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5 * All or some portions of this file are derived from material licensed
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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>
55 #include <sys/systm.h>
57 #include <sys/fcntl.h>
60 #include <sys/ktrace.h>
61 #include <sys/syslog.h>
63 #include <sys/sysent.h>
64 #include <sys/sysctl.h>
65 #include <sys/malloc.h>
66 #include <sys/interrupt.h>
67 #include <sys/unistd.h>
68 #include <sys/kern_syscall.h>
69 #include <sys/vkernel.h>
71 #include <sys/signal2.h>
72 #include <sys/thread2.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 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(&proc_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 (SIGISMEMBER(ps->ps_sigmailbox, sig))
260 oact->sa_flags |= SA_MAILBOX;
261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
262 oact->sa_flags |= SA_NOCLDSTOP;
263 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
264 oact->sa_flags |= SA_NOCLDWAIT;
268 * Check for invalid requests. KILL and STOP cannot be
271 if (sig == SIGKILL || sig == SIGSTOP) {
272 if (act->sa_handler != SIG_DFL) {
273 lwkt_reltoken(&proc_token);
277 /* (not needed, SIG_DFL forces action to occur) */
278 if (act->sa_flags & SA_MAILBOX)
284 * Change setting atomically.
288 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
289 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
290 if (act->sa_flags & SA_SIGINFO) {
291 ps->ps_sigact[_SIG_IDX(sig)] =
292 (__sighandler_t *)act->sa_sigaction;
293 SIGADDSET(ps->ps_siginfo, sig);
295 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
296 SIGDELSET(ps->ps_siginfo, sig);
298 if (!(act->sa_flags & SA_RESTART))
299 SIGADDSET(ps->ps_sigintr, sig);
301 SIGDELSET(ps->ps_sigintr, sig);
302 if (act->sa_flags & SA_ONSTACK)
303 SIGADDSET(ps->ps_sigonstack, sig);
305 SIGDELSET(ps->ps_sigonstack, sig);
306 if (act->sa_flags & SA_RESETHAND)
307 SIGADDSET(ps->ps_sigreset, sig);
309 SIGDELSET(ps->ps_sigreset, sig);
310 if (act->sa_flags & SA_NODEFER)
311 SIGADDSET(ps->ps_signodefer, sig);
313 SIGDELSET(ps->ps_signodefer, sig);
314 if (act->sa_flags & SA_MAILBOX)
315 SIGADDSET(ps->ps_sigmailbox, sig);
317 SIGDELSET(ps->ps_sigmailbox, sig);
318 if (sig == SIGCHLD) {
319 if (act->sa_flags & SA_NOCLDSTOP)
320 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
322 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
323 if (act->sa_flags & SA_NOCLDWAIT) {
325 * Paranoia: since SA_NOCLDWAIT is implemented
326 * by reparenting the dying child to PID 1 (and
327 * trust it to reap the zombie), PID 1 itself
328 * is forbidden to set SA_NOCLDWAIT.
331 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
333 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
335 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
339 * Set bit in p_sigignore for signals that are set to SIG_IGN,
340 * and for signals set to SIG_DFL where the default is to
341 * ignore. However, don't put SIGCONT in p_sigignore, as we
342 * have to restart the process.
344 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
345 (sigprop(sig) & SA_IGNORE &&
346 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
347 /* never to be seen again */
348 SIGDELSET(p->p_siglist, sig);
350 * Remove the signal also from the thread lists.
352 FOREACH_LWP_IN_PROC(lp, p) {
353 SIGDELSET(lp->lwp_siglist, sig);
356 /* easier in ksignal */
357 SIGADDSET(p->p_sigignore, sig);
358 SIGDELSET(p->p_sigcatch, sig);
360 SIGDELSET(p->p_sigignore, sig);
361 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
362 SIGDELSET(p->p_sigcatch, sig);
364 SIGADDSET(p->p_sigcatch, sig);
369 lwkt_reltoken(&proc_token);
374 sys_sigaction(struct sigaction_args *uap)
376 struct sigaction act, oact;
377 struct sigaction *actp, *oactp;
380 actp = (uap->act != NULL) ? &act : NULL;
381 oactp = (uap->oact != NULL) ? &oact : NULL;
383 error = copyin(uap->act, actp, sizeof(act));
387 error = kern_sigaction(uap->sig, actp, oactp);
388 if (oactp && !error) {
389 error = copyout(oactp, uap->oact, sizeof(oact));
395 * Initialize signal state for process 0;
396 * set to ignore signals that are ignored by default.
399 siginit(struct proc *p)
403 for (i = 1; i <= NSIG; i++)
404 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
405 SIGADDSET(p->p_sigignore, i);
409 * Reset signals for an exec of the specified process.
412 execsigs(struct proc *p)
414 struct sigacts *ps = p->p_sigacts;
418 lp = ONLY_LWP_IN_PROC(p);
421 * Reset caught signals. Held signals remain held
422 * through p_sigmask (unless they were caught,
423 * and are now ignored by default).
425 while (SIGNOTEMPTY(p->p_sigcatch)) {
426 sig = sig_ffs(&p->p_sigcatch);
427 SIGDELSET(p->p_sigcatch, sig);
428 if (sigprop(sig) & SA_IGNORE) {
430 SIGADDSET(p->p_sigignore, sig);
431 SIGDELSET(p->p_siglist, sig);
432 SIGDELSET(lp->lwp_siglist, sig);
434 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
438 * Reset stack state to the user stack.
439 * Clear set of signals caught on the signal stack.
441 lp->lwp_sigstk.ss_flags = SS_DISABLE;
442 lp->lwp_sigstk.ss_size = 0;
443 lp->lwp_sigstk.ss_sp = 0;
444 lp->lwp_flag &= ~LWP_ALTSTACK;
446 * Reset no zombies if child dies flag as Solaris does.
448 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
452 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
454 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
458 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
460 struct thread *td = curthread;
461 struct lwp *lp = td->td_lwp;
464 lwkt_gettoken(&proc_token);
467 *oset = lp->lwp_sigmask;
474 SIGSETOR(lp->lwp_sigmask, *set);
477 SIGSETNAND(lp->lwp_sigmask, *set);
481 lp->lwp_sigmask = *set;
489 lwkt_reltoken(&proc_token);
500 sys_sigprocmask(struct sigprocmask_args *uap)
503 sigset_t *setp, *osetp;
506 setp = (uap->set != NULL) ? &set : NULL;
507 osetp = (uap->oset != NULL) ? &oset : NULL;
509 error = copyin(uap->set, setp, sizeof(set));
513 error = kern_sigprocmask(uap->how, setp, osetp);
514 if (osetp && !error) {
515 error = copyout(osetp, uap->oset, sizeof(oset));
524 kern_sigpending(struct __sigset *set)
526 struct lwp *lp = curthread->td_lwp;
528 *set = lwp_sigpend(lp);
537 sys_sigpending(struct sigpending_args *uap)
542 error = kern_sigpending(&set);
545 error = copyout(&set, uap->set, sizeof(set));
550 * Suspend process until signal, providing mask to be set
556 kern_sigsuspend(struct __sigset *set)
558 struct thread *td = curthread;
559 struct lwp *lp = td->td_lwp;
560 struct proc *p = td->td_proc;
561 struct sigacts *ps = p->p_sigacts;
564 * When returning from sigsuspend, we want
565 * the old mask to be restored after the
566 * signal handler has finished. Thus, we
567 * save it here and mark the sigacts structure
570 lp->lwp_oldsigmask = lp->lwp_sigmask;
571 lp->lwp_flag |= LWP_OLDMASK;
574 lp->lwp_sigmask = *set;
575 while (tsleep(ps, PCATCH, "pause", 0) == 0)
577 /* always return EINTR rather than ERESTART... */
582 * Note nonstandard calling convention: libc stub passes mask, not
583 * pointer, to save a copyin.
588 sys_sigsuspend(struct sigsuspend_args *uap)
593 error = copyin(uap->sigmask, &mask, sizeof(mask));
597 error = kern_sigsuspend(&mask);
606 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
608 struct thread *td = curthread;
609 struct lwp *lp = td->td_lwp;
610 struct proc *p = td->td_proc;
612 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
613 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
616 *oss = lp->lwp_sigstk;
619 if (ss->ss_flags & SS_DISABLE) {
620 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
622 lp->lwp_flag &= ~LWP_ALTSTACK;
623 lp->lwp_sigstk.ss_flags = ss->ss_flags;
625 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
627 lp->lwp_flag |= LWP_ALTSTACK;
628 lp->lwp_sigstk = *ss;
639 sys_sigaltstack(struct sigaltstack_args *uap)
645 error = copyin(uap->ss, &ss, sizeof(ss));
650 error = kern_sigaltstack(uap->ss ? &ss : NULL,
651 uap->oss ? &oss : NULL);
653 if (error == 0 && uap->oss)
654 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
659 * Common code for kill process group/broadcast kill.
660 * cp is calling process.
667 static int killpg_all_callback(struct proc *p, void *data);
670 dokillpg(int sig, int pgid, int all)
672 struct killpg_info info;
673 struct proc *cp = curproc;
684 allproc_scan(killpg_all_callback, &info);
688 * zero pgid means send to my process group.
696 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
697 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
699 p->p_stat == SZOMB ||
700 (p->p_flag & P_SYSTEM) ||
701 !CANSIGNAL(p, sig)) {
708 lockmgr(&pgrp->pg_lock, LK_RELEASE);
710 return (info.nfound ? 0 : ESRCH);
714 killpg_all_callback(struct proc *p, void *data)
716 struct killpg_info *info = data;
718 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
719 p == curproc || !CANSIGNAL(p, info->sig)) {
724 ksignal(p, info->sig);
729 * Send a general signal to a process or LWPs within that process. Note
730 * that new signals cannot be sent if a process is exiting.
735 kern_kill(int sig, pid_t pid, lwpid_t tid)
739 if ((u_int)sig > _SIG_MAXSIG)
742 lwkt_gettoken(&proc_token);
746 struct lwp *lp = NULL;
748 /* kill single process */
749 if ((p = pfind(pid)) == NULL) {
750 lwkt_reltoken(&proc_token);
753 if (!CANSIGNAL(p, sig)) {
754 lwkt_reltoken(&proc_token);
759 * NOP if the process is exiting. Note that lwpsignal() is
760 * called directly with P_WEXIT set to kill individual LWPs
761 * during exit, which is allowed.
763 if (p->p_flag & P_WEXIT) {
764 lwkt_reltoken(&proc_token);
768 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
770 lwkt_reltoken(&proc_token);
775 lwpsignal(p, lp, sig);
776 lwkt_reltoken(&proc_token);
780 * If we come here, pid is a special broadcast pid.
781 * This doesn't mix with a tid.
784 lwkt_reltoken(&proc_token);
788 case -1: /* broadcast signal */
789 t = (dokillpg(sig, 0, 1));
791 case 0: /* signal own process group */
792 t = (dokillpg(sig, 0, 0));
794 default: /* negative explicit process group */
795 t = (dokillpg(sig, -pid, 0));
798 lwkt_reltoken(&proc_token);
803 sys_kill(struct kill_args *uap)
807 error = kern_kill(uap->signum, uap->pid, -1);
812 sys_lwp_kill(struct lwp_kill_args *uap)
815 pid_t pid = uap->pid;
818 * A tid is mandatory for lwp_kill(), otherwise
819 * you could simply use kill().
825 * To save on a getpid() function call for intra-process
826 * signals, pid == -1 means current process.
829 pid = curproc->p_pid;
831 error = kern_kill(uap->signum, pid, uap->tid);
836 * Send a signal to a process group.
839 gsignal(int pgid, int sig)
843 if (pgid && (pgrp = pgfind(pgid)))
844 pgsignal(pgrp, sig, 0);
848 * Send a signal to a process group. If checktty is 1,
849 * limit to members which have a controlling terminal.
851 * pg_lock interlocks against a fork that might be in progress, to
852 * ensure that the new child process picks up the signal.
855 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
860 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
861 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
862 if (checkctty == 0 || p->p_flag & P_CONTROLT)
865 lockmgr(&pgrp->pg_lock, LK_RELEASE);
870 * Send a signal caused by a trap to the current lwp. If it will be caught
871 * immediately, deliver it with correct code. Otherwise, post it normally.
873 * These signals may ONLY be delivered to the specified lwp and may never
874 * be delivered to the process generically.
877 trapsignal(struct lwp *lp, int sig, u_long code)
879 struct proc *p = lp->lwp_proc;
880 struct sigacts *ps = p->p_sigacts;
883 * If we are a virtual kernel running an emulated user process
884 * context, switch back to the virtual kernel context before
885 * trying to post the signal.
887 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
888 struct trapframe *tf = lp->lwp_md.md_regs;
890 vkernel_trap(lp, tf);
894 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
895 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
896 lp->lwp_ru.ru_nsignals++;
898 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
899 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
900 &lp->lwp_sigmask, code);
902 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
903 &lp->lwp_sigmask, code);
904 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
905 if (!SIGISMEMBER(ps->ps_signodefer, sig))
906 SIGADDSET(lp->lwp_sigmask, sig);
907 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
909 * See kern_sigaction() for origin of this code.
911 SIGDELSET(p->p_sigcatch, sig);
912 if (sig != SIGCONT &&
913 sigprop(sig) & SA_IGNORE)
914 SIGADDSET(p->p_sigignore, sig);
915 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
918 lp->lwp_code = code; /* XXX for core dump/debugger */
919 lp->lwp_sig = sig; /* XXX to verify code */
920 lwpsignal(p, lp, sig);
925 * Find a suitable lwp to deliver the signal to.
927 * Returns NULL if all lwps hold the signal blocked.
930 find_lwp_for_signal(struct proc *p, int sig)
933 struct lwp *run, *sleep, *stop;
936 * If the running/preempted thread belongs to the proc to which
937 * the signal is being delivered and this thread does not block
938 * the signal, then we can avoid a context switch by delivering
939 * the signal to this thread, because it will return to userland
942 lp = lwkt_preempted_proc();
943 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
946 run = sleep = stop = NULL;
947 FOREACH_LWP_IN_PROC(lp, p) {
949 * If the signal is being blocked by the lwp, then this
950 * lwp is not eligible for receiving the signal.
952 if (SIGISMEMBER(lp->lwp_sigmask, sig))
955 switch (lp->lwp_stat) {
965 if (lp->lwp_flag & LWP_SINTR)
973 else if (sleep != NULL)
980 * Send the signal to the process. If the signal has an action, the action
981 * is usually performed by the target process rather than the caller; we add
982 * the signal to the set of pending signals for the process.
985 * o When a stop signal is sent to a sleeping process that takes the
986 * default action, the process is stopped without awakening it.
987 * o SIGCONT restarts stopped processes (or puts them back to sleep)
988 * regardless of the signal action (eg, blocked or ignored).
990 * Other ignored signals are discarded immediately.
995 ksignal(struct proc *p, int sig)
997 lwpsignal(p, NULL, sig);
1001 * The core for ksignal. lp may be NULL, then a suitable thread
1002 * will be chosen. If not, lp MUST be a member of p.
1007 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1012 if (sig > _SIG_MAXSIG || sig <= 0) {
1013 kprintf("lwpsignal: signal %d\n", sig);
1014 panic("lwpsignal signal number");
1017 KKASSERT(lp == NULL || lp->lwp_proc == p);
1019 lwkt_gettoken(&proc_token);
1021 prop = sigprop(sig);
1024 * If proc is traced, always give parent a chance;
1025 * if signal event is tracked by procfs, give *that*
1026 * a chance, as well.
1028 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1032 * Do not try to deliver signals to an exiting lwp. Note
1033 * that we must still deliver the signal if P_WEXIT is set
1034 * in the process flags.
1036 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
1037 lwkt_reltoken(&proc_token);
1042 * If the signal is being ignored, then we forget about
1043 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1044 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1046 if (SIGISMEMBER(p->p_sigignore, sig)) {
1047 lwkt_reltoken(&proc_token);
1050 if (SIGISMEMBER(p->p_sigcatch, sig))
1057 * If continuing, clear any pending STOP signals.
1060 SIG_STOPSIGMASK(p->p_siglist);
1062 if (prop & SA_STOP) {
1064 * If sending a tty stop signal to a member of an orphaned
1065 * process group, discard the signal here if the action
1066 * is default; don't stop the process below if sleeping,
1067 * and don't clear any pending SIGCONT.
1069 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1070 action == SIG_DFL) {
1071 lwkt_reltoken(&proc_token);
1074 SIG_CONTSIGMASK(p->p_siglist);
1075 p->p_flag &= ~P_CONTINUED;
1080 if (p->p_stat == SSTOP) {
1082 * Nobody can handle this signal, add it to the lwp or
1083 * process pending list
1086 SIGADDSET(lp->lwp_siglist, sig);
1088 SIGADDSET(p->p_siglist, sig);
1091 * If the process is stopped and is being traced, then no
1092 * further action is necessary.
1094 if (p->p_flag & P_TRACED)
1098 * If the process is stopped and receives a KILL signal,
1099 * make the process runnable.
1101 if (sig == SIGKILL) {
1103 goto active_process;
1107 * If the process is stopped and receives a CONT signal,
1108 * then try to make the process runnable again.
1110 if (prop & SA_CONT) {
1112 * If SIGCONT is default (or ignored), we continue the
1113 * process but don't leave the signal in p_siglist, as
1114 * it has no further action. If SIGCONT is held, we
1115 * continue the process and leave the signal in
1116 * p_siglist. If the process catches SIGCONT, let it
1117 * handle the signal itself.
1119 /* XXX what if the signal is being held blocked? */
1120 p->p_flag |= P_CONTINUED;
1122 if (action == SIG_DFL)
1123 SIGDELSET(p->p_siglist, sig);
1125 if (action == SIG_CATCH)
1126 goto active_process;
1131 * If the process is stopped and receives another STOP
1132 * signal, we do not need to stop it again. If we did
1133 * the shell could get confused.
1135 * However, if the current/preempted lwp is part of the
1136 * process receiving the signal, we need to keep it,
1137 * so that this lwp can stop in issignal() later, as
1138 * we don't want to wait until it reaches userret!
1140 if (prop & SA_STOP) {
1141 if (lwkt_preempted_proc() == NULL ||
1142 lwkt_preempted_proc()->lwp_proc != p)
1143 SIGDELSET(p->p_siglist, sig);
1147 * Otherwise the process is stopped and it received some
1148 * signal, which does not change its stopped state.
1150 * We have to select one thread to set LWP_BREAKTSLEEP,
1151 * so that the current signal will break the sleep
1152 * as soon as a SA_CONT signal will unstop the process.
1155 lp = find_lwp_for_signal(p, sig);
1157 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1158 lp->lwp_flag |= LWP_BREAKTSLEEP;
1163 /* else not stopped */
1167 * Never deliver a lwp-specific signal to a random lwp.
1170 lp = find_lwp_for_signal(p, sig);
1171 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1176 * Deliver to the process generically if (1) the signal is being
1177 * sent to any thread or (2) we could not find a thread to deliver
1181 SIGADDSET(p->p_siglist, sig);
1186 * Deliver to a specific LWP whether it masks it or not. It will
1187 * not be dispatched if masked but we must still deliver it.
1189 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1190 (p->p_flag & P_TRACED) == 0) {
1195 * If the process receives a STOP signal which indeed needs to
1196 * stop the process, do so. If the process chose to catch the
1197 * signal, it will be treated like any other signal.
1199 if ((prop & SA_STOP) && action == SIG_DFL) {
1201 * If a child holding parent blocked, stopping
1202 * could cause deadlock. Take no action at this
1205 if (p->p_flag & P_PPWAIT) {
1206 SIGADDSET(p->p_siglist, sig);
1211 * Do not actually try to manipulate the process, but simply
1212 * stop it. Lwps will stop as soon as they safely can.
1220 * If it is a CONT signal with default action, just ignore it.
1222 if ((prop & SA_CONT) && action == SIG_DFL)
1226 * Mark signal pending at this specific thread.
1228 SIGADDSET(lp->lwp_siglist, sig);
1233 lwkt_reltoken(&proc_token);
1238 * proc_token must be held
1241 lwp_signotify(struct lwp *lp)
1243 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1246 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1248 * Thread is in tsleep.
1252 * If the thread is sleeping uninterruptibly
1253 * we can't interrupt the sleep... the signal will
1254 * be noticed when the lwp returns through
1255 * trap() or syscall().
1257 * Otherwise the signal can interrupt the sleep.
1259 * If the process is traced, the lwp will handle the
1260 * tracing in issignal() when it returns to userland.
1262 if (lp->lwp_flag & LWP_SINTR) {
1264 * Make runnable and break out of any tsleep as well.
1266 lp->lwp_flag |= LWP_BREAKTSLEEP;
1271 * Otherwise the thread is running
1273 * LSRUN does nothing with the signal, other than kicking
1274 * ourselves if we are running.
1275 * SZOMB and SIDL mean that it will either never be noticed,
1276 * or noticed very soon.
1278 * Note that lwp_thread may be NULL or may not be completely
1279 * initialized if the process is in the SIDL or SZOMB state.
1281 * For SMP we may have to forward the request to another cpu.
1282 * YYY the MP lock prevents the target process from moving
1283 * to another cpu, see kern/kern_switch.c
1285 * If the target thread is waiting on its message port,
1286 * wakeup the target thread so it can check (or ignore)
1287 * the new signal. YYY needs cleanup.
1289 if (lp == lwkt_preempted_proc()) {
1291 } else if (lp->lwp_stat == LSRUN) {
1292 struct thread *td = lp->lwp_thread;
1293 struct proc *p __debugvar = lp->lwp_proc;
1296 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1297 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1298 p->p_flag, lp->lwp_flag));
1301 * To prevent a MP race with TDF_SINTR we must
1302 * schedule the thread on the correct cpu.
1305 if (td->td_gd != mycpu) {
1307 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1310 if (td->td_flags & TDF_SINTR)
1320 * This function is called via an IPI. We will be in a critical section but
1321 * the MP lock will NOT be held. Also note that by the time the ipi message
1322 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1325 signotify_remote(void *arg)
1327 struct lwp *lp = arg;
1329 if (lp == lwkt_preempted_proc()) {
1332 struct thread *td = lp->lwp_thread;
1333 if (td->td_flags & TDF_SINTR)
1342 * Caller must hold proc_token
1345 proc_stop(struct proc *p)
1349 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1352 /* If somebody raced us, be happy with it */
1353 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1359 FOREACH_LWP_IN_PROC(lp, p) {
1360 switch (lp->lwp_stat) {
1363 * Do nothing, we are already counted in
1370 * We're sleeping, but we will stop before
1371 * returning to userspace, so count us
1372 * as stopped as well. We set LWP_WSTOP
1373 * to signal the lwp that it should not
1374 * increase p_nstopped when reaching tstop().
1376 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1377 lp->lwp_flag |= LWP_WSTOP;
1384 * We might notify ourself, but that's not
1392 if (p->p_nstopped == p->p_nthreads) {
1393 p->p_flag &= ~P_WAITED;
1395 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1396 ksignal(p->p_pptr, SIGCHLD);
1402 * Caller must hold proc_token
1405 proc_unstop(struct proc *p)
1409 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1412 if (p->p_stat != SSTOP) {
1417 p->p_stat = SACTIVE;
1419 FOREACH_LWP_IN_PROC(lp, p) {
1420 switch (lp->lwp_stat) {
1423 * Uh? Not stopped? Well, I guess that's okay.
1426 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1427 p->p_pid, lp->lwp_tid);
1432 * Still sleeping. Don't bother waking it up.
1433 * However, if this thread was counted as
1434 * stopped, undo this.
1436 * Nevertheless we call setrunnable() so that it
1437 * will wake up in case a signal or timeout arrived
1440 if (lp->lwp_flag & LWP_WSTOP) {
1441 lp->lwp_flag &= ~LWP_WSTOP;
1445 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1446 p->p_pid, lp->lwp_tid);
1462 * XXX: Holds the proc_token for longer than it probably needs to.
1465 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1467 sigset_t savedmask, set;
1468 struct proc *p = curproc;
1469 struct lwp *lp = curthread->td_lwp;
1470 int error, sig, hz, timevalid = 0;
1471 struct timespec rts, ets, ts;
1474 lwkt_gettoken(&proc_token);
1478 ets.tv_sec = 0; /* silence compiler warning */
1479 ets.tv_nsec = 0; /* silence compiler warning */
1480 SIG_CANTMASK(waitset);
1481 savedmask = lp->lwp_sigmask;
1484 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1485 timeout->tv_nsec < 1000000000) {
1487 getnanouptime(&rts);
1489 timespecadd(&ets, timeout);
1494 set = lwp_sigpend(lp);
1495 SIGSETAND(set, waitset);
1496 if ((sig = sig_ffs(&set)) != 0) {
1497 SIGFILLSET(lp->lwp_sigmask);
1498 SIGDELSET(lp->lwp_sigmask, sig);
1499 SIG_CANTMASK(lp->lwp_sigmask);
1500 sig = issignal(lp, 1);
1502 * It may be a STOP signal, in the case, issignal
1503 * returns 0, because we may stop there, and new
1504 * signal can come in, we should restart if we got
1514 * Previous checking got nothing, and we retried but still
1515 * got nothing, we should return the error status.
1521 * POSIX says this must be checked after looking for pending
1525 if (timevalid == 0) {
1529 getnanouptime(&rts);
1530 if (timespeccmp(&rts, &ets, >=)) {
1535 timespecsub(&ts, &rts);
1536 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1537 hz = tvtohz_high(&tv);
1541 lp->lwp_sigmask = savedmask;
1542 SIGSETNAND(lp->lwp_sigmask, waitset);
1544 * We won't ever be woken up. Instead, our sleep will
1545 * be broken in lwpsignal().
1547 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1549 if (error == ERESTART) {
1550 /* can not restart a timeout wait. */
1552 } else if (error == EAGAIN) {
1553 /* will calculate timeout by ourself. */
1560 lp->lwp_sigmask = savedmask;
1563 bzero(info, sizeof(*info));
1564 info->si_signo = sig;
1565 lwp_delsig(lp, sig); /* take the signal! */
1571 lwkt_reltoken(&proc_token);
1580 sys_sigtimedwait(struct sigtimedwait_args *uap)
1583 struct timespec *timeout;
1589 error = copyin(uap->timeout, &ts, sizeof(ts));
1596 error = copyin(uap->set, &set, sizeof(set));
1599 error = kern_sigtimedwait(set, &info, timeout);
1603 error = copyout(&info, uap->info, sizeof(info));
1604 /* Repost if we got an error. */
1608 * This could transform a thread-specific signal to another
1609 * thread / process pending signal.
1612 ksignal(curproc, info.si_signo);
1614 uap->sysmsg_result = info.si_signo;
1623 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1629 error = copyin(uap->set, &set, sizeof(set));
1632 error = kern_sigtimedwait(set, &info, NULL);
1636 error = copyout(&info, uap->info, sizeof(info));
1637 /* Repost if we got an error. */
1641 * This could transform a thread-specific signal to another
1642 * thread / process pending signal.
1645 ksignal(curproc, info.si_signo);
1647 uap->sysmsg_result = info.si_signo;
1653 * If the current process has received a signal that would interrupt a
1654 * system call, return EINTR or ERESTART as appropriate.
1657 iscaught(struct lwp *lp)
1659 struct proc *p = lp->lwp_proc;
1663 if ((sig = CURSIG(lp)) != 0) {
1664 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1669 return(EWOULDBLOCK);
1673 * If the current process has received a signal (should be caught or cause
1674 * termination, should interrupt current syscall), return the signal number.
1675 * Stop signals with default action are processed immediately, then cleared;
1676 * they aren't returned. This is checked after each entry to the system for
1677 * a syscall or trap (though this can usually be done without calling issignal
1678 * by checking the pending signal masks in the CURSIG macro.) The normal call
1681 * This routine is called via CURSIG/__cursig and the MP lock might not be
1682 * held. Obtain the MP lock for the duration of the operation.
1684 * while (sig = CURSIG(curproc))
1688 issignal(struct lwp *lp, int maytrace)
1690 struct proc *p = lp->lwp_proc;
1694 lwkt_gettoken(&proc_token);
1697 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1700 * If this process is supposed to stop, stop this thread.
1702 if (p->p_stat == SSTOP)
1705 mask = lwp_sigpend(lp);
1706 SIGSETNAND(mask, lp->lwp_sigmask);
1707 if (p->p_flag & P_PPWAIT)
1708 SIG_STOPSIGMASK(mask);
1709 if (SIGISEMPTY(mask)) { /* no signal to send */
1710 lwkt_reltoken(&proc_token);
1713 sig = sig_ffs(&mask);
1715 STOPEVENT(p, S_SIG, sig);
1718 * We should see pending but ignored signals
1719 * only if P_TRACED was on when they were posted.
1721 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1722 lwp_delsig(lp, sig);
1725 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1727 * If traced, always stop, and stay stopped until
1728 * released by the parent.
1730 * NOTE: SSTOP may get cleared during the loop,
1731 * but we do not re-notify the parent if we have
1732 * to loop several times waiting for the parent
1733 * to let us continue.
1735 * XXX not sure if this is still true
1741 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1744 * If parent wants us to take the signal,
1745 * then it will leave it in p->p_xstat;
1746 * otherwise we just look for signals again.
1748 lwp_delsig(lp, sig); /* clear old signal */
1754 * Put the new signal into p_siglist. If the
1755 * signal is being masked, look for other signals.
1757 * XXX lwp might need a call to ksignal()
1759 SIGADDSET(p->p_siglist, sig);
1760 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1764 * If the traced bit got turned off, go back up
1765 * to the top to rescan signals. This ensures
1766 * that p_sig* and ps_sigact are consistent.
1768 if ((p->p_flag & P_TRACED) == 0)
1772 prop = sigprop(sig);
1775 * Decide whether the signal should be returned.
1776 * Return the signal's number, or fall through
1777 * to clear it from the pending mask.
1779 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1780 case (intptr_t)SIG_DFL:
1782 * Don't take default actions on system processes.
1784 if (p->p_pid <= 1) {
1787 * Are you sure you want to ignore SIGSEGV
1790 kprintf("Process (pid %lu) got signal %d\n",
1791 (u_long)p->p_pid, sig);
1793 break; /* == ignore */
1797 * Handle the in-kernel checkpoint action
1799 if (prop & SA_CKPT) {
1800 checkpoint_signal_handler(lp);
1805 * If there is a pending stop signal to process
1806 * with default action, stop here,
1807 * then clear the signal. However,
1808 * if process is member of an orphaned
1809 * process group, ignore tty stop signals.
1811 if (prop & SA_STOP) {
1812 if (p->p_flag & P_TRACED ||
1813 (p->p_pgrp->pg_jobc == 0 &&
1815 break; /* == ignore */
1820 } else if (prop & SA_IGNORE) {
1822 * Except for SIGCONT, shouldn't get here.
1823 * Default action is to ignore; drop it.
1825 break; /* == ignore */
1827 lwkt_reltoken(&proc_token);
1833 case (intptr_t)SIG_IGN:
1835 * Masking above should prevent us ever trying
1836 * to take action on an ignored signal other
1837 * than SIGCONT, unless process is traced.
1839 if ((prop & SA_CONT) == 0 &&
1840 (p->p_flag & P_TRACED) == 0)
1841 kprintf("issignal\n");
1842 break; /* == ignore */
1846 * This signal has an action, let
1847 * postsig() process it.
1849 lwkt_reltoken(&proc_token);
1852 lwp_delsig(lp, sig); /* take the signal! */
1858 * Take the action for the specified signal
1859 * from the current set of pending signals.
1864 struct lwp *lp = curthread->td_lwp;
1865 struct proc *p = lp->lwp_proc;
1866 struct sigacts *ps = p->p_sigacts;
1868 sigset_t returnmask;
1871 KASSERT(sig != 0, ("postsig"));
1873 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1876 * If we are a virtual kernel running an emulated user process
1877 * context, switch back to the virtual kernel context before
1878 * trying to post the signal.
1880 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1881 struct trapframe *tf = lp->lwp_md.md_regs;
1883 vkernel_trap(lp, tf);
1886 lwp_delsig(lp, sig);
1887 action = ps->ps_sigact[_SIG_IDX(sig)];
1889 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1890 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1891 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1893 STOPEVENT(p, S_SIG, sig);
1895 if (action == SIG_DFL) {
1897 * Default action, where the default is to kill
1898 * the process. (Other cases were ignored above.)
1904 * If we get here, the signal must be caught.
1906 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1907 ("postsig action"));
1912 * Reset the signal handler if asked to
1914 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1916 * See kern_sigaction() for origin of this code.
1918 SIGDELSET(p->p_sigcatch, sig);
1919 if (sig != SIGCONT &&
1920 sigprop(sig) & SA_IGNORE)
1921 SIGADDSET(p->p_sigignore, sig);
1922 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1926 * Handle the mailbox case. Copyout to the appropriate
1927 * location but do not generate a signal frame. The system
1928 * call simply returns EINTR and the user is responsible for
1929 * polling the mailbox.
1931 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1933 copyout(&sig_copy, (void *)action, sizeof(int));
1934 curproc->p_flag |= P_MAILBOX;
1940 * Set the signal mask and calculate the mask to restore
1941 * when the signal function returns.
1943 * Special case: user has done a sigsuspend. Here the
1944 * current mask is not of interest, but rather the
1945 * mask from before the sigsuspend is what we want
1946 * restored after the signal processing is completed.
1948 if (lp->lwp_flag & LWP_OLDMASK) {
1949 returnmask = lp->lwp_oldsigmask;
1950 lp->lwp_flag &= ~LWP_OLDMASK;
1952 returnmask = lp->lwp_sigmask;
1955 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1956 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1957 SIGADDSET(lp->lwp_sigmask, sig);
1960 lp->lwp_ru.ru_nsignals++;
1961 if (lp->lwp_sig != sig) {
1964 code = lp->lwp_code;
1968 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1975 * Kill the current process for stated reason.
1978 killproc(struct proc *p, char *why)
1980 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1981 p->p_pid, p->p_comm,
1982 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1983 ksignal(p, SIGKILL);
1987 * Force the current process to exit with the specified signal, dumping core
1988 * if appropriate. We bypass the normal tests for masked and caught signals,
1989 * allowing unrecoverable failures to terminate the process without changing
1990 * signal state. Mark the accounting record with the signal termination.
1991 * If dumping core, save the signal number for the debugger. Calls exit and
1995 sigexit(struct lwp *lp, int sig)
1997 struct proc *p = lp->lwp_proc;
1999 p->p_acflag |= AXSIG;
2000 if (sigprop(sig) & SA_CORE) {
2003 * Log signals which would cause core dumps
2004 * (Log as LOG_INFO to appease those who don't want
2006 * XXX : Todo, as well as euid, write out ruid too
2008 if (coredump(lp, sig) == 0)
2010 if (kern_logsigexit)
2012 "pid %d (%s), uid %d: exited on signal %d%s\n",
2013 p->p_pid, p->p_comm,
2014 p->p_ucred ? p->p_ucred->cr_uid : -1,
2016 sig & WCOREFLAG ? " (core dumped)" : "");
2018 exit1(W_EXITCODE(0, sig));
2022 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2023 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2024 sizeof(corefilename), "process corefile name format string");
2027 * expand_name(name, uid, pid)
2028 * Expand the name described in corefilename, using name, uid, and pid.
2029 * corefilename is a kprintf-like string, with three format specifiers:
2030 * %N name of process ("name")
2031 * %P process id (pid)
2033 * For example, "%N.core" is the default; they can be disabled completely
2034 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2035 * This is controlled by the sysctl variable kern.corefile (see above).
2039 expand_name(const char *name, uid_t uid, pid_t pid)
2042 char buf[11]; /* Buffer for pid/uid -- max 4B */
2044 char *format = corefilename;
2047 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2050 namelen = strlen(name);
2051 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2053 switch (format[i]) {
2054 case '%': /* Format character */
2056 switch (format[i]) {
2060 case 'N': /* process name */
2061 if ((n + namelen) > MAXPATHLEN) {
2062 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2063 pid, name, uid, temp, name);
2064 kfree(temp, M_TEMP);
2067 memcpy(temp+n, name, namelen);
2070 case 'P': /* process id */
2071 l = ksprintf(buf, "%u", pid);
2072 if ((n + l) > MAXPATHLEN) {
2073 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2074 pid, name, uid, temp, name);
2075 kfree(temp, M_TEMP);
2078 memcpy(temp+n, buf, l);
2081 case 'U': /* user id */
2082 l = ksprintf(buf, "%u", uid);
2083 if ((n + l) > MAXPATHLEN) {
2084 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2085 pid, name, uid, temp, name);
2086 kfree(temp, M_TEMP);
2089 memcpy(temp+n, buf, l);
2093 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2097 temp[n++] = format[i];
2105 * Dump a process' core. The main routine does some
2106 * policy checking, and creates the name of the coredump;
2107 * then it passes on a vnode and a size limit to the process-specific
2108 * coredump routine if there is one; if there _is not_ one, it returns
2109 * ENOSYS; otherwise it returns the error from the process-specific routine.
2111 * The parameter `lp' is the lwp which triggered the coredump.
2115 coredump(struct lwp *lp, int sig)
2117 struct proc *p = lp->lwp_proc;
2119 struct ucred *cred = p->p_ucred;
2121 struct nlookupdata nd;
2124 char *name; /* name of corefile */
2127 STOPEVENT(p, S_CORE, 0);
2129 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2133 * Note that the bulk of limit checking is done after
2134 * the corefile is created. The exception is if the limit
2135 * for corefiles is 0, in which case we don't bother
2136 * creating the corefile at all. This layout means that
2137 * a corefile is truncated instead of not being created,
2138 * if it is larger than the limit.
2140 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2144 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2147 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2149 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2150 kfree(name, M_TEMP);
2156 nd.nl_open_vp = NULL;
2160 lf.l_whence = SEEK_SET;
2163 lf.l_type = F_WRLCK;
2164 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2168 /* Don't dump to non-regular files or files with links. */
2169 if (vp->v_type != VREG ||
2170 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2175 /* Don't dump to files current user does not own */
2176 if (vattr.va_uid != p->p_ucred->cr_uid) {
2182 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2184 VOP_SETATTR(vp, &vattr, cred);
2185 p->p_acflag |= ACORE;
2188 error = p->p_sysent->sv_coredump ?
2189 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2192 lf.l_type = F_UNLCK;
2193 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2195 error1 = vn_close(vp, FWRITE);
2202 * Nonexistent system call-- signal process (may want to handle it).
2203 * Flag error in case process won't see signal immediately (blocked or ignored).
2209 sys_nosys(struct nosys_args *args)
2211 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2216 * Send a SIGIO or SIGURG signal to a process or process group using
2217 * stored credentials rather than those of the current process.
2220 pgsigio(struct sigio *sigio, int sig, int checkctty)
2225 if (sigio->sio_pgid > 0) {
2226 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2228 ksignal(sigio->sio_proc, sig);
2229 } else if (sigio->sio_pgid < 0) {
2232 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2233 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2234 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2235 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2238 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2243 filt_sigattach(struct knote *kn)
2245 struct proc *p = curproc;
2247 kn->kn_ptr.p_proc = p;
2248 kn->kn_flags |= EV_CLEAR; /* automatically set */
2250 /* XXX lock the proc here while adding to the list? */
2251 knote_insert(&p->p_klist, kn);
2257 filt_sigdetach(struct knote *kn)
2259 struct proc *p = kn->kn_ptr.p_proc;
2261 knote_remove(&p->p_klist, kn);
2265 * signal knotes are shared with proc knotes, so we apply a mask to
2266 * the hint in order to differentiate them from process hints. This
2267 * could be avoided by using a signal-specific knote list, but probably
2268 * isn't worth the trouble.
2271 filt_signal(struct knote *kn, long hint)
2273 if (hint & NOTE_SIGNAL) {
2274 hint &= ~NOTE_SIGNAL;
2276 if (kn->kn_id == hint)
2279 return (kn->kn_data != 0);