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