Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/capsicum.h> 47 #include <sys/ctype.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 #include <sys/acct.h> 52 #include <sys/capsicum.h> 53 #include <sys/compressor.h> 54 #include <sys/condvar.h> 55 #include <sys/devctl.h> 56 #include <sys/event.h> 57 #include <sys/fcntl.h> 58 #include <sys/imgact.h> 59 #include <sys/kernel.h> 60 #include <sys/ktr.h> 61 #include <sys/ktrace.h> 62 #include <sys/limits.h> 63 #include <sys/lock.h> 64 #include <sys/malloc.h> 65 #include <sys/mutex.h> 66 #include <sys/refcount.h> 67 #include <sys/namei.h> 68 #include <sys/proc.h> 69 #include <sys/procdesc.h> 70 #include <sys/ptrace.h> 71 #include <sys/posix4.h> 72 #include <sys/racct.h> 73 #include <sys/resourcevar.h> 74 #include <sys/sdt.h> 75 #include <sys/sbuf.h> 76 #include <sys/sleepqueue.h> 77 #include <sys/smp.h> 78 #include <sys/stat.h> 79 #include <sys/sx.h> 80 #include <sys/syscall.h> 81 #include <sys/syscallsubr.h> 82 #include <sys/sysctl.h> 83 #include <sys/sysent.h> 84 #include <sys/syslog.h> 85 #include <sys/sysproto.h> 86 #include <sys/timers.h> 87 #include <sys/unistd.h> 88 #include <sys/vmmeter.h> 89 #include <sys/wait.h> 90 #include <vm/vm.h> 91 #include <vm/vm_extern.h> 92 #include <vm/uma.h> 93 94 #include <sys/jail.h> 95 96 #include <machine/cpu.h> 97 98 #include <security/audit/audit.h> 99 100 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 101 102 SDT_PROVIDER_DECLARE(proc); 103 SDT_PROBE_DEFINE3(proc, , , signal__send, 104 "struct thread *", "struct proc *", "int"); 105 SDT_PROBE_DEFINE2(proc, , , signal__clear, 106 "int", "ksiginfo_t *"); 107 SDT_PROBE_DEFINE3(proc, , , signal__discard, 108 "struct thread *", "struct proc *", "int"); 109 110 static int coredump(struct thread *); 111 static int killpg1(struct thread *td, int sig, int pgid, int all, 112 ksiginfo_t *ksi); 113 static int issignal(struct thread *td); 114 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 115 static int sigprop(int sig); 116 static void tdsigwakeup(struct thread *, int, sig_t, int); 117 static int sig_suspend_threads(struct thread *, struct proc *); 118 static int filt_sigattach(struct knote *kn); 119 static void filt_sigdetach(struct knote *kn); 120 static int filt_signal(struct knote *kn, long hint); 121 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 122 static void sigqueue_start(void); 123 static void sigfastblock_setpend(struct thread *td, bool resched); 124 125 static uma_zone_t ksiginfo_zone = NULL; 126 struct filterops sig_filtops = { 127 .f_isfd = 0, 128 .f_attach = filt_sigattach, 129 .f_detach = filt_sigdetach, 130 .f_event = filt_signal, 131 }; 132 133 static int kern_logsigexit = 1; 134 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 135 &kern_logsigexit, 0, 136 "Log processes quitting on abnormal signals to syslog(3)"); 137 138 static int kern_forcesigexit = 1; 139 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 140 &kern_forcesigexit, 0, "Force trap signal to be handled"); 141 142 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 143 "POSIX real time signal"); 144 145 static int max_pending_per_proc = 128; 146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 147 &max_pending_per_proc, 0, "Max pending signals per proc"); 148 149 static int preallocate_siginfo = 1024; 150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 151 &preallocate_siginfo, 0, "Preallocated signal memory size"); 152 153 static int signal_overflow = 0; 154 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 155 &signal_overflow, 0, "Number of signals overflew"); 156 157 static int signal_alloc_fail = 0; 158 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 159 &signal_alloc_fail, 0, "signals failed to be allocated"); 160 161 static int kern_lognosys = 0; 162 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 163 "Log invalid syscalls"); 164 165 __read_frequently bool sigfastblock_fetch_always = false; 166 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 167 &sigfastblock_fetch_always, 0, 168 "Fetch sigfastblock word on each syscall entry for proper " 169 "blocking semantic"); 170 171 static bool kern_sig_discard_ign = true; 172 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 173 &kern_sig_discard_ign, 0, 174 "Discard ignored signals on delivery, otherwise queue them to " 175 "the target queue"); 176 177 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 178 179 /* 180 * Policy -- Can ucred cr1 send SIGIO to process cr2? 181 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 182 * in the right situations. 183 */ 184 #define CANSIGIO(cr1, cr2) \ 185 ((cr1)->cr_uid == 0 || \ 186 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 187 (cr1)->cr_uid == (cr2)->cr_ruid || \ 188 (cr1)->cr_ruid == (cr2)->cr_uid || \ 189 (cr1)->cr_uid == (cr2)->cr_uid) 190 191 static int sugid_coredump; 192 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 193 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 194 195 static int capmode_coredump; 196 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 197 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 198 199 static int do_coredump = 1; 200 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 201 &do_coredump, 0, "Enable/Disable coredumps"); 202 203 static int set_core_nodump_flag = 0; 204 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 205 0, "Enable setting the NODUMP flag on coredump files"); 206 207 static int coredump_devctl = 0; 208 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 209 0, "Generate a devctl notification when processes coredump"); 210 211 /* 212 * Signal properties and actions. 213 * The array below categorizes the signals and their default actions 214 * according to the following properties: 215 */ 216 #define SIGPROP_KILL 0x01 /* terminates process by default */ 217 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 218 #define SIGPROP_STOP 0x04 /* suspend process */ 219 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 220 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 221 #define SIGPROP_CONT 0x20 /* continue if suspended */ 222 223 static int sigproptbl[NSIG] = { 224 [SIGHUP] = SIGPROP_KILL, 225 [SIGINT] = SIGPROP_KILL, 226 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 228 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 232 [SIGKILL] = SIGPROP_KILL, 233 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 234 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 235 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 236 [SIGPIPE] = SIGPROP_KILL, 237 [SIGALRM] = SIGPROP_KILL, 238 [SIGTERM] = SIGPROP_KILL, 239 [SIGURG] = SIGPROP_IGNORE, 240 [SIGSTOP] = SIGPROP_STOP, 241 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 242 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 243 [SIGCHLD] = SIGPROP_IGNORE, 244 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 245 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 246 [SIGIO] = SIGPROP_IGNORE, 247 [SIGXCPU] = SIGPROP_KILL, 248 [SIGXFSZ] = SIGPROP_KILL, 249 [SIGVTALRM] = SIGPROP_KILL, 250 [SIGPROF] = SIGPROP_KILL, 251 [SIGWINCH] = SIGPROP_IGNORE, 252 [SIGINFO] = SIGPROP_IGNORE, 253 [SIGUSR1] = SIGPROP_KILL, 254 [SIGUSR2] = SIGPROP_KILL, 255 }; 256 257 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 258 int __found; \ 259 for (;;) { \ 260 if (__bits != 0) { \ 261 int __sig = ffs(__bits); \ 262 __bits &= ~(1u << (__sig - 1)); \ 263 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 264 __found = 1; \ 265 break; \ 266 } \ 267 if (++__i == _SIG_WORDS) { \ 268 __found = 0; \ 269 break; \ 270 } \ 271 __bits = (set)->__bits[__i]; \ 272 } \ 273 __found != 0; \ 274 }) 275 276 #define SIG_FOREACH(i, set) \ 277 for (int32_t __i = -1, __bits = 0; \ 278 _SIG_FOREACH_ADVANCE(i, set); ) \ 279 280 static sigset_t fastblock_mask; 281 282 static void 283 ast_sig(struct thread *td, int tda) 284 { 285 struct proc *p; 286 int old_boundary, sig; 287 bool resched_sigs; 288 289 p = td->td_proc; 290 291 #ifdef DIAGNOSTIC 292 if (p->p_numthreads == 1 && (tda & (TDAI(TDA_SIG) | 293 TDAI(TDA_AST))) == 0) { 294 PROC_LOCK(p); 295 thread_lock(td); 296 /* 297 * Note that TDA_SIG should be re-read from 298 * td_ast, since signal might have been delivered 299 * after we cleared td_flags above. This is one of 300 * the reason for looping check for AST condition. 301 * See comment in userret() about P_PPWAIT. 302 */ 303 if ((p->p_flag & P_PPWAIT) == 0 && 304 (td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 305 if (SIGPENDING(td) && ((tda | td->td_ast) & 306 (TDAI(TDA_SIG) | TDAI(TDA_AST))) == 0) { 307 thread_unlock(td); /* fix dumps */ 308 panic( 309 "failed2 to set signal flags for ast p %p " 310 "td %p tda %#x td_ast %#x fl %#x", 311 p, td, tda, td->td_ast, td->td_flags); 312 } 313 } 314 thread_unlock(td); 315 PROC_UNLOCK(p); 316 } 317 #endif 318 319 /* 320 * Check for signals. Unlocked reads of p_pendingcnt or 321 * p_siglist might cause process-directed signal to be handled 322 * later. 323 */ 324 if ((tda & TDAI(TDA_SIG)) != 0 || p->p_pendingcnt > 0 || 325 !SIGISEMPTY(p->p_siglist)) { 326 sigfastblock_fetch(td); 327 PROC_LOCK(p); 328 old_boundary = ~TDB_BOUNDARY | (td->td_dbgflags & TDB_BOUNDARY); 329 td->td_dbgflags |= TDB_BOUNDARY; 330 mtx_lock(&p->p_sigacts->ps_mtx); 331 while ((sig = cursig(td)) != 0) { 332 KASSERT(sig >= 0, ("sig %d", sig)); 333 postsig(sig); 334 } 335 mtx_unlock(&p->p_sigacts->ps_mtx); 336 td->td_dbgflags &= old_boundary; 337 PROC_UNLOCK(p); 338 resched_sigs = true; 339 } else { 340 resched_sigs = false; 341 } 342 343 /* 344 * Handle deferred update of the fast sigblock value, after 345 * the postsig() loop was performed. 346 */ 347 sigfastblock_setpend(td, resched_sigs); 348 } 349 350 static void 351 ast_sigsuspend(struct thread *td, int tda __unused) 352 { 353 MPASS((td->td_pflags & TDP_OLDMASK) != 0); 354 td->td_pflags &= ~TDP_OLDMASK; 355 kern_sigprocmask(td, SIG_SETMASK, &td->td_oldsigmask, NULL, 0); 356 } 357 358 static void 359 sigqueue_start(void) 360 { 361 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 362 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 363 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 364 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 365 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 366 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 367 SIGFILLSET(fastblock_mask); 368 SIG_CANTMASK(fastblock_mask); 369 ast_register(TDA_SIG, ASTR_UNCOND, 0, ast_sig); 370 ast_register(TDA_SIGSUSPEND, ASTR_ASTF_REQUIRED | ASTR_TDP, 371 TDP_OLDMASK, ast_sigsuspend); 372 } 373 374 ksiginfo_t * 375 ksiginfo_alloc(int mwait) 376 { 377 MPASS(mwait == M_WAITOK || mwait == M_NOWAIT); 378 379 if (ksiginfo_zone == NULL) 380 return (NULL); 381 return (uma_zalloc(ksiginfo_zone, mwait | M_ZERO)); 382 } 383 384 void 385 ksiginfo_free(ksiginfo_t *ksi) 386 { 387 uma_zfree(ksiginfo_zone, ksi); 388 } 389 390 static __inline bool 391 ksiginfo_tryfree(ksiginfo_t *ksi) 392 { 393 if ((ksi->ksi_flags & KSI_EXT) == 0) { 394 uma_zfree(ksiginfo_zone, ksi); 395 return (true); 396 } 397 return (false); 398 } 399 400 void 401 sigqueue_init(sigqueue_t *list, struct proc *p) 402 { 403 SIGEMPTYSET(list->sq_signals); 404 SIGEMPTYSET(list->sq_kill); 405 SIGEMPTYSET(list->sq_ptrace); 406 TAILQ_INIT(&list->sq_list); 407 list->sq_proc = p; 408 list->sq_flags = SQ_INIT; 409 } 410 411 /* 412 * Get a signal's ksiginfo. 413 * Return: 414 * 0 - signal not found 415 * others - signal number 416 */ 417 static int 418 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 419 { 420 struct proc *p = sq->sq_proc; 421 struct ksiginfo *ksi, *next; 422 int count = 0; 423 424 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 425 426 if (!SIGISMEMBER(sq->sq_signals, signo)) 427 return (0); 428 429 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 430 count++; 431 SIGDELSET(sq->sq_ptrace, signo); 432 si->ksi_flags |= KSI_PTRACE; 433 } 434 if (SIGISMEMBER(sq->sq_kill, signo)) { 435 count++; 436 if (count == 1) 437 SIGDELSET(sq->sq_kill, signo); 438 } 439 440 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 441 if (ksi->ksi_signo == signo) { 442 if (count == 0) { 443 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 444 ksi->ksi_sigq = NULL; 445 ksiginfo_copy(ksi, si); 446 if (ksiginfo_tryfree(ksi) && p != NULL) 447 p->p_pendingcnt--; 448 } 449 if (++count > 1) 450 break; 451 } 452 } 453 454 if (count <= 1) 455 SIGDELSET(sq->sq_signals, signo); 456 si->ksi_signo = signo; 457 return (signo); 458 } 459 460 void 461 sigqueue_take(ksiginfo_t *ksi) 462 { 463 struct ksiginfo *kp; 464 struct proc *p; 465 sigqueue_t *sq; 466 467 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 468 return; 469 470 p = sq->sq_proc; 471 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 472 ksi->ksi_sigq = NULL; 473 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 474 p->p_pendingcnt--; 475 476 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 477 kp = TAILQ_NEXT(kp, ksi_link)) { 478 if (kp->ksi_signo == ksi->ksi_signo) 479 break; 480 } 481 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 482 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 483 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 484 } 485 486 static int 487 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 488 { 489 struct proc *p = sq->sq_proc; 490 struct ksiginfo *ksi; 491 int ret = 0; 492 493 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 494 495 /* 496 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 497 * for these signals. 498 */ 499 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 500 SIGADDSET(sq->sq_kill, signo); 501 goto out_set_bit; 502 } 503 504 /* directly insert the ksi, don't copy it */ 505 if (si->ksi_flags & KSI_INS) { 506 if (si->ksi_flags & KSI_HEAD) 507 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 508 else 509 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 510 si->ksi_sigq = sq; 511 goto out_set_bit; 512 } 513 514 if (__predict_false(ksiginfo_zone == NULL)) { 515 SIGADDSET(sq->sq_kill, signo); 516 goto out_set_bit; 517 } 518 519 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 520 signal_overflow++; 521 ret = EAGAIN; 522 } else if ((ksi = ksiginfo_alloc(M_NOWAIT)) == NULL) { 523 signal_alloc_fail++; 524 ret = EAGAIN; 525 } else { 526 if (p != NULL) 527 p->p_pendingcnt++; 528 ksiginfo_copy(si, ksi); 529 ksi->ksi_signo = signo; 530 if (si->ksi_flags & KSI_HEAD) 531 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 532 else 533 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 534 ksi->ksi_sigq = sq; 535 } 536 537 if (ret != 0) { 538 if ((si->ksi_flags & KSI_PTRACE) != 0) { 539 SIGADDSET(sq->sq_ptrace, signo); 540 ret = 0; 541 goto out_set_bit; 542 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 543 (si->ksi_flags & KSI_SIGQ) == 0) { 544 SIGADDSET(sq->sq_kill, signo); 545 ret = 0; 546 goto out_set_bit; 547 } 548 return (ret); 549 } 550 551 out_set_bit: 552 SIGADDSET(sq->sq_signals, signo); 553 return (ret); 554 } 555 556 void 557 sigqueue_flush(sigqueue_t *sq) 558 { 559 struct proc *p = sq->sq_proc; 560 ksiginfo_t *ksi; 561 562 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 563 564 if (p != NULL) 565 PROC_LOCK_ASSERT(p, MA_OWNED); 566 567 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 568 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 569 ksi->ksi_sigq = NULL; 570 if (ksiginfo_tryfree(ksi) && p != NULL) 571 p->p_pendingcnt--; 572 } 573 574 SIGEMPTYSET(sq->sq_signals); 575 SIGEMPTYSET(sq->sq_kill); 576 SIGEMPTYSET(sq->sq_ptrace); 577 } 578 579 static void 580 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 581 { 582 sigset_t tmp; 583 struct proc *p1, *p2; 584 ksiginfo_t *ksi, *next; 585 586 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 587 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 588 p1 = src->sq_proc; 589 p2 = dst->sq_proc; 590 /* Move siginfo to target list */ 591 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 592 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 593 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 594 if (p1 != NULL) 595 p1->p_pendingcnt--; 596 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 597 ksi->ksi_sigq = dst; 598 if (p2 != NULL) 599 p2->p_pendingcnt++; 600 } 601 } 602 603 /* Move pending bits to target list */ 604 tmp = src->sq_kill; 605 SIGSETAND(tmp, *set); 606 SIGSETOR(dst->sq_kill, tmp); 607 SIGSETNAND(src->sq_kill, tmp); 608 609 tmp = src->sq_ptrace; 610 SIGSETAND(tmp, *set); 611 SIGSETOR(dst->sq_ptrace, tmp); 612 SIGSETNAND(src->sq_ptrace, tmp); 613 614 tmp = src->sq_signals; 615 SIGSETAND(tmp, *set); 616 SIGSETOR(dst->sq_signals, tmp); 617 SIGSETNAND(src->sq_signals, tmp); 618 } 619 620 #if 0 621 static void 622 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 623 { 624 sigset_t set; 625 626 SIGEMPTYSET(set); 627 SIGADDSET(set, signo); 628 sigqueue_move_set(src, dst, &set); 629 } 630 #endif 631 632 static void 633 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 634 { 635 struct proc *p = sq->sq_proc; 636 ksiginfo_t *ksi, *next; 637 638 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 639 640 /* Remove siginfo queue */ 641 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 642 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 643 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 644 ksi->ksi_sigq = NULL; 645 if (ksiginfo_tryfree(ksi) && p != NULL) 646 p->p_pendingcnt--; 647 } 648 } 649 SIGSETNAND(sq->sq_kill, *set); 650 SIGSETNAND(sq->sq_ptrace, *set); 651 SIGSETNAND(sq->sq_signals, *set); 652 } 653 654 void 655 sigqueue_delete(sigqueue_t *sq, int signo) 656 { 657 sigset_t set; 658 659 SIGEMPTYSET(set); 660 SIGADDSET(set, signo); 661 sigqueue_delete_set(sq, &set); 662 } 663 664 /* Remove a set of signals for a process */ 665 static void 666 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 667 { 668 sigqueue_t worklist; 669 struct thread *td0; 670 671 PROC_LOCK_ASSERT(p, MA_OWNED); 672 673 sigqueue_init(&worklist, NULL); 674 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 675 676 FOREACH_THREAD_IN_PROC(p, td0) 677 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 678 679 sigqueue_flush(&worklist); 680 } 681 682 void 683 sigqueue_delete_proc(struct proc *p, int signo) 684 { 685 sigset_t set; 686 687 SIGEMPTYSET(set); 688 SIGADDSET(set, signo); 689 sigqueue_delete_set_proc(p, &set); 690 } 691 692 static void 693 sigqueue_delete_stopmask_proc(struct proc *p) 694 { 695 sigset_t set; 696 697 SIGEMPTYSET(set); 698 SIGADDSET(set, SIGSTOP); 699 SIGADDSET(set, SIGTSTP); 700 SIGADDSET(set, SIGTTIN); 701 SIGADDSET(set, SIGTTOU); 702 sigqueue_delete_set_proc(p, &set); 703 } 704 705 /* 706 * Determine signal that should be delivered to thread td, the current 707 * thread, 0 if none. If there is a pending stop signal with default 708 * action, the process stops in issignal(). 709 */ 710 int 711 cursig(struct thread *td) 712 { 713 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 714 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 715 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 716 return (SIGPENDING(td) ? issignal(td) : 0); 717 } 718 719 /* 720 * Arrange for ast() to handle unmasked pending signals on return to user 721 * mode. This must be called whenever a signal is added to td_sigqueue or 722 * unmasked in td_sigmask. 723 */ 724 void 725 signotify(struct thread *td) 726 { 727 728 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 729 730 if (SIGPENDING(td)) 731 ast_sched(td, TDA_SIG); 732 } 733 734 /* 735 * Returns 1 (true) if altstack is configured for the thread, and the 736 * passed stack bottom address falls into the altstack range. Handles 737 * the 43 compat special case where the alt stack size is zero. 738 */ 739 int 740 sigonstack(size_t sp) 741 { 742 struct thread *td; 743 744 td = curthread; 745 if ((td->td_pflags & TDP_ALTSTACK) == 0) 746 return (0); 747 #if defined(COMPAT_43) 748 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 749 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 750 #endif 751 return (sp >= (size_t)td->td_sigstk.ss_sp && 752 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 753 } 754 755 static __inline int 756 sigprop(int sig) 757 { 758 759 if (sig > 0 && sig < nitems(sigproptbl)) 760 return (sigproptbl[sig]); 761 return (0); 762 } 763 764 static bool 765 sigact_flag_test(const struct sigaction *act, int flag) 766 { 767 768 /* 769 * SA_SIGINFO is reset when signal disposition is set to 770 * ignore or default. Other flags are kept according to user 771 * settings. 772 */ 773 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 774 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 775 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 776 } 777 778 /* 779 * kern_sigaction 780 * sigaction 781 * freebsd4_sigaction 782 * osigaction 783 */ 784 int 785 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 786 struct sigaction *oact, int flags) 787 { 788 struct sigacts *ps; 789 struct proc *p = td->td_proc; 790 791 if (!_SIG_VALID(sig)) 792 return (EINVAL); 793 if (act != NULL && act->sa_handler != SIG_DFL && 794 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 795 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 796 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 797 return (EINVAL); 798 799 PROC_LOCK(p); 800 ps = p->p_sigacts; 801 mtx_lock(&ps->ps_mtx); 802 if (oact) { 803 memset(oact, 0, sizeof(*oact)); 804 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 805 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 806 oact->sa_flags |= SA_ONSTACK; 807 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 808 oact->sa_flags |= SA_RESTART; 809 if (SIGISMEMBER(ps->ps_sigreset, sig)) 810 oact->sa_flags |= SA_RESETHAND; 811 if (SIGISMEMBER(ps->ps_signodefer, sig)) 812 oact->sa_flags |= SA_NODEFER; 813 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 814 oact->sa_flags |= SA_SIGINFO; 815 oact->sa_sigaction = 816 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 817 } else 818 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 819 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 820 oact->sa_flags |= SA_NOCLDSTOP; 821 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 822 oact->sa_flags |= SA_NOCLDWAIT; 823 } 824 if (act) { 825 if ((sig == SIGKILL || sig == SIGSTOP) && 826 act->sa_handler != SIG_DFL) { 827 mtx_unlock(&ps->ps_mtx); 828 PROC_UNLOCK(p); 829 return (EINVAL); 830 } 831 832 /* 833 * Change setting atomically. 834 */ 835 836 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 837 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 838 if (sigact_flag_test(act, SA_SIGINFO)) { 839 ps->ps_sigact[_SIG_IDX(sig)] = 840 (__sighandler_t *)act->sa_sigaction; 841 SIGADDSET(ps->ps_siginfo, sig); 842 } else { 843 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 844 SIGDELSET(ps->ps_siginfo, sig); 845 } 846 if (!sigact_flag_test(act, SA_RESTART)) 847 SIGADDSET(ps->ps_sigintr, sig); 848 else 849 SIGDELSET(ps->ps_sigintr, sig); 850 if (sigact_flag_test(act, SA_ONSTACK)) 851 SIGADDSET(ps->ps_sigonstack, sig); 852 else 853 SIGDELSET(ps->ps_sigonstack, sig); 854 if (sigact_flag_test(act, SA_RESETHAND)) 855 SIGADDSET(ps->ps_sigreset, sig); 856 else 857 SIGDELSET(ps->ps_sigreset, sig); 858 if (sigact_flag_test(act, SA_NODEFER)) 859 SIGADDSET(ps->ps_signodefer, sig); 860 else 861 SIGDELSET(ps->ps_signodefer, sig); 862 if (sig == SIGCHLD) { 863 if (act->sa_flags & SA_NOCLDSTOP) 864 ps->ps_flag |= PS_NOCLDSTOP; 865 else 866 ps->ps_flag &= ~PS_NOCLDSTOP; 867 if (act->sa_flags & SA_NOCLDWAIT) { 868 /* 869 * Paranoia: since SA_NOCLDWAIT is implemented 870 * by reparenting the dying child to PID 1 (and 871 * trust it to reap the zombie), PID 1 itself 872 * is forbidden to set SA_NOCLDWAIT. 873 */ 874 if (p->p_pid == 1) 875 ps->ps_flag &= ~PS_NOCLDWAIT; 876 else 877 ps->ps_flag |= PS_NOCLDWAIT; 878 } else 879 ps->ps_flag &= ~PS_NOCLDWAIT; 880 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 881 ps->ps_flag |= PS_CLDSIGIGN; 882 else 883 ps->ps_flag &= ~PS_CLDSIGIGN; 884 } 885 /* 886 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 887 * and for signals set to SIG_DFL where the default is to 888 * ignore. However, don't put SIGCONT in ps_sigignore, as we 889 * have to restart the process. 890 */ 891 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 892 (sigprop(sig) & SIGPROP_IGNORE && 893 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 894 /* never to be seen again */ 895 sigqueue_delete_proc(p, sig); 896 if (sig != SIGCONT) 897 /* easier in psignal */ 898 SIGADDSET(ps->ps_sigignore, sig); 899 SIGDELSET(ps->ps_sigcatch, sig); 900 } else { 901 SIGDELSET(ps->ps_sigignore, sig); 902 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 903 SIGDELSET(ps->ps_sigcatch, sig); 904 else 905 SIGADDSET(ps->ps_sigcatch, sig); 906 } 907 #ifdef COMPAT_FREEBSD4 908 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 909 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 910 (flags & KSA_FREEBSD4) == 0) 911 SIGDELSET(ps->ps_freebsd4, sig); 912 else 913 SIGADDSET(ps->ps_freebsd4, sig); 914 #endif 915 #ifdef COMPAT_43 916 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 917 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 918 (flags & KSA_OSIGSET) == 0) 919 SIGDELSET(ps->ps_osigset, sig); 920 else 921 SIGADDSET(ps->ps_osigset, sig); 922 #endif 923 } 924 mtx_unlock(&ps->ps_mtx); 925 PROC_UNLOCK(p); 926 return (0); 927 } 928 929 #ifndef _SYS_SYSPROTO_H_ 930 struct sigaction_args { 931 int sig; 932 struct sigaction *act; 933 struct sigaction *oact; 934 }; 935 #endif 936 int 937 sys_sigaction(struct thread *td, struct sigaction_args *uap) 938 { 939 struct sigaction act, oact; 940 struct sigaction *actp, *oactp; 941 int error; 942 943 actp = (uap->act != NULL) ? &act : NULL; 944 oactp = (uap->oact != NULL) ? &oact : NULL; 945 if (actp) { 946 error = copyin(uap->act, actp, sizeof(act)); 947 if (error) 948 return (error); 949 } 950 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 951 if (oactp && !error) 952 error = copyout(oactp, uap->oact, sizeof(oact)); 953 return (error); 954 } 955 956 #ifdef COMPAT_FREEBSD4 957 #ifndef _SYS_SYSPROTO_H_ 958 struct freebsd4_sigaction_args { 959 int sig; 960 struct sigaction *act; 961 struct sigaction *oact; 962 }; 963 #endif 964 int 965 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 966 { 967 struct sigaction act, oact; 968 struct sigaction *actp, *oactp; 969 int error; 970 971 actp = (uap->act != NULL) ? &act : NULL; 972 oactp = (uap->oact != NULL) ? &oact : NULL; 973 if (actp) { 974 error = copyin(uap->act, actp, sizeof(act)); 975 if (error) 976 return (error); 977 } 978 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 979 if (oactp && !error) 980 error = copyout(oactp, uap->oact, sizeof(oact)); 981 return (error); 982 } 983 #endif /* COMAPT_FREEBSD4 */ 984 985 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 986 #ifndef _SYS_SYSPROTO_H_ 987 struct osigaction_args { 988 int signum; 989 struct osigaction *nsa; 990 struct osigaction *osa; 991 }; 992 #endif 993 int 994 osigaction(struct thread *td, struct osigaction_args *uap) 995 { 996 struct osigaction sa; 997 struct sigaction nsa, osa; 998 struct sigaction *nsap, *osap; 999 int error; 1000 1001 if (uap->signum <= 0 || uap->signum >= ONSIG) 1002 return (EINVAL); 1003 1004 nsap = (uap->nsa != NULL) ? &nsa : NULL; 1005 osap = (uap->osa != NULL) ? &osa : NULL; 1006 1007 if (nsap) { 1008 error = copyin(uap->nsa, &sa, sizeof(sa)); 1009 if (error) 1010 return (error); 1011 nsap->sa_handler = sa.sa_handler; 1012 nsap->sa_flags = sa.sa_flags; 1013 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 1014 } 1015 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1016 if (osap && !error) { 1017 sa.sa_handler = osap->sa_handler; 1018 sa.sa_flags = osap->sa_flags; 1019 SIG2OSIG(osap->sa_mask, sa.sa_mask); 1020 error = copyout(&sa, uap->osa, sizeof(sa)); 1021 } 1022 return (error); 1023 } 1024 1025 #if !defined(__i386__) 1026 /* Avoid replicating the same stub everywhere */ 1027 int 1028 osigreturn(struct thread *td, struct osigreturn_args *uap) 1029 { 1030 1031 return (nosys(td, (struct nosys_args *)uap)); 1032 } 1033 #endif 1034 #endif /* COMPAT_43 */ 1035 1036 /* 1037 * Initialize signal state for process 0; 1038 * set to ignore signals that are ignored by default. 1039 */ 1040 void 1041 siginit(struct proc *p) 1042 { 1043 int i; 1044 struct sigacts *ps; 1045 1046 PROC_LOCK(p); 1047 ps = p->p_sigacts; 1048 mtx_lock(&ps->ps_mtx); 1049 for (i = 1; i <= NSIG; i++) { 1050 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 1051 SIGADDSET(ps->ps_sigignore, i); 1052 } 1053 } 1054 mtx_unlock(&ps->ps_mtx); 1055 PROC_UNLOCK(p); 1056 } 1057 1058 /* 1059 * Reset specified signal to the default disposition. 1060 */ 1061 static void 1062 sigdflt(struct sigacts *ps, int sig) 1063 { 1064 1065 mtx_assert(&ps->ps_mtx, MA_OWNED); 1066 SIGDELSET(ps->ps_sigcatch, sig); 1067 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 1068 SIGADDSET(ps->ps_sigignore, sig); 1069 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1070 SIGDELSET(ps->ps_siginfo, sig); 1071 } 1072 1073 /* 1074 * Reset signals for an exec of the specified process. 1075 */ 1076 void 1077 execsigs(struct proc *p) 1078 { 1079 struct sigacts *ps; 1080 struct thread *td; 1081 1082 /* 1083 * Reset caught signals. Held signals remain held 1084 * through td_sigmask (unless they were caught, 1085 * and are now ignored by default). 1086 */ 1087 PROC_LOCK_ASSERT(p, MA_OWNED); 1088 ps = p->p_sigacts; 1089 mtx_lock(&ps->ps_mtx); 1090 sig_drop_caught(p); 1091 1092 /* 1093 * Reset stack state to the user stack. 1094 * Clear set of signals caught on the signal stack. 1095 */ 1096 td = curthread; 1097 MPASS(td->td_proc == p); 1098 td->td_sigstk.ss_flags = SS_DISABLE; 1099 td->td_sigstk.ss_size = 0; 1100 td->td_sigstk.ss_sp = 0; 1101 td->td_pflags &= ~TDP_ALTSTACK; 1102 /* 1103 * Reset no zombies if child dies flag as Solaris does. 1104 */ 1105 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1106 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1107 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1108 mtx_unlock(&ps->ps_mtx); 1109 } 1110 1111 /* 1112 * kern_sigprocmask() 1113 * 1114 * Manipulate signal mask. 1115 */ 1116 int 1117 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1118 int flags) 1119 { 1120 sigset_t new_block, oset1; 1121 struct proc *p; 1122 int error; 1123 1124 p = td->td_proc; 1125 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1126 PROC_LOCK_ASSERT(p, MA_OWNED); 1127 else 1128 PROC_LOCK(p); 1129 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1130 ? MA_OWNED : MA_NOTOWNED); 1131 if (oset != NULL) 1132 *oset = td->td_sigmask; 1133 1134 error = 0; 1135 if (set != NULL) { 1136 switch (how) { 1137 case SIG_BLOCK: 1138 SIG_CANTMASK(*set); 1139 oset1 = td->td_sigmask; 1140 SIGSETOR(td->td_sigmask, *set); 1141 new_block = td->td_sigmask; 1142 SIGSETNAND(new_block, oset1); 1143 break; 1144 case SIG_UNBLOCK: 1145 SIGSETNAND(td->td_sigmask, *set); 1146 signotify(td); 1147 goto out; 1148 case SIG_SETMASK: 1149 SIG_CANTMASK(*set); 1150 oset1 = td->td_sigmask; 1151 if (flags & SIGPROCMASK_OLD) 1152 SIGSETLO(td->td_sigmask, *set); 1153 else 1154 td->td_sigmask = *set; 1155 new_block = td->td_sigmask; 1156 SIGSETNAND(new_block, oset1); 1157 signotify(td); 1158 break; 1159 default: 1160 error = EINVAL; 1161 goto out; 1162 } 1163 1164 /* 1165 * The new_block set contains signals that were not previously 1166 * blocked, but are blocked now. 1167 * 1168 * In case we block any signal that was not previously blocked 1169 * for td, and process has the signal pending, try to schedule 1170 * signal delivery to some thread that does not block the 1171 * signal, possibly waking it up. 1172 */ 1173 if (p->p_numthreads != 1) 1174 reschedule_signals(p, new_block, flags); 1175 } 1176 1177 out: 1178 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1179 PROC_UNLOCK(p); 1180 return (error); 1181 } 1182 1183 #ifndef _SYS_SYSPROTO_H_ 1184 struct sigprocmask_args { 1185 int how; 1186 const sigset_t *set; 1187 sigset_t *oset; 1188 }; 1189 #endif 1190 int 1191 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1192 { 1193 sigset_t set, oset; 1194 sigset_t *setp, *osetp; 1195 int error; 1196 1197 setp = (uap->set != NULL) ? &set : NULL; 1198 osetp = (uap->oset != NULL) ? &oset : NULL; 1199 if (setp) { 1200 error = copyin(uap->set, setp, sizeof(set)); 1201 if (error) 1202 return (error); 1203 } 1204 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1205 if (osetp && !error) { 1206 error = copyout(osetp, uap->oset, sizeof(oset)); 1207 } 1208 return (error); 1209 } 1210 1211 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1212 #ifndef _SYS_SYSPROTO_H_ 1213 struct osigprocmask_args { 1214 int how; 1215 osigset_t mask; 1216 }; 1217 #endif 1218 int 1219 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1220 { 1221 sigset_t set, oset; 1222 int error; 1223 1224 OSIG2SIG(uap->mask, set); 1225 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1226 SIG2OSIG(oset, td->td_retval[0]); 1227 return (error); 1228 } 1229 #endif /* COMPAT_43 */ 1230 1231 int 1232 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1233 { 1234 ksiginfo_t ksi; 1235 sigset_t set; 1236 int error; 1237 1238 error = copyin(uap->set, &set, sizeof(set)); 1239 if (error) { 1240 td->td_retval[0] = error; 1241 return (0); 1242 } 1243 1244 error = kern_sigtimedwait(td, set, &ksi, NULL); 1245 if (error) { 1246 /* 1247 * sigwait() function shall not return EINTR, but 1248 * the syscall does. Non-ancient libc provides the 1249 * wrapper which hides EINTR. Otherwise, EINTR return 1250 * is used by libthr to handle required cancellation 1251 * point in the sigwait(). 1252 */ 1253 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1254 return (ERESTART); 1255 td->td_retval[0] = error; 1256 return (0); 1257 } 1258 1259 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1260 td->td_retval[0] = error; 1261 return (0); 1262 } 1263 1264 int 1265 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1266 { 1267 struct timespec ts; 1268 struct timespec *timeout; 1269 sigset_t set; 1270 ksiginfo_t ksi; 1271 int error; 1272 1273 if (uap->timeout) { 1274 error = copyin(uap->timeout, &ts, sizeof(ts)); 1275 if (error) 1276 return (error); 1277 1278 timeout = &ts; 1279 } else 1280 timeout = NULL; 1281 1282 error = copyin(uap->set, &set, sizeof(set)); 1283 if (error) 1284 return (error); 1285 1286 error = kern_sigtimedwait(td, set, &ksi, timeout); 1287 if (error) 1288 return (error); 1289 1290 if (uap->info) 1291 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1292 1293 if (error == 0) 1294 td->td_retval[0] = ksi.ksi_signo; 1295 return (error); 1296 } 1297 1298 int 1299 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1300 { 1301 ksiginfo_t ksi; 1302 sigset_t set; 1303 int error; 1304 1305 error = copyin(uap->set, &set, sizeof(set)); 1306 if (error) 1307 return (error); 1308 1309 error = kern_sigtimedwait(td, set, &ksi, NULL); 1310 if (error) 1311 return (error); 1312 1313 if (uap->info) 1314 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1315 1316 if (error == 0) 1317 td->td_retval[0] = ksi.ksi_signo; 1318 return (error); 1319 } 1320 1321 static void 1322 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1323 { 1324 struct thread *thr; 1325 1326 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1327 if (thr == td) 1328 thr->td_si = *si; 1329 else 1330 thr->td_si.si_signo = 0; 1331 } 1332 } 1333 1334 int 1335 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1336 struct timespec *timeout) 1337 { 1338 struct sigacts *ps; 1339 sigset_t saved_mask, new_block; 1340 struct proc *p; 1341 int error, sig, timevalid = 0; 1342 sbintime_t sbt, precision, tsbt; 1343 struct timespec ts; 1344 bool traced; 1345 1346 p = td->td_proc; 1347 error = 0; 1348 traced = false; 1349 1350 /* Ensure the sigfastblock value is up to date. */ 1351 sigfastblock_fetch(td); 1352 1353 if (timeout != NULL) { 1354 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1355 timevalid = 1; 1356 ts = *timeout; 1357 if (ts.tv_sec < INT32_MAX / 2) { 1358 tsbt = tstosbt(ts); 1359 precision = tsbt; 1360 precision >>= tc_precexp; 1361 if (TIMESEL(&sbt, tsbt)) 1362 sbt += tc_tick_sbt; 1363 sbt += tsbt; 1364 } else 1365 precision = sbt = 0; 1366 } 1367 } else 1368 precision = sbt = 0; 1369 ksiginfo_init(ksi); 1370 /* Some signals can not be waited for. */ 1371 SIG_CANTMASK(waitset); 1372 ps = p->p_sigacts; 1373 PROC_LOCK(p); 1374 saved_mask = td->td_sigmask; 1375 SIGSETNAND(td->td_sigmask, waitset); 1376 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1377 !kern_sig_discard_ign) { 1378 thread_lock(td); 1379 td->td_flags |= TDF_SIGWAIT; 1380 thread_unlock(td); 1381 } 1382 for (;;) { 1383 mtx_lock(&ps->ps_mtx); 1384 sig = cursig(td); 1385 mtx_unlock(&ps->ps_mtx); 1386 KASSERT(sig >= 0, ("sig %d", sig)); 1387 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1388 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1389 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1390 error = 0; 1391 break; 1392 } 1393 } 1394 1395 if (error != 0) 1396 break; 1397 1398 /* 1399 * POSIX says this must be checked after looking for pending 1400 * signals. 1401 */ 1402 if (timeout != NULL && !timevalid) { 1403 error = EINVAL; 1404 break; 1405 } 1406 1407 if (traced) { 1408 error = EINTR; 1409 break; 1410 } 1411 1412 error = msleep_sbt(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1413 "sigwait", sbt, precision, C_ABSOLUTE); 1414 1415 /* The syscalls can not be restarted. */ 1416 if (error == ERESTART) 1417 error = EINTR; 1418 1419 /* 1420 * If PTRACE_SCE or PTRACE_SCX were set after 1421 * userspace entered the syscall, return spurious 1422 * EINTR after wait was done. Only do this as last 1423 * resort after rechecking for possible queued signals 1424 * and expired timeouts. 1425 */ 1426 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1427 traced = true; 1428 } 1429 thread_lock(td); 1430 td->td_flags &= ~TDF_SIGWAIT; 1431 thread_unlock(td); 1432 1433 new_block = saved_mask; 1434 SIGSETNAND(new_block, td->td_sigmask); 1435 td->td_sigmask = saved_mask; 1436 /* 1437 * Fewer signals can be delivered to us, reschedule signal 1438 * notification. 1439 */ 1440 if (p->p_numthreads != 1) 1441 reschedule_signals(p, new_block, 0); 1442 1443 if (error == 0) { 1444 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1445 1446 if (ksi->ksi_code == SI_TIMER) 1447 itimer_accept(p, ksi->ksi_timerid, ksi); 1448 1449 #ifdef KTRACE 1450 if (KTRPOINT(td, KTR_PSIG)) { 1451 sig_t action; 1452 1453 mtx_lock(&ps->ps_mtx); 1454 action = ps->ps_sigact[_SIG_IDX(sig)]; 1455 mtx_unlock(&ps->ps_mtx); 1456 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1457 } 1458 #endif 1459 if (sig == SIGKILL) { 1460 proc_td_siginfo_capture(td, &ksi->ksi_info); 1461 sigexit(td, sig); 1462 } 1463 } 1464 PROC_UNLOCK(p); 1465 return (error); 1466 } 1467 1468 #ifndef _SYS_SYSPROTO_H_ 1469 struct sigpending_args { 1470 sigset_t *set; 1471 }; 1472 #endif 1473 int 1474 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1475 { 1476 struct proc *p = td->td_proc; 1477 sigset_t pending; 1478 1479 PROC_LOCK(p); 1480 pending = p->p_sigqueue.sq_signals; 1481 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1482 PROC_UNLOCK(p); 1483 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1484 } 1485 1486 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1487 #ifndef _SYS_SYSPROTO_H_ 1488 struct osigpending_args { 1489 int dummy; 1490 }; 1491 #endif 1492 int 1493 osigpending(struct thread *td, struct osigpending_args *uap) 1494 { 1495 struct proc *p = td->td_proc; 1496 sigset_t pending; 1497 1498 PROC_LOCK(p); 1499 pending = p->p_sigqueue.sq_signals; 1500 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1501 PROC_UNLOCK(p); 1502 SIG2OSIG(pending, td->td_retval[0]); 1503 return (0); 1504 } 1505 #endif /* COMPAT_43 */ 1506 1507 #if defined(COMPAT_43) 1508 /* 1509 * Generalized interface signal handler, 4.3-compatible. 1510 */ 1511 #ifndef _SYS_SYSPROTO_H_ 1512 struct osigvec_args { 1513 int signum; 1514 struct sigvec *nsv; 1515 struct sigvec *osv; 1516 }; 1517 #endif 1518 /* ARGSUSED */ 1519 int 1520 osigvec(struct thread *td, struct osigvec_args *uap) 1521 { 1522 struct sigvec vec; 1523 struct sigaction nsa, osa; 1524 struct sigaction *nsap, *osap; 1525 int error; 1526 1527 if (uap->signum <= 0 || uap->signum >= ONSIG) 1528 return (EINVAL); 1529 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1530 osap = (uap->osv != NULL) ? &osa : NULL; 1531 if (nsap) { 1532 error = copyin(uap->nsv, &vec, sizeof(vec)); 1533 if (error) 1534 return (error); 1535 nsap->sa_handler = vec.sv_handler; 1536 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1537 nsap->sa_flags = vec.sv_flags; 1538 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1539 } 1540 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1541 if (osap && !error) { 1542 vec.sv_handler = osap->sa_handler; 1543 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1544 vec.sv_flags = osap->sa_flags; 1545 vec.sv_flags &= ~SA_NOCLDWAIT; 1546 vec.sv_flags ^= SA_RESTART; 1547 error = copyout(&vec, uap->osv, sizeof(vec)); 1548 } 1549 return (error); 1550 } 1551 1552 #ifndef _SYS_SYSPROTO_H_ 1553 struct osigblock_args { 1554 int mask; 1555 }; 1556 #endif 1557 int 1558 osigblock(struct thread *td, struct osigblock_args *uap) 1559 { 1560 sigset_t set, oset; 1561 1562 OSIG2SIG(uap->mask, set); 1563 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1564 SIG2OSIG(oset, td->td_retval[0]); 1565 return (0); 1566 } 1567 1568 #ifndef _SYS_SYSPROTO_H_ 1569 struct osigsetmask_args { 1570 int mask; 1571 }; 1572 #endif 1573 int 1574 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1575 { 1576 sigset_t set, oset; 1577 1578 OSIG2SIG(uap->mask, set); 1579 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1580 SIG2OSIG(oset, td->td_retval[0]); 1581 return (0); 1582 } 1583 #endif /* COMPAT_43 */ 1584 1585 /* 1586 * Suspend calling thread until signal, providing mask to be set in the 1587 * meantime. 1588 */ 1589 #ifndef _SYS_SYSPROTO_H_ 1590 struct sigsuspend_args { 1591 const sigset_t *sigmask; 1592 }; 1593 #endif 1594 /* ARGSUSED */ 1595 int 1596 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1597 { 1598 sigset_t mask; 1599 int error; 1600 1601 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1602 if (error) 1603 return (error); 1604 return (kern_sigsuspend(td, mask)); 1605 } 1606 1607 int 1608 kern_sigsuspend(struct thread *td, sigset_t mask) 1609 { 1610 struct proc *p = td->td_proc; 1611 int has_sig, sig; 1612 1613 /* Ensure the sigfastblock value is up to date. */ 1614 sigfastblock_fetch(td); 1615 1616 /* 1617 * When returning from sigsuspend, we want 1618 * the old mask to be restored after the 1619 * signal handler has finished. Thus, we 1620 * save it here and mark the sigacts structure 1621 * to indicate this. 1622 */ 1623 PROC_LOCK(p); 1624 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1625 SIGPROCMASK_PROC_LOCKED); 1626 td->td_pflags |= TDP_OLDMASK; 1627 ast_sched(td, TDA_SIGSUSPEND); 1628 1629 /* 1630 * Process signals now. Otherwise, we can get spurious wakeup 1631 * due to signal entered process queue, but delivered to other 1632 * thread. But sigsuspend should return only on signal 1633 * delivery. 1634 */ 1635 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1636 for (has_sig = 0; !has_sig;) { 1637 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1638 0) == 0) 1639 /* void */; 1640 thread_suspend_check(0); 1641 mtx_lock(&p->p_sigacts->ps_mtx); 1642 while ((sig = cursig(td)) != 0) { 1643 KASSERT(sig >= 0, ("sig %d", sig)); 1644 has_sig += postsig(sig); 1645 } 1646 mtx_unlock(&p->p_sigacts->ps_mtx); 1647 1648 /* 1649 * If PTRACE_SCE or PTRACE_SCX were set after 1650 * userspace entered the syscall, return spurious 1651 * EINTR. 1652 */ 1653 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1654 has_sig += 1; 1655 } 1656 PROC_UNLOCK(p); 1657 td->td_errno = EINTR; 1658 td->td_pflags |= TDP_NERRNO; 1659 return (EJUSTRETURN); 1660 } 1661 1662 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1663 /* 1664 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1665 * convention: libc stub passes mask, not pointer, to save a copyin. 1666 */ 1667 #ifndef _SYS_SYSPROTO_H_ 1668 struct osigsuspend_args { 1669 osigset_t mask; 1670 }; 1671 #endif 1672 /* ARGSUSED */ 1673 int 1674 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1675 { 1676 sigset_t mask; 1677 1678 OSIG2SIG(uap->mask, mask); 1679 return (kern_sigsuspend(td, mask)); 1680 } 1681 #endif /* COMPAT_43 */ 1682 1683 #if defined(COMPAT_43) 1684 #ifndef _SYS_SYSPROTO_H_ 1685 struct osigstack_args { 1686 struct sigstack *nss; 1687 struct sigstack *oss; 1688 }; 1689 #endif 1690 /* ARGSUSED */ 1691 int 1692 osigstack(struct thread *td, struct osigstack_args *uap) 1693 { 1694 struct sigstack nss, oss; 1695 int error = 0; 1696 1697 if (uap->nss != NULL) { 1698 error = copyin(uap->nss, &nss, sizeof(nss)); 1699 if (error) 1700 return (error); 1701 } 1702 oss.ss_sp = td->td_sigstk.ss_sp; 1703 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1704 if (uap->nss != NULL) { 1705 td->td_sigstk.ss_sp = nss.ss_sp; 1706 td->td_sigstk.ss_size = 0; 1707 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1708 td->td_pflags |= TDP_ALTSTACK; 1709 } 1710 if (uap->oss != NULL) 1711 error = copyout(&oss, uap->oss, sizeof(oss)); 1712 1713 return (error); 1714 } 1715 #endif /* COMPAT_43 */ 1716 1717 #ifndef _SYS_SYSPROTO_H_ 1718 struct sigaltstack_args { 1719 stack_t *ss; 1720 stack_t *oss; 1721 }; 1722 #endif 1723 /* ARGSUSED */ 1724 int 1725 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1726 { 1727 stack_t ss, oss; 1728 int error; 1729 1730 if (uap->ss != NULL) { 1731 error = copyin(uap->ss, &ss, sizeof(ss)); 1732 if (error) 1733 return (error); 1734 } 1735 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1736 (uap->oss != NULL) ? &oss : NULL); 1737 if (error) 1738 return (error); 1739 if (uap->oss != NULL) 1740 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1741 return (error); 1742 } 1743 1744 int 1745 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1746 { 1747 struct proc *p = td->td_proc; 1748 int oonstack; 1749 1750 oonstack = sigonstack(cpu_getstack(td)); 1751 1752 if (oss != NULL) { 1753 *oss = td->td_sigstk; 1754 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1755 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1756 } 1757 1758 if (ss != NULL) { 1759 if (oonstack) 1760 return (EPERM); 1761 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1762 return (EINVAL); 1763 if (!(ss->ss_flags & SS_DISABLE)) { 1764 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1765 return (ENOMEM); 1766 1767 td->td_sigstk = *ss; 1768 td->td_pflags |= TDP_ALTSTACK; 1769 } else { 1770 td->td_pflags &= ~TDP_ALTSTACK; 1771 } 1772 } 1773 return (0); 1774 } 1775 1776 struct killpg1_ctx { 1777 struct thread *td; 1778 ksiginfo_t *ksi; 1779 int sig; 1780 bool sent; 1781 bool found; 1782 int ret; 1783 }; 1784 1785 static void 1786 killpg1_sendsig_locked(struct proc *p, struct killpg1_ctx *arg) 1787 { 1788 int err; 1789 1790 err = p_cansignal(arg->td, p, arg->sig); 1791 if (err == 0 && arg->sig != 0) 1792 pksignal(p, arg->sig, arg->ksi); 1793 if (err != ESRCH) 1794 arg->found = true; 1795 if (err == 0) 1796 arg->sent = true; 1797 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1798 arg->ret = err; 1799 } 1800 1801 static void 1802 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1803 { 1804 1805 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1806 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1807 return; 1808 1809 PROC_LOCK(p); 1810 killpg1_sendsig_locked(p, arg); 1811 PROC_UNLOCK(p); 1812 } 1813 1814 static void 1815 kill_processes_prison_cb(struct proc *p, void *arg) 1816 { 1817 struct killpg1_ctx *ctx = arg; 1818 1819 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1820 (p == ctx->td->td_proc) || p->p_state == PRS_NEW) 1821 return; 1822 1823 killpg1_sendsig_locked(p, ctx); 1824 } 1825 1826 /* 1827 * Common code for kill process group/broadcast kill. 1828 * cp is calling process. 1829 */ 1830 static int 1831 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1832 { 1833 struct proc *p; 1834 struct pgrp *pgrp; 1835 struct killpg1_ctx arg; 1836 1837 arg.td = td; 1838 arg.ksi = ksi; 1839 arg.sig = sig; 1840 arg.sent = false; 1841 arg.found = false; 1842 arg.ret = 0; 1843 if (all) { 1844 /* 1845 * broadcast 1846 */ 1847 prison_proc_iterate(td->td_ucred->cr_prison, 1848 kill_processes_prison_cb, &arg); 1849 } else { 1850 sx_slock(&proctree_lock); 1851 if (pgid == 0) { 1852 /* 1853 * zero pgid means send to my process group. 1854 */ 1855 pgrp = td->td_proc->p_pgrp; 1856 PGRP_LOCK(pgrp); 1857 } else { 1858 pgrp = pgfind(pgid); 1859 if (pgrp == NULL) { 1860 sx_sunlock(&proctree_lock); 1861 return (ESRCH); 1862 } 1863 } 1864 sx_sunlock(&proctree_lock); 1865 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1866 killpg1_sendsig(p, false, &arg); 1867 } 1868 PGRP_UNLOCK(pgrp); 1869 } 1870 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1871 if (arg.ret == 0 && !arg.sent) 1872 arg.ret = arg.found ? EPERM : ESRCH; 1873 return (arg.ret); 1874 } 1875 1876 #ifndef _SYS_SYSPROTO_H_ 1877 struct kill_args { 1878 int pid; 1879 int signum; 1880 }; 1881 #endif 1882 /* ARGSUSED */ 1883 int 1884 sys_kill(struct thread *td, struct kill_args *uap) 1885 { 1886 1887 return (kern_kill(td, uap->pid, uap->signum)); 1888 } 1889 1890 int 1891 kern_kill(struct thread *td, pid_t pid, int signum) 1892 { 1893 ksiginfo_t ksi; 1894 struct proc *p; 1895 int error; 1896 1897 /* 1898 * A process in capability mode can send signals only to himself. 1899 * The main rationale behind this is that abort(3) is implemented as 1900 * kill(getpid(), SIGABRT). 1901 */ 1902 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1903 return (ECAPMODE); 1904 1905 AUDIT_ARG_SIGNUM(signum); 1906 AUDIT_ARG_PID(pid); 1907 if ((u_int)signum > _SIG_MAXSIG) 1908 return (EINVAL); 1909 1910 ksiginfo_init(&ksi); 1911 ksi.ksi_signo = signum; 1912 ksi.ksi_code = SI_USER; 1913 ksi.ksi_pid = td->td_proc->p_pid; 1914 ksi.ksi_uid = td->td_ucred->cr_ruid; 1915 1916 if (pid > 0) { 1917 /* kill single process */ 1918 if ((p = pfind_any(pid)) == NULL) 1919 return (ESRCH); 1920 AUDIT_ARG_PROCESS(p); 1921 error = p_cansignal(td, p, signum); 1922 if (error == 0 && signum) 1923 pksignal(p, signum, &ksi); 1924 PROC_UNLOCK(p); 1925 return (error); 1926 } 1927 switch (pid) { 1928 case -1: /* broadcast signal */ 1929 return (killpg1(td, signum, 0, 1, &ksi)); 1930 case 0: /* signal own process group */ 1931 return (killpg1(td, signum, 0, 0, &ksi)); 1932 default: /* negative explicit process group */ 1933 return (killpg1(td, signum, -pid, 0, &ksi)); 1934 } 1935 /* NOTREACHED */ 1936 } 1937 1938 int 1939 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1940 { 1941 struct proc *p; 1942 int error; 1943 1944 AUDIT_ARG_SIGNUM(uap->signum); 1945 AUDIT_ARG_FD(uap->fd); 1946 if ((u_int)uap->signum > _SIG_MAXSIG) 1947 return (EINVAL); 1948 1949 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1950 if (error) 1951 return (error); 1952 AUDIT_ARG_PROCESS(p); 1953 error = p_cansignal(td, p, uap->signum); 1954 if (error == 0 && uap->signum) 1955 kern_psignal(p, uap->signum); 1956 PROC_UNLOCK(p); 1957 return (error); 1958 } 1959 1960 #if defined(COMPAT_43) 1961 #ifndef _SYS_SYSPROTO_H_ 1962 struct okillpg_args { 1963 int pgid; 1964 int signum; 1965 }; 1966 #endif 1967 /* ARGSUSED */ 1968 int 1969 okillpg(struct thread *td, struct okillpg_args *uap) 1970 { 1971 ksiginfo_t ksi; 1972 1973 AUDIT_ARG_SIGNUM(uap->signum); 1974 AUDIT_ARG_PID(uap->pgid); 1975 if ((u_int)uap->signum > _SIG_MAXSIG) 1976 return (EINVAL); 1977 1978 ksiginfo_init(&ksi); 1979 ksi.ksi_signo = uap->signum; 1980 ksi.ksi_code = SI_USER; 1981 ksi.ksi_pid = td->td_proc->p_pid; 1982 ksi.ksi_uid = td->td_ucred->cr_ruid; 1983 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1984 } 1985 #endif /* COMPAT_43 */ 1986 1987 #ifndef _SYS_SYSPROTO_H_ 1988 struct sigqueue_args { 1989 pid_t pid; 1990 int signum; 1991 /* union sigval */ void *value; 1992 }; 1993 #endif 1994 int 1995 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1996 { 1997 union sigval sv; 1998 1999 sv.sival_ptr = uap->value; 2000 2001 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 2002 } 2003 2004 int 2005 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 2006 { 2007 ksiginfo_t ksi; 2008 struct proc *p; 2009 int error; 2010 2011 if ((u_int)signum > _SIG_MAXSIG) 2012 return (EINVAL); 2013 2014 /* 2015 * Specification says sigqueue can only send signal to 2016 * single process. 2017 */ 2018 if (pid <= 0) 2019 return (EINVAL); 2020 2021 if ((p = pfind_any(pid)) == NULL) 2022 return (ESRCH); 2023 error = p_cansignal(td, p, signum); 2024 if (error == 0 && signum != 0) { 2025 ksiginfo_init(&ksi); 2026 ksi.ksi_flags = KSI_SIGQ; 2027 ksi.ksi_signo = signum; 2028 ksi.ksi_code = SI_QUEUE; 2029 ksi.ksi_pid = td->td_proc->p_pid; 2030 ksi.ksi_uid = td->td_ucred->cr_ruid; 2031 ksi.ksi_value = *value; 2032 error = pksignal(p, ksi.ksi_signo, &ksi); 2033 } 2034 PROC_UNLOCK(p); 2035 return (error); 2036 } 2037 2038 /* 2039 * Send a signal to a process group. 2040 */ 2041 void 2042 gsignal(int pgid, int sig, ksiginfo_t *ksi) 2043 { 2044 struct pgrp *pgrp; 2045 2046 if (pgid != 0) { 2047 sx_slock(&proctree_lock); 2048 pgrp = pgfind(pgid); 2049 sx_sunlock(&proctree_lock); 2050 if (pgrp != NULL) { 2051 pgsignal(pgrp, sig, 0, ksi); 2052 PGRP_UNLOCK(pgrp); 2053 } 2054 } 2055 } 2056 2057 /* 2058 * Send a signal to a process group. If checktty is 1, 2059 * limit to members which have a controlling terminal. 2060 */ 2061 void 2062 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 2063 { 2064 struct proc *p; 2065 2066 if (pgrp) { 2067 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 2068 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 2069 PROC_LOCK(p); 2070 if (p->p_state == PRS_NORMAL && 2071 (checkctty == 0 || p->p_flag & P_CONTROLT)) 2072 pksignal(p, sig, ksi); 2073 PROC_UNLOCK(p); 2074 } 2075 } 2076 } 2077 2078 /* 2079 * Recalculate the signal mask and reset the signal disposition after 2080 * usermode frame for delivery is formed. Should be called after 2081 * mach-specific routine, because sysent->sv_sendsig() needs correct 2082 * ps_siginfo and signal mask. 2083 */ 2084 static void 2085 postsig_done(int sig, struct thread *td, struct sigacts *ps) 2086 { 2087 sigset_t mask; 2088 2089 mtx_assert(&ps->ps_mtx, MA_OWNED); 2090 td->td_ru.ru_nsignals++; 2091 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2092 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2093 SIGADDSET(mask, sig); 2094 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2095 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2096 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2097 sigdflt(ps, sig); 2098 } 2099 2100 /* 2101 * Send a signal caused by a trap to the current thread. If it will be 2102 * caught immediately, deliver it with correct code. Otherwise, post it 2103 * normally. 2104 */ 2105 void 2106 trapsignal(struct thread *td, ksiginfo_t *ksi) 2107 { 2108 struct sigacts *ps; 2109 struct proc *p; 2110 sigset_t sigmask; 2111 int sig; 2112 2113 p = td->td_proc; 2114 sig = ksi->ksi_signo; 2115 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2116 2117 sigfastblock_fetch(td); 2118 PROC_LOCK(p); 2119 ps = p->p_sigacts; 2120 mtx_lock(&ps->ps_mtx); 2121 sigmask = td->td_sigmask; 2122 if (td->td_sigblock_val != 0) 2123 SIGSETOR(sigmask, fastblock_mask); 2124 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2125 !SIGISMEMBER(sigmask, sig)) { 2126 #ifdef KTRACE 2127 if (KTRPOINT(curthread, KTR_PSIG)) 2128 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2129 &td->td_sigmask, ksi->ksi_code); 2130 #endif 2131 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2132 ksi, &td->td_sigmask); 2133 postsig_done(sig, td, ps); 2134 mtx_unlock(&ps->ps_mtx); 2135 } else { 2136 /* 2137 * Avoid a possible infinite loop if the thread 2138 * masking the signal or process is ignoring the 2139 * signal. 2140 */ 2141 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2142 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2143 SIGDELSET(td->td_sigmask, sig); 2144 SIGDELSET(ps->ps_sigcatch, sig); 2145 SIGDELSET(ps->ps_sigignore, sig); 2146 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2147 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2148 td->td_sigblock_val = 0; 2149 } 2150 mtx_unlock(&ps->ps_mtx); 2151 p->p_sig = sig; /* XXX to verify code */ 2152 tdsendsignal(p, td, sig, ksi); 2153 } 2154 PROC_UNLOCK(p); 2155 } 2156 2157 static struct thread * 2158 sigtd(struct proc *p, int sig, bool fast_sigblock) 2159 { 2160 struct thread *td, *signal_td; 2161 2162 PROC_LOCK_ASSERT(p, MA_OWNED); 2163 MPASS(!fast_sigblock || p == curproc); 2164 2165 /* 2166 * Check if current thread can handle the signal without 2167 * switching context to another thread. 2168 */ 2169 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2170 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2171 return (curthread); 2172 signal_td = NULL; 2173 FOREACH_THREAD_IN_PROC(p, td) { 2174 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2175 td != curthread || td->td_sigblock_val == 0)) { 2176 signal_td = td; 2177 break; 2178 } 2179 } 2180 if (signal_td == NULL) 2181 signal_td = FIRST_THREAD_IN_PROC(p); 2182 return (signal_td); 2183 } 2184 2185 /* 2186 * Send the signal to the process. If the signal has an action, the action 2187 * is usually performed by the target process rather than the caller; we add 2188 * the signal to the set of pending signals for the process. 2189 * 2190 * Exceptions: 2191 * o When a stop signal is sent to a sleeping process that takes the 2192 * default action, the process is stopped without awakening it. 2193 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2194 * regardless of the signal action (eg, blocked or ignored). 2195 * 2196 * Other ignored signals are discarded immediately. 2197 * 2198 * NB: This function may be entered from the debugger via the "kill" DDB 2199 * command. There is little that can be done to mitigate the possibly messy 2200 * side effects of this unwise possibility. 2201 */ 2202 void 2203 kern_psignal(struct proc *p, int sig) 2204 { 2205 ksiginfo_t ksi; 2206 2207 ksiginfo_init(&ksi); 2208 ksi.ksi_signo = sig; 2209 ksi.ksi_code = SI_KERNEL; 2210 (void) tdsendsignal(p, NULL, sig, &ksi); 2211 } 2212 2213 int 2214 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2215 { 2216 2217 return (tdsendsignal(p, NULL, sig, ksi)); 2218 } 2219 2220 /* Utility function for finding a thread to send signal event to. */ 2221 int 2222 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2223 { 2224 struct thread *td; 2225 2226 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2227 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2228 if (td == NULL) 2229 return (ESRCH); 2230 *ttd = td; 2231 } else { 2232 *ttd = NULL; 2233 PROC_LOCK(p); 2234 } 2235 return (0); 2236 } 2237 2238 void 2239 tdsignal(struct thread *td, int sig) 2240 { 2241 ksiginfo_t ksi; 2242 2243 ksiginfo_init(&ksi); 2244 ksi.ksi_signo = sig; 2245 ksi.ksi_code = SI_KERNEL; 2246 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2247 } 2248 2249 void 2250 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2251 { 2252 2253 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2254 } 2255 2256 static int 2257 sig_sleepq_abort(struct thread *td, int intrval) 2258 { 2259 THREAD_LOCK_ASSERT(td, MA_OWNED); 2260 2261 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2262 thread_unlock(td); 2263 return (0); 2264 } 2265 return (sleepq_abort(td, intrval)); 2266 } 2267 2268 int 2269 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2270 { 2271 sig_t action; 2272 sigqueue_t *sigqueue; 2273 int prop; 2274 struct sigacts *ps; 2275 int intrval; 2276 int ret = 0; 2277 int wakeup_swapper; 2278 2279 MPASS(td == NULL || p == td->td_proc); 2280 PROC_LOCK_ASSERT(p, MA_OWNED); 2281 2282 if (!_SIG_VALID(sig)) 2283 panic("%s(): invalid signal %d", __func__, sig); 2284 2285 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2286 2287 /* 2288 * IEEE Std 1003.1-2001: return success when killing a zombie. 2289 */ 2290 if (p->p_state == PRS_ZOMBIE) { 2291 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2292 ksiginfo_tryfree(ksi); 2293 return (ret); 2294 } 2295 2296 ps = p->p_sigacts; 2297 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2298 prop = sigprop(sig); 2299 2300 if (td == NULL) { 2301 td = sigtd(p, sig, false); 2302 sigqueue = &p->p_sigqueue; 2303 } else 2304 sigqueue = &td->td_sigqueue; 2305 2306 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2307 2308 /* 2309 * If the signal is being ignored, then we forget about it 2310 * immediately, except when the target process executes 2311 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2312 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2313 */ 2314 mtx_lock(&ps->ps_mtx); 2315 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2316 if (kern_sig_discard_ign && 2317 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2318 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2319 2320 mtx_unlock(&ps->ps_mtx); 2321 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2322 ksiginfo_tryfree(ksi); 2323 return (ret); 2324 } else { 2325 action = SIG_CATCH; 2326 intrval = 0; 2327 } 2328 } else { 2329 if (SIGISMEMBER(td->td_sigmask, sig)) 2330 action = SIG_HOLD; 2331 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2332 action = SIG_CATCH; 2333 else 2334 action = SIG_DFL; 2335 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2336 intrval = EINTR; 2337 else 2338 intrval = ERESTART; 2339 } 2340 mtx_unlock(&ps->ps_mtx); 2341 2342 if (prop & SIGPROP_CONT) 2343 sigqueue_delete_stopmask_proc(p); 2344 else if (prop & SIGPROP_STOP) { 2345 /* 2346 * If sending a tty stop signal to a member of an orphaned 2347 * process group, discard the signal here if the action 2348 * is default; don't stop the process below if sleeping, 2349 * and don't clear any pending SIGCONT. 2350 */ 2351 if ((prop & SIGPROP_TTYSTOP) != 0 && 2352 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2353 action == SIG_DFL) { 2354 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2355 ksiginfo_tryfree(ksi); 2356 return (ret); 2357 } 2358 sigqueue_delete_proc(p, SIGCONT); 2359 if (p->p_flag & P_CONTINUED) { 2360 p->p_flag &= ~P_CONTINUED; 2361 PROC_LOCK(p->p_pptr); 2362 sigqueue_take(p->p_ksi); 2363 PROC_UNLOCK(p->p_pptr); 2364 } 2365 } 2366 2367 ret = sigqueue_add(sigqueue, sig, ksi); 2368 if (ret != 0) 2369 return (ret); 2370 signotify(td); 2371 /* 2372 * Defer further processing for signals which are held, 2373 * except that stopped processes must be continued by SIGCONT. 2374 */ 2375 if (action == SIG_HOLD && 2376 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2377 return (ret); 2378 2379 wakeup_swapper = 0; 2380 2381 /* 2382 * Some signals have a process-wide effect and a per-thread 2383 * component. Most processing occurs when the process next 2384 * tries to cross the user boundary, however there are some 2385 * times when processing needs to be done immediately, such as 2386 * waking up threads so that they can cross the user boundary. 2387 * We try to do the per-process part here. 2388 */ 2389 if (P_SHOULDSTOP(p)) { 2390 KASSERT(!(p->p_flag & P_WEXIT), 2391 ("signal to stopped but exiting process")); 2392 if (sig == SIGKILL) { 2393 /* 2394 * If traced process is already stopped, 2395 * then no further action is necessary. 2396 */ 2397 if (p->p_flag & P_TRACED) 2398 goto out; 2399 /* 2400 * SIGKILL sets process running. 2401 * It will die elsewhere. 2402 * All threads must be restarted. 2403 */ 2404 p->p_flag &= ~P_STOPPED_SIG; 2405 goto runfast; 2406 } 2407 2408 if (prop & SIGPROP_CONT) { 2409 /* 2410 * If traced process is already stopped, 2411 * then no further action is necessary. 2412 */ 2413 if (p->p_flag & P_TRACED) 2414 goto out; 2415 /* 2416 * If SIGCONT is default (or ignored), we continue the 2417 * process but don't leave the signal in sigqueue as 2418 * it has no further action. If SIGCONT is held, we 2419 * continue the process and leave the signal in 2420 * sigqueue. If the process catches SIGCONT, let it 2421 * handle the signal itself. If it isn't waiting on 2422 * an event, it goes back to run state. 2423 * Otherwise, process goes back to sleep state. 2424 */ 2425 p->p_flag &= ~P_STOPPED_SIG; 2426 PROC_SLOCK(p); 2427 if (p->p_numthreads == p->p_suspcount) { 2428 PROC_SUNLOCK(p); 2429 p->p_flag |= P_CONTINUED; 2430 p->p_xsig = SIGCONT; 2431 PROC_LOCK(p->p_pptr); 2432 childproc_continued(p); 2433 PROC_UNLOCK(p->p_pptr); 2434 PROC_SLOCK(p); 2435 } 2436 if (action == SIG_DFL) { 2437 thread_unsuspend(p); 2438 PROC_SUNLOCK(p); 2439 sigqueue_delete(sigqueue, sig); 2440 goto out_cont; 2441 } 2442 if (action == SIG_CATCH) { 2443 /* 2444 * The process wants to catch it so it needs 2445 * to run at least one thread, but which one? 2446 */ 2447 PROC_SUNLOCK(p); 2448 goto runfast; 2449 } 2450 /* 2451 * The signal is not ignored or caught. 2452 */ 2453 thread_unsuspend(p); 2454 PROC_SUNLOCK(p); 2455 goto out_cont; 2456 } 2457 2458 if (prop & SIGPROP_STOP) { 2459 /* 2460 * If traced process is already stopped, 2461 * then no further action is necessary. 2462 */ 2463 if (p->p_flag & P_TRACED) 2464 goto out; 2465 /* 2466 * Already stopped, don't need to stop again 2467 * (If we did the shell could get confused). 2468 * Just make sure the signal STOP bit set. 2469 */ 2470 p->p_flag |= P_STOPPED_SIG; 2471 sigqueue_delete(sigqueue, sig); 2472 goto out; 2473 } 2474 2475 /* 2476 * All other kinds of signals: 2477 * If a thread is sleeping interruptibly, simulate a 2478 * wakeup so that when it is continued it will be made 2479 * runnable and can look at the signal. However, don't make 2480 * the PROCESS runnable, leave it stopped. 2481 * It may run a bit until it hits a thread_suspend_check(). 2482 */ 2483 PROC_SLOCK(p); 2484 thread_lock(td); 2485 if (TD_CAN_ABORT(td)) 2486 wakeup_swapper = sig_sleepq_abort(td, intrval); 2487 else 2488 thread_unlock(td); 2489 PROC_SUNLOCK(p); 2490 goto out; 2491 /* 2492 * Mutexes are short lived. Threads waiting on them will 2493 * hit thread_suspend_check() soon. 2494 */ 2495 } else if (p->p_state == PRS_NORMAL) { 2496 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2497 tdsigwakeup(td, sig, action, intrval); 2498 goto out; 2499 } 2500 2501 MPASS(action == SIG_DFL); 2502 2503 if (prop & SIGPROP_STOP) { 2504 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2505 goto out; 2506 p->p_flag |= P_STOPPED_SIG; 2507 p->p_xsig = sig; 2508 PROC_SLOCK(p); 2509 wakeup_swapper = sig_suspend_threads(td, p); 2510 if (p->p_numthreads == p->p_suspcount) { 2511 /* 2512 * only thread sending signal to another 2513 * process can reach here, if thread is sending 2514 * signal to its process, because thread does 2515 * not suspend itself here, p_numthreads 2516 * should never be equal to p_suspcount. 2517 */ 2518 thread_stopped(p); 2519 PROC_SUNLOCK(p); 2520 sigqueue_delete_proc(p, p->p_xsig); 2521 } else 2522 PROC_SUNLOCK(p); 2523 goto out; 2524 } 2525 } else { 2526 /* Not in "NORMAL" state. discard the signal. */ 2527 sigqueue_delete(sigqueue, sig); 2528 goto out; 2529 } 2530 2531 /* 2532 * The process is not stopped so we need to apply the signal to all the 2533 * running threads. 2534 */ 2535 runfast: 2536 tdsigwakeup(td, sig, action, intrval); 2537 PROC_SLOCK(p); 2538 thread_unsuspend(p); 2539 PROC_SUNLOCK(p); 2540 out_cont: 2541 itimer_proc_continue(p); 2542 kqtimer_proc_continue(p); 2543 out: 2544 /* If we jump here, proc slock should not be owned. */ 2545 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2546 if (wakeup_swapper) 2547 kick_proc0(); 2548 2549 return (ret); 2550 } 2551 2552 /* 2553 * The force of a signal has been directed against a single 2554 * thread. We need to see what we can do about knocking it 2555 * out of any sleep it may be in etc. 2556 */ 2557 static void 2558 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2559 { 2560 struct proc *p = td->td_proc; 2561 int prop, wakeup_swapper; 2562 2563 PROC_LOCK_ASSERT(p, MA_OWNED); 2564 prop = sigprop(sig); 2565 2566 PROC_SLOCK(p); 2567 thread_lock(td); 2568 /* 2569 * Bring the priority of a thread up if we want it to get 2570 * killed in this lifetime. Be careful to avoid bumping the 2571 * priority of the idle thread, since we still allow to signal 2572 * kernel processes. 2573 */ 2574 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2575 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2576 sched_prio(td, PUSER); 2577 if (TD_ON_SLEEPQ(td)) { 2578 /* 2579 * If thread is sleeping uninterruptibly 2580 * we can't interrupt the sleep... the signal will 2581 * be noticed when the process returns through 2582 * trap() or syscall(). 2583 */ 2584 if ((td->td_flags & TDF_SINTR) == 0) 2585 goto out; 2586 /* 2587 * If SIGCONT is default (or ignored) and process is 2588 * asleep, we are finished; the process should not 2589 * be awakened. 2590 */ 2591 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2592 thread_unlock(td); 2593 PROC_SUNLOCK(p); 2594 sigqueue_delete(&p->p_sigqueue, sig); 2595 /* 2596 * It may be on either list in this state. 2597 * Remove from both for now. 2598 */ 2599 sigqueue_delete(&td->td_sigqueue, sig); 2600 return; 2601 } 2602 2603 /* 2604 * Don't awaken a sleeping thread for SIGSTOP if the 2605 * STOP signal is deferred. 2606 */ 2607 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2608 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2609 goto out; 2610 2611 /* 2612 * Give low priority threads a better chance to run. 2613 */ 2614 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2615 sched_prio(td, PUSER); 2616 2617 wakeup_swapper = sig_sleepq_abort(td, intrval); 2618 PROC_SUNLOCK(p); 2619 if (wakeup_swapper) 2620 kick_proc0(); 2621 return; 2622 } 2623 2624 /* 2625 * Other states do nothing with the signal immediately, 2626 * other than kicking ourselves if we are running. 2627 * It will either never be noticed, or noticed very soon. 2628 */ 2629 #ifdef SMP 2630 if (TD_IS_RUNNING(td) && td != curthread) 2631 forward_signal(td); 2632 #endif 2633 2634 out: 2635 PROC_SUNLOCK(p); 2636 thread_unlock(td); 2637 } 2638 2639 static void 2640 ptrace_coredumpreq(struct thread *td, struct proc *p, 2641 struct thr_coredump_req *tcq) 2642 { 2643 void *rl_cookie; 2644 2645 if (p->p_sysent->sv_coredump == NULL) { 2646 tcq->tc_error = ENOSYS; 2647 return; 2648 } 2649 2650 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2651 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2652 tcq->tc_limit, tcq->tc_flags); 2653 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2654 } 2655 2656 static void 2657 ptrace_syscallreq(struct thread *td, struct proc *p, 2658 struct thr_syscall_req *tsr) 2659 { 2660 struct sysentvec *sv; 2661 struct sysent *se; 2662 register_t rv_saved[2]; 2663 int error, nerror; 2664 int sc; 2665 bool audited, sy_thr_static; 2666 2667 sv = p->p_sysent; 2668 if (sv->sv_table == NULL || sv->sv_size < tsr->ts_sa.code) { 2669 tsr->ts_ret.sr_error = ENOSYS; 2670 return; 2671 } 2672 2673 sc = tsr->ts_sa.code; 2674 if (sc == SYS_syscall || sc == SYS___syscall) { 2675 sc = tsr->ts_sa.args[0]; 2676 memmove(&tsr->ts_sa.args[0], &tsr->ts_sa.args[1], 2677 sizeof(register_t) * (tsr->ts_nargs - 1)); 2678 } 2679 2680 tsr->ts_sa.callp = se = &sv->sv_table[sc]; 2681 2682 VM_CNT_INC(v_syscall); 2683 td->td_pticks = 0; 2684 if (__predict_false(td->td_cowgen != atomic_load_int( 2685 &td->td_proc->p_cowgen))) 2686 thread_cow_update(td); 2687 2688 #ifdef CAPABILITY_MODE 2689 if (IN_CAPABILITY_MODE(td) && (se->sy_flags & SYF_CAPENABLED) == 0) { 2690 tsr->ts_ret.sr_error = ECAPMODE; 2691 return; 2692 } 2693 #endif 2694 2695 sy_thr_static = (se->sy_thrcnt & SY_THR_STATIC) != 0; 2696 audited = AUDIT_SYSCALL_ENTER(sc, td) != 0; 2697 2698 if (!sy_thr_static) { 2699 error = syscall_thread_enter(td, se); 2700 if (error != 0) { 2701 tsr->ts_ret.sr_error = error; 2702 return; 2703 } 2704 } 2705 2706 rv_saved[0] = td->td_retval[0]; 2707 rv_saved[1] = td->td_retval[1]; 2708 nerror = td->td_errno; 2709 td->td_retval[0] = 0; 2710 td->td_retval[1] = 0; 2711 2712 #ifdef KDTRACE_HOOKS 2713 if (se->sy_entry != 0) 2714 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_ENTRY, 0); 2715 #endif 2716 tsr->ts_ret.sr_error = se->sy_call(td, tsr->ts_sa.args); 2717 #ifdef KDTRACE_HOOKS 2718 if (se->sy_return != 0) 2719 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_RETURN, 2720 tsr->ts_ret.sr_error != 0 ? -1 : td->td_retval[0]); 2721 #endif 2722 2723 tsr->ts_ret.sr_retval[0] = td->td_retval[0]; 2724 tsr->ts_ret.sr_retval[1] = td->td_retval[1]; 2725 td->td_retval[0] = rv_saved[0]; 2726 td->td_retval[1] = rv_saved[1]; 2727 td->td_errno = nerror; 2728 2729 if (audited) 2730 AUDIT_SYSCALL_EXIT(error, td); 2731 if (!sy_thr_static) 2732 syscall_thread_exit(td, se); 2733 } 2734 2735 static void 2736 ptrace_remotereq(struct thread *td, int flag) 2737 { 2738 struct proc *p; 2739 2740 MPASS(td == curthread); 2741 p = td->td_proc; 2742 PROC_LOCK_ASSERT(p, MA_OWNED); 2743 if ((td->td_dbgflags & flag) == 0) 2744 return; 2745 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2746 KASSERT(td->td_remotereq != NULL, ("td_remotereq is NULL")); 2747 2748 PROC_UNLOCK(p); 2749 switch (flag) { 2750 case TDB_COREDUMPREQ: 2751 ptrace_coredumpreq(td, p, td->td_remotereq); 2752 break; 2753 case TDB_SCREMOTEREQ: 2754 ptrace_syscallreq(td, p, td->td_remotereq); 2755 break; 2756 default: 2757 __unreachable(); 2758 } 2759 PROC_LOCK(p); 2760 2761 MPASS((td->td_dbgflags & flag) != 0); 2762 td->td_dbgflags &= ~flag; 2763 td->td_remotereq = NULL; 2764 wakeup(p); 2765 } 2766 2767 static int 2768 sig_suspend_threads(struct thread *td, struct proc *p) 2769 { 2770 struct thread *td2; 2771 int wakeup_swapper; 2772 2773 PROC_LOCK_ASSERT(p, MA_OWNED); 2774 PROC_SLOCK_ASSERT(p, MA_OWNED); 2775 2776 wakeup_swapper = 0; 2777 FOREACH_THREAD_IN_PROC(p, td2) { 2778 thread_lock(td2); 2779 ast_sched_locked(td2, TDA_SUSPEND); 2780 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2781 (td2->td_flags & TDF_SINTR)) { 2782 if (td2->td_flags & TDF_SBDRY) { 2783 /* 2784 * Once a thread is asleep with 2785 * TDF_SBDRY and without TDF_SERESTART 2786 * or TDF_SEINTR set, it should never 2787 * become suspended due to this check. 2788 */ 2789 KASSERT(!TD_IS_SUSPENDED(td2), 2790 ("thread with deferred stops suspended")); 2791 if (TD_SBDRY_INTR(td2)) { 2792 wakeup_swapper |= sleepq_abort(td2, 2793 TD_SBDRY_ERRNO(td2)); 2794 continue; 2795 } 2796 } else if (!TD_IS_SUSPENDED(td2)) 2797 thread_suspend_one(td2); 2798 } else if (!TD_IS_SUSPENDED(td2)) { 2799 #ifdef SMP 2800 if (TD_IS_RUNNING(td2) && td2 != td) 2801 forward_signal(td2); 2802 #endif 2803 } 2804 thread_unlock(td2); 2805 } 2806 return (wakeup_swapper); 2807 } 2808 2809 /* 2810 * Stop the process for an event deemed interesting to the debugger. If si is 2811 * non-NULL, this is a signal exchange; the new signal requested by the 2812 * debugger will be returned for handling. If si is NULL, this is some other 2813 * type of interesting event. The debugger may request a signal be delivered in 2814 * that case as well, however it will be deferred until it can be handled. 2815 */ 2816 int 2817 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2818 { 2819 struct proc *p = td->td_proc; 2820 struct thread *td2; 2821 ksiginfo_t ksi; 2822 2823 PROC_LOCK_ASSERT(p, MA_OWNED); 2824 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2825 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2826 &p->p_mtx.lock_object, "Stopping for traced signal"); 2827 2828 td->td_xsig = sig; 2829 2830 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2831 td->td_dbgflags |= TDB_XSIG; 2832 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2833 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2834 PROC_SLOCK(p); 2835 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2836 if (P_KILLED(p)) { 2837 /* 2838 * Ensure that, if we've been PT_KILLed, the 2839 * exit status reflects that. Another thread 2840 * may also be in ptracestop(), having just 2841 * received the SIGKILL, but this thread was 2842 * unsuspended first. 2843 */ 2844 td->td_dbgflags &= ~TDB_XSIG; 2845 td->td_xsig = SIGKILL; 2846 p->p_ptevents = 0; 2847 break; 2848 } 2849 if (p->p_flag & P_SINGLE_EXIT && 2850 !(td->td_dbgflags & TDB_EXIT)) { 2851 /* 2852 * Ignore ptrace stops except for thread exit 2853 * events when the process exits. 2854 */ 2855 td->td_dbgflags &= ~TDB_XSIG; 2856 PROC_SUNLOCK(p); 2857 return (0); 2858 } 2859 2860 /* 2861 * Make wait(2) work. Ensure that right after the 2862 * attach, the thread which was decided to become the 2863 * leader of attach gets reported to the waiter. 2864 * Otherwise, just avoid overwriting another thread's 2865 * assignment to p_xthread. If another thread has 2866 * already set p_xthread, the current thread will get 2867 * a chance to report itself upon the next iteration. 2868 */ 2869 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2870 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2871 p->p_xthread == NULL)) { 2872 p->p_xsig = sig; 2873 p->p_xthread = td; 2874 2875 /* 2876 * If we are on sleepqueue already, 2877 * let sleepqueue code decide if it 2878 * needs to go sleep after attach. 2879 */ 2880 if (td->td_wchan == NULL) 2881 td->td_dbgflags &= ~TDB_FSTP; 2882 2883 p->p_flag2 &= ~P2_PTRACE_FSTP; 2884 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2885 sig_suspend_threads(td, p); 2886 } 2887 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2888 td->td_dbgflags &= ~TDB_STOPATFORK; 2889 } 2890 stopme: 2891 td->td_dbgflags |= TDB_SSWITCH; 2892 thread_suspend_switch(td, p); 2893 td->td_dbgflags &= ~TDB_SSWITCH; 2894 if ((td->td_dbgflags & (TDB_COREDUMPREQ | 2895 TDB_SCREMOTEREQ)) != 0) { 2896 MPASS((td->td_dbgflags & (TDB_COREDUMPREQ | 2897 TDB_SCREMOTEREQ)) != 2898 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2899 PROC_SUNLOCK(p); 2900 ptrace_remotereq(td, td->td_dbgflags & 2901 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2902 PROC_SLOCK(p); 2903 goto stopme; 2904 } 2905 if (p->p_xthread == td) 2906 p->p_xthread = NULL; 2907 if (!(p->p_flag & P_TRACED)) 2908 break; 2909 if (td->td_dbgflags & TDB_SUSPEND) { 2910 if (p->p_flag & P_SINGLE_EXIT) 2911 break; 2912 goto stopme; 2913 } 2914 } 2915 PROC_SUNLOCK(p); 2916 } 2917 2918 if (si != NULL && sig == td->td_xsig) { 2919 /* Parent wants us to take the original signal unchanged. */ 2920 si->ksi_flags |= KSI_HEAD; 2921 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2922 si->ksi_signo = 0; 2923 } else if (td->td_xsig != 0) { 2924 /* 2925 * If parent wants us to take a new signal, then it will leave 2926 * it in td->td_xsig; otherwise we just look for signals again. 2927 */ 2928 ksiginfo_init(&ksi); 2929 ksi.ksi_signo = td->td_xsig; 2930 ksi.ksi_flags |= KSI_PTRACE; 2931 td2 = sigtd(p, td->td_xsig, false); 2932 tdsendsignal(p, td2, td->td_xsig, &ksi); 2933 if (td != td2) 2934 return (0); 2935 } 2936 2937 return (td->td_xsig); 2938 } 2939 2940 static void 2941 reschedule_signals(struct proc *p, sigset_t block, int flags) 2942 { 2943 struct sigacts *ps; 2944 struct thread *td; 2945 int sig; 2946 bool fastblk, pslocked; 2947 2948 PROC_LOCK_ASSERT(p, MA_OWNED); 2949 ps = p->p_sigacts; 2950 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2951 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2952 if (SIGISEMPTY(p->p_siglist)) 2953 return; 2954 SIGSETAND(block, p->p_siglist); 2955 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2956 SIG_FOREACH(sig, &block) { 2957 td = sigtd(p, sig, fastblk); 2958 2959 /* 2960 * If sigtd() selected us despite sigfastblock is 2961 * blocking, do not activate AST or wake us, to avoid 2962 * loop in AST handler. 2963 */ 2964 if (fastblk && td == curthread) 2965 continue; 2966 2967 signotify(td); 2968 if (!pslocked) 2969 mtx_lock(&ps->ps_mtx); 2970 if (p->p_flag & P_TRACED || 2971 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2972 !SIGISMEMBER(td->td_sigmask, sig))) { 2973 tdsigwakeup(td, sig, SIG_CATCH, 2974 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2975 ERESTART)); 2976 } 2977 if (!pslocked) 2978 mtx_unlock(&ps->ps_mtx); 2979 } 2980 } 2981 2982 void 2983 tdsigcleanup(struct thread *td) 2984 { 2985 struct proc *p; 2986 sigset_t unblocked; 2987 2988 p = td->td_proc; 2989 PROC_LOCK_ASSERT(p, MA_OWNED); 2990 2991 sigqueue_flush(&td->td_sigqueue); 2992 if (p->p_numthreads == 1) 2993 return; 2994 2995 /* 2996 * Since we cannot handle signals, notify signal post code 2997 * about this by filling the sigmask. 2998 * 2999 * Also, if needed, wake up thread(s) that do not block the 3000 * same signals as the exiting thread, since the thread might 3001 * have been selected for delivery and woken up. 3002 */ 3003 SIGFILLSET(unblocked); 3004 SIGSETNAND(unblocked, td->td_sigmask); 3005 SIGFILLSET(td->td_sigmask); 3006 reschedule_signals(p, unblocked, 0); 3007 3008 } 3009 3010 static int 3011 sigdeferstop_curr_flags(int cflags) 3012 { 3013 3014 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 3015 (cflags & TDF_SBDRY) != 0); 3016 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 3017 } 3018 3019 /* 3020 * Defer the delivery of SIGSTOP for the current thread, according to 3021 * the requested mode. Returns previous flags, which must be restored 3022 * by sigallowstop(). 3023 * 3024 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 3025 * cleared by the current thread, which allow the lock-less read-only 3026 * accesses below. 3027 */ 3028 int 3029 sigdeferstop_impl(int mode) 3030 { 3031 struct thread *td; 3032 int cflags, nflags; 3033 3034 td = curthread; 3035 cflags = sigdeferstop_curr_flags(td->td_flags); 3036 switch (mode) { 3037 case SIGDEFERSTOP_NOP: 3038 nflags = cflags; 3039 break; 3040 case SIGDEFERSTOP_OFF: 3041 nflags = 0; 3042 break; 3043 case SIGDEFERSTOP_SILENT: 3044 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 3045 break; 3046 case SIGDEFERSTOP_EINTR: 3047 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 3048 break; 3049 case SIGDEFERSTOP_ERESTART: 3050 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 3051 break; 3052 default: 3053 panic("sigdeferstop: invalid mode %x", mode); 3054 break; 3055 } 3056 if (cflags == nflags) 3057 return (SIGDEFERSTOP_VAL_NCHG); 3058 thread_lock(td); 3059 td->td_flags = (td->td_flags & ~cflags) | nflags; 3060 thread_unlock(td); 3061 return (cflags); 3062 } 3063 3064 /* 3065 * Restores the STOP handling mode, typically permitting the delivery 3066 * of SIGSTOP for the current thread. This does not immediately 3067 * suspend if a stop was posted. Instead, the thread will suspend 3068 * either via ast() or a subsequent interruptible sleep. 3069 */ 3070 void 3071 sigallowstop_impl(int prev) 3072 { 3073 struct thread *td; 3074 int cflags; 3075 3076 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 3077 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 3078 ("sigallowstop: incorrect previous mode %x", prev)); 3079 td = curthread; 3080 cflags = sigdeferstop_curr_flags(td->td_flags); 3081 if (cflags != prev) { 3082 thread_lock(td); 3083 td->td_flags = (td->td_flags & ~cflags) | prev; 3084 thread_unlock(td); 3085 } 3086 } 3087 3088 enum sigstatus { 3089 SIGSTATUS_HANDLE, 3090 SIGSTATUS_HANDLED, 3091 SIGSTATUS_IGNORE, 3092 SIGSTATUS_SBDRY_STOP, 3093 }; 3094 3095 /* 3096 * The thread has signal "sig" pending. Figure out what to do with it: 3097 * 3098 * _HANDLE -> the caller should handle the signal 3099 * _HANDLED -> handled internally, reload pending signal set 3100 * _IGNORE -> ignored, remove from the set of pending signals and try the 3101 * next pending signal 3102 * _SBDRY_STOP -> the signal should stop the thread but this is not 3103 * permitted in the current context 3104 */ 3105 static enum sigstatus 3106 sigprocess(struct thread *td, int sig) 3107 { 3108 struct proc *p; 3109 struct sigacts *ps; 3110 struct sigqueue *queue; 3111 ksiginfo_t ksi; 3112 int prop; 3113 3114 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 3115 3116 p = td->td_proc; 3117 ps = p->p_sigacts; 3118 mtx_assert(&ps->ps_mtx, MA_OWNED); 3119 PROC_LOCK_ASSERT(p, MA_OWNED); 3120 3121 /* 3122 * We should allow pending but ignored signals below 3123 * if there is sigwait() active, or P_TRACED was 3124 * on when they were posted. 3125 */ 3126 if (SIGISMEMBER(ps->ps_sigignore, sig) && 3127 (p->p_flag & P_TRACED) == 0 && 3128 (td->td_flags & TDF_SIGWAIT) == 0) { 3129 return (SIGSTATUS_IGNORE); 3130 } 3131 3132 /* 3133 * If the process is going to single-thread mode to prepare 3134 * for exit, there is no sense in delivering any signal 3135 * to usermode. Another important consequence is that 3136 * msleep(..., PCATCH, ...) now is only interruptible by a 3137 * suspend request. 3138 */ 3139 if ((p->p_flag2 & P2_WEXIT) != 0) 3140 return (SIGSTATUS_IGNORE); 3141 3142 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 3143 /* 3144 * If traced, always stop. 3145 * Remove old signal from queue before the stop. 3146 * XXX shrug off debugger, it causes siginfo to 3147 * be thrown away. 3148 */ 3149 queue = &td->td_sigqueue; 3150 ksiginfo_init(&ksi); 3151 if (sigqueue_get(queue, sig, &ksi) == 0) { 3152 queue = &p->p_sigqueue; 3153 sigqueue_get(queue, sig, &ksi); 3154 } 3155 td->td_si = ksi.ksi_info; 3156 3157 mtx_unlock(&ps->ps_mtx); 3158 sig = ptracestop(td, sig, &ksi); 3159 mtx_lock(&ps->ps_mtx); 3160 3161 td->td_si.si_signo = 0; 3162 3163 /* 3164 * Keep looking if the debugger discarded or 3165 * replaced the signal. 3166 */ 3167 if (sig == 0) 3168 return (SIGSTATUS_HANDLED); 3169 3170 /* 3171 * If the signal became masked, re-queue it. 3172 */ 3173 if (SIGISMEMBER(td->td_sigmask, sig)) { 3174 ksi.ksi_flags |= KSI_HEAD; 3175 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3176 return (SIGSTATUS_HANDLED); 3177 } 3178 3179 /* 3180 * If the traced bit got turned off, requeue the signal and 3181 * reload the set of pending signals. This ensures that p_sig* 3182 * and p_sigact are consistent. 3183 */ 3184 if ((p->p_flag & P_TRACED) == 0) { 3185 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 3186 ksi.ksi_flags |= KSI_HEAD; 3187 sigqueue_add(queue, sig, &ksi); 3188 } 3189 return (SIGSTATUS_HANDLED); 3190 } 3191 } 3192 3193 /* 3194 * Decide whether the signal should be returned. 3195 * Return the signal's number, or fall through 3196 * to clear it from the pending mask. 3197 */ 3198 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3199 case (intptr_t)SIG_DFL: 3200 /* 3201 * Don't take default actions on system processes. 3202 */ 3203 if (p->p_pid <= 1) { 3204 #ifdef DIAGNOSTIC 3205 /* 3206 * Are you sure you want to ignore SIGSEGV 3207 * in init? XXX 3208 */ 3209 printf("Process (pid %lu) got signal %d\n", 3210 (u_long)p->p_pid, sig); 3211 #endif 3212 return (SIGSTATUS_IGNORE); 3213 } 3214 3215 /* 3216 * If there is a pending stop signal to process with 3217 * default action, stop here, then clear the signal. 3218 * Traced or exiting processes should ignore stops. 3219 * Additionally, a member of an orphaned process group 3220 * should ignore tty stops. 3221 */ 3222 prop = sigprop(sig); 3223 if (prop & SIGPROP_STOP) { 3224 mtx_unlock(&ps->ps_mtx); 3225 if ((p->p_flag & (P_TRACED | P_WEXIT | 3226 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3227 pg_flags & PGRP_ORPHANED) != 0 && 3228 (prop & SIGPROP_TTYSTOP) != 0)) { 3229 mtx_lock(&ps->ps_mtx); 3230 return (SIGSTATUS_IGNORE); 3231 } 3232 if (TD_SBDRY_INTR(td)) { 3233 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3234 ("lost TDF_SBDRY")); 3235 mtx_lock(&ps->ps_mtx); 3236 return (SIGSTATUS_SBDRY_STOP); 3237 } 3238 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3239 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3240 sigqueue_delete(&td->td_sigqueue, sig); 3241 sigqueue_delete(&p->p_sigqueue, sig); 3242 p->p_flag |= P_STOPPED_SIG; 3243 p->p_xsig = sig; 3244 PROC_SLOCK(p); 3245 sig_suspend_threads(td, p); 3246 thread_suspend_switch(td, p); 3247 PROC_SUNLOCK(p); 3248 mtx_lock(&ps->ps_mtx); 3249 return (SIGSTATUS_HANDLED); 3250 } else if ((prop & SIGPROP_IGNORE) != 0 && 3251 (td->td_flags & TDF_SIGWAIT) == 0) { 3252 /* 3253 * Default action is to ignore; drop it if 3254 * not in kern_sigtimedwait(). 3255 */ 3256 return (SIGSTATUS_IGNORE); 3257 } else { 3258 return (SIGSTATUS_HANDLE); 3259 } 3260 3261 case (intptr_t)SIG_IGN: 3262 if ((td->td_flags & TDF_SIGWAIT) == 0) 3263 return (SIGSTATUS_IGNORE); 3264 else 3265 return (SIGSTATUS_HANDLE); 3266 3267 default: 3268 /* 3269 * This signal has an action, let postsig() process it. 3270 */ 3271 return (SIGSTATUS_HANDLE); 3272 } 3273 } 3274 3275 /* 3276 * If the current process has received a signal (should be caught or cause 3277 * termination, should interrupt current syscall), return the signal number. 3278 * Stop signals with default action are processed immediately, then cleared; 3279 * they aren't returned. This is checked after each entry to the system for 3280 * a syscall or trap (though this can usually be done without calling 3281 * issignal by checking the pending signal masks in cursig.) The normal call 3282 * sequence is 3283 * 3284 * while (sig = cursig(curthread)) 3285 * postsig(sig); 3286 */ 3287 static int 3288 issignal(struct thread *td) 3289 { 3290 struct proc *p; 3291 sigset_t sigpending; 3292 int sig; 3293 3294 p = td->td_proc; 3295 PROC_LOCK_ASSERT(p, MA_OWNED); 3296 3297 for (;;) { 3298 sigpending = td->td_sigqueue.sq_signals; 3299 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3300 SIGSETNAND(sigpending, td->td_sigmask); 3301 3302 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3303 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3304 SIG_STOPSIGMASK(sigpending); 3305 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3306 return (0); 3307 3308 /* 3309 * Do fast sigblock if requested by usermode. Since 3310 * we do know that there was a signal pending at this 3311 * point, set the FAST_SIGBLOCK_PEND as indicator for 3312 * usermode to perform a dummy call to 3313 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3314 * delivery of postponed pending signal. 3315 */ 3316 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3317 if (td->td_sigblock_val != 0) 3318 SIGSETNAND(sigpending, fastblock_mask); 3319 if (SIGISEMPTY(sigpending)) { 3320 td->td_pflags |= TDP_SIGFASTPENDING; 3321 return (0); 3322 } 3323 } 3324 3325 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3326 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3327 SIGISMEMBER(sigpending, SIGSTOP)) { 3328 /* 3329 * If debugger just attached, always consume 3330 * SIGSTOP from ptrace(PT_ATTACH) first, to 3331 * execute the debugger attach ritual in 3332 * order. 3333 */ 3334 td->td_dbgflags |= TDB_FSTP; 3335 SIGEMPTYSET(sigpending); 3336 SIGADDSET(sigpending, SIGSTOP); 3337 } 3338 3339 SIG_FOREACH(sig, &sigpending) { 3340 switch (sigprocess(td, sig)) { 3341 case SIGSTATUS_HANDLE: 3342 return (sig); 3343 case SIGSTATUS_HANDLED: 3344 goto next; 3345 case SIGSTATUS_IGNORE: 3346 sigqueue_delete(&td->td_sigqueue, sig); 3347 sigqueue_delete(&p->p_sigqueue, sig); 3348 break; 3349 case SIGSTATUS_SBDRY_STOP: 3350 return (-1); 3351 } 3352 } 3353 next:; 3354 } 3355 } 3356 3357 void 3358 thread_stopped(struct proc *p) 3359 { 3360 int n; 3361 3362 PROC_LOCK_ASSERT(p, MA_OWNED); 3363 PROC_SLOCK_ASSERT(p, MA_OWNED); 3364 n = p->p_suspcount; 3365 if (p == curproc) 3366 n++; 3367 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3368 PROC_SUNLOCK(p); 3369 p->p_flag &= ~P_WAITED; 3370 PROC_LOCK(p->p_pptr); 3371 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3372 CLD_TRAPPED : CLD_STOPPED); 3373 PROC_UNLOCK(p->p_pptr); 3374 PROC_SLOCK(p); 3375 } 3376 } 3377 3378 /* 3379 * Take the action for the specified signal 3380 * from the current set of pending signals. 3381 */ 3382 int 3383 postsig(int sig) 3384 { 3385 struct thread *td; 3386 struct proc *p; 3387 struct sigacts *ps; 3388 sig_t action; 3389 ksiginfo_t ksi; 3390 sigset_t returnmask; 3391 3392 KASSERT(sig != 0, ("postsig")); 3393 3394 td = curthread; 3395 p = td->td_proc; 3396 PROC_LOCK_ASSERT(p, MA_OWNED); 3397 ps = p->p_sigacts; 3398 mtx_assert(&ps->ps_mtx, MA_OWNED); 3399 ksiginfo_init(&ksi); 3400 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3401 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3402 return (0); 3403 ksi.ksi_signo = sig; 3404 if (ksi.ksi_code == SI_TIMER) 3405 itimer_accept(p, ksi.ksi_timerid, &ksi); 3406 action = ps->ps_sigact[_SIG_IDX(sig)]; 3407 #ifdef KTRACE 3408 if (KTRPOINT(td, KTR_PSIG)) 3409 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3410 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3411 #endif 3412 3413 if (action == SIG_DFL) { 3414 /* 3415 * Default action, where the default is to kill 3416 * the process. (Other cases were ignored above.) 3417 */ 3418 mtx_unlock(&ps->ps_mtx); 3419 proc_td_siginfo_capture(td, &ksi.ksi_info); 3420 sigexit(td, sig); 3421 /* NOTREACHED */ 3422 } else { 3423 /* 3424 * If we get here, the signal must be caught. 3425 */ 3426 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3427 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3428 ("postsig action: blocked sig %d", sig)); 3429 3430 /* 3431 * Set the new mask value and also defer further 3432 * occurrences of this signal. 3433 * 3434 * Special case: user has done a sigsuspend. Here the 3435 * current mask is not of interest, but rather the 3436 * mask from before the sigsuspend is what we want 3437 * restored after the signal processing is completed. 3438 */ 3439 if (td->td_pflags & TDP_OLDMASK) { 3440 returnmask = td->td_oldsigmask; 3441 td->td_pflags &= ~TDP_OLDMASK; 3442 } else 3443 returnmask = td->td_sigmask; 3444 3445 if (p->p_sig == sig) { 3446 p->p_sig = 0; 3447 } 3448 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3449 postsig_done(sig, td, ps); 3450 } 3451 return (1); 3452 } 3453 3454 int 3455 sig_ast_checksusp(struct thread *td) 3456 { 3457 struct proc *p __diagused; 3458 int ret; 3459 3460 p = td->td_proc; 3461 PROC_LOCK_ASSERT(p, MA_OWNED); 3462 3463 if (!td_ast_pending(td, TDA_SUSPEND)) 3464 return (0); 3465 3466 ret = thread_suspend_check(1); 3467 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3468 return (ret); 3469 } 3470 3471 int 3472 sig_ast_needsigchk(struct thread *td) 3473 { 3474 struct proc *p; 3475 struct sigacts *ps; 3476 int ret, sig; 3477 3478 p = td->td_proc; 3479 PROC_LOCK_ASSERT(p, MA_OWNED); 3480 3481 if (!td_ast_pending(td, TDA_SIG)) 3482 return (0); 3483 3484 ps = p->p_sigacts; 3485 mtx_lock(&ps->ps_mtx); 3486 sig = cursig(td); 3487 if (sig == -1) { 3488 mtx_unlock(&ps->ps_mtx); 3489 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3490 KASSERT(TD_SBDRY_INTR(td), 3491 ("lost TDF_SERESTART of TDF_SEINTR")); 3492 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3493 (TDF_SEINTR | TDF_SERESTART), 3494 ("both TDF_SEINTR and TDF_SERESTART")); 3495 ret = TD_SBDRY_ERRNO(td); 3496 } else if (sig != 0) { 3497 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3498 mtx_unlock(&ps->ps_mtx); 3499 } else { 3500 mtx_unlock(&ps->ps_mtx); 3501 ret = 0; 3502 } 3503 3504 /* 3505 * Do not go into sleep if this thread was the ptrace(2) 3506 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3507 * but we usually act on the signal by interrupting sleep, and 3508 * should do that here as well. 3509 */ 3510 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3511 if (ret == 0) 3512 ret = EINTR; 3513 td->td_dbgflags &= ~TDB_FSTP; 3514 } 3515 3516 return (ret); 3517 } 3518 3519 int 3520 sig_intr(void) 3521 { 3522 struct thread *td; 3523 struct proc *p; 3524 int ret; 3525 3526 td = curthread; 3527 if (!td_ast_pending(td, TDA_SIG) && !td_ast_pending(td, TDA_SUSPEND)) 3528 return (0); 3529 3530 p = td->td_proc; 3531 3532 PROC_LOCK(p); 3533 ret = sig_ast_checksusp(td); 3534 if (ret == 0) 3535 ret = sig_ast_needsigchk(td); 3536 PROC_UNLOCK(p); 3537 return (ret); 3538 } 3539 3540 bool 3541 curproc_sigkilled(void) 3542 { 3543 struct thread *td; 3544 struct proc *p; 3545 struct sigacts *ps; 3546 bool res; 3547 3548 td = curthread; 3549 if (!td_ast_pending(td, TDA_SIG)) 3550 return (false); 3551 3552 p = td->td_proc; 3553 PROC_LOCK(p); 3554 ps = p->p_sigacts; 3555 mtx_lock(&ps->ps_mtx); 3556 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3557 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3558 mtx_unlock(&ps->ps_mtx); 3559 PROC_UNLOCK(p); 3560 return (res); 3561 } 3562 3563 void 3564 proc_wkilled(struct proc *p) 3565 { 3566 3567 PROC_LOCK_ASSERT(p, MA_OWNED); 3568 if ((p->p_flag & P_WKILLED) == 0) { 3569 p->p_flag |= P_WKILLED; 3570 /* 3571 * Notify swapper that there is a process to swap in. 3572 * The notification is racy, at worst it would take 10 3573 * seconds for the swapper process to notice. 3574 */ 3575 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3576 wakeup(&proc0); 3577 } 3578 } 3579 3580 /* 3581 * Kill the current process for stated reason. 3582 */ 3583 void 3584 killproc(struct proc *p, const char *why) 3585 { 3586 3587 PROC_LOCK_ASSERT(p, MA_OWNED); 3588 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3589 p->p_comm); 3590 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3591 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3592 p->p_ucred->cr_uid, why); 3593 proc_wkilled(p); 3594 kern_psignal(p, SIGKILL); 3595 } 3596 3597 /* 3598 * Force the current process to exit with the specified signal, dumping core 3599 * if appropriate. We bypass the normal tests for masked and caught signals, 3600 * allowing unrecoverable failures to terminate the process without changing 3601 * signal state. Mark the accounting record with the signal termination. 3602 * If dumping core, save the signal number for the debugger. Calls exit and 3603 * does not return. 3604 */ 3605 void 3606 sigexit(struct thread *td, int sig) 3607 { 3608 struct proc *p = td->td_proc; 3609 3610 PROC_LOCK_ASSERT(p, MA_OWNED); 3611 proc_set_p2_wexit(p); 3612 3613 p->p_acflag |= AXSIG; 3614 /* 3615 * We must be single-threading to generate a core dump. This 3616 * ensures that the registers in the core file are up-to-date. 3617 * Also, the ELF dump handler assumes that the thread list doesn't 3618 * change out from under it. 3619 * 3620 * XXX If another thread attempts to single-thread before us 3621 * (e.g. via fork()), we won't get a dump at all. 3622 */ 3623 if ((sigprop(sig) & SIGPROP_CORE) && 3624 thread_single(p, SINGLE_NO_EXIT) == 0) { 3625 p->p_sig = sig; 3626 /* 3627 * Log signals which would cause core dumps 3628 * (Log as LOG_INFO to appease those who don't want 3629 * these messages.) 3630 * XXX : Todo, as well as euid, write out ruid too 3631 * Note that coredump() drops proc lock. 3632 */ 3633 if (coredump(td) == 0) 3634 sig |= WCOREFLAG; 3635 if (kern_logsigexit) 3636 log(LOG_INFO, 3637 "pid %d (%s), jid %d, uid %d: exited on " 3638 "signal %d%s\n", p->p_pid, p->p_comm, 3639 p->p_ucred->cr_prison->pr_id, 3640 td->td_ucred->cr_uid, 3641 sig &~ WCOREFLAG, 3642 sig & WCOREFLAG ? " (core dumped)" : ""); 3643 } else 3644 PROC_UNLOCK(p); 3645 exit1(td, 0, sig); 3646 /* NOTREACHED */ 3647 } 3648 3649 /* 3650 * Send queued SIGCHLD to parent when child process's state 3651 * is changed. 3652 */ 3653 static void 3654 sigparent(struct proc *p, int reason, int status) 3655 { 3656 PROC_LOCK_ASSERT(p, MA_OWNED); 3657 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3658 3659 if (p->p_ksi != NULL) { 3660 p->p_ksi->ksi_signo = SIGCHLD; 3661 p->p_ksi->ksi_code = reason; 3662 p->p_ksi->ksi_status = status; 3663 p->p_ksi->ksi_pid = p->p_pid; 3664 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3665 if (KSI_ONQ(p->p_ksi)) 3666 return; 3667 } 3668 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3669 } 3670 3671 static void 3672 childproc_jobstate(struct proc *p, int reason, int sig) 3673 { 3674 struct sigacts *ps; 3675 3676 PROC_LOCK_ASSERT(p, MA_OWNED); 3677 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3678 3679 /* 3680 * Wake up parent sleeping in kern_wait(), also send 3681 * SIGCHLD to parent, but SIGCHLD does not guarantee 3682 * that parent will awake, because parent may masked 3683 * the signal. 3684 */ 3685 p->p_pptr->p_flag |= P_STATCHILD; 3686 wakeup(p->p_pptr); 3687 3688 ps = p->p_pptr->p_sigacts; 3689 mtx_lock(&ps->ps_mtx); 3690 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3691 mtx_unlock(&ps->ps_mtx); 3692 sigparent(p, reason, sig); 3693 } else 3694 mtx_unlock(&ps->ps_mtx); 3695 } 3696 3697 void 3698 childproc_stopped(struct proc *p, int reason) 3699 { 3700 3701 childproc_jobstate(p, reason, p->p_xsig); 3702 } 3703 3704 void 3705 childproc_continued(struct proc *p) 3706 { 3707 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3708 } 3709 3710 void 3711 childproc_exited(struct proc *p) 3712 { 3713 int reason, status; 3714 3715 if (WCOREDUMP(p->p_xsig)) { 3716 reason = CLD_DUMPED; 3717 status = WTERMSIG(p->p_xsig); 3718 } else if (WIFSIGNALED(p->p_xsig)) { 3719 reason = CLD_KILLED; 3720 status = WTERMSIG(p->p_xsig); 3721 } else { 3722 reason = CLD_EXITED; 3723 status = p->p_xexit; 3724 } 3725 /* 3726 * XXX avoid calling wakeup(p->p_pptr), the work is 3727 * done in exit1(). 3728 */ 3729 sigparent(p, reason, status); 3730 } 3731 3732 #define MAX_NUM_CORE_FILES 100000 3733 #ifndef NUM_CORE_FILES 3734 #define NUM_CORE_FILES 5 3735 #endif 3736 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3737 static int num_cores = NUM_CORE_FILES; 3738 3739 static int 3740 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3741 { 3742 int error; 3743 int new_val; 3744 3745 new_val = num_cores; 3746 error = sysctl_handle_int(oidp, &new_val, 0, req); 3747 if (error != 0 || req->newptr == NULL) 3748 return (error); 3749 if (new_val > MAX_NUM_CORE_FILES) 3750 new_val = MAX_NUM_CORE_FILES; 3751 if (new_val < 0) 3752 new_val = 0; 3753 num_cores = new_val; 3754 return (0); 3755 } 3756 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3757 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3758 sysctl_debug_num_cores_check, "I", 3759 "Maximum number of generated process corefiles while using index format"); 3760 3761 #define GZIP_SUFFIX ".gz" 3762 #define ZSTD_SUFFIX ".zst" 3763 3764 int compress_user_cores = 0; 3765 3766 static int 3767 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3768 { 3769 int error, val; 3770 3771 val = compress_user_cores; 3772 error = sysctl_handle_int(oidp, &val, 0, req); 3773 if (error != 0 || req->newptr == NULL) 3774 return (error); 3775 if (val != 0 && !compressor_avail(val)) 3776 return (EINVAL); 3777 compress_user_cores = val; 3778 return (error); 3779 } 3780 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3781 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3782 sysctl_compress_user_cores, "I", 3783 "Enable compression of user corefiles (" 3784 __XSTRING(COMPRESS_GZIP) " = gzip, " 3785 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3786 3787 int compress_user_cores_level = 6; 3788 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3789 &compress_user_cores_level, 0, 3790 "Corefile compression level"); 3791 3792 /* 3793 * Protect the access to corefilename[] by allproc_lock. 3794 */ 3795 #define corefilename_lock allproc_lock 3796 3797 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3798 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3799 3800 static int 3801 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3802 { 3803 int error; 3804 3805 sx_xlock(&corefilename_lock); 3806 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3807 req); 3808 sx_xunlock(&corefilename_lock); 3809 3810 return (error); 3811 } 3812 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3813 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3814 "Process corefile name format string"); 3815 3816 static void 3817 vnode_close_locked(struct thread *td, struct vnode *vp) 3818 { 3819 3820 VOP_UNLOCK(vp); 3821 vn_close(vp, FWRITE, td->td_ucred, td); 3822 } 3823 3824 /* 3825 * If the core format has a %I in it, then we need to check 3826 * for existing corefiles before defining a name. 3827 * To do this we iterate over 0..ncores to find a 3828 * non-existing core file name to use. If all core files are 3829 * already used we choose the oldest one. 3830 */ 3831 static int 3832 corefile_open_last(struct thread *td, char *name, int indexpos, 3833 int indexlen, int ncores, struct vnode **vpp) 3834 { 3835 struct vnode *oldvp, *nextvp, *vp; 3836 struct vattr vattr; 3837 struct nameidata nd; 3838 int error, i, flags, oflags, cmode; 3839 char ch; 3840 struct timespec lasttime; 3841 3842 nextvp = oldvp = NULL; 3843 cmode = S_IRUSR | S_IWUSR; 3844 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3845 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3846 3847 for (i = 0; i < ncores; i++) { 3848 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3849 3850 ch = name[indexpos + indexlen]; 3851 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3852 i); 3853 name[indexpos + indexlen] = ch; 3854 3855 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3856 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3857 NULL); 3858 if (error != 0) 3859 break; 3860 3861 vp = nd.ni_vp; 3862 NDFREE_PNBUF(&nd); 3863 if ((flags & O_CREAT) == O_CREAT) { 3864 nextvp = vp; 3865 break; 3866 } 3867 3868 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3869 if (error != 0) { 3870 vnode_close_locked(td, vp); 3871 break; 3872 } 3873 3874 if (oldvp == NULL || 3875 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3876 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3877 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3878 if (oldvp != NULL) 3879 vn_close(oldvp, FWRITE, td->td_ucred, td); 3880 oldvp = vp; 3881 VOP_UNLOCK(oldvp); 3882 lasttime = vattr.va_mtime; 3883 } else { 3884 vnode_close_locked(td, vp); 3885 } 3886 } 3887 3888 if (oldvp != NULL) { 3889 if (nextvp == NULL) { 3890 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3891 error = EFAULT; 3892 vn_close(oldvp, FWRITE, td->td_ucred, td); 3893 } else { 3894 nextvp = oldvp; 3895 error = vn_lock(nextvp, LK_EXCLUSIVE); 3896 if (error != 0) { 3897 vn_close(nextvp, FWRITE, td->td_ucred, 3898 td); 3899 nextvp = NULL; 3900 } 3901 } 3902 } else { 3903 vn_close(oldvp, FWRITE, td->td_ucred, td); 3904 } 3905 } 3906 if (error != 0) { 3907 if (nextvp != NULL) 3908 vnode_close_locked(td, oldvp); 3909 } else { 3910 *vpp = nextvp; 3911 } 3912 3913 return (error); 3914 } 3915 3916 /* 3917 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3918 * Expand the name described in corefilename, using name, uid, and pid 3919 * and open/create core file. 3920 * corefilename is a printf-like string, with three format specifiers: 3921 * %N name of process ("name") 3922 * %P process id (pid) 3923 * %U user id (uid) 3924 * For example, "%N.core" is the default; they can be disabled completely 3925 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3926 * This is controlled by the sysctl variable kern.corefile (see above). 3927 */ 3928 static int 3929 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3930 int compress, int signum, struct vnode **vpp, char **namep) 3931 { 3932 struct sbuf sb; 3933 struct nameidata nd; 3934 const char *format; 3935 char *hostname, *name; 3936 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3937 3938 hostname = NULL; 3939 format = corefilename; 3940 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3941 indexlen = 0; 3942 indexpos = -1; 3943 ncores = num_cores; 3944 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3945 sx_slock(&corefilename_lock); 3946 for (i = 0; format[i] != '\0'; i++) { 3947 switch (format[i]) { 3948 case '%': /* Format character */ 3949 i++; 3950 switch (format[i]) { 3951 case '%': 3952 sbuf_putc(&sb, '%'); 3953 break; 3954 case 'H': /* hostname */ 3955 if (hostname == NULL) { 3956 hostname = malloc(MAXHOSTNAMELEN, 3957 M_TEMP, M_WAITOK); 3958 } 3959 getcredhostname(td->td_ucred, hostname, 3960 MAXHOSTNAMELEN); 3961 sbuf_printf(&sb, "%s", hostname); 3962 break; 3963 case 'I': /* autoincrementing index */ 3964 if (indexpos != -1) { 3965 sbuf_printf(&sb, "%%I"); 3966 break; 3967 } 3968 3969 indexpos = sbuf_len(&sb); 3970 sbuf_printf(&sb, "%u", ncores - 1); 3971 indexlen = sbuf_len(&sb) - indexpos; 3972 break; 3973 case 'N': /* process name */ 3974 sbuf_printf(&sb, "%s", comm); 3975 break; 3976 case 'P': /* process id */ 3977 sbuf_printf(&sb, "%u", pid); 3978 break; 3979 case 'S': /* signal number */ 3980 sbuf_printf(&sb, "%i", signum); 3981 break; 3982 case 'U': /* user id */ 3983 sbuf_printf(&sb, "%u", uid); 3984 break; 3985 default: 3986 log(LOG_ERR, 3987 "Unknown format character %c in " 3988 "corename `%s'\n", format[i], format); 3989 break; 3990 } 3991 break; 3992 default: 3993 sbuf_putc(&sb, format[i]); 3994 break; 3995 } 3996 } 3997 sx_sunlock(&corefilename_lock); 3998 free(hostname, M_TEMP); 3999 if (compress == COMPRESS_GZIP) 4000 sbuf_printf(&sb, GZIP_SUFFIX); 4001 else if (compress == COMPRESS_ZSTD) 4002 sbuf_printf(&sb, ZSTD_SUFFIX); 4003 if (sbuf_error(&sb) != 0) { 4004 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 4005 "long\n", (long)pid, comm, (u_long)uid); 4006 sbuf_delete(&sb); 4007 free(name, M_TEMP); 4008 return (ENOMEM); 4009 } 4010 sbuf_finish(&sb); 4011 sbuf_delete(&sb); 4012 4013 if (indexpos != -1) { 4014 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 4015 vpp); 4016 if (error != 0) { 4017 log(LOG_ERR, 4018 "pid %d (%s), uid (%u): Path `%s' failed " 4019 "on initial open test, error = %d\n", 4020 pid, comm, uid, name, error); 4021 } 4022 } else { 4023 cmode = S_IRUSR | S_IWUSR; 4024 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 4025 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 4026 flags = O_CREAT | FWRITE | O_NOFOLLOW; 4027 if ((td->td_proc->p_flag & P_SUGID) != 0) 4028 flags |= O_EXCL; 4029 4030 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 4031 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 4032 NULL); 4033 if (error == 0) { 4034 *vpp = nd.ni_vp; 4035 NDFREE_PNBUF(&nd); 4036 } 4037 } 4038 4039 if (error != 0) { 4040 #ifdef AUDIT 4041 audit_proc_coredump(td, name, error); 4042 #endif 4043 free(name, M_TEMP); 4044 return (error); 4045 } 4046 *namep = name; 4047 return (0); 4048 } 4049 4050 /* 4051 * Dump a process' core. The main routine does some 4052 * policy checking, and creates the name of the coredump; 4053 * then it passes on a vnode and a size limit to the process-specific 4054 * coredump routine if there is one; if there _is not_ one, it returns 4055 * ENOSYS; otherwise it returns the error from the process-specific routine. 4056 */ 4057 4058 static int 4059 coredump(struct thread *td) 4060 { 4061 struct proc *p = td->td_proc; 4062 struct ucred *cred = td->td_ucred; 4063 struct vnode *vp; 4064 struct flock lf; 4065 struct vattr vattr; 4066 size_t fullpathsize; 4067 int error, error1, locked; 4068 char *name; /* name of corefile */ 4069 void *rl_cookie; 4070 off_t limit; 4071 char *fullpath, *freepath = NULL; 4072 struct sbuf *sb; 4073 4074 PROC_LOCK_ASSERT(p, MA_OWNED); 4075 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 4076 4077 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 4078 (p->p_flag2 & P2_NOTRACE) != 0) { 4079 PROC_UNLOCK(p); 4080 return (EFAULT); 4081 } 4082 4083 /* 4084 * Note that the bulk of limit checking is done after 4085 * the corefile is created. The exception is if the limit 4086 * for corefiles is 0, in which case we don't bother 4087 * creating the corefile at all. This layout means that 4088 * a corefile is truncated instead of not being created, 4089 * if it is larger than the limit. 4090 */ 4091 limit = (off_t)lim_cur(td, RLIMIT_CORE); 4092 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 4093 PROC_UNLOCK(p); 4094 return (EFBIG); 4095 } 4096 PROC_UNLOCK(p); 4097 4098 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 4099 compress_user_cores, p->p_sig, &vp, &name); 4100 if (error != 0) 4101 return (error); 4102 4103 /* 4104 * Don't dump to non-regular files or files with links. 4105 * Do not dump into system files. Effective user must own the corefile. 4106 */ 4107 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 4108 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 4109 vattr.va_uid != cred->cr_uid) { 4110 VOP_UNLOCK(vp); 4111 error = EFAULT; 4112 goto out; 4113 } 4114 4115 VOP_UNLOCK(vp); 4116 4117 /* Postpone other writers, including core dumps of other processes. */ 4118 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 4119 4120 lf.l_whence = SEEK_SET; 4121 lf.l_start = 0; 4122 lf.l_len = 0; 4123 lf.l_type = F_WRLCK; 4124 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 4125 4126 VATTR_NULL(&vattr); 4127 vattr.va_size = 0; 4128 if (set_core_nodump_flag) 4129 vattr.va_flags = UF_NODUMP; 4130 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4131 VOP_SETATTR(vp, &vattr, cred); 4132 VOP_UNLOCK(vp); 4133 PROC_LOCK(p); 4134 p->p_acflag |= ACORE; 4135 PROC_UNLOCK(p); 4136 4137 if (p->p_sysent->sv_coredump != NULL) { 4138 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 4139 } else { 4140 error = ENOSYS; 4141 } 4142 4143 if (locked) { 4144 lf.l_type = F_UNLCK; 4145 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 4146 } 4147 vn_rangelock_unlock(vp, rl_cookie); 4148 4149 /* 4150 * Notify the userland helper that a process triggered a core dump. 4151 * This allows the helper to run an automated debugging session. 4152 */ 4153 if (error != 0 || coredump_devctl == 0) 4154 goto out; 4155 sb = sbuf_new_auto(); 4156 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 4157 goto out2; 4158 sbuf_printf(sb, "comm=\""); 4159 devctl_safe_quote_sb(sb, fullpath); 4160 free(freepath, M_TEMP); 4161 sbuf_printf(sb, "\" core=\""); 4162 4163 /* 4164 * We can't lookup core file vp directly. When we're replacing a core, and 4165 * other random times, we flush the name cache, so it will fail. Instead, 4166 * if the path of the core is relative, add the current dir in front if it. 4167 */ 4168 if (name[0] != '/') { 4169 fullpathsize = MAXPATHLEN; 4170 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 4171 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 4172 free(freepath, M_TEMP); 4173 goto out2; 4174 } 4175 devctl_safe_quote_sb(sb, fullpath); 4176 free(freepath, M_TEMP); 4177 sbuf_putc(sb, '/'); 4178 } 4179 devctl_safe_quote_sb(sb, name); 4180 sbuf_printf(sb, "\""); 4181 if (sbuf_finish(sb) == 0) 4182 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 4183 out2: 4184 sbuf_delete(sb); 4185 out: 4186 error1 = vn_close(vp, FWRITE, cred, td); 4187 if (error == 0) 4188 error = error1; 4189 #ifdef AUDIT 4190 audit_proc_coredump(td, name, error); 4191 #endif 4192 free(name, M_TEMP); 4193 return (error); 4194 } 4195 4196 /* 4197 * Nonexistent system call-- signal process (may want to handle it). Flag 4198 * error in case process won't see signal immediately (blocked or ignored). 4199 */ 4200 #ifndef _SYS_SYSPROTO_H_ 4201 struct nosys_args { 4202 int dummy; 4203 }; 4204 #endif 4205 /* ARGSUSED */ 4206 int 4207 nosys(struct thread *td, struct nosys_args *args) 4208 { 4209 struct proc *p; 4210 4211 p = td->td_proc; 4212 4213 PROC_LOCK(p); 4214 tdsignal(td, SIGSYS); 4215 PROC_UNLOCK(p); 4216 if (kern_lognosys == 1 || kern_lognosys == 3) { 4217 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4218 td->td_sa.code); 4219 } 4220 if (kern_lognosys == 2 || kern_lognosys == 3 || 4221 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4222 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4223 td->td_sa.code); 4224 } 4225 return (ENOSYS); 4226 } 4227 4228 /* 4229 * Send a SIGIO or SIGURG signal to a process or process group using stored 4230 * credentials rather than those of the current process. 4231 */ 4232 void 4233 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4234 { 4235 ksiginfo_t ksi; 4236 struct sigio *sigio; 4237 4238 ksiginfo_init(&ksi); 4239 ksi.ksi_signo = sig; 4240 ksi.ksi_code = SI_KERNEL; 4241 4242 SIGIO_LOCK(); 4243 sigio = *sigiop; 4244 if (sigio == NULL) { 4245 SIGIO_UNLOCK(); 4246 return; 4247 } 4248 if (sigio->sio_pgid > 0) { 4249 PROC_LOCK(sigio->sio_proc); 4250 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4251 kern_psignal(sigio->sio_proc, sig); 4252 PROC_UNLOCK(sigio->sio_proc); 4253 } else if (sigio->sio_pgid < 0) { 4254 struct proc *p; 4255 4256 PGRP_LOCK(sigio->sio_pgrp); 4257 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4258 PROC_LOCK(p); 4259 if (p->p_state == PRS_NORMAL && 4260 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4261 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4262 kern_psignal(p, sig); 4263 PROC_UNLOCK(p); 4264 } 4265 PGRP_UNLOCK(sigio->sio_pgrp); 4266 } 4267 SIGIO_UNLOCK(); 4268 } 4269 4270 static int 4271 filt_sigattach(struct knote *kn) 4272 { 4273 struct proc *p = curproc; 4274 4275 kn->kn_ptr.p_proc = p; 4276 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4277 4278 knlist_add(p->p_klist, kn, 0); 4279 4280 return (0); 4281 } 4282 4283 static void 4284 filt_sigdetach(struct knote *kn) 4285 { 4286 struct proc *p = kn->kn_ptr.p_proc; 4287 4288 knlist_remove(p->p_klist, kn, 0); 4289 } 4290 4291 /* 4292 * signal knotes are shared with proc knotes, so we apply a mask to 4293 * the hint in order to differentiate them from process hints. This 4294 * could be avoided by using a signal-specific knote list, but probably 4295 * isn't worth the trouble. 4296 */ 4297 static int 4298 filt_signal(struct knote *kn, long hint) 4299 { 4300 4301 if (hint & NOTE_SIGNAL) { 4302 hint &= ~NOTE_SIGNAL; 4303 4304 if (kn->kn_id == hint) 4305 kn->kn_data++; 4306 } 4307 return (kn->kn_data != 0); 4308 } 4309 4310 struct sigacts * 4311 sigacts_alloc(void) 4312 { 4313 struct sigacts *ps; 4314 4315 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4316 refcount_init(&ps->ps_refcnt, 1); 4317 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4318 return (ps); 4319 } 4320 4321 void 4322 sigacts_free(struct sigacts *ps) 4323 { 4324 4325 if (refcount_release(&ps->ps_refcnt) == 0) 4326 return; 4327 mtx_destroy(&ps->ps_mtx); 4328 free(ps, M_SUBPROC); 4329 } 4330 4331 struct sigacts * 4332 sigacts_hold(struct sigacts *ps) 4333 { 4334 4335 refcount_acquire(&ps->ps_refcnt); 4336 return (ps); 4337 } 4338 4339 void 4340 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4341 { 4342 4343 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4344 mtx_lock(&src->ps_mtx); 4345 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4346 mtx_unlock(&src->ps_mtx); 4347 } 4348 4349 int 4350 sigacts_shared(struct sigacts *ps) 4351 { 4352 4353 return (ps->ps_refcnt > 1); 4354 } 4355 4356 void 4357 sig_drop_caught(struct proc *p) 4358 { 4359 int sig; 4360 struct sigacts *ps; 4361 4362 ps = p->p_sigacts; 4363 PROC_LOCK_ASSERT(p, MA_OWNED); 4364 mtx_assert(&ps->ps_mtx, MA_OWNED); 4365 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4366 sigdflt(ps, sig); 4367 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4368 sigqueue_delete_proc(p, sig); 4369 } 4370 } 4371 4372 static void 4373 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4374 { 4375 ksiginfo_t ksi; 4376 4377 /* 4378 * Prevent further fetches and SIGSEGVs, allowing thread to 4379 * issue syscalls despite corruption. 4380 */ 4381 sigfastblock_clear(td); 4382 4383 if (!sendsig) 4384 return; 4385 ksiginfo_init_trap(&ksi); 4386 ksi.ksi_signo = SIGSEGV; 4387 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4388 ksi.ksi_addr = td->td_sigblock_ptr; 4389 trapsignal(td, &ksi); 4390 } 4391 4392 static bool 4393 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4394 { 4395 uint32_t res; 4396 4397 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4398 return (true); 4399 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4400 sigfastblock_failed(td, sendsig, false); 4401 return (false); 4402 } 4403 *valp = res; 4404 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4405 return (true); 4406 } 4407 4408 static void 4409 sigfastblock_resched(struct thread *td, bool resched) 4410 { 4411 struct proc *p; 4412 4413 if (resched) { 4414 p = td->td_proc; 4415 PROC_LOCK(p); 4416 reschedule_signals(p, td->td_sigmask, 0); 4417 PROC_UNLOCK(p); 4418 } 4419 ast_sched(td, TDA_SIG); 4420 } 4421 4422 int 4423 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4424 { 4425 struct proc *p; 4426 int error, res; 4427 uint32_t oldval; 4428 4429 error = 0; 4430 p = td->td_proc; 4431 switch (uap->cmd) { 4432 case SIGFASTBLOCK_SETPTR: 4433 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4434 error = EBUSY; 4435 break; 4436 } 4437 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4438 error = EINVAL; 4439 break; 4440 } 4441 td->td_pflags |= TDP_SIGFASTBLOCK; 4442 td->td_sigblock_ptr = uap->ptr; 4443 break; 4444 4445 case SIGFASTBLOCK_UNBLOCK: 4446 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4447 error = EINVAL; 4448 break; 4449 } 4450 4451 for (;;) { 4452 res = casueword32(td->td_sigblock_ptr, 4453 SIGFASTBLOCK_PEND, &oldval, 0); 4454 if (res == -1) { 4455 error = EFAULT; 4456 sigfastblock_failed(td, false, true); 4457 break; 4458 } 4459 if (res == 0) 4460 break; 4461 MPASS(res == 1); 4462 if (oldval != SIGFASTBLOCK_PEND) { 4463 error = EBUSY; 4464 break; 4465 } 4466 error = thread_check_susp(td, false); 4467 if (error != 0) 4468 break; 4469 } 4470 if (error != 0) 4471 break; 4472 4473 /* 4474 * td_sigblock_val is cleared there, but not on a 4475 * syscall exit. The end effect is that a single 4476 * interruptible sleep, while user sigblock word is 4477 * set, might return EINTR or ERESTART to usermode 4478 * without delivering signal. All further sleeps, 4479 * until userspace clears the word and does 4480 * sigfastblock(UNBLOCK), observe current word and no 4481 * longer get interrupted. It is slight 4482 * non-conformance, with alternative to have read the 4483 * sigblock word on each syscall entry. 4484 */ 4485 td->td_sigblock_val = 0; 4486 4487 /* 4488 * Rely on normal ast mechanism to deliver pending 4489 * signals to current thread. But notify others about 4490 * fake unblock. 4491 */ 4492 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4493 4494 break; 4495 4496 case SIGFASTBLOCK_UNSETPTR: 4497 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4498 error = EINVAL; 4499 break; 4500 } 4501 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4502 error = EFAULT; 4503 break; 4504 } 4505 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4506 error = EBUSY; 4507 break; 4508 } 4509 sigfastblock_clear(td); 4510 break; 4511 4512 default: 4513 error = EINVAL; 4514 break; 4515 } 4516 return (error); 4517 } 4518 4519 void 4520 sigfastblock_clear(struct thread *td) 4521 { 4522 bool resched; 4523 4524 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4525 return; 4526 td->td_sigblock_val = 0; 4527 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4528 SIGPENDING(td); 4529 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4530 sigfastblock_resched(td, resched); 4531 } 4532 4533 void 4534 sigfastblock_fetch(struct thread *td) 4535 { 4536 uint32_t val; 4537 4538 (void)sigfastblock_fetch_sig(td, true, &val); 4539 } 4540 4541 static void 4542 sigfastblock_setpend1(struct thread *td) 4543 { 4544 int res; 4545 uint32_t oldval; 4546 4547 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4548 return; 4549 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4550 if (res == -1) { 4551 sigfastblock_failed(td, true, false); 4552 return; 4553 } 4554 for (;;) { 4555 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4556 oldval | SIGFASTBLOCK_PEND); 4557 if (res == -1) { 4558 sigfastblock_failed(td, true, true); 4559 return; 4560 } 4561 if (res == 0) { 4562 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4563 td->td_pflags &= ~TDP_SIGFASTPENDING; 4564 break; 4565 } 4566 MPASS(res == 1); 4567 if (thread_check_susp(td, false) != 0) 4568 break; 4569 } 4570 } 4571 4572 static void 4573 sigfastblock_setpend(struct thread *td, bool resched) 4574 { 4575 struct proc *p; 4576 4577 sigfastblock_setpend1(td); 4578 if (resched) { 4579 p = td->td_proc; 4580 PROC_LOCK(p); 4581 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4582 PROC_UNLOCK(p); 4583 } 4584 }
Cache object: d23efc377739a3e0d63bcc66d1e48587
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