1/*
2 * Copyright (c) 1995-2016 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1982, 1986, 1989, 1991, 1993
30 * The Regents of the University of California. All rights reserved.
31 * (c) UNIX System Laboratories, Inc.
32 * All or some portions of this file are derived from material licensed
33 * to the University of California by American Telephone and Telegraph
34 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
35 * the permission of UNIX System Laboratories, Inc.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. All advertising materials mentioning features or use of this software
46 * must display the following acknowledgement:
47 * This product includes software developed by the University of
48 * California, Berkeley and its contributors.
49 * 4. 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 8.7 (Berkeley) 4/18/94
66 */
67/*
68 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
69 * support for mandatory and extensible security protections. This notice
70 * is included in support of clause 2.2 (b) of the Apple Public License,
71 * Version 2.0.
72 */
73
74#define SIGPROP /* include signal properties table */
75#include <sys/param.h>
76#include <sys/resourcevar.h>
77#include <sys/proc_internal.h>
78#include <sys/kauth.h>
79#include <sys/systm.h>
80#include <sys/timeb.h>
81#include <sys/times.h>
82#include <sys/acct.h>
83#include <sys/file_internal.h>
84#include <sys/kernel.h>
85#include <sys/wait.h>
86#include <sys/signalvar.h>
87#include <sys/syslog.h>
88#include <sys/stat.h>
89#include <sys/lock.h>
90#include <sys/kdebug.h>
91#include <sys/reason.h>
92
93#include <sys/mount.h>
94#include <sys/sysproto.h>
95
96#include <security/audit/audit.h>
97
98#include <kern/cpu_number.h>
99
100#include <sys/vm.h>
101#include <sys/user.h> /* for coredump */
102#include <kern/ast.h> /* for APC support */
103#include <kern/kalloc.h>
104#include <kern/task.h> /* extern void *get_bsdtask_info(task_t); */
105#include <kern/thread.h>
106#include <kern/sched_prim.h>
107#include <kern/thread_call.h>
108#include <kern/policy_internal.h>
109
110#include <mach/exception.h>
111#include <mach/task.h>
112#include <mach/thread_act.h>
113#include <libkern/OSAtomic.h>
114
115#include <sys/sdt.h>
116#include <sys/codesign.h>
117#include <sys/random.h>
118#include <libkern/section_keywords.h>
119
120#if CONFIG_MACF
121#include <security/mac_framework.h>
122#endif
123
124/*
125 * Missing prototypes that Mach should export
126 *
127 * +++
128 */
129extern int thread_enable_fpe(thread_t act, int onoff);
130extern thread_t port_name_to_thread(mach_port_name_t port_name);
131extern kern_return_t get_signalact(task_t , thread_t *, int);
132extern unsigned int get_useraddr(void);
133extern boolean_t task_did_exec(task_t task);
134extern boolean_t task_is_exec_copy(task_t task);
135
136/*
137 * ---
138 */
139
140extern void doexception(int exc, mach_exception_code_t code,
141 mach_exception_subcode_t sub);
142
143static void stop(proc_t, proc_t);
144static int cansignal_nomac(proc_t, kauth_cred_t, proc_t, int);
145int cansignal(proc_t, kauth_cred_t, proc_t, int);
146int killpg1(proc_t, int, int, int, int);
147kern_return_t do_bsdexception(int, int, int);
148void __posix_sem_syscall_return(kern_return_t);
149char *proc_name_address(void *p);
150
151/* implementations in osfmk/kern/sync_sema.c. We do not want port.h in this scope, so void * them */
152kern_return_t semaphore_timedwait_signal_trap_internal(mach_port_name_t, mach_port_name_t, unsigned int, clock_res_t, void (*)(kern_return_t));
153kern_return_t semaphore_timedwait_trap_internal(mach_port_name_t, unsigned int, clock_res_t, void (*)(kern_return_t));
154kern_return_t semaphore_wait_signal_trap_internal(mach_port_name_t, mach_port_name_t, void (*)(kern_return_t));
155kern_return_t semaphore_wait_trap_internal(mach_port_name_t, void (*)(kern_return_t));
156
157static int filt_sigattach(struct knote *kn, struct kevent_internal_s *kev);
158static void filt_sigdetach(struct knote *kn);
159static int filt_signal(struct knote *kn, long hint);
160static int filt_signaltouch(struct knote *kn, struct kevent_internal_s *kev);
161static int filt_signalprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
162
163SECURITY_READ_ONLY_EARLY(struct filterops) sig_filtops = {
164 .f_attach = filt_sigattach,
165 .f_detach = filt_sigdetach,
166 .f_event = filt_signal,
167 .f_touch = filt_signaltouch,
168 .f_process = filt_signalprocess,
169};
170
171/* structures and fns for killpg1 iterartion callback and filters */
172struct killpg1_filtargs {
173 bool posix;
174 proc_t curproc;
175};
176
177struct killpg1_iterargs {
178 proc_t curproc;
179 kauth_cred_t uc;
180 int signum;
181 int nfound;
182};
183
184static int killpg1_allfilt(proc_t p, void * arg);
185static int killpg1_pgrpfilt(proc_t p, __unused void * arg);
186static int killpg1_callback(proc_t p, void * arg);
187
188static int pgsignal_filt(proc_t p, void * arg);
189static int pgsignal_callback(proc_t p, void * arg);
190static kern_return_t get_signalthread(proc_t, int, thread_t *);
191
192
193/* flags for psignal_internal */
194#define PSIG_LOCKED 0x1
195#define PSIG_VFORK 0x2
196#define PSIG_THREAD 0x4
197#define PSIG_TRY_THREAD 0x8
198
199static os_reason_t build_signal_reason(int signum, const char *procname);
200static void psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum, os_reason_t signal_reason);
201
202/*
203 * NOTE: Source and target may *NOT* overlap! (target is smaller)
204 */
205static void
206sigaltstack_kern_to_user32(struct kern_sigaltstack *in, struct user32_sigaltstack *out)
207{
208 out->ss_sp = CAST_DOWN_EXPLICIT(user32_addr_t, in->ss_sp);
209 out->ss_size = CAST_DOWN_EXPLICIT(user32_size_t, in->ss_size);
210 out->ss_flags = in->ss_flags;
211}
212
213static void
214sigaltstack_kern_to_user64(struct kern_sigaltstack *in, struct user64_sigaltstack *out)
215{
216 out->ss_sp = in->ss_sp;
217 out->ss_size = in->ss_size;
218 out->ss_flags = in->ss_flags;
219}
220
221/*
222 * NOTE: Source and target may are permitted to overlap! (source is smaller);
223 * this works because we copy fields in order from the end of the struct to
224 * the beginning.
225 */
226static void
227sigaltstack_user32_to_kern(struct user32_sigaltstack *in, struct kern_sigaltstack *out)
228{
229 out->ss_flags = in->ss_flags;
230 out->ss_size = in->ss_size;
231 out->ss_sp = CAST_USER_ADDR_T(in->ss_sp);
232}
233static void
234sigaltstack_user64_to_kern(struct user64_sigaltstack *in, struct kern_sigaltstack *out)
235{
236 out->ss_flags = in->ss_flags;
237 out->ss_size = in->ss_size;
238 out->ss_sp = in->ss_sp;
239}
240
241static void
242sigaction_kern_to_user32(struct kern_sigaction *in, struct user32_sigaction *out)
243{
244 /* This assumes 32 bit __sa_handler is of type sig_t */
245 out->__sigaction_u.__sa_handler = CAST_DOWN_EXPLICIT(user32_addr_t,in->__sigaction_u.__sa_handler);
246 out->sa_mask = in->sa_mask;
247 out->sa_flags = in->sa_flags;
248}
249static void
250sigaction_kern_to_user64(struct kern_sigaction *in, struct user64_sigaction *out)
251{
252 /* This assumes 32 bit __sa_handler is of type sig_t */
253 out->__sigaction_u.__sa_handler = in->__sigaction_u.__sa_handler;
254 out->sa_mask = in->sa_mask;
255 out->sa_flags = in->sa_flags;
256}
257
258static void
259__sigaction_user32_to_kern(struct __user32_sigaction *in, struct __kern_sigaction *out)
260{
261 out->__sigaction_u.__sa_handler = CAST_USER_ADDR_T(in->__sigaction_u.__sa_handler);
262 out->sa_tramp = CAST_USER_ADDR_T(in->sa_tramp);
263 out->sa_mask = in->sa_mask;
264 out->sa_flags = in->sa_flags;
265
266 kern_return_t kr;
267 kr = machine_thread_function_pointers_convert_from_user(current_thread(),
268 &out->sa_tramp, 1);
269 assert(kr == KERN_SUCCESS);
270}
271
272static void
273__sigaction_user64_to_kern(struct __user64_sigaction *in, struct __kern_sigaction *out)
274{
275 out->__sigaction_u.__sa_handler = in->__sigaction_u.__sa_handler;
276 out->sa_tramp = in->sa_tramp;
277 out->sa_mask = in->sa_mask;
278 out->sa_flags = in->sa_flags;
279
280 kern_return_t kr;
281 kr = machine_thread_function_pointers_convert_from_user(current_thread(),
282 &out->sa_tramp, 1);
283 assert(kr == KERN_SUCCESS);
284}
285
286#if SIGNAL_DEBUG
287void ram_printf(int);
288int ram_debug=0;
289unsigned int rdebug_proc=0;
290void
291ram_printf(int x)
292{
293 printf("x is %d",x);
294
295}
296#endif /* SIGNAL_DEBUG */
297
298
299void
300signal_setast(thread_t sig_actthread)
301{
302 act_set_astbsd(sig_actthread);
303}
304
305static int
306cansignal_nomac(proc_t src, kauth_cred_t uc_src, proc_t dst, int signum)
307{
308 /* you can signal yourself */
309 if (src == dst) {
310 return 1;
311 }
312
313 /* you can't send the init proc SIGKILL, even if root */
314 if (signum == SIGKILL && dst == initproc) {
315 return 0;
316 }
317
318 /* otherwise, root can always signal */
319 if (kauth_cred_issuser(uc_src)) {
320 return 1;
321 }
322
323 /* processes in the same session can send SIGCONT to each other */
324 {
325 struct session *sess_src = SESSION_NULL;
326 struct session *sess_dst = SESSION_NULL;
327
328 /* The session field is protected by the list lock. */
329 proc_list_lock();
330 if (src->p_pgrp != PGRP_NULL) {
331 sess_src = src->p_pgrp->pg_session;
332 }
333 if (dst->p_pgrp != PGRP_NULL) {
334 sess_dst = dst->p_pgrp->pg_session;
335 }
336 proc_list_unlock();
337
338 /* allow SIGCONT within session and for processes without session */
339 if (signum == SIGCONT && sess_src == sess_dst) {
340 return 1;
341 }
342 }
343
344 /* the source process must be authorized to signal the target */
345 {
346 int allowed = 0;
347 kauth_cred_t uc_dst = NOCRED, uc_ref = NOCRED;
348
349 uc_dst = uc_ref = kauth_cred_proc_ref(dst);
350
351 /*
352 * If the real or effective UID of the sender matches the real or saved
353 * UID of the target, allow the signal to be sent.
354 */
355 if (kauth_cred_getruid(uc_src) == kauth_cred_getruid(uc_dst) ||
356 kauth_cred_getruid(uc_src) == kauth_cred_getsvuid(uc_dst) ||
357 kauth_cred_getuid(uc_src) == kauth_cred_getruid(uc_dst) ||
358 kauth_cred_getuid(uc_src) == kauth_cred_getsvuid(uc_dst)) {
359 allowed = 1;
360 }
361
362 if (uc_ref != NOCRED) {
363 kauth_cred_unref(&uc_ref);
364 uc_ref = NOCRED;
365 }
366
367 return allowed;
368 }
369}
370
371/*
372 * Can process `src`, with ucred `uc_src`, send the signal `signum` to process
373 * `dst`? The ucred is referenced by the caller so internal fileds can be used
374 * safely.
375 */
376int
377cansignal(proc_t src, kauth_cred_t uc_src, proc_t dst, int signum)
378{
379#if CONFIG_MACF
380 if (mac_proc_check_signal(src, dst, signum)) {
381 return 0;
382 }
383#endif
384
385 return cansignal_nomac(src, uc_src, dst, signum);
386}
387
388/*
389 * <rdar://problem/21952708> Some signals can be restricted from being handled,
390 * forcing the default action for that signal. This behavior applies only to
391 * non-root (EUID != 0) processes, and is configured with the "sigrestrict=x"
392 * bootarg:
393 *
394 * 0 (default): Disallow use of restricted signals. Trying to register a handler
395 * returns ENOTSUP, which userspace may use to take special action (e.g. abort).
396 * 1: As above, but return EINVAL. Restricted signals behave similarly to SIGKILL.
397 * 2: Usual POSIX semantics.
398 */
399unsigned sigrestrict_arg = 0;
400
401#if PLATFORM_WatchOS
402static int
403sigrestrictmask(void)
404{
405 if (kauth_getuid() != 0 && sigrestrict_arg != 2) {
406 return SIGRESTRICTMASK;
407 }
408 return 0;
409}
410
411static int
412signal_is_restricted(proc_t p, int signum)
413{
414 if (sigmask(signum) & sigrestrictmask()) {
415 if (sigrestrict_arg == 0 &&
416 task_get_apptype(p->task) == TASK_APPTYPE_APP_DEFAULT) {
417 return ENOTSUP;
418 } else {
419 return EINVAL;
420 }
421 }
422 return 0;
423}
424
425#else
426
427static inline int
428signal_is_restricted(proc_t p, int signum)
429{
430 (void)p;
431 (void)signum;
432 return 0;
433}
434#endif /* !PLATFORM_WatchOS */
435
436/*
437 * Returns: 0 Success
438 * EINVAL
439 * copyout:EFAULT
440 * copyin:EFAULT
441 *
442 * Notes: Uses current thread as a parameter to inform PPC to enable
443 * FPU exceptions via setsigvec(); this operation is not proxy
444 * safe!
445 */
446/* ARGSUSED */
447int
448sigaction(proc_t p, struct sigaction_args *uap, __unused int32_t *retval)
449{
450 struct kern_sigaction vec;
451 struct __kern_sigaction __vec;
452
453 struct kern_sigaction *sa = &vec;
454 struct sigacts *ps = p->p_sigacts;
455
456 int signum;
457 int bit, error=0;
458 uint32_t sigreturn_validation = PS_SIGRETURN_VALIDATION_DEFAULT;
459
460 signum = uap->signum;
461 if (signum <= 0 || signum >= NSIG ||
462 signum == SIGKILL || signum == SIGSTOP)
463 return (EINVAL);
464
465 if (uap->nsa) {
466 if (IS_64BIT_PROCESS(p)) {
467 struct __user64_sigaction __vec64;
468 error = copyin(uap->nsa, &__vec64, sizeof(__vec64));
469 __sigaction_user64_to_kern(&__vec64, &__vec);
470 } else {
471 struct __user32_sigaction __vec32;
472 error = copyin(uap->nsa, &__vec32, sizeof(__vec32));
473 __sigaction_user32_to_kern(&__vec32, &__vec);
474 }
475 if (error)
476 return (error);
477
478 sigreturn_validation = (__vec.sa_flags & SA_VALIDATE_SIGRETURN_FROM_SIGTRAMP) ?
479 PS_SIGRETURN_VALIDATION_ENABLED : PS_SIGRETURN_VALIDATION_DISABLED;
480 __vec.sa_flags &= SA_USERSPACE_MASK; /* Only pass on valid sa_flags */
481
482 if ((__vec.sa_flags & SA_SIGINFO) || __vec.sa_handler != SIG_DFL) {
483 if ((error = signal_is_restricted(p, signum))) {
484 if (error == ENOTSUP) {
485 printf("%s(%d): denied attempt to register action for signal %d\n",
486 proc_name_address(p), proc_pid(p), signum);
487 }
488 return error;
489 }
490 }
491 }
492
493 if (uap->osa) {
494 sa->sa_handler = ps->ps_sigact[signum];
495 sa->sa_mask = ps->ps_catchmask[signum];
496 bit = sigmask(signum);
497 sa->sa_flags = 0;
498 if ((ps->ps_sigonstack & bit) != 0)
499 sa->sa_flags |= SA_ONSTACK;
500 if ((ps->ps_sigintr & bit) == 0)
501 sa->sa_flags |= SA_RESTART;
502 if (ps->ps_siginfo & bit)
503 sa->sa_flags |= SA_SIGINFO;
504 if (ps->ps_signodefer & bit)
505 sa->sa_flags |= SA_NODEFER;
506 if ((signum == SIGCHLD) && (p->p_flag & P_NOCLDSTOP))
507 sa->sa_flags |= SA_NOCLDSTOP;
508 if ((signum == SIGCHLD) && (p->p_flag & P_NOCLDWAIT))
509 sa->sa_flags |= SA_NOCLDWAIT;
510
511 if (IS_64BIT_PROCESS(p)) {
512 struct user64_sigaction vec64 = {};
513 sigaction_kern_to_user64(sa, &vec64);
514 error = copyout(&vec64, uap->osa, sizeof(vec64));
515 } else {
516 struct user32_sigaction vec32 = {};
517 sigaction_kern_to_user32(sa, &vec32);
518 error = copyout(&vec32, uap->osa, sizeof(vec32));
519 }
520 if (error)
521 return (error);
522 }
523
524 if (uap->nsa) {
525 uint32_t old_sigreturn_validation = atomic_load_explicit(
526 &ps->ps_sigreturn_validation, memory_order_relaxed);
527 if (old_sigreturn_validation == PS_SIGRETURN_VALIDATION_DEFAULT) {
528 atomic_compare_exchange_strong_explicit(&ps->ps_sigreturn_validation,
529 &old_sigreturn_validation, sigreturn_validation,
530 memory_order_relaxed, memory_order_relaxed);
531 }
532 error = setsigvec(p, current_thread(), signum, &__vec, FALSE);
533 }
534
535 return (error);
536}
537
538/* Routines to manipulate bits on all threads */
539int
540clear_procsiglist(proc_t p, int bit, boolean_t in_signalstart)
541{
542 struct uthread * uth;
543 thread_t thact;
544
545 proc_lock(p);
546 if (!in_signalstart)
547 proc_signalstart(p, 1);
548
549 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
550 thact = p->p_vforkact;
551 uth = (struct uthread *)get_bsdthread_info(thact);
552 if (uth) {
553 uth->uu_siglist &= ~bit;
554 }
555 if (!in_signalstart)
556 proc_signalend(p, 1);
557 proc_unlock(p);
558 return(0);
559 }
560
561 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
562 uth->uu_siglist &= ~bit;
563 }
564 p->p_siglist &= ~bit;
565 if (!in_signalstart)
566 proc_signalend(p, 1);
567 proc_unlock(p);
568
569 return(0);
570}
571
572
573static int
574unblock_procsigmask(proc_t p, int bit)
575{
576 struct uthread * uth;
577 thread_t thact;
578
579 proc_lock(p);
580 proc_signalstart(p, 1);
581
582 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
583 thact = p->p_vforkact;
584 uth = (struct uthread *)get_bsdthread_info(thact);
585 if (uth) {
586 uth->uu_sigmask &= ~bit;
587 }
588 p->p_sigmask &= ~bit;
589 proc_signalend(p, 1);
590 proc_unlock(p);
591 return(0);
592 }
593 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
594 uth->uu_sigmask &= ~bit;
595 }
596 p->p_sigmask &= ~bit;
597
598 proc_signalend(p, 1);
599 proc_unlock(p);
600 return(0);
601}
602
603static int
604block_procsigmask(proc_t p, int bit)
605{
606 struct uthread * uth;
607 thread_t thact;
608
609 proc_lock(p);
610 proc_signalstart(p, 1);
611
612 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
613 thact = p->p_vforkact;
614 uth = (struct uthread *)get_bsdthread_info(thact);
615 if (uth) {
616 uth->uu_sigmask |= bit;
617 }
618 p->p_sigmask |= bit;
619 proc_signalend(p, 1);
620 proc_unlock(p);
621 return(0);
622 }
623 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
624 uth->uu_sigmask |= bit;
625 }
626 p->p_sigmask |= bit;
627
628 proc_signalend(p, 1);
629 proc_unlock(p);
630 return(0);
631}
632
633int
634set_procsigmask(proc_t p, int bit)
635{
636 struct uthread * uth;
637 thread_t thact;
638
639 proc_lock(p);
640 proc_signalstart(p, 1);
641
642 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
643 thact = p->p_vforkact;
644 uth = (struct uthread *)get_bsdthread_info(thact);
645 if (uth) {
646 uth->uu_sigmask = bit;
647 }
648 p->p_sigmask = bit;
649 proc_signalend(p, 1);
650 proc_unlock(p);
651 return(0);
652 }
653 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
654 uth->uu_sigmask = bit;
655 }
656 p->p_sigmask = bit;
657 proc_signalend(p, 1);
658 proc_unlock(p);
659
660 return(0);
661}
662
663/* XXX should be static? */
664/*
665 * Notes: The thread parameter is used in the PPC case to select the
666 * thread on which the floating point exception will be enabled
667 * or disabled. We can't simply take current_thread(), since
668 * this is called from posix_spawn() on the not currently running
669 * process/thread pair.
670 *
671 * We mark thread as unused to alow compilation without warning
672 * on non-PPC platforms.
673 */
674int
675setsigvec(proc_t p, __unused thread_t thread, int signum, struct __kern_sigaction *sa, boolean_t in_sigstart)
676{
677 struct sigacts *ps = p->p_sigacts;
678 int bit;
679
680 assert(signum < NSIG);
681
682 if ((signum == SIGKILL || signum == SIGSTOP) &&
683 sa->sa_handler != SIG_DFL)
684 return(EINVAL);
685 bit = sigmask(signum);
686 /*
687 * Change setting atomically.
688 */
689 ps->ps_sigact[signum] = sa->sa_handler;
690 ps->ps_trampact[signum] = sa->sa_tramp;
691 ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask;
692 if (sa->sa_flags & SA_SIGINFO)
693 ps->ps_siginfo |= bit;
694 else
695 ps->ps_siginfo &= ~bit;
696 if ((sa->sa_flags & SA_RESTART) == 0)
697 ps->ps_sigintr |= bit;
698 else
699 ps->ps_sigintr &= ~bit;
700 if (sa->sa_flags & SA_ONSTACK)
701 ps->ps_sigonstack |= bit;
702 else
703 ps->ps_sigonstack &= ~bit;
704 if (sa->sa_flags & SA_RESETHAND)
705 ps->ps_sigreset |= bit;
706 else
707 ps->ps_sigreset &= ~bit;
708 if (sa->sa_flags & SA_NODEFER)
709 ps->ps_signodefer |= bit;
710 else
711 ps->ps_signodefer &= ~bit;
712 if (signum == SIGCHLD) {
713 if (sa->sa_flags & SA_NOCLDSTOP)
714 OSBitOrAtomic(P_NOCLDSTOP, &p->p_flag);
715 else
716 OSBitAndAtomic(~((uint32_t)P_NOCLDSTOP), &p->p_flag);
717 if ((sa->sa_flags & SA_NOCLDWAIT) || (sa->sa_handler == SIG_IGN))
718 OSBitOrAtomic(P_NOCLDWAIT, &p->p_flag);
719 else
720 OSBitAndAtomic(~((uint32_t)P_NOCLDWAIT), &p->p_flag);
721 }
722
723 /*
724 * Set bit in p_sigignore for signals that are set to SIG_IGN,
725 * and for signals set to SIG_DFL where the default is to ignore.
726 * However, don't put SIGCONT in p_sigignore,
727 * as we have to restart the process.
728 */
729 if (sa->sa_handler == SIG_IGN ||
730 (sigprop[signum] & SA_IGNORE && sa->sa_handler == SIG_DFL)) {
731
732 clear_procsiglist(p, bit, in_sigstart);
733 if (signum != SIGCONT)
734 p->p_sigignore |= bit; /* easier in psignal */
735 p->p_sigcatch &= ~bit;
736 } else {
737 p->p_sigignore &= ~bit;
738 if (sa->sa_handler == SIG_DFL)
739 p->p_sigcatch &= ~bit;
740 else
741 p->p_sigcatch |= bit;
742 }
743 return(0);
744}
745
746/*
747 * Initialize signal state for process 0;
748 * set to ignore signals that are ignored by default.
749 */
750void
751siginit(proc_t p)
752{
753 int i;
754
755 for (i = 1; i < NSIG; i++)
756 if (sigprop[i] & SA_IGNORE && i != SIGCONT)
757 p->p_sigignore |= sigmask(i);
758}
759
760/*
761 * Reset signals for an exec of the specified process.
762 */
763void
764execsigs(proc_t p, thread_t thread)
765{
766 struct sigacts *ps = p->p_sigacts;
767 int nc, mask;
768 struct uthread *ut;
769
770 ut = (struct uthread *)get_bsdthread_info(thread);
771
772 /*
773 * transfer saved signal states from the process
774 * back to the current thread.
775 *
776 * NOTE: We do this without the process locked,
777 * because we are guaranteed to be single-threaded
778 * by this point in exec and the p_siglist is
779 * only accessed by threads inside the process.
780 */
781 ut->uu_siglist |= p->p_siglist;
782 p->p_siglist = 0;
783
784 /*
785 * Reset caught signals. Held signals remain held
786 * through p_sigmask (unless they were caught,
787 * and are now ignored by default).
788 */
789 while (p->p_sigcatch) {
790 nc = ffs((long)p->p_sigcatch);
791 mask = sigmask(nc);
792 p->p_sigcatch &= ~mask;
793 if (sigprop[nc] & SA_IGNORE) {
794 if (nc != SIGCONT)
795 p->p_sigignore |= mask;
796 ut->uu_siglist &= ~mask;
797 }
798 ps->ps_sigact[nc] = SIG_DFL;
799 }
800
801 atomic_store_explicit(&ps->ps_sigreturn_validation,
802 PS_SIGRETURN_VALIDATION_DEFAULT, memory_order_relaxed);
803 /* Generate random token value used to validate sigreturn arguments */
804 read_random(&ps->ps_sigreturn_token, sizeof(ps->ps_sigreturn_token));
805
806 /*
807 * Reset stack state to the user stack.
808 * Clear set of signals caught on the signal stack.
809 */
810 /* thread */
811 ut->uu_sigstk.ss_flags = SA_DISABLE;
812 ut->uu_sigstk.ss_size = 0;
813 ut->uu_sigstk.ss_sp = USER_ADDR_NULL;
814 ut->uu_flag &= ~UT_ALTSTACK;
815 /* process */
816 ps->ps_sigonstack = 0;
817}
818
819/*
820 * Manipulate signal mask.
821 * Note that we receive new mask, not pointer,
822 * and return old mask as return value;
823 * the library stub does the rest.
824 */
825int
826sigprocmask(proc_t p, struct sigprocmask_args *uap, __unused int32_t *retval)
827{
828 int error = 0;
829 sigset_t oldmask, nmask;
830 user_addr_t omask = uap->omask;
831 struct uthread *ut;
832
833 ut = (struct uthread *)get_bsdthread_info(current_thread());
834 oldmask = ut->uu_sigmask;
835
836 if (uap->mask == USER_ADDR_NULL) {
837 /* just want old mask */
838 goto out;
839 }
840 error = copyin(uap->mask, &nmask, sizeof(sigset_t));
841 if (error)
842 goto out;
843
844 switch (uap->how) {
845 case SIG_BLOCK:
846 block_procsigmask(p, (nmask & ~sigcantmask));
847 signal_setast(current_thread());
848 break;
849
850 case SIG_UNBLOCK:
851 unblock_procsigmask(p, (nmask & ~sigcantmask));
852 signal_setast(current_thread());
853 break;
854
855 case SIG_SETMASK:
856 set_procsigmask(p, (nmask & ~sigcantmask));
857 signal_setast(current_thread());
858 break;
859
860 default:
861 error = EINVAL;
862 break;
863 }
864out:
865 if (!error && omask != USER_ADDR_NULL)
866 copyout(&oldmask, omask, sizeof(sigset_t));
867 return (error);
868}
869
870int
871sigpending(__unused proc_t p, struct sigpending_args *uap, __unused int32_t *retval)
872{
873 struct uthread *ut;
874 sigset_t pendlist;
875
876 ut = (struct uthread *)get_bsdthread_info(current_thread());
877 pendlist = ut->uu_siglist;
878
879 if (uap->osv)
880 copyout(&pendlist, uap->osv, sizeof(sigset_t));
881 return(0);
882}
883
884/*
885 * Suspend process until signal, providing mask to be set
886 * in the meantime. Note nonstandard calling convention:
887 * libc stub passes mask, not pointer, to save a copyin.
888 */
889
890static int
891sigcontinue(__unused int error)
892{
893// struct uthread *ut = get_bsdthread_info(current_thread());
894 unix_syscall_return(EINTR);
895}
896
897int
898sigsuspend(proc_t p, struct sigsuspend_args *uap, int32_t *retval)
899{
900 __pthread_testcancel(1);
901 return(sigsuspend_nocancel(p, (struct sigsuspend_nocancel_args *)uap, retval));
902}
903
904int
905sigsuspend_nocancel(proc_t p, struct sigsuspend_nocancel_args *uap, __unused int32_t *retval)
906{
907 struct uthread *ut;
908
909 ut = (struct uthread *)get_bsdthread_info(current_thread());
910
911 /*
912 * When returning from sigpause, we want
913 * the old mask to be restored after the
914 * signal handler has finished. Thus, we
915 * save it here and mark the sigacts structure
916 * to indicate this.
917 */
918 ut->uu_oldmask = ut->uu_sigmask;
919 ut->uu_flag |= UT_SAS_OLDMASK;
920 ut->uu_sigmask = (uap->mask & ~sigcantmask);
921 (void) tsleep0((caddr_t) p, PPAUSE|PCATCH, "pause", 0, sigcontinue);
922 /* always return EINTR rather than ERESTART... */
923 return (EINTR);
924}
925
926
927int
928__disable_threadsignal(__unused proc_t p,
929 __unused struct __disable_threadsignal_args *uap,
930 __unused int32_t *retval)
931{
932 struct uthread *uth;
933
934 uth = (struct uthread *)get_bsdthread_info(current_thread());
935
936 /* No longer valid to have any signal delivered */
937 uth->uu_flag |= (UT_NO_SIGMASK | UT_CANCELDISABLE);
938
939 return(0);
940
941}
942
943void
944__pthread_testcancel(int presyscall)
945{
946
947 thread_t self = current_thread();
948 struct uthread * uthread;
949
950 uthread = (struct uthread *)get_bsdthread_info(self);
951
952
953 uthread->uu_flag &= ~UT_NOTCANCELPT;
954
955 if ((uthread->uu_flag & (UT_CANCELDISABLE | UT_CANCEL | UT_CANCELED)) == UT_CANCEL) {
956 if(presyscall != 0) {
957 unix_syscall_return(EINTR);
958 /* NOTREACHED */
959 } else
960 thread_abort_safely(self);
961 }
962}
963
964
965
966int
967__pthread_markcancel(__unused proc_t p,
968 struct __pthread_markcancel_args *uap, __unused int32_t *retval)
969{
970 thread_act_t target_act;
971 int error = 0;
972 struct uthread *uth;
973
974 target_act = (thread_act_t)port_name_to_thread(uap->thread_port);
975
976 if (target_act == THR_ACT_NULL)
977 return (ESRCH);
978
979 uth = (struct uthread *)get_bsdthread_info(target_act);
980
981 /* if the thread is in vfork do not cancel */
982 if ((uth->uu_flag & (UT_VFORK | UT_CANCEL | UT_CANCELED )) == 0) {
983 uth->uu_flag |= (UT_CANCEL | UT_NO_SIGMASK);
984 if (((uth->uu_flag & UT_NOTCANCELPT) == 0)
985 && ((uth->uu_flag & UT_CANCELDISABLE) == 0))
986 thread_abort_safely(target_act);
987 }
988
989 thread_deallocate(target_act);
990 return (error);
991}
992
993/* if action =0 ; return the cancellation state ,
994 * if marked for cancellation, make the thread canceled
995 * if action = 1 ; Enable the cancel handling
996 * if action = 2; Disable the cancel handling
997 */
998int
999__pthread_canceled(__unused proc_t p,
1000 struct __pthread_canceled_args *uap, __unused int32_t *retval)
1001{
1002 thread_act_t thread;
1003 struct uthread *uth;
1004 int action = uap->action;
1005
1006 thread = current_thread();
1007 uth = (struct uthread *)get_bsdthread_info(thread);
1008
1009 switch (action) {
1010 case 1:
1011 uth->uu_flag &= ~UT_CANCELDISABLE;
1012 return(0);
1013 case 2:
1014 uth->uu_flag |= UT_CANCELDISABLE;
1015 return(0);
1016 case 0:
1017 default:
1018 /* if the thread is in vfork do not cancel */
1019 if((uth->uu_flag & ( UT_CANCELDISABLE | UT_CANCEL | UT_CANCELED)) == UT_CANCEL) {
1020 uth->uu_flag &= ~UT_CANCEL;
1021 uth->uu_flag |= (UT_CANCELED | UT_NO_SIGMASK);
1022 return(0);
1023 }
1024 return(EINVAL);
1025 }
1026 return(EINVAL);
1027}
1028
1029__attribute__((noreturn))
1030void
1031__posix_sem_syscall_return(kern_return_t kern_result)
1032{
1033 int error = 0;
1034
1035 if (kern_result == KERN_SUCCESS)
1036 error = 0;
1037 else if (kern_result == KERN_ABORTED)
1038 error = EINTR;
1039 else if (kern_result == KERN_OPERATION_TIMED_OUT)
1040 error = ETIMEDOUT;
1041 else
1042 error = EINVAL;
1043 unix_syscall_return(error);
1044 /* does not return */
1045}
1046
1047#if OLD_SEMWAIT_SIGNAL
1048/*
1049 * Returns: 0 Success
1050 * EINTR
1051 * ETIMEDOUT
1052 * EINVAL
1053 * EFAULT if timespec is NULL
1054 */
1055int
1056__old_semwait_signal(proc_t p, struct __old_semwait_signal_args *uap,
1057 int32_t *retval)
1058{
1059 __pthread_testcancel(0);
1060 return(__old_semwait_signal_nocancel(p, (struct __old_semwait_signal_nocancel_args *)uap, retval));
1061}
1062
1063int
1064__old_semwait_signal_nocancel(proc_t p, struct __old_semwait_signal_nocancel_args *uap,
1065 __unused int32_t *retval)
1066{
1067
1068 kern_return_t kern_result;
1069 int error;
1070 mach_timespec_t then;
1071 struct timespec now;
1072 struct user_timespec ts;
1073 boolean_t truncated_timeout = FALSE;
1074
1075 if(uap->timeout) {
1076
1077 if (IS_64BIT_PROCESS(p)) {
1078 struct user64_timespec ts64;
1079 error = copyin(uap->ts, &ts64, sizeof(ts64));
1080 ts.tv_sec = ts64.tv_sec;
1081 ts.tv_nsec = ts64.tv_nsec;
1082 } else {
1083 struct user32_timespec ts32;
1084 error = copyin(uap->ts, &ts32, sizeof(ts32));
1085 ts.tv_sec = ts32.tv_sec;
1086 ts.tv_nsec = ts32.tv_nsec;
1087 }
1088
1089 if (error) {
1090 return error;
1091 }
1092
1093 if ((ts.tv_sec & 0xFFFFFFFF00000000ULL) != 0) {
1094 ts.tv_sec = 0xFFFFFFFF;
1095 ts.tv_nsec = 0;
1096 truncated_timeout = TRUE;
1097 }
1098
1099 if (uap->relative) {
1100 then.tv_sec = ts.tv_sec;
1101 then.tv_nsec = ts.tv_nsec;
1102 } else {
1103 nanotime(&now);
1104
1105 /* if time has elapsed, set time to null timepsec to bailout rightaway */
1106 if (now.tv_sec == ts.tv_sec ?
1107 now.tv_nsec > ts.tv_nsec :
1108 now.tv_sec > ts.tv_sec) {
1109 then.tv_sec = 0;
1110 then.tv_nsec = 0;
1111 } else {
1112 then.tv_sec = ts.tv_sec - now.tv_sec;
1113 then.tv_nsec = ts.tv_nsec - now.tv_nsec;
1114 if (then.tv_nsec < 0) {
1115 then.tv_nsec += NSEC_PER_SEC;
1116 then.tv_sec--;
1117 }
1118 }
1119 }
1120
1121 if (uap->mutex_sem == 0)
1122 kern_result = semaphore_timedwait_trap_internal((mach_port_name_t)uap->cond_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return);
1123 else
1124 kern_result = semaphore_timedwait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return);
1125
1126 } else {
1127
1128 if (uap->mutex_sem == 0)
1129 kern_result = semaphore_wait_trap_internal(uap->cond_sem, __posix_sem_syscall_return);
1130 else
1131
1132 kern_result = semaphore_wait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, __posix_sem_syscall_return);
1133 }
1134
1135 if (kern_result == KERN_SUCCESS && !truncated_timeout)
1136 return(0);
1137 else if (kern_result == KERN_SUCCESS && truncated_timeout)
1138 return(EINTR); /* simulate an exceptional condition because Mach doesn't support a longer timeout */
1139 else if (kern_result == KERN_ABORTED)
1140 return(EINTR);
1141 else if (kern_result == KERN_OPERATION_TIMED_OUT)
1142 return(ETIMEDOUT);
1143 else
1144 return(EINVAL);
1145}
1146#endif /* OLD_SEMWAIT_SIGNAL*/
1147
1148/*
1149 * Returns: 0 Success
1150 * EINTR
1151 * ETIMEDOUT
1152 * EINVAL
1153 * EFAULT if timespec is NULL
1154 */
1155int
1156__semwait_signal(proc_t p, struct __semwait_signal_args *uap,
1157 int32_t *retval)
1158{
1159 __pthread_testcancel(0);
1160 return(__semwait_signal_nocancel(p, (struct __semwait_signal_nocancel_args *)uap, retval));
1161}
1162
1163int
1164__semwait_signal_nocancel(__unused proc_t p, struct __semwait_signal_nocancel_args *uap,
1165 __unused int32_t *retval)
1166{
1167
1168 kern_return_t kern_result;
1169 mach_timespec_t then;
1170 struct timespec now;
1171 struct user_timespec ts;
1172 boolean_t truncated_timeout = FALSE;
1173
1174 if(uap->timeout) {
1175
1176 ts.tv_sec = uap->tv_sec;
1177 ts.tv_nsec = uap->tv_nsec;
1178
1179 if ((ts.tv_sec & 0xFFFFFFFF00000000ULL) != 0) {
1180 ts.tv_sec = 0xFFFFFFFF;
1181 ts.tv_nsec = 0;
1182 truncated_timeout = TRUE;
1183 }
1184
1185 if (uap->relative) {
1186 then.tv_sec = ts.tv_sec;
1187 then.tv_nsec = ts.tv_nsec;
1188 } else {
1189 nanotime(&now);
1190
1191 /* if time has elapsed, set time to null timepsec to bailout rightaway */
1192 if (now.tv_sec == ts.tv_sec ?
1193 now.tv_nsec > ts.tv_nsec :
1194 now.tv_sec > ts.tv_sec) {
1195 then.tv_sec = 0;
1196 then.tv_nsec = 0;
1197 } else {
1198 then.tv_sec = ts.tv_sec - now.tv_sec;
1199 then.tv_nsec = ts.tv_nsec - now.tv_nsec;
1200 if (then.tv_nsec < 0) {
1201 then.tv_nsec += NSEC_PER_SEC;
1202 then.tv_sec--;
1203 }
1204 }
1205 }
1206
1207 if (uap->mutex_sem == 0)
1208 kern_result = semaphore_timedwait_trap_internal((mach_port_name_t)uap->cond_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return);
1209 else
1210 kern_result = semaphore_timedwait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return);
1211
1212 } else {
1213
1214 if (uap->mutex_sem == 0)
1215 kern_result = semaphore_wait_trap_internal(uap->cond_sem, __posix_sem_syscall_return);
1216 else
1217
1218 kern_result = semaphore_wait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, __posix_sem_syscall_return);
1219 }
1220
1221 if (kern_result == KERN_SUCCESS && !truncated_timeout)
1222 return(0);
1223 else if (kern_result == KERN_SUCCESS && truncated_timeout)
1224 return(EINTR); /* simulate an exceptional condition because Mach doesn't support a longer timeout */
1225 else if (kern_result == KERN_ABORTED)
1226 return(EINTR);
1227 else if (kern_result == KERN_OPERATION_TIMED_OUT)
1228 return(ETIMEDOUT);
1229 else
1230 return(EINVAL);
1231}
1232
1233
1234int
1235__pthread_kill(__unused proc_t p, struct __pthread_kill_args *uap,
1236 __unused int32_t *retval)
1237{
1238 thread_t target_act;
1239 int error = 0;
1240 int signum = uap->sig;
1241 struct uthread *uth;
1242
1243 target_act = (thread_t)port_name_to_thread(uap->thread_port);
1244
1245 if (target_act == THREAD_NULL)
1246 return (ESRCH);
1247 if ((u_int)signum >= NSIG) {
1248 error = EINVAL;
1249 goto out;
1250 }
1251
1252 uth = (struct uthread *)get_bsdthread_info(target_act);
1253
1254 if (uth->uu_flag & UT_NO_SIGMASK) {
1255 error = ESRCH;
1256 goto out;
1257 }
1258
1259 if (signum)
1260 psignal_uthread(target_act, signum);
1261out:
1262 thread_deallocate(target_act);
1263 return (error);
1264}
1265
1266
1267int
1268__pthread_sigmask(__unused proc_t p, struct __pthread_sigmask_args *uap,
1269 __unused int32_t *retval)
1270{
1271 user_addr_t set = uap->set;
1272 user_addr_t oset = uap->oset;
1273 sigset_t nset;
1274 int error = 0;
1275 struct uthread *ut;
1276 sigset_t oldset;
1277
1278 ut = (struct uthread *)get_bsdthread_info(current_thread());
1279 oldset = ut->uu_sigmask;
1280
1281 if (set == USER_ADDR_NULL) {
1282 /* need only old mask */
1283 goto out;
1284 }
1285
1286 error = copyin(set, &nset, sizeof(sigset_t));
1287 if (error)
1288 goto out;
1289
1290 switch (uap->how) {
1291 case SIG_BLOCK:
1292 ut->uu_sigmask |= (nset & ~sigcantmask);
1293 break;
1294
1295 case SIG_UNBLOCK:
1296 ut->uu_sigmask &= ~(nset);
1297 signal_setast(current_thread());
1298 break;
1299
1300 case SIG_SETMASK:
1301 ut->uu_sigmask = (nset & ~sigcantmask);
1302 signal_setast(current_thread());
1303 break;
1304
1305 default:
1306 error = EINVAL;
1307
1308 }
1309out:
1310 if (!error && oset != USER_ADDR_NULL)
1311 copyout(&oldset, oset, sizeof(sigset_t));
1312
1313 return(error);
1314}
1315
1316/*
1317 * Returns: 0 Success
1318 * EINVAL
1319 * copyin:EFAULT
1320 * copyout:EFAULT
1321 */
1322int
1323__sigwait(proc_t p, struct __sigwait_args *uap, int32_t *retval)
1324{
1325 __pthread_testcancel(1);
1326 return(__sigwait_nocancel(p, (struct __sigwait_nocancel_args *)uap, retval));
1327}
1328
1329int
1330__sigwait_nocancel(proc_t p, struct __sigwait_nocancel_args *uap, __unused int32_t *retval)
1331{
1332 struct uthread *ut;
1333 struct uthread *uth;
1334 int error = 0;
1335 sigset_t mask;
1336 sigset_t siglist;
1337 sigset_t sigw=0;
1338 int signum;
1339
1340 ut = (struct uthread *)get_bsdthread_info(current_thread());
1341
1342 if (uap->set == USER_ADDR_NULL)
1343 return(EINVAL);
1344
1345 error = copyin(uap->set, &mask, sizeof(sigset_t));
1346 if (error)
1347 return(error);
1348
1349 siglist = (mask & ~sigcantmask);
1350
1351 if (siglist == 0)
1352 return(EINVAL);
1353
1354 proc_lock(p);
1355 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
1356 proc_unlock(p);
1357 return(EINVAL);
1358 } else {
1359 proc_signalstart(p, 1);
1360 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
1361 if ( (sigw = uth->uu_siglist & siglist) ) {
1362 break;
1363 }
1364 }
1365 proc_signalend(p, 1);
1366 }
1367
1368 if (sigw) {
1369 /* The signal was pending on a thread */
1370 goto sigwait1;
1371 }
1372 /*
1373 * When returning from sigwait, we want
1374 * the old mask to be restored after the
1375 * signal handler has finished. Thus, we
1376 * save it here and mark the sigacts structure
1377 * to indicate this.
1378 */
1379 uth = ut; /* wait for it to be delivered to us */
1380 ut->uu_oldmask = ut->uu_sigmask;
1381 ut->uu_flag |= UT_SAS_OLDMASK;
1382 if (siglist == (sigset_t)0) {
1383 proc_unlock(p);
1384 return(EINVAL);
1385 }
1386 /* SIGKILL and SIGSTOP are not maskable as well */
1387 ut->uu_sigmask = ~(siglist|sigcantmask);
1388 ut->uu_sigwait = siglist;
1389
1390 /* No Continuations for now */
1391 error = msleep((caddr_t)&ut->uu_sigwait, &p->p_mlock, PPAUSE|PCATCH, "pause", 0);
1392
1393 if (error == ERESTART)
1394 error = 0;
1395
1396 sigw = (ut->uu_sigwait & siglist);
1397 ut->uu_sigmask = ut->uu_oldmask;
1398 ut->uu_oldmask = 0;
1399 ut->uu_flag &= ~UT_SAS_OLDMASK;
1400sigwait1:
1401 ut->uu_sigwait = 0;
1402 if (!error) {
1403 signum = ffs((unsigned int)sigw);
1404 if (!signum)
1405 panic("sigwait with no signal wakeup");
1406 /* Clear the pending signal in the thread it was delivered */
1407 uth->uu_siglist &= ~(sigmask(signum));
1408
1409#if CONFIG_DTRACE
1410 DTRACE_PROC2(signal__clear, int, signum, siginfo_t *, &(ut->t_dtrace_siginfo));
1411#endif
1412
1413 proc_unlock(p);
1414 if (uap->sig != USER_ADDR_NULL)
1415 error = copyout(&signum, uap->sig, sizeof(int));
1416 } else
1417 proc_unlock(p);
1418
1419 return(error);
1420
1421}
1422
1423int
1424sigaltstack(__unused proc_t p, struct sigaltstack_args *uap, __unused int32_t *retval)
1425{
1426 struct kern_sigaltstack ss;
1427 struct kern_sigaltstack *pstk;
1428 int error;
1429 struct uthread *uth;
1430 int onstack;
1431
1432 uth = (struct uthread *)get_bsdthread_info(current_thread());
1433
1434 pstk = &uth->uu_sigstk;
1435 if ((uth->uu_flag & UT_ALTSTACK) == 0)
1436 uth->uu_sigstk.ss_flags |= SA_DISABLE;
1437 onstack = pstk->ss_flags & SA_ONSTACK;
1438 if (uap->oss) {
1439 if (IS_64BIT_PROCESS(p)) {
1440 struct user64_sigaltstack ss64 = {};
1441 sigaltstack_kern_to_user64(pstk, &ss64);
1442 error = copyout(&ss64, uap->oss, sizeof(ss64));
1443 } else {
1444 struct user32_sigaltstack ss32 = {};
1445 sigaltstack_kern_to_user32(pstk, &ss32);
1446 error = copyout(&ss32, uap->oss, sizeof(ss32));
1447 }
1448 if (error)
1449 return (error);
1450 }
1451 if (uap->nss == USER_ADDR_NULL)
1452 return (0);
1453 if (IS_64BIT_PROCESS(p)) {
1454 struct user64_sigaltstack ss64;
1455 error = copyin(uap->nss, &ss64, sizeof(ss64));
1456 sigaltstack_user64_to_kern(&ss64, &ss);
1457 } else {
1458 struct user32_sigaltstack ss32;
1459 error = copyin(uap->nss, &ss32, sizeof(ss32));
1460 sigaltstack_user32_to_kern(&ss32, &ss);
1461 }
1462 if (error)
1463 return (error);
1464 if ((ss.ss_flags & ~SA_DISABLE) != 0) {
1465 return(EINVAL);
1466 }
1467
1468 if (ss.ss_flags & SA_DISABLE) {
1469 /* if we are here we are not in the signal handler ;so no need to check */
1470 if (uth->uu_sigstk.ss_flags & SA_ONSTACK)
1471 return (EINVAL);
1472 uth->uu_flag &= ~UT_ALTSTACK;
1473 uth->uu_sigstk.ss_flags = ss.ss_flags;
1474 return (0);
1475 }
1476 if (onstack)
1477 return (EPERM);
1478/* The older stacksize was 8K, enforce that one so no compat problems */
1479#define OLDMINSIGSTKSZ 8*1024
1480 if (ss.ss_size < OLDMINSIGSTKSZ)
1481 return (ENOMEM);
1482 uth->uu_flag |= UT_ALTSTACK;
1483 uth->uu_sigstk= ss;
1484 return (0);
1485}
1486
1487int
1488kill(proc_t cp, struct kill_args *uap, __unused int32_t *retval)
1489{
1490 proc_t p;
1491 kauth_cred_t uc = kauth_cred_get();
1492 int posix = uap->posix; /* !0 if posix behaviour desired */
1493
1494 AUDIT_ARG(pid, uap->pid);
1495 AUDIT_ARG(signum, uap->signum);
1496
1497 if ((u_int)uap->signum >= NSIG)
1498 return (EINVAL);
1499 if (uap->pid > 0) {
1500 /* kill single process */
1501 if ((p = proc_find(uap->pid)) == NULL) {
1502 if ((p = pzfind(uap->pid)) != NULL) {
1503 /*
1504 * POSIX 1003.1-2001 requires returning success when killing a
1505 * zombie; see Rationale for kill(2).
1506 */
1507 return (0);
1508 }
1509 return (ESRCH);
1510 }
1511 AUDIT_ARG(process, p);
1512 if (!cansignal(cp, uc, p, uap->signum)) {
1513 proc_rele(p);
1514 return(EPERM);
1515 }
1516 if (uap->signum)
1517 psignal(p, uap->signum);
1518 proc_rele(p);
1519 return (0);
1520 }
1521 switch (uap->pid) {
1522 case -1: /* broadcast signal */
1523 return (killpg1(cp, uap->signum, 0, 1, posix));
1524 case 0: /* signal own process group */
1525 return (killpg1(cp, uap->signum, 0, 0, posix));
1526 default: /* negative explicit process group */
1527 return (killpg1(cp, uap->signum, -(uap->pid), 0, posix));
1528 }
1529 /* NOTREACHED */
1530}
1531
1532os_reason_t
1533build_userspace_exit_reason(uint32_t reason_namespace, uint64_t reason_code, user_addr_t payload, uint32_t payload_size,
1534 user_addr_t reason_string, uint64_t reason_flags)
1535{
1536 os_reason_t exit_reason = OS_REASON_NULL;
1537
1538 int error = 0;
1539 int num_items_to_copy = 0;
1540 uint32_t user_data_to_copy = 0;
1541 char *reason_user_desc = NULL;
1542 size_t reason_user_desc_len = 0;
1543
1544 exit_reason = os_reason_create(reason_namespace, reason_code);
1545 if (exit_reason == OS_REASON_NULL) {
1546 printf("build_userspace_exit_reason: failed to allocate exit reason\n");
1547 return exit_reason;
1548 }
1549
1550 exit_reason->osr_flags |= OS_REASON_FLAG_FROM_USERSPACE;
1551
1552 /*
1553 * Only apply flags that are allowed to be passed from userspace.
1554 */
1555 exit_reason->osr_flags |= (reason_flags & OS_REASON_FLAG_MASK_ALLOWED_FROM_USER);
1556 if ((reason_flags & OS_REASON_FLAG_MASK_ALLOWED_FROM_USER) != reason_flags) {
1557 printf("build_userspace_exit_reason: illegal flags passed from userspace (some masked off) 0x%llx, ns: %u, code 0x%llx\n",
1558 reason_flags, reason_namespace, reason_code);
1559 }
1560
1561 if (!(exit_reason->osr_flags & OS_REASON_FLAG_NO_CRASH_REPORT)) {
1562 exit_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1563 }
1564
1565 if (payload != USER_ADDR_NULL) {
1566 if (payload_size == 0) {
1567 printf("build_userspace_exit_reason: exit reason with namespace %u, nonzero payload but zero length\n",
1568 reason_namespace);
1569 exit_reason->osr_flags |= OS_REASON_FLAG_BAD_PARAMS;
1570 payload = USER_ADDR_NULL;
1571 } else {
1572 num_items_to_copy++;
1573
1574 if (payload_size > EXIT_REASON_PAYLOAD_MAX_LEN) {
1575 exit_reason->osr_flags |= OS_REASON_FLAG_PAYLOAD_TRUNCATED;
1576 payload_size = EXIT_REASON_PAYLOAD_MAX_LEN;
1577 }
1578
1579 user_data_to_copy += payload_size;
1580 }
1581 }
1582
1583 if (reason_string != USER_ADDR_NULL) {
1584 reason_user_desc = (char *) kalloc(EXIT_REASON_USER_DESC_MAX_LEN);
1585
1586 if (reason_user_desc != NULL) {
1587 error = copyinstr(reason_string, (void *) reason_user_desc,
1588 EXIT_REASON_USER_DESC_MAX_LEN, &reason_user_desc_len);
1589
1590 if (error == 0) {
1591 num_items_to_copy++;
1592 user_data_to_copy += reason_user_desc_len;
1593 } else if (error == ENAMETOOLONG) {
1594 num_items_to_copy++;
1595 reason_user_desc[EXIT_REASON_USER_DESC_MAX_LEN - 1] = '\0';
1596 user_data_to_copy += reason_user_desc_len;
1597 } else {
1598 exit_reason->osr_flags |= OS_REASON_FLAG_FAILED_DATA_COPYIN;
1599 kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN);
1600 reason_user_desc = NULL;
1601 reason_user_desc_len = 0;
1602 }
1603 }
1604 }
1605
1606 if (num_items_to_copy != 0) {
1607 uint32_t reason_buffer_size_estimate = 0;
1608 mach_vm_address_t data_addr = 0;
1609
1610 reason_buffer_size_estimate = kcdata_estimate_required_buffer_size(num_items_to_copy, user_data_to_copy);
1611
1612 error = os_reason_alloc_buffer(exit_reason, reason_buffer_size_estimate);
1613 if (error != 0) {
1614 printf("build_userspace_exit_reason: failed to allocate signal reason buffer\n");
1615 goto out_failed_copyin;
1616 }
1617
1618 if (reason_user_desc != NULL && reason_user_desc_len != 0) {
1619 if (KERN_SUCCESS == kcdata_get_memory_addr(&exit_reason->osr_kcd_descriptor,
1620 EXIT_REASON_USER_DESC,
1621 reason_user_desc_len,
1622 &data_addr)) {
1623
1624 kcdata_memcpy(&exit_reason->osr_kcd_descriptor, (mach_vm_address_t) data_addr,
1625 reason_user_desc, reason_user_desc_len);
1626 } else {
1627 printf("build_userspace_exit_reason: failed to allocate space for reason string\n");
1628 goto out_failed_copyin;
1629 }
1630 }
1631
1632 if (payload != USER_ADDR_NULL) {
1633 if (KERN_SUCCESS ==
1634 kcdata_get_memory_addr(&exit_reason->osr_kcd_descriptor,
1635 EXIT_REASON_USER_PAYLOAD,
1636 payload_size,
1637 &data_addr)) {
1638 error = copyin(payload, (void *) data_addr, payload_size);
1639 if (error) {
1640 printf("build_userspace_exit_reason: failed to copy in payload data with error %d\n", error);
1641 goto out_failed_copyin;
1642 }
1643 } else {
1644 printf("build_userspace_exit_reason: failed to allocate space for payload data\n");
1645 goto out_failed_copyin;
1646 }
1647 }
1648 }
1649
1650 if (reason_user_desc != NULL) {
1651 kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN);
1652 reason_user_desc = NULL;
1653 reason_user_desc_len = 0;
1654 }
1655
1656 return exit_reason;
1657
1658out_failed_copyin:
1659
1660 if (reason_user_desc != NULL) {
1661 kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN);
1662 reason_user_desc = NULL;
1663 reason_user_desc_len = 0;
1664 }
1665
1666 exit_reason->osr_flags |= OS_REASON_FLAG_FAILED_DATA_COPYIN;
1667 os_reason_alloc_buffer(exit_reason, 0);
1668 return exit_reason;
1669}
1670
1671static int
1672terminate_with_payload_internal(struct proc *cur_proc, int target_pid, uint32_t reason_namespace,
1673 uint64_t reason_code, user_addr_t payload, uint32_t payload_size,
1674 user_addr_t reason_string, uint64_t reason_flags)
1675{
1676 proc_t target_proc = PROC_NULL;
1677 kauth_cred_t cur_cred = kauth_cred_get();
1678
1679 os_reason_t signal_reason = OS_REASON_NULL;
1680
1681 AUDIT_ARG(pid, target_pid);
1682 if ((target_pid <= 0)) {
1683 return EINVAL;
1684 }
1685
1686 target_proc = proc_find(target_pid);
1687 if (target_proc == PROC_NULL) {
1688 return ESRCH;
1689 }
1690
1691 AUDIT_ARG(process, target_proc);
1692
1693 if (!cansignal(cur_proc, cur_cred, target_proc, SIGKILL)) {
1694 proc_rele(target_proc);
1695 return EPERM;
1696 }
1697
1698 if (target_pid != cur_proc->p_pid) {
1699 /*
1700 * FLAG_ABORT should only be set on terminate_with_reason(getpid()) that
1701 * was a fallback from an unsuccessful abort_with_reason(). In that case
1702 * caller's pid matches the target one. Otherwise remove the flag.
1703 */
1704 reason_flags &= ~((typeof(reason_flags))OS_REASON_FLAG_ABORT);
1705 }
1706
1707 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1708 target_proc->p_pid, reason_namespace,
1709 reason_code, 0, 0);
1710
1711 signal_reason = build_userspace_exit_reason(reason_namespace, reason_code, payload, payload_size,
1712 reason_string, (reason_flags | OS_REASON_FLAG_NO_CRASHED_TID));
1713
1714 if (target_pid == cur_proc->p_pid) {
1715 /*
1716 * psignal_thread_with_reason() will pend a SIGKILL on the specified thread or
1717 * return if the thread and/or task are already terminating. Either way, the
1718 * current thread won't return to userspace.
1719 */
1720 psignal_thread_with_reason(target_proc, current_thread(), SIGKILL, signal_reason);
1721 } else {
1722 psignal_with_reason(target_proc, SIGKILL, signal_reason);
1723 }
1724
1725 proc_rele(target_proc);
1726
1727 return 0;
1728}
1729
1730int
1731terminate_with_payload(struct proc *cur_proc, struct terminate_with_payload_args *args,
1732 __unused int32_t *retval)
1733{
1734 return terminate_with_payload_internal(cur_proc, args->pid, args->reason_namespace, args->reason_code, args->payload,
1735 args->payload_size, args->reason_string, args->reason_flags);
1736}
1737
1738static int
1739killpg1_allfilt(proc_t p, void * arg)
1740{
1741 struct killpg1_filtargs * kfargp = (struct killpg1_filtargs *)arg;
1742
1743 /*
1744 * Don't signal initproc, a system process, or the current process if POSIX
1745 * isn't specified.
1746 */
1747 return (p->p_pid > 1 && !(p->p_flag & P_SYSTEM) &&
1748 (kfargp->posix ? true : p != kfargp->curproc));
1749}
1750
1751static int
1752killpg1_pgrpfilt(proc_t p, __unused void * arg)
1753{
1754 /* XXX shouldn't this allow signalling zombies? */
1755 return (p->p_pid > 1 && !(p->p_flag & P_SYSTEM) && p->p_stat != SZOMB);
1756}
1757
1758static int
1759killpg1_callback(proc_t p, void *arg)
1760{
1761 struct killpg1_iterargs *kargp = (struct killpg1_iterargs *)arg;
1762 int signum = kargp->signum;
1763
1764 if ((p->p_listflag & P_LIST_EXITED) == P_LIST_EXITED) {
1765 /*
1766 * Count zombies as found for the purposes of signalling, since POSIX
1767 * 1003.1-2001 sees signalling zombies as successful. If killpg(2) or
1768 * kill(2) with pid -1 only finds zombies that can be signalled, it
1769 * shouldn't return ESRCH. See the Rationale for kill(2).
1770 *
1771 * Don't call into MAC -- it's not expecting signal checks for exited
1772 * processes.
1773 */
1774 if (cansignal_nomac(kargp->curproc, kargp->uc, p, signum)) {
1775 kargp->nfound++;
1776 }
1777 } else if (cansignal(kargp->curproc, kargp->uc, p, signum)) {
1778 kargp->nfound++;
1779
1780 if (signum != 0) {
1781 psignal(p, signum);
1782 }
1783 }
1784
1785 return PROC_RETURNED;
1786}
1787
1788/*
1789 * Common code for kill process group/broadcast kill.
1790 */
1791int
1792killpg1(proc_t curproc, int signum, int pgid, int all, int posix)
1793{
1794 kauth_cred_t uc;
1795 struct pgrp *pgrp;
1796 int error = 0;
1797
1798 uc = kauth_cred_proc_ref(curproc);
1799 struct killpg1_iterargs karg = {
1800 .curproc = curproc, .uc = uc, .nfound = 0, .signum = signum
1801 };
1802
1803 if (all) {
1804 /*
1805 * Broadcast to all processes that the user can signal (pid was -1).
1806 */
1807 struct killpg1_filtargs kfarg = {
1808 .posix = posix, .curproc = curproc
1809 };
1810 proc_iterate(PROC_ALLPROCLIST | PROC_ZOMBPROCLIST, killpg1_callback,
1811 &karg, killpg1_allfilt, &kfarg);
1812 } else {
1813 if (pgid == 0) {
1814 /*
1815 * Send to current the current process' process group.
1816 */
1817 pgrp = proc_pgrp(curproc);
1818 } else {
1819 pgrp = pgfind(pgid);
1820 if (pgrp == NULL) {
1821 error = ESRCH;
1822 goto out;
1823 }
1824 }
1825
1826 /* PGRP_DROPREF drops the pgrp refernce */
1827 pgrp_iterate(pgrp, PGRP_DROPREF, killpg1_callback, &karg,
1828 killpg1_pgrpfilt, NULL);
1829 }
1830 error = (karg.nfound > 0 ? 0 : (posix ? EPERM : ESRCH));
1831out:
1832 kauth_cred_unref(&uc);
1833 return (error);
1834}
1835
1836/*
1837 * Send a signal to a process group.
1838 */
1839void
1840gsignal(int pgid, int signum)
1841{
1842 struct pgrp *pgrp;
1843
1844 if (pgid && (pgrp = pgfind(pgid))) {
1845 pgsignal(pgrp, signum, 0);
1846 pg_rele(pgrp);
1847 }
1848}
1849
1850/*
1851 * Send a signal to a process group. If checkctty is 1,
1852 * limit to members which have a controlling terminal.
1853 */
1854
1855static int
1856pgsignal_filt(proc_t p, void * arg)
1857{
1858 int checkctty = *(int*)arg;
1859
1860 if ((checkctty == 0) || p->p_flag & P_CONTROLT)
1861 return(1);
1862 else
1863 return(0);
1864}
1865
1866
1867static int
1868pgsignal_callback(proc_t p, void * arg)
1869{
1870 int signum = *(int*)arg;
1871
1872 psignal(p, signum);
1873 return(PROC_RETURNED);
1874}
1875
1876
1877void
1878pgsignal(struct pgrp *pgrp, int signum, int checkctty)
1879{
1880 if (pgrp != PGRP_NULL) {
1881 pgrp_iterate(pgrp, 0, pgsignal_callback, &signum, pgsignal_filt, &checkctty);
1882 }
1883}
1884
1885
1886void
1887tty_pgsignal(struct tty *tp, int signum, int checkctty)
1888{
1889 struct pgrp * pg;
1890
1891 pg = tty_pgrp(tp);
1892 if (pg != PGRP_NULL) {
1893 pgrp_iterate(pg, 0, pgsignal_callback, &signum, pgsignal_filt, &checkctty);
1894 pg_rele(pg);
1895 }
1896}
1897/*
1898 * Send a signal caused by a trap to a specific thread.
1899 */
1900void
1901threadsignal(thread_t sig_actthread, int signum, mach_exception_code_t code, boolean_t set_exitreason)
1902{
1903 struct uthread *uth;
1904 struct task * sig_task;
1905 proc_t p;
1906 int mask;
1907
1908 if ((u_int)signum >= NSIG || signum == 0)
1909 return;
1910
1911 mask = sigmask(signum);
1912 if ((mask & threadmask) == 0)
1913 return;
1914 sig_task = get_threadtask(sig_actthread);
1915 p = (proc_t)(get_bsdtask_info(sig_task));
1916
1917 uth = get_bsdthread_info(sig_actthread);
1918 if (uth->uu_flag & UT_VFORK)
1919 p = uth->uu_proc;
1920
1921 proc_lock(p);
1922 if (!(p->p_lflag & P_LTRACED) && (p->p_sigignore & mask)) {
1923 proc_unlock(p);
1924 return;
1925 }
1926
1927 uth->uu_siglist |= mask;
1928 uth->uu_code = code;
1929
1930 /* Attempt to establish whether the signal will be fatal (mirrors logic in psignal_internal()) */
1931 if (set_exitreason && ((p->p_lflag & P_LTRACED) || (!(uth->uu_sigwait & mask)
1932 && !(uth->uu_sigmask & mask) && !(p->p_sigcatch & mask))) &&
1933 !(mask & stopsigmask) && !(mask & contsigmask)) {
1934
1935 if (uth->uu_exit_reason == OS_REASON_NULL) {
1936 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1937 p->p_pid, OS_REASON_SIGNAL, signum, 0, 0);
1938
1939 os_reason_t signal_reason = build_signal_reason(signum, "exc handler");
1940
1941 set_thread_exit_reason(sig_actthread, signal_reason, TRUE);
1942
1943 /* We dropped/consumed the reference in set_thread_exit_reason() */
1944 signal_reason = OS_REASON_NULL;
1945 }
1946 }
1947
1948 proc_unlock(p);
1949
1950 /* mark on process as well */
1951 signal_setast(sig_actthread);
1952}
1953
1954void
1955set_thread_exit_reason(void *th, void *reason, boolean_t proc_locked)
1956{
1957 struct uthread *targ_uth = get_bsdthread_info(th);
1958 struct task *targ_task = NULL;
1959 proc_t targ_proc = NULL;
1960
1961 os_reason_t exit_reason = (os_reason_t)reason;
1962
1963 if (exit_reason == OS_REASON_NULL)
1964 return;
1965
1966 if (!proc_locked) {
1967 targ_task = get_threadtask(th);
1968 targ_proc = (proc_t)(get_bsdtask_info(targ_task));
1969
1970 proc_lock(targ_proc);
1971 }
1972
1973 if (targ_uth->uu_exit_reason == OS_REASON_NULL) {
1974 targ_uth->uu_exit_reason = exit_reason;
1975 } else {
1976 /* The caller expects that we drop a reference on the exit reason */
1977 os_reason_free(exit_reason);
1978 }
1979
1980 if (!proc_locked) {
1981 assert(targ_proc != NULL);
1982 proc_unlock(targ_proc);
1983 }
1984}
1985
1986/*
1987 * get_signalthread
1988 *
1989 * Picks an appropriate thread from a process to target with a signal.
1990 *
1991 * Called with proc locked.
1992 * Returns thread with BSD ast set.
1993 *
1994 * We attempt to deliver a proc-wide signal to the first thread in the task.
1995 * This allows single threaded applications which use signals to
1996 * be able to be linked with multithreaded libraries.
1997 */
1998static kern_return_t
1999get_signalthread(proc_t p, int signum, thread_t * thr)
2000{
2001 struct uthread *uth;
2002 sigset_t mask = sigmask(signum);
2003 thread_t sig_thread;
2004 struct task * sig_task = p->task;
2005 kern_return_t kret;
2006
2007 *thr = THREAD_NULL;
2008
2009 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
2010 sig_thread = p->p_vforkact;
2011 kret = check_actforsig(sig_task, sig_thread, 1);
2012 if (kret == KERN_SUCCESS) {
2013 *thr = sig_thread;
2014 return(KERN_SUCCESS);
2015 }else
2016 return(KERN_FAILURE);
2017 }
2018
2019 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
2020 if(((uth->uu_flag & UT_NO_SIGMASK)== 0) &&
2021 (((uth->uu_sigmask & mask) == 0) || (uth->uu_sigwait & mask))) {
2022 if (check_actforsig(p->task, uth->uu_context.vc_thread, 1) == KERN_SUCCESS) {
2023 *thr = uth->uu_context.vc_thread;
2024 return(KERN_SUCCESS);
2025 }
2026 }
2027 }
2028 if (get_signalact(p->task, thr, 1) == KERN_SUCCESS) {
2029 return(KERN_SUCCESS);
2030 }
2031
2032 return(KERN_FAILURE);
2033}
2034
2035static os_reason_t
2036build_signal_reason(int signum, const char *procname)
2037{
2038 os_reason_t signal_reason = OS_REASON_NULL;
2039 proc_t sender_proc = current_proc();
2040 uint32_t reason_buffer_size_estimate = 0, proc_name_length = 0;
2041 const char *default_sender_procname = "unknown";
2042 mach_vm_address_t data_addr;
2043 int ret;
2044
2045 signal_reason = os_reason_create(OS_REASON_SIGNAL, signum);
2046 if (signal_reason == OS_REASON_NULL) {
2047 printf("build_signal_reason: unable to allocate signal reason structure.\n");
2048 return signal_reason;
2049 }
2050
2051 reason_buffer_size_estimate = kcdata_estimate_required_buffer_size(2, sizeof(sender_proc->p_name) +
2052 sizeof(sender_proc->p_pid));
2053
2054 ret = os_reason_alloc_buffer_noblock(signal_reason, reason_buffer_size_estimate);
2055 if (ret != 0) {
2056 printf("build_signal_reason: unable to allocate signal reason buffer.\n");
2057 return signal_reason;
2058 }
2059
2060 if (KERN_SUCCESS == kcdata_get_memory_addr(&signal_reason->osr_kcd_descriptor, KCDATA_TYPE_PID,
2061 sizeof(sender_proc->p_pid), &data_addr)) {
2062 kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, &sender_proc->p_pid,
2063 sizeof(sender_proc->p_pid));
2064 } else {
2065 printf("build_signal_reason: exceeded space in signal reason buf, unable to log PID\n");
2066 }
2067
2068 proc_name_length = sizeof(sender_proc->p_name);
2069 if (KERN_SUCCESS == kcdata_get_memory_addr(&signal_reason->osr_kcd_descriptor, KCDATA_TYPE_PROCNAME,
2070 proc_name_length, &data_addr)) {
2071 if (procname) {
2072 char truncated_procname[proc_name_length];
2073 strncpy((char *) &truncated_procname, procname, proc_name_length);
2074 truncated_procname[proc_name_length - 1] = '\0';
2075
2076 kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, truncated_procname,
2077 strlen((char *) &truncated_procname));
2078 } else if (*sender_proc->p_name) {
2079 kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, &sender_proc->p_name,
2080 sizeof(sender_proc->p_name));
2081 } else {
2082 kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, &default_sender_procname,
2083 strlen(default_sender_procname) + 1);
2084 }
2085 } else {
2086 printf("build_signal_reason: exceeded space in signal reason buf, unable to log procname\n");
2087 }
2088
2089 return signal_reason;
2090}
2091
2092/*
2093 * Send the signal to the process. If the signal has an action, the action
2094 * is usually performed by the target process rather than the caller; we add
2095 * the signal to the set of pending signals for the process.
2096 *
2097 * Always drops a reference on a signal_reason if one is provided, whether via
2098 * passing it to a thread or deallocating directly.
2099 *
2100 * Exceptions:
2101 * o When a stop signal is sent to a sleeping process that takes the
2102 * default action, the process is stopped without awakening it.
2103 * o SIGCONT restarts stopped processes (or puts them back to sleep)
2104 * regardless of the signal action (eg, blocked or ignored).
2105 *
2106 * Other ignored signals are discarded immediately.
2107 */
2108static void
2109psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum, os_reason_t signal_reason)
2110{
2111 int prop;
2112 user_addr_t action = USER_ADDR_NULL;
2113 proc_t sig_proc;
2114 thread_t sig_thread;
2115 task_t sig_task;
2116 int mask;
2117 struct uthread *uth;
2118 kern_return_t kret;
2119 uid_t r_uid;
2120 proc_t pp;
2121 kauth_cred_t my_cred;
2122 char *launchd_exit_reason_desc = NULL;
2123 boolean_t update_thread_policy = FALSE;
2124
2125 if ((u_int)signum >= NSIG || signum == 0)
2126 panic("psignal: bad signal number %d", signum);
2127
2128 mask = sigmask(signum);
2129 prop = sigprop[signum];
2130
2131#if SIGNAL_DEBUG
2132 if(rdebug_proc && (p != PROC_NULL) && (p == rdebug_proc)) {
2133 ram_printf(3);
2134 }
2135#endif /* SIGNAL_DEBUG */
2136
2137 /* catch unexpected initproc kills early for easier debuggging */
2138 if (signum == SIGKILL && p == initproc) {
2139 if (signal_reason == NULL) {
2140 panic_plain("unexpected SIGKILL of %s %s (no reason provided)",
2141 (p->p_name[0] != '\0' ? p->p_name : "initproc"),
2142 ((p->p_csflags & CS_KILLED) ? "(CS_KILLED)" : ""));
2143 } else {
2144 launchd_exit_reason_desc = launchd_exit_reason_get_string_desc(signal_reason);
2145 panic_plain("unexpected SIGKILL of %s %s with reason -- namespace %d code 0x%llx description %." LAUNCHD_PANIC_REASON_STRING_MAXLEN "s",
2146 (p->p_name[0] != '\0' ? p->p_name : "initproc"),
2147 ((p->p_csflags & CS_KILLED) ? "(CS_KILLED)" : ""),
2148 signal_reason->osr_namespace, signal_reason->osr_code,
2149 launchd_exit_reason_desc ? launchd_exit_reason_desc : "none");
2150 }
2151 }
2152
2153 /*
2154 * We will need the task pointer later. Grab it now to
2155 * check for a zombie process. Also don't send signals
2156 * to kernel internal tasks.
2157 */
2158 if (flavor & PSIG_VFORK) {
2159 sig_task = task;
2160 sig_thread = thread;
2161 sig_proc = p;
2162 } else if (flavor & PSIG_THREAD) {
2163 sig_task = get_threadtask(thread);
2164 sig_thread = thread;
2165 sig_proc = (proc_t)get_bsdtask_info(sig_task);
2166 } else if (flavor & PSIG_TRY_THREAD) {
2167 assert((thread == current_thread()) && (p == current_proc()));
2168 sig_task = p->task;
2169 sig_thread = thread;
2170 sig_proc = p;
2171 } else {
2172 sig_task = p->task;
2173 sig_thread = THREAD_NULL;
2174 sig_proc = p;
2175 }
2176
2177 if ((sig_task == TASK_NULL) || is_kerneltask(sig_task)) {
2178 os_reason_free(signal_reason);
2179 return;
2180 }
2181
2182 /*
2183 * do not send signals to the process that has the thread
2184 * doing a reboot(). Not doing so will mark that thread aborted
2185 * and can cause IO failures wich will cause data loss. There's
2186 * also no need to send a signal to a process that is in the middle
2187 * of being torn down.
2188 */
2189 if (ISSET(sig_proc->p_flag, P_REBOOT) || ISSET(sig_proc->p_lflag, P_LEXIT)) {
2190 DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum);
2191 os_reason_free(signal_reason);
2192 return;
2193 }
2194
2195 if( (flavor & (PSIG_VFORK | PSIG_THREAD)) == 0) {
2196 proc_knote(sig_proc, NOTE_SIGNAL | signum);
2197 }
2198
2199 if ((flavor & PSIG_LOCKED)== 0)
2200 proc_signalstart(sig_proc, 0);
2201
2202 /* Don't send signals to a process that has ignored them. */
2203 if (((flavor & PSIG_VFORK) == 0) && ((sig_proc->p_lflag & P_LTRACED) == 0) && (sig_proc->p_sigignore & mask)) {
2204 DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum);
2205 goto sigout_unlocked;
2206 }
2207
2208 /*
2209 * The proc_lock prevents the targeted thread from being deallocated
2210 * or handling the signal until we're done signaling it.
2211 *
2212 * Once the proc_lock is dropped, we have no guarantee the thread or uthread exists anymore.
2213 *
2214 * XXX: What if the thread goes inactive after the thread passes bsd ast point?
2215 */
2216 proc_lock(sig_proc);
2217
2218 if (flavor & PSIG_VFORK) {
2219 action = SIG_DFL;
2220 act_set_astbsd(sig_thread);
2221 kret = KERN_SUCCESS;
2222 } else if (flavor & PSIG_TRY_THREAD) {
2223 uth = get_bsdthread_info(sig_thread);
2224 if (((uth->uu_flag & UT_NO_SIGMASK) == 0) &&
2225 (((uth->uu_sigmask & mask) == 0) || (uth->uu_sigwait & mask)) &&
2226 ((kret = check_actforsig(sig_proc->task, sig_thread, 1)) == KERN_SUCCESS)) {
2227 /* deliver to specified thread */
2228 } else {
2229 /* deliver to any willing thread */
2230 kret = get_signalthread(sig_proc, signum, &sig_thread);
2231 }
2232 } else if (flavor & PSIG_THREAD) {
2233 /* If successful return with ast set */
2234 kret = check_actforsig(sig_task, sig_thread, 1);
2235 } else {
2236 /* If successful return with ast set */
2237 kret = get_signalthread(sig_proc, signum, &sig_thread);
2238 }
2239
2240 if (kret != KERN_SUCCESS) {
2241 DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum);
2242 proc_unlock(sig_proc);
2243 goto sigout_unlocked;
2244 }
2245
2246 uth = get_bsdthread_info(sig_thread);
2247
2248 /*
2249 * If proc is traced, always give parent a chance.
2250 */
2251
2252 if ((flavor & PSIG_VFORK) == 0) {
2253 if (sig_proc->p_lflag & P_LTRACED)
2254 action = SIG_DFL;
2255 else {
2256 /*
2257 * If the signal is being ignored,
2258 * then we forget about it immediately.
2259 * (Note: we don't set SIGCONT in p_sigignore,
2260 * and if it is set to SIG_IGN,
2261 * action will be SIG_DFL here.)
2262 */
2263 if (sig_proc->p_sigignore & mask)
2264 goto sigout_locked;
2265
2266 if (uth->uu_sigwait & mask)
2267 action = KERN_SIG_WAIT;
2268 else if (uth->uu_sigmask & mask)
2269 action = KERN_SIG_HOLD;
2270 else if (sig_proc->p_sigcatch & mask)
2271 action = KERN_SIG_CATCH;
2272 else
2273 action = SIG_DFL;
2274 }
2275 }
2276
2277 /* TODO: p_nice isn't hooked up to the scheduler... */
2278 if (sig_proc->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
2279 (sig_proc->p_lflag & P_LTRACED) == 0)
2280 sig_proc->p_nice = NZERO;
2281
2282 if (prop & SA_CONT)
2283 uth->uu_siglist &= ~stopsigmask;
2284
2285 if (prop & SA_STOP) {
2286 struct pgrp *pg;
2287 /*
2288 * If sending a tty stop signal to a member of an orphaned
2289 * process group, discard the signal here if the action
2290 * is default; don't stop the process below if sleeping,
2291 * and don't clear any pending SIGCONT.
2292 */
2293 pg = proc_pgrp(sig_proc);
2294 if (prop & SA_TTYSTOP && pg->pg_jobc == 0 &&
2295 action == SIG_DFL) {
2296 pg_rele(pg);
2297 goto sigout_locked;
2298 }
2299 pg_rele(pg);
2300 uth->uu_siglist &= ~contsigmask;
2301 }
2302
2303 uth->uu_siglist |= mask;
2304
2305 /*
2306 * Defer further processing for signals which are held,
2307 * except that stopped processes must be continued by SIGCONT.
2308 */
2309 /* vfork will not go thru as action is SIG_DFL */
2310 if ((action == KERN_SIG_HOLD) && ((prop & SA_CONT) == 0 || sig_proc->p_stat != SSTOP))
2311 goto sigout_locked;
2312
2313 /*
2314 * SIGKILL priority twiddling moved here from above because
2315 * it needs sig_thread. Could merge it into large switch
2316 * below if we didn't care about priority for tracing
2317 * as SIGKILL's action is always SIG_DFL.
2318 *
2319 * TODO: p_nice isn't hooked up to the scheduler...
2320 */
2321 if ((signum == SIGKILL) && (sig_proc->p_nice > NZERO)) {
2322 sig_proc->p_nice = NZERO;
2323 }
2324
2325 /*
2326 * Process is traced - wake it up (if not already
2327 * stopped) so that it can discover the signal in
2328 * issig() and stop for the parent.
2329 */
2330 if (sig_proc->p_lflag & P_LTRACED) {
2331 if (sig_proc->p_stat != SSTOP)
2332 goto runlocked;
2333 else
2334 goto sigout_locked;
2335 }
2336
2337 if ((flavor & PSIG_VFORK) != 0)
2338 goto runlocked;
2339
2340 if (action == KERN_SIG_WAIT) {
2341#if CONFIG_DTRACE
2342 /*
2343 * DTrace proc signal-clear returns a siginfo_t. Collect the needed info.
2344 */
2345 r_uid = kauth_getruid(); /* per thread credential; protected by our thread context */
2346
2347 bzero((caddr_t)&(uth->t_dtrace_siginfo), sizeof(uth->t_dtrace_siginfo));
2348
2349 uth->t_dtrace_siginfo.si_signo = signum;
2350 uth->t_dtrace_siginfo.si_pid = current_proc()->p_pid;
2351 uth->t_dtrace_siginfo.si_status = W_EXITCODE(signum, 0);
2352 uth->t_dtrace_siginfo.si_uid = r_uid;
2353 uth->t_dtrace_siginfo.si_code = 0;
2354#endif
2355 uth->uu_sigwait = mask;
2356 uth->uu_siglist &= ~mask;
2357 wakeup(&uth->uu_sigwait);
2358 /* if it is SIGCONT resume whole process */
2359 if (prop & SA_CONT) {
2360 OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag);
2361 sig_proc->p_contproc = current_proc()->p_pid;
2362 (void) task_resume_internal(sig_task);
2363 }
2364 goto sigout_locked;
2365 }
2366
2367 if (action != SIG_DFL) {
2368 /*
2369 * User wants to catch the signal.
2370 * Wake up the thread, but don't un-suspend it
2371 * (except for SIGCONT).
2372 */
2373 if (prop & SA_CONT) {
2374 OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag);
2375 (void) task_resume_internal(sig_task);
2376 sig_proc->p_stat = SRUN;
2377 } else if (sig_proc->p_stat == SSTOP) {
2378 goto sigout_locked;
2379 }
2380 /*
2381 * Fill out siginfo structure information to pass to the
2382 * signalled process/thread sigaction handler, when it
2383 * wakes up. si_code is 0 because this is an ordinary
2384 * signal, not a SIGCHLD, and so si_status is the signal
2385 * number itself, instead of the child process exit status.
2386 * We shift this left because it will be shifted right before
2387 * it is passed to user space. kind of ugly to use W_EXITCODE
2388 * this way, but it beats defining a new macro.
2389 *
2390 * Note: Avoid the SIGCHLD recursion case!
2391 */
2392 if (signum != SIGCHLD) {
2393 r_uid = kauth_getruid();
2394
2395 sig_proc->si_pid = current_proc()->p_pid;
2396 sig_proc->si_status = W_EXITCODE(signum, 0);
2397 sig_proc->si_uid = r_uid;
2398 sig_proc->si_code = 0;
2399 }
2400
2401 goto runlocked;
2402 } else {
2403 /* Default action - varies */
2404 if (mask & stopsigmask) {
2405 assert(signal_reason == NULL);
2406 /*
2407 * These are the signals which by default
2408 * stop a process.
2409 *
2410 * Don't clog system with children of init
2411 * stopped from the keyboard.
2412 */
2413 if (!(prop & SA_STOP) && sig_proc->p_pptr == initproc) {
2414 uth->uu_siglist &= ~mask;
2415 proc_unlock(sig_proc);
2416 /* siglock still locked, proc_lock not locked */
2417 psignal_locked(sig_proc, SIGKILL);
2418 goto sigout_unlocked;
2419 }
2420
2421 /*
2422 * Stop the task
2423 * if task hasn't already been stopped by
2424 * a signal.
2425 */
2426 uth->uu_siglist &= ~mask;
2427 if (sig_proc->p_stat != SSTOP) {
2428 sig_proc->p_xstat = signum;
2429 sig_proc->p_stat = SSTOP;
2430 OSBitAndAtomic(~((uint32_t)P_CONTINUED), &sig_proc->p_flag);
2431 sig_proc->p_lflag &= ~P_LWAITED;
2432 proc_unlock(sig_proc);
2433
2434 pp = proc_parentholdref(sig_proc);
2435 stop(sig_proc, pp);
2436 if (( pp != PROC_NULL) && ((pp->p_flag & P_NOCLDSTOP) == 0)) {
2437
2438 my_cred = kauth_cred_proc_ref(sig_proc);
2439 r_uid = kauth_cred_getruid(my_cred);
2440 kauth_cred_unref(&my_cred);
2441
2442 proc_lock(sig_proc);
2443 pp->si_pid = sig_proc->p_pid;
2444 /*
2445 * POSIX: sigaction for a stopped child
2446 * when sent to the parent must set the
2447 * child's signal number into si_status.
2448 */
2449 if (signum != SIGSTOP)
2450 pp->si_status = WEXITSTATUS(sig_proc->p_xstat);
2451 else
2452 pp->si_status = W_EXITCODE(signum, signum);
2453 pp->si_code = CLD_STOPPED;
2454 pp->si_uid = r_uid;
2455 proc_unlock(sig_proc);
2456
2457 psignal(pp, SIGCHLD);
2458 }
2459 if (pp != PROC_NULL) {
2460 proc_parentdropref(pp, 0);
2461 }
2462
2463 goto sigout_unlocked;
2464 }
2465
2466 goto sigout_locked;
2467 }
2468
2469 DTRACE_PROC3(signal__send, thread_t, sig_thread, proc_t, p, int, signum);
2470
2471 switch (signum) {
2472 /*
2473 * Signals ignored by default have been dealt
2474 * with already, since their bits are on in
2475 * p_sigignore.
2476 */
2477
2478 case SIGKILL:
2479 /*
2480 * Kill signal always sets process running and
2481 * unsuspends it.
2482 */
2483 /*
2484 * Process will be running after 'run'
2485 */
2486 sig_proc->p_stat = SRUN;
2487 /*
2488 * In scenarios where suspend/resume are racing
2489 * the signal we are missing AST_BSD by the time
2490 * we get here, set again to avoid races. This
2491 * was the scenario with spindump enabled shutdowns.
2492 * We would need to cover this approp down the line.
2493 */
2494 act_set_astbsd(sig_thread);
2495 kret = thread_abort(sig_thread);
2496 update_thread_policy = (kret == KERN_SUCCESS);
2497
2498 if (uth->uu_exit_reason == OS_REASON_NULL) {
2499 if (signal_reason == OS_REASON_NULL) {
2500 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2501 sig_proc->p_pid, OS_REASON_SIGNAL, signum, 0, 0);
2502
2503 signal_reason = build_signal_reason(signum, NULL);
2504 }
2505
2506 os_reason_ref(signal_reason);
2507 set_thread_exit_reason(sig_thread, signal_reason, TRUE);
2508 }
2509
2510 goto sigout_locked;
2511
2512 case SIGCONT:
2513 /*
2514 * Let the process run. If it's sleeping on an
2515 * event, it remains so.
2516 */
2517 assert(signal_reason == NULL);
2518 OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag);
2519 sig_proc->p_contproc = sig_proc->p_pid;
2520 sig_proc->p_xstat = signum;
2521
2522 (void) task_resume_internal(sig_task);
2523
2524 /*
2525 * When processing a SIGCONT, we need to check
2526 * to see if there are signals pending that
2527 * were not delivered because we had been
2528 * previously stopped. If that's the case,
2529 * we need to thread_abort_safely() to trigger
2530 * interruption of the current system call to
2531 * cause their handlers to fire. If it's only
2532 * the SIGCONT, then don't wake up.
2533 */
2534 if (((flavor & (PSIG_VFORK|PSIG_THREAD)) == 0) && (((uth->uu_siglist & ~uth->uu_sigmask) & ~sig_proc->p_sigignore) & ~mask)) {
2535 uth->uu_siglist &= ~mask;
2536 sig_proc->p_stat = SRUN;
2537 goto runlocked;
2538 }
2539
2540 uth->uu_siglist &= ~mask;
2541 sig_proc->p_stat = SRUN;
2542 goto sigout_locked;
2543
2544 default:
2545 /*
2546 * A signal which has a default action of killing
2547 * the process, and for which there is no handler,
2548 * needs to act like SIGKILL
2549 */
2550 if (((flavor & (PSIG_VFORK|PSIG_THREAD)) == 0) && (action == SIG_DFL) && (prop & SA_KILL)) {
2551 sig_proc->p_stat = SRUN;
2552 kret = thread_abort(sig_thread);
2553 update_thread_policy = (kret == KERN_SUCCESS);
2554
2555 if (uth->uu_exit_reason == OS_REASON_NULL) {
2556 if (signal_reason == OS_REASON_NULL) {
2557 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2558 sig_proc->p_pid, OS_REASON_SIGNAL, signum, 0, 0);
2559
2560 signal_reason = build_signal_reason(signum, NULL);
2561 }
2562
2563 os_reason_ref(signal_reason);
2564 set_thread_exit_reason(sig_thread, signal_reason, TRUE);
2565 }
2566
2567 goto sigout_locked;
2568 }
2569
2570 /*
2571 * All other signals wake up the process, but don't
2572 * resume it.
2573 */
2574 if (sig_proc->p_stat == SSTOP) {
2575 goto sigout_locked;
2576 }
2577 goto runlocked;
2578 }
2579 }
2580 /*NOTREACHED*/
2581
2582runlocked:
2583 /*
2584 * If we're being traced (possibly because someone attached us
2585 * while we were stopped), check for a signal from the debugger.
2586 */
2587 if (sig_proc->p_stat == SSTOP) {
2588 if ((sig_proc->p_lflag & P_LTRACED) != 0 && sig_proc->p_xstat != 0)
2589 uth->uu_siglist |= sigmask(sig_proc->p_xstat);
2590
2591 if ((flavor & PSIG_VFORK) != 0) {
2592 sig_proc->p_stat = SRUN;
2593 }
2594 } else {
2595 /*
2596 * setrunnable(p) in BSD and
2597 * Wake up the thread if it is interruptible.
2598 */
2599 sig_proc->p_stat = SRUN;
2600 if ((flavor & PSIG_VFORK) == 0)
2601 thread_abort_safely(sig_thread);
2602 }
2603
2604sigout_locked:
2605 if (update_thread_policy) {
2606 /*
2607 * Update the thread policy to heading to terminate, increase priority if
2608 * necessary. This needs to be done before we drop the proc lock because the
2609 * thread can take the fatal signal once it's dropped.
2610 */
2611 proc_set_thread_policy(sig_thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_TERMINATED, TASK_POLICY_ENABLE);
2612 }
2613
2614 proc_unlock(sig_proc);
2615
2616sigout_unlocked:
2617 os_reason_free(signal_reason);
2618 if ((flavor & PSIG_LOCKED)== 0) {
2619 proc_signalend(sig_proc, 0);
2620 }
2621}
2622
2623void
2624psignal(proc_t p, int signum)
2625{
2626 psignal_internal(p, NULL, NULL, 0, signum, NULL);
2627}
2628
2629void
2630psignal_with_reason(proc_t p, int signum, struct os_reason *signal_reason)
2631{
2632 psignal_internal(p, NULL, NULL, 0, signum, signal_reason);
2633}
2634
2635void
2636psignal_locked(proc_t p, int signum)
2637{
2638 psignal_internal(p, NULL, NULL, PSIG_LOCKED, signum, NULL);
2639}
2640
2641void
2642psignal_vfork_with_reason(proc_t p, task_t new_task, thread_t thread, int signum, struct os_reason *signal_reason)
2643{
2644 psignal_internal(p, new_task, thread, PSIG_VFORK, signum, signal_reason);
2645}
2646
2647
2648void
2649psignal_vfork(proc_t p, task_t new_task, thread_t thread, int signum)
2650{
2651 psignal_internal(p, new_task, thread, PSIG_VFORK, signum, NULL);
2652}
2653
2654void
2655psignal_uthread(thread_t thread, int signum)
2656{
2657 psignal_internal(PROC_NULL, TASK_NULL, thread, PSIG_THREAD, signum, NULL);
2658}
2659
2660/* same as psignal(), but prefer delivery to 'thread' if possible */
2661void
2662psignal_try_thread(proc_t p, thread_t thread, int signum)
2663{
2664 psignal_internal(p, NULL, thread, PSIG_TRY_THREAD, signum, NULL);
2665}
2666
2667void
2668psignal_try_thread_with_reason(proc_t p, thread_t thread, int signum, struct os_reason *signal_reason)
2669{
2670 psignal_internal(p, TASK_NULL, thread, PSIG_TRY_THREAD, signum, signal_reason);
2671}
2672
2673void
2674psignal_thread_with_reason(proc_t p, thread_t thread, int signum, struct os_reason *signal_reason)
2675{
2676 psignal_internal(p, TASK_NULL, thread, PSIG_THREAD, signum, signal_reason);
2677}
2678
2679/*
2680 * If the current process has received a signal (should be caught or cause
2681 * termination, should interrupt current syscall), return the signal number.
2682 * Stop signals with default action are processed immediately, then cleared;
2683 * they aren't returned. This is checked after each entry to the system for
2684 * a syscall or trap (though this can usually be done without calling issignal
2685 * by checking the pending signal masks in the CURSIG macro.) The normal call
2686 * sequence is
2687 *
2688 * while (signum = CURSIG(curproc))
2689 * postsig(signum);
2690 */
2691int
2692issignal_locked(proc_t p)
2693{
2694 int signum, mask, prop, sigbits;
2695 thread_t cur_act;
2696 struct uthread * ut;
2697 proc_t pp;
2698 kauth_cred_t my_cred;
2699 int retval = 0;
2700 uid_t r_uid;
2701
2702 cur_act = current_thread();
2703
2704#if SIGNAL_DEBUG
2705 if(rdebug_proc && (p == rdebug_proc)) {
2706 ram_printf(3);
2707 }
2708#endif /* SIGNAL_DEBUG */
2709
2710 /*
2711 * Try to grab the signal lock.
2712 */
2713 if (sig_try_locked(p) <= 0) {
2714 return 0;
2715 }
2716
2717 proc_signalstart(p, 1);
2718
2719 ut = get_bsdthread_info(cur_act);
2720 for (;;) {
2721 sigbits = ut->uu_siglist & ~ut->uu_sigmask;
2722
2723 if (p->p_lflag & P_LPPWAIT)
2724 sigbits &= ~stopsigmask;
2725 if (sigbits == 0) { /* no signal to send */
2726 retval = 0;
2727 goto out;
2728 }
2729
2730 signum = ffs((long)sigbits);
2731 mask = sigmask(signum);
2732 prop = sigprop[signum];
2733
2734 /*
2735 * We should see pending but ignored signals
2736 * only if P_LTRACED was on when they were posted.
2737 */
2738 if (mask & p->p_sigignore && (p->p_lflag & P_LTRACED) == 0) {
2739 ut->uu_siglist &= ~mask;
2740 continue;
2741 }
2742
2743 if (p->p_lflag & P_LTRACED && (p->p_lflag & P_LPPWAIT) == 0) {
2744 /*
2745 * If traced, deliver the signal to the debugger, and wait to be
2746 * released.
2747 */
2748 task_t task;
2749 p->p_xstat = signum;
2750
2751 if (p->p_lflag & P_LSIGEXC) {
2752 p->sigwait = TRUE;
2753 p->sigwait_thread = cur_act;
2754 p->p_stat = SSTOP;
2755 OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag);
2756 p->p_lflag &= ~P_LWAITED;
2757 ut->uu_siglist &= ~mask; /* clear the current signal from the pending list */
2758 proc_signalend(p, 1);
2759 proc_unlock(p);
2760 do_bsdexception(EXC_SOFTWARE, EXC_SOFT_SIGNAL, signum);
2761 proc_lock(p);
2762 proc_signalstart(p, 1);
2763 } else {
2764 proc_unlock(p);
2765 my_cred = kauth_cred_proc_ref(p);
2766 r_uid = kauth_cred_getruid(my_cred);
2767 kauth_cred_unref(&my_cred);
2768
2769 pp = proc_parentholdref(p);
2770 if (pp != PROC_NULL) {
2771 proc_lock(pp);
2772
2773 pp->si_pid = p->p_pid;
2774 pp->p_xhighbits = p->p_xhighbits;
2775 p->p_xhighbits = 0;
2776 pp->si_status = p->p_xstat;
2777 pp->si_code = CLD_TRAPPED;
2778 pp->si_uid = r_uid;
2779
2780 proc_unlock(pp);
2781 }
2782
2783 /*
2784 * XXX Have to really stop for debuggers;
2785 * XXX stop() doesn't do the right thing.
2786 */
2787 task = p->task;
2788 task_suspend_internal(task);
2789
2790 proc_lock(p);
2791 p->sigwait = TRUE;
2792 p->sigwait_thread = cur_act;
2793 p->p_stat = SSTOP;
2794 OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag);
2795 p->p_lflag &= ~P_LWAITED;
2796 ut->uu_siglist &= ~mask;
2797
2798 proc_signalend(p, 1);
2799 proc_unlock(p);
2800
2801 if (pp != PROC_NULL) {
2802 psignal(pp, SIGCHLD);
2803 proc_list_lock();
2804 wakeup((caddr_t)pp);
2805 proc_parentdropref(pp, 1);
2806 proc_list_unlock();
2807 }
2808
2809 assert_wait((caddr_t)&p->sigwait, (THREAD_INTERRUPTIBLE));
2810 thread_block(THREAD_CONTINUE_NULL);
2811 proc_lock(p);
2812 proc_signalstart(p, 1);
2813 }
2814
2815 p->sigwait = FALSE;
2816 p->sigwait_thread = NULL;
2817 wakeup((caddr_t)&p->sigwait_thread);
2818
2819 if (signum == SIGKILL || ut->uu_siglist & sigmask(SIGKILL)) {
2820 /*
2821 * Deliver a pending sigkill even if it's not the current signal.
2822 * Necessary for PT_KILL, which should not be delivered to the
2823 * debugger, but we can't differentiate it from any other KILL.
2824 */
2825 signum = SIGKILL;
2826 goto deliver_sig;
2827 }
2828
2829 /* We may have to quit. */
2830 if (thread_should_abort(current_thread())) {
2831 retval = 0;
2832 goto out;
2833 }
2834
2835 /*
2836 * If parent wants us to take the signal,
2837 * then it will leave it in p->p_xstat;
2838 * otherwise we just look for signals again.
2839 */
2840 signum = p->p_xstat;
2841 if (signum == 0)
2842 continue;
2843
2844 /*
2845 * Put the new signal into p_siglist. If the
2846 * signal is being masked, look for other signals.
2847 */
2848 mask = sigmask(signum);
2849 ut->uu_siglist |= mask;
2850 if (ut->uu_sigmask & mask)
2851 continue;
2852 }
2853
2854 /*
2855 * Decide whether the signal should be returned.
2856 * Return the signal's number, or fall through
2857 * to clear it from the pending mask.
2858 */
2859
2860 switch ((long)p->p_sigacts->ps_sigact[signum]) {
2861
2862 case (long)SIG_DFL:
2863 /*
2864 * If there is a pending stop signal to process
2865 * with default action, stop here,
2866 * then clear the signal. However,
2867 * if process is member of an orphaned
2868 * process group, ignore tty stop signals.
2869 */
2870 if (prop & SA_STOP) {
2871 struct pgrp * pg;
2872
2873 proc_unlock(p);
2874 pg = proc_pgrp(p);
2875 if (p->p_lflag & P_LTRACED ||
2876 (pg->pg_jobc == 0 &&
2877 prop & SA_TTYSTOP)) {
2878 proc_lock(p);
2879 pg_rele(pg);
2880 break; /* ignore signal */
2881 }
2882 pg_rele(pg);
2883 if (p->p_stat != SSTOP) {
2884 proc_lock(p);
2885 p->p_xstat = signum;
2886 p->p_stat = SSTOP;
2887 p->p_lflag &= ~P_LWAITED;
2888 proc_unlock(p);
2889
2890 pp = proc_parentholdref(p);
2891 stop(p, pp);
2892 if ((pp != PROC_NULL) && ((pp->p_flag & P_NOCLDSTOP) == 0)) {
2893 my_cred = kauth_cred_proc_ref(p);
2894 r_uid = kauth_cred_getruid(my_cred);
2895 kauth_cred_unref(&my_cred);
2896
2897 proc_lock(pp);
2898 pp->si_pid = p->p_pid;
2899 pp->si_status = WEXITSTATUS(p->p_xstat);
2900 pp->si_code = CLD_STOPPED;
2901 pp->si_uid = r_uid;
2902 proc_unlock(pp);
2903
2904 psignal(pp, SIGCHLD);
2905 }
2906 if (pp != PROC_NULL)
2907 proc_parentdropref(pp, 0);
2908 }
2909 proc_lock(p);
2910 break;
2911 } else if (prop & SA_IGNORE) {
2912 /*
2913 * Except for SIGCONT, shouldn't get here.
2914 * Default action is to ignore; drop it.
2915 */
2916 break; /* ignore signal */
2917 } else {
2918 goto deliver_sig;
2919 }
2920
2921 case (long)SIG_IGN:
2922 /*
2923 * Masking above should prevent us ever trying
2924 * to take action on an ignored signal other
2925 * than SIGCONT, unless process is traced.
2926 */
2927 if ((prop & SA_CONT) == 0 &&
2928 (p->p_lflag & P_LTRACED) == 0)
2929 printf("issignal\n");
2930 break; /* ignore signal */
2931
2932 default:
2933 /* This signal has an action - deliver it. */
2934 goto deliver_sig;
2935 }
2936
2937 /* If we dropped through, the signal was ignored - remove it from pending list. */
2938 ut->uu_siglist &= ~mask;
2939
2940 } /* for(;;) */
2941
2942 /* NOTREACHED */
2943
2944deliver_sig:
2945 ut->uu_siglist &= ~mask;
2946 retval = signum;
2947
2948out:
2949 proc_signalend(p, 1);
2950 return retval;
2951}
2952
2953/* called from _sleep */
2954int
2955CURSIG(proc_t p)
2956{
2957 int signum, mask, prop, sigbits;
2958 thread_t cur_act;
2959 struct uthread * ut;
2960 int retnum = 0;
2961
2962
2963 cur_act = current_thread();
2964
2965 ut = get_bsdthread_info(cur_act);
2966
2967 if (ut->uu_siglist == 0)
2968 return (0);
2969
2970 if (((ut->uu_siglist & ~ut->uu_sigmask) == 0) && ((p->p_lflag & P_LTRACED) == 0))
2971 return (0);
2972
2973 sigbits = ut->uu_siglist & ~ut->uu_sigmask;
2974
2975 for(;;) {
2976 if (p->p_lflag & P_LPPWAIT)
2977 sigbits &= ~stopsigmask;
2978 if (sigbits == 0) { /* no signal to send */
2979 return (retnum);
2980 }
2981
2982 signum = ffs((long)sigbits);
2983 mask = sigmask(signum);
2984 prop = sigprop[signum];
2985 sigbits &= ~mask; /* take the signal out */
2986
2987 /*
2988 * We should see pending but ignored signals
2989 * only if P_LTRACED was on when they were posted.
2990 */
2991 if (mask & p->p_sigignore && (p->p_lflag & P_LTRACED) == 0) {
2992 continue;
2993 }
2994
2995 if (p->p_lflag & P_LTRACED && (p->p_lflag & P_LPPWAIT) == 0) {
2996 return(signum);
2997 }
2998
2999 /*
3000 * Decide whether the signal should be returned.
3001 * Return the signal's number, or fall through
3002 * to clear it from the pending mask.
3003 */
3004
3005 switch ((long)p->p_sigacts->ps_sigact[signum]) {
3006
3007 case (long)SIG_DFL:
3008 /*
3009 * If there is a pending stop signal to process
3010 * with default action, stop here,
3011 * then clear the signal. However,
3012 * if process is member of an orphaned
3013 * process group, ignore tty stop signals.
3014 */
3015 if (prop & SA_STOP) {
3016 struct pgrp *pg;
3017
3018 pg = proc_pgrp(p);
3019
3020 if (p->p_lflag & P_LTRACED ||
3021 (pg->pg_jobc == 0 &&
3022 prop & SA_TTYSTOP)) {
3023 pg_rele(pg);
3024 break; /* == ignore */
3025 }
3026 pg_rele(pg);
3027 retnum = signum;
3028 break;
3029 } else if (prop & SA_IGNORE) {
3030 /*
3031 * Except for SIGCONT, shouldn't get here.
3032 * Default action is to ignore; drop it.
3033 */
3034 break; /* == ignore */
3035 } else {
3036 return (signum);
3037 }
3038 /*NOTREACHED*/
3039
3040 case (long)SIG_IGN:
3041 /*
3042 * Masking above should prevent us ever trying
3043 * to take action on an ignored signal other
3044 * than SIGCONT, unless process is traced.
3045 */
3046 if ((prop & SA_CONT) == 0 &&
3047 (p->p_lflag & P_LTRACED) == 0)
3048 printf("issignal\n");
3049 break; /* == ignore */
3050
3051 default:
3052 /*
3053 * This signal has an action, let
3054 * postsig() process it.
3055 */
3056 return (signum);
3057 }
3058 }
3059 /* NOTREACHED */
3060}
3061
3062/*
3063 * Put the argument process into the stopped state and notify the parent
3064 * via wakeup. Signals are handled elsewhere. The process must not be
3065 * on the run queue.
3066 */
3067static void
3068stop(proc_t p, proc_t parent)
3069{
3070 OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag);
3071 if ((parent != PROC_NULL) && (parent->p_stat != SSTOP)) {
3072 proc_list_lock();
3073 wakeup((caddr_t)parent);
3074 proc_list_unlock();
3075 }
3076 (void) task_suspend_internal(p->task);
3077}
3078
3079/*
3080 * Take the action for the specified signal
3081 * from the current set of pending signals.
3082 */
3083void
3084postsig_locked(int signum)
3085{
3086 proc_t p = current_proc();
3087 struct sigacts *ps = p->p_sigacts;
3088 user_addr_t catcher;
3089 uint32_t code;
3090 int mask, returnmask;
3091 struct uthread * ut;
3092 os_reason_t ut_exit_reason = OS_REASON_NULL;
3093
3094#if DIAGNOSTIC
3095 if (signum == 0)
3096 panic("postsig");
3097 /*
3098 * This must be called on master cpu
3099 */
3100 if (cpu_number() != master_cpu)
3101 panic("psig not on master");
3102#endif
3103
3104 /*
3105 * Try to grab the signal lock.
3106 */
3107 if (sig_try_locked(p) <= 0) {
3108 return;
3109 }
3110
3111 proc_signalstart(p, 1);
3112
3113 ut = (struct uthread *)get_bsdthread_info(current_thread());
3114 mask = sigmask(signum);
3115 ut->uu_siglist &= ~mask;
3116 catcher = ps->ps_sigact[signum];
3117 if (catcher == SIG_DFL) {
3118 /*
3119 * Default catcher, where the default is to kill
3120 * the process. (Other cases were ignored above.)
3121 */
3122 sig_lock_to_exit(p);
3123
3124 /*
3125 * exit_with_reason() below will consume a reference to the thread's exit reason, so we take another
3126 * reference so the thread still has one even after we call exit_with_reason(). The thread's reference will
3127 * ultimately be destroyed in uthread_cleanup().
3128 */
3129 ut_exit_reason = ut->uu_exit_reason;
3130 os_reason_ref(ut_exit_reason);
3131
3132 p->p_acflag |= AXSIG;
3133 if (sigprop[signum] & SA_CORE) {
3134 p->p_sigacts->ps_sig = signum;
3135 proc_signalend(p, 1);
3136 proc_unlock(p);
3137#if CONFIG_COREDUMP
3138 if (coredump(p, 0, 0) == 0)
3139 signum |= WCOREFLAG;
3140#endif
3141 } else {
3142 proc_signalend(p, 1);
3143 proc_unlock(p);
3144 }
3145
3146#if CONFIG_DTRACE
3147 bzero((caddr_t)&(ut->t_dtrace_siginfo), sizeof(ut->t_dtrace_siginfo));
3148
3149 ut->t_dtrace_siginfo.si_signo = signum;
3150 ut->t_dtrace_siginfo.si_pid = p->si_pid;
3151 ut->t_dtrace_siginfo.si_uid = p->si_uid;
3152 ut->t_dtrace_siginfo.si_status = WEXITSTATUS(p->si_status);
3153
3154 /* Fire DTrace proc:::fault probe when signal is generated by hardware. */
3155 switch (signum) {
3156 case SIGILL: case SIGBUS: case SIGSEGV: case SIGFPE: case SIGTRAP:
3157 DTRACE_PROC2(fault, int, (int)(ut->uu_code), siginfo_t *, &(ut->t_dtrace_siginfo));
3158 break;
3159 default:
3160 break;
3161 }
3162
3163
3164 DTRACE_PROC3(signal__handle, int, signum, siginfo_t *, &(ut->t_dtrace_siginfo),
3165 void (*)(void), SIG_DFL);
3166#endif
3167
3168 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE,
3169 p->p_pid, W_EXITCODE(0, signum), 3, 0, 0);
3170
3171 exit_with_reason(p, W_EXITCODE(0, signum), (int *)NULL, TRUE, TRUE, 0, ut_exit_reason);
3172
3173 proc_lock(p);
3174 return;
3175 } else {
3176 /*
3177 * If we get here, the signal must be caught.
3178 */
3179#if DIAGNOSTIC
3180 if (catcher == SIG_IGN || (ut->uu_sigmask & mask))
3181 log(LOG_WARNING,
3182 "postsig: processing masked or ignored signal\n");
3183#endif
3184
3185 /*
3186 * Set the new mask value and also defer further
3187 * occurences of this signal.
3188 *
3189 * Special case: user has done a sigpause. Here the
3190 * current mask is not of interest, but rather the
3191 * mask from before the sigpause is what we want
3192 * restored after the signal processing is completed.
3193 */
3194 if (ut->uu_flag & UT_SAS_OLDMASK) {
3195 returnmask = ut->uu_oldmask;
3196 ut->uu_flag &= ~UT_SAS_OLDMASK;
3197 ut->uu_oldmask = 0;
3198 } else
3199 returnmask = ut->uu_sigmask;
3200 ut->uu_sigmask |= ps->ps_catchmask[signum];
3201 if ((ps->ps_signodefer & mask) == 0)
3202 ut->uu_sigmask |= mask;
3203 if ((signum != SIGILL) && (signum != SIGTRAP) && (ps->ps_sigreset & mask)) {
3204 if ((signum != SIGCONT) && (sigprop[signum] & SA_IGNORE))
3205 p->p_sigignore |= mask;
3206 ps->ps_sigact[signum] = SIG_DFL;
3207 ps->ps_siginfo &= ~mask;
3208 ps->ps_signodefer &= ~mask;
3209 }
3210
3211 if (ps->ps_sig != signum) {
3212 code = 0;
3213 } else {
3214 code = ps->ps_code;
3215 ps->ps_code = 0;
3216 }
3217 OSIncrementAtomicLong(&p->p_stats->p_ru.ru_nsignals);
3218 sendsig(p, catcher, signum, returnmask, code);
3219 }
3220 proc_signalend(p, 1);
3221}
3222
3223/*
3224 * Attach a signal knote to the list of knotes for this process.
3225 *
3226 * Signal knotes share the knote list with proc knotes. This
3227 * could be avoided by using a signal-specific knote list, but
3228 * probably isn't worth the trouble.
3229 */
3230
3231static int
3232filt_sigattach(struct knote *kn, __unused struct kevent_internal_s *kev)
3233{
3234 proc_t p = current_proc(); /* can attach only to oneself */
3235
3236 proc_klist_lock();
3237
3238 kn->kn_ptr.p_proc = p;
3239
3240 KNOTE_ATTACH(&p->p_klist, kn);
3241
3242 proc_klist_unlock();
3243
3244 /* edge-triggered events can't have fired before we attached */
3245 return (0);
3246}
3247
3248/*
3249 * remove the knote from the process list, if it hasn't already
3250 * been removed by exit processing.
3251 */
3252
3253static void
3254filt_sigdetach(struct knote *kn)
3255{
3256 proc_t p = kn->kn_ptr.p_proc;
3257
3258 proc_klist_lock();
3259 kn->kn_ptr.p_proc = NULL;
3260 KNOTE_DETACH(&p->p_klist, kn);
3261 proc_klist_unlock();
3262}
3263
3264/*
3265 * Post an event to the signal filter. Because we share the same list
3266 * as process knotes, we have to filter out and handle only signal events.
3267 *
3268 * We assume that we process fdfree() before we post the NOTE_EXIT for
3269 * a process during exit. Therefore, since signal filters can only be
3270 * set up "in-process", we should have already torn down the kqueue
3271 * hosting the EVFILT_SIGNAL knote and should never see NOTE_EXIT.
3272 */
3273static int
3274filt_signal(struct knote *kn, long hint)
3275{
3276
3277 if (hint & NOTE_SIGNAL) {
3278 hint &= ~NOTE_SIGNAL;
3279
3280 if (kn->kn_id == (unsigned int)hint)
3281 kn->kn_data++;
3282 } else if (hint & NOTE_EXIT) {
3283 panic("filt_signal: detected NOTE_EXIT event");
3284 }
3285
3286 return (kn->kn_data != 0);
3287}
3288
3289static int
3290filt_signaltouch(
3291 struct knote *kn,
3292 struct kevent_internal_s *kev)
3293{
3294#pragma unused(kev)
3295
3296 int res;
3297
3298 proc_klist_lock();
3299
3300 /*
3301 * No data to save - just capture if it is already fired
3302 */
3303 res = (kn->kn_data > 0);
3304
3305 proc_klist_unlock();
3306
3307 return res;
3308}
3309
3310static int
3311filt_signalprocess(
3312 struct knote *kn,
3313 __unused struct filt_process_s *data,
3314 struct kevent_internal_s *kev)
3315{
3316 proc_klist_lock();
3317
3318 if (kn->kn_data == 0) {
3319 proc_klist_unlock();
3320 return 0;
3321 }
3322
3323 /*
3324 * Snapshot the event data.
3325 * All signal events are EV_CLEAR, so
3326 * add that and clear out the data field.
3327 */
3328 *kev = kn->kn_kevent;
3329 kev->flags |= EV_CLEAR;
3330 kn->kn_data = 0;
3331
3332 proc_klist_unlock();
3333 return 1;
3334}
3335
3336void
3337bsd_ast(thread_t thread)
3338{
3339 proc_t p = current_proc();
3340 struct uthread *ut = get_bsdthread_info(thread);
3341 int signum;
3342 user_addr_t pc;
3343 static int bsd_init_done = 0;
3344
3345 if (p == NULL)
3346 return;
3347
3348 /* don't run bsd ast on exec copy or exec'ed tasks */
3349 if (task_did_exec(current_task()) || task_is_exec_copy(current_task())) {
3350 return;
3351 }
3352
3353 if ((p->p_flag & P_OWEUPC) && (p->p_flag & P_PROFIL)) {
3354 pc = get_useraddr();
3355 addupc_task(p, pc, 1);
3356 OSBitAndAtomic(~((uint32_t)P_OWEUPC), &p->p_flag);
3357 }
3358
3359 if (timerisset(&p->p_vtimer_user.it_value)) {
3360 uint32_t microsecs;
3361
3362 task_vtimer_update(p->task, TASK_VTIMER_USER, &microsecs);
3363
3364 if (!itimerdecr(p, &p->p_vtimer_user, microsecs)) {
3365 if (timerisset(&p->p_vtimer_user.it_value))
3366 task_vtimer_set(p->task, TASK_VTIMER_USER);
3367 else
3368 task_vtimer_clear(p->task, TASK_VTIMER_USER);
3369
3370 psignal_try_thread(p, thread, SIGVTALRM);
3371 }
3372 }
3373
3374 if (timerisset(&p->p_vtimer_prof.it_value)) {
3375 uint32_t microsecs;
3376
3377 task_vtimer_update(p->task, TASK_VTIMER_PROF, &microsecs);
3378
3379 if (!itimerdecr(p, &p->p_vtimer_prof, microsecs)) {
3380 if (timerisset(&p->p_vtimer_prof.it_value))
3381 task_vtimer_set(p->task, TASK_VTIMER_PROF);
3382 else
3383 task_vtimer_clear(p->task, TASK_VTIMER_PROF);
3384
3385 psignal_try_thread(p, thread, SIGPROF);
3386 }
3387 }
3388
3389 if (timerisset(&p->p_rlim_cpu)) {
3390 struct timeval tv;
3391
3392 task_vtimer_update(p->task, TASK_VTIMER_RLIM, (uint32_t *) &tv.tv_usec);
3393
3394 proc_spinlock(p);
3395 if (p->p_rlim_cpu.tv_sec > 0 || p->p_rlim_cpu.tv_usec > tv.tv_usec) {
3396 tv.tv_sec = 0;
3397 timersub(&p->p_rlim_cpu, &tv, &p->p_rlim_cpu);
3398 proc_spinunlock(p);
3399 } else {
3400
3401 timerclear(&p->p_rlim_cpu);
3402 proc_spinunlock(p);
3403
3404 task_vtimer_clear(p->task, TASK_VTIMER_RLIM);
3405
3406 psignal_try_thread(p, thread, SIGXCPU);
3407 }
3408 }
3409
3410#if CONFIG_DTRACE
3411 if (ut->t_dtrace_sig) {
3412 uint8_t dt_action_sig = ut->t_dtrace_sig;
3413 ut->t_dtrace_sig = 0;
3414 psignal(p, dt_action_sig);
3415 }
3416
3417 if (ut->t_dtrace_stop) {
3418 ut->t_dtrace_stop = 0;
3419 proc_lock(p);
3420 p->p_dtrace_stop = 1;
3421 proc_unlock(p);
3422 (void)task_suspend_internal(p->task);
3423 }
3424
3425 if (ut->t_dtrace_resumepid) {
3426 proc_t resumeproc = proc_find(ut->t_dtrace_resumepid);
3427 ut->t_dtrace_resumepid = 0;
3428 if (resumeproc != PROC_NULL) {
3429 proc_lock(resumeproc);
3430 /* We only act on processes stopped by dtrace */
3431 if (resumeproc->p_dtrace_stop) {
3432 resumeproc->p_dtrace_stop = 0;
3433 proc_unlock(resumeproc);
3434 task_resume_internal(resumeproc->task);
3435 }
3436 else {
3437 proc_unlock(resumeproc);
3438 }
3439 proc_rele(resumeproc);
3440 }
3441 }
3442
3443#endif /* CONFIG_DTRACE */
3444
3445 proc_lock(p);
3446 if (CHECK_SIGNALS(p, current_thread(), ut)) {
3447 while ( (signum = issignal_locked(p)) )
3448 postsig_locked(signum);
3449 }
3450 proc_unlock(p);
3451
3452#ifdef CONFIG_32BIT_TELEMETRY
3453 if (task_consume_32bit_log_flag(p->task)) {
3454 proc_log_32bit_telemetry(p);
3455 }
3456#endif /* CONFIG_32BIT_TELEMETRY */
3457
3458 if (!bsd_init_done) {
3459 bsd_init_done = 1;
3460 bsdinit_task();
3461 }
3462}
3463
3464/* ptrace set runnable */
3465void
3466pt_setrunnable(proc_t p)
3467{
3468 task_t task;
3469
3470 task = p->task;
3471
3472 if (p->p_lflag & P_LTRACED) {
3473 proc_lock(p);
3474 p->p_stat = SRUN;
3475 proc_unlock(p);
3476 if (p->sigwait) {
3477 wakeup((caddr_t)&(p->sigwait));
3478 if ((p->p_lflag & P_LSIGEXC) == 0) { // 5878479
3479 task_release(task);
3480 }
3481 }
3482 }
3483}
3484
3485kern_return_t
3486do_bsdexception(
3487 int exc,
3488 int code,
3489 int sub)
3490{
3491 mach_exception_data_type_t codes[EXCEPTION_CODE_MAX];
3492
3493 codes[0] = code;
3494 codes[1] = sub;
3495 return(bsd_exception(exc, codes, 2));
3496}
3497
3498int
3499proc_pendingsignals(proc_t p, sigset_t mask)
3500{
3501 struct uthread * uth;
3502 thread_t th;
3503 sigset_t bits = 0;
3504
3505 proc_lock(p);
3506 /* If the process is in proc exit return no signal info */
3507 if (p->p_lflag & P_LPEXIT) {
3508 goto out;
3509 }
3510
3511 if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
3512 th = p->p_vforkact;
3513 uth = (struct uthread *)get_bsdthread_info(th);
3514 if (uth) {
3515 bits = (((uth->uu_siglist & ~uth->uu_sigmask) & ~p->p_sigignore) & mask);
3516 }
3517 goto out;
3518 }
3519
3520 bits = 0;
3521 TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
3522 bits |= (((uth->uu_siglist & ~uth->uu_sigmask) & ~p->p_sigignore) & mask);
3523 }
3524out:
3525 proc_unlock(p);
3526 return(bits);
3527}
3528
3529int
3530thread_issignal(proc_t p, thread_t th, sigset_t mask)
3531{
3532 struct uthread * uth;
3533 sigset_t bits=0;
3534
3535 proc_lock(p);
3536 uth = (struct uthread *)get_bsdthread_info(th);
3537 if (uth) {
3538 bits = (((uth->uu_siglist & ~uth->uu_sigmask) & ~p->p_sigignore) & mask);
3539 }
3540 proc_unlock(p);
3541 return(bits);
3542}
3543
3544/*
3545 * Allow external reads of the sigprop array.
3546 */
3547int
3548hassigprop(int sig, int prop)
3549{
3550 return (sigprop[sig] & prop);
3551}
3552
3553void
3554pgsigio(pid_t pgid, int sig)
3555{
3556 proc_t p = PROC_NULL;
3557
3558 if (pgid < 0)
3559 gsignal(-(pgid), sig);
3560
3561 else if (pgid > 0 && (p = proc_find(pgid)) != 0)
3562 psignal(p, sig);
3563 if (p != PROC_NULL)
3564 proc_rele(p);
3565}
3566
3567void
3568proc_signalstart(proc_t p, int locked)
3569{
3570 if (!locked)
3571 proc_lock(p);
3572
3573 if(p->p_signalholder == current_thread())
3574 panic("proc_signalstart: thread attempting to signal a process for which it holds the signal lock");
3575
3576 p->p_sigwaitcnt++;
3577 while ((p->p_lflag & P_LINSIGNAL) == P_LINSIGNAL)
3578 msleep(&p->p_sigmask, &p->p_mlock, 0, "proc_signstart", NULL);
3579 p->p_sigwaitcnt--;
3580
3581 p->p_lflag |= P_LINSIGNAL;
3582 p->p_signalholder = current_thread();
3583 if (!locked)
3584 proc_unlock(p);
3585}
3586
3587void
3588proc_signalend(proc_t p, int locked)
3589{
3590 if (!locked)
3591 proc_lock(p);
3592 p->p_lflag &= ~P_LINSIGNAL;
3593
3594 if (p->p_sigwaitcnt > 0)
3595 wakeup(&p->p_sigmask);
3596
3597 p->p_signalholder = NULL;
3598 if (!locked)
3599 proc_unlock(p);
3600}
3601
3602void
3603sig_lock_to_exit(proc_t p)
3604{
3605 thread_t self = current_thread();
3606
3607 p->exit_thread = self;
3608 proc_unlock(p);
3609
3610 task_hold(p->task);
3611 task_wait(p->task, FALSE);
3612
3613 proc_lock(p);
3614}
3615
3616int
3617sig_try_locked(proc_t p)
3618{
3619 thread_t self = current_thread();
3620
3621 while (p->sigwait || p->exit_thread) {
3622 if (p->exit_thread) {
3623 return(0);
3624 }
3625 msleep((caddr_t)&p->sigwait_thread, &p->p_mlock, PCATCH | PDROP, 0, 0);
3626 if (thread_should_abort(self)) {
3627 /*
3628 * Terminate request - clean up.
3629 */
3630 proc_lock(p);
3631 return -1;
3632 }
3633 proc_lock(p);
3634 }
3635 return 1;
3636}
3637