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