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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);
355 if (sig != SIGCONT) {
356 /* easier in ksignal */
357 SIGADDSET(p->p_sigignore, sig);
359 SIGDELSET(p->p_sigcatch, sig);
361 SIGDELSET(p->p_sigignore, sig);
362 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
363 SIGDELSET(p->p_sigcatch, sig);
365 SIGADDSET(p->p_sigcatch, sig);
370 lwkt_reltoken(&proc_token);
375 sys_sigaction(struct sigaction_args *uap)
377 struct sigaction act, oact;
378 struct sigaction *actp, *oactp;
381 actp = (uap->act != NULL) ? &act : NULL;
382 oactp = (uap->oact != NULL) ? &oact : NULL;
384 error = copyin(uap->act, actp, sizeof(act));
388 error = kern_sigaction(uap->sig, actp, oactp);
389 if (oactp && !error) {
390 error = copyout(oactp, uap->oact, sizeof(oact));
396 * Initialize signal state for process 0;
397 * set to ignore signals that are ignored by default.
400 siginit(struct proc *p)
404 for (i = 1; i <= NSIG; i++)
405 if (sigprop(i) & SA_IGNORE && i != SIGCONT)
406 SIGADDSET(p->p_sigignore, i);
410 * Reset signals for an exec of the specified process.
413 execsigs(struct proc *p)
415 struct sigacts *ps = p->p_sigacts;
419 lp = ONLY_LWP_IN_PROC(p);
422 * Reset caught signals. Held signals remain held
423 * through p_sigmask (unless they were caught,
424 * and are now ignored by default).
426 while (SIGNOTEMPTY(p->p_sigcatch)) {
427 sig = sig_ffs(&p->p_sigcatch);
428 SIGDELSET(p->p_sigcatch, sig);
429 if (sigprop(sig) & SA_IGNORE) {
431 SIGADDSET(p->p_sigignore, sig);
432 SIGDELSET(p->p_siglist, sig);
433 SIGDELSET(lp->lwp_siglist, sig);
435 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
439 * Reset stack state to the user stack.
440 * Clear set of signals caught on the signal stack.
442 lp->lwp_sigstk.ss_flags = SS_DISABLE;
443 lp->lwp_sigstk.ss_size = 0;
444 lp->lwp_sigstk.ss_sp = 0;
445 lp->lwp_flag &= ~LWP_ALTSTACK;
447 * Reset no zombies if child dies flag as Solaris does.
449 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT;
453 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
455 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
459 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset)
461 struct thread *td = curthread;
462 struct lwp *lp = td->td_lwp;
465 lwkt_gettoken(&proc_token);
468 *oset = lp->lwp_sigmask;
475 SIGSETOR(lp->lwp_sigmask, *set);
478 SIGSETNAND(lp->lwp_sigmask, *set);
482 lp->lwp_sigmask = *set;
490 lwkt_reltoken(&proc_token);
501 sys_sigprocmask(struct sigprocmask_args *uap)
504 sigset_t *setp, *osetp;
507 setp = (uap->set != NULL) ? &set : NULL;
508 osetp = (uap->oset != NULL) ? &oset : NULL;
510 error = copyin(uap->set, setp, sizeof(set));
514 error = kern_sigprocmask(uap->how, setp, osetp);
515 if (osetp && !error) {
516 error = copyout(osetp, uap->oset, sizeof(oset));
525 kern_sigpending(struct __sigset *set)
527 struct lwp *lp = curthread->td_lwp;
529 *set = lwp_sigpend(lp);
538 sys_sigpending(struct sigpending_args *uap)
543 error = kern_sigpending(&set);
546 error = copyout(&set, uap->set, sizeof(set));
551 * Suspend process until signal, providing mask to be set
557 kern_sigsuspend(struct __sigset *set)
559 struct thread *td = curthread;
560 struct lwp *lp = td->td_lwp;
561 struct proc *p = td->td_proc;
562 struct sigacts *ps = p->p_sigacts;
565 * When returning from sigsuspend, we want
566 * the old mask to be restored after the
567 * signal handler has finished. Thus, we
568 * save it here and mark the sigacts structure
571 lp->lwp_oldsigmask = lp->lwp_sigmask;
572 lp->lwp_flag |= LWP_OLDMASK;
575 lp->lwp_sigmask = *set;
576 while (tsleep(ps, PCATCH, "pause", 0) == 0)
578 /* always return EINTR rather than ERESTART... */
583 * Note nonstandard calling convention: libc stub passes mask, not
584 * pointer, to save a copyin.
589 sys_sigsuspend(struct sigsuspend_args *uap)
594 error = copyin(uap->sigmask, &mask, sizeof(mask));
598 error = kern_sigsuspend(&mask);
607 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss)
609 struct thread *td = curthread;
610 struct lwp *lp = td->td_lwp;
611 struct proc *p = td->td_proc;
613 if ((lp->lwp_flag & LWP_ALTSTACK) == 0)
614 lp->lwp_sigstk.ss_flags |= SS_DISABLE;
617 *oss = lp->lwp_sigstk;
620 if (ss->ss_flags & SS_DISABLE) {
621 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
623 lp->lwp_flag &= ~LWP_ALTSTACK;
624 lp->lwp_sigstk.ss_flags = ss->ss_flags;
626 if (ss->ss_size < p->p_sysent->sv_minsigstksz)
628 lp->lwp_flag |= LWP_ALTSTACK;
629 lp->lwp_sigstk = *ss;
640 sys_sigaltstack(struct sigaltstack_args *uap)
646 error = copyin(uap->ss, &ss, sizeof(ss));
651 error = kern_sigaltstack(uap->ss ? &ss : NULL,
652 uap->oss ? &oss : NULL);
654 if (error == 0 && uap->oss)
655 error = copyout(&oss, uap->oss, sizeof(*uap->oss));
660 * Common code for kill process group/broadcast kill.
661 * cp is calling process.
668 static int killpg_all_callback(struct proc *p, void *data);
671 dokillpg(int sig, int pgid, int all)
673 struct killpg_info info;
674 struct proc *cp = curproc;
685 allproc_scan(killpg_all_callback, &info);
689 * zero pgid means send to my process group.
697 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
698 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
700 p->p_stat == SZOMB ||
701 (p->p_flag & P_SYSTEM) ||
702 !CANSIGNAL(p, sig)) {
709 lockmgr(&pgrp->pg_lock, LK_RELEASE);
711 return (info.nfound ? 0 : ESRCH);
715 killpg_all_callback(struct proc *p, void *data)
717 struct killpg_info *info = data;
719 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) ||
720 p == curproc || !CANSIGNAL(p, info->sig)) {
725 ksignal(p, info->sig);
730 * Send a general signal to a process or LWPs within that process. Note
731 * that new signals cannot be sent if a process is exiting.
736 kern_kill(int sig, pid_t pid, lwpid_t tid)
740 if ((u_int)sig > _SIG_MAXSIG)
743 lwkt_gettoken(&proc_token);
747 struct lwp *lp = NULL;
749 /* kill single process */
750 if ((p = pfind(pid)) == NULL) {
751 lwkt_reltoken(&proc_token);
754 if (!CANSIGNAL(p, sig)) {
755 lwkt_reltoken(&proc_token);
760 * NOP if the process is exiting. Note that lwpsignal() is
761 * called directly with P_WEXIT set to kill individual LWPs
762 * during exit, which is allowed.
764 if (p->p_flag & P_WEXIT) {
765 lwkt_reltoken(&proc_token);
769 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid);
771 lwkt_reltoken(&proc_token);
776 lwpsignal(p, lp, sig);
777 lwkt_reltoken(&proc_token);
781 * If we come here, pid is a special broadcast pid.
782 * This doesn't mix with a tid.
785 lwkt_reltoken(&proc_token);
789 case -1: /* broadcast signal */
790 t = (dokillpg(sig, 0, 1));
792 case 0: /* signal own process group */
793 t = (dokillpg(sig, 0, 0));
795 default: /* negative explicit process group */
796 t = (dokillpg(sig, -pid, 0));
799 lwkt_reltoken(&proc_token);
804 sys_kill(struct kill_args *uap)
808 error = kern_kill(uap->signum, uap->pid, -1);
813 sys_lwp_kill(struct lwp_kill_args *uap)
816 pid_t pid = uap->pid;
819 * A tid is mandatory for lwp_kill(), otherwise
820 * you could simply use kill().
826 * To save on a getpid() function call for intra-process
827 * signals, pid == -1 means current process.
830 pid = curproc->p_pid;
832 error = kern_kill(uap->signum, pid, uap->tid);
837 * Send a signal to a process group.
840 gsignal(int pgid, int sig)
844 if (pgid && (pgrp = pgfind(pgid)))
845 pgsignal(pgrp, sig, 0);
849 * Send a signal to a process group. If checktty is 1,
850 * limit to members which have a controlling terminal.
852 * pg_lock interlocks against a fork that might be in progress, to
853 * ensure that the new child process picks up the signal.
856 pgsignal(struct pgrp *pgrp, int sig, int checkctty)
861 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE);
862 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
863 if (checkctty == 0 || p->p_flag & P_CONTROLT)
866 lockmgr(&pgrp->pg_lock, LK_RELEASE);
871 * Send a signal caused by a trap to the current lwp. If it will be caught
872 * immediately, deliver it with correct code. Otherwise, post it normally.
874 * These signals may ONLY be delivered to the specified lwp and may never
875 * be delivered to the process generically.
878 trapsignal(struct lwp *lp, int sig, u_long code)
880 struct proc *p = lp->lwp_proc;
881 struct sigacts *ps = p->p_sigacts;
884 * If we are a virtual kernel running an emulated user process
885 * context, switch back to the virtual kernel context before
886 * trying to post the signal.
888 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
889 struct trapframe *tf = lp->lwp_md.md_regs;
891 vkernel_trap(lp, tf);
895 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
896 !SIGISMEMBER(lp->lwp_sigmask, sig)) {
897 lp->lwp_ru.ru_nsignals++;
899 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
900 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)],
901 &lp->lwp_sigmask, code);
903 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
904 &lp->lwp_sigmask, code);
905 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
906 if (!SIGISMEMBER(ps->ps_signodefer, sig))
907 SIGADDSET(lp->lwp_sigmask, sig);
908 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
910 * See kern_sigaction() for origin of this code.
912 SIGDELSET(p->p_sigcatch, sig);
913 if (sig != SIGCONT &&
914 sigprop(sig) & SA_IGNORE)
915 SIGADDSET(p->p_sigignore, sig);
916 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
919 lp->lwp_code = code; /* XXX for core dump/debugger */
920 lp->lwp_sig = sig; /* XXX to verify code */
921 lwpsignal(p, lp, sig);
926 * Find a suitable lwp to deliver the signal to.
928 * Returns NULL if all lwps hold the signal blocked.
931 find_lwp_for_signal(struct proc *p, int sig)
934 struct lwp *run, *sleep, *stop;
937 * If the running/preempted thread belongs to the proc to which
938 * the signal is being delivered and this thread does not block
939 * the signal, then we can avoid a context switch by delivering
940 * the signal to this thread, because it will return to userland
943 lp = lwkt_preempted_proc();
944 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig))
947 run = sleep = stop = NULL;
948 FOREACH_LWP_IN_PROC(lp, p) {
950 * If the signal is being blocked by the lwp, then this
951 * lwp is not eligible for receiving the signal.
953 if (SIGISMEMBER(lp->lwp_sigmask, sig))
956 switch (lp->lwp_stat) {
966 if (lp->lwp_flag & LWP_SINTR)
974 else if (sleep != NULL)
981 * Send the signal to the process. If the signal has an action, the action
982 * is usually performed by the target process rather than the caller; we add
983 * the signal to the set of pending signals for the process.
986 * o When a stop signal is sent to a sleeping process that takes the
987 * default action, the process is stopped without awakening it.
988 * o SIGCONT restarts stopped processes (or puts them back to sleep)
989 * regardless of the signal action (eg, blocked or ignored).
991 * Other ignored signals are discarded immediately.
996 ksignal(struct proc *p, int sig)
998 lwpsignal(p, NULL, sig);
1002 * The core for ksignal. lp may be NULL, then a suitable thread
1003 * will be chosen. If not, lp MUST be a member of p.
1008 lwpsignal(struct proc *p, struct lwp *lp, int sig)
1013 if (sig > _SIG_MAXSIG || sig <= 0) {
1014 kprintf("lwpsignal: signal %d\n", sig);
1015 panic("lwpsignal signal number");
1018 KKASSERT(lp == NULL || lp->lwp_proc == p);
1020 lwkt_gettoken(&proc_token);
1022 prop = sigprop(sig);
1025 * If proc is traced, always give parent a chance;
1026 * if signal event is tracked by procfs, give *that*
1027 * a chance, as well.
1029 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1033 * Do not try to deliver signals to an exiting lwp. Note
1034 * that we must still deliver the signal if P_WEXIT is set
1035 * in the process flags.
1037 if (lp && (lp->lwp_flag & LWP_WEXIT)) {
1038 lwkt_reltoken(&proc_token);
1043 * If the signal is being ignored, then we forget about
1044 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1045 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1047 if (SIGISMEMBER(p->p_sigignore, sig)) {
1048 lwkt_reltoken(&proc_token);
1051 if (SIGISMEMBER(p->p_sigcatch, sig))
1058 * If continuing, clear any pending STOP signals.
1061 SIG_STOPSIGMASK(p->p_siglist);
1063 if (prop & SA_STOP) {
1065 * If sending a tty stop signal to a member of an orphaned
1066 * process group, discard the signal here if the action
1067 * is default; don't stop the process below if sleeping,
1068 * and don't clear any pending SIGCONT.
1070 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 &&
1071 action == SIG_DFL) {
1072 lwkt_reltoken(&proc_token);
1075 SIG_CONTSIGMASK(p->p_siglist);
1076 p->p_flag &= ~P_CONTINUED;
1081 if (p->p_stat == SSTOP) {
1083 * Nobody can handle this signal, add it to the lwp or
1084 * process pending list
1087 SIGADDSET(lp->lwp_siglist, sig);
1089 SIGADDSET(p->p_siglist, sig);
1092 * If the process is stopped and is being traced, then no
1093 * further action is necessary.
1095 if (p->p_flag & P_TRACED)
1099 * If the process is stopped and receives a KILL signal,
1100 * make the process runnable.
1102 if (sig == SIGKILL) {
1104 goto active_process;
1108 * If the process is stopped and receives a CONT signal,
1109 * then try to make the process runnable again.
1111 if (prop & SA_CONT) {
1113 * If SIGCONT is default (or ignored), we continue the
1114 * process but don't leave the signal in p_siglist, as
1115 * it has no further action. If SIGCONT is held, we
1116 * continue the process and leave the signal in
1117 * p_siglist. If the process catches SIGCONT, let it
1118 * handle the signal itself.
1120 /* XXX what if the signal is being held blocked? */
1121 p->p_flag |= P_CONTINUED;
1123 if (action == SIG_DFL)
1124 SIGDELSET(p->p_siglist, sig);
1126 if (action == SIG_CATCH)
1127 goto active_process;
1132 * If the process is stopped and receives another STOP
1133 * signal, we do not need to stop it again. If we did
1134 * the shell could get confused.
1136 * However, if the current/preempted lwp is part of the
1137 * process receiving the signal, we need to keep it,
1138 * so that this lwp can stop in issignal() later, as
1139 * we don't want to wait until it reaches userret!
1141 if (prop & SA_STOP) {
1142 if (lwkt_preempted_proc() == NULL ||
1143 lwkt_preempted_proc()->lwp_proc != p)
1144 SIGDELSET(p->p_siglist, sig);
1148 * Otherwise the process is stopped and it received some
1149 * signal, which does not change its stopped state.
1151 * We have to select one thread to set LWP_BREAKTSLEEP,
1152 * so that the current signal will break the sleep
1153 * as soon as a SA_CONT signal will unstop the process.
1156 lp = find_lwp_for_signal(p, sig);
1158 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP))
1159 lp->lwp_flag |= LWP_BREAKTSLEEP;
1164 /* else not stopped */
1168 * Never deliver a lwp-specific signal to a random lwp.
1171 lp = find_lwp_for_signal(p, sig);
1172 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig))
1177 * Deliver to the process generically if (1) the signal is being
1178 * sent to any thread or (2) we could not find a thread to deliver
1182 SIGADDSET(p->p_siglist, sig);
1187 * Deliver to a specific LWP whether it masks it or not. It will
1188 * not be dispatched if masked but we must still deliver it.
1190 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
1191 (p->p_flag & P_TRACED) == 0) {
1196 * If the process receives a STOP signal which indeed needs to
1197 * stop the process, do so. If the process chose to catch the
1198 * signal, it will be treated like any other signal.
1200 if ((prop & SA_STOP) && action == SIG_DFL) {
1202 * If a child holding parent blocked, stopping
1203 * could cause deadlock. Take no action at this
1206 if (p->p_flag & P_PPWAIT) {
1207 SIGADDSET(p->p_siglist, sig);
1212 * Do not actually try to manipulate the process, but simply
1213 * stop it. Lwps will stop as soon as they safely can.
1221 * If it is a CONT signal with default action, just ignore it.
1223 if ((prop & SA_CONT) && action == SIG_DFL)
1227 * Mark signal pending at this specific thread.
1229 SIGADDSET(lp->lwp_siglist, sig);
1234 lwkt_reltoken(&proc_token);
1239 * proc_token must be held
1242 lwp_signotify(struct lwp *lp)
1244 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1247 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) {
1249 * Thread is in tsleep.
1253 * If the thread is sleeping uninterruptibly
1254 * we can't interrupt the sleep... the signal will
1255 * be noticed when the lwp returns through
1256 * trap() or syscall().
1258 * Otherwise the signal can interrupt the sleep.
1260 * If the process is traced, the lwp will handle the
1261 * tracing in issignal() when it returns to userland.
1263 if (lp->lwp_flag & LWP_SINTR) {
1265 * Make runnable and break out of any tsleep as well.
1267 lp->lwp_flag |= LWP_BREAKTSLEEP;
1272 * Otherwise the thread is running
1274 * LSRUN does nothing with the signal, other than kicking
1275 * ourselves if we are running.
1276 * SZOMB and SIDL mean that it will either never be noticed,
1277 * or noticed very soon.
1279 * Note that lwp_thread may be NULL or may not be completely
1280 * initialized if the process is in the SIDL or SZOMB state.
1282 * For SMP we may have to forward the request to another cpu.
1283 * YYY the MP lock prevents the target process from moving
1284 * to another cpu, see kern/kern_switch.c
1286 * If the target thread is waiting on its message port,
1287 * wakeup the target thread so it can check (or ignore)
1288 * the new signal. YYY needs cleanup.
1290 if (lp == lwkt_preempted_proc()) {
1292 } else if (lp->lwp_stat == LSRUN) {
1293 struct thread *td = lp->lwp_thread;
1294 struct proc *p __debugvar = lp->lwp_proc;
1297 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1298 p->p_pid, lp->lwp_tid, lp->lwp_stat,
1299 p->p_flag, lp->lwp_flag));
1302 * To prevent a MP race with TDF_SINTR we must
1303 * schedule the thread on the correct cpu.
1306 if (td->td_gd != mycpu) {
1308 lwkt_send_ipiq(td->td_gd, signotify_remote, lp);
1311 if (td->td_flags & TDF_SINTR)
1321 * This function is called via an IPI. We will be in a critical section but
1322 * the MP lock will NOT be held. Also note that by the time the ipi message
1323 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1326 signotify_remote(void *arg)
1328 struct lwp *lp = arg;
1330 if (lp == lwkt_preempted_proc()) {
1333 struct thread *td = lp->lwp_thread;
1334 if (td->td_flags & TDF_SINTR)
1343 * Caller must hold proc_token
1346 proc_stop(struct proc *p)
1350 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1353 /* If somebody raced us, be happy with it */
1354 if (p->p_stat == SSTOP || p->p_stat == SZOMB) {
1360 FOREACH_LWP_IN_PROC(lp, p) {
1361 switch (lp->lwp_stat) {
1364 * Do nothing, we are already counted in
1371 * We're sleeping, but we will stop before
1372 * returning to userspace, so count us
1373 * as stopped as well. We set LWP_WSTOP
1374 * to signal the lwp that it should not
1375 * increase p_nstopped when reaching tstop().
1377 if ((lp->lwp_flag & LWP_WSTOP) == 0) {
1378 lp->lwp_flag |= LWP_WSTOP;
1385 * We might notify ourself, but that's not
1393 if (p->p_nstopped == p->p_nthreads) {
1394 p->p_flag &= ~P_WAITED;
1396 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0)
1397 ksignal(p->p_pptr, SIGCHLD);
1403 * Caller must hold proc_token
1406 proc_unstop(struct proc *p)
1410 ASSERT_LWKT_TOKEN_HELD(&proc_token);
1413 if (p->p_stat != SSTOP) {
1418 p->p_stat = SACTIVE;
1420 FOREACH_LWP_IN_PROC(lp, p) {
1421 switch (lp->lwp_stat) {
1424 * Uh? Not stopped? Well, I guess that's okay.
1427 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1428 p->p_pid, lp->lwp_tid);
1433 * Still sleeping. Don't bother waking it up.
1434 * However, if this thread was counted as
1435 * stopped, undo this.
1437 * Nevertheless we call setrunnable() so that it
1438 * will wake up in case a signal or timeout arrived
1441 if (lp->lwp_flag & LWP_WSTOP) {
1442 lp->lwp_flag &= ~LWP_WSTOP;
1446 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1447 p->p_pid, lp->lwp_tid);
1464 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout)
1466 sigset_t savedmask, set;
1467 struct proc *p = curproc;
1468 struct lwp *lp = curthread->td_lwp;
1469 int error, sig, hz, timevalid = 0;
1470 struct timespec rts, ets, ts;
1473 lwkt_gettoken(&proc_token);
1477 ets.tv_sec = 0; /* silence compiler warning */
1478 ets.tv_nsec = 0; /* silence compiler warning */
1479 SIG_CANTMASK(waitset);
1480 savedmask = lp->lwp_sigmask;
1483 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 &&
1484 timeout->tv_nsec < 1000000000) {
1486 getnanouptime(&rts);
1488 timespecadd(&ets, timeout);
1493 set = lwp_sigpend(lp);
1494 SIGSETAND(set, waitset);
1495 if ((sig = sig_ffs(&set)) != 0) {
1496 SIGFILLSET(lp->lwp_sigmask);
1497 SIGDELSET(lp->lwp_sigmask, sig);
1498 SIG_CANTMASK(lp->lwp_sigmask);
1499 sig = issignal(lp, 1);
1501 * It may be a STOP signal, in the case, issignal
1502 * returns 0, because we may stop there, and new
1503 * signal can come in, we should restart if we got
1513 * Previous checking got nothing, and we retried but still
1514 * got nothing, we should return the error status.
1520 * POSIX says this must be checked after looking for pending
1524 if (timevalid == 0) {
1528 getnanouptime(&rts);
1529 if (timespeccmp(&rts, &ets, >=)) {
1534 timespecsub(&ts, &rts);
1535 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1536 hz = tvtohz_high(&tv);
1540 lp->lwp_sigmask = savedmask;
1541 SIGSETNAND(lp->lwp_sigmask, waitset);
1543 * We won't ever be woken up. Instead, our sleep will
1544 * be broken in lwpsignal().
1546 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz);
1548 if (error == ERESTART) {
1549 /* can not restart a timeout wait. */
1551 } else if (error == EAGAIN) {
1552 /* will calculate timeout by ourself. */
1559 lp->lwp_sigmask = savedmask;
1562 bzero(info, sizeof(*info));
1563 info->si_signo = sig;
1564 lwp_delsig(lp, sig); /* take the signal! */
1566 if (sig == SIGKILL) {
1567 lwkt_reltoken(&proc_token);
1573 lwkt_reltoken(&proc_token);
1582 sys_sigtimedwait(struct sigtimedwait_args *uap)
1585 struct timespec *timeout;
1591 error = copyin(uap->timeout, &ts, sizeof(ts));
1598 error = copyin(uap->set, &set, sizeof(set));
1601 error = kern_sigtimedwait(set, &info, timeout);
1605 error = copyout(&info, uap->info, sizeof(info));
1606 /* Repost if we got an error. */
1610 * This could transform a thread-specific signal to another
1611 * thread / process pending signal.
1614 ksignal(curproc, info.si_signo);
1616 uap->sysmsg_result = info.si_signo;
1625 sys_sigwaitinfo(struct sigwaitinfo_args *uap)
1631 error = copyin(uap->set, &set, sizeof(set));
1634 error = kern_sigtimedwait(set, &info, NULL);
1638 error = copyout(&info, uap->info, sizeof(info));
1639 /* Repost if we got an error. */
1643 * This could transform a thread-specific signal to another
1644 * thread / process pending signal.
1647 ksignal(curproc, info.si_signo);
1649 uap->sysmsg_result = info.si_signo;
1655 * If the current process has received a signal that would interrupt a
1656 * system call, return EINTR or ERESTART as appropriate.
1659 iscaught(struct lwp *lp)
1661 struct proc *p = lp->lwp_proc;
1665 if ((sig = CURSIG(lp)) != 0) {
1666 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig))
1671 return(EWOULDBLOCK);
1675 * If the current process has received a signal (should be caught or cause
1676 * termination, should interrupt current syscall), return the signal number.
1677 * Stop signals with default action are processed immediately, then cleared;
1678 * they aren't returned. This is checked after each entry to the system for
1679 * a syscall or trap (though this can usually be done without calling issignal
1680 * by checking the pending signal masks in the CURSIG macro.) The normal call
1683 * This routine is called via CURSIG/__cursig and the MP lock might not be
1684 * held. Obtain the MP lock for the duration of the operation.
1686 * while (sig = CURSIG(curproc))
1690 issignal(struct lwp *lp, int maytrace)
1692 struct proc *p = lp->lwp_proc;
1696 lwkt_gettoken(&proc_token);
1699 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
1702 * If this process is supposed to stop, stop this thread.
1704 if (p->p_stat == SSTOP)
1707 mask = lwp_sigpend(lp);
1708 SIGSETNAND(mask, lp->lwp_sigmask);
1709 if (p->p_flag & P_PPWAIT)
1710 SIG_STOPSIGMASK(mask);
1711 if (SIGISEMPTY(mask)) { /* no signal to send */
1712 lwkt_reltoken(&proc_token);
1715 sig = sig_ffs(&mask);
1717 STOPEVENT(p, S_SIG, sig);
1720 * We should see pending but ignored signals
1721 * only if P_TRACED was on when they were posted.
1723 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
1724 lwp_delsig(lp, sig);
1727 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) {
1729 * If traced, always stop, and stay stopped until
1730 * released by the parent.
1732 * NOTE: SSTOP may get cleared during the loop,
1733 * but we do not re-notify the parent if we have
1734 * to loop several times waiting for the parent
1735 * to let us continue.
1737 * XXX not sure if this is still true
1743 } while (!trace_req(p) && (p->p_flag & P_TRACED));
1746 * If parent wants us to take the signal,
1747 * then it will leave it in p->p_xstat;
1748 * otherwise we just look for signals again.
1750 lwp_delsig(lp, sig); /* clear old signal */
1756 * Put the new signal into p_siglist. If the
1757 * signal is being masked, look for other signals.
1759 * XXX lwp might need a call to ksignal()
1761 SIGADDSET(p->p_siglist, sig);
1762 if (SIGISMEMBER(lp->lwp_sigmask, sig))
1766 * If the traced bit got turned off, go back up
1767 * to the top to rescan signals. This ensures
1768 * that p_sig* and ps_sigact are consistent.
1770 if ((p->p_flag & P_TRACED) == 0)
1774 prop = sigprop(sig);
1777 * Decide whether the signal should be returned.
1778 * Return the signal's number, or fall through
1779 * to clear it from the pending mask.
1781 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1782 case (intptr_t)SIG_DFL:
1784 * Don't take default actions on system processes.
1786 if (p->p_pid <= 1) {
1789 * Are you sure you want to ignore SIGSEGV
1792 kprintf("Process (pid %lu) got signal %d\n",
1793 (u_long)p->p_pid, sig);
1795 break; /* == ignore */
1799 * Handle the in-kernel checkpoint action
1801 if (prop & SA_CKPT) {
1802 checkpoint_signal_handler(lp);
1807 * If there is a pending stop signal to process
1808 * with default action, stop here,
1809 * then clear the signal. However,
1810 * if process is member of an orphaned
1811 * process group, ignore tty stop signals.
1813 if (prop & SA_STOP) {
1814 if (p->p_flag & P_TRACED ||
1815 (p->p_pgrp->pg_jobc == 0 &&
1817 break; /* == ignore */
1822 } else if (prop & SA_IGNORE) {
1824 * Except for SIGCONT, shouldn't get here.
1825 * Default action is to ignore; drop it.
1827 break; /* == ignore */
1829 lwkt_reltoken(&proc_token);
1835 case (intptr_t)SIG_IGN:
1837 * Masking above should prevent us ever trying
1838 * to take action on an ignored signal other
1839 * than SIGCONT, unless process is traced.
1841 if ((prop & SA_CONT) == 0 &&
1842 (p->p_flag & P_TRACED) == 0)
1843 kprintf("issignal\n");
1844 break; /* == ignore */
1848 * This signal has an action, let
1849 * postsig() process it.
1851 lwkt_reltoken(&proc_token);
1854 lwp_delsig(lp, sig); /* take the signal! */
1860 * Take the action for the specified signal
1861 * from the current set of pending signals.
1866 struct lwp *lp = curthread->td_lwp;
1867 struct proc *p = lp->lwp_proc;
1868 struct sigacts *ps = p->p_sigacts;
1870 sigset_t returnmask;
1873 KASSERT(sig != 0, ("postsig"));
1875 KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
1878 * If we are a virtual kernel running an emulated user process
1879 * context, switch back to the virtual kernel context before
1880 * trying to post the signal.
1882 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
1883 struct trapframe *tf = lp->lwp_md.md_regs;
1885 vkernel_trap(lp, tf);
1888 lwp_delsig(lp, sig);
1889 action = ps->ps_sigact[_SIG_IDX(sig)];
1891 if (KTRPOINT(lp->lwp_thread, KTR_PSIG))
1892 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ?
1893 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0);
1895 STOPEVENT(p, S_SIG, sig);
1897 if (action == SIG_DFL) {
1899 * Default action, where the default is to kill
1900 * the process. (Other cases were ignored above.)
1906 * If we get here, the signal must be caught.
1908 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig),
1909 ("postsig action"));
1914 * Reset the signal handler if asked to
1916 if (SIGISMEMBER(ps->ps_sigreset, sig)) {
1918 * See kern_sigaction() for origin of this code.
1920 SIGDELSET(p->p_sigcatch, sig);
1921 if (sig != SIGCONT &&
1922 sigprop(sig) & SA_IGNORE)
1923 SIGADDSET(p->p_sigignore, sig);
1924 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1928 * Handle the mailbox case. Copyout to the appropriate
1929 * location but do not generate a signal frame. The system
1930 * call simply returns EINTR and the user is responsible for
1931 * polling the mailbox.
1933 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) {
1935 copyout(&sig_copy, (void *)action, sizeof(int));
1936 curproc->p_flag |= P_MAILBOX;
1942 * Set the signal mask and calculate the mask to restore
1943 * when the signal function returns.
1945 * Special case: user has done a sigsuspend. Here the
1946 * current mask is not of interest, but rather the
1947 * mask from before the sigsuspend is what we want
1948 * restored after the signal processing is completed.
1950 if (lp->lwp_flag & LWP_OLDMASK) {
1951 returnmask = lp->lwp_oldsigmask;
1952 lp->lwp_flag &= ~LWP_OLDMASK;
1954 returnmask = lp->lwp_sigmask;
1957 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
1958 if (!SIGISMEMBER(ps->ps_signodefer, sig))
1959 SIGADDSET(lp->lwp_sigmask, sig);
1962 lp->lwp_ru.ru_nsignals++;
1963 if (lp->lwp_sig != sig) {
1966 code = lp->lwp_code;
1970 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
1977 * Kill the current process for stated reason.
1980 killproc(struct proc *p, char *why)
1982 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n",
1983 p->p_pid, p->p_comm,
1984 p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1985 ksignal(p, SIGKILL);
1989 * Force the current process to exit with the specified signal, dumping core
1990 * if appropriate. We bypass the normal tests for masked and caught signals,
1991 * allowing unrecoverable failures to terminate the process without changing
1992 * signal state. Mark the accounting record with the signal termination.
1993 * If dumping core, save the signal number for the debugger. Calls exit and
1996 * This routine does not return.
1999 sigexit(struct lwp *lp, int sig)
2001 struct proc *p = lp->lwp_proc;
2003 p->p_acflag |= AXSIG;
2004 if (sigprop(sig) & SA_CORE) {
2007 * Log signals which would cause core dumps
2008 * (Log as LOG_INFO to appease those who don't want
2010 * XXX : Todo, as well as euid, write out ruid too
2012 if (coredump(lp, sig) == 0)
2014 if (kern_logsigexit)
2016 "pid %d (%s), uid %d: exited on signal %d%s\n",
2017 p->p_pid, p->p_comm,
2018 p->p_ucred ? p->p_ucred->cr_uid : -1,
2020 sig & WCOREFLAG ? " (core dumped)" : "");
2022 exit1(W_EXITCODE(0, sig));
2026 static char corefilename[MAXPATHLEN+1] = {"%N.core"};
2027 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
2028 sizeof(corefilename), "process corefile name format string");
2031 * expand_name(name, uid, pid)
2032 * Expand the name described in corefilename, using name, uid, and pid.
2033 * corefilename is a kprintf-like string, with three format specifiers:
2034 * %N name of process ("name")
2035 * %P process id (pid)
2037 * For example, "%N.core" is the default; they can be disabled completely
2038 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2039 * This is controlled by the sysctl variable kern.corefile (see above).
2043 expand_name(const char *name, uid_t uid, pid_t pid)
2046 char buf[11]; /* Buffer for pid/uid -- max 4B */
2048 char *format = corefilename;
2051 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
2054 namelen = strlen(name);
2055 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
2057 switch (format[i]) {
2058 case '%': /* Format character */
2060 switch (format[i]) {
2064 case 'N': /* process name */
2065 if ((n + namelen) > MAXPATHLEN) {
2066 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2067 pid, name, uid, temp, name);
2068 kfree(temp, M_TEMP);
2071 memcpy(temp+n, name, namelen);
2074 case 'P': /* process id */
2075 l = ksprintf(buf, "%u", pid);
2076 if ((n + l) > MAXPATHLEN) {
2077 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2078 pid, name, uid, temp, name);
2079 kfree(temp, M_TEMP);
2082 memcpy(temp+n, buf, l);
2085 case 'U': /* user id */
2086 l = ksprintf(buf, "%u", uid);
2087 if ((n + l) > MAXPATHLEN) {
2088 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2089 pid, name, uid, temp, name);
2090 kfree(temp, M_TEMP);
2093 memcpy(temp+n, buf, l);
2097 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
2101 temp[n++] = format[i];
2109 * Dump a process' core. The main routine does some
2110 * policy checking, and creates the name of the coredump;
2111 * then it passes on a vnode and a size limit to the process-specific
2112 * coredump routine if there is one; if there _is not_ one, it returns
2113 * ENOSYS; otherwise it returns the error from the process-specific routine.
2115 * The parameter `lp' is the lwp which triggered the coredump.
2119 coredump(struct lwp *lp, int sig)
2121 struct proc *p = lp->lwp_proc;
2123 struct ucred *cred = p->p_ucred;
2125 struct nlookupdata nd;
2128 char *name; /* name of corefile */
2131 STOPEVENT(p, S_CORE, 0);
2133 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
2137 * Note that the bulk of limit checking is done after
2138 * the corefile is created. The exception is if the limit
2139 * for corefiles is 0, in which case we don't bother
2140 * creating the corefile at all. This layout means that
2141 * a corefile is truncated instead of not being created,
2142 * if it is larger than the limit.
2144 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
2148 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
2151 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP);
2153 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
2154 kfree(name, M_TEMP);
2160 nd.nl_open_vp = NULL;
2164 lf.l_whence = SEEK_SET;
2167 lf.l_type = F_WRLCK;
2168 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0);
2172 /* Don't dump to non-regular files or files with links. */
2173 if (vp->v_type != VREG ||
2174 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) {
2179 /* Don't dump to files current user does not own */
2180 if (vattr.va_uid != p->p_ucred->cr_uid) {
2186 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2188 VOP_SETATTR(vp, &vattr, cred);
2189 p->p_acflag |= ACORE;
2192 error = p->p_sysent->sv_coredump ?
2193 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS;
2196 lf.l_type = F_UNLCK;
2197 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0);
2199 error1 = vn_close(vp, FWRITE);
2206 * Nonexistent system call-- signal process (may want to handle it).
2207 * Flag error in case process won't see signal immediately (blocked or ignored).
2213 sys_nosys(struct nosys_args *args)
2215 lwpsignal(curproc, curthread->td_lwp, SIGSYS);
2220 * Send a SIGIO or SIGURG signal to a process or process group using
2221 * stored credentials rather than those of the current process.
2224 pgsigio(struct sigio *sigio, int sig, int checkctty)
2229 if (sigio->sio_pgid > 0) {
2230 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
2232 ksignal(sigio->sio_proc, sig);
2233 } else if (sigio->sio_pgid < 0) {
2236 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE);
2237 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
2238 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
2239 (checkctty == 0 || (p->p_flag & P_CONTROLT)))
2242 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE);
2247 filt_sigattach(struct knote *kn)
2249 struct proc *p = curproc;
2251 kn->kn_ptr.p_proc = p;
2252 kn->kn_flags |= EV_CLEAR; /* automatically set */
2254 /* XXX lock the proc here while adding to the list? */
2255 knote_insert(&p->p_klist, kn);
2261 filt_sigdetach(struct knote *kn)
2263 struct proc *p = kn->kn_ptr.p_proc;
2265 knote_remove(&p->p_klist, kn);
2269 * signal knotes are shared with proc knotes, so we apply a mask to
2270 * the hint in order to differentiate them from process hints. This
2271 * could be avoided by using a signal-specific knote list, but probably
2272 * isn't worth the trouble.
2275 filt_signal(struct knote *kn, long hint)
2277 if (hint & NOTE_SIGNAL) {
2278 hint &= ~NOTE_SIGNAL;
2280 if (kn->kn_id == hint)
2283 return (kn->kn_data != 0);