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/jail.h> 60 #include <sys/kernel.h> 61 #include <sys/ktr.h> 62 #include <sys/ktrace.h> 63 #include <sys/limits.h> 64 #include <sys/lock.h> 65 #include <sys/malloc.h> 66 #include <sys/mutex.h> 67 #include <sys/refcount.h> 68 #include <sys/namei.h> 69 #include <sys/proc.h> 70 #include <sys/procdesc.h> 71 #include <sys/ptrace.h> 72 #include <sys/posix4.h> 73 #include <sys/racct.h> 74 #include <sys/resourcevar.h> 75 #include <sys/sdt.h> 76 #include <sys/sbuf.h> 77 #include <sys/sleepqueue.h> 78 #include <sys/smp.h> 79 #include <sys/stat.h> 80 #include <sys/sx.h> 81 #include <sys/syscall.h> 82 #include <sys/syscallsubr.h> 83 #include <sys/sysctl.h> 84 #include <sys/sysent.h> 85 #include <sys/syslog.h> 86 #include <sys/sysproto.h> 87 #include <sys/timers.h> 88 #include <sys/unistd.h> 89 #include <sys/vmmeter.h> 90 #include <sys/wait.h> 91 #include <vm/vm.h> 92 #include <vm/vm_extern.h> 93 #include <vm/uma.h> 94 95 #include <machine/cpu.h> 96 97 #include <security/audit/audit.h> 98 99 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 100 101 SDT_PROVIDER_DECLARE(proc); 102 SDT_PROBE_DEFINE3(proc, , , signal__send, 103 "struct thread *", "struct proc *", "int"); 104 SDT_PROBE_DEFINE2(proc, , , signal__clear, 105 "int", "ksiginfo_t *"); 106 SDT_PROBE_DEFINE3(proc, , , signal__discard, 107 "struct thread *", "struct proc *", "int"); 108 109 static int coredump(struct thread *); 110 static int killpg1(struct thread *td, int sig, int pgid, int all, 111 ksiginfo_t *ksi); 112 static int issignal(struct thread *td); 113 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 114 static int sigprop(int sig); 115 static void tdsigwakeup(struct thread *, int, sig_t, int); 116 static int sig_suspend_threads(struct thread *, struct proc *); 117 static int filt_sigattach(struct knote *kn); 118 static void filt_sigdetach(struct knote *kn); 119 static int filt_signal(struct knote *kn, long hint); 120 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 121 static void sigqueue_start(void); 122 static void sigfastblock_setpend(struct thread *td, bool resched); 123 124 static uma_zone_t ksiginfo_zone = NULL; 125 struct filterops sig_filtops = { 126 .f_isfd = 0, 127 .f_attach = filt_sigattach, 128 .f_detach = filt_sigdetach, 129 .f_event = filt_signal, 130 }; 131 132 static int kern_logsigexit = 1; 133 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 134 &kern_logsigexit, 0, 135 "Log processes quitting on abnormal signals to syslog(3)"); 136 137 static int kern_forcesigexit = 1; 138 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 139 &kern_forcesigexit, 0, "Force trap signal to be handled"); 140 141 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 142 "POSIX real time signal"); 143 144 static int max_pending_per_proc = 128; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 146 &max_pending_per_proc, 0, "Max pending signals per proc"); 147 148 static int preallocate_siginfo = 1024; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 150 &preallocate_siginfo, 0, "Preallocated signal memory size"); 151 152 static int signal_overflow = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 154 &signal_overflow, 0, "Number of signals overflew"); 155 156 static int signal_alloc_fail = 0; 157 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 158 &signal_alloc_fail, 0, "signals failed to be allocated"); 159 160 static int kern_lognosys = 0; 161 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 162 "Log invalid syscalls"); 163 164 __read_frequently bool sigfastblock_fetch_always = false; 165 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 166 &sigfastblock_fetch_always, 0, 167 "Fetch sigfastblock word on each syscall entry for proper " 168 "blocking semantic"); 169 170 static bool kern_sig_discard_ign = true; 171 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 172 &kern_sig_discard_ign, 0, 173 "Discard ignored signals on delivery, otherwise queue them to " 174 "the target queue"); 175 176 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 177 178 /* 179 * Policy -- Can ucred cr1 send SIGIO to process cr2? 180 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 181 * in the right situations. 182 */ 183 #define CANSIGIO(cr1, cr2) \ 184 ((cr1)->cr_uid == 0 || \ 185 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 186 (cr1)->cr_uid == (cr2)->cr_ruid || \ 187 (cr1)->cr_ruid == (cr2)->cr_uid || \ 188 (cr1)->cr_uid == (cr2)->cr_uid) 189 190 static int sugid_coredump; 191 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 192 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 193 194 static int capmode_coredump; 195 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 196 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 197 198 static int do_coredump = 1; 199 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 200 &do_coredump, 0, "Enable/Disable coredumps"); 201 202 static int set_core_nodump_flag = 0; 203 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 204 0, "Enable setting the NODUMP flag on coredump files"); 205 206 static int coredump_devctl = 0; 207 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 208 0, "Generate a devctl notification when processes coredump"); 209 210 /* 211 * Signal properties and actions. 212 * The array below categorizes the signals and their default actions 213 * according to the following properties: 214 */ 215 #define SIGPROP_KILL 0x01 /* terminates process by default */ 216 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 217 #define SIGPROP_STOP 0x04 /* suspend process */ 218 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 219 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 220 #define SIGPROP_CONT 0x20 /* continue if suspended */ 221 222 static const int sigproptbl[NSIG] = { 223 [SIGHUP] = SIGPROP_KILL, 224 [SIGINT] = SIGPROP_KILL, 225 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 228 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGKILL] = SIGPROP_KILL, 232 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 233 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 234 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 235 [SIGPIPE] = SIGPROP_KILL, 236 [SIGALRM] = SIGPROP_KILL, 237 [SIGTERM] = SIGPROP_KILL, 238 [SIGURG] = SIGPROP_IGNORE, 239 [SIGSTOP] = SIGPROP_STOP, 240 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 241 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 242 [SIGCHLD] = SIGPROP_IGNORE, 243 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 244 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 245 [SIGIO] = SIGPROP_IGNORE, 246 [SIGXCPU] = SIGPROP_KILL, 247 [SIGXFSZ] = SIGPROP_KILL, 248 [SIGVTALRM] = SIGPROP_KILL, 249 [SIGPROF] = SIGPROP_KILL, 250 [SIGWINCH] = SIGPROP_IGNORE, 251 [SIGINFO] = SIGPROP_IGNORE, 252 [SIGUSR1] = SIGPROP_KILL, 253 [SIGUSR2] = SIGPROP_KILL, 254 }; 255 256 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 257 int __found; \ 258 for (;;) { \ 259 if (__bits != 0) { \ 260 int __sig = ffs(__bits); \ 261 __bits &= ~(1u << (__sig - 1)); \ 262 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 263 __found = 1; \ 264 break; \ 265 } \ 266 if (++__i == _SIG_WORDS) { \ 267 __found = 0; \ 268 break; \ 269 } \ 270 __bits = (set)->__bits[__i]; \ 271 } \ 272 __found != 0; \ 273 }) 274 275 #define SIG_FOREACH(i, set) \ 276 for (int32_t __i = -1, __bits = 0; \ 277 _SIG_FOREACH_ADVANCE(i, set); ) \ 278 279 static sigset_t fastblock_mask; 280 281 static void 282 ast_sig(struct thread *td, int tda) 283 { 284 struct proc *p; 285 int old_boundary, sig; 286 bool resched_sigs; 287 288 p = td->td_proc; 289 290 #ifdef DIAGNOSTIC 291 if (p->p_numthreads == 1 && (tda & (TDAI(TDA_SIG) | 292 TDAI(TDA_AST))) == 0) { 293 PROC_LOCK(p); 294 thread_lock(td); 295 /* 296 * Note that TDA_SIG should be re-read from 297 * td_ast, since signal might have been delivered 298 * after we cleared td_flags above. This is one of 299 * the reason for looping check for AST condition. 300 * See comment in userret() about P_PPWAIT. 301 */ 302 if ((p->p_flag & P_PPWAIT) == 0 && 303 (td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 304 if (SIGPENDING(td) && ((tda | td->td_ast) & 305 (TDAI(TDA_SIG) | TDAI(TDA_AST))) == 0) { 306 thread_unlock(td); /* fix dumps */ 307 panic( 308 "failed2 to set signal flags for ast p %p " 309 "td %p tda %#x td_ast %#x fl %#x", 310 p, td, tda, td->td_ast, td->td_flags); 311 } 312 } 313 thread_unlock(td); 314 PROC_UNLOCK(p); 315 } 316 #endif 317 318 /* 319 * Check for signals. Unlocked reads of p_pendingcnt or 320 * p_siglist might cause process-directed signal to be handled 321 * later. 322 */ 323 if ((tda & TDAI(TDA_SIG)) != 0 || p->p_pendingcnt > 0 || 324 !SIGISEMPTY(p->p_siglist)) { 325 sigfastblock_fetch(td); 326 PROC_LOCK(p); 327 old_boundary = ~TDB_BOUNDARY | (td->td_dbgflags & TDB_BOUNDARY); 328 td->td_dbgflags |= TDB_BOUNDARY; 329 mtx_lock(&p->p_sigacts->ps_mtx); 330 while ((sig = cursig(td)) != 0) { 331 KASSERT(sig >= 0, ("sig %d", sig)); 332 postsig(sig); 333 } 334 mtx_unlock(&p->p_sigacts->ps_mtx); 335 td->td_dbgflags &= old_boundary; 336 PROC_UNLOCK(p); 337 resched_sigs = true; 338 } else { 339 resched_sigs = false; 340 } 341 342 /* 343 * Handle deferred update of the fast sigblock value, after 344 * the postsig() loop was performed. 345 */ 346 sigfastblock_setpend(td, resched_sigs); 347 } 348 349 static void 350 ast_sigsuspend(struct thread *td, int tda __unused) 351 { 352 MPASS((td->td_pflags & TDP_OLDMASK) != 0); 353 td->td_pflags &= ~TDP_OLDMASK; 354 kern_sigprocmask(td, SIG_SETMASK, &td->td_oldsigmask, NULL, 0); 355 } 356 357 static void 358 sigqueue_start(void) 359 { 360 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 361 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 362 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 363 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 364 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 365 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 366 SIGFILLSET(fastblock_mask); 367 SIG_CANTMASK(fastblock_mask); 368 ast_register(TDA_SIG, ASTR_UNCOND, 0, ast_sig); 369 ast_register(TDA_SIGSUSPEND, ASTR_ASTF_REQUIRED | ASTR_TDP, 370 TDP_OLDMASK, ast_sigsuspend); 371 } 372 373 ksiginfo_t * 374 ksiginfo_alloc(int mwait) 375 { 376 MPASS(mwait == M_WAITOK || mwait == M_NOWAIT); 377 378 if (ksiginfo_zone == NULL) 379 return (NULL); 380 return (uma_zalloc(ksiginfo_zone, mwait | M_ZERO)); 381 } 382 383 void 384 ksiginfo_free(ksiginfo_t *ksi) 385 { 386 uma_zfree(ksiginfo_zone, ksi); 387 } 388 389 static __inline bool 390 ksiginfo_tryfree(ksiginfo_t *ksi) 391 { 392 if ((ksi->ksi_flags & KSI_EXT) == 0) { 393 uma_zfree(ksiginfo_zone, ksi); 394 return (true); 395 } 396 return (false); 397 } 398 399 void 400 sigqueue_init(sigqueue_t *list, struct proc *p) 401 { 402 SIGEMPTYSET(list->sq_signals); 403 SIGEMPTYSET(list->sq_kill); 404 SIGEMPTYSET(list->sq_ptrace); 405 TAILQ_INIT(&list->sq_list); 406 list->sq_proc = p; 407 list->sq_flags = SQ_INIT; 408 } 409 410 /* 411 * Get a signal's ksiginfo. 412 * Return: 413 * 0 - signal not found 414 * others - signal number 415 */ 416 static int 417 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 418 { 419 struct proc *p = sq->sq_proc; 420 struct ksiginfo *ksi, *next; 421 int count = 0; 422 423 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 424 425 if (!SIGISMEMBER(sq->sq_signals, signo)) 426 return (0); 427 428 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 429 count++; 430 SIGDELSET(sq->sq_ptrace, signo); 431 si->ksi_flags |= KSI_PTRACE; 432 } 433 if (SIGISMEMBER(sq->sq_kill, signo)) { 434 count++; 435 if (count == 1) 436 SIGDELSET(sq->sq_kill, signo); 437 } 438 439 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 440 if (ksi->ksi_signo == signo) { 441 if (count == 0) { 442 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 443 ksi->ksi_sigq = NULL; 444 ksiginfo_copy(ksi, si); 445 if (ksiginfo_tryfree(ksi) && p != NULL) 446 p->p_pendingcnt--; 447 } 448 if (++count > 1) 449 break; 450 } 451 } 452 453 if (count <= 1) 454 SIGDELSET(sq->sq_signals, signo); 455 si->ksi_signo = signo; 456 return (signo); 457 } 458 459 void 460 sigqueue_take(ksiginfo_t *ksi) 461 { 462 struct ksiginfo *kp; 463 struct proc *p; 464 sigqueue_t *sq; 465 466 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 467 return; 468 469 p = sq->sq_proc; 470 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 471 ksi->ksi_sigq = NULL; 472 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 473 p->p_pendingcnt--; 474 475 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 476 kp = TAILQ_NEXT(kp, ksi_link)) { 477 if (kp->ksi_signo == ksi->ksi_signo) 478 break; 479 } 480 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 481 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 482 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 483 } 484 485 static int 486 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 487 { 488 struct proc *p = sq->sq_proc; 489 struct ksiginfo *ksi; 490 int ret = 0; 491 492 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 493 494 /* 495 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 496 * for these signals. 497 */ 498 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 499 SIGADDSET(sq->sq_kill, signo); 500 goto out_set_bit; 501 } 502 503 /* directly insert the ksi, don't copy it */ 504 if (si->ksi_flags & KSI_INS) { 505 if (si->ksi_flags & KSI_HEAD) 506 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 507 else 508 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 509 si->ksi_sigq = sq; 510 goto out_set_bit; 511 } 512 513 if (__predict_false(ksiginfo_zone == NULL)) { 514 SIGADDSET(sq->sq_kill, signo); 515 goto out_set_bit; 516 } 517 518 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 519 signal_overflow++; 520 ret = EAGAIN; 521 } else if ((ksi = ksiginfo_alloc(M_NOWAIT)) == NULL) { 522 signal_alloc_fail++; 523 ret = EAGAIN; 524 } else { 525 if (p != NULL) 526 p->p_pendingcnt++; 527 ksiginfo_copy(si, ksi); 528 ksi->ksi_signo = signo; 529 if (si->ksi_flags & KSI_HEAD) 530 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 531 else 532 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 533 ksi->ksi_sigq = sq; 534 } 535 536 if (ret != 0) { 537 if ((si->ksi_flags & KSI_PTRACE) != 0) { 538 SIGADDSET(sq->sq_ptrace, signo); 539 ret = 0; 540 goto out_set_bit; 541 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 542 (si->ksi_flags & KSI_SIGQ) == 0) { 543 SIGADDSET(sq->sq_kill, signo); 544 ret = 0; 545 goto out_set_bit; 546 } 547 return (ret); 548 } 549 550 out_set_bit: 551 SIGADDSET(sq->sq_signals, signo); 552 return (ret); 553 } 554 555 void 556 sigqueue_flush(sigqueue_t *sq) 557 { 558 struct proc *p = sq->sq_proc; 559 ksiginfo_t *ksi; 560 561 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 562 563 if (p != NULL) 564 PROC_LOCK_ASSERT(p, MA_OWNED); 565 566 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 567 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 568 ksi->ksi_sigq = NULL; 569 if (ksiginfo_tryfree(ksi) && p != NULL) 570 p->p_pendingcnt--; 571 } 572 573 SIGEMPTYSET(sq->sq_signals); 574 SIGEMPTYSET(sq->sq_kill); 575 SIGEMPTYSET(sq->sq_ptrace); 576 } 577 578 static void 579 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 580 { 581 sigset_t tmp; 582 struct proc *p1, *p2; 583 ksiginfo_t *ksi, *next; 584 585 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 586 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 587 p1 = src->sq_proc; 588 p2 = dst->sq_proc; 589 /* Move siginfo to target list */ 590 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 591 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 592 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 593 if (p1 != NULL) 594 p1->p_pendingcnt--; 595 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 596 ksi->ksi_sigq = dst; 597 if (p2 != NULL) 598 p2->p_pendingcnt++; 599 } 600 } 601 602 /* Move pending bits to target list */ 603 tmp = src->sq_kill; 604 SIGSETAND(tmp, *set); 605 SIGSETOR(dst->sq_kill, tmp); 606 SIGSETNAND(src->sq_kill, tmp); 607 608 tmp = src->sq_ptrace; 609 SIGSETAND(tmp, *set); 610 SIGSETOR(dst->sq_ptrace, tmp); 611 SIGSETNAND(src->sq_ptrace, tmp); 612 613 tmp = src->sq_signals; 614 SIGSETAND(tmp, *set); 615 SIGSETOR(dst->sq_signals, tmp); 616 SIGSETNAND(src->sq_signals, tmp); 617 } 618 619 #if 0 620 static void 621 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 622 { 623 sigset_t set; 624 625 SIGEMPTYSET(set); 626 SIGADDSET(set, signo); 627 sigqueue_move_set(src, dst, &set); 628 } 629 #endif 630 631 static void 632 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 633 { 634 struct proc *p = sq->sq_proc; 635 ksiginfo_t *ksi, *next; 636 637 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 638 639 /* Remove siginfo queue */ 640 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 641 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 642 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 643 ksi->ksi_sigq = NULL; 644 if (ksiginfo_tryfree(ksi) && p != NULL) 645 p->p_pendingcnt--; 646 } 647 } 648 SIGSETNAND(sq->sq_kill, *set); 649 SIGSETNAND(sq->sq_ptrace, *set); 650 SIGSETNAND(sq->sq_signals, *set); 651 } 652 653 void 654 sigqueue_delete(sigqueue_t *sq, int signo) 655 { 656 sigset_t set; 657 658 SIGEMPTYSET(set); 659 SIGADDSET(set, signo); 660 sigqueue_delete_set(sq, &set); 661 } 662 663 /* Remove a set of signals for a process */ 664 static void 665 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 666 { 667 sigqueue_t worklist; 668 struct thread *td0; 669 670 PROC_LOCK_ASSERT(p, MA_OWNED); 671 672 sigqueue_init(&worklist, NULL); 673 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 674 675 FOREACH_THREAD_IN_PROC(p, td0) 676 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 677 678 sigqueue_flush(&worklist); 679 } 680 681 void 682 sigqueue_delete_proc(struct proc *p, int signo) 683 { 684 sigset_t set; 685 686 SIGEMPTYSET(set); 687 SIGADDSET(set, signo); 688 sigqueue_delete_set_proc(p, &set); 689 } 690 691 static void 692 sigqueue_delete_stopmask_proc(struct proc *p) 693 { 694 sigset_t set; 695 696 SIGEMPTYSET(set); 697 SIGADDSET(set, SIGSTOP); 698 SIGADDSET(set, SIGTSTP); 699 SIGADDSET(set, SIGTTIN); 700 SIGADDSET(set, SIGTTOU); 701 sigqueue_delete_set_proc(p, &set); 702 } 703 704 /* 705 * Determine signal that should be delivered to thread td, the current 706 * thread, 0 if none. If there is a pending stop signal with default 707 * action, the process stops in issignal(). 708 */ 709 int 710 cursig(struct thread *td) 711 { 712 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 713 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 714 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 715 return (SIGPENDING(td) ? issignal(td) : 0); 716 } 717 718 /* 719 * Arrange for ast() to handle unmasked pending signals on return to user 720 * mode. This must be called whenever a signal is added to td_sigqueue or 721 * unmasked in td_sigmask. 722 */ 723 void 724 signotify(struct thread *td) 725 { 726 727 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 728 729 if (SIGPENDING(td)) 730 ast_sched(td, TDA_SIG); 731 } 732 733 /* 734 * Returns 1 (true) if altstack is configured for the thread, and the 735 * passed stack bottom address falls into the altstack range. Handles 736 * the 43 compat special case where the alt stack size is zero. 737 */ 738 int 739 sigonstack(size_t sp) 740 { 741 struct thread *td; 742 743 td = curthread; 744 if ((td->td_pflags & TDP_ALTSTACK) == 0) 745 return (0); 746 #if defined(COMPAT_43) 747 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 748 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 749 #endif 750 return (sp >= (size_t)td->td_sigstk.ss_sp && 751 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 752 } 753 754 static __inline int 755 sigprop(int sig) 756 { 757 758 if (sig > 0 && sig < nitems(sigproptbl)) 759 return (sigproptbl[sig]); 760 return (0); 761 } 762 763 static bool 764 sigact_flag_test(const struct sigaction *act, int flag) 765 { 766 767 /* 768 * SA_SIGINFO is reset when signal disposition is set to 769 * ignore or default. Other flags are kept according to user 770 * settings. 771 */ 772 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 773 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 774 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 775 } 776 777 /* 778 * kern_sigaction 779 * sigaction 780 * freebsd4_sigaction 781 * osigaction 782 */ 783 int 784 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 785 struct sigaction *oact, int flags) 786 { 787 struct sigacts *ps; 788 struct proc *p = td->td_proc; 789 790 if (!_SIG_VALID(sig)) 791 return (EINVAL); 792 if (act != NULL && act->sa_handler != SIG_DFL && 793 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 794 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 795 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 796 return (EINVAL); 797 798 PROC_LOCK(p); 799 ps = p->p_sigacts; 800 mtx_lock(&ps->ps_mtx); 801 if (oact) { 802 memset(oact, 0, sizeof(*oact)); 803 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 804 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 805 oact->sa_flags |= SA_ONSTACK; 806 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 807 oact->sa_flags |= SA_RESTART; 808 if (SIGISMEMBER(ps->ps_sigreset, sig)) 809 oact->sa_flags |= SA_RESETHAND; 810 if (SIGISMEMBER(ps->ps_signodefer, sig)) 811 oact->sa_flags |= SA_NODEFER; 812 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 813 oact->sa_flags |= SA_SIGINFO; 814 oact->sa_sigaction = 815 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 816 } else 817 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 818 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 819 oact->sa_flags |= SA_NOCLDSTOP; 820 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 821 oact->sa_flags |= SA_NOCLDWAIT; 822 } 823 if (act) { 824 if ((sig == SIGKILL || sig == SIGSTOP) && 825 act->sa_handler != SIG_DFL) { 826 mtx_unlock(&ps->ps_mtx); 827 PROC_UNLOCK(p); 828 return (EINVAL); 829 } 830 831 /* 832 * Change setting atomically. 833 */ 834 835 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 836 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 837 if (sigact_flag_test(act, SA_SIGINFO)) { 838 ps->ps_sigact[_SIG_IDX(sig)] = 839 (__sighandler_t *)act->sa_sigaction; 840 SIGADDSET(ps->ps_siginfo, sig); 841 } else { 842 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 843 SIGDELSET(ps->ps_siginfo, sig); 844 } 845 if (!sigact_flag_test(act, SA_RESTART)) 846 SIGADDSET(ps->ps_sigintr, sig); 847 else 848 SIGDELSET(ps->ps_sigintr, sig); 849 if (sigact_flag_test(act, SA_ONSTACK)) 850 SIGADDSET(ps->ps_sigonstack, sig); 851 else 852 SIGDELSET(ps->ps_sigonstack, sig); 853 if (sigact_flag_test(act, SA_RESETHAND)) 854 SIGADDSET(ps->ps_sigreset, sig); 855 else 856 SIGDELSET(ps->ps_sigreset, sig); 857 if (sigact_flag_test(act, SA_NODEFER)) 858 SIGADDSET(ps->ps_signodefer, sig); 859 else 860 SIGDELSET(ps->ps_signodefer, sig); 861 if (sig == SIGCHLD) { 862 if (act->sa_flags & SA_NOCLDSTOP) 863 ps->ps_flag |= PS_NOCLDSTOP; 864 else 865 ps->ps_flag &= ~PS_NOCLDSTOP; 866 if (act->sa_flags & SA_NOCLDWAIT) { 867 /* 868 * Paranoia: since SA_NOCLDWAIT is implemented 869 * by reparenting the dying child to PID 1 (and 870 * trust it to reap the zombie), PID 1 itself 871 * is forbidden to set SA_NOCLDWAIT. 872 */ 873 if (p->p_pid == 1) 874 ps->ps_flag &= ~PS_NOCLDWAIT; 875 else 876 ps->ps_flag |= PS_NOCLDWAIT; 877 } else 878 ps->ps_flag &= ~PS_NOCLDWAIT; 879 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 880 ps->ps_flag |= PS_CLDSIGIGN; 881 else 882 ps->ps_flag &= ~PS_CLDSIGIGN; 883 } 884 /* 885 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 886 * and for signals set to SIG_DFL where the default is to 887 * ignore. However, don't put SIGCONT in ps_sigignore, as we 888 * have to restart the process. 889 */ 890 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 891 (sigprop(sig) & SIGPROP_IGNORE && 892 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 893 /* never to be seen again */ 894 sigqueue_delete_proc(p, sig); 895 if (sig != SIGCONT) 896 /* easier in psignal */ 897 SIGADDSET(ps->ps_sigignore, sig); 898 SIGDELSET(ps->ps_sigcatch, sig); 899 } else { 900 SIGDELSET(ps->ps_sigignore, sig); 901 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 902 SIGDELSET(ps->ps_sigcatch, sig); 903 else 904 SIGADDSET(ps->ps_sigcatch, sig); 905 } 906 #ifdef COMPAT_FREEBSD4 907 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 908 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 909 (flags & KSA_FREEBSD4) == 0) 910 SIGDELSET(ps->ps_freebsd4, sig); 911 else 912 SIGADDSET(ps->ps_freebsd4, sig); 913 #endif 914 #ifdef COMPAT_43 915 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 916 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 917 (flags & KSA_OSIGSET) == 0) 918 SIGDELSET(ps->ps_osigset, sig); 919 else 920 SIGADDSET(ps->ps_osigset, sig); 921 #endif 922 } 923 mtx_unlock(&ps->ps_mtx); 924 PROC_UNLOCK(p); 925 return (0); 926 } 927 928 #ifndef _SYS_SYSPROTO_H_ 929 struct sigaction_args { 930 int sig; 931 struct sigaction *act; 932 struct sigaction *oact; 933 }; 934 #endif 935 int 936 sys_sigaction(struct thread *td, struct sigaction_args *uap) 937 { 938 struct sigaction act, oact; 939 struct sigaction *actp, *oactp; 940 int error; 941 942 actp = (uap->act != NULL) ? &act : NULL; 943 oactp = (uap->oact != NULL) ? &oact : NULL; 944 if (actp) { 945 error = copyin(uap->act, actp, sizeof(act)); 946 if (error) 947 return (error); 948 } 949 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 950 if (oactp && !error) 951 error = copyout(oactp, uap->oact, sizeof(oact)); 952 return (error); 953 } 954 955 #ifdef COMPAT_FREEBSD4 956 #ifndef _SYS_SYSPROTO_H_ 957 struct freebsd4_sigaction_args { 958 int sig; 959 struct sigaction *act; 960 struct sigaction *oact; 961 }; 962 #endif 963 int 964 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 965 { 966 struct sigaction act, oact; 967 struct sigaction *actp, *oactp; 968 int error; 969 970 actp = (uap->act != NULL) ? &act : NULL; 971 oactp = (uap->oact != NULL) ? &oact : NULL; 972 if (actp) { 973 error = copyin(uap->act, actp, sizeof(act)); 974 if (error) 975 return (error); 976 } 977 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 978 if (oactp && !error) 979 error = copyout(oactp, uap->oact, sizeof(oact)); 980 return (error); 981 } 982 #endif /* COMAPT_FREEBSD4 */ 983 984 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 985 #ifndef _SYS_SYSPROTO_H_ 986 struct osigaction_args { 987 int signum; 988 struct osigaction *nsa; 989 struct osigaction *osa; 990 }; 991 #endif 992 int 993 osigaction(struct thread *td, struct osigaction_args *uap) 994 { 995 struct osigaction sa; 996 struct sigaction nsa, osa; 997 struct sigaction *nsap, *osap; 998 int error; 999 1000 if (uap->signum <= 0 || uap->signum >= ONSIG) 1001 return (EINVAL); 1002 1003 nsap = (uap->nsa != NULL) ? &nsa : NULL; 1004 osap = (uap->osa != NULL) ? &osa : NULL; 1005 1006 if (nsap) { 1007 error = copyin(uap->nsa, &sa, sizeof(sa)); 1008 if (error) 1009 return (error); 1010 nsap->sa_handler = sa.sa_handler; 1011 nsap->sa_flags = sa.sa_flags; 1012 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 1013 } 1014 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1015 if (osap && !error) { 1016 sa.sa_handler = osap->sa_handler; 1017 sa.sa_flags = osap->sa_flags; 1018 SIG2OSIG(osap->sa_mask, sa.sa_mask); 1019 error = copyout(&sa, uap->osa, sizeof(sa)); 1020 } 1021 return (error); 1022 } 1023 1024 #if !defined(__i386__) 1025 /* Avoid replicating the same stub everywhere */ 1026 int 1027 osigreturn(struct thread *td, struct osigreturn_args *uap) 1028 { 1029 1030 return (nosys(td, (struct nosys_args *)uap)); 1031 } 1032 #endif 1033 #endif /* COMPAT_43 */ 1034 1035 /* 1036 * Initialize signal state for process 0; 1037 * set to ignore signals that are ignored by default. 1038 */ 1039 void 1040 siginit(struct proc *p) 1041 { 1042 int i; 1043 struct sigacts *ps; 1044 1045 PROC_LOCK(p); 1046 ps = p->p_sigacts; 1047 mtx_lock(&ps->ps_mtx); 1048 for (i = 1; i <= NSIG; i++) { 1049 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 1050 SIGADDSET(ps->ps_sigignore, i); 1051 } 1052 } 1053 mtx_unlock(&ps->ps_mtx); 1054 PROC_UNLOCK(p); 1055 } 1056 1057 /* 1058 * Reset specified signal to the default disposition. 1059 */ 1060 static void 1061 sigdflt(struct sigacts *ps, int sig) 1062 { 1063 1064 mtx_assert(&ps->ps_mtx, MA_OWNED); 1065 SIGDELSET(ps->ps_sigcatch, sig); 1066 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 1067 SIGADDSET(ps->ps_sigignore, sig); 1068 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1069 SIGDELSET(ps->ps_siginfo, sig); 1070 } 1071 1072 /* 1073 * Reset signals for an exec of the specified process. 1074 */ 1075 void 1076 execsigs(struct proc *p) 1077 { 1078 struct sigacts *ps; 1079 struct thread *td; 1080 1081 /* 1082 * Reset caught signals. Held signals remain held 1083 * through td_sigmask (unless they were caught, 1084 * and are now ignored by default). 1085 */ 1086 PROC_LOCK_ASSERT(p, MA_OWNED); 1087 ps = p->p_sigacts; 1088 mtx_lock(&ps->ps_mtx); 1089 sig_drop_caught(p); 1090 1091 /* 1092 * Reset stack state to the user stack. 1093 * Clear set of signals caught on the signal stack. 1094 */ 1095 td = curthread; 1096 MPASS(td->td_proc == p); 1097 td->td_sigstk.ss_flags = SS_DISABLE; 1098 td->td_sigstk.ss_size = 0; 1099 td->td_sigstk.ss_sp = 0; 1100 td->td_pflags &= ~TDP_ALTSTACK; 1101 /* 1102 * Reset no zombies if child dies flag as Solaris does. 1103 */ 1104 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1105 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1106 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1107 mtx_unlock(&ps->ps_mtx); 1108 } 1109 1110 /* 1111 * kern_sigprocmask() 1112 * 1113 * Manipulate signal mask. 1114 */ 1115 int 1116 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1117 int flags) 1118 { 1119 sigset_t new_block, oset1; 1120 struct proc *p; 1121 int error; 1122 1123 p = td->td_proc; 1124 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1125 PROC_LOCK_ASSERT(p, MA_OWNED); 1126 else 1127 PROC_LOCK(p); 1128 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1129 ? MA_OWNED : MA_NOTOWNED); 1130 if (oset != NULL) 1131 *oset = td->td_sigmask; 1132 1133 error = 0; 1134 if (set != NULL) { 1135 switch (how) { 1136 case SIG_BLOCK: 1137 SIG_CANTMASK(*set); 1138 oset1 = td->td_sigmask; 1139 SIGSETOR(td->td_sigmask, *set); 1140 new_block = td->td_sigmask; 1141 SIGSETNAND(new_block, oset1); 1142 break; 1143 case SIG_UNBLOCK: 1144 SIGSETNAND(td->td_sigmask, *set); 1145 signotify(td); 1146 goto out; 1147 case SIG_SETMASK: 1148 SIG_CANTMASK(*set); 1149 oset1 = td->td_sigmask; 1150 if (flags & SIGPROCMASK_OLD) 1151 SIGSETLO(td->td_sigmask, *set); 1152 else 1153 td->td_sigmask = *set; 1154 new_block = td->td_sigmask; 1155 SIGSETNAND(new_block, oset1); 1156 signotify(td); 1157 break; 1158 default: 1159 error = EINVAL; 1160 goto out; 1161 } 1162 1163 /* 1164 * The new_block set contains signals that were not previously 1165 * blocked, but are blocked now. 1166 * 1167 * In case we block any signal that was not previously blocked 1168 * for td, and process has the signal pending, try to schedule 1169 * signal delivery to some thread that does not block the 1170 * signal, possibly waking it up. 1171 */ 1172 if (p->p_numthreads != 1) 1173 reschedule_signals(p, new_block, flags); 1174 } 1175 1176 out: 1177 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1178 PROC_UNLOCK(p); 1179 return (error); 1180 } 1181 1182 #ifndef _SYS_SYSPROTO_H_ 1183 struct sigprocmask_args { 1184 int how; 1185 const sigset_t *set; 1186 sigset_t *oset; 1187 }; 1188 #endif 1189 int 1190 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1191 { 1192 sigset_t set, oset; 1193 sigset_t *setp, *osetp; 1194 int error; 1195 1196 setp = (uap->set != NULL) ? &set : NULL; 1197 osetp = (uap->oset != NULL) ? &oset : NULL; 1198 if (setp) { 1199 error = copyin(uap->set, setp, sizeof(set)); 1200 if (error) 1201 return (error); 1202 } 1203 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1204 if (osetp && !error) { 1205 error = copyout(osetp, uap->oset, sizeof(oset)); 1206 } 1207 return (error); 1208 } 1209 1210 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1211 #ifndef _SYS_SYSPROTO_H_ 1212 struct osigprocmask_args { 1213 int how; 1214 osigset_t mask; 1215 }; 1216 #endif 1217 int 1218 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1219 { 1220 sigset_t set, oset; 1221 int error; 1222 1223 OSIG2SIG(uap->mask, set); 1224 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1225 SIG2OSIG(oset, td->td_retval[0]); 1226 return (error); 1227 } 1228 #endif /* COMPAT_43 */ 1229 1230 int 1231 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1232 { 1233 ksiginfo_t ksi; 1234 sigset_t set; 1235 int error; 1236 1237 error = copyin(uap->set, &set, sizeof(set)); 1238 if (error) { 1239 td->td_retval[0] = error; 1240 return (0); 1241 } 1242 1243 error = kern_sigtimedwait(td, set, &ksi, NULL); 1244 if (error) { 1245 /* 1246 * sigwait() function shall not return EINTR, but 1247 * the syscall does. Non-ancient libc provides the 1248 * wrapper which hides EINTR. Otherwise, EINTR return 1249 * is used by libthr to handle required cancellation 1250 * point in the sigwait(). 1251 */ 1252 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1253 return (ERESTART); 1254 td->td_retval[0] = error; 1255 return (0); 1256 } 1257 1258 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1259 td->td_retval[0] = error; 1260 return (0); 1261 } 1262 1263 int 1264 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1265 { 1266 struct timespec ts; 1267 struct timespec *timeout; 1268 sigset_t set; 1269 ksiginfo_t ksi; 1270 int error; 1271 1272 if (uap->timeout) { 1273 error = copyin(uap->timeout, &ts, sizeof(ts)); 1274 if (error) 1275 return (error); 1276 1277 timeout = &ts; 1278 } else 1279 timeout = NULL; 1280 1281 error = copyin(uap->set, &set, sizeof(set)); 1282 if (error) 1283 return (error); 1284 1285 error = kern_sigtimedwait(td, set, &ksi, timeout); 1286 if (error) 1287 return (error); 1288 1289 if (uap->info) 1290 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1291 1292 if (error == 0) 1293 td->td_retval[0] = ksi.ksi_signo; 1294 return (error); 1295 } 1296 1297 int 1298 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1299 { 1300 ksiginfo_t ksi; 1301 sigset_t set; 1302 int error; 1303 1304 error = copyin(uap->set, &set, sizeof(set)); 1305 if (error) 1306 return (error); 1307 1308 error = kern_sigtimedwait(td, set, &ksi, NULL); 1309 if (error) 1310 return (error); 1311 1312 if (uap->info) 1313 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1314 1315 if (error == 0) 1316 td->td_retval[0] = ksi.ksi_signo; 1317 return (error); 1318 } 1319 1320 static void 1321 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1322 { 1323 struct thread *thr; 1324 1325 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1326 if (thr == td) 1327 thr->td_si = *si; 1328 else 1329 thr->td_si.si_signo = 0; 1330 } 1331 } 1332 1333 int 1334 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1335 struct timespec *timeout) 1336 { 1337 struct sigacts *ps; 1338 sigset_t saved_mask, new_block; 1339 struct proc *p; 1340 int error, sig, timevalid = 0; 1341 sbintime_t sbt, precision, tsbt; 1342 struct timespec ts; 1343 bool traced; 1344 1345 p = td->td_proc; 1346 error = 0; 1347 traced = false; 1348 1349 /* Ensure the sigfastblock value is up to date. */ 1350 sigfastblock_fetch(td); 1351 1352 if (timeout != NULL) { 1353 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1354 timevalid = 1; 1355 ts = *timeout; 1356 if (ts.tv_sec < INT32_MAX / 2) { 1357 tsbt = tstosbt(ts); 1358 precision = tsbt; 1359 precision >>= tc_precexp; 1360 if (TIMESEL(&sbt, tsbt)) 1361 sbt += tc_tick_sbt; 1362 sbt += tsbt; 1363 } else 1364 precision = sbt = 0; 1365 } 1366 } else 1367 precision = sbt = 0; 1368 ksiginfo_init(ksi); 1369 /* Some signals can not be waited for. */ 1370 SIG_CANTMASK(waitset); 1371 ps = p->p_sigacts; 1372 PROC_LOCK(p); 1373 saved_mask = td->td_sigmask; 1374 SIGSETNAND(td->td_sigmask, waitset); 1375 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1376 !kern_sig_discard_ign) { 1377 thread_lock(td); 1378 td->td_flags |= TDF_SIGWAIT; 1379 thread_unlock(td); 1380 } 1381 for (;;) { 1382 mtx_lock(&ps->ps_mtx); 1383 sig = cursig(td); 1384 mtx_unlock(&ps->ps_mtx); 1385 KASSERT(sig >= 0, ("sig %d", sig)); 1386 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1387 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1388 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1389 error = 0; 1390 break; 1391 } 1392 } 1393 1394 if (error != 0) 1395 break; 1396 1397 /* 1398 * POSIX says this must be checked after looking for pending 1399 * signals. 1400 */ 1401 if (timeout != NULL && !timevalid) { 1402 error = EINVAL; 1403 break; 1404 } 1405 1406 if (traced) { 1407 error = EINTR; 1408 break; 1409 } 1410 1411 error = msleep_sbt(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1412 "sigwait", sbt, precision, C_ABSOLUTE); 1413 1414 /* The syscalls can not be restarted. */ 1415 if (error == ERESTART) 1416 error = EINTR; 1417 1418 /* 1419 * If PTRACE_SCE or PTRACE_SCX were set after 1420 * userspace entered the syscall, return spurious 1421 * EINTR after wait was done. Only do this as last 1422 * resort after rechecking for possible queued signals 1423 * and expired timeouts. 1424 */ 1425 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1426 traced = true; 1427 } 1428 thread_lock(td); 1429 td->td_flags &= ~TDF_SIGWAIT; 1430 thread_unlock(td); 1431 1432 new_block = saved_mask; 1433 SIGSETNAND(new_block, td->td_sigmask); 1434 td->td_sigmask = saved_mask; 1435 /* 1436 * Fewer signals can be delivered to us, reschedule signal 1437 * notification. 1438 */ 1439 if (p->p_numthreads != 1) 1440 reschedule_signals(p, new_block, 0); 1441 1442 if (error == 0) { 1443 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1444 1445 if (ksi->ksi_code == SI_TIMER) 1446 itimer_accept(p, ksi->ksi_timerid, ksi); 1447 1448 #ifdef KTRACE 1449 if (KTRPOINT(td, KTR_PSIG)) { 1450 sig_t action; 1451 1452 mtx_lock(&ps->ps_mtx); 1453 action = ps->ps_sigact[_SIG_IDX(sig)]; 1454 mtx_unlock(&ps->ps_mtx); 1455 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1456 } 1457 #endif 1458 if (sig == SIGKILL) { 1459 proc_td_siginfo_capture(td, &ksi->ksi_info); 1460 sigexit(td, sig); 1461 } 1462 } 1463 PROC_UNLOCK(p); 1464 return (error); 1465 } 1466 1467 #ifndef _SYS_SYSPROTO_H_ 1468 struct sigpending_args { 1469 sigset_t *set; 1470 }; 1471 #endif 1472 int 1473 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1474 { 1475 struct proc *p = td->td_proc; 1476 sigset_t pending; 1477 1478 PROC_LOCK(p); 1479 pending = p->p_sigqueue.sq_signals; 1480 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1481 PROC_UNLOCK(p); 1482 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1483 } 1484 1485 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1486 #ifndef _SYS_SYSPROTO_H_ 1487 struct osigpending_args { 1488 int dummy; 1489 }; 1490 #endif 1491 int 1492 osigpending(struct thread *td, struct osigpending_args *uap) 1493 { 1494 struct proc *p = td->td_proc; 1495 sigset_t pending; 1496 1497 PROC_LOCK(p); 1498 pending = p->p_sigqueue.sq_signals; 1499 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1500 PROC_UNLOCK(p); 1501 SIG2OSIG(pending, td->td_retval[0]); 1502 return (0); 1503 } 1504 #endif /* COMPAT_43 */ 1505 1506 #if defined(COMPAT_43) 1507 /* 1508 * Generalized interface signal handler, 4.3-compatible. 1509 */ 1510 #ifndef _SYS_SYSPROTO_H_ 1511 struct osigvec_args { 1512 int signum; 1513 struct sigvec *nsv; 1514 struct sigvec *osv; 1515 }; 1516 #endif 1517 /* ARGSUSED */ 1518 int 1519 osigvec(struct thread *td, struct osigvec_args *uap) 1520 { 1521 struct sigvec vec; 1522 struct sigaction nsa, osa; 1523 struct sigaction *nsap, *osap; 1524 int error; 1525 1526 if (uap->signum <= 0 || uap->signum >= ONSIG) 1527 return (EINVAL); 1528 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1529 osap = (uap->osv != NULL) ? &osa : NULL; 1530 if (nsap) { 1531 error = copyin(uap->nsv, &vec, sizeof(vec)); 1532 if (error) 1533 return (error); 1534 nsap->sa_handler = vec.sv_handler; 1535 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1536 nsap->sa_flags = vec.sv_flags; 1537 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1538 } 1539 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1540 if (osap && !error) { 1541 vec.sv_handler = osap->sa_handler; 1542 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1543 vec.sv_flags = osap->sa_flags; 1544 vec.sv_flags &= ~SA_NOCLDWAIT; 1545 vec.sv_flags ^= SA_RESTART; 1546 error = copyout(&vec, uap->osv, sizeof(vec)); 1547 } 1548 return (error); 1549 } 1550 1551 #ifndef _SYS_SYSPROTO_H_ 1552 struct osigblock_args { 1553 int mask; 1554 }; 1555 #endif 1556 int 1557 osigblock(struct thread *td, struct osigblock_args *uap) 1558 { 1559 sigset_t set, oset; 1560 1561 OSIG2SIG(uap->mask, set); 1562 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1563 SIG2OSIG(oset, td->td_retval[0]); 1564 return (0); 1565 } 1566 1567 #ifndef _SYS_SYSPROTO_H_ 1568 struct osigsetmask_args { 1569 int mask; 1570 }; 1571 #endif 1572 int 1573 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1574 { 1575 sigset_t set, oset; 1576 1577 OSIG2SIG(uap->mask, set); 1578 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1579 SIG2OSIG(oset, td->td_retval[0]); 1580 return (0); 1581 } 1582 #endif /* COMPAT_43 */ 1583 1584 /* 1585 * Suspend calling thread until signal, providing mask to be set in the 1586 * meantime. 1587 */ 1588 #ifndef _SYS_SYSPROTO_H_ 1589 struct sigsuspend_args { 1590 const sigset_t *sigmask; 1591 }; 1592 #endif 1593 /* ARGSUSED */ 1594 int 1595 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1596 { 1597 sigset_t mask; 1598 int error; 1599 1600 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1601 if (error) 1602 return (error); 1603 return (kern_sigsuspend(td, mask)); 1604 } 1605 1606 int 1607 kern_sigsuspend(struct thread *td, sigset_t mask) 1608 { 1609 struct proc *p = td->td_proc; 1610 int has_sig, sig; 1611 1612 /* Ensure the sigfastblock value is up to date. */ 1613 sigfastblock_fetch(td); 1614 1615 /* 1616 * When returning from sigsuspend, we want 1617 * the old mask to be restored after the 1618 * signal handler has finished. Thus, we 1619 * save it here and mark the sigacts structure 1620 * to indicate this. 1621 */ 1622 PROC_LOCK(p); 1623 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1624 SIGPROCMASK_PROC_LOCKED); 1625 td->td_pflags |= TDP_OLDMASK; 1626 ast_sched(td, TDA_SIGSUSPEND); 1627 1628 /* 1629 * Process signals now. Otherwise, we can get spurious wakeup 1630 * due to signal entered process queue, but delivered to other 1631 * thread. But sigsuspend should return only on signal 1632 * delivery. 1633 */ 1634 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1635 for (has_sig = 0; !has_sig;) { 1636 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1637 0) == 0) 1638 /* void */; 1639 thread_suspend_check(0); 1640 mtx_lock(&p->p_sigacts->ps_mtx); 1641 while ((sig = cursig(td)) != 0) { 1642 KASSERT(sig >= 0, ("sig %d", sig)); 1643 has_sig += postsig(sig); 1644 } 1645 mtx_unlock(&p->p_sigacts->ps_mtx); 1646 1647 /* 1648 * If PTRACE_SCE or PTRACE_SCX were set after 1649 * userspace entered the syscall, return spurious 1650 * EINTR. 1651 */ 1652 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1653 has_sig += 1; 1654 } 1655 PROC_UNLOCK(p); 1656 td->td_errno = EINTR; 1657 td->td_pflags |= TDP_NERRNO; 1658 return (EJUSTRETURN); 1659 } 1660 1661 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1662 /* 1663 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1664 * convention: libc stub passes mask, not pointer, to save a copyin. 1665 */ 1666 #ifndef _SYS_SYSPROTO_H_ 1667 struct osigsuspend_args { 1668 osigset_t mask; 1669 }; 1670 #endif 1671 /* ARGSUSED */ 1672 int 1673 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1674 { 1675 sigset_t mask; 1676 1677 OSIG2SIG(uap->mask, mask); 1678 return (kern_sigsuspend(td, mask)); 1679 } 1680 #endif /* COMPAT_43 */ 1681 1682 #if defined(COMPAT_43) 1683 #ifndef _SYS_SYSPROTO_H_ 1684 struct osigstack_args { 1685 struct sigstack *nss; 1686 struct sigstack *oss; 1687 }; 1688 #endif 1689 /* ARGSUSED */ 1690 int 1691 osigstack(struct thread *td, struct osigstack_args *uap) 1692 { 1693 struct sigstack nss, oss; 1694 int error = 0; 1695 1696 if (uap->nss != NULL) { 1697 error = copyin(uap->nss, &nss, sizeof(nss)); 1698 if (error) 1699 return (error); 1700 } 1701 oss.ss_sp = td->td_sigstk.ss_sp; 1702 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1703 if (uap->nss != NULL) { 1704 td->td_sigstk.ss_sp = nss.ss_sp; 1705 td->td_sigstk.ss_size = 0; 1706 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1707 td->td_pflags |= TDP_ALTSTACK; 1708 } 1709 if (uap->oss != NULL) 1710 error = copyout(&oss, uap->oss, sizeof(oss)); 1711 1712 return (error); 1713 } 1714 #endif /* COMPAT_43 */ 1715 1716 #ifndef _SYS_SYSPROTO_H_ 1717 struct sigaltstack_args { 1718 stack_t *ss; 1719 stack_t *oss; 1720 }; 1721 #endif 1722 /* ARGSUSED */ 1723 int 1724 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1725 { 1726 stack_t ss, oss; 1727 int error; 1728 1729 if (uap->ss != NULL) { 1730 error = copyin(uap->ss, &ss, sizeof(ss)); 1731 if (error) 1732 return (error); 1733 } 1734 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1735 (uap->oss != NULL) ? &oss : NULL); 1736 if (error) 1737 return (error); 1738 if (uap->oss != NULL) 1739 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1740 return (error); 1741 } 1742 1743 int 1744 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1745 { 1746 struct proc *p = td->td_proc; 1747 int oonstack; 1748 1749 oonstack = sigonstack(cpu_getstack(td)); 1750 1751 if (oss != NULL) { 1752 *oss = td->td_sigstk; 1753 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1754 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1755 } 1756 1757 if (ss != NULL) { 1758 if (oonstack) 1759 return (EPERM); 1760 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1761 return (EINVAL); 1762 if (!(ss->ss_flags & SS_DISABLE)) { 1763 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1764 return (ENOMEM); 1765 1766 td->td_sigstk = *ss; 1767 td->td_pflags |= TDP_ALTSTACK; 1768 } else { 1769 td->td_pflags &= ~TDP_ALTSTACK; 1770 } 1771 } 1772 return (0); 1773 } 1774 1775 struct killpg1_ctx { 1776 struct thread *td; 1777 ksiginfo_t *ksi; 1778 int sig; 1779 bool sent; 1780 bool found; 1781 int ret; 1782 }; 1783 1784 static void 1785 killpg1_sendsig_locked(struct proc *p, struct killpg1_ctx *arg) 1786 { 1787 int err; 1788 1789 err = p_cansignal(arg->td, p, arg->sig); 1790 if (err == 0 && arg->sig != 0) 1791 pksignal(p, arg->sig, arg->ksi); 1792 if (err != ESRCH) 1793 arg->found = true; 1794 if (err == 0) 1795 arg->sent = true; 1796 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1797 arg->ret = err; 1798 } 1799 1800 static void 1801 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1802 { 1803 1804 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1805 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1806 return; 1807 1808 PROC_LOCK(p); 1809 killpg1_sendsig_locked(p, arg); 1810 PROC_UNLOCK(p); 1811 } 1812 1813 static void 1814 kill_processes_prison_cb(struct proc *p, void *arg) 1815 { 1816 struct killpg1_ctx *ctx = arg; 1817 1818 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1819 (p == ctx->td->td_proc) || p->p_state == PRS_NEW) 1820 return; 1821 1822 killpg1_sendsig_locked(p, ctx); 1823 } 1824 1825 /* 1826 * Common code for kill process group/broadcast kill. 1827 * td is the calling thread, as usual. 1828 */ 1829 static int 1830 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1831 { 1832 struct proc *p; 1833 struct pgrp *pgrp; 1834 struct killpg1_ctx arg; 1835 1836 arg.td = td; 1837 arg.ksi = ksi; 1838 arg.sig = sig; 1839 arg.sent = false; 1840 arg.found = false; 1841 arg.ret = 0; 1842 if (all) { 1843 /* 1844 * broadcast 1845 */ 1846 prison_proc_iterate(td->td_ucred->cr_prison, 1847 kill_processes_prison_cb, &arg); 1848 } else { 1849 again: 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 if (!sx_try_xlock(&pgrp->pg_killsx)) { 1866 PGRP_UNLOCK(pgrp); 1867 sx_xlock(&pgrp->pg_killsx); 1868 sx_xunlock(&pgrp->pg_killsx); 1869 goto again; 1870 } 1871 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1872 killpg1_sendsig(p, false, &arg); 1873 } 1874 PGRP_UNLOCK(pgrp); 1875 sx_xunlock(&pgrp->pg_killsx); 1876 } 1877 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1878 if (arg.ret == 0 && !arg.sent) 1879 arg.ret = arg.found ? EPERM : ESRCH; 1880 return (arg.ret); 1881 } 1882 1883 #ifndef _SYS_SYSPROTO_H_ 1884 struct kill_args { 1885 int pid; 1886 int signum; 1887 }; 1888 #endif 1889 /* ARGSUSED */ 1890 int 1891 sys_kill(struct thread *td, struct kill_args *uap) 1892 { 1893 1894 return (kern_kill(td, uap->pid, uap->signum)); 1895 } 1896 1897 int 1898 kern_kill(struct thread *td, pid_t pid, int signum) 1899 { 1900 ksiginfo_t ksi; 1901 struct proc *p; 1902 int error; 1903 1904 /* 1905 * A process in capability mode can send signals only to himself. 1906 * The main rationale behind this is that abort(3) is implemented as 1907 * kill(getpid(), SIGABRT). 1908 */ 1909 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1910 return (ECAPMODE); 1911 1912 AUDIT_ARG_SIGNUM(signum); 1913 AUDIT_ARG_PID(pid); 1914 if ((u_int)signum > _SIG_MAXSIG) 1915 return (EINVAL); 1916 1917 ksiginfo_init(&ksi); 1918 ksi.ksi_signo = signum; 1919 ksi.ksi_code = SI_USER; 1920 ksi.ksi_pid = td->td_proc->p_pid; 1921 ksi.ksi_uid = td->td_ucred->cr_ruid; 1922 1923 if (pid > 0) { 1924 /* kill single process */ 1925 if ((p = pfind_any(pid)) == NULL) 1926 return (ESRCH); 1927 AUDIT_ARG_PROCESS(p); 1928 error = p_cansignal(td, p, signum); 1929 if (error == 0 && signum) 1930 pksignal(p, signum, &ksi); 1931 PROC_UNLOCK(p); 1932 return (error); 1933 } 1934 switch (pid) { 1935 case -1: /* broadcast signal */ 1936 return (killpg1(td, signum, 0, 1, &ksi)); 1937 case 0: /* signal own process group */ 1938 return (killpg1(td, signum, 0, 0, &ksi)); 1939 default: /* negative explicit process group */ 1940 return (killpg1(td, signum, -pid, 0, &ksi)); 1941 } 1942 /* NOTREACHED */ 1943 } 1944 1945 int 1946 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1947 { 1948 struct proc *p; 1949 int error; 1950 1951 AUDIT_ARG_SIGNUM(uap->signum); 1952 AUDIT_ARG_FD(uap->fd); 1953 if ((u_int)uap->signum > _SIG_MAXSIG) 1954 return (EINVAL); 1955 1956 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1957 if (error) 1958 return (error); 1959 AUDIT_ARG_PROCESS(p); 1960 error = p_cansignal(td, p, uap->signum); 1961 if (error == 0 && uap->signum) 1962 kern_psignal(p, uap->signum); 1963 PROC_UNLOCK(p); 1964 return (error); 1965 } 1966 1967 #if defined(COMPAT_43) 1968 #ifndef _SYS_SYSPROTO_H_ 1969 struct okillpg_args { 1970 int pgid; 1971 int signum; 1972 }; 1973 #endif 1974 /* ARGSUSED */ 1975 int 1976 okillpg(struct thread *td, struct okillpg_args *uap) 1977 { 1978 ksiginfo_t ksi; 1979 1980 AUDIT_ARG_SIGNUM(uap->signum); 1981 AUDIT_ARG_PID(uap->pgid); 1982 if ((u_int)uap->signum > _SIG_MAXSIG) 1983 return (EINVAL); 1984 1985 ksiginfo_init(&ksi); 1986 ksi.ksi_signo = uap->signum; 1987 ksi.ksi_code = SI_USER; 1988 ksi.ksi_pid = td->td_proc->p_pid; 1989 ksi.ksi_uid = td->td_ucred->cr_ruid; 1990 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1991 } 1992 #endif /* COMPAT_43 */ 1993 1994 #ifndef _SYS_SYSPROTO_H_ 1995 struct sigqueue_args { 1996 pid_t pid; 1997 int signum; 1998 /* union sigval */ void *value; 1999 }; 2000 #endif 2001 int 2002 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 2003 { 2004 union sigval sv; 2005 2006 sv.sival_ptr = uap->value; 2007 2008 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 2009 } 2010 2011 int 2012 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 2013 { 2014 ksiginfo_t ksi; 2015 struct proc *p; 2016 int error; 2017 2018 if ((u_int)signum > _SIG_MAXSIG) 2019 return (EINVAL); 2020 2021 /* 2022 * Specification says sigqueue can only send signal to 2023 * single process. 2024 */ 2025 if (pid <= 0) 2026 return (EINVAL); 2027 2028 if ((p = pfind_any(pid)) == NULL) 2029 return (ESRCH); 2030 error = p_cansignal(td, p, signum); 2031 if (error == 0 && signum != 0) { 2032 ksiginfo_init(&ksi); 2033 ksi.ksi_flags = KSI_SIGQ; 2034 ksi.ksi_signo = signum; 2035 ksi.ksi_code = SI_QUEUE; 2036 ksi.ksi_pid = td->td_proc->p_pid; 2037 ksi.ksi_uid = td->td_ucred->cr_ruid; 2038 ksi.ksi_value = *value; 2039 error = pksignal(p, ksi.ksi_signo, &ksi); 2040 } 2041 PROC_UNLOCK(p); 2042 return (error); 2043 } 2044 2045 /* 2046 * Send a signal to a process group. If checktty is 1, 2047 * limit to members which have a controlling terminal. 2048 */ 2049 void 2050 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 2051 { 2052 struct proc *p; 2053 2054 if (pgrp) { 2055 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 2056 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 2057 PROC_LOCK(p); 2058 if (p->p_state == PRS_NORMAL && 2059 (checkctty == 0 || p->p_flag & P_CONTROLT)) 2060 pksignal(p, sig, ksi); 2061 PROC_UNLOCK(p); 2062 } 2063 } 2064 } 2065 2066 /* 2067 * Recalculate the signal mask and reset the signal disposition after 2068 * usermode frame for delivery is formed. Should be called after 2069 * mach-specific routine, because sysent->sv_sendsig() needs correct 2070 * ps_siginfo and signal mask. 2071 */ 2072 static void 2073 postsig_done(int sig, struct thread *td, struct sigacts *ps) 2074 { 2075 sigset_t mask; 2076 2077 mtx_assert(&ps->ps_mtx, MA_OWNED); 2078 td->td_ru.ru_nsignals++; 2079 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2080 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2081 SIGADDSET(mask, sig); 2082 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2083 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2084 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2085 sigdflt(ps, sig); 2086 } 2087 2088 /* 2089 * Send a signal caused by a trap to the current thread. If it will be 2090 * caught immediately, deliver it with correct code. Otherwise, post it 2091 * normally. 2092 */ 2093 void 2094 trapsignal(struct thread *td, ksiginfo_t *ksi) 2095 { 2096 struct sigacts *ps; 2097 struct proc *p; 2098 sigset_t sigmask; 2099 int sig; 2100 2101 p = td->td_proc; 2102 sig = ksi->ksi_signo; 2103 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2104 2105 sigfastblock_fetch(td); 2106 PROC_LOCK(p); 2107 ps = p->p_sigacts; 2108 mtx_lock(&ps->ps_mtx); 2109 sigmask = td->td_sigmask; 2110 if (td->td_sigblock_val != 0) 2111 SIGSETOR(sigmask, fastblock_mask); 2112 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2113 !SIGISMEMBER(sigmask, sig)) { 2114 #ifdef KTRACE 2115 if (KTRPOINT(curthread, KTR_PSIG)) 2116 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2117 &td->td_sigmask, ksi->ksi_code); 2118 #endif 2119 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2120 ksi, &td->td_sigmask); 2121 postsig_done(sig, td, ps); 2122 mtx_unlock(&ps->ps_mtx); 2123 } else { 2124 /* 2125 * Avoid a possible infinite loop if the thread 2126 * masking the signal or process is ignoring the 2127 * signal. 2128 */ 2129 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2130 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2131 SIGDELSET(td->td_sigmask, sig); 2132 SIGDELSET(ps->ps_sigcatch, sig); 2133 SIGDELSET(ps->ps_sigignore, sig); 2134 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2135 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2136 td->td_sigblock_val = 0; 2137 } 2138 mtx_unlock(&ps->ps_mtx); 2139 p->p_sig = sig; /* XXX to verify code */ 2140 tdsendsignal(p, td, sig, ksi); 2141 } 2142 PROC_UNLOCK(p); 2143 } 2144 2145 static struct thread * 2146 sigtd(struct proc *p, int sig, bool fast_sigblock) 2147 { 2148 struct thread *td, *signal_td; 2149 2150 PROC_LOCK_ASSERT(p, MA_OWNED); 2151 MPASS(!fast_sigblock || p == curproc); 2152 2153 /* 2154 * Check if current thread can handle the signal without 2155 * switching context to another thread. 2156 */ 2157 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2158 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2159 return (curthread); 2160 2161 /* Find a non-stopped thread that does not mask the signal. */ 2162 signal_td = NULL; 2163 FOREACH_THREAD_IN_PROC(p, td) { 2164 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2165 td != curthread || td->td_sigblock_val == 0) && 2166 (td->td_flags & TDF_BOUNDARY) == 0) { 2167 signal_td = td; 2168 break; 2169 } 2170 } 2171 /* Select random (first) thread if no better match was found. */ 2172 if (signal_td == NULL) 2173 signal_td = FIRST_THREAD_IN_PROC(p); 2174 return (signal_td); 2175 } 2176 2177 /* 2178 * Send the signal to the process. If the signal has an action, the action 2179 * is usually performed by the target process rather than the caller; we add 2180 * the signal to the set of pending signals for the process. 2181 * 2182 * Exceptions: 2183 * o When a stop signal is sent to a sleeping process that takes the 2184 * default action, the process is stopped without awakening it. 2185 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2186 * regardless of the signal action (eg, blocked or ignored). 2187 * 2188 * Other ignored signals are discarded immediately. 2189 * 2190 * NB: This function may be entered from the debugger via the "kill" DDB 2191 * command. There is little that can be done to mitigate the possibly messy 2192 * side effects of this unwise possibility. 2193 */ 2194 void 2195 kern_psignal(struct proc *p, int sig) 2196 { 2197 ksiginfo_t ksi; 2198 2199 ksiginfo_init(&ksi); 2200 ksi.ksi_signo = sig; 2201 ksi.ksi_code = SI_KERNEL; 2202 (void) tdsendsignal(p, NULL, sig, &ksi); 2203 } 2204 2205 int 2206 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2207 { 2208 2209 return (tdsendsignal(p, NULL, sig, ksi)); 2210 } 2211 2212 /* Utility function for finding a thread to send signal event to. */ 2213 int 2214 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2215 { 2216 struct thread *td; 2217 2218 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2219 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2220 if (td == NULL) 2221 return (ESRCH); 2222 *ttd = td; 2223 } else { 2224 *ttd = NULL; 2225 PROC_LOCK(p); 2226 } 2227 return (0); 2228 } 2229 2230 void 2231 tdsignal(struct thread *td, int sig) 2232 { 2233 ksiginfo_t ksi; 2234 2235 ksiginfo_init(&ksi); 2236 ksi.ksi_signo = sig; 2237 ksi.ksi_code = SI_KERNEL; 2238 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2239 } 2240 2241 void 2242 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2243 { 2244 2245 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2246 } 2247 2248 static int 2249 sig_sleepq_abort(struct thread *td, int intrval) 2250 { 2251 THREAD_LOCK_ASSERT(td, MA_OWNED); 2252 2253 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2254 thread_unlock(td); 2255 return (0); 2256 } 2257 return (sleepq_abort(td, intrval)); 2258 } 2259 2260 int 2261 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2262 { 2263 sig_t action; 2264 sigqueue_t *sigqueue; 2265 int prop; 2266 struct sigacts *ps; 2267 int intrval; 2268 int ret = 0; 2269 int wakeup_swapper; 2270 2271 MPASS(td == NULL || p == td->td_proc); 2272 PROC_LOCK_ASSERT(p, MA_OWNED); 2273 2274 if (!_SIG_VALID(sig)) 2275 panic("%s(): invalid signal %d", __func__, sig); 2276 2277 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2278 2279 /* 2280 * IEEE Std 1003.1-2001: return success when killing a zombie. 2281 */ 2282 if (p->p_state == PRS_ZOMBIE) { 2283 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2284 ksiginfo_tryfree(ksi); 2285 return (ret); 2286 } 2287 2288 ps = p->p_sigacts; 2289 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2290 prop = sigprop(sig); 2291 2292 if (td == NULL) { 2293 td = sigtd(p, sig, false); 2294 sigqueue = &p->p_sigqueue; 2295 } else 2296 sigqueue = &td->td_sigqueue; 2297 2298 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2299 2300 /* 2301 * If the signal is being ignored, then we forget about it 2302 * immediately, except when the target process executes 2303 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2304 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2305 */ 2306 mtx_lock(&ps->ps_mtx); 2307 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2308 if (kern_sig_discard_ign && 2309 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2310 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2311 2312 mtx_unlock(&ps->ps_mtx); 2313 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2314 ksiginfo_tryfree(ksi); 2315 return (ret); 2316 } else { 2317 action = SIG_CATCH; 2318 intrval = 0; 2319 } 2320 } else { 2321 if (SIGISMEMBER(td->td_sigmask, sig)) 2322 action = SIG_HOLD; 2323 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2324 action = SIG_CATCH; 2325 else 2326 action = SIG_DFL; 2327 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2328 intrval = EINTR; 2329 else 2330 intrval = ERESTART; 2331 } 2332 mtx_unlock(&ps->ps_mtx); 2333 2334 if (prop & SIGPROP_CONT) 2335 sigqueue_delete_stopmask_proc(p); 2336 else if (prop & SIGPROP_STOP) { 2337 /* 2338 * If sending a tty stop signal to a member of an orphaned 2339 * process group, discard the signal here if the action 2340 * is default; don't stop the process below if sleeping, 2341 * and don't clear any pending SIGCONT. 2342 */ 2343 if ((prop & SIGPROP_TTYSTOP) != 0 && 2344 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2345 action == SIG_DFL) { 2346 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2347 ksiginfo_tryfree(ksi); 2348 return (ret); 2349 } 2350 sigqueue_delete_proc(p, SIGCONT); 2351 if (p->p_flag & P_CONTINUED) { 2352 p->p_flag &= ~P_CONTINUED; 2353 PROC_LOCK(p->p_pptr); 2354 sigqueue_take(p->p_ksi); 2355 PROC_UNLOCK(p->p_pptr); 2356 } 2357 } 2358 2359 ret = sigqueue_add(sigqueue, sig, ksi); 2360 if (ret != 0) 2361 return (ret); 2362 signotify(td); 2363 /* 2364 * Defer further processing for signals which are held, 2365 * except that stopped processes must be continued by SIGCONT. 2366 */ 2367 if (action == SIG_HOLD && 2368 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2369 return (ret); 2370 2371 wakeup_swapper = 0; 2372 2373 /* 2374 * Some signals have a process-wide effect and a per-thread 2375 * component. Most processing occurs when the process next 2376 * tries to cross the user boundary, however there are some 2377 * times when processing needs to be done immediately, such as 2378 * waking up threads so that they can cross the user boundary. 2379 * We try to do the per-process part here. 2380 */ 2381 if (P_SHOULDSTOP(p)) { 2382 KASSERT(!(p->p_flag & P_WEXIT), 2383 ("signal to stopped but exiting process")); 2384 if (sig == SIGKILL) { 2385 /* 2386 * If traced process is already stopped, 2387 * then no further action is necessary. 2388 */ 2389 if (p->p_flag & P_TRACED) 2390 goto out; 2391 /* 2392 * SIGKILL sets process running. 2393 * It will die elsewhere. 2394 * All threads must be restarted. 2395 */ 2396 p->p_flag &= ~P_STOPPED_SIG; 2397 goto runfast; 2398 } 2399 2400 if (prop & SIGPROP_CONT) { 2401 /* 2402 * If traced process is already stopped, 2403 * then no further action is necessary. 2404 */ 2405 if (p->p_flag & P_TRACED) 2406 goto out; 2407 /* 2408 * If SIGCONT is default (or ignored), we continue the 2409 * process but don't leave the signal in sigqueue as 2410 * it has no further action. If SIGCONT is held, we 2411 * continue the process and leave the signal in 2412 * sigqueue. If the process catches SIGCONT, let it 2413 * handle the signal itself. If it isn't waiting on 2414 * an event, it goes back to run state. 2415 * Otherwise, process goes back to sleep state. 2416 */ 2417 p->p_flag &= ~P_STOPPED_SIG; 2418 PROC_SLOCK(p); 2419 if (p->p_numthreads == p->p_suspcount) { 2420 PROC_SUNLOCK(p); 2421 p->p_flag |= P_CONTINUED; 2422 p->p_xsig = SIGCONT; 2423 PROC_LOCK(p->p_pptr); 2424 childproc_continued(p); 2425 PROC_UNLOCK(p->p_pptr); 2426 PROC_SLOCK(p); 2427 } 2428 if (action == SIG_DFL) { 2429 thread_unsuspend(p); 2430 PROC_SUNLOCK(p); 2431 sigqueue_delete(sigqueue, sig); 2432 goto out_cont; 2433 } 2434 if (action == SIG_CATCH) { 2435 /* 2436 * The process wants to catch it so it needs 2437 * to run at least one thread, but which one? 2438 */ 2439 PROC_SUNLOCK(p); 2440 goto runfast; 2441 } 2442 /* 2443 * The signal is not ignored or caught. 2444 */ 2445 thread_unsuspend(p); 2446 PROC_SUNLOCK(p); 2447 goto out_cont; 2448 } 2449 2450 if (prop & SIGPROP_STOP) { 2451 /* 2452 * If traced process is already stopped, 2453 * then no further action is necessary. 2454 */ 2455 if (p->p_flag & P_TRACED) 2456 goto out; 2457 /* 2458 * Already stopped, don't need to stop again 2459 * (If we did the shell could get confused). 2460 * Just make sure the signal STOP bit set. 2461 */ 2462 p->p_flag |= P_STOPPED_SIG; 2463 sigqueue_delete(sigqueue, sig); 2464 goto out; 2465 } 2466 2467 /* 2468 * All other kinds of signals: 2469 * If a thread is sleeping interruptibly, simulate a 2470 * wakeup so that when it is continued it will be made 2471 * runnable and can look at the signal. However, don't make 2472 * the PROCESS runnable, leave it stopped. 2473 * It may run a bit until it hits a thread_suspend_check(). 2474 */ 2475 PROC_SLOCK(p); 2476 thread_lock(td); 2477 if (TD_CAN_ABORT(td)) 2478 wakeup_swapper = sig_sleepq_abort(td, intrval); 2479 else 2480 thread_unlock(td); 2481 PROC_SUNLOCK(p); 2482 goto out; 2483 /* 2484 * Mutexes are short lived. Threads waiting on them will 2485 * hit thread_suspend_check() soon. 2486 */ 2487 } else if (p->p_state == PRS_NORMAL) { 2488 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2489 tdsigwakeup(td, sig, action, intrval); 2490 goto out; 2491 } 2492 2493 MPASS(action == SIG_DFL); 2494 2495 if (prop & SIGPROP_STOP) { 2496 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2497 goto out; 2498 p->p_flag |= P_STOPPED_SIG; 2499 p->p_xsig = sig; 2500 PROC_SLOCK(p); 2501 wakeup_swapper = sig_suspend_threads(td, p); 2502 if (p->p_numthreads == p->p_suspcount) { 2503 /* 2504 * only thread sending signal to another 2505 * process can reach here, if thread is sending 2506 * signal to its process, because thread does 2507 * not suspend itself here, p_numthreads 2508 * should never be equal to p_suspcount. 2509 */ 2510 thread_stopped(p); 2511 PROC_SUNLOCK(p); 2512 sigqueue_delete_proc(p, p->p_xsig); 2513 } else 2514 PROC_SUNLOCK(p); 2515 goto out; 2516 } 2517 } else { 2518 /* Not in "NORMAL" state. discard the signal. */ 2519 sigqueue_delete(sigqueue, sig); 2520 goto out; 2521 } 2522 2523 /* 2524 * The process is not stopped so we need to apply the signal to all the 2525 * running threads. 2526 */ 2527 runfast: 2528 tdsigwakeup(td, sig, action, intrval); 2529 PROC_SLOCK(p); 2530 thread_unsuspend(p); 2531 PROC_SUNLOCK(p); 2532 out_cont: 2533 itimer_proc_continue(p); 2534 kqtimer_proc_continue(p); 2535 out: 2536 /* If we jump here, proc slock should not be owned. */ 2537 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2538 if (wakeup_swapper) 2539 kick_proc0(); 2540 2541 return (ret); 2542 } 2543 2544 /* 2545 * The force of a signal has been directed against a single 2546 * thread. We need to see what we can do about knocking it 2547 * out of any sleep it may be in etc. 2548 */ 2549 static void 2550 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2551 { 2552 struct proc *p = td->td_proc; 2553 int prop, wakeup_swapper; 2554 2555 PROC_LOCK_ASSERT(p, MA_OWNED); 2556 prop = sigprop(sig); 2557 2558 PROC_SLOCK(p); 2559 thread_lock(td); 2560 /* 2561 * Bring the priority of a thread up if we want it to get 2562 * killed in this lifetime. Be careful to avoid bumping the 2563 * priority of the idle thread, since we still allow to signal 2564 * kernel processes. 2565 */ 2566 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2567 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2568 sched_prio(td, PUSER); 2569 if (TD_ON_SLEEPQ(td)) { 2570 /* 2571 * If thread is sleeping uninterruptibly 2572 * we can't interrupt the sleep... the signal will 2573 * be noticed when the process returns through 2574 * trap() or syscall(). 2575 */ 2576 if ((td->td_flags & TDF_SINTR) == 0) 2577 goto out; 2578 /* 2579 * If SIGCONT is default (or ignored) and process is 2580 * asleep, we are finished; the process should not 2581 * be awakened. 2582 */ 2583 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2584 thread_unlock(td); 2585 PROC_SUNLOCK(p); 2586 sigqueue_delete(&p->p_sigqueue, sig); 2587 /* 2588 * It may be on either list in this state. 2589 * Remove from both for now. 2590 */ 2591 sigqueue_delete(&td->td_sigqueue, sig); 2592 return; 2593 } 2594 2595 /* 2596 * Don't awaken a sleeping thread for SIGSTOP if the 2597 * STOP signal is deferred. 2598 */ 2599 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2600 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2601 goto out; 2602 2603 /* 2604 * Give low priority threads a better chance to run. 2605 */ 2606 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2607 sched_prio(td, PUSER); 2608 2609 wakeup_swapper = sig_sleepq_abort(td, intrval); 2610 PROC_SUNLOCK(p); 2611 if (wakeup_swapper) 2612 kick_proc0(); 2613 return; 2614 } 2615 2616 /* 2617 * Other states do nothing with the signal immediately, 2618 * other than kicking ourselves if we are running. 2619 * It will either never be noticed, or noticed very soon. 2620 */ 2621 #ifdef SMP 2622 if (TD_IS_RUNNING(td) && td != curthread) 2623 forward_signal(td); 2624 #endif 2625 2626 out: 2627 PROC_SUNLOCK(p); 2628 thread_unlock(td); 2629 } 2630 2631 static void 2632 ptrace_coredumpreq(struct thread *td, struct proc *p, 2633 struct thr_coredump_req *tcq) 2634 { 2635 void *rl_cookie; 2636 2637 if (p->p_sysent->sv_coredump == NULL) { 2638 tcq->tc_error = ENOSYS; 2639 return; 2640 } 2641 2642 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2643 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2644 tcq->tc_limit, tcq->tc_flags); 2645 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2646 } 2647 2648 static void 2649 ptrace_syscallreq(struct thread *td, struct proc *p, 2650 struct thr_syscall_req *tsr) 2651 { 2652 struct sysentvec *sv; 2653 struct sysent *se; 2654 register_t rv_saved[2]; 2655 int error, nerror; 2656 int sc; 2657 bool audited, sy_thr_static; 2658 2659 sv = p->p_sysent; 2660 if (sv->sv_table == NULL || sv->sv_size < tsr->ts_sa.code) { 2661 tsr->ts_ret.sr_error = ENOSYS; 2662 return; 2663 } 2664 2665 sc = tsr->ts_sa.code; 2666 if (sc == SYS_syscall || sc == SYS___syscall) { 2667 sc = tsr->ts_sa.args[0]; 2668 memmove(&tsr->ts_sa.args[0], &tsr->ts_sa.args[1], 2669 sizeof(register_t) * (tsr->ts_nargs - 1)); 2670 } 2671 2672 tsr->ts_sa.callp = se = &sv->sv_table[sc]; 2673 2674 VM_CNT_INC(v_syscall); 2675 td->td_pticks = 0; 2676 if (__predict_false(td->td_cowgen != atomic_load_int( 2677 &td->td_proc->p_cowgen))) 2678 thread_cow_update(td); 2679 2680 #ifdef CAPABILITY_MODE 2681 if (IN_CAPABILITY_MODE(td) && (se->sy_flags & SYF_CAPENABLED) == 0) { 2682 tsr->ts_ret.sr_error = ECAPMODE; 2683 return; 2684 } 2685 #endif 2686 2687 sy_thr_static = (se->sy_thrcnt & SY_THR_STATIC) != 0; 2688 audited = AUDIT_SYSCALL_ENTER(sc, td) != 0; 2689 2690 if (!sy_thr_static) { 2691 error = syscall_thread_enter(td, se); 2692 if (error != 0) { 2693 tsr->ts_ret.sr_error = error; 2694 return; 2695 } 2696 } 2697 2698 rv_saved[0] = td->td_retval[0]; 2699 rv_saved[1] = td->td_retval[1]; 2700 nerror = td->td_errno; 2701 td->td_retval[0] = 0; 2702 td->td_retval[1] = 0; 2703 2704 #ifdef KDTRACE_HOOKS 2705 if (se->sy_entry != 0) 2706 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_ENTRY, 0); 2707 #endif 2708 tsr->ts_ret.sr_error = se->sy_call(td, tsr->ts_sa.args); 2709 #ifdef KDTRACE_HOOKS 2710 if (se->sy_return != 0) 2711 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_RETURN, 2712 tsr->ts_ret.sr_error != 0 ? -1 : td->td_retval[0]); 2713 #endif 2714 2715 tsr->ts_ret.sr_retval[0] = td->td_retval[0]; 2716 tsr->ts_ret.sr_retval[1] = td->td_retval[1]; 2717 td->td_retval[0] = rv_saved[0]; 2718 td->td_retval[1] = rv_saved[1]; 2719 td->td_errno = nerror; 2720 2721 if (audited) 2722 AUDIT_SYSCALL_EXIT(error, td); 2723 if (!sy_thr_static) 2724 syscall_thread_exit(td, se); 2725 } 2726 2727 static void 2728 ptrace_remotereq(struct thread *td, int flag) 2729 { 2730 struct proc *p; 2731 2732 MPASS(td == curthread); 2733 p = td->td_proc; 2734 PROC_LOCK_ASSERT(p, MA_OWNED); 2735 if ((td->td_dbgflags & flag) == 0) 2736 return; 2737 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2738 KASSERT(td->td_remotereq != NULL, ("td_remotereq is NULL")); 2739 2740 PROC_UNLOCK(p); 2741 switch (flag) { 2742 case TDB_COREDUMPREQ: 2743 ptrace_coredumpreq(td, p, td->td_remotereq); 2744 break; 2745 case TDB_SCREMOTEREQ: 2746 ptrace_syscallreq(td, p, td->td_remotereq); 2747 break; 2748 default: 2749 __unreachable(); 2750 } 2751 PROC_LOCK(p); 2752 2753 MPASS((td->td_dbgflags & flag) != 0); 2754 td->td_dbgflags &= ~flag; 2755 td->td_remotereq = NULL; 2756 wakeup(p); 2757 } 2758 2759 static int 2760 sig_suspend_threads(struct thread *td, struct proc *p) 2761 { 2762 struct thread *td2; 2763 int wakeup_swapper; 2764 2765 PROC_LOCK_ASSERT(p, MA_OWNED); 2766 PROC_SLOCK_ASSERT(p, MA_OWNED); 2767 2768 wakeup_swapper = 0; 2769 FOREACH_THREAD_IN_PROC(p, td2) { 2770 thread_lock(td2); 2771 ast_sched_locked(td2, TDA_SUSPEND); 2772 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2773 (td2->td_flags & TDF_SINTR)) { 2774 if (td2->td_flags & TDF_SBDRY) { 2775 /* 2776 * Once a thread is asleep with 2777 * TDF_SBDRY and without TDF_SERESTART 2778 * or TDF_SEINTR set, it should never 2779 * become suspended due to this check. 2780 */ 2781 KASSERT(!TD_IS_SUSPENDED(td2), 2782 ("thread with deferred stops suspended")); 2783 if (TD_SBDRY_INTR(td2)) { 2784 wakeup_swapper |= sleepq_abort(td2, 2785 TD_SBDRY_ERRNO(td2)); 2786 continue; 2787 } 2788 } else if (!TD_IS_SUSPENDED(td2)) 2789 thread_suspend_one(td2); 2790 } else if (!TD_IS_SUSPENDED(td2)) { 2791 #ifdef SMP 2792 if (TD_IS_RUNNING(td2) && td2 != td) 2793 forward_signal(td2); 2794 #endif 2795 } 2796 thread_unlock(td2); 2797 } 2798 return (wakeup_swapper); 2799 } 2800 2801 /* 2802 * Stop the process for an event deemed interesting to the debugger. If si is 2803 * non-NULL, this is a signal exchange; the new signal requested by the 2804 * debugger will be returned for handling. If si is NULL, this is some other 2805 * type of interesting event. The debugger may request a signal be delivered in 2806 * that case as well, however it will be deferred until it can be handled. 2807 */ 2808 int 2809 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2810 { 2811 struct proc *p = td->td_proc; 2812 struct thread *td2; 2813 ksiginfo_t ksi; 2814 2815 PROC_LOCK_ASSERT(p, MA_OWNED); 2816 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2817 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2818 &p->p_mtx.lock_object, "Stopping for traced signal"); 2819 2820 td->td_xsig = sig; 2821 2822 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2823 td->td_dbgflags |= TDB_XSIG; 2824 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2825 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2826 PROC_SLOCK(p); 2827 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2828 if (P_KILLED(p)) { 2829 /* 2830 * Ensure that, if we've been PT_KILLed, the 2831 * exit status reflects that. Another thread 2832 * may also be in ptracestop(), having just 2833 * received the SIGKILL, but this thread was 2834 * unsuspended first. 2835 */ 2836 td->td_dbgflags &= ~TDB_XSIG; 2837 td->td_xsig = SIGKILL; 2838 p->p_ptevents = 0; 2839 break; 2840 } 2841 if (p->p_flag & P_SINGLE_EXIT && 2842 !(td->td_dbgflags & TDB_EXIT)) { 2843 /* 2844 * Ignore ptrace stops except for thread exit 2845 * events when the process exits. 2846 */ 2847 td->td_dbgflags &= ~TDB_XSIG; 2848 PROC_SUNLOCK(p); 2849 return (0); 2850 } 2851 2852 /* 2853 * Make wait(2) work. Ensure that right after the 2854 * attach, the thread which was decided to become the 2855 * leader of attach gets reported to the waiter. 2856 * Otherwise, just avoid overwriting another thread's 2857 * assignment to p_xthread. If another thread has 2858 * already set p_xthread, the current thread will get 2859 * a chance to report itself upon the next iteration. 2860 */ 2861 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2862 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2863 p->p_xthread == NULL)) { 2864 p->p_xsig = sig; 2865 p->p_xthread = td; 2866 2867 /* 2868 * If we are on sleepqueue already, 2869 * let sleepqueue code decide if it 2870 * needs to go sleep after attach. 2871 */ 2872 if (td->td_wchan == NULL) 2873 td->td_dbgflags &= ~TDB_FSTP; 2874 2875 p->p_flag2 &= ~P2_PTRACE_FSTP; 2876 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2877 sig_suspend_threads(td, p); 2878 } 2879 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2880 td->td_dbgflags &= ~TDB_STOPATFORK; 2881 } 2882 stopme: 2883 td->td_dbgflags |= TDB_SSWITCH; 2884 thread_suspend_switch(td, p); 2885 td->td_dbgflags &= ~TDB_SSWITCH; 2886 if ((td->td_dbgflags & (TDB_COREDUMPREQ | 2887 TDB_SCREMOTEREQ)) != 0) { 2888 MPASS((td->td_dbgflags & (TDB_COREDUMPREQ | 2889 TDB_SCREMOTEREQ)) != 2890 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2891 PROC_SUNLOCK(p); 2892 ptrace_remotereq(td, td->td_dbgflags & 2893 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2894 PROC_SLOCK(p); 2895 goto stopme; 2896 } 2897 if (p->p_xthread == td) 2898 p->p_xthread = NULL; 2899 if (!(p->p_flag & P_TRACED)) 2900 break; 2901 if (td->td_dbgflags & TDB_SUSPEND) { 2902 if (p->p_flag & P_SINGLE_EXIT) 2903 break; 2904 goto stopme; 2905 } 2906 } 2907 PROC_SUNLOCK(p); 2908 } 2909 2910 if (si != NULL && sig == td->td_xsig) { 2911 /* Parent wants us to take the original signal unchanged. */ 2912 si->ksi_flags |= KSI_HEAD; 2913 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2914 si->ksi_signo = 0; 2915 } else if (td->td_xsig != 0) { 2916 /* 2917 * If parent wants us to take a new signal, then it will leave 2918 * it in td->td_xsig; otherwise we just look for signals again. 2919 */ 2920 ksiginfo_init(&ksi); 2921 ksi.ksi_signo = td->td_xsig; 2922 ksi.ksi_flags |= KSI_PTRACE; 2923 td2 = sigtd(p, td->td_xsig, false); 2924 tdsendsignal(p, td2, td->td_xsig, &ksi); 2925 if (td != td2) 2926 return (0); 2927 } 2928 2929 return (td->td_xsig); 2930 } 2931 2932 static void 2933 reschedule_signals(struct proc *p, sigset_t block, int flags) 2934 { 2935 struct sigacts *ps; 2936 struct thread *td; 2937 int sig; 2938 bool fastblk, pslocked; 2939 2940 PROC_LOCK_ASSERT(p, MA_OWNED); 2941 ps = p->p_sigacts; 2942 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2943 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2944 if (SIGISEMPTY(p->p_siglist)) 2945 return; 2946 SIGSETAND(block, p->p_siglist); 2947 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2948 SIG_FOREACH(sig, &block) { 2949 td = sigtd(p, sig, fastblk); 2950 2951 /* 2952 * If sigtd() selected us despite sigfastblock is 2953 * blocking, do not activate AST or wake us, to avoid 2954 * loop in AST handler. 2955 */ 2956 if (fastblk && td == curthread) 2957 continue; 2958 2959 signotify(td); 2960 if (!pslocked) 2961 mtx_lock(&ps->ps_mtx); 2962 if (p->p_flag & P_TRACED || 2963 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2964 !SIGISMEMBER(td->td_sigmask, sig))) { 2965 tdsigwakeup(td, sig, SIG_CATCH, 2966 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2967 ERESTART)); 2968 } 2969 if (!pslocked) 2970 mtx_unlock(&ps->ps_mtx); 2971 } 2972 } 2973 2974 void 2975 tdsigcleanup(struct thread *td) 2976 { 2977 struct proc *p; 2978 sigset_t unblocked; 2979 2980 p = td->td_proc; 2981 PROC_LOCK_ASSERT(p, MA_OWNED); 2982 2983 sigqueue_flush(&td->td_sigqueue); 2984 if (p->p_numthreads == 1) 2985 return; 2986 2987 /* 2988 * Since we cannot handle signals, notify signal post code 2989 * about this by filling the sigmask. 2990 * 2991 * Also, if needed, wake up thread(s) that do not block the 2992 * same signals as the exiting thread, since the thread might 2993 * have been selected for delivery and woken up. 2994 */ 2995 SIGFILLSET(unblocked); 2996 SIGSETNAND(unblocked, td->td_sigmask); 2997 SIGFILLSET(td->td_sigmask); 2998 reschedule_signals(p, unblocked, 0); 2999 3000 } 3001 3002 static int 3003 sigdeferstop_curr_flags(int cflags) 3004 { 3005 3006 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 3007 (cflags & TDF_SBDRY) != 0); 3008 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 3009 } 3010 3011 /* 3012 * Defer the delivery of SIGSTOP for the current thread, according to 3013 * the requested mode. Returns previous flags, which must be restored 3014 * by sigallowstop(). 3015 * 3016 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 3017 * cleared by the current thread, which allow the lock-less read-only 3018 * accesses below. 3019 */ 3020 int 3021 sigdeferstop_impl(int mode) 3022 { 3023 struct thread *td; 3024 int cflags, nflags; 3025 3026 td = curthread; 3027 cflags = sigdeferstop_curr_flags(td->td_flags); 3028 switch (mode) { 3029 case SIGDEFERSTOP_NOP: 3030 nflags = cflags; 3031 break; 3032 case SIGDEFERSTOP_OFF: 3033 nflags = 0; 3034 break; 3035 case SIGDEFERSTOP_SILENT: 3036 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 3037 break; 3038 case SIGDEFERSTOP_EINTR: 3039 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 3040 break; 3041 case SIGDEFERSTOP_ERESTART: 3042 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 3043 break; 3044 default: 3045 panic("sigdeferstop: invalid mode %x", mode); 3046 break; 3047 } 3048 if (cflags == nflags) 3049 return (SIGDEFERSTOP_VAL_NCHG); 3050 thread_lock(td); 3051 td->td_flags = (td->td_flags & ~cflags) | nflags; 3052 thread_unlock(td); 3053 return (cflags); 3054 } 3055 3056 /* 3057 * Restores the STOP handling mode, typically permitting the delivery 3058 * of SIGSTOP for the current thread. This does not immediately 3059 * suspend if a stop was posted. Instead, the thread will suspend 3060 * either via ast() or a subsequent interruptible sleep. 3061 */ 3062 void 3063 sigallowstop_impl(int prev) 3064 { 3065 struct thread *td; 3066 int cflags; 3067 3068 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 3069 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 3070 ("sigallowstop: incorrect previous mode %x", prev)); 3071 td = curthread; 3072 cflags = sigdeferstop_curr_flags(td->td_flags); 3073 if (cflags != prev) { 3074 thread_lock(td); 3075 td->td_flags = (td->td_flags & ~cflags) | prev; 3076 thread_unlock(td); 3077 } 3078 } 3079 3080 enum sigstatus { 3081 SIGSTATUS_HANDLE, 3082 SIGSTATUS_HANDLED, 3083 SIGSTATUS_IGNORE, 3084 SIGSTATUS_SBDRY_STOP, 3085 }; 3086 3087 /* 3088 * The thread has signal "sig" pending. Figure out what to do with it: 3089 * 3090 * _HANDLE -> the caller should handle the signal 3091 * _HANDLED -> handled internally, reload pending signal set 3092 * _IGNORE -> ignored, remove from the set of pending signals and try the 3093 * next pending signal 3094 * _SBDRY_STOP -> the signal should stop the thread but this is not 3095 * permitted in the current context 3096 */ 3097 static enum sigstatus 3098 sigprocess(struct thread *td, int sig) 3099 { 3100 struct proc *p; 3101 struct sigacts *ps; 3102 struct sigqueue *queue; 3103 ksiginfo_t ksi; 3104 int prop; 3105 3106 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 3107 3108 p = td->td_proc; 3109 ps = p->p_sigacts; 3110 mtx_assert(&ps->ps_mtx, MA_OWNED); 3111 PROC_LOCK_ASSERT(p, MA_OWNED); 3112 3113 /* 3114 * We should allow pending but ignored signals below 3115 * if there is sigwait() active, or P_TRACED was 3116 * on when they were posted. 3117 */ 3118 if (SIGISMEMBER(ps->ps_sigignore, sig) && 3119 (p->p_flag & P_TRACED) == 0 && 3120 (td->td_flags & TDF_SIGWAIT) == 0) { 3121 return (SIGSTATUS_IGNORE); 3122 } 3123 3124 /* 3125 * If the process is going to single-thread mode to prepare 3126 * for exit, there is no sense in delivering any signal 3127 * to usermode. Another important consequence is that 3128 * msleep(..., PCATCH, ...) now is only interruptible by a 3129 * suspend request. 3130 */ 3131 if ((p->p_flag2 & P2_WEXIT) != 0) 3132 return (SIGSTATUS_IGNORE); 3133 3134 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 3135 /* 3136 * If traced, always stop. 3137 * Remove old signal from queue before the stop. 3138 * XXX shrug off debugger, it causes siginfo to 3139 * be thrown away. 3140 */ 3141 queue = &td->td_sigqueue; 3142 ksiginfo_init(&ksi); 3143 if (sigqueue_get(queue, sig, &ksi) == 0) { 3144 queue = &p->p_sigqueue; 3145 sigqueue_get(queue, sig, &ksi); 3146 } 3147 td->td_si = ksi.ksi_info; 3148 3149 mtx_unlock(&ps->ps_mtx); 3150 sig = ptracestop(td, sig, &ksi); 3151 mtx_lock(&ps->ps_mtx); 3152 3153 td->td_si.si_signo = 0; 3154 3155 /* 3156 * Keep looking if the debugger discarded or 3157 * replaced the signal. 3158 */ 3159 if (sig == 0) 3160 return (SIGSTATUS_HANDLED); 3161 3162 /* 3163 * If the signal became masked, re-queue it. 3164 */ 3165 if (SIGISMEMBER(td->td_sigmask, sig)) { 3166 ksi.ksi_flags |= KSI_HEAD; 3167 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3168 return (SIGSTATUS_HANDLED); 3169 } 3170 3171 /* 3172 * If the traced bit got turned off, requeue the signal and 3173 * reload the set of pending signals. This ensures that p_sig* 3174 * and p_sigact are consistent. 3175 */ 3176 if ((p->p_flag & P_TRACED) == 0) { 3177 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 3178 ksi.ksi_flags |= KSI_HEAD; 3179 sigqueue_add(queue, sig, &ksi); 3180 } 3181 return (SIGSTATUS_HANDLED); 3182 } 3183 } 3184 3185 /* 3186 * Decide whether the signal should be returned. 3187 * Return the signal's number, or fall through 3188 * to clear it from the pending mask. 3189 */ 3190 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3191 case (intptr_t)SIG_DFL: 3192 /* 3193 * Don't take default actions on system processes. 3194 */ 3195 if (p->p_pid <= 1) { 3196 #ifdef DIAGNOSTIC 3197 /* 3198 * Are you sure you want to ignore SIGSEGV 3199 * in init? XXX 3200 */ 3201 printf("Process (pid %lu) got signal %d\n", 3202 (u_long)p->p_pid, sig); 3203 #endif 3204 return (SIGSTATUS_IGNORE); 3205 } 3206 3207 /* 3208 * If there is a pending stop signal to process with 3209 * default action, stop here, then clear the signal. 3210 * Traced or exiting processes should ignore stops. 3211 * Additionally, a member of an orphaned process group 3212 * should ignore tty stops. 3213 */ 3214 prop = sigprop(sig); 3215 if (prop & SIGPROP_STOP) { 3216 mtx_unlock(&ps->ps_mtx); 3217 if ((p->p_flag & (P_TRACED | P_WEXIT | 3218 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3219 pg_flags & PGRP_ORPHANED) != 0 && 3220 (prop & SIGPROP_TTYSTOP) != 0)) { 3221 mtx_lock(&ps->ps_mtx); 3222 return (SIGSTATUS_IGNORE); 3223 } 3224 if (TD_SBDRY_INTR(td)) { 3225 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3226 ("lost TDF_SBDRY")); 3227 mtx_lock(&ps->ps_mtx); 3228 return (SIGSTATUS_SBDRY_STOP); 3229 } 3230 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3231 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3232 sigqueue_delete(&td->td_sigqueue, sig); 3233 sigqueue_delete(&p->p_sigqueue, sig); 3234 p->p_flag |= P_STOPPED_SIG; 3235 p->p_xsig = sig; 3236 PROC_SLOCK(p); 3237 sig_suspend_threads(td, p); 3238 thread_suspend_switch(td, p); 3239 PROC_SUNLOCK(p); 3240 mtx_lock(&ps->ps_mtx); 3241 return (SIGSTATUS_HANDLED); 3242 } else if ((prop & SIGPROP_IGNORE) != 0 && 3243 (td->td_flags & TDF_SIGWAIT) == 0) { 3244 /* 3245 * Default action is to ignore; drop it if 3246 * not in kern_sigtimedwait(). 3247 */ 3248 return (SIGSTATUS_IGNORE); 3249 } else { 3250 return (SIGSTATUS_HANDLE); 3251 } 3252 3253 case (intptr_t)SIG_IGN: 3254 if ((td->td_flags & TDF_SIGWAIT) == 0) 3255 return (SIGSTATUS_IGNORE); 3256 else 3257 return (SIGSTATUS_HANDLE); 3258 3259 default: 3260 /* 3261 * This signal has an action, let postsig() process it. 3262 */ 3263 return (SIGSTATUS_HANDLE); 3264 } 3265 } 3266 3267 /* 3268 * If the current process has received a signal (should be caught or cause 3269 * termination, should interrupt current syscall), return the signal number. 3270 * Stop signals with default action are processed immediately, then cleared; 3271 * they aren't returned. This is checked after each entry to the system for 3272 * a syscall or trap (though this can usually be done without calling 3273 * issignal by checking the pending signal masks in cursig.) The normal call 3274 * sequence is 3275 * 3276 * while (sig = cursig(curthread)) 3277 * postsig(sig); 3278 */ 3279 static int 3280 issignal(struct thread *td) 3281 { 3282 struct proc *p; 3283 sigset_t sigpending; 3284 int sig; 3285 3286 p = td->td_proc; 3287 PROC_LOCK_ASSERT(p, MA_OWNED); 3288 3289 for (;;) { 3290 sigpending = td->td_sigqueue.sq_signals; 3291 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3292 SIGSETNAND(sigpending, td->td_sigmask); 3293 3294 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3295 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3296 SIG_STOPSIGMASK(sigpending); 3297 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3298 return (0); 3299 3300 /* 3301 * Do fast sigblock if requested by usermode. Since 3302 * we do know that there was a signal pending at this 3303 * point, set the FAST_SIGBLOCK_PEND as indicator for 3304 * usermode to perform a dummy call to 3305 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3306 * delivery of postponed pending signal. 3307 */ 3308 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3309 if (td->td_sigblock_val != 0) 3310 SIGSETNAND(sigpending, fastblock_mask); 3311 if (SIGISEMPTY(sigpending)) { 3312 td->td_pflags |= TDP_SIGFASTPENDING; 3313 return (0); 3314 } 3315 } 3316 3317 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3318 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3319 SIGISMEMBER(sigpending, SIGSTOP)) { 3320 /* 3321 * If debugger just attached, always consume 3322 * SIGSTOP from ptrace(PT_ATTACH) first, to 3323 * execute the debugger attach ritual in 3324 * order. 3325 */ 3326 td->td_dbgflags |= TDB_FSTP; 3327 SIGEMPTYSET(sigpending); 3328 SIGADDSET(sigpending, SIGSTOP); 3329 } 3330 3331 SIG_FOREACH(sig, &sigpending) { 3332 switch (sigprocess(td, sig)) { 3333 case SIGSTATUS_HANDLE: 3334 return (sig); 3335 case SIGSTATUS_HANDLED: 3336 goto next; 3337 case SIGSTATUS_IGNORE: 3338 sigqueue_delete(&td->td_sigqueue, sig); 3339 sigqueue_delete(&p->p_sigqueue, sig); 3340 break; 3341 case SIGSTATUS_SBDRY_STOP: 3342 return (-1); 3343 } 3344 } 3345 next:; 3346 } 3347 } 3348 3349 void 3350 thread_stopped(struct proc *p) 3351 { 3352 int n; 3353 3354 PROC_LOCK_ASSERT(p, MA_OWNED); 3355 PROC_SLOCK_ASSERT(p, MA_OWNED); 3356 n = p->p_suspcount; 3357 if (p == curproc) 3358 n++; 3359 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3360 PROC_SUNLOCK(p); 3361 p->p_flag &= ~P_WAITED; 3362 PROC_LOCK(p->p_pptr); 3363 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3364 CLD_TRAPPED : CLD_STOPPED); 3365 PROC_UNLOCK(p->p_pptr); 3366 PROC_SLOCK(p); 3367 } 3368 } 3369 3370 /* 3371 * Take the action for the specified signal 3372 * from the current set of pending signals. 3373 */ 3374 int 3375 postsig(int sig) 3376 { 3377 struct thread *td; 3378 struct proc *p; 3379 struct sigacts *ps; 3380 sig_t action; 3381 ksiginfo_t ksi; 3382 sigset_t returnmask; 3383 3384 KASSERT(sig != 0, ("postsig")); 3385 3386 td = curthread; 3387 p = td->td_proc; 3388 PROC_LOCK_ASSERT(p, MA_OWNED); 3389 ps = p->p_sigacts; 3390 mtx_assert(&ps->ps_mtx, MA_OWNED); 3391 ksiginfo_init(&ksi); 3392 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3393 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3394 return (0); 3395 ksi.ksi_signo = sig; 3396 if (ksi.ksi_code == SI_TIMER) 3397 itimer_accept(p, ksi.ksi_timerid, &ksi); 3398 action = ps->ps_sigact[_SIG_IDX(sig)]; 3399 #ifdef KTRACE 3400 if (KTRPOINT(td, KTR_PSIG)) 3401 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3402 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3403 #endif 3404 3405 if (action == SIG_DFL) { 3406 /* 3407 * Default action, where the default is to kill 3408 * the process. (Other cases were ignored above.) 3409 */ 3410 mtx_unlock(&ps->ps_mtx); 3411 proc_td_siginfo_capture(td, &ksi.ksi_info); 3412 sigexit(td, sig); 3413 /* NOTREACHED */ 3414 } else { 3415 /* 3416 * If we get here, the signal must be caught. 3417 */ 3418 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3419 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3420 ("postsig action: blocked sig %d", sig)); 3421 3422 /* 3423 * Set the new mask value and also defer further 3424 * occurrences of this signal. 3425 * 3426 * Special case: user has done a sigsuspend. Here the 3427 * current mask is not of interest, but rather the 3428 * mask from before the sigsuspend is what we want 3429 * restored after the signal processing is completed. 3430 */ 3431 if (td->td_pflags & TDP_OLDMASK) { 3432 returnmask = td->td_oldsigmask; 3433 td->td_pflags &= ~TDP_OLDMASK; 3434 } else 3435 returnmask = td->td_sigmask; 3436 3437 if (p->p_sig == sig) { 3438 p->p_sig = 0; 3439 } 3440 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3441 postsig_done(sig, td, ps); 3442 } 3443 return (1); 3444 } 3445 3446 int 3447 sig_ast_checksusp(struct thread *td) 3448 { 3449 struct proc *p __diagused; 3450 int ret; 3451 3452 p = td->td_proc; 3453 PROC_LOCK_ASSERT(p, MA_OWNED); 3454 3455 if (!td_ast_pending(td, TDA_SUSPEND)) 3456 return (0); 3457 3458 ret = thread_suspend_check(1); 3459 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3460 return (ret); 3461 } 3462 3463 int 3464 sig_ast_needsigchk(struct thread *td) 3465 { 3466 struct proc *p; 3467 struct sigacts *ps; 3468 int ret, sig; 3469 3470 p = td->td_proc; 3471 PROC_LOCK_ASSERT(p, MA_OWNED); 3472 3473 if (!td_ast_pending(td, TDA_SIG)) 3474 return (0); 3475 3476 ps = p->p_sigacts; 3477 mtx_lock(&ps->ps_mtx); 3478 sig = cursig(td); 3479 if (sig == -1) { 3480 mtx_unlock(&ps->ps_mtx); 3481 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3482 KASSERT(TD_SBDRY_INTR(td), 3483 ("lost TDF_SERESTART of TDF_SEINTR")); 3484 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3485 (TDF_SEINTR | TDF_SERESTART), 3486 ("both TDF_SEINTR and TDF_SERESTART")); 3487 ret = TD_SBDRY_ERRNO(td); 3488 } else if (sig != 0) { 3489 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3490 mtx_unlock(&ps->ps_mtx); 3491 } else { 3492 mtx_unlock(&ps->ps_mtx); 3493 ret = 0; 3494 } 3495 3496 /* 3497 * Do not go into sleep if this thread was the ptrace(2) 3498 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3499 * but we usually act on the signal by interrupting sleep, and 3500 * should do that here as well. 3501 */ 3502 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3503 if (ret == 0) 3504 ret = EINTR; 3505 td->td_dbgflags &= ~TDB_FSTP; 3506 } 3507 3508 return (ret); 3509 } 3510 3511 int 3512 sig_intr(void) 3513 { 3514 struct thread *td; 3515 struct proc *p; 3516 int ret; 3517 3518 td = curthread; 3519 if (!td_ast_pending(td, TDA_SIG) && !td_ast_pending(td, TDA_SUSPEND)) 3520 return (0); 3521 3522 p = td->td_proc; 3523 3524 PROC_LOCK(p); 3525 ret = sig_ast_checksusp(td); 3526 if (ret == 0) 3527 ret = sig_ast_needsigchk(td); 3528 PROC_UNLOCK(p); 3529 return (ret); 3530 } 3531 3532 bool 3533 curproc_sigkilled(void) 3534 { 3535 struct thread *td; 3536 struct proc *p; 3537 struct sigacts *ps; 3538 bool res; 3539 3540 td = curthread; 3541 if (!td_ast_pending(td, TDA_SIG)) 3542 return (false); 3543 3544 p = td->td_proc; 3545 PROC_LOCK(p); 3546 ps = p->p_sigacts; 3547 mtx_lock(&ps->ps_mtx); 3548 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3549 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3550 mtx_unlock(&ps->ps_mtx); 3551 PROC_UNLOCK(p); 3552 return (res); 3553 } 3554 3555 void 3556 proc_wkilled(struct proc *p) 3557 { 3558 3559 PROC_LOCK_ASSERT(p, MA_OWNED); 3560 if ((p->p_flag & P_WKILLED) == 0) { 3561 p->p_flag |= P_WKILLED; 3562 /* 3563 * Notify swapper that there is a process to swap in. 3564 * The notification is racy, at worst it would take 10 3565 * seconds for the swapper process to notice. 3566 */ 3567 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3568 wakeup(&proc0); 3569 } 3570 } 3571 3572 /* 3573 * Kill the current process for stated reason. 3574 */ 3575 void 3576 killproc(struct proc *p, const char *why) 3577 { 3578 3579 PROC_LOCK_ASSERT(p, MA_OWNED); 3580 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3581 p->p_comm); 3582 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3583 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3584 p->p_ucred->cr_uid, why); 3585 proc_wkilled(p); 3586 kern_psignal(p, SIGKILL); 3587 } 3588 3589 /* 3590 * Force the current process to exit with the specified signal, dumping core 3591 * if appropriate. We bypass the normal tests for masked and caught signals, 3592 * allowing unrecoverable failures to terminate the process without changing 3593 * signal state. Mark the accounting record with the signal termination. 3594 * If dumping core, save the signal number for the debugger. Calls exit and 3595 * does not return. 3596 */ 3597 void 3598 sigexit(struct thread *td, int sig) 3599 { 3600 struct proc *p = td->td_proc; 3601 const char *coreinfo; 3602 int rv; 3603 3604 PROC_LOCK_ASSERT(p, MA_OWNED); 3605 proc_set_p2_wexit(p); 3606 3607 p->p_acflag |= AXSIG; 3608 /* 3609 * We must be single-threading to generate a core dump. This 3610 * ensures that the registers in the core file are up-to-date. 3611 * Also, the ELF dump handler assumes that the thread list doesn't 3612 * change out from under it. 3613 * 3614 * XXX If another thread attempts to single-thread before us 3615 * (e.g. via fork()), we won't get a dump at all. 3616 */ 3617 if ((sigprop(sig) & SIGPROP_CORE) && 3618 thread_single(p, SINGLE_NO_EXIT) == 0) { 3619 p->p_sig = sig; 3620 /* 3621 * Log signals which would cause core dumps 3622 * (Log as LOG_INFO to appease those who don't want 3623 * these messages.) 3624 * XXX : Todo, as well as euid, write out ruid too 3625 * Note that coredump() drops proc lock. 3626 */ 3627 rv = coredump(td); 3628 switch (rv) { 3629 case 0: 3630 sig |= WCOREFLAG; 3631 coreinfo = " (core dumped)"; 3632 break; 3633 case EFAULT: 3634 coreinfo = " (no core dump - bad address)"; 3635 break; 3636 case EINVAL: 3637 coreinfo = " (no core dump - invalid argument)"; 3638 break; 3639 case EFBIG: 3640 coreinfo = " (no core dump - too large)"; 3641 break; 3642 default: 3643 coreinfo = " (no core dump - other error)"; 3644 break; 3645 } 3646 if (kern_logsigexit) 3647 log(LOG_INFO, 3648 "pid %d (%s), jid %d, uid %d: exited on " 3649 "signal %d%s\n", p->p_pid, p->p_comm, 3650 p->p_ucred->cr_prison->pr_id, 3651 td->td_ucred->cr_uid, 3652 sig &~ WCOREFLAG, coreinfo); 3653 } else 3654 PROC_UNLOCK(p); 3655 exit1(td, 0, sig); 3656 /* NOTREACHED */ 3657 } 3658 3659 /* 3660 * Send queued SIGCHLD to parent when child process's state 3661 * is changed. 3662 */ 3663 static void 3664 sigparent(struct proc *p, int reason, int status) 3665 { 3666 PROC_LOCK_ASSERT(p, MA_OWNED); 3667 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3668 3669 if (p->p_ksi != NULL) { 3670 p->p_ksi->ksi_signo = SIGCHLD; 3671 p->p_ksi->ksi_code = reason; 3672 p->p_ksi->ksi_status = status; 3673 p->p_ksi->ksi_pid = p->p_pid; 3674 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3675 if (KSI_ONQ(p->p_ksi)) 3676 return; 3677 } 3678 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3679 } 3680 3681 static void 3682 childproc_jobstate(struct proc *p, int reason, int sig) 3683 { 3684 struct sigacts *ps; 3685 3686 PROC_LOCK_ASSERT(p, MA_OWNED); 3687 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3688 3689 /* 3690 * Wake up parent sleeping in kern_wait(), also send 3691 * SIGCHLD to parent, but SIGCHLD does not guarantee 3692 * that parent will awake, because parent may masked 3693 * the signal. 3694 */ 3695 p->p_pptr->p_flag |= P_STATCHILD; 3696 wakeup(p->p_pptr); 3697 3698 ps = p->p_pptr->p_sigacts; 3699 mtx_lock(&ps->ps_mtx); 3700 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3701 mtx_unlock(&ps->ps_mtx); 3702 sigparent(p, reason, sig); 3703 } else 3704 mtx_unlock(&ps->ps_mtx); 3705 } 3706 3707 void 3708 childproc_stopped(struct proc *p, int reason) 3709 { 3710 3711 childproc_jobstate(p, reason, p->p_xsig); 3712 } 3713 3714 void 3715 childproc_continued(struct proc *p) 3716 { 3717 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3718 } 3719 3720 void 3721 childproc_exited(struct proc *p) 3722 { 3723 int reason, status; 3724 3725 if (WCOREDUMP(p->p_xsig)) { 3726 reason = CLD_DUMPED; 3727 status = WTERMSIG(p->p_xsig); 3728 } else if (WIFSIGNALED(p->p_xsig)) { 3729 reason = CLD_KILLED; 3730 status = WTERMSIG(p->p_xsig); 3731 } else { 3732 reason = CLD_EXITED; 3733 status = p->p_xexit; 3734 } 3735 /* 3736 * XXX avoid calling wakeup(p->p_pptr), the work is 3737 * done in exit1(). 3738 */ 3739 sigparent(p, reason, status); 3740 } 3741 3742 #define MAX_NUM_CORE_FILES 100000 3743 #ifndef NUM_CORE_FILES 3744 #define NUM_CORE_FILES 5 3745 #endif 3746 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3747 static int num_cores = NUM_CORE_FILES; 3748 3749 static int 3750 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3751 { 3752 int error; 3753 int new_val; 3754 3755 new_val = num_cores; 3756 error = sysctl_handle_int(oidp, &new_val, 0, req); 3757 if (error != 0 || req->newptr == NULL) 3758 return (error); 3759 if (new_val > MAX_NUM_CORE_FILES) 3760 new_val = MAX_NUM_CORE_FILES; 3761 if (new_val < 0) 3762 new_val = 0; 3763 num_cores = new_val; 3764 return (0); 3765 } 3766 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3767 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3768 sysctl_debug_num_cores_check, "I", 3769 "Maximum number of generated process corefiles while using index format"); 3770 3771 #define GZIP_SUFFIX ".gz" 3772 #define ZSTD_SUFFIX ".zst" 3773 3774 int compress_user_cores = 0; 3775 3776 static int 3777 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3778 { 3779 int error, val; 3780 3781 val = compress_user_cores; 3782 error = sysctl_handle_int(oidp, &val, 0, req); 3783 if (error != 0 || req->newptr == NULL) 3784 return (error); 3785 if (val != 0 && !compressor_avail(val)) 3786 return (EINVAL); 3787 compress_user_cores = val; 3788 return (error); 3789 } 3790 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3791 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3792 sysctl_compress_user_cores, "I", 3793 "Enable compression of user corefiles (" 3794 __XSTRING(COMPRESS_GZIP) " = gzip, " 3795 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3796 3797 int compress_user_cores_level = 6; 3798 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3799 &compress_user_cores_level, 0, 3800 "Corefile compression level"); 3801 3802 /* 3803 * Protect the access to corefilename[] by allproc_lock. 3804 */ 3805 #define corefilename_lock allproc_lock 3806 3807 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3808 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3809 3810 static int 3811 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3812 { 3813 int error; 3814 3815 sx_xlock(&corefilename_lock); 3816 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3817 req); 3818 sx_xunlock(&corefilename_lock); 3819 3820 return (error); 3821 } 3822 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3823 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3824 "Process corefile name format string"); 3825 3826 static void 3827 vnode_close_locked(struct thread *td, struct vnode *vp) 3828 { 3829 3830 VOP_UNLOCK(vp); 3831 vn_close(vp, FWRITE, td->td_ucred, td); 3832 } 3833 3834 /* 3835 * If the core format has a %I in it, then we need to check 3836 * for existing corefiles before defining a name. 3837 * To do this we iterate over 0..ncores to find a 3838 * non-existing core file name to use. If all core files are 3839 * already used we choose the oldest one. 3840 */ 3841 static int 3842 corefile_open_last(struct thread *td, char *name, int indexpos, 3843 int indexlen, int ncores, struct vnode **vpp) 3844 { 3845 struct vnode *oldvp, *nextvp, *vp; 3846 struct vattr vattr; 3847 struct nameidata nd; 3848 int error, i, flags, oflags, cmode; 3849 char ch; 3850 struct timespec lasttime; 3851 3852 nextvp = oldvp = NULL; 3853 cmode = S_IRUSR | S_IWUSR; 3854 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3855 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3856 3857 for (i = 0; i < ncores; i++) { 3858 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3859 3860 ch = name[indexpos + indexlen]; 3861 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3862 i); 3863 name[indexpos + indexlen] = ch; 3864 3865 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3866 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3867 NULL); 3868 if (error != 0) 3869 break; 3870 3871 vp = nd.ni_vp; 3872 NDFREE_PNBUF(&nd); 3873 if ((flags & O_CREAT) == O_CREAT) { 3874 nextvp = vp; 3875 break; 3876 } 3877 3878 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3879 if (error != 0) { 3880 vnode_close_locked(td, vp); 3881 break; 3882 } 3883 3884 if (oldvp == NULL || 3885 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3886 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3887 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3888 if (oldvp != NULL) 3889 vn_close(oldvp, FWRITE, td->td_ucred, td); 3890 oldvp = vp; 3891 VOP_UNLOCK(oldvp); 3892 lasttime = vattr.va_mtime; 3893 } else { 3894 vnode_close_locked(td, vp); 3895 } 3896 } 3897 3898 if (oldvp != NULL) { 3899 if (nextvp == NULL) { 3900 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3901 error = EFAULT; 3902 vn_close(oldvp, FWRITE, td->td_ucred, td); 3903 } else { 3904 nextvp = oldvp; 3905 error = vn_lock(nextvp, LK_EXCLUSIVE); 3906 if (error != 0) { 3907 vn_close(nextvp, FWRITE, td->td_ucred, 3908 td); 3909 nextvp = NULL; 3910 } 3911 } 3912 } else { 3913 vn_close(oldvp, FWRITE, td->td_ucred, td); 3914 } 3915 } 3916 if (error != 0) { 3917 if (nextvp != NULL) 3918 vnode_close_locked(td, oldvp); 3919 } else { 3920 *vpp = nextvp; 3921 } 3922 3923 return (error); 3924 } 3925 3926 /* 3927 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3928 * Expand the name described in corefilename, using name, uid, and pid 3929 * and open/create core file. 3930 * corefilename is a printf-like string, with three format specifiers: 3931 * %N name of process ("name") 3932 * %P process id (pid) 3933 * %U user id (uid) 3934 * For example, "%N.core" is the default; they can be disabled completely 3935 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3936 * This is controlled by the sysctl variable kern.corefile (see above). 3937 */ 3938 static int 3939 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3940 int compress, int signum, struct vnode **vpp, char **namep) 3941 { 3942 struct sbuf sb; 3943 struct nameidata nd; 3944 const char *format; 3945 char *hostname, *name; 3946 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3947 3948 hostname = NULL; 3949 format = corefilename; 3950 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3951 indexlen = 0; 3952 indexpos = -1; 3953 ncores = num_cores; 3954 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3955 sx_slock(&corefilename_lock); 3956 for (i = 0; format[i] != '\0'; i++) { 3957 switch (format[i]) { 3958 case '%': /* Format character */ 3959 i++; 3960 switch (format[i]) { 3961 case '%': 3962 sbuf_putc(&sb, '%'); 3963 break; 3964 case 'H': /* hostname */ 3965 if (hostname == NULL) { 3966 hostname = malloc(MAXHOSTNAMELEN, 3967 M_TEMP, M_WAITOK); 3968 } 3969 getcredhostname(td->td_ucred, hostname, 3970 MAXHOSTNAMELEN); 3971 sbuf_printf(&sb, "%s", hostname); 3972 break; 3973 case 'I': /* autoincrementing index */ 3974 if (indexpos != -1) { 3975 sbuf_printf(&sb, "%%I"); 3976 break; 3977 } 3978 3979 indexpos = sbuf_len(&sb); 3980 sbuf_printf(&sb, "%u", ncores - 1); 3981 indexlen = sbuf_len(&sb) - indexpos; 3982 break; 3983 case 'N': /* process name */ 3984 sbuf_printf(&sb, "%s", comm); 3985 break; 3986 case 'P': /* process id */ 3987 sbuf_printf(&sb, "%u", pid); 3988 break; 3989 case 'S': /* signal number */ 3990 sbuf_printf(&sb, "%i", signum); 3991 break; 3992 case 'U': /* user id */ 3993 sbuf_printf(&sb, "%u", uid); 3994 break; 3995 default: 3996 log(LOG_ERR, 3997 "Unknown format character %c in " 3998 "corename `%s'\n", format[i], format); 3999 break; 4000 } 4001 break; 4002 default: 4003 sbuf_putc(&sb, format[i]); 4004 break; 4005 } 4006 } 4007 sx_sunlock(&corefilename_lock); 4008 free(hostname, M_TEMP); 4009 if (compress == COMPRESS_GZIP) 4010 sbuf_printf(&sb, GZIP_SUFFIX); 4011 else if (compress == COMPRESS_ZSTD) 4012 sbuf_printf(&sb, ZSTD_SUFFIX); 4013 if (sbuf_error(&sb) != 0) { 4014 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 4015 "long\n", (long)pid, comm, (u_long)uid); 4016 sbuf_delete(&sb); 4017 free(name, M_TEMP); 4018 return (ENOMEM); 4019 } 4020 sbuf_finish(&sb); 4021 sbuf_delete(&sb); 4022 4023 if (indexpos != -1) { 4024 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 4025 vpp); 4026 if (error != 0) { 4027 log(LOG_ERR, 4028 "pid %d (%s), uid (%u): Path `%s' failed " 4029 "on initial open test, error = %d\n", 4030 pid, comm, uid, name, error); 4031 } 4032 } else { 4033 cmode = S_IRUSR | S_IWUSR; 4034 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 4035 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 4036 flags = O_CREAT | FWRITE | O_NOFOLLOW; 4037 if ((td->td_proc->p_flag & P_SUGID) != 0) 4038 flags |= O_EXCL; 4039 4040 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 4041 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 4042 NULL); 4043 if (error == 0) { 4044 *vpp = nd.ni_vp; 4045 NDFREE_PNBUF(&nd); 4046 } 4047 } 4048 4049 if (error != 0) { 4050 #ifdef AUDIT 4051 audit_proc_coredump(td, name, error); 4052 #endif 4053 free(name, M_TEMP); 4054 return (error); 4055 } 4056 *namep = name; 4057 return (0); 4058 } 4059 4060 /* 4061 * Dump a process' core. The main routine does some 4062 * policy checking, and creates the name of the coredump; 4063 * then it passes on a vnode and a size limit to the process-specific 4064 * coredump routine if there is one; if there _is not_ one, it returns 4065 * ENOSYS; otherwise it returns the error from the process-specific routine. 4066 */ 4067 4068 static int 4069 coredump(struct thread *td) 4070 { 4071 struct proc *p = td->td_proc; 4072 struct ucred *cred = td->td_ucred; 4073 struct vnode *vp; 4074 struct flock lf; 4075 struct vattr vattr; 4076 size_t fullpathsize; 4077 int error, error1, locked; 4078 char *name; /* name of corefile */ 4079 void *rl_cookie; 4080 off_t limit; 4081 char *fullpath, *freepath = NULL; 4082 struct sbuf *sb; 4083 4084 PROC_LOCK_ASSERT(p, MA_OWNED); 4085 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 4086 4087 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 4088 (p->p_flag2 & P2_NOTRACE) != 0) { 4089 PROC_UNLOCK(p); 4090 return (EFAULT); 4091 } 4092 4093 /* 4094 * Note that the bulk of limit checking is done after 4095 * the corefile is created. The exception is if the limit 4096 * for corefiles is 0, in which case we don't bother 4097 * creating the corefile at all. This layout means that 4098 * a corefile is truncated instead of not being created, 4099 * if it is larger than the limit. 4100 */ 4101 limit = (off_t)lim_cur(td, RLIMIT_CORE); 4102 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 4103 PROC_UNLOCK(p); 4104 return (EFBIG); 4105 } 4106 PROC_UNLOCK(p); 4107 4108 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 4109 compress_user_cores, p->p_sig, &vp, &name); 4110 if (error != 0) 4111 return (error); 4112 4113 /* 4114 * Don't dump to non-regular files or files with links. 4115 * Do not dump into system files. Effective user must own the corefile. 4116 */ 4117 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 4118 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 4119 vattr.va_uid != cred->cr_uid) { 4120 VOP_UNLOCK(vp); 4121 error = EFAULT; 4122 goto out; 4123 } 4124 4125 VOP_UNLOCK(vp); 4126 4127 /* Postpone other writers, including core dumps of other processes. */ 4128 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 4129 4130 lf.l_whence = SEEK_SET; 4131 lf.l_start = 0; 4132 lf.l_len = 0; 4133 lf.l_type = F_WRLCK; 4134 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 4135 4136 VATTR_NULL(&vattr); 4137 vattr.va_size = 0; 4138 if (set_core_nodump_flag) 4139 vattr.va_flags = UF_NODUMP; 4140 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4141 VOP_SETATTR(vp, &vattr, cred); 4142 VOP_UNLOCK(vp); 4143 PROC_LOCK(p); 4144 p->p_acflag |= ACORE; 4145 PROC_UNLOCK(p); 4146 4147 if (p->p_sysent->sv_coredump != NULL) { 4148 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 4149 } else { 4150 error = ENOSYS; 4151 } 4152 4153 if (locked) { 4154 lf.l_type = F_UNLCK; 4155 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 4156 } 4157 vn_rangelock_unlock(vp, rl_cookie); 4158 4159 /* 4160 * Notify the userland helper that a process triggered a core dump. 4161 * This allows the helper to run an automated debugging session. 4162 */ 4163 if (error != 0 || coredump_devctl == 0) 4164 goto out; 4165 sb = sbuf_new_auto(); 4166 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 4167 goto out2; 4168 sbuf_printf(sb, "comm=\""); 4169 devctl_safe_quote_sb(sb, fullpath); 4170 free(freepath, M_TEMP); 4171 sbuf_printf(sb, "\" core=\""); 4172 4173 /* 4174 * We can't lookup core file vp directly. When we're replacing a core, and 4175 * other random times, we flush the name cache, so it will fail. Instead, 4176 * if the path of the core is relative, add the current dir in front if it. 4177 */ 4178 if (name[0] != '/') { 4179 fullpathsize = MAXPATHLEN; 4180 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 4181 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 4182 free(freepath, M_TEMP); 4183 goto out2; 4184 } 4185 devctl_safe_quote_sb(sb, fullpath); 4186 free(freepath, M_TEMP); 4187 sbuf_putc(sb, '/'); 4188 } 4189 devctl_safe_quote_sb(sb, name); 4190 sbuf_printf(sb, "\""); 4191 if (sbuf_finish(sb) == 0) 4192 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 4193 out2: 4194 sbuf_delete(sb); 4195 out: 4196 error1 = vn_close(vp, FWRITE, cred, td); 4197 if (error == 0) 4198 error = error1; 4199 #ifdef AUDIT 4200 audit_proc_coredump(td, name, error); 4201 #endif 4202 free(name, M_TEMP); 4203 return (error); 4204 } 4205 4206 /* 4207 * Nonexistent system call-- signal process (may want to handle it). Flag 4208 * error in case process won't see signal immediately (blocked or ignored). 4209 */ 4210 #ifndef _SYS_SYSPROTO_H_ 4211 struct nosys_args { 4212 int dummy; 4213 }; 4214 #endif 4215 /* ARGSUSED */ 4216 int 4217 nosys(struct thread *td, struct nosys_args *args) 4218 { 4219 struct proc *p; 4220 4221 p = td->td_proc; 4222 4223 PROC_LOCK(p); 4224 tdsignal(td, SIGSYS); 4225 PROC_UNLOCK(p); 4226 if (kern_lognosys == 1 || kern_lognosys == 3) { 4227 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4228 td->td_sa.code); 4229 } 4230 if (kern_lognosys == 2 || kern_lognosys == 3 || 4231 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4232 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4233 td->td_sa.code); 4234 } 4235 return (ENOSYS); 4236 } 4237 4238 /* 4239 * Send a SIGIO or SIGURG signal to a process or process group using stored 4240 * credentials rather than those of the current process. 4241 */ 4242 void 4243 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4244 { 4245 ksiginfo_t ksi; 4246 struct sigio *sigio; 4247 4248 ksiginfo_init(&ksi); 4249 ksi.ksi_signo = sig; 4250 ksi.ksi_code = SI_KERNEL; 4251 4252 SIGIO_LOCK(); 4253 sigio = *sigiop; 4254 if (sigio == NULL) { 4255 SIGIO_UNLOCK(); 4256 return; 4257 } 4258 if (sigio->sio_pgid > 0) { 4259 PROC_LOCK(sigio->sio_proc); 4260 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4261 kern_psignal(sigio->sio_proc, sig); 4262 PROC_UNLOCK(sigio->sio_proc); 4263 } else if (sigio->sio_pgid < 0) { 4264 struct proc *p; 4265 4266 PGRP_LOCK(sigio->sio_pgrp); 4267 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4268 PROC_LOCK(p); 4269 if (p->p_state == PRS_NORMAL && 4270 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4271 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4272 kern_psignal(p, sig); 4273 PROC_UNLOCK(p); 4274 } 4275 PGRP_UNLOCK(sigio->sio_pgrp); 4276 } 4277 SIGIO_UNLOCK(); 4278 } 4279 4280 static int 4281 filt_sigattach(struct knote *kn) 4282 { 4283 struct proc *p = curproc; 4284 4285 kn->kn_ptr.p_proc = p; 4286 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4287 4288 knlist_add(p->p_klist, kn, 0); 4289 4290 return (0); 4291 } 4292 4293 static void 4294 filt_sigdetach(struct knote *kn) 4295 { 4296 struct proc *p = kn->kn_ptr.p_proc; 4297 4298 knlist_remove(p->p_klist, kn, 0); 4299 } 4300 4301 /* 4302 * signal knotes are shared with proc knotes, so we apply a mask to 4303 * the hint in order to differentiate them from process hints. This 4304 * could be avoided by using a signal-specific knote list, but probably 4305 * isn't worth the trouble. 4306 */ 4307 static int 4308 filt_signal(struct knote *kn, long hint) 4309 { 4310 4311 if (hint & NOTE_SIGNAL) { 4312 hint &= ~NOTE_SIGNAL; 4313 4314 if (kn->kn_id == hint) 4315 kn->kn_data++; 4316 } 4317 return (kn->kn_data != 0); 4318 } 4319 4320 struct sigacts * 4321 sigacts_alloc(void) 4322 { 4323 struct sigacts *ps; 4324 4325 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4326 refcount_init(&ps->ps_refcnt, 1); 4327 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4328 return (ps); 4329 } 4330 4331 void 4332 sigacts_free(struct sigacts *ps) 4333 { 4334 4335 if (refcount_release(&ps->ps_refcnt) == 0) 4336 return; 4337 mtx_destroy(&ps->ps_mtx); 4338 free(ps, M_SUBPROC); 4339 } 4340 4341 struct sigacts * 4342 sigacts_hold(struct sigacts *ps) 4343 { 4344 4345 refcount_acquire(&ps->ps_refcnt); 4346 return (ps); 4347 } 4348 4349 void 4350 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4351 { 4352 4353 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4354 mtx_lock(&src->ps_mtx); 4355 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4356 mtx_unlock(&src->ps_mtx); 4357 } 4358 4359 int 4360 sigacts_shared(struct sigacts *ps) 4361 { 4362 4363 return (ps->ps_refcnt > 1); 4364 } 4365 4366 void 4367 sig_drop_caught(struct proc *p) 4368 { 4369 int sig; 4370 struct sigacts *ps; 4371 4372 ps = p->p_sigacts; 4373 PROC_LOCK_ASSERT(p, MA_OWNED); 4374 mtx_assert(&ps->ps_mtx, MA_OWNED); 4375 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4376 sigdflt(ps, sig); 4377 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4378 sigqueue_delete_proc(p, sig); 4379 } 4380 } 4381 4382 static void 4383 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4384 { 4385 ksiginfo_t ksi; 4386 4387 /* 4388 * Prevent further fetches and SIGSEGVs, allowing thread to 4389 * issue syscalls despite corruption. 4390 */ 4391 sigfastblock_clear(td); 4392 4393 if (!sendsig) 4394 return; 4395 ksiginfo_init_trap(&ksi); 4396 ksi.ksi_signo = SIGSEGV; 4397 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4398 ksi.ksi_addr = td->td_sigblock_ptr; 4399 trapsignal(td, &ksi); 4400 } 4401 4402 static bool 4403 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4404 { 4405 uint32_t res; 4406 4407 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4408 return (true); 4409 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4410 sigfastblock_failed(td, sendsig, false); 4411 return (false); 4412 } 4413 *valp = res; 4414 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4415 return (true); 4416 } 4417 4418 static void 4419 sigfastblock_resched(struct thread *td, bool resched) 4420 { 4421 struct proc *p; 4422 4423 if (resched) { 4424 p = td->td_proc; 4425 PROC_LOCK(p); 4426 reschedule_signals(p, td->td_sigmask, 0); 4427 PROC_UNLOCK(p); 4428 } 4429 ast_sched(td, TDA_SIG); 4430 } 4431 4432 int 4433 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4434 { 4435 struct proc *p; 4436 int error, res; 4437 uint32_t oldval; 4438 4439 error = 0; 4440 p = td->td_proc; 4441 switch (uap->cmd) { 4442 case SIGFASTBLOCK_SETPTR: 4443 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4444 error = EBUSY; 4445 break; 4446 } 4447 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4448 error = EINVAL; 4449 break; 4450 } 4451 td->td_pflags |= TDP_SIGFASTBLOCK; 4452 td->td_sigblock_ptr = uap->ptr; 4453 break; 4454 4455 case SIGFASTBLOCK_UNBLOCK: 4456 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4457 error = EINVAL; 4458 break; 4459 } 4460 4461 for (;;) { 4462 res = casueword32(td->td_sigblock_ptr, 4463 SIGFASTBLOCK_PEND, &oldval, 0); 4464 if (res == -1) { 4465 error = EFAULT; 4466 sigfastblock_failed(td, false, true); 4467 break; 4468 } 4469 if (res == 0) 4470 break; 4471 MPASS(res == 1); 4472 if (oldval != SIGFASTBLOCK_PEND) { 4473 error = EBUSY; 4474 break; 4475 } 4476 error = thread_check_susp(td, false); 4477 if (error != 0) 4478 break; 4479 } 4480 if (error != 0) 4481 break; 4482 4483 /* 4484 * td_sigblock_val is cleared there, but not on a 4485 * syscall exit. The end effect is that a single 4486 * interruptible sleep, while user sigblock word is 4487 * set, might return EINTR or ERESTART to usermode 4488 * without delivering signal. All further sleeps, 4489 * until userspace clears the word and does 4490 * sigfastblock(UNBLOCK), observe current word and no 4491 * longer get interrupted. It is slight 4492 * non-conformance, with alternative to have read the 4493 * sigblock word on each syscall entry. 4494 */ 4495 td->td_sigblock_val = 0; 4496 4497 /* 4498 * Rely on normal ast mechanism to deliver pending 4499 * signals to current thread. But notify others about 4500 * fake unblock. 4501 */ 4502 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4503 4504 break; 4505 4506 case SIGFASTBLOCK_UNSETPTR: 4507 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4508 error = EINVAL; 4509 break; 4510 } 4511 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4512 error = EFAULT; 4513 break; 4514 } 4515 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4516 error = EBUSY; 4517 break; 4518 } 4519 sigfastblock_clear(td); 4520 break; 4521 4522 default: 4523 error = EINVAL; 4524 break; 4525 } 4526 return (error); 4527 } 4528 4529 void 4530 sigfastblock_clear(struct thread *td) 4531 { 4532 bool resched; 4533 4534 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4535 return; 4536 td->td_sigblock_val = 0; 4537 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4538 SIGPENDING(td); 4539 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4540 sigfastblock_resched(td, resched); 4541 } 4542 4543 void 4544 sigfastblock_fetch(struct thread *td) 4545 { 4546 uint32_t val; 4547 4548 (void)sigfastblock_fetch_sig(td, true, &val); 4549 } 4550 4551 static void 4552 sigfastblock_setpend1(struct thread *td) 4553 { 4554 int res; 4555 uint32_t oldval; 4556 4557 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4558 return; 4559 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4560 if (res == -1) { 4561 sigfastblock_failed(td, true, false); 4562 return; 4563 } 4564 for (;;) { 4565 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4566 oldval | SIGFASTBLOCK_PEND); 4567 if (res == -1) { 4568 sigfastblock_failed(td, true, true); 4569 return; 4570 } 4571 if (res == 0) { 4572 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4573 td->td_pflags &= ~TDP_SIGFASTPENDING; 4574 break; 4575 } 4576 MPASS(res == 1); 4577 if (thread_check_susp(td, false) != 0) 4578 break; 4579 } 4580 } 4581 4582 static void 4583 sigfastblock_setpend(struct thread *td, bool resched) 4584 { 4585 struct proc *p; 4586 4587 sigfastblock_setpend1(td); 4588 if (resched) { 4589 p = td->td_proc; 4590 PROC_LOCK(p); 4591 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4592 PROC_UNLOCK(p); 4593 } 4594 } 4595