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