1 | /* $NetBSD: sys_sig.c,v 1.46 2016/08/04 06:43:43 christos Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Andrew Doran. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
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 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | /* |
33 | * Copyright (c) 1982, 1986, 1989, 1991, 1993 |
34 | * The Regents of the University of California. All rights reserved. |
35 | * (c) UNIX System Laboratories, Inc. |
36 | * All or some portions of this file are derived from material licensed |
37 | * to the University of California by American Telephone and Telegraph |
38 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
39 | * the permission of UNIX System Laboratories, Inc. |
40 | * |
41 | * Redistribution and use in source and binary forms, with or without |
42 | * modification, are permitted provided that the following conditions |
43 | * are met: |
44 | * 1. Redistributions of source code must retain the above copyright |
45 | * notice, this list of conditions and the following disclaimer. |
46 | * 2. Redistributions in binary form must reproduce the above copyright |
47 | * notice, this list of conditions and the following disclaimer in the |
48 | * documentation and/or other materials provided with the distribution. |
49 | * 3. Neither the name of the University nor the names of its contributors |
50 | * may be used to endorse or promote products derived from this software |
51 | * without specific prior written permission. |
52 | * |
53 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
54 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
55 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
56 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
57 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
58 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
59 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
60 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
61 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
62 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
63 | * SUCH DAMAGE. |
64 | * |
65 | * @(#)kern_sig.c 8.14 (Berkeley) 5/14/95 |
66 | */ |
67 | |
68 | #include <sys/cdefs.h> |
69 | __KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.46 2016/08/04 06:43:43 christos Exp $" ); |
70 | |
71 | #include "opt_dtrace.h" |
72 | |
73 | #include <sys/param.h> |
74 | #include <sys/kernel.h> |
75 | #include <sys/signalvar.h> |
76 | #include <sys/proc.h> |
77 | #include <sys/pool.h> |
78 | #include <sys/syscallargs.h> |
79 | #include <sys/kauth.h> |
80 | #include <sys/wait.h> |
81 | #include <sys/kmem.h> |
82 | #include <sys/module.h> |
83 | #include <sys/sdt.h> |
84 | |
85 | SDT_PROVIDER_DECLARE(proc); |
86 | SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, |
87 | "int" , /* signal */ |
88 | "ksiginfo_t *" ); /* signal-info */ |
89 | |
90 | int |
91 | sys___sigaction_sigtramp(struct lwp *l, |
92 | const struct sys___sigaction_sigtramp_args *uap, register_t *retval) |
93 | { |
94 | /* { |
95 | syscallarg(int) signum; |
96 | syscallarg(const struct sigaction *) nsa; |
97 | syscallarg(struct sigaction *) osa; |
98 | syscallarg(void *) tramp; |
99 | syscallarg(int) vers; |
100 | } */ |
101 | struct sigaction nsa, osa; |
102 | int error; |
103 | |
104 | if (SCARG(uap, nsa)) { |
105 | error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa)); |
106 | if (error) |
107 | return (error); |
108 | } |
109 | error = sigaction1(l, SCARG(uap, signum), |
110 | SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0, |
111 | SCARG(uap, tramp), SCARG(uap, vers)); |
112 | if (error) |
113 | return (error); |
114 | if (SCARG(uap, osa)) { |
115 | error = copyout(&osa, SCARG(uap, osa), sizeof(osa)); |
116 | if (error) |
117 | return (error); |
118 | } |
119 | return 0; |
120 | } |
121 | |
122 | /* |
123 | * Manipulate signal mask. Note that we receive new mask, not pointer, and |
124 | * return old mask as return value; the library stub does the rest. |
125 | */ |
126 | int |
127 | sys___sigprocmask14(struct lwp *l, const struct sys___sigprocmask14_args *uap, |
128 | register_t *retval) |
129 | { |
130 | /* { |
131 | syscallarg(int) how; |
132 | syscallarg(const sigset_t *) set; |
133 | syscallarg(sigset_t *) oset; |
134 | } */ |
135 | struct proc *p = l->l_proc; |
136 | sigset_t nss, oss; |
137 | int error; |
138 | |
139 | if (SCARG(uap, set)) { |
140 | error = copyin(SCARG(uap, set), &nss, sizeof(nss)); |
141 | if (error) |
142 | return error; |
143 | } |
144 | mutex_enter(p->p_lock); |
145 | error = sigprocmask1(l, SCARG(uap, how), |
146 | SCARG(uap, set) ? &nss : 0, SCARG(uap, oset) ? &oss : 0); |
147 | mutex_exit(p->p_lock); |
148 | if (error) |
149 | return error; |
150 | if (SCARG(uap, oset)) { |
151 | error = copyout(&oss, SCARG(uap, oset), sizeof(oss)); |
152 | if (error) |
153 | return error; |
154 | } |
155 | return 0; |
156 | } |
157 | |
158 | int |
159 | sys___sigpending14(struct lwp *l, const struct sys___sigpending14_args *uap, |
160 | register_t *retval) |
161 | { |
162 | /* { |
163 | syscallarg(sigset_t *) set; |
164 | } */ |
165 | sigset_t ss; |
166 | |
167 | sigpending1(l, &ss); |
168 | return copyout(&ss, SCARG(uap, set), sizeof(ss)); |
169 | } |
170 | |
171 | /* |
172 | * Suspend process until signal, providing mask to be set in the meantime. |
173 | * Note nonstandard calling convention: libc stub passes mask, not pointer, |
174 | * to save a copyin. |
175 | */ |
176 | int |
177 | sys___sigsuspend14(struct lwp *l, const struct sys___sigsuspend14_args *uap, |
178 | register_t *retval) |
179 | { |
180 | /* { |
181 | syscallarg(const sigset_t *) set; |
182 | } */ |
183 | sigset_t ss; |
184 | int error; |
185 | |
186 | if (SCARG(uap, set)) { |
187 | error = copyin(SCARG(uap, set), &ss, sizeof(ss)); |
188 | if (error) |
189 | return error; |
190 | } |
191 | return sigsuspend1(l, SCARG(uap, set) ? &ss : 0); |
192 | } |
193 | |
194 | int |
195 | sys___sigaltstack14(struct lwp *l, const struct sys___sigaltstack14_args *uap, |
196 | register_t *retval) |
197 | { |
198 | /* { |
199 | syscallarg(const struct sigaltstack *) nss; |
200 | syscallarg(struct sigaltstack *) oss; |
201 | } */ |
202 | struct sigaltstack nss, oss; |
203 | int error; |
204 | |
205 | if (SCARG(uap, nss)) { |
206 | error = copyin(SCARG(uap, nss), &nss, sizeof(nss)); |
207 | if (error) |
208 | return error; |
209 | } |
210 | error = sigaltstack1(l, |
211 | SCARG(uap, nss) ? &nss : 0, SCARG(uap, oss) ? &oss : 0); |
212 | if (error) |
213 | return error; |
214 | if (SCARG(uap, oss)) { |
215 | error = copyout(&oss, SCARG(uap, oss), sizeof(oss)); |
216 | if (error) |
217 | return error; |
218 | } |
219 | return 0; |
220 | } |
221 | |
222 | int |
223 | kill1(struct lwp *l, pid_t pid, ksiginfo_t *ksi, register_t *retval) |
224 | { |
225 | int error; |
226 | struct proc *p; |
227 | |
228 | if ((u_int)ksi->ksi_signo >= NSIG) |
229 | return EINVAL; |
230 | |
231 | if (pid != l->l_proc->p_pid) { |
232 | if (ksi->ksi_pid != l->l_proc->p_pid) |
233 | return EPERM; |
234 | |
235 | if (ksi->ksi_uid != kauth_cred_geteuid(l->l_cred)) |
236 | return EPERM; |
237 | |
238 | switch (ksi->ksi_code) { |
239 | case SI_USER: |
240 | case SI_QUEUE: |
241 | break; |
242 | default: |
243 | return EPERM; |
244 | } |
245 | } |
246 | |
247 | if (pid > 0) { |
248 | /* kill single process */ |
249 | mutex_enter(proc_lock); |
250 | p = proc_find_raw(pid); |
251 | if (p == NULL || (p->p_stat != SACTIVE && p->p_stat != SSTOP)) { |
252 | mutex_exit(proc_lock); |
253 | /* IEEE Std 1003.1-2001: return success for zombies */ |
254 | return p ? 0 : ESRCH; |
255 | } |
256 | mutex_enter(p->p_lock); |
257 | error = kauth_authorize_process(l->l_cred, |
258 | KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(ksi->ksi_signo), |
259 | NULL, NULL); |
260 | if (!error && ksi->ksi_signo) { |
261 | error = kpsignal2(p, ksi); |
262 | } |
263 | mutex_exit(p->p_lock); |
264 | mutex_exit(proc_lock); |
265 | return error; |
266 | } |
267 | |
268 | switch (pid) { |
269 | case -1: /* broadcast signal */ |
270 | return killpg1(l, ksi, 0, 1); |
271 | case 0: /* signal own process group */ |
272 | return killpg1(l, ksi, 0, 0); |
273 | default: /* negative explicit process group */ |
274 | return killpg1(l, ksi, -pid, 0); |
275 | } |
276 | /* NOTREACHED */ |
277 | } |
278 | |
279 | int |
280 | sys_sigqueueinfo(struct lwp *l, const struct sys_sigqueueinfo_args *uap, |
281 | register_t *retval) |
282 | { |
283 | /* { |
284 | syscallarg(pid_t int) pid; |
285 | syscallarg(const siginfo_t *) info; |
286 | } */ |
287 | ksiginfo_t ksi; |
288 | int error; |
289 | |
290 | KSI_INIT(&ksi); |
291 | |
292 | if ((error = copyin(&SCARG(uap, info)->_info, &ksi.ksi_info, |
293 | sizeof(ksi.ksi_info))) != 0) |
294 | return error; |
295 | |
296 | return kill1(l, SCARG(uap, pid), &ksi, retval); |
297 | } |
298 | |
299 | int |
300 | sys_kill(struct lwp *l, const struct sys_kill_args *uap, register_t *retval) |
301 | { |
302 | /* { |
303 | syscallarg(pid_t) pid; |
304 | syscallarg(int) signum; |
305 | } */ |
306 | ksiginfo_t ksi; |
307 | |
308 | KSI_INIT(&ksi); |
309 | |
310 | ksi.ksi_signo = SCARG(uap, signum); |
311 | ksi.ksi_code = SI_USER; |
312 | ksi.ksi_pid = l->l_proc->p_pid; |
313 | ksi.ksi_uid = kauth_cred_geteuid(l->l_cred); |
314 | |
315 | return kill1(l, SCARG(uap, pid), &ksi, retval); |
316 | } |
317 | |
318 | int |
319 | sys_getcontext(struct lwp *l, const struct sys_getcontext_args *uap, |
320 | register_t *retval) |
321 | { |
322 | /* { |
323 | syscallarg(struct __ucontext *) ucp; |
324 | } */ |
325 | struct proc *p = l->l_proc; |
326 | ucontext_t uc; |
327 | |
328 | memset(&uc, 0, sizeof(uc)); |
329 | |
330 | mutex_enter(p->p_lock); |
331 | getucontext(l, &uc); |
332 | mutex_exit(p->p_lock); |
333 | |
334 | return copyout(&uc, SCARG(uap, ucp), sizeof (*SCARG(uap, ucp))); |
335 | } |
336 | |
337 | int |
338 | sys_setcontext(struct lwp *l, const struct sys_setcontext_args *uap, |
339 | register_t *retval) |
340 | { |
341 | /* { |
342 | syscallarg(const ucontext_t *) ucp; |
343 | } */ |
344 | struct proc *p = l->l_proc; |
345 | ucontext_t uc; |
346 | int error; |
347 | |
348 | error = copyin(SCARG(uap, ucp), &uc, sizeof (uc)); |
349 | if (error) |
350 | return error; |
351 | if ((uc.uc_flags & _UC_CPU) == 0) |
352 | return EINVAL; |
353 | mutex_enter(p->p_lock); |
354 | error = setucontext(l, &uc); |
355 | mutex_exit(p->p_lock); |
356 | if (error) |
357 | return error; |
358 | |
359 | return EJUSTRETURN; |
360 | } |
361 | |
362 | /* |
363 | * sigtimedwait(2) system call, used also for implementation |
364 | * of sigwaitinfo() and sigwait(). |
365 | * |
366 | * This only handles single LWP in signal wait. libpthread provides |
367 | * its own sigtimedwait() wrapper to DTRT WRT individual threads. |
368 | */ |
369 | int |
370 | sys_____sigtimedwait50(struct lwp *l, |
371 | const struct sys_____sigtimedwait50_args *uap, register_t *retval) |
372 | { |
373 | |
374 | return sigtimedwait1(l, uap, retval, copyin, copyout, copyin, copyout); |
375 | } |
376 | |
377 | int |
378 | sigaction1(struct lwp *l, int signum, const struct sigaction *nsa, |
379 | struct sigaction *osa, const void *tramp, int vers) |
380 | { |
381 | struct proc *p; |
382 | struct sigacts *ps; |
383 | sigset_t tset; |
384 | int prop, error; |
385 | ksiginfoq_t kq; |
386 | static bool v0v1valid; |
387 | |
388 | if (signum <= 0 || signum >= NSIG) |
389 | return EINVAL; |
390 | |
391 | p = l->l_proc; |
392 | error = 0; |
393 | ksiginfo_queue_init(&kq); |
394 | |
395 | /* |
396 | * Trampoline ABI version 0 is reserved for the legacy kernel |
397 | * provided on-stack trampoline. Conversely, if we are using a |
398 | * non-0 ABI version, we must have a trampoline. Only validate the |
399 | * vers if a new sigaction was supplied and there was an actual |
400 | * handler specified (not SIG_IGN or SIG_DFL), which don't require |
401 | * a trampoline. Emulations use legacy kernel trampolines with |
402 | * version 0, alternatively check for that too. |
403 | * |
404 | * If version < 2, we try to autoload the compat module. Note |
405 | * that we interlock with the unload check in compat_modcmd() |
406 | * using kernconfig_lock. If the autoload fails, we don't try it |
407 | * again for this process. |
408 | */ |
409 | if (nsa != NULL && nsa->sa_handler != SIG_IGN |
410 | && nsa->sa_handler != SIG_DFL) { |
411 | if (__predict_false(vers < 2)) { |
412 | if (p->p_flag & PK_32) |
413 | v0v1valid = true; |
414 | else if ((p->p_lflag & PL_SIGCOMPAT) == 0) { |
415 | kernconfig_lock(); |
416 | if (sendsig_sigcontext_vec == NULL) { |
417 | (void)module_autoload("compat" , |
418 | MODULE_CLASS_ANY); |
419 | } |
420 | if (sendsig_sigcontext_vec != NULL) { |
421 | /* |
422 | * We need to remember if the |
423 | * sigcontext method may be useable, |
424 | * because libc may use it even |
425 | * if siginfo is available. |
426 | */ |
427 | v0v1valid = true; |
428 | } |
429 | mutex_enter(proc_lock); |
430 | /* |
431 | * Prevent unload of compat module while |
432 | * this process remains. |
433 | */ |
434 | p->p_lflag |= PL_SIGCOMPAT; |
435 | mutex_exit(proc_lock); |
436 | kernconfig_unlock(); |
437 | } |
438 | } |
439 | |
440 | switch (vers) { |
441 | case 0: |
442 | /* sigcontext, kernel supplied trampoline. */ |
443 | if (tramp != NULL || !v0v1valid) { |
444 | return EINVAL; |
445 | } |
446 | break; |
447 | case 1: |
448 | /* sigcontext, user supplied trampoline. */ |
449 | if (tramp == NULL || !v0v1valid) { |
450 | return EINVAL; |
451 | } |
452 | break; |
453 | case 2: |
454 | case 3: |
455 | /* siginfo, user supplied trampoline. */ |
456 | if (tramp == NULL) { |
457 | return EINVAL; |
458 | } |
459 | break; |
460 | default: |
461 | return EINVAL; |
462 | } |
463 | } |
464 | |
465 | mutex_enter(p->p_lock); |
466 | |
467 | ps = p->p_sigacts; |
468 | if (osa) |
469 | *osa = SIGACTION_PS(ps, signum); |
470 | if (!nsa) |
471 | goto out; |
472 | |
473 | prop = sigprop[signum]; |
474 | if ((nsa->sa_flags & ~SA_ALLBITS) || (prop & SA_CANTMASK)) { |
475 | error = EINVAL; |
476 | goto out; |
477 | } |
478 | |
479 | SIGACTION_PS(ps, signum) = *nsa; |
480 | ps->sa_sigdesc[signum].sd_tramp = tramp; |
481 | ps->sa_sigdesc[signum].sd_vers = vers; |
482 | sigminusset(&sigcantmask, &SIGACTION_PS(ps, signum).sa_mask); |
483 | |
484 | if ((prop & SA_NORESET) != 0) |
485 | SIGACTION_PS(ps, signum).sa_flags &= ~SA_RESETHAND; |
486 | |
487 | if (signum == SIGCHLD) { |
488 | if (nsa->sa_flags & SA_NOCLDSTOP) |
489 | p->p_sflag |= PS_NOCLDSTOP; |
490 | else |
491 | p->p_sflag &= ~PS_NOCLDSTOP; |
492 | if (nsa->sa_flags & SA_NOCLDWAIT) { |
493 | /* |
494 | * Paranoia: since SA_NOCLDWAIT is implemented by |
495 | * reparenting the dying child to PID 1 (and trust |
496 | * it to reap the zombie), PID 1 itself is forbidden |
497 | * to set SA_NOCLDWAIT. |
498 | */ |
499 | if (p->p_pid == 1) |
500 | p->p_flag &= ~PK_NOCLDWAIT; |
501 | else |
502 | p->p_flag |= PK_NOCLDWAIT; |
503 | } else |
504 | p->p_flag &= ~PK_NOCLDWAIT; |
505 | |
506 | if (nsa->sa_handler == SIG_IGN) { |
507 | /* |
508 | * Paranoia: same as above. |
509 | */ |
510 | if (p->p_pid == 1) |
511 | p->p_flag &= ~PK_CLDSIGIGN; |
512 | else |
513 | p->p_flag |= PK_CLDSIGIGN; |
514 | } else |
515 | p->p_flag &= ~PK_CLDSIGIGN; |
516 | } |
517 | |
518 | if ((nsa->sa_flags & SA_NODEFER) == 0) |
519 | sigaddset(&SIGACTION_PS(ps, signum).sa_mask, signum); |
520 | else |
521 | sigdelset(&SIGACTION_PS(ps, signum).sa_mask, signum); |
522 | |
523 | /* |
524 | * Set bit in p_sigctx.ps_sigignore for signals that are set to |
525 | * SIG_IGN, and for signals set to SIG_DFL where the default is to |
526 | * ignore. However, don't put SIGCONT in p_sigctx.ps_sigignore, as |
527 | * we have to restart the process. |
528 | */ |
529 | if (nsa->sa_handler == SIG_IGN || |
530 | (nsa->sa_handler == SIG_DFL && (prop & SA_IGNORE) != 0)) { |
531 | /* Never to be seen again. */ |
532 | sigemptyset(&tset); |
533 | sigaddset(&tset, signum); |
534 | sigclearall(p, &tset, &kq); |
535 | if (signum != SIGCONT) { |
536 | /* Easier in psignal */ |
537 | sigaddset(&p->p_sigctx.ps_sigignore, signum); |
538 | } |
539 | sigdelset(&p->p_sigctx.ps_sigcatch, signum); |
540 | } else { |
541 | sigdelset(&p->p_sigctx.ps_sigignore, signum); |
542 | if (nsa->sa_handler == SIG_DFL) |
543 | sigdelset(&p->p_sigctx.ps_sigcatch, signum); |
544 | else |
545 | sigaddset(&p->p_sigctx.ps_sigcatch, signum); |
546 | } |
547 | |
548 | /* |
549 | * Previously held signals may now have become visible. Ensure that |
550 | * we check for them before returning to userspace. |
551 | */ |
552 | if (sigispending(l, 0)) { |
553 | lwp_lock(l); |
554 | l->l_flag |= LW_PENDSIG; |
555 | lwp_unlock(l); |
556 | } |
557 | out: |
558 | mutex_exit(p->p_lock); |
559 | ksiginfo_queue_drain(&kq); |
560 | |
561 | return error; |
562 | } |
563 | |
564 | int |
565 | sigprocmask1(struct lwp *l, int how, const sigset_t *nss, sigset_t *oss) |
566 | { |
567 | sigset_t *mask = &l->l_sigmask; |
568 | bool more; |
569 | |
570 | KASSERT(mutex_owned(l->l_proc->p_lock)); |
571 | |
572 | if (oss) { |
573 | *oss = *mask; |
574 | } |
575 | |
576 | if (nss == NULL) { |
577 | return 0; |
578 | } |
579 | |
580 | switch (how) { |
581 | case SIG_BLOCK: |
582 | sigplusset(nss, mask); |
583 | more = false; |
584 | break; |
585 | case SIG_UNBLOCK: |
586 | sigminusset(nss, mask); |
587 | more = true; |
588 | break; |
589 | case SIG_SETMASK: |
590 | *mask = *nss; |
591 | more = true; |
592 | break; |
593 | default: |
594 | return EINVAL; |
595 | } |
596 | sigminusset(&sigcantmask, mask); |
597 | if (more && sigispending(l, 0)) { |
598 | /* |
599 | * Check for pending signals on return to user. |
600 | */ |
601 | lwp_lock(l); |
602 | l->l_flag |= LW_PENDSIG; |
603 | lwp_unlock(l); |
604 | } |
605 | return 0; |
606 | } |
607 | |
608 | void |
609 | sigpending1(struct lwp *l, sigset_t *ss) |
610 | { |
611 | struct proc *p = l->l_proc; |
612 | |
613 | mutex_enter(p->p_lock); |
614 | *ss = l->l_sigpend.sp_set; |
615 | sigplusset(&p->p_sigpend.sp_set, ss); |
616 | mutex_exit(p->p_lock); |
617 | } |
618 | |
619 | void |
620 | sigsuspendsetup(struct lwp *l, const sigset_t *ss) |
621 | { |
622 | struct proc *p = l->l_proc; |
623 | |
624 | /* |
625 | * When returning from sigsuspend/pselect/pollts, we want |
626 | * the old mask to be restored after the |
627 | * signal handler has finished. Thus, we |
628 | * save it here and mark the sigctx structure |
629 | * to indicate this. |
630 | */ |
631 | mutex_enter(p->p_lock); |
632 | l->l_sigrestore = 1; |
633 | l->l_sigoldmask = l->l_sigmask; |
634 | l->l_sigmask = *ss; |
635 | sigminusset(&sigcantmask, &l->l_sigmask); |
636 | |
637 | /* Check for pending signals when sleeping. */ |
638 | if (sigispending(l, 0)) { |
639 | lwp_lock(l); |
640 | l->l_flag |= LW_PENDSIG; |
641 | lwp_unlock(l); |
642 | } |
643 | mutex_exit(p->p_lock); |
644 | } |
645 | |
646 | void |
647 | sigsuspendteardown(struct lwp *l) |
648 | { |
649 | struct proc *p = l->l_proc; |
650 | |
651 | mutex_enter(p->p_lock); |
652 | /* Check for pending signals when sleeping. */ |
653 | if (l->l_sigrestore) { |
654 | if (sigispending(l, 0)) { |
655 | lwp_lock(l); |
656 | l->l_flag |= LW_PENDSIG; |
657 | lwp_unlock(l); |
658 | } else { |
659 | l->l_sigrestore = 0; |
660 | l->l_sigmask = l->l_sigoldmask; |
661 | } |
662 | } |
663 | mutex_exit(p->p_lock); |
664 | } |
665 | |
666 | int |
667 | sigsuspend1(struct lwp *l, const sigset_t *ss) |
668 | { |
669 | |
670 | if (ss) |
671 | sigsuspendsetup(l, ss); |
672 | |
673 | while (kpause("pause" , true, 0, NULL) == 0) |
674 | ; |
675 | |
676 | /* always return EINTR rather than ERESTART... */ |
677 | return EINTR; |
678 | } |
679 | |
680 | int |
681 | sigaltstack1(struct lwp *l, const struct sigaltstack *nss, |
682 | struct sigaltstack *oss) |
683 | { |
684 | struct proc *p = l->l_proc; |
685 | int error = 0; |
686 | |
687 | mutex_enter(p->p_lock); |
688 | |
689 | if (oss) |
690 | *oss = l->l_sigstk; |
691 | |
692 | if (nss) { |
693 | if (nss->ss_flags & ~SS_ALLBITS) |
694 | error = EINVAL; |
695 | else if (nss->ss_flags & SS_DISABLE) { |
696 | if (l->l_sigstk.ss_flags & SS_ONSTACK) |
697 | error = EINVAL; |
698 | } else if (nss->ss_size < MINSIGSTKSZ) |
699 | error = ENOMEM; |
700 | |
701 | if (!error) |
702 | l->l_sigstk = *nss; |
703 | } |
704 | |
705 | mutex_exit(p->p_lock); |
706 | |
707 | return error; |
708 | } |
709 | |
710 | int |
711 | sigtimedwait1(struct lwp *l, const struct sys_____sigtimedwait50_args *uap, |
712 | register_t *retval, copyin_t fetchss, copyout_t storeinf, copyin_t fetchts, |
713 | copyout_t storets) |
714 | { |
715 | /* { |
716 | syscallarg(const sigset_t *) set; |
717 | syscallarg(siginfo_t *) info; |
718 | syscallarg(struct timespec *) timeout; |
719 | } */ |
720 | struct proc *p = l->l_proc; |
721 | int error, signum, timo; |
722 | struct timespec ts, tsstart, tsnow; |
723 | ksiginfo_t ksi; |
724 | |
725 | /* |
726 | * Calculate timeout, if it was specified. |
727 | * |
728 | * NULL pointer means an infinite timeout. |
729 | * {.tv_sec = 0, .tv_nsec = 0} means do not block. |
730 | */ |
731 | if (SCARG(uap, timeout)) { |
732 | error = (*fetchts)(SCARG(uap, timeout), &ts, sizeof(ts)); |
733 | if (error) |
734 | return error; |
735 | |
736 | if ((error = itimespecfix(&ts)) != 0) |
737 | return error; |
738 | |
739 | timo = tstohz(&ts); |
740 | if (timo == 0) { |
741 | if (ts.tv_sec == 0 && ts.tv_nsec == 0) |
742 | timo = -1; /* do not block */ |
743 | else |
744 | timo = 1; /* the shortest possible timeout */ |
745 | } |
746 | |
747 | /* |
748 | * Remember current uptime, it would be used in |
749 | * ECANCELED/ERESTART case. |
750 | */ |
751 | getnanouptime(&tsstart); |
752 | } else { |
753 | memset(&tsstart, 0, sizeof(tsstart)); /* XXXgcc */ |
754 | timo = 0; /* infinite timeout */ |
755 | } |
756 | |
757 | error = (*fetchss)(SCARG(uap, set), &l->l_sigwaitset, |
758 | sizeof(l->l_sigwaitset)); |
759 | if (error) |
760 | return error; |
761 | |
762 | /* |
763 | * Silently ignore SA_CANTMASK signals. psignal1() would ignore |
764 | * SA_CANTMASK signals in waitset, we do this only for the below |
765 | * siglist check. |
766 | */ |
767 | sigminusset(&sigcantmask, &l->l_sigwaitset); |
768 | |
769 | mutex_enter(p->p_lock); |
770 | |
771 | /* Check for pending signals in the process, if no - then in LWP. */ |
772 | if ((signum = sigget(&p->p_sigpend, &ksi, 0, &l->l_sigwaitset)) == 0) |
773 | signum = sigget(&l->l_sigpend, &ksi, 0, &l->l_sigwaitset); |
774 | |
775 | if (signum != 0) { |
776 | /* If found a pending signal, just copy it out to the user. */ |
777 | mutex_exit(p->p_lock); |
778 | goto out; |
779 | } |
780 | |
781 | if (timo < 0) { |
782 | /* If not allowed to block, return an error */ |
783 | mutex_exit(p->p_lock); |
784 | return EAGAIN; |
785 | } |
786 | |
787 | /* |
788 | * Set up the sigwait list and wait for signal to arrive. |
789 | * We can either be woken up or time out. |
790 | */ |
791 | l->l_sigwaited = &ksi; |
792 | LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter); |
793 | error = cv_timedwait_sig(&l->l_sigcv, p->p_lock, timo); |
794 | |
795 | /* |
796 | * Need to find out if we woke as a result of _lwp_wakeup() or a |
797 | * signal outside our wait set. |
798 | */ |
799 | if (l->l_sigwaited != NULL) { |
800 | if (error == EINTR) { |
801 | /* Wakeup via _lwp_wakeup(). */ |
802 | error = ECANCELED; |
803 | } else if (!error) { |
804 | /* Spurious wakeup - arrange for syscall restart. */ |
805 | error = ERESTART; |
806 | } |
807 | l->l_sigwaited = NULL; |
808 | LIST_REMOVE(l, l_sigwaiter); |
809 | } |
810 | mutex_exit(p->p_lock); |
811 | |
812 | /* |
813 | * If the sleep was interrupted (either by signal or wakeup), update |
814 | * the timeout and copyout new value back. It would be used when |
815 | * the syscall would be restarted or called again. |
816 | */ |
817 | if (timo && (error == ERESTART || error == ECANCELED)) { |
818 | getnanouptime(&tsnow); |
819 | |
820 | /* Compute how much time has passed since start. */ |
821 | timespecsub(&tsnow, &tsstart, &tsnow); |
822 | |
823 | /* Substract passed time from timeout. */ |
824 | timespecsub(&ts, &tsnow, &ts); |
825 | |
826 | if (ts.tv_sec < 0) |
827 | error = EAGAIN; |
828 | else { |
829 | /* Copy updated timeout to userland. */ |
830 | error = (*storets)(&ts, SCARG(uap, timeout), |
831 | sizeof(ts)); |
832 | } |
833 | } |
834 | out: |
835 | /* |
836 | * If a signal from the wait set arrived, copy it to userland. |
837 | * Copy only the used part of siginfo, the padding part is |
838 | * left unchanged (userland is not supposed to touch it anyway). |
839 | */ |
840 | if (error == 0 && SCARG(uap, info)) { |
841 | error = (*storeinf)(&ksi.ksi_info, SCARG(uap, info), |
842 | sizeof(ksi.ksi_info)); |
843 | } |
844 | if (error == 0) { |
845 | *retval = ksi.ksi_info._signo; |
846 | SDT_PROBE(proc, kernel, , signal__clear, *retval, |
847 | &ksi, 0, 0, 0); |
848 | } |
849 | return error; |
850 | } |
851 | |