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