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38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.90 2008/06/09 04:33:08 dillon Exp $
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/sysproto.h>
49 #include <sys/signalvar.h>
50 #include <sys/resourcevar.h>
51 #include <sys/vnode.h>
52 #include <sys/event.h>
54 #include <sys/nlookup.h>
55 #include <sys/pioctl.h>
56 #include <sys/systm.h>
58 #include <sys/fcntl.h>
61 #include <sys/ktrace.h>
62 #include <sys/syslog.h>
64 #include <sys/sysent.h>
65 #include <sys/sysctl.h>
66 #include <sys/malloc.h>
67 #include <sys/interrupt.h>
68 #include <sys/unistd.h>
69 #include <sys/kern_syscall.h>
70 #include <sys/vkernel.h>
72 #include <sys/signal2.h>
73 #include <sys/thread2.h>
74 #include <sys/mplock2.h>
76 #include <machine/cpu.h>
77 #include <machine/smp.h>
79 static int coredump(struct lwp *, int);
80 static char *expand_name(const char *, uid_t, pid_t);
81 static int dokillpg(int sig, int pgid, int all);
82 static int sig_ffs(sigset_t *set);
83 static int sigprop(int sig);
85 static void signotify_remote(void *arg);
87 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
88 struct timespec *timeout);
90 static int filt_sigattach(struct knote *kn);
91 static void filt_sigdetach(struct knote *kn);
92 static int filt_signal(struct knote *kn, long hint);
94 struct filterops sig_filtops =
95 { 0, filt_sigattach, filt_sigdetach, filt_signal };
97 static int kern_logsigexit = 1;
98 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
100 "Log processes quitting on abnormal signals to syslog(3)");
103 * Can process p, with pcred pc, send the signal sig to process q?
105 #define CANSIGNAL(q, sig) \
106 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
107 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
110 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
112 #define CANSIGIO(ruid, uc, q) \
113 ((uc)->cr_uid == 0 || \
114 (ruid) == (q)->p_ucred->cr_ruid || \
115 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
116 (ruid) == (q)->p_ucred->cr_uid || \
117 (uc)->cr_uid == (q)->p_ucred->cr_uid)
120 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
121 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
123 static int do_coredump = 1;
124 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
125 &do_coredump, 0, "Enable/Disable coredumps");
128 * Signal properties and actions.
129 * The array below categorizes the signals and their default actions
130 * according to the following properties:
132 #define SA_KILL 0x01 /* terminates process by default */
133 #define SA_CORE 0x02 /* ditto and coredumps */
134 #define SA_STOP 0x04 /* suspend process */
135 #define SA_TTYSTOP 0x08 /* ditto, from tty */
136 #define SA_IGNORE 0x10 /* ignore by default */
137 #define SA_CONT 0x20 /* continue if suspended */
138 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
139 #define SA_CKPT 0x80 /* checkpoint process */
142 static int sigproptbl[NSIG] = {
143 SA_KILL, /* SIGHUP */
144 SA_KILL, /* SIGINT */
145 SA_KILL|SA_CORE, /* SIGQUIT */
146 SA_KILL|SA_CORE, /* SIGILL */
147 SA_KILL|SA_CORE, /* SIGTRAP */
148 SA_KILL|SA_CORE, /* SIGABRT */
149 SA_KILL|SA_CORE, /* SIGEMT */
150 SA_KILL|SA_CORE, /* SIGFPE */
151 SA_KILL, /* SIGKILL */
152 SA_KILL|SA_CORE, /* SIGBUS */
153 SA_KILL|SA_CORE, /* SIGSEGV */
154 SA_KILL|SA_CORE, /* SIGSYS */
155 SA_KILL, /* SIGPIPE */
156 SA_KILL, /* SIGALRM */
157 SA_KILL, /* SIGTERM */
158 SA_IGNORE, /* SIGURG */
159 SA_STOP, /* SIGSTOP */
160 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
161 SA_IGNORE|SA_CONT, /* SIGCONT */
162 SA_IGNORE, /* SIGCHLD */
163 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
164 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
165 SA_IGNORE, /* SIGIO */
166 SA_KILL, /* SIGXCPU */
167 SA_KILL, /* SIGXFSZ */
168 SA_KILL, /* SIGVTALRM */
169 SA_KILL, /* SIGPROF */
170 SA_IGNORE, /* SIGWINCH */
171 SA_IGNORE, /* SIGINFO */
172 SA_KILL, /* SIGUSR1 */
173 SA_KILL, /* SIGUSR2 */
174 SA_IGNORE, /* SIGTHR */
175 SA_CKPT, /* SIGCKPT */
176 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
214 if (sig > 0 && sig < NSIG)
215 return (sigproptbl[_SIG_IDX(sig)]);
220 sig_ffs(sigset_t *set)
224 for (i = 0; i < _SIG_WORDS; i++)
226 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)
242 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
243 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
245 if (SIGISMEMBER(ps->ps_sigonstack, sig))
246 oact->sa_flags |= SA_ONSTACK;
247 if (!SIGISMEMBER(ps->ps_sigintr, sig))
248 oact->sa_flags |= SA_RESTART;
249 if (SIGISMEMBER(ps->ps_sigreset, sig))
250 oact->sa_flags |= SA_RESETHAND;
251 if (SIGISMEMBER(ps->ps_signodefer, sig))
252 oact->sa_flags |= SA_NODEFER;
253 if (SIGISMEMBER(ps->ps_siginfo, sig))
254 oact->sa_flags |= SA_SIGINFO;
255 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
256 oact->sa_flags |= SA_MAILBOX;
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)
271 /* (not needed, SIG_DFL forces action to occur) */
272 if (act->sa_flags & SA_MAILBOX)
278 * Change setting atomically.
282 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
283 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
284 if (act->sa_flags & SA_SIGINFO) {
285 ps->ps_sigact[_SIG_IDX(sig)] =
286 (__sighandler_t *)act->sa_sigaction;
287 SIGADDSET(ps->ps_siginfo, sig);
289 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
290 SIGDELSET(ps->ps_siginfo, sig);
292 if (!(act->sa_flags & SA_RESTART))
293 SIGADDSET(ps->ps_sigintr, sig);
295 SIGDELSET(ps->ps_sigintr, sig);
296 if (act->sa_flags & SA_ONSTACK)
297 SIGADDSET(ps->ps_sigonstack, sig);
299 SIGDELSET(ps->ps_sigonstack, sig);
300 if (act->sa_flags & SA_RESETHAND)
301 SIGADDSET(ps->ps_sigreset, sig);
303 SIGDELSET(ps->ps_sigreset, sig);
304 if (act->sa_flags & SA_NODEFER)
305 SIGADDSET(ps->ps_signodefer, sig);
307 SIGDELSET(ps->ps_signodefer, sig);
308 if (act->sa_flags & SA_MAILBOX)
309 SIGADDSET(ps->ps_sigmailbox, sig);
311 SIGDELSET(ps->ps_sigmailbox, sig);
312 if (sig == SIGCHLD) {
313 if (act->sa_flags & SA_NOCLDSTOP)
314 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
316 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
317 if (act->sa_flags & SA_NOCLDWAIT) {
319 * Paranoia: since SA_NOCLDWAIT is implemented
320 * by reparenting the dying child to PID 1 (and
321 * trust it to reap the zombie), PID 1 itself
322 * is forbidden to set SA_NOCLDWAIT.
325 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
327 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
329 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
333 * Set bit in p_sigignore for signals that are set to SIG_IGN,
334 * and for signals set to SIG_DFL where the default is to
335 * ignore. However, don't put SIGCONT in p_sigignore, as we
336 * have to restart the process.
338 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
339 (sigprop(sig) & SA_IGNORE &&
340 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
341 /* never to be seen again */
342 SIGDELSET(p->p_siglist, sig);
344 * Remove the signal also from the thread lists.
346 FOREACH_LWP_IN_PROC(lp, p) {
347 SIGDELSET(lp->lwp_siglist, sig);
350 /* easier in ksignal */
351 SIGADDSET(p->p_sigignore, sig);
352 SIGDELSET(p->p_sigcatch, sig);
354 SIGDELSET(p->p_sigignore, sig);
355 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
356 SIGDELSET(p->p_sigcatch, sig);
358 SIGADDSET(p->p_sigcatch, sig);
370 sys_sigaction(struct sigaction_args *uap)
372 struct sigaction act, oact;
373 struct sigaction *actp, *oactp;
376 actp = (uap->act != NULL) ? &act : NULL;
377 oactp = (uap->oact != NULL) ? &oact : NULL;
379 error = copyin(uap->act, actp, sizeof(act));
384 error = kern_sigaction(uap->sig, actp, oactp);
386 if (oactp && !error) {
387 error = copyout(oactp, uap->oact, sizeof(oact));
393 * Initialize signal state for process 0;
394 * set to ignore signals that are ignored by default.
397 siginit(struct proc *p)
401 for (i = 1; i <= NSIG; i++)
402 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
403 SIGADDSET(p->p_sigignore, i);
407 * Reset signals for an exec of the specified process.
410 execsigs(struct proc *p)
412 struct sigacts *ps = p->p_sigacts;
416 lp = ONLY_LWP_IN_PROC(p);
419 * Reset caught signals. Held signals remain held
420 * through p_sigmask (unless they were caught,
421 * and are now ignored by default).
423 while (SIGNOTEMPTY(p->p_sigcatch)) {
424 sig = sig_ffs(&p->p_sigcatch);
425 SIGDELSET(p->p_sigcatch, sig);
426 if (sigprop(sig) & SA_IGNORE) {
428 SIGADDSET(p->p_sigignore, sig);
429 SIGDELSET(p->p_siglist, sig);
430 SIGDELSET(lp->lwp_siglist, sig);
432 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
436 * Reset stack state to the user stack.
437 * Clear set of signals caught on the signal stack.
439 lp->lwp_sigstk.ss_flags = SS_DISABLE;
440 lp->lwp_sigstk.ss_size = 0;
441 lp->lwp_sigstk.ss_sp = 0;
442 lp->lwp_flag &= ~LWP_ALTSTACK;
444 * Reset no zombies if child dies flag as Solaris does.
446 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
450 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
452 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
456 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
458 struct thread *td = curthread;
459 struct lwp *lp = td->td_lwp;
463 *oset = lp->lwp_sigmask;
470 SIGSETOR(lp->lwp_sigmask, *set);
473 SIGSETNAND(lp->lwp_sigmask, *set);
477 lp->lwp_sigmask = *set;
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_flag |= 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_flag & 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_flag &= ~LWP_ALTSTACK;
616 lp->lwp_sigstk.ss_flags = ss->ss_flags;
618 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
620 lp->lwp_flag |= 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.
689 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
690 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
692 p->p_stat == SZOMB ||
693 (p->p_flag & P_SYSTEM) ||
694 !CANSIGNAL(p, sig)) {
701 lockmgr(&pgrp->pg_lock, LK_RELEASE);
703 return (info.nfound ? 0 : ESRCH);
707 killpg_all_callback(struct proc *p, void *data)
709 struct killpg_info *info = data;
711 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
712 p == curproc || !CANSIGNAL(p, info->sig)) {
717 ksignal(p, info->sig);
722 * Send a general signal to a process or LWPs within that process. Note
723 * that new signals cannot be sent if a process is exiting.
726 kern_kill(int sig, pid_t pid, lwpid_t tid)
728 if ((u_int)sig > _SIG_MAXSIG)
732 struct lwp *lp = NULL;
734 /* kill single process */
735 if ((p = pfind(pid)) == NULL)
737 if (!CANSIGNAL(p, sig))
741 * NOP if the process is exiting. Note that lwpsignal() is
742 * called directly with P_WEXIT set to kill individual LWPs
743 * during exit, which is allowed.
745 if (p->p_flag & P_WEXIT)
748 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
753 lwpsignal(p, lp, sig);
757 * If we come here, pid is a special broadcast pid.
758 * This doesn't mix with a tid.
763 case -1: /* broadcast signal */
764 return (dokillpg(sig, 0, 1));
765 case 0: /* signal own process group */
766 return (dokillpg(sig, 0, 0));
767 default: /* negative explicit process group */
768 return (dokillpg(sig, -pid, 0));
777 sys_kill(struct kill_args *uap)
782 error = kern_kill(uap->signum, uap->pid, -1);
791 sys_lwp_kill(struct lwp_kill_args *uap)
794 pid_t pid = uap->pid;
797 * A tid is mandatory for lwp_kill(), otherwise
798 * you could simply use kill().
804 * To save on a getpid() function call for intra-process
805 * signals, pid == -1 means current process.
808 pid = curproc->p_pid;
811 error = kern_kill(uap->signum, pid, uap->tid);
817 * Send a signal to a process group.
820 gsignal(int pgid, int sig)
824 if (pgid && (pgrp = pgfind(pgid)))
825 pgsignal(pgrp, sig, 0);
829 * Send a signal to a process group. If checktty is 1,
830 * limit to members which have a controlling terminal.
832 * pg_lock interlocks against a fork that might be in progress, to
833 * ensure that the new child process picks up the signal.
836 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
841 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
842 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
843 if (checkctty == 0 || p->p_flag & P_CONTROLT)
846 lockmgr(&pgrp->pg_lock, LK_RELEASE);
851 * Send a signal caused by a trap to the current lwp. If it will be caught
852 * immediately, deliver it with correct code. Otherwise, post it normally.
854 * These signals may ONLY be delivered to the specified lwp and may never
855 * be delivered to the process generically.
858 trapsignal(struct lwp *lp, int sig, u_long code)
860 struct proc *p = lp->lwp_proc;
861 struct sigacts *ps = p->p_sigacts;
864 * If we are a virtual kernel running an emulated user process
865 * context, switch back to the virtual kernel context before
866 * trying to post the signal.
868 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
869 struct trapframe *tf = lp->lwp_md.md_regs;
871 vkernel_trap(lp, tf);
875 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
876 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
877 lp->lwp_ru.ru_nsignals++;
879 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
880 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
881 &lp->lwp_sigmask, code);
883 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
884 &lp->lwp_sigmask, code);
885 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
886 if (!SIGISMEMBER(ps->ps_signodefer, sig))
887 SIGADDSET(lp->lwp_sigmask, sig);
888 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
890 * See kern_sigaction() for origin of this code.
892 SIGDELSET(p->p_sigcatch, sig);
893 if (sig != SIGCONT &&
894 sigprop(sig) & SA_IGNORE)
895 SIGADDSET(p->p_sigignore, sig);
896 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
899 lp->lwp_code = code; /* XXX for core dump/debugger */
900 lp->lwp_sig = sig; /* XXX to verify code */
901 lwpsignal(p, lp, sig);
906 * Find a suitable lwp to deliver the signal to.
908 * Returns NULL if all lwps hold the signal blocked.
911 find_lwp_for_signal(struct proc *p, int sig)
914 struct lwp *run, *sleep, *stop;
917 * If the running/preempted thread belongs to the proc to which
918 * the signal is being delivered and this thread does not block
919 * the signal, then we can avoid a context switch by delivering
920 * the signal to this thread, because it will return to userland
923 lp = lwkt_preempted_proc();
924 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
927 run = sleep = stop = NULL;
928 FOREACH_LWP_IN_PROC(lp, p) {
930 * If the signal is being blocked by the lwp, then this
931 * lwp is not eligible for receiving the signal.
933 if (SIGISMEMBER(lp->lwp_sigmask, sig))
936 switch (lp->lwp_stat) {
946 if (lp->lwp_flag & LWP_SINTR)
954 else if (sleep != NULL)
961 * Send the signal to the process. If the signal has an action, the action
962 * is usually performed by the target process rather than the caller; we add
963 * the signal to the set of pending signals for the process.
966 * o When a stop signal is sent to a sleeping process that takes the
967 * default action, the process is stopped without awakening it.
968 * o SIGCONT restarts stopped processes (or puts them back to sleep)
969 * regardless of the signal action (eg, blocked or ignored).
971 * Other ignored signals are discarded immediately.
974 ksignal(struct proc *p, int sig)
976 lwpsignal(p, NULL, sig);
980 * The core for ksignal. lp may be NULL, then a suitable thread
981 * will be chosen. If not, lp MUST be a member of p.
984 lwpsignal(struct proc *p, struct lwp *lp, int sig)
989 if (sig > _SIG_MAXSIG || sig <= 0) {
990 kprintf("lwpsignal: signal %d\n", sig);
991 panic("lwpsignal signal number");
994 KKASSERT(lp == NULL || lp->lwp_proc == p);
999 * If proc is traced, always give parent a chance;
1000 * if signal event is tracked by procfs, give *that*
1001 * a chance, as well.
1003 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1007 * Do not try to deliver signals to an exiting lwp. Note
1008 * that we must still deliver the signal if P_WEXIT is set
1009 * in the process flags.
1011 if (lp && (lp->lwp_flag & LWP_WEXIT))
1015 * If the signal is being ignored, then we forget about
1016 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1017 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1019 if (SIGISMEMBER(p->p_sigignore, sig))
1021 if (SIGISMEMBER(p->p_sigcatch, sig))
1028 * If continuing, clear any pending STOP signals.
1031 SIG_STOPSIGMASK(p->p_siglist);
1033 if (prop & SA_STOP) {
1035 * If sending a tty stop signal to a member of an orphaned
1036 * process group, discard the signal here if the action
1037 * is default; don't stop the process below if sleeping,
1038 * and don't clear any pending SIGCONT.
1040 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1041 action == SIG_DFL) {
1044 SIG_CONTSIGMASK(p->p_siglist);
1045 p->p_flag &= ~P_CONTINUED;
1050 if (p->p_stat == SSTOP) {
1052 * Nobody can handle this signal, add it to the lwp or
1053 * process pending list
1056 SIGADDSET(lp->lwp_siglist, sig);
1058 SIGADDSET(p->p_siglist, sig);
1061 * If the process is stopped and is being traced, then no
1062 * further action is necessary.
1064 if (p->p_flag & P_TRACED)
1068 * If the process is stopped and receives a KILL signal,
1069 * make the process runnable.
1071 if (sig == SIGKILL) {
1073 goto active_process;
1077 * If the process is stopped and receives a CONT signal,
1078 * then try to make the process runnable again.
1080 if (prop & SA_CONT) {
1082 * If SIGCONT is default (or ignored), we continue the
1083 * process but don't leave the signal in p_siglist, as
1084 * it has no further action. If SIGCONT is held, we
1085 * continue the process and leave the signal in
1086 * p_siglist. If the process catches SIGCONT, let it
1087 * handle the signal itself.
1089 /* XXX what if the signal is being held blocked? */
1090 p->p_flag |= P_CONTINUED;
1092 if (action == SIG_DFL)
1093 SIGDELSET(p->p_siglist, sig);
1095 if (action == SIG_CATCH)
1096 goto active_process;
1101 * If the process is stopped and receives another STOP
1102 * signal, we do not need to stop it again. If we did
1103 * the shell could get confused.
1105 * However, if the current/preempted lwp is part of the
1106 * process receiving the signal, we need to keep it,
1107 * so that this lwp can stop in issignal() later, as
1108 * we don't want to wait until it reaches userret!
1110 if (prop & SA_STOP) {
1111 if (lwkt_preempted_proc() == NULL ||
1112 lwkt_preempted_proc()->lwp_proc != p)
1113 SIGDELSET(p->p_siglist, sig);
1117 * Otherwise the process is stopped and it received some
1118 * signal, which does not change its stopped state.
1120 * We have to select one thread to set LWP_BREAKTSLEEP,
1121 * so that the current signal will break the sleep
1122 * as soon as a SA_CONT signal will unstop the process.
1125 lp = find_lwp_for_signal(p, sig);
1127 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1128 lp->lwp_flag |= LWP_BREAKTSLEEP;
1133 /* else not stopped */
1137 * Never deliver a lwp-specific signal to a random lwp.
1140 lp = find_lwp_for_signal(p, sig);
1141 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1146 * Deliver to the process generically if (1) the signal is being
1147 * sent to any thread or (2) we could not find a thread to deliver
1151 SIGADDSET(p->p_siglist, sig);
1156 * Deliver to a specific LWP whether it masks it or not. It will
1157 * not be dispatched if masked but we must still deliver it.
1159 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1160 (p->p_flag & P_TRACED) == 0) {
1165 * If the process receives a STOP signal which indeed needs to
1166 * stop the process, do so. If the process chose to catch the
1167 * signal, it will be treated like any other signal.
1169 if ((prop & SA_STOP) && action == SIG_DFL) {
1171 * If a child holding parent blocked, stopping
1172 * could cause deadlock. Take no action at this
1175 if (p->p_flag & P_PPWAIT) {
1176 SIGADDSET(p->p_siglist, sig);
1181 * Do not actually try to manipulate the process, but simply
1182 * stop it. Lwps will stop as soon as they safely can.
1190 * If it is a CONT signal with default action, just ignore it.
1192 if ((prop & SA_CONT) && action == SIG_DFL)
1196 * Mark signal pending at this specific thread.
1198 SIGADDSET(lp->lwp_siglist, sig);
1207 lwp_signotify(struct lwp *lp)
1210 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1212 * Thread is in tsleep.
1216 * If the thread is sleeping uninterruptibly
1217 * we can't interrupt the sleep... the signal will
1218 * be noticed when the lwp returns through
1219 * trap() or syscall().
1221 * Otherwise the signal can interrupt the sleep.
1223 * If the process is traced, the lwp will handle the
1224 * tracing in issignal() when it returns to userland.
1226 if (lp->lwp_flag & LWP_SINTR) {
1228 * Make runnable and break out of any tsleep as well.
1230 lp->lwp_flag |= LWP_BREAKTSLEEP;
1235 * Otherwise the thread is running
1237 * LSRUN does nothing with the signal, other than kicking
1238 * ourselves if we are running.
1239 * SZOMB and SIDL mean that it will either never be noticed,
1240 * or noticed very soon.
1242 * Note that lwp_thread may be NULL or may not be completely
1243 * initialized if the process is in the SIDL or SZOMB state.
1245 * For SMP we may have to forward the request to another cpu.
1246 * YYY the MP lock prevents the target process from moving
1247 * to another cpu, see kern/kern_switch.c
1249 * If the target thread is waiting on its message port,
1250 * wakeup the target thread so it can check (or ignore)
1251 * the new signal. YYY needs cleanup.
1253 if (lp == lwkt_preempted_proc()) {
1255 } else if (lp->lwp_stat == LSRUN) {
1256 struct thread *td = lp->lwp_thread;
1257 struct proc *p __debugvar = lp->lwp_proc;
1260 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1261 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1262 p->p_flag, lp->lwp_flag));
1265 * To prevent a MP race with TDF_SINTR we must
1266 * schedule the thread on the correct cpu.
1269 if (td->td_gd != mycpu) {
1271 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1274 if (td->td_flags & TDF_SINTR)
1284 * This function is called via an IPI. We will be in a critical section but
1285 * the MP lock will NOT be held. Also note that by the time the ipi message
1286 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1289 signotify_remote(void *arg)
1291 struct lwp *lp = arg;
1293 if (lp == lwkt_preempted_proc()) {
1296 struct thread *td = lp->lwp_thread;
1297 if (td->td_flags & TDF_SINTR)
1306 proc_stop(struct proc *p)
1310 /* If somebody raced us, be happy with it */
1311 if (p->p_stat == SSTOP || p->p_stat == SZOMB)
1317 FOREACH_LWP_IN_PROC(lp, p) {
1318 switch (lp->lwp_stat) {
1321 * Do nothing, we are already counted in
1328 * We're sleeping, but we will stop before
1329 * returning to userspace, so count us
1330 * as stopped as well. We set LWP_WSTOP
1331 * to signal the lwp that it should not
1332 * increase p_nstopped when reaching tstop().
1334 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1335 lp->lwp_flag |= LWP_WSTOP;
1342 * We might notify ourself, but that's not
1350 if (p->p_nstopped == p->p_nthreads) {
1351 p->p_flag &= ~P_WAITED;
1353 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1354 ksignal(p->p_pptr, SIGCHLD);
1360 proc_unstop(struct proc *p)
1364 if (p->p_stat != SSTOP)
1368 p->p_stat = SACTIVE;
1370 FOREACH_LWP_IN_PROC(lp, p) {
1371 switch (lp->lwp_stat) {
1374 * Uh? Not stopped? Well, I guess that's okay.
1377 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1378 p->p_pid, lp->lwp_tid);
1383 * Still sleeping. Don't bother waking it up.
1384 * However, if this thread was counted as
1385 * stopped, undo this.
1387 * Nevertheless we call setrunnable() so that it
1388 * will wake up in case a signal or timeout arrived
1391 if (lp->lwp_flag & LWP_WSTOP) {
1392 lp->lwp_flag &= ~LWP_WSTOP;
1396 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1397 p->p_pid, lp->lwp_tid);
1411 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1413 sigset_t savedmask, set;
1414 struct proc *p = curproc;
1415 struct lwp *lp = curthread->td_lwp;
1416 int error, sig, hz, timevalid = 0;
1417 struct timespec rts, ets, ts;
1422 ets.tv_sec = 0; /* silence compiler warning */
1423 ets.tv_nsec = 0; /* silence compiler warning */
1424 SIG_CANTMASK(waitset);
1425 savedmask = lp->lwp_sigmask;
1428 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1429 timeout->tv_nsec < 1000000000) {
1431 getnanouptime(&rts);
1433 timespecadd(&ets, timeout);
1438 set = lwp_sigpend(lp);
1439 SIGSETAND(set, waitset);
1440 if ((sig = sig_ffs(&set)) != 0) {
1441 SIGFILLSET(lp->lwp_sigmask);
1442 SIGDELSET(lp->lwp_sigmask, sig);
1443 SIG_CANTMASK(lp->lwp_sigmask);
1444 sig = issignal(lp, 1);
1446 * It may be a STOP signal, in the case, issignal
1447 * returns 0, because we may stop there, and new
1448 * signal can come in, we should restart if we got
1458 * Previous checking got nothing, and we retried but still
1459 * got nothing, we should return the error status.
1465 * POSIX says this must be checked after looking for pending
1469 if (timevalid == 0) {
1473 getnanouptime(&rts);
1474 if (timespeccmp(&rts, &ets, >=)) {
1479 timespecsub(&ts, &rts);
1480 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1481 hz = tvtohz_high(&tv);
1485 lp->lwp_sigmask = savedmask;
1486 SIGSETNAND(lp->lwp_sigmask, waitset);
1488 * We won't ever be woken up. Instead, our sleep will
1489 * be broken in lwpsignal().
1491 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1493 if (error == ERESTART) {
1494 /* can not restart a timeout wait. */
1496 } else if (error == EAGAIN) {
1497 /* will calculate timeout by ourself. */
1504 lp->lwp_sigmask = savedmask;
1507 bzero(info, sizeof(*info));
1508 info->si_signo = sig;
1509 lwp_delsig(lp, sig); /* take the signal! */
1521 sys_sigtimedwait(struct sigtimedwait_args *uap)
1524 struct timespec *timeout;
1530 error = copyin(uap->timeout, &ts, sizeof(ts));
1537 error = copyin(uap->set, &set, sizeof(set));
1541 error = kern_sigtimedwait(set, &info, timeout);
1546 error = copyout(&info, uap->info, sizeof(info));
1547 /* Repost if we got an error. */
1551 * This could transform a thread-specific signal to another
1552 * thread / process pending signal.
1556 ksignal(curproc, info.si_signo);
1559 uap->sysmsg_result = info.si_signo;
1568 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1574 error = copyin(uap->set, &set, sizeof(set));
1578 error = kern_sigtimedwait(set, &info, NULL);
1583 error = copyout(&info, uap->info, sizeof(info));
1584 /* Repost if we got an error. */
1588 * This could transform a thread-specific signal to another
1589 * thread / process pending signal.
1593 ksignal(curproc, info.si_signo);
1596 uap->sysmsg_result = info.si_signo;
1602 * If the current process has received a signal that would interrupt a
1603 * system call, return EINTR or ERESTART as appropriate.
1606 iscaught(struct lwp *lp)
1608 struct proc *p = lp->lwp_proc;
1612 if ((sig = CURSIG(lp)) != 0) {
1613 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1618 return(EWOULDBLOCK);
1622 * If the current process has received a signal (should be caught or cause
1623 * termination, should interrupt current syscall), return the signal number.
1624 * Stop signals with default action are processed immediately, then cleared;
1625 * they aren't returned. This is checked after each entry to the system for
1626 * a syscall or trap (though this can usually be done without calling issignal
1627 * by checking the pending signal masks in the CURSIG macro.) The normal call
1630 * This routine is called via CURSIG/__cursig and the MP lock might not be
1631 * held. Obtain the MP lock for the duration of the operation.
1633 * while (sig = CURSIG(curproc))
1637 issignal(struct lwp *lp, int maytrace)
1639 struct proc *p = lp->lwp_proc;
1645 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1648 * If this process is supposed to stop, stop this thread.
1650 if (p->p_stat == SSTOP)
1653 mask = lwp_sigpend(lp);
1654 SIGSETNAND(mask, lp->lwp_sigmask);
1655 if (p->p_flag & P_PPWAIT)
1656 SIG_STOPSIGMASK(mask);
1657 if (SIGISEMPTY(mask)) { /* no signal to send */
1661 sig = sig_ffs(&mask);
1663 STOPEVENT(p, S_SIG, sig);
1666 * We should see pending but ignored signals
1667 * only if P_TRACED was on when they were posted.
1669 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1670 lwp_delsig(lp, sig);
1673 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1675 * If traced, always stop, and stay stopped until
1676 * released by the parent.
1678 * NOTE: SSTOP may get cleared during the loop,
1679 * but we do not re-notify the parent if we have
1680 * to loop several times waiting for the parent
1681 * to let us continue.
1683 * XXX not sure if this is still true
1689 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1692 * If parent wants us to take the signal,
1693 * then it will leave it in p->p_xstat;
1694 * otherwise we just look for signals again.
1696 lwp_delsig(lp, sig); /* clear old signal */
1702 * Put the new signal into p_siglist. If the
1703 * signal is being masked, look for other signals.
1705 * XXX lwp might need a call to ksignal()
1707 SIGADDSET(p->p_siglist, sig);
1708 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1712 * If the traced bit got turned off, go back up
1713 * to the top to rescan signals. This ensures
1714 * that p_sig* and ps_sigact are consistent.
1716 if ((p->p_flag & P_TRACED) == 0)
1720 prop = sigprop(sig);
1723 * Decide whether the signal should be returned.
1724 * Return the signal's number, or fall through
1725 * to clear it from the pending mask.
1727 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1728 case (intptr_t)SIG_DFL:
1730 * Don't take default actions on system processes.
1732 if (p->p_pid <= 1) {
1735 * Are you sure you want to ignore SIGSEGV
1738 kprintf("Process (pid %lu) got signal %d\n",
1739 (u_long)p->p_pid, sig);
1741 break; /* == ignore */
1745 * Handle the in-kernel checkpoint action
1747 if (prop & SA_CKPT) {
1748 checkpoint_signal_handler(lp);
1753 * If there is a pending stop signal to process
1754 * with default action, stop here,
1755 * then clear the signal. However,
1756 * if process is member of an orphaned
1757 * process group, ignore tty stop signals.
1759 if (prop & SA_STOP) {
1760 if (p->p_flag & P_TRACED ||
1761 (p->p_pgrp->pg_jobc == 0 &&
1763 break; /* == ignore */
1768 } else if (prop & SA_IGNORE) {
1770 * Except for SIGCONT, shouldn't get here.
1771 * Default action is to ignore; drop it.
1773 break; /* == ignore */
1781 case (intptr_t)SIG_IGN:
1783 * Masking above should prevent us ever trying
1784 * to take action on an ignored signal other
1785 * than SIGCONT, unless process is traced.
1787 if ((prop & SA_CONT) == 0 &&
1788 (p->p_flag & P_TRACED) == 0)
1789 kprintf("issignal\n");
1790 break; /* == ignore */
1794 * This signal has an action, let
1795 * postsig() process it.
1800 lwp_delsig(lp, sig); /* take the signal! */
1806 * Take the action for the specified signal
1807 * from the current set of pending signals.
1812 struct lwp *lp = curthread->td_lwp;
1813 struct proc *p = lp->lwp_proc;
1814 struct sigacts *ps = p->p_sigacts;
1816 sigset_t returnmask;
1819 KASSERT(sig != 0, ("postsig"));
1821 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1824 * If we are a virtual kernel running an emulated user process
1825 * context, switch back to the virtual kernel context before
1826 * trying to post the signal.
1828 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1829 struct trapframe *tf = lp->lwp_md.md_regs;
1831 vkernel_trap(lp, tf);
1834 lwp_delsig(lp, sig);
1835 action = ps->ps_sigact[_SIG_IDX(sig)];
1837 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1838 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1839 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1841 STOPEVENT(p, S_SIG, sig);
1843 if (action == SIG_DFL) {
1845 * Default action, where the default is to kill
1846 * the process. (Other cases were ignored above.)
1852 * If we get here, the signal must be caught.
1854 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1855 ("postsig action"));
1860 * Reset the signal handler if asked to
1862 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1864 * See kern_sigaction() for origin of this code.
1866 SIGDELSET(p->p_sigcatch, sig);
1867 if (sig != SIGCONT &&
1868 sigprop(sig) & SA_IGNORE)
1869 SIGADDSET(p->p_sigignore, sig);
1870 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1874 * Handle the mailbox case. Copyout to the appropriate
1875 * location but do not generate a signal frame. The system
1876 * call simply returns EINTR and the user is responsible for
1877 * polling the mailbox.
1879 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1881 copyout(&sig_copy, (void *)action, sizeof(int));
1882 curproc->p_flag |= P_MAILBOX;
1888 * Set the signal mask and calculate the mask to restore
1889 * when the signal function returns.
1891 * Special case: user has done a sigsuspend. Here the
1892 * current mask is not of interest, but rather the
1893 * mask from before the sigsuspend is what we want
1894 * restored after the signal processing is completed.
1896 if (lp->lwp_flag & LWP_OLDMASK) {
1897 returnmask = lp->lwp_oldsigmask;
1898 lp->lwp_flag &= ~LWP_OLDMASK;
1900 returnmask = lp->lwp_sigmask;
1903 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1904 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1905 SIGADDSET(lp->lwp_sigmask, sig);
1908 lp->lwp_ru.ru_nsignals++;
1909 if (lp->lwp_sig != sig) {
1912 code = lp->lwp_code;
1916 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1923 * Kill the current process for stated reason.
1926 killproc(struct proc *p, char *why)
1928 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1929 p->p_pid, p->p_comm,
1930 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1931 ksignal(p, SIGKILL);
1935 * Force the current process to exit with the specified signal, dumping core
1936 * if appropriate. We bypass the normal tests for masked and caught signals,
1937 * allowing unrecoverable failures to terminate the process without changing
1938 * signal state. Mark the accounting record with the signal termination.
1939 * If dumping core, save the signal number for the debugger. Calls exit and
1943 sigexit(struct lwp *lp, int sig)
1945 struct proc *p = lp->lwp_proc;
1947 p->p_acflag |= AXSIG;
1948 if (sigprop(sig) & SA_CORE) {
1951 * Log signals which would cause core dumps
1952 * (Log as LOG_INFO to appease those who don't want
1954 * XXX : Todo, as well as euid, write out ruid too
1956 if (coredump(lp, sig) == 0)
1958 if (kern_logsigexit)
1960 "pid %d (%s), uid %d: exited on signal %d%s\n",
1961 p->p_pid, p->p_comm,
1962 p->p_ucred ? p->p_ucred->cr_uid : -1,
1964 sig & WCOREFLAG ? " (core dumped)" : "");
1966 exit1(W_EXITCODE(0, sig));
1970 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1971 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1972 sizeof(corefilename), "process corefile name format string");
1975 * expand_name(name, uid, pid)
1976 * Expand the name described in corefilename, using name, uid, and pid.
1977 * corefilename is a kprintf-like string, with three format specifiers:
1978 * %N name of process ("name")
1979 * %P process id (pid)
1981 * For example, "%N.core" is the default; they can be disabled completely
1982 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1983 * This is controlled by the sysctl variable kern.corefile (see above).
1987 expand_name(const char *name, uid_t uid, pid_t pid)
1990 char buf[11]; /* Buffer for pid/uid -- max 4B */
1992 char *format = corefilename;
1995 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1998 namelen = strlen(name);
1999 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2001 switch (format[i]) {
2002 case '%': /* Format character */
2004 switch (format[i]) {
2008 case 'N': /* process name */
2009 if ((n + namelen) > MAXPATHLEN) {
2010 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2011 pid, name, uid, temp, name);
2012 kfree(temp, M_TEMP);
2015 memcpy(temp+n, name, namelen);
2018 case 'P': /* process id */
2019 l = ksprintf(buf, "%u", pid);
2020 if ((n + l) > MAXPATHLEN) {
2021 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2022 pid, name, uid, temp, name);
2023 kfree(temp, M_TEMP);
2026 memcpy(temp+n, buf, l);
2029 case 'U': /* user id */
2030 l = ksprintf(buf, "%u", uid);
2031 if ((n + l) > MAXPATHLEN) {
2032 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2033 pid, name, uid, temp, name);
2034 kfree(temp, M_TEMP);
2037 memcpy(temp+n, buf, l);
2041 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2045 temp[n++] = format[i];
2053 * Dump a process' core. The main routine does some
2054 * policy checking, and creates the name of the coredump;
2055 * then it passes on a vnode and a size limit to the process-specific
2056 * coredump routine if there is one; if there _is not_ one, it returns
2057 * ENOSYS; otherwise it returns the error from the process-specific routine.
2059 * The parameter `lp' is the lwp which triggered the coredump.
2063 coredump(struct lwp *lp, int sig)
2065 struct proc *p = lp->lwp_proc;
2067 struct ucred *cred = p->p_ucred;
2069 struct nlookupdata nd;
2072 char *name; /* name of corefile */
2075 STOPEVENT(p, S_CORE, 0);
2077 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2081 * Note that the bulk of limit checking is done after
2082 * the corefile is created. The exception is if the limit
2083 * for corefiles is 0, in which case we don't bother
2084 * creating the corefile at all. This layout means that
2085 * a corefile is truncated instead of not being created,
2086 * if it is larger than the limit.
2088 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2092 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2095 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2097 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2098 kfree(name, M_TEMP);
2104 nd.nl_open_vp = NULL;
2108 lf.l_whence = SEEK_SET;
2111 lf.l_type = F_WRLCK;
2112 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2116 /* Don't dump to non-regular files or files with links. */
2117 if (vp->v_type != VREG ||
2118 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2123 /* Don't dump to files current user does not own */
2124 if (vattr.va_uid != p->p_ucred->cr_uid) {
2130 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2132 VOP_SETATTR(vp, &vattr, cred);
2133 p->p_acflag |= ACORE;
2136 error = p->p_sysent->sv_coredump ?
2137 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2140 lf.l_type = F_UNLCK;
2141 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2143 error1 = vn_close(vp, FWRITE);
2150 * Nonexistent system call-- signal process (may want to handle it).
2151 * Flag error in case process won't see signal immediately (blocked or ignored).
2157 sys_nosys(struct nosys_args *args)
2160 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2166 * Send a SIGIO or SIGURG signal to a process or process group using
2167 * stored credentials rather than those of the current process.
2170 pgsigio(struct sigio *sigio, int sig, int checkctty)
2175 if (sigio->sio_pgid > 0) {
2176 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2178 ksignal(sigio->sio_proc, sig);
2179 } else if (sigio->sio_pgid < 0) {
2182 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2183 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2184 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2185 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2188 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2193 filt_sigattach(struct knote *kn)
2195 struct proc *p = curproc;
2197 kn->kn_ptr.p_proc = p;
2198 kn->kn_flags |= EV_CLEAR; /* automatically set */
2200 /* XXX lock the proc here while adding to the list? */
2201 knote_insert(&p->p_klist, kn);
2207 filt_sigdetach(struct knote *kn)
2209 struct proc *p = kn->kn_ptr.p_proc;
2211 knote_remove(&p->p_klist, kn);
2215 * signal knotes are shared with proc knotes, so we apply a mask to
2216 * the hint in order to differentiate them from process hints. This
2217 * could be avoided by using a signal-specific knote list, but probably
2218 * isn't worth the trouble.
2221 filt_signal(struct knote *kn, long hint)
2223 if (hint & NOTE_SIGNAL) {
2224 hint &= ~NOTE_SIGNAL;
2226 if (kn->kn_id == hint)
2229 return (kn->kn_data != 0);