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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 1.74 2007/02/26 03:55:22 corecode 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/signal2.h>
51 #include <sys/resourcevar.h>
52 #include <sys/vnode.h>
53 #include <sys/event.h>
55 #include <sys/nlookup.h>
56 #include <sys/pioctl.h>
57 #include <sys/systm.h>
59 #include <sys/fcntl.h>
62 #include <sys/ktrace.h>
63 #include <sys/syslog.h>
65 #include <sys/sysent.h>
66 #include <sys/sysctl.h>
67 #include <sys/malloc.h>
68 #include <sys/interrupt.h>
69 #include <sys/unistd.h>
70 #include <sys/kern_syscall.h>
71 #include <sys/vkernel.h>
72 #include <sys/thread2.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);
83 static void signotify_remote(void *arg);
85 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
86 struct timespec *timeout);
88 static int filt_sigattach(struct knote *kn);
89 static void filt_sigdetach(struct knote *kn);
90 static int filt_signal(struct knote *kn, long hint);
92 struct filterops sig_filtops =
93 { 0, filt_sigattach, filt_sigdetach, filt_signal };
95 static int kern_logsigexit = 1;
96 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
98 "Log processes quitting on abnormal signals to syslog(3)");
101 * Can process p, with pcred pc, send the signal sig to process q?
103 #define CANSIGNAL(q, sig) \
104 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
105 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
108 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
110 #define CANSIGIO(ruid, uc, q) \
111 ((uc)->cr_uid == 0 || \
112 (ruid) == (q)->p_ucred->cr_ruid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
114 (ruid) == (q)->p_ucred->cr_uid || \
115 (uc)->cr_uid == (q)->p_ucred->cr_uid)
118 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
119 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
121 static int do_coredump = 1;
122 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
123 &do_coredump, 0, "Enable/Disable coredumps");
126 * Signal properties and actions.
127 * The array below categorizes the signals and their default actions
128 * according to the following properties:
130 #define SA_KILL 0x01 /* terminates process by default */
131 #define SA_CORE 0x02 /* ditto and coredumps */
132 #define SA_STOP 0x04 /* suspend process */
133 #define SA_TTYSTOP 0x08 /* ditto, from tty */
134 #define SA_IGNORE 0x10 /* ignore by default */
135 #define SA_CONT 0x20 /* continue if suspended */
136 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
137 #define SA_CKPT 0x80 /* checkpoint process */
140 static int sigproptbl[NSIG] = {
141 SA_KILL, /* SIGHUP */
142 SA_KILL, /* SIGINT */
143 SA_KILL|SA_CORE, /* SIGQUIT */
144 SA_KILL|SA_CORE, /* SIGILL */
145 SA_KILL|SA_CORE, /* SIGTRAP */
146 SA_KILL|SA_CORE, /* SIGABRT */
147 SA_KILL|SA_CORE, /* SIGEMT */
148 SA_KILL|SA_CORE, /* SIGFPE */
149 SA_KILL, /* SIGKILL */
150 SA_KILL|SA_CORE, /* SIGBUS */
151 SA_KILL|SA_CORE, /* SIGSEGV */
152 SA_KILL|SA_CORE, /* SIGSYS */
153 SA_KILL, /* SIGPIPE */
154 SA_KILL, /* SIGALRM */
155 SA_KILL, /* SIGTERM */
156 SA_IGNORE, /* SIGURG */
157 SA_STOP, /* SIGSTOP */
158 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
159 SA_IGNORE|SA_CONT, /* SIGCONT */
160 SA_IGNORE, /* SIGCHLD */
161 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
162 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
163 SA_IGNORE, /* SIGIO */
164 SA_KILL, /* SIGXCPU */
165 SA_KILL, /* SIGXFSZ */
166 SA_KILL, /* SIGVTALRM */
167 SA_KILL, /* SIGPROF */
168 SA_IGNORE, /* SIGWINCH */
169 SA_IGNORE, /* SIGINFO */
170 SA_KILL, /* SIGUSR1 */
171 SA_KILL, /* SIGUSR2 */
172 SA_IGNORE, /* SIGTHR */
173 SA_CKPT, /* SIGCKPT */
174 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
212 if (sig > 0 && sig < NSIG)
213 return (sigproptbl[_SIG_IDX(sig)]);
218 sig_ffs(sigset_t *set)
222 for (i = 0; i < _SIG_WORDS; i++)
224 return (ffs(set->__bits[i]) + (i * 32));
229 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
231 struct thread *td = curthread;
232 struct proc *p = td->td_proc;
234 struct sigacts *ps = p->p_sigacts;
236 if (sig <= 0 || sig > _SIG_MAXSIG)
240 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
241 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
243 if (SIGISMEMBER(ps->ps_sigonstack, sig))
244 oact->sa_flags |= SA_ONSTACK;
245 if (!SIGISMEMBER(ps->ps_sigintr, sig))
246 oact->sa_flags |= SA_RESTART;
247 if (SIGISMEMBER(ps->ps_sigreset, sig))
248 oact->sa_flags |= SA_RESETHAND;
249 if (SIGISMEMBER(ps->ps_signodefer, sig))
250 oact->sa_flags |= SA_NODEFER;
251 if (SIGISMEMBER(ps->ps_siginfo, sig))
252 oact->sa_flags |= SA_SIGINFO;
253 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
254 oact->sa_flags |= SA_MAILBOX;
255 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
256 oact->sa_flags |= SA_NOCLDSTOP;
257 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
258 oact->sa_flags |= SA_NOCLDWAIT;
262 * Check for invalid requests. KILL and STOP cannot be
265 if (sig == SIGKILL || sig == SIGSTOP) {
266 if (act->sa_handler != SIG_DFL)
269 /* (not needed, SIG_DFL forces action to occur) */
270 if (act->sa_flags & SA_MAILBOX)
276 * Change setting atomically.
280 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
281 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
282 if (act->sa_flags & SA_SIGINFO) {
283 ps->ps_sigact[_SIG_IDX(sig)] =
284 (__sighandler_t *)act->sa_sigaction;
285 SIGADDSET(ps->ps_siginfo, sig);
287 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
288 SIGDELSET(ps->ps_siginfo, sig);
290 if (!(act->sa_flags & SA_RESTART))
291 SIGADDSET(ps->ps_sigintr, sig);
293 SIGDELSET(ps->ps_sigintr, sig);
294 if (act->sa_flags & SA_ONSTACK)
295 SIGADDSET(ps->ps_sigonstack, sig);
297 SIGDELSET(ps->ps_sigonstack, sig);
298 if (act->sa_flags & SA_RESETHAND)
299 SIGADDSET(ps->ps_sigreset, sig);
301 SIGDELSET(ps->ps_sigreset, sig);
302 if (act->sa_flags & SA_NODEFER)
303 SIGADDSET(ps->ps_signodefer, sig);
305 SIGDELSET(ps->ps_signodefer, sig);
306 if (act->sa_flags & SA_MAILBOX)
307 SIGADDSET(ps->ps_sigmailbox, sig);
309 SIGDELSET(ps->ps_sigmailbox, sig);
310 if (sig == SIGCHLD) {
311 if (act->sa_flags & SA_NOCLDSTOP)
312 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
314 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
315 if (act->sa_flags & SA_NOCLDWAIT) {
317 * Paranoia: since SA_NOCLDWAIT is implemented
318 * by reparenting the dying child to PID 1 (and
319 * trust it to reap the zombie), PID 1 itself
320 * is forbidden to set SA_NOCLDWAIT.
323 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
325 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
327 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
331 * Set bit in p_sigignore for signals that are set to SIG_IGN,
332 * and for signals set to SIG_DFL where the default is to
333 * ignore. However, don't put SIGCONT in p_sigignore, as we
334 * have to restart the process.
336 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
337 (sigprop(sig) & SA_IGNORE &&
338 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
339 /* never to be seen again */
340 SIGDELSET(p->p_siglist, sig);
342 * Remove the signal also from the thread lists.
344 FOREACH_LWP_IN_PROC(lp, p) {
345 SIGDELSET(lp->lwp_siglist, sig);
348 /* easier in ksignal */
349 SIGADDSET(p->p_sigignore, sig);
350 SIGDELSET(p->p_sigcatch, sig);
352 SIGDELSET(p->p_sigignore, sig);
353 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
354 SIGDELSET(p->p_sigcatch, sig);
356 SIGADDSET(p->p_sigcatch, sig);
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 SIGDELSET(lp->lwp_siglist, sig);
425 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
429 * Reset stack state to the user stack.
430 * Clear set of signals caught on the signal stack.
432 lp->lwp_sigstk.ss_flags = SS_DISABLE;
433 lp->lwp_sigstk.ss_size = 0;
434 lp->lwp_sigstk.ss_sp = 0;
435 lp->lwp_flag &= ~LWP_ALTSTACK;
437 * Reset no zombies if child dies flag as Solaris does.
439 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
443 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
445 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
449 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
451 struct thread *td = curthread;
452 struct lwp *lp = td->td_lwp;
456 *oset = lp->lwp_sigmask;
463 SIGSETOR(lp->lwp_sigmask, *set);
466 SIGSETNAND(lp->lwp_sigmask, *set);
470 lp->lwp_sigmask = *set;
481 * sigprocmask() - MP SAFE
484 sys_sigprocmask(struct sigprocmask_args *uap)
487 sigset_t *setp, *osetp;
490 setp = (uap->set != NULL) ? &set : NULL;
491 osetp = (uap->oset != NULL) ? &oset : NULL;
493 error = copyin(uap->set, setp, sizeof(set));
497 error = kern_sigprocmask(uap->how, setp, osetp);
498 if (osetp && !error) {
499 error = copyout(osetp, uap->oset, sizeof(oset));
505 kern_sigpending(struct __sigset *set)
507 struct lwp *lp = curthread->td_lwp;
509 *set = lwp_sigpend(lp);
515 sys_sigpending(struct sigpending_args *uap)
520 error = kern_sigpending(&set);
523 error = copyout(&set, uap->set, sizeof(set));
528 * Suspend process until signal, providing mask to be set
532 kern_sigsuspend(struct __sigset *set)
534 struct thread *td = curthread;
535 struct lwp *lp = td->td_lwp;
536 struct proc *p = td->td_proc;
537 struct sigacts *ps = p->p_sigacts;
540 * When returning from sigsuspend, we want
541 * the old mask to be restored after the
542 * signal handler has finished. Thus, we
543 * save it here and mark the sigacts structure
546 lp->lwp_oldsigmask = lp->lwp_sigmask;
547 lp->lwp_flag |= LWP_OLDMASK;
550 lp->lwp_sigmask = *set;
551 while (tsleep(ps, PCATCH, "pause", 0) == 0)
553 /* always return EINTR rather than ERESTART... */
558 * Note nonstandard calling convention: libc stub passes mask, not
559 * pointer, to save a copyin.
562 sys_sigsuspend(struct sigsuspend_args *uap)
567 error = copyin(uap->sigmask, &mask, sizeof(mask));
571 error = kern_sigsuspend(&mask);
577 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
579 struct thread *td = curthread;
580 struct lwp *lp = td->td_lwp;
581 struct proc *p = td->td_proc;
583 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
584 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
587 *oss = lp->lwp_sigstk;
590 if (ss->ss_flags & SS_DISABLE) {
591 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
593 lp->lwp_flag &= ~LWP_ALTSTACK;
594 lp->lwp_sigstk.ss_flags = ss->ss_flags;
596 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
598 lp->lwp_flag |= LWP_ALTSTACK;
599 lp->lwp_sigstk = *ss;
607 sys_sigaltstack(struct sigaltstack_args *uap)
613 error = copyin(uap->ss, &ss, sizeof(ss));
618 error = kern_sigaltstack(uap->ss ? &ss : NULL,
619 uap->oss ? &oss : NULL);
621 if (error == 0 && uap->oss)
622 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
627 * Common code for kill process group/broadcast kill.
628 * cp is calling process.
635 static int killpg_all_callback(struct proc *p, void *data);
638 dokillpg(int sig, int pgid, int all)
640 struct killpg_info info;
641 struct proc *cp = curproc;
652 allproc_scan(killpg_all_callback, &info);
656 * zero pgid means send to my process group.
664 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
665 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
667 p->p_stat == SZOMB ||
668 (p->p_flag & P_SYSTEM) ||
669 !CANSIGNAL(p, sig)) {
676 lockmgr(&pgrp->pg_lock, LK_RELEASE);
678 return (info.nfound ? 0 : ESRCH);
682 killpg_all_callback(struct proc *p, void *data)
684 struct killpg_info *info = data;
686 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
687 p == curproc || !CANSIGNAL(p, info->sig)) {
692 ksignal(p, info->sig);
697 kern_kill(int sig, int pid)
699 struct thread *td = curthread;
700 struct proc *p = td->td_proc;
702 if ((u_int)sig > _SIG_MAXSIG)
705 /* kill single process */
706 if ((p = pfind(pid)) == NULL)
708 if (!CANSIGNAL(p, sig))
715 case -1: /* broadcast signal */
716 return (dokillpg(sig, 0, 1));
717 case 0: /* signal own process group */
718 return (dokillpg(sig, 0, 0));
719 default: /* negative explicit process group */
720 return (dokillpg(sig, -pid, 0));
726 sys_kill(struct kill_args *uap)
730 error = kern_kill(uap->signum, uap->pid);
736 * Send a signal to a process group.
739 gsignal(int pgid, int sig)
743 if (pgid && (pgrp = pgfind(pgid)))
744 pgsignal(pgrp, sig, 0);
748 * Send a signal to a process group. If checktty is 1,
749 * limit to members which have a controlling terminal.
751 * pg_lock interlocks against a fork that might be in progress, to
752 * ensure that the new child process picks up the signal.
755 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
760 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
761 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
762 if (checkctty == 0 || p->p_flag & P_CONTROLT)
765 lockmgr(&pgrp->pg_lock, LK_RELEASE);
770 * Send a signal caused by a trap to the current process.
771 * If it will be caught immediately, deliver it with correct code.
772 * Otherwise, post it normally.
775 trapsignal(struct lwp *lp, int sig, u_long code)
777 struct proc *p = lp->lwp_proc;
778 struct sigacts *ps = p->p_sigacts;
781 * If we are a virtual kernel running an emulated user process
782 * context, switch back to the virtual kernel context before
783 * trying to post the signal.
785 if (p->p_vkernel && p->p_vkernel->vk_current) {
786 struct trapframe *tf = curthread->td_lwp->lwp_md.md_regs;
792 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
793 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
794 lp->lwp_ru.ru_nsignals++;
796 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
797 ktrpsig(p, sig, ps->ps_sigact[_SIG_IDX(sig)],
798 &lp->lwp_sigmask, code);
800 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
801 &lp->lwp_sigmask, code);
802 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
803 if (!SIGISMEMBER(ps->ps_signodefer, sig))
804 SIGADDSET(lp->lwp_sigmask, sig);
805 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
807 * See kern_sigaction() for origin of this code.
809 SIGDELSET(p->p_sigcatch, sig);
810 if (sig != SIGCONT &&
811 sigprop(sig) & SA_IGNORE)
812 SIGADDSET(p->p_sigignore, sig);
813 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
816 lp->lwp_code = code; /* XXX for core dump/debugger */
817 lp->lwp_sig = sig; /* XXX to verify code */
818 lwpsignal(p, lp, sig);
823 * Find a suitable lwp to deliver the signal to.
825 * Returns NULL if all lwps hold the signal blocked.
828 find_lwp_for_signal(struct proc *p, int sig)
831 struct lwp *run, *sleep, *stop;
834 * If the running/preempted thread belongs to the proc to which
835 * the signal is being delivered and this thread does not block
836 * the signal, then we can avoid a context switch by delivering
837 * the signal to this thread, because it will return to userland
840 lp = lwkt_preempted_proc();
841 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
844 run = sleep = stop = NULL;
845 FOREACH_LWP_IN_PROC(lp, p) {
847 * If the signal is being blocked by the lwp, then this
848 * lwp is not eligible for receiving the signal.
850 if (SIGISMEMBER(lp->lwp_sigmask, sig))
853 switch (lp->lwp_stat) {
863 if (lp->lwp_flag & LWP_SINTR)
871 else if (sleep != NULL)
878 * Send the signal to the process. If the signal has an action, the action
879 * is usually performed by the target process rather than the caller; we add
880 * the signal to the set of pending signals for the process.
883 * o When a stop signal is sent to a sleeping process that takes the
884 * default action, the process is stopped without awakening it.
885 * o SIGCONT restarts stopped processes (or puts them back to sleep)
886 * regardless of the signal action (eg, blocked or ignored).
888 * Other ignored signals are discarded immediately.
891 ksignal(struct proc *p, int sig)
893 lwpsignal(p, NULL, sig);
897 * The core for ksignal. lp may be NULL, then a suitable thread
898 * will be chosen. If not, lp MUST be a member of p.
901 lwpsignal(struct proc *p, struct lwp *lp, int sig)
906 if (sig > _SIG_MAXSIG || sig <= 0) {
907 kprintf("lwpsignal: signal %d\n", sig);
908 panic("lwpsignal signal number");
911 KKASSERT(lp == NULL || lp->lwp_proc == p);
914 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
920 * If proc is traced, always give parent a chance;
921 * if signal event is tracked by procfs, give *that*
924 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
928 * If the signal is being ignored,
929 * then we forget about it immediately.
930 * (Note: we don't set SIGCONT in p_sigignore,
931 * and if it is set to SIG_IGN,
932 * action will be SIG_DFL here.)
934 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
936 if (SIGISMEMBER(p->p_sigcatch, sig))
943 * If continuing, clear any pending STOP signals.
946 SIG_STOPSIGMASK(p->p_siglist);
948 if (prop & SA_STOP) {
950 * If sending a tty stop signal to a member of an orphaned
951 * process group, discard the signal here if the action
952 * is default; don't stop the process below if sleeping,
953 * and don't clear any pending SIGCONT.
955 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
959 SIG_CONTSIGMASK(p->p_siglist);
964 if (p->p_stat == SSTOP) {
966 * Nobody can handle this signal, so add it to the process
969 SIGADDSET(p->p_siglist, sig);
972 * If the process is stopped and is being traced, then no
973 * further action is necessary.
975 if (p->p_flag & P_TRACED)
979 * If the process is stopped and receives a KILL signal,
980 * make the process runnable.
982 if (sig == SIGKILL) {
988 * If the process is stopped and receives a CONT signal,
989 * then try to make the process runnable again.
991 if (prop & SA_CONT) {
993 * If SIGCONT is default (or ignored), we continue the
994 * process but don't leave the signal in p_siglist, as
995 * it has no further action. If SIGCONT is held, we
996 * continue the process and leave the signal in
997 * p_siglist. If the process catches SIGCONT, let it
998 * handle the signal itself.
1000 /* XXX what if the signal is being held blocked? */
1001 if (action == SIG_DFL)
1002 SIGDELSET(p->p_siglist, sig);
1004 if (action == SIG_CATCH)
1005 goto active_process;
1010 * If the process is stopped and receives another STOP
1011 * signal, we do not need to stop it again. If we did
1012 * the shell could get confused.
1014 * However, if the current/preempted lwp is part of the
1015 * process receiving the signal, we need to keep it,
1016 * so that this lwp can stop in issignal() later, as
1017 * we don't want to wait until it reaches userret!
1019 if (prop & SA_STOP) {
1020 if (lwkt_preempted_proc() == NULL ||
1021 lwkt_preempted_proc()->lwp_proc != p)
1022 SIGDELSET(p->p_siglist, sig);
1026 * Otherwise the process is stopped and it received some
1027 * signal, which does not change its stopped state.
1029 * We have to select one thread to set LWP_BREAKTSLEEP,
1030 * so that the current signal will break the sleep
1031 * as soon as a SA_CONT signal will unstop the process.
1034 lp = find_lwp_for_signal(p, sig);
1036 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1037 lp->lwp_flag |= LWP_BREAKTSLEEP;
1042 /* else not stopped */
1046 lp = find_lwp_for_signal(p, sig);
1049 * If lp == NULL, there is no thread available which does
1050 * not block the signal. If lp is set, it might be a thread
1051 * specific signal, so we have to check for the thread ignoring
1054 * If so, defer further processing for this signal.
1055 * Add the signal to the process pending list.
1057 if (lp == NULL || SIGISMEMBER(lp->lwp_sigmask, sig)) {
1058 SIGADDSET(p->p_siglist, sig);
1061 /* else we have a lwp to deliver the signal to */
1063 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1064 (p->p_flag & P_TRACED) == 0) {
1069 * If the process receives a STOP signal which indeed needs to
1070 * stop the process, do so. If the process chose to catch the
1071 * signal, it will be treated like any other signal.
1073 if ((prop & SA_STOP) && action == SIG_DFL) {
1075 * If a child holding parent blocked, stopping
1076 * could cause deadlock. Take no action at this
1079 if (p->p_flag & P_PPWAIT) {
1080 SIGADDSET(p->p_siglist, sig);
1085 * Do not actually try to manipulate the process, but simply
1086 * stop it. Lwps will stop as soon as they safely can.
1094 * If it is a CONT signal with default action, just ignore it.
1096 if ((prop & SA_CONT) && action == SIG_DFL)
1100 * Mark signal pending at this specific thread.
1102 SIGADDSET(lp->lwp_siglist, sig);
1111 lwp_signotify(struct lwp *lp)
1114 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1116 * Thread is in tsleep.
1120 * If the thread is sleeping uninterruptibly
1121 * we can't interrupt the sleep... the signal will
1122 * be noticed when the lwp returns through
1123 * trap() or syscall().
1125 * Otherwise the signal can interrupt the sleep.
1127 * If the process is traced, the lwp will handle the
1128 * tracing in issignal() when it returns to userland.
1130 if (lp->lwp_flag & LWP_SINTR) {
1132 * Make runnable and break out of any tsleep as well.
1134 lp->lwp_flag |= LWP_BREAKTSLEEP;
1139 * Otherwise the thread is running
1141 * LSRUN does nothing with the signal, other than kicking
1142 * ourselves if we are running.
1143 * SZOMB and SIDL mean that it will either never be noticed,
1144 * or noticed very soon.
1146 * Note that lwp_thread may be NULL or may not be completely
1147 * initialized if the process is in the SIDL or SZOMB state.
1149 * For SMP we may have to forward the request to another cpu.
1150 * YYY the MP lock prevents the target process from moving
1151 * to another cpu, see kern/kern_switch.c
1153 * If the target thread is waiting on its message port,
1154 * wakeup the target thread so it can check (or ignore)
1155 * the new signal. YYY needs cleanup.
1157 if (lp == lwkt_preempted_proc()) {
1159 } else if (lp->lwp_stat == LSRUN) {
1160 struct thread *td = lp->lwp_thread;
1161 struct proc *p = lp->lwp_proc;
1164 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1165 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1166 p->p_flag, lp->lwp_flag));
1169 if (td->td_gd != mycpu)
1170 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1173 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1183 * This function is called via an IPI. We will be in a critical section but
1184 * the MP lock will NOT be held. Also note that by the time the ipi message
1185 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1188 signotify_remote(void *arg)
1190 struct lwp *lp = arg;
1192 if (lp == lwkt_preempted_proc()) {
1195 struct thread *td = lp->lwp_thread;
1196 if (td->td_msgport.mp_flags & MSGPORTF_WAITING)
1204 proc_stop(struct proc *p, int notify)
1206 struct lwp *lp, *preempted;
1209 /* If somebody raced us, be happy with it */
1210 if (p->p_stat == SSTOP)
1215 preempted = lwkt_preempted_proc();
1217 FOREACH_LWP_IN_PROC(lp, p) {
1218 switch (lp->lwp_stat) {
1221 * Do nothing, we are already counted in
1228 * We're sleeping, but we will stop before
1229 * returning to userspace, so count us
1230 * as stopped as well. Don't increment
1231 * p_nstopped, that will happen in tstop().
1239 * No need to wait for the preempted/current
1240 * lwp. It will stop on return to userland
1241 * later, so consider it as stopped.
1243 if (lp == preempted)
1249 while (p->p_nstopped + stopped < p->p_nthreads)
1250 tsleep(&p->p_nstopped, 0, "pstop", hz);
1252 p->p_flag &= ~P_WAITED;
1255 (notify && (p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0))
1256 ksignal(p->p_pptr, SIGCHLD);
1260 proc_unstop(struct proc *p)
1264 if (p->p_stat != SSTOP)
1266 p->p_stat = SACTIVE;
1268 FOREACH_LWP_IN_PROC(lp, p) {
1269 switch (lp->lwp_stat) {
1272 * Uh? Not stopped? Well, I guess that's okay.
1275 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1276 p->p_pid, lp->lwp_tid);
1285 * Still sleeping. Don't bother waking it up.
1293 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1295 sigset_t savedmask, set;
1296 struct proc *p = curproc;
1297 struct lwp *lp = curthread->td_lwp;
1298 int error, sig, hz, timevalid = 0;
1299 struct timespec rts, ets, ts;
1304 SIG_CANTMASK(waitset);
1305 savedmask = lp->lwp_sigmask;
1308 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1309 timeout->tv_nsec < 1000000000) {
1311 getnanouptime(&rts);
1313 timespecadd(&ets, timeout);
1318 set = lwp_sigpend(lp);
1319 SIGSETAND(set, waitset);
1320 if ((sig = sig_ffs(&set)) != 0) {
1321 SIGFILLSET(lp->lwp_sigmask);
1322 SIGDELSET(lp->lwp_sigmask, sig);
1323 SIG_CANTMASK(lp->lwp_sigmask);
1326 * It may be a STOP signal, in the case, issignal
1327 * returns 0, because we may stop there, and new
1328 * signal can come in, we should restart if we got
1338 * Previous checking got nothing, and we retried but still
1339 * got nothing, we should return the error status.
1345 * POSIX says this must be checked after looking for pending
1353 getnanouptime(&rts);
1354 if (timespeccmp(&rts, &ets, >=)) {
1359 timespecsub(&ts, &rts);
1360 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1361 hz = tvtohz_high(&tv);
1365 lp->lwp_sigmask = savedmask;
1366 SIGSETNAND(lp->lwp_sigmask, waitset);
1368 * We won't ever be woken up. Instead, our sleep will
1369 * be broken in lwpsignal().
1371 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1373 if (error == ERESTART) {
1374 /* can not restart a timeout wait. */
1376 } else if (error == EAGAIN) {
1377 /* will calculate timeout by ourself. */
1384 lp->lwp_sigmask = savedmask;
1387 bzero(info, sizeof(*info));
1388 info->si_signo = sig;
1389 lwp_delsig(lp, sig); /* take the signal! */
1398 sys_sigtimedwait(struct sigtimedwait_args *uap)
1401 struct timespec *timeout;
1407 error = copyin(uap->timeout, &ts, sizeof(ts));
1414 error = copyin(uap->set, &set, sizeof(set));
1417 error = kern_sigtimedwait(set, &info, timeout);
1421 error = copyout(&info, uap->info, sizeof(info));
1422 /* Repost if we got an error. */
1426 * This could transform a thread-specific signal to another
1427 * thread / process pending signal.
1430 ksignal(curproc, info.si_signo);
1432 uap->sysmsg_result = info.si_signo;
1437 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1443 error = copyin(uap->set, &set, sizeof(set));
1446 error = kern_sigtimedwait(set, &info, NULL);
1450 error = copyout(&info, uap->info, sizeof(info));
1451 /* Repost if we got an error. */
1455 * This could transform a thread-specific signal to another
1456 * thread / process pending signal.
1459 ksignal(curproc, info.si_signo);
1461 uap->sysmsg_result = info.si_signo;
1466 * If the current process has received a signal that would interrupt a
1467 * system call, return EINTR or ERESTART as appropriate.
1470 iscaught(struct lwp *lp)
1472 struct proc *p = lp->lwp_proc;
1476 if ((sig = CURSIG(lp)) != 0) {
1477 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1482 return(EWOULDBLOCK);
1486 * If the current process has received a signal (should be caught or cause
1487 * termination, should interrupt current syscall), return the signal number.
1488 * Stop signals with default action are processed immediately, then cleared;
1489 * they aren't returned. This is checked after each entry to the system for
1490 * a syscall or trap (though this can usually be done without calling issignal
1491 * by checking the pending signal masks in the CURSIG macro.) The normal call
1494 * This routine is called via CURSIG/__cursig and the MP lock might not be
1495 * held. Obtain the MP lock for the duration of the operation.
1497 * while (sig = CURSIG(curproc))
1501 issignal(struct lwp *lp)
1503 struct proc *p = lp->lwp_proc;
1509 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1511 mask = lwp_sigpend(lp);
1512 SIGSETNAND(mask, lp->lwp_sigmask);
1513 if (p->p_flag & P_PPWAIT)
1514 SIG_STOPSIGMASK(mask);
1515 if (SIGISEMPTY(mask)) { /* no signal to send */
1519 sig = sig_ffs(&mask);
1521 STOPEVENT(p, S_SIG, sig);
1524 * We should see pending but ignored signals
1525 * only if P_TRACED was on when they were posted.
1527 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1528 lwp_delsig(lp, sig);
1531 if ((p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1533 * If traced, always stop, and stay stopped until
1534 * released by the parent.
1536 * NOTE: SSTOP may get cleared during the loop,
1537 * but we do not re-notify the parent if we have
1538 * to loop several times waiting for the parent
1539 * to let us continue.
1541 * XXX not sure if this is still true
1547 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1550 * If parent wants us to take the signal,
1551 * then it will leave it in p->p_xstat;
1552 * otherwise we just look for signals again.
1554 lwp_delsig(lp, sig); /* clear old signal */
1560 * Put the new signal into p_siglist. If the
1561 * signal is being masked, look for other signals.
1563 * XXX lwp might need a call to ksignal()
1565 SIGADDSET(p->p_siglist, sig);
1566 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1570 * If the traced bit got turned off, go back up
1571 * to the top to rescan signals. This ensures
1572 * that p_sig* and ps_sigact are consistent.
1574 if ((p->p_flag & P_TRACED) == 0)
1578 prop = sigprop(sig);
1581 * Decide whether the signal should be returned.
1582 * Return the signal's number, or fall through
1583 * to clear it from the pending mask.
1585 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1588 * Don't take default actions on system processes.
1590 if (p->p_pid <= 1) {
1593 * Are you sure you want to ignore SIGSEGV
1596 kprintf("Process (pid %lu) got signal %d\n",
1597 (u_long)p->p_pid, sig);
1599 break; /* == ignore */
1603 * Handle the in-kernel checkpoint action
1605 if (prop & SA_CKPT) {
1606 checkpoint_signal_handler(lp);
1611 * If there is a pending stop signal to process
1612 * with default action, stop here,
1613 * then clear the signal. However,
1614 * if process is member of an orphaned
1615 * process group, ignore tty stop signals.
1617 if (prop & SA_STOP) {
1618 if (p->p_flag & P_TRACED ||
1619 (p->p_pgrp->pg_jobc == 0 &&
1621 break; /* == ignore */
1624 while (p->p_stat == SSTOP) {
1628 } else if (prop & SA_IGNORE) {
1630 * Except for SIGCONT, shouldn't get here.
1631 * Default action is to ignore; drop it.
1633 break; /* == ignore */
1643 * Masking above should prevent us ever trying
1644 * to take action on an ignored signal other
1645 * than SIGCONT, unless process is traced.
1647 if ((prop & SA_CONT) == 0 &&
1648 (p->p_flag & P_TRACED) == 0)
1649 kprintf("issignal\n");
1650 break; /* == ignore */
1654 * This signal has an action, let
1655 * postsig() process it.
1660 lwp_delsig(lp, sig); /* take the signal! */
1666 * Take the action for the specified signal
1667 * from the current set of pending signals.
1672 struct lwp *lp = curthread->td_lwp;
1673 struct proc *p = lp->lwp_proc;
1674 struct sigacts *ps = p->p_sigacts;
1676 sigset_t returnmask;
1679 KASSERT(sig != 0, ("postsig"));
1682 * If we are a virtual kernel running an emulated user process
1683 * context, switch back to the virtual kernel context before
1684 * trying to post the signal.
1686 if (p->p_vkernel && p->p_vkernel->vk_current) {
1687 struct trapframe *tf = curthread->td_lwp->lwp_md.md_regs;
1689 vkernel_trap(p, tf);
1692 lwp_delsig(lp, sig);
1693 action = ps->ps_sigact[_SIG_IDX(sig)];
1695 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1696 ktrpsig(p, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1697 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1699 STOPEVENT(p, S_SIG, sig);
1701 if (action == SIG_DFL) {
1703 * Default action, where the default is to kill
1704 * the process. (Other cases were ignored above.)
1710 * If we get here, the signal must be caught.
1712 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1713 ("postsig action"));
1718 * Reset the signal handler if asked to
1720 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1722 * See kern_sigaction() for origin of this code.
1724 SIGDELSET(p->p_sigcatch, sig);
1725 if (sig != SIGCONT &&
1726 sigprop(sig) & SA_IGNORE)
1727 SIGADDSET(p->p_sigignore, sig);
1728 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1732 * Handle the mailbox case. Copyout to the appropriate
1733 * location but do not generate a signal frame. The system
1734 * call simply returns EINTR and the user is responsible for
1735 * polling the mailbox.
1737 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1739 copyout(&sig_copy, (void *)action, sizeof(int));
1740 curproc->p_flag |= P_MAILBOX;
1746 * Set the signal mask and calculate the mask to restore
1747 * when the signal function returns.
1749 * Special case: user has done a sigsuspend. Here the
1750 * current mask is not of interest, but rather the
1751 * mask from before the sigsuspend is what we want
1752 * restored after the signal processing is completed.
1754 if (lp->lwp_flag & LWP_OLDMASK) {
1755 returnmask = lp->lwp_oldsigmask;
1756 lp->lwp_flag &= ~LWP_OLDMASK;
1758 returnmask = lp->lwp_sigmask;
1761 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1762 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1763 SIGADDSET(lp->lwp_sigmask, sig);
1766 lp->lwp_ru.ru_nsignals++;
1767 if (lp->lwp_sig != sig) {
1770 code = lp->lwp_code;
1774 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1781 * Kill the current process for stated reason.
1784 killproc(struct proc *p, char *why)
1786 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1787 p->p_pid, p->p_comm,
1788 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1789 ksignal(p, SIGKILL);
1793 * Force the current process to exit with the specified signal, dumping core
1794 * if appropriate. We bypass the normal tests for masked and caught signals,
1795 * allowing unrecoverable failures to terminate the process without changing
1796 * signal state. Mark the accounting record with the signal termination.
1797 * If dumping core, save the signal number for the debugger. Calls exit and
1801 sigexit(struct proc *p, int sig)
1803 struct lwp *lp = FIRST_LWP_IN_PROC(p); /* XXX lwp */
1805 p->p_acflag |= AXSIG;
1806 if (sigprop(sig) & SA_CORE) {
1809 * Log signals which would cause core dumps
1810 * (Log as LOG_INFO to appease those who don't want
1812 * XXX : Todo, as well as euid, write out ruid too
1814 if (coredump(lp, sig) == 0)
1816 if (kern_logsigexit)
1818 "pid %d (%s), uid %d: exited on signal %d%s\n",
1819 p->p_pid, p->p_comm,
1820 p->p_ucred ? p->p_ucred->cr_uid : -1,
1822 sig & WCOREFLAG ? " (core dumped)" : "");
1824 exit1(W_EXITCODE(0, sig));
1828 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1829 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1830 sizeof(corefilename), "process corefile name format string");
1833 * expand_name(name, uid, pid)
1834 * Expand the name described in corefilename, using name, uid, and pid.
1835 * corefilename is a kprintf-like string, with three format specifiers:
1836 * %N name of process ("name")
1837 * %P process id (pid)
1839 * For example, "%N.core" is the default; they can be disabled completely
1840 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1841 * This is controlled by the sysctl variable kern.corefile (see above).
1845 expand_name(const char *name, uid_t uid, pid_t pid)
1848 char buf[11]; /* Buffer for pid/uid -- max 4B */
1850 char *format = corefilename;
1853 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1856 namelen = strlen(name);
1857 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1859 switch (format[i]) {
1860 case '%': /* Format character */
1862 switch (format[i]) {
1866 case 'N': /* process name */
1867 if ((n + namelen) > MAXPATHLEN) {
1868 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1869 pid, name, uid, temp, name);
1870 kfree(temp, M_TEMP);
1873 memcpy(temp+n, name, namelen);
1876 case 'P': /* process id */
1877 l = ksprintf(buf, "%u", pid);
1878 if ((n + l) > MAXPATHLEN) {
1879 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1880 pid, name, uid, temp, name);
1881 kfree(temp, M_TEMP);
1884 memcpy(temp+n, buf, l);
1887 case 'U': /* user id */
1888 l = ksprintf(buf, "%u", uid);
1889 if ((n + l) > MAXPATHLEN) {
1890 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1891 pid, name, uid, temp, name);
1892 kfree(temp, M_TEMP);
1895 memcpy(temp+n, buf, l);
1899 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1903 temp[n++] = format[i];
1911 * Dump a process' core. The main routine does some
1912 * policy checking, and creates the name of the coredump;
1913 * then it passes on a vnode and a size limit to the process-specific
1914 * coredump routine if there is one; if there _is not_ one, it returns
1915 * ENOSYS; otherwise it returns the error from the process-specific routine.
1917 * The parameter `lp' is the lwp which triggered the coredump.
1921 coredump(struct lwp *lp, int sig)
1923 struct proc *p = lp->lwp_proc;
1925 struct ucred *cred = p->p_ucred;
1927 struct nlookupdata nd;
1930 char *name; /* name of corefile */
1933 STOPEVENT(p, S_CORE, 0);
1935 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
1939 * Note that the bulk of limit checking is done after
1940 * the corefile is created. The exception is if the limit
1941 * for corefiles is 0, in which case we don't bother
1942 * creating the corefile at all. This layout means that
1943 * a corefile is truncated instead of not being created,
1944 * if it is larger than the limit.
1946 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
1950 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
1953 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
1955 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
1956 kfree(name, M_TEMP);
1962 nd.nl_open_vp = NULL;
1966 lf.l_whence = SEEK_SET;
1969 lf.l_type = F_WRLCK;
1970 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
1974 /* Don't dump to non-regular files or files with links. */
1975 if (vp->v_type != VREG ||
1976 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
1982 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1984 VOP_SETATTR(vp, &vattr, cred);
1985 p->p_acflag |= ACORE;
1988 error = p->p_sysent->sv_coredump ?
1989 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
1992 lf.l_type = F_UNLCK;
1993 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
1995 error1 = vn_close(vp, FWRITE);
2002 * Nonexistent system call-- signal process (may want to handle it).
2003 * Flag error in case process won't see signal immediately (blocked or ignored).
2007 sys_nosys(struct nosys_args *args)
2009 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2014 * Send a SIGIO or SIGURG signal to a process or process group using
2015 * stored credentials rather than those of the current process.
2018 pgsigio(struct sigio *sigio, int sig, int checkctty)
2023 if (sigio->sio_pgid > 0) {
2024 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2026 ksignal(sigio->sio_proc, sig);
2027 } else if (sigio->sio_pgid < 0) {
2030 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2031 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2032 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2033 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2036 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2041 filt_sigattach(struct knote *kn)
2043 struct proc *p = curproc;
2045 kn->kn_ptr.p_proc = p;
2046 kn->kn_flags |= EV_CLEAR; /* automatically set */
2048 /* XXX lock the proc here while adding to the list? */
2049 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
2055 filt_sigdetach(struct knote *kn)
2057 struct proc *p = kn->kn_ptr.p_proc;
2059 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
2063 * signal knotes are shared with proc knotes, so we apply a mask to
2064 * the hint in order to differentiate them from process hints. This
2065 * could be avoided by using a signal-specific knote list, but probably
2066 * isn't worth the trouble.
2069 filt_signal(struct knote *kn, long hint)
2071 if (hint & NOTE_SIGNAL) {
2072 hint &= ~NOTE_SIGNAL;
2074 if (kn->kn_id == hint)
2077 return (kn->kn_data != 0);