2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
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11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
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23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
35 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
38 #include "opt_ktrace.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/sysproto.h>
44 #include <sys/signalvar.h>
45 #include <sys/resourcevar.h>
46 #include <sys/vnode.h>
47 #include <sys/event.h>
49 #include <sys/nlookup.h>
50 #include <sys/pioctl.h>
52 #include <sys/fcntl.h>
55 #include <sys/ktrace.h>
56 #include <sys/syslog.h>
58 #include <sys/sysent.h>
59 #include <sys/sysctl.h>
60 #include <sys/malloc.h>
61 #include <sys/interrupt.h>
62 #include <sys/unistd.h>
63 #include <sys/kern_syscall.h>
64 #include <sys/vkernel.h>
66 #include <sys/signal2.h>
67 #include <sys/thread2.h>
68 #include <sys/spinlock2.h>
70 #include <machine/cpu.h>
71 #include <machine/smp.h>
73 static int coredump(struct lwp
*, int);
74 static char *expand_name(const char *, uid_t
, pid_t
);
75 static int dokillpg(int sig
, int pgid
, int all
);
76 static int sig_ffs(sigset_t
*set
);
77 static int sigprop(int sig
);
78 static void lwp_signotify(struct lwp
*lp
);
79 static void lwp_signotify_remote(void *arg
);
80 static int kern_sigtimedwait(sigset_t set
, siginfo_t
*info
,
81 struct timespec
*timeout
);
82 static void proc_stopwait(struct proc
*p
);
84 static int filt_sigattach(struct knote
*kn
);
85 static void filt_sigdetach(struct knote
*kn
);
86 static int filt_signal(struct knote
*kn
, long hint
);
88 struct filterops sig_filtops
=
89 { FILTEROP_MPSAFE
, filt_sigattach
, filt_sigdetach
, filt_signal
};
91 static int kern_logsigexit
= 1;
92 SYSCTL_INT(_kern
, KERN_LOGSIGEXIT
, logsigexit
, CTLFLAG_RW
,
94 "Log processes quitting on abnormal signals to syslog(3)");
97 * Can process p send the signal sig to process q? Only processes within
98 * the current reaper or children of the current reaper can be signaled.
99 * Normally the reaper itself cannot be signalled, unless initok is set.
101 #define CANSIGNAL(q, sig, initok) \
102 ((!p_trespass(curproc->p_ucred, (q)->p_ucred) && \
103 reaper_sigtest(curproc, p, initok)) || \
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 * Allows us to populate siginfo->si_pid and si_uid in the target process
229 * (p) from the originating thread (td). This function must work properly
230 * even if a kernel thread is sending the signal.
232 * NOTE: Signals are not queued, so if multiple signals are received the
233 * signal handler will only see the most recent pid and uid for any
234 * given signal number.
237 sigsetfrompid(thread_t td
, struct proc
*p
, int sig
)
241 if ((sap
= p
->p_sigacts
) == NULL
)
244 sap
->ps_frominfo
[sig
].pid
= td
->td_proc
->p_pid
;
245 sap
->ps_frominfo
[sig
].uid
= td
->td_ucred
->cr_uid
;
247 sap
->ps_frominfo
[sig
].pid
= 0;
248 sap
->ps_frominfo
[sig
].uid
= 0;
256 kern_sigaction(int sig
, struct sigaction
*act
, struct sigaction
*oact
)
258 struct thread
*td
= curthread
;
259 struct proc
*p
= td
->td_proc
;
261 struct sigacts
*ps
= p
->p_sigacts
;
263 if (sig
<= 0 || sig
> _SIG_MAXSIG
)
266 lwkt_gettoken(&p
->p_token
);
269 oact
->sa_handler
= ps
->ps_sigact
[_SIG_IDX(sig
)];
270 oact
->sa_mask
= ps
->ps_catchmask
[_SIG_IDX(sig
)];
272 if (SIGISMEMBER(ps
->ps_sigonstack
, sig
))
273 oact
->sa_flags
|= SA_ONSTACK
;
274 if (!SIGISMEMBER(ps
->ps_sigintr
, sig
))
275 oact
->sa_flags
|= SA_RESTART
;
276 if (SIGISMEMBER(ps
->ps_sigreset
, sig
))
277 oact
->sa_flags
|= SA_RESETHAND
;
278 if (SIGISMEMBER(ps
->ps_signodefer
, sig
))
279 oact
->sa_flags
|= SA_NODEFER
;
280 if (SIGISMEMBER(ps
->ps_siginfo
, sig
))
281 oact
->sa_flags
|= SA_SIGINFO
;
282 if (sig
== SIGCHLD
&& p
->p_sigacts
->ps_flag
& PS_NOCLDSTOP
)
283 oact
->sa_flags
|= SA_NOCLDSTOP
;
284 if (sig
== SIGCHLD
&& p
->p_sigacts
->ps_flag
& PS_NOCLDWAIT
)
285 oact
->sa_flags
|= SA_NOCLDWAIT
;
289 * Check for invalid requests. KILL and STOP cannot be
292 if (sig
== SIGKILL
|| sig
== SIGSTOP
) {
293 if (act
->sa_handler
!= SIG_DFL
) {
294 lwkt_reltoken(&p
->p_token
);
300 * Change setting atomically.
302 ps
->ps_catchmask
[_SIG_IDX(sig
)] = act
->sa_mask
;
303 SIG_CANTMASK(ps
->ps_catchmask
[_SIG_IDX(sig
)]);
304 if (act
->sa_flags
& SA_SIGINFO
) {
305 ps
->ps_sigact
[_SIG_IDX(sig
)] =
306 (__sighandler_t
*)act
->sa_sigaction
;
307 SIGADDSET(ps
->ps_siginfo
, sig
);
309 ps
->ps_sigact
[_SIG_IDX(sig
)] = act
->sa_handler
;
310 SIGDELSET(ps
->ps_siginfo
, sig
);
312 if (!(act
->sa_flags
& SA_RESTART
))
313 SIGADDSET(ps
->ps_sigintr
, sig
);
315 SIGDELSET(ps
->ps_sigintr
, sig
);
316 if (act
->sa_flags
& SA_ONSTACK
)
317 SIGADDSET(ps
->ps_sigonstack
, sig
);
319 SIGDELSET(ps
->ps_sigonstack
, sig
);
320 if (act
->sa_flags
& SA_RESETHAND
)
321 SIGADDSET(ps
->ps_sigreset
, sig
);
323 SIGDELSET(ps
->ps_sigreset
, sig
);
324 if (act
->sa_flags
& SA_NODEFER
)
325 SIGADDSET(ps
->ps_signodefer
, sig
);
327 SIGDELSET(ps
->ps_signodefer
, sig
);
328 if (sig
== SIGCHLD
) {
329 if (act
->sa_flags
& SA_NOCLDSTOP
)
330 p
->p_sigacts
->ps_flag
|= PS_NOCLDSTOP
;
332 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDSTOP
;
333 if (act
->sa_flags
& SA_NOCLDWAIT
) {
335 * Paranoia: since SA_NOCLDWAIT is implemented
336 * by reparenting the dying child to PID 1 (and
337 * trust it to reap the zombie), PID 1 itself
338 * is forbidden to set SA_NOCLDWAIT.
341 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
343 p
->p_sigacts
->ps_flag
|= PS_NOCLDWAIT
;
345 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
347 if (ps
->ps_sigact
[_SIG_IDX(SIGCHLD
)] == SIG_IGN
)
348 ps
->ps_flag
|= PS_CLDSIGIGN
;
350 ps
->ps_flag
&= ~PS_CLDSIGIGN
;
353 * Set bit in p_sigignore for signals that are set to SIG_IGN,
354 * and for signals set to SIG_DFL where the default is to
355 * ignore. However, don't put SIGCONT in p_sigignore, as we
356 * have to restart the process.
358 * Also remove the signal from the process and lwp signal
361 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_IGN
||
362 (sigprop(sig
) & SA_IGNORE
&&
363 ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)) {
364 SIGDELSET_ATOMIC(p
->p_siglist
, sig
);
365 FOREACH_LWP_IN_PROC(lp
, p
) {
366 spin_lock(&lp
->lwp_spin
);
367 SIGDELSET(lp
->lwp_siglist
, sig
);
368 spin_unlock(&lp
->lwp_spin
);
370 if (sig
!= SIGCONT
) {
371 /* easier in ksignal */
372 SIGADDSET(p
->p_sigignore
, sig
);
374 SIGDELSET(p
->p_sigcatch
, sig
);
376 SIGDELSET(p
->p_sigignore
, sig
);
377 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)
378 SIGDELSET(p
->p_sigcatch
, sig
);
380 SIGADDSET(p
->p_sigcatch
, sig
);
383 lwkt_reltoken(&p
->p_token
);
388 sys_sigaction(struct sigaction_args
*uap
)
390 struct sigaction act
, oact
;
391 struct sigaction
*actp
, *oactp
;
394 actp
= (uap
->act
!= NULL
) ? &act
: NULL
;
395 oactp
= (uap
->oact
!= NULL
) ? &oact
: NULL
;
397 error
= copyin(uap
->act
, actp
, sizeof(act
));
401 error
= kern_sigaction(uap
->sig
, actp
, oactp
);
402 if (oactp
&& !error
) {
403 error
= copyout(oactp
, uap
->oact
, sizeof(oact
));
409 * Initialize signal state for process 0;
410 * set to ignore signals that are ignored by default.
413 siginit(struct proc
*p
)
417 for (i
= 1; i
<= NSIG
; i
++)
418 if (sigprop(i
) & SA_IGNORE
&& i
!= SIGCONT
)
419 SIGADDSET(p
->p_sigignore
, i
);
423 * Reset signals for an exec of the specified process.
426 execsigs(struct proc
*p
)
428 struct sigacts
*ps
= p
->p_sigacts
;
432 lp
= ONLY_LWP_IN_PROC(p
);
435 * Reset caught signals. Held signals remain held
436 * through p_sigmask (unless they were caught,
437 * and are now ignored by default).
439 while (SIGNOTEMPTY(p
->p_sigcatch
)) {
440 sig
= sig_ffs(&p
->p_sigcatch
);
441 SIGDELSET(p
->p_sigcatch
, sig
);
442 if (sigprop(sig
) & SA_IGNORE
) {
444 SIGADDSET(p
->p_sigignore
, sig
);
445 SIGDELSET_ATOMIC(p
->p_siglist
, sig
);
446 /* don't need spinlock */
447 SIGDELSET(lp
->lwp_siglist
, sig
);
449 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
453 * Reset stack state to the user stack.
454 * Clear set of signals caught on the signal stack.
456 lp
->lwp_sigstk
.ss_flags
= SS_DISABLE
;
457 lp
->lwp_sigstk
.ss_size
= 0;
458 lp
->lwp_sigstk
.ss_sp
= NULL
;
459 lp
->lwp_flags
&= ~LWP_ALTSTACK
;
461 * Reset no zombies if child dies flag as Solaris does.
463 p
->p_sigacts
->ps_flag
&= ~(PS_NOCLDWAIT
| PS_CLDSIGIGN
);
464 if (ps
->ps_sigact
[_SIG_IDX(SIGCHLD
)] == SIG_IGN
)
465 ps
->ps_sigact
[_SIG_IDX(SIGCHLD
)] = SIG_DFL
;
469 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
471 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
475 kern_sigprocmask(int how
, sigset_t
*set
, sigset_t
*oset
)
477 struct thread
*td
= curthread
;
478 struct lwp
*lp
= td
->td_lwp
;
479 struct proc
*p
= td
->td_proc
;
482 lwkt_gettoken(&p
->p_token
);
485 *oset
= lp
->lwp_sigmask
;
492 SIGSETOR(lp
->lwp_sigmask
, *set
);
495 SIGSETNAND(lp
->lwp_sigmask
, *set
);
499 lp
->lwp_sigmask
= *set
;
507 lwkt_reltoken(&p
->p_token
);
518 sys_sigprocmask(struct sigprocmask_args
*uap
)
521 sigset_t
*setp
, *osetp
;
524 setp
= (uap
->set
!= NULL
) ? &set
: NULL
;
525 osetp
= (uap
->oset
!= NULL
) ? &oset
: NULL
;
527 error
= copyin(uap
->set
, setp
, sizeof(set
));
531 error
= kern_sigprocmask(uap
->how
, setp
, osetp
);
532 if (osetp
&& !error
) {
533 error
= copyout(osetp
, uap
->oset
, sizeof(oset
));
542 kern_sigpending(struct __sigset
*set
)
544 struct lwp
*lp
= curthread
->td_lwp
;
546 *set
= lwp_sigpend(lp
);
555 sys_sigpending(struct sigpending_args
*uap
)
560 error
= kern_sigpending(&set
);
563 error
= copyout(&set
, uap
->set
, sizeof(set
));
568 * Suspend process until signal, providing mask to be set
574 kern_sigsuspend(struct __sigset
*set
)
576 struct thread
*td
= curthread
;
577 struct lwp
*lp
= td
->td_lwp
;
578 struct proc
*p
= td
->td_proc
;
579 struct sigacts
*ps
= p
->p_sigacts
;
582 * When returning from sigsuspend, we want
583 * the old mask to be restored after the
584 * signal handler has finished. Thus, we
585 * save it here and mark the sigacts structure
588 lp
->lwp_oldsigmask
= lp
->lwp_sigmask
;
589 lp
->lwp_flags
|= LWP_OLDMASK
;
592 lp
->lwp_sigmask
= *set
;
593 while (tsleep(ps
, PCATCH
, "pause", 0) == 0)
595 /* always return EINTR rather than ERESTART... */
600 * Note nonstandard calling convention: libc stub passes mask, not
601 * pointer, to save a copyin.
606 sys_sigsuspend(struct sigsuspend_args
*uap
)
611 error
= copyin(uap
->sigmask
, &mask
, sizeof(mask
));
615 error
= kern_sigsuspend(&mask
);
624 kern_sigaltstack(struct sigaltstack
*ss
, struct sigaltstack
*oss
)
626 struct thread
*td
= curthread
;
627 struct lwp
*lp
= td
->td_lwp
;
628 struct proc
*p
= td
->td_proc
;
630 if ((lp
->lwp_flags
& LWP_ALTSTACK
) == 0)
631 lp
->lwp_sigstk
.ss_flags
|= SS_DISABLE
;
634 *oss
= lp
->lwp_sigstk
;
637 if (ss
->ss_flags
& ~SS_DISABLE
)
639 if (ss
->ss_flags
& SS_DISABLE
) {
640 if (lp
->lwp_sigstk
.ss_flags
& SS_ONSTACK
)
642 lp
->lwp_flags
&= ~LWP_ALTSTACK
;
643 lp
->lwp_sigstk
.ss_flags
= ss
->ss_flags
;
645 if (ss
->ss_size
< p
->p_sysent
->sv_minsigstksz
)
647 lp
->lwp_flags
|= LWP_ALTSTACK
;
648 lp
->lwp_sigstk
= *ss
;
659 sys_sigaltstack(struct sigaltstack_args
*uap
)
665 error
= copyin(uap
->ss
, &ss
, sizeof(ss
));
670 error
= kern_sigaltstack(uap
->ss
? &ss
: NULL
, uap
->oss
? &oss
: NULL
);
672 if (error
== 0 && uap
->oss
)
673 error
= copyout(&oss
, uap
->oss
, sizeof(*uap
->oss
));
678 * Common code for kill process group/broadcast kill.
679 * cp is calling process.
686 static int killpg_all_callback(struct proc
*p
, void *data
);
689 dokillpg(int sig
, int pgid
, int all
)
691 struct killpg_info info
;
692 struct proc
*cp
= curproc
;
703 allproc_scan(killpg_all_callback
, &info
, 0);
707 * zero pgid means send to my process group.
718 * Must interlock all signals against fork
720 lockmgr(&pgrp
->pg_lock
, LK_EXCLUSIVE
);
721 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
723 p
->p_stat
== SZOMB
||
724 (p
->p_flags
& P_SYSTEM
) ||
725 !CANSIGNAL(p
, sig
, 0)) {
732 lockmgr(&pgrp
->pg_lock
, LK_RELEASE
);
735 return (info
.nfound
? 0 : ESRCH
);
739 killpg_all_callback(struct proc
*p
, void *data
)
741 struct killpg_info
*info
= data
;
743 if (p
->p_pid
<= 1 || (p
->p_flags
& P_SYSTEM
) ||
744 p
== curproc
|| !CANSIGNAL(p
, info
->sig
, 0)) {
749 ksignal(p
, info
->sig
);
754 * Send a general signal to a process or LWPs within that process.
756 * Note that new signals cannot be sent if a process is exiting or already
757 * a zombie, but we return success anyway as userland is likely to not handle
763 kern_kill(int sig
, pid_t pid
, lwpid_t tid
)
767 if ((u_int
)sig
> _SIG_MAXSIG
)
772 struct lwp
*lp
= NULL
;
775 * Send a signal to a single process. If the kill() is
776 * racing an exiting process which has not yet been reaped
777 * act as though the signal was delivered successfully but
778 * don't actually try to deliver the signal.
780 if ((p
= pfind(pid
)) == NULL
) {
781 if ((p
= zpfind(pid
)) == NULL
)
787 lwkt_gettoken_shared(&p
->p_token
);
788 if (!CANSIGNAL(p
, sig
, 1)) {
789 lwkt_reltoken(&p
->p_token
);
793 lwkt_reltoken(&p
->p_token
);
797 * NOP if the process is exiting. Note that lwpsignal() is
798 * called directly with P_WEXIT set to kill individual LWPs
799 * during exit, which is allowed.
801 if (p
->p_flags
& P_WEXIT
) {
806 lwkt_gettoken_shared(&p
->p_token
);
807 lp
= lwp_rb_tree_RB_LOOKUP(&p
->p_lwp_tree
, tid
);
809 lwkt_reltoken(&p
->p_token
);
814 lwkt_reltoken(&p
->p_token
);
817 lwpsignal(p
, lp
, sig
);
826 * If we come here, pid is a special broadcast pid.
827 * This doesn't mix with a tid.
833 case -1: /* broadcast signal */
834 t
= (dokillpg(sig
, 0, 1));
836 case 0: /* signal own process group */
837 t
= (dokillpg(sig
, 0, 0));
839 default: /* negative explicit process group */
840 t
= (dokillpg(sig
, -pid
, 0));
847 sys_kill(struct kill_args
*uap
)
851 error
= kern_kill(uap
->signum
, uap
->pid
, -1);
856 sys_lwp_kill(struct lwp_kill_args
*uap
)
859 pid_t pid
= uap
->pid
;
862 * A tid is mandatory for lwp_kill(), otherwise
863 * you could simply use kill().
869 * To save on a getpid() function call for intra-process
870 * signals, pid == -1 means current process.
873 pid
= curproc
->p_pid
;
875 error
= kern_kill(uap
->signum
, pid
, uap
->tid
);
880 * Send a signal to a process group.
883 gsignal(int pgid
, int sig
)
887 if (pgid
&& (pgrp
= pgfind(pgid
)))
888 pgsignal(pgrp
, sig
, 0);
892 * Send a signal to a process group. If checktty is 1,
893 * limit to members which have a controlling terminal.
895 * pg_lock interlocks against a fork that might be in progress, to
896 * ensure that the new child process picks up the signal.
899 pgsignal(struct pgrp
*pgrp
, int sig
, int checkctty
)
904 * Must interlock all signals against fork
908 lockmgr(&pgrp
->pg_lock
, LK_EXCLUSIVE
);
909 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
910 if (checkctty
== 0 || p
->p_flags
& P_CONTROLT
)
913 lockmgr(&pgrp
->pg_lock
, LK_RELEASE
);
919 * Send a signal caused by a trap to the current lwp. If it will be caught
920 * immediately, deliver it with correct code. Otherwise, post it normally.
922 * These signals may ONLY be delivered to the specified lwp and may never
923 * be delivered to the process generically.
926 trapsignal(struct lwp
*lp
, int sig
, u_long code
)
928 struct proc
*p
= lp
->lwp_proc
;
929 struct sigacts
*ps
= p
->p_sigacts
;
932 * If we are a virtual kernel running an emulated user process
933 * context, switch back to the virtual kernel context before
934 * trying to post the signal.
936 if (lp
->lwp_vkernel
&& lp
->lwp_vkernel
->ve
) {
937 struct trapframe
*tf
= lp
->lwp_md
.md_regs
;
939 vkernel_trap(lp
, tf
);
942 if ((p
->p_flags
& P_TRACED
) == 0 && SIGISMEMBER(p
->p_sigcatch
, sig
) &&
943 !SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
944 lp
->lwp_ru
.ru_nsignals
++;
946 if (KTRPOINT(lp
->lwp_thread
, KTR_PSIG
))
947 ktrpsig(lp
, sig
, ps
->ps_sigact
[_SIG_IDX(sig
)],
948 &lp
->lwp_sigmask
, code
);
950 (*p
->p_sysent
->sv_sendsig
)(ps
->ps_sigact
[_SIG_IDX(sig
)], sig
,
951 &lp
->lwp_sigmask
, code
);
952 SIGSETOR(lp
->lwp_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
953 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
954 SIGADDSET(lp
->lwp_sigmask
, sig
);
955 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
957 * See kern_sigaction() for origin of this code.
959 SIGDELSET(p
->p_sigcatch
, sig
);
960 if (sig
!= SIGCONT
&&
961 sigprop(sig
) & SA_IGNORE
)
962 SIGADDSET(p
->p_sigignore
, sig
);
963 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
966 lp
->lwp_code
= code
; /* XXX for core dump/debugger */
967 lp
->lwp_sig
= sig
; /* XXX to verify code */
968 lwpsignal(p
, lp
, sig
);
973 * Find a suitable lwp to deliver the signal to. Returns NULL if all
974 * lwps hold the signal blocked.
976 * Caller must hold p->p_token.
978 * Returns a lp or NULL. If non-NULL the lp is held and its token is
982 find_lwp_for_signal(struct proc
*p
, int sig
)
985 struct lwp
*run
, *sleep
, *stop
;
988 * If the running/preempted thread belongs to the proc to which
989 * the signal is being delivered and this thread does not block
990 * the signal, then we can avoid a context switch by delivering
991 * the signal to this thread, because it will return to userland
994 lp
= lwkt_preempted_proc();
995 if (lp
!= NULL
&& lp
->lwp_proc
== p
) {
997 lwkt_gettoken(&lp
->lwp_token
);
998 if (!SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
999 /* return w/ token held */
1002 lwkt_reltoken(&lp
->lwp_token
);
1006 run
= sleep
= stop
= NULL
;
1007 FOREACH_LWP_IN_PROC(lp
, p
) {
1009 * If the signal is being blocked by the lwp, then this
1010 * lwp is not eligible for receiving the signal.
1013 lwkt_gettoken(&lp
->lwp_token
);
1015 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
1016 lwkt_reltoken(&lp
->lwp_token
);
1021 switch (lp
->lwp_stat
) {
1025 lwkt_reltoken(&sleep
->lwp_token
);
1031 lwkt_reltoken(&stop
->lwp_token
);
1040 if (lp
->lwp_flags
& LWP_SINTR
) {
1042 lwkt_reltoken(&lp
->lwp_token
);
1046 lwkt_reltoken(&stop
->lwp_token
);
1054 lwkt_reltoken(&lp
->lwp_token
);
1060 lwkt_reltoken(&lp
->lwp_token
);
1063 lwkt_reltoken(&lp
->lwp_token
);
1076 else if (sleep
!= NULL
)
1083 * Send the signal to the process. If the signal has an action, the action
1084 * is usually performed by the target process rather than the caller; we add
1085 * the signal to the set of pending signals for the process.
1088 * o When a stop signal is sent to a sleeping process that takes the
1089 * default action, the process is stopped without awakening it.
1090 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1091 * regardless of the signal action (eg, blocked or ignored).
1093 * Other ignored signals are discarded immediately.
1095 * If the caller wishes to call this function from a hard code section the
1096 * caller must already hold p->p_token (see kern_clock.c).
1101 ksignal(struct proc
*p
, int sig
)
1103 lwpsignal(p
, NULL
, sig
);
1107 * The core for ksignal. lp may be NULL, then a suitable thread
1108 * will be chosen. If not, lp MUST be a member of p.
1110 * If the caller wishes to call this function from a hard code section the
1111 * caller must already hold p->p_token.
1116 lwpsignal(struct proc
*p
, struct lwp
*lp
, int sig
)
1122 if (sig
> _SIG_MAXSIG
|| sig
<= 0) {
1123 kprintf("lwpsignal: signal %d\n", sig
);
1124 panic("lwpsignal signal number");
1127 KKASSERT(lp
== NULL
|| lp
->lwp_proc
== p
);
1130 * We don't want to race... well, all sorts of things. Get appropriate
1133 * Don't try to deliver a generic signal to an exiting process,
1134 * the signal structures could be in flux. We check the LWP later
1140 lwkt_gettoken(&lp
->lwp_token
);
1142 lwkt_gettoken(&p
->p_token
);
1143 if (p
->p_flags
& P_WEXIT
)
1147 prop
= sigprop(sig
);
1150 * If proc is traced, always give parent a chance;
1151 * if signal event is tracked by procfs, give *that*
1152 * a chance, as well.
1154 if ((p
->p_flags
& P_TRACED
) || (p
->p_stops
& S_SIG
)) {
1158 * Do not try to deliver signals to an exiting lwp other
1159 * than SIGKILL. Note that we must still deliver the signal
1160 * if P_WEXIT is set in the process flags.
1162 if (lp
&& (lp
->lwp_mpflags
& LWP_MP_WEXIT
) && sig
!= SIGKILL
) {
1163 lwkt_reltoken(&lp
->lwp_token
);
1170 * If the signal is being ignored, then we forget about
1171 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1172 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1174 if (SIGISMEMBER(p
->p_sigignore
, sig
)) {
1176 * Even if a signal is set SIG_IGN, it may still be
1177 * lurking in a kqueue.
1179 KNOTE(&p
->p_klist
, NOTE_SIGNAL
| sig
);
1181 lwkt_reltoken(&lp
->lwp_token
);
1184 lwkt_reltoken(&p
->p_token
);
1189 if (SIGISMEMBER(p
->p_sigcatch
, sig
))
1196 * If continuing, clear any pending STOP signals for the whole
1199 if (prop
& SA_CONT
) {
1200 lwkt_gettoken(&p
->p_token
);
1201 SIG_STOPSIGMASK_ATOMIC(p
->p_siglist
);
1202 lwkt_reltoken(&p
->p_token
);
1205 if (prop
& SA_STOP
) {
1207 * If sending a tty stop signal to a member of an orphaned
1208 * process group, discard the signal here if the action
1209 * is default; don't stop the process below if sleeping,
1210 * and don't clear any pending SIGCONT.
1212 if ((prop
& SA_TTYSTOP
) && p
->p_pgrp
->pg_jobc
== 0 &&
1213 action
== SIG_DFL
) {
1215 lwkt_reltoken(&lp
->lwp_token
);
1218 lwkt_reltoken(&p
->p_token
);
1223 lwkt_gettoken(&p
->p_token
);
1224 SIG_CONTSIGMASK_ATOMIC(p
->p_siglist
);
1225 p
->p_flags
&= ~P_CONTINUED
;
1226 lwkt_reltoken(&p
->p_token
);
1229 if (p
->p_stat
== SSTOP
) {
1231 * Nobody can handle this signal, add it to the lwp or
1232 * process pending list
1234 lwkt_gettoken(&p
->p_token
);
1235 if (p
->p_stat
!= SSTOP
) {
1236 lwkt_reltoken(&p
->p_token
);
1239 sigsetfrompid(curthread
, p
, sig
);
1241 spin_lock(&lp
->lwp_spin
);
1242 SIGADDSET(lp
->lwp_siglist
, sig
);
1243 spin_unlock(&lp
->lwp_spin
);
1245 SIGADDSET_ATOMIC(p
->p_siglist
, sig
);
1249 * If the process is stopped and is being traced, then no
1250 * further action is necessary.
1252 if (p
->p_flags
& P_TRACED
) {
1253 lwkt_reltoken(&p
->p_token
);
1258 * If the process is stopped and receives a KILL signal,
1259 * make the process runnable.
1261 if (sig
== SIGKILL
) {
1262 proc_unstop(p
, SSTOP
);
1263 lwkt_reltoken(&p
->p_token
);
1264 goto active_process
;
1268 * If the process is stopped and receives a CONT signal,
1269 * then try to make the process runnable again.
1271 if (prop
& SA_CONT
) {
1273 * If SIGCONT is default (or ignored), we continue the
1274 * process but don't leave the signal in p_siglist, as
1275 * it has no further action. If SIGCONT is held, we
1276 * continue the process and leave the signal in
1277 * p_siglist. If the process catches SIGCONT, let it
1278 * handle the signal itself.
1280 * XXX what if the signal is being held blocked?
1282 * Token required to interlock kern_wait().
1283 * Reparenting can also cause a race so we have to
1288 lwkt_gettoken(&q
->p_token
);
1289 p
->p_flags
|= P_CONTINUED
;
1291 if (action
== SIG_DFL
)
1292 SIGDELSET_ATOMIC(p
->p_siglist
, sig
);
1293 proc_unstop(p
, SSTOP
);
1294 lwkt_reltoken(&q
->p_token
);
1296 lwkt_reltoken(&p
->p_token
);
1297 if (action
== SIG_CATCH
)
1298 goto active_process
;
1303 * If the process is stopped and receives another STOP
1304 * signal, we do not need to stop it again. If we did
1305 * the shell could get confused.
1307 * However, if the current/preempted lwp is part of the
1308 * process receiving the signal, we need to keep it,
1309 * so that this lwp can stop in issignal() later, as
1310 * we don't want to wait until it reaches userret!
1312 if (prop
& SA_STOP
) {
1313 if (lwkt_preempted_proc() == NULL
||
1314 lwkt_preempted_proc()->lwp_proc
!= p
) {
1315 SIGDELSET_ATOMIC(p
->p_siglist
, sig
);
1320 * Otherwise the process is stopped and it received some
1321 * signal, which does not change its stopped state. When
1322 * the process is continued a wakeup(p) will be issued which
1323 * will wakeup any threads sleeping in tstop().
1325 lwkt_reltoken(&p
->p_token
);
1331 /* else not stopped */
1335 * Never deliver a lwp-specific signal to a random lwp.
1338 /* NOTE: returns lp w/ token held */
1339 lp
= find_lwp_for_signal(p
, sig
);
1341 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
1342 lwkt_reltoken(&lp
->lwp_token
);
1345 /* maintain proc token */
1348 lwkt_reltoken(&p
->p_token
);
1349 /* maintain lp token */
1355 * Deliver to the process generically if (1) the signal is being
1356 * sent to any thread or (2) we could not find a thread to deliver
1360 sigsetfrompid(curthread
, p
, sig
);
1361 KNOTE(&p
->p_klist
, NOTE_SIGNAL
| sig
);
1362 SIGADDSET_ATOMIC(p
->p_siglist
, sig
);
1367 * Deliver to a specific LWP whether it masks it or not. It will
1368 * not be dispatched if masked but we must still deliver it.
1370 if (p
->p_nice
> NZERO
&& action
== SIG_DFL
&& (prop
& SA_KILL
) &&
1371 (p
->p_flags
& P_TRACED
) == 0) {
1372 lwkt_gettoken(&p
->p_token
);
1374 lwkt_reltoken(&p
->p_token
);
1378 * If the process receives a STOP signal which indeed needs to
1379 * stop the process, do so. If the process chose to catch the
1380 * signal, it will be treated like any other signal.
1382 if ((prop
& SA_STOP
) && action
== SIG_DFL
) {
1384 * If a child holding parent blocked, stopping
1385 * could cause deadlock. Take no action at this
1388 lwkt_gettoken(&p
->p_token
);
1389 if (p
->p_flags
& P_PPWAIT
) {
1390 sigsetfrompid(curthread
, p
, sig
);
1391 SIGADDSET_ATOMIC(p
->p_siglist
, sig
);
1392 lwkt_reltoken(&p
->p_token
);
1397 * Do not actually try to manipulate the process, but simply
1398 * stop it. Lwps will stop as soon as they safely can.
1400 * Ignore stop if the process is exiting.
1402 if ((p
->p_flags
& P_WEXIT
) == 0) {
1404 proc_stop(p
, SSTOP
);
1406 lwkt_reltoken(&p
->p_token
);
1411 * If it is a CONT signal with default action, just ignore it.
1413 if ((prop
& SA_CONT
) && action
== SIG_DFL
)
1417 * Mark signal pending at this specific thread.
1419 sigsetfrompid(curthread
, p
, sig
);
1420 spin_lock(&lp
->lwp_spin
);
1421 SIGADDSET(lp
->lwp_siglist
, sig
);
1422 spin_unlock(&lp
->lwp_spin
);
1428 lwkt_reltoken(&lp
->lwp_token
);
1431 lwkt_reltoken(&p
->p_token
);
1437 * Notify the LWP that a signal has arrived. The LWP does not have to be
1438 * sleeping on the current cpu.
1440 * p->p_token and lp->lwp_token must be held on call.
1442 * We can only safely schedule the thread on its current cpu and only if
1443 * one of the SINTR flags is set. If an SINTR flag is set AND we are on
1444 * the correct cpu we are properly interlocked, otherwise we could be
1445 * racing other thread transition states (or the lwp is on the user scheduler
1446 * runq but not scheduled) and must not do anything.
1448 * Since we hold the lwp token we know the lwp cannot be ripped out from
1449 * under us so we can safely hold it to prevent it from being ripped out
1450 * from under us if we are forced to IPI another cpu to make the local
1453 * Adjustment of lp->lwp_stat can only occur when we hold the lwp_token,
1454 * which we won't in an IPI so any fixups have to be done here, effectively
1455 * replicating part of what setrunnable() does.
1458 lwp_signotify(struct lwp
*lp
)
1462 ASSERT_LWKT_TOKEN_HELD(&lp
->lwp_token
);
1463 dtd
= lp
->lwp_thread
;
1466 if (lp
== lwkt_preempted_proc()) {
1468 * lwp is on the current cpu AND it is currently running
1469 * (we preempted it).
1472 } else if (lp
->lwp_flags
& LWP_SINTR
) {
1474 * lwp is sitting in tsleep() with PCATCH set
1476 if (dtd
->td_gd
== mycpu
) {
1480 * We can only adjust lwp_stat while we hold the
1481 * lwp_token, and we won't in the IPI function.
1484 if (lp
->lwp_stat
== LSSTOP
)
1485 lp
->lwp_stat
= LSSLEEP
;
1486 lwkt_send_ipiq(dtd
->td_gd
, lwp_signotify_remote
, lp
);
1488 } else if (dtd
->td_flags
& TDF_SINTR
) {
1490 * lwp is sitting in lwkt_sleep() with PCATCH set.
1492 if (dtd
->td_gd
== mycpu
) {
1496 * We can only adjust lwp_stat while we hold the
1497 * lwp_token, and we won't in the IPI function.
1500 if (lp
->lwp_stat
== LSSTOP
)
1501 lp
->lwp_stat
= LSSLEEP
;
1502 lwkt_send_ipiq(dtd
->td_gd
, lwp_signotify_remote
, lp
);
1506 * Otherwise the lwp is either in some uninterruptible state
1507 * or it is on the userland scheduler's runqueue waiting to
1508 * be scheduled to a cpu, or it is running in userland. We
1509 * generally want to send an IPI so a running target gets the
1510 * signal ASAP, otherwise a scheduler-tick worth of latency
1513 * Issue an IPI to the remote cpu to knock it into the kernel,
1514 * remote cpu will issue the cpu-local signotify() if the IPI
1515 * preempts the desired thread.
1517 if (dtd
->td_gd
!= mycpu
) {
1519 lwkt_send_ipiq(dtd
->td_gd
, lwp_signotify_remote
, lp
);
1526 * This function is called via an IPI so we cannot call setrunnable() here
1527 * (because while we hold the lp we don't own its token, and can't get it
1530 * We are interlocked by virtue of being on the same cpu as the target. If
1531 * we still are and LWP_SINTR or TDF_SINTR is set we can safely schedule
1532 * the target thread.
1535 lwp_signotify_remote(void *arg
)
1537 struct lwp
*lp
= arg
;
1538 thread_t td
= lp
->lwp_thread
;
1540 if (lp
== lwkt_preempted_proc()) {
1543 } else if (td
->td_gd
== mycpu
) {
1544 if ((lp
->lwp_flags
& LWP_SINTR
) ||
1545 (td
->td_flags
& TDF_SINTR
)) {
1550 lwkt_send_ipiq(td
->td_gd
, lwp_signotify_remote
, lp
);
1551 /* LWPHOLD() is forwarded to the target cpu */
1556 * Caller must hold p->p_token
1559 proc_stop(struct proc
*p
, int sig
)
1564 ASSERT_LWKT_TOKEN_HELD(&p
->p_token
);
1567 * If somebody raced us, be happy with it. SCORE overrides SSTOP.
1570 if (p
->p_stat
== SCORE
|| p
->p_stat
== SZOMB
)
1573 if (p
->p_stat
== SSTOP
|| p
->p_stat
== SCORE
||
1574 p
->p_stat
== SZOMB
) {
1580 FOREACH_LWP_IN_PROC(lp
, p
) {
1582 lwkt_gettoken(&lp
->lwp_token
);
1584 switch (lp
->lwp_stat
) {
1587 * Do nothing, we are already counted in
1594 * We're sleeping, but we will stop before
1595 * returning to userspace, so count us
1596 * as stopped as well. We set LWP_MP_WSTOP
1597 * to signal the lwp that it should not
1598 * increase p_nstopped when reaching tstop().
1600 * LWP_MP_WSTOP is protected by lp->lwp_token.
1602 if ((lp
->lwp_mpflags
& LWP_MP_WSTOP
) == 0) {
1603 atomic_set_int(&lp
->lwp_mpflags
, LWP_MP_WSTOP
);
1610 * We might notify ourself, but that's not
1616 lwkt_reltoken(&lp
->lwp_token
);
1620 if (p
->p_nstopped
== p
->p_nthreads
) {
1622 * Token required to interlock kern_wait(). Reparenting can
1623 * also cause a race so we have to hold (q).
1627 lwkt_gettoken(&q
->p_token
);
1628 p
->p_flags
&= ~P_WAITED
;
1630 if ((q
->p_sigacts
->ps_flag
& PS_NOCLDSTOP
) == 0)
1631 ksignal(p
->p_pptr
, SIGCHLD
);
1632 lwkt_reltoken(&q
->p_token
);
1638 * Caller must hold p_token
1641 proc_unstop(struct proc
*p
, int sig
)
1645 ASSERT_LWKT_TOKEN_HELD(&p
->p_token
);
1647 if (p
->p_stat
!= sig
)
1650 p
->p_stat
= SACTIVE
;
1652 FOREACH_LWP_IN_PROC(lp
, p
) {
1654 lwkt_gettoken(&lp
->lwp_token
);
1656 switch (lp
->lwp_stat
) {
1659 * Uh? Not stopped? Well, I guess that's okay.
1662 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1663 p
->p_pid
, lp
->lwp_tid
);
1668 * Still sleeping. Don't bother waking it up.
1669 * However, if this thread was counted as
1670 * stopped, undo this.
1672 * Nevertheless we call setrunnable() so that it
1673 * will wake up in case a signal or timeout arrived
1676 * LWP_MP_WSTOP is protected by lp->lwp_token.
1678 if (lp
->lwp_mpflags
& LWP_MP_WSTOP
) {
1679 atomic_clear_int(&lp
->lwp_mpflags
,
1684 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1685 p
->p_pid
, lp
->lwp_tid
);
1691 * This handles any lwp's waiting in a tsleep with
1698 lwkt_reltoken(&lp
->lwp_token
);
1703 * This handles any lwp's waiting in tstop(). We have interlocked
1704 * the setting of p_stat by acquiring and releasing each lpw's
1711 * Wait for all threads except the current thread to stop.
1714 proc_stopwait(struct proc
*p
)
1716 while ((p
->p_stat
== SSTOP
|| p
->p_stat
== SCORE
) &&
1717 p
->p_nstopped
< p
->p_nthreads
- 1) {
1718 tsleep_interlock(&p
->p_nstopped
, 0);
1719 if (p
->p_nstopped
< p
->p_nthreads
- 1) {
1720 tsleep(&p
->p_nstopped
, PINTERLOCKED
, "stopwt", hz
);
1729 kern_sigtimedwait(sigset_t waitset
, siginfo_t
*info
, struct timespec
*timeout
)
1731 sigset_t savedmask
, set
;
1732 struct proc
*p
= curproc
;
1733 struct lwp
*lp
= curthread
->td_lwp
;
1734 int error
, sig
, hz
, timevalid
= 0;
1735 struct timespec rts
, ets
, ts
;
1740 ets
.tv_sec
= 0; /* silence compiler warning */
1741 ets
.tv_nsec
= 0; /* silence compiler warning */
1742 SIG_CANTMASK(waitset
);
1743 savedmask
= lp
->lwp_sigmask
;
1746 if (timeout
->tv_sec
>= 0 && timeout
->tv_nsec
>= 0 &&
1747 timeout
->tv_nsec
< 1000000000) {
1749 getnanouptime(&rts
);
1751 timespecadd(&ets
, timeout
);
1756 set
= lwp_sigpend(lp
);
1757 SIGSETAND(set
, waitset
);
1758 if ((sig
= sig_ffs(&set
)) != 0) {
1759 SIGFILLSET(lp
->lwp_sigmask
);
1760 SIGDELSET(lp
->lwp_sigmask
, sig
);
1761 SIG_CANTMASK(lp
->lwp_sigmask
);
1762 sig
= issignal(lp
, 1, 0);
1764 * It may be a STOP signal, in the case, issignal
1765 * returns 0, because we may stop there, and new
1766 * signal can come in, we should restart if we got
1776 * Previous checking got nothing, and we retried but still
1777 * got nothing, we should return the error status.
1783 * POSIX says this must be checked after looking for pending
1787 if (timevalid
== 0) {
1791 getnanouptime(&rts
);
1792 if (timespeccmp(&rts
, &ets
, >=)) {
1797 timespecsub(&ts
, &rts
);
1798 TIMESPEC_TO_TIMEVAL(&tv
, &ts
);
1799 hz
= tvtohz_high(&tv
);
1804 lp
->lwp_sigmask
= savedmask
;
1805 SIGSETNAND(lp
->lwp_sigmask
, waitset
);
1807 * We won't ever be woken up. Instead, our sleep will
1808 * be broken in lwpsignal().
1810 error
= tsleep(&p
->p_sigacts
, PCATCH
, "sigwt", hz
);
1812 if (error
== ERESTART
) {
1813 /* can not restart a timeout wait. */
1815 } else if (error
== EAGAIN
) {
1816 /* will calculate timeout by ourself. */
1823 lp
->lwp_sigmask
= savedmask
;
1826 bzero(info
, sizeof(*info
));
1827 info
->si_signo
= sig
;
1828 spin_lock(&lp
->lwp_spin
);
1829 lwp_delsig(lp
, sig
, 1); /* take the signal! */
1830 spin_unlock(&lp
->lwp_spin
);
1832 if (sig
== SIGKILL
) {
1845 sys_sigtimedwait(struct sigtimedwait_args
*uap
)
1848 struct timespec
*timeout
;
1854 error
= copyin(uap
->timeout
, &ts
, sizeof(ts
));
1861 error
= copyin(uap
->set
, &set
, sizeof(set
));
1864 error
= kern_sigtimedwait(set
, &info
, timeout
);
1868 error
= copyout(&info
, uap
->info
, sizeof(info
));
1869 /* Repost if we got an error. */
1873 * This could transform a thread-specific signal to another
1874 * thread / process pending signal.
1877 ksignal(curproc
, info
.si_signo
);
1879 uap
->sysmsg_result
= info
.si_signo
;
1888 sys_sigwaitinfo(struct sigwaitinfo_args
*uap
)
1894 error
= copyin(uap
->set
, &set
, sizeof(set
));
1897 error
= kern_sigtimedwait(set
, &info
, NULL
);
1901 error
= copyout(&info
, uap
->info
, sizeof(info
));
1902 /* Repost if we got an error. */
1906 * This could transform a thread-specific signal to another
1907 * thread / process pending signal.
1910 ksignal(curproc
, info
.si_signo
);
1912 uap
->sysmsg_result
= info
.si_signo
;
1918 * If the current process has received a signal that would interrupt a
1919 * system call, return EINTR or ERESTART as appropriate.
1922 iscaught(struct lwp
*lp
)
1924 struct proc
*p
= lp
->lwp_proc
;
1928 if ((sig
= CURSIG(lp
)) != 0) {
1929 if (SIGISMEMBER(p
->p_sigacts
->ps_sigintr
, sig
))
1934 return(EWOULDBLOCK
);
1938 * If the current lwp/proc has received a signal (should be caught or cause
1939 * termination, should interrupt current syscall), return the signal number.
1940 * Stop signals with default action are processed immediately, then cleared;
1941 * they aren't returned. This is checked after each entry to the system for
1942 * a syscall or trap (though this can usually be done without calling issignal
1943 * by checking the pending signal masks in the CURSIG macro).
1945 * This routine is called via CURSIG/__cursig. We will acquire and release
1946 * p->p_token but if the caller needs to interlock the test the caller must
1947 * also hold p->p_token.
1949 * while (sig = CURSIG(curproc))
1953 issignal(struct lwp
*lp
, int maytrace
, int *ptokp
)
1955 struct proc
*p
= lp
->lwp_proc
;
1961 int traced
= (p
->p_flags
& P_TRACED
) || (p
->p_stops
& S_SIG
);
1966 * If this process is supposed to stop, stop this thread.
1968 if (STOPLWP(p
, lp
)) {
1969 lwkt_gettoken(&p
->p_token
);
1971 lwkt_reltoken(&p
->p_token
);
1975 * Quick check without token
1977 mask
= lwp_sigpend(lp
);
1978 SIGSETNAND(mask
, lp
->lwp_sigmask
);
1979 if (p
->p_flags
& P_PPWAIT
)
1980 SIG_STOPSIGMASK(mask
);
1981 if (SIGISEMPTY(mask
)) /* no signal to send */
1985 * If the signal is a member of the process signal set
1986 * we need p_token (even if it is also a member of the
1989 sig
= sig_ffs(&mask
);
1990 if (SIGISMEMBER(p
->p_siglist
, sig
)) {
1992 * Recheck with token
1995 lwkt_gettoken(&p
->p_token
);
1997 mask
= lwp_sigpend(lp
);
1998 SIGSETNAND(mask
, lp
->lwp_sigmask
);
1999 if (p
->p_flags
& P_PPWAIT
)
2000 SIG_STOPSIGMASK(mask
);
2001 if (SIGISEMPTY(mask
)) { /* no signal to send */
2002 /* haveptok is TRUE */
2003 lwkt_reltoken(&p
->p_token
);
2006 sig
= sig_ffs(&mask
);
2009 STOPEVENT(p
, S_SIG
, sig
);
2012 * We should see pending but ignored signals
2013 * only if P_TRACED was on when they were posted.
2015 if (SIGISMEMBER(p
->p_sigignore
, sig
) && (traced
== 0)) {
2016 spin_lock(&lp
->lwp_spin
);
2017 lwp_delsig(lp
, sig
, haveptok
);
2018 spin_unlock(&lp
->lwp_spin
);
2020 lwkt_reltoken(&p
->p_token
);
2024 (p
->p_flags
& P_TRACED
) &&
2025 (p
->p_flags
& P_PPWAIT
) == 0) {
2027 * If traced, always stop, and stay stopped until
2028 * released by the parent.
2030 * NOTE: SSTOP may get cleared during the loop,
2031 * but we do not re-notify the parent if we have
2032 * to loop several times waiting for the parent
2033 * to let us continue.
2035 * XXX not sure if this is still true
2037 if (haveptok
== 0) {
2038 lwkt_gettoken(&p
->p_token
);
2042 proc_stop(p
, SSTOP
);
2045 } while (!trace_req(p
) && (p
->p_flags
& P_TRACED
));
2048 * If parent wants us to take the signal,
2049 * then it will leave it in p->p_xstat;
2050 * otherwise we just look for signals again.
2052 spin_lock(&lp
->lwp_spin
);
2053 lwp_delsig(lp
, sig
, 1); /* clear old signal */
2054 spin_unlock(&lp
->lwp_spin
);
2057 /* haveptok is TRUE */
2058 lwkt_reltoken(&p
->p_token
);
2063 * Put the new signal into p_siglist. If the
2064 * signal is being masked, look for other signals.
2066 * XXX lwp might need a call to ksignal()
2068 SIGADDSET_ATOMIC(p
->p_siglist
, sig
);
2069 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
2070 /* haveptok is TRUE */
2071 lwkt_reltoken(&p
->p_token
);
2076 * If the traced bit got turned off, go back up
2077 * to the top to rescan signals. This ensures
2078 * that p_sig* and ps_sigact are consistent.
2080 if ((p
->p_flags
& P_TRACED
) == 0) {
2081 /* haveptok is TRUE */
2082 lwkt_reltoken(&p
->p_token
);
2088 * p_token may be held here
2090 prop
= sigprop(sig
);
2093 * Decide whether the signal should be returned.
2094 * Return the signal's number, or fall through
2095 * to clear it from the pending mask.
2097 switch ((intptr_t)p
->p_sigacts
->ps_sigact
[_SIG_IDX(sig
)]) {
2098 case (intptr_t)SIG_DFL
:
2100 * Don't take default actions on system processes.
2102 if (p
->p_pid
<= 1) {
2105 * Are you sure you want to ignore SIGSEGV
2108 kprintf("Process (pid %lu) got signal %d\n",
2109 (u_long
)p
->p_pid
, sig
);
2111 break; /* == ignore */
2115 * Handle the in-kernel checkpoint action
2117 if (prop
& SA_CKPT
) {
2118 if (haveptok
== 0) {
2119 lwkt_gettoken(&p
->p_token
);
2122 checkpoint_signal_handler(lp
);
2127 * If there is a pending stop signal to process
2128 * with default action, stop here,
2129 * then clear the signal. However,
2130 * if process is member of an orphaned
2131 * process group, ignore tty stop signals.
2133 if (prop
& SA_STOP
) {
2134 if (haveptok
== 0) {
2135 lwkt_gettoken(&p
->p_token
);
2138 if (p
->p_flags
& P_TRACED
||
2139 (p
->p_pgrp
->pg_jobc
== 0 &&
2141 break; /* == ignore */
2142 if ((p
->p_flags
& P_WEXIT
) == 0) {
2144 proc_stop(p
, SSTOP
);
2148 } else if (prop
& SA_IGNORE
) {
2150 * Except for SIGCONT, shouldn't get here.
2151 * Default action is to ignore; drop it.
2153 break; /* == ignore */
2158 lwkt_reltoken(&p
->p_token
);
2164 case (intptr_t)SIG_IGN
:
2166 * Masking above should prevent us ever trying
2167 * to take action on an ignored signal other
2168 * than SIGCONT, unless process is traced.
2170 if ((prop
& SA_CONT
) == 0 &&
2171 (p
->p_flags
& P_TRACED
) == 0)
2172 kprintf("issignal\n");
2173 break; /* == ignore */
2177 * This signal has an action, let
2178 * postsig() process it.
2183 lwkt_reltoken(&p
->p_token
);
2186 spin_lock(&lp
->lwp_spin
);
2187 lwp_delsig(lp
, sig
, haveptok
); /* take the signal! */
2188 spin_unlock(&lp
->lwp_spin
);
2191 lwkt_reltoken(&p
->p_token
);
2197 * Take the action for the specified signal from the current set of
2200 * haveptok indicates whether the caller is holding p->p_token. If the
2201 * caller is, we are responsible for releasing it.
2203 * This routine can only be called from the top-level trap from usermode.
2204 * It is expecting to be able to modify the top-level stack frame.
2207 postsig(int sig
, int haveptok
)
2209 struct lwp
*lp
= curthread
->td_lwp
;
2210 struct proc
*p
= lp
->lwp_proc
;
2211 struct sigacts
*ps
= p
->p_sigacts
;
2213 sigset_t returnmask
;
2216 KASSERT(sig
!= 0, ("postsig"));
2219 * If we are a virtual kernel running an emulated user process
2220 * context, switch back to the virtual kernel context before
2221 * trying to post the signal.
2223 if (lp
->lwp_vkernel
&& lp
->lwp_vkernel
->ve
) {
2224 struct trapframe
*tf
= lp
->lwp_md
.md_regs
;
2226 vkernel_trap(lp
, tf
);
2229 KNOTE(&p
->p_klist
, NOTE_SIGNAL
| sig
);
2231 spin_lock(&lp
->lwp_spin
);
2232 lwp_delsig(lp
, sig
, haveptok
);
2233 spin_unlock(&lp
->lwp_spin
);
2234 action
= ps
->ps_sigact
[_SIG_IDX(sig
)];
2236 if (KTRPOINT(lp
->lwp_thread
, KTR_PSIG
))
2237 ktrpsig(lp
, sig
, action
, lp
->lwp_flags
& LWP_OLDMASK
?
2238 &lp
->lwp_oldsigmask
: &lp
->lwp_sigmask
, 0);
2241 * We don't need p_token after this point.
2244 lwkt_reltoken(&p
->p_token
);
2246 STOPEVENT(p
, S_SIG
, sig
);
2248 if (action
== SIG_DFL
) {
2250 * Default action, where the default is to kill
2251 * the process. (Other cases were ignored above.)
2257 * If we get here, the signal must be caught.
2259 KASSERT(action
!= SIG_IGN
&& !SIGISMEMBER(lp
->lwp_sigmask
, sig
),
2260 ("postsig action"));
2263 * Reset the signal handler if asked to
2265 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
2267 * See kern_sigaction() for origin of this code.
2269 SIGDELSET(p
->p_sigcatch
, sig
);
2270 if (sig
!= SIGCONT
&&
2271 sigprop(sig
) & SA_IGNORE
)
2272 SIGADDSET(p
->p_sigignore
, sig
);
2273 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
2277 * Set the signal mask and calculate the mask to restore
2278 * when the signal function returns.
2280 * Special case: user has done a sigsuspend. Here the
2281 * current mask is not of interest, but rather the
2282 * mask from before the sigsuspend is what we want
2283 * restored after the signal processing is completed.
2285 if (lp
->lwp_flags
& LWP_OLDMASK
) {
2286 returnmask
= lp
->lwp_oldsigmask
;
2287 lp
->lwp_flags
&= ~LWP_OLDMASK
;
2289 returnmask
= lp
->lwp_sigmask
;
2292 SIGSETOR(lp
->lwp_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
2293 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
2294 SIGADDSET(lp
->lwp_sigmask
, sig
);
2296 lp
->lwp_ru
.ru_nsignals
++;
2297 if (lp
->lwp_sig
!= sig
) {
2300 code
= lp
->lwp_code
;
2304 (*p
->p_sysent
->sv_sendsig
)(action
, sig
, &returnmask
, code
);
2309 * Kill the current process for stated reason.
2312 killproc(struct proc
*p
, char *why
)
2314 log(LOG_ERR
, "pid %d (%s), uid %d, was killed: %s\n",
2315 p
->p_pid
, p
->p_comm
,
2316 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1, why
);
2317 ksignal(p
, SIGKILL
);
2321 * Force the current process to exit with the specified signal, dumping core
2322 * if appropriate. We bypass the normal tests for masked and caught signals,
2323 * allowing unrecoverable failures to terminate the process without changing
2324 * signal state. Mark the accounting record with the signal termination.
2325 * If dumping core, save the signal number for the debugger. Calls exit and
2328 * This routine does not return.
2331 sigexit(struct lwp
*lp
, int sig
)
2333 struct proc
*p
= lp
->lwp_proc
;
2335 lwkt_gettoken(&p
->p_token
);
2336 p
->p_acflag
|= AXSIG
;
2337 if (sigprop(sig
) & SA_CORE
) {
2341 * All threads must be stopped before we can safely coredump.
2342 * Stop threads using SCORE, which cannot be overridden.
2344 if (p
->p_stat
!= SCORE
) {
2345 proc_stop(p
, SCORE
);
2348 if (coredump(lp
, sig
) == 0)
2354 * Log signals which would cause core dumps
2355 * (Log as LOG_INFO to appease those who don't want
2357 * XXX : Todo, as well as euid, write out ruid too
2359 if (kern_logsigexit
) {
2361 "pid %d (%s), uid %d: exited on signal %d%s\n",
2362 p
->p_pid
, p
->p_comm
,
2363 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1,
2365 sig
& WCOREFLAG
? " (core dumped)" : "");
2368 lwkt_reltoken(&p
->p_token
);
2369 exit1(W_EXITCODE(0, sig
));
2373 static char corefilename
[MAXPATHLEN
+1] = {"%N.core"};
2374 SYSCTL_STRING(_kern
, OID_AUTO
, corefile
, CTLFLAG_RW
, corefilename
,
2375 sizeof(corefilename
), "process corefile name format string");
2378 * expand_name(name, uid, pid)
2379 * Expand the name described in corefilename, using name, uid, and pid.
2380 * corefilename is a kprintf-like string, with three format specifiers:
2381 * %N name of process ("name")
2382 * %P process id (pid)
2384 * For example, "%N.core" is the default; they can be disabled completely
2385 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2386 * This is controlled by the sysctl variable kern.corefile (see above).
2390 expand_name(const char *name
, uid_t uid
, pid_t pid
)
2393 char buf
[11]; /* Buffer for pid/uid -- max 4B */
2395 char *format
= corefilename
;
2398 temp
= kmalloc(MAXPATHLEN
+ 1, M_TEMP
, M_NOWAIT
);
2401 namelen
= strlen(name
);
2402 for (i
= 0, n
= 0; n
< MAXPATHLEN
&& format
[i
]; i
++) {
2404 switch (format
[i
]) {
2405 case '%': /* Format character */
2407 switch (format
[i
]) {
2411 case 'N': /* process name */
2412 if ((n
+ namelen
) > MAXPATHLEN
) {
2413 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2414 pid
, name
, uid
, temp
, name
);
2415 kfree(temp
, M_TEMP
);
2418 memcpy(temp
+n
, name
, namelen
);
2421 case 'P': /* process id */
2422 l
= ksprintf(buf
, "%u", pid
);
2423 if ((n
+ l
) > MAXPATHLEN
) {
2424 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2425 pid
, name
, uid
, temp
, name
);
2426 kfree(temp
, M_TEMP
);
2429 memcpy(temp
+n
, buf
, l
);
2432 case 'U': /* user id */
2433 l
= ksprintf(buf
, "%u", uid
);
2434 if ((n
+ l
) > MAXPATHLEN
) {
2435 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2436 pid
, name
, uid
, temp
, name
);
2437 kfree(temp
, M_TEMP
);
2440 memcpy(temp
+n
, buf
, l
);
2444 log(LOG_ERR
, "Unknown format character %c in `%s'\n", format
[i
], format
);
2448 temp
[n
++] = format
[i
];
2456 * Dump a process' core. The main routine does some
2457 * policy checking, and creates the name of the coredump;
2458 * then it passes on a vnode and a size limit to the process-specific
2459 * coredump routine if there is one; if there _is not_ one, it returns
2460 * ENOSYS; otherwise it returns the error from the process-specific routine.
2462 * The parameter `lp' is the lwp which triggered the coredump.
2466 coredump(struct lwp
*lp
, int sig
)
2468 struct proc
*p
= lp
->lwp_proc
;
2470 struct ucred
*cred
= p
->p_ucred
;
2472 struct nlookupdata nd
;
2475 char *name
; /* name of corefile */
2478 STOPEVENT(p
, S_CORE
, 0);
2480 if (((sugid_coredump
== 0) && p
->p_flags
& P_SUGID
) || do_coredump
== 0)
2484 * Note that the bulk of limit checking is done after
2485 * the corefile is created. The exception is if the limit
2486 * for corefiles is 0, in which case we don't bother
2487 * creating the corefile at all. This layout means that
2488 * a corefile is truncated instead of not being created,
2489 * if it is larger than the limit.
2491 limit
= p
->p_rlimit
[RLIMIT_CORE
].rlim_cur
;
2495 name
= expand_name(p
->p_comm
, p
->p_ucred
->cr_uid
, p
->p_pid
);
2498 error
= nlookup_init(&nd
, name
, UIO_SYSSPACE
, NLC_LOCKVP
);
2500 error
= vn_open(&nd
, NULL
,
2501 O_CREAT
| FWRITE
| O_NOFOLLOW
,
2503 kfree(name
, M_TEMP
);
2509 nd
.nl_open_vp
= NULL
;
2513 lf
.l_whence
= SEEK_SET
;
2516 lf
.l_type
= F_WRLCK
;
2517 error
= VOP_ADVLOCK(vp
, (caddr_t
)p
, F_SETLK
, &lf
, 0);
2521 /* Don't dump to non-regular files or files with links. */
2522 if (vp
->v_type
!= VREG
||
2523 VOP_GETATTR(vp
, &vattr
) || vattr
.va_nlink
!= 1) {
2528 /* Don't dump to files current user does not own */
2529 if (vattr
.va_uid
!= p
->p_ucred
->cr_uid
) {
2535 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
2537 VOP_SETATTR(vp
, &vattr
, cred
);
2538 p
->p_acflag
|= ACORE
;
2541 error
= p
->p_sysent
->sv_coredump
?
2542 p
->p_sysent
->sv_coredump(lp
, sig
, vp
, limit
) : ENOSYS
;
2545 lf
.l_type
= F_UNLCK
;
2546 VOP_ADVLOCK(vp
, (caddr_t
)p
, F_UNLCK
, &lf
, 0);
2548 error1
= vn_close(vp
, FWRITE
, NULL
);
2555 * Nonexistent system call-- signal process (may want to handle it).
2556 * Flag error in case process won't see signal immediately (blocked or ignored).
2562 sys_nosys(struct nosys_args
*args
)
2564 lwpsignal(curproc
, curthread
->td_lwp
, SIGSYS
);
2569 * Send a SIGIO or SIGURG signal to a process or process group using
2570 * stored credentials rather than those of the current process.
2573 pgsigio(struct sigio
*sigio
, int sig
, int checkctty
)
2578 if (sigio
->sio_pgid
> 0) {
2579 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
,
2581 ksignal(sigio
->sio_proc
, sig
);
2582 } else if (sigio
->sio_pgid
< 0) {
2584 struct pgrp
*pg
= sigio
->sio_pgrp
;
2587 * Must interlock all signals against fork
2590 lockmgr(&pg
->pg_lock
, LK_EXCLUSIVE
);
2591 LIST_FOREACH(p
, &pg
->pg_members
, p_pglist
) {
2592 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
, p
) &&
2593 (checkctty
== 0 || (p
->p_flags
& P_CONTROLT
)))
2596 lockmgr(&pg
->pg_lock
, LK_RELEASE
);
2602 filt_sigattach(struct knote
*kn
)
2604 struct proc
*p
= curproc
;
2606 kn
->kn_ptr
.p_proc
= p
;
2607 kn
->kn_flags
|= EV_CLEAR
; /* automatically set */
2609 /* XXX lock the proc here while adding to the list? */
2610 knote_insert(&p
->p_klist
, kn
);
2616 filt_sigdetach(struct knote
*kn
)
2618 struct proc
*p
= kn
->kn_ptr
.p_proc
;
2620 knote_remove(&p
->p_klist
, kn
);
2624 * signal knotes are shared with proc knotes, so we apply a mask to
2625 * the hint in order to differentiate them from process hints. This
2626 * could be avoided by using a signal-specific knote list, but probably
2627 * isn't worth the trouble.
2630 filt_signal(struct knote
*kn
, long hint
)
2632 if (hint
& NOTE_SIGNAL
) {
2633 hint
&= ~NOTE_SIGNAL
;
2635 if (kn
->kn_id
== hint
)
2638 return (kn
->kn_data
!= 0);