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5 * All or some portions of this file are derived from material licensed
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38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $
40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.90 2008/06/09 04:33:08 dillon Exp $
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/sysproto.h>
49 #include <sys/signalvar.h>
50 #include <sys/signal2.h>
51 #include <sys/resourcevar.h>
52 #include <sys/vnode.h>
53 #include <sys/event.h>
55 #include <sys/nlookup.h>
56 #include <sys/pioctl.h>
57 #include <sys/systm.h>
59 #include <sys/fcntl.h>
62 #include <sys/ktrace.h>
63 #include <sys/syslog.h>
65 #include <sys/sysent.h>
66 #include <sys/sysctl.h>
67 #include <sys/malloc.h>
68 #include <sys/interrupt.h>
69 #include <sys/unistd.h>
70 #include <sys/kern_syscall.h>
71 #include <sys/vkernel.h>
72 #include <sys/thread2.h>
74 #include <machine/cpu.h>
75 #include <machine/smp.h>
77 static int coredump(struct lwp
*, int);
78 static char *expand_name(const char *, uid_t
, pid_t
);
79 static int dokillpg(int sig
, int pgid
, int all
);
80 static int sig_ffs(sigset_t
*set
);
81 static int sigprop(int sig
);
83 static void signotify_remote(void *arg
);
85 static int kern_sigtimedwait(sigset_t set
, siginfo_t
*info
,
86 struct timespec
*timeout
);
88 static int filt_sigattach(struct knote
*kn
);
89 static void filt_sigdetach(struct knote
*kn
);
90 static int filt_signal(struct knote
*kn
, long hint
);
92 struct filterops sig_filtops
=
93 { 0, filt_sigattach
, filt_sigdetach
, filt_signal
};
95 static int kern_logsigexit
= 1;
96 SYSCTL_INT(_kern
, KERN_LOGSIGEXIT
, logsigexit
, CTLFLAG_RW
,
98 "Log processes quitting on abnormal signals to syslog(3)");
101 * Can process p, with pcred pc, send the signal sig to process q?
103 #define CANSIGNAL(q, sig) \
104 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \
105 ((sig) == SIGCONT && (q)->p_session == curproc->p_session))
108 * Policy -- Can real uid ruid with ucred uc send a signal to process q?
110 #define CANSIGIO(ruid, uc, q) \
111 ((uc)->cr_uid == 0 || \
112 (ruid) == (q)->p_ucred->cr_ruid || \
113 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \
114 (ruid) == (q)->p_ucred->cr_uid || \
115 (uc)->cr_uid == (q)->p_ucred->cr_uid)
118 SYSCTL_INT(_kern
, OID_AUTO
, sugid_coredump
, CTLFLAG_RW
,
119 &sugid_coredump
, 0, "Enable coredumping set user/group ID processes");
121 static int do_coredump
= 1;
122 SYSCTL_INT(_kern
, OID_AUTO
, coredump
, CTLFLAG_RW
,
123 &do_coredump
, 0, "Enable/Disable coredumps");
126 * Signal properties and actions.
127 * The array below categorizes the signals and their default actions
128 * according to the following properties:
130 #define SA_KILL 0x01 /* terminates process by default */
131 #define SA_CORE 0x02 /* ditto and coredumps */
132 #define SA_STOP 0x04 /* suspend process */
133 #define SA_TTYSTOP 0x08 /* ditto, from tty */
134 #define SA_IGNORE 0x10 /* ignore by default */
135 #define SA_CONT 0x20 /* continue if suspended */
136 #define SA_CANTMASK 0x40 /* non-maskable, catchable */
137 #define SA_CKPT 0x80 /* checkpoint process */
140 static int sigproptbl
[NSIG
] = {
141 SA_KILL
, /* SIGHUP */
142 SA_KILL
, /* SIGINT */
143 SA_KILL
|SA_CORE
, /* SIGQUIT */
144 SA_KILL
|SA_CORE
, /* SIGILL */
145 SA_KILL
|SA_CORE
, /* SIGTRAP */
146 SA_KILL
|SA_CORE
, /* SIGABRT */
147 SA_KILL
|SA_CORE
, /* SIGEMT */
148 SA_KILL
|SA_CORE
, /* SIGFPE */
149 SA_KILL
, /* SIGKILL */
150 SA_KILL
|SA_CORE
, /* SIGBUS */
151 SA_KILL
|SA_CORE
, /* SIGSEGV */
152 SA_KILL
|SA_CORE
, /* SIGSYS */
153 SA_KILL
, /* SIGPIPE */
154 SA_KILL
, /* SIGALRM */
155 SA_KILL
, /* SIGTERM */
156 SA_IGNORE
, /* SIGURG */
157 SA_STOP
, /* SIGSTOP */
158 SA_STOP
|SA_TTYSTOP
, /* SIGTSTP */
159 SA_IGNORE
|SA_CONT
, /* SIGCONT */
160 SA_IGNORE
, /* SIGCHLD */
161 SA_STOP
|SA_TTYSTOP
, /* SIGTTIN */
162 SA_STOP
|SA_TTYSTOP
, /* SIGTTOU */
163 SA_IGNORE
, /* SIGIO */
164 SA_KILL
, /* SIGXCPU */
165 SA_KILL
, /* SIGXFSZ */
166 SA_KILL
, /* SIGVTALRM */
167 SA_KILL
, /* SIGPROF */
168 SA_IGNORE
, /* SIGWINCH */
169 SA_IGNORE
, /* SIGINFO */
170 SA_KILL
, /* SIGUSR1 */
171 SA_KILL
, /* SIGUSR2 */
172 SA_IGNORE
, /* SIGTHR */
173 SA_CKPT
, /* SIGCKPT */
174 SA_KILL
|SA_CKPT
, /* SIGCKPTEXIT */
212 if (sig
> 0 && sig
< NSIG
)
213 return (sigproptbl
[_SIG_IDX(sig
)]);
218 sig_ffs(sigset_t
*set
)
222 for (i
= 0; i
< _SIG_WORDS
; i
++)
224 return (ffs(set
->__bits
[i
]) + (i
* 32));
229 kern_sigaction(int sig
, struct sigaction
*act
, struct sigaction
*oact
)
231 struct thread
*td
= curthread
;
232 struct proc
*p
= td
->td_proc
;
234 struct sigacts
*ps
= p
->p_sigacts
;
236 if (sig
<= 0 || sig
> _SIG_MAXSIG
)
240 oact
->sa_handler
= ps
->ps_sigact
[_SIG_IDX(sig
)];
241 oact
->sa_mask
= ps
->ps_catchmask
[_SIG_IDX(sig
)];
243 if (SIGISMEMBER(ps
->ps_sigonstack
, sig
))
244 oact
->sa_flags
|= SA_ONSTACK
;
245 if (!SIGISMEMBER(ps
->ps_sigintr
, sig
))
246 oact
->sa_flags
|= SA_RESTART
;
247 if (SIGISMEMBER(ps
->ps_sigreset
, sig
))
248 oact
->sa_flags
|= SA_RESETHAND
;
249 if (SIGISMEMBER(ps
->ps_signodefer
, sig
))
250 oact
->sa_flags
|= SA_NODEFER
;
251 if (SIGISMEMBER(ps
->ps_siginfo
, sig
))
252 oact
->sa_flags
|= SA_SIGINFO
;
253 if (SIGISMEMBER(ps
->ps_sigmailbox
, sig
))
254 oact
->sa_flags
|= SA_MAILBOX
;
255 if (sig
== SIGCHLD
&& p
->p_sigacts
->ps_flag
& PS_NOCLDSTOP
)
256 oact
->sa_flags
|= SA_NOCLDSTOP
;
257 if (sig
== SIGCHLD
&& p
->p_sigacts
->ps_flag
& PS_NOCLDWAIT
)
258 oact
->sa_flags
|= SA_NOCLDWAIT
;
262 * Check for invalid requests. KILL and STOP cannot be
265 if (sig
== SIGKILL
|| sig
== SIGSTOP
) {
266 if (act
->sa_handler
!= SIG_DFL
)
269 /* (not needed, SIG_DFL forces action to occur) */
270 if (act
->sa_flags
& SA_MAILBOX
)
276 * Change setting atomically.
280 ps
->ps_catchmask
[_SIG_IDX(sig
)] = act
->sa_mask
;
281 SIG_CANTMASK(ps
->ps_catchmask
[_SIG_IDX(sig
)]);
282 if (act
->sa_flags
& SA_SIGINFO
) {
283 ps
->ps_sigact
[_SIG_IDX(sig
)] =
284 (__sighandler_t
*)act
->sa_sigaction
;
285 SIGADDSET(ps
->ps_siginfo
, sig
);
287 ps
->ps_sigact
[_SIG_IDX(sig
)] = act
->sa_handler
;
288 SIGDELSET(ps
->ps_siginfo
, sig
);
290 if (!(act
->sa_flags
& SA_RESTART
))
291 SIGADDSET(ps
->ps_sigintr
, sig
);
293 SIGDELSET(ps
->ps_sigintr
, sig
);
294 if (act
->sa_flags
& SA_ONSTACK
)
295 SIGADDSET(ps
->ps_sigonstack
, sig
);
297 SIGDELSET(ps
->ps_sigonstack
, sig
);
298 if (act
->sa_flags
& SA_RESETHAND
)
299 SIGADDSET(ps
->ps_sigreset
, sig
);
301 SIGDELSET(ps
->ps_sigreset
, sig
);
302 if (act
->sa_flags
& SA_NODEFER
)
303 SIGADDSET(ps
->ps_signodefer
, sig
);
305 SIGDELSET(ps
->ps_signodefer
, sig
);
306 if (act
->sa_flags
& SA_MAILBOX
)
307 SIGADDSET(ps
->ps_sigmailbox
, sig
);
309 SIGDELSET(ps
->ps_sigmailbox
, sig
);
310 if (sig
== SIGCHLD
) {
311 if (act
->sa_flags
& SA_NOCLDSTOP
)
312 p
->p_sigacts
->ps_flag
|= PS_NOCLDSTOP
;
314 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDSTOP
;
315 if (act
->sa_flags
& SA_NOCLDWAIT
) {
317 * Paranoia: since SA_NOCLDWAIT is implemented
318 * by reparenting the dying child to PID 1 (and
319 * trust it to reap the zombie), PID 1 itself
320 * is forbidden to set SA_NOCLDWAIT.
323 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
325 p
->p_sigacts
->ps_flag
|= PS_NOCLDWAIT
;
327 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
331 * Set bit in p_sigignore for signals that are set to SIG_IGN,
332 * and for signals set to SIG_DFL where the default is to
333 * ignore. However, don't put SIGCONT in p_sigignore, as we
334 * have to restart the process.
336 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_IGN
||
337 (sigprop(sig
) & SA_IGNORE
&&
338 ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)) {
339 /* never to be seen again */
340 SIGDELSET(p
->p_siglist
, sig
);
342 * Remove the signal also from the thread lists.
344 FOREACH_LWP_IN_PROC(lp
, p
) {
345 SIGDELSET(lp
->lwp_siglist
, sig
);
348 /* easier in ksignal */
349 SIGADDSET(p
->p_sigignore
, sig
);
350 SIGDELSET(p
->p_sigcatch
, sig
);
352 SIGDELSET(p
->p_sigignore
, sig
);
353 if (ps
->ps_sigact
[_SIG_IDX(sig
)] == SIG_DFL
)
354 SIGDELSET(p
->p_sigcatch
, sig
);
356 SIGADDSET(p
->p_sigcatch
, sig
);
365 sys_sigaction(struct sigaction_args
*uap
)
367 struct sigaction act
, oact
;
368 struct sigaction
*actp
, *oactp
;
371 actp
= (uap
->act
!= NULL
) ? &act
: NULL
;
372 oactp
= (uap
->oact
!= NULL
) ? &oact
: NULL
;
374 error
= copyin(uap
->act
, actp
, sizeof(act
));
378 error
= kern_sigaction(uap
->sig
, actp
, oactp
);
379 if (oactp
&& !error
) {
380 error
= copyout(oactp
, uap
->oact
, sizeof(oact
));
386 * Initialize signal state for process 0;
387 * set to ignore signals that are ignored by default.
390 siginit(struct proc
*p
)
394 for (i
= 1; i
<= NSIG
; i
++)
395 if (sigprop(i
) & SA_IGNORE
&& i
!= SIGCONT
)
396 SIGADDSET(p
->p_sigignore
, i
);
400 * Reset signals for an exec of the specified process.
403 execsigs(struct proc
*p
)
405 struct sigacts
*ps
= p
->p_sigacts
;
409 lp
= ONLY_LWP_IN_PROC(p
);
412 * Reset caught signals. Held signals remain held
413 * through p_sigmask (unless they were caught,
414 * and are now ignored by default).
416 while (SIGNOTEMPTY(p
->p_sigcatch
)) {
417 sig
= sig_ffs(&p
->p_sigcatch
);
418 SIGDELSET(p
->p_sigcatch
, sig
);
419 if (sigprop(sig
) & SA_IGNORE
) {
421 SIGADDSET(p
->p_sigignore
, sig
);
422 SIGDELSET(p
->p_siglist
, sig
);
423 SIGDELSET(lp
->lwp_siglist
, sig
);
425 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
429 * Reset stack state to the user stack.
430 * Clear set of signals caught on the signal stack.
432 lp
->lwp_sigstk
.ss_flags
= SS_DISABLE
;
433 lp
->lwp_sigstk
.ss_size
= 0;
434 lp
->lwp_sigstk
.ss_sp
= 0;
435 lp
->lwp_flag
&= ~LWP_ALTSTACK
;
437 * Reset no zombies if child dies flag as Solaris does.
439 p
->p_sigacts
->ps_flag
&= ~PS_NOCLDWAIT
;
443 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc
445 * Manipulate signal mask. This routine is MP SAFE *ONLY* if
449 kern_sigprocmask(int how
, sigset_t
*set
, sigset_t
*oset
)
451 struct thread
*td
= curthread
;
452 struct lwp
*lp
= td
->td_lwp
;
456 *oset
= lp
->lwp_sigmask
;
463 SIGSETOR(lp
->lwp_sigmask
, *set
);
466 SIGSETNAND(lp
->lwp_sigmask
, *set
);
470 lp
->lwp_sigmask
= *set
;
481 * sigprocmask() - MP SAFE
484 sys_sigprocmask(struct sigprocmask_args
*uap
)
487 sigset_t
*setp
, *osetp
;
490 setp
= (uap
->set
!= NULL
) ? &set
: NULL
;
491 osetp
= (uap
->oset
!= NULL
) ? &oset
: NULL
;
493 error
= copyin(uap
->set
, setp
, sizeof(set
));
497 error
= kern_sigprocmask(uap
->how
, setp
, osetp
);
498 if (osetp
&& !error
) {
499 error
= copyout(osetp
, uap
->oset
, sizeof(oset
));
505 kern_sigpending(struct __sigset
*set
)
507 struct lwp
*lp
= curthread
->td_lwp
;
509 *set
= lwp_sigpend(lp
);
515 sys_sigpending(struct sigpending_args
*uap
)
520 error
= kern_sigpending(&set
);
523 error
= copyout(&set
, uap
->set
, sizeof(set
));
528 * Suspend process until signal, providing mask to be set
532 kern_sigsuspend(struct __sigset
*set
)
534 struct thread
*td
= curthread
;
535 struct lwp
*lp
= td
->td_lwp
;
536 struct proc
*p
= td
->td_proc
;
537 struct sigacts
*ps
= p
->p_sigacts
;
540 * When returning from sigsuspend, we want
541 * the old mask to be restored after the
542 * signal handler has finished. Thus, we
543 * save it here and mark the sigacts structure
546 lp
->lwp_oldsigmask
= lp
->lwp_sigmask
;
547 lp
->lwp_flag
|= LWP_OLDMASK
;
550 lp
->lwp_sigmask
= *set
;
551 while (tsleep(ps
, PCATCH
, "pause", 0) == 0)
553 /* always return EINTR rather than ERESTART... */
558 * Note nonstandard calling convention: libc stub passes mask, not
559 * pointer, to save a copyin.
562 sys_sigsuspend(struct sigsuspend_args
*uap
)
567 error
= copyin(uap
->sigmask
, &mask
, sizeof(mask
));
571 error
= kern_sigsuspend(&mask
);
577 kern_sigaltstack(struct sigaltstack
*ss
, struct sigaltstack
*oss
)
579 struct thread
*td
= curthread
;
580 struct lwp
*lp
= td
->td_lwp
;
581 struct proc
*p
= td
->td_proc
;
583 if ((lp
->lwp_flag
& LWP_ALTSTACK
) == 0)
584 lp
->lwp_sigstk
.ss_flags
|= SS_DISABLE
;
587 *oss
= lp
->lwp_sigstk
;
590 if (ss
->ss_flags
& SS_DISABLE
) {
591 if (lp
->lwp_sigstk
.ss_flags
& SS_ONSTACK
)
593 lp
->lwp_flag
&= ~LWP_ALTSTACK
;
594 lp
->lwp_sigstk
.ss_flags
= ss
->ss_flags
;
596 if (ss
->ss_size
< p
->p_sysent
->sv_minsigstksz
)
598 lp
->lwp_flag
|= LWP_ALTSTACK
;
599 lp
->lwp_sigstk
= *ss
;
607 sys_sigaltstack(struct sigaltstack_args
*uap
)
613 error
= copyin(uap
->ss
, &ss
, sizeof(ss
));
618 error
= kern_sigaltstack(uap
->ss
? &ss
: NULL
,
619 uap
->oss
? &oss
: NULL
);
621 if (error
== 0 && uap
->oss
)
622 error
= copyout(&oss
, uap
->oss
, sizeof(*uap
->oss
));
627 * Common code for kill process group/broadcast kill.
628 * cp is calling process.
635 static int killpg_all_callback(struct proc
*p
, void *data
);
638 dokillpg(int sig
, int pgid
, int all
)
640 struct killpg_info info
;
641 struct proc
*cp
= curproc
;
652 allproc_scan(killpg_all_callback
, &info
);
656 * zero pgid means send to my process group.
664 lockmgr(&pgrp
->pg_lock
, LK_EXCLUSIVE
);
665 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
667 p
->p_stat
== SZOMB
||
668 (p
->p_flag
& P_SYSTEM
) ||
669 !CANSIGNAL(p
, sig
)) {
676 lockmgr(&pgrp
->pg_lock
, LK_RELEASE
);
678 return (info
.nfound
? 0 : ESRCH
);
682 killpg_all_callback(struct proc
*p
, void *data
)
684 struct killpg_info
*info
= data
;
686 if (p
->p_pid
<= 1 || (p
->p_flag
& P_SYSTEM
) ||
687 p
== curproc
|| !CANSIGNAL(p
, info
->sig
)) {
692 ksignal(p
, info
->sig
);
697 * Send a general signal to a process or LWPs within that process. Note
698 * that new signals cannot be sent if a process is exiting.
701 kern_kill(int sig
, pid_t pid
, lwpid_t tid
)
703 if ((u_int
)sig
> _SIG_MAXSIG
)
707 struct lwp
*lp
= NULL
;
709 /* kill single process */
710 if ((p
= pfind(pid
)) == NULL
)
712 if (!CANSIGNAL(p
, sig
))
716 * NOP if the process is exiting. Note that lwpsignal() is
717 * called directly with P_WEXIT set to kill individual LWPs
718 * during exit, which is allowed.
720 if (p
->p_flag
& P_WEXIT
)
723 lp
= lwp_rb_tree_RB_LOOKUP(&p
->p_lwp_tree
, tid
);
728 lwpsignal(p
, lp
, sig
);
732 * If we come here, pid is a special broadcast pid.
733 * This doesn't mix with a tid.
738 case -1: /* broadcast signal */
739 return (dokillpg(sig
, 0, 1));
740 case 0: /* signal own process group */
741 return (dokillpg(sig
, 0, 0));
742 default: /* negative explicit process group */
743 return (dokillpg(sig
, -pid
, 0));
749 sys_kill(struct kill_args
*uap
)
753 error
= kern_kill(uap
->signum
, uap
->pid
, -1);
758 sys_lwp_kill(struct lwp_kill_args
*uap
)
761 pid_t pid
= uap
->pid
;
764 * A tid is mandatory for lwp_kill(), otherwise
765 * you could simply use kill().
771 * To save on a getpid() function call for intra-process
772 * signals, pid == -1 means current process.
775 pid
= curproc
->p_pid
;
777 error
= kern_kill(uap
->signum
, pid
, uap
->tid
);
782 * Send a signal to a process group.
785 gsignal(int pgid
, int sig
)
789 if (pgid
&& (pgrp
= pgfind(pgid
)))
790 pgsignal(pgrp
, sig
, 0);
794 * Send a signal to a process group. If checktty is 1,
795 * limit to members which have a controlling terminal.
797 * pg_lock interlocks against a fork that might be in progress, to
798 * ensure that the new child process picks up the signal.
801 pgsignal(struct pgrp
*pgrp
, int sig
, int checkctty
)
806 lockmgr(&pgrp
->pg_lock
, LK_EXCLUSIVE
);
807 LIST_FOREACH(p
, &pgrp
->pg_members
, p_pglist
) {
808 if (checkctty
== 0 || p
->p_flag
& P_CONTROLT
)
811 lockmgr(&pgrp
->pg_lock
, LK_RELEASE
);
816 * Send a signal caused by a trap to the current lwp. If it will be caught
817 * immediately, deliver it with correct code. Otherwise, post it normally.
819 * These signals may ONLY be delivered to the specified lwp and may never
820 * be delivered to the process generically.
823 trapsignal(struct lwp
*lp
, int sig
, u_long code
)
825 struct proc
*p
= lp
->lwp_proc
;
826 struct sigacts
*ps
= p
->p_sigacts
;
829 * If we are a virtual kernel running an emulated user process
830 * context, switch back to the virtual kernel context before
831 * trying to post the signal.
833 if (lp
->lwp_vkernel
&& lp
->lwp_vkernel
->ve
) {
834 struct trapframe
*tf
= lp
->lwp_md
.md_regs
;
836 vkernel_trap(lp
, tf
);
840 if ((p
->p_flag
& P_TRACED
) == 0 && SIGISMEMBER(p
->p_sigcatch
, sig
) &&
841 !SIGISMEMBER(lp
->lwp_sigmask
, sig
)) {
842 lp
->lwp_ru
.ru_nsignals
++;
844 if (KTRPOINT(lp
->lwp_thread
, KTR_PSIG
))
845 ktrpsig(lp
, sig
, ps
->ps_sigact
[_SIG_IDX(sig
)],
846 &lp
->lwp_sigmask
, code
);
848 (*p
->p_sysent
->sv_sendsig
)(ps
->ps_sigact
[_SIG_IDX(sig
)], sig
,
849 &lp
->lwp_sigmask
, code
);
850 SIGSETOR(lp
->lwp_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
851 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
852 SIGADDSET(lp
->lwp_sigmask
, sig
);
853 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
855 * See kern_sigaction() for origin of this code.
857 SIGDELSET(p
->p_sigcatch
, sig
);
858 if (sig
!= SIGCONT
&&
859 sigprop(sig
) & SA_IGNORE
)
860 SIGADDSET(p
->p_sigignore
, sig
);
861 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
864 lp
->lwp_code
= code
; /* XXX for core dump/debugger */
865 lp
->lwp_sig
= sig
; /* XXX to verify code */
866 lwpsignal(p
, lp
, sig
);
871 * Find a suitable lwp to deliver the signal to.
873 * Returns NULL if all lwps hold the signal blocked.
876 find_lwp_for_signal(struct proc
*p
, int sig
)
879 struct lwp
*run
, *sleep
, *stop
;
882 * If the running/preempted thread belongs to the proc to which
883 * the signal is being delivered and this thread does not block
884 * the signal, then we can avoid a context switch by delivering
885 * the signal to this thread, because it will return to userland
888 lp
= lwkt_preempted_proc();
889 if (lp
!= NULL
&& lp
->lwp_proc
== p
&& !SIGISMEMBER(lp
->lwp_sigmask
, sig
))
892 run
= sleep
= stop
= NULL
;
893 FOREACH_LWP_IN_PROC(lp
, p
) {
895 * If the signal is being blocked by the lwp, then this
896 * lwp is not eligible for receiving the signal.
898 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
))
901 switch (lp
->lwp_stat
) {
911 if (lp
->lwp_flag
& LWP_SINTR
)
919 else if (sleep
!= NULL
)
926 * Send the signal to the process. If the signal has an action, the action
927 * is usually performed by the target process rather than the caller; we add
928 * the signal to the set of pending signals for the process.
931 * o When a stop signal is sent to a sleeping process that takes the
932 * default action, the process is stopped without awakening it.
933 * o SIGCONT restarts stopped processes (or puts them back to sleep)
934 * regardless of the signal action (eg, blocked or ignored).
936 * Other ignored signals are discarded immediately.
939 ksignal(struct proc
*p
, int sig
)
941 lwpsignal(p
, NULL
, sig
);
945 * The core for ksignal. lp may be NULL, then a suitable thread
946 * will be chosen. If not, lp MUST be a member of p.
949 lwpsignal(struct proc
*p
, struct lwp
*lp
, int sig
)
954 if (sig
> _SIG_MAXSIG
|| sig
<= 0) {
955 kprintf("lwpsignal: signal %d\n", sig
);
956 panic("lwpsignal signal number");
959 KKASSERT(lp
== NULL
|| lp
->lwp_proc
== p
);
962 KNOTE(&p
->p_klist
, NOTE_SIGNAL
| sig
);
968 * If proc is traced, always give parent a chance;
969 * if signal event is tracked by procfs, give *that*
972 if ((p
->p_flag
& P_TRACED
) || (p
->p_stops
& S_SIG
)) {
976 * Do not try to deliver signals to an exiting lwp. Note
977 * that we must still deliver the signal if P_WEXIT is set
978 * in the process flags.
980 if (lp
&& (lp
->lwp_flag
& LWP_WEXIT
))
984 * If the signal is being ignored, then we forget about
985 * it immediately. NOTE: We don't set SIGCONT in p_sigignore,
986 * and if it is set to SIG_IGN, action will be SIG_DFL here.
988 if (SIGISMEMBER(p
->p_sigignore
, sig
))
990 if (SIGISMEMBER(p
->p_sigcatch
, sig
))
997 * If continuing, clear any pending STOP signals.
1000 SIG_STOPSIGMASK(p
->p_siglist
);
1002 if (prop
& SA_STOP
) {
1004 * If sending a tty stop signal to a member of an orphaned
1005 * process group, discard the signal here if the action
1006 * is default; don't stop the process below if sleeping,
1007 * and don't clear any pending SIGCONT.
1009 if (prop
& SA_TTYSTOP
&& p
->p_pgrp
->pg_jobc
== 0 &&
1010 action
== SIG_DFL
) {
1013 SIG_CONTSIGMASK(p
->p_siglist
);
1014 p
->p_flag
&= ~P_CONTINUED
;
1019 if (p
->p_stat
== SSTOP
) {
1021 * Nobody can handle this signal, add it to the lwp or
1022 * process pending list
1025 SIGADDSET(lp
->lwp_siglist
, sig
);
1027 SIGADDSET(p
->p_siglist
, sig
);
1030 * If the process is stopped and is being traced, then no
1031 * further action is necessary.
1033 if (p
->p_flag
& P_TRACED
)
1037 * If the process is stopped and receives a KILL signal,
1038 * make the process runnable.
1040 if (sig
== SIGKILL
) {
1042 goto active_process
;
1046 * If the process is stopped and receives a CONT signal,
1047 * then try to make the process runnable again.
1049 if (prop
& SA_CONT
) {
1051 * If SIGCONT is default (or ignored), we continue the
1052 * process but don't leave the signal in p_siglist, as
1053 * it has no further action. If SIGCONT is held, we
1054 * continue the process and leave the signal in
1055 * p_siglist. If the process catches SIGCONT, let it
1056 * handle the signal itself.
1058 /* XXX what if the signal is being held blocked? */
1059 p
->p_flag
|= P_CONTINUED
;
1061 if (action
== SIG_DFL
)
1062 SIGDELSET(p
->p_siglist
, sig
);
1064 if (action
== SIG_CATCH
)
1065 goto active_process
;
1070 * If the process is stopped and receives another STOP
1071 * signal, we do not need to stop it again. If we did
1072 * the shell could get confused.
1074 * However, if the current/preempted lwp is part of the
1075 * process receiving the signal, we need to keep it,
1076 * so that this lwp can stop in issignal() later, as
1077 * we don't want to wait until it reaches userret!
1079 if (prop
& SA_STOP
) {
1080 if (lwkt_preempted_proc() == NULL
||
1081 lwkt_preempted_proc()->lwp_proc
!= p
)
1082 SIGDELSET(p
->p_siglist
, sig
);
1086 * Otherwise the process is stopped and it received some
1087 * signal, which does not change its stopped state.
1089 * We have to select one thread to set LWP_BREAKTSLEEP,
1090 * so that the current signal will break the sleep
1091 * as soon as a SA_CONT signal will unstop the process.
1094 lp
= find_lwp_for_signal(p
, sig
);
1096 (lp
->lwp_stat
== LSSLEEP
|| lp
->lwp_stat
== LSSTOP
))
1097 lp
->lwp_flag
|= LWP_BREAKTSLEEP
;
1102 /* else not stopped */
1106 * Never deliver a lwp-specific signal to a random lwp.
1109 lp
= find_lwp_for_signal(p
, sig
);
1110 if (lp
&& SIGISMEMBER(lp
->lwp_sigmask
, sig
))
1115 * Deliver to the process generically if (1) the signal is being
1116 * sent to any thread or (2) we could not find a thread to deliver
1120 SIGADDSET(p
->p_siglist
, sig
);
1125 * Deliver to a specific LWP whether it masks it or not. It will
1126 * not be dispatched if masked but we must still deliver it.
1128 if (p
->p_nice
> NZERO
&& action
== SIG_DFL
&& (prop
& SA_KILL
) &&
1129 (p
->p_flag
& P_TRACED
) == 0) {
1134 * If the process receives a STOP signal which indeed needs to
1135 * stop the process, do so. If the process chose to catch the
1136 * signal, it will be treated like any other signal.
1138 if ((prop
& SA_STOP
) && action
== SIG_DFL
) {
1140 * If a child holding parent blocked, stopping
1141 * could cause deadlock. Take no action at this
1144 if (p
->p_flag
& P_PPWAIT
) {
1145 SIGADDSET(p
->p_siglist
, sig
);
1150 * Do not actually try to manipulate the process, but simply
1151 * stop it. Lwps will stop as soon as they safely can.
1159 * If it is a CONT signal with default action, just ignore it.
1161 if ((prop
& SA_CONT
) && action
== SIG_DFL
)
1165 * Mark signal pending at this specific thread.
1167 SIGADDSET(lp
->lwp_siglist
, sig
);
1176 lwp_signotify(struct lwp
*lp
)
1179 if (lp
->lwp_stat
== LSSLEEP
|| lp
->lwp_stat
== LSSTOP
) {
1181 * Thread is in tsleep.
1185 * If the thread is sleeping uninterruptibly
1186 * we can't interrupt the sleep... the signal will
1187 * be noticed when the lwp returns through
1188 * trap() or syscall().
1190 * Otherwise the signal can interrupt the sleep.
1192 * If the process is traced, the lwp will handle the
1193 * tracing in issignal() when it returns to userland.
1195 if (lp
->lwp_flag
& LWP_SINTR
) {
1197 * Make runnable and break out of any tsleep as well.
1199 lp
->lwp_flag
|= LWP_BREAKTSLEEP
;
1204 * Otherwise the thread is running
1206 * LSRUN does nothing with the signal, other than kicking
1207 * ourselves if we are running.
1208 * SZOMB and SIDL mean that it will either never be noticed,
1209 * or noticed very soon.
1211 * Note that lwp_thread may be NULL or may not be completely
1212 * initialized if the process is in the SIDL or SZOMB state.
1214 * For SMP we may have to forward the request to another cpu.
1215 * YYY the MP lock prevents the target process from moving
1216 * to another cpu, see kern/kern_switch.c
1218 * If the target thread is waiting on its message port,
1219 * wakeup the target thread so it can check (or ignore)
1220 * the new signal. YYY needs cleanup.
1222 if (lp
== lwkt_preempted_proc()) {
1224 } else if (lp
->lwp_stat
== LSRUN
) {
1225 struct thread
*td
= lp
->lwp_thread
;
1226 struct proc
*p
= lp
->lwp_proc
;
1229 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x",
1230 p
->p_pid
, lp
->lwp_tid
, lp
->lwp_stat
,
1231 p
->p_flag
, lp
->lwp_flag
));
1234 * To prevent a MP race with TDF_SINTR we must
1235 * schedule the thread on the correct cpu.
1238 if (td
->td_gd
!= mycpu
) {
1240 lwkt_send_ipiq(td
->td_gd
, signotify_remote
, lp
);
1243 if (td
->td_flags
& TDF_SINTR
)
1253 * This function is called via an IPI. We will be in a critical section but
1254 * the MP lock will NOT be held. Also note that by the time the ipi message
1255 * gets to us the process 'p' (arg) may no longer be scheduled or even valid.
1258 signotify_remote(void *arg
)
1260 struct lwp
*lp
= arg
;
1262 if (lp
== lwkt_preempted_proc()) {
1265 struct thread
*td
= lp
->lwp_thread
;
1266 if (td
->td_flags
& TDF_SINTR
)
1275 proc_stop(struct proc
*p
)
1279 /* If somebody raced us, be happy with it */
1280 if (p
->p_stat
== SSTOP
|| p
->p_stat
== SZOMB
)
1286 FOREACH_LWP_IN_PROC(lp
, p
) {
1287 switch (lp
->lwp_stat
) {
1290 * Do nothing, we are already counted in
1297 * We're sleeping, but we will stop before
1298 * returning to userspace, so count us
1299 * as stopped as well. We set LWP_WSTOP
1300 * to signal the lwp that it should not
1301 * increase p_nstopped when reaching tstop().
1303 if ((lp
->lwp_flag
& LWP_WSTOP
) == 0) {
1304 lp
->lwp_flag
|= LWP_WSTOP
;
1311 * We might notify ourself, but that's not
1319 if (p
->p_nstopped
== p
->p_nthreads
) {
1320 p
->p_flag
&= ~P_WAITED
;
1322 if ((p
->p_pptr
->p_sigacts
->ps_flag
& PS_NOCLDSTOP
) == 0)
1323 ksignal(p
->p_pptr
, SIGCHLD
);
1329 proc_unstop(struct proc
*p
)
1333 if (p
->p_stat
!= SSTOP
)
1337 p
->p_stat
= SACTIVE
;
1339 FOREACH_LWP_IN_PROC(lp
, p
) {
1340 switch (lp
->lwp_stat
) {
1343 * Uh? Not stopped? Well, I guess that's okay.
1346 kprintf("proc_unstop: lwp %d/%d not sleeping\n",
1347 p
->p_pid
, lp
->lwp_tid
);
1352 * Still sleeping. Don't bother waking it up.
1353 * However, if this thread was counted as
1354 * stopped, undo this.
1356 * Nevertheless we call setrunnable() so that it
1357 * will wake up in case a signal or timeout arrived
1360 if (lp
->lwp_flag
& LWP_WSTOP
) {
1361 lp
->lwp_flag
&= ~LWP_WSTOP
;
1365 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n",
1366 p
->p_pid
, lp
->lwp_tid
);
1380 kern_sigtimedwait(sigset_t waitset
, siginfo_t
*info
, struct timespec
*timeout
)
1382 sigset_t savedmask
, set
;
1383 struct proc
*p
= curproc
;
1384 struct lwp
*lp
= curthread
->td_lwp
;
1385 int error
, sig
, hz
, timevalid
= 0;
1386 struct timespec rts
, ets
, ts
;
1391 ets
.tv_sec
= 0; /* silence compiler warning */
1392 ets
.tv_nsec
= 0; /* silence compiler warning */
1393 SIG_CANTMASK(waitset
);
1394 savedmask
= lp
->lwp_sigmask
;
1397 if (timeout
->tv_sec
>= 0 && timeout
->tv_nsec
>= 0 &&
1398 timeout
->tv_nsec
< 1000000000) {
1400 getnanouptime(&rts
);
1402 timespecadd(&ets
, timeout
);
1407 set
= lwp_sigpend(lp
);
1408 SIGSETAND(set
, waitset
);
1409 if ((sig
= sig_ffs(&set
)) != 0) {
1410 SIGFILLSET(lp
->lwp_sigmask
);
1411 SIGDELSET(lp
->lwp_sigmask
, sig
);
1412 SIG_CANTMASK(lp
->lwp_sigmask
);
1413 sig
= issignal(lp
, 1);
1415 * It may be a STOP signal, in the case, issignal
1416 * returns 0, because we may stop there, and new
1417 * signal can come in, we should restart if we got
1427 * Previous checking got nothing, and we retried but still
1428 * got nothing, we should return the error status.
1434 * POSIX says this must be checked after looking for pending
1438 if (timevalid
== 0) {
1442 getnanouptime(&rts
);
1443 if (timespeccmp(&rts
, &ets
, >=)) {
1448 timespecsub(&ts
, &rts
);
1449 TIMESPEC_TO_TIMEVAL(&tv
, &ts
);
1450 hz
= tvtohz_high(&tv
);
1454 lp
->lwp_sigmask
= savedmask
;
1455 SIGSETNAND(lp
->lwp_sigmask
, waitset
);
1457 * We won't ever be woken up. Instead, our sleep will
1458 * be broken in lwpsignal().
1460 error
= tsleep(&p
->p_sigacts
, PCATCH
, "sigwt", hz
);
1462 if (error
== ERESTART
) {
1463 /* can not restart a timeout wait. */
1465 } else if (error
== EAGAIN
) {
1466 /* will calculate timeout by ourself. */
1473 lp
->lwp_sigmask
= savedmask
;
1476 bzero(info
, sizeof(*info
));
1477 info
->si_signo
= sig
;
1478 lwp_delsig(lp
, sig
); /* take the signal! */
1487 sys_sigtimedwait(struct sigtimedwait_args
*uap
)
1490 struct timespec
*timeout
;
1496 error
= copyin(uap
->timeout
, &ts
, sizeof(ts
));
1503 error
= copyin(uap
->set
, &set
, sizeof(set
));
1506 error
= kern_sigtimedwait(set
, &info
, timeout
);
1510 error
= copyout(&info
, uap
->info
, sizeof(info
));
1511 /* Repost if we got an error. */
1515 * This could transform a thread-specific signal to another
1516 * thread / process pending signal.
1519 ksignal(curproc
, info
.si_signo
);
1521 uap
->sysmsg_result
= info
.si_signo
;
1526 sys_sigwaitinfo(struct sigwaitinfo_args
*uap
)
1532 error
= copyin(uap
->set
, &set
, sizeof(set
));
1535 error
= kern_sigtimedwait(set
, &info
, NULL
);
1539 error
= copyout(&info
, uap
->info
, sizeof(info
));
1540 /* Repost if we got an error. */
1544 * This could transform a thread-specific signal to another
1545 * thread / process pending signal.
1548 ksignal(curproc
, info
.si_signo
);
1550 uap
->sysmsg_result
= info
.si_signo
;
1555 * If the current process has received a signal that would interrupt a
1556 * system call, return EINTR or ERESTART as appropriate.
1559 iscaught(struct lwp
*lp
)
1561 struct proc
*p
= lp
->lwp_proc
;
1565 if ((sig
= CURSIG(lp
)) != 0) {
1566 if (SIGISMEMBER(p
->p_sigacts
->ps_sigintr
, sig
))
1571 return(EWOULDBLOCK
);
1575 * If the current process has received a signal (should be caught or cause
1576 * termination, should interrupt current syscall), return the signal number.
1577 * Stop signals with default action are processed immediately, then cleared;
1578 * they aren't returned. This is checked after each entry to the system for
1579 * a syscall or trap (though this can usually be done without calling issignal
1580 * by checking the pending signal masks in the CURSIG macro.) The normal call
1583 * This routine is called via CURSIG/__cursig and the MP lock might not be
1584 * held. Obtain the MP lock for the duration of the operation.
1586 * while (sig = CURSIG(curproc))
1590 issignal(struct lwp
*lp
, int maytrace
)
1592 struct proc
*p
= lp
->lwp_proc
;
1598 int traced
= (p
->p_flag
& P_TRACED
) || (p
->p_stops
& S_SIG
);
1601 * If this process is supposed to stop, stop this thread.
1603 if (p
->p_stat
== SSTOP
)
1606 mask
= lwp_sigpend(lp
);
1607 SIGSETNAND(mask
, lp
->lwp_sigmask
);
1608 if (p
->p_flag
& P_PPWAIT
)
1609 SIG_STOPSIGMASK(mask
);
1610 if (SIGISEMPTY(mask
)) { /* no signal to send */
1614 sig
= sig_ffs(&mask
);
1616 STOPEVENT(p
, S_SIG
, sig
);
1619 * We should see pending but ignored signals
1620 * only if P_TRACED was on when they were posted.
1622 if (SIGISMEMBER(p
->p_sigignore
, sig
) && (traced
== 0)) {
1623 lwp_delsig(lp
, sig
);
1626 if (maytrace
&& (p
->p_flag
& P_TRACED
) && (p
->p_flag
& P_PPWAIT
) == 0) {
1628 * If traced, always stop, and stay stopped until
1629 * released by the parent.
1631 * NOTE: SSTOP may get cleared during the loop,
1632 * but we do not re-notify the parent if we have
1633 * to loop several times waiting for the parent
1634 * to let us continue.
1636 * XXX not sure if this is still true
1642 } while (!trace_req(p
) && (p
->p_flag
& P_TRACED
));
1645 * If parent wants us to take the signal,
1646 * then it will leave it in p->p_xstat;
1647 * otherwise we just look for signals again.
1649 lwp_delsig(lp
, sig
); /* clear old signal */
1655 * Put the new signal into p_siglist. If the
1656 * signal is being masked, look for other signals.
1658 * XXX lwp might need a call to ksignal()
1660 SIGADDSET(p
->p_siglist
, sig
);
1661 if (SIGISMEMBER(lp
->lwp_sigmask
, sig
))
1665 * If the traced bit got turned off, go back up
1666 * to the top to rescan signals. This ensures
1667 * that p_sig* and ps_sigact are consistent.
1669 if ((p
->p_flag
& P_TRACED
) == 0)
1673 prop
= sigprop(sig
);
1676 * Decide whether the signal should be returned.
1677 * Return the signal's number, or fall through
1678 * to clear it from the pending mask.
1680 switch ((int)(intptr_t)p
->p_sigacts
->ps_sigact
[_SIG_IDX(sig
)]) {
1683 * Don't take default actions on system processes.
1685 if (p
->p_pid
<= 1) {
1688 * Are you sure you want to ignore SIGSEGV
1691 kprintf("Process (pid %lu) got signal %d\n",
1692 (u_long
)p
->p_pid
, sig
);
1694 break; /* == ignore */
1698 * Handle the in-kernel checkpoint action
1700 if (prop
& SA_CKPT
) {
1701 checkpoint_signal_handler(lp
);
1706 * If there is a pending stop signal to process
1707 * with default action, stop here,
1708 * then clear the signal. However,
1709 * if process is member of an orphaned
1710 * process group, ignore tty stop signals.
1712 if (prop
& SA_STOP
) {
1713 if (p
->p_flag
& P_TRACED
||
1714 (p
->p_pgrp
->pg_jobc
== 0 &&
1716 break; /* == ignore */
1721 } else if (prop
& SA_IGNORE
) {
1723 * Except for SIGCONT, shouldn't get here.
1724 * Default action is to ignore; drop it.
1726 break; /* == ignore */
1736 * Masking above should prevent us ever trying
1737 * to take action on an ignored signal other
1738 * than SIGCONT, unless process is traced.
1740 if ((prop
& SA_CONT
) == 0 &&
1741 (p
->p_flag
& P_TRACED
) == 0)
1742 kprintf("issignal\n");
1743 break; /* == ignore */
1747 * This signal has an action, let
1748 * postsig() process it.
1753 lwp_delsig(lp
, sig
); /* take the signal! */
1759 * Take the action for the specified signal
1760 * from the current set of pending signals.
1765 struct lwp
*lp
= curthread
->td_lwp
;
1766 struct proc
*p
= lp
->lwp_proc
;
1767 struct sigacts
*ps
= p
->p_sigacts
;
1769 sigset_t returnmask
;
1772 KASSERT(sig
!= 0, ("postsig"));
1775 * If we are a virtual kernel running an emulated user process
1776 * context, switch back to the virtual kernel context before
1777 * trying to post the signal.
1779 if (lp
->lwp_vkernel
&& lp
->lwp_vkernel
->ve
) {
1780 struct trapframe
*tf
= lp
->lwp_md
.md_regs
;
1782 vkernel_trap(lp
, tf
);
1785 lwp_delsig(lp
, sig
);
1786 action
= ps
->ps_sigact
[_SIG_IDX(sig
)];
1788 if (KTRPOINT(lp
->lwp_thread
, KTR_PSIG
))
1789 ktrpsig(lp
, sig
, action
, lp
->lwp_flag
& LWP_OLDMASK
?
1790 &lp
->lwp_oldsigmask
: &lp
->lwp_sigmask
, 0);
1792 STOPEVENT(p
, S_SIG
, sig
);
1794 if (action
== SIG_DFL
) {
1796 * Default action, where the default is to kill
1797 * the process. (Other cases were ignored above.)
1803 * If we get here, the signal must be caught.
1805 KASSERT(action
!= SIG_IGN
&& !SIGISMEMBER(lp
->lwp_sigmask
, sig
),
1806 ("postsig action"));
1811 * Reset the signal handler if asked to
1813 if (SIGISMEMBER(ps
->ps_sigreset
, sig
)) {
1815 * See kern_sigaction() for origin of this code.
1817 SIGDELSET(p
->p_sigcatch
, sig
);
1818 if (sig
!= SIGCONT
&&
1819 sigprop(sig
) & SA_IGNORE
)
1820 SIGADDSET(p
->p_sigignore
, sig
);
1821 ps
->ps_sigact
[_SIG_IDX(sig
)] = SIG_DFL
;
1825 * Handle the mailbox case. Copyout to the appropriate
1826 * location but do not generate a signal frame. The system
1827 * call simply returns EINTR and the user is responsible for
1828 * polling the mailbox.
1830 if (SIGISMEMBER(ps
->ps_sigmailbox
, sig
)) {
1832 copyout(&sig_copy
, (void *)action
, sizeof(int));
1833 curproc
->p_flag
|= P_MAILBOX
;
1839 * Set the signal mask and calculate the mask to restore
1840 * when the signal function returns.
1842 * Special case: user has done a sigsuspend. Here the
1843 * current mask is not of interest, but rather the
1844 * mask from before the sigsuspend is what we want
1845 * restored after the signal processing is completed.
1847 if (lp
->lwp_flag
& LWP_OLDMASK
) {
1848 returnmask
= lp
->lwp_oldsigmask
;
1849 lp
->lwp_flag
&= ~LWP_OLDMASK
;
1851 returnmask
= lp
->lwp_sigmask
;
1854 SIGSETOR(lp
->lwp_sigmask
, ps
->ps_catchmask
[_SIG_IDX(sig
)]);
1855 if (!SIGISMEMBER(ps
->ps_signodefer
, sig
))
1856 SIGADDSET(lp
->lwp_sigmask
, sig
);
1859 lp
->lwp_ru
.ru_nsignals
++;
1860 if (lp
->lwp_sig
!= sig
) {
1863 code
= lp
->lwp_code
;
1867 (*p
->p_sysent
->sv_sendsig
)(action
, sig
, &returnmask
, code
);
1874 * Kill the current process for stated reason.
1877 killproc(struct proc
*p
, char *why
)
1879 log(LOG_ERR
, "pid %d (%s), uid %d, was killed: %s\n",
1880 p
->p_pid
, p
->p_comm
,
1881 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1, why
);
1882 ksignal(p
, SIGKILL
);
1886 * Force the current process to exit with the specified signal, dumping core
1887 * if appropriate. We bypass the normal tests for masked and caught signals,
1888 * allowing unrecoverable failures to terminate the process without changing
1889 * signal state. Mark the accounting record with the signal termination.
1890 * If dumping core, save the signal number for the debugger. Calls exit and
1894 sigexit(struct lwp
*lp
, int sig
)
1896 struct proc
*p
= lp
->lwp_proc
;
1898 p
->p_acflag
|= AXSIG
;
1899 if (sigprop(sig
) & SA_CORE
) {
1902 * Log signals which would cause core dumps
1903 * (Log as LOG_INFO to appease those who don't want
1905 * XXX : Todo, as well as euid, write out ruid too
1907 if (coredump(lp
, sig
) == 0)
1909 if (kern_logsigexit
)
1911 "pid %d (%s), uid %d: exited on signal %d%s\n",
1912 p
->p_pid
, p
->p_comm
,
1913 p
->p_ucred
? p
->p_ucred
->cr_uid
: -1,
1915 sig
& WCOREFLAG
? " (core dumped)" : "");
1917 exit1(W_EXITCODE(0, sig
));
1921 static char corefilename
[MAXPATHLEN
+1] = {"%N.core"};
1922 SYSCTL_STRING(_kern
, OID_AUTO
, corefile
, CTLFLAG_RW
, corefilename
,
1923 sizeof(corefilename
), "process corefile name format string");
1926 * expand_name(name, uid, pid)
1927 * Expand the name described in corefilename, using name, uid, and pid.
1928 * corefilename is a kprintf-like string, with three format specifiers:
1929 * %N name of process ("name")
1930 * %P process id (pid)
1932 * For example, "%N.core" is the default; they can be disabled completely
1933 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
1934 * This is controlled by the sysctl variable kern.corefile (see above).
1938 expand_name(const char *name
, uid_t uid
, pid_t pid
)
1941 char buf
[11]; /* Buffer for pid/uid -- max 4B */
1943 char *format
= corefilename
;
1946 temp
= kmalloc(MAXPATHLEN
+ 1, M_TEMP
, M_NOWAIT
);
1949 namelen
= strlen(name
);
1950 for (i
= 0, n
= 0; n
< MAXPATHLEN
&& format
[i
]; i
++) {
1952 switch (format
[i
]) {
1953 case '%': /* Format character */
1955 switch (format
[i
]) {
1959 case 'N': /* process name */
1960 if ((n
+ namelen
) > MAXPATHLEN
) {
1961 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1962 pid
, name
, uid
, temp
, name
);
1963 kfree(temp
, M_TEMP
);
1966 memcpy(temp
+n
, name
, namelen
);
1969 case 'P': /* process id */
1970 l
= ksprintf(buf
, "%u", pid
);
1971 if ((n
+ l
) > MAXPATHLEN
) {
1972 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1973 pid
, name
, uid
, temp
, name
);
1974 kfree(temp
, M_TEMP
);
1977 memcpy(temp
+n
, buf
, l
);
1980 case 'U': /* user id */
1981 l
= ksprintf(buf
, "%u", uid
);
1982 if ((n
+ l
) > MAXPATHLEN
) {
1983 log(LOG_ERR
, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
1984 pid
, name
, uid
, temp
, name
);
1985 kfree(temp
, M_TEMP
);
1988 memcpy(temp
+n
, buf
, l
);
1992 log(LOG_ERR
, "Unknown format character %c in `%s'\n", format
[i
], format
);
1996 temp
[n
++] = format
[i
];
2004 * Dump a process' core. The main routine does some
2005 * policy checking, and creates the name of the coredump;
2006 * then it passes on a vnode and a size limit to the process-specific
2007 * coredump routine if there is one; if there _is not_ one, it returns
2008 * ENOSYS; otherwise it returns the error from the process-specific routine.
2010 * The parameter `lp' is the lwp which triggered the coredump.
2014 coredump(struct lwp
*lp
, int sig
)
2016 struct proc
*p
= lp
->lwp_proc
;
2018 struct ucred
*cred
= p
->p_ucred
;
2020 struct nlookupdata nd
;
2023 char *name
; /* name of corefile */
2026 STOPEVENT(p
, S_CORE
, 0);
2028 if (((sugid_coredump
== 0) && p
->p_flag
& P_SUGID
) || do_coredump
== 0)
2032 * Note that the bulk of limit checking is done after
2033 * the corefile is created. The exception is if the limit
2034 * for corefiles is 0, in which case we don't bother
2035 * creating the corefile at all. This layout means that
2036 * a corefile is truncated instead of not being created,
2037 * if it is larger than the limit.
2039 limit
= p
->p_rlimit
[RLIMIT_CORE
].rlim_cur
;
2043 name
= expand_name(p
->p_comm
, p
->p_ucred
->cr_uid
, p
->p_pid
);
2046 error
= nlookup_init(&nd
, name
, UIO_SYSSPACE
, NLC_LOCKVP
);
2048 error
= vn_open(&nd
, NULL
, O_CREAT
| FWRITE
| O_NOFOLLOW
, S_IRUSR
| S_IWUSR
);
2049 kfree(name
, M_TEMP
);
2055 nd
.nl_open_vp
= NULL
;
2059 lf
.l_whence
= SEEK_SET
;
2062 lf
.l_type
= F_WRLCK
;
2063 error
= VOP_ADVLOCK(vp
, (caddr_t
)p
, F_SETLK
, &lf
, 0);
2067 /* Don't dump to non-regular files or files with links. */
2068 if (vp
->v_type
!= VREG
||
2069 VOP_GETATTR(vp
, &vattr
) || vattr
.va_nlink
!= 1) {
2074 /* Don't dump to files current user does not own */
2075 if (vattr
.va_uid
!= p
->p_ucred
->cr_uid
) {
2081 vn_lock(vp
, LK_EXCLUSIVE
| LK_RETRY
);
2083 VOP_SETATTR(vp
, &vattr
, cred
);
2084 p
->p_acflag
|= ACORE
;
2087 error
= p
->p_sysent
->sv_coredump
?
2088 p
->p_sysent
->sv_coredump(lp
, sig
, vp
, limit
) : ENOSYS
;
2091 lf
.l_type
= F_UNLCK
;
2092 VOP_ADVLOCK(vp
, (caddr_t
)p
, F_UNLCK
, &lf
, 0);
2094 error1
= vn_close(vp
, FWRITE
);
2101 * Nonexistent system call-- signal process (may want to handle it).
2102 * Flag error in case process won't see signal immediately (blocked or ignored).
2106 sys_nosys(struct nosys_args
*args
)
2108 lwpsignal(curproc
, curthread
->td_lwp
, SIGSYS
);
2113 * Send a SIGIO or SIGURG signal to a process or process group using
2114 * stored credentials rather than those of the current process.
2117 pgsigio(struct sigio
*sigio
, int sig
, int checkctty
)
2122 if (sigio
->sio_pgid
> 0) {
2123 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
,
2125 ksignal(sigio
->sio_proc
, sig
);
2126 } else if (sigio
->sio_pgid
< 0) {
2129 lockmgr(&sigio
->sio_pgrp
->pg_lock
, LK_EXCLUSIVE
);
2130 LIST_FOREACH(p
, &sigio
->sio_pgrp
->pg_members
, p_pglist
) {
2131 if (CANSIGIO(sigio
->sio_ruid
, sigio
->sio_ucred
, p
) &&
2132 (checkctty
== 0 || (p
->p_flag
& P_CONTROLT
)))
2135 lockmgr(&sigio
->sio_pgrp
->pg_lock
, LK_RELEASE
);
2140 filt_sigattach(struct knote
*kn
)
2142 struct proc
*p
= curproc
;
2144 kn
->kn_ptr
.p_proc
= p
;
2145 kn
->kn_flags
|= EV_CLEAR
; /* automatically set */
2147 /* XXX lock the proc here while adding to the list? */
2148 SLIST_INSERT_HEAD(&p
->p_klist
, kn
, kn_selnext
);
2154 filt_sigdetach(struct knote
*kn
)
2156 struct proc
*p
= kn
->kn_ptr
.p_proc
;
2158 SLIST_REMOVE(&p
->p_klist
, kn
, knote
, kn_selnext
);
2162 * signal knotes are shared with proc knotes, so we apply a mask to
2163 * the hint in order to differentiate them from process hints. This
2164 * could be avoided by using a signal-specific knote list, but probably
2165 * isn't worth the trouble.
2168 filt_signal(struct knote
*kn
, long hint
)
2170 if (hint
& NOTE_SIGNAL
) {
2171 hint
&= ~NOTE_SIGNAL
;
2173 if (kn
->kn_id
== hint
)
2176 return (kn
->kn_data
!= 0);