1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/capsicum.h> 47 #include <sys/ctype.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 #include <sys/acct.h> 52 #include <sys/capsicum.h> 53 #include <sys/compressor.h> 54 #include <sys/condvar.h> 55 #include <sys/devctl.h> 56 #include <sys/event.h> 57 #include <sys/fcntl.h> 58 #include <sys/imgact.h> 59 #include <sys/kernel.h> 60 #include <sys/ktr.h> 61 #include <sys/ktrace.h> 62 #include <sys/limits.h> 63 #include <sys/lock.h> 64 #include <sys/malloc.h> 65 #include <sys/mutex.h> 66 #include <sys/refcount.h> 67 #include <sys/namei.h> 68 #include <sys/proc.h> 69 #include <sys/procdesc.h> 70 #include <sys/ptrace.h> 71 #include <sys/posix4.h> 72 #include <sys/racct.h> 73 #include <sys/resourcevar.h> 74 #include <sys/sdt.h> 75 #include <sys/sbuf.h> 76 #include <sys/sleepqueue.h> 77 #include <sys/smp.h> 78 #include <sys/stat.h> 79 #include <sys/sx.h> 80 #include <sys/syscall.h> 81 #include <sys/syscallsubr.h> 82 #include <sys/sysctl.h> 83 #include <sys/sysent.h> 84 #include <sys/syslog.h> 85 #include <sys/sysproto.h> 86 #include <sys/timers.h> 87 #include <sys/unistd.h> 88 #include <sys/vmmeter.h> 89 #include <sys/wait.h> 90 #include <vm/vm.h> 91 #include <vm/vm_extern.h> 92 #include <vm/uma.h> 93 94 #include <sys/jail.h> 95 96 #include <machine/cpu.h> 97 98 #include <security/audit/audit.h> 99 100 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 101 102 SDT_PROVIDER_DECLARE(proc); 103 SDT_PROBE_DEFINE3(proc, , , signal__send, 104 "struct thread *", "struct proc *", "int"); 105 SDT_PROBE_DEFINE2(proc, , , signal__clear, 106 "int", "ksiginfo_t *"); 107 SDT_PROBE_DEFINE3(proc, , , signal__discard, 108 "struct thread *", "struct proc *", "int"); 109 110 static int coredump(struct thread *); 111 static int killpg1(struct thread *td, int sig, int pgid, int all, 112 ksiginfo_t *ksi); 113 static int issignal(struct thread *td); 114 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 115 static int sigprop(int sig); 116 static void tdsigwakeup(struct thread *, int, sig_t, int); 117 static int sig_suspend_threads(struct thread *, struct proc *); 118 static int filt_sigattach(struct knote *kn); 119 static void filt_sigdetach(struct knote *kn); 120 static int filt_signal(struct knote *kn, long hint); 121 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 122 static void sigqueue_start(void); 123 static void sigfastblock_setpend(struct thread *td, bool resched); 124 static void sigexit1(struct thread *td, int sig, ksiginfo_t *ksi) __dead2; 125 126 static uma_zone_t ksiginfo_zone = NULL; 127 struct filterops sig_filtops = { 128 .f_isfd = 0, 129 .f_attach = filt_sigattach, 130 .f_detach = filt_sigdetach, 131 .f_event = filt_signal, 132 }; 133 134 static int kern_logsigexit = 1; 135 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 136 &kern_logsigexit, 0, 137 "Log processes quitting on abnormal signals to syslog(3)"); 138 139 static int kern_forcesigexit = 1; 140 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 141 &kern_forcesigexit, 0, "Force trap signal to be handled"); 142 143 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 144 "POSIX real time signal"); 145 146 static int max_pending_per_proc = 128; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 148 &max_pending_per_proc, 0, "Max pending signals per proc"); 149 150 static int preallocate_siginfo = 1024; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 152 &preallocate_siginfo, 0, "Preallocated signal memory size"); 153 154 static int signal_overflow = 0; 155 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 156 &signal_overflow, 0, "Number of signals overflew"); 157 158 static int signal_alloc_fail = 0; 159 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 160 &signal_alloc_fail, 0, "signals failed to be allocated"); 161 162 static int kern_lognosys = 0; 163 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 164 "Log invalid syscalls"); 165 166 __read_frequently bool sigfastblock_fetch_always = false; 167 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 168 &sigfastblock_fetch_always, 0, 169 "Fetch sigfastblock word on each syscall entry for proper " 170 "blocking semantic"); 171 172 static bool kern_sig_discard_ign = true; 173 SYSCTL_BOOL(_kern, OID_AUTO, sig_discard_ign, CTLFLAG_RWTUN, 174 &kern_sig_discard_ign, 0, 175 "Discard ignored signals on delivery, otherwise queue them to " 176 "the target queue"); 177 178 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 179 180 /* 181 * Policy -- Can ucred cr1 send SIGIO to process cr2? 182 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 183 * in the right situations. 184 */ 185 #define CANSIGIO(cr1, cr2) \ 186 ((cr1)->cr_uid == 0 || \ 187 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 188 (cr1)->cr_uid == (cr2)->cr_ruid || \ 189 (cr1)->cr_ruid == (cr2)->cr_uid || \ 190 (cr1)->cr_uid == (cr2)->cr_uid) 191 192 static int sugid_coredump; 193 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 194 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 195 196 static int capmode_coredump; 197 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 198 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 199 200 static int do_coredump = 1; 201 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 202 &do_coredump, 0, "Enable/Disable coredumps"); 203 204 static int set_core_nodump_flag = 0; 205 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 206 0, "Enable setting the NODUMP flag on coredump files"); 207 208 static int coredump_devctl = 0; 209 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 210 0, "Generate a devctl notification when processes coredump"); 211 212 /* 213 * Signal properties and actions. 214 * The array below categorizes the signals and their default actions 215 * according to the following properties: 216 */ 217 #define SIGPROP_KILL 0x01 /* terminates process by default */ 218 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 219 #define SIGPROP_STOP 0x04 /* suspend process */ 220 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 221 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 222 #define SIGPROP_CONT 0x20 /* continue if suspended */ 223 224 static const int sigproptbl[NSIG] = { 225 [SIGHUP] = SIGPROP_KILL, 226 [SIGINT] = SIGPROP_KILL, 227 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 228 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 229 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 230 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 231 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 232 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 233 [SIGKILL] = SIGPROP_KILL, 234 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 235 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 236 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 237 [SIGPIPE] = SIGPROP_KILL, 238 [SIGALRM] = SIGPROP_KILL, 239 [SIGTERM] = SIGPROP_KILL, 240 [SIGURG] = SIGPROP_IGNORE, 241 [SIGSTOP] = SIGPROP_STOP, 242 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 243 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 244 [SIGCHLD] = SIGPROP_IGNORE, 245 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 246 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 247 [SIGIO] = SIGPROP_IGNORE, 248 [SIGXCPU] = SIGPROP_KILL, 249 [SIGXFSZ] = SIGPROP_KILL, 250 [SIGVTALRM] = SIGPROP_KILL, 251 [SIGPROF] = SIGPROP_KILL, 252 [SIGWINCH] = SIGPROP_IGNORE, 253 [SIGINFO] = SIGPROP_IGNORE, 254 [SIGUSR1] = SIGPROP_KILL, 255 [SIGUSR2] = SIGPROP_KILL, 256 }; 257 258 #define _SIG_FOREACH_ADVANCE(i, set) ({ \ 259 int __found; \ 260 for (;;) { \ 261 if (__bits != 0) { \ 262 int __sig = ffs(__bits); \ 263 __bits &= ~(1u << (__sig - 1)); \ 264 sig = __i * sizeof((set)->__bits[0]) * NBBY + __sig; \ 265 __found = 1; \ 266 break; \ 267 } \ 268 if (++__i == _SIG_WORDS) { \ 269 __found = 0; \ 270 break; \ 271 } \ 272 __bits = (set)->__bits[__i]; \ 273 } \ 274 __found != 0; \ 275 }) 276 277 #define SIG_FOREACH(i, set) \ 278 for (int32_t __i = -1, __bits = 0; \ 279 _SIG_FOREACH_ADVANCE(i, set); ) \ 280 281 static sigset_t fastblock_mask; 282 283 static void 284 ast_sig(struct thread *td, int tda) 285 { 286 struct proc *p; 287 int old_boundary, sig; 288 bool resched_sigs; 289 290 p = td->td_proc; 291 292 #ifdef DIAGNOSTIC 293 if (p->p_numthreads == 1 && (tda & (TDAI(TDA_SIG) | 294 TDAI(TDA_AST))) == 0) { 295 PROC_LOCK(p); 296 thread_lock(td); 297 /* 298 * Note that TDA_SIG should be re-read from 299 * td_ast, since signal might have been delivered 300 * after we cleared td_flags above. This is one of 301 * the reason for looping check for AST condition. 302 * See comment in userret() about P_PPWAIT. 303 */ 304 if ((p->p_flag & P_PPWAIT) == 0 && 305 (td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 306 if (SIGPENDING(td) && ((tda | td->td_ast) & 307 (TDAI(TDA_SIG) | TDAI(TDA_AST))) == 0) { 308 thread_unlock(td); /* fix dumps */ 309 panic( 310 "failed2 to set signal flags for ast p %p " 311 "td %p tda %#x td_ast %#x fl %#x", 312 p, td, tda, td->td_ast, td->td_flags); 313 } 314 } 315 thread_unlock(td); 316 PROC_UNLOCK(p); 317 } 318 #endif 319 320 /* 321 * Check for signals. Unlocked reads of p_pendingcnt or 322 * p_siglist might cause process-directed signal to be handled 323 * later. 324 */ 325 if ((tda & TDAI(TDA_SIG)) != 0 || p->p_pendingcnt > 0 || 326 !SIGISEMPTY(p->p_siglist)) { 327 sigfastblock_fetch(td); 328 PROC_LOCK(p); 329 old_boundary = ~TDB_BOUNDARY | (td->td_dbgflags & TDB_BOUNDARY); 330 td->td_dbgflags |= TDB_BOUNDARY; 331 mtx_lock(&p->p_sigacts->ps_mtx); 332 while ((sig = cursig(td)) != 0) { 333 KASSERT(sig >= 0, ("sig %d", sig)); 334 postsig(sig); 335 } 336 mtx_unlock(&p->p_sigacts->ps_mtx); 337 td->td_dbgflags &= old_boundary; 338 PROC_UNLOCK(p); 339 resched_sigs = true; 340 } else { 341 resched_sigs = false; 342 } 343 344 /* 345 * Handle deferred update of the fast sigblock value, after 346 * the postsig() loop was performed. 347 */ 348 sigfastblock_setpend(td, resched_sigs); 349 } 350 351 static void 352 ast_sigsuspend(struct thread *td, int tda __unused) 353 { 354 MPASS((td->td_pflags & TDP_OLDMASK) != 0); 355 td->td_pflags &= ~TDP_OLDMASK; 356 kern_sigprocmask(td, SIG_SETMASK, &td->td_oldsigmask, NULL, 0); 357 } 358 359 static void 360 sigqueue_start(void) 361 { 362 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 363 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 364 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 365 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 366 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 367 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 368 SIGFILLSET(fastblock_mask); 369 SIG_CANTMASK(fastblock_mask); 370 ast_register(TDA_SIG, ASTR_UNCOND, 0, ast_sig); 371 ast_register(TDA_SIGSUSPEND, ASTR_ASTF_REQUIRED | ASTR_TDP, 372 TDP_OLDMASK, ast_sigsuspend); 373 } 374 375 static void 376 sig_handle_killpg(struct proc *p, ksiginfo_t *ksi) 377 { 378 if ((ksi->ksi_flags & KSI_KILLPG) != 0 && p != NULL) { 379 MPASS(atomic_load_int(&p->p_killpg_cnt) > 0); 380 atomic_add_int(&p->p_killpg_cnt, -1); 381 } 382 } 383 384 ksiginfo_t * 385 ksiginfo_alloc(int mwait) 386 { 387 MPASS(mwait == M_WAITOK || mwait == M_NOWAIT); 388 389 if (ksiginfo_zone == NULL) 390 return (NULL); 391 return (uma_zalloc(ksiginfo_zone, mwait | M_ZERO)); 392 } 393 394 void 395 ksiginfo_free(ksiginfo_t *ksi) 396 { 397 uma_zfree(ksiginfo_zone, ksi); 398 } 399 400 static __inline bool 401 ksiginfo_tryfree(ksiginfo_t *ksi) 402 { 403 if ((ksi->ksi_flags & KSI_EXT) == 0) { 404 uma_zfree(ksiginfo_zone, ksi); 405 return (true); 406 } 407 return (false); 408 } 409 410 void 411 sigqueue_init(sigqueue_t *list, struct proc *p) 412 { 413 SIGEMPTYSET(list->sq_signals); 414 SIGEMPTYSET(list->sq_kill); 415 SIGEMPTYSET(list->sq_ptrace); 416 TAILQ_INIT(&list->sq_list); 417 list->sq_proc = p; 418 list->sq_flags = SQ_INIT; 419 } 420 421 /* 422 * Get a signal's ksiginfo. 423 * Return: 424 * 0 - signal not found 425 * others - signal number 426 */ 427 static int 428 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 429 { 430 struct proc *p = sq->sq_proc; 431 struct ksiginfo *ksi, *next; 432 int count = 0; 433 434 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 435 436 if (!SIGISMEMBER(sq->sq_signals, signo)) 437 return (0); 438 439 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 440 count++; 441 SIGDELSET(sq->sq_ptrace, signo); 442 si->ksi_flags |= KSI_PTRACE; 443 } 444 if (SIGISMEMBER(sq->sq_kill, signo)) { 445 count++; 446 if (count == 1) 447 SIGDELSET(sq->sq_kill, signo); 448 } 449 450 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 451 if (ksi->ksi_signo == signo) { 452 if (count == 0) { 453 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 454 ksi->ksi_sigq = NULL; 455 ksiginfo_copy(ksi, si); 456 if (ksiginfo_tryfree(ksi) && p != NULL) 457 p->p_pendingcnt--; 458 } 459 if (++count > 1) 460 break; 461 } 462 } 463 464 if (count <= 1) 465 SIGDELSET(sq->sq_signals, signo); 466 si->ksi_signo = signo; 467 return (signo); 468 } 469 470 void 471 sigqueue_take(ksiginfo_t *ksi) 472 { 473 struct ksiginfo *kp; 474 struct proc *p; 475 sigqueue_t *sq; 476 477 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 478 return; 479 480 p = sq->sq_proc; 481 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 482 ksi->ksi_sigq = NULL; 483 sig_handle_killpg(p, ksi); 484 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 485 p->p_pendingcnt--; 486 487 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 488 kp = TAILQ_NEXT(kp, ksi_link)) { 489 if (kp->ksi_signo == ksi->ksi_signo) 490 break; 491 } 492 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 493 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 494 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 495 } 496 497 static int 498 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 499 { 500 struct proc *p = sq->sq_proc; 501 struct ksiginfo *ksi; 502 int ret = 0; 503 504 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 505 506 /* 507 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 508 * for these signals. 509 */ 510 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 511 SIGADDSET(sq->sq_kill, signo); 512 goto out_set_bit; 513 } 514 515 /* directly insert the ksi, don't copy it */ 516 if (si->ksi_flags & KSI_INS) { 517 if (si->ksi_flags & KSI_HEAD) 518 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 519 else 520 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 521 si->ksi_sigq = sq; 522 goto out_set_bit; 523 } 524 525 if (__predict_false(ksiginfo_zone == NULL)) { 526 SIGADDSET(sq->sq_kill, signo); 527 goto out_set_bit; 528 } 529 530 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 531 signal_overflow++; 532 ret = EAGAIN; 533 } else if ((ksi = ksiginfo_alloc(M_NOWAIT)) == NULL) { 534 signal_alloc_fail++; 535 ret = EAGAIN; 536 } else { 537 if (p != NULL) 538 p->p_pendingcnt++; 539 ksiginfo_copy(si, ksi); 540 ksi->ksi_signo = signo; 541 if (si->ksi_flags & KSI_HEAD) 542 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 543 else 544 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 545 ksi->ksi_sigq = sq; 546 } 547 548 if (ret != 0) { 549 if ((si->ksi_flags & KSI_PTRACE) != 0) { 550 SIGADDSET(sq->sq_ptrace, signo); 551 ret = 0; 552 goto out_set_bit; 553 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 554 (si->ksi_flags & KSI_SIGQ) == 0) { 555 SIGADDSET(sq->sq_kill, signo); 556 ret = 0; 557 goto out_set_bit; 558 } 559 return (ret); 560 } 561 562 out_set_bit: 563 SIGADDSET(sq->sq_signals, signo); 564 return (ret); 565 } 566 567 void 568 sigqueue_flush(sigqueue_t *sq) 569 { 570 struct proc *p = sq->sq_proc; 571 ksiginfo_t *ksi; 572 573 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 574 575 if (p != NULL) 576 PROC_LOCK_ASSERT(p, MA_OWNED); 577 578 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 579 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 580 ksi->ksi_sigq = NULL; 581 sig_handle_killpg(p, ksi); 582 if (ksiginfo_tryfree(ksi) && p != NULL) 583 p->p_pendingcnt--; 584 } 585 586 SIGEMPTYSET(sq->sq_signals); 587 SIGEMPTYSET(sq->sq_kill); 588 SIGEMPTYSET(sq->sq_ptrace); 589 } 590 591 static void 592 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 593 { 594 sigset_t tmp; 595 struct proc *p1, *p2; 596 ksiginfo_t *ksi, *next; 597 598 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 599 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 600 p1 = src->sq_proc; 601 p2 = dst->sq_proc; 602 /* Move siginfo to target list */ 603 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 604 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 605 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 606 if (p1 != NULL) 607 p1->p_pendingcnt--; 608 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 609 ksi->ksi_sigq = dst; 610 if (p2 != NULL) 611 p2->p_pendingcnt++; 612 } 613 } 614 615 /* Move pending bits to target list */ 616 tmp = src->sq_kill; 617 SIGSETAND(tmp, *set); 618 SIGSETOR(dst->sq_kill, tmp); 619 SIGSETNAND(src->sq_kill, tmp); 620 621 tmp = src->sq_ptrace; 622 SIGSETAND(tmp, *set); 623 SIGSETOR(dst->sq_ptrace, tmp); 624 SIGSETNAND(src->sq_ptrace, tmp); 625 626 tmp = src->sq_signals; 627 SIGSETAND(tmp, *set); 628 SIGSETOR(dst->sq_signals, tmp); 629 SIGSETNAND(src->sq_signals, tmp); 630 } 631 632 #if 0 633 static void 634 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 635 { 636 sigset_t set; 637 638 SIGEMPTYSET(set); 639 SIGADDSET(set, signo); 640 sigqueue_move_set(src, dst, &set); 641 } 642 #endif 643 644 static void 645 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 646 { 647 struct proc *p = sq->sq_proc; 648 ksiginfo_t *ksi, *next; 649 650 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 651 652 /* Remove siginfo queue */ 653 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 654 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 655 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 656 ksi->ksi_sigq = NULL; 657 sig_handle_killpg(p, ksi); 658 if (ksiginfo_tryfree(ksi) && p != NULL) 659 p->p_pendingcnt--; 660 } 661 } 662 SIGSETNAND(sq->sq_kill, *set); 663 SIGSETNAND(sq->sq_ptrace, *set); 664 SIGSETNAND(sq->sq_signals, *set); 665 } 666 667 void 668 sigqueue_delete(sigqueue_t *sq, int signo) 669 { 670 sigset_t set; 671 672 SIGEMPTYSET(set); 673 SIGADDSET(set, signo); 674 sigqueue_delete_set(sq, &set); 675 } 676 677 /* Remove a set of signals for a process */ 678 static void 679 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 680 { 681 sigqueue_t worklist; 682 struct thread *td0; 683 684 PROC_LOCK_ASSERT(p, MA_OWNED); 685 686 sigqueue_init(&worklist, NULL); 687 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 688 689 FOREACH_THREAD_IN_PROC(p, td0) 690 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 691 692 sigqueue_flush(&worklist); 693 } 694 695 void 696 sigqueue_delete_proc(struct proc *p, int signo) 697 { 698 sigset_t set; 699 700 SIGEMPTYSET(set); 701 SIGADDSET(set, signo); 702 sigqueue_delete_set_proc(p, &set); 703 } 704 705 static void 706 sigqueue_delete_stopmask_proc(struct proc *p) 707 { 708 sigset_t set; 709 710 SIGEMPTYSET(set); 711 SIGADDSET(set, SIGSTOP); 712 SIGADDSET(set, SIGTSTP); 713 SIGADDSET(set, SIGTTIN); 714 SIGADDSET(set, SIGTTOU); 715 sigqueue_delete_set_proc(p, &set); 716 } 717 718 /* 719 * Determine signal that should be delivered to thread td, the current 720 * thread, 0 if none. If there is a pending stop signal with default 721 * action, the process stops in issignal(). 722 */ 723 int 724 cursig(struct thread *td) 725 { 726 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 727 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 728 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 729 return (SIGPENDING(td) ? issignal(td) : 0); 730 } 731 732 /* 733 * Arrange for ast() to handle unmasked pending signals on return to user 734 * mode. This must be called whenever a signal is added to td_sigqueue or 735 * unmasked in td_sigmask. 736 */ 737 void 738 signotify(struct thread *td) 739 { 740 741 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 742 743 if (SIGPENDING(td)) 744 ast_sched(td, TDA_SIG); 745 } 746 747 /* 748 * Returns 1 (true) if altstack is configured for the thread, and the 749 * passed stack bottom address falls into the altstack range. Handles 750 * the 43 compat special case where the alt stack size is zero. 751 */ 752 int 753 sigonstack(size_t sp) 754 { 755 struct thread *td; 756 757 td = curthread; 758 if ((td->td_pflags & TDP_ALTSTACK) == 0) 759 return (0); 760 #if defined(COMPAT_43) 761 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 762 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 763 #endif 764 return (sp >= (size_t)td->td_sigstk.ss_sp && 765 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 766 } 767 768 static __inline int 769 sigprop(int sig) 770 { 771 772 if (sig > 0 && sig < nitems(sigproptbl)) 773 return (sigproptbl[sig]); 774 return (0); 775 } 776 777 static bool 778 sigact_flag_test(const struct sigaction *act, int flag) 779 { 780 781 /* 782 * SA_SIGINFO is reset when signal disposition is set to 783 * ignore or default. Other flags are kept according to user 784 * settings. 785 */ 786 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 787 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 788 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 789 } 790 791 /* 792 * kern_sigaction 793 * sigaction 794 * freebsd4_sigaction 795 * osigaction 796 */ 797 int 798 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 799 struct sigaction *oact, int flags) 800 { 801 struct sigacts *ps; 802 struct proc *p = td->td_proc; 803 804 if (!_SIG_VALID(sig)) 805 return (EINVAL); 806 if (act != NULL && act->sa_handler != SIG_DFL && 807 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 808 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 809 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 810 return (EINVAL); 811 812 PROC_LOCK(p); 813 ps = p->p_sigacts; 814 mtx_lock(&ps->ps_mtx); 815 if (oact) { 816 memset(oact, 0, sizeof(*oact)); 817 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 818 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 819 oact->sa_flags |= SA_ONSTACK; 820 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 821 oact->sa_flags |= SA_RESTART; 822 if (SIGISMEMBER(ps->ps_sigreset, sig)) 823 oact->sa_flags |= SA_RESETHAND; 824 if (SIGISMEMBER(ps->ps_signodefer, sig)) 825 oact->sa_flags |= SA_NODEFER; 826 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 827 oact->sa_flags |= SA_SIGINFO; 828 oact->sa_sigaction = 829 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 830 } else 831 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 832 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 833 oact->sa_flags |= SA_NOCLDSTOP; 834 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 835 oact->sa_flags |= SA_NOCLDWAIT; 836 } 837 if (act) { 838 if ((sig == SIGKILL || sig == SIGSTOP) && 839 act->sa_handler != SIG_DFL) { 840 mtx_unlock(&ps->ps_mtx); 841 PROC_UNLOCK(p); 842 return (EINVAL); 843 } 844 845 /* 846 * Change setting atomically. 847 */ 848 849 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 850 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 851 if (sigact_flag_test(act, SA_SIGINFO)) { 852 ps->ps_sigact[_SIG_IDX(sig)] = 853 (__sighandler_t *)act->sa_sigaction; 854 SIGADDSET(ps->ps_siginfo, sig); 855 } else { 856 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 857 SIGDELSET(ps->ps_siginfo, sig); 858 } 859 if (!sigact_flag_test(act, SA_RESTART)) 860 SIGADDSET(ps->ps_sigintr, sig); 861 else 862 SIGDELSET(ps->ps_sigintr, sig); 863 if (sigact_flag_test(act, SA_ONSTACK)) 864 SIGADDSET(ps->ps_sigonstack, sig); 865 else 866 SIGDELSET(ps->ps_sigonstack, sig); 867 if (sigact_flag_test(act, SA_RESETHAND)) 868 SIGADDSET(ps->ps_sigreset, sig); 869 else 870 SIGDELSET(ps->ps_sigreset, sig); 871 if (sigact_flag_test(act, SA_NODEFER)) 872 SIGADDSET(ps->ps_signodefer, sig); 873 else 874 SIGDELSET(ps->ps_signodefer, sig); 875 if (sig == SIGCHLD) { 876 if (act->sa_flags & SA_NOCLDSTOP) 877 ps->ps_flag |= PS_NOCLDSTOP; 878 else 879 ps->ps_flag &= ~PS_NOCLDSTOP; 880 if (act->sa_flags & SA_NOCLDWAIT) { 881 /* 882 * Paranoia: since SA_NOCLDWAIT is implemented 883 * by reparenting the dying child to PID 1 (and 884 * trust it to reap the zombie), PID 1 itself 885 * is forbidden to set SA_NOCLDWAIT. 886 */ 887 if (p->p_pid == 1) 888 ps->ps_flag &= ~PS_NOCLDWAIT; 889 else 890 ps->ps_flag |= PS_NOCLDWAIT; 891 } else 892 ps->ps_flag &= ~PS_NOCLDWAIT; 893 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 894 ps->ps_flag |= PS_CLDSIGIGN; 895 else 896 ps->ps_flag &= ~PS_CLDSIGIGN; 897 } 898 /* 899 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 900 * and for signals set to SIG_DFL where the default is to 901 * ignore. However, don't put SIGCONT in ps_sigignore, as we 902 * have to restart the process. 903 */ 904 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 905 (sigprop(sig) & SIGPROP_IGNORE && 906 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 907 /* never to be seen again */ 908 sigqueue_delete_proc(p, sig); 909 if (sig != SIGCONT) 910 /* easier in psignal */ 911 SIGADDSET(ps->ps_sigignore, sig); 912 SIGDELSET(ps->ps_sigcatch, sig); 913 } else { 914 SIGDELSET(ps->ps_sigignore, sig); 915 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 916 SIGDELSET(ps->ps_sigcatch, sig); 917 else 918 SIGADDSET(ps->ps_sigcatch, sig); 919 } 920 #ifdef COMPAT_FREEBSD4 921 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 922 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 923 (flags & KSA_FREEBSD4) == 0) 924 SIGDELSET(ps->ps_freebsd4, sig); 925 else 926 SIGADDSET(ps->ps_freebsd4, sig); 927 #endif 928 #ifdef COMPAT_43 929 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 930 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 931 (flags & KSA_OSIGSET) == 0) 932 SIGDELSET(ps->ps_osigset, sig); 933 else 934 SIGADDSET(ps->ps_osigset, sig); 935 #endif 936 } 937 mtx_unlock(&ps->ps_mtx); 938 PROC_UNLOCK(p); 939 return (0); 940 } 941 942 #ifndef _SYS_SYSPROTO_H_ 943 struct sigaction_args { 944 int sig; 945 struct sigaction *act; 946 struct sigaction *oact; 947 }; 948 #endif 949 int 950 sys_sigaction(struct thread *td, struct sigaction_args *uap) 951 { 952 struct sigaction act, oact; 953 struct sigaction *actp, *oactp; 954 int error; 955 956 actp = (uap->act != NULL) ? &act : NULL; 957 oactp = (uap->oact != NULL) ? &oact : NULL; 958 if (actp) { 959 error = copyin(uap->act, actp, sizeof(act)); 960 if (error) 961 return (error); 962 } 963 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 964 if (oactp && !error) 965 error = copyout(oactp, uap->oact, sizeof(oact)); 966 return (error); 967 } 968 969 #ifdef COMPAT_FREEBSD4 970 #ifndef _SYS_SYSPROTO_H_ 971 struct freebsd4_sigaction_args { 972 int sig; 973 struct sigaction *act; 974 struct sigaction *oact; 975 }; 976 #endif 977 int 978 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 979 { 980 struct sigaction act, oact; 981 struct sigaction *actp, *oactp; 982 int error; 983 984 actp = (uap->act != NULL) ? &act : NULL; 985 oactp = (uap->oact != NULL) ? &oact : NULL; 986 if (actp) { 987 error = copyin(uap->act, actp, sizeof(act)); 988 if (error) 989 return (error); 990 } 991 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 992 if (oactp && !error) 993 error = copyout(oactp, uap->oact, sizeof(oact)); 994 return (error); 995 } 996 #endif /* COMAPT_FREEBSD4 */ 997 998 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 999 #ifndef _SYS_SYSPROTO_H_ 1000 struct osigaction_args { 1001 int signum; 1002 struct osigaction *nsa; 1003 struct osigaction *osa; 1004 }; 1005 #endif 1006 int 1007 osigaction(struct thread *td, struct osigaction_args *uap) 1008 { 1009 struct osigaction sa; 1010 struct sigaction nsa, osa; 1011 struct sigaction *nsap, *osap; 1012 int error; 1013 1014 if (uap->signum <= 0 || uap->signum >= ONSIG) 1015 return (EINVAL); 1016 1017 nsap = (uap->nsa != NULL) ? &nsa : NULL; 1018 osap = (uap->osa != NULL) ? &osa : NULL; 1019 1020 if (nsap) { 1021 error = copyin(uap->nsa, &sa, sizeof(sa)); 1022 if (error) 1023 return (error); 1024 nsap->sa_handler = sa.sa_handler; 1025 nsap->sa_flags = sa.sa_flags; 1026 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 1027 } 1028 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1029 if (osap && !error) { 1030 sa.sa_handler = osap->sa_handler; 1031 sa.sa_flags = osap->sa_flags; 1032 SIG2OSIG(osap->sa_mask, sa.sa_mask); 1033 error = copyout(&sa, uap->osa, sizeof(sa)); 1034 } 1035 return (error); 1036 } 1037 1038 #if !defined(__i386__) 1039 /* Avoid replicating the same stub everywhere */ 1040 int 1041 osigreturn(struct thread *td, struct osigreturn_args *uap) 1042 { 1043 1044 return (nosys(td, (struct nosys_args *)uap)); 1045 } 1046 #endif 1047 #endif /* COMPAT_43 */ 1048 1049 /* 1050 * Initialize signal state for process 0; 1051 * set to ignore signals that are ignored by default. 1052 */ 1053 void 1054 siginit(struct proc *p) 1055 { 1056 int i; 1057 struct sigacts *ps; 1058 1059 PROC_LOCK(p); 1060 ps = p->p_sigacts; 1061 mtx_lock(&ps->ps_mtx); 1062 for (i = 1; i <= NSIG; i++) { 1063 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 1064 SIGADDSET(ps->ps_sigignore, i); 1065 } 1066 } 1067 mtx_unlock(&ps->ps_mtx); 1068 PROC_UNLOCK(p); 1069 } 1070 1071 /* 1072 * Reset specified signal to the default disposition. 1073 */ 1074 static void 1075 sigdflt(struct sigacts *ps, int sig) 1076 { 1077 1078 mtx_assert(&ps->ps_mtx, MA_OWNED); 1079 SIGDELSET(ps->ps_sigcatch, sig); 1080 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 1081 SIGADDSET(ps->ps_sigignore, sig); 1082 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1083 SIGDELSET(ps->ps_siginfo, sig); 1084 } 1085 1086 /* 1087 * Reset signals for an exec of the specified process. 1088 */ 1089 void 1090 execsigs(struct proc *p) 1091 { 1092 struct sigacts *ps; 1093 struct thread *td; 1094 1095 /* 1096 * Reset caught signals. Held signals remain held 1097 * through td_sigmask (unless they were caught, 1098 * and are now ignored by default). 1099 */ 1100 PROC_LOCK_ASSERT(p, MA_OWNED); 1101 ps = p->p_sigacts; 1102 mtx_lock(&ps->ps_mtx); 1103 sig_drop_caught(p); 1104 1105 /* 1106 * Reset stack state to the user stack. 1107 * Clear set of signals caught on the signal stack. 1108 */ 1109 td = curthread; 1110 MPASS(td->td_proc == p); 1111 td->td_sigstk.ss_flags = SS_DISABLE; 1112 td->td_sigstk.ss_size = 0; 1113 td->td_sigstk.ss_sp = 0; 1114 td->td_pflags &= ~TDP_ALTSTACK; 1115 /* 1116 * Reset no zombies if child dies flag as Solaris does. 1117 */ 1118 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1119 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1120 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1121 mtx_unlock(&ps->ps_mtx); 1122 } 1123 1124 /* 1125 * kern_sigprocmask() 1126 * 1127 * Manipulate signal mask. 1128 */ 1129 int 1130 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1131 int flags) 1132 { 1133 sigset_t new_block, oset1; 1134 struct proc *p; 1135 int error; 1136 1137 p = td->td_proc; 1138 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1139 PROC_LOCK_ASSERT(p, MA_OWNED); 1140 else 1141 PROC_LOCK(p); 1142 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1143 ? MA_OWNED : MA_NOTOWNED); 1144 if (oset != NULL) 1145 *oset = td->td_sigmask; 1146 1147 error = 0; 1148 if (set != NULL) { 1149 switch (how) { 1150 case SIG_BLOCK: 1151 SIG_CANTMASK(*set); 1152 oset1 = td->td_sigmask; 1153 SIGSETOR(td->td_sigmask, *set); 1154 new_block = td->td_sigmask; 1155 SIGSETNAND(new_block, oset1); 1156 break; 1157 case SIG_UNBLOCK: 1158 SIGSETNAND(td->td_sigmask, *set); 1159 signotify(td); 1160 goto out; 1161 case SIG_SETMASK: 1162 SIG_CANTMASK(*set); 1163 oset1 = td->td_sigmask; 1164 if (flags & SIGPROCMASK_OLD) 1165 SIGSETLO(td->td_sigmask, *set); 1166 else 1167 td->td_sigmask = *set; 1168 new_block = td->td_sigmask; 1169 SIGSETNAND(new_block, oset1); 1170 signotify(td); 1171 break; 1172 default: 1173 error = EINVAL; 1174 goto out; 1175 } 1176 1177 /* 1178 * The new_block set contains signals that were not previously 1179 * blocked, but are blocked now. 1180 * 1181 * In case we block any signal that was not previously blocked 1182 * for td, and process has the signal pending, try to schedule 1183 * signal delivery to some thread that does not block the 1184 * signal, possibly waking it up. 1185 */ 1186 if (p->p_numthreads != 1) 1187 reschedule_signals(p, new_block, flags); 1188 } 1189 1190 out: 1191 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1192 PROC_UNLOCK(p); 1193 return (error); 1194 } 1195 1196 #ifndef _SYS_SYSPROTO_H_ 1197 struct sigprocmask_args { 1198 int how; 1199 const sigset_t *set; 1200 sigset_t *oset; 1201 }; 1202 #endif 1203 int 1204 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1205 { 1206 sigset_t set, oset; 1207 sigset_t *setp, *osetp; 1208 int error; 1209 1210 setp = (uap->set != NULL) ? &set : NULL; 1211 osetp = (uap->oset != NULL) ? &oset : NULL; 1212 if (setp) { 1213 error = copyin(uap->set, setp, sizeof(set)); 1214 if (error) 1215 return (error); 1216 } 1217 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1218 if (osetp && !error) { 1219 error = copyout(osetp, uap->oset, sizeof(oset)); 1220 } 1221 return (error); 1222 } 1223 1224 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1225 #ifndef _SYS_SYSPROTO_H_ 1226 struct osigprocmask_args { 1227 int how; 1228 osigset_t mask; 1229 }; 1230 #endif 1231 int 1232 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1233 { 1234 sigset_t set, oset; 1235 int error; 1236 1237 OSIG2SIG(uap->mask, set); 1238 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1239 SIG2OSIG(oset, td->td_retval[0]); 1240 return (error); 1241 } 1242 #endif /* COMPAT_43 */ 1243 1244 int 1245 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1246 { 1247 ksiginfo_t ksi; 1248 sigset_t set; 1249 int error; 1250 1251 error = copyin(uap->set, &set, sizeof(set)); 1252 if (error) { 1253 td->td_retval[0] = error; 1254 return (0); 1255 } 1256 1257 error = kern_sigtimedwait(td, set, &ksi, NULL); 1258 if (error) { 1259 /* 1260 * sigwait() function shall not return EINTR, but 1261 * the syscall does. Non-ancient libc provides the 1262 * wrapper which hides EINTR. Otherwise, EINTR return 1263 * is used by libthr to handle required cancellation 1264 * point in the sigwait(). 1265 */ 1266 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1267 return (ERESTART); 1268 td->td_retval[0] = error; 1269 return (0); 1270 } 1271 1272 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1273 td->td_retval[0] = error; 1274 return (0); 1275 } 1276 1277 int 1278 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1279 { 1280 struct timespec ts; 1281 struct timespec *timeout; 1282 sigset_t set; 1283 ksiginfo_t ksi; 1284 int error; 1285 1286 if (uap->timeout) { 1287 error = copyin(uap->timeout, &ts, sizeof(ts)); 1288 if (error) 1289 return (error); 1290 1291 timeout = &ts; 1292 } else 1293 timeout = NULL; 1294 1295 error = copyin(uap->set, &set, sizeof(set)); 1296 if (error) 1297 return (error); 1298 1299 error = kern_sigtimedwait(td, set, &ksi, timeout); 1300 if (error) 1301 return (error); 1302 1303 if (uap->info) 1304 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1305 1306 if (error == 0) 1307 td->td_retval[0] = ksi.ksi_signo; 1308 return (error); 1309 } 1310 1311 int 1312 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1313 { 1314 ksiginfo_t ksi; 1315 sigset_t set; 1316 int error; 1317 1318 error = copyin(uap->set, &set, sizeof(set)); 1319 if (error) 1320 return (error); 1321 1322 error = kern_sigtimedwait(td, set, &ksi, NULL); 1323 if (error) 1324 return (error); 1325 1326 if (uap->info) 1327 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1328 1329 if (error == 0) 1330 td->td_retval[0] = ksi.ksi_signo; 1331 return (error); 1332 } 1333 1334 static void 1335 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1336 { 1337 struct thread *thr; 1338 1339 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1340 if (thr == td) 1341 thr->td_si = *si; 1342 else 1343 thr->td_si.si_signo = 0; 1344 } 1345 } 1346 1347 int 1348 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1349 struct timespec *timeout) 1350 { 1351 struct sigacts *ps; 1352 sigset_t saved_mask, new_block; 1353 struct proc *p; 1354 int error, sig, timevalid = 0; 1355 sbintime_t sbt, precision, tsbt; 1356 struct timespec ts; 1357 bool traced; 1358 1359 p = td->td_proc; 1360 error = 0; 1361 traced = false; 1362 1363 /* Ensure the sigfastblock value is up to date. */ 1364 sigfastblock_fetch(td); 1365 1366 if (timeout != NULL) { 1367 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1368 timevalid = 1; 1369 ts = *timeout; 1370 if (ts.tv_sec < INT32_MAX / 2) { 1371 tsbt = tstosbt(ts); 1372 precision = tsbt; 1373 precision >>= tc_precexp; 1374 if (TIMESEL(&sbt, tsbt)) 1375 sbt += tc_tick_sbt; 1376 sbt += tsbt; 1377 } else 1378 precision = sbt = 0; 1379 } 1380 } else 1381 precision = sbt = 0; 1382 ksiginfo_init(ksi); 1383 /* Some signals can not be waited for. */ 1384 SIG_CANTMASK(waitset); 1385 ps = p->p_sigacts; 1386 PROC_LOCK(p); 1387 saved_mask = td->td_sigmask; 1388 SIGSETNAND(td->td_sigmask, waitset); 1389 if ((p->p_sysent->sv_flags & SV_SIG_DISCIGN) != 0 || 1390 !kern_sig_discard_ign) { 1391 thread_lock(td); 1392 td->td_flags |= TDF_SIGWAIT; 1393 thread_unlock(td); 1394 } 1395 for (;;) { 1396 mtx_lock(&ps->ps_mtx); 1397 sig = cursig(td); 1398 mtx_unlock(&ps->ps_mtx); 1399 KASSERT(sig >= 0, ("sig %d", sig)); 1400 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1401 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1402 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1403 error = 0; 1404 break; 1405 } 1406 } 1407 1408 if (error != 0) 1409 break; 1410 1411 /* 1412 * POSIX says this must be checked after looking for pending 1413 * signals. 1414 */ 1415 if (timeout != NULL && !timevalid) { 1416 error = EINVAL; 1417 break; 1418 } 1419 1420 if (traced) { 1421 error = EINTR; 1422 break; 1423 } 1424 1425 error = msleep_sbt(&p->p_sigacts, &p->p_mtx, PPAUSE | PCATCH, 1426 "sigwait", sbt, precision, C_ABSOLUTE); 1427 1428 /* The syscalls can not be restarted. */ 1429 if (error == ERESTART) 1430 error = EINTR; 1431 1432 /* 1433 * If PTRACE_SCE or PTRACE_SCX were set after 1434 * userspace entered the syscall, return spurious 1435 * EINTR after wait was done. Only do this as last 1436 * resort after rechecking for possible queued signals 1437 * and expired timeouts. 1438 */ 1439 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1440 traced = true; 1441 } 1442 thread_lock(td); 1443 td->td_flags &= ~TDF_SIGWAIT; 1444 thread_unlock(td); 1445 1446 new_block = saved_mask; 1447 SIGSETNAND(new_block, td->td_sigmask); 1448 td->td_sigmask = saved_mask; 1449 /* 1450 * Fewer signals can be delivered to us, reschedule signal 1451 * notification. 1452 */ 1453 if (p->p_numthreads != 1) 1454 reschedule_signals(p, new_block, 0); 1455 1456 if (error == 0) { 1457 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1458 1459 if (ksi->ksi_code == SI_TIMER) 1460 itimer_accept(p, ksi->ksi_timerid, ksi); 1461 1462 #ifdef KTRACE 1463 if (KTRPOINT(td, KTR_PSIG)) { 1464 sig_t action; 1465 1466 mtx_lock(&ps->ps_mtx); 1467 action = ps->ps_sigact[_SIG_IDX(sig)]; 1468 mtx_unlock(&ps->ps_mtx); 1469 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1470 } 1471 #endif 1472 if (sig == SIGKILL) { 1473 proc_td_siginfo_capture(td, &ksi->ksi_info); 1474 sigexit1(td, sig, ksi); 1475 } 1476 } 1477 PROC_UNLOCK(p); 1478 return (error); 1479 } 1480 1481 #ifndef _SYS_SYSPROTO_H_ 1482 struct sigpending_args { 1483 sigset_t *set; 1484 }; 1485 #endif 1486 int 1487 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1488 { 1489 struct proc *p = td->td_proc; 1490 sigset_t pending; 1491 1492 PROC_LOCK(p); 1493 pending = p->p_sigqueue.sq_signals; 1494 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1495 PROC_UNLOCK(p); 1496 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1497 } 1498 1499 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1500 #ifndef _SYS_SYSPROTO_H_ 1501 struct osigpending_args { 1502 int dummy; 1503 }; 1504 #endif 1505 int 1506 osigpending(struct thread *td, struct osigpending_args *uap) 1507 { 1508 struct proc *p = td->td_proc; 1509 sigset_t pending; 1510 1511 PROC_LOCK(p); 1512 pending = p->p_sigqueue.sq_signals; 1513 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1514 PROC_UNLOCK(p); 1515 SIG2OSIG(pending, td->td_retval[0]); 1516 return (0); 1517 } 1518 #endif /* COMPAT_43 */ 1519 1520 #if defined(COMPAT_43) 1521 /* 1522 * Generalized interface signal handler, 4.3-compatible. 1523 */ 1524 #ifndef _SYS_SYSPROTO_H_ 1525 struct osigvec_args { 1526 int signum; 1527 struct sigvec *nsv; 1528 struct sigvec *osv; 1529 }; 1530 #endif 1531 /* ARGSUSED */ 1532 int 1533 osigvec(struct thread *td, struct osigvec_args *uap) 1534 { 1535 struct sigvec vec; 1536 struct sigaction nsa, osa; 1537 struct sigaction *nsap, *osap; 1538 int error; 1539 1540 if (uap->signum <= 0 || uap->signum >= ONSIG) 1541 return (EINVAL); 1542 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1543 osap = (uap->osv != NULL) ? &osa : NULL; 1544 if (nsap) { 1545 error = copyin(uap->nsv, &vec, sizeof(vec)); 1546 if (error) 1547 return (error); 1548 nsap->sa_handler = vec.sv_handler; 1549 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1550 nsap->sa_flags = vec.sv_flags; 1551 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1552 } 1553 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1554 if (osap && !error) { 1555 vec.sv_handler = osap->sa_handler; 1556 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1557 vec.sv_flags = osap->sa_flags; 1558 vec.sv_flags &= ~SA_NOCLDWAIT; 1559 vec.sv_flags ^= SA_RESTART; 1560 error = copyout(&vec, uap->osv, sizeof(vec)); 1561 } 1562 return (error); 1563 } 1564 1565 #ifndef _SYS_SYSPROTO_H_ 1566 struct osigblock_args { 1567 int mask; 1568 }; 1569 #endif 1570 int 1571 osigblock(struct thread *td, struct osigblock_args *uap) 1572 { 1573 sigset_t set, oset; 1574 1575 OSIG2SIG(uap->mask, set); 1576 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1577 SIG2OSIG(oset, td->td_retval[0]); 1578 return (0); 1579 } 1580 1581 #ifndef _SYS_SYSPROTO_H_ 1582 struct osigsetmask_args { 1583 int mask; 1584 }; 1585 #endif 1586 int 1587 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1588 { 1589 sigset_t set, oset; 1590 1591 OSIG2SIG(uap->mask, set); 1592 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1593 SIG2OSIG(oset, td->td_retval[0]); 1594 return (0); 1595 } 1596 #endif /* COMPAT_43 */ 1597 1598 /* 1599 * Suspend calling thread until signal, providing mask to be set in the 1600 * meantime. 1601 */ 1602 #ifndef _SYS_SYSPROTO_H_ 1603 struct sigsuspend_args { 1604 const sigset_t *sigmask; 1605 }; 1606 #endif 1607 /* ARGSUSED */ 1608 int 1609 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1610 { 1611 sigset_t mask; 1612 int error; 1613 1614 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1615 if (error) 1616 return (error); 1617 return (kern_sigsuspend(td, mask)); 1618 } 1619 1620 int 1621 kern_sigsuspend(struct thread *td, sigset_t mask) 1622 { 1623 struct proc *p = td->td_proc; 1624 int has_sig, sig; 1625 1626 /* Ensure the sigfastblock value is up to date. */ 1627 sigfastblock_fetch(td); 1628 1629 /* 1630 * When returning from sigsuspend, we want 1631 * the old mask to be restored after the 1632 * signal handler has finished. Thus, we 1633 * save it here and mark the sigacts structure 1634 * to indicate this. 1635 */ 1636 PROC_LOCK(p); 1637 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1638 SIGPROCMASK_PROC_LOCKED); 1639 td->td_pflags |= TDP_OLDMASK; 1640 ast_sched(td, TDA_SIGSUSPEND); 1641 1642 /* 1643 * Process signals now. Otherwise, we can get spurious wakeup 1644 * due to signal entered process queue, but delivered to other 1645 * thread. But sigsuspend should return only on signal 1646 * delivery. 1647 */ 1648 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1649 for (has_sig = 0; !has_sig;) { 1650 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1651 0) == 0) 1652 /* void */; 1653 thread_suspend_check(0); 1654 mtx_lock(&p->p_sigacts->ps_mtx); 1655 while ((sig = cursig(td)) != 0) { 1656 KASSERT(sig >= 0, ("sig %d", sig)); 1657 has_sig += postsig(sig); 1658 } 1659 mtx_unlock(&p->p_sigacts->ps_mtx); 1660 1661 /* 1662 * If PTRACE_SCE or PTRACE_SCX were set after 1663 * userspace entered the syscall, return spurious 1664 * EINTR. 1665 */ 1666 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1667 has_sig += 1; 1668 } 1669 PROC_UNLOCK(p); 1670 td->td_errno = EINTR; 1671 td->td_pflags |= TDP_NERRNO; 1672 return (EJUSTRETURN); 1673 } 1674 1675 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1676 /* 1677 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1678 * convention: libc stub passes mask, not pointer, to save a copyin. 1679 */ 1680 #ifndef _SYS_SYSPROTO_H_ 1681 struct osigsuspend_args { 1682 osigset_t mask; 1683 }; 1684 #endif 1685 /* ARGSUSED */ 1686 int 1687 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1688 { 1689 sigset_t mask; 1690 1691 OSIG2SIG(uap->mask, mask); 1692 return (kern_sigsuspend(td, mask)); 1693 } 1694 #endif /* COMPAT_43 */ 1695 1696 #if defined(COMPAT_43) 1697 #ifndef _SYS_SYSPROTO_H_ 1698 struct osigstack_args { 1699 struct sigstack *nss; 1700 struct sigstack *oss; 1701 }; 1702 #endif 1703 /* ARGSUSED */ 1704 int 1705 osigstack(struct thread *td, struct osigstack_args *uap) 1706 { 1707 struct sigstack nss, oss; 1708 int error = 0; 1709 1710 if (uap->nss != NULL) { 1711 error = copyin(uap->nss, &nss, sizeof(nss)); 1712 if (error) 1713 return (error); 1714 } 1715 oss.ss_sp = td->td_sigstk.ss_sp; 1716 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1717 if (uap->nss != NULL) { 1718 td->td_sigstk.ss_sp = nss.ss_sp; 1719 td->td_sigstk.ss_size = 0; 1720 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1721 td->td_pflags |= TDP_ALTSTACK; 1722 } 1723 if (uap->oss != NULL) 1724 error = copyout(&oss, uap->oss, sizeof(oss)); 1725 1726 return (error); 1727 } 1728 #endif /* COMPAT_43 */ 1729 1730 #ifndef _SYS_SYSPROTO_H_ 1731 struct sigaltstack_args { 1732 stack_t *ss; 1733 stack_t *oss; 1734 }; 1735 #endif 1736 /* ARGSUSED */ 1737 int 1738 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1739 { 1740 stack_t ss, oss; 1741 int error; 1742 1743 if (uap->ss != NULL) { 1744 error = copyin(uap->ss, &ss, sizeof(ss)); 1745 if (error) 1746 return (error); 1747 } 1748 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1749 (uap->oss != NULL) ? &oss : NULL); 1750 if (error) 1751 return (error); 1752 if (uap->oss != NULL) 1753 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1754 return (error); 1755 } 1756 1757 int 1758 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1759 { 1760 struct proc *p = td->td_proc; 1761 int oonstack; 1762 1763 oonstack = sigonstack(cpu_getstack(td)); 1764 1765 if (oss != NULL) { 1766 *oss = td->td_sigstk; 1767 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1768 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1769 } 1770 1771 if (ss != NULL) { 1772 if (oonstack) 1773 return (EPERM); 1774 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1775 return (EINVAL); 1776 if (!(ss->ss_flags & SS_DISABLE)) { 1777 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1778 return (ENOMEM); 1779 1780 td->td_sigstk = *ss; 1781 td->td_pflags |= TDP_ALTSTACK; 1782 } else { 1783 td->td_pflags &= ~TDP_ALTSTACK; 1784 } 1785 } 1786 return (0); 1787 } 1788 1789 struct killpg1_ctx { 1790 struct thread *td; 1791 ksiginfo_t *ksi; 1792 int sig; 1793 bool sent; 1794 bool found; 1795 int ret; 1796 }; 1797 1798 static void 1799 killpg1_sendsig_locked(struct proc *p, struct killpg1_ctx *arg) 1800 { 1801 int err; 1802 1803 err = p_cansignal(arg->td, p, arg->sig); 1804 if (err == 0 && arg->sig != 0) 1805 pksignal(p, arg->sig, arg->ksi); 1806 if (err != ESRCH) 1807 arg->found = true; 1808 if (err == 0) 1809 arg->sent = true; 1810 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1811 arg->ret = err; 1812 } 1813 1814 static void 1815 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1816 { 1817 1818 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1819 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1820 return; 1821 1822 PROC_LOCK(p); 1823 killpg1_sendsig_locked(p, arg); 1824 PROC_UNLOCK(p); 1825 } 1826 1827 static void 1828 kill_processes_prison_cb(struct proc *p, void *arg) 1829 { 1830 struct killpg1_ctx *ctx = arg; 1831 1832 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1833 (p == ctx->td->td_proc) || p->p_state == PRS_NEW) 1834 return; 1835 1836 killpg1_sendsig_locked(p, ctx); 1837 } 1838 1839 /* 1840 * Common code for kill process group/broadcast kill. 1841 * td is the calling thread, as usual. 1842 */ 1843 static int 1844 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1845 { 1846 struct proc *p; 1847 struct pgrp *pgrp; 1848 struct killpg1_ctx arg; 1849 1850 arg.td = td; 1851 arg.ksi = ksi; 1852 arg.sig = sig; 1853 arg.sent = false; 1854 arg.found = false; 1855 arg.ret = 0; 1856 if (all) { 1857 /* 1858 * broadcast 1859 */ 1860 prison_proc_iterate(td->td_ucred->cr_prison, 1861 kill_processes_prison_cb, &arg); 1862 } else { 1863 again: 1864 sx_slock(&proctree_lock); 1865 if (pgid == 0) { 1866 /* 1867 * zero pgid means send to my process group. 1868 */ 1869 pgrp = td->td_proc->p_pgrp; 1870 PGRP_LOCK(pgrp); 1871 } else { 1872 pgrp = pgfind(pgid); 1873 if (pgrp == NULL) { 1874 sx_sunlock(&proctree_lock); 1875 return (ESRCH); 1876 } 1877 } 1878 sx_sunlock(&proctree_lock); 1879 if (!sx_try_xlock(&pgrp->pg_killsx)) { 1880 PGRP_UNLOCK(pgrp); 1881 sx_xlock(&pgrp->pg_killsx); 1882 sx_xunlock(&pgrp->pg_killsx); 1883 goto again; 1884 } 1885 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1886 killpg1_sendsig(p, false, &arg); 1887 } 1888 PGRP_UNLOCK(pgrp); 1889 sx_xunlock(&pgrp->pg_killsx); 1890 } 1891 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1892 if (arg.ret == 0 && !arg.sent) 1893 arg.ret = arg.found ? EPERM : ESRCH; 1894 return (arg.ret); 1895 } 1896 1897 #ifndef _SYS_SYSPROTO_H_ 1898 struct kill_args { 1899 int pid; 1900 int signum; 1901 }; 1902 #endif 1903 /* ARGSUSED */ 1904 int 1905 sys_kill(struct thread *td, struct kill_args *uap) 1906 { 1907 1908 return (kern_kill(td, uap->pid, uap->signum)); 1909 } 1910 1911 int 1912 kern_kill(struct thread *td, pid_t pid, int signum) 1913 { 1914 ksiginfo_t ksi; 1915 struct proc *p; 1916 int error; 1917 1918 /* 1919 * A process in capability mode can send signals only to himself. 1920 * The main rationale behind this is that abort(3) is implemented as 1921 * kill(getpid(), SIGABRT). 1922 */ 1923 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1924 return (ECAPMODE); 1925 1926 AUDIT_ARG_SIGNUM(signum); 1927 AUDIT_ARG_PID(pid); 1928 if ((u_int)signum > _SIG_MAXSIG) 1929 return (EINVAL); 1930 1931 ksiginfo_init(&ksi); 1932 ksi.ksi_signo = signum; 1933 ksi.ksi_code = SI_USER; 1934 ksi.ksi_pid = td->td_proc->p_pid; 1935 ksi.ksi_uid = td->td_ucred->cr_ruid; 1936 1937 if (pid > 0) { 1938 /* kill single process */ 1939 if ((p = pfind_any(pid)) == NULL) 1940 return (ESRCH); 1941 AUDIT_ARG_PROCESS(p); 1942 error = p_cansignal(td, p, signum); 1943 if (error == 0 && signum) 1944 pksignal(p, signum, &ksi); 1945 PROC_UNLOCK(p); 1946 return (error); 1947 } 1948 switch (pid) { 1949 case -1: /* broadcast signal */ 1950 return (killpg1(td, signum, 0, 1, &ksi)); 1951 case 0: /* signal own process group */ 1952 ksi.ksi_flags |= KSI_KILLPG; 1953 return (killpg1(td, signum, 0, 0, &ksi)); 1954 default: /* negative explicit process group */ 1955 ksi.ksi_flags |= KSI_KILLPG; 1956 return (killpg1(td, signum, -pid, 0, &ksi)); 1957 } 1958 /* NOTREACHED */ 1959 } 1960 1961 int 1962 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1963 { 1964 struct proc *p; 1965 int error; 1966 1967 AUDIT_ARG_SIGNUM(uap->signum); 1968 AUDIT_ARG_FD(uap->fd); 1969 if ((u_int)uap->signum > _SIG_MAXSIG) 1970 return (EINVAL); 1971 1972 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1973 if (error) 1974 return (error); 1975 AUDIT_ARG_PROCESS(p); 1976 error = p_cansignal(td, p, uap->signum); 1977 if (error == 0 && uap->signum) 1978 kern_psignal(p, uap->signum); 1979 PROC_UNLOCK(p); 1980 return (error); 1981 } 1982 1983 #if defined(COMPAT_43) 1984 #ifndef _SYS_SYSPROTO_H_ 1985 struct okillpg_args { 1986 int pgid; 1987 int signum; 1988 }; 1989 #endif 1990 /* ARGSUSED */ 1991 int 1992 okillpg(struct thread *td, struct okillpg_args *uap) 1993 { 1994 ksiginfo_t ksi; 1995 1996 AUDIT_ARG_SIGNUM(uap->signum); 1997 AUDIT_ARG_PID(uap->pgid); 1998 if ((u_int)uap->signum > _SIG_MAXSIG) 1999 return (EINVAL); 2000 2001 ksiginfo_init(&ksi); 2002 ksi.ksi_signo = uap->signum; 2003 ksi.ksi_code = SI_USER; 2004 ksi.ksi_pid = td->td_proc->p_pid; 2005 ksi.ksi_uid = td->td_ucred->cr_ruid; 2006 ksi.ksi_flags |= KSI_KILLPG; 2007 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 2008 } 2009 #endif /* COMPAT_43 */ 2010 2011 #ifndef _SYS_SYSPROTO_H_ 2012 struct sigqueue_args { 2013 pid_t pid; 2014 int signum; 2015 /* union sigval */ void *value; 2016 }; 2017 #endif 2018 int 2019 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 2020 { 2021 union sigval sv; 2022 2023 sv.sival_ptr = uap->value; 2024 2025 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 2026 } 2027 2028 int 2029 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 2030 { 2031 ksiginfo_t ksi; 2032 struct proc *p; 2033 int error; 2034 2035 if ((u_int)signum > _SIG_MAXSIG) 2036 return (EINVAL); 2037 2038 /* 2039 * Specification says sigqueue can only send signal to 2040 * single process. 2041 */ 2042 if (pid <= 0) 2043 return (EINVAL); 2044 2045 if ((p = pfind_any(pid)) == NULL) 2046 return (ESRCH); 2047 error = p_cansignal(td, p, signum); 2048 if (error == 0 && signum != 0) { 2049 ksiginfo_init(&ksi); 2050 ksi.ksi_flags = KSI_SIGQ; 2051 ksi.ksi_signo = signum; 2052 ksi.ksi_code = SI_QUEUE; 2053 ksi.ksi_pid = td->td_proc->p_pid; 2054 ksi.ksi_uid = td->td_ucred->cr_ruid; 2055 ksi.ksi_value = *value; 2056 error = pksignal(p, ksi.ksi_signo, &ksi); 2057 } 2058 PROC_UNLOCK(p); 2059 return (error); 2060 } 2061 2062 /* 2063 * Send a signal to a process group. 2064 */ 2065 void 2066 gsignal(int pgid, int sig, ksiginfo_t *ksi) 2067 { 2068 struct pgrp *pgrp; 2069 2070 if (pgid != 0) { 2071 sx_slock(&proctree_lock); 2072 pgrp = pgfind(pgid); 2073 sx_sunlock(&proctree_lock); 2074 if (pgrp != NULL) { 2075 pgsignal(pgrp, sig, 0, ksi); 2076 PGRP_UNLOCK(pgrp); 2077 } 2078 } 2079 } 2080 2081 /* 2082 * Send a signal to a process group. If checktty is 1, 2083 * limit to members which have a controlling terminal. 2084 */ 2085 void 2086 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 2087 { 2088 struct proc *p; 2089 2090 if (pgrp) { 2091 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 2092 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 2093 PROC_LOCK(p); 2094 if (p->p_state == PRS_NORMAL && 2095 (checkctty == 0 || p->p_flag & P_CONTROLT)) 2096 pksignal(p, sig, ksi); 2097 PROC_UNLOCK(p); 2098 } 2099 } 2100 } 2101 2102 /* 2103 * Recalculate the signal mask and reset the signal disposition after 2104 * usermode frame for delivery is formed. Should be called after 2105 * mach-specific routine, because sysent->sv_sendsig() needs correct 2106 * ps_siginfo and signal mask. 2107 */ 2108 static void 2109 postsig_done(int sig, struct thread *td, struct sigacts *ps) 2110 { 2111 sigset_t mask; 2112 2113 mtx_assert(&ps->ps_mtx, MA_OWNED); 2114 td->td_ru.ru_nsignals++; 2115 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2116 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2117 SIGADDSET(mask, sig); 2118 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2119 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2120 if (SIGISMEMBER(ps->ps_sigreset, sig)) 2121 sigdflt(ps, sig); 2122 } 2123 2124 /* 2125 * Send a signal caused by a trap to the current thread. If it will be 2126 * caught immediately, deliver it with correct code. Otherwise, post it 2127 * normally. 2128 */ 2129 void 2130 trapsignal(struct thread *td, ksiginfo_t *ksi) 2131 { 2132 struct sigacts *ps; 2133 struct proc *p; 2134 sigset_t sigmask; 2135 int sig; 2136 2137 p = td->td_proc; 2138 sig = ksi->ksi_signo; 2139 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2140 2141 sigfastblock_fetch(td); 2142 PROC_LOCK(p); 2143 ps = p->p_sigacts; 2144 mtx_lock(&ps->ps_mtx); 2145 sigmask = td->td_sigmask; 2146 if (td->td_sigblock_val != 0) 2147 SIGSETOR(sigmask, fastblock_mask); 2148 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2149 !SIGISMEMBER(sigmask, sig)) { 2150 #ifdef KTRACE 2151 if (KTRPOINT(curthread, KTR_PSIG)) 2152 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2153 &td->td_sigmask, ksi->ksi_code); 2154 #endif 2155 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2156 ksi, &td->td_sigmask); 2157 postsig_done(sig, td, ps); 2158 mtx_unlock(&ps->ps_mtx); 2159 } else { 2160 /* 2161 * Avoid a possible infinite loop if the thread 2162 * masking the signal or process is ignoring the 2163 * signal. 2164 */ 2165 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2166 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2167 SIGDELSET(td->td_sigmask, sig); 2168 SIGDELSET(ps->ps_sigcatch, sig); 2169 SIGDELSET(ps->ps_sigignore, sig); 2170 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2171 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2172 td->td_sigblock_val = 0; 2173 } 2174 mtx_unlock(&ps->ps_mtx); 2175 p->p_sig = sig; /* XXX to verify code */ 2176 tdsendsignal(p, td, sig, ksi); 2177 } 2178 PROC_UNLOCK(p); 2179 } 2180 2181 static struct thread * 2182 sigtd(struct proc *p, int sig, bool fast_sigblock) 2183 { 2184 struct thread *td, *signal_td; 2185 2186 PROC_LOCK_ASSERT(p, MA_OWNED); 2187 MPASS(!fast_sigblock || p == curproc); 2188 2189 /* 2190 * Check if current thread can handle the signal without 2191 * switching context to another thread. 2192 */ 2193 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2194 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2195 return (curthread); 2196 signal_td = NULL; 2197 FOREACH_THREAD_IN_PROC(p, td) { 2198 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2199 td != curthread || td->td_sigblock_val == 0)) { 2200 signal_td = td; 2201 break; 2202 } 2203 } 2204 if (signal_td == NULL) 2205 signal_td = FIRST_THREAD_IN_PROC(p); 2206 return (signal_td); 2207 } 2208 2209 /* 2210 * Send the signal to the process. If the signal has an action, the action 2211 * is usually performed by the target process rather than the caller; we add 2212 * the signal to the set of pending signals for the process. 2213 * 2214 * Exceptions: 2215 * o When a stop signal is sent to a sleeping process that takes the 2216 * default action, the process is stopped without awakening it. 2217 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2218 * regardless of the signal action (eg, blocked or ignored). 2219 * 2220 * Other ignored signals are discarded immediately. 2221 * 2222 * NB: This function may be entered from the debugger via the "kill" DDB 2223 * command. There is little that can be done to mitigate the possibly messy 2224 * side effects of this unwise possibility. 2225 */ 2226 void 2227 kern_psignal(struct proc *p, int sig) 2228 { 2229 ksiginfo_t ksi; 2230 2231 ksiginfo_init(&ksi); 2232 ksi.ksi_signo = sig; 2233 ksi.ksi_code = SI_KERNEL; 2234 (void) tdsendsignal(p, NULL, sig, &ksi); 2235 } 2236 2237 int 2238 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2239 { 2240 2241 return (tdsendsignal(p, NULL, sig, ksi)); 2242 } 2243 2244 /* Utility function for finding a thread to send signal event to. */ 2245 int 2246 sigev_findtd(struct proc *p, struct sigevent *sigev, struct thread **ttd) 2247 { 2248 struct thread *td; 2249 2250 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2251 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2252 if (td == NULL) 2253 return (ESRCH); 2254 *ttd = td; 2255 } else { 2256 *ttd = NULL; 2257 PROC_LOCK(p); 2258 } 2259 return (0); 2260 } 2261 2262 void 2263 tdsignal(struct thread *td, int sig) 2264 { 2265 ksiginfo_t ksi; 2266 2267 ksiginfo_init(&ksi); 2268 ksi.ksi_signo = sig; 2269 ksi.ksi_code = SI_KERNEL; 2270 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2271 } 2272 2273 void 2274 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2275 { 2276 2277 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2278 } 2279 2280 static int 2281 sig_sleepq_abort(struct thread *td, int intrval) 2282 { 2283 THREAD_LOCK_ASSERT(td, MA_OWNED); 2284 2285 if (intrval == 0 && (td->td_flags & TDF_SIGWAIT) == 0) { 2286 thread_unlock(td); 2287 return (0); 2288 } 2289 return (sleepq_abort(td, intrval)); 2290 } 2291 2292 int 2293 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2294 { 2295 sig_t action; 2296 sigqueue_t *sigqueue; 2297 int prop; 2298 struct sigacts *ps; 2299 int intrval; 2300 int ret = 0; 2301 int wakeup_swapper; 2302 2303 MPASS(td == NULL || p == td->td_proc); 2304 PROC_LOCK_ASSERT(p, MA_OWNED); 2305 2306 if (!_SIG_VALID(sig)) 2307 panic("%s(): invalid signal %d", __func__, sig); 2308 2309 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2310 2311 /* 2312 * IEEE Std 1003.1-2001: return success when killing a zombie. 2313 */ 2314 if (p->p_state == PRS_ZOMBIE) { 2315 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2316 ksiginfo_tryfree(ksi); 2317 return (ret); 2318 } 2319 2320 ps = p->p_sigacts; 2321 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2322 prop = sigprop(sig); 2323 2324 if (td == NULL) { 2325 td = sigtd(p, sig, false); 2326 sigqueue = &p->p_sigqueue; 2327 } else 2328 sigqueue = &td->td_sigqueue; 2329 2330 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2331 2332 /* 2333 * If the signal is being ignored, then we forget about it 2334 * immediately, except when the target process executes 2335 * sigwait(). (Note: we don't set SIGCONT in ps_sigignore, 2336 * and if it is set to SIG_IGN, action will be SIG_DFL here.) 2337 */ 2338 mtx_lock(&ps->ps_mtx); 2339 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2340 if (kern_sig_discard_ign && 2341 (p->p_sysent->sv_flags & SV_SIG_DISCIGN) == 0) { 2342 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2343 2344 mtx_unlock(&ps->ps_mtx); 2345 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2346 ksiginfo_tryfree(ksi); 2347 return (ret); 2348 } else { 2349 action = SIG_CATCH; 2350 intrval = 0; 2351 } 2352 } else { 2353 if (SIGISMEMBER(td->td_sigmask, sig)) 2354 action = SIG_HOLD; 2355 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2356 action = SIG_CATCH; 2357 else 2358 action = SIG_DFL; 2359 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2360 intrval = EINTR; 2361 else 2362 intrval = ERESTART; 2363 } 2364 mtx_unlock(&ps->ps_mtx); 2365 2366 if (prop & SIGPROP_CONT) 2367 sigqueue_delete_stopmask_proc(p); 2368 else if (prop & SIGPROP_STOP) { 2369 /* 2370 * If sending a tty stop signal to a member of an orphaned 2371 * process group, discard the signal here if the action 2372 * is default; don't stop the process below if sleeping, 2373 * and don't clear any pending SIGCONT. 2374 */ 2375 if ((prop & SIGPROP_TTYSTOP) != 0 && 2376 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2377 action == SIG_DFL) { 2378 if (ksi != NULL && (ksi->ksi_flags & KSI_INS) != 0) 2379 ksiginfo_tryfree(ksi); 2380 return (ret); 2381 } 2382 sigqueue_delete_proc(p, SIGCONT); 2383 if (p->p_flag & P_CONTINUED) { 2384 p->p_flag &= ~P_CONTINUED; 2385 PROC_LOCK(p->p_pptr); 2386 sigqueue_take(p->p_ksi); 2387 PROC_UNLOCK(p->p_pptr); 2388 } 2389 } 2390 2391 ret = sigqueue_add(sigqueue, sig, ksi); 2392 if (ret != 0) 2393 return (ret); 2394 if ((ksi->ksi_flags & KSI_KILLPG) != 0) { 2395 sx_assert(&p->p_pgrp->pg_killsx, SX_XLOCKED); 2396 atomic_add_int(&p->p_killpg_cnt, 1); 2397 } 2398 signotify(td); 2399 /* 2400 * Defer further processing for signals which are held, 2401 * except that stopped processes must be continued by SIGCONT. 2402 */ 2403 if (action == SIG_HOLD && 2404 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2405 return (ret); 2406 2407 wakeup_swapper = 0; 2408 2409 /* 2410 * Some signals have a process-wide effect and a per-thread 2411 * component. Most processing occurs when the process next 2412 * tries to cross the user boundary, however there are some 2413 * times when processing needs to be done immediately, such as 2414 * waking up threads so that they can cross the user boundary. 2415 * We try to do the per-process part here. 2416 */ 2417 if (P_SHOULDSTOP(p)) { 2418 KASSERT(!(p->p_flag & P_WEXIT), 2419 ("signal to stopped but exiting process")); 2420 if (sig == SIGKILL) { 2421 /* 2422 * If traced process is already stopped, 2423 * then no further action is necessary. 2424 */ 2425 if (p->p_flag & P_TRACED) 2426 goto out; 2427 /* 2428 * SIGKILL sets process running. 2429 * It will die elsewhere. 2430 * All threads must be restarted. 2431 */ 2432 p->p_flag &= ~P_STOPPED_SIG; 2433 goto runfast; 2434 } 2435 2436 if (prop & SIGPROP_CONT) { 2437 /* 2438 * If traced process is already stopped, 2439 * then no further action is necessary. 2440 */ 2441 if (p->p_flag & P_TRACED) 2442 goto out; 2443 /* 2444 * If SIGCONT is default (or ignored), we continue the 2445 * process but don't leave the signal in sigqueue as 2446 * it has no further action. If SIGCONT is held, we 2447 * continue the process and leave the signal in 2448 * sigqueue. If the process catches SIGCONT, let it 2449 * handle the signal itself. If it isn't waiting on 2450 * an event, it goes back to run state. 2451 * Otherwise, process goes back to sleep state. 2452 */ 2453 p->p_flag &= ~P_STOPPED_SIG; 2454 PROC_SLOCK(p); 2455 if (p->p_numthreads == p->p_suspcount) { 2456 PROC_SUNLOCK(p); 2457 p->p_flag |= P_CONTINUED; 2458 p->p_xsig = SIGCONT; 2459 PROC_LOCK(p->p_pptr); 2460 childproc_continued(p); 2461 PROC_UNLOCK(p->p_pptr); 2462 PROC_SLOCK(p); 2463 } 2464 if (action == SIG_DFL) { 2465 thread_unsuspend(p); 2466 PROC_SUNLOCK(p); 2467 sigqueue_delete(sigqueue, sig); 2468 goto out_cont; 2469 } 2470 if (action == SIG_CATCH) { 2471 /* 2472 * The process wants to catch it so it needs 2473 * to run at least one thread, but which one? 2474 */ 2475 PROC_SUNLOCK(p); 2476 goto runfast; 2477 } 2478 /* 2479 * The signal is not ignored or caught. 2480 */ 2481 thread_unsuspend(p); 2482 PROC_SUNLOCK(p); 2483 goto out_cont; 2484 } 2485 2486 if (prop & SIGPROP_STOP) { 2487 /* 2488 * If traced process is already stopped, 2489 * then no further action is necessary. 2490 */ 2491 if (p->p_flag & P_TRACED) 2492 goto out; 2493 /* 2494 * Already stopped, don't need to stop again 2495 * (If we did the shell could get confused). 2496 * Just make sure the signal STOP bit set. 2497 */ 2498 p->p_flag |= P_STOPPED_SIG; 2499 sigqueue_delete(sigqueue, sig); 2500 goto out; 2501 } 2502 2503 /* 2504 * All other kinds of signals: 2505 * If a thread is sleeping interruptibly, simulate a 2506 * wakeup so that when it is continued it will be made 2507 * runnable and can look at the signal. However, don't make 2508 * the PROCESS runnable, leave it stopped. 2509 * It may run a bit until it hits a thread_suspend_check(). 2510 */ 2511 PROC_SLOCK(p); 2512 thread_lock(td); 2513 if (TD_CAN_ABORT(td)) 2514 wakeup_swapper = sig_sleepq_abort(td, intrval); 2515 else 2516 thread_unlock(td); 2517 PROC_SUNLOCK(p); 2518 goto out; 2519 /* 2520 * Mutexes are short lived. Threads waiting on them will 2521 * hit thread_suspend_check() soon. 2522 */ 2523 } else if (p->p_state == PRS_NORMAL) { 2524 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2525 tdsigwakeup(td, sig, action, intrval); 2526 goto out; 2527 } 2528 2529 MPASS(action == SIG_DFL); 2530 2531 if (prop & SIGPROP_STOP) { 2532 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2533 goto out; 2534 p->p_flag |= P_STOPPED_SIG; 2535 p->p_xsig = sig; 2536 PROC_SLOCK(p); 2537 wakeup_swapper = sig_suspend_threads(td, p); 2538 if (p->p_numthreads == p->p_suspcount) { 2539 /* 2540 * only thread sending signal to another 2541 * process can reach here, if thread is sending 2542 * signal to its process, because thread does 2543 * not suspend itself here, p_numthreads 2544 * should never be equal to p_suspcount. 2545 */ 2546 thread_stopped(p); 2547 PROC_SUNLOCK(p); 2548 sigqueue_delete_proc(p, p->p_xsig); 2549 } else 2550 PROC_SUNLOCK(p); 2551 goto out; 2552 } 2553 } else { 2554 /* Not in "NORMAL" state. discard the signal. */ 2555 sigqueue_delete(sigqueue, sig); 2556 goto out; 2557 } 2558 2559 /* 2560 * The process is not stopped so we need to apply the signal to all the 2561 * running threads. 2562 */ 2563 runfast: 2564 tdsigwakeup(td, sig, action, intrval); 2565 PROC_SLOCK(p); 2566 thread_unsuspend(p); 2567 PROC_SUNLOCK(p); 2568 out_cont: 2569 itimer_proc_continue(p); 2570 kqtimer_proc_continue(p); 2571 out: 2572 /* If we jump here, proc slock should not be owned. */ 2573 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2574 if (wakeup_swapper) 2575 kick_proc0(); 2576 2577 return (ret); 2578 } 2579 2580 /* 2581 * The force of a signal has been directed against a single 2582 * thread. We need to see what we can do about knocking it 2583 * out of any sleep it may be in etc. 2584 */ 2585 static void 2586 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2587 { 2588 struct proc *p = td->td_proc; 2589 int prop, wakeup_swapper; 2590 2591 PROC_LOCK_ASSERT(p, MA_OWNED); 2592 prop = sigprop(sig); 2593 2594 PROC_SLOCK(p); 2595 thread_lock(td); 2596 /* 2597 * Bring the priority of a thread up if we want it to get 2598 * killed in this lifetime. Be careful to avoid bumping the 2599 * priority of the idle thread, since we still allow to signal 2600 * kernel processes. 2601 */ 2602 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2603 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2604 sched_prio(td, PUSER); 2605 if (TD_ON_SLEEPQ(td)) { 2606 /* 2607 * If thread is sleeping uninterruptibly 2608 * we can't interrupt the sleep... the signal will 2609 * be noticed when the process returns through 2610 * trap() or syscall(). 2611 */ 2612 if ((td->td_flags & TDF_SINTR) == 0) 2613 goto out; 2614 /* 2615 * If SIGCONT is default (or ignored) and process is 2616 * asleep, we are finished; the process should not 2617 * be awakened. 2618 */ 2619 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2620 thread_unlock(td); 2621 PROC_SUNLOCK(p); 2622 sigqueue_delete(&p->p_sigqueue, sig); 2623 /* 2624 * It may be on either list in this state. 2625 * Remove from both for now. 2626 */ 2627 sigqueue_delete(&td->td_sigqueue, sig); 2628 return; 2629 } 2630 2631 /* 2632 * Don't awaken a sleeping thread for SIGSTOP if the 2633 * STOP signal is deferred. 2634 */ 2635 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2636 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2637 goto out; 2638 2639 /* 2640 * Give low priority threads a better chance to run. 2641 */ 2642 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2643 sched_prio(td, PUSER); 2644 2645 wakeup_swapper = sig_sleepq_abort(td, intrval); 2646 PROC_SUNLOCK(p); 2647 if (wakeup_swapper) 2648 kick_proc0(); 2649 return; 2650 } 2651 2652 /* 2653 * Other states do nothing with the signal immediately, 2654 * other than kicking ourselves if we are running. 2655 * It will either never be noticed, or noticed very soon. 2656 */ 2657 #ifdef SMP 2658 if (TD_IS_RUNNING(td) && td != curthread) 2659 forward_signal(td); 2660 #endif 2661 2662 out: 2663 PROC_SUNLOCK(p); 2664 thread_unlock(td); 2665 } 2666 2667 static void 2668 ptrace_coredumpreq(struct thread *td, struct proc *p, 2669 struct thr_coredump_req *tcq) 2670 { 2671 void *rl_cookie; 2672 2673 if (p->p_sysent->sv_coredump == NULL) { 2674 tcq->tc_error = ENOSYS; 2675 return; 2676 } 2677 2678 rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX); 2679 tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp, 2680 tcq->tc_limit, tcq->tc_flags); 2681 vn_rangelock_unlock(tcq->tc_vp, rl_cookie); 2682 } 2683 2684 static void 2685 ptrace_syscallreq(struct thread *td, struct proc *p, 2686 struct thr_syscall_req *tsr) 2687 { 2688 struct sysentvec *sv; 2689 struct sysent *se; 2690 register_t rv_saved[2]; 2691 int error, nerror; 2692 int sc; 2693 bool audited, sy_thr_static; 2694 2695 sv = p->p_sysent; 2696 if (sv->sv_table == NULL || sv->sv_size < tsr->ts_sa.code) { 2697 tsr->ts_ret.sr_error = ENOSYS; 2698 return; 2699 } 2700 2701 sc = tsr->ts_sa.code; 2702 if (sc == SYS_syscall || sc == SYS___syscall) { 2703 sc = tsr->ts_sa.args[0]; 2704 memmove(&tsr->ts_sa.args[0], &tsr->ts_sa.args[1], 2705 sizeof(register_t) * (tsr->ts_nargs - 1)); 2706 } 2707 2708 tsr->ts_sa.callp = se = &sv->sv_table[sc]; 2709 2710 VM_CNT_INC(v_syscall); 2711 td->td_pticks = 0; 2712 if (__predict_false(td->td_cowgen != atomic_load_int( 2713 &td->td_proc->p_cowgen))) 2714 thread_cow_update(td); 2715 2716 #ifdef CAPABILITY_MODE 2717 if (IN_CAPABILITY_MODE(td) && (se->sy_flags & SYF_CAPENABLED) == 0) { 2718 tsr->ts_ret.sr_error = ECAPMODE; 2719 return; 2720 } 2721 #endif 2722 2723 sy_thr_static = (se->sy_thrcnt & SY_THR_STATIC) != 0; 2724 audited = AUDIT_SYSCALL_ENTER(sc, td) != 0; 2725 2726 if (!sy_thr_static) { 2727 error = syscall_thread_enter(td, se); 2728 if (error != 0) { 2729 tsr->ts_ret.sr_error = error; 2730 return; 2731 } 2732 } 2733 2734 rv_saved[0] = td->td_retval[0]; 2735 rv_saved[1] = td->td_retval[1]; 2736 nerror = td->td_errno; 2737 td->td_retval[0] = 0; 2738 td->td_retval[1] = 0; 2739 2740 #ifdef KDTRACE_HOOKS 2741 if (se->sy_entry != 0) 2742 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_ENTRY, 0); 2743 #endif 2744 tsr->ts_ret.sr_error = se->sy_call(td, tsr->ts_sa.args); 2745 #ifdef KDTRACE_HOOKS 2746 if (se->sy_return != 0) 2747 (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_RETURN, 2748 tsr->ts_ret.sr_error != 0 ? -1 : td->td_retval[0]); 2749 #endif 2750 2751 tsr->ts_ret.sr_retval[0] = td->td_retval[0]; 2752 tsr->ts_ret.sr_retval[1] = td->td_retval[1]; 2753 td->td_retval[0] = rv_saved[0]; 2754 td->td_retval[1] = rv_saved[1]; 2755 td->td_errno = nerror; 2756 2757 if (audited) 2758 AUDIT_SYSCALL_EXIT(error, td); 2759 if (!sy_thr_static) 2760 syscall_thread_exit(td, se); 2761 } 2762 2763 static void 2764 ptrace_remotereq(struct thread *td, int flag) 2765 { 2766 struct proc *p; 2767 2768 MPASS(td == curthread); 2769 p = td->td_proc; 2770 PROC_LOCK_ASSERT(p, MA_OWNED); 2771 if ((td->td_dbgflags & flag) == 0) 2772 return; 2773 KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped")); 2774 KASSERT(td->td_remotereq != NULL, ("td_remotereq is NULL")); 2775 2776 PROC_UNLOCK(p); 2777 switch (flag) { 2778 case TDB_COREDUMPREQ: 2779 ptrace_coredumpreq(td, p, td->td_remotereq); 2780 break; 2781 case TDB_SCREMOTEREQ: 2782 ptrace_syscallreq(td, p, td->td_remotereq); 2783 break; 2784 default: 2785 __unreachable(); 2786 } 2787 PROC_LOCK(p); 2788 2789 MPASS((td->td_dbgflags & flag) != 0); 2790 td->td_dbgflags &= ~flag; 2791 td->td_remotereq = NULL; 2792 wakeup(p); 2793 } 2794 2795 static int 2796 sig_suspend_threads(struct thread *td, struct proc *p) 2797 { 2798 struct thread *td2; 2799 int wakeup_swapper; 2800 2801 PROC_LOCK_ASSERT(p, MA_OWNED); 2802 PROC_SLOCK_ASSERT(p, MA_OWNED); 2803 2804 wakeup_swapper = 0; 2805 FOREACH_THREAD_IN_PROC(p, td2) { 2806 thread_lock(td2); 2807 ast_sched_locked(td2, TDA_SUSPEND); 2808 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2809 (td2->td_flags & TDF_SINTR)) { 2810 if (td2->td_flags & TDF_SBDRY) { 2811 /* 2812 * Once a thread is asleep with 2813 * TDF_SBDRY and without TDF_SERESTART 2814 * or TDF_SEINTR set, it should never 2815 * become suspended due to this check. 2816 */ 2817 KASSERT(!TD_IS_SUSPENDED(td2), 2818 ("thread with deferred stops suspended")); 2819 if (TD_SBDRY_INTR(td2)) { 2820 wakeup_swapper |= sleepq_abort(td2, 2821 TD_SBDRY_ERRNO(td2)); 2822 continue; 2823 } 2824 } else if (!TD_IS_SUSPENDED(td2)) 2825 thread_suspend_one(td2); 2826 } else if (!TD_IS_SUSPENDED(td2)) { 2827 #ifdef SMP 2828 if (TD_IS_RUNNING(td2) && td2 != td) 2829 forward_signal(td2); 2830 #endif 2831 } 2832 thread_unlock(td2); 2833 } 2834 return (wakeup_swapper); 2835 } 2836 2837 /* 2838 * Stop the process for an event deemed interesting to the debugger. If si is 2839 * non-NULL, this is a signal exchange; the new signal requested by the 2840 * debugger will be returned for handling. If si is NULL, this is some other 2841 * type of interesting event. The debugger may request a signal be delivered in 2842 * that case as well, however it will be deferred until it can be handled. 2843 */ 2844 int 2845 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2846 { 2847 struct proc *p = td->td_proc; 2848 struct thread *td2; 2849 ksiginfo_t ksi; 2850 2851 PROC_LOCK_ASSERT(p, MA_OWNED); 2852 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2853 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2854 &p->p_mtx.lock_object, "Stopping for traced signal"); 2855 2856 td->td_xsig = sig; 2857 2858 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2859 td->td_dbgflags |= TDB_XSIG; 2860 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2861 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2862 PROC_SLOCK(p); 2863 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2864 if (P_KILLED(p)) { 2865 /* 2866 * Ensure that, if we've been PT_KILLed, the 2867 * exit status reflects that. Another thread 2868 * may also be in ptracestop(), having just 2869 * received the SIGKILL, but this thread was 2870 * unsuspended first. 2871 */ 2872 td->td_dbgflags &= ~TDB_XSIG; 2873 td->td_xsig = SIGKILL; 2874 p->p_ptevents = 0; 2875 break; 2876 } 2877 if (p->p_flag & P_SINGLE_EXIT && 2878 !(td->td_dbgflags & TDB_EXIT)) { 2879 /* 2880 * Ignore ptrace stops except for thread exit 2881 * events when the process exits. 2882 */ 2883 td->td_dbgflags &= ~TDB_XSIG; 2884 PROC_SUNLOCK(p); 2885 return (0); 2886 } 2887 2888 /* 2889 * Make wait(2) work. Ensure that right after the 2890 * attach, the thread which was decided to become the 2891 * leader of attach gets reported to the waiter. 2892 * Otherwise, just avoid overwriting another thread's 2893 * assignment to p_xthread. If another thread has 2894 * already set p_xthread, the current thread will get 2895 * a chance to report itself upon the next iteration. 2896 */ 2897 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2898 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2899 p->p_xthread == NULL)) { 2900 p->p_xsig = sig; 2901 p->p_xthread = td; 2902 2903 /* 2904 * If we are on sleepqueue already, 2905 * let sleepqueue code decide if it 2906 * needs to go sleep after attach. 2907 */ 2908 if (td->td_wchan == NULL) 2909 td->td_dbgflags &= ~TDB_FSTP; 2910 2911 p->p_flag2 &= ~P2_PTRACE_FSTP; 2912 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2913 sig_suspend_threads(td, p); 2914 } 2915 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2916 td->td_dbgflags &= ~TDB_STOPATFORK; 2917 } 2918 stopme: 2919 td->td_dbgflags |= TDB_SSWITCH; 2920 thread_suspend_switch(td, p); 2921 td->td_dbgflags &= ~TDB_SSWITCH; 2922 if ((td->td_dbgflags & (TDB_COREDUMPREQ | 2923 TDB_SCREMOTEREQ)) != 0) { 2924 MPASS((td->td_dbgflags & (TDB_COREDUMPREQ | 2925 TDB_SCREMOTEREQ)) != 2926 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2927 PROC_SUNLOCK(p); 2928 ptrace_remotereq(td, td->td_dbgflags & 2929 (TDB_COREDUMPREQ | TDB_SCREMOTEREQ)); 2930 PROC_SLOCK(p); 2931 goto stopme; 2932 } 2933 if (p->p_xthread == td) 2934 p->p_xthread = NULL; 2935 if (!(p->p_flag & P_TRACED)) 2936 break; 2937 if (td->td_dbgflags & TDB_SUSPEND) { 2938 if (p->p_flag & P_SINGLE_EXIT) 2939 break; 2940 goto stopme; 2941 } 2942 } 2943 PROC_SUNLOCK(p); 2944 } 2945 2946 if (si != NULL && sig == td->td_xsig) { 2947 /* Parent wants us to take the original signal unchanged. */ 2948 si->ksi_flags |= KSI_HEAD; 2949 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2950 si->ksi_signo = 0; 2951 } else if (td->td_xsig != 0) { 2952 /* 2953 * If parent wants us to take a new signal, then it will leave 2954 * it in td->td_xsig; otherwise we just look for signals again. 2955 */ 2956 ksiginfo_init(&ksi); 2957 ksi.ksi_signo = td->td_xsig; 2958 ksi.ksi_flags |= KSI_PTRACE; 2959 td2 = sigtd(p, td->td_xsig, false); 2960 tdsendsignal(p, td2, td->td_xsig, &ksi); 2961 if (td != td2) 2962 return (0); 2963 } 2964 2965 return (td->td_xsig); 2966 } 2967 2968 static void 2969 reschedule_signals(struct proc *p, sigset_t block, int flags) 2970 { 2971 struct sigacts *ps; 2972 struct thread *td; 2973 int sig; 2974 bool fastblk, pslocked; 2975 2976 PROC_LOCK_ASSERT(p, MA_OWNED); 2977 ps = p->p_sigacts; 2978 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2979 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2980 if (SIGISEMPTY(p->p_siglist)) 2981 return; 2982 SIGSETAND(block, p->p_siglist); 2983 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2984 SIG_FOREACH(sig, &block) { 2985 td = sigtd(p, sig, fastblk); 2986 2987 /* 2988 * If sigtd() selected us despite sigfastblock is 2989 * blocking, do not activate AST or wake us, to avoid 2990 * loop in AST handler. 2991 */ 2992 if (fastblk && td == curthread) 2993 continue; 2994 2995 signotify(td); 2996 if (!pslocked) 2997 mtx_lock(&ps->ps_mtx); 2998 if (p->p_flag & P_TRACED || 2999 (SIGISMEMBER(ps->ps_sigcatch, sig) && 3000 !SIGISMEMBER(td->td_sigmask, sig))) { 3001 tdsigwakeup(td, sig, SIG_CATCH, 3002 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 3003 ERESTART)); 3004 } 3005 if (!pslocked) 3006 mtx_unlock(&ps->ps_mtx); 3007 } 3008 } 3009 3010 void 3011 tdsigcleanup(struct thread *td) 3012 { 3013 struct proc *p; 3014 sigset_t unblocked; 3015 3016 p = td->td_proc; 3017 PROC_LOCK_ASSERT(p, MA_OWNED); 3018 3019 sigqueue_flush(&td->td_sigqueue); 3020 if (p->p_numthreads == 1) 3021 return; 3022 3023 /* 3024 * Since we cannot handle signals, notify signal post code 3025 * about this by filling the sigmask. 3026 * 3027 * Also, if needed, wake up thread(s) that do not block the 3028 * same signals as the exiting thread, since the thread might 3029 * have been selected for delivery and woken up. 3030 */ 3031 SIGFILLSET(unblocked); 3032 SIGSETNAND(unblocked, td->td_sigmask); 3033 SIGFILLSET(td->td_sigmask); 3034 reschedule_signals(p, unblocked, 0); 3035 3036 } 3037 3038 static int 3039 sigdeferstop_curr_flags(int cflags) 3040 { 3041 3042 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 3043 (cflags & TDF_SBDRY) != 0); 3044 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 3045 } 3046 3047 /* 3048 * Defer the delivery of SIGSTOP for the current thread, according to 3049 * the requested mode. Returns previous flags, which must be restored 3050 * by sigallowstop(). 3051 * 3052 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 3053 * cleared by the current thread, which allow the lock-less read-only 3054 * accesses below. 3055 */ 3056 int 3057 sigdeferstop_impl(int mode) 3058 { 3059 struct thread *td; 3060 int cflags, nflags; 3061 3062 td = curthread; 3063 cflags = sigdeferstop_curr_flags(td->td_flags); 3064 switch (mode) { 3065 case SIGDEFERSTOP_NOP: 3066 nflags = cflags; 3067 break; 3068 case SIGDEFERSTOP_OFF: 3069 nflags = 0; 3070 break; 3071 case SIGDEFERSTOP_SILENT: 3072 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 3073 break; 3074 case SIGDEFERSTOP_EINTR: 3075 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 3076 break; 3077 case SIGDEFERSTOP_ERESTART: 3078 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 3079 break; 3080 default: 3081 panic("sigdeferstop: invalid mode %x", mode); 3082 break; 3083 } 3084 if (cflags == nflags) 3085 return (SIGDEFERSTOP_VAL_NCHG); 3086 thread_lock(td); 3087 td->td_flags = (td->td_flags & ~cflags) | nflags; 3088 thread_unlock(td); 3089 return (cflags); 3090 } 3091 3092 /* 3093 * Restores the STOP handling mode, typically permitting the delivery 3094 * of SIGSTOP for the current thread. This does not immediately 3095 * suspend if a stop was posted. Instead, the thread will suspend 3096 * either via ast() or a subsequent interruptible sleep. 3097 */ 3098 void 3099 sigallowstop_impl(int prev) 3100 { 3101 struct thread *td; 3102 int cflags; 3103 3104 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 3105 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 3106 ("sigallowstop: incorrect previous mode %x", prev)); 3107 td = curthread; 3108 cflags = sigdeferstop_curr_flags(td->td_flags); 3109 if (cflags != prev) { 3110 thread_lock(td); 3111 td->td_flags = (td->td_flags & ~cflags) | prev; 3112 thread_unlock(td); 3113 } 3114 } 3115 3116 enum sigstatus { 3117 SIGSTATUS_HANDLE, 3118 SIGSTATUS_HANDLED, 3119 SIGSTATUS_IGNORE, 3120 SIGSTATUS_SBDRY_STOP, 3121 }; 3122 3123 /* 3124 * The thread has signal "sig" pending. Figure out what to do with it: 3125 * 3126 * _HANDLE -> the caller should handle the signal 3127 * _HANDLED -> handled internally, reload pending signal set 3128 * _IGNORE -> ignored, remove from the set of pending signals and try the 3129 * next pending signal 3130 * _SBDRY_STOP -> the signal should stop the thread but this is not 3131 * permitted in the current context 3132 */ 3133 static enum sigstatus 3134 sigprocess(struct thread *td, int sig) 3135 { 3136 struct proc *p; 3137 struct sigacts *ps; 3138 struct sigqueue *queue; 3139 ksiginfo_t ksi; 3140 int prop; 3141 3142 KASSERT(_SIG_VALID(sig), ("%s: invalid signal %d", __func__, sig)); 3143 3144 p = td->td_proc; 3145 ps = p->p_sigacts; 3146 mtx_assert(&ps->ps_mtx, MA_OWNED); 3147 PROC_LOCK_ASSERT(p, MA_OWNED); 3148 3149 /* 3150 * We should allow pending but ignored signals below 3151 * if there is sigwait() active, or P_TRACED was 3152 * on when they were posted. 3153 */ 3154 if (SIGISMEMBER(ps->ps_sigignore, sig) && 3155 (p->p_flag & P_TRACED) == 0 && 3156 (td->td_flags & TDF_SIGWAIT) == 0) { 3157 return (SIGSTATUS_IGNORE); 3158 } 3159 3160 /* 3161 * If the process is going to single-thread mode to prepare 3162 * for exit, there is no sense in delivering any signal 3163 * to usermode. Another important consequence is that 3164 * msleep(..., PCATCH, ...) now is only interruptible by a 3165 * suspend request. 3166 */ 3167 if ((p->p_flag2 & P2_WEXIT) != 0) 3168 return (SIGSTATUS_IGNORE); 3169 3170 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 3171 /* 3172 * If traced, always stop. 3173 * Remove old signal from queue before the stop. 3174 * XXX shrug off debugger, it causes siginfo to 3175 * be thrown away. 3176 */ 3177 queue = &td->td_sigqueue; 3178 ksiginfo_init(&ksi); 3179 if (sigqueue_get(queue, sig, &ksi) == 0) { 3180 queue = &p->p_sigqueue; 3181 sigqueue_get(queue, sig, &ksi); 3182 } 3183 td->td_si = ksi.ksi_info; 3184 3185 mtx_unlock(&ps->ps_mtx); 3186 sig = ptracestop(td, sig, &ksi); 3187 mtx_lock(&ps->ps_mtx); 3188 3189 td->td_si.si_signo = 0; 3190 3191 /* 3192 * Keep looking if the debugger discarded or 3193 * replaced the signal. 3194 */ 3195 if (sig == 0) 3196 return (SIGSTATUS_HANDLED); 3197 3198 /* 3199 * If the signal became masked, re-queue it. 3200 */ 3201 if (SIGISMEMBER(td->td_sigmask, sig)) { 3202 ksi.ksi_flags |= KSI_HEAD; 3203 sigqueue_add(&p->p_sigqueue, sig, &ksi); 3204 return (SIGSTATUS_HANDLED); 3205 } 3206 3207 /* 3208 * If the traced bit got turned off, requeue the signal and 3209 * reload the set of pending signals. This ensures that p_sig* 3210 * and p_sigact are consistent. 3211 */ 3212 if ((p->p_flag & P_TRACED) == 0) { 3213 if ((ksi.ksi_flags & KSI_PTRACE) == 0) { 3214 ksi.ksi_flags |= KSI_HEAD; 3215 sigqueue_add(queue, sig, &ksi); 3216 } 3217 return (SIGSTATUS_HANDLED); 3218 } 3219 } 3220 3221 /* 3222 * Decide whether the signal should be returned. 3223 * Return the signal's number, or fall through 3224 * to clear it from the pending mask. 3225 */ 3226 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 3227 case (intptr_t)SIG_DFL: 3228 /* 3229 * Don't take default actions on system processes. 3230 */ 3231 if (p->p_pid <= 1) { 3232 #ifdef DIAGNOSTIC 3233 /* 3234 * Are you sure you want to ignore SIGSEGV 3235 * in init? XXX 3236 */ 3237 printf("Process (pid %lu) got signal %d\n", 3238 (u_long)p->p_pid, sig); 3239 #endif 3240 return (SIGSTATUS_IGNORE); 3241 } 3242 3243 /* 3244 * If there is a pending stop signal to process with 3245 * default action, stop here, then clear the signal. 3246 * Traced or exiting processes should ignore stops. 3247 * Additionally, a member of an orphaned process group 3248 * should ignore tty stops. 3249 */ 3250 prop = sigprop(sig); 3251 if (prop & SIGPROP_STOP) { 3252 mtx_unlock(&ps->ps_mtx); 3253 if ((p->p_flag & (P_TRACED | P_WEXIT | 3254 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 3255 pg_flags & PGRP_ORPHANED) != 0 && 3256 (prop & SIGPROP_TTYSTOP) != 0)) { 3257 mtx_lock(&ps->ps_mtx); 3258 return (SIGSTATUS_IGNORE); 3259 } 3260 if (TD_SBDRY_INTR(td)) { 3261 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3262 ("lost TDF_SBDRY")); 3263 mtx_lock(&ps->ps_mtx); 3264 return (SIGSTATUS_SBDRY_STOP); 3265 } 3266 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3267 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3268 sigqueue_delete(&td->td_sigqueue, sig); 3269 sigqueue_delete(&p->p_sigqueue, sig); 3270 p->p_flag |= P_STOPPED_SIG; 3271 p->p_xsig = sig; 3272 PROC_SLOCK(p); 3273 sig_suspend_threads(td, p); 3274 thread_suspend_switch(td, p); 3275 PROC_SUNLOCK(p); 3276 mtx_lock(&ps->ps_mtx); 3277 return (SIGSTATUS_HANDLED); 3278 } else if ((prop & SIGPROP_IGNORE) != 0 && 3279 (td->td_flags & TDF_SIGWAIT) == 0) { 3280 /* 3281 * Default action is to ignore; drop it if 3282 * not in kern_sigtimedwait(). 3283 */ 3284 return (SIGSTATUS_IGNORE); 3285 } else { 3286 return (SIGSTATUS_HANDLE); 3287 } 3288 3289 case (intptr_t)SIG_IGN: 3290 if ((td->td_flags & TDF_SIGWAIT) == 0) 3291 return (SIGSTATUS_IGNORE); 3292 else 3293 return (SIGSTATUS_HANDLE); 3294 3295 default: 3296 /* 3297 * This signal has an action, let postsig() process it. 3298 */ 3299 return (SIGSTATUS_HANDLE); 3300 } 3301 } 3302 3303 /* 3304 * If the current process has received a signal (should be caught or cause 3305 * termination, should interrupt current syscall), return the signal number. 3306 * Stop signals with default action are processed immediately, then cleared; 3307 * they aren't returned. This is checked after each entry to the system for 3308 * a syscall or trap (though this can usually be done without calling 3309 * issignal by checking the pending signal masks in cursig.) The normal call 3310 * sequence is 3311 * 3312 * while (sig = cursig(curthread)) 3313 * postsig(sig); 3314 */ 3315 static int 3316 issignal(struct thread *td) 3317 { 3318 struct proc *p; 3319 sigset_t sigpending; 3320 int sig; 3321 3322 p = td->td_proc; 3323 PROC_LOCK_ASSERT(p, MA_OWNED); 3324 3325 for (;;) { 3326 sigpending = td->td_sigqueue.sq_signals; 3327 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 3328 SIGSETNAND(sigpending, td->td_sigmask); 3329 3330 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 3331 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 3332 SIG_STOPSIGMASK(sigpending); 3333 if (SIGISEMPTY(sigpending)) /* no signal to send */ 3334 return (0); 3335 3336 /* 3337 * Do fast sigblock if requested by usermode. Since 3338 * we do know that there was a signal pending at this 3339 * point, set the FAST_SIGBLOCK_PEND as indicator for 3340 * usermode to perform a dummy call to 3341 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 3342 * delivery of postponed pending signal. 3343 */ 3344 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3345 if (td->td_sigblock_val != 0) 3346 SIGSETNAND(sigpending, fastblock_mask); 3347 if (SIGISEMPTY(sigpending)) { 3348 td->td_pflags |= TDP_SIGFASTPENDING; 3349 return (0); 3350 } 3351 } 3352 3353 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 3354 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 3355 SIGISMEMBER(sigpending, SIGSTOP)) { 3356 /* 3357 * If debugger just attached, always consume 3358 * SIGSTOP from ptrace(PT_ATTACH) first, to 3359 * execute the debugger attach ritual in 3360 * order. 3361 */ 3362 td->td_dbgflags |= TDB_FSTP; 3363 SIGEMPTYSET(sigpending); 3364 SIGADDSET(sigpending, SIGSTOP); 3365 } 3366 3367 SIG_FOREACH(sig, &sigpending) { 3368 switch (sigprocess(td, sig)) { 3369 case SIGSTATUS_HANDLE: 3370 return (sig); 3371 case SIGSTATUS_HANDLED: 3372 goto next; 3373 case SIGSTATUS_IGNORE: 3374 sigqueue_delete(&td->td_sigqueue, sig); 3375 sigqueue_delete(&p->p_sigqueue, sig); 3376 break; 3377 case SIGSTATUS_SBDRY_STOP: 3378 return (-1); 3379 } 3380 } 3381 next:; 3382 } 3383 } 3384 3385 void 3386 thread_stopped(struct proc *p) 3387 { 3388 int n; 3389 3390 PROC_LOCK_ASSERT(p, MA_OWNED); 3391 PROC_SLOCK_ASSERT(p, MA_OWNED); 3392 n = p->p_suspcount; 3393 if (p == curproc) 3394 n++; 3395 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3396 PROC_SUNLOCK(p); 3397 p->p_flag &= ~P_WAITED; 3398 PROC_LOCK(p->p_pptr); 3399 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3400 CLD_TRAPPED : CLD_STOPPED); 3401 PROC_UNLOCK(p->p_pptr); 3402 PROC_SLOCK(p); 3403 } 3404 } 3405 3406 /* 3407 * Take the action for the specified signal 3408 * from the current set of pending signals. 3409 */ 3410 int 3411 postsig(int sig) 3412 { 3413 struct thread *td; 3414 struct proc *p; 3415 struct sigacts *ps; 3416 sig_t action; 3417 ksiginfo_t ksi; 3418 sigset_t returnmask; 3419 3420 KASSERT(sig != 0, ("postsig")); 3421 3422 td = curthread; 3423 p = td->td_proc; 3424 PROC_LOCK_ASSERT(p, MA_OWNED); 3425 ps = p->p_sigacts; 3426 mtx_assert(&ps->ps_mtx, MA_OWNED); 3427 ksiginfo_init(&ksi); 3428 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3429 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3430 return (0); 3431 ksi.ksi_signo = sig; 3432 if (ksi.ksi_code == SI_TIMER) 3433 itimer_accept(p, ksi.ksi_timerid, &ksi); 3434 action = ps->ps_sigact[_SIG_IDX(sig)]; 3435 #ifdef KTRACE 3436 if (KTRPOINT(td, KTR_PSIG)) 3437 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3438 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3439 #endif 3440 3441 if (action == SIG_DFL) { 3442 /* 3443 * Default action, where the default is to kill 3444 * the process. (Other cases were ignored above.) 3445 */ 3446 mtx_unlock(&ps->ps_mtx); 3447 proc_td_siginfo_capture(td, &ksi.ksi_info); 3448 sigexit1(td, sig, &ksi); 3449 /* NOTREACHED */ 3450 } else { 3451 /* 3452 * If we get here, the signal must be caught. 3453 */ 3454 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3455 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3456 ("postsig action: blocked sig %d", sig)); 3457 3458 /* 3459 * Set the new mask value and also defer further 3460 * occurrences of this signal. 3461 * 3462 * Special case: user has done a sigsuspend. Here the 3463 * current mask is not of interest, but rather the 3464 * mask from before the sigsuspend is what we want 3465 * restored after the signal processing is completed. 3466 */ 3467 if (td->td_pflags & TDP_OLDMASK) { 3468 returnmask = td->td_oldsigmask; 3469 td->td_pflags &= ~TDP_OLDMASK; 3470 } else 3471 returnmask = td->td_sigmask; 3472 3473 if (p->p_sig == sig) { 3474 p->p_sig = 0; 3475 } 3476 sig_handle_killpg(p, &ksi); 3477 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3478 postsig_done(sig, td, ps); 3479 } 3480 return (1); 3481 } 3482 3483 int 3484 sig_ast_checksusp(struct thread *td) 3485 { 3486 struct proc *p __diagused; 3487 int ret; 3488 3489 p = td->td_proc; 3490 PROC_LOCK_ASSERT(p, MA_OWNED); 3491 3492 if (!td_ast_pending(td, TDA_SUSPEND)) 3493 return (0); 3494 3495 ret = thread_suspend_check(1); 3496 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3497 return (ret); 3498 } 3499 3500 int 3501 sig_ast_needsigchk(struct thread *td) 3502 { 3503 struct proc *p; 3504 struct sigacts *ps; 3505 int ret, sig; 3506 3507 p = td->td_proc; 3508 PROC_LOCK_ASSERT(p, MA_OWNED); 3509 3510 if (!td_ast_pending(td, TDA_SIG)) 3511 return (0); 3512 3513 ps = p->p_sigacts; 3514 mtx_lock(&ps->ps_mtx); 3515 sig = cursig(td); 3516 if (sig == -1) { 3517 mtx_unlock(&ps->ps_mtx); 3518 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3519 KASSERT(TD_SBDRY_INTR(td), 3520 ("lost TDF_SERESTART of TDF_SEINTR")); 3521 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3522 (TDF_SEINTR | TDF_SERESTART), 3523 ("both TDF_SEINTR and TDF_SERESTART")); 3524 ret = TD_SBDRY_ERRNO(td); 3525 } else if (sig != 0) { 3526 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3527 mtx_unlock(&ps->ps_mtx); 3528 } else { 3529 mtx_unlock(&ps->ps_mtx); 3530 ret = 0; 3531 } 3532 3533 /* 3534 * Do not go into sleep if this thread was the ptrace(2) 3535 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3536 * but we usually act on the signal by interrupting sleep, and 3537 * should do that here as well. 3538 */ 3539 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3540 if (ret == 0) 3541 ret = EINTR; 3542 td->td_dbgflags &= ~TDB_FSTP; 3543 } 3544 3545 return (ret); 3546 } 3547 3548 int 3549 sig_intr(void) 3550 { 3551 struct thread *td; 3552 struct proc *p; 3553 int ret; 3554 3555 td = curthread; 3556 if (!td_ast_pending(td, TDA_SIG) && !td_ast_pending(td, TDA_SUSPEND)) 3557 return (0); 3558 3559 p = td->td_proc; 3560 3561 PROC_LOCK(p); 3562 ret = sig_ast_checksusp(td); 3563 if (ret == 0) 3564 ret = sig_ast_needsigchk(td); 3565 PROC_UNLOCK(p); 3566 return (ret); 3567 } 3568 3569 bool 3570 curproc_sigkilled(void) 3571 { 3572 struct thread *td; 3573 struct proc *p; 3574 struct sigacts *ps; 3575 bool res; 3576 3577 td = curthread; 3578 if (!td_ast_pending(td, TDA_SIG)) 3579 return (false); 3580 3581 p = td->td_proc; 3582 PROC_LOCK(p); 3583 ps = p->p_sigacts; 3584 mtx_lock(&ps->ps_mtx); 3585 res = SIGISMEMBER(td->td_sigqueue.sq_signals, SIGKILL) || 3586 SIGISMEMBER(p->p_sigqueue.sq_signals, SIGKILL); 3587 mtx_unlock(&ps->ps_mtx); 3588 PROC_UNLOCK(p); 3589 return (res); 3590 } 3591 3592 void 3593 proc_wkilled(struct proc *p) 3594 { 3595 3596 PROC_LOCK_ASSERT(p, MA_OWNED); 3597 if ((p->p_flag & P_WKILLED) == 0) { 3598 p->p_flag |= P_WKILLED; 3599 /* 3600 * Notify swapper that there is a process to swap in. 3601 * The notification is racy, at worst it would take 10 3602 * seconds for the swapper process to notice. 3603 */ 3604 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3605 wakeup(&proc0); 3606 } 3607 } 3608 3609 /* 3610 * Kill the current process for stated reason. 3611 */ 3612 void 3613 killproc(struct proc *p, const char *why) 3614 { 3615 3616 PROC_LOCK_ASSERT(p, MA_OWNED); 3617 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3618 p->p_comm); 3619 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3620 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3621 p->p_ucred->cr_uid, why); 3622 proc_wkilled(p); 3623 kern_psignal(p, SIGKILL); 3624 } 3625 3626 /* 3627 * Force the current process to exit with the specified signal, dumping core 3628 * if appropriate. We bypass the normal tests for masked and caught signals, 3629 * allowing unrecoverable failures to terminate the process without changing 3630 * signal state. Mark the accounting record with the signal termination. 3631 * If dumping core, save the signal number for the debugger. Calls exit and 3632 * does not return. 3633 */ 3634 static void 3635 sigexit1(struct thread *td, int sig, ksiginfo_t *ksi) 3636 { 3637 struct proc *p = td->td_proc; 3638 3639 PROC_LOCK_ASSERT(p, MA_OWNED); 3640 proc_set_p2_wexit(p); 3641 3642 p->p_acflag |= AXSIG; 3643 /* 3644 * We must be single-threading to generate a core dump. This 3645 * ensures that the registers in the core file are up-to-date. 3646 * Also, the ELF dump handler assumes that the thread list doesn't 3647 * change out from under it. 3648 * 3649 * XXX If another thread attempts to single-thread before us 3650 * (e.g. via fork()), we won't get a dump at all. 3651 */ 3652 if ((sigprop(sig) & SIGPROP_CORE) && 3653 thread_single(p, SINGLE_NO_EXIT) == 0) { 3654 p->p_sig = sig; 3655 /* 3656 * Log signals which would cause core dumps 3657 * (Log as LOG_INFO to appease those who don't want 3658 * these messages.) 3659 * XXX : Todo, as well as euid, write out ruid too 3660 * Note that coredump() drops proc lock. 3661 */ 3662 if (coredump(td) == 0) 3663 sig |= WCOREFLAG; 3664 if (kern_logsigexit) 3665 log(LOG_INFO, 3666 "pid %d (%s), jid %d, uid %d: exited on " 3667 "signal %d%s\n", p->p_pid, p->p_comm, 3668 p->p_ucred->cr_prison->pr_id, 3669 td->td_ucred->cr_uid, 3670 sig &~ WCOREFLAG, 3671 sig & WCOREFLAG ? " (core dumped)" : ""); 3672 } else 3673 PROC_UNLOCK(p); 3674 exit2(td, 0, sig, ksi != NULL && (ksi->ksi_flags & KSI_KILLPG) != 0); 3675 /* NOTREACHED */ 3676 } 3677 3678 void 3679 sigexit(struct thread *td, int sig) 3680 { 3681 sigexit1(td, sig, NULL); 3682 } 3683 3684 /* 3685 * Send queued SIGCHLD to parent when child process's state 3686 * is changed. 3687 */ 3688 static void 3689 sigparent(struct proc *p, int reason, int status) 3690 { 3691 PROC_LOCK_ASSERT(p, MA_OWNED); 3692 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3693 3694 if (p->p_ksi != NULL) { 3695 p->p_ksi->ksi_signo = SIGCHLD; 3696 p->p_ksi->ksi_code = reason; 3697 p->p_ksi->ksi_status = status; 3698 p->p_ksi->ksi_pid = p->p_pid; 3699 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3700 if (KSI_ONQ(p->p_ksi)) 3701 return; 3702 } 3703 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3704 } 3705 3706 static void 3707 childproc_jobstate(struct proc *p, int reason, int sig) 3708 { 3709 struct sigacts *ps; 3710 3711 PROC_LOCK_ASSERT(p, MA_OWNED); 3712 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3713 3714 /* 3715 * Wake up parent sleeping in kern_wait(), also send 3716 * SIGCHLD to parent, but SIGCHLD does not guarantee 3717 * that parent will awake, because parent may masked 3718 * the signal. 3719 */ 3720 p->p_pptr->p_flag |= P_STATCHILD; 3721 wakeup(p->p_pptr); 3722 3723 ps = p->p_pptr->p_sigacts; 3724 mtx_lock(&ps->ps_mtx); 3725 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3726 mtx_unlock(&ps->ps_mtx); 3727 sigparent(p, reason, sig); 3728 } else 3729 mtx_unlock(&ps->ps_mtx); 3730 } 3731 3732 void 3733 childproc_stopped(struct proc *p, int reason) 3734 { 3735 3736 childproc_jobstate(p, reason, p->p_xsig); 3737 } 3738 3739 void 3740 childproc_continued(struct proc *p) 3741 { 3742 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3743 } 3744 3745 void 3746 childproc_exited(struct proc *p) 3747 { 3748 int reason, status; 3749 3750 if (WCOREDUMP(p->p_xsig)) { 3751 reason = CLD_DUMPED; 3752 status = WTERMSIG(p->p_xsig); 3753 } else if (WIFSIGNALED(p->p_xsig)) { 3754 reason = CLD_KILLED; 3755 status = WTERMSIG(p->p_xsig); 3756 } else { 3757 reason = CLD_EXITED; 3758 status = p->p_xexit; 3759 } 3760 /* 3761 * XXX avoid calling wakeup(p->p_pptr), the work is 3762 * done in exit1(). 3763 */ 3764 sigparent(p, reason, status); 3765 } 3766 3767 #define MAX_NUM_CORE_FILES 100000 3768 #ifndef NUM_CORE_FILES 3769 #define NUM_CORE_FILES 5 3770 #endif 3771 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3772 static int num_cores = NUM_CORE_FILES; 3773 3774 static int 3775 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3776 { 3777 int error; 3778 int new_val; 3779 3780 new_val = num_cores; 3781 error = sysctl_handle_int(oidp, &new_val, 0, req); 3782 if (error != 0 || req->newptr == NULL) 3783 return (error); 3784 if (new_val > MAX_NUM_CORE_FILES) 3785 new_val = MAX_NUM_CORE_FILES; 3786 if (new_val < 0) 3787 new_val = 0; 3788 num_cores = new_val; 3789 return (0); 3790 } 3791 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3792 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int), 3793 sysctl_debug_num_cores_check, "I", 3794 "Maximum number of generated process corefiles while using index format"); 3795 3796 #define GZIP_SUFFIX ".gz" 3797 #define ZSTD_SUFFIX ".zst" 3798 3799 int compress_user_cores = 0; 3800 3801 static int 3802 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3803 { 3804 int error, val; 3805 3806 val = compress_user_cores; 3807 error = sysctl_handle_int(oidp, &val, 0, req); 3808 if (error != 0 || req->newptr == NULL) 3809 return (error); 3810 if (val != 0 && !compressor_avail(val)) 3811 return (EINVAL); 3812 compress_user_cores = val; 3813 return (error); 3814 } 3815 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3816 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3817 sysctl_compress_user_cores, "I", 3818 "Enable compression of user corefiles (" 3819 __XSTRING(COMPRESS_GZIP) " = gzip, " 3820 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3821 3822 int compress_user_cores_level = 6; 3823 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3824 &compress_user_cores_level, 0, 3825 "Corefile compression level"); 3826 3827 /* 3828 * Protect the access to corefilename[] by allproc_lock. 3829 */ 3830 #define corefilename_lock allproc_lock 3831 3832 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3833 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3834 3835 static int 3836 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3837 { 3838 int error; 3839 3840 sx_xlock(&corefilename_lock); 3841 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3842 req); 3843 sx_xunlock(&corefilename_lock); 3844 3845 return (error); 3846 } 3847 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3848 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3849 "Process corefile name format string"); 3850 3851 static void 3852 vnode_close_locked(struct thread *td, struct vnode *vp) 3853 { 3854 3855 VOP_UNLOCK(vp); 3856 vn_close(vp, FWRITE, td->td_ucred, td); 3857 } 3858 3859 /* 3860 * If the core format has a %I in it, then we need to check 3861 * for existing corefiles before defining a name. 3862 * To do this we iterate over 0..ncores to find a 3863 * non-existing core file name to use. If all core files are 3864 * already used we choose the oldest one. 3865 */ 3866 static int 3867 corefile_open_last(struct thread *td, char *name, int indexpos, 3868 int indexlen, int ncores, struct vnode **vpp) 3869 { 3870 struct vnode *oldvp, *nextvp, *vp; 3871 struct vattr vattr; 3872 struct nameidata nd; 3873 int error, i, flags, oflags, cmode; 3874 char ch; 3875 struct timespec lasttime; 3876 3877 nextvp = oldvp = NULL; 3878 cmode = S_IRUSR | S_IWUSR; 3879 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3880 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3881 3882 for (i = 0; i < ncores; i++) { 3883 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3884 3885 ch = name[indexpos + indexlen]; 3886 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3887 i); 3888 name[indexpos + indexlen] = ch; 3889 3890 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 3891 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3892 NULL); 3893 if (error != 0) 3894 break; 3895 3896 vp = nd.ni_vp; 3897 NDFREE_PNBUF(&nd); 3898 if ((flags & O_CREAT) == O_CREAT) { 3899 nextvp = vp; 3900 break; 3901 } 3902 3903 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3904 if (error != 0) { 3905 vnode_close_locked(td, vp); 3906 break; 3907 } 3908 3909 if (oldvp == NULL || 3910 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3911 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3912 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3913 if (oldvp != NULL) 3914 vn_close(oldvp, FWRITE, td->td_ucred, td); 3915 oldvp = vp; 3916 VOP_UNLOCK(oldvp); 3917 lasttime = vattr.va_mtime; 3918 } else { 3919 vnode_close_locked(td, vp); 3920 } 3921 } 3922 3923 if (oldvp != NULL) { 3924 if (nextvp == NULL) { 3925 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3926 error = EFAULT; 3927 vn_close(oldvp, FWRITE, td->td_ucred, td); 3928 } else { 3929 nextvp = oldvp; 3930 error = vn_lock(nextvp, LK_EXCLUSIVE); 3931 if (error != 0) { 3932 vn_close(nextvp, FWRITE, td->td_ucred, 3933 td); 3934 nextvp = NULL; 3935 } 3936 } 3937 } else { 3938 vn_close(oldvp, FWRITE, td->td_ucred, td); 3939 } 3940 } 3941 if (error != 0) { 3942 if (nextvp != NULL) 3943 vnode_close_locked(td, oldvp); 3944 } else { 3945 *vpp = nextvp; 3946 } 3947 3948 return (error); 3949 } 3950 3951 /* 3952 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3953 * Expand the name described in corefilename, using name, uid, and pid 3954 * and open/create core file. 3955 * corefilename is a printf-like string, with three format specifiers: 3956 * %N name of process ("name") 3957 * %P process id (pid) 3958 * %U user id (uid) 3959 * For example, "%N.core" is the default; they can be disabled completely 3960 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3961 * This is controlled by the sysctl variable kern.corefile (see above). 3962 */ 3963 static int 3964 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3965 int compress, int signum, struct vnode **vpp, char **namep) 3966 { 3967 struct sbuf sb; 3968 struct nameidata nd; 3969 const char *format; 3970 char *hostname, *name; 3971 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3972 3973 hostname = NULL; 3974 format = corefilename; 3975 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3976 indexlen = 0; 3977 indexpos = -1; 3978 ncores = num_cores; 3979 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3980 sx_slock(&corefilename_lock); 3981 for (i = 0; format[i] != '\0'; i++) { 3982 switch (format[i]) { 3983 case '%': /* Format character */ 3984 i++; 3985 switch (format[i]) { 3986 case '%': 3987 sbuf_putc(&sb, '%'); 3988 break; 3989 case 'H': /* hostname */ 3990 if (hostname == NULL) { 3991 hostname = malloc(MAXHOSTNAMELEN, 3992 M_TEMP, M_WAITOK); 3993 } 3994 getcredhostname(td->td_ucred, hostname, 3995 MAXHOSTNAMELEN); 3996 sbuf_printf(&sb, "%s", hostname); 3997 break; 3998 case 'I': /* autoincrementing index */ 3999 if (indexpos != -1) { 4000 sbuf_printf(&sb, "%%I"); 4001 break; 4002 } 4003 4004 indexpos = sbuf_len(&sb); 4005 sbuf_printf(&sb, "%u", ncores - 1); 4006 indexlen = sbuf_len(&sb) - indexpos; 4007 break; 4008 case 'N': /* process name */ 4009 sbuf_printf(&sb, "%s", comm); 4010 break; 4011 case 'P': /* process id */ 4012 sbuf_printf(&sb, "%u", pid); 4013 break; 4014 case 'S': /* signal number */ 4015 sbuf_printf(&sb, "%i", signum); 4016 break; 4017 case 'U': /* user id */ 4018 sbuf_printf(&sb, "%u", uid); 4019 break; 4020 default: 4021 log(LOG_ERR, 4022 "Unknown format character %c in " 4023 "corename `%s'\n", format[i], format); 4024 break; 4025 } 4026 break; 4027 default: 4028 sbuf_putc(&sb, format[i]); 4029 break; 4030 } 4031 } 4032 sx_sunlock(&corefilename_lock); 4033 free(hostname, M_TEMP); 4034 if (compress == COMPRESS_GZIP) 4035 sbuf_printf(&sb, GZIP_SUFFIX); 4036 else if (compress == COMPRESS_ZSTD) 4037 sbuf_printf(&sb, ZSTD_SUFFIX); 4038 if (sbuf_error(&sb) != 0) { 4039 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 4040 "long\n", (long)pid, comm, (u_long)uid); 4041 sbuf_delete(&sb); 4042 free(name, M_TEMP); 4043 return (ENOMEM); 4044 } 4045 sbuf_finish(&sb); 4046 sbuf_delete(&sb); 4047 4048 if (indexpos != -1) { 4049 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 4050 vpp); 4051 if (error != 0) { 4052 log(LOG_ERR, 4053 "pid %d (%s), uid (%u): Path `%s' failed " 4054 "on initial open test, error = %d\n", 4055 pid, comm, uid, name, error); 4056 } 4057 } else { 4058 cmode = S_IRUSR | S_IWUSR; 4059 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 4060 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 4061 flags = O_CREAT | FWRITE | O_NOFOLLOW; 4062 if ((td->td_proc->p_flag & P_SUGID) != 0) 4063 flags |= O_EXCL; 4064 4065 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name); 4066 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 4067 NULL); 4068 if (error == 0) { 4069 *vpp = nd.ni_vp; 4070 NDFREE_PNBUF(&nd); 4071 } 4072 } 4073 4074 if (error != 0) { 4075 #ifdef AUDIT 4076 audit_proc_coredump(td, name, error); 4077 #endif 4078 free(name, M_TEMP); 4079 return (error); 4080 } 4081 *namep = name; 4082 return (0); 4083 } 4084 4085 /* 4086 * Dump a process' core. The main routine does some 4087 * policy checking, and creates the name of the coredump; 4088 * then it passes on a vnode and a size limit to the process-specific 4089 * coredump routine if there is one; if there _is not_ one, it returns 4090 * ENOSYS; otherwise it returns the error from the process-specific routine. 4091 */ 4092 4093 static int 4094 coredump(struct thread *td) 4095 { 4096 struct proc *p = td->td_proc; 4097 struct ucred *cred = td->td_ucred; 4098 struct vnode *vp; 4099 struct flock lf; 4100 struct vattr vattr; 4101 size_t fullpathsize; 4102 int error, error1, locked; 4103 char *name; /* name of corefile */ 4104 void *rl_cookie; 4105 off_t limit; 4106 char *fullpath, *freepath = NULL; 4107 struct sbuf *sb; 4108 4109 PROC_LOCK_ASSERT(p, MA_OWNED); 4110 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 4111 4112 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 4113 (p->p_flag2 & P2_NOTRACE) != 0) { 4114 PROC_UNLOCK(p); 4115 return (EFAULT); 4116 } 4117 4118 /* 4119 * Note that the bulk of limit checking is done after 4120 * the corefile is created. The exception is if the limit 4121 * for corefiles is 0, in which case we don't bother 4122 * creating the corefile at all. This layout means that 4123 * a corefile is truncated instead of not being created, 4124 * if it is larger than the limit. 4125 */ 4126 limit = (off_t)lim_cur(td, RLIMIT_CORE); 4127 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 4128 PROC_UNLOCK(p); 4129 return (EFBIG); 4130 } 4131 PROC_UNLOCK(p); 4132 4133 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 4134 compress_user_cores, p->p_sig, &vp, &name); 4135 if (error != 0) 4136 return (error); 4137 4138 /* 4139 * Don't dump to non-regular files or files with links. 4140 * Do not dump into system files. Effective user must own the corefile. 4141 */ 4142 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 4143 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 4144 vattr.va_uid != cred->cr_uid) { 4145 VOP_UNLOCK(vp); 4146 error = EFAULT; 4147 goto out; 4148 } 4149 4150 VOP_UNLOCK(vp); 4151 4152 /* Postpone other writers, including core dumps of other processes. */ 4153 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 4154 4155 lf.l_whence = SEEK_SET; 4156 lf.l_start = 0; 4157 lf.l_len = 0; 4158 lf.l_type = F_WRLCK; 4159 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 4160 4161 VATTR_NULL(&vattr); 4162 vattr.va_size = 0; 4163 if (set_core_nodump_flag) 4164 vattr.va_flags = UF_NODUMP; 4165 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4166 VOP_SETATTR(vp, &vattr, cred); 4167 VOP_UNLOCK(vp); 4168 PROC_LOCK(p); 4169 p->p_acflag |= ACORE; 4170 PROC_UNLOCK(p); 4171 4172 if (p->p_sysent->sv_coredump != NULL) { 4173 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 4174 } else { 4175 error = ENOSYS; 4176 } 4177 4178 if (locked) { 4179 lf.l_type = F_UNLCK; 4180 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 4181 } 4182 vn_rangelock_unlock(vp, rl_cookie); 4183 4184 /* 4185 * Notify the userland helper that a process triggered a core dump. 4186 * This allows the helper to run an automated debugging session. 4187 */ 4188 if (error != 0 || coredump_devctl == 0) 4189 goto out; 4190 sb = sbuf_new_auto(); 4191 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 4192 goto out2; 4193 sbuf_printf(sb, "comm=\""); 4194 devctl_safe_quote_sb(sb, fullpath); 4195 free(freepath, M_TEMP); 4196 sbuf_printf(sb, "\" core=\""); 4197 4198 /* 4199 * We can't lookup core file vp directly. When we're replacing a core, and 4200 * other random times, we flush the name cache, so it will fail. Instead, 4201 * if the path of the core is relative, add the current dir in front if it. 4202 */ 4203 if (name[0] != '/') { 4204 fullpathsize = MAXPATHLEN; 4205 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 4206 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 4207 free(freepath, M_TEMP); 4208 goto out2; 4209 } 4210 devctl_safe_quote_sb(sb, fullpath); 4211 free(freepath, M_TEMP); 4212 sbuf_putc(sb, '/'); 4213 } 4214 devctl_safe_quote_sb(sb, name); 4215 sbuf_printf(sb, "\""); 4216 if (sbuf_finish(sb) == 0) 4217 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 4218 out2: 4219 sbuf_delete(sb); 4220 out: 4221 error1 = vn_close(vp, FWRITE, cred, td); 4222 if (error == 0) 4223 error = error1; 4224 #ifdef AUDIT 4225 audit_proc_coredump(td, name, error); 4226 #endif 4227 free(name, M_TEMP); 4228 return (error); 4229 } 4230 4231 /* 4232 * Nonexistent system call-- signal process (may want to handle it). Flag 4233 * error in case process won't see signal immediately (blocked or ignored). 4234 */ 4235 #ifndef _SYS_SYSPROTO_H_ 4236 struct nosys_args { 4237 int dummy; 4238 }; 4239 #endif 4240 /* ARGSUSED */ 4241 int 4242 nosys(struct thread *td, struct nosys_args *args) 4243 { 4244 struct proc *p; 4245 4246 p = td->td_proc; 4247 4248 PROC_LOCK(p); 4249 tdsignal(td, SIGSYS); 4250 PROC_UNLOCK(p); 4251 if (kern_lognosys == 1 || kern_lognosys == 3) { 4252 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4253 td->td_sa.code); 4254 } 4255 if (kern_lognosys == 2 || kern_lognosys == 3 || 4256 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 4257 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 4258 td->td_sa.code); 4259 } 4260 return (ENOSYS); 4261 } 4262 4263 /* 4264 * Send a SIGIO or SIGURG signal to a process or process group using stored 4265 * credentials rather than those of the current process. 4266 */ 4267 void 4268 pgsigio(struct sigio **sigiop, int sig, int checkctty) 4269 { 4270 ksiginfo_t ksi; 4271 struct sigio *sigio; 4272 4273 ksiginfo_init(&ksi); 4274 ksi.ksi_signo = sig; 4275 ksi.ksi_code = SI_KERNEL; 4276 4277 SIGIO_LOCK(); 4278 sigio = *sigiop; 4279 if (sigio == NULL) { 4280 SIGIO_UNLOCK(); 4281 return; 4282 } 4283 if (sigio->sio_pgid > 0) { 4284 PROC_LOCK(sigio->sio_proc); 4285 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 4286 kern_psignal(sigio->sio_proc, sig); 4287 PROC_UNLOCK(sigio->sio_proc); 4288 } else if (sigio->sio_pgid < 0) { 4289 struct proc *p; 4290 4291 PGRP_LOCK(sigio->sio_pgrp); 4292 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 4293 PROC_LOCK(p); 4294 if (p->p_state == PRS_NORMAL && 4295 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 4296 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 4297 kern_psignal(p, sig); 4298 PROC_UNLOCK(p); 4299 } 4300 PGRP_UNLOCK(sigio->sio_pgrp); 4301 } 4302 SIGIO_UNLOCK(); 4303 } 4304 4305 static int 4306 filt_sigattach(struct knote *kn) 4307 { 4308 struct proc *p = curproc; 4309 4310 kn->kn_ptr.p_proc = p; 4311 kn->kn_flags |= EV_CLEAR; /* automatically set */ 4312 4313 knlist_add(p->p_klist, kn, 0); 4314 4315 return (0); 4316 } 4317 4318 static void 4319 filt_sigdetach(struct knote *kn) 4320 { 4321 struct proc *p = kn->kn_ptr.p_proc; 4322 4323 knlist_remove(p->p_klist, kn, 0); 4324 } 4325 4326 /* 4327 * signal knotes are shared with proc knotes, so we apply a mask to 4328 * the hint in order to differentiate them from process hints. This 4329 * could be avoided by using a signal-specific knote list, but probably 4330 * isn't worth the trouble. 4331 */ 4332 static int 4333 filt_signal(struct knote *kn, long hint) 4334 { 4335 4336 if (hint & NOTE_SIGNAL) { 4337 hint &= ~NOTE_SIGNAL; 4338 4339 if (kn->kn_id == hint) 4340 kn->kn_data++; 4341 } 4342 return (kn->kn_data != 0); 4343 } 4344 4345 struct sigacts * 4346 sigacts_alloc(void) 4347 { 4348 struct sigacts *ps; 4349 4350 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 4351 refcount_init(&ps->ps_refcnt, 1); 4352 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 4353 return (ps); 4354 } 4355 4356 void 4357 sigacts_free(struct sigacts *ps) 4358 { 4359 4360 if (refcount_release(&ps->ps_refcnt) == 0) 4361 return; 4362 mtx_destroy(&ps->ps_mtx); 4363 free(ps, M_SUBPROC); 4364 } 4365 4366 struct sigacts * 4367 sigacts_hold(struct sigacts *ps) 4368 { 4369 4370 refcount_acquire(&ps->ps_refcnt); 4371 return (ps); 4372 } 4373 4374 void 4375 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4376 { 4377 4378 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4379 mtx_lock(&src->ps_mtx); 4380 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4381 mtx_unlock(&src->ps_mtx); 4382 } 4383 4384 int 4385 sigacts_shared(struct sigacts *ps) 4386 { 4387 4388 return (ps->ps_refcnt > 1); 4389 } 4390 4391 void 4392 sig_drop_caught(struct proc *p) 4393 { 4394 int sig; 4395 struct sigacts *ps; 4396 4397 ps = p->p_sigacts; 4398 PROC_LOCK_ASSERT(p, MA_OWNED); 4399 mtx_assert(&ps->ps_mtx, MA_OWNED); 4400 SIG_FOREACH(sig, &ps->ps_sigcatch) { 4401 sigdflt(ps, sig); 4402 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4403 sigqueue_delete_proc(p, sig); 4404 } 4405 } 4406 4407 static void 4408 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4409 { 4410 ksiginfo_t ksi; 4411 4412 /* 4413 * Prevent further fetches and SIGSEGVs, allowing thread to 4414 * issue syscalls despite corruption. 4415 */ 4416 sigfastblock_clear(td); 4417 4418 if (!sendsig) 4419 return; 4420 ksiginfo_init_trap(&ksi); 4421 ksi.ksi_signo = SIGSEGV; 4422 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4423 ksi.ksi_addr = td->td_sigblock_ptr; 4424 trapsignal(td, &ksi); 4425 } 4426 4427 static bool 4428 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4429 { 4430 uint32_t res; 4431 4432 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4433 return (true); 4434 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4435 sigfastblock_failed(td, sendsig, false); 4436 return (false); 4437 } 4438 *valp = res; 4439 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4440 return (true); 4441 } 4442 4443 static void 4444 sigfastblock_resched(struct thread *td, bool resched) 4445 { 4446 struct proc *p; 4447 4448 if (resched) { 4449 p = td->td_proc; 4450 PROC_LOCK(p); 4451 reschedule_signals(p, td->td_sigmask, 0); 4452 PROC_UNLOCK(p); 4453 } 4454 ast_sched(td, TDA_SIG); 4455 } 4456 4457 int 4458 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4459 { 4460 struct proc *p; 4461 int error, res; 4462 uint32_t oldval; 4463 4464 error = 0; 4465 p = td->td_proc; 4466 switch (uap->cmd) { 4467 case SIGFASTBLOCK_SETPTR: 4468 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4469 error = EBUSY; 4470 break; 4471 } 4472 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4473 error = EINVAL; 4474 break; 4475 } 4476 td->td_pflags |= TDP_SIGFASTBLOCK; 4477 td->td_sigblock_ptr = uap->ptr; 4478 break; 4479 4480 case SIGFASTBLOCK_UNBLOCK: 4481 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4482 error = EINVAL; 4483 break; 4484 } 4485 4486 for (;;) { 4487 res = casueword32(td->td_sigblock_ptr, 4488 SIGFASTBLOCK_PEND, &oldval, 0); 4489 if (res == -1) { 4490 error = EFAULT; 4491 sigfastblock_failed(td, false, true); 4492 break; 4493 } 4494 if (res == 0) 4495 break; 4496 MPASS(res == 1); 4497 if (oldval != SIGFASTBLOCK_PEND) { 4498 error = EBUSY; 4499 break; 4500 } 4501 error = thread_check_susp(td, false); 4502 if (error != 0) 4503 break; 4504 } 4505 if (error != 0) 4506 break; 4507 4508 /* 4509 * td_sigblock_val is cleared there, but not on a 4510 * syscall exit. The end effect is that a single 4511 * interruptible sleep, while user sigblock word is 4512 * set, might return EINTR or ERESTART to usermode 4513 * without delivering signal. All further sleeps, 4514 * until userspace clears the word and does 4515 * sigfastblock(UNBLOCK), observe current word and no 4516 * longer get interrupted. It is slight 4517 * non-conformance, with alternative to have read the 4518 * sigblock word on each syscall entry. 4519 */ 4520 td->td_sigblock_val = 0; 4521 4522 /* 4523 * Rely on normal ast mechanism to deliver pending 4524 * signals to current thread. But notify others about 4525 * fake unblock. 4526 */ 4527 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4528 4529 break; 4530 4531 case SIGFASTBLOCK_UNSETPTR: 4532 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4533 error = EINVAL; 4534 break; 4535 } 4536 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4537 error = EFAULT; 4538 break; 4539 } 4540 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4541 error = EBUSY; 4542 break; 4543 } 4544 sigfastblock_clear(td); 4545 break; 4546 4547 default: 4548 error = EINVAL; 4549 break; 4550 } 4551 return (error); 4552 } 4553 4554 void 4555 sigfastblock_clear(struct thread *td) 4556 { 4557 bool resched; 4558 4559 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4560 return; 4561 td->td_sigblock_val = 0; 4562 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4563 SIGPENDING(td); 4564 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4565 sigfastblock_resched(td, resched); 4566 } 4567 4568 void 4569 sigfastblock_fetch(struct thread *td) 4570 { 4571 uint32_t val; 4572 4573 (void)sigfastblock_fetch_sig(td, true, &val); 4574 } 4575 4576 static void 4577 sigfastblock_setpend1(struct thread *td) 4578 { 4579 int res; 4580 uint32_t oldval; 4581 4582 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4583 return; 4584 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4585 if (res == -1) { 4586 sigfastblock_failed(td, true, false); 4587 return; 4588 } 4589 for (;;) { 4590 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4591 oldval | SIGFASTBLOCK_PEND); 4592 if (res == -1) { 4593 sigfastblock_failed(td, true, true); 4594 return; 4595 } 4596 if (res == 0) { 4597 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4598 td->td_pflags &= ~TDP_SIGFASTPENDING; 4599 break; 4600 } 4601 MPASS(res == 1); 4602 if (thread_check_susp(td, false) != 0) 4603 break; 4604 } 4605 } 4606 4607 static void 4608 sigfastblock_setpend(struct thread *td, bool resched) 4609 { 4610 struct proc *p; 4611 4612 sigfastblock_setpend1(td); 4613 if (resched) { 4614 p = td->td_proc; 4615 PROC_LOCK(p); 4616 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4617 PROC_UNLOCK(p); 4618 } 4619 } 4620