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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);
83 static void lwp_signotify_remote(void *arg);
84 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
85 struct timespec *timeout);
87 static int filt_sigattach(struct knote *kn);
88 static void filt_sigdetach(struct knote *kn);
89 static int filt_signal(struct knote *kn, long hint);
91 struct filterops sig_filtops =
92 { 0, filt_sigattach, filt_sigdetach, filt_signal };
94 static int kern_logsigexit = 1;
95 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
97 "Log processes quitting on abnormal signals to syslog(3)");
100 * Can process p, with pcred pc, send the signal sig to process q?
102 #define CANSIGNAL(q, sig) \
103 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
104 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
107 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
109 #define CANSIGIO(ruid, uc, q) \
110 ((uc)->cr_uid == 0 || \
111 (ruid) == (q)->p_ucred->cr_ruid || \
112 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
113 (ruid) == (q)->p_ucred->cr_uid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_uid)
117 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
118 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
120 static int do_coredump = 1;
121 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
122 &do_coredump, 0, "Enable/Disable coredumps");
125 * Signal properties and actions.
126 * The array below categorizes the signals and their default actions
127 * according to the following properties:
129 #define SA_KILL 0x01 /* terminates process by default */
130 #define SA_CORE 0x02 /* ditto and coredumps */
131 #define SA_STOP 0x04 /* suspend process */
132 #define SA_TTYSTOP 0x08 /* ditto, from tty */
133 #define SA_IGNORE 0x10 /* ignore by default */
134 #define SA_CONT 0x20 /* continue if suspended */
135 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
136 #define SA_CKPT 0x80 /* checkpoint process */
139 static int sigproptbl[NSIG] = {
140 SA_KILL, /* SIGHUP */
141 SA_KILL, /* SIGINT */
142 SA_KILL|SA_CORE, /* SIGQUIT */
143 SA_KILL|SA_CORE, /* SIGILL */
144 SA_KILL|SA_CORE, /* SIGTRAP */
145 SA_KILL|SA_CORE, /* SIGABRT */
146 SA_KILL|SA_CORE, /* SIGEMT */
147 SA_KILL|SA_CORE, /* SIGFPE */
148 SA_KILL, /* SIGKILL */
149 SA_KILL|SA_CORE, /* SIGBUS */
150 SA_KILL|SA_CORE, /* SIGSEGV */
151 SA_KILL|SA_CORE, /* SIGSYS */
152 SA_KILL, /* SIGPIPE */
153 SA_KILL, /* SIGALRM */
154 SA_KILL, /* SIGTERM */
155 SA_IGNORE, /* SIGURG */
156 SA_STOP, /* SIGSTOP */
157 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
158 SA_IGNORE|SA_CONT, /* SIGCONT */
159 SA_IGNORE, /* SIGCHLD */
160 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
161 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
162 SA_IGNORE, /* SIGIO */
163 SA_KILL, /* SIGXCPU */
164 SA_KILL, /* SIGXFSZ */
165 SA_KILL, /* SIGVTALRM */
166 SA_KILL, /* SIGPROF */
167 SA_IGNORE, /* SIGWINCH */
168 SA_IGNORE, /* SIGINFO */
169 SA_KILL, /* SIGUSR1 */
170 SA_KILL, /* SIGUSR2 */
171 SA_IGNORE, /* SIGTHR */
172 SA_CKPT, /* SIGCKPT */
173 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
211 if (sig > 0 && sig < NSIG)
212 return (sigproptbl[_SIG_IDX(sig)]);
217 sig_ffs(sigset_t *set)
221 for (i = 0; i < _SIG_WORDS; i++)
223 return (ffs(set->__bits[i]) + (i * 32));
231 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
233 struct thread *td = curthread;
234 struct proc *p = td->td_proc;
236 struct sigacts *ps = p->p_sigacts;
238 if (sig <= 0 || sig > _SIG_MAXSIG)
241 lwkt_gettoken(&p->p_token);
244 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
245 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
247 if (SIGISMEMBER(ps->ps_sigonstack, sig))
248 oact->sa_flags |= SA_ONSTACK;
249 if (!SIGISMEMBER(ps->ps_sigintr, sig))
250 oact->sa_flags |= SA_RESTART;
251 if (SIGISMEMBER(ps->ps_sigreset, sig))
252 oact->sa_flags |= SA_RESETHAND;
253 if (SIGISMEMBER(ps->ps_signodefer, sig))
254 oact->sa_flags |= SA_NODEFER;
255 if (SIGISMEMBER(ps->ps_siginfo, sig))
256 oact->sa_flags |= SA_SIGINFO;
257 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
258 oact->sa_flags |= SA_NOCLDSTOP;
259 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
260 oact->sa_flags |= SA_NOCLDWAIT;
264 * Check for invalid requests. KILL and STOP cannot be
267 if (sig == SIGKILL || sig == SIGSTOP) {
268 if (act->sa_handler != SIG_DFL) {
269 lwkt_reltoken(&p->p_token);
275 * Change setting atomically.
277 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
278 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
279 if (act->sa_flags & SA_SIGINFO) {
280 ps->ps_sigact[_SIG_IDX(sig)] =
281 (__sighandler_t *)act->sa_sigaction;
282 SIGADDSET(ps->ps_siginfo, sig);
284 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
285 SIGDELSET(ps->ps_siginfo, sig);
287 if (!(act->sa_flags & SA_RESTART))
288 SIGADDSET(ps->ps_sigintr, sig);
290 SIGDELSET(ps->ps_sigintr, sig);
291 if (act->sa_flags & SA_ONSTACK)
292 SIGADDSET(ps->ps_sigonstack, sig);
294 SIGDELSET(ps->ps_sigonstack, sig);
295 if (act->sa_flags & SA_RESETHAND)
296 SIGADDSET(ps->ps_sigreset, sig);
298 SIGDELSET(ps->ps_sigreset, sig);
299 if (act->sa_flags & SA_NODEFER)
300 SIGADDSET(ps->ps_signodefer, sig);
302 SIGDELSET(ps->ps_signodefer, sig);
303 if (sig == SIGCHLD) {
304 if (act->sa_flags & SA_NOCLDSTOP)
305 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
307 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
308 if (act->sa_flags & SA_NOCLDWAIT) {
310 * Paranoia: since SA_NOCLDWAIT is implemented
311 * by reparenting the dying child to PID 1 (and
312 * trust it to reap the zombie), PID 1 itself
313 * is forbidden to set SA_NOCLDWAIT.
316 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
318 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
320 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
322 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
323 ps->ps_flag |= PS_CLDSIGIGN;
325 ps->ps_flag &= ~PS_CLDSIGIGN;
328 * Set bit in p_sigignore for signals that are set to SIG_IGN,
329 * and for signals set to SIG_DFL where the default is to
330 * ignore. However, don't put SIGCONT in p_sigignore, as we
331 * have to restart the process.
333 * Also remove the signal from the process and lwp signal
336 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
337 (sigprop(sig) & SA_IGNORE &&
338 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
339 SIGDELSET(p->p_siglist, sig);
340 FOREACH_LWP_IN_PROC(lp, p) {
341 spin_lock(&lp->lwp_spin);
342 SIGDELSET(lp->lwp_siglist, sig);
343 spin_unlock(&lp->lwp_spin);
345 if (sig != SIGCONT) {
346 /* easier in ksignal */
347 SIGADDSET(p->p_sigignore, sig);
349 SIGDELSET(p->p_sigcatch, sig);
351 SIGDELSET(p->p_sigignore, sig);
352 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
353 SIGDELSET(p->p_sigcatch, sig);
355 SIGADDSET(p->p_sigcatch, sig);
358 lwkt_reltoken(&p->p_token);
363 sys_sigaction(struct sigaction_args *uap)
365 struct sigaction act, oact;
366 struct sigaction *actp, *oactp;
369 actp = (uap->act != NULL) ? &act : NULL;
370 oactp = (uap->oact != NULL) ? &oact : NULL;
372 error = copyin(uap->act, actp, sizeof(act));
376 error = kern_sigaction(uap->sig, actp, oactp);
377 if (oactp && !error) {
378 error = copyout(oactp, uap->oact, sizeof(oact));
384 * Initialize signal state for process 0;
385 * set to ignore signals that are ignored by default.
388 siginit(struct proc *p)
392 for (i = 1; i <= NSIG; i++)
393 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
394 SIGADDSET(p->p_sigignore, i);
398 * Reset signals for an exec of the specified process.
401 execsigs(struct proc *p)
403 struct sigacts *ps = p->p_sigacts;
407 lp = ONLY_LWP_IN_PROC(p);
410 * Reset caught signals. Held signals remain held
411 * through p_sigmask (unless they were caught,
412 * and are now ignored by default).
414 while (SIGNOTEMPTY(p->p_sigcatch)) {
415 sig = sig_ffs(&p->p_sigcatch);
416 SIGDELSET(p->p_sigcatch, sig);
417 if (sigprop(sig) & SA_IGNORE) {
419 SIGADDSET(p->p_sigignore, sig);
420 SIGDELSET(p->p_siglist, sig);
421 /* don't need spinlock */
422 SIGDELSET(lp->lwp_siglist, sig);
424 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
428 * Reset stack state to the user stack.
429 * Clear set of signals caught on the signal stack.
431 lp->lwp_sigstk.ss_flags = SS_DISABLE;
432 lp->lwp_sigstk.ss_size = 0;
433 lp->lwp_sigstk.ss_sp = NULL;
434 lp->lwp_flags &= ~LWP_ALTSTACK;
436 * Reset no zombies if child dies flag as Solaris does.
438 p->p_sigacts->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
439 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
440 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
444 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
446 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
450 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
452 struct thread *td = curthread;
453 struct lwp *lp = td->td_lwp;
454 struct proc *p = td->td_proc;
457 lwkt_gettoken(&p->p_token);
460 *oset = lp->lwp_sigmask;
467 SIGSETOR(lp->lwp_sigmask, *set);
470 SIGSETNAND(lp->lwp_sigmask, *set);
474 lp->lwp_sigmask = *set;
482 lwkt_reltoken(&p->p_token);
493 sys_sigprocmask(struct sigprocmask_args *uap)
496 sigset_t *setp, *osetp;
499 setp = (uap->set != NULL) ? &set : NULL;
500 osetp = (uap->oset != NULL) ? &oset : NULL;
502 error = copyin(uap->set, setp, sizeof(set));
506 error = kern_sigprocmask(uap->how, setp, osetp);
507 if (osetp && !error) {
508 error = copyout(osetp, uap->oset, sizeof(oset));
517 kern_sigpending(struct __sigset *set)
519 struct lwp *lp = curthread->td_lwp;
521 *set = lwp_sigpend(lp);
530 sys_sigpending(struct sigpending_args *uap)
535 error = kern_sigpending(&set);
538 error = copyout(&set, uap->set, sizeof(set));
543 * Suspend process until signal, providing mask to be set
549 kern_sigsuspend(struct __sigset *set)
551 struct thread *td = curthread;
552 struct lwp *lp = td->td_lwp;
553 struct proc *p = td->td_proc;
554 struct sigacts *ps = p->p_sigacts;
557 * When returning from sigsuspend, we want
558 * the old mask to be restored after the
559 * signal handler has finished. Thus, we
560 * save it here and mark the sigacts structure
563 lp->lwp_oldsigmask = lp->lwp_sigmask;
564 lp->lwp_flags |= LWP_OLDMASK;
567 lp->lwp_sigmask = *set;
568 while (tsleep(ps, PCATCH, "pause", 0) == 0)
570 /* always return EINTR rather than ERESTART... */
575 * Note nonstandard calling convention: libc stub passes mask, not
576 * pointer, to save a copyin.
581 sys_sigsuspend(struct sigsuspend_args *uap)
586 error = copyin(uap->sigmask, &mask, sizeof(mask));
590 error = kern_sigsuspend(&mask);
599 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
601 struct thread *td = curthread;
602 struct lwp *lp = td->td_lwp;
603 struct proc *p = td->td_proc;
605 if ((lp->lwp_flags & LWP_ALTSTACK) == 0)
606 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
609 *oss = lp->lwp_sigstk;
612 if (ss->ss_flags & SS_DISABLE) {
613 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
615 lp->lwp_flags &= ~LWP_ALTSTACK;
616 lp->lwp_sigstk.ss_flags = ss->ss_flags;
618 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
620 lp->lwp_flags |= LWP_ALTSTACK;
621 lp->lwp_sigstk = *ss;
632 sys_sigaltstack(struct sigaltstack_args *uap)
638 error = copyin(uap->ss, &ss, sizeof(ss));
643 error = kern_sigaltstack(uap->ss ? &ss : NULL,
644 uap->oss ? &oss : NULL);
646 if (error == 0 && uap->oss)
647 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
652 * Common code for kill process group/broadcast kill.
653 * cp is calling process.
660 static int killpg_all_callback(struct proc *p, void *data);
663 dokillpg(int sig, int pgid, int all)
665 struct killpg_info info;
666 struct proc *cp = curproc;
677 allproc_scan(killpg_all_callback, &info);
681 * zero pgid means send to my process group.
692 * Must interlock all signals against fork
694 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
695 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
697 p->p_stat == SZOMB ||
698 (p->p_flags & P_SYSTEM) ||
699 !CANSIGNAL(p, sig)) {
706 lockmgr(&pgrp->pg_lock, LK_RELEASE);
709 return (info.nfound ? 0 : ESRCH);
713 killpg_all_callback(struct proc *p, void *data)
715 struct killpg_info *info = data;
717 if (p->p_pid <= 1 || (p->p_flags & P_SYSTEM) ||
718 p == curproc || !CANSIGNAL(p, info->sig)) {
723 ksignal(p, info->sig);
728 * Send a general signal to a process or LWPs within that process.
730 * Note that new signals cannot be sent if a process is exiting or already
731 * a zombie, but we return success anyway as userland is likely to not handle
737 kern_kill(int sig, pid_t pid, lwpid_t tid)
741 if ((u_int)sig > _SIG_MAXSIG)
744 lwkt_gettoken(&proc_token);
748 struct lwp *lp = NULL;
751 * Send a signal to a single process. If the kill() is
752 * racing an exiting process which has not yet been reaped
753 * act as though the signal was delivered successfully but
754 * don't actually try to deliver the signal.
756 if ((p = pfind(pid)) == NULL) {
757 if ((p = zpfind(pid)) == NULL) {
758 lwkt_reltoken(&proc_token);
761 lwkt_reltoken(&proc_token);
765 lwkt_gettoken(&p->p_token);
766 if (!CANSIGNAL(p, sig)) {
767 lwkt_reltoken(&p->p_token);
769 lwkt_reltoken(&proc_token);
774 * NOP if the process is exiting. Note that lwpsignal() is
775 * called directly with P_WEXIT set to kill individual LWPs
776 * during exit, which is allowed.
778 if (p->p_flags & P_WEXIT) {
779 lwkt_reltoken(&p->p_token);
781 lwkt_reltoken(&proc_token);
785 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
787 lwkt_reltoken(&p->p_token);
789 lwkt_reltoken(&proc_token);
794 lwpsignal(p, lp, sig);
795 lwkt_reltoken(&p->p_token);
797 lwkt_reltoken(&proc_token);
802 * If we come here, pid is a special broadcast pid.
803 * This doesn't mix with a tid.
806 lwkt_reltoken(&proc_token);
810 case -1: /* broadcast signal */
811 t = (dokillpg(sig, 0, 1));
813 case 0: /* signal own process group */
814 t = (dokillpg(sig, 0, 0));
816 default: /* negative explicit process group */
817 t = (dokillpg(sig, -pid, 0));
820 lwkt_reltoken(&proc_token);
825 sys_kill(struct kill_args *uap)
829 error = kern_kill(uap->signum, uap->pid, -1);
834 sys_lwp_kill(struct lwp_kill_args *uap)
837 pid_t pid = uap->pid;
840 * A tid is mandatory for lwp_kill(), otherwise
841 * you could simply use kill().
847 * To save on a getpid() function call for intra-process
848 * signals, pid == -1 means current process.
851 pid = curproc->p_pid;
853 error = kern_kill(uap->signum, pid, uap->tid);
858 * Send a signal to a process group.
861 gsignal(int pgid, int sig)
865 if (pgid && (pgrp = pgfind(pgid)))
866 pgsignal(pgrp, sig, 0);
870 * Send a signal to a process group. If checktty is 1,
871 * limit to members which have a controlling terminal.
873 * pg_lock interlocks against a fork that might be in progress, to
874 * ensure that the new child process picks up the signal.
877 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
882 * Must interlock all signals against fork
886 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
887 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
888 if (checkctty == 0 || p->p_flags & P_CONTROLT)
891 lockmgr(&pgrp->pg_lock, LK_RELEASE);
897 * Send a signal caused by a trap to the current lwp. If it will be caught
898 * immediately, deliver it with correct code. Otherwise, post it normally.
900 * These signals may ONLY be delivered to the specified lwp and may never
901 * be delivered to the process generically.
904 trapsignal(struct lwp *lp, int sig, u_long code)
906 struct proc *p = lp->lwp_proc;
907 struct sigacts *ps = p->p_sigacts;
910 * If we are a virtual kernel running an emulated user process
911 * context, switch back to the virtual kernel context before
912 * trying to post the signal.
914 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
915 struct trapframe *tf = lp->lwp_md.md_regs;
917 vkernel_trap(lp, tf);
921 if ((p->p_flags & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
922 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
923 lp->lwp_ru.ru_nsignals++;
925 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
926 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
927 &lp->lwp_sigmask, code);
929 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
930 &lp->lwp_sigmask, code);
931 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
932 if (!SIGISMEMBER(ps->ps_signodefer, sig))
933 SIGADDSET(lp->lwp_sigmask, sig);
934 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
936 * See kern_sigaction() for origin of this code.
938 SIGDELSET(p->p_sigcatch, sig);
939 if (sig != SIGCONT &&
940 sigprop(sig) & SA_IGNORE)
941 SIGADDSET(p->p_sigignore, sig);
942 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
945 lp->lwp_code = code; /* XXX for core dump/debugger */
946 lp->lwp_sig = sig; /* XXX to verify code */
947 lwpsignal(p, lp, sig);
952 * Find a suitable lwp to deliver the signal to. Returns NULL if all
953 * lwps hold the signal blocked.
955 * Caller must hold p->p_token.
957 * Returns a lp or NULL. If non-NULL the lp is held and its token is
961 find_lwp_for_signal(struct proc *p, int sig)
964 struct lwp *run, *sleep, *stop;
967 * If the running/preempted thread belongs to the proc to which
968 * the signal is being delivered and this thread does not block
969 * the signal, then we can avoid a context switch by delivering
970 * the signal to this thread, because it will return to userland
973 lp = lwkt_preempted_proc();
974 if (lp != NULL && lp->lwp_proc == p) {
976 lwkt_gettoken(&lp->lwp_token);
977 if (!SIGISMEMBER(lp->lwp_sigmask, sig)) {
978 /* return w/ token held */
981 lwkt_reltoken(&lp->lwp_token);
985 run = sleep = stop = NULL;
986 FOREACH_LWP_IN_PROC(lp, p) {
988 * If the signal is being blocked by the lwp, then this
989 * lwp is not eligible for receiving the signal.
992 lwkt_gettoken(&lp->lwp_token);
994 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
995 lwkt_reltoken(&lp->lwp_token);
1000 switch (lp->lwp_stat) {
1004 lwkt_reltoken(&sleep->lwp_token);
1010 lwkt_reltoken(&stop->lwp_token);
1019 if (lp->lwp_flags & LWP_SINTR) {
1021 lwkt_reltoken(&lp->lwp_token);
1025 lwkt_reltoken(&stop->lwp_token);
1033 lwkt_reltoken(&lp->lwp_token);
1039 lwkt_reltoken(&lp->lwp_token);
1042 lwkt_reltoken(&lp->lwp_token);
1055 else if (sleep != NULL)
1062 * Send the signal to the process. If the signal has an action, the action
1063 * is usually performed by the target process rather than the caller; we add
1064 * the signal to the set of pending signals for the process.
1067 * o When a stop signal is sent to a sleeping process that takes the
1068 * default action, the process is stopped without awakening it.
1069 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1070 * regardless of the signal action (eg, blocked or ignored).
1072 * Other ignored signals are discarded immediately.
1074 * If the caller wishes to call this function from a hard code section the
1075 * caller must already hold p->p_token (see kern_clock.c).
1080 ksignal(struct proc *p, int sig)
1082 lwpsignal(p, NULL, sig);
1086 * The core for ksignal. lp may be NULL, then a suitable thread
1087 * will be chosen. If not, lp MUST be a member of p.
1089 * If the caller wishes to call this function from a hard code section the
1090 * caller must already hold p->p_token.
1095 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1101 if (sig > _SIG_MAXSIG || sig <= 0) {
1102 kprintf("lwpsignal: signal %d\n", sig);
1103 panic("lwpsignal signal number");
1106 KKASSERT(lp == NULL || lp->lwp_proc == p);
1109 * We don't want to race... well, all sorts of things. Get appropriate
1112 * Don't try to deliver a generic signal to an exiting process,
1113 * the signal structures could be in flux. We check the LWP later
1117 lwkt_gettoken(&p->p_token);
1120 lwkt_gettoken(&lp->lwp_token);
1121 } else if (p->p_flags & P_WEXIT) {
1125 prop = sigprop(sig);
1128 * If proc is traced, always give parent a chance;
1129 * if signal event is tracked by procfs, give *that*
1130 * a chance, as well.
1132 if ((p->p_flags & P_TRACED) || (p->p_stops & S_SIG)) {
1136 * Do not try to deliver signals to an exiting lwp. Note
1137 * that we must still deliver the signal if P_WEXIT is set
1138 * in the process flags.
1140 if (lp && (lp->lwp_mpflags & LWP_MP_WEXIT)) {
1142 lwkt_reltoken(&lp->lwp_token);
1145 lwkt_reltoken(&p->p_token);
1151 * If the signal is being ignored, then we forget about
1152 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1153 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1155 if (SIGISMEMBER(p->p_sigignore, sig)) {
1157 * Even if a signal is set SIG_IGN, it may still be
1158 * lurking in a kqueue.
1160 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1162 lwkt_reltoken(&lp->lwp_token);
1165 lwkt_reltoken(&p->p_token);
1169 if (SIGISMEMBER(p->p_sigcatch, sig))
1176 * If continuing, clear any pending STOP signals.
1179 SIG_STOPSIGMASK(p->p_siglist);
1181 if (prop & SA_STOP) {
1183 * If sending a tty stop signal to a member of an orphaned
1184 * process group, discard the signal here if the action
1185 * is default; don't stop the process below if sleeping,
1186 * and don't clear any pending SIGCONT.
1188 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1189 action == SIG_DFL) {
1190 lwkt_reltoken(&p->p_token);
1194 SIG_CONTSIGMASK(p->p_siglist);
1195 p->p_flags &= ~P_CONTINUED;
1198 if (p->p_stat == SSTOP) {
1200 * Nobody can handle this signal, add it to the lwp or
1201 * process pending list
1204 spin_lock(&lp->lwp_spin);
1205 SIGADDSET(lp->lwp_siglist, sig);
1206 spin_unlock(&lp->lwp_spin);
1208 SIGADDSET(p->p_siglist, sig);
1212 * If the process is stopped and is being traced, then no
1213 * further action is necessary.
1215 if (p->p_flags & P_TRACED)
1219 * If the process is stopped and receives a KILL signal,
1220 * make the process runnable.
1222 if (sig == SIGKILL) {
1224 goto active_process;
1228 * If the process is stopped and receives a CONT signal,
1229 * then try to make the process runnable again.
1231 if (prop & SA_CONT) {
1233 * If SIGCONT is default (or ignored), we continue the
1234 * process but don't leave the signal in p_siglist, as
1235 * it has no further action. If SIGCONT is held, we
1236 * continue the process and leave the signal in
1237 * p_siglist. If the process catches SIGCONT, let it
1238 * handle the signal itself.
1240 * XXX what if the signal is being held blocked?
1242 * Token required to interlock kern_wait().
1243 * Reparenting can also cause a race so we have to
1248 lwkt_gettoken(&q->p_token);
1249 p->p_flags |= P_CONTINUED;
1251 if (action == SIG_DFL)
1252 SIGDELSET(p->p_siglist, sig);
1254 lwkt_reltoken(&q->p_token);
1256 if (action == SIG_CATCH)
1257 goto active_process;
1262 * If the process is stopped and receives another STOP
1263 * signal, we do not need to stop it again. If we did
1264 * the shell could get confused.
1266 * However, if the current/preempted lwp is part of the
1267 * process receiving the signal, we need to keep it,
1268 * so that this lwp can stop in issignal() later, as
1269 * we don't want to wait until it reaches userret!
1271 if (prop & SA_STOP) {
1272 if (lwkt_preempted_proc() == NULL ||
1273 lwkt_preempted_proc()->lwp_proc != p)
1274 SIGDELSET(p->p_siglist, sig);
1278 * Otherwise the process is stopped and it received some
1279 * signal, which does not change its stopped state. When
1280 * the process is continued a wakeup(p) will be issued which
1281 * will wakeup any threads sleeping in tstop().
1284 /* NOTE: returns lp w/ token held */
1285 lp = find_lwp_for_signal(p, sig);
1291 /* else not stopped */
1295 * Never deliver a lwp-specific signal to a random lwp.
1298 /* NOTE: returns lp w/ token held */
1299 lp = find_lwp_for_signal(p, sig);
1301 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
1302 lwkt_reltoken(&lp->lwp_token);
1310 * Deliver to the process generically if (1) the signal is being
1311 * sent to any thread or (2) we could not find a thread to deliver
1315 SIGADDSET(p->p_siglist, sig);
1320 * Deliver to a specific LWP whether it masks it or not. It will
1321 * not be dispatched if masked but we must still deliver it.
1323 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1324 (p->p_flags & P_TRACED) == 0) {
1329 * If the process receives a STOP signal which indeed needs to
1330 * stop the process, do so. If the process chose to catch the
1331 * signal, it will be treated like any other signal.
1333 if ((prop & SA_STOP) && action == SIG_DFL) {
1335 * If a child holding parent blocked, stopping
1336 * could cause deadlock. Take no action at this
1339 if (p->p_flags & P_PPWAIT) {
1340 SIGADDSET(p->p_siglist, sig);
1345 * Do not actually try to manipulate the process, but simply
1346 * stop it. Lwps will stop as soon as they safely can.
1348 * Ignore stop if the process is exiting.
1350 if ((p->p_flags & P_WEXIT) == 0) {
1358 * If it is a CONT signal with default action, just ignore it.
1360 if ((prop & SA_CONT) && action == SIG_DFL)
1364 * Mark signal pending at this specific thread.
1366 spin_lock(&lp->lwp_spin);
1367 SIGADDSET(lp->lwp_siglist, sig);
1368 spin_unlock(&lp->lwp_spin);
1374 lwkt_reltoken(&lp->lwp_token);
1377 lwkt_reltoken(&p->p_token);
1382 * Notify the LWP that a signal has arrived. The LWP does not have to be
1383 * sleeping on the current cpu.
1385 * p->p_token and lp->lwp_token must be held on call.
1387 * We can only safely schedule the thread on its current cpu and only if
1388 * one of the SINTR flags is set. If an SINTR flag is set AND we are on
1389 * the correct cpu we are properly interlocked, otherwise we could be
1390 * racing other thread transition states (or the lwp is on the user scheduler
1391 * runq but not scheduled) and must not do anything.
1393 * Since we hold the lwp token we know the lwp cannot be ripped out from
1394 * under us so we can safely hold it to prevent it from being ripped out
1395 * from under us if we are forced to IPI another cpu to make the local
1398 * Adjustment of lp->lwp_stat can only occur when we hold the lwp_token,
1399 * which we won't in an IPI so any fixups have to be done here, effectively
1400 * replicating part of what setrunnable() does.
1403 lwp_signotify(struct lwp *lp)
1405 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
1408 if (lp == lwkt_preempted_proc()) {
1410 * lwp is on the current cpu AND it is currently running
1411 * (we preempted it).
1414 } else if (lp->lwp_flags & LWP_SINTR) {
1416 * lwp is sitting in tsleep() with PCATCH set
1418 if (lp->lwp_thread->td_gd == mycpu) {
1422 * We can only adjust lwp_stat while we hold the
1423 * lwp_token, and we won't in the IPI function.
1426 if (lp->lwp_stat == LSSTOP)
1427 lp->lwp_stat = LSSLEEP;
1428 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1429 lwp_signotify_remote, lp);
1431 } else if (lp->lwp_thread->td_flags & TDF_SINTR) {
1433 * lwp is sitting in lwkt_sleep() with PCATCH set.
1435 if (lp->lwp_thread->td_gd == mycpu) {
1439 * We can only adjust lwp_stat while we hold the
1440 * lwp_token, and we won't in the IPI function.
1443 if (lp->lwp_stat == LSSTOP)
1444 lp->lwp_stat = LSSLEEP;
1445 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1446 lwp_signotify_remote, lp);
1450 * Otherwise the lwp is either in some uninterruptable state
1451 * or it is on the userland scheduler's runqueue waiting to
1452 * be scheduled to a cpu.
1459 * This function is called via an IPI so we cannot call setrunnable() here
1460 * (because while we hold the lp we don't own its token, and can't get it
1463 * We are interlocked by virtue of being on the same cpu as the target. If
1464 * we still are and LWP_SINTR or TDF_SINTR is set we can safely schedule
1465 * the target thread.
1468 lwp_signotify_remote(void *arg)
1470 struct lwp *lp = arg;
1471 thread_t td = lp->lwp_thread;
1473 if (lp == lwkt_preempted_proc()) {
1476 } else if (td->td_gd == mycpu) {
1477 if ((lp->lwp_flags & LWP_SINTR) ||
1478 (td->td_flags & TDF_SINTR)) {
1483 lwkt_send_ipiq(td->td_gd, lwp_signotify_remote, lp);
1484 /* LWPHOLD() is forwarded to the target cpu */
1489 * Caller must hold p->p_token
1492 proc_stop(struct proc *p)
1497 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1499 /* If somebody raced us, be happy with it */
1500 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1505 FOREACH_LWP_IN_PROC(lp, p) {
1507 lwkt_gettoken(&lp->lwp_token);
1509 switch (lp->lwp_stat) {
1512 * Do nothing, we are already counted in
1519 * We're sleeping, but we will stop before
1520 * returning to userspace, so count us
1521 * as stopped as well. We set LWP_MP_WSTOP
1522 * to signal the lwp that it should not
1523 * increase p_nstopped when reaching tstop().
1525 * LWP_MP_WSTOP is protected by lp->lwp_token.
1527 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1528 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1535 * We might notify ourself, but that's not
1541 lwkt_reltoken(&lp->lwp_token);
1545 if (p->p_nstopped == p->p_nthreads) {
1547 * Token required to interlock kern_wait(). Reparenting can
1548 * also cause a race so we have to hold (q).
1552 lwkt_gettoken(&q->p_token);
1553 p->p_flags &= ~P_WAITED;
1555 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1556 ksignal(p->p_pptr, SIGCHLD);
1557 lwkt_reltoken(&q->p_token);
1563 * Caller must hold proc_token
1566 proc_unstop(struct proc *p)
1570 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1572 if (p->p_stat != SSTOP)
1575 p->p_stat = SACTIVE;
1577 FOREACH_LWP_IN_PROC(lp, p) {
1579 lwkt_gettoken(&lp->lwp_token);
1581 switch (lp->lwp_stat) {
1584 * Uh? Not stopped? Well, I guess that's okay.
1587 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1588 p->p_pid, lp->lwp_tid);
1593 * Still sleeping. Don't bother waking it up.
1594 * However, if this thread was counted as
1595 * stopped, undo this.
1597 * Nevertheless we call setrunnable() so that it
1598 * will wake up in case a signal or timeout arrived
1601 * LWP_MP_WSTOP is protected by lp->lwp_token.
1603 if (lp->lwp_mpflags & LWP_MP_WSTOP) {
1604 atomic_clear_int(&lp->lwp_mpflags,
1609 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1610 p->p_pid, lp->lwp_tid);
1616 * This handles any lwp's waiting in a tsleep with
1623 lwkt_reltoken(&lp->lwp_token);
1628 * This handles any lwp's waiting in tstop(). We have interlocked
1629 * the setting of p_stat by acquiring and releasing each lpw's
1639 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1641 sigset_t savedmask, set;
1642 struct proc *p = curproc;
1643 struct lwp *lp = curthread->td_lwp;
1644 int error, sig, hz, timevalid = 0;
1645 struct timespec rts, ets, ts;
1650 ets.tv_sec = 0; /* silence compiler warning */
1651 ets.tv_nsec = 0; /* silence compiler warning */
1652 SIG_CANTMASK(waitset);
1653 savedmask = lp->lwp_sigmask;
1656 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1657 timeout->tv_nsec < 1000000000) {
1659 getnanouptime(&rts);
1661 timespecadd(&ets, timeout);
1666 set = lwp_sigpend(lp);
1667 SIGSETAND(set, waitset);
1668 if ((sig = sig_ffs(&set)) != 0) {
1669 SIGFILLSET(lp->lwp_sigmask);
1670 SIGDELSET(lp->lwp_sigmask, sig);
1671 SIG_CANTMASK(lp->lwp_sigmask);
1672 sig = issignal(lp, 1);
1674 * It may be a STOP signal, in the case, issignal
1675 * returns 0, because we may stop there, and new
1676 * signal can come in, we should restart if we got
1686 * Previous checking got nothing, and we retried but still
1687 * got nothing, we should return the error status.
1693 * POSIX says this must be checked after looking for pending
1697 if (timevalid == 0) {
1701 getnanouptime(&rts);
1702 if (timespeccmp(&rts, &ets, >=)) {
1707 timespecsub(&ts, &rts);
1708 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1709 hz = tvtohz_high(&tv);
1714 lp->lwp_sigmask = savedmask;
1715 SIGSETNAND(lp->lwp_sigmask, waitset);
1717 * We won't ever be woken up. Instead, our sleep will
1718 * be broken in lwpsignal().
1720 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1722 if (error == ERESTART) {
1723 /* can not restart a timeout wait. */
1725 } else if (error == EAGAIN) {
1726 /* will calculate timeout by ourself. */
1733 lp->lwp_sigmask = savedmask;
1736 bzero(info, sizeof(*info));
1737 info->si_signo = sig;
1738 spin_lock(&lp->lwp_spin);
1739 lwp_delsig(lp, sig); /* take the signal! */
1740 spin_unlock(&lp->lwp_spin);
1742 if (sig == SIGKILL) {
1755 sys_sigtimedwait(struct sigtimedwait_args *uap)
1758 struct timespec *timeout;
1764 error = copyin(uap->timeout, &ts, sizeof(ts));
1771 error = copyin(uap->set, &set, sizeof(set));
1774 error = kern_sigtimedwait(set, &info, timeout);
1778 error = copyout(&info, uap->info, sizeof(info));
1779 /* Repost if we got an error. */
1783 * This could transform a thread-specific signal to another
1784 * thread / process pending signal.
1787 ksignal(curproc, info.si_signo);
1789 uap->sysmsg_result = info.si_signo;
1798 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1804 error = copyin(uap->set, &set, sizeof(set));
1807 error = kern_sigtimedwait(set, &info, NULL);
1811 error = copyout(&info, uap->info, sizeof(info));
1812 /* Repost if we got an error. */
1816 * This could transform a thread-specific signal to another
1817 * thread / process pending signal.
1820 ksignal(curproc, info.si_signo);
1822 uap->sysmsg_result = info.si_signo;
1828 * If the current process has received a signal that would interrupt a
1829 * system call, return EINTR or ERESTART as appropriate.
1832 iscaught(struct lwp *lp)
1834 struct proc *p = lp->lwp_proc;
1838 if ((sig = CURSIG(lp)) != 0) {
1839 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1844 return(EWOULDBLOCK);
1848 * If the current process has received a signal (should be caught or cause
1849 * termination, should interrupt current syscall), return the signal number.
1850 * Stop signals with default action are processed immediately, then cleared;
1851 * they aren't returned. This is checked after each entry to the system for
1852 * a syscall or trap (though this can usually be done without calling issignal
1853 * by checking the pending signal masks in the CURSIG macro).
1855 * This routine is called via CURSIG/__cursig. We will acquire and release
1856 * p->p_token but if the caller needs to interlock the test the caller must
1857 * also hold p->p_token.
1859 * while (sig = CURSIG(curproc))
1865 issignal(struct lwp *lp, int maytrace)
1867 struct proc *p = lp->lwp_proc;
1871 lwkt_gettoken(&p->p_token);
1874 int traced = (p->p_flags & P_TRACED) || (p->p_stops & S_SIG);
1877 * If this process is supposed to stop, stop this thread.
1879 if (p->p_stat == SSTOP)
1882 mask = lwp_sigpend(lp);
1883 SIGSETNAND(mask, lp->lwp_sigmask);
1884 if (p->p_flags & P_PPWAIT)
1885 SIG_STOPSIGMASK(mask);
1886 if (SIGISEMPTY(mask)) { /* no signal to send */
1887 lwkt_reltoken(&p->p_token);
1890 sig = sig_ffs(&mask);
1892 STOPEVENT(p, S_SIG, sig);
1895 * We should see pending but ignored signals
1896 * only if P_TRACED was on when they were posted.
1898 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1899 spin_lock(&lp->lwp_spin);
1900 lwp_delsig(lp, sig);
1901 spin_unlock(&lp->lwp_spin);
1905 (p->p_flags & P_TRACED) &&
1906 (p->p_flags & P_PPWAIT) == 0) {
1908 * If traced, always stop, and stay stopped until
1909 * released by the parent.
1911 * NOTE: SSTOP may get cleared during the loop,
1912 * but we do not re-notify the parent if we have
1913 * to loop several times waiting for the parent
1914 * to let us continue.
1916 * XXX not sure if this is still true
1922 } while (!trace_req(p) && (p->p_flags & P_TRACED));
1925 * If parent wants us to take the signal,
1926 * then it will leave it in p->p_xstat;
1927 * otherwise we just look for signals again.
1929 spin_lock(&lp->lwp_spin);
1930 lwp_delsig(lp, sig); /* clear old signal */
1931 spin_unlock(&lp->lwp_spin);
1937 * Put the new signal into p_siglist. If the
1938 * signal is being masked, look for other signals.
1940 * XXX lwp might need a call to ksignal()
1942 SIGADDSET(p->p_siglist, sig);
1943 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1947 * If the traced bit got turned off, go back up
1948 * to the top to rescan signals. This ensures
1949 * that p_sig* and ps_sigact are consistent.
1951 if ((p->p_flags & P_TRACED) == 0)
1955 prop = sigprop(sig);
1958 * Decide whether the signal should be returned.
1959 * Return the signal's number, or fall through
1960 * to clear it from the pending mask.
1962 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1963 case (intptr_t)SIG_DFL:
1965 * Don't take default actions on system processes.
1967 if (p->p_pid <= 1) {
1970 * Are you sure you want to ignore SIGSEGV
1973 kprintf("Process (pid %lu) got signal %d\n",
1974 (u_long)p->p_pid, sig);
1976 break; /* == ignore */
1980 * Handle the in-kernel checkpoint action
1982 if (prop & SA_CKPT) {
1983 checkpoint_signal_handler(lp);
1988 * If there is a pending stop signal to process
1989 * with default action, stop here,
1990 * then clear the signal. However,
1991 * if process is member of an orphaned
1992 * process group, ignore tty stop signals.
1994 if (prop & SA_STOP) {
1995 if (p->p_flags & P_TRACED ||
1996 (p->p_pgrp->pg_jobc == 0 &&
1998 break; /* == ignore */
1999 if ((p->p_flags & P_WEXIT) == 0) {
2005 } else if (prop & SA_IGNORE) {
2007 * Except for SIGCONT, shouldn't get here.
2008 * Default action is to ignore; drop it.
2010 break; /* == ignore */
2012 lwkt_reltoken(&p->p_token);
2018 case (intptr_t)SIG_IGN:
2020 * Masking above should prevent us ever trying
2021 * to take action on an ignored signal other
2022 * than SIGCONT, unless process is traced.
2024 if ((prop & SA_CONT) == 0 &&
2025 (p->p_flags & P_TRACED) == 0)
2026 kprintf("issignal\n");
2027 break; /* == ignore */
2031 * This signal has an action, let
2032 * postsig() process it.
2034 lwkt_reltoken(&p->p_token);
2037 spin_lock(&lp->lwp_spin);
2038 lwp_delsig(lp, sig); /* take the signal! */
2039 spin_unlock(&lp->lwp_spin);
2045 * Take the action for the specified signal
2046 * from the current set of pending signals.
2048 * Caller must hold p->p_token
2053 struct lwp *lp = curthread->td_lwp;
2054 struct proc *p = lp->lwp_proc;
2055 struct sigacts *ps = p->p_sigacts;
2057 sigset_t returnmask;
2060 KASSERT(sig != 0, ("postsig"));
2062 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
2065 * If we are a virtual kernel running an emulated user process
2066 * context, switch back to the virtual kernel context before
2067 * trying to post the signal.
2069 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
2070 struct trapframe *tf = lp->lwp_md.md_regs;
2072 vkernel_trap(lp, tf);
2075 spin_lock(&lp->lwp_spin);
2076 lwp_delsig(lp, sig);
2077 spin_unlock(&lp->lwp_spin);
2078 action = ps->ps_sigact[_SIG_IDX(sig)];
2080 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
2081 ktrpsig(lp, sig, action, lp->lwp_flags & LWP_OLDMASK ?
2082 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
2084 STOPEVENT(p, S_SIG, sig);
2086 if (action == SIG_DFL) {
2088 * Default action, where the default is to kill
2089 * the process. (Other cases were ignored above.)
2095 * If we get here, the signal must be caught.
2097 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
2098 ("postsig action"));
2101 * Reset the signal handler if asked to
2103 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2105 * See kern_sigaction() for origin of this code.
2107 SIGDELSET(p->p_sigcatch, sig);
2108 if (sig != SIGCONT &&
2109 sigprop(sig) & SA_IGNORE)
2110 SIGADDSET(p->p_sigignore, sig);
2111 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2115 * Set the signal mask and calculate the mask to restore
2116 * when the signal function returns.
2118 * Special case: user has done a sigsuspend. Here the
2119 * current mask is not of interest, but rather the
2120 * mask from before the sigsuspend is what we want
2121 * restored after the signal processing is completed.
2123 if (lp->lwp_flags & LWP_OLDMASK) {
2124 returnmask = lp->lwp_oldsigmask;
2125 lp->lwp_flags &= ~LWP_OLDMASK;
2127 returnmask = lp->lwp_sigmask;
2130 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2131 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2132 SIGADDSET(lp->lwp_sigmask, sig);
2134 lp->lwp_ru.ru_nsignals++;
2135 if (lp->lwp_sig != sig) {
2138 code = lp->lwp_code;
2142 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2147 * Kill the current process for stated reason.
2150 killproc(struct proc *p, char *why)
2152 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2153 p->p_pid, p->p_comm,
2154 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2155 ksignal(p, SIGKILL);
2159 * Force the current process to exit with the specified signal, dumping core
2160 * if appropriate. We bypass the normal tests for masked and caught signals,
2161 * allowing unrecoverable failures to terminate the process without changing
2162 * signal state. Mark the accounting record with the signal termination.
2163 * If dumping core, save the signal number for the debugger. Calls exit and
2166 * This routine does not return.
2169 sigexit(struct lwp *lp, int sig)
2171 struct proc *p = lp->lwp_proc;
2173 lwkt_gettoken(&p->p_token);
2174 p->p_acflag |= AXSIG;
2175 if (sigprop(sig) & SA_CORE) {
2178 * Log signals which would cause core dumps
2179 * (Log as LOG_INFO to appease those who don't want
2181 * XXX : Todo, as well as euid, write out ruid too
2183 if (coredump(lp, sig) == 0)
2185 if (kern_logsigexit)
2187 "pid %d (%s), uid %d: exited on signal %d%s\n",
2188 p->p_pid, p->p_comm,
2189 p->p_ucred ? p->p_ucred->cr_uid : -1,
2191 sig & WCOREFLAG ? " (core dumped)" : "");
2193 lwkt_reltoken(&p->p_token);
2194 exit1(W_EXITCODE(0, sig));
2198 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2199 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2200 sizeof(corefilename), "process corefile name format string");
2203 * expand_name(name, uid, pid)
2204 * Expand the name described in corefilename, using name, uid, and pid.
2205 * corefilename is a kprintf-like string, with three format specifiers:
2206 * %N name of process ("name")
2207 * %P process id (pid)
2209 * For example, "%N.core" is the default; they can be disabled completely
2210 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2211 * This is controlled by the sysctl variable kern.corefile (see above).
2215 expand_name(const char *name, uid_t uid, pid_t pid)
2218 char buf[11]; /* Buffer for pid/uid -- max 4B */
2220 char *format = corefilename;
2223 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2226 namelen = strlen(name);
2227 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2229 switch (format[i]) {
2230 case '%': /* Format character */
2232 switch (format[i]) {
2236 case 'N': /* process name */
2237 if ((n + namelen) > MAXPATHLEN) {
2238 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2239 pid, name, uid, temp, name);
2240 kfree(temp, M_TEMP);
2243 memcpy(temp+n, name, namelen);
2246 case 'P': /* process id */
2247 l = ksprintf(buf, "%u", pid);
2248 if ((n + l) > MAXPATHLEN) {
2249 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2250 pid, name, uid, temp, name);
2251 kfree(temp, M_TEMP);
2254 memcpy(temp+n, buf, l);
2257 case 'U': /* user id */
2258 l = ksprintf(buf, "%u", uid);
2259 if ((n + l) > MAXPATHLEN) {
2260 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2261 pid, name, uid, temp, name);
2262 kfree(temp, M_TEMP);
2265 memcpy(temp+n, buf, l);
2269 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2273 temp[n++] = format[i];
2281 * Dump a process' core. The main routine does some
2282 * policy checking, and creates the name of the coredump;
2283 * then it passes on a vnode and a size limit to the process-specific
2284 * coredump routine if there is one; if there _is not_ one, it returns
2285 * ENOSYS; otherwise it returns the error from the process-specific routine.
2287 * The parameter `lp' is the lwp which triggered the coredump.
2291 coredump(struct lwp *lp, int sig)
2293 struct proc *p = lp->lwp_proc;
2295 struct ucred *cred = p->p_ucred;
2297 struct nlookupdata nd;
2300 char *name; /* name of corefile */
2303 STOPEVENT(p, S_CORE, 0);
2305 if (((sugid_coredump == 0) && p->p_flags & P_SUGID) || do_coredump == 0)
2309 * Note that the bulk of limit checking is done after
2310 * the corefile is created. The exception is if the limit
2311 * for corefiles is 0, in which case we don't bother
2312 * creating the corefile at all. This layout means that
2313 * a corefile is truncated instead of not being created,
2314 * if it is larger than the limit.
2316 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2320 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2323 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2325 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2326 kfree(name, M_TEMP);
2332 nd.nl_open_vp = NULL;
2336 lf.l_whence = SEEK_SET;
2339 lf.l_type = F_WRLCK;
2340 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2344 /* Don't dump to non-regular files or files with links. */
2345 if (vp->v_type != VREG ||
2346 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2351 /* Don't dump to files current user does not own */
2352 if (vattr.va_uid != p->p_ucred->cr_uid) {
2358 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2360 VOP_SETATTR(vp, &vattr, cred);
2361 p->p_acflag |= ACORE;
2364 error = p->p_sysent->sv_coredump ?
2365 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2368 lf.l_type = F_UNLCK;
2369 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2371 error1 = vn_close(vp, FWRITE);
2378 * Nonexistent system call-- signal process (may want to handle it).
2379 * Flag error in case process won't see signal immediately (blocked or ignored).
2385 sys_nosys(struct nosys_args *args)
2387 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2392 * Send a SIGIO or SIGURG signal to a process or process group using
2393 * stored credentials rather than those of the current process.
2396 pgsigio(struct sigio *sigio, int sig, int checkctty)
2401 if (sigio->sio_pgid > 0) {
2402 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2404 ksignal(sigio->sio_proc, sig);
2405 } else if (sigio->sio_pgid < 0) {
2407 struct pgrp *pg = sigio->sio_pgrp;
2410 * Must interlock all signals against fork
2413 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2414 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
2415 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2416 (checkctty == 0 || (p->p_flags & P_CONTROLT)))
2419 lockmgr(&pg->pg_lock, LK_RELEASE);
2425 filt_sigattach(struct knote *kn)
2427 struct proc *p = curproc;
2429 kn->kn_ptr.p_proc = p;
2430 kn->kn_flags |= EV_CLEAR; /* automatically set */
2432 /* XXX lock the proc here while adding to the list? */
2433 knote_insert(&p->p_klist, kn);
2439 filt_sigdetach(struct knote *kn)
2441 struct proc *p = kn->kn_ptr.p_proc;
2443 knote_remove(&p->p_klist, kn);
2447 * signal knotes are shared with proc knotes, so we apply a mask to
2448 * the hint in order to differentiate them from process hints. This
2449 * could be avoided by using a signal-specific knote list, but probably
2450 * isn't worth the trouble.
2453 filt_signal(struct knote *kn, long hint)
2455 if (hint & NOTE_SIGNAL) {
2456 hint &= ~NOTE_SIGNAL;
2458 if (kn->kn_id == hint)
2461 return (kn->kn_data != 0);