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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 $
40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.37 2005/06/06 15:02:28 dillon Exp $
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/sysproto.h>
49 #include <sys/signalvar.h>
50 #include <sys/resourcevar.h>
51 #include <sys/vnode.h>
52 #include <sys/event.h>
54 #include <sys/nlookup.h>
55 #include <sys/pioctl.h>
56 #include <sys/systm.h>
58 #include <sys/fcntl.h>
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/unistd.h>
67 #include <sys/kern_syscall.h>
68 #include <sys/thread2.h>
71 #include <machine/ipl.h>
72 #include <machine/cpu.h>
73 #include <machine/smp.h>
75 static int coredump(struct proc
*);
76 static char *expand_name(const char *, uid_t
, pid_t
);
77 static int killpg(int sig
, int pgid
, int all
);
78 static int sig_ffs(sigset_t
*set
);
79 static int sigprop(int sig
);
80 static void stop(struct proc
*);
82 static void signotify_remote(void *arg
);
84 static int kern_sigtimedwait(sigset_t set
, siginfo_t
*info
,
85 struct timespec
*timeout
);
87 static int filt_sigattach(struct knote
*kn
);
88 static void filt_sigdetach(struct knote
*kn
);
89 static int filt_signal(struct knote
*kn
, long hint
);
91 struct filterops sig_filtops
=
92 { 0, filt_sigattach
, filt_sigdetach
, filt_signal
};
94 static int kern_logsigexit
= 1;
95 SYSCTL_INT(_kern
, KERN_LOGSIGEXIT
, logsigexit
, CTLFLAG_RW
,
97 "Log processes quitting on abnormal signals to syslog(3)");
100 * Can process p, with pcred pc, send the signal sig to process q?
102 #define CANSIGNAL(q, sig) \
103 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
104 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
107 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
109 #define CANSIGIO(ruid, uc, q) \
110 ((uc)->cr_uid == 0 || \
111 (ruid) == (q)->p_ucred->cr_ruid || \
112 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
113 (ruid) == (q)->p_ucred->cr_uid || \
114 (uc)->cr_uid == (q)->p_ucred->cr_uid)
117 SYSCTL_INT(_kern
, OID_AUTO
, sugid_coredump
, CTLFLAG_RW
,
118 &sugid_coredump
, 0, "Enable coredumping set user/group ID processes");
120 static int do_coredump
= 1;
121 SYSCTL_INT(_kern
, OID_AUTO
, coredump
, CTLFLAG_RW
,
122 &do_coredump
, 0, "Enable/Disable coredumps");
125 * Signal properties and actions.
126 * The array below categorizes the signals and their default actions
127 * according to the following properties:
129 #define SA_KILL 0x01 /* terminates process by default */
130 #define SA_CORE 0x02 /* ditto and coredumps */
131 #define SA_STOP 0x04 /* suspend process */
132 #define SA_TTYSTOP 0x08 /* ditto, from tty */
133 #define SA_IGNORE 0x10 /* ignore by default */
134 #define SA_CONT 0x20 /* continue if suspended */
135 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
136 #define SA_CKPT 0x80 /* checkpoint process */
139 static int sigproptbl
[NSIG
] = {
140 SA_KILL
, /* SIGHUP */
141 SA_KILL
, /* SIGINT */
142 SA_KILL
|SA_CORE
, /* SIGQUIT */
143 SA_KILL
|SA_CORE
, /* SIGILL */
144 SA_KILL
|SA_CORE
, /* SIGTRAP */
145 SA_KILL
|SA_CORE
, /* SIGABRT */
146 SA_KILL
|SA_CORE
, /* SIGEMT */
147 SA_KILL
|SA_CORE
, /* SIGFPE */
148 SA_KILL
, /* SIGKILL */
149 SA_KILL
|SA_CORE
, /* SIGBUS */
150 SA_KILL
|SA_CORE
, /* SIGSEGV */
151 SA_KILL
|SA_CORE
, /* SIGSYS */
152 SA_KILL
, /* SIGPIPE */
153 SA_KILL
, /* SIGALRM */
154 SA_KILL
, /* SIGTERM */
155 SA_IGNORE
, /* SIGURG */
156 SA_STOP
, /* SIGSTOP */
157 SA_STOP
|SA_TTYSTOP
, /* SIGTSTP */
158 SA_IGNORE
|SA_CONT
, /* SIGCONT */
159 SA_IGNORE
, /* SIGCHLD */
160 SA_STOP
|SA_TTYSTOP
, /* SIGTTIN */
161 SA_STOP
|SA_TTYSTOP
, /* SIGTTOU */
162 SA_IGNORE
, /* SIGIO */
163 SA_KILL
, /* SIGXCPU */
164 SA_KILL
, /* SIGXFSZ */
165 SA_KILL
, /* SIGVTALRM */
166 SA_KILL
, /* SIGPROF */
167 SA_IGNORE
, /* SIGWINCH */
168 SA_IGNORE
, /* SIGINFO */
169 SA_KILL
, /* SIGUSR1 */
170 SA_KILL
, /* SIGUSR2 */
171 SA_IGNORE
, /* SIGTHR */
172 SA_CKPT
, /* SIGCKPT */
173 SA_KILL
|SA_CKPT
, /* SIGCKPTEXIT */
211 if (sig
> 0 && sig
< NSIG
)
212 return (sigproptbl
[_SIG_IDX(sig
)]);
217 sig_ffs(sigset_t
*set
)
221 for (i
= 0; i
< _SIG_WORDS
; i
++)
223 return (ffs(set
->__bits
[i
]) + (i
* 32));
228 kern_sigaction(int sig
, struct sigaction
*act
, struct sigaction
*oact
)
230 struct thread
*td
= curthread
;
231 struct proc
*p
= td
->td_proc
;
232 struct sigacts
*ps
= p
->p_sigacts
;
234 if (sig
<= 0 || sig
> _SIG_MAXSIG
)
238 oact
->sa_handler
= ps
->ps_sigact
[_SIG_IDX(sig
)];
239 oact
->sa_mask
= ps
->ps_catchmask
[_SIG_IDX(sig
)];
241 if (SIGISMEMBER(ps
->ps_sigonstack
, sig
))
242 oact
->sa_flags
|= SA_ONSTACK
;
243 if (!SIGISMEMBER(ps
->ps_sigintr
, sig
))
244 oact
->sa_flags
|= SA_RESTART
;
245 if (SIGISMEMBER(ps
->ps_sigreset
, sig
))
246 oact
->sa_flags
|= SA_RESETHAND
;
247 if (SIGISMEMBER(ps
->ps_signodefer
, sig
))
248 oact
->sa_flags
|= SA_NODEFER
;
249 if (SIGISMEMBER(ps
->ps_siginfo
, sig
))
250 oact
->sa_flags
|= SA_SIGINFO
;
251 if (sig
== SIGCHLD
&& p
->p_procsig
->ps_flag
& PS_NOCLDSTOP
)
252 oact
->sa_flags
|= SA_NOCLDSTOP
;
253 if (sig
== SIGCHLD
&& p
->p_procsig
->ps_flag
& PS_NOCLDWAIT
)
254 oact
->sa_flags
|= SA_NOCLDWAIT
;
257 if ((sig
== SIGKILL
|| sig
== SIGSTOP
) &&
258 act
->sa_handler
!= SIG_DFL
)
262 * Change setting atomically.
266 ps
->ps_catchmask
[_SIG_IDX(sig
)] = act
->sa_mask
;
267 SIG_CANTMASK(ps
->ps_catchmask
[_SIG_IDX(sig
)]);
268 if (act
->sa_flags
& SA_SIGINFO
) {
269 ps
->ps_sigact
[_SIG_IDX(sig
)] =
270 (__sighandler_t
*)act
->sa_sigaction
;
271 SIGADDSET(ps
->ps_siginfo
, sig
);
273 ps
->ps_sigact
[_SIG_IDX(sig
)] = act
->sa_handler
;
274 SIGDELSET(ps
->ps_siginfo
, sig
);
276 if (!(act
->sa_flags
& SA_RESTART
))
277 SIGADDSET(ps
->ps_sigintr
, sig
);
279 SIGDELSET(ps
->ps_sigintr
, sig
);
280 if (act
->sa_flags
& SA_ONSTACK
)
281 SIGADDSET(ps
->ps_sigonstack
, sig
);
283 SIGDELSET(ps
->ps_sigonstack
, sig
);
284 if (act
->sa_flags
& SA_RESETHAND
)
285 SIGADDSET(ps
->ps_sigreset
, sig
);
287 SIGDELSET(ps
->ps_sigreset
, sig
);
288 if (act
->sa_flags
& SA_NODEFER
)
289 SIGADDSET(ps
->ps_signodefer
, sig
);
291 SIGDELSET(ps
->ps_signodefer
, sig
);
292 if (sig
== SIGCHLD
) {
293 if (act
->sa_flags
& SA_NOCLDSTOP
)
294 p
->p_procsig
->ps_flag
|= PS_NOCLDSTOP
;
296 p
->p_procsig
->ps_flag
&= ~PS_NOCLDSTOP
;
297 if (act
->sa_flags
& SA_NOCLDWAIT
) {
299 * Paranoia: since SA_NOCLDWAIT is implemented
300 * by reparenting the dying child to PID 1 (and
301 * trust it to reap the zombie), PID 1 itself
302 * is forbidden to set SA_NOCLDWAIT.
305 p
->p_procsig
->ps_flag
&= ~PS_NOCLDWAIT
;
307 p
->p_procsig
->ps_flag
|= PS_NOCLDWAIT
;
309 p
->p_procsig
->ps_flag
&= ~PS_NOCLDWAIT
;
313 * Set bit in p_sigignore for signals that are set to SIG_IGN,
314 * and for signals set to SIG_DFL where the default is to
315 * ignore. However, don't put SIGCONT in p_sigignore, as we
316 * have to restart the process.
318 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_IGN
||
319 (sigprop(sig
) & SA_IGNORE
&&
320 ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)) {
321 /* never to be seen again */
322 SIGDELSET(p
->p_siglist
, sig
);
324 /* easier in psignal */
325 SIGADDSET(p
->p_sigignore
, sig
);
326 SIGDELSET(p
->p_sigcatch
, sig
);
328 SIGDELSET(p
->p_sigignore
, sig
);
329 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)
330 SIGDELSET(p
->p_sigcatch
, sig
);
332 SIGADDSET(p
->p_sigcatch
, sig
);
341 sigaction(struct sigaction_args
*uap
)
343 struct sigaction act
, oact
;
344 struct sigaction
*actp
, *oactp
;
347 actp
= (uap
->act
!= NULL
) ? &act
: NULL
;
348 oactp
= (uap
->oact
!= NULL
) ? &oact
: NULL
;
350 error
= copyin(uap
->act
, actp
, sizeof(act
));
354 error
= kern_sigaction(uap
->sig
, actp
, oactp
);
355 if (oactp
&& !error
) {
356 error
= copyout(oactp
, uap
->oact
, sizeof(oact
));
362 * Initialize signal state for process 0;
363 * set to ignore signals that are ignored by default.
366 siginit(struct proc
*p
)
370 for (i
= 1; i
<= NSIG
; i
++)
371 if (sigprop(i
) & SA_IGNORE
&& i
!= SIGCONT
)
372 SIGADDSET(p
->p_sigignore
, i
);
376 * Reset signals for an exec of the specified process.
379 execsigs(struct proc
*p
)
381 struct sigacts
*ps
= p
->p_sigacts
;
385 * Reset caught signals. Held signals remain held
386 * through p_sigmask (unless they were caught,
387 * and are now ignored by default).
389 while (SIGNOTEMPTY(p
->p_sigcatch
)) {
390 sig
= sig_ffs(&p
->p_sigcatch
);
391 SIGDELSET(p
->p_sigcatch
, sig
);
392 if (sigprop(sig
) & SA_IGNORE
) {
394 SIGADDSET(p
->p_sigignore
, sig
);
395 SIGDELSET(p
->p_siglist
, sig
);
397 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
400 * Reset stack state to the user stack.
401 * Clear set of signals caught on the signal stack.
403 p
->p_sigstk
.ss_flags
= SS_DISABLE
;
404 p
->p_sigstk
.ss_size
= 0;
405 p
->p_sigstk
.ss_sp
= 0;
406 p
->p_flag
&= ~P_ALTSTACK
;
408 * Reset no zombies if child dies flag as Solaris does.
410 p
->p_procsig
->ps_flag
&= ~PS_NOCLDWAIT
;
414 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
416 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
420 kern_sigprocmask(int how
, sigset_t
*set
, sigset_t
*oset
)
422 struct thread
*td
= curthread
;
423 struct proc
*p
= td
->td_proc
;
427 *oset
= p
->p_sigmask
;
434 SIGSETOR(p
->p_sigmask
, *set
);
437 SIGSETNAND(p
->p_sigmask
, *set
);
452 * sigprocmask() - MP SAFE
455 sigprocmask(struct sigprocmask_args
*uap
)
458 sigset_t
*setp
, *osetp
;
461 setp
= (uap
->set
!= NULL
) ? &set
: NULL
;
462 osetp
= (uap
->oset
!= NULL
) ? &oset
: NULL
;
464 error
= copyin(uap
->set
, setp
, sizeof(set
));
468 error
= kern_sigprocmask(uap
->how
, setp
, osetp
);
469 if (osetp
&& !error
) {
470 error
= copyout(osetp
, uap
->oset
, sizeof(oset
));
476 kern_sigpending(struct __sigset
*set
)
478 struct thread
*td
= curthread
;
479 struct proc
*p
= td
->td_proc
;
487 sigpending(struct sigpending_args
*uap
)
492 error
= kern_sigpending(&set
);
495 error
= copyout(&set
, uap
->set
, sizeof(set
));
500 * Suspend process until signal, providing mask to be set
504 kern_sigsuspend(struct __sigset
*set
)
506 struct thread
*td
= curthread
;
507 struct proc
*p
= td
->td_proc
;
508 struct sigacts
*ps
= p
->p_sigacts
;
511 * When returning from sigsuspend, we want
512 * the old mask to be restored after the
513 * signal handler has finished. Thus, we
514 * save it here and mark the sigacts structure
517 p
->p_oldsigmask
= p
->p_sigmask
;
518 p
->p_flag
|= P_OLDMASK
;
522 while (tsleep(ps
, PCATCH
, "pause", 0) == 0)
524 /* always return EINTR rather than ERESTART... */
529 * Note nonstandard calling convention: libc stub passes mask, not
530 * pointer, to save a copyin.
533 sigsuspend(struct sigsuspend_args
*uap
)
538 error
= copyin(uap
->sigmask
, &mask
, sizeof(mask
));
542 error
= kern_sigsuspend(&mask
);
548 kern_sigaltstack(struct sigaltstack
*ss
, struct sigaltstack
*oss
)
550 struct thread
*td
= curthread
;
551 struct proc
*p
= td
->td_proc
;
553 if ((p
->p_flag
& P_ALTSTACK
) == 0)
554 p
->p_sigstk
.ss_flags
|= SS_DISABLE
;
560 if (ss
->ss_flags
& SS_DISABLE
) {
561 if (p
->p_sigstk
.ss_flags
& SS_ONSTACK
)
563 p
->p_flag
&= ~P_ALTSTACK
;
564 p
->p_sigstk
.ss_flags
= ss
->ss_flags
;
566 if (ss
->ss_size
< p
->p_sysent
->sv_minsigstksz
)
568 p
->p_flag
|= P_ALTSTACK
;
577 sigaltstack(struct sigaltstack_args
*uap
)
583 error
= copyin(uap
->ss
, &ss
, sizeof(ss
));
588 error
= kern_sigaltstack(uap
->ss
? &ss
: NULL
,
589 uap
->oss
? &oss
: NULL
);
591 if (error
== 0 && uap
->oss
)
592 error
= copyout(&oss
, uap
->oss
, sizeof(*uap
->oss
));
597 * Common code for kill process group/broadcast kill.
598 * cp is calling process.
601 killpg(int sig
, int pgid
, int all
)
603 struct proc
*cp
= curproc
;
612 FOREACH_PROC_IN_SYSTEM(p
) {
613 if (p
->p_pid
<= 1 || p
->p_flag
& P_SYSTEM
||
614 p
== cp
|| !CANSIGNAL(p
, sig
))
623 * zero pgid means send to my process group.
631 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
632 if (p
->p_pid
<= 1 || p
->p_flag
& P_SYSTEM
||
633 p
->p_stat
== SZOMB
||
641 return (nfound
? 0 : ESRCH
);
645 kern_kill(int sig
, int pid
)
647 struct thread
*td
= curthread
;
648 struct proc
*p
= td
->td_proc
;
650 if ((u_int
)sig
> _SIG_MAXSIG
)
653 /* kill single process */
654 if ((p
= pfind(pid
)) == NULL
)
656 if (!CANSIGNAL(p
, sig
))
663 case -1: /* broadcast signal */
664 return (killpg(sig
, 0, 1));
665 case 0: /* signal own process group */
666 return (killpg(sig
, 0, 0));
667 default: /* negative explicit process group */
668 return (killpg(sig
, -pid
, 0));
674 kill(struct kill_args
*uap
)
678 error
= kern_kill(uap
->signum
, uap
->pid
);
684 * Send a signal to a process group.
687 gsignal(int pgid
, int sig
)
691 if (pgid
&& (pgrp
= pgfind(pgid
)))
692 pgsignal(pgrp
, sig
, 0);
696 * Send a signal to a process group. If checktty is 1,
697 * limit to members which have a controlling terminal.
700 pgsignal(struct pgrp
*pgrp
, int sig
, int checkctty
)
705 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
)
706 if (checkctty
== 0 || p
->p_flag
& P_CONTROLT
)
711 * Send a signal caused by a trap to the current process.
712 * If it will be caught immediately, deliver it with correct code.
713 * Otherwise, post it normally.
716 trapsignal(struct proc
*p
, int sig
, u_long code
)
718 struct sigacts
*ps
= p
->p_sigacts
;
720 if ((p
->p_flag
& P_TRACED
) == 0 && SIGISMEMBER(p
->p_sigcatch
, sig
) &&
721 !SIGISMEMBER(p
->p_sigmask
, sig
)) {
722 p
->p_stats
->p_ru
.ru_nsignals
++;
724 if (KTRPOINT(p
->p_thread
, KTR_PSIG
))
725 ktrpsig(p
->p_tracep
, sig
, ps
->ps_sigact
[_SIG_IDX(sig
)],
726 &p
->p_sigmask
, code
);
728 (*p
->p_sysent
->sv_sendsig
)(ps
->ps_sigact
[_SIG_IDX(sig
)], sig
,
729 &p
->p_sigmask
, code
);
730 SIGSETOR(p
->p_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
731 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
732 SIGADDSET(p
->p_sigmask
, sig
);
733 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
735 * See kern_sigaction() for origin of this code.
737 SIGDELSET(p
->p_sigcatch
, sig
);
738 if (sig
!= SIGCONT
&&
739 sigprop(sig
) & SA_IGNORE
)
740 SIGADDSET(p
->p_sigignore
, sig
);
741 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
744 p
->p_code
= code
; /* XXX for core dump/debugger */
745 p
->p_sig
= sig
; /* XXX to verify code */
751 * Send the signal to the process. If the signal has an action, the action
752 * is usually performed by the target process rather than the caller; we add
753 * the signal to the set of pending signals for the process.
756 * o When a stop signal is sent to a sleeping process that takes the
757 * default action, the process is stopped without awakening it.
758 * o SIGCONT restarts stopped processes (or puts them back to sleep)
759 * regardless of the signal action (eg, blocked or ignored).
761 * Other ignored signals are discarded immediately.
765 * temporary hack to allow checkpoint code to continue to
766 * be in a module for the moment
770 psignal(struct proc
*p
, int sig
)
775 if (sig
> _SIG_MAXSIG
|| sig
<= 0) {
776 printf("psignal: signal %d\n", sig
);
777 panic("psignal signal number");
781 KNOTE(&p
->p_klist
, NOTE_SIGNAL
| sig
);
787 * If proc is traced, always give parent a chance;
788 * if signal event is tracked by procfs, give *that*
791 if ((p
->p_flag
& P_TRACED
) || (p
->p_stops
& S_SIG
)) {
795 * If the signal is being ignored,
796 * then we forget about it immediately.
797 * (Note: we don't set SIGCONT in p_sigignore,
798 * and if it is set to SIG_IGN,
799 * action will be SIG_DFL here.)
801 if (SIGISMEMBER(p
->p_sigignore
, sig
) || (p
->p_flag
& P_WEXIT
))
803 if (SIGISMEMBER(p
->p_sigmask
, sig
))
805 else if (SIGISMEMBER(p
->p_sigcatch
, sig
))
811 if (p
->p_nice
> NZERO
&& action
== SIG_DFL
&& (prop
& SA_KILL
) &&
812 (p
->p_flag
& P_TRACED
) == 0) {
817 SIG_STOPSIGMASK(p
->p_siglist
);
820 if (prop
& SA_STOP
) {
822 * If sending a tty stop signal to a member of an orphaned
823 * process group, discard the signal here if the action
824 * is default; don't stop the process below if sleeping,
825 * and don't clear any pending SIGCONT.
827 if (prop
& SA_TTYSTOP
&& p
->p_pgrp
->pg_jobc
== 0 &&
831 SIG_CONTSIGMASK(p
->p_siglist
);
833 SIGADDSET(p
->p_siglist
, sig
);
836 * Defer further processing for signals which are held,
837 * except that stopped processes must be continued by SIGCONT.
839 if (action
== SIG_HOLD
&& (!(prop
& SA_CONT
) || p
->p_stat
!= SSTOP
))
847 * If process is sleeping uninterruptibly
848 * we can't interrupt the sleep... the signal will
849 * be noticed when the process returns through
850 * trap() or syscall().
852 if ((p
->p_flag
& P_SINTR
) == 0)
855 * Process is sleeping and traced... make it runnable
856 * so it can discover the signal in issignal() and stop
859 if (p
->p_flag
& P_TRACED
)
862 * If SIGCONT is default (or ignored) and process is
863 * asleep, we are finished; the process should not
866 if ((prop
& SA_CONT
) && action
== SIG_DFL
) {
867 SIGDELSET(p
->p_siglist
, sig
);
871 * When a sleeping process receives a stop
872 * signal, process immediately if possible.
873 * All other (caught or default) signals
874 * cause the process to run.
876 if (prop
& SA_STOP
) {
877 if (action
!= SIG_DFL
)
880 * If a child holding parent blocked,
881 * stopping could cause deadlock.
883 if (p
->p_flag
& P_PPWAIT
)
885 SIGDELSET(p
->p_siglist
, sig
);
887 if ((p
->p_pptr
->p_procsig
->ps_flag
& PS_NOCLDSTOP
) == 0)
888 psignal(p
->p_pptr
, SIGCHLD
);
897 * If traced process is already stopped,
898 * then no further action is necessary.
900 if (p
->p_flag
& P_TRACED
)
904 * Kill signal always sets processes running.
909 if (prop
& SA_CONT
) {
911 * If SIGCONT is default (or ignored), we continue the
912 * process but don't leave the signal in p_siglist, as
913 * it has no further action. If SIGCONT is held, we
914 * continue the process and leave the signal in
915 * p_siglist. If the process catches SIGCONT, let it
916 * handle the signal itself. If it isn't waiting on
917 * an event, then it goes back to run state.
918 * Otherwise, process goes back to sleep state.
920 if (action
== SIG_DFL
)
921 SIGDELSET(p
->p_siglist
, sig
);
922 if (action
== SIG_CATCH
)
926 clrrunnable(p
, SSLEEP
);
930 if (prop
& SA_STOP
) {
932 * Already stopped, don't need to stop again.
933 * (If we did the shell could get confused.)
935 SIGDELSET(p
->p_siglist
, sig
);
940 * If process is sleeping interruptibly, then simulate a
941 * wakeup so that when it is continued, it will be made
942 * runnable and can look at the signal. But don't make
943 * the process runnable, leave it stopped.
945 if (p
->p_wchan
&& (p
->p_flag
& P_SINTR
))
946 unsleep(p
->p_thread
);
950 * SRUN, SIDL, SZOMB do nothing with the signal,
951 * other than kicking ourselves if we are running.
952 * It will either never be noticed, or noticed very soon.
954 * Note that p_thread may be NULL or may not be completely
955 * initialized if the process is in the SIDL or SZOMB state.
957 * For SMP we may have to forward the request to another cpu.
958 * YYY the MP lock prevents the target process from moving
959 * to another cpu, see kern/kern_switch.c
961 * If the target thread is waiting on its message port,
962 * wakeup the target thread so it can check (or ignore)
963 * the new signal. YYY needs cleanup.
966 if (p
== lwkt_preempted_proc()) {
968 } else if (p
->p_stat
== SRUN
) {
969 struct thread
*td
= p
->p_thread
;
972 ("pid %d NULL p_thread stat %d flags %08x",
973 p
->p_pid
, p
->p_stat
, p
->p_flag
));
975 if (td
->td_gd
!= mycpu
)
976 lwkt_send_ipiq(td
->td_gd
, signotify_remote
, p
);
977 else if (td
->td_msgport
.mp_flags
& MSGPORTF_WAITING
)
981 if (p
== lwkt_preempted_proc()) {
983 } else if (p
->p_stat
== SRUN
) {
984 struct thread
*td
= p
->p_thread
;
987 ("pid %d NULL p_thread stat %d flags %08x",
988 p
->p_pid
, p
->p_stat
, p
->p_flag
));
990 if (td
->td_msgport
.mp_flags
& MSGPORTF_WAITING
)
1006 * This function is called via an IPI. We will be in a critical section but
1007 * the MP lock will NOT be held. Also note that by the time the ipi message
1008 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1011 signotify_remote(void *arg
)
1013 struct proc
*p
= arg
;
1015 if (p
== lwkt_preempted_proc()) {
1018 struct thread
*td
= p
->p_thread
;
1019 if (td
->td_msgport
.mp_flags
& MSGPORTF_WAITING
)
1027 kern_sigtimedwait(sigset_t waitset
, siginfo_t
*info
, struct timespec
*timeout
)
1029 sigset_t savedmask
, set
;
1030 struct proc
*p
= curproc
;
1031 int error
, sig
, hz
, timevalid
= 0;
1032 struct timespec rts
, ets
, ts
;
1037 SIG_CANTMASK(waitset
);
1038 savedmask
= p
->p_sigmask
;
1041 if (timeout
->tv_sec
>= 0 && timeout
->tv_nsec
>= 0 &&
1042 timeout
->tv_nsec
< 1000000000) {
1044 getnanouptime(&rts
);
1046 timespecadd(&ets
, timeout
);
1052 SIGSETAND(set
, waitset
);
1053 if ((sig
= sig_ffs(&set
)) != 0) {
1054 SIGFILLSET(p
->p_sigmask
);
1055 SIGDELSET(p
->p_sigmask
, sig
);
1056 SIG_CANTMASK(p
->p_sigmask
);
1059 * It may be a STOP signal, in the case, issignal
1060 * returns 0, because we may stop there, and new
1061 * signal can come in, we should restart if we got
1071 * Previous checking got nothing, and we retried but still
1072 * got nothing, we should return the error status.
1078 * POSIX says this must be checked after looking for pending
1086 getnanouptime(&rts
);
1087 if (timespeccmp(&rts
, &ets
, >=)) {
1092 timespecsub(&ts
, &rts
);
1093 TIMESPEC_TO_TIMEVAL(&tv
, &ts
);
1094 hz
= tvtohz_high(&tv
);
1098 p
->p_sigmask
= savedmask
;
1099 SIGSETNAND(p
->p_sigmask
, waitset
);
1100 error
= tsleep(&p
->p_sigacts
, PCATCH
, "sigwt", hz
);
1102 if (error
== ERESTART
) {
1103 /* can not restart a timeout wait. */
1105 } else if (error
== EAGAIN
) {
1106 /* will calculate timeout by ourself. */
1113 p
->p_sigmask
= savedmask
;
1116 bzero(info
, sizeof(*info
));
1117 info
->si_signo
= sig
;
1118 SIGDELSET(p
->p_siglist
, sig
); /* take the signal! */
1124 sigtimedwait(struct sigtimedwait_args
*uap
)
1127 struct timespec
*timeout
;
1133 error
= copyin(uap
->timeout
, &ts
, sizeof(ts
));
1140 error
= copyin(uap
->set
, &set
, sizeof(set
));
1143 error
= kern_sigtimedwait(set
, &info
, timeout
);
1147 error
= copyout(&info
, uap
->info
, sizeof(info
));
1148 /* Repost if we got an error. */
1150 psignal(curproc
, info
.si_signo
);
1152 uap
->sysmsg_result
= info
.si_signo
;
1157 sigwaitinfo(struct sigwaitinfo_args
*uap
)
1163 error
= copyin(uap
->set
, &set
, sizeof(set
));
1166 error
= kern_sigtimedwait(set
, &info
, NULL
);
1170 error
= copyout(&info
, uap
->info
, sizeof(info
));
1171 /* Repost if we got an error. */
1173 psignal(curproc
, info
.si_signo
);
1175 uap
->sysmsg_result
= info
.si_signo
;
1180 * If the current process has received a signal that would interrupt a
1181 * system call, return EINTR or ERESTART as appropriate.
1184 iscaught(struct proc
*p
)
1189 if ((sig
= CURSIG(p
)) != 0) {
1190 if (SIGISMEMBER(p
->p_sigacts
->ps_sigintr
, sig
))
1195 return(EWOULDBLOCK
);
1199 * If the current process has received a signal (should be caught or cause
1200 * termination, should interrupt current syscall), return the signal number.
1201 * Stop signals with default action are processed immediately, then cleared;
1202 * they aren't returned. This is checked after each entry to the system for
1203 * a syscall or trap (though this can usually be done without calling issignal
1204 * by checking the pending signal masks in the CURSIG macro.) The normal call
1207 * while (sig = CURSIG(curproc))
1211 issignal(struct proc
*p
)
1217 int traced
= (p
->p_flag
& P_TRACED
) || (p
->p_stops
& S_SIG
);
1219 mask
= p
->p_siglist
;
1220 SIGSETNAND(mask
, p
->p_sigmask
);
1221 if (p
->p_flag
& P_PPWAIT
)
1222 SIG_STOPSIGMASK(mask
);
1223 if (!SIGNOTEMPTY(mask
)) /* no signal to send */
1225 sig
= sig_ffs(&mask
);
1227 STOPEVENT(p
, S_SIG
, sig
);
1230 * We should see pending but ignored signals
1231 * only if P_TRACED was on when they were posted.
1233 if (SIGISMEMBER(p
->p_sigignore
, sig
) && (traced
== 0)) {
1234 SIGDELSET(p
->p_siglist
, sig
);
1237 if (p
->p_flag
& P_TRACED
&& (p
->p_flag
& P_PPWAIT
) == 0) {
1239 * If traced, always stop, and stay
1240 * stopped until released by the parent.
1243 psignal(p
->p_pptr
, SIGCHLD
);
1247 } while (!trace_req(p
) && p
->p_flag
& P_TRACED
);
1250 * If parent wants us to take the signal,
1251 * then it will leave it in p->p_xstat;
1252 * otherwise we just look for signals again.
1254 SIGDELSET(p
->p_siglist
, sig
); /* clear old signal */
1260 * Put the new signal into p_siglist. If the
1261 * signal is being masked, look for other signals.
1263 SIGADDSET(p
->p_siglist
, sig
);
1264 if (SIGISMEMBER(p
->p_sigmask
, sig
))
1268 * If the traced bit got turned off, go back up
1269 * to the top to rescan signals. This ensures
1270 * that p_sig* and ps_sigact are consistent.
1272 if ((p
->p_flag
& P_TRACED
) == 0)
1276 prop
= sigprop(sig
);
1279 * Decide whether the signal should be returned.
1280 * Return the signal's number, or fall through
1281 * to clear it from the pending mask.
1283 switch ((int)(intptr_t)p
->p_sigacts
->ps_sigact
[_SIG_IDX(sig
)]) {
1287 * Don't take default actions on system processes.
1289 if (p
->p_pid
<= 1) {
1292 * Are you sure you want to ignore SIGSEGV
1295 printf("Process (pid %lu) got signal %d\n",
1296 (u_long
)p
->p_pid
, sig
);
1298 break; /* == ignore */
1302 * Handle the in-kernel checkpoint action
1304 if (prop
& SA_CKPT
) {
1305 checkpoint_signal_handler(p
);
1310 * If there is a pending stop signal to process
1311 * with default action, stop here,
1312 * then clear the signal. However,
1313 * if process is member of an orphaned
1314 * process group, ignore tty stop signals.
1316 if (prop
& SA_STOP
) {
1317 if (p
->p_flag
& P_TRACED
||
1318 (p
->p_pgrp
->pg_jobc
== 0 &&
1320 break; /* == ignore */
1323 if ((p
->p_pptr
->p_procsig
->ps_flag
& PS_NOCLDSTOP
) == 0)
1324 psignal(p
->p_pptr
, SIGCHLD
);
1327 } else if (prop
& SA_IGNORE
) {
1329 * Except for SIGCONT, shouldn't get here.
1330 * Default action is to ignore; drop it.
1332 break; /* == ignore */
1341 * Masking above should prevent us ever trying
1342 * to take action on an ignored signal other
1343 * than SIGCONT, unless process is traced.
1345 if ((prop
& SA_CONT
) == 0 &&
1346 (p
->p_flag
& P_TRACED
) == 0)
1347 printf("issignal\n");
1348 break; /* == ignore */
1352 * This signal has an action, let
1353 * postsig() process it.
1357 SIGDELSET(p
->p_siglist
, sig
); /* take the signal! */
1363 * Put the argument process into the stopped state and notify the parent
1364 * via wakeup. Signals are handled elsewhere. The process must not be
1368 stop(struct proc
*p
)
1371 p
->p_flag
&= ~P_WAITED
;
1372 wakeup((caddr_t
)p
->p_pptr
);
1376 * Take the action for the specified signal
1377 * from the current set of pending signals.
1382 struct proc
*p
= curproc
;
1383 struct sigacts
*ps
= p
->p_sigacts
;
1385 sigset_t returnmask
;
1388 KASSERT(sig
!= 0, ("postsig"));
1390 SIGDELSET(p
->p_siglist
, sig
);
1391 action
= ps
->ps_sigact
[_SIG_IDX(sig
)];
1393 if (KTRPOINT(p
->p_thread
, KTR_PSIG
))
1394 ktrpsig(p
->p_tracep
, sig
, action
, p
->p_flag
& P_OLDMASK
?
1395 &p
->p_oldsigmask
: &p
->p_sigmask
, 0);
1397 STOPEVENT(p
, S_SIG
, sig
);
1399 if (action
== SIG_DFL
) {
1401 * Default action, where the default is to kill
1402 * the process. (Other cases were ignored above.)
1408 * If we get here, the signal must be caught.
1410 KASSERT(action
!= SIG_IGN
&& !SIGISMEMBER(p
->p_sigmask
, sig
),
1411 ("postsig action"));
1413 * Set the new mask value and also defer further
1414 * occurrences of this signal.
1416 * Special case: user has done a sigsuspend. Here the
1417 * current mask is not of interest, but rather the
1418 * mask from before the sigsuspend is what we want
1419 * restored after the signal processing is completed.
1422 if (p
->p_flag
& P_OLDMASK
) {
1423 returnmask
= p
->p_oldsigmask
;
1424 p
->p_flag
&= ~P_OLDMASK
;
1426 returnmask
= p
->p_sigmask
;
1429 SIGSETOR(p
->p_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
1430 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
1431 SIGADDSET(p
->p_sigmask
, sig
);
1433 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
1435 * See kern_sigaction() for origin of this code.
1437 SIGDELSET(p
->p_sigcatch
, sig
);
1438 if (sig
!= SIGCONT
&&
1439 sigprop(sig
) & SA_IGNORE
)
1440 SIGADDSET(p
->p_sigignore
, sig
);
1441 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
1444 p
->p_stats
->p_ru
.ru_nsignals
++;
1445 if (p
->p_sig
!= sig
) {
1452 (*p
->p_sysent
->sv_sendsig
)(action
, sig
, &returnmask
, code
);
1457 * Kill the current process for stated reason.
1460 killproc(struct proc
*p
, char *why
)
1462 log(LOG_ERR
, "pid %d (%s), uid %d, was killed: %s\n", p
->p_pid
, p
->p_comm
,
1463 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1, why
);
1464 psignal(p
, SIGKILL
);
1468 * Force the current process to exit with the specified signal, dumping core
1469 * if appropriate. We bypass the normal tests for masked and caught signals,
1470 * allowing unrecoverable failures to terminate the process without changing
1471 * signal state. Mark the accounting record with the signal termination.
1472 * If dumping core, save the signal number for the debugger. Calls exit and
1476 sigexit(struct proc
*p
, int sig
)
1478 p
->p_acflag
|= AXSIG
;
1479 if (sigprop(sig
) & SA_CORE
) {
1482 * Log signals which would cause core dumps
1483 * (Log as LOG_INFO to appease those who don't want
1485 * XXX : Todo, as well as euid, write out ruid too
1487 if (coredump(p
) == 0)
1489 if (kern_logsigexit
)
1491 "pid %d (%s), uid %d: exited on signal %d%s\n",
1492 p
->p_pid
, p
->p_comm
,
1493 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1,
1495 sig
& WCOREFLAG
? " (core dumped)" : "");
1497 exit1(W_EXITCODE(0, sig
));
1501 static char corefilename
[MAXPATHLEN
+1] = {"%N.core"};
1502 SYSCTL_STRING(_kern
, OID_AUTO
, corefile
, CTLFLAG_RW
, corefilename
,
1503 sizeof(corefilename
), "process corefile name format string");
1506 * expand_name(name, uid, pid)
1507 * Expand the name described in corefilename, using name, uid, and pid.
1508 * corefilename is a printf-like string, with three format specifiers:
1509 * %N name of process ("name")
1510 * %P process id (pid)
1512 * For example, "%N.core" is the default; they can be disabled completely
1513 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1514 * This is controlled by the sysctl variable kern.corefile (see above).
1518 expand_name(const char *name
, uid_t uid
, pid_t pid
)
1521 char buf
[11]; /* Buffer for pid/uid -- max 4B */
1523 char *format
= corefilename
;
1526 temp
= malloc(MAXPATHLEN
+ 1, M_TEMP
, M_NOWAIT
);
1529 namelen
= strlen(name
);
1530 for (i
= 0, n
= 0; n
< MAXPATHLEN
&& format
[i
]; i
++) {
1532 switch (format
[i
]) {
1533 case '%': /* Format character */
1535 switch (format
[i
]) {
1539 case 'N': /* process name */
1540 if ((n
+ namelen
) > MAXPATHLEN
) {
1541 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1542 pid
, name
, uid
, temp
, name
);
1546 memcpy(temp
+n
, name
, namelen
);
1549 case 'P': /* process id */
1550 l
= sprintf(buf
, "%u", pid
);
1551 if ((n
+ l
) > MAXPATHLEN
) {
1552 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1553 pid
, name
, uid
, temp
, name
);
1557 memcpy(temp
+n
, buf
, l
);
1560 case 'U': /* user id */
1561 l
= sprintf(buf
, "%u", uid
);
1562 if ((n
+ l
) > MAXPATHLEN
) {
1563 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1564 pid
, name
, uid
, temp
, name
);
1568 memcpy(temp
+n
, buf
, l
);
1572 log(LOG_ERR
, "Unknown format character %c in `%s'\n", format
[i
], format
);
1576 temp
[n
++] = format
[i
];
1584 * Dump a process' core. The main routine does some
1585 * policy checking, and creates the name of the coredump;
1586 * then it passes on a vnode and a size limit to the process-specific
1587 * coredump routine if there is one; if there _is not_ one, it returns
1588 * ENOSYS; otherwise it returns the error from the process-specific routine.
1592 coredump(struct proc
*p
)
1595 struct ucred
*cred
= p
->p_ucred
;
1596 struct thread
*td
= p
->p_thread
;
1598 struct nlookupdata nd
;
1601 char *name
; /* name of corefile */
1604 STOPEVENT(p
, S_CORE
, 0);
1606 if (((sugid_coredump
== 0) && p
->p_flag
& P_SUGID
) || do_coredump
== 0)
1610 * Note that the bulk of limit checking is done after
1611 * the corefile is created. The exception is if the limit
1612 * for corefiles is 0, in which case we don't bother
1613 * creating the corefile at all. This layout means that
1614 * a corefile is truncated instead of not being created,
1615 * if it is larger than the limit.
1617 limit
= p
->p_rlimit
[RLIMIT_CORE
].rlim_cur
;
1621 name
= expand_name(p
->p_comm
, p
->p_ucred
->cr_uid
, p
->p_pid
);
1624 error
= nlookup_init(&nd
, name
, UIO_SYSSPACE
, NLC_LOCKVP
);
1626 error
= vn_open(&nd
, NULL
, O_CREAT
| FWRITE
| O_NOFOLLOW
, S_IRUSR
| S_IWUSR
);
1633 nd
.nl_open_vp
= NULL
;
1636 VOP_UNLOCK(vp
, 0, td
);
1637 lf
.l_whence
= SEEK_SET
;
1640 lf
.l_type
= F_WRLCK
;
1641 error
= VOP_ADVLOCK(vp
, (caddr_t
)p
, F_SETLK
, &lf
, F_FLOCK
);
1645 /* Don't dump to non-regular files or files with links. */
1646 if (vp
->v_type
!= VREG
||
1647 VOP_GETATTR(vp
, &vattr
, td
) || vattr
.va_nlink
!= 1) {
1653 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
, td
);
1655 VOP_LEASE(vp
, td
, cred
, LEASE_WRITE
);
1656 VOP_SETATTR(vp
, &vattr
, cred
, td
);
1657 p
->p_acflag
|= ACORE
;
1658 VOP_UNLOCK(vp
, 0, td
);
1660 error
= p
->p_sysent
->sv_coredump
?
1661 p
->p_sysent
->sv_coredump(p
, vp
, limit
) : ENOSYS
;
1664 lf
.l_type
= F_UNLCK
;
1665 VOP_ADVLOCK(vp
, (caddr_t
)p
, F_UNLCK
, &lf
, F_FLOCK
);
1667 error1
= vn_close(vp
, FWRITE
, td
);
1674 * Nonexistent system call-- signal process (may want to handle it).
1675 * Flag error in case process won't see signal immediately (blocked or ignored).
1679 nosys(struct nosys_args
*args
)
1681 psignal(curproc
, SIGSYS
);
1686 * Send a SIGIO or SIGURG signal to a process or process group using
1687 * stored credentials rather than those of the current process.
1690 pgsigio(struct sigio
*sigio
, int sig
, int checkctty
)
1695 if (sigio
->sio_pgid
> 0) {
1696 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
,
1698 psignal(sigio
->sio_proc
, sig
);
1699 } else if (sigio
->sio_pgid
< 0) {
1702 LIST_FOREACH(p
, &sigio
->sio_pgrp
->pg_members
, p_pglist
)
1703 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
, p
) &&
1704 (checkctty
== 0 || (p
->p_flag
& P_CONTROLT
)))
1710 filt_sigattach(struct knote
*kn
)
1712 struct proc
*p
= curproc
;
1714 kn
->kn_ptr
.p_proc
= p
;
1715 kn
->kn_flags
|= EV_CLEAR
; /* automatically set */
1717 /* XXX lock the proc here while adding to the list? */
1718 SLIST_INSERT_HEAD(&p
->p_klist
, kn
, kn_selnext
);
1724 filt_sigdetach(struct knote
*kn
)
1726 struct proc
*p
= kn
->kn_ptr
.p_proc
;
1728 SLIST_REMOVE(&p
->p_klist
, kn
, knote
, kn_selnext
);
1732 * signal knotes are shared with proc knotes, so we apply a mask to
1733 * the hint in order to differentiate them from process hints. This
1734 * could be avoided by using a signal-specific knote list, but probably
1735 * isn't worth the trouble.
1738 filt_signal(struct knote
*kn
, long hint
)
1740 if (hint
& NOTE_SIGNAL
) {
1741 hint
&= ~NOTE_SIGNAL
;
1743 if (kn
->kn_id
== hint
)
1746 return (kn
->kn_data
!= 0);