flags |= SA_RESTART;
253 if (SIGISMEMBER(ps->ps_sigreset, sig))
254 oact->sa_flags |= SA_RESETHAND;
255 if (SIGISMEMBER(ps->ps_signodefer, sig))
256 oact->sa_flags |= SA_NODEFER;
257 if (SIGISMEMBER(ps->ps_siginfo, sig))
258 oact->sa_flags |= SA_SIGINFO;
259 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
260 oact->sa_flags |= SA_NOCLDSTOP;
261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
262 oact->sa_flags |= SA_NOCLDWAIT;
266 * Check for invalid requests. KILL and STOP cannot be
269 if (sig == SIGKILL || sig == SIGSTOP) {
270 if (act->sa_handler != SIG_DFL) {
271 lwkt_reltoken(&p->p_token);
277 * Change setting atomically.
279 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
280 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
281 if (act->sa_flags & SA_SIGINFO) {
282 ps->ps_sigact[_SIG_IDX(sig)] =
283 (__sighandler_t *)act->sa_sigaction;
284 SIGADDSET(ps->ps_siginfo, sig);
286 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
287 SIGDELSET(ps->ps_siginfo, sig);
289 if (!(act->sa_flags & SA_RESTART))
290 SIGADDSET(ps->ps_sigintr, sig);
292 SIGDELSET(ps->ps_sigintr, sig);
293 if (act->sa_flags & SA_ONSTACK)
294 SIGADDSET(ps->ps_sigonstack, sig);
296 SIGDELSET(ps->ps_sigonstack, sig);
297 if (act->sa_flags & SA_RESETHAND)
298 SIGADDSET(ps->ps_sigreset, sig);
300 SIGDELSET(ps->ps_sigreset, sig);
301 if (act->sa_flags & SA_NODEFER)
302 SIGADDSET(ps->ps_signodefer, sig);
304 SIGDELSET(ps->ps_signodefer, sig);
305 if (sig == SIGCHLD) {
306 if (act->sa_flags & SA_NOCLDSTOP)
307 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
309 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
310 if (act->sa_flags & SA_NOCLDWAIT) {
312 * Paranoia: since SA_NOCLDWAIT is implemented
313 * by reparenting the dying child to PID 1 (and
314 * trust it to reap the zombie), PID 1 itself
315 * is forbidden to set SA_NOCLDWAIT.
318 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
320 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
322 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
324 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
325 ps->ps_flag |= PS_CLDSIGIGN;
327 ps->ps_flag &= ~PS_CLDSIGIGN;
330 * Set bit in p_sigignore for signals that are set to SIG_IGN,
331 * and for signals set to SIG_DFL where the default is to
332 * ignore. However, don't put SIGCONT in p_sigignore, as we
333 * have to restart the process.
335 * Also remove the signal from the process and lwp signal
338 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
339 (sigprop(sig) & SA_IGNORE &&
340 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
341 SIGDELSET(p->p_siglist, sig);
342 FOREACH_LWP_IN_PROC(lp, p) {
343 spin_lock(&lp->lwp_spin);
344 SIGDELSET(lp->lwp_siglist, sig);
345 spin_unlock(&lp->lwp_spin);
347 if (sig != SIGCONT) {
348 /* easier in ksignal */
349 SIGADDSET(p->p_sigignore, sig);
351 SIGDELSET(p->p_sigcatch, sig);
353 SIGDELSET(p->p_sigignore, sig);
354 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
355 SIGDELSET(p->p_sigcatch, sig);
357 SIGADDSET(p->p_sigcatch, sig);
360 lwkt_reltoken(&p->p_token);
365 sys_sigaction(struct sigaction_args *uap)
367 struct sigaction act, oact;
368 struct sigaction *actp, *oactp;
371 actp = (uap->act != NULL) ? &act : NULL;
372 oactp = (uap->oact != NULL) ? &oact : NULL;
374 error = copyin(uap->act, actp, sizeof(act));
378 error = kern_sigaction(uap->sig, actp, oactp);
379 if (oactp && !error) {
380 error = copyout(oactp, uap->oact, sizeof(oact));
386 * Initialize signal state for process 0;
387 * set to ignore signals that are ignored by default.
390 siginit(struct proc *p)
394 for (i = 1; i <= NSIG; i++)
395 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
396 SIGADDSET(p->p_sigignore, i);
400 * Reset signals for an exec of the specified process.
403 execsigs(struct proc *p)
405 struct sigacts *ps = p->p_sigacts;
409 lp = ONLY_LWP_IN_PROC(p);
412 * Reset caught signals. Held signals remain held
413 * through p_sigmask (unless they were caught,
414 * and are now ignored by default).
416 while (SIGNOTEMPTY(p->p_sigcatch)) {
417 sig = sig_ffs(&p->p_sigcatch);
418 SIGDELSET(p->p_sigcatch, sig);
419 if (sigprop(sig) & SA_IGNORE) {
421 SIGADDSET(p->p_sigignore, sig);
422 SIGDELSET(p->p_siglist, sig);
423 /* don't need spinlock */
424 SIGDELSET(lp->lwp_siglist, sig);
426 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
430 * Reset stack state to the user stack.
431 * Clear set of signals caught on the signal stack.
433 lp->lwp_sigstk.ss_flags = SS_DISABLE;
434 lp->lwp_sigstk.ss_size = 0;
435 lp->lwp_sigstk.ss_sp = 0;
436 lp->lwp_flags &= ~LWP_ALTSTACK;
438 * Reset no zombies if child dies flag as Solaris does.
440 p->p_sigacts->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
441 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
442 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
446 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
448 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
452 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
454 struct thread *td = curthread;
455 struct lwp *lp = td->td_lwp;
456 struct proc *p = td->td_proc;
459 lwkt_gettoken(&p->p_token);
462 *oset = lp->lwp_sigmask;
469 SIGSETOR(lp->lwp_sigmask, *set);
472 SIGSETNAND(lp->lwp_sigmask, *set);
476 lp->lwp_sigmask = *set;
484 lwkt_reltoken(&p->p_token);
495 sys_sigprocmask(struct sigprocmask_args *uap)
498 sigset_t *setp, *osetp;
501 setp = (uap->set != NULL) ? &set : NULL;
502 osetp = (uap->oset != NULL) ? &oset : NULL;
504 error = copyin(uap->set, setp, sizeof(set));
508 error = kern_sigprocmask(uap->how, setp, osetp);
509 if (osetp && !error) {
510 error = copyout(osetp, uap->oset, sizeof(oset));
519 kern_sigpending(struct __sigset *set)
521 struct lwp *lp = curthread->td_lwp;
523 *set = lwp_sigpend(lp);
532 sys_sigpending(struct sigpending_args *uap)
537 error = kern_sigpending(&set);
540 error = copyout(&set, uap->set, sizeof(set));
545 * Suspend process until signal, providing mask to be set
551 kern_sigsuspend(struct __sigset *set)
553 struct thread *td = curthread;
554 struct lwp *lp = td->td_lwp;
555 struct proc *p = td->td_proc;
556 struct sigacts *ps = p->p_sigacts;
559 * When returning from sigsuspend, we want
560 * the old mask to be restored after the
561 * signal handler has finished. Thus, we
562 * save it here and mark the sigacts structure
565 lp->lwp_oldsigmask = lp->lwp_sigmask;
566 lp->lwp_flags |= LWP_OLDMASK;
569 lp->lwp_sigmask = *set;
570 while (tsleep(ps, PCATCH, "pause", 0) == 0)
572 /* always return EINTR rather than ERESTART... */
577 * Note nonstandard calling convention: libc stub passes mask, not
578 * pointer, to save a copyin.
583 sys_sigsuspend(struct sigsuspend_args *uap)
588 error = copyin(uap->sigmask, &mask, sizeof(mask));
592 error = kern_sigsuspend(&mask);
601 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
603 struct thread *td = curthread;
604 struct lwp *lp = td->td_lwp;
605 struct proc *p = td->td_proc;
607 if ((lp->lwp_flags & LWP_ALTSTACK) == 0)
608 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
611 *oss = lp->lwp_sigstk;
614 if (ss->ss_flags & SS_DISABLE) {
615 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
617 lp->lwp_flags &= ~LWP_ALTSTACK;
618 lp->lwp_sigstk.ss_flags = ss->ss_flags;
620 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
622 lp->lwp_flags |= LWP_ALTSTACK;
623 lp->lwp_sigstk = *ss;
634 sys_sigaltstack(struct sigaltstack_args *uap)
640 error = copyin(uap->ss, &ss, sizeof(ss));
645 error = kern_sigaltstack(uap->ss ? &ss : NULL,
646 uap->oss ? &oss : NULL);
648 if (error == 0 && uap->oss)
649 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
654 * Common code for kill process group/broadcast kill.
655 * cp is calling process.
662 static int killpg_all_callback(struct proc *p, void *data);
665 dokillpg(int sig, int pgid, int all)
667 struct killpg_info info;
668 struct proc *cp = curproc;
679 allproc_scan(killpg_all_callback, &info);
683 * zero pgid means send to my process group.
694 * Must interlock all signals against fork
696 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
697 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
699 p->p_stat == SZOMB ||
700 (p->p_flags & P_SYSTEM) ||
701 !CANSIGNAL(p, sig)) {
708 lockmgr(&pgrp->pg_lock, LK_RELEASE);
711 return (info.nfound ? 0 : ESRCH);
715 killpg_all_callback(struct proc *p, void *data)
717 struct killpg_info *info = data;
719 if (p->p_pid <= 1 || (p->p_flags & P_SYSTEM) ||
720 p == curproc || !CANSIGNAL(p, info->sig)) {
725 ksignal(p, info->sig);
730 * Send a general signal to a process or LWPs within that process.
732 * Note that new signals cannot be sent if a process is exiting or already
733 * a zombie, but we return success anyway as userland is likely to not handle
739 kern_kill(int sig, pid_t pid, lwpid_t tid)
743 if ((u_int)sig > _SIG_MAXSIG)
746 lwkt_gettoken(&proc_token);
750 struct lwp *lp = NULL;
753 * Send a signal to a single process. If the kill() is
754 * racing an exiting process which has not yet been reaped
755 * act as though the signal was delivered successfully but
756 * don't actually try to deliver the signal.
758 if ((p = pfind(pid)) == NULL) {
759 if ((p = zpfind(pid)) == NULL) {
760 lwkt_reltoken(&proc_token);
763 lwkt_reltoken(&proc_token);
767 lwkt_gettoken(&p->p_token);
768 if (!CANSIGNAL(p, sig)) {
769 lwkt_reltoken(&p->p_token);
771 lwkt_reltoken(&proc_token);
776 * NOP if the process is exiting. Note that lwpsignal() is
777 * called directly with P_WEXIT set to kill individual LWPs
778 * during exit, which is allowed.
780 if (p->p_flags & P_WEXIT) {
781 lwkt_reltoken(&p->p_token);
783 lwkt_reltoken(&proc_token);
787 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
789 lwkt_reltoken(&p->p_token);
791 lwkt_reltoken(&proc_token);
796 lwpsignal(p, lp, sig);
797 lwkt_reltoken(&p->p_token);
799 lwkt_reltoken(&proc_token);
804 * If we come here, pid is a special broadcast pid.
805 * This doesn't mix with a tid.
808 lwkt_reltoken(&proc_token);
812 case -1: /* broadcast signal */
813 t = (dokillpg(sig, 0, 1));
815 case 0: /* signal own process group */
816 t = (dokillpg(sig, 0, 0));
818 default: /* negative explicit process group */
819 t = (dokillpg(sig, -pid, 0));
822 lwkt_reltoken(&proc_token);
827 sys_kill(struct kill_args *uap)
831 error = kern_kill(uap->signum, uap->pid, -1);
836 sys_lwp_kill(struct lwp_kill_args *uap)
839 pid_t pid = uap->pid;
842 * A tid is mandatory for lwp_kill(), otherwise
843 * you could simply use kill().
849 * To save on a getpid() function call for intra-process
850 * signals, pid == -1 means current process.
853 pid = curproc->p_pid;
855 error = kern_kill(uap->signum, pid, uap->tid);
860 * Send a signal to a process group.
863 gsignal(int pgid, int sig)
867 if (pgid && (pgrp = pgfind(pgid)))
868 pgsignal(pgrp, sig, 0);
872 * Send a signal to a process group. If checktty is 1,
873 * limit to members which have a controlling terminal.
875 * pg_lock interlocks against a fork that might be in progress, to
876 * ensure that the new child process picks up the signal.
879 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
884 * Must interlock all signals against fork
888 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
889 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
890 if (checkctty == 0 || p->p_flags & P_CONTROLT)
893 lockmgr(&pgrp->pg_lock, LK_RELEASE);
899 * Send a signal caused by a trap to the current lwp. If it will be caught
900 * immediately, deliver it with correct code. Otherwise, post it normally.
902 * These signals may ONLY be delivered to the specified lwp and may never
903 * be delivered to the process generically.
906 trapsignal(struct lwp *lp, int sig, u_long code)
908 struct proc *p = lp->lwp_proc;
909 struct sigacts *ps = p->p_sigacts;
912 * If we are a virtual kernel running an emulated user process
913 * context, switch back to the virtual kernel context before
914 * trying to post the signal.
916 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
917 struct trapframe *tf = lp->lwp_md.md_regs;
919 vkernel_trap(lp, tf);
923 if ((p->p_flags & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
924 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
925 lp->lwp_ru.ru_nsignals++;
927 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
928 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
929 &lp->lwp_sigmask, code);
931 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
932 &lp->lwp_sigmask, code);
933 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
934 if (!SIGISMEMBER(ps->ps_signodefer, sig))
935 SIGADDSET(lp->lwp_sigmask, sig);
936 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
938 * See kern_sigaction() for origin of this code.
940 SIGDELSET(p->p_sigcatch, sig);
941 if (sig != SIGCONT &&
942 sigprop(sig) & SA_IGNORE)
943 SIGADDSET(p->p_sigignore, sig);
944 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
947 lp->lwp_code = code; /* XXX for core dump/debugger */
948 lp->lwp_sig = sig; /* XXX to verify code */
949 lwpsignal(p, lp, sig);
954 * Find a suitable lwp to deliver the signal to. Returns NULL if all
955 * lwps hold the signal blocked.
957 * Caller must hold p->p_token.
959 * Returns a lp or NULL. If non-NULL the lp is held and its token is
963 find_lwp_for_signal(struct proc *p, int sig)
966 struct lwp *run, *sleep, *stop;
969 * If the running/preempted thread belongs to the proc to which
970 * the signal is being delivered and this thread does not block
971 * the signal, then we can avoid a context switch by delivering
972 * the signal to this thread, because it will return to userland
975 lp = lwkt_preempted_proc();
976 if (lp != NULL && lp->lwp_proc == p) {
978 lwkt_gettoken(&lp->lwp_token);
979 if (!SIGISMEMBER(lp->lwp_sigmask, sig)) {
980 /* return w/ token held */
983 lwkt_reltoken(&lp->lwp_token);
987 run = sleep = stop = NULL;
988 FOREACH_LWP_IN_PROC(lp, p) {
990 * If the signal is being blocked by the lwp, then this
991 * lwp is not eligible for receiving the signal.
994 lwkt_gettoken(&lp->lwp_token);
996 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
997 lwkt_reltoken(&lp->lwp_token);
1002 switch (lp->lwp_stat) {
1006 lwkt_reltoken(&sleep->lwp_token);
1012 lwkt_reltoken(&stop->lwp_token);
1021 if (lp->lwp_flags & LWP_SINTR) {
1023 lwkt_reltoken(&lp->lwp_token);
1027 lwkt_reltoken(&stop->lwp_token);
1035 lwkt_reltoken(&lp->lwp_token);
1041 lwkt_reltoken(&lp->lwp_token);
1044 lwkt_reltoken(&lp->lwp_token);
1057 else if (sleep != NULL)
1064 * Send the signal to the process. If the signal has an action, the action
1065 * is usually performed by the target process rather than the caller; we add
1066 * the signal to the set of pending signals for the process.
1069 * o When a stop signal is sent to a sleeping process that takes the
1070 * default action, the process is stopped without awakening it.
1071 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1072 * regardless of the signal action (eg, blocked or ignored).
1074 * Other ignored signals are discarded immediately.
1076 * If the caller wishes to call this function from a hard code section the
1077 * caller must already hold p->p_token (see kern_clock.c).
1082 ksignal(struct proc *p, int sig)
1084 lwpsignal(p, NULL, sig);
1088 * The core for ksignal. lp may be NULL, then a suitable thread
1089 * will be chosen. If not, lp MUST be a member of p.
1091 * If the caller wishes to call this function from a hard code section the
1092 * caller must already hold p->p_token.
1097 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1103 if (sig > _SIG_MAXSIG || sig <= 0) {
1104 kprintf("lwpsignal: signal %d\n", sig);
1105 panic("lwpsignal signal number");
1108 KKASSERT(lp == NULL || lp->lwp_proc == p);
1111 * We don't want to race... well, all sorts of things. Get appropriate
1114 * Don't try to deliver a generic signal to an exiting process,
1115 * the signal structures could be in flux. We check the LWP later
1119 lwkt_gettoken(&p->p_token);
1122 lwkt_gettoken(&lp->lwp_token);
1123 } else if (p->p_flags & P_WEXIT) {
1127 prop = sigprop(sig);
1130 * If proc is traced, always give parent a chance;
1131 * if signal event is tracked by procfs, give *that*
1132 * a chance, as well.
1134 if ((p->p_flags & P_TRACED) || (p->p_stops & S_SIG)) {
1138 * Do not try to deliver signals to an exiting lwp. Note
1139 * that we must still deliver the signal if P_WEXIT is set
1140 * in the process flags.
1142 if (lp && (lp->lwp_mpflags & LWP_MP_WEXIT)) {
1144 lwkt_reltoken(&lp->lwp_token);
1147 lwkt_reltoken(&p->p_token);
1153 * If the signal is being ignored, then we forget about
1154 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1155 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1157 if (SIGISMEMBER(p->p_sigignore, sig)) {
1159 * Even if a signal is set SIG_IGN, it may still be
1160 * lurking in a kqueue.
1162 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1164 lwkt_reltoken(&lp->lwp_token);
1167 lwkt_reltoken(&p->p_token);
1171 if (SIGISMEMBER(p->p_sigcatch, sig))
1178 * If continuing, clear any pending STOP signals.
1181 SIG_STOPSIGMASK(p->p_siglist);
1183 if (prop & SA_STOP) {
1185 * If sending a tty stop signal to a member of an orphaned
1186 * process group, discard the signal here if the action
1187 * is default; don't stop the process below if sleeping,
1188 * and don't clear any pending SIGCONT.
1190 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1191 action == SIG_DFL) {
1192 lwkt_reltoken(&p->p_token);
1196 SIG_CONTSIGMASK(p->p_siglist);
1197 p->p_flags &= ~P_CONTINUED;
1200 if (p->p_stat == SSTOP) {
1202 * Nobody can handle this signal, add it to the lwp or
1203 * process pending list
1206 spin_lock(&lp->lwp_spin);
1207 SIGADDSET(lp->lwp_siglist, sig);
1208 spin_unlock(&lp->lwp_spin);
1210 SIGADDSET(p->p_siglist, sig);
1214 * If the process is stopped and is being traced, then no
1215 * further action is necessary.
1217 if (p->p_flags & P_TRACED)
1221 * If the process is stopped and receives a KILL signal,
1222 * make the process runnable.
1224 if (sig == SIGKILL) {
1226 goto active_process;
1230 * If the process is stopped and receives a CONT signal,
1231 * then try to make the process runnable again.
1233 if (prop & SA_CONT) {
1235 * If SIGCONT is default (or ignored), we continue the
1236 * process but don't leave the signal in p_siglist, as
1237 * it has no further action. If SIGCONT is held, we
1238 * continue the process and leave the signal in
1239 * p_siglist. If the process catches SIGCONT, let it
1240 * handle the signal itself.
1242 * XXX what if the signal is being held blocked?
1244 * Token required to interlock kern_wait().
1245 * Reparenting can also cause a race so we have to
1250 lwkt_gettoken(&q->p_token);
1251 p->p_flags |= P_CONTINUED;
1253 if (action == SIG_DFL)
1254 SIGDELSET(p->p_siglist, sig);
1256 lwkt_reltoken(&q->p_token);
1258 if (action == SIG_CATCH)
1259 goto active_process;
1264 * If the process is stopped and receives another STOP
1265 * signal, we do not need to stop it again. If we did
1266 * the shell could get confused.
1268 * However, if the current/preempted lwp is part of the
1269 * process receiving the signal, we need to keep it,
1270 * so that this lwp can stop in issignal() later, as
1271 * we don't want to wait until it reaches userret!
1273 if (prop & SA_STOP) {
1274 if (lwkt_preempted_proc() == NULL ||
1275 lwkt_preempted_proc()->lwp_proc != p)
1276 SIGDELSET(p->p_siglist, sig);
1280 * Otherwise the process is stopped and it received some
1281 * signal, which does not change its stopped state. When
1282 * the process is continued a wakeup(p) will be issued which
1283 * will wakeup any threads sleeping in tstop().
1286 /* NOTE: returns lp w/ token held */
1287 lp = find_lwp_for_signal(p, sig);
1293 /* else not stopped */
1297 * Never deliver a lwp-specific signal to a random lwp.
1300 /* NOTE: returns lp w/ token held */
1301 lp = find_lwp_for_signal(p, sig);
1303 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
1304 lwkt_reltoken(&lp->lwp_token);
1312 * Deliver to the process generically if (1) the signal is being
1313 * sent to any thread or (2) we could not find a thread to deliver
1317 SIGADDSET(p->p_siglist, sig);
1322 * Deliver to a specific LWP whether it masks it or not. It will
1323 * not be dispatched if masked but we must still deliver it.
1325 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1326 (p->p_flags & P_TRACED) == 0) {
1331 * If the process receives a STOP signal which indeed needs to
1332 * stop the process, do so. If the process chose to catch the
1333 * signal, it will be treated like any other signal.
1335 if ((prop & SA_STOP) && action == SIG_DFL) {
1337 * If a child holding parent blocked, stopping
1338 * could cause deadlock. Take no action at this
1341 if (p->p_flags & P_PPWAIT) {
1342 SIGADDSET(p->p_siglist, sig);
1347 * Do not actually try to manipulate the process, but simply
1348 * stop it. Lwps will stop as soon as they safely can.
1350 * Ignore stop if the process is exiting.
1352 if ((p->p_flags & P_WEXIT) == 0) {
1360 * If it is a CONT signal with default action, just ignore it.
1362 if ((prop & SA_CONT) && action == SIG_DFL)
1366 * Mark signal pending at this specific thread.
1368 spin_lock(&lp->lwp_spin);
1369 SIGADDSET(lp->lwp_siglist, sig);
1370 spin_unlock(&lp->lwp_spin);
1376 lwkt_reltoken(&lp->lwp_token);
1379 lwkt_reltoken(&p->p_token);
1384 * Notify the LWP that a signal has arrived. The LWP does not have to be
1385 * sleeping on the current cpu.
1387 * p->p_token and lp->lwp_token must be held on call.
1389 * We can only safely schedule the thread on its current cpu and only if
1390 * one of the SINTR flags is set. If an SINTR flag is set AND we are on
1391 * the correct cpu we are properly interlocked, otherwise we could be
1392 * racing other thread transition states (or the lwp is on the user scheduler
1393 * runq but not scheduled) and must not do anything.
1395 * Since we hold the lwp token we know the lwp cannot be ripped out from
1396 * under us so we can safely hold it to prevent it from being ripped out
1397 * from under us if we are forced to IPI another cpu to make the local
1400 * Adjustment of lp->lwp_stat can only occur when we hold the lwp_token,
1401 * which we won't in an IPI so any fixups have to be done here, effectively
1402 * replicating part of what setrunnable() does.
1405 lwp_signotify(struct lwp *lp)
1407 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
1410 if (lp == lwkt_preempted_proc()) {
1412 * lwp is on the current cpu AND it is currently running
1413 * (we preempted it).
1416 } else if (lp->lwp_flags & LWP_SINTR) {
1418 * lwp is sitting in tsleep() with PCATCH set
1421 if (lp->lwp_thread->td_gd == mycpu) {
1425 * We can only adjust lwp_stat while we hold the
1426 * lwp_token, and we won't in the IPI function.
1429 if (lp->lwp_stat == LSSTOP)
1430 lp->lwp_stat = LSSLEEP;
1431 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1432 lwp_signotify_remote, lp);
1437 } else if (lp->lwp_thread->td_flags & TDF_SINTR) {
1439 * lwp is sitting in lwkt_sleep() with PCATCH set.
1442 if (lp->lwp_thread->td_gd == mycpu) {
1446 * We can only adjust lwp_stat while we hold the
1447 * lwp_token, and we won't in the IPI function.
1450 if (lp->lwp_stat == LSSTOP)
1451 lp->lwp_stat = LSSLEEP;
1452 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1453 lwp_signotify_remote, lp);
1460 * Otherwise the lwp is either in some uninterruptable state
1461 * or it is on the userland scheduler's runqueue waiting to
1462 * be scheduled to a cpu.
1471 * This function is called via an IPI so we cannot call setrunnable() here
1472 * (because while we hold the lp we don't own its token, and can't get it
1475 * We are interlocked by virtue of being on the same cpu as the target. If
1476 * we still are and LWP_SINTR or TDF_SINTR is set we can safely schedule
1477 * the target thread.
1480 lwp_signotify_remote(void *arg)
1482 struct lwp *lp = arg;
1483 thread_t td = lp->lwp_thread;
1485 if (lp == lwkt_preempted_proc()) {
1488 } else if (td->td_gd == mycpu) {
1489 if ((lp->lwp_flags & LWP_SINTR) ||
1490 (td->td_flags & TDF_SINTR)) {
1495 lwkt_send_ipiq(td->td_gd, lwp_signotify_remote, lp);
1496 /* LWPHOLD() is forwarded to the target cpu */
1503 * Caller must hold p->p_token
1506 proc_stop(struct proc *p)
1511 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1513 /* If somebody raced us, be happy with it */
1514 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1519 FOREACH_LWP_IN_PROC(lp, p) {
1521 lwkt_gettoken(&lp->lwp_token);
1523 switch (lp->lwp_stat) {
1526 * Do nothing, we are already counted in
1533 * We're sleeping, but we will stop before
1534 * returning to userspace, so count us
1535 * as stopped as well. We set LWP_MP_WSTOP
1536 * to signal the lwp that it should not
1537 * increase p_nstopped when reaching tstop().
1539 * LWP_MP_WSTOP is protected by lp->lwp_token.
1541 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1542 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1549 * We might notify ourself, but that's not
1555 lwkt_reltoken(&lp->lwp_token);
1559 if (p->p_nstopped == p->p_nthreads) {
1561 * Token required to interlock kern_wait(). Reparenting can
1562 * also cause a race so we have to hold (q).
1566 lwkt_gettoken(&q->p_token);
1567 p->p_flags &= ~P_WAITED;
1569 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1570 ksignal(p->p_pptr, SIGCHLD);
1571 lwkt_reltoken(&q->p_token);
1577 * Caller must hold proc_token
1580 proc_unstop(struct proc *p)
1584 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1586 if (p->p_stat != SSTOP)
1589 p->p_stat = SACTIVE;
1591 FOREACH_LWP_IN_PROC(lp, p) {
1593 lwkt_gettoken(&lp->lwp_token);
1595 switch (lp->lwp_stat) {
1598 * Uh? Not stopped? Well, I guess that's okay.
1601 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1602 p->p_pid, lp->lwp_tid);
1607 * Still sleeping. Don't bother waking it up.
1608 * However, if this thread was counted as
1609 * stopped, undo this.
1611 * Nevertheless we call setrunnable() so that it
1612 * will wake up in case a signal or timeout arrived
1615 * LWP_MP_WSTOP is protected by lp->lwp_token.
1617 if (lp->lwp_mpflags & LWP_MP_WSTOP) {
1618 atomic_clear_int(&lp->lwp_mpflags,
1623 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1624 p->p_pid, lp->lwp_tid);
1630 * This handles any lwp's waiting in a tsleep with
1637 lwkt_reltoken(&lp->lwp_token);
1642 * This handles any lwp's waiting in tstop(). We have interlocked
1643 * the setting of p_stat by acquiring and releasing each lpw's
1653 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1655 sigset_t savedmask, set;
1656 struct proc *p = curproc;
1657 struct lwp *lp = curthread->td_lwp;
1658 int error, sig, hz, timevalid = 0;
1659 struct timespec rts, ets, ts;
1664 ets.tv_sec = 0; /* silence compiler warning */
1665 ets.tv_nsec = 0; /* silence compiler warning */
1666 SIG_CANTMASK(waitset);
1667 savedmask = lp->lwp_sigmask;
1670 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1671 timeout->tv_nsec < 1000000000) {
1673 getnanouptime(&rts);
1675 timespecadd(&ets, timeout);
1680 set = lwp_sigpend(lp);
1681 SIGSETAND(set, waitset);
1682 if ((sig = sig_ffs(&set)) != 0) {
1683 SIGFILLSET(lp->lwp_sigmask);
1684 SIGDELSET(lp->lwp_sigmask, sig);
1685 SIG_CANTMASK(lp->lwp_sigmask);
1686 sig = issignal(lp, 1);
1688 * It may be a STOP signal, in the case, issignal
1689 * returns 0, because we may stop there, and new
1690 * signal can come in, we should restart if we got
1700 * Previous checking got nothing, and we retried but still
1701 * got nothing, we should return the error status.
1707 * POSIX says this must be checked after looking for pending
1711 if (timevalid == 0) {
1715 getnanouptime(&rts);
1716 if (timespeccmp(&rts, &ets, >=)) {
1721 timespecsub(&ts, &rts);
1722 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1723 hz = tvtohz_high(&tv);
1728 lp->lwp_sigmask = savedmask;
1729 SIGSETNAND(lp->lwp_sigmask, waitset);
1731 * We won't ever be woken up. Instead, our sleep will
1732 * be broken in lwpsignal().
1734 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1736 if (error == ERESTART) {
1737 /* can not restart a timeout wait. */
1739 } else if (error == EAGAIN) {
1740 /* will calculate timeout by ourself. */
1747 lp->lwp_sigmask = savedmask;
1750 bzero(info, sizeof(*info));
1751 info->si_signo = sig;
1752 spin_lock(&lp->lwp_spin);
1753 lwp_delsig(lp, sig); /* take the signal! */
1754 spin_unlock(&lp->lwp_spin);
1756 if (sig == SIGKILL) {
1769 sys_sigtimedwait(struct sigtimedwait_args *uap)
1772 struct timespec *timeout;
1778 error = copyin(uap->timeout, &ts, sizeof(ts));
1785 error = copyin(uap->set, &set, sizeof(set));
1788 error = kern_sigtimedwait(set, &info, timeout);
1792 error = copyout(&info, uap->info, sizeof(info));
1793 /* Repost if we got an error. */
1797 * This could transform a thread-specific signal to another
1798 * thread / process pending signal.
1801 ksignal(curproc, info.si_signo);
1803 uap->sysmsg_result = info.si_signo;
1812 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1818 error = copyin(uap->set, &set, sizeof(set));
1821 error = kern_sigtimedwait(set, &info, NULL);
1825 error = copyout(&info, uap->info, sizeof(info));
1826 /* Repost if we got an error. */
1830 * This could transform a thread-specific signal to another
1831 * thread / process pending signal.
1834 ksignal(curproc, info.si_signo);
1836 uap->sysmsg_result = info.si_signo;
1842 * If the current process has received a signal that would interrupt a
1843 * system call, return EINTR or ERESTART as appropriate.
1846 iscaught(struct lwp *lp)
1848 struct proc *p = lp->lwp_proc;
1852 if ((sig = CURSIG(lp)) != 0) {
1853 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1858 return(EWOULDBLOCK);
1862 * If the current process has received a signal (should be caught or cause
1863 * termination, should interrupt current syscall), return the signal number.
1864 * Stop signals with default action are processed immediately, then cleared;
1865 * they aren't returned. This is checked after each entry to the system for
1866 * a syscall or trap (though this can usually be done without calling issignal
1867 * by checking the pending signal masks in the CURSIG macro).
1869 * This routine is called via CURSIG/__cursig. We will acquire and release
1870 * p->p_token but if the caller needs to interlock the test the caller must
1871 * also hold p->p_token.
1873 * while (sig = CURSIG(curproc))
1879 issignal(struct lwp *lp, int maytrace)
1881 struct proc *p = lp->lwp_proc;
1885 lwkt_gettoken(&p->p_token);
1888 int traced = (p->p_flags & P_TRACED) || (p->p_stops & S_SIG);
1891 * If this process is supposed to stop, stop this thread.
1893 if (p->p_stat == SSTOP)
1896 mask = lwp_sigpend(lp);
1897 SIGSETNAND(mask, lp->lwp_sigmask);
1898 if (p->p_flags & P_PPWAIT)
1899 SIG_STOPSIGMASK(mask);
1900 if (SIGISEMPTY(mask)) { /* no signal to send */
1901 lwkt_reltoken(&p->p_token);
1904 sig = sig_ffs(&mask);
1906 STOPEVENT(p, S_SIG, sig);
1909 * We should see pending but ignored signals
1910 * only if P_TRACED was on when they were posted.
1912 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1913 spin_lock(&lp->lwp_spin);
1914 lwp_delsig(lp, sig);
1915 spin_unlock(&lp->lwp_spin);
1919 (p->p_flags & P_TRACED) &&
1920 (p->p_flags & P_PPWAIT) == 0) {
1922 * If traced, always stop, and stay stopped until
1923 * released by the parent.
1925 * NOTE: SSTOP may get cleared during the loop,
1926 * but we do not re-notify the parent if we have
1927 * to loop several times waiting for the parent
1928 * to let us continue.
1930 * XXX not sure if this is still true
1936 } while (!trace_req(p) && (p->p_flags & P_TRACED));
1939 * If parent wants us to take the signal,
1940 * then it will leave it in p->p_xstat;
1941 * otherwise we just look for signals again.
1943 spin_lock(&lp->lwp_spin);
1944 lwp_delsig(lp, sig); /* clear old signal */
1945 spin_unlock(&lp->lwp_spin);
1951 * Put the new signal into p_siglist. If the
1952 * signal is being masked, look for other signals.
1954 * XXX lwp might need a call to ksignal()
1956 SIGADDSET(p->p_siglist, sig);
1957 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1961 * If the traced bit got turned off, go back up
1962 * to the top to rescan signals. This ensures
1963 * that p_sig* and ps_sigact are consistent.
1965 if ((p->p_flags & P_TRACED) == 0)
1969 prop = sigprop(sig);
1972 * Decide whether the signal should be returned.
1973 * Return the signal's number, or fall through
1974 * to clear it from the pending mask.
1976 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1977 case (intptr_t)SIG_DFL:
1979 * Don't take default actions on system processes.
1981 if (p->p_pid <= 1) {
1984 * Are you sure you want to ignore SIGSEGV
1987 kprintf("Process (pid %lu) got signal %d\n",
1988 (u_long)p->p_pid, sig);
1990 break; /* == ignore */
1994 * Handle the in-kernel checkpoint action
1996 if (prop & SA_CKPT) {
1997 checkpoint_signal_handler(lp);
2002 * If there is a pending stop signal to process
2003 * with default action, stop here,
2004 * then clear the signal. However,
2005 * if process is member of an orphaned
2006 * process group, ignore tty stop signals.
2008 if (prop & SA_STOP) {
2009 if (p->p_flags & P_TRACED ||
2010 (p->p_pgrp->pg_jobc == 0 &&
2012 break; /* == ignore */
2013 if ((p->p_flags & P_WEXIT) == 0) {
2019 } else if (prop & SA_IGNORE) {
2021 * Except for SIGCONT, shouldn't get here.
2022 * Default action is to ignore; drop it.
2024 break; /* == ignore */
2026 lwkt_reltoken(&p->p_token);
2032 case (intptr_t)SIG_IGN:
2034 * Masking above should prevent us ever trying
2035 * to take action on an ignored signal other
2036 * than SIGCONT, unless process is traced.
2038 if ((prop & SA_CONT) == 0 &&
2039 (p->p_flags & P_TRACED) == 0)
2040 kprintf("issignal\n");
2041 break; /* == ignore */
2045 * This signal has an action, let
2046 * postsig() process it.
2048 lwkt_reltoken(&p->p_token);
2051 spin_lock(&lp->lwp_spin);
2052 lwp_delsig(lp, sig); /* take the signal! */
2053 spin_unlock(&lp->lwp_spin);
2059 * Take the action for the specified signal
2060 * from the current set of pending signals.
2062 * Caller must hold p->p_token
2067 struct lwp *lp = curthread->td_lwp;
2068 struct proc *p = lp->lwp_proc;
2069 struct sigacts *ps = p->p_sigacts;
2071 sigset_t returnmask;
2074 KASSERT(sig != 0, ("postsig"));
2076 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
2079 * If we are a virtual kernel running an emulated user process
2080 * context, switch back to the virtual kernel context before
2081 * trying to post the signal.
2083 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
2084 struct trapframe *tf = lp->lwp_md.md_regs;
2086 vkernel_trap(lp, tf);
2089 spin_lock(&lp->lwp_spin);
2090 lwp_delsig(lp, sig);
2091 spin_unlock(&lp->lwp_spin);
2092 action = ps->ps_sigact[_SIG_IDX(sig)];
2094 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
2095 ktrpsig(lp, sig, action, lp->lwp_flags & LWP_OLDMASK ?
2096 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
2098 STOPEVENT(p, S_SIG, sig);
2100 if (action == SIG_DFL) {
2102 * Default action, where the default is to kill
2103 * the process. (Other cases were ignored above.)
2109 * If we get here, the signal must be caught.
2111 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
2112 ("postsig action"));
2115 * Reset the signal handler if asked to
2117 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2119 * See kern_sigaction() for origin of this code.
2121 SIGDELSET(p->p_sigcatch, sig);
2122 if (sig != SIGCONT &&
2123 sigprop(sig) & SA_IGNORE)
2124 SIGADDSET(p->p_sigignore, sig);
2125 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2129 * Set the signal mask and calculate the mask to restore
2130 * when the signal function returns.
2132 * Special case: user has done a sigsuspend. Here the
2133 * current mask is not of interest, but rather the
2134 * mask from before the sigsuspend is what we want
2135 * restored after the signal processing is completed.
2137 if (lp->lwp_flags & LWP_OLDMASK) {
2138 returnmask = lp->lwp_oldsigmask;
2139 lp->lwp_flags &= ~LWP_OLDMASK;
2141 returnmask = lp->lwp_sigmask;
2144 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2145 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2146 SIGADDSET(lp->lwp_sigmask, sig);
2148 lp->lwp_ru.ru_nsignals++;
2149 if (lp->lwp_sig != sig) {
2152 code = lp->lwp_code;
2156 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2161 * Kill the current process for stated reason.
2164 killproc(struct proc *p, char *why)
2166 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2167 p->p_pid, p->p_comm,
2168 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2169 ksignal(p, SIGKILL);
2173 * Force the current process to exit with the specified signal, dumping core
2174 * if appropriate. We bypass the normal tests for masked and caught signals,
2175 * allowing unrecoverable failures to terminate the process without changing
2176 * signal state. Mark the accounting record with the signal termination.
2177 * If dumping core, save the signal number for the debugger. Calls exit and
2180 * This routine does not return.
2183 sigexit(struct lwp *lp, int sig)
2185 struct proc *p = lp->lwp_proc;
2187 lwkt_gettoken(&p->p_token);
2188 p->p_acflag |= AXSIG;
2189 if (sigprop(sig) & SA_CORE) {
2192 * Log signals which would cause core dumps
2193 * (Log as LOG_INFO to appease those who don't want
2195 * XXX : Todo, as well as euid, write out ruid too
2197 if (coredump(lp, sig) == 0)
2199 if (kern_logsigexit)
2201 "pid %d (%s), uid %d: exited on signal %d%s\n",
2202 p->p_pid, p->p_comm,
2203 p->p_ucred ? p->p_ucred->cr_uid : -1,
2205 sig & WCOREFLAG ? " (core dumped)" : "");
2207 lwkt_reltoken(&p->p_token);
2208 exit1(W_EXITCODE(0, sig));
2212 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2213 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2214 sizeof(corefilename), "process corefile name format string");
2217 * expand_name(name, uid, pid)
2218 * Expand the name described in corefilename, using name, uid, and pid.
2219 * corefilename is a kprintf-like string, with three format specifiers:
2220 * %N name of process ("name")
2221 * %P process id (pid)
2223 * For example, "%N.core" is the default; they can be disabled completely
2224 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2225 * This is controlled by the sysctl variable kern.corefile (see above).
2229 expand_name(const char *name, uid_t uid, pid_t pid)
2232 char buf[11]; /* Buffer for pid/uid -- max 4B */
2234 char *format = corefilename;
2237 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2240 namelen = strlen(name);
2241 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2243 switch (format[i]) {
2244 case '%': /* Format character */
2246 switch (format[i]) {
2250 case 'N': /* process name */
2251 if ((n + namelen) > MAXPATHLEN) {
2252 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2253 pid, name, uid, temp, name);
2254 kfree(temp, M_TEMP);
2257 memcpy(temp+n, name, namelen);
2260 case 'P': /* process id */
2261 l = ksprintf(buf, "%u", pid);
2262 if ((n + l) > MAXPATHLEN) {
2263 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2264 pid, name, uid, temp, name);
2265 kfree(temp, M_TEMP);
2268 memcpy(temp+n, buf, l);
2271 case 'U': /* user id */
2272 l = ksprintf(buf, "%u", uid);
2273 if ((n + l) > MAXPATHLEN) {
2274 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2275 pid, name, uid, temp, name);
2276 kfree(temp, M_TEMP);
2279 memcpy(temp+n, buf, l);
2283 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2287 temp[n++] = format[i];
2295 * Dump a process' core. The main routine does some
2296 * policy checking, and creates the name of the coredump;
2297 * then it passes on a vnode and a size limit to the process-specific
2298 * coredump routine if there is one; if there _is not_ one, it returns
2299 * ENOSYS; otherwise it returns the error from the process-specific routine.
2301 * The parameter `lp' is the lwp which triggered the coredump.
2305 coredump(struct lwp *lp, int sig)
2307 struct proc *p = lp->lwp_proc;
2309 struct ucred *cred = p->p_ucred;
2311 struct nlookupdata nd;
2314 char *name; /* name of corefile */
2317 STOPEVENT(p, S_CORE, 0);
2319 if (((sugid_coredump == 0) && p->p_flags & P_SUGID) || do_coredump == 0)
2323 * Note that the bulk of limit checking is done after
2324 * the corefile is created. The exception is if the limit
2325 * for corefiles is 0, in which case we don't bother
2326 * creating the corefile at all. This layout means that
2327 * a corefile is truncated instead of not being created,
2328 * if it is larger than the limit.
2330 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2334 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2337 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2339 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2340 kfree(name, M_TEMP);
2346 nd.nl_open_vp = NULL;
2350 lf.l_whence = SEEK_SET;
2353 lf.l_type = F_WRLCK;
2354 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2358 /* Don't dump to non-regular files or files with links. */
2359 if (vp->v_type != VREG ||
2360 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2365 /* Don't dump to files current user does not own */
2366 if (vattr.va_uid != p->p_ucred->cr_uid) {
2372 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2374 VOP_SETATTR(vp, &vattr, cred);
2375 p->p_acflag |= ACORE;
2378 error = p->p_sysent->sv_coredump ?
2379 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2382 lf.l_type = F_UNLCK;
2383 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2385 error1 = vn_close(vp, FWRITE);
2392 * Nonexistent system call-- signal process (may want to handle it).
2393 * Flag error in case process won't see signal immediately (blocked or ignored).
2399 sys_nosys(struct nosys_args *args)
2401 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2406 * Send a SIGIO or SIGURG signal to a process or process group using
2407 * stored credentials rather than those of the current process.
2410 pgsigio(struct sigio *sigio, int sig, int checkctty)
2415 if (sigio->sio_pgid > 0) {
2416 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2418 ksignal(sigio->sio_proc, sig);
2419 } else if (sigio->sio_pgid < 0) {
2421 struct pgrp *pg = sigio->sio_pgrp;
2424 * Must interlock all signals against fork
2427 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2428 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
2429 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2430 (checkctty == 0 || (p->p_flags & P_CONTROLT)))
2433 lockmgr(&pg->pg_lock, LK_RELEASE);
2439 filt_sigattach(struct knote *kn)
2441 struct proc *p = curproc;
2443 kn->kn_ptr.p_proc = p;
2444 kn->kn_flags |= EV_CLEAR; /* automatically set */
2446 /* XXX lock the proc here while adding to the list? */
2447 knote_insert(&p->p_klist, kn);
2453 filt_sigdetach(struct knote *kn)
2455 struct proc *p = kn->kn_ptr.p_proc;
2457 knote_remove(&p->p_klist, kn);
2461 * signal knotes are shared with proc knotes, so we apply a mask to
2462 * the hint in order to differentiate them from process hints. This
2463 * could be avoided by using a signal-specific knote list, but probably
2464 * isn't worth the trouble.
2467 filt_signal(struct knote *kn, long hint)
2469 if (hint & NOTE_SIGNAL) {
2470 hint &= ~NOTE_SIGNAL;
2472 if (kn->kn_id == hint)
2475 return (kn->kn_data != 0);