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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 $
40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.35 2005/02/21 01:36:05 davidxu Exp $
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/sysproto.h>
49 #include <sys/signalvar.h>
50 #include <sys/resourcevar.h>
51 #include <sys/vnode.h>
52 #include <sys/event.h>
54 #include <sys/nlookup.h>
55 #include <sys/pioctl.h>
56 #include <sys/systm.h>
58 #include <sys/fcntl.h>
60 #include <sys/ktrace.h>
61 #include <sys/syslog.h>
63 #include <sys/sysent.h>
64 #include <sys/sysctl.h>
65 #include <sys/malloc.h>
66 #include <sys/unistd.h>
67 #include <sys/kern_syscall.h>
70 #include <machine/ipl.h>
71 #include <machine/cpu.h>
72 #include <machine/smp.h>
74 static int coredump(struct proc *);
75 static char *expand_name(const char *, uid_t, pid_t);
76 static int killpg(int sig, int pgid, int all);
77 static int sig_ffs(sigset_t *set);
78 static int sigprop(int sig);
79 static void stop(struct proc *);
81 static void signotify_remote(void *arg);
83 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
84 struct timespec *timeout);
86 static int filt_sigattach(struct knote *kn);
87 static void filt_sigdetach(struct knote *kn);
88 static int filt_signal(struct knote *kn, long hint);
90 struct filterops sig_filtops =
91 { 0, filt_sigattach, filt_sigdetach, filt_signal };
93 static int kern_logsigexit = 1;
94 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
96 "Log processes quitting on abnormal signals to syslog(3)");
99 * Can process p, with pcred pc, send the signal sig to process q?
101 #define CANSIGNAL(q, sig) \
102 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
103 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
106 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
108 #define CANSIGIO(ruid, uc, q) \
109 ((uc)->cr_uid == 0 || \
110 (ruid) == (q)->p_ucred->cr_ruid || \
111 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
112 (ruid) == (q)->p_ucred->cr_uid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_uid)
116 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
117 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
119 static int do_coredump = 1;
120 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
121 &do_coredump, 0, "Enable/Disable coredumps");
124 * Signal properties and actions.
125 * The array below categorizes the signals and their default actions
126 * according to the following properties:
128 #define SA_KILL 0x01 /* terminates process by default */
129 #define SA_CORE 0x02 /* ditto and coredumps */
130 #define SA_STOP 0x04 /* suspend process */
131 #define SA_TTYSTOP 0x08 /* ditto, from tty */
132 #define SA_IGNORE 0x10 /* ignore by default */
133 #define SA_CONT 0x20 /* continue if suspended */
134 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
135 #define SA_CKPT 0x80 /* checkpoint process */
138 static int sigproptbl[NSIG] = {
139 SA_KILL, /* SIGHUP */
140 SA_KILL, /* SIGINT */
141 SA_KILL|SA_CORE, /* SIGQUIT */
142 SA_KILL|SA_CORE, /* SIGILL */
143 SA_KILL|SA_CORE, /* SIGTRAP */
144 SA_KILL|SA_CORE, /* SIGABRT */
145 SA_KILL|SA_CORE, /* SIGEMT */
146 SA_KILL|SA_CORE, /* SIGFPE */
147 SA_KILL, /* SIGKILL */
148 SA_KILL|SA_CORE, /* SIGBUS */
149 SA_KILL|SA_CORE, /* SIGSEGV */
150 SA_KILL|SA_CORE, /* SIGSYS */
151 SA_KILL, /* SIGPIPE */
152 SA_KILL, /* SIGALRM */
153 SA_KILL, /* SIGTERM */
154 SA_IGNORE, /* SIGURG */
155 SA_STOP, /* SIGSTOP */
156 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
157 SA_IGNORE|SA_CONT, /* SIGCONT */
158 SA_IGNORE, /* SIGCHLD */
159 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
160 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
161 SA_IGNORE, /* SIGIO */
162 SA_KILL, /* SIGXCPU */
163 SA_KILL, /* SIGXFSZ */
164 SA_KILL, /* SIGVTALRM */
165 SA_KILL, /* SIGPROF */
166 SA_IGNORE, /* SIGWINCH */
167 SA_IGNORE, /* SIGINFO */
168 SA_KILL, /* SIGUSR1 */
169 SA_KILL, /* SIGUSR2 */
170 SA_IGNORE, /* SIGTHR */
171 SA_CKPT, /* SIGCKPT */
172 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
210 if (sig > 0 && sig < NSIG)
211 return (sigproptbl[_SIG_IDX(sig)]);
216 sig_ffs(sigset_t *set)
220 for (i = 0; i < _SIG_WORDS; i++)
222 return (ffs(set->__bits[i]) + (i * 32));
227 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
229 struct thread *td = curthread;
230 struct proc *p = td->td_proc;
231 struct sigacts *ps = p->p_sigacts;
233 if (sig <= 0 || sig > _SIG_MAXSIG)
237 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
238 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
240 if (SIGISMEMBER(ps->ps_sigonstack, sig))
241 oact->sa_flags |= SA_ONSTACK;
242 if (!SIGISMEMBER(ps->ps_sigintr, sig))
243 oact->sa_flags |= SA_RESTART;
244 if (SIGISMEMBER(ps->ps_sigreset, sig))
245 oact->sa_flags |= SA_RESETHAND;
246 if (SIGISMEMBER(ps->ps_signodefer, sig))
247 oact->sa_flags |= SA_NODEFER;
248 if (SIGISMEMBER(ps->ps_siginfo, sig))
249 oact->sa_flags |= SA_SIGINFO;
250 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP)
251 oact->sa_flags |= SA_NOCLDSTOP;
252 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT)
253 oact->sa_flags |= SA_NOCLDWAIT;
256 if ((sig == SIGKILL || sig == SIGSTOP) &&
257 act->sa_handler != SIG_DFL)
261 * Change setting atomically.
265 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
266 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
267 if (act->sa_flags & SA_SIGINFO) {
268 ps->ps_sigact[_SIG_IDX(sig)] =
269 (__sighandler_t *)act->sa_sigaction;
270 SIGADDSET(ps->ps_siginfo, sig);
272 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
273 SIGDELSET(ps->ps_siginfo, sig);
275 if (!(act->sa_flags & SA_RESTART))
276 SIGADDSET(ps->ps_sigintr, sig);
278 SIGDELSET(ps->ps_sigintr, sig);
279 if (act->sa_flags & SA_ONSTACK)
280 SIGADDSET(ps->ps_sigonstack, sig);
282 SIGDELSET(ps->ps_sigonstack, sig);
283 if (act->sa_flags & SA_RESETHAND)
284 SIGADDSET(ps->ps_sigreset, sig);
286 SIGDELSET(ps->ps_sigreset, sig);
287 if (act->sa_flags & SA_NODEFER)
288 SIGADDSET(ps->ps_signodefer, sig);
290 SIGDELSET(ps->ps_signodefer, sig);
291 if (sig == SIGCHLD) {
292 if (act->sa_flags & SA_NOCLDSTOP)
293 p->p_procsig->ps_flag |= PS_NOCLDSTOP;
295 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP;
296 if (act->sa_flags & SA_NOCLDWAIT) {
298 * Paranoia: since SA_NOCLDWAIT is implemented
299 * by reparenting the dying child to PID 1 (and
300 * trust it to reap the zombie), PID 1 itself
301 * is forbidden to set SA_NOCLDWAIT.
304 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
306 p->p_procsig->ps_flag |= PS_NOCLDWAIT;
308 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
312 * Set bit in p_sigignore for signals that are set to SIG_IGN,
313 * and for signals set to SIG_DFL where the default is to
314 * ignore. However, don't put SIGCONT in p_sigignore, as we
315 * have to restart the process.
317 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
318 (sigprop(sig) & SA_IGNORE &&
319 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
320 /* never to be seen again */
321 SIGDELSET(p->p_siglist, sig);
323 /* easier in psignal */
324 SIGADDSET(p->p_sigignore, sig);
325 SIGDELSET(p->p_sigcatch, sig);
327 SIGDELSET(p->p_sigignore, sig);
328 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
329 SIGDELSET(p->p_sigcatch, sig);
331 SIGADDSET(p->p_sigcatch, sig);
340 sigaction(struct sigaction_args *uap)
342 struct sigaction act, oact;
343 struct sigaction *actp, *oactp;
346 actp = (uap->act != NULL) ? &act : NULL;
347 oactp = (uap->oact != NULL) ? &oact : NULL;
349 error = copyin(uap->act, actp, sizeof(act));
353 error = kern_sigaction(uap->sig, actp, oactp);
354 if (oactp && !error) {
355 error = copyout(oactp, uap->oact, sizeof(oact));
361 * Initialize signal state for process 0;
362 * set to ignore signals that are ignored by default.
365 siginit(struct proc *p)
369 for (i = 1; i <= NSIG; i++)
370 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
371 SIGADDSET(p->p_sigignore, i);
375 * Reset signals for an exec of the specified process.
378 execsigs(struct proc *p)
380 struct sigacts *ps = p->p_sigacts;
384 * Reset caught signals. Held signals remain held
385 * through p_sigmask (unless they were caught,
386 * and are now ignored by default).
388 while (SIGNOTEMPTY(p->p_sigcatch)) {
389 sig = sig_ffs(&p->p_sigcatch);
390 SIGDELSET(p->p_sigcatch, sig);
391 if (sigprop(sig) & SA_IGNORE) {
393 SIGADDSET(p->p_sigignore, sig);
394 SIGDELSET(p->p_siglist, sig);
396 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
399 * Reset stack state to the user stack.
400 * Clear set of signals caught on the signal stack.
402 p->p_sigstk.ss_flags = SS_DISABLE;
403 p->p_sigstk.ss_size = 0;
404 p->p_sigstk.ss_sp = 0;
405 p->p_flag &= ~P_ALTSTACK;
407 * Reset no zombies if child dies flag as Solaris does.
409 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
413 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
415 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
416 * p == curproc. Also remember that in order to remain MP SAFE
417 * no spl*() calls may be made.
420 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
422 struct thread *td = curthread;
423 struct proc *p = td->td_proc;
427 *oset = p->p_sigmask;
434 SIGSETOR(p->p_sigmask, *set);
437 SIGSETNAND(p->p_sigmask, *set);
452 * sigprocmask() - MP SAFE
455 sigprocmask(struct sigprocmask_args *uap)
458 sigset_t *setp, *osetp;
461 setp = (uap->set != NULL) ? &set : NULL;
462 osetp = (uap->oset != NULL) ? &oset : NULL;
464 error = copyin(uap->set, setp, sizeof(set));
468 error = kern_sigprocmask(uap->how, setp, osetp);
469 if (osetp && !error) {
470 error = copyout(osetp, uap->oset, sizeof(oset));
476 kern_sigpending(struct __sigset *set)
478 struct thread *td = curthread;
479 struct proc *p = td->td_proc;
487 sigpending(struct sigpending_args *uap)
492 error = kern_sigpending(&set);
495 error = copyout(&set, uap->set, sizeof(set));
500 * Suspend process until signal, providing mask to be set
504 kern_sigsuspend(struct __sigset *set)
506 struct thread *td = curthread;
507 struct proc *p = td->td_proc;
508 struct sigacts *ps = p->p_sigacts;
511 * When returning from sigsuspend, we want
512 * the old mask to be restored after the
513 * signal handler has finished. Thus, we
514 * save it here and mark the sigacts structure
517 p->p_oldsigmask = p->p_sigmask;
518 p->p_flag |= P_OLDMASK;
522 while (tsleep(ps, PCATCH, "pause", 0) == 0)
524 /* always return EINTR rather than ERESTART... */
529 * Note nonstandard calling convention: libc stub passes mask, not
530 * pointer, to save a copyin.
533 sigsuspend(struct sigsuspend_args *uap)
538 error = copyin(uap->sigmask, &mask, sizeof(mask));
542 error = kern_sigsuspend(&mask);
548 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
550 struct thread *td = curthread;
551 struct proc *p = td->td_proc;
553 if ((p->p_flag & P_ALTSTACK) == 0)
554 p->p_sigstk.ss_flags |= SS_DISABLE;
560 if (ss->ss_flags & SS_DISABLE) {
561 if (p->p_sigstk.ss_flags & SS_ONSTACK)
563 p->p_flag &= ~P_ALTSTACK;
564 p->p_sigstk.ss_flags = ss->ss_flags;
566 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
568 p->p_flag |= P_ALTSTACK;
577 sigaltstack(struct sigaltstack_args *uap)
583 error = copyin(uap->ss, &ss, sizeof(ss));
588 error = kern_sigaltstack(uap->ss ? &ss : NULL,
589 uap->oss ? &oss : NULL);
591 if (error == 0 && uap->oss)
592 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
597 * Common code for kill process group/broadcast kill.
598 * cp is calling process.
601 killpg(int sig, int pgid, int all)
603 struct proc *cp = curproc;
612 FOREACH_PROC_IN_SYSTEM(p) {
613 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
614 p == cp || !CANSIGNAL(p, sig))
623 * zero pgid means send to my process group.
631 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
632 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
633 p->p_stat == SZOMB ||
641 return (nfound ? 0 : ESRCH);
645 kern_kill(int sig, int pid)
647 struct thread *td = curthread;
648 struct proc *p = td->td_proc;
650 if ((u_int)sig > _SIG_MAXSIG)
653 /* kill single process */
654 if ((p = pfind(pid)) == NULL)
656 if (!CANSIGNAL(p, sig))
663 case -1: /* broadcast signal */
664 return (killpg(sig, 0, 1));
665 case 0: /* signal own process group */
666 return (killpg(sig, 0, 0));
667 default: /* negative explicit process group */
668 return (killpg(sig, -pid, 0));
674 kill(struct kill_args *uap)
678 error = kern_kill(uap->signum, uap->pid);
684 * Send a signal to a process group.
687 gsignal(int pgid, int sig)
691 if (pgid && (pgrp = pgfind(pgid)))
692 pgsignal(pgrp, sig, 0);
696 * Send a signal to a process group. If checktty is 1,
697 * limit to members which have a controlling terminal.
700 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
705 LIST_FOREACH(p, &pgrp->pg_members, p_pglist)
706 if (checkctty == 0 || p->p_flag & P_CONTROLT)
711 * Send a signal caused by a trap to the current process.
712 * If it will be caught immediately, deliver it with correct code.
713 * Otherwise, post it normally.
716 trapsignal(struct proc *p, int sig, u_long code)
718 struct sigacts *ps = p->p_sigacts;
720 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
721 !SIGISMEMBER(p->p_sigmask, sig)) {
722 p->p_stats->p_ru.ru_nsignals++;
724 if (KTRPOINT(p->p_thread, KTR_PSIG))
725 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)],
726 &p->p_sigmask, code);
728 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
729 &p->p_sigmask, code);
730 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
731 if (!SIGISMEMBER(ps->ps_signodefer, sig))
732 SIGADDSET(p->p_sigmask, sig);
733 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
735 * See kern_sigaction() for origin of this code.
737 SIGDELSET(p->p_sigcatch, sig);
738 if (sig != SIGCONT &&
739 sigprop(sig) & SA_IGNORE)
740 SIGADDSET(p->p_sigignore, sig);
741 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
744 p->p_code = code; /* XXX for core dump/debugger */
745 p->p_sig = sig; /* XXX to verify code */
751 * Send the signal to the process. If the signal has an action, the action
752 * is usually performed by the target process rather than the caller; we add
753 * the signal to the set of pending signals for the process.
756 * o When a stop signal is sent to a sleeping process that takes the
757 * default action, the process is stopped without awakening it.
758 * o SIGCONT restarts stopped processes (or puts them back to sleep)
759 * regardless of the signal action (eg, blocked or ignored).
761 * Other ignored signals are discarded immediately.
765 * temporary hack to allow checkpoint code to continue to
766 * be in a module for the moment
770 psignal(struct proc *p, int sig)
775 if (sig > _SIG_MAXSIG || sig <= 0) {
776 printf("psignal: signal %d\n", sig);
777 panic("psignal signal number");
781 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
787 * If proc is traced, always give parent a chance;
788 * if signal event is tracked by procfs, give *that*
791 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
795 * If the signal is being ignored,
796 * then we forget about it immediately.
797 * (Note: we don't set SIGCONT in p_sigignore,
798 * and if it is set to SIG_IGN,
799 * action will be SIG_DFL here.)
801 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
803 if (SIGISMEMBER(p->p_sigmask, sig))
805 else if (SIGISMEMBER(p->p_sigcatch, sig))
811 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
812 (p->p_flag & P_TRACED) == 0) {
817 SIG_STOPSIGMASK(p->p_siglist);
820 if (prop & SA_STOP) {
822 * If sending a tty stop signal to a member of an orphaned
823 * process group, discard the signal here if the action
824 * is default; don't stop the process below if sleeping,
825 * and don't clear any pending SIGCONT.
827 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
831 SIG_CONTSIGMASK(p->p_siglist);
833 SIGADDSET(p->p_siglist, sig);
836 * Defer further processing for signals which are held,
837 * except that stopped processes must be continued by SIGCONT.
839 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP))
845 * If process is sleeping uninterruptibly
846 * we can't interrupt the sleep... the signal will
847 * be noticed when the process returns through
848 * trap() or syscall().
850 if ((p->p_flag & P_SINTR) == 0)
853 * Process is sleeping and traced... make it runnable
854 * so it can discover the signal in issignal() and stop
857 if (p->p_flag & P_TRACED)
860 * If SIGCONT is default (or ignored) and process is
861 * asleep, we are finished; the process should not
864 if ((prop & SA_CONT) && action == SIG_DFL) {
865 SIGDELSET(p->p_siglist, sig);
869 * When a sleeping process receives a stop
870 * signal, process immediately if possible.
871 * All other (caught or default) signals
872 * cause the process to run.
874 if (prop & SA_STOP) {
875 if (action != SIG_DFL)
878 * If a child holding parent blocked,
879 * stopping could cause deadlock.
881 if (p->p_flag & P_PPWAIT)
883 SIGDELSET(p->p_siglist, sig);
885 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
886 psignal(p->p_pptr, SIGCHLD);
895 * If traced process is already stopped,
896 * then no further action is necessary.
898 if (p->p_flag & P_TRACED)
902 * Kill signal always sets processes running.
907 if (prop & SA_CONT) {
909 * If SIGCONT is default (or ignored), we continue the
910 * process but don't leave the signal in p_siglist, as
911 * it has no further action. If SIGCONT is held, we
912 * continue the process and leave the signal in
913 * p_siglist. If the process catches SIGCONT, let it
914 * handle the signal itself. If it isn't waiting on
915 * an event, then it goes back to run state.
916 * Otherwise, process goes back to sleep state.
918 if (action == SIG_DFL)
919 SIGDELSET(p->p_siglist, sig);
920 if (action == SIG_CATCH)
924 clrrunnable(p, SSLEEP);
928 if (prop & SA_STOP) {
930 * Already stopped, don't need to stop again.
931 * (If we did the shell could get confused.)
933 SIGDELSET(p->p_siglist, sig);
938 * If process is sleeping interruptibly, then simulate a
939 * wakeup so that when it is continued, it will be made
940 * runnable and can look at the signal. But don't make
941 * the process runnable, leave it stopped.
943 if (p->p_wchan && (p->p_flag & P_SINTR))
944 unsleep(p->p_thread);
948 * SRUN, SIDL, SZOMB do nothing with the signal,
949 * other than kicking ourselves if we are running.
950 * It will either never be noticed, or noticed very soon.
952 * Note that p_thread may be NULL or may not be completely
953 * initialized if the process is in the SIDL or SZOMB state.
955 * For SMP we may have to forward the request to another cpu.
956 * YYY the MP lock prevents the target process from moving
957 * to another cpu, see kern/kern_switch.c
959 * If the target thread is waiting on its message port,
960 * wakeup the target thread so it can check (or ignore)
961 * the new signal. YYY needs cleanup.
964 if (p == lwkt_preempted_proc()) {
966 } else if (p->p_stat == SRUN) {
967 struct thread *td = p->p_thread;
970 ("pid %d NULL p_thread stat %d flags %08x",
971 p->p_pid, p->p_stat, p->p_flag));
973 if (td->td_gd != mycpu)
974 lwkt_send_ipiq(td->td_gd, signotify_remote, p);
975 else if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
979 if (p == lwkt_preempted_proc()) {
981 } else if (p->p_stat == SRUN) {
982 struct thread *td = p->p_thread;
985 ("pid %d NULL p_thread stat %d flags %08x",
986 p->p_pid, p->p_stat, p->p_flag));
988 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1004 * This function is called via an IPI. We will be in a critical section but
1005 * the MP lock will NOT be held. Also note that by the time the ipi message
1006 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1009 signotify_remote(void *arg)
1011 struct proc *p = arg;
1013 if (p == lwkt_preempted_proc()) {
1016 struct thread *td = p->p_thread;
1017 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1025 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1027 sigset_t savedmask, set;
1028 struct proc *p = curproc;
1029 int error, sig, hz, timevalid = 0;
1030 struct timespec rts, ets, ts;
1035 SIG_CANTMASK(waitset);
1036 savedmask = p->p_sigmask;
1039 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1040 timeout->tv_nsec < 1000000000) {
1042 getnanouptime(&rts);
1044 timespecadd(&ets, timeout);
1050 SIGSETAND(set, waitset);
1051 if ((sig = sig_ffs(&set)) != 0) {
1052 SIGFILLSET(p->p_sigmask);
1053 SIGDELSET(p->p_sigmask, sig);
1056 * It may be a STOP signal, in the case, issignal
1057 * returns 0, because we may stop there, and new
1058 * signal can come in, we should restart if we got
1068 * Previous checking got nothing, and we retried but still
1069 * got nothing, we should return the error status.
1075 * POSIX says this must be checked after looking for pending
1083 getnanouptime(&rts);
1084 if (timespeccmp(&rts, &ets, >=)) {
1089 timespecsub(&ts, &rts);
1090 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1091 hz = tvtohz_high(&tv);
1095 p->p_sigmask = savedmask;
1096 SIGSETNAND(p->p_sigmask, waitset);
1097 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1099 if (error == ERESTART) {
1100 /* can not restart a timeout wait. */
1102 } else if (error == EAGAIN) {
1103 /* will calculate timeout by ourself. */
1110 p->p_sigmask = savedmask;
1113 bzero(info, sizeof(*info));
1114 info->si_signo = sig;
1115 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1121 sigtimedwait(struct sigtimedwait_args *uap)
1124 struct timespec *timeout;
1130 error = copyin(uap->timeout, &ts, sizeof(ts));
1137 error = copyin(uap->set, &set, sizeof(set));
1140 error = kern_sigtimedwait(set, &info, timeout);
1144 error = copyout(&info, uap->info, sizeof(info));
1145 /* Repost if we got an error. */
1147 psignal(curproc, info.si_signo);
1149 uap->sysmsg_result = info.si_signo;
1154 sigwaitinfo(struct sigwaitinfo_args *uap)
1160 error = copyin(uap->set, &set, sizeof(set));
1163 error = kern_sigtimedwait(set, &info, NULL);
1167 error = copyout(&info, uap->info, sizeof(info));
1168 /* Repost if we got an error. */
1170 psignal(curproc, info.si_signo);
1172 uap->sysmsg_result = info.si_signo;
1177 * If the current process has received a signal that would interrupt a
1178 * system call, return EINTR or ERESTART as appropriate.
1181 iscaught(struct proc *p)
1186 if ((sig = CURSIG(p)) != 0) {
1187 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1192 return(EWOULDBLOCK);
1196 * If the current process has received a signal (should be caught or cause
1197 * termination, should interrupt current syscall), return the signal number.
1198 * Stop signals with default action are processed immediately, then cleared;
1199 * they aren't returned. This is checked after each entry to the system for
1200 * a syscall or trap (though this can usually be done without calling issignal
1201 * by checking the pending signal masks in the CURSIG macro.) The normal call
1204 * while (sig = CURSIG(curproc))
1208 issignal(struct proc *p)
1214 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1216 mask = p->p_siglist;
1217 SIGSETNAND(mask, p->p_sigmask);
1218 if (p->p_flag & P_PPWAIT)
1219 SIG_STOPSIGMASK(mask);
1220 if (!SIGNOTEMPTY(mask)) /* no signal to send */
1222 sig = sig_ffs(&mask);
1224 STOPEVENT(p, S_SIG, sig);
1227 * We should see pending but ignored signals
1228 * only if P_TRACED was on when they were posted.
1230 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1231 SIGDELSET(p->p_siglist, sig);
1234 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
1236 * If traced, always stop, and stay
1237 * stopped until released by the parent.
1240 psignal(p->p_pptr, SIGCHLD);
1244 } while (!trace_req(p) && p->p_flag & P_TRACED);
1247 * If parent wants us to take the signal,
1248 * then it will leave it in p->p_xstat;
1249 * otherwise we just look for signals again.
1251 SIGDELSET(p->p_siglist, sig); /* clear old signal */
1257 * Put the new signal into p_siglist. If the
1258 * signal is being masked, look for other signals.
1260 SIGADDSET(p->p_siglist, sig);
1261 if (SIGISMEMBER(p->p_sigmask, sig))
1265 * If the traced bit got turned off, go back up
1266 * to the top to rescan signals. This ensures
1267 * that p_sig* and ps_sigact are consistent.
1269 if ((p->p_flag & P_TRACED) == 0)
1273 prop = sigprop(sig);
1276 * Decide whether the signal should be returned.
1277 * Return the signal's number, or fall through
1278 * to clear it from the pending mask.
1280 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1284 * Don't take default actions on system processes.
1286 if (p->p_pid <= 1) {
1289 * Are you sure you want to ignore SIGSEGV
1292 printf("Process (pid %lu) got signal %d\n",
1293 (u_long)p->p_pid, sig);
1295 break; /* == ignore */
1299 * Handle the in-kernel checkpoint action
1301 if (prop & SA_CKPT) {
1302 checkpoint_signal_handler(p);
1307 * If there is a pending stop signal to process
1308 * with default action, stop here,
1309 * then clear the signal. However,
1310 * if process is member of an orphaned
1311 * process group, ignore tty stop signals.
1313 if (prop & SA_STOP) {
1314 if (p->p_flag & P_TRACED ||
1315 (p->p_pgrp->pg_jobc == 0 &&
1317 break; /* == ignore */
1320 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
1321 psignal(p->p_pptr, SIGCHLD);
1324 } else if (prop & SA_IGNORE) {
1326 * Except for SIGCONT, shouldn't get here.
1327 * Default action is to ignore; drop it.
1329 break; /* == ignore */
1338 * Masking above should prevent us ever trying
1339 * to take action on an ignored signal other
1340 * than SIGCONT, unless process is traced.
1342 if ((prop & SA_CONT) == 0 &&
1343 (p->p_flag & P_TRACED) == 0)
1344 printf("issignal\n");
1345 break; /* == ignore */
1349 * This signal has an action, let
1350 * postsig() process it.
1354 SIGDELSET(p->p_siglist, sig); /* take the signal! */
1360 * Put the argument process into the stopped state and notify the parent
1361 * via wakeup. Signals are handled elsewhere. The process must not be
1365 stop(struct proc *p)
1368 p->p_flag &= ~P_WAITED;
1369 wakeup((caddr_t)p->p_pptr);
1373 * Take the action for the specified signal
1374 * from the current set of pending signals.
1379 struct proc *p = curproc;
1380 struct sigacts *ps = p->p_sigacts;
1382 sigset_t returnmask;
1385 KASSERT(sig != 0, ("postsig"));
1387 SIGDELSET(p->p_siglist, sig);
1388 action = ps->ps_sigact[_SIG_IDX(sig)];
1390 if (KTRPOINT(p->p_thread, KTR_PSIG))
1391 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ?
1392 &p->p_oldsigmask : &p->p_sigmask, 0);
1394 STOPEVENT(p, S_SIG, sig);
1396 if (action == SIG_DFL) {
1398 * Default action, where the default is to kill
1399 * the process. (Other cases were ignored above.)
1405 * If we get here, the signal must be caught.
1407 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig),
1408 ("postsig action"));
1410 * Set the new mask value and also defer further
1411 * occurrences of this signal.
1413 * Special case: user has done a sigsuspend. Here the
1414 * current mask is not of interest, but rather the
1415 * mask from before the sigsuspend is what we want
1416 * restored after the signal processing is completed.
1419 if (p->p_flag & P_OLDMASK) {
1420 returnmask = p->p_oldsigmask;
1421 p->p_flag &= ~P_OLDMASK;
1423 returnmask = p->p_sigmask;
1426 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1427 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1428 SIGADDSET(p->p_sigmask, sig);
1430 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1432 * See kern_sigaction() for origin of this code.
1434 SIGDELSET(p->p_sigcatch, sig);
1435 if (sig != SIGCONT &&
1436 sigprop(sig) & SA_IGNORE)
1437 SIGADDSET(p->p_sigignore, sig);
1438 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1441 p->p_stats->p_ru.ru_nsignals++;
1442 if (p->p_sig != sig) {
1449 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1454 * Kill the current process for stated reason.
1457 killproc(struct proc *p, char *why)
1459 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
1460 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1461 psignal(p, SIGKILL);
1465 * Force the current process to exit with the specified signal, dumping core
1466 * if appropriate. We bypass the normal tests for masked and caught signals,
1467 * allowing unrecoverable failures to terminate the process without changing
1468 * signal state. Mark the accounting record with the signal termination.
1469 * If dumping core, save the signal number for the debugger. Calls exit and
1473 sigexit(struct proc *p, int sig)
1475 p->p_acflag |= AXSIG;
1476 if (sigprop(sig) & SA_CORE) {
1479 * Log signals which would cause core dumps
1480 * (Log as LOG_INFO to appease those who don't want
1482 * XXX : Todo, as well as euid, write out ruid too
1484 if (coredump(p) == 0)
1486 if (kern_logsigexit)
1488 "pid %d (%s), uid %d: exited on signal %d%s\n",
1489 p->p_pid, p->p_comm,
1490 p->p_ucred ? p->p_ucred->cr_uid : -1,
1492 sig & WCOREFLAG ? " (core dumped)" : "");
1494 exit1(W_EXITCODE(0, sig));
1498 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1499 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1500 sizeof(corefilename), "process corefile name format string");
1503 * expand_name(name, uid, pid)
1504 * Expand the name described in corefilename, using name, uid, and pid.
1505 * corefilename is a printf-like string, with three format specifiers:
1506 * %N name of process ("name")
1507 * %P process id (pid)
1509 * For example, "%N.core" is the default; they can be disabled completely
1510 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1511 * This is controlled by the sysctl variable kern.corefile (see above).
1515 expand_name(const char *name, uid_t uid, pid_t pid)
1518 char buf[11]; /* Buffer for pid/uid -- max 4B */
1520 char *format = corefilename;
1523 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1526 namelen = strlen(name);
1527 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1529 switch (format[i]) {
1530 case '%': /* Format character */
1532 switch (format[i]) {
1536 case 'N': /* process name */
1537 if ((n + namelen) > MAXPATHLEN) {
1538 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1539 pid, name, uid, temp, name);
1543 memcpy(temp+n, name, namelen);
1546 case 'P': /* process id */
1547 l = sprintf(buf, "%u", pid);
1548 if ((n + l) > MAXPATHLEN) {
1549 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1550 pid, name, uid, temp, name);
1554 memcpy(temp+n, buf, l);
1557 case 'U': /* user id */
1558 l = sprintf(buf, "%u", uid);
1559 if ((n + l) > MAXPATHLEN) {
1560 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1561 pid, name, uid, temp, name);
1565 memcpy(temp+n, buf, l);
1569 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1573 temp[n++] = format[i];
1581 * Dump a process' core. The main routine does some
1582 * policy checking, and creates the name of the coredump;
1583 * then it passes on a vnode and a size limit to the process-specific
1584 * coredump routine if there is one; if there _is not_ one, it returns
1585 * ENOSYS; otherwise it returns the error from the process-specific routine.
1589 coredump(struct proc *p)
1592 struct ucred *cred = p->p_ucred;
1593 struct thread *td = p->p_thread;
1595 struct nlookupdata nd;
1598 char *name; /* name of corefile */
1601 STOPEVENT(p, S_CORE, 0);
1603 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
1607 * Note that the bulk of limit checking is done after
1608 * the corefile is created. The exception is if the limit
1609 * for corefiles is 0, in which case we don't bother
1610 * creating the corefile at all. This layout means that
1611 * a corefile is truncated instead of not being created,
1612 * if it is larger than the limit.
1614 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
1618 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
1621 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
1623 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
1630 nd.nl_open_vp = NULL;
1633 VOP_UNLOCK(vp, 0, td);
1634 lf.l_whence = SEEK_SET;
1637 lf.l_type = F_WRLCK;
1638 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK);
1642 /* Don't dump to non-regular files or files with links. */
1643 if (vp->v_type != VREG ||
1644 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) {
1650 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1652 VOP_LEASE(vp, td, cred, LEASE_WRITE);
1653 VOP_SETATTR(vp, &vattr, cred, td);
1654 p->p_acflag |= ACORE;
1655 VOP_UNLOCK(vp, 0, td);
1657 error = p->p_sysent->sv_coredump ?
1658 p->p_sysent->sv_coredump(p, vp, limit) : ENOSYS;
1661 lf.l_type = F_UNLCK;
1662 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
1664 error1 = vn_close(vp, FWRITE, td);
1671 * Nonexistent system call-- signal process (may want to handle it).
1672 * Flag error in case process won't see signal immediately (blocked or ignored).
1676 nosys(struct nosys_args *args)
1678 psignal(curproc, SIGSYS);
1683 * Send a SIGIO or SIGURG signal to a process or process group using
1684 * stored credentials rather than those of the current process.
1687 pgsigio(struct sigio *sigio, int sig, int checkctty)
1692 if (sigio->sio_pgid > 0) {
1693 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
1695 psignal(sigio->sio_proc, sig);
1696 } else if (sigio->sio_pgid < 0) {
1699 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist)
1700 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
1701 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
1707 filt_sigattach(struct knote *kn)
1709 struct proc *p = curproc;
1711 kn->kn_ptr.p_proc = p;
1712 kn->kn_flags |= EV_CLEAR; /* automatically set */
1714 /* XXX lock the proc here while adding to the list? */
1715 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
1721 filt_sigdetach(struct knote *kn)
1723 struct proc *p = kn->kn_ptr.p_proc;
1725 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
1729 * signal knotes are shared with proc knotes, so we apply a mask to
1730 * the hint in order to differentiate them from process hints. This
1731 * could be avoided by using a signal-specific knote list, but probably
1732 * isn't worth the trouble.
1735 filt_signal(struct knote *kn, long hint)
1737 if (hint & NOTE_SIGNAL) {
1738 hint &= ~NOTE_SIGNAL;
1740 if (kn->kn_id == hint)
1743 return (kn->kn_data != 0);