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38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
42 #include "opt_ktrace.h"
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/sysproto.h>
48 #include <sys/signalvar.h>
49 #include <sys/resourcevar.h>
50 #include <sys/vnode.h>
51 #include <sys/event.h>
53 #include <sys/nlookup.h>
54 #include <sys/pioctl.h>
56 #include <sys/fcntl.h>
59 #include <sys/ktrace.h>
60 #include <sys/syslog.h>
62 #include <sys/sysent.h>
63 #include <sys/sysctl.h>
64 #include <sys/malloc.h>
65 #include <sys/interrupt.h>
66 #include <sys/unistd.h>
67 #include <sys/kern_syscall.h>
68 #include <sys/vkernel.h>
70 #include <sys/signal2.h>
71 #include <sys/thread2.h>
72 #include <sys/spinlock2.h>
74 #include <machine/cpu.h>
75 #include <machine/smp.h>
77 static int coredump(struct lwp *, int);
78 static char *expand_name(const char *, uid_t, pid_t);
79 static int dokillpg(int sig, int pgid, int all);
80 static int sig_ffs(sigset_t *set);
81 static int sigprop(int sig);
82 static void lwp_signotify(struct lwp *lp);
84 static void lwp_signotify_remote(void *arg);
86 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
87 struct timespec *timeout);
89 static int filt_sigattach(struct knote *kn);
90 static void filt_sigdetach(struct knote *kn);
91 static int filt_signal(struct knote *kn, long hint);
93 struct filterops sig_filtops =
94 { 0, filt_sigattach, filt_sigdetach, filt_signal };
96 static int kern_logsigexit = 1;
97 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
99 "Log processes quitting on abnormal signals to syslog(3)");
102 * Can process p, with pcred pc, send the signal sig to process q?
104 #define CANSIGNAL(q, sig) \
105 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
106 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
109 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
111 #define CANSIGIO(ruid, uc, q) \
112 ((uc)->cr_uid == 0 || \
113 (ruid) == (q)->p_ucred->cr_ruid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
115 (ruid) == (q)->p_ucred->cr_uid || \
116 (uc)->cr_uid == (q)->p_ucred->cr_uid)
119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
122 static int do_coredump = 1;
123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
124 &do_coredump, 0, "Enable/Disable coredumps");
127 * Signal properties and actions.
128 * The array below categorizes the signals and their default actions
129 * according to the following properties:
131 #define SA_KILL 0x01 /* terminates process by default */
132 #define SA_CORE 0x02 /* ditto and coredumps */
133 #define SA_STOP 0x04 /* suspend process */
134 #define SA_TTYSTOP 0x08 /* ditto, from tty */
135 #define SA_IGNORE 0x10 /* ignore by default */
136 #define SA_CONT 0x20 /* continue if suspended */
137 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
138 #define SA_CKPT 0x80 /* checkpoint process */
141 static int sigproptbl[NSIG] = {
142 SA_KILL, /* SIGHUP */
143 SA_KILL, /* SIGINT */
144 SA_KILL|SA_CORE, /* SIGQUIT */
145 SA_KILL|SA_CORE, /* SIGILL */
146 SA_KILL|SA_CORE, /* SIGTRAP */
147 SA_KILL|SA_CORE, /* SIGABRT */
148 SA_KILL|SA_CORE, /* SIGEMT */
149 SA_KILL|SA_CORE, /* SIGFPE */
150 SA_KILL, /* SIGKILL */
151 SA_KILL|SA_CORE, /* SIGBUS */
152 SA_KILL|SA_CORE, /* SIGSEGV */
153 SA_KILL|SA_CORE, /* SIGSYS */
154 SA_KILL, /* SIGPIPE */
155 SA_KILL, /* SIGALRM */
156 SA_KILL, /* SIGTERM */
157 SA_IGNORE, /* SIGURG */
158 SA_STOP, /* SIGSTOP */
159 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
160 SA_IGNORE|SA_CONT, /* SIGCONT */
161 SA_IGNORE, /* SIGCHLD */
162 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
163 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
164 SA_IGNORE, /* SIGIO */
165 SA_KILL, /* SIGXCPU */
166 SA_KILL, /* SIGXFSZ */
167 SA_KILL, /* SIGVTALRM */
168 SA_KILL, /* SIGPROF */
169 SA_IGNORE, /* SIGWINCH */
170 SA_IGNORE, /* SIGINFO */
171 SA_KILL, /* SIGUSR1 */
172 SA_KILL, /* SIGUSR2 */
173 SA_IGNORE, /* SIGTHR */
174 SA_CKPT, /* SIGCKPT */
175 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
213 if (sig > 0 && sig < NSIG)
214 return (sigproptbl[_SIG_IDX(sig)]);
219 sig_ffs(sigset_t *set)
223 for (i = 0; i < _SIG_WORDS; i++)
225 return (ffs(set->__bits[i]) + (i * 32));
233 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
235 struct thread *td = curthread;
236 struct proc *p = td->td_proc;
238 struct sigacts *ps = p->p_sigacts;
240 if (sig <= 0 || sig > _SIG_MAXSIG)
243 lwkt_gettoken(&p->p_token);
246 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
247 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
249 if (SIGISMEMBER(ps->ps_sigonstack, sig))
250 oact->sa_flags |= SA_ONSTACK;
251 if (!SIGISMEMBER(ps->ps_sigintr, sig))
252 oact->sa_flags |= SA_RESTART;
253 if (SIGISMEMBER(ps->ps_sigreset, sig))
254 oact->sa_flags |= SA_RESETHAND;
255 if (SIGISMEMBER(ps->ps_signodefer, sig))
256 oact->sa_flags |= SA_NODEFER;
257 if (SIGISMEMBER(ps->ps_siginfo, sig))
258 oact->sa_flags |= SA_SIGINFO;
259 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
260 oact->sa_flags |= SA_NOCLDSTOP;
261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
262 oact->sa_flags |= SA_NOCLDWAIT;
266 * Check for invalid requests. KILL and STOP cannot be
269 if (sig == SIGKILL || sig == SIGSTOP) {
270 if (act->sa_handler != SIG_DFL) {
271 lwkt_reltoken(&p->p_token);
277 * Change setting atomically.
281 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
282 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
283 if (act->sa_flags & SA_SIGINFO) {
284 ps->ps_sigact[_SIG_IDX(sig)] =
285 (__sighandler_t *)act->sa_sigaction;
286 SIGADDSET(ps->ps_siginfo, sig);
288 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
289 SIGDELSET(ps->ps_siginfo, sig);
291 if (!(act->sa_flags & SA_RESTART))
292 SIGADDSET(ps->ps_sigintr, sig);
294 SIGDELSET(ps->ps_sigintr, sig);
295 if (act->sa_flags & SA_ONSTACK)
296 SIGADDSET(ps->ps_sigonstack, sig);
298 SIGDELSET(ps->ps_sigonstack, sig);
299 if (act->sa_flags & SA_RESETHAND)
300 SIGADDSET(ps->ps_sigreset, sig);
302 SIGDELSET(ps->ps_sigreset, sig);
303 if (act->sa_flags & SA_NODEFER)
304 SIGADDSET(ps->ps_signodefer, sig);
306 SIGDELSET(ps->ps_signodefer, sig);
307 if (sig == SIGCHLD) {
308 if (act->sa_flags & SA_NOCLDSTOP)
309 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
311 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
312 if (act->sa_flags & SA_NOCLDWAIT) {
314 * Paranoia: since SA_NOCLDWAIT is implemented
315 * by reparenting the dying child to PID 1 (and
316 * trust it to reap the zombie), PID 1 itself
317 * is forbidden to set SA_NOCLDWAIT.
320 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
322 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
324 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
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);
360 lwkt_reltoken(&p->p_token);
365 sys_sigaction(struct sigaction_args *uap)
367 struct sigaction act, oact;
368 struct sigaction *actp, *oactp;
371 actp = (uap->act != NULL) ? &act : NULL;
372 oactp = (uap->oact != NULL) ? &oact : NULL;
374 error = copyin(uap->act, actp, sizeof(act));
378 error = kern_sigaction(uap->sig, actp, oactp);
379 if (oactp && !error) {
380 error = copyout(oactp, uap->oact, sizeof(oact));
386 * Initialize signal state for process 0;
387 * set to ignore signals that are ignored by default.
390 siginit(struct proc *p)
394 for (i = 1; i <= NSIG; i++)
395 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
396 SIGADDSET(p->p_sigignore, i);
400 * Reset signals for an exec of the specified process.
403 execsigs(struct proc *p)
405 struct sigacts *ps = p->p_sigacts;
409 lp = ONLY_LWP_IN_PROC(p);
412 * Reset caught signals. Held signals remain held
413 * through p_sigmask (unless they were caught,
414 * and are now ignored by default).
416 while (SIGNOTEMPTY(p->p_sigcatch)) {
417 sig = sig_ffs(&p->p_sigcatch);
418 SIGDELSET(p->p_sigcatch, sig);
419 if (sigprop(sig) & SA_IGNORE) {
421 SIGADDSET(p->p_sigignore, sig);
422 SIGDELSET(p->p_siglist, sig);
423 /* don't need spinlock */
424 SIGDELSET(lp->lwp_siglist, sig);
426 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
430 * Reset stack state to the user stack.
431 * Clear set of signals caught on the signal stack.
433 lp->lwp_sigstk.ss_flags = SS_DISABLE;
434 lp->lwp_sigstk.ss_size = 0;
435 lp->lwp_sigstk.ss_sp = 0;
436 lp->lwp_flags &= ~LWP_ALTSTACK;
438 * Reset no zombies if child dies flag as Solaris does.
440 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
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. Note
729 * that new signals cannot be sent if a process is exiting.
734 kern_kill(int sig, pid_t pid, lwpid_t tid)
738 if ((u_int)sig > _SIG_MAXSIG)
741 lwkt_gettoken(&proc_token);
745 struct lwp *lp = NULL;
747 /* kill single process */
748 if ((p = pfind(pid)) == NULL) {
749 lwkt_reltoken(&proc_token);
752 lwkt_gettoken(&p->p_token);
753 if (!CANSIGNAL(p, sig)) {
754 lwkt_reltoken(&p->p_token);
756 lwkt_reltoken(&proc_token);
761 * NOP if the process is exiting. Note that lwpsignal() is
762 * called directly with P_WEXIT set to kill individual LWPs
763 * during exit, which is allowed.
765 if (p->p_flags & P_WEXIT) {
766 lwkt_reltoken(&p->p_token);
768 lwkt_reltoken(&proc_token);
772 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
774 lwkt_reltoken(&p->p_token);
776 lwkt_reltoken(&proc_token);
781 lwpsignal(p, lp, sig);
782 lwkt_reltoken(&p->p_token);
784 lwkt_reltoken(&proc_token);
789 * If we come here, pid is a special broadcast pid.
790 * This doesn't mix with a tid.
793 lwkt_reltoken(&proc_token);
797 case -1: /* broadcast signal */
798 t = (dokillpg(sig, 0, 1));
800 case 0: /* signal own process group */
801 t = (dokillpg(sig, 0, 0));
803 default: /* negative explicit process group */
804 t = (dokillpg(sig, -pid, 0));
807 lwkt_reltoken(&proc_token);
812 sys_kill(struct kill_args *uap)
816 error = kern_kill(uap->signum, uap->pid, -1);
821 sys_lwp_kill(struct lwp_kill_args *uap)
824 pid_t pid = uap->pid;
827 * A tid is mandatory for lwp_kill(), otherwise
828 * you could simply use kill().
834 * To save on a getpid() function call for intra-process
835 * signals, pid == -1 means current process.
838 pid = curproc->p_pid;
840 error = kern_kill(uap->signum, pid, uap->tid);
845 * Send a signal to a process group.
848 gsignal(int pgid, int sig)
852 if (pgid && (pgrp = pgfind(pgid)))
853 pgsignal(pgrp, sig, 0);
857 * Send a signal to a process group. If checktty is 1,
858 * limit to members which have a controlling terminal.
860 * pg_lock interlocks against a fork that might be in progress, to
861 * ensure that the new child process picks up the signal.
864 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
869 * Must interlock all signals against fork
873 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
874 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
875 if (checkctty == 0 || p->p_flags & P_CONTROLT)
878 lockmgr(&pgrp->pg_lock, LK_RELEASE);
884 * Send a signal caused by a trap to the current lwp. If it will be caught
885 * immediately, deliver it with correct code. Otherwise, post it normally.
887 * These signals may ONLY be delivered to the specified lwp and may never
888 * be delivered to the process generically.
891 trapsignal(struct lwp *lp, int sig, u_long code)
893 struct proc *p = lp->lwp_proc;
894 struct sigacts *ps = p->p_sigacts;
897 * If we are a virtual kernel running an emulated user process
898 * context, switch back to the virtual kernel context before
899 * trying to post the signal.
901 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
902 struct trapframe *tf = lp->lwp_md.md_regs;
904 vkernel_trap(lp, tf);
908 if ((p->p_flags & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
909 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
910 lp->lwp_ru.ru_nsignals++;
912 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
913 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
914 &lp->lwp_sigmask, code);
916 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
917 &lp->lwp_sigmask, code);
918 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
919 if (!SIGISMEMBER(ps->ps_signodefer, sig))
920 SIGADDSET(lp->lwp_sigmask, sig);
921 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
923 * See kern_sigaction() for origin of this code.
925 SIGDELSET(p->p_sigcatch, sig);
926 if (sig != SIGCONT &&
927 sigprop(sig) & SA_IGNORE)
928 SIGADDSET(p->p_sigignore, sig);
929 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
932 lp->lwp_code = code; /* XXX for core dump/debugger */
933 lp->lwp_sig = sig; /* XXX to verify code */
934 lwpsignal(p, lp, sig);
939 * Find a suitable lwp to deliver the signal to. Returns NULL if all
940 * lwps hold the signal blocked.
942 * Caller must hold p->p_token.
944 * Returns a lp or NULL. If non-NULL the lp is held and its token is
948 find_lwp_for_signal(struct proc *p, int sig)
951 struct lwp *run, *sleep, *stop;
954 * If the running/preempted thread belongs to the proc to which
955 * the signal is being delivered and this thread does not block
956 * the signal, then we can avoid a context switch by delivering
957 * the signal to this thread, because it will return to userland
960 lp = lwkt_preempted_proc();
961 if (lp != NULL && lp->lwp_proc == p) {
963 lwkt_gettoken(&lp->lwp_token);
964 if (!SIGISMEMBER(lp->lwp_sigmask, sig)) {
965 /* return w/ token held */
968 lwkt_reltoken(&lp->lwp_token);
972 run = sleep = stop = NULL;
973 FOREACH_LWP_IN_PROC(lp, p) {
975 * If the signal is being blocked by the lwp, then this
976 * lwp is not eligible for receiving the signal.
979 lwkt_gettoken(&lp->lwp_token);
981 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
982 lwkt_reltoken(&lp->lwp_token);
987 switch (lp->lwp_stat) {
991 lwkt_reltoken(&sleep->lwp_token);
997 lwkt_reltoken(&stop->lwp_token);
1006 if (lp->lwp_flags & LWP_SINTR) {
1008 lwkt_reltoken(&lp->lwp_token);
1012 lwkt_reltoken(&stop->lwp_token);
1020 lwkt_reltoken(&lp->lwp_token);
1026 lwkt_reltoken(&lp->lwp_token);
1029 lwkt_reltoken(&lp->lwp_token);
1042 else if (sleep != NULL)
1049 * Send the signal to the process. If the signal has an action, the action
1050 * is usually performed by the target process rather than the caller; we add
1051 * the signal to the set of pending signals for the process.
1054 * o When a stop signal is sent to a sleeping process that takes the
1055 * default action, the process is stopped without awakening it.
1056 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1057 * regardless of the signal action (eg, blocked or ignored).
1059 * Other ignored signals are discarded immediately.
1061 * If the caller wishes to call this function from a hard code section the
1062 * caller must already hold p->p_token (see kern_clock.c).
1067 ksignal(struct proc *p, int sig)
1069 lwpsignal(p, NULL, sig);
1073 * The core for ksignal. lp may be NULL, then a suitable thread
1074 * will be chosen. If not, lp MUST be a member of p.
1076 * If the caller wishes to call this function from a hard code section the
1077 * caller must already hold p->p_token.
1082 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1088 if (sig > _SIG_MAXSIG || sig <= 0) {
1089 kprintf("lwpsignal: signal %d\n", sig);
1090 panic("lwpsignal signal number");
1093 KKASSERT(lp == NULL || lp->lwp_proc == p);
1096 lwkt_gettoken(&p->p_token);
1099 lwkt_gettoken(&lp->lwp_token);
1102 prop = sigprop(sig);
1105 * If proc is traced, always give parent a chance;
1106 * if signal event is tracked by procfs, give *that*
1107 * a chance, as well.
1109 if ((p->p_flags & P_TRACED) || (p->p_stops & S_SIG)) {
1113 * Do not try to deliver signals to an exiting lwp. Note
1114 * that we must still deliver the signal if P_WEXIT is set
1115 * in the process flags.
1117 if (lp && (lp->lwp_mpflags & LWP_MP_WEXIT)) {
1119 lwkt_reltoken(&lp->lwp_token);
1122 lwkt_reltoken(&p->p_token);
1128 * If the signal is being ignored, then we forget about
1129 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1130 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1132 if (SIGISMEMBER(p->p_sigignore, sig)) {
1134 * Even if a signal is set SIG_IGN, it may still be
1135 * lurking in a kqueue.
1137 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1139 lwkt_reltoken(&lp->lwp_token);
1142 lwkt_reltoken(&p->p_token);
1146 if (SIGISMEMBER(p->p_sigcatch, sig))
1153 * If continuing, clear any pending STOP signals.
1156 SIG_STOPSIGMASK(p->p_siglist);
1158 if (prop & SA_STOP) {
1160 * If sending a tty stop signal to a member of an orphaned
1161 * process group, discard the signal here if the action
1162 * is default; don't stop the process below if sleeping,
1163 * and don't clear any pending SIGCONT.
1165 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1166 action == SIG_DFL) {
1167 lwkt_reltoken(&p->p_token);
1171 SIG_CONTSIGMASK(p->p_siglist);
1172 p->p_flags &= ~P_CONTINUED;
1177 if (p->p_stat == SSTOP) {
1179 * Nobody can handle this signal, add it to the lwp or
1180 * process pending list
1183 spin_lock(&lp->lwp_spin);
1184 SIGADDSET(lp->lwp_siglist, sig);
1185 spin_unlock(&lp->lwp_spin);
1187 SIGADDSET(p->p_siglist, sig);
1191 * If the process is stopped and is being traced, then no
1192 * further action is necessary.
1194 if (p->p_flags & P_TRACED)
1198 * If the process is stopped and receives a KILL signal,
1199 * make the process runnable.
1201 if (sig == SIGKILL) {
1203 goto active_process;
1207 * If the process is stopped and receives a CONT signal,
1208 * then try to make the process runnable again.
1210 if (prop & SA_CONT) {
1212 * If SIGCONT is default (or ignored), we continue the
1213 * process but don't leave the signal in p_siglist, as
1214 * it has no further action. If SIGCONT is held, we
1215 * continue the process and leave the signal in
1216 * p_siglist. If the process catches SIGCONT, let it
1217 * handle the signal itself.
1219 * XXX what if the signal is being held blocked?
1221 * Token required to interlock kern_wait().
1222 * Reparenting can also cause a race so we have to
1227 lwkt_gettoken(&q->p_token);
1228 p->p_flags |= P_CONTINUED;
1230 if (action == SIG_DFL)
1231 SIGDELSET(p->p_siglist, sig);
1233 lwkt_reltoken(&q->p_token);
1235 if (action == SIG_CATCH)
1236 goto active_process;
1241 * If the process is stopped and receives another STOP
1242 * signal, we do not need to stop it again. If we did
1243 * the shell could get confused.
1245 * However, if the current/preempted lwp is part of the
1246 * process receiving the signal, we need to keep it,
1247 * so that this lwp can stop in issignal() later, as
1248 * we don't want to wait until it reaches userret!
1250 if (prop & SA_STOP) {
1251 if (lwkt_preempted_proc() == NULL ||
1252 lwkt_preempted_proc()->lwp_proc != p)
1253 SIGDELSET(p->p_siglist, sig);
1257 * Otherwise the process is stopped and it received some
1258 * signal, which does not change its stopped state. When
1259 * the process is continued a wakeup(p) will be issued which
1260 * will wakeup any threads sleeping in tstop().
1263 /* NOTE: returns lp w/ token held */
1264 lp = find_lwp_for_signal(p, sig);
1270 /* else not stopped */
1274 * Never deliver a lwp-specific signal to a random lwp.
1277 /* NOTE: returns lp w/ token held */
1278 lp = find_lwp_for_signal(p, sig);
1280 if (SIGISMEMBER(lp->lwp_sigmask, sig)) {
1281 lwkt_reltoken(&lp->lwp_token);
1289 * Deliver to the process generically if (1) the signal is being
1290 * sent to any thread or (2) we could not find a thread to deliver
1294 SIGADDSET(p->p_siglist, sig);
1299 * Deliver to a specific LWP whether it masks it or not. It will
1300 * not be dispatched if masked but we must still deliver it.
1302 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1303 (p->p_flags & P_TRACED) == 0) {
1308 * If the process receives a STOP signal which indeed needs to
1309 * stop the process, do so. If the process chose to catch the
1310 * signal, it will be treated like any other signal.
1312 if ((prop & SA_STOP) && action == SIG_DFL) {
1314 * If a child holding parent blocked, stopping
1315 * could cause deadlock. Take no action at this
1318 if (p->p_flags & P_PPWAIT) {
1319 SIGADDSET(p->p_siglist, sig);
1324 * Do not actually try to manipulate the process, but simply
1325 * stop it. Lwps will stop as soon as they safely can.
1333 * If it is a CONT signal with default action, just ignore it.
1335 if ((prop & SA_CONT) && action == SIG_DFL)
1339 * Mark signal pending at this specific thread.
1341 spin_lock(&lp->lwp_spin);
1342 SIGADDSET(lp->lwp_siglist, sig);
1343 spin_unlock(&lp->lwp_spin);
1349 lwkt_reltoken(&lp->lwp_token);
1352 lwkt_reltoken(&p->p_token);
1358 * Notify the LWP that a signal has arrived. The LWP does not have to be
1359 * sleeping on the current cpu.
1361 * p->p_token and lp->lwp_token must be held on call.
1363 * We can only safely schedule the thread on its current cpu and only if
1364 * one of the SINTR flags is set. If an SINTR flag is set AND we are on
1365 * the correct cpu we are properly interlocked, otherwise we could be
1366 * racing other thread transition states (or the lwp is on the user scheduler
1367 * runq but not scheduled) and must not do anything.
1369 * Since we hold the lwp token we know the lwp cannot be ripped out from
1370 * under us so we can safely hold it to prevent it from being ripped out
1371 * from under us if we are forced to IPI another cpu to make the local
1374 * Adjustment of lp->lwp_stat can only occur when we hold the lwp_token,
1375 * which we won't in an IPI so any fixups have to be done here, effectively
1376 * replicating part of what setrunnable() does.
1379 lwp_signotify(struct lwp *lp)
1381 ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token);
1384 if (lp == lwkt_preempted_proc()) {
1386 * lwp is on the current cpu AND it is currently running
1387 * (we preempted it).
1390 } else if (lp->lwp_flags & LWP_SINTR) {
1392 * lwp is sitting in tsleep() with PCATCH set
1395 if (lp->lwp_thread->td_gd == mycpu) {
1399 * We can only adjust lwp_stat while we hold the
1400 * lwp_token, and we won't in the IPI function.
1403 if (lp->lwp_stat == LSSTOP)
1404 lp->lwp_stat = LSSLEEP;
1405 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1406 lwp_signotify_remote, lp);
1411 } else if (lp->lwp_thread->td_flags & TDF_SINTR) {
1413 * lwp is sitting in lwkt_sleep() with PCATCH set.
1416 if (lp->lwp_thread->td_gd == mycpu) {
1420 * We can only adjust lwp_stat while we hold the
1421 * lwp_token, and we won't in the IPI function.
1424 if (lp->lwp_stat == LSSTOP)
1425 lp->lwp_stat = LSSLEEP;
1426 lwkt_send_ipiq(lp->lwp_thread->td_gd,
1427 lwp_signotify_remote, lp);
1434 * Otherwise the lwp is either in some uninterruptable state
1435 * or it is on the userland scheduler's runqueue waiting to
1436 * be scheduled to a cpu.
1445 * This function is called via an IPI so we cannot call setrunnable() here
1446 * (because while we hold the lp we don't own its token, and can't get it
1449 * We are interlocked by virtue of being on the same cpu as the target. If
1450 * we still are and LWP_SINTR or TDF_SINTR is set we can safely schedule
1451 * the target thread.
1454 lwp_signotify_remote(void *arg)
1456 struct lwp *lp = arg;
1457 thread_t td = lp->lwp_thread;
1459 if (lp == lwkt_preempted_proc()) {
1462 } else if (td->td_gd == mycpu) {
1463 if ((lp->lwp_flags & LWP_SINTR) ||
1464 (td->td_flags & TDF_SINTR)) {
1469 lwkt_send_ipiq(td->td_gd, lwp_signotify_remote, lp);
1470 /* LWPHOLD() is forwarded to the target cpu */
1477 * Caller must hold p->p_token
1480 proc_stop(struct proc *p)
1485 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1488 /* If somebody raced us, be happy with it */
1489 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1495 FOREACH_LWP_IN_PROC(lp, p) {
1497 lwkt_gettoken(&lp->lwp_token);
1499 switch (lp->lwp_stat) {
1502 * Do nothing, we are already counted in
1509 * We're sleeping, but we will stop before
1510 * returning to userspace, so count us
1511 * as stopped as well. We set LWP_MP_WSTOP
1512 * to signal the lwp that it should not
1513 * increase p_nstopped when reaching tstop().
1515 * LWP_MP_WSTOP is protected by lp->lwp_token.
1517 if ((lp->lwp_mpflags & LWP_MP_WSTOP) == 0) {
1518 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WSTOP);
1525 * We might notify ourself, but that's not
1531 lwkt_reltoken(&lp->lwp_token);
1535 if (p->p_nstopped == p->p_nthreads) {
1537 * Token required to interlock kern_wait(). Reparenting can
1538 * also cause a race so we have to hold (q).
1542 lwkt_gettoken(&q->p_token);
1543 p->p_flags &= ~P_WAITED;
1545 if ((q->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1546 ksignal(p->p_pptr, SIGCHLD);
1547 lwkt_reltoken(&q->p_token);
1554 * Caller must hold proc_token
1557 proc_unstop(struct proc *p)
1561 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
1564 if (p->p_stat != SSTOP) {
1569 p->p_stat = SACTIVE;
1571 FOREACH_LWP_IN_PROC(lp, p) {
1573 lwkt_gettoken(&lp->lwp_token);
1575 switch (lp->lwp_stat) {
1578 * Uh? Not stopped? Well, I guess that's okay.
1581 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1582 p->p_pid, lp->lwp_tid);
1587 * Still sleeping. Don't bother waking it up.
1588 * However, if this thread was counted as
1589 * stopped, undo this.
1591 * Nevertheless we call setrunnable() so that it
1592 * will wake up in case a signal or timeout arrived
1595 * LWP_MP_WSTOP is protected by lp->lwp_token.
1597 if (lp->lwp_mpflags & LWP_MP_WSTOP) {
1598 atomic_clear_int(&lp->lwp_mpflags,
1603 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1604 p->p_pid, lp->lwp_tid);
1610 * This handles any lwp's waiting in a tsleep with
1617 lwkt_reltoken(&lp->lwp_token);
1622 * This handles any lwp's waiting in tstop(). We have interlocked
1623 * the setting of p_stat by acquiring and releasing each lpw's
1634 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1636 sigset_t savedmask, set;
1637 struct proc *p = curproc;
1638 struct lwp *lp = curthread->td_lwp;
1639 int error, sig, hz, timevalid = 0;
1640 struct timespec rts, ets, ts;
1645 ets.tv_sec = 0; /* silence compiler warning */
1646 ets.tv_nsec = 0; /* silence compiler warning */
1647 SIG_CANTMASK(waitset);
1648 savedmask = lp->lwp_sigmask;
1651 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1652 timeout->tv_nsec < 1000000000) {
1654 getnanouptime(&rts);
1656 timespecadd(&ets, timeout);
1661 set = lwp_sigpend(lp);
1662 SIGSETAND(set, waitset);
1663 if ((sig = sig_ffs(&set)) != 0) {
1664 SIGFILLSET(lp->lwp_sigmask);
1665 SIGDELSET(lp->lwp_sigmask, sig);
1666 SIG_CANTMASK(lp->lwp_sigmask);
1667 sig = issignal(lp, 1);
1669 * It may be a STOP signal, in the case, issignal
1670 * returns 0, because we may stop there, and new
1671 * signal can come in, we should restart if we got
1681 * Previous checking got nothing, and we retried but still
1682 * got nothing, we should return the error status.
1688 * POSIX says this must be checked after looking for pending
1692 if (timevalid == 0) {
1696 getnanouptime(&rts);
1697 if (timespeccmp(&rts, &ets, >=)) {
1702 timespecsub(&ts, &rts);
1703 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1704 hz = tvtohz_high(&tv);
1709 lp->lwp_sigmask = savedmask;
1710 SIGSETNAND(lp->lwp_sigmask, waitset);
1712 * We won't ever be woken up. Instead, our sleep will
1713 * be broken in lwpsignal().
1715 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1717 if (error == ERESTART) {
1718 /* can not restart a timeout wait. */
1720 } else if (error == EAGAIN) {
1721 /* will calculate timeout by ourself. */
1728 lp->lwp_sigmask = savedmask;
1731 bzero(info, sizeof(*info));
1732 info->si_signo = sig;
1733 spin_lock(&lp->lwp_spin);
1734 lwp_delsig(lp, sig); /* take the signal! */
1735 spin_unlock(&lp->lwp_spin);
1737 if (sig == SIGKILL) {
1750 sys_sigtimedwait(struct sigtimedwait_args *uap)
1753 struct timespec *timeout;
1759 error = copyin(uap->timeout, &ts, sizeof(ts));
1766 error = copyin(uap->set, &set, sizeof(set));
1769 error = kern_sigtimedwait(set, &info, timeout);
1773 error = copyout(&info, uap->info, sizeof(info));
1774 /* Repost if we got an error. */
1778 * This could transform a thread-specific signal to another
1779 * thread / process pending signal.
1782 ksignal(curproc, info.si_signo);
1784 uap->sysmsg_result = info.si_signo;
1793 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1799 error = copyin(uap->set, &set, sizeof(set));
1802 error = kern_sigtimedwait(set, &info, NULL);
1806 error = copyout(&info, uap->info, sizeof(info));
1807 /* Repost if we got an error. */
1811 * This could transform a thread-specific signal to another
1812 * thread / process pending signal.
1815 ksignal(curproc, info.si_signo);
1817 uap->sysmsg_result = info.si_signo;
1823 * If the current process has received a signal that would interrupt a
1824 * system call, return EINTR or ERESTART as appropriate.
1827 iscaught(struct lwp *lp)
1829 struct proc *p = lp->lwp_proc;
1833 if ((sig = CURSIG(lp)) != 0) {
1834 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1839 return(EWOULDBLOCK);
1843 * If the current process has received a signal (should be caught or cause
1844 * termination, should interrupt current syscall), return the signal number.
1845 * Stop signals with default action are processed immediately, then cleared;
1846 * they aren't returned. This is checked after each entry to the system for
1847 * a syscall or trap (though this can usually be done without calling issignal
1848 * by checking the pending signal masks in the CURSIG macro).
1850 * This routine is called via CURSIG/__cursig. We will acquire and release
1851 * p->p_token but if the caller needs to interlock the test the caller must
1852 * also hold p->p_token.
1854 * while (sig = CURSIG(curproc))
1860 issignal(struct lwp *lp, int maytrace)
1862 struct proc *p = lp->lwp_proc;
1866 lwkt_gettoken(&p->p_token);
1869 int traced = (p->p_flags & P_TRACED) || (p->p_stops & S_SIG);
1872 * If this process is supposed to stop, stop this thread.
1874 if (p->p_stat == SSTOP)
1877 mask = lwp_sigpend(lp);
1878 SIGSETNAND(mask, lp->lwp_sigmask);
1879 if (p->p_flags & P_PPWAIT)
1880 SIG_STOPSIGMASK(mask);
1881 if (SIGISEMPTY(mask)) { /* no signal to send */
1882 lwkt_reltoken(&p->p_token);
1885 sig = sig_ffs(&mask);
1887 STOPEVENT(p, S_SIG, sig);
1890 * We should see pending but ignored signals
1891 * only if P_TRACED was on when they were posted.
1893 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1894 spin_lock(&lp->lwp_spin);
1895 lwp_delsig(lp, sig);
1896 spin_unlock(&lp->lwp_spin);
1900 (p->p_flags & P_TRACED) &&
1901 (p->p_flags & P_PPWAIT) == 0) {
1903 * If traced, always stop, and stay stopped until
1904 * released by the parent.
1906 * NOTE: SSTOP may get cleared during the loop,
1907 * but we do not re-notify the parent if we have
1908 * to loop several times waiting for the parent
1909 * to let us continue.
1911 * XXX not sure if this is still true
1917 } while (!trace_req(p) && (p->p_flags & P_TRACED));
1920 * If parent wants us to take the signal,
1921 * then it will leave it in p->p_xstat;
1922 * otherwise we just look for signals again.
1924 spin_lock(&lp->lwp_spin);
1925 lwp_delsig(lp, sig); /* clear old signal */
1926 spin_unlock(&lp->lwp_spin);
1932 * Put the new signal into p_siglist. If the
1933 * signal is being masked, look for other signals.
1935 * XXX lwp might need a call to ksignal()
1937 SIGADDSET(p->p_siglist, sig);
1938 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1942 * If the traced bit got turned off, go back up
1943 * to the top to rescan signals. This ensures
1944 * that p_sig* and ps_sigact are consistent.
1946 if ((p->p_flags & P_TRACED) == 0)
1950 prop = sigprop(sig);
1953 * Decide whether the signal should be returned.
1954 * Return the signal's number, or fall through
1955 * to clear it from the pending mask.
1957 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1958 case (intptr_t)SIG_DFL:
1960 * Don't take default actions on system processes.
1962 if (p->p_pid <= 1) {
1965 * Are you sure you want to ignore SIGSEGV
1968 kprintf("Process (pid %lu) got signal %d\n",
1969 (u_long)p->p_pid, sig);
1971 break; /* == ignore */
1975 * Handle the in-kernel checkpoint action
1977 if (prop & SA_CKPT) {
1978 checkpoint_signal_handler(lp);
1983 * If there is a pending stop signal to process
1984 * with default action, stop here,
1985 * then clear the signal. However,
1986 * if process is member of an orphaned
1987 * process group, ignore tty stop signals.
1989 if (prop & SA_STOP) {
1990 if (p->p_flags & P_TRACED ||
1991 (p->p_pgrp->pg_jobc == 0 &&
1993 break; /* == ignore */
1998 } else if (prop & SA_IGNORE) {
2000 * Except for SIGCONT, shouldn't get here.
2001 * Default action is to ignore; drop it.
2003 break; /* == ignore */
2005 lwkt_reltoken(&p->p_token);
2011 case (intptr_t)SIG_IGN:
2013 * Masking above should prevent us ever trying
2014 * to take action on an ignored signal other
2015 * than SIGCONT, unless process is traced.
2017 if ((prop & SA_CONT) == 0 &&
2018 (p->p_flags & P_TRACED) == 0)
2019 kprintf("issignal\n");
2020 break; /* == ignore */
2024 * This signal has an action, let
2025 * postsig() process it.
2027 lwkt_reltoken(&p->p_token);
2030 spin_lock(&lp->lwp_spin);
2031 lwp_delsig(lp, sig); /* take the signal! */
2032 spin_unlock(&lp->lwp_spin);
2038 * Take the action for the specified signal
2039 * from the current set of pending signals.
2041 * Caller must hold p->p_token
2046 struct lwp *lp = curthread->td_lwp;
2047 struct proc *p = lp->lwp_proc;
2048 struct sigacts *ps = p->p_sigacts;
2050 sigset_t returnmask;
2053 KASSERT(sig != 0, ("postsig"));
2055 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
2058 * If we are a virtual kernel running an emulated user process
2059 * context, switch back to the virtual kernel context before
2060 * trying to post the signal.
2062 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
2063 struct trapframe *tf = lp->lwp_md.md_regs;
2065 vkernel_trap(lp, tf);
2068 spin_lock(&lp->lwp_spin);
2069 lwp_delsig(lp, sig);
2070 spin_unlock(&lp->lwp_spin);
2071 action = ps->ps_sigact[_SIG_IDX(sig)];
2073 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
2074 ktrpsig(lp, sig, action, lp->lwp_flags & LWP_OLDMASK ?
2075 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
2077 STOPEVENT(p, S_SIG, sig);
2079 if (action == SIG_DFL) {
2081 * Default action, where the default is to kill
2082 * the process. (Other cases were ignored above.)
2088 * If we get here, the signal must be caught.
2090 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
2091 ("postsig action"));
2096 * Reset the signal handler if asked to
2098 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
2100 * See kern_sigaction() for origin of this code.
2102 SIGDELSET(p->p_sigcatch, sig);
2103 if (sig != SIGCONT &&
2104 sigprop(sig) & SA_IGNORE)
2105 SIGADDSET(p->p_sigignore, sig);
2106 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
2110 * Set the signal mask and calculate the mask to restore
2111 * when the signal function returns.
2113 * Special case: user has done a sigsuspend. Here the
2114 * current mask is not of interest, but rather the
2115 * mask from before the sigsuspend is what we want
2116 * restored after the signal processing is completed.
2118 if (lp->lwp_flags & LWP_OLDMASK) {
2119 returnmask = lp->lwp_oldsigmask;
2120 lp->lwp_flags &= ~LWP_OLDMASK;
2122 returnmask = lp->lwp_sigmask;
2125 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
2126 if (!SIGISMEMBER(ps->ps_signodefer, sig))
2127 SIGADDSET(lp->lwp_sigmask, sig);
2130 lp->lwp_ru.ru_nsignals++;
2131 if (lp->lwp_sig != sig) {
2134 code = lp->lwp_code;
2138 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
2143 * Kill the current process for stated reason.
2146 killproc(struct proc *p, char *why)
2148 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
2149 p->p_pid, p->p_comm,
2150 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
2151 ksignal(p, SIGKILL);
2155 * Force the current process to exit with the specified signal, dumping core
2156 * if appropriate. We bypass the normal tests for masked and caught signals,
2157 * allowing unrecoverable failures to terminate the process without changing
2158 * signal state. Mark the accounting record with the signal termination.
2159 * If dumping core, save the signal number for the debugger. Calls exit and
2162 * This routine does not return.
2165 sigexit(struct lwp *lp, int sig)
2167 struct proc *p = lp->lwp_proc;
2169 lwkt_gettoken(&p->p_token);
2170 p->p_acflag |= AXSIG;
2171 if (sigprop(sig) & SA_CORE) {
2174 * Log signals which would cause core dumps
2175 * (Log as LOG_INFO to appease those who don't want
2177 * XXX : Todo, as well as euid, write out ruid too
2179 if (coredump(lp, sig) == 0)
2181 if (kern_logsigexit)
2183 "pid %d (%s), uid %d: exited on signal %d%s\n",
2184 p->p_pid, p->p_comm,
2185 p->p_ucred ? p->p_ucred->cr_uid : -1,
2187 sig & WCOREFLAG ? " (core dumped)" : "");
2189 lwkt_reltoken(&p->p_token);
2190 exit1(W_EXITCODE(0, sig));
2194 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2195 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2196 sizeof(corefilename), "process corefile name format string");
2199 * expand_name(name, uid, pid)
2200 * Expand the name described in corefilename, using name, uid, and pid.
2201 * corefilename is a kprintf-like string, with three format specifiers:
2202 * %N name of process ("name")
2203 * %P process id (pid)
2205 * For example, "%N.core" is the default; they can be disabled completely
2206 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2207 * This is controlled by the sysctl variable kern.corefile (see above).
2211 expand_name(const char *name, uid_t uid, pid_t pid)
2214 char buf[11]; /* Buffer for pid/uid -- max 4B */
2216 char *format = corefilename;
2219 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2222 namelen = strlen(name);
2223 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2225 switch (format[i]) {
2226 case '%': /* Format character */
2228 switch (format[i]) {
2232 case 'N': /* process name */
2233 if ((n + namelen) > MAXPATHLEN) {
2234 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2235 pid, name, uid, temp, name);
2236 kfree(temp, M_TEMP);
2239 memcpy(temp+n, name, namelen);
2242 case 'P': /* process id */
2243 l = ksprintf(buf, "%u", pid);
2244 if ((n + l) > MAXPATHLEN) {
2245 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2246 pid, name, uid, temp, name);
2247 kfree(temp, M_TEMP);
2250 memcpy(temp+n, buf, l);
2253 case 'U': /* user id */
2254 l = ksprintf(buf, "%u", uid);
2255 if ((n + l) > MAXPATHLEN) {
2256 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2257 pid, name, uid, temp, name);
2258 kfree(temp, M_TEMP);
2261 memcpy(temp+n, buf, l);
2265 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2269 temp[n++] = format[i];
2277 * Dump a process' core. The main routine does some
2278 * policy checking, and creates the name of the coredump;
2279 * then it passes on a vnode and a size limit to the process-specific
2280 * coredump routine if there is one; if there _is not_ one, it returns
2281 * ENOSYS; otherwise it returns the error from the process-specific routine.
2283 * The parameter `lp' is the lwp which triggered the coredump.
2287 coredump(struct lwp *lp, int sig)
2289 struct proc *p = lp->lwp_proc;
2291 struct ucred *cred = p->p_ucred;
2293 struct nlookupdata nd;
2296 char *name; /* name of corefile */
2299 STOPEVENT(p, S_CORE, 0);
2301 if (((sugid_coredump == 0) && p->p_flags & P_SUGID) || do_coredump == 0)
2305 * Note that the bulk of limit checking is done after
2306 * the corefile is created. The exception is if the limit
2307 * for corefiles is 0, in which case we don't bother
2308 * creating the corefile at all. This layout means that
2309 * a corefile is truncated instead of not being created,
2310 * if it is larger than the limit.
2312 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2316 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2319 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2321 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2322 kfree(name, M_TEMP);
2328 nd.nl_open_vp = NULL;
2332 lf.l_whence = SEEK_SET;
2335 lf.l_type = F_WRLCK;
2336 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2340 /* Don't dump to non-regular files or files with links. */
2341 if (vp->v_type != VREG ||
2342 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2347 /* Don't dump to files current user does not own */
2348 if (vattr.va_uid != p->p_ucred->cr_uid) {
2354 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2356 VOP_SETATTR(vp, &vattr, cred);
2357 p->p_acflag |= ACORE;
2360 error = p->p_sysent->sv_coredump ?
2361 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2364 lf.l_type = F_UNLCK;
2365 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2367 error1 = vn_close(vp, FWRITE);
2374 * Nonexistent system call-- signal process (may want to handle it).
2375 * Flag error in case process won't see signal immediately (blocked or ignored).
2381 sys_nosys(struct nosys_args *args)
2383 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2388 * Send a SIGIO or SIGURG signal to a process or process group using
2389 * stored credentials rather than those of the current process.
2392 pgsigio(struct sigio *sigio, int sig, int checkctty)
2397 if (sigio->sio_pgid > 0) {
2398 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2400 ksignal(sigio->sio_proc, sig);
2401 } else if (sigio->sio_pgid < 0) {
2403 struct pgrp *pg = sigio->sio_pgrp;
2406 * Must interlock all signals against fork
2409 lockmgr(&pg->pg_lock, LK_EXCLUSIVE);
2410 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
2411 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2412 (checkctty == 0 || (p->p_flags & P_CONTROLT)))
2415 lockmgr(&pg->pg_lock, LK_RELEASE);
2421 filt_sigattach(struct knote *kn)
2423 struct proc *p = curproc;
2425 kn->kn_ptr.p_proc = p;
2426 kn->kn_flags |= EV_CLEAR; /* automatically set */
2428 /* XXX lock the proc here while adding to the list? */
2429 knote_insert(&p->p_klist, kn);
2435 filt_sigdetach(struct knote *kn)
2437 struct proc *p = kn->kn_ptr.p_proc;
2439 knote_remove(&p->p_klist, kn);
2443 * signal knotes are shared with proc knotes, so we apply a mask to
2444 * the hint in order to differentiate them from process hints. This
2445 * could be avoided by using a signal-specific knote list, but probably
2446 * isn't worth the trouble.
2449 filt_signal(struct knote *kn, long hint)
2451 if (hint & NOTE_SIGNAL) {
2452 hint &= ~NOTE_SIGNAL;
2454 if (kn->kn_id == hint)
2457 return (kn->kn_data != 0);