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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 $
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;
326 * Set bit in p_sigignore for signals that are set to SIG_IGN,
327 * and for signals set to SIG_DFL where the default is to
328 * ignore. However, don't put SIGCONT in p_sigignore, as we
329 * have to restart the process.
331 * Also remove the signal from the process and lwp signal
334 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
335 (sigprop(sig) & SA_IGNORE &&
336 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
337 SIGDELSET(p->p_siglist, sig);
338 FOREACH_LWP_IN_PROC(lp, p) {
339 spin_lock(&lp->lwp_spin);
340 SIGDELSET(lp->lwp_siglist, sig);
341 spin_unlock(&lp->lwp_spin);
343 if (sig != SIGCONT) {
344 /* easier in ksignal */
345 SIGADDSET(p->p_sigignore, sig);
347 SIGDELSET(p->p_sigcatch, sig);
349 SIGDELSET(p->p_sigignore, sig);
350 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
351 SIGDELSET(p->p_sigcatch, sig);
353 SIGADDSET(p->p_sigcatch, sig);
356 lwkt_reltoken(&p->p_token);
361 sys_sigaction(struct sigaction_args *uap)
363 struct sigaction act, oact;
364 struct sigaction *actp, *oactp;
367 actp = (uap->act != NULL) ? &act : NULL;
368 oactp = (uap->oact != NULL) ? &oact : NULL;
370 error = copyin(uap->act, actp, sizeof(act));
374 error = kern_sigaction(uap->sig, actp, oactp);
375 if (oactp && !error) {
376 error = copyout(oactp, uap->oact, sizeof(oact));
382 * Initialize signal state for process 0;
383 * set to ignore signals that are ignored by default.
386 siginit(struct proc *p)
390 for (i = 1; i <= NSIG; i++)
391 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
392 SIGADDSET(p->p_sigignore, i);
396 * Reset signals for an exec of the specified process.
399 execsigs(struct proc *p)
401 struct sigacts *ps = p->p_sigacts;
405 lp = ONLY_LWP_IN_PROC(p);
408 * Reset caught signals. Held signals remain held
409 * through p_sigmask (unless they were caught,
410 * and are now ignored by default).
412 while (SIGNOTEMPTY(p->p_sigcatch)) {
413 sig = sig_ffs(&p->p_sigcatch);
414 SIGDELSET(p->p_sigcatch, sig);
415 if (sigprop(sig) & SA_IGNORE) {
417 SIGADDSET(p->p_sigignore, sig);
418 SIGDELSET(p->p_siglist, sig);
419 /* don't need spinlock */
420 SIGDELSET(lp->lwp_siglist, sig);
422 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
426 * Reset stack state to the user stack.
427 * Clear set of signals caught on the signal stack.
429 lp->lwp_sigstk.ss_flags = SS_DISABLE;
430 lp->lwp_sigstk.ss_size = 0;
431 lp->lwp_sigstk.ss_sp = 0;
432 lp->lwp_flags &= ~LWP_ALTSTACK;
434 * Reset no zombies if child dies flag as Solaris does.
436 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
440 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
442 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
446 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
448 struct thread *td = curthread;
449 struct lwp *lp = td->td_lwp;
450 struct proc *p = td->td_proc;
453 lwkt_gettoken(&p->p_token);
456 *oset = lp->lwp_sigmask;
463 SIGSETOR(lp->lwp_sigmask, *set);
466 SIGSETNAND(lp->lwp_sigmask, *set);
470 lp->lwp_sigmask = *set;
478 lwkt_reltoken(&p->p_token);
489 sys_sigprocmask(struct sigprocmask_args *uap)
492 sigset_t *setp, *osetp;
495 setp = (uap->set != NULL) ? &set : NULL;
496 osetp = (uap->oset != NULL) ? &oset : NULL;
498 error = copyin(uap->set, setp, sizeof(set));
502 error = kern_sigprocmask(uap->how, setp, osetp);
503 if (osetp && !error) {
504 error = copyout(osetp, uap->oset, sizeof(oset));
513 kern_sigpending(struct __sigset *set)
515 struct lwp *lp = curthread->td_lwp;
517 *set = lwp_sigpend(lp);
526 sys_sigpending(struct sigpending_args *uap)
531 error = kern_sigpending(&set);
534 error = copyout(&set, uap->set, sizeof(set));
539 * Suspend process until signal, providing mask to be set
545 kern_sigsuspend(struct __sigset *set)
547 struct thread *td = curthread;
548 struct lwp *lp = td->td_lwp;
549 struct proc *p = td->td_proc;
550 struct sigacts *ps = p->p_sigacts;
553 * When returning from sigsuspend, we want
554 * the old mask to be restored after the
555 * signal handler has finished. Thus, we
556 * save it here and mark the sigacts structure
559 lp->lwp_oldsigmask = lp->lwp_sigmask;
560 lp->lwp_flags |= LWP_OLDMASK;
563 lp->lwp_sigmask = *set;
564 while (tsleep(ps, PCATCH, "pause", 0) == 0)
566 /* always return EINTR rather than ERESTART... */
571 * Note nonstandard calling convention: libc stub passes mask, not
572 * pointer, to save a copyin.
577 sys_sigsuspend(struct sigsuspend_args *uap)
582 error = copyin(uap->sigmask, &mask, sizeof(mask));
586 error = kern_sigsuspend(&mask);
595 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
597 struct thread *td = curthread;
598 struct lwp *lp = td->td_lwp;
599 struct proc *p = td->td_proc;
601 if ((lp->lwp_flags & LWP_ALTSTACK) == 0)
602 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
605 *oss = lp->lwp_sigstk;
608 if (ss->ss_flags & SS_DISABLE) {
609 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
611 lp->lwp_flags &= ~LWP_ALTSTACK;
612 lp->lwp_sigstk.ss_flags = ss->ss_flags;
614 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
616 lp->lwp_flags |= LWP_ALTSTACK;
617 lp->lwp_sigstk = *ss;
628 sys_sigaltstack(struct sigaltstack_args *uap)
634 error = copyin(uap->ss, &ss, sizeof(ss));
639 error = kern_sigaltstack(uap->ss ? &ss : NULL,
640 uap->oss ? &oss : NULL);
642 if (error == 0 && uap->oss)
643 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
648 * Common code for kill process group/broadcast kill.
649 * cp is calling process.
656 static int killpg_all_callback(struct proc *p, void *data);
659 dokillpg(int sig, int pgid, int all)
661 struct killpg_info info;
662 struct proc *cp = curproc;
673 allproc_scan(killpg_all_callback, &info);
677 * zero pgid means send to my process group.
688 * Must interlock all signals against fork
690 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
691 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
693 p->p_stat == SZOMB ||
694 (p->p_flags & P_SYSTEM) ||
695 !CANSIGNAL(p, sig)) {
702 lockmgr(&pgrp->pg_lock, LK_RELEASE);
705 return (info.nfound ? 0 : ESRCH);
709 killpg_all_callback(struct proc *p, void *data)
711 struct killpg_info *info = data;
713 if (p->p_pid <= 1 || (p->p_flags & P_SYSTEM) ||
714 p == curproc || !CANSIGNAL(p, info->sig)) {
719 ksignal(p, info->sig);
724 * Send a general signal to a process or LWPs within that process.
726 * Note that new signals cannot be sent if a process is exiting or already
727 * a zombie, but we return success anyway as userland is likely to not handle
733 kern_kill(int sig, pid_t pid, lwpid_t tid)
737 if ((u_int)sig > _SIG_MAXSIG)
740 lwkt_gettoken(&proc_token);
744 struct lwp *lp = NULL;
747 * Send a signal to a single process. If the kill() is
748 * racing an exiting process which has not yet been reaped
749 * act as though the signal was delivered successfully but
750 * don't actually try to deliver the signal.
752 if ((p = pfind(pid)) == NULL) {
753 if ((p = zpfind(pid)) == NULL) {
754 lwkt_reltoken(&proc_token);
757 lwkt_reltoken(&proc_token);
761 lwkt_gettoken(&p->p_token);
762 if (!CANSIGNAL(p, sig)) {
763 lwkt_reltoken(&p->p_token);
765 lwkt_reltoken(&proc_token);
770 * NOP if the process is exiting. Note that lwpsignal() is
771 * called directly with P_WEXIT set to kill individual LWPs
772 * during exit, which is allowed.
774 if (p->p_flags & P_WEXIT) {
775 lwkt_reltoken(&p->p_token);
777 lwkt_reltoken(&proc_token);
781 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
783 lwkt_reltoken(&p->p_token);
785 lwkt_reltoken(&proc_token);
790 lwpsignal(p, lp, sig);
791 lwkt_reltoken(&p->p_token);
793 lwkt_reltoken(&proc_token);
798 * If we come here, pid is a special broadcast pid.
799 * This doesn't mix with a tid.
802 lwkt_reltoken(&proc_token);
806 case -1: /* broadcast signal */
807 t = (dokillpg(sig, 0, 1));
809 case 0: /* signal own process group */
810 t = (dokillpg(sig, 0, 0));
812 default: /* negative explicit process group */
813 t = (dokillpg(sig, -pid, 0));
816 lwkt_reltoken(&proc_token);
821 sys_kill(struct kill_args *uap)
825 error = kern_kill(uap->signum, uap->pid, -1);
830 sys_lwp_kill(struct lwp_kill_args *uap)
833 pid_t pid = uap->pid;
836 * A tid is mandatory for lwp_kill(), otherwise
837 * you could simply use kill().
843 * To save on a getpid() function call for intra-process
844 * signals, pid == -1 means current process.
847 pid = curproc->p_pid;
849 error = kern_kill(uap->signum, pid, uap->tid);
854 * Send a signal to a process group.
857 gsignal(int pgid, int sig)
861 if (pgid && (pgrp = pgfind(pgid)))
862 pgsignal(pgrp, sig, 0);
866 * Send a signal to a process group. If checktty is 1,
867 * limit to members which have a controlling terminal.
869 * pg_lock interlocks against a fork that might be in progress, to
870 * ensure that the new child process picks up the signal.
873 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
878 * Must interlock all signals against fork
882 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
883 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
884 if (checkctty == 0 || p->p_flags & P_CONTROLT)
887 lockmgr(&pgrp->pg_lock, LK_RELEASE);
893 * Send a signal caused by a trap to the current lwp. If it will be caught
894 * immediately, deliver it with correct code. Otherwise, post it normally.
896 * These signals may ONLY be delivered to the specified lwp and may never
897 * be delivered to the process generically.
900 trapsignal(struct lwp *lp, int sig, u_long code)
902 struct proc *p = lp->lwp_proc;
903 struct sigacts *ps = p->p_sigacts;
906 * If we are a virtual kernel running an emulated user process
907 * context, switch back to the virtual kernel context before
908 * trying to post the signal.
910 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
911 struct trapframe *tf = lp->lwp_md.md_regs;
913 vkernel_trap(lp, tf);
917 if ((p->p_flags & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
918 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
919 lp->lwp_ru.ru_nsignals++;
921 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
922 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
923 &lp->lwp_sigmask, code);
925 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
926 &lp->lwp_sigmask, code);
927 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
928 if (!SIGISMEMBER(ps->ps_signodefer, sig))
929 SIGADDSET(lp->lwp_sigmask, sig);
930 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
932 * See kern_sigaction() for origin of this code.
934 SIGDELSET(p->p_sigcatch, sig);
935 if (sig != SIGCONT &&
936 sigprop(sig) & SA_IGNORE)
937 SIGADDSET(p->p_sigignore, sig);
938 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
941 lp->lwp_code = code; /* XXX for core dump/debugger */
942 lp->lwp_sig = sig; /* XXX to verify code */
943 lwpsignal(p, lp, sig);
948 * Find a suitable lwp to deliver the signal to. Returns NULL if all
949 * lwps hold the signal blocked.
951 * Caller must hold p->p_token.
953 * Returns a lp or NULL. If non-NULL the lp is held and its token is
957 find_lwp_for_signal(struct proc *p, int sig)
960 struct lwp *run, *sleep, *stop;
963 * If the running/preempted thread belongs to the proc to which
964 * the signal is being delivered and this thread does not block
965 * the signal, then we can avoid a context switch by delivering
966 * the signal to this thread, because it will return to userland
969 lp = lwkt_preempted_proc();
970 if (lp != NULL && lp->lwp_proc == p) {
972 lwkt_gettoken(&lp->lwp_token);
973 if (!SIGISMEMBER(lp->lwp_sigmask, sig)) {
974 /* return w/ token held */
977 lwkt_reltoken(&lp->lwp_token);
981 run = sleep = stop = NULL;
982 FOREACH_LWP_IN_PROC(lp, p) {
984 * If the signal is being blocked by the lwp, then this
985 * lwp is not eligible for receiving the signal.
988 lwkt_gettoken(&lp->lwp_token);
990 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
991 lwkt_reltoken(&lp->lwp_token);
996 switch (lp->lwp_stat) {
1000 lwkt_reltoken(&sleep->lwp_token);
1006 lwkt_reltoken(&stop->lwp_token);
1015 if (lp->lwp_flags & LWP_SINTR) {
1017 lwkt_reltoken(&lp->lwp_token);
1021 lwkt_reltoken(&stop->lwp_token);
1029 lwkt_reltoken(&lp->lwp_token);
1035 lwkt_reltoken(&lp->lwp_token);
1038 lwkt_reltoken(&lp->lwp_token);
1051 else if (sleep != NULL)
1058 * Send the signal to the process. If the signal has an action, the action
1059 * is usually performed by the target process rather than the caller; we add
1060 * the signal to the set of pending signals for the process.
1063 * o When a stop signal is sent to a sleeping process that takes the
1064 * default action, the process is stopped without awakening it.
1065 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1066 * regardless of the signal action (eg, blocked or ignored).
1068 * Other ignored signals are discarded immediately.
1070 * If the caller wishes to call this function from a hard code section the
1071 * caller must already hold p->p_token (see kern_clock.c).
1076 ksignal(struct proc *p, int sig)
1078 lwpsignal(p, NULL, sig);
1082 * The core for ksignal. lp may be NULL, then a suitable thread
1083 * will be chosen. If not, lp MUST be a member of p.
1085 * If the caller wishes to call this function from a hard code section the
1086 * caller must already hold p->p_token.
1091 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1097 if (sig > _SIG_MAXSIG || sig <= 0) {
1098 kprintf("lwpsignal: signal %d\n", sig);
1099 panic("lwpsignal signal number");
1102 KKASSERT(lp == NULL || lp->lwp_proc == p);
1105 * We don't want to race... well, all sorts of things. Get appropriate
1108 * Don't try to deliver a generic signal to an exiting process,
1109 * the signal structures could be in flux. We check the LWP later
1113 lwkt_gettoken(&p->p_token);
1116 lwkt_gettoken(&lp->lwp_token);
1117 } else if (p->p_flags & P_WEXIT) {
1121 prop = sigprop(sig);
1124 * If proc is traced, always give parent a chance;
1125 * if signal event is tracked by procfs, give *that*
1126 * a chance, as well.
1128 if ((p->p_flags & P_TRACED) || (p->p_stops & S_SIG)) {
1132 * Do not try to deliver signals to an exiting lwp. Note
1133 * that we must still deliver the signal if P_WEXIT is set
1134 * in the process flags.
1136 if (lp && (lp->lwp_mpflags & LWP_MP_WEXIT)) {
1138 lwkt_reltoken(&lp->lwp_token);
1141 lwkt_reltoken(&p->p_token);
1147 * If the signal is being ignored, then we forget about
1148 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1149 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1151 if (SIGISMEMBER(p->p_sigignore, sig)) {
1153 * Even if a signal is set SIG_IGN, it may still be
1154 * lurking in a kqueue.
1156 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1158 lwkt_reltoken(&lp->lwp_token);
1161 lwkt_reltoken(&p->p_token);
1165 if (SIGISMEMBER(p->p_sigcatch, sig))
1172 * If continuing, clear any pending STOP signals.
1175 SIG_STOPSIGMASK(p->p_siglist);
1177 if (prop & SA_STOP) {
1179 * If sending a tty stop signal to a member of an orphaned
1180 * process group, discard the signal here if the action
1181 * is default; don't stop the process below if sleeping,
1182 * and don't clear any pending SIGCONT.
1184 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1185 action == SIG_DFL) {
1186 lwkt_reltoken(&p->p_token);
1190 SIG_CONTSIGMASK(p->p_siglist);
1191 p->p_flags &= ~P_CONTINUED;
1194 if (p->p_stat == SSTOP) {
1196 * Nobody can handle this signal, add it to the lwp or
1197 * process pending list
1200 spin_lock(&lp->lwp_spin);
1201 SIGADDSET(lp->lwp_siglist, sig);
1202 spin_unlock(&lp->lwp_spin);
1204 SIGADDSET(p->p_siglist, sig);
1208 * If the process is stopped and is being traced, then no
1209 * further action is necessary.
1211 if (p->p_flags & P_TRACED)
1215 * If the process is stopped and receives a KILL signal,
1216 * make the process runnable.
1218 if (sig == SIGKILL) {
1220 goto active_process;
1224 * If the process is stopped and receives a CONT signal,
1225 * then try to make the process runnable again.
1227 if (prop & SA_CONT) {
1229 * If SIGCONT is default (or ignored), we continue the
1230 * process but don't leave the signal in p_siglist, as
1231 * it has no further action. If SIGCONT is held, we
1232 * continue the process and leave the signal in
1233 * p_siglist. If the process catches SIGCONT, let it
1234 * handle the signal itself.
1236 * XXX what if the signal is being held blocked?
1238 * Token required to interlock kern_wait().
1239 * Reparenting can also cause a race so we have to
1244 lwkt_gettoken(&q->p_token);
1245 p->p_flags |= P_CONTINUED;
1247 if (action == SIG_DFL)
1248 SIGDELSET(p->p_siglist, sig);
1250 lwkt_reltoken(&q->p_token);
1252 if (action == SIG_CATCH)
1253 goto active_process;
1258 * If the process is stopped and receives another STOP
1259 * signal, we do not need to stop it again. If we did
1260 * the shell could get confused.
1262 * However, if the current/preempted lwp is part of the
1263 * process receiving the signal, we need to keep it,
1264 * so that this lwp can stop in issignal() later, as
1265 * we don't want to wait until it reaches userret!
1267 if (prop & SA_STOP) {
1268 if (lwkt_preempted_proc() == NULL ||
1269 lwkt_preempted_proc()->lwp_proc != p)
1270 SIGDELSET(p->p_siglist, sig);
1274 * Otherwise the process is stopped and it received some
1275 * signal, which does not change its stopped state. When
1276 * the process is continued a wakeup(p) will be issued which
1277 * will wakeup any threads sleeping in tstop().
1280 /* NOTE: returns lp w/ token held */
1281 lp = find_lwp_for_signal(p, sig);
1287 /* else not stopped */
1291 * Never deliver a lwp-specific signal to a random lwp.
1294 /* NOTE: returns lp w/ token held */
1295 lp = find_lwp_for_signal(p, sig);
1297 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
1298 lwkt_reltoken(&lp->lwp_token);
1306 * Deliver to the process generically if (1) the signal is being
1307 * sent to any thread or (2) we could not find a thread to deliver
1311 SIGADDSET(p->p_siglist, sig);
1316 * Deliver to a specific LWP whether it masks it or not. It will
1317 * not be dispatched if masked but we must still deliver it.
1319 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1320 (p->p_flags & P_TRACED) == 0) {
1325 * If the process receives a STOP signal which indeed needs to
1326 * stop the process, do so. If the process chose to catch the
1327 * signal, it will be treated like any other signal.
1329 if ((prop & SA_STOP) && action == SIG_DFL) {
1331 * If a child holding parent blocked, stopping
1332 * could cause deadlock. Take no action at this
1335 if (p->p_flags & P_PPWAIT) {
1336 SIGADDSET(p->p_siglist, sig);
1341 * Do not actually try to manipulate the process, but simply
1342 * stop it. Lwps will stop as soon as they safely can.
1344 * Ignore stop if the process is exiting.
1346 if ((p->p_flags & P_WEXIT) == 0) {
1354 * If it is a CONT signal with default action, just ignore it.
1356 if ((prop & SA_CONT) && action == SIG_DFL)
1360 * Mark signal pending at this specific thread.
1362 spin_lock(&lp->lwp_spin);
1363 SIGADDSET(lp->lwp_siglist, sig);
1364 spin_unlock(&lp->lwp_spin);
1370 lwkt_reltoken(&lp->lwp_token);
1373 lwkt_reltoken(&p->p_token);
1378 * Notify the LWP that a signal has arrived. The LWP does not have to be
1379 * sleeping on the current cpu.
1381 * p->p_token and lp->lwp_token must be held on call.
1383 * We can only safely schedule the thread on its current cpu and only if
1384 * one of the SINTR flags is set. If an SINTR flag is set AND we are on
1385 * the correct cpu we are properly interlocked, otherwise we could be
1386 * racing other thread transition states (or the lwp is on the user scheduler
1387 * runq but not scheduled) and must not do anything.
1389 * Since we hold the lwp token we know the lwp cannot be ripped out from
1390 * under us so we can safely hold it to prevent it from being ripped out
1391 * from under us if we are forced to IPI another cpu to make the local
1394 * Adjustment of lp->lwp_stat can only occur when we hold the lwp_token,
1395 * which we won't in an IPI so any fixups have to be done here, effectively
1396 * replicating part of what setrunnable() does.
1399 lwp_signotify(struct lwp *lp)
1401 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
1404 if (lp == lwkt_preempted_proc()) {
1406 * lwp is on the current cpu AND it is currently running
1407 * (we preempted it).
1410 } else if (lp->lwp_flags & LWP_SINTR) {
1412 * lwp is sitting in tsleep() with PCATCH set
1415 if (lp->lwp_thread->td_gd == mycpu) {
1419 * We can only adjust lwp_stat while we hold the
1420 * lwp_token, and we won't in the IPI function.
1423 if (lp->lwp_stat == LSSTOP)
1424 lp->lwp_stat = LSSLEEP;
1425 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1426 lwp_signotify_remote, lp);
1431 } else if (lp->lwp_thread->td_flags & TDF_SINTR) {
1433 * lwp is sitting in lwkt_sleep() with PCATCH set.
1436 if (lp->lwp_thread->td_gd == mycpu) {
1440 * We can only adjust lwp_stat while we hold the
1441 * lwp_token, and we won't in the IPI function.
1444 if (lp->lwp_stat == LSSTOP)
1445 lp->lwp_stat = LSSLEEP;
1446 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1447 lwp_signotify_remote, lp);
1454 * Otherwise the lwp is either in some uninterruptable state
1455 * or it is on the userland scheduler's runqueue waiting to
1456 * be scheduled to a cpu.
1465 * This function is called via an IPI so we cannot call setrunnable() here
1466 * (because while we hold the lp we don't own its token, and can't get it
1469 * We are interlocked by virtue of being on the same cpu as the target. If
1470 * we still are and LWP_SINTR or TDF_SINTR is set we can safely schedule
1471 * the target thread.
1474 lwp_signotify_remote(void *arg)
1476 struct lwp *lp = arg;
1477 thread_t td = lp->lwp_thread;
1479 if (lp == lwkt_preempted_proc()) {
1482 } else if (td->td_gd == mycpu) {
1483 if ((lp->lwp_flags & LWP_SINTR) ||
1484 (td->td_flags & TDF_SINTR)) {
1489 lwkt_send_ipiq(td->td_gd, lwp_signotify_remote, lp);
1490 /* LWPHOLD() is forwarded to the target cpu */
1497 * Caller must hold p->p_token
1500 proc_stop(struct proc *p)
1505 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1507 /* If somebody raced us, be happy with it */
1508 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1513 FOREACH_LWP_IN_PROC(lp, p) {
1515 lwkt_gettoken(&lp->lwp_token);
1517 switch (lp->lwp_stat) {
1520 * Do nothing, we are already counted in
1527 * We're sleeping, but we will stop before
1528 * returning to userspace, so count us
1529 * as stopped as well. We set LWP_MP_WSTOP
1530 * to signal the lwp that it should not
1531 * increase p_nstopped when reaching tstop().
1533 * LWP_MP_WSTOP is protected by lp->lwp_token.
1535 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1536 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1543 * We might notify ourself, but that's not
1549 lwkt_reltoken(&lp->lwp_token);
1553 if (p->p_nstopped == p->p_nthreads) {
1555 * Token required to interlock kern_wait(). Reparenting can
1556 * also cause a race so we have to hold (q).
1560 lwkt_gettoken(&q->p_token);
1561 p->p_flags &= ~P_WAITED;
1563 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1564 ksignal(p->p_pptr, SIGCHLD);
1565 lwkt_reltoken(&q->p_token);
1571 * Caller must hold proc_token
1574 proc_unstop(struct proc *p)
1578 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1580 if (p->p_stat != SSTOP)
1583 p->p_stat = SACTIVE;
1585 FOREACH_LWP_IN_PROC(lp, p) {
1587 lwkt_gettoken(&lp->lwp_token);
1589 switch (lp->lwp_stat) {
1592 * Uh? Not stopped? Well, I guess that's okay.
1595 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1596 p->p_pid, lp->lwp_tid);
1601 * Still sleeping. Don't bother waking it up.
1602 * However, if this thread was counted as
1603 * stopped, undo this.
1605 * Nevertheless we call setrunnable() so that it
1606 * will wake up in case a signal or timeout arrived
1609 * LWP_MP_WSTOP is protected by lp->lwp_token.
1611 if (lp->lwp_mpflags & LWP_MP_WSTOP) {
1612 atomic_clear_int(&lp->lwp_mpflags,
1617 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1618 p->p_pid, lp->lwp_tid);
1624 * This handles any lwp's waiting in a tsleep with
1631 lwkt_reltoken(&lp->lwp_token);
1636 * This handles any lwp's waiting in tstop(). We have interlocked
1637 * the setting of p_stat by acquiring and releasing each lpw's
1647 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1649 sigset_t savedmask, set;
1650 struct proc *p = curproc;
1651 struct lwp *lp = curthread->td_lwp;
1652 int error, sig, hz, timevalid = 0;
1653 struct timespec rts, ets, ts;
1658 ets.tv_sec = 0; /* silence compiler warning */
1659 ets.tv_nsec = 0; /* silence compiler warning */
1660 SIG_CANTMASK(waitset);
1661 savedmask = lp->lwp_sigmask;
1664 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1665 timeout->tv_nsec < 1000000000) {
1667 getnanouptime(&rts);
1669 timespecadd(&ets, timeout);
1674 set = lwp_sigpend(lp);
1675 SIGSETAND(set, waitset);
1676 if ((sig = sig_ffs(&set)) != 0) {
1677 SIGFILLSET(lp->lwp_sigmask);
1678 SIGDELSET(lp->lwp_sigmask, sig);
1679 SIG_CANTMASK(lp->lwp_sigmask);
1680 sig = issignal(lp, 1);
1682 * It may be a STOP signal, in the case, issignal
1683 * returns 0, because we may stop there, and new
1684 * signal can come in, we should restart if we got
1694 * Previous checking got nothing, and we retried but still
1695 * got nothing, we should return the error status.
1701 * POSIX says this must be checked after looking for pending
1705 if (timevalid == 0) {
1709 getnanouptime(&rts);
1710 if (timespeccmp(&rts, &ets, >=)) {
1715 timespecsub(&ts, &rts);
1716 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1717 hz = tvtohz_high(&tv);
1722 lp->lwp_sigmask = savedmask;
1723 SIGSETNAND(lp->lwp_sigmask, waitset);
1725 * We won't ever be woken up. Instead, our sleep will
1726 * be broken in lwpsignal().
1728 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1730 if (error == ERESTART) {
1731 /* can not restart a timeout wait. */
1733 } else if (error == EAGAIN) {
1734 /* will calculate timeout by ourself. */
1741 lp->lwp_sigmask = savedmask;
1744 bzero(info, sizeof(*info));
1745 info->si_signo = sig;
1746 spin_lock(&lp->lwp_spin);
1747 lwp_delsig(lp, sig); /* take the signal! */
1748 spin_unlock(&lp->lwp_spin);
1750 if (sig == SIGKILL) {
1763 sys_sigtimedwait(struct sigtimedwait_args *uap)
1766 struct timespec *timeout;
1772 error = copyin(uap->timeout, &ts, sizeof(ts));
1779 error = copyin(uap->set, &set, sizeof(set));
1782 error = kern_sigtimedwait(set, &info, timeout);
1786 error = copyout(&info, uap->info, sizeof(info));
1787 /* Repost if we got an error. */
1791 * This could transform a thread-specific signal to another
1792 * thread / process pending signal.
1795 ksignal(curproc, info.si_signo);
1797 uap->sysmsg_result = info.si_signo;
1806 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1812 error = copyin(uap->set, &set, sizeof(set));
1815 error = kern_sigtimedwait(set, &info, NULL);
1819 error = copyout(&info, uap->info, sizeof(info));
1820 /* Repost if we got an error. */
1824 * This could transform a thread-specific signal to another
1825 * thread / process pending signal.
1828 ksignal(curproc, info.si_signo);
1830 uap->sysmsg_result = info.si_signo;
1836 * If the current process has received a signal that would interrupt a
1837 * system call, return EINTR or ERESTART as appropriate.
1840 iscaught(struct lwp *lp)
1842 struct proc *p = lp->lwp_proc;
1846 if ((sig = CURSIG(lp)) != 0) {
1847 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1852 return(EWOULDBLOCK);
1856 * If the current process has received a signal (should be caught or cause
1857 * termination, should interrupt current syscall), return the signal number.
1858 * Stop signals with default action are processed immediately, then cleared;
1859 * they aren't returned. This is checked after each entry to the system for
1860 * a syscall or trap (though this can usually be done without calling issignal
1861 * by checking the pending signal masks in the CURSIG macro).
1863 * This routine is called via CURSIG/__cursig. We will acquire and release
1864 * p->p_token but if the caller needs to interlock the test the caller must
1865 * also hold p->p_token.
1867 * while (sig = CURSIG(curproc))
1873 issignal(struct lwp *lp, int maytrace)
1875 struct proc *p = lp->lwp_proc;
1879 lwkt_gettoken(&p->p_token);
1882 int traced = (p->p_flags & P_TRACED) || (p->p_stops & S_SIG);
1885 * If this process is supposed to stop, stop this thread.
1887 if (p->p_stat == SSTOP)
1890 mask = lwp_sigpend(lp);
1891 SIGSETNAND(mask, lp->lwp_sigmask);
1892 if (p->p_flags & P_PPWAIT)
1893 SIG_STOPSIGMASK(mask);
1894 if (SIGISEMPTY(mask)) { /* no signal to send */
1895 lwkt_reltoken(&p->p_token);
1898 sig = sig_ffs(&mask);
1900 STOPEVENT(p, S_SIG, sig);
1903 * We should see pending but ignored signals
1904 * only if P_TRACED was on when they were posted.
1906 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1907 spin_lock(&lp->lwp_spin);
1908 lwp_delsig(lp, sig);
1909 spin_unlock(&lp->lwp_spin);
1913 (p->p_flags & P_TRACED) &&
1914 (p->p_flags & P_PPWAIT) == 0) {
1916 * If traced, always stop, and stay stopped until
1917 * released by the parent.
1919 * NOTE: SSTOP may get cleared during the loop,
1920 * but we do not re-notify the parent if we have
1921 * to loop several times waiting for the parent
1922 * to let us continue.
1924 * XXX not sure if this is still true
1930 } while (!trace_req(p) && (p->p_flags & P_TRACED));
1933 * If parent wants us to take the signal,
1934 * then it will leave it in p->p_xstat;
1935 * otherwise we just look for signals again.
1937 spin_lock(&lp->lwp_spin);
1938 lwp_delsig(lp, sig); /* clear old signal */
1939 spin_unlock(&lp->lwp_spin);
1945 * Put the new signal into p_siglist. If the
1946 * signal is being masked, look for other signals.
1948 * XXX lwp might need a call to ksignal()
1950 SIGADDSET(p->p_siglist, sig);
1951 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1955 * If the traced bit got turned off, go back up
1956 * to the top to rescan signals. This ensures
1957 * that p_sig* and ps_sigact are consistent.
1959 if ((p->p_flags & P_TRACED) == 0)
1963 prop = sigprop(sig);
1966 * Decide whether the signal should be returned.
1967 * Return the signal's number, or fall through
1968 * to clear it from the pending mask.
1970 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1971 case (intptr_t)SIG_DFL:
1973 * Don't take default actions on system processes.
1975 if (p->p_pid <= 1) {
1978 * Are you sure you want to ignore SIGSEGV
1981 kprintf("Process (pid %lu) got signal %d\n",
1982 (u_long)p->p_pid, sig);
1984 break; /* == ignore */
1988 * Handle the in-kernel checkpoint action
1990 if (prop & SA_CKPT) {
1991 checkpoint_signal_handler(lp);
1996 * If there is a pending stop signal to process
1997 * with default action, stop here,
1998 * then clear the signal. However,
1999 * if process is member of an orphaned
2000 * process group, ignore tty stop signals.
2002 if (prop & SA_STOP) {
2003 if (p->p_flags & P_TRACED ||
2004 (p->p_pgrp->pg_jobc == 0 &&
2006 break; /* == ignore */
2007 if ((p->p_flags & P_WEXIT) == 0) {
2013 } else if (prop & SA_IGNORE) {
2015 * Except for SIGCONT, shouldn't get here.
2016 * Default action is to ignore; drop it.
2018 break; /* == ignore */
2020 lwkt_reltoken(&p->p_token);
2026 case (intptr_t)SIG_IGN:
2028 * Masking above should prevent us ever trying
2029 * to take action on an ignored signal other
2030 * than SIGCONT, unless process is traced.
2032 if ((prop & SA_CONT) == 0 &&
2033 (p->p_flags & P_TRACED) == 0)
2034 kprintf("issignal\n");
2035 break; /* == ignore */
2039 * This signal has an action, let
2040 * postsig() process it.
2042 lwkt_reltoken(&p->p_token);
2045 spin_lock(&lp->lwp_spin);
2046 lwp_delsig(lp, sig); /* take the signal! */
2047 spin_unlock(&lp->lwp_spin);
2053 * Take the action for the specified signal
2054 * from the current set of pending signals.
2056 * Caller must hold p->p_token
2061 struct lwp *lp = curthread->td_lwp;
2062 struct proc *p = lp->lwp_proc;
2063 struct sigacts *ps = p->p_sigacts;
2065 sigset_t returnmask;
2068 KASSERT(sig != 0, ("postsig"));
2070 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
2073 * If we are a virtual kernel running an emulated user process
2074 * context, switch back to the virtual kernel context before
2075 * trying to post the signal.
2077 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
2078 struct trapframe *tf = lp->lwp_md.md_regs;
2080 vkernel_trap(lp, tf);
2083 spin_lock(&lp->lwp_spin);
2084 lwp_delsig(lp, sig);
2085 spin_unlock(&lp->lwp_spin);
2086 action = ps->ps_sigact[_SIG_IDX(sig)];
2088 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
2089 ktrpsig(lp, sig, action, lp->lwp_flags & LWP_OLDMASK ?
2090 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
2092 STOPEVENT(p, S_SIG, sig);
2094 if (action == SIG_DFL) {
2096 * Default action, where the default is to kill
2097 * the process. (Other cases were ignored above.)
2103 * If we get here, the signal must be caught.
2105 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
2106 ("postsig action"));
2109 * Reset the signal handler if asked to
2111 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2113 * See kern_sigaction() for origin of this code.
2115 SIGDELSET(p->p_sigcatch, sig);
2116 if (sig != SIGCONT &&
2117 sigprop(sig) & SA_IGNORE)
2118 SIGADDSET(p->p_sigignore, sig);
2119 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2123 * Set the signal mask and calculate the mask to restore
2124 * when the signal function returns.
2126 * Special case: user has done a sigsuspend. Here the
2127 * current mask is not of interest, but rather the
2128 * mask from before the sigsuspend is what we want
2129 * restored after the signal processing is completed.
2131 if (lp->lwp_flags & LWP_OLDMASK) {
2132 returnmask = lp->lwp_oldsigmask;
2133 lp->lwp_flags &= ~LWP_OLDMASK;
2135 returnmask = lp->lwp_sigmask;
2138 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2139 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2140 SIGADDSET(lp->lwp_sigmask, sig);
2142 lp->lwp_ru.ru_nsignals++;
2143 if (lp->lwp_sig != sig) {
2146 code = lp->lwp_code;
2150 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2155 * Kill the current process for stated reason.
2158 killproc(struct proc *p, char *why)
2160 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2161 p->p_pid, p->p_comm,
2162 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2163 ksignal(p, SIGKILL);
2167 * Force the current process to exit with the specified signal, dumping core
2168 * if appropriate. We bypass the normal tests for masked and caught signals,
2169 * allowing unrecoverable failures to terminate the process without changing
2170 * signal state. Mark the accounting record with the signal termination.
2171 * If dumping core, save the signal number for the debugger. Calls exit and
2174 * This routine does not return.
2177 sigexit(struct lwp *lp, int sig)
2179 struct proc *p = lp->lwp_proc;
2181 lwkt_gettoken(&p->p_token);
2182 p->p_acflag |= AXSIG;
2183 if (sigprop(sig) & SA_CORE) {
2186 * Log signals which would cause core dumps
2187 * (Log as LOG_INFO to appease those who don't want
2189 * XXX : Todo, as well as euid, write out ruid too
2191 if (coredump(lp, sig) == 0)
2193 if (kern_logsigexit)
2195 "pid %d (%s), uid %d: exited on signal %d%s\n",
2196 p->p_pid, p->p_comm,
2197 p->p_ucred ? p->p_ucred->cr_uid : -1,
2199 sig & WCOREFLAG ? " (core dumped)" : "");
2201 lwkt_reltoken(&p->p_token);
2202 exit1(W_EXITCODE(0, sig));
2206 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2207 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2208 sizeof(corefilename), "process corefile name format string");
2211 * expand_name(name, uid, pid)
2212 * Expand the name described in corefilename, using name, uid, and pid.
2213 * corefilename is a kprintf-like string, with three format specifiers:
2214 * %N name of process ("name")
2215 * %P process id (pid)
2217 * For example, "%N.core" is the default; they can be disabled completely
2218 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2219 * This is controlled by the sysctl variable kern.corefile (see above).
2223 expand_name(const char *name, uid_t uid, pid_t pid)
2226 char buf[11]; /* Buffer for pid/uid -- max 4B */
2228 char *format = corefilename;
2231 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2234 namelen = strlen(name);
2235 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2237 switch (format[i]) {
2238 case '%': /* Format character */
2240 switch (format[i]) {
2244 case 'N': /* process name */
2245 if ((n + namelen) > MAXPATHLEN) {
2246 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2247 pid, name, uid, temp, name);
2248 kfree(temp, M_TEMP);
2251 memcpy(temp+n, name, namelen);
2254 case 'P': /* process id */
2255 l = ksprintf(buf, "%u", pid);
2256 if ((n + l) > MAXPATHLEN) {
2257 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2258 pid, name, uid, temp, name);
2259 kfree(temp, M_TEMP);
2262 memcpy(temp+n, buf, l);
2265 case 'U': /* user id */
2266 l = ksprintf(buf, "%u", uid);
2267 if ((n + l) > MAXPATHLEN) {
2268 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2269 pid, name, uid, temp, name);
2270 kfree(temp, M_TEMP);
2273 memcpy(temp+n, buf, l);
2277 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2281 temp[n++] = format[i];
2289 * Dump a process' core. The main routine does some
2290 * policy checking, and creates the name of the coredump;
2291 * then it passes on a vnode and a size limit to the process-specific
2292 * coredump routine if there is one; if there _is not_ one, it returns
2293 * ENOSYS; otherwise it returns the error from the process-specific routine.
2295 * The parameter `lp' is the lwp which triggered the coredump.
2299 coredump(struct lwp *lp, int sig)
2301 struct proc *p = lp->lwp_proc;
2303 struct ucred *cred = p->p_ucred;
2305 struct nlookupdata nd;
2308 char *name; /* name of corefile */
2311 STOPEVENT(p, S_CORE, 0);
2313 if (((sugid_coredump == 0) && p->p_flags & P_SUGID) || do_coredump == 0)
2317 * Note that the bulk of limit checking is done after
2318 * the corefile is created. The exception is if the limit
2319 * for corefiles is 0, in which case we don't bother
2320 * creating the corefile at all. This layout means that
2321 * a corefile is truncated instead of not being created,
2322 * if it is larger than the limit.
2324 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2328 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2331 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2333 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2334 kfree(name, M_TEMP);
2340 nd.nl_open_vp = NULL;
2344 lf.l_whence = SEEK_SET;
2347 lf.l_type = F_WRLCK;
2348 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2352 /* Don't dump to non-regular files or files with links. */
2353 if (vp->v_type != VREG ||
2354 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2359 /* Don't dump to files current user does not own */
2360 if (vattr.va_uid != p->p_ucred->cr_uid) {
2366 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2368 VOP_SETATTR(vp, &vattr, cred);
2369 p->p_acflag |= ACORE;
2372 error = p->p_sysent->sv_coredump ?
2373 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2376 lf.l_type = F_UNLCK;
2377 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2379 error1 = vn_close(vp, FWRITE);
2386 * Nonexistent system call-- signal process (may want to handle it).
2387 * Flag error in case process won't see signal immediately (blocked or ignored).
2393 sys_nosys(struct nosys_args *args)
2395 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2400 * Send a SIGIO or SIGURG signal to a process or process group using
2401 * stored credentials rather than those of the current process.
2404 pgsigio(struct sigio *sigio, int sig, int checkctty)
2409 if (sigio->sio_pgid > 0) {
2410 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2412 ksignal(sigio->sio_proc, sig);
2413 } else if (sigio->sio_pgid < 0) {
2415 struct pgrp *pg = sigio->sio_pgrp;
2418 * Must interlock all signals against fork
2421 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2422 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
2423 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2424 (checkctty == 0 || (p->p_flags & P_CONTROLT)))
2427 lockmgr(&pg->pg_lock, LK_RELEASE);
2433 filt_sigattach(struct knote *kn)
2435 struct proc *p = curproc;
2437 kn->kn_ptr.p_proc = p;
2438 kn->kn_flags |= EV_CLEAR; /* automatically set */
2440 /* XXX lock the proc here while adding to the list? */
2441 knote_insert(&p->p_klist, kn);
2447 filt_sigdetach(struct knote *kn)
2449 struct proc *p = kn->kn_ptr.p_proc;
2451 knote_remove(&p->p_klist, kn);
2455 * signal knotes are shared with proc knotes, so we apply a mask to
2456 * the hint in order to differentiate them from process hints. This
2457 * could be avoided by using a signal-specific knote list, but probably
2458 * isn't worth the trouble.
2461 filt_signal(struct knote *kn, long hint)
2463 if (hint & NOTE_SIGNAL) {
2464 hint &= ~NOTE_SIGNAL;
2466 if (kn->kn_id == hint)
2469 return (kn->kn_data != 0);