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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>
73 #include <machine/cpu.h>
74 #include <machine/smp.h>
76 static int coredump(struct lwp *, int);
77 static char *expand_name(const char *, uid_t, pid_t);
78 static int dokillpg(int sig, int pgid, int all);
79 static int sig_ffs(sigset_t *set);
80 static int sigprop(int sig);
81 static void lwp_signotify(struct lwp *lp);
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));
232 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
234 struct thread *td = curthread;
235 struct proc *p = td->td_proc;
237 struct sigacts *ps = p->p_sigacts;
239 if (sig <= 0 || sig > _SIG_MAXSIG)
242 lwkt_gettoken(&p->p_token);
245 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
246 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
248 if (SIGISMEMBER(ps->ps_sigonstack, sig))
249 oact->sa_flags |= SA_ONSTACK;
250 if (!SIGISMEMBER(ps->ps_sigintr, sig))
251 oact->sa_flags |= SA_RESTART;
252 if (SIGISMEMBER(ps->ps_sigreset, sig))
253 oact->sa_flags |= SA_RESETHAND;
254 if (SIGISMEMBER(ps->ps_signodefer, sig))
255 oact->sa_flags |= SA_NODEFER;
256 if (SIGISMEMBER(ps->ps_siginfo, sig))
257 oact->sa_flags |= SA_SIGINFO;
258 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
259 oact->sa_flags |= SA_MAILBOX;
260 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
261 oact->sa_flags |= SA_NOCLDSTOP;
262 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
263 oact->sa_flags |= SA_NOCLDWAIT;
267 * Check for invalid requests. KILL and STOP cannot be
270 if (sig == SIGKILL || sig == SIGSTOP) {
271 if (act->sa_handler != SIG_DFL) {
272 lwkt_reltoken(&p->p_token);
276 /* (not needed, SIG_DFL forces action to occur) */
277 if (act->sa_flags & SA_MAILBOX) {
278 lwkt_reltoken(&p->p_token);
285 * Change setting atomically.
289 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
290 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
291 if (act->sa_flags & SA_SIGINFO) {
292 ps->ps_sigact[_SIG_IDX(sig)] =
293 (__sighandler_t *)act->sa_sigaction;
294 SIGADDSET(ps->ps_siginfo, sig);
296 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
297 SIGDELSET(ps->ps_siginfo, sig);
299 if (!(act->sa_flags & SA_RESTART))
300 SIGADDSET(ps->ps_sigintr, sig);
302 SIGDELSET(ps->ps_sigintr, sig);
303 if (act->sa_flags & SA_ONSTACK)
304 SIGADDSET(ps->ps_sigonstack, sig);
306 SIGDELSET(ps->ps_sigonstack, sig);
307 if (act->sa_flags & SA_RESETHAND)
308 SIGADDSET(ps->ps_sigreset, sig);
310 SIGDELSET(ps->ps_sigreset, sig);
311 if (act->sa_flags & SA_NODEFER)
312 SIGADDSET(ps->ps_signodefer, sig);
314 SIGDELSET(ps->ps_signodefer, sig);
315 if (act->sa_flags & SA_MAILBOX)
316 SIGADDSET(ps->ps_sigmailbox, sig);
318 SIGDELSET(ps->ps_sigmailbox, sig);
319 if (sig == SIGCHLD) {
320 if (act->sa_flags & SA_NOCLDSTOP)
321 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
323 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
324 if (act->sa_flags & SA_NOCLDWAIT) {
326 * Paranoia: since SA_NOCLDWAIT is implemented
327 * by reparenting the dying child to PID 1 (and
328 * trust it to reap the zombie), PID 1 itself
329 * is forbidden to set SA_NOCLDWAIT.
332 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
334 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
336 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
340 * Set bit in p_sigignore for signals that are set to SIG_IGN,
341 * and for signals set to SIG_DFL where the default is to
342 * ignore. However, don't put SIGCONT in p_sigignore, as we
343 * have to restart the process.
345 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
346 (sigprop(sig) & SA_IGNORE &&
347 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
348 /* never to be seen again */
349 SIGDELSET(p->p_siglist, sig);
351 * Remove the signal also from the thread lists.
353 FOREACH_LWP_IN_PROC(lp, p) {
354 SIGDELSET(lp->lwp_siglist, sig);
356 if (sig != SIGCONT) {
357 /* easier in ksignal */
358 SIGADDSET(p->p_sigignore, sig);
360 SIGDELSET(p->p_sigcatch, sig);
362 SIGDELSET(p->p_sigignore, sig);
363 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
364 SIGDELSET(p->p_sigcatch, sig);
366 SIGADDSET(p->p_sigcatch, sig);
371 lwkt_reltoken(&p->p_token);
376 sys_sigaction(struct sigaction_args *uap)
378 struct sigaction act, oact;
379 struct sigaction *actp, *oactp;
382 actp = (uap->act != NULL) ? &act : NULL;
383 oactp = (uap->oact != NULL) ? &oact : NULL;
385 error = copyin(uap->act, actp, sizeof(act));
389 error = kern_sigaction(uap->sig, actp, oactp);
390 if (oactp && !error) {
391 error = copyout(oactp, uap->oact, sizeof(oact));
397 * Initialize signal state for process 0;
398 * set to ignore signals that are ignored by default.
401 siginit(struct proc *p)
405 for (i = 1; i <= NSIG; i++)
406 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
407 SIGADDSET(p->p_sigignore, i);
411 * Reset signals for an exec of the specified process.
414 execsigs(struct proc *p)
416 struct sigacts *ps = p->p_sigacts;
420 lp = ONLY_LWP_IN_PROC(p);
423 * Reset caught signals. Held signals remain held
424 * through p_sigmask (unless they were caught,
425 * and are now ignored by default).
427 while (SIGNOTEMPTY(p->p_sigcatch)) {
428 sig = sig_ffs(&p->p_sigcatch);
429 SIGDELSET(p->p_sigcatch, sig);
430 if (sigprop(sig) & SA_IGNORE) {
432 SIGADDSET(p->p_sigignore, sig);
433 SIGDELSET(p->p_siglist, sig);
434 SIGDELSET(lp->lwp_siglist, sig);
436 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
440 * Reset stack state to the user stack.
441 * Clear set of signals caught on the signal stack.
443 lp->lwp_sigstk.ss_flags = SS_DISABLE;
444 lp->lwp_sigstk.ss_size = 0;
445 lp->lwp_sigstk.ss_sp = 0;
446 lp->lwp_flag &= ~LWP_ALTSTACK;
448 * Reset no zombies if child dies flag as Solaris does.
450 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
454 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
456 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
460 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
462 struct thread *td = curthread;
463 struct lwp *lp = td->td_lwp;
464 struct proc *p = td->td_proc;
467 lwkt_gettoken(&p->p_token);
470 *oset = lp->lwp_sigmask;
477 SIGSETOR(lp->lwp_sigmask, *set);
480 SIGSETNAND(lp->lwp_sigmask, *set);
484 lp->lwp_sigmask = *set;
492 lwkt_reltoken(&p->p_token);
503 sys_sigprocmask(struct sigprocmask_args *uap)
506 sigset_t *setp, *osetp;
509 setp = (uap->set != NULL) ? &set : NULL;
510 osetp = (uap->oset != NULL) ? &oset : NULL;
512 error = copyin(uap->set, setp, sizeof(set));
516 error = kern_sigprocmask(uap->how, setp, osetp);
517 if (osetp && !error) {
518 error = copyout(osetp, uap->oset, sizeof(oset));
527 kern_sigpending(struct __sigset *set)
529 struct lwp *lp = curthread->td_lwp;
531 *set = lwp_sigpend(lp);
540 sys_sigpending(struct sigpending_args *uap)
545 error = kern_sigpending(&set);
548 error = copyout(&set, uap->set, sizeof(set));
553 * Suspend process until signal, providing mask to be set
559 kern_sigsuspend(struct __sigset *set)
561 struct thread *td = curthread;
562 struct lwp *lp = td->td_lwp;
563 struct proc *p = td->td_proc;
564 struct sigacts *ps = p->p_sigacts;
567 * When returning from sigsuspend, we want
568 * the old mask to be restored after the
569 * signal handler has finished. Thus, we
570 * save it here and mark the sigacts structure
573 lp->lwp_oldsigmask = lp->lwp_sigmask;
574 lp->lwp_flag |= LWP_OLDMASK;
577 lp->lwp_sigmask = *set;
578 while (tsleep(ps, PCATCH, "pause", 0) == 0)
580 /* always return EINTR rather than ERESTART... */
585 * Note nonstandard calling convention: libc stub passes mask, not
586 * pointer, to save a copyin.
591 sys_sigsuspend(struct sigsuspend_args *uap)
596 error = copyin(uap->sigmask, &mask, sizeof(mask));
600 error = kern_sigsuspend(&mask);
609 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
611 struct thread *td = curthread;
612 struct lwp *lp = td->td_lwp;
613 struct proc *p = td->td_proc;
615 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
616 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
619 *oss = lp->lwp_sigstk;
622 if (ss->ss_flags & SS_DISABLE) {
623 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
625 lp->lwp_flag &= ~LWP_ALTSTACK;
626 lp->lwp_sigstk.ss_flags = ss->ss_flags;
628 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
630 lp->lwp_flag |= LWP_ALTSTACK;
631 lp->lwp_sigstk = *ss;
642 sys_sigaltstack(struct sigaltstack_args *uap)
648 error = copyin(uap->ss, &ss, sizeof(ss));
653 error = kern_sigaltstack(uap->ss ? &ss : NULL,
654 uap->oss ? &oss : NULL);
656 if (error == 0 && uap->oss)
657 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
662 * Common code for kill process group/broadcast kill.
663 * cp is calling process.
670 static int killpg_all_callback(struct proc *p, void *data);
673 dokillpg(int sig, int pgid, int all)
675 struct killpg_info info;
676 struct proc *cp = curproc;
687 allproc_scan(killpg_all_callback, &info);
691 * zero pgid means send to my process group.
702 * Must interlock all signals against fork
704 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
705 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
707 p->p_stat == SZOMB ||
708 (p->p_flag & P_SYSTEM) ||
709 !CANSIGNAL(p, sig)) {
716 lockmgr(&pgrp->pg_lock, LK_RELEASE);
719 return (info.nfound ? 0 : ESRCH);
723 killpg_all_callback(struct proc *p, void *data)
725 struct killpg_info *info = data;
727 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
728 p == curproc || !CANSIGNAL(p, info->sig)) {
733 ksignal(p, info->sig);
738 * Send a general signal to a process or LWPs within that process. Note
739 * that new signals cannot be sent if a process is exiting.
744 kern_kill(int sig, pid_t pid, lwpid_t tid)
748 if ((u_int)sig > _SIG_MAXSIG)
751 lwkt_gettoken(&proc_token);
755 struct lwp *lp = NULL;
757 /* kill single process */
758 if ((p = pfind(pid)) == NULL) {
759 lwkt_reltoken(&proc_token);
762 lwkt_gettoken(&p->p_token);
763 if (!CANSIGNAL(p, sig)) {
764 lwkt_reltoken(&p->p_token);
766 lwkt_reltoken(&proc_token);
771 * NOP if the process is exiting. Note that lwpsignal() is
772 * called directly with P_WEXIT set to kill individual LWPs
773 * during exit, which is allowed.
775 if (p->p_flag & P_WEXIT) {
776 lwkt_reltoken(&p->p_token);
778 lwkt_reltoken(&proc_token);
782 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
784 lwkt_reltoken(&p->p_token);
786 lwkt_reltoken(&proc_token);
791 lwpsignal(p, lp, sig);
792 lwkt_reltoken(&p->p_token);
794 lwkt_reltoken(&proc_token);
799 * If we come here, pid is a special broadcast pid.
800 * This doesn't mix with a tid.
803 lwkt_reltoken(&proc_token);
807 case -1: /* broadcast signal */
808 t = (dokillpg(sig, 0, 1));
810 case 0: /* signal own process group */
811 t = (dokillpg(sig, 0, 0));
813 default: /* negative explicit process group */
814 t = (dokillpg(sig, -pid, 0));
817 lwkt_reltoken(&proc_token);
822 sys_kill(struct kill_args *uap)
826 error = kern_kill(uap->signum, uap->pid, -1);
831 sys_lwp_kill(struct lwp_kill_args *uap)
834 pid_t pid = uap->pid;
837 * A tid is mandatory for lwp_kill(), otherwise
838 * you could simply use kill().
844 * To save on a getpid() function call for intra-process
845 * signals, pid == -1 means current process.
848 pid = curproc->p_pid;
850 error = kern_kill(uap->signum, pid, uap->tid);
855 * Send a signal to a process group.
858 gsignal(int pgid, int sig)
862 if (pgid && (pgrp = pgfind(pgid)))
863 pgsignal(pgrp, sig, 0);
867 * Send a signal to a process group. If checktty is 1,
868 * limit to members which have a controlling terminal.
870 * pg_lock interlocks against a fork that might be in progress, to
871 * ensure that the new child process picks up the signal.
874 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
879 * Must interlock all signals against fork
883 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
884 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
885 if (checkctty == 0 || p->p_flag & P_CONTROLT)
888 lockmgr(&pgrp->pg_lock, LK_RELEASE);
894 * Send a signal caused by a trap to the current lwp. If it will be caught
895 * immediately, deliver it with correct code. Otherwise, post it normally.
897 * These signals may ONLY be delivered to the specified lwp and may never
898 * be delivered to the process generically.
901 trapsignal(struct lwp *lp, int sig, u_long code)
903 struct proc *p = lp->lwp_proc;
904 struct sigacts *ps = p->p_sigacts;
907 * If we are a virtual kernel running an emulated user process
908 * context, switch back to the virtual kernel context before
909 * trying to post the signal.
911 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
912 struct trapframe *tf = lp->lwp_md.md_regs;
914 vkernel_trap(lp, tf);
918 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
919 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
920 lp->lwp_ru.ru_nsignals++;
922 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
923 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
924 &lp->lwp_sigmask, code);
926 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
927 &lp->lwp_sigmask, code);
928 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
929 if (!SIGISMEMBER(ps->ps_signodefer, sig))
930 SIGADDSET(lp->lwp_sigmask, sig);
931 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
933 * See kern_sigaction() for origin of this code.
935 SIGDELSET(p->p_sigcatch, sig);
936 if (sig != SIGCONT &&
937 sigprop(sig) & SA_IGNORE)
938 SIGADDSET(p->p_sigignore, sig);
939 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
942 lp->lwp_code = code; /* XXX for core dump/debugger */
943 lp->lwp_sig = sig; /* XXX to verify code */
944 lwpsignal(p, lp, sig);
949 * Find a suitable lwp to deliver the signal to. Returns NULL if all
950 * lwps hold the signal blocked.
952 * Caller must hold p->p_token.
955 find_lwp_for_signal(struct proc *p, int sig)
958 struct lwp *run, *sleep, *stop;
961 * If the running/preempted thread belongs to the proc to which
962 * the signal is being delivered and this thread does not block
963 * the signal, then we can avoid a context switch by delivering
964 * the signal to this thread, because it will return to userland
967 lp = lwkt_preempted_proc();
968 if (lp != NULL && lp->lwp_proc == p &&
969 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
973 run = sleep = stop = NULL;
974 FOREACH_LWP_IN_PROC(lp, p) {
976 * If the signal is being blocked by the lwp, then this
977 * lwp is not eligible for receiving the signal.
979 if (SIGISMEMBER(lp->lwp_sigmask, sig))
982 switch (lp->lwp_stat) {
992 if (lp->lwp_flag & LWP_SINTR)
1000 else if (sleep != NULL)
1007 * Send the signal to the process. If the signal has an action, the action
1008 * is usually performed by the target process rather than the caller; we add
1009 * the signal to the set of pending signals for the process.
1012 * o When a stop signal is sent to a sleeping process that takes the
1013 * default action, the process is stopped without awakening it.
1014 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1015 * regardless of the signal action (eg, blocked or ignored).
1017 * Other ignored signals are discarded immediately.
1019 * If the caller wishes to call this function from a hard code section the
1020 * caller must already hold p->p_token (see kern_clock.c).
1025 ksignal(struct proc *p, int sig)
1027 lwpsignal(p, NULL, sig);
1031 * The core for ksignal. lp may be NULL, then a suitable thread
1032 * will be chosen. If not, lp MUST be a member of p.
1034 * If the caller wishes to call this function from a hard code section the
1035 * caller must already hold p->p_token.
1040 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1046 if (sig > _SIG_MAXSIG || sig <= 0) {
1047 kprintf("lwpsignal: signal %d\n", sig);
1048 panic("lwpsignal signal number");
1051 KKASSERT(lp == NULL || lp->lwp_proc == p);
1054 lwkt_gettoken(&p->p_token);
1056 prop = sigprop(sig);
1059 * If proc is traced, always give parent a chance;
1060 * if signal event is tracked by procfs, give *that*
1061 * a chance, as well.
1063 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1067 * Do not try to deliver signals to an exiting lwp. Note
1068 * that we must still deliver the signal if P_WEXIT is set
1069 * in the process flags.
1071 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
1072 lwkt_reltoken(&p->p_token);
1078 * If the signal is being ignored, then we forget about
1079 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1080 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1082 if (SIGISMEMBER(p->p_sigignore, sig)) {
1084 * Even if a signal is set SIG_IGN, it may still be
1085 * lurking in a kqueue.
1087 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1088 lwkt_reltoken(&p->p_token);
1092 if (SIGISMEMBER(p->p_sigcatch, sig))
1099 * If continuing, clear any pending STOP signals.
1102 SIG_STOPSIGMASK(p->p_siglist);
1104 if (prop & SA_STOP) {
1106 * If sending a tty stop signal to a member of an orphaned
1107 * process group, discard the signal here if the action
1108 * is default; don't stop the process below if sleeping,
1109 * and don't clear any pending SIGCONT.
1111 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1112 action == SIG_DFL) {
1113 lwkt_reltoken(&p->p_token);
1117 SIG_CONTSIGMASK(p->p_siglist);
1118 p->p_flag &= ~P_CONTINUED;
1123 if (p->p_stat == SSTOP) {
1125 * Nobody can handle this signal, add it to the lwp or
1126 * process pending list
1129 SIGADDSET(lp->lwp_siglist, sig);
1131 SIGADDSET(p->p_siglist, sig);
1134 * If the process is stopped and is being traced, then no
1135 * further action is necessary.
1137 if (p->p_flag & P_TRACED)
1141 * If the process is stopped and receives a KILL signal,
1142 * make the process runnable.
1144 if (sig == SIGKILL) {
1146 goto active_process;
1150 * If the process is stopped and receives a CONT signal,
1151 * then try to make the process runnable again.
1153 if (prop & SA_CONT) {
1155 * If SIGCONT is default (or ignored), we continue the
1156 * process but don't leave the signal in p_siglist, as
1157 * it has no further action. If SIGCONT is held, we
1158 * continue the process and leave the signal in
1159 * p_siglist. If the process catches SIGCONT, let it
1160 * handle the signal itself.
1162 * XXX what if the signal is being held blocked?
1164 * Token required to interlock kern_wait().
1165 * Reparenting can also cause a race so we have to
1170 lwkt_gettoken(&q->p_token);
1171 p->p_flag |= P_CONTINUED;
1173 if (action == SIG_DFL)
1174 SIGDELSET(p->p_siglist, sig);
1176 lwkt_reltoken(&q->p_token);
1178 if (action == SIG_CATCH)
1179 goto active_process;
1184 * If the process is stopped and receives another STOP
1185 * signal, we do not need to stop it again. If we did
1186 * the shell could get confused.
1188 * However, if the current/preempted lwp is part of the
1189 * process receiving the signal, we need to keep it,
1190 * so that this lwp can stop in issignal() later, as
1191 * we don't want to wait until it reaches userret!
1193 if (prop & SA_STOP) {
1194 if (lwkt_preempted_proc() == NULL ||
1195 lwkt_preempted_proc()->lwp_proc != p)
1196 SIGDELSET(p->p_siglist, sig);
1200 * Otherwise the process is stopped and it received some
1201 * signal, which does not change its stopped state.
1203 * We have to select one thread to set LWP_BREAKTSLEEP,
1204 * so that the current signal will break the sleep
1205 * as soon as a SA_CONT signal will unstop the process.
1208 lp = find_lwp_for_signal(p, sig);
1210 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1211 lp->lwp_flag |= LWP_BREAKTSLEEP;
1216 /* else not stopped */
1220 * Never deliver a lwp-specific signal to a random lwp.
1223 lp = find_lwp_for_signal(p, sig);
1224 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1229 * Deliver to the process generically if (1) the signal is being
1230 * sent to any thread or (2) we could not find a thread to deliver
1234 SIGADDSET(p->p_siglist, sig);
1239 * Deliver to a specific LWP whether it masks it or not. It will
1240 * not be dispatched if masked but we must still deliver it.
1242 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1243 (p->p_flag & P_TRACED) == 0) {
1248 * If the process receives a STOP signal which indeed needs to
1249 * stop the process, do so. If the process chose to catch the
1250 * signal, it will be treated like any other signal.
1252 if ((prop & SA_STOP) && action == SIG_DFL) {
1254 * If a child holding parent blocked, stopping
1255 * could cause deadlock. Take no action at this
1258 if (p->p_flag & P_PPWAIT) {
1259 SIGADDSET(p->p_siglist, sig);
1264 * Do not actually try to manipulate the process, but simply
1265 * stop it. Lwps will stop as soon as they safely can.
1273 * If it is a CONT signal with default action, just ignore it.
1275 if ((prop & SA_CONT) && action == SIG_DFL)
1279 * Mark signal pending at this specific thread.
1281 SIGADDSET(lp->lwp_siglist, sig);
1286 lwkt_reltoken(&p->p_token);
1292 * p->p_token must be held
1295 lwp_signotify(struct lwp *lp)
1297 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
1300 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1302 * Thread is in tsleep.
1306 * If the thread is sleeping uninterruptibly
1307 * we can't interrupt the sleep... the signal will
1308 * be noticed when the lwp returns through
1309 * trap() or syscall().
1311 * Otherwise the signal can interrupt the sleep.
1313 * If the process is traced, the lwp will handle the
1314 * tracing in issignal() when it returns to userland.
1316 if (lp->lwp_flag & LWP_SINTR) {
1318 * Make runnable and break out of any tsleep as well.
1320 lp->lwp_flag |= LWP_BREAKTSLEEP;
1325 * Otherwise the thread is running
1327 * LSRUN does nothing with the signal, other than kicking
1328 * ourselves if we are running.
1329 * SZOMB and SIDL mean that it will either never be noticed,
1330 * or noticed very soon.
1332 * Note that lwp_thread may be NULL or may not be completely
1333 * initialized if the process is in the SIDL or SZOMB state.
1335 * For SMP we may have to forward the request to another cpu.
1336 * YYY the MP lock prevents the target process from moving
1337 * to another cpu, see kern/kern_switch.c
1339 * If the target thread is waiting on its message port,
1340 * wakeup the target thread so it can check (or ignore)
1341 * the new signal. YYY needs cleanup.
1343 if (lp == lwkt_preempted_proc()) {
1345 } else if (lp->lwp_stat == LSRUN) {
1346 struct thread *td = lp->lwp_thread;
1347 struct proc *p __debugvar = lp->lwp_proc;
1350 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1351 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1352 p->p_flag, lp->lwp_flag));
1355 * To prevent a MP race with TDF_SINTR we must
1356 * schedule the thread on the correct cpu.
1359 if (td->td_gd != mycpu) {
1361 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1364 if (td->td_flags & TDF_SINTR)
1374 * This function is called via an IPI. We will be in a critical section but
1375 * the MP lock will NOT be held. The passed lp will be held.
1377 * We must essentially repeat the code at the end of lwp_signotify(),
1378 * in particular rechecking all races. If we are still not on the
1379 * correct cpu we leave the lwp ref intact and continue the chase.
1381 * XXX this may still not be entirely correct, since we are checking
1382 * lwp_stat asynchronously.
1385 signotify_remote(void *arg)
1387 struct lwp *lp = arg;
1390 if (lp == lwkt_preempted_proc()) {
1392 } else if (lp->lwp_stat == LSRUN) {
1394 * To prevent a MP race with TDF_SINTR we must
1395 * schedule the thread on the correct cpu.
1397 td = lp->lwp_thread;
1398 if (td->td_gd != mycpu) {
1399 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1403 if (td->td_flags & TDF_SINTR)
1412 * Caller must hold p->p_token
1415 proc_stop(struct proc *p)
1420 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1423 /* If somebody raced us, be happy with it */
1424 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1430 FOREACH_LWP_IN_PROC(lp, p) {
1431 switch (lp->lwp_stat) {
1434 * Do nothing, we are already counted in
1441 * We're sleeping, but we will stop before
1442 * returning to userspace, so count us
1443 * as stopped as well. We set LWP_WSTOP
1444 * to signal the lwp that it should not
1445 * increase p_nstopped when reaching tstop().
1447 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1448 lp->lwp_flag |= LWP_WSTOP;
1455 * We might notify ourself, but that's not
1463 if (p->p_nstopped == p->p_nthreads) {
1465 * Token required to interlock kern_wait(). Reparenting can
1466 * also cause a race so we have to hold (q).
1470 lwkt_gettoken(&q->p_token);
1471 p->p_flag &= ~P_WAITED;
1473 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1474 ksignal(p->p_pptr, SIGCHLD);
1475 lwkt_reltoken(&q->p_token);
1482 * Caller must hold proc_token
1485 proc_unstop(struct proc *p)
1489 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1492 if (p->p_stat != SSTOP) {
1497 p->p_stat = SACTIVE;
1499 FOREACH_LWP_IN_PROC(lp, p) {
1500 switch (lp->lwp_stat) {
1503 * Uh? Not stopped? Well, I guess that's okay.
1506 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1507 p->p_pid, lp->lwp_tid);
1512 * Still sleeping. Don't bother waking it up.
1513 * However, if this thread was counted as
1514 * stopped, undo this.
1516 * Nevertheless we call setrunnable() so that it
1517 * will wake up in case a signal or timeout arrived
1520 if (lp->lwp_flag & LWP_WSTOP) {
1521 lp->lwp_flag &= ~LWP_WSTOP;
1525 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1526 p->p_pid, lp->lwp_tid);
1543 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1545 sigset_t savedmask, set;
1546 struct proc *p = curproc;
1547 struct lwp *lp = curthread->td_lwp;
1548 int error, sig, hz, timevalid = 0;
1549 struct timespec rts, ets, ts;
1554 ets.tv_sec = 0; /* silence compiler warning */
1555 ets.tv_nsec = 0; /* silence compiler warning */
1556 SIG_CANTMASK(waitset);
1557 savedmask = lp->lwp_sigmask;
1560 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1561 timeout->tv_nsec < 1000000000) {
1563 getnanouptime(&rts);
1565 timespecadd(&ets, timeout);
1570 set = lwp_sigpend(lp);
1571 SIGSETAND(set, waitset);
1572 if ((sig = sig_ffs(&set)) != 0) {
1573 SIGFILLSET(lp->lwp_sigmask);
1574 SIGDELSET(lp->lwp_sigmask, sig);
1575 SIG_CANTMASK(lp->lwp_sigmask);
1576 sig = issignal(lp, 1);
1578 * It may be a STOP signal, in the case, issignal
1579 * returns 0, because we may stop there, and new
1580 * signal can come in, we should restart if we got
1590 * Previous checking got nothing, and we retried but still
1591 * got nothing, we should return the error status.
1597 * POSIX says this must be checked after looking for pending
1601 if (timevalid == 0) {
1605 getnanouptime(&rts);
1606 if (timespeccmp(&rts, &ets, >=)) {
1611 timespecsub(&ts, &rts);
1612 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1613 hz = tvtohz_high(&tv);
1618 lp->lwp_sigmask = savedmask;
1619 SIGSETNAND(lp->lwp_sigmask, waitset);
1621 * We won't ever be woken up. Instead, our sleep will
1622 * be broken in lwpsignal().
1624 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1626 if (error == ERESTART) {
1627 /* can not restart a timeout wait. */
1629 } else if (error == EAGAIN) {
1630 /* will calculate timeout by ourself. */
1637 lp->lwp_sigmask = savedmask;
1640 bzero(info, sizeof(*info));
1641 info->si_signo = sig;
1642 lwp_delsig(lp, sig); /* take the signal! */
1644 if (sig == SIGKILL) {
1657 sys_sigtimedwait(struct sigtimedwait_args *uap)
1660 struct timespec *timeout;
1666 error = copyin(uap->timeout, &ts, sizeof(ts));
1673 error = copyin(uap->set, &set, sizeof(set));
1676 error = kern_sigtimedwait(set, &info, timeout);
1680 error = copyout(&info, uap->info, sizeof(info));
1681 /* Repost if we got an error. */
1685 * This could transform a thread-specific signal to another
1686 * thread / process pending signal.
1689 ksignal(curproc, info.si_signo);
1691 uap->sysmsg_result = info.si_signo;
1700 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1706 error = copyin(uap->set, &set, sizeof(set));
1709 error = kern_sigtimedwait(set, &info, NULL);
1713 error = copyout(&info, uap->info, sizeof(info));
1714 /* Repost if we got an error. */
1718 * This could transform a thread-specific signal to another
1719 * thread / process pending signal.
1722 ksignal(curproc, info.si_signo);
1724 uap->sysmsg_result = info.si_signo;
1730 * If the current process has received a signal that would interrupt a
1731 * system call, return EINTR or ERESTART as appropriate.
1734 iscaught(struct lwp *lp)
1736 struct proc *p = lp->lwp_proc;
1740 if ((sig = CURSIG(lp)) != 0) {
1741 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1746 return(EWOULDBLOCK);
1750 * If the current process has received a signal (should be caught or cause
1751 * termination, should interrupt current syscall), return the signal number.
1752 * Stop signals with default action are processed immediately, then cleared;
1753 * they aren't returned. This is checked after each entry to the system for
1754 * a syscall or trap (though this can usually be done without calling issignal
1755 * by checking the pending signal masks in the CURSIG macro).
1757 * This routine is called via CURSIG/__cursig. We will acquire and release
1758 * p->p_token but if the caller needs to interlock the test the caller must
1759 * also hold p->p_token.
1761 * while (sig = CURSIG(curproc))
1767 issignal(struct lwp *lp, int maytrace)
1769 struct proc *p = lp->lwp_proc;
1773 lwkt_gettoken(&p->p_token);
1776 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1779 * If this process is supposed to stop, stop this thread.
1781 if (p->p_stat == SSTOP)
1784 mask = lwp_sigpend(lp);
1785 SIGSETNAND(mask, lp->lwp_sigmask);
1786 if (p->p_flag & P_PPWAIT)
1787 SIG_STOPSIGMASK(mask);
1788 if (SIGISEMPTY(mask)) { /* no signal to send */
1789 lwkt_reltoken(&p->p_token);
1792 sig = sig_ffs(&mask);
1794 STOPEVENT(p, S_SIG, sig);
1797 * We should see pending but ignored signals
1798 * only if P_TRACED was on when they were posted.
1800 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1801 lwp_delsig(lp, sig);
1804 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1806 * If traced, always stop, and stay stopped until
1807 * released by the parent.
1809 * NOTE: SSTOP may get cleared during the loop,
1810 * but we do not re-notify the parent if we have
1811 * to loop several times waiting for the parent
1812 * to let us continue.
1814 * XXX not sure if this is still true
1820 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1823 * If parent wants us to take the signal,
1824 * then it will leave it in p->p_xstat;
1825 * otherwise we just look for signals again.
1827 lwp_delsig(lp, sig); /* clear old signal */
1833 * Put the new signal into p_siglist. If the
1834 * signal is being masked, look for other signals.
1836 * XXX lwp might need a call to ksignal()
1838 SIGADDSET(p->p_siglist, sig);
1839 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1843 * If the traced bit got turned off, go back up
1844 * to the top to rescan signals. This ensures
1845 * that p_sig* and ps_sigact are consistent.
1847 if ((p->p_flag & P_TRACED) == 0)
1851 prop = sigprop(sig);
1854 * Decide whether the signal should be returned.
1855 * Return the signal's number, or fall through
1856 * to clear it from the pending mask.
1858 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1859 case (intptr_t)SIG_DFL:
1861 * Don't take default actions on system processes.
1863 if (p->p_pid <= 1) {
1866 * Are you sure you want to ignore SIGSEGV
1869 kprintf("Process (pid %lu) got signal %d\n",
1870 (u_long)p->p_pid, sig);
1872 break; /* == ignore */
1876 * Handle the in-kernel checkpoint action
1878 if (prop & SA_CKPT) {
1879 checkpoint_signal_handler(lp);
1884 * If there is a pending stop signal to process
1885 * with default action, stop here,
1886 * then clear the signal. However,
1887 * if process is member of an orphaned
1888 * process group, ignore tty stop signals.
1890 if (prop & SA_STOP) {
1891 if (p->p_flag & P_TRACED ||
1892 (p->p_pgrp->pg_jobc == 0 &&
1894 break; /* == ignore */
1899 } else if (prop & SA_IGNORE) {
1901 * Except for SIGCONT, shouldn't get here.
1902 * Default action is to ignore; drop it.
1904 break; /* == ignore */
1906 lwkt_reltoken(&p->p_token);
1912 case (intptr_t)SIG_IGN:
1914 * Masking above should prevent us ever trying
1915 * to take action on an ignored signal other
1916 * than SIGCONT, unless process is traced.
1918 if ((prop & SA_CONT) == 0 &&
1919 (p->p_flag & P_TRACED) == 0)
1920 kprintf("issignal\n");
1921 break; /* == ignore */
1925 * This signal has an action, let
1926 * postsig() process it.
1928 lwkt_reltoken(&p->p_token);
1931 lwp_delsig(lp, sig); /* take the signal! */
1937 * Take the action for the specified signal
1938 * from the current set of pending signals.
1940 * Caller must hold p->p_token
1945 struct lwp *lp = curthread->td_lwp;
1946 struct proc *p = lp->lwp_proc;
1947 struct sigacts *ps = p->p_sigacts;
1949 sigset_t returnmask;
1952 KASSERT(sig != 0, ("postsig"));
1954 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1957 * If we are a virtual kernel running an emulated user process
1958 * context, switch back to the virtual kernel context before
1959 * trying to post the signal.
1961 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1962 struct trapframe *tf = lp->lwp_md.md_regs;
1964 vkernel_trap(lp, tf);
1967 lwp_delsig(lp, sig);
1968 action = ps->ps_sigact[_SIG_IDX(sig)];
1970 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1971 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1972 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1974 STOPEVENT(p, S_SIG, sig);
1976 if (action == SIG_DFL) {
1978 * Default action, where the default is to kill
1979 * the process. (Other cases were ignored above.)
1985 * If we get here, the signal must be caught.
1987 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1988 ("postsig action"));
1993 * Reset the signal handler if asked to
1995 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1997 * See kern_sigaction() for origin of this code.
1999 SIGDELSET(p->p_sigcatch, sig);
2000 if (sig != SIGCONT &&
2001 sigprop(sig) & SA_IGNORE)
2002 SIGADDSET(p->p_sigignore, sig);
2003 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2007 * Handle the mailbox case. Copyout to the appropriate
2008 * location but do not generate a signal frame. The system
2009 * call simply returns EINTR and the user is responsible for
2010 * polling the mailbox.
2012 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
2014 copyout(&sig_copy, (void *)action, sizeof(int));
2015 curproc->p_flag |= P_MAILBOX;
2021 * Set the signal mask and calculate the mask to restore
2022 * when the signal function returns.
2024 * Special case: user has done a sigsuspend. Here the
2025 * current mask is not of interest, but rather the
2026 * mask from before the sigsuspend is what we want
2027 * restored after the signal processing is completed.
2029 if (lp->lwp_flag & LWP_OLDMASK) {
2030 returnmask = lp->lwp_oldsigmask;
2031 lp->lwp_flag &= ~LWP_OLDMASK;
2033 returnmask = lp->lwp_sigmask;
2036 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2037 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2038 SIGADDSET(lp->lwp_sigmask, sig);
2041 lp->lwp_ru.ru_nsignals++;
2042 if (lp->lwp_sig != sig) {
2045 code = lp->lwp_code;
2049 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2056 * Kill the current process for stated reason.
2059 killproc(struct proc *p, char *why)
2061 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2062 p->p_pid, p->p_comm,
2063 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2064 ksignal(p, SIGKILL);
2068 * Force the current process to exit with the specified signal, dumping core
2069 * if appropriate. We bypass the normal tests for masked and caught signals,
2070 * allowing unrecoverable failures to terminate the process without changing
2071 * signal state. Mark the accounting record with the signal termination.
2072 * If dumping core, save the signal number for the debugger. Calls exit and
2075 * This routine does not return.
2078 sigexit(struct lwp *lp, int sig)
2080 struct proc *p = lp->lwp_proc;
2082 lwkt_gettoken(&p->p_token);
2083 p->p_acflag |= AXSIG;
2084 if (sigprop(sig) & SA_CORE) {
2087 * Log signals which would cause core dumps
2088 * (Log as LOG_INFO to appease those who don't want
2090 * XXX : Todo, as well as euid, write out ruid too
2092 if (coredump(lp, sig) == 0)
2094 if (kern_logsigexit)
2096 "pid %d (%s), uid %d: exited on signal %d%s\n",
2097 p->p_pid, p->p_comm,
2098 p->p_ucred ? p->p_ucred->cr_uid : -1,
2100 sig & WCOREFLAG ? " (core dumped)" : "");
2102 lwkt_reltoken(&p->p_token);
2103 exit1(W_EXITCODE(0, sig));
2107 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2108 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2109 sizeof(corefilename), "process corefile name format string");
2112 * expand_name(name, uid, pid)
2113 * Expand the name described in corefilename, using name, uid, and pid.
2114 * corefilename is a kprintf-like string, with three format specifiers:
2115 * %N name of process ("name")
2116 * %P process id (pid)
2118 * For example, "%N.core" is the default; they can be disabled completely
2119 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2120 * This is controlled by the sysctl variable kern.corefile (see above).
2124 expand_name(const char *name, uid_t uid, pid_t pid)
2127 char buf[11]; /* Buffer for pid/uid -- max 4B */
2129 char *format = corefilename;
2132 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2135 namelen = strlen(name);
2136 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2138 switch (format[i]) {
2139 case '%': /* Format character */
2141 switch (format[i]) {
2145 case 'N': /* process name */
2146 if ((n + namelen) > MAXPATHLEN) {
2147 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2148 pid, name, uid, temp, name);
2149 kfree(temp, M_TEMP);
2152 memcpy(temp+n, name, namelen);
2155 case 'P': /* process id */
2156 l = ksprintf(buf, "%u", pid);
2157 if ((n + l) > MAXPATHLEN) {
2158 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2159 pid, name, uid, temp, name);
2160 kfree(temp, M_TEMP);
2163 memcpy(temp+n, buf, l);
2166 case 'U': /* user id */
2167 l = ksprintf(buf, "%u", uid);
2168 if ((n + l) > MAXPATHLEN) {
2169 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2170 pid, name, uid, temp, name);
2171 kfree(temp, M_TEMP);
2174 memcpy(temp+n, buf, l);
2178 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2182 temp[n++] = format[i];
2190 * Dump a process' core. The main routine does some
2191 * policy checking, and creates the name of the coredump;
2192 * then it passes on a vnode and a size limit to the process-specific
2193 * coredump routine if there is one; if there _is not_ one, it returns
2194 * ENOSYS; otherwise it returns the error from the process-specific routine.
2196 * The parameter `lp' is the lwp which triggered the coredump.
2200 coredump(struct lwp *lp, int sig)
2202 struct proc *p = lp->lwp_proc;
2204 struct ucred *cred = p->p_ucred;
2206 struct nlookupdata nd;
2209 char *name; /* name of corefile */
2212 STOPEVENT(p, S_CORE, 0);
2214 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2218 * Note that the bulk of limit checking is done after
2219 * the corefile is created. The exception is if the limit
2220 * for corefiles is 0, in which case we don't bother
2221 * creating the corefile at all. This layout means that
2222 * a corefile is truncated instead of not being created,
2223 * if it is larger than the limit.
2225 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2229 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2232 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2234 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2235 kfree(name, M_TEMP);
2241 nd.nl_open_vp = NULL;
2245 lf.l_whence = SEEK_SET;
2248 lf.l_type = F_WRLCK;
2249 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2253 /* Don't dump to non-regular files or files with links. */
2254 if (vp->v_type != VREG ||
2255 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2260 /* Don't dump to files current user does not own */
2261 if (vattr.va_uid != p->p_ucred->cr_uid) {
2267 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2269 VOP_SETATTR(vp, &vattr, cred);
2270 p->p_acflag |= ACORE;
2273 error = p->p_sysent->sv_coredump ?
2274 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2277 lf.l_type = F_UNLCK;
2278 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2280 error1 = vn_close(vp, FWRITE);
2287 * Nonexistent system call-- signal process (may want to handle it).
2288 * Flag error in case process won't see signal immediately (blocked or ignored).
2294 sys_nosys(struct nosys_args *args)
2296 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2301 * Send a SIGIO or SIGURG signal to a process or process group using
2302 * stored credentials rather than those of the current process.
2305 pgsigio(struct sigio *sigio, int sig, int checkctty)
2310 if (sigio->sio_pgid > 0) {
2311 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2313 ksignal(sigio->sio_proc, sig);
2314 } else if (sigio->sio_pgid < 0) {
2316 struct pgrp *pg = sigio->sio_pgrp;
2319 * Must interlock all signals against fork
2322 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2323 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
2324 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2325 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2328 lockmgr(&pg->pg_lock, LK_RELEASE);
2334 filt_sigattach(struct knote *kn)
2336 struct proc *p = curproc;
2338 kn->kn_ptr.p_proc = p;
2339 kn->kn_flags |= EV_CLEAR; /* automatically set */
2341 /* XXX lock the proc here while adding to the list? */
2342 knote_insert(&p->p_klist, kn);
2348 filt_sigdetach(struct knote *kn)
2350 struct proc *p = kn->kn_ptr.p_proc;
2352 knote_remove(&p->p_klist, kn);
2356 * signal knotes are shared with proc knotes, so we apply a mask to
2357 * the hint in order to differentiate them from process hints. This
2358 * could be avoided by using a signal-specific knote list, but probably
2359 * isn't worth the trouble.
2362 filt_signal(struct knote *kn, long hint)
2364 if (hint & NOTE_SIGNAL) {
2365 hint &= ~NOTE_SIGNAL;
2367 if (kn->kn_id == hint)
2370 return (kn->kn_data != 0);