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. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
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31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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(&p
->p_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(&p
->p_token
);
277 /* (not needed, SIG_DFL forces action to occur) */
278 if (act
->sa_flags
& SA_MAILBOX
) {
279 lwkt_reltoken(&p
->p_token
);
286 * Change setting atomically.
290 ps
->ps_catchmask
[_SIG_IDX(sig
)] = act
->sa_mask
;
291 SIG_CANTMASK(ps
->ps_catchmask
[_SIG_IDX(sig
)]);
292 if (act
->sa_flags
& SA_SIGINFO
) {
293 ps
->ps_sigact
[_SIG_IDX(sig
)] =
294 (__sighandler_t
*)act
->sa_sigaction
;
295 SIGADDSET(ps
->ps_siginfo
, sig
);
297 ps
->ps_sigact
[_SIG_IDX(sig
)] = act
->sa_handler
;
298 SIGDELSET(ps
->ps_siginfo
, sig
);
300 if (!(act
->sa_flags
& SA_RESTART
))
301 SIGADDSET(ps
->ps_sigintr
, sig
);
303 SIGDELSET(ps
->ps_sigintr
, sig
);
304 if (act
->sa_flags
& SA_ONSTACK
)
305 SIGADDSET(ps
->ps_sigonstack
, sig
);
307 SIGDELSET(ps
->ps_sigonstack
, sig
);
308 if (act
->sa_flags
& SA_RESETHAND
)
309 SIGADDSET(ps
->ps_sigreset
, sig
);
311 SIGDELSET(ps
->ps_sigreset
, sig
);
312 if (act
->sa_flags
& SA_NODEFER
)
313 SIGADDSET(ps
->ps_signodefer
, sig
);
315 SIGDELSET(ps
->ps_signodefer
, sig
);
316 if (act
->sa_flags
& SA_MAILBOX
)
317 SIGADDSET(ps
->ps_sigmailbox
, sig
);
319 SIGDELSET(ps
->ps_sigmailbox
, sig
);
320 if (sig
== SIGCHLD
) {
321 if (act
->sa_flags
& SA_NOCLDSTOP
)
322 p
->p_sigacts
->ps_flag
|= PS_NOCLDSTOP
;
324 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDSTOP
;
325 if (act
->sa_flags
& SA_NOCLDWAIT
) {
327 * Paranoia: since SA_NOCLDWAIT is implemented
328 * by reparenting the dying child to PID 1 (and
329 * trust it to reap the zombie), PID 1 itself
330 * is forbidden to set SA_NOCLDWAIT.
333 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
335 p
->p_sigacts
->ps_flag
|= PS_NOCLDWAIT
;
337 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
341 * Set bit in p_sigignore for signals that are set to SIG_IGN,
342 * and for signals set to SIG_DFL where the default is to
343 * ignore. However, don't put SIGCONT in p_sigignore, as we
344 * have to restart the process.
346 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_IGN
||
347 (sigprop(sig
) & SA_IGNORE
&&
348 ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)) {
349 /* never to be seen again */
350 SIGDELSET(p
->p_siglist
, sig
);
352 * Remove the signal also from the thread lists.
354 FOREACH_LWP_IN_PROC(lp
, p
) {
355 SIGDELSET(lp
->lwp_siglist
, sig
);
357 if (sig
!= SIGCONT
) {
358 /* easier in ksignal */
359 SIGADDSET(p
->p_sigignore
, sig
);
361 SIGDELSET(p
->p_sigcatch
, sig
);
363 SIGDELSET(p
->p_sigignore
, sig
);
364 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)
365 SIGDELSET(p
->p_sigcatch
, sig
);
367 SIGADDSET(p
->p_sigcatch
, sig
);
372 lwkt_reltoken(&p
->p_token
);
377 sys_sigaction(struct sigaction_args
*uap
)
379 struct sigaction act
, oact
;
380 struct sigaction
*actp
, *oactp
;
383 actp
= (uap
->act
!= NULL
) ? &act
: NULL
;
384 oactp
= (uap
->oact
!= NULL
) ? &oact
: NULL
;
386 error
= copyin(uap
->act
, actp
, sizeof(act
));
390 error
= kern_sigaction(uap
->sig
, actp
, oactp
);
391 if (oactp
&& !error
) {
392 error
= copyout(oactp
, uap
->oact
, sizeof(oact
));
398 * Initialize signal state for process 0;
399 * set to ignore signals that are ignored by default.
402 siginit(struct proc
*p
)
406 for (i
= 1; i
<= NSIG
; i
++)
407 if (sigprop(i
) & SA_IGNORE
&& i
!= SIGCONT
)
408 SIGADDSET(p
->p_sigignore
, i
);
412 * Reset signals for an exec of the specified process.
415 execsigs(struct proc
*p
)
417 struct sigacts
*ps
= p
->p_sigacts
;
421 lp
= ONLY_LWP_IN_PROC(p
);
424 * Reset caught signals. Held signals remain held
425 * through p_sigmask (unless they were caught,
426 * and are now ignored by default).
428 while (SIGNOTEMPTY(p
->p_sigcatch
)) {
429 sig
= sig_ffs(&p
->p_sigcatch
);
430 SIGDELSET(p
->p_sigcatch
, sig
);
431 if (sigprop(sig
) & SA_IGNORE
) {
433 SIGADDSET(p
->p_sigignore
, sig
);
434 SIGDELSET(p
->p_siglist
, sig
);
435 SIGDELSET(lp
->lwp_siglist
, sig
);
437 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
441 * Reset stack state to the user stack.
442 * Clear set of signals caught on the signal stack.
444 lp
->lwp_sigstk
.ss_flags
= SS_DISABLE
;
445 lp
->lwp_sigstk
.ss_size
= 0;
446 lp
->lwp_sigstk
.ss_sp
= 0;
447 lp
->lwp_flag
&= ~LWP_ALTSTACK
;
449 * Reset no zombies if child dies flag as Solaris does.
451 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
455 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
457 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
461 kern_sigprocmask(int how
, sigset_t
*set
, sigset_t
*oset
)
463 struct thread
*td
= curthread
;
464 struct lwp
*lp
= td
->td_lwp
;
465 struct proc
*p
= td
->td_proc
;
468 lwkt_gettoken(&p
->p_token
);
471 *oset
= lp
->lwp_sigmask
;
478 SIGSETOR(lp
->lwp_sigmask
, *set
);
481 SIGSETNAND(lp
->lwp_sigmask
, *set
);
485 lp
->lwp_sigmask
= *set
;
493 lwkt_reltoken(&p
->p_token
);
504 sys_sigprocmask(struct sigprocmask_args
*uap
)
507 sigset_t
*setp
, *osetp
;
510 setp
= (uap
->set
!= NULL
) ? &set
: NULL
;
511 osetp
= (uap
->oset
!= NULL
) ? &oset
: NULL
;
513 error
= copyin(uap
->set
, setp
, sizeof(set
));
517 error
= kern_sigprocmask(uap
->how
, setp
, osetp
);
518 if (osetp
&& !error
) {
519 error
= copyout(osetp
, uap
->oset
, sizeof(oset
));
528 kern_sigpending(struct __sigset
*set
)
530 struct lwp
*lp
= curthread
->td_lwp
;
532 *set
= lwp_sigpend(lp
);
541 sys_sigpending(struct sigpending_args
*uap
)
546 error
= kern_sigpending(&set
);
549 error
= copyout(&set
, uap
->set
, sizeof(set
));
554 * Suspend process until signal, providing mask to be set
560 kern_sigsuspend(struct __sigset
*set
)
562 struct thread
*td
= curthread
;
563 struct lwp
*lp
= td
->td_lwp
;
564 struct proc
*p
= td
->td_proc
;
565 struct sigacts
*ps
= p
->p_sigacts
;
568 * When returning from sigsuspend, we want
569 * the old mask to be restored after the
570 * signal handler has finished. Thus, we
571 * save it here and mark the sigacts structure
574 lp
->lwp_oldsigmask
= lp
->lwp_sigmask
;
575 lp
->lwp_flag
|= LWP_OLDMASK
;
578 lp
->lwp_sigmask
= *set
;
579 while (tsleep(ps
, PCATCH
, "pause", 0) == 0)
581 /* always return EINTR rather than ERESTART... */
586 * Note nonstandard calling convention: libc stub passes mask, not
587 * pointer, to save a copyin.
592 sys_sigsuspend(struct sigsuspend_args
*uap
)
597 error
= copyin(uap
->sigmask
, &mask
, sizeof(mask
));
601 error
= kern_sigsuspend(&mask
);
610 kern_sigaltstack(struct sigaltstack
*ss
, struct sigaltstack
*oss
)
612 struct thread
*td
= curthread
;
613 struct lwp
*lp
= td
->td_lwp
;
614 struct proc
*p
= td
->td_proc
;
616 if ((lp
->lwp_flag
& LWP_ALTSTACK
) == 0)
617 lp
->lwp_sigstk
.ss_flags
|= SS_DISABLE
;
620 *oss
= lp
->lwp_sigstk
;
623 if (ss
->ss_flags
& SS_DISABLE
) {
624 if (lp
->lwp_sigstk
.ss_flags
& SS_ONSTACK
)
626 lp
->lwp_flag
&= ~LWP_ALTSTACK
;
627 lp
->lwp_sigstk
.ss_flags
= ss
->ss_flags
;
629 if (ss
->ss_size
< p
->p_sysent
->sv_minsigstksz
)
631 lp
->lwp_flag
|= LWP_ALTSTACK
;
632 lp
->lwp_sigstk
= *ss
;
643 sys_sigaltstack(struct sigaltstack_args
*uap
)
649 error
= copyin(uap
->ss
, &ss
, sizeof(ss
));
654 error
= kern_sigaltstack(uap
->ss
? &ss
: NULL
,
655 uap
->oss
? &oss
: NULL
);
657 if (error
== 0 && uap
->oss
)
658 error
= copyout(&oss
, uap
->oss
, sizeof(*uap
->oss
));
663 * Common code for kill process group/broadcast kill.
664 * cp is calling process.
671 static int killpg_all_callback(struct proc
*p
, void *data
);
674 dokillpg(int sig
, int pgid
, int all
)
676 struct killpg_info info
;
677 struct proc
*cp
= curproc
;
688 allproc_scan(killpg_all_callback
, &info
);
692 * zero pgid means send to my process group.
703 * Must interlock all signals against fork
705 lockmgr(&pgrp
->pg_lock
, LK_EXCLUSIVE
);
706 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
708 p
->p_stat
== SZOMB
||
709 (p
->p_flag
& P_SYSTEM
) ||
710 !CANSIGNAL(p
, sig
)) {
717 lockmgr(&pgrp
->pg_lock
, LK_RELEASE
);
720 return (info
.nfound
? 0 : ESRCH
);
724 killpg_all_callback(struct proc
*p
, void *data
)
726 struct killpg_info
*info
= data
;
728 if (p
->p_pid
<= 1 || (p
->p_flag
& P_SYSTEM
) ||
729 p
== curproc
|| !CANSIGNAL(p
, info
->sig
)) {
734 ksignal(p
, info
->sig
);
739 * Send a general signal to a process or LWPs within that process. Note
740 * that new signals cannot be sent if a process is exiting.
745 kern_kill(int sig
, pid_t pid
, lwpid_t tid
)
749 if ((u_int
)sig
> _SIG_MAXSIG
)
752 lwkt_gettoken(&proc_token
);
756 struct lwp
*lp
= NULL
;
758 /* kill single process */
759 if ((p
= pfind(pid
)) == NULL
) {
760 lwkt_reltoken(&proc_token
);
763 lwkt_gettoken(&p
->p_token
);
764 if (!CANSIGNAL(p
, sig
)) {
765 lwkt_reltoken(&p
->p_token
);
767 lwkt_reltoken(&proc_token
);
772 * NOP if the process is exiting. Note that lwpsignal() is
773 * called directly with P_WEXIT set to kill individual LWPs
774 * during exit, which is allowed.
776 if (p
->p_flag
& P_WEXIT
) {
777 lwkt_reltoken(&p
->p_token
);
779 lwkt_reltoken(&proc_token
);
783 lp
= lwp_rb_tree_RB_LOOKUP(&p
->p_lwp_tree
, tid
);
785 lwkt_reltoken(&p
->p_token
);
787 lwkt_reltoken(&proc_token
);
792 lwpsignal(p
, lp
, sig
);
793 lwkt_reltoken(&p
->p_token
);
795 lwkt_reltoken(&proc_token
);
800 * If we come here, pid is a special broadcast pid.
801 * This doesn't mix with a tid.
804 lwkt_reltoken(&proc_token
);
808 case -1: /* broadcast signal */
809 t
= (dokillpg(sig
, 0, 1));
811 case 0: /* signal own process group */
812 t
= (dokillpg(sig
, 0, 0));
814 default: /* negative explicit process group */
815 t
= (dokillpg(sig
, -pid
, 0));
818 lwkt_reltoken(&proc_token
);
823 sys_kill(struct kill_args
*uap
)
827 error
= kern_kill(uap
->signum
, uap
->pid
, -1);
832 sys_lwp_kill(struct lwp_kill_args
*uap
)
835 pid_t pid
= uap
->pid
;
838 * A tid is mandatory for lwp_kill(), otherwise
839 * you could simply use kill().
845 * To save on a getpid() function call for intra-process
846 * signals, pid == -1 means current process.
849 pid
= curproc
->p_pid
;
851 error
= kern_kill(uap
->signum
, pid
, uap
->tid
);
856 * Send a signal to a process group.
859 gsignal(int pgid
, int sig
)
863 if (pgid
&& (pgrp
= pgfind(pgid
)))
864 pgsignal(pgrp
, sig
, 0);
868 * Send a signal to a process group. If checktty is 1,
869 * limit to members which have a controlling terminal.
871 * pg_lock interlocks against a fork that might be in progress, to
872 * ensure that the new child process picks up the signal.
875 pgsignal(struct pgrp
*pgrp
, int sig
, int checkctty
)
880 * Must interlock all signals against fork
884 lockmgr(&pgrp
->pg_lock
, LK_EXCLUSIVE
);
885 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
886 if (checkctty
== 0 || p
->p_flag
& P_CONTROLT
)
889 lockmgr(&pgrp
->pg_lock
, LK_RELEASE
);
895 * Send a signal caused by a trap to the current lwp. If it will be caught
896 * immediately, deliver it with correct code. Otherwise, post it normally.
898 * These signals may ONLY be delivered to the specified lwp and may never
899 * be delivered to the process generically.
902 trapsignal(struct lwp
*lp
, int sig
, u_long code
)
904 struct proc
*p
= lp
->lwp_proc
;
905 struct sigacts
*ps
= p
->p_sigacts
;
908 * If we are a virtual kernel running an emulated user process
909 * context, switch back to the virtual kernel context before
910 * trying to post the signal.
912 if (lp
->lwp_vkernel
&& lp
->lwp_vkernel
->ve
) {
913 struct trapframe
*tf
= lp
->lwp_md
.md_regs
;
915 vkernel_trap(lp
, tf
);
919 if ((p
->p_flag
& P_TRACED
) == 0 && SIGISMEMBER(p
->p_sigcatch
, sig
) &&
920 !SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
921 lp
->lwp_ru
.ru_nsignals
++;
923 if (KTRPOINT(lp
->lwp_thread
, KTR_PSIG
))
924 ktrpsig(lp
, sig
, ps
->ps_sigact
[_SIG_IDX(sig
)],
925 &lp
->lwp_sigmask
, code
);
927 (*p
->p_sysent
->sv_sendsig
)(ps
->ps_sigact
[_SIG_IDX(sig
)], sig
,
928 &lp
->lwp_sigmask
, code
);
929 SIGSETOR(lp
->lwp_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
930 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
931 SIGADDSET(lp
->lwp_sigmask
, sig
);
932 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
934 * See kern_sigaction() for origin of this code.
936 SIGDELSET(p
->p_sigcatch
, sig
);
937 if (sig
!= SIGCONT
&&
938 sigprop(sig
) & SA_IGNORE
)
939 SIGADDSET(p
->p_sigignore
, sig
);
940 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
943 lp
->lwp_code
= code
; /* XXX for core dump/debugger */
944 lp
->lwp_sig
= sig
; /* XXX to verify code */
945 lwpsignal(p
, lp
, sig
);
950 * Find a suitable lwp to deliver the signal to. Returns NULL if all
951 * lwps hold the signal blocked.
953 * Caller must hold p->p_token.
956 find_lwp_for_signal(struct proc
*p
, int sig
)
959 struct lwp
*run
, *sleep
, *stop
;
962 * If the running/preempted thread belongs to the proc to which
963 * the signal is being delivered and this thread does not block
964 * the signal, then we can avoid a context switch by delivering
965 * the signal to this thread, because it will return to userland
968 lp
= lwkt_preempted_proc();
969 if (lp
!= NULL
&& lp
->lwp_proc
== p
&&
970 !SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
974 run
= sleep
= stop
= NULL
;
975 FOREACH_LWP_IN_PROC(lp
, p
) {
977 * If the signal is being blocked by the lwp, then this
978 * lwp is not eligible for receiving the signal.
980 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
))
983 switch (lp
->lwp_stat
) {
993 if (lp
->lwp_flag
& LWP_SINTR
)
1001 else if (sleep
!= NULL
)
1008 * Send the signal to the process. If the signal has an action, the action
1009 * is usually performed by the target process rather than the caller; we add
1010 * the signal to the set of pending signals for the process.
1013 * o When a stop signal is sent to a sleeping process that takes the
1014 * default action, the process is stopped without awakening it.
1015 * o SIGCONT restarts stopped processes (or puts them back to sleep)
1016 * regardless of the signal action (eg, blocked or ignored).
1018 * Other ignored signals are discarded immediately.
1020 * If the caller wishes to call this function from a hard code section the
1021 * caller must already hold p->p_token (see kern_clock.c).
1026 ksignal(struct proc
*p
, int sig
)
1028 lwpsignal(p
, NULL
, sig
);
1032 * The core for ksignal. lp may be NULL, then a suitable thread
1033 * will be chosen. If not, lp MUST be a member of p.
1035 * If the caller wishes to call this function from a hard code section the
1036 * caller must already hold p->p_token.
1041 lwpsignal(struct proc
*p
, struct lwp
*lp
, int sig
)
1046 if (sig
> _SIG_MAXSIG
|| sig
<= 0) {
1047 kprintf("lwpsignal: signal %d\n", sig
);
1048 panic("lwpsignal signal number");
1051 KKASSERT(lp
== NULL
|| lp
->lwp_proc
== p
);
1054 lwkt_gettoken(&p
->p_token
);
1056 prop
= sigprop(sig
);
1059 * If proc is traced, always give parent a chance;
1060 * if signal event is tracked by procfs, give *that*
1061 * a chance, as well.
1063 if ((p
->p_flag
& P_TRACED
) || (p
->p_stops
& S_SIG
)) {
1067 * Do not try to deliver signals to an exiting lwp. Note
1068 * that we must still deliver the signal if P_WEXIT is set
1069 * in the process flags.
1071 if (lp
&& (lp
->lwp_flag
& LWP_WEXIT
)) {
1072 lwkt_reltoken(&p
->p_token
);
1078 * If the signal is being ignored, then we forget about
1079 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
1080 * and if it is set to SIG_IGN, action will be SIG_DFL here.
1082 if (SIGISMEMBER(p
->p_sigignore
, sig
)) {
1083 lwkt_reltoken(&p
->p_token
);
1087 if (SIGISMEMBER(p
->p_sigcatch
, sig
))
1094 * If continuing, clear any pending STOP signals.
1097 SIG_STOPSIGMASK(p
->p_siglist
);
1099 if (prop
& SA_STOP
) {
1101 * If sending a tty stop signal to a member of an orphaned
1102 * process group, discard the signal here if the action
1103 * is default; don't stop the process below if sleeping,
1104 * and don't clear any pending SIGCONT.
1106 if (prop
& SA_TTYSTOP
&& p
->p_pgrp
->pg_jobc
== 0 &&
1107 action
== SIG_DFL
) {
1108 lwkt_reltoken(&p
->p_token
);
1112 SIG_CONTSIGMASK(p
->p_siglist
);
1113 p
->p_flag
&= ~P_CONTINUED
;
1118 if (p
->p_stat
== SSTOP
) {
1120 * Nobody can handle this signal, add it to the lwp or
1121 * process pending list
1124 SIGADDSET(lp
->lwp_siglist
, sig
);
1126 SIGADDSET(p
->p_siglist
, sig
);
1129 * If the process is stopped and is being traced, then no
1130 * further action is necessary.
1132 if (p
->p_flag
& P_TRACED
)
1136 * If the process is stopped and receives a KILL signal,
1137 * make the process runnable.
1139 if (sig
== SIGKILL
) {
1141 goto active_process
;
1145 * If the process is stopped and receives a CONT signal,
1146 * then try to make the process runnable again.
1148 if (prop
& SA_CONT
) {
1150 * If SIGCONT is default (or ignored), we continue the
1151 * process but don't leave the signal in p_siglist, as
1152 * it has no further action. If SIGCONT is held, we
1153 * continue the process and leave the signal in
1154 * p_siglist. If the process catches SIGCONT, let it
1155 * handle the signal itself.
1157 /* XXX what if the signal is being held blocked? */
1158 p
->p_flag
|= P_CONTINUED
;
1160 if (action
== SIG_DFL
)
1161 SIGDELSET(p
->p_siglist
, sig
);
1163 if (action
== SIG_CATCH
)
1164 goto active_process
;
1169 * If the process is stopped and receives another STOP
1170 * signal, we do not need to stop it again. If we did
1171 * the shell could get confused.
1173 * However, if the current/preempted lwp is part of the
1174 * process receiving the signal, we need to keep it,
1175 * so that this lwp can stop in issignal() later, as
1176 * we don't want to wait until it reaches userret!
1178 if (prop
& SA_STOP
) {
1179 if (lwkt_preempted_proc() == NULL
||
1180 lwkt_preempted_proc()->lwp_proc
!= p
)
1181 SIGDELSET(p
->p_siglist
, sig
);
1185 * Otherwise the process is stopped and it received some
1186 * signal, which does not change its stopped state.
1188 * We have to select one thread to set LWP_BREAKTSLEEP,
1189 * so that the current signal will break the sleep
1190 * as soon as a SA_CONT signal will unstop the process.
1193 lp
= find_lwp_for_signal(p
, sig
);
1195 (lp
->lwp_stat
== LSSLEEP
|| lp
->lwp_stat
== LSSTOP
))
1196 lp
->lwp_flag
|= LWP_BREAKTSLEEP
;
1201 /* else not stopped */
1205 * Never deliver a lwp-specific signal to a random lwp.
1208 lp
= find_lwp_for_signal(p
, sig
);
1209 if (lp
&& SIGISMEMBER(lp
->lwp_sigmask
, sig
))
1214 * Deliver to the process generically if (1) the signal is being
1215 * sent to any thread or (2) we could not find a thread to deliver
1219 SIGADDSET(p
->p_siglist
, sig
);
1224 * Deliver to a specific LWP whether it masks it or not. It will
1225 * not be dispatched if masked but we must still deliver it.
1227 if (p
->p_nice
> NZERO
&& action
== SIG_DFL
&& (prop
& SA_KILL
) &&
1228 (p
->p_flag
& P_TRACED
) == 0) {
1233 * If the process receives a STOP signal which indeed needs to
1234 * stop the process, do so. If the process chose to catch the
1235 * signal, it will be treated like any other signal.
1237 if ((prop
& SA_STOP
) && action
== SIG_DFL
) {
1239 * If a child holding parent blocked, stopping
1240 * could cause deadlock. Take no action at this
1243 if (p
->p_flag
& P_PPWAIT
) {
1244 SIGADDSET(p
->p_siglist
, sig
);
1249 * Do not actually try to manipulate the process, but simply
1250 * stop it. Lwps will stop as soon as they safely can.
1258 * If it is a CONT signal with default action, just ignore it.
1260 if ((prop
& SA_CONT
) && action
== SIG_DFL
)
1264 * Mark signal pending at this specific thread.
1266 SIGADDSET(lp
->lwp_siglist
, sig
);
1271 lwkt_reltoken(&p
->p_token
);
1277 * p->p_token must be held
1280 lwp_signotify(struct lwp
*lp
)
1282 ASSERT_LWKT_TOKEN_HELD(&lp
->lwp_proc
->p_token
);
1285 if (lp
->lwp_stat
== LSSLEEP
|| lp
->lwp_stat
== LSSTOP
) {
1287 * Thread is in tsleep.
1291 * If the thread is sleeping uninterruptibly
1292 * we can't interrupt the sleep... the signal will
1293 * be noticed when the lwp returns through
1294 * trap() or syscall().
1296 * Otherwise the signal can interrupt the sleep.
1298 * If the process is traced, the lwp will handle the
1299 * tracing in issignal() when it returns to userland.
1301 if (lp
->lwp_flag
& LWP_SINTR
) {
1303 * Make runnable and break out of any tsleep as well.
1305 lp
->lwp_flag
|= LWP_BREAKTSLEEP
;
1310 * Otherwise the thread is running
1312 * LSRUN does nothing with the signal, other than kicking
1313 * ourselves if we are running.
1314 * SZOMB and SIDL mean that it will either never be noticed,
1315 * or noticed very soon.
1317 * Note that lwp_thread may be NULL or may not be completely
1318 * initialized if the process is in the SIDL or SZOMB state.
1320 * For SMP we may have to forward the request to another cpu.
1321 * YYY the MP lock prevents the target process from moving
1322 * to another cpu, see kern/kern_switch.c
1324 * If the target thread is waiting on its message port,
1325 * wakeup the target thread so it can check (or ignore)
1326 * the new signal. YYY needs cleanup.
1328 if (lp
== lwkt_preempted_proc()) {
1330 } else if (lp
->lwp_stat
== LSRUN
) {
1331 struct thread
*td
= lp
->lwp_thread
;
1332 struct proc
*p __debugvar
= lp
->lwp_proc
;
1335 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1336 p
->p_pid
, lp
->lwp_tid
, lp
->lwp_stat
,
1337 p
->p_flag
, lp
->lwp_flag
));
1340 * To prevent a MP race with TDF_SINTR we must
1341 * schedule the thread on the correct cpu.
1344 if (td
->td_gd
!= mycpu
) {
1346 lwkt_send_ipiq(td
->td_gd
, signotify_remote
, lp
);
1349 if (td
->td_flags
& TDF_SINTR
)
1359 * This function is called via an IPI. We will be in a critical section but
1360 * the MP lock will NOT be held. The passed lp will be held.
1362 * We must essentially repeat the code at the end of lwp_signotify(),
1363 * in particular rechecking all races. If we are still not on the
1364 * correct cpu we leave the lwp ref intact and continue the chase.
1366 * XXX this may still not be entirely correct, since we are checking
1367 * lwp_stat asynchronously.
1370 signotify_remote(void *arg
)
1372 struct lwp
*lp
= arg
;
1375 if (lp
== lwkt_preempted_proc()) {
1377 } else if (lp
->lwp_stat
== LSRUN
) {
1379 * To prevent a MP race with TDF_SINTR we must
1380 * schedule the thread on the correct cpu.
1382 td
= lp
->lwp_thread
;
1383 if (td
->td_gd
!= mycpu
) {
1384 lwkt_send_ipiq(td
->td_gd
, signotify_remote
, lp
);
1388 if (td
->td_flags
& TDF_SINTR
)
1397 * Caller must hold p->p_token
1400 proc_stop(struct proc
*p
)
1404 ASSERT_LWKT_TOKEN_HELD(&p
->p_token
);
1407 /* If somebody raced us, be happy with it */
1408 if (p
->p_stat
== SSTOP
|| p
->p_stat
== SZOMB
) {
1414 FOREACH_LWP_IN_PROC(lp
, p
) {
1415 switch (lp
->lwp_stat
) {
1418 * Do nothing, we are already counted in
1425 * We're sleeping, but we will stop before
1426 * returning to userspace, so count us
1427 * as stopped as well. We set LWP_WSTOP
1428 * to signal the lwp that it should not
1429 * increase p_nstopped when reaching tstop().
1431 if ((lp
->lwp_flag
& LWP_WSTOP
) == 0) {
1432 lp
->lwp_flag
|= LWP_WSTOP
;
1439 * We might notify ourself, but that's not
1447 if (p
->p_nstopped
== p
->p_nthreads
) {
1448 p
->p_flag
&= ~P_WAITED
;
1450 if ((p
->p_pptr
->p_sigacts
->ps_flag
& PS_NOCLDSTOP
) == 0)
1451 ksignal(p
->p_pptr
, SIGCHLD
);
1457 * Caller must hold proc_token
1460 proc_unstop(struct proc
*p
)
1464 ASSERT_LWKT_TOKEN_HELD(&p
->p_token
);
1467 if (p
->p_stat
!= SSTOP
) {
1472 p
->p_stat
= SACTIVE
;
1474 FOREACH_LWP_IN_PROC(lp
, p
) {
1475 switch (lp
->lwp_stat
) {
1478 * Uh? Not stopped? Well, I guess that's okay.
1481 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1482 p
->p_pid
, lp
->lwp_tid
);
1487 * Still sleeping. Don't bother waking it up.
1488 * However, if this thread was counted as
1489 * stopped, undo this.
1491 * Nevertheless we call setrunnable() so that it
1492 * will wake up in case a signal or timeout arrived
1495 if (lp
->lwp_flag
& LWP_WSTOP
) {
1496 lp
->lwp_flag
&= ~LWP_WSTOP
;
1500 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1501 p
->p_pid
, lp
->lwp_tid
);
1518 kern_sigtimedwait(sigset_t waitset
, siginfo_t
*info
, struct timespec
*timeout
)
1520 sigset_t savedmask
, set
;
1521 struct proc
*p
= curproc
;
1522 struct lwp
*lp
= curthread
->td_lwp
;
1523 int error
, sig
, hz
, timevalid
= 0;
1524 struct timespec rts
, ets
, ts
;
1529 ets
.tv_sec
= 0; /* silence compiler warning */
1530 ets
.tv_nsec
= 0; /* silence compiler warning */
1531 SIG_CANTMASK(waitset
);
1532 savedmask
= lp
->lwp_sigmask
;
1535 if (timeout
->tv_sec
>= 0 && timeout
->tv_nsec
>= 0 &&
1536 timeout
->tv_nsec
< 1000000000) {
1538 getnanouptime(&rts
);
1540 timespecadd(&ets
, timeout
);
1545 set
= lwp_sigpend(lp
);
1546 SIGSETAND(set
, waitset
);
1547 if ((sig
= sig_ffs(&set
)) != 0) {
1548 SIGFILLSET(lp
->lwp_sigmask
);
1549 SIGDELSET(lp
->lwp_sigmask
, sig
);
1550 SIG_CANTMASK(lp
->lwp_sigmask
);
1551 sig
= issignal(lp
, 1);
1553 * It may be a STOP signal, in the case, issignal
1554 * returns 0, because we may stop there, and new
1555 * signal can come in, we should restart if we got
1565 * Previous checking got nothing, and we retried but still
1566 * got nothing, we should return the error status.
1572 * POSIX says this must be checked after looking for pending
1576 if (timevalid
== 0) {
1580 getnanouptime(&rts
);
1581 if (timespeccmp(&rts
, &ets
, >=)) {
1586 timespecsub(&ts
, &rts
);
1587 TIMESPEC_TO_TIMEVAL(&tv
, &ts
);
1588 hz
= tvtohz_high(&tv
);
1593 lp
->lwp_sigmask
= savedmask
;
1594 SIGSETNAND(lp
->lwp_sigmask
, waitset
);
1596 * We won't ever be woken up. Instead, our sleep will
1597 * be broken in lwpsignal().
1599 error
= tsleep(&p
->p_sigacts
, PCATCH
, "sigwt", hz
);
1601 if (error
== ERESTART
) {
1602 /* can not restart a timeout wait. */
1604 } else if (error
== EAGAIN
) {
1605 /* will calculate timeout by ourself. */
1612 lp
->lwp_sigmask
= savedmask
;
1615 bzero(info
, sizeof(*info
));
1616 info
->si_signo
= sig
;
1617 lwp_delsig(lp
, sig
); /* take the signal! */
1619 if (sig
== SIGKILL
) {
1632 sys_sigtimedwait(struct sigtimedwait_args
*uap
)
1635 struct timespec
*timeout
;
1641 error
= copyin(uap
->timeout
, &ts
, sizeof(ts
));
1648 error
= copyin(uap
->set
, &set
, sizeof(set
));
1651 error
= kern_sigtimedwait(set
, &info
, timeout
);
1655 error
= copyout(&info
, uap
->info
, sizeof(info
));
1656 /* Repost if we got an error. */
1660 * This could transform a thread-specific signal to another
1661 * thread / process pending signal.
1664 ksignal(curproc
, info
.si_signo
);
1666 uap
->sysmsg_result
= info
.si_signo
;
1675 sys_sigwaitinfo(struct sigwaitinfo_args
*uap
)
1681 error
= copyin(uap
->set
, &set
, sizeof(set
));
1684 error
= kern_sigtimedwait(set
, &info
, NULL
);
1688 error
= copyout(&info
, uap
->info
, sizeof(info
));
1689 /* Repost if we got an error. */
1693 * This could transform a thread-specific signal to another
1694 * thread / process pending signal.
1697 ksignal(curproc
, info
.si_signo
);
1699 uap
->sysmsg_result
= info
.si_signo
;
1705 * If the current process has received a signal that would interrupt a
1706 * system call, return EINTR or ERESTART as appropriate.
1709 iscaught(struct lwp
*lp
)
1711 struct proc
*p
= lp
->lwp_proc
;
1715 if ((sig
= CURSIG(lp
)) != 0) {
1716 if (SIGISMEMBER(p
->p_sigacts
->ps_sigintr
, sig
))
1721 return(EWOULDBLOCK
);
1725 * If the current process has received a signal (should be caught or cause
1726 * termination, should interrupt current syscall), return the signal number.
1727 * Stop signals with default action are processed immediately, then cleared;
1728 * they aren't returned. This is checked after each entry to the system for
1729 * a syscall or trap (though this can usually be done without calling issignal
1730 * by checking the pending signal masks in the CURSIG macro).
1732 * This routine is called via CURSIG/__cursig. We will acquire and release
1733 * p->p_token but if the caller needs to interlock the test the caller must
1734 * also hold p->p_token.
1736 * while (sig = CURSIG(curproc))
1742 issignal(struct lwp
*lp
, int maytrace
)
1744 struct proc
*p
= lp
->lwp_proc
;
1748 lwkt_gettoken(&p
->p_token
);
1751 int traced
= (p
->p_flag
& P_TRACED
) || (p
->p_stops
& S_SIG
);
1754 * If this process is supposed to stop, stop this thread.
1756 if (p
->p_stat
== SSTOP
)
1759 mask
= lwp_sigpend(lp
);
1760 SIGSETNAND(mask
, lp
->lwp_sigmask
);
1761 if (p
->p_flag
& P_PPWAIT
)
1762 SIG_STOPSIGMASK(mask
);
1763 if (SIGISEMPTY(mask
)) { /* no signal to send */
1764 lwkt_reltoken(&p
->p_token
);
1767 sig
= sig_ffs(&mask
);
1769 STOPEVENT(p
, S_SIG
, sig
);
1772 * We should see pending but ignored signals
1773 * only if P_TRACED was on when they were posted.
1775 if (SIGISMEMBER(p
->p_sigignore
, sig
) && (traced
== 0)) {
1776 lwp_delsig(lp
, sig
);
1779 if (maytrace
&& (p
->p_flag
& P_TRACED
) && (p
->p_flag
& P_PPWAIT
) == 0) {
1781 * If traced, always stop, and stay stopped until
1782 * released by the parent.
1784 * NOTE: SSTOP may get cleared during the loop,
1785 * but we do not re-notify the parent if we have
1786 * to loop several times waiting for the parent
1787 * to let us continue.
1789 * XXX not sure if this is still true
1795 } while (!trace_req(p
) && (p
->p_flag
& P_TRACED
));
1798 * If parent wants us to take the signal,
1799 * then it will leave it in p->p_xstat;
1800 * otherwise we just look for signals again.
1802 lwp_delsig(lp
, sig
); /* clear old signal */
1808 * Put the new signal into p_siglist. If the
1809 * signal is being masked, look for other signals.
1811 * XXX lwp might need a call to ksignal()
1813 SIGADDSET(p
->p_siglist
, sig
);
1814 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
))
1818 * If the traced bit got turned off, go back up
1819 * to the top to rescan signals. This ensures
1820 * that p_sig* and ps_sigact are consistent.
1822 if ((p
->p_flag
& P_TRACED
) == 0)
1826 prop
= sigprop(sig
);
1829 * Decide whether the signal should be returned.
1830 * Return the signal's number, or fall through
1831 * to clear it from the pending mask.
1833 switch ((intptr_t)p
->p_sigacts
->ps_sigact
[_SIG_IDX(sig
)]) {
1834 case (intptr_t)SIG_DFL
:
1836 * Don't take default actions on system processes.
1838 if (p
->p_pid
<= 1) {
1841 * Are you sure you want to ignore SIGSEGV
1844 kprintf("Process (pid %lu) got signal %d\n",
1845 (u_long
)p
->p_pid
, sig
);
1847 break; /* == ignore */
1851 * Handle the in-kernel checkpoint action
1853 if (prop
& SA_CKPT
) {
1854 checkpoint_signal_handler(lp
);
1859 * If there is a pending stop signal to process
1860 * with default action, stop here,
1861 * then clear the signal. However,
1862 * if process is member of an orphaned
1863 * process group, ignore tty stop signals.
1865 if (prop
& SA_STOP
) {
1866 if (p
->p_flag
& P_TRACED
||
1867 (p
->p_pgrp
->pg_jobc
== 0 &&
1869 break; /* == ignore */
1874 } else if (prop
& SA_IGNORE
) {
1876 * Except for SIGCONT, shouldn't get here.
1877 * Default action is to ignore; drop it.
1879 break; /* == ignore */
1881 lwkt_reltoken(&p
->p_token
);
1887 case (intptr_t)SIG_IGN
:
1889 * Masking above should prevent us ever trying
1890 * to take action on an ignored signal other
1891 * than SIGCONT, unless process is traced.
1893 if ((prop
& SA_CONT
) == 0 &&
1894 (p
->p_flag
& P_TRACED
) == 0)
1895 kprintf("issignal\n");
1896 break; /* == ignore */
1900 * This signal has an action, let
1901 * postsig() process it.
1903 lwkt_reltoken(&p
->p_token
);
1906 lwp_delsig(lp
, sig
); /* take the signal! */
1912 * Take the action for the specified signal
1913 * from the current set of pending signals.
1918 struct lwp
*lp
= curthread
->td_lwp
;
1919 struct proc
*p
= lp
->lwp_proc
;
1920 struct sigacts
*ps
= p
->p_sigacts
;
1922 sigset_t returnmask
;
1925 KASSERT(sig
!= 0, ("postsig"));
1927 KNOTE(&p
->p_klist
, NOTE_SIGNAL
| sig
);
1930 * If we are a virtual kernel running an emulated user process
1931 * context, switch back to the virtual kernel context before
1932 * trying to post the signal.
1934 if (lp
->lwp_vkernel
&& lp
->lwp_vkernel
->ve
) {
1935 struct trapframe
*tf
= lp
->lwp_md
.md_regs
;
1937 vkernel_trap(lp
, tf
);
1940 lwp_delsig(lp
, sig
);
1941 action
= ps
->ps_sigact
[_SIG_IDX(sig
)];
1943 if (KTRPOINT(lp
->lwp_thread
, KTR_PSIG
))
1944 ktrpsig(lp
, sig
, action
, lp
->lwp_flag
& LWP_OLDMASK
?
1945 &lp
->lwp_oldsigmask
: &lp
->lwp_sigmask
, 0);
1947 STOPEVENT(p
, S_SIG
, sig
);
1949 if (action
== SIG_DFL
) {
1951 * Default action, where the default is to kill
1952 * the process. (Other cases were ignored above.)
1958 * If we get here, the signal must be caught.
1960 KASSERT(action
!= SIG_IGN
&& !SIGISMEMBER(lp
->lwp_sigmask
, sig
),
1961 ("postsig action"));
1966 * Reset the signal handler if asked to
1968 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
1970 * See kern_sigaction() for origin of this code.
1972 SIGDELSET(p
->p_sigcatch
, sig
);
1973 if (sig
!= SIGCONT
&&
1974 sigprop(sig
) & SA_IGNORE
)
1975 SIGADDSET(p
->p_sigignore
, sig
);
1976 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
1980 * Handle the mailbox case. Copyout to the appropriate
1981 * location but do not generate a signal frame. The system
1982 * call simply returns EINTR and the user is responsible for
1983 * polling the mailbox.
1985 if (SIGISMEMBER(ps
->ps_sigmailbox
, sig
)) {
1987 copyout(&sig_copy
, (void *)action
, sizeof(int));
1988 curproc
->p_flag
|= P_MAILBOX
;
1994 * Set the signal mask and calculate the mask to restore
1995 * when the signal function returns.
1997 * Special case: user has done a sigsuspend. Here the
1998 * current mask is not of interest, but rather the
1999 * mask from before the sigsuspend is what we want
2000 * restored after the signal processing is completed.
2002 if (lp
->lwp_flag
& LWP_OLDMASK
) {
2003 returnmask
= lp
->lwp_oldsigmask
;
2004 lp
->lwp_flag
&= ~LWP_OLDMASK
;
2006 returnmask
= lp
->lwp_sigmask
;
2009 SIGSETOR(lp
->lwp_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
2010 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
2011 SIGADDSET(lp
->lwp_sigmask
, sig
);
2014 lp
->lwp_ru
.ru_nsignals
++;
2015 if (lp
->lwp_sig
!= sig
) {
2018 code
= lp
->lwp_code
;
2022 (*p
->p_sysent
->sv_sendsig
)(action
, sig
, &returnmask
, code
);
2029 * Kill the current process for stated reason.
2032 killproc(struct proc
*p
, char *why
)
2034 log(LOG_ERR
, "pid %d (%s), uid %d, was killed: %s\n",
2035 p
->p_pid
, p
->p_comm
,
2036 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1, why
);
2037 ksignal(p
, SIGKILL
);
2041 * Force the current process to exit with the specified signal, dumping core
2042 * if appropriate. We bypass the normal tests for masked and caught signals,
2043 * allowing unrecoverable failures to terminate the process without changing
2044 * signal state. Mark the accounting record with the signal termination.
2045 * If dumping core, save the signal number for the debugger. Calls exit and
2048 * This routine does not return.
2051 sigexit(struct lwp
*lp
, int sig
)
2053 struct proc
*p
= lp
->lwp_proc
;
2055 lwkt_gettoken(&p
->p_token
);
2056 p
->p_acflag
|= AXSIG
;
2057 if (sigprop(sig
) & SA_CORE
) {
2060 * Log signals which would cause core dumps
2061 * (Log as LOG_INFO to appease those who don't want
2063 * XXX : Todo, as well as euid, write out ruid too
2065 if (coredump(lp
, sig
) == 0)
2067 if (kern_logsigexit
)
2069 "pid %d (%s), uid %d: exited on signal %d%s\n",
2070 p
->p_pid
, p
->p_comm
,
2071 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1,
2073 sig
& WCOREFLAG
? " (core dumped)" : "");
2075 lwkt_reltoken(&p
->p_token
);
2076 exit1(W_EXITCODE(0, sig
));
2080 static char corefilename
[MAXPATHLEN
+1] = {"%N.core"};
2081 SYSCTL_STRING(_kern
, OID_AUTO
, corefile
, CTLFLAG_RW
, corefilename
,
2082 sizeof(corefilename
), "process corefile name format string");
2085 * expand_name(name, uid, pid)
2086 * Expand the name described in corefilename, using name, uid, and pid.
2087 * corefilename is a kprintf-like string, with three format specifiers:
2088 * %N name of process ("name")
2089 * %P process id (pid)
2091 * For example, "%N.core" is the default; they can be disabled completely
2092 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
2093 * This is controlled by the sysctl variable kern.corefile (see above).
2097 expand_name(const char *name
, uid_t uid
, pid_t pid
)
2100 char buf
[11]; /* Buffer for pid/uid -- max 4B */
2102 char *format
= corefilename
;
2105 temp
= kmalloc(MAXPATHLEN
+ 1, M_TEMP
, M_NOWAIT
);
2108 namelen
= strlen(name
);
2109 for (i
= 0, n
= 0; n
< MAXPATHLEN
&& format
[i
]; i
++) {
2111 switch (format
[i
]) {
2112 case '%': /* Format character */
2114 switch (format
[i
]) {
2118 case 'N': /* process name */
2119 if ((n
+ namelen
) > MAXPATHLEN
) {
2120 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2121 pid
, name
, uid
, temp
, name
);
2122 kfree(temp
, M_TEMP
);
2125 memcpy(temp
+n
, name
, namelen
);
2128 case 'P': /* process id */
2129 l
= ksprintf(buf
, "%u", pid
);
2130 if ((n
+ l
) > MAXPATHLEN
) {
2131 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2132 pid
, name
, uid
, temp
, name
);
2133 kfree(temp
, M_TEMP
);
2136 memcpy(temp
+n
, buf
, l
);
2139 case 'U': /* user id */
2140 l
= ksprintf(buf
, "%u", uid
);
2141 if ((n
+ l
) > MAXPATHLEN
) {
2142 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
2143 pid
, name
, uid
, temp
, name
);
2144 kfree(temp
, M_TEMP
);
2147 memcpy(temp
+n
, buf
, l
);
2151 log(LOG_ERR
, "Unknown format character %c in `%s'\n", format
[i
], format
);
2155 temp
[n
++] = format
[i
];
2163 * Dump a process' core. The main routine does some
2164 * policy checking, and creates the name of the coredump;
2165 * then it passes on a vnode and a size limit to the process-specific
2166 * coredump routine if there is one; if there _is not_ one, it returns
2167 * ENOSYS; otherwise it returns the error from the process-specific routine.
2169 * The parameter `lp' is the lwp which triggered the coredump.
2173 coredump(struct lwp
*lp
, int sig
)
2175 struct proc
*p
= lp
->lwp_proc
;
2177 struct ucred
*cred
= p
->p_ucred
;
2179 struct nlookupdata nd
;
2182 char *name
; /* name of corefile */
2185 STOPEVENT(p
, S_CORE
, 0);
2187 if (((sugid_coredump
== 0) && p
->p_flag
& P_SUGID
) || do_coredump
== 0)
2191 * Note that the bulk of limit checking is done after
2192 * the corefile is created. The exception is if the limit
2193 * for corefiles is 0, in which case we don't bother
2194 * creating the corefile at all. This layout means that
2195 * a corefile is truncated instead of not being created,
2196 * if it is larger than the limit.
2198 limit
= p
->p_rlimit
[RLIMIT_CORE
].rlim_cur
;
2202 name
= expand_name(p
->p_comm
, p
->p_ucred
->cr_uid
, p
->p_pid
);
2205 error
= nlookup_init(&nd
, name
, UIO_SYSSPACE
, NLC_LOCKVP
);
2207 error
= vn_open(&nd
, NULL
, O_CREAT
| FWRITE
| O_NOFOLLOW
, S_IRUSR
| S_IWUSR
);
2208 kfree(name
, M_TEMP
);
2214 nd
.nl_open_vp
= NULL
;
2218 lf
.l_whence
= SEEK_SET
;
2221 lf
.l_type
= F_WRLCK
;
2222 error
= VOP_ADVLOCK(vp
, (caddr_t
)p
, F_SETLK
, &lf
, 0);
2226 /* Don't dump to non-regular files or files with links. */
2227 if (vp
->v_type
!= VREG
||
2228 VOP_GETATTR(vp
, &vattr
) || vattr
.va_nlink
!= 1) {
2233 /* Don't dump to files current user does not own */
2234 if (vattr
.va_uid
!= p
->p_ucred
->cr_uid
) {
2240 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
2242 VOP_SETATTR(vp
, &vattr
, cred
);
2243 p
->p_acflag
|= ACORE
;
2246 error
= p
->p_sysent
->sv_coredump
?
2247 p
->p_sysent
->sv_coredump(lp
, sig
, vp
, limit
) : ENOSYS
;
2250 lf
.l_type
= F_UNLCK
;
2251 VOP_ADVLOCK(vp
, (caddr_t
)p
, F_UNLCK
, &lf
, 0);
2253 error1
= vn_close(vp
, FWRITE
);
2260 * Nonexistent system call-- signal process (may want to handle it).
2261 * Flag error in case process won't see signal immediately (blocked or ignored).
2267 sys_nosys(struct nosys_args
*args
)
2269 lwpsignal(curproc
, curthread
->td_lwp
, SIGSYS
);
2274 * Send a SIGIO or SIGURG signal to a process or process group using
2275 * stored credentials rather than those of the current process.
2278 pgsigio(struct sigio
*sigio
, int sig
, int checkctty
)
2283 if (sigio
->sio_pgid
> 0) {
2284 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
,
2286 ksignal(sigio
->sio_proc
, sig
);
2287 } else if (sigio
->sio_pgid
< 0) {
2289 struct pgrp
*pg
= sigio
->sio_pgrp
;
2292 * Must interlock all signals against fork
2295 lockmgr(&pg
->pg_lock
, LK_EXCLUSIVE
);
2296 LIST_FOREACH(p
, &pg
->pg_members
, p_pglist
) {
2297 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
, p
) &&
2298 (checkctty
== 0 || (p
->p_flag
& P_CONTROLT
)))
2301 lockmgr(&pg
->pg_lock
, LK_RELEASE
);
2307 filt_sigattach(struct knote
*kn
)
2309 struct proc
*p
= curproc
;
2311 kn
->kn_ptr
.p_proc
= p
;
2312 kn
->kn_flags
|= EV_CLEAR
; /* automatically set */
2314 /* XXX lock the proc here while adding to the list? */
2315 knote_insert(&p
->p_klist
, kn
);
2321 filt_sigdetach(struct knote
*kn
)
2323 struct proc
*p
= kn
->kn_ptr
.p_proc
;
2325 knote_remove(&p
->p_klist
, kn
);
2329 * signal knotes are shared with proc knotes, so we apply a mask to
2330 * the hint in order to differentiate them from process hints. This
2331 * could be avoided by using a signal-specific knote list, but probably
2332 * isn't worth the trouble.
2335 filt_signal(struct knote
*kn
, long hint
)
2337 if (hint
& NOTE_SIGNAL
) {
2338 hint
&= ~NOTE_SIGNAL
;
2340 if (kn
->kn_id
== hint
)
2343 return (kn
->kn_data
!= 0);