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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/signal2.h>
51 #include <sys/resourcevar.h>
52 #include <sys/vnode.h>
53 #include <sys/event.h>
55 #include <sys/nlookup.h>
56 #include <sys/pioctl.h>
57 #include <sys/systm.h>
59 #include <sys/fcntl.h>
62 #include <sys/ktrace.h>
63 #include <sys/syslog.h>
65 #include <sys/sysent.h>
66 #include <sys/sysctl.h>
67 #include <sys/malloc.h>
68 #include <sys/interrupt.h>
69 #include <sys/unistd.h>
70 #include <sys/kern_syscall.h>
71 #include <sys/vkernel.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);
83 static void signotify_remote(void *arg);
85 static int kern_sigtimedwait(sigset_t set, siginfo_t *info,
86 struct timespec *timeout);
88 static int filt_sigattach(struct knote *kn);
89 static void filt_sigdetach(struct knote *kn);
90 static int filt_signal(struct knote *kn, long hint);
92 struct filterops sig_filtops =
93 { 0, filt_sigattach, filt_sigdetach, filt_signal };
95 static int kern_logsigexit = 1;
96 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
98 "Log processes quitting on abnormal signals to syslog(3)");
101 * Can process p, with pcred pc, send the signal sig to process q?
103 #define CANSIGNAL(q, sig) \
104 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
105 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
108 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
110 #define CANSIGIO(ruid, uc, q) \
111 ((uc)->cr_uid == 0 || \
112 (ruid) == (q)->p_ucred->cr_ruid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
114 (ruid) == (q)->p_ucred->cr_uid || \
115 (uc)->cr_uid == (q)->p_ucred->cr_uid)
118 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
119 &sugid_coredump, 0, "Enable coredumping set user/group ID processes");
121 static int do_coredump = 1;
122 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
123 &do_coredump, 0, "Enable/Disable coredumps");
126 * Signal properties and actions.
127 * The array below categorizes the signals and their default actions
128 * according to the following properties:
130 #define SA_KILL 0x01 /* terminates process by default */
131 #define SA_CORE 0x02 /* ditto and coredumps */
132 #define SA_STOP 0x04 /* suspend process */
133 #define SA_TTYSTOP 0x08 /* ditto, from tty */
134 #define SA_IGNORE 0x10 /* ignore by default */
135 #define SA_CONT 0x20 /* continue if suspended */
136 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
137 #define SA_CKPT 0x80 /* checkpoint process */
140 static int sigproptbl[NSIG] = {
141 SA_KILL, /* SIGHUP */
142 SA_KILL, /* SIGINT */
143 SA_KILL|SA_CORE, /* SIGQUIT */
144 SA_KILL|SA_CORE, /* SIGILL */
145 SA_KILL|SA_CORE, /* SIGTRAP */
146 SA_KILL|SA_CORE, /* SIGABRT */
147 SA_KILL|SA_CORE, /* SIGEMT */
148 SA_KILL|SA_CORE, /* SIGFPE */
149 SA_KILL, /* SIGKILL */
150 SA_KILL|SA_CORE, /* SIGBUS */
151 SA_KILL|SA_CORE, /* SIGSEGV */
152 SA_KILL|SA_CORE, /* SIGSYS */
153 SA_KILL, /* SIGPIPE */
154 SA_KILL, /* SIGALRM */
155 SA_KILL, /* SIGTERM */
156 SA_IGNORE, /* SIGURG */
157 SA_STOP, /* SIGSTOP */
158 SA_STOP|SA_TTYSTOP, /* SIGTSTP */
159 SA_IGNORE|SA_CONT, /* SIGCONT */
160 SA_IGNORE, /* SIGCHLD */
161 SA_STOP|SA_TTYSTOP, /* SIGTTIN */
162 SA_STOP|SA_TTYSTOP, /* SIGTTOU */
163 SA_IGNORE, /* SIGIO */
164 SA_KILL, /* SIGXCPU */
165 SA_KILL, /* SIGXFSZ */
166 SA_KILL, /* SIGVTALRM */
167 SA_KILL, /* SIGPROF */
168 SA_IGNORE, /* SIGWINCH */
169 SA_IGNORE, /* SIGINFO */
170 SA_KILL, /* SIGUSR1 */
171 SA_KILL, /* SIGUSR2 */
172 SA_IGNORE, /* SIGTHR */
173 SA_CKPT, /* SIGCKPT */
174 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */
212 if (sig > 0 && sig < NSIG)
213 return (sigproptbl[_SIG_IDX(sig)]);
218 sig_ffs(sigset_t *set)
222 for (i = 0; i < _SIG_WORDS; i++)
224 return (ffs(set->__bits[i]) + (i * 32));
229 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact)
231 struct thread *td = curthread;
232 struct proc *p = td->td_proc;
234 struct sigacts *ps = p->p_sigacts;
236 if (sig <= 0 || sig > _SIG_MAXSIG)
240 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
241 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
243 if (SIGISMEMBER(ps->ps_sigonstack, sig))
244 oact->sa_flags |= SA_ONSTACK;
245 if (!SIGISMEMBER(ps->ps_sigintr, sig))
246 oact->sa_flags |= SA_RESTART;
247 if (SIGISMEMBER(ps->ps_sigreset, sig))
248 oact->sa_flags |= SA_RESETHAND;
249 if (SIGISMEMBER(ps->ps_signodefer, sig))
250 oact->sa_flags |= SA_NODEFER;
251 if (SIGISMEMBER(ps->ps_siginfo, sig))
252 oact->sa_flags |= SA_SIGINFO;
253 if (SIGISMEMBER(ps->ps_sigmailbox, sig))
254 oact->sa_flags |= SA_MAILBOX;
255 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP)
256 oact->sa_flags |= SA_NOCLDSTOP;
257 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT)
258 oact->sa_flags |= SA_NOCLDWAIT;
262 * Check for invalid requests. KILL and STOP cannot be
265 if (sig == SIGKILL || sig == SIGSTOP) {
266 if (act->sa_handler != SIG_DFL)
269 /* (not needed, SIG_DFL forces action to occur) */
270 if (act->sa_flags & SA_MAILBOX)
276 * Change setting atomically.
280 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
281 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
282 if (act->sa_flags & SA_SIGINFO) {
283 ps->ps_sigact[_SIG_IDX(sig)] =
284 (__sighandler_t *)act->sa_sigaction;
285 SIGADDSET(ps->ps_siginfo, sig);
287 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
288 SIGDELSET(ps->ps_siginfo, sig);
290 if (!(act->sa_flags & SA_RESTART))
291 SIGADDSET(ps->ps_sigintr, sig);
293 SIGDELSET(ps->ps_sigintr, sig);
294 if (act->sa_flags & SA_ONSTACK)
295 SIGADDSET(ps->ps_sigonstack, sig);
297 SIGDELSET(ps->ps_sigonstack, sig);
298 if (act->sa_flags & SA_RESETHAND)
299 SIGADDSET(ps->ps_sigreset, sig);
301 SIGDELSET(ps->ps_sigreset, sig);
302 if (act->sa_flags & SA_NODEFER)
303 SIGADDSET(ps->ps_signodefer, sig);
305 SIGDELSET(ps->ps_signodefer, sig);
306 if (act->sa_flags & SA_MAILBOX)
307 SIGADDSET(ps->ps_sigmailbox, sig);
309 SIGDELSET(ps->ps_sigmailbox, sig);
310 if (sig == SIGCHLD) {
311 if (act->sa_flags & SA_NOCLDSTOP)
312 p->p_sigacts->ps_flag |= PS_NOCLDSTOP;
314 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP;
315 if (act->sa_flags & SA_NOCLDWAIT) {
317 * Paranoia: since SA_NOCLDWAIT is implemented
318 * by reparenting the dying child to PID 1 (and
319 * trust it to reap the zombie), PID 1 itself
320 * is forbidden to set SA_NOCLDWAIT.
323 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
325 p->p_sigacts->ps_flag |= PS_NOCLDWAIT;
327 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
331 * Set bit in p_sigignore for signals that are set to SIG_IGN,
332 * and for signals set to SIG_DFL where the default is to
333 * ignore. However, don't put SIGCONT in p_sigignore, as we
334 * have to restart the process.
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 /* never to be seen again */
340 SIGDELSET(p->p_siglist, sig);
342 * Remove the signal also from the thread lists.
344 FOREACH_LWP_IN_PROC(lp, p) {
345 SIGDELSET(lp->lwp_siglist, sig);
348 /* easier in ksignal */
349 SIGADDSET(p->p_sigignore, sig);
350 SIGDELSET(p->p_sigcatch, sig);
352 SIGDELSET(p->p_sigignore, sig);
353 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
354 SIGDELSET(p->p_sigcatch, sig);
356 SIGADDSET(p->p_sigcatch, sig);
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 SIGDELSET(lp->lwp_siglist, sig);
425 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
429 * Reset stack state to the user stack.
430 * Clear set of signals caught on the signal stack.
432 lp->lwp_sigstk.ss_flags = SS_DISABLE;
433 lp->lwp_sigstk.ss_size = 0;
434 lp->lwp_sigstk.ss_sp = 0;
435 lp->lwp_flag &= ~LWP_ALTSTACK;
437 * Reset no zombies if child dies flag as Solaris does.
439 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
443 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
445 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
449 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
451 struct thread *td = curthread;
452 struct lwp *lp = td->td_lwp;
456 *oset = lp->lwp_sigmask;
463 SIGSETOR(lp->lwp_sigmask, *set);
466 SIGSETNAND(lp->lwp_sigmask, *set);
470 lp->lwp_sigmask = *set;
481 * sigprocmask() - MP SAFE
484 sys_sigprocmask(struct sigprocmask_args *uap)
487 sigset_t *setp, *osetp;
490 setp = (uap->set != NULL) ? &set : NULL;
491 osetp = (uap->oset != NULL) ? &oset : NULL;
493 error = copyin(uap->set, setp, sizeof(set));
497 error = kern_sigprocmask(uap->how, setp, osetp);
498 if (osetp && !error) {
499 error = copyout(osetp, uap->oset, sizeof(oset));
505 kern_sigpending(struct __sigset *set)
507 struct lwp *lp = curthread->td_lwp;
509 *set = lwp_sigpend(lp);
515 sys_sigpending(struct sigpending_args *uap)
520 error = kern_sigpending(&set);
523 error = copyout(&set, uap->set, sizeof(set));
528 * Suspend process until signal, providing mask to be set
532 kern_sigsuspend(struct __sigset *set)
534 struct thread *td = curthread;
535 struct lwp *lp = td->td_lwp;
536 struct proc *p = td->td_proc;
537 struct sigacts *ps = p->p_sigacts;
540 * When returning from sigsuspend, we want
541 * the old mask to be restored after the
542 * signal handler has finished. Thus, we
543 * save it here and mark the sigacts structure
546 lp->lwp_oldsigmask = lp->lwp_sigmask;
547 lp->lwp_flag |= LWP_OLDMASK;
550 lp->lwp_sigmask = *set;
551 while (tsleep(ps, PCATCH, "pause", 0) == 0)
553 /* always return EINTR rather than ERESTART... */
558 * Note nonstandard calling convention: libc stub passes mask, not
559 * pointer, to save a copyin.
562 sys_sigsuspend(struct sigsuspend_args *uap)
567 error = copyin(uap->sigmask, &mask, sizeof(mask));
571 error = kern_sigsuspend(&mask);
577 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
579 struct thread *td = curthread;
580 struct lwp *lp = td->td_lwp;
581 struct proc *p = td->td_proc;
583 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
584 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
587 *oss = lp->lwp_sigstk;
590 if (ss->ss_flags & SS_DISABLE) {
591 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
593 lp->lwp_flag &= ~LWP_ALTSTACK;
594 lp->lwp_sigstk.ss_flags = ss->ss_flags;
596 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
598 lp->lwp_flag |= LWP_ALTSTACK;
599 lp->lwp_sigstk = *ss;
607 sys_sigaltstack(struct sigaltstack_args *uap)
613 error = copyin(uap->ss, &ss, sizeof(ss));
618 error = kern_sigaltstack(uap->ss ? &ss : NULL,
619 uap->oss ? &oss : NULL);
621 if (error == 0 && uap->oss)
622 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
627 * Common code for kill process group/broadcast kill.
628 * cp is calling process.
635 static int killpg_all_callback(struct proc *p, void *data);
638 dokillpg(int sig, int pgid, int all)
640 struct killpg_info info;
641 struct proc *cp = curproc;
652 allproc_scan(killpg_all_callback, &info);
656 * zero pgid means send to my process group.
664 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
665 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
667 p->p_stat == SZOMB ||
668 (p->p_flag & P_SYSTEM) ||
669 !CANSIGNAL(p, sig)) {
676 lockmgr(&pgrp->pg_lock, LK_RELEASE);
678 return (info.nfound ? 0 : ESRCH);
682 killpg_all_callback(struct proc *p, void *data)
684 struct killpg_info *info = data;
686 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
687 p == curproc || !CANSIGNAL(p, info->sig)) {
692 ksignal(p, info->sig);
697 * Send a general signal to a process or LWPs within that process. Note
698 * that new signals cannot be sent if a process is exiting.
701 kern_kill(int sig, pid_t pid, lwpid_t tid)
703 struct thread *td = curthread;
704 struct proc *p = td->td_proc;
705 struct lwp *lp = NULL;
707 if ((u_int)sig > _SIG_MAXSIG)
710 /* kill single process */
711 if ((p = pfind(pid)) == NULL)
713 if (!CANSIGNAL(p, sig))
717 * NOP if the process is exiting. Note that lwpsignal() is
718 * called directly with P_WEXIT set to kill individual LWPs
719 * during exit, which is allowed.
721 if (p->p_flag & P_WEXIT)
724 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
729 lwpsignal(p, lp, sig);
733 * If we come here, pid is a special broadcast pid.
734 * This doesn't mix with a tid.
739 case -1: /* broadcast signal */
740 return (dokillpg(sig, 0, 1));
741 case 0: /* signal own process group */
742 return (dokillpg(sig, 0, 0));
743 default: /* negative explicit process group */
744 return (dokillpg(sig, -pid, 0));
750 sys_kill(struct kill_args *uap)
754 error = kern_kill(uap->signum, uap->pid, -1);
759 sys_lwp_kill(struct lwp_kill_args *uap)
762 pid_t pid = uap->pid;
765 * A tid is mandatory for lwp_kill(), otherwise
766 * you could simply use kill().
772 * To save on a getpid() function call for intra-process
773 * signals, pid == -1 means current process.
776 pid = curproc->p_pid;
778 error = kern_kill(uap->signum, pid, uap->tid);
783 * Send a signal to a process group.
786 gsignal(int pgid, int sig)
790 if (pgid && (pgrp = pgfind(pgid)))
791 pgsignal(pgrp, sig, 0);
795 * Send a signal to a process group. If checktty is 1,
796 * limit to members which have a controlling terminal.
798 * pg_lock interlocks against a fork that might be in progress, to
799 * ensure that the new child process picks up the signal.
802 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
807 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
808 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
809 if (checkctty == 0 || p->p_flag & P_CONTROLT)
812 lockmgr(&pgrp->pg_lock, LK_RELEASE);
817 * Send a signal caused by a trap to the current lwp. If it will be caught
818 * immediately, deliver it with correct code. Otherwise, post it normally.
820 * These signals may ONLY be delivered to the specified lwp and may never
821 * be delivered to the process generically.
824 trapsignal(struct lwp *lp, int sig, u_long code)
826 struct proc *p = lp->lwp_proc;
827 struct sigacts *ps = p->p_sigacts;
830 * If we are a virtual kernel running an emulated user process
831 * context, switch back to the virtual kernel context before
832 * trying to post the signal.
834 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
835 struct trapframe *tf = lp->lwp_md.md_regs;
837 vkernel_trap(lp, tf);
841 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
842 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
843 lp->lwp_ru.ru_nsignals++;
845 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
846 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
847 &lp->lwp_sigmask, code);
849 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
850 &lp->lwp_sigmask, code);
851 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
852 if (!SIGISMEMBER(ps->ps_signodefer, sig))
853 SIGADDSET(lp->lwp_sigmask, sig);
854 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
856 * See kern_sigaction() for origin of this code.
858 SIGDELSET(p->p_sigcatch, sig);
859 if (sig != SIGCONT &&
860 sigprop(sig) & SA_IGNORE)
861 SIGADDSET(p->p_sigignore, sig);
862 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
865 lp->lwp_code = code; /* XXX for core dump/debugger */
866 lp->lwp_sig = sig; /* XXX to verify code */
867 lwpsignal(p, lp, sig);
872 * Find a suitable lwp to deliver the signal to.
874 * Returns NULL if all lwps hold the signal blocked.
877 find_lwp_for_signal(struct proc *p, int sig)
880 struct lwp *run, *sleep, *stop;
883 * If the running/preempted thread belongs to the proc to which
884 * the signal is being delivered and this thread does not block
885 * the signal, then we can avoid a context switch by delivering
886 * the signal to this thread, because it will return to userland
889 lp = lwkt_preempted_proc();
890 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
893 run = sleep = stop = NULL;
894 FOREACH_LWP_IN_PROC(lp, p) {
896 * If the signal is being blocked by the lwp, then this
897 * lwp is not eligible for receiving the signal.
899 if (SIGISMEMBER(lp->lwp_sigmask, sig))
902 switch (lp->lwp_stat) {
912 if (lp->lwp_flag & LWP_SINTR)
920 else if (sleep != NULL)
927 * Send the signal to the process. If the signal has an action, the action
928 * is usually performed by the target process rather than the caller; we add
929 * the signal to the set of pending signals for the process.
932 * o When a stop signal is sent to a sleeping process that takes the
933 * default action, the process is stopped without awakening it.
934 * o SIGCONT restarts stopped processes (or puts them back to sleep)
935 * regardless of the signal action (eg, blocked or ignored).
937 * Other ignored signals are discarded immediately.
940 ksignal(struct proc *p, int sig)
942 lwpsignal(p, NULL, sig);
946 * The core for ksignal. lp may be NULL, then a suitable thread
947 * will be chosen. If not, lp MUST be a member of p.
950 lwpsignal(struct proc *p, struct lwp *lp, int sig)
955 if (sig > _SIG_MAXSIG || sig <= 0) {
956 kprintf("lwpsignal: signal %d\n", sig);
957 panic("lwpsignal signal number");
960 KKASSERT(lp == NULL || lp->lwp_proc == p);
963 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
969 * If proc is traced, always give parent a chance;
970 * if signal event is tracked by procfs, give *that*
973 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
977 * Do not try to deliver signals to an exiting lwp. Note
978 * that we must still deliver the signal if P_WEXIT is set
979 * in the process flags.
981 if (lp && (lp->lwp_flag & LWP_WEXIT))
985 * Ig the signal is being ignored, then we forget about
986 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
987 * and if it is set to SIG_IGN, action will be SIG_DFL here.
989 if (SIGISMEMBER(p->p_sigignore, sig))
991 if (SIGISMEMBER(p->p_sigcatch, sig))
998 * If continuing, clear any pending STOP signals.
1001 SIG_STOPSIGMASK(p->p_siglist);
1003 if (prop & SA_STOP) {
1005 * If sending a tty stop signal to a member of an orphaned
1006 * process group, discard the signal here if the action
1007 * is default; don't stop the process below if sleeping,
1008 * and don't clear any pending SIGCONT.
1010 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1011 action == SIG_DFL) {
1014 SIG_CONTSIGMASK(p->p_siglist);
1015 p->p_flag &= ~P_CONTINUED;
1020 if (p->p_stat == SSTOP) {
1022 * Nobody can handle this signal, add it to the lwp or
1023 * process pending list
1026 SIGADDSET(lp->lwp_siglist, sig);
1028 SIGADDSET(p->p_siglist, sig);
1031 * If the process is stopped and is being traced, then no
1032 * further action is necessary.
1034 if (p->p_flag & P_TRACED)
1038 * If the process is stopped and receives a KILL signal,
1039 * make the process runnable.
1041 if (sig == SIGKILL) {
1043 goto active_process;
1047 * If the process is stopped and receives a CONT signal,
1048 * then try to make the process runnable again.
1050 if (prop & SA_CONT) {
1052 * If SIGCONT is default (or ignored), we continue the
1053 * process but don't leave the signal in p_siglist, as
1054 * it has no further action. If SIGCONT is held, we
1055 * continue the process and leave the signal in
1056 * p_siglist. If the process catches SIGCONT, let it
1057 * handle the signal itself.
1059 /* XXX what if the signal is being held blocked? */
1060 p->p_flag |= P_CONTINUED;
1062 if (action == SIG_DFL)
1063 SIGDELSET(p->p_siglist, sig);
1065 if (action == SIG_CATCH)
1066 goto active_process;
1071 * If the process is stopped and receives another STOP
1072 * signal, we do not need to stop it again. If we did
1073 * the shell could get confused.
1075 * However, if the current/preempted lwp is part of the
1076 * process receiving the signal, we need to keep it,
1077 * so that this lwp can stop in issignal() later, as
1078 * we don't want to wait until it reaches userret!
1080 if (prop & SA_STOP) {
1081 if (lwkt_preempted_proc() == NULL ||
1082 lwkt_preempted_proc()->lwp_proc != p)
1083 SIGDELSET(p->p_siglist, sig);
1087 * Otherwise the process is stopped and it received some
1088 * signal, which does not change its stopped state.
1090 * We have to select one thread to set LWP_BREAKTSLEEP,
1091 * so that the current signal will break the sleep
1092 * as soon as a SA_CONT signal will unstop the process.
1095 lp = find_lwp_for_signal(p, sig);
1097 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1098 lp->lwp_flag |= LWP_BREAKTSLEEP;
1103 /* else not stopped */
1107 * Never deliver a lwp-specific signal to a random lwp.
1110 lp = find_lwp_for_signal(p, sig);
1111 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1116 * Deliver to the process generically if (1) the signal is being
1117 * sent to any thread or (2) we could not find a thread to deliver
1121 SIGADDSET(p->p_siglist, sig);
1126 * Deliver to a specific LWP whether it masks it or not. It will
1127 * not be dispatched if masked but we must still deliver it.
1129 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1130 (p->p_flag & P_TRACED) == 0) {
1135 * If the process receives a STOP signal which indeed needs to
1136 * stop the process, do so. If the process chose to catch the
1137 * signal, it will be treated like any other signal.
1139 if ((prop & SA_STOP) && action == SIG_DFL) {
1141 * If a child holding parent blocked, stopping
1142 * could cause deadlock. Take no action at this
1145 if (p->p_flag & P_PPWAIT) {
1146 SIGADDSET(p->p_siglist, sig);
1151 * Do not actually try to manipulate the process, but simply
1152 * stop it. Lwps will stop as soon as they safely can.
1160 * If it is a CONT signal with default action, just ignore it.
1162 if ((prop & SA_CONT) && action == SIG_DFL)
1166 * Mark signal pending at this specific thread.
1168 SIGADDSET(lp->lwp_siglist, sig);
1177 lwp_signotify(struct lwp *lp)
1180 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1182 * Thread is in tsleep.
1186 * If the thread is sleeping uninterruptibly
1187 * we can't interrupt the sleep... the signal will
1188 * be noticed when the lwp returns through
1189 * trap() or syscall().
1191 * Otherwise the signal can interrupt the sleep.
1193 * If the process is traced, the lwp will handle the
1194 * tracing in issignal() when it returns to userland.
1196 if (lp->lwp_flag & LWP_SINTR) {
1198 * Make runnable and break out of any tsleep as well.
1200 lp->lwp_flag |= LWP_BREAKTSLEEP;
1205 * Otherwise the thread is running
1207 * LSRUN does nothing with the signal, other than kicking
1208 * ourselves if we are running.
1209 * SZOMB and SIDL mean that it will either never be noticed,
1210 * or noticed very soon.
1212 * Note that lwp_thread may be NULL or may not be completely
1213 * initialized if the process is in the SIDL or SZOMB state.
1215 * For SMP we may have to forward the request to another cpu.
1216 * YYY the MP lock prevents the target process from moving
1217 * to another cpu, see kern/kern_switch.c
1219 * If the target thread is waiting on its message port,
1220 * wakeup the target thread so it can check (or ignore)
1221 * the new signal. YYY needs cleanup.
1223 if (lp == lwkt_preempted_proc()) {
1225 } else if (lp->lwp_stat == LSRUN) {
1226 struct thread *td = lp->lwp_thread;
1227 struct proc *p = lp->lwp_proc;
1230 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1231 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1232 p->p_flag, lp->lwp_flag));
1235 * To prevent a MP race with TDF_SINTR we must
1236 * schedule the thread on the correct cpu.
1239 if (td->td_gd != mycpu) {
1241 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1244 if (td->td_flags & TDF_SINTR)
1254 * This function is called via an IPI. We will be in a critical section but
1255 * the MP lock will NOT be held. Also note that by the time the ipi message
1256 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1259 signotify_remote(void *arg)
1261 struct lwp *lp = arg;
1263 if (lp == lwkt_preempted_proc()) {
1266 struct thread *td = lp->lwp_thread;
1267 if (td->td_flags & TDF_SINTR)
1276 proc_stop(struct proc *p)
1280 /* If somebody raced us, be happy with it */
1281 if (p->p_stat == SSTOP)
1287 FOREACH_LWP_IN_PROC(lp, p) {
1288 switch (lp->lwp_stat) {
1291 * Do nothing, we are already counted in
1298 * We're sleeping, but we will stop before
1299 * returning to userspace, so count us
1300 * as stopped as well. We set LWP_WSTOP
1301 * to signal the lwp that it should not
1302 * increase p_nstopped when reaching tstop().
1304 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1305 lp->lwp_flag |= LWP_WSTOP;
1312 * We might notify ourself, but that's not
1320 if (p->p_nstopped == p->p_nthreads) {
1321 p->p_flag &= ~P_WAITED;
1323 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1324 ksignal(p->p_pptr, SIGCHLD);
1330 proc_unstop(struct proc *p)
1334 if (p->p_stat != SSTOP)
1338 p->p_stat = SACTIVE;
1340 FOREACH_LWP_IN_PROC(lp, p) {
1341 switch (lp->lwp_stat) {
1344 * Uh? Not stopped? Well, I guess that's okay.
1347 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1348 p->p_pid, lp->lwp_tid);
1353 * Still sleeping. Don't bother waking it up.
1354 * However, if this thread was counted as
1355 * stopped, undo this.
1357 * Nevertheless we call setrunnable() so that it
1358 * will wake up in case a signal or timeout arrived
1361 if (lp->lwp_flag & LWP_WSTOP) {
1362 lp->lwp_flag &= ~LWP_WSTOP;
1366 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1367 p->p_pid, lp->lwp_tid);
1381 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1383 sigset_t savedmask, set;
1384 struct proc *p = curproc;
1385 struct lwp *lp = curthread->td_lwp;
1386 int error, sig, hz, timevalid = 0;
1387 struct timespec rts, ets, ts;
1392 ets.tv_sec = 0; /* silence compiler warning */
1393 ets.tv_nsec = 0; /* silence compiler warning */
1394 SIG_CANTMASK(waitset);
1395 savedmask = lp->lwp_sigmask;
1398 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1399 timeout->tv_nsec < 1000000000) {
1401 getnanouptime(&rts);
1403 timespecadd(&ets, timeout);
1408 set = lwp_sigpend(lp);
1409 SIGSETAND(set, waitset);
1410 if ((sig = sig_ffs(&set)) != 0) {
1411 SIGFILLSET(lp->lwp_sigmask);
1412 SIGDELSET(lp->lwp_sigmask, sig);
1413 SIG_CANTMASK(lp->lwp_sigmask);
1416 * It may be a STOP signal, in the case, issignal
1417 * returns 0, because we may stop there, and new
1418 * signal can come in, we should restart if we got
1428 * Previous checking got nothing, and we retried but still
1429 * got nothing, we should return the error status.
1435 * POSIX says this must be checked after looking for pending
1439 if (timevalid == 0) {
1443 getnanouptime(&rts);
1444 if (timespeccmp(&rts, &ets, >=)) {
1449 timespecsub(&ts, &rts);
1450 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1451 hz = tvtohz_high(&tv);
1455 lp->lwp_sigmask = savedmask;
1456 SIGSETNAND(lp->lwp_sigmask, waitset);
1458 * We won't ever be woken up. Instead, our sleep will
1459 * be broken in lwpsignal().
1461 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1463 if (error == ERESTART) {
1464 /* can not restart a timeout wait. */
1466 } else if (error == EAGAIN) {
1467 /* will calculate timeout by ourself. */
1474 lp->lwp_sigmask = savedmask;
1477 bzero(info, sizeof(*info));
1478 info->si_signo = sig;
1479 lwp_delsig(lp, sig); /* take the signal! */
1488 sys_sigtimedwait(struct sigtimedwait_args *uap)
1491 struct timespec *timeout;
1497 error = copyin(uap->timeout, &ts, sizeof(ts));
1504 error = copyin(uap->set, &set, sizeof(set));
1507 error = kern_sigtimedwait(set, &info, timeout);
1511 error = copyout(&info, uap->info, sizeof(info));
1512 /* Repost if we got an error. */
1516 * This could transform a thread-specific signal to another
1517 * thread / process pending signal.
1520 ksignal(curproc, info.si_signo);
1522 uap->sysmsg_result = info.si_signo;
1527 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1533 error = copyin(uap->set, &set, sizeof(set));
1536 error = kern_sigtimedwait(set, &info, NULL);
1540 error = copyout(&info, uap->info, sizeof(info));
1541 /* Repost if we got an error. */
1545 * This could transform a thread-specific signal to another
1546 * thread / process pending signal.
1549 ksignal(curproc, info.si_signo);
1551 uap->sysmsg_result = info.si_signo;
1556 * If the current process has received a signal that would interrupt a
1557 * system call, return EINTR or ERESTART as appropriate.
1560 iscaught(struct lwp *lp)
1562 struct proc *p = lp->lwp_proc;
1566 if ((sig = CURSIG(lp)) != 0) {
1567 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1572 return(EWOULDBLOCK);
1576 * If the current process has received a signal (should be caught or cause
1577 * termination, should interrupt current syscall), return the signal number.
1578 * Stop signals with default action are processed immediately, then cleared;
1579 * they aren't returned. This is checked after each entry to the system for
1580 * a syscall or trap (though this can usually be done without calling issignal
1581 * by checking the pending signal masks in the CURSIG macro.) The normal call
1584 * This routine is called via CURSIG/__cursig and the MP lock might not be
1585 * held. Obtain the MP lock for the duration of the operation.
1587 * while (sig = CURSIG(curproc))
1591 issignal(struct lwp *lp)
1593 struct proc *p = lp->lwp_proc;
1599 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1601 mask = lwp_sigpend(lp);
1602 SIGSETNAND(mask, lp->lwp_sigmask);
1603 if (p->p_flag & P_PPWAIT)
1604 SIG_STOPSIGMASK(mask);
1605 if (SIGISEMPTY(mask)) { /* no signal to send */
1609 sig = sig_ffs(&mask);
1611 STOPEVENT(p, S_SIG, sig);
1614 * We should see pending but ignored signals
1615 * only if P_TRACED was on when they were posted.
1617 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1618 lwp_delsig(lp, sig);
1621 if ((p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1623 * If traced, always stop, and stay stopped until
1624 * released by the parent.
1626 * NOTE: SSTOP may get cleared during the loop,
1627 * but we do not re-notify the parent if we have
1628 * to loop several times waiting for the parent
1629 * to let us continue.
1631 * XXX not sure if this is still true
1637 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1640 * If parent wants us to take the signal,
1641 * then it will leave it in p->p_xstat;
1642 * otherwise we just look for signals again.
1644 lwp_delsig(lp, sig); /* clear old signal */
1650 * Put the new signal into p_siglist. If the
1651 * signal is being masked, look for other signals.
1653 * XXX lwp might need a call to ksignal()
1655 SIGADDSET(p->p_siglist, sig);
1656 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1660 * If the traced bit got turned off, go back up
1661 * to the top to rescan signals. This ensures
1662 * that p_sig* and ps_sigact are consistent.
1664 if ((p->p_flag & P_TRACED) == 0)
1668 prop = sigprop(sig);
1671 * Decide whether the signal should be returned.
1672 * Return the signal's number, or fall through
1673 * to clear it from the pending mask.
1675 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1678 * Don't take default actions on system processes.
1680 if (p->p_pid <= 1) {
1683 * Are you sure you want to ignore SIGSEGV
1686 kprintf("Process (pid %lu) got signal %d\n",
1687 (u_long)p->p_pid, sig);
1689 break; /* == ignore */
1693 * Handle the in-kernel checkpoint action
1695 if (prop & SA_CKPT) {
1696 checkpoint_signal_handler(lp);
1701 * If there is a pending stop signal to process
1702 * with default action, stop here,
1703 * then clear the signal. However,
1704 * if process is member of an orphaned
1705 * process group, ignore tty stop signals.
1707 if (prop & SA_STOP) {
1708 if (p->p_flag & P_TRACED ||
1709 (p->p_pgrp->pg_jobc == 0 &&
1711 break; /* == ignore */
1714 while (p->p_stat == SSTOP) {
1718 } else if (prop & SA_IGNORE) {
1720 * Except for SIGCONT, shouldn't get here.
1721 * Default action is to ignore; drop it.
1723 break; /* == ignore */
1733 * Masking above should prevent us ever trying
1734 * to take action on an ignored signal other
1735 * than SIGCONT, unless process is traced.
1737 if ((prop & SA_CONT) == 0 &&
1738 (p->p_flag & P_TRACED) == 0)
1739 kprintf("issignal\n");
1740 break; /* == ignore */
1744 * This signal has an action, let
1745 * postsig() process it.
1750 lwp_delsig(lp, sig); /* take the signal! */
1756 * Take the action for the specified signal
1757 * from the current set of pending signals.
1762 struct lwp *lp = curthread->td_lwp;
1763 struct proc *p = lp->lwp_proc;
1764 struct sigacts *ps = p->p_sigacts;
1766 sigset_t returnmask;
1769 KASSERT(sig != 0, ("postsig"));
1772 * If we are a virtual kernel running an emulated user process
1773 * context, switch back to the virtual kernel context before
1774 * trying to post the signal.
1776 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1777 struct trapframe *tf = lp->lwp_md.md_regs;
1779 vkernel_trap(lp, tf);
1782 lwp_delsig(lp, sig);
1783 action = ps->ps_sigact[_SIG_IDX(sig)];
1785 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1786 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1787 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1789 STOPEVENT(p, S_SIG, sig);
1791 if (action == SIG_DFL) {
1793 * Default action, where the default is to kill
1794 * the process. (Other cases were ignored above.)
1800 * If we get here, the signal must be caught.
1802 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1803 ("postsig action"));
1808 * Reset the signal handler if asked to
1810 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1812 * See kern_sigaction() for origin of this code.
1814 SIGDELSET(p->p_sigcatch, sig);
1815 if (sig != SIGCONT &&
1816 sigprop(sig) & SA_IGNORE)
1817 SIGADDSET(p->p_sigignore, sig);
1818 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1822 * Handle the mailbox case. Copyout to the appropriate
1823 * location but do not generate a signal frame. The system
1824 * call simply returns EINTR and the user is responsible for
1825 * polling the mailbox.
1827 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1829 copyout(&sig_copy, (void *)action, sizeof(int));
1830 curproc->p_flag |= P_MAILBOX;
1836 * Set the signal mask and calculate the mask to restore
1837 * when the signal function returns.
1839 * Special case: user has done a sigsuspend. Here the
1840 * current mask is not of interest, but rather the
1841 * mask from before the sigsuspend is what we want
1842 * restored after the signal processing is completed.
1844 if (lp->lwp_flag & LWP_OLDMASK) {
1845 returnmask = lp->lwp_oldsigmask;
1846 lp->lwp_flag &= ~LWP_OLDMASK;
1848 returnmask = lp->lwp_sigmask;
1851 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1852 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1853 SIGADDSET(lp->lwp_sigmask, sig);
1856 lp->lwp_ru.ru_nsignals++;
1857 if (lp->lwp_sig != sig) {
1860 code = lp->lwp_code;
1864 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1871 * Kill the current process for stated reason.
1874 killproc(struct proc *p, char *why)
1876 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1877 p->p_pid, p->p_comm,
1878 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1879 ksignal(p, SIGKILL);
1883 * Force the current process to exit with the specified signal, dumping core
1884 * if appropriate. We bypass the normal tests for masked and caught signals,
1885 * allowing unrecoverable failures to terminate the process without changing
1886 * signal state. Mark the accounting record with the signal termination.
1887 * If dumping core, save the signal number for the debugger. Calls exit and
1891 sigexit(struct lwp *lp, int sig)
1893 struct proc *p = lp->lwp_proc;
1895 p->p_acflag |= AXSIG;
1896 if (sigprop(sig) & SA_CORE) {
1899 * Log signals which would cause core dumps
1900 * (Log as LOG_INFO to appease those who don't want
1902 * XXX : Todo, as well as euid, write out ruid too
1904 if (coredump(lp, sig) == 0)
1906 if (kern_logsigexit)
1908 "pid %d (%s), uid %d: exited on signal %d%s\n",
1909 p->p_pid, p->p_comm,
1910 p->p_ucred ? p->p_ucred->cr_uid : -1,
1912 sig & WCOREFLAG ? " (core dumped)" : "");
1914 exit1(W_EXITCODE(0, sig));
1918 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
1919 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
1920 sizeof(corefilename), "process corefile name format string");
1923 * expand_name(name, uid, pid)
1924 * Expand the name described in corefilename, using name, uid, and pid.
1925 * corefilename is a kprintf-like string, with three format specifiers:
1926 * %N name of process ("name")
1927 * %P process id (pid)
1929 * For example, "%N.core" is the default; they can be disabled completely
1930 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1931 * This is controlled by the sysctl variable kern.corefile (see above).
1935 expand_name(const char *name, uid_t uid, pid_t pid)
1938 char buf[11]; /* Buffer for pid/uid -- max 4B */
1940 char *format = corefilename;
1943 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
1946 namelen = strlen(name);
1947 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
1949 switch (format[i]) {
1950 case '%': /* Format character */
1952 switch (format[i]) {
1956 case 'N': /* process name */
1957 if ((n + namelen) > MAXPATHLEN) {
1958 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1959 pid, name, uid, temp, name);
1960 kfree(temp, M_TEMP);
1963 memcpy(temp+n, name, namelen);
1966 case 'P': /* process id */
1967 l = ksprintf(buf, "%u", pid);
1968 if ((n + l) > MAXPATHLEN) {
1969 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1970 pid, name, uid, temp, name);
1971 kfree(temp, M_TEMP);
1974 memcpy(temp+n, buf, l);
1977 case 'U': /* user id */
1978 l = ksprintf(buf, "%u", uid);
1979 if ((n + l) > MAXPATHLEN) {
1980 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1981 pid, name, uid, temp, name);
1982 kfree(temp, M_TEMP);
1985 memcpy(temp+n, buf, l);
1989 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
1993 temp[n++] = format[i];
2001 * Dump a process' core. The main routine does some
2002 * policy checking, and creates the name of the coredump;
2003 * then it passes on a vnode and a size limit to the process-specific
2004 * coredump routine if there is one; if there _is not_ one, it returns
2005 * ENOSYS; otherwise it returns the error from the process-specific routine.
2007 * The parameter `lp' is the lwp which triggered the coredump.
2011 coredump(struct lwp *lp, int sig)
2013 struct proc *p = lp->lwp_proc;
2015 struct ucred *cred = p->p_ucred;
2017 struct nlookupdata nd;
2020 char *name; /* name of corefile */
2023 STOPEVENT(p, S_CORE, 0);
2025 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2029 * Note that the bulk of limit checking is done after
2030 * the corefile is created. The exception is if the limit
2031 * for corefiles is 0, in which case we don't bother
2032 * creating the corefile at all. This layout means that
2033 * a corefile is truncated instead of not being created,
2034 * if it is larger than the limit.
2036 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2040 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2043 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2045 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2046 kfree(name, M_TEMP);
2052 nd.nl_open_vp = NULL;
2056 lf.l_whence = SEEK_SET;
2059 lf.l_type = F_WRLCK;
2060 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2064 /* Don't dump to non-regular files or files with links. */
2065 if (vp->v_type != VREG ||
2066 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2071 /* Don't dump to files current user does not own */
2072 if (vattr.va_uid != p->p_ucred->cr_uid) {
2078 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2080 VOP_SETATTR(vp, &vattr, cred);
2081 p->p_acflag |= ACORE;
2084 error = p->p_sysent->sv_coredump ?
2085 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2088 lf.l_type = F_UNLCK;
2089 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2091 error1 = vn_close(vp, FWRITE);
2098 * Nonexistent system call-- signal process (may want to handle it).
2099 * Flag error in case process won't see signal immediately (blocked or ignored).
2103 sys_nosys(struct nosys_args *args)
2105 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2110 * Send a SIGIO or SIGURG signal to a process or process group using
2111 * stored credentials rather than those of the current process.
2114 pgsigio(struct sigio *sigio, int sig, int checkctty)
2119 if (sigio->sio_pgid > 0) {
2120 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2122 ksignal(sigio->sio_proc, sig);
2123 } else if (sigio->sio_pgid < 0) {
2126 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2127 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2128 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2129 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2132 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2137 filt_sigattach(struct knote *kn)
2139 struct proc *p = curproc;
2141 kn->kn_ptr.p_proc = p;
2142 kn->kn_flags |= EV_CLEAR; /* automatically set */
2144 /* XXX lock the proc here while adding to the list? */
2145 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
2151 filt_sigdetach(struct knote *kn)
2153 struct proc *p = kn->kn_ptr.p_proc;
2155 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
2159 * signal knotes are shared with proc knotes, so we apply a mask to
2160 * the hint in order to differentiate them from process hints. This
2161 * could be avoided by using a signal-specific knote list, but probably
2162 * isn't worth the trouble.
2165 filt_signal(struct knote *kn, long hint)
2167 if (hint & NOTE_SIGNAL) {
2168 hint &= ~NOTE_SIGNAL;
2170 if (kn->kn_id == hint)
2173 return (kn->kn_data != 0);