Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: src/sys/kern/kern_sig.c,v 1.289.2.9 2006/02/28 15:02:51 emaste Exp $"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/signalvar.h> 46 #include <sys/vnode.h> 47 #include <sys/acct.h> 48 #include <sys/condvar.h> 49 #include <sys/event.h> 50 #include <sys/fcntl.h> 51 #include <sys/kernel.h> 52 #include <sys/kse.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/pioctl.h> 61 #include <sys/resourcevar.h> 62 #include <sys/sleepqueue.h> 63 #include <sys/smp.h> 64 #include <sys/stat.h> 65 #include <sys/sx.h> 66 #include <sys/syscallsubr.h> 67 #include <sys/sysctl.h> 68 #include <sys/sysent.h> 69 #include <sys/syslog.h> 70 #include <sys/sysproto.h> 71 #include <sys/unistd.h> 72 #include <sys/wait.h> 73 74 #include <machine/cpu.h> 75 76 #if defined (__alpha__) && !defined(COMPAT_43) 77 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 78 #endif 79 80 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 81 82 static int coredump(struct thread *); 83 static char *expand_name(const char *, uid_t, pid_t); 84 static int killpg1(struct thread *td, int sig, int pgid, int all); 85 static int issignal(struct thread *p); 86 static int sigprop(int sig); 87 static void tdsigwakeup(struct thread *td, int sig, sig_t action); 88 static int filt_sigattach(struct knote *kn); 89 static void filt_sigdetach(struct knote *kn); 90 static int filt_signal(struct knote *kn, long hint); 91 static struct thread *sigtd(struct proc *p, int sig, int prop); 92 static int kern_sigtimedwait(struct thread *td, sigset_t set, 93 siginfo_t *info, struct timespec *timeout); 94 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target); 95 96 struct filterops sig_filtops = 97 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 98 99 static int kern_logsigexit = 1; 100 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 101 &kern_logsigexit, 0, 102 "Log processes quitting on abnormal signals to syslog(3)"); 103 104 /* 105 * Policy -- Can ucred cr1 send SIGIO to process cr2? 106 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 107 * in the right situations. 108 */ 109 #define CANSIGIO(cr1, cr2) \ 110 ((cr1)->cr_uid == 0 || \ 111 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 112 (cr1)->cr_uid == (cr2)->cr_ruid || \ 113 (cr1)->cr_ruid == (cr2)->cr_uid || \ 114 (cr1)->cr_uid == (cr2)->cr_uid) 115 116 int sugid_coredump; 117 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 118 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 119 120 static int do_coredump = 1; 121 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 122 &do_coredump, 0, "Enable/Disable coredumps"); 123 124 static int set_core_nodump_flag = 0; 125 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 126 0, "Enable setting the NODUMP flag on coredump files"); 127 128 /* 129 * Signal properties and actions. 130 * The array below categorizes the signals and their default actions 131 * according to the following properties: 132 */ 133 #define SA_KILL 0x01 /* terminates process by default */ 134 #define SA_CORE 0x02 /* ditto and coredumps */ 135 #define SA_STOP 0x04 /* suspend process */ 136 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 137 #define SA_IGNORE 0x10 /* ignore by default */ 138 #define SA_CONT 0x20 /* continue if suspended */ 139 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 140 #define SA_PROC 0x80 /* deliverable to any thread */ 141 142 static int sigproptbl[NSIG] = { 143 SA_KILL|SA_PROC, /* SIGHUP */ 144 SA_KILL|SA_PROC, /* SIGINT */ 145 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 146 SA_KILL|SA_CORE, /* SIGILL */ 147 SA_KILL|SA_CORE, /* SIGTRAP */ 148 SA_KILL|SA_CORE, /* SIGABRT */ 149 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 150 SA_KILL|SA_CORE, /* SIGFPE */ 151 SA_KILL|SA_PROC, /* SIGKILL */ 152 SA_KILL|SA_CORE, /* SIGBUS */ 153 SA_KILL|SA_CORE, /* SIGSEGV */ 154 SA_KILL|SA_CORE, /* SIGSYS */ 155 SA_KILL|SA_PROC, /* SIGPIPE */ 156 SA_KILL|SA_PROC, /* SIGALRM */ 157 SA_KILL|SA_PROC, /* SIGTERM */ 158 SA_IGNORE|SA_PROC, /* SIGURG */ 159 SA_STOP|SA_PROC, /* SIGSTOP */ 160 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 161 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 162 SA_IGNORE|SA_PROC, /* SIGCHLD */ 163 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 164 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 165 SA_IGNORE|SA_PROC, /* SIGIO */ 166 SA_KILL, /* SIGXCPU */ 167 SA_KILL, /* SIGXFSZ */ 168 SA_KILL|SA_PROC, /* SIGVTALRM */ 169 SA_KILL|SA_PROC, /* SIGPROF */ 170 SA_IGNORE|SA_PROC, /* SIGWINCH */ 171 SA_IGNORE|SA_PROC, /* SIGINFO */ 172 SA_KILL|SA_PROC, /* SIGUSR1 */ 173 SA_KILL|SA_PROC, /* SIGUSR2 */ 174 }; 175 176 /* 177 * Determine signal that should be delivered to process p, the current 178 * process, 0 if none. If there is a pending stop signal with default 179 * action, the process stops in issignal(). 180 * XXXKSE the check for a pending stop is not done under KSE 181 * 182 * MP SAFE. 183 */ 184 int 185 cursig(struct thread *td) 186 { 187 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 188 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 189 mtx_assert(&sched_lock, MA_NOTOWNED); 190 return (SIGPENDING(td) ? issignal(td) : 0); 191 } 192 193 /* 194 * Arrange for ast() to handle unmasked pending signals on return to user 195 * mode. This must be called whenever a signal is added to td_siglist or 196 * unmasked in td_sigmask. 197 */ 198 void 199 signotify(struct thread *td) 200 { 201 struct proc *p; 202 sigset_t set, saved; 203 204 p = td->td_proc; 205 206 PROC_LOCK_ASSERT(p, MA_OWNED); 207 208 /* 209 * If our mask changed we may have to move signal that were 210 * previously masked by all threads to our siglist. 211 */ 212 set = p->p_siglist; 213 if (p->p_flag & P_SA) 214 saved = p->p_siglist; 215 SIGSETNAND(set, td->td_sigmask); 216 SIGSETNAND(p->p_siglist, set); 217 SIGSETOR(td->td_siglist, set); 218 219 if (SIGPENDING(td)) { 220 mtx_lock_spin(&sched_lock); 221 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 222 mtx_unlock_spin(&sched_lock); 223 } 224 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 225 if (!SIGSETEQ(saved, p->p_siglist)) { 226 /* pending set changed */ 227 p->p_flag |= P_SIGEVENT; 228 wakeup(&p->p_siglist); 229 } 230 } 231 } 232 233 int 234 sigonstack(size_t sp) 235 { 236 struct thread *td = curthread; 237 238 return ((td->td_pflags & TDP_ALTSTACK) ? 239 #if defined(COMPAT_43) 240 ((td->td_sigstk.ss_size == 0) ? 241 (td->td_sigstk.ss_flags & SS_ONSTACK) : 242 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 243 #else 244 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 245 #endif 246 : 0); 247 } 248 249 static __inline int 250 sigprop(int sig) 251 { 252 253 if (sig > 0 && sig < NSIG) 254 return (sigproptbl[_SIG_IDX(sig)]); 255 return (0); 256 } 257 258 int 259 sig_ffs(sigset_t *set) 260 { 261 int i; 262 263 for (i = 0; i < _SIG_WORDS; i++) 264 if (set->__bits[i]) 265 return (ffs(set->__bits[i]) + (i * 32)); 266 return (0); 267 } 268 269 /* 270 * kern_sigaction 271 * sigaction 272 * freebsd4_sigaction 273 * osigaction 274 * 275 * MPSAFE 276 */ 277 int 278 kern_sigaction(td, sig, act, oact, flags) 279 struct thread *td; 280 register int sig; 281 struct sigaction *act, *oact; 282 int flags; 283 { 284 struct sigacts *ps; 285 struct thread *td0; 286 struct proc *p = td->td_proc; 287 288 if (!_SIG_VALID(sig)) 289 return (EINVAL); 290 291 PROC_LOCK(p); 292 ps = p->p_sigacts; 293 mtx_lock(&ps->ps_mtx); 294 if (oact) { 295 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 296 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 297 oact->sa_flags = 0; 298 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 299 oact->sa_flags |= SA_ONSTACK; 300 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 301 oact->sa_flags |= SA_RESTART; 302 if (SIGISMEMBER(ps->ps_sigreset, sig)) 303 oact->sa_flags |= SA_RESETHAND; 304 if (SIGISMEMBER(ps->ps_signodefer, sig)) 305 oact->sa_flags |= SA_NODEFER; 306 if (SIGISMEMBER(ps->ps_siginfo, sig)) 307 oact->sa_flags |= SA_SIGINFO; 308 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 309 oact->sa_flags |= SA_NOCLDSTOP; 310 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 311 oact->sa_flags |= SA_NOCLDWAIT; 312 } 313 if (act) { 314 if ((sig == SIGKILL || sig == SIGSTOP) && 315 act->sa_handler != SIG_DFL) { 316 mtx_unlock(&ps->ps_mtx); 317 PROC_UNLOCK(p); 318 return (EINVAL); 319 } 320 321 /* 322 * Change setting atomically. 323 */ 324 325 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 326 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 327 if (act->sa_flags & SA_SIGINFO) { 328 ps->ps_sigact[_SIG_IDX(sig)] = 329 (__sighandler_t *)act->sa_sigaction; 330 SIGADDSET(ps->ps_siginfo, sig); 331 } else { 332 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 333 SIGDELSET(ps->ps_siginfo, sig); 334 } 335 if (!(act->sa_flags & SA_RESTART)) 336 SIGADDSET(ps->ps_sigintr, sig); 337 else 338 SIGDELSET(ps->ps_sigintr, sig); 339 if (act->sa_flags & SA_ONSTACK) 340 SIGADDSET(ps->ps_sigonstack, sig); 341 else 342 SIGDELSET(ps->ps_sigonstack, sig); 343 if (act->sa_flags & SA_RESETHAND) 344 SIGADDSET(ps->ps_sigreset, sig); 345 else 346 SIGDELSET(ps->ps_sigreset, sig); 347 if (act->sa_flags & SA_NODEFER) 348 SIGADDSET(ps->ps_signodefer, sig); 349 else 350 SIGDELSET(ps->ps_signodefer, sig); 351 if (sig == SIGCHLD) { 352 if (act->sa_flags & SA_NOCLDSTOP) 353 ps->ps_flag |= PS_NOCLDSTOP; 354 else 355 ps->ps_flag &= ~PS_NOCLDSTOP; 356 if (act->sa_flags & SA_NOCLDWAIT) { 357 /* 358 * Paranoia: since SA_NOCLDWAIT is implemented 359 * by reparenting the dying child to PID 1 (and 360 * trust it to reap the zombie), PID 1 itself 361 * is forbidden to set SA_NOCLDWAIT. 362 */ 363 if (p->p_pid == 1) 364 ps->ps_flag &= ~PS_NOCLDWAIT; 365 else 366 ps->ps_flag |= PS_NOCLDWAIT; 367 } else 368 ps->ps_flag &= ~PS_NOCLDWAIT; 369 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 370 ps->ps_flag |= PS_CLDSIGIGN; 371 else 372 ps->ps_flag &= ~PS_CLDSIGIGN; 373 } 374 /* 375 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 376 * and for signals set to SIG_DFL where the default is to 377 * ignore. However, don't put SIGCONT in ps_sigignore, as we 378 * have to restart the process. 379 */ 380 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 381 (sigprop(sig) & SA_IGNORE && 382 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 383 if ((p->p_flag & P_SA) && 384 SIGISMEMBER(p->p_siglist, sig)) { 385 p->p_flag |= P_SIGEVENT; 386 wakeup(&p->p_siglist); 387 } 388 /* never to be seen again */ 389 SIGDELSET(p->p_siglist, sig); 390 mtx_lock_spin(&sched_lock); 391 FOREACH_THREAD_IN_PROC(p, td0) 392 SIGDELSET(td0->td_siglist, sig); 393 mtx_unlock_spin(&sched_lock); 394 if (sig != SIGCONT) 395 /* easier in psignal */ 396 SIGADDSET(ps->ps_sigignore, sig); 397 SIGDELSET(ps->ps_sigcatch, sig); 398 } else { 399 SIGDELSET(ps->ps_sigignore, sig); 400 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 401 SIGDELSET(ps->ps_sigcatch, sig); 402 else 403 SIGADDSET(ps->ps_sigcatch, sig); 404 } 405 #ifdef COMPAT_FREEBSD4 406 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 407 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 408 (flags & KSA_FREEBSD4) == 0) 409 SIGDELSET(ps->ps_freebsd4, sig); 410 else 411 SIGADDSET(ps->ps_freebsd4, sig); 412 #endif 413 #ifdef COMPAT_43 414 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 415 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 416 (flags & KSA_OSIGSET) == 0) 417 SIGDELSET(ps->ps_osigset, sig); 418 else 419 SIGADDSET(ps->ps_osigset, sig); 420 #endif 421 } 422 mtx_unlock(&ps->ps_mtx); 423 PROC_UNLOCK(p); 424 return (0); 425 } 426 427 #ifndef _SYS_SYSPROTO_H_ 428 struct sigaction_args { 429 int sig; 430 struct sigaction *act; 431 struct sigaction *oact; 432 }; 433 #endif 434 /* 435 * MPSAFE 436 */ 437 int 438 sigaction(td, uap) 439 struct thread *td; 440 register struct sigaction_args *uap; 441 { 442 struct sigaction act, oact; 443 register struct sigaction *actp, *oactp; 444 int error; 445 446 actp = (uap->act != NULL) ? &act : NULL; 447 oactp = (uap->oact != NULL) ? &oact : NULL; 448 if (actp) { 449 error = copyin(uap->act, actp, sizeof(act)); 450 if (error) 451 return (error); 452 } 453 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 454 if (oactp && !error) 455 error = copyout(oactp, uap->oact, sizeof(oact)); 456 return (error); 457 } 458 459 #ifdef COMPAT_FREEBSD4 460 #ifndef _SYS_SYSPROTO_H_ 461 struct freebsd4_sigaction_args { 462 int sig; 463 struct sigaction *act; 464 struct sigaction *oact; 465 }; 466 #endif 467 /* 468 * MPSAFE 469 */ 470 int 471 freebsd4_sigaction(td, uap) 472 struct thread *td; 473 register struct freebsd4_sigaction_args *uap; 474 { 475 struct sigaction act, oact; 476 register struct sigaction *actp, *oactp; 477 int error; 478 479 480 actp = (uap->act != NULL) ? &act : NULL; 481 oactp = (uap->oact != NULL) ? &oact : NULL; 482 if (actp) { 483 error = copyin(uap->act, actp, sizeof(act)); 484 if (error) 485 return (error); 486 } 487 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 488 if (oactp && !error) 489 error = copyout(oactp, uap->oact, sizeof(oact)); 490 return (error); 491 } 492 #endif /* COMAPT_FREEBSD4 */ 493 494 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 495 #ifndef _SYS_SYSPROTO_H_ 496 struct osigaction_args { 497 int signum; 498 struct osigaction *nsa; 499 struct osigaction *osa; 500 }; 501 #endif 502 /* 503 * MPSAFE 504 */ 505 int 506 osigaction(td, uap) 507 struct thread *td; 508 register struct osigaction_args *uap; 509 { 510 struct osigaction sa; 511 struct sigaction nsa, osa; 512 register struct sigaction *nsap, *osap; 513 int error; 514 515 if (uap->signum <= 0 || uap->signum >= ONSIG) 516 return (EINVAL); 517 518 nsap = (uap->nsa != NULL) ? &nsa : NULL; 519 osap = (uap->osa != NULL) ? &osa : NULL; 520 521 if (nsap) { 522 error = copyin(uap->nsa, &sa, sizeof(sa)); 523 if (error) 524 return (error); 525 nsap->sa_handler = sa.sa_handler; 526 nsap->sa_flags = sa.sa_flags; 527 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 528 } 529 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 530 if (osap && !error) { 531 sa.sa_handler = osap->sa_handler; 532 sa.sa_flags = osap->sa_flags; 533 SIG2OSIG(osap->sa_mask, sa.sa_mask); 534 error = copyout(&sa, uap->osa, sizeof(sa)); 535 } 536 return (error); 537 } 538 539 #if !defined(__i386__) && !defined(__alpha__) 540 /* Avoid replicating the same stub everywhere */ 541 int 542 osigreturn(td, uap) 543 struct thread *td; 544 struct osigreturn_args *uap; 545 { 546 547 return (nosys(td, (struct nosys_args *)uap)); 548 } 549 #endif 550 #endif /* COMPAT_43 */ 551 552 /* 553 * Initialize signal state for process 0; 554 * set to ignore signals that are ignored by default. 555 */ 556 void 557 siginit(p) 558 struct proc *p; 559 { 560 register int i; 561 struct sigacts *ps; 562 563 PROC_LOCK(p); 564 ps = p->p_sigacts; 565 mtx_lock(&ps->ps_mtx); 566 for (i = 1; i <= NSIG; i++) 567 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 568 SIGADDSET(ps->ps_sigignore, i); 569 mtx_unlock(&ps->ps_mtx); 570 PROC_UNLOCK(p); 571 } 572 573 /* 574 * Reset signals for an exec of the specified process. 575 */ 576 void 577 execsigs(struct proc *p) 578 { 579 struct sigacts *ps; 580 int sig; 581 struct thread *td; 582 583 /* 584 * Reset caught signals. Held signals remain held 585 * through td_sigmask (unless they were caught, 586 * and are now ignored by default). 587 */ 588 PROC_LOCK_ASSERT(p, MA_OWNED); 589 td = FIRST_THREAD_IN_PROC(p); 590 ps = p->p_sigacts; 591 mtx_lock(&ps->ps_mtx); 592 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 593 sig = sig_ffs(&ps->ps_sigcatch); 594 SIGDELSET(ps->ps_sigcatch, sig); 595 if (sigprop(sig) & SA_IGNORE) { 596 if (sig != SIGCONT) 597 SIGADDSET(ps->ps_sigignore, sig); 598 SIGDELSET(p->p_siglist, sig); 599 /* 600 * There is only one thread at this point. 601 */ 602 SIGDELSET(td->td_siglist, sig); 603 } 604 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 605 } 606 /* 607 * Reset stack state to the user stack. 608 * Clear set of signals caught on the signal stack. 609 */ 610 td->td_sigstk.ss_flags = SS_DISABLE; 611 td->td_sigstk.ss_size = 0; 612 td->td_sigstk.ss_sp = 0; 613 td->td_pflags &= ~TDP_ALTSTACK; 614 /* 615 * Reset no zombies if child dies flag as Solaris does. 616 */ 617 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 618 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 619 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 620 mtx_unlock(&ps->ps_mtx); 621 } 622 623 /* 624 * kern_sigprocmask() 625 * 626 * Manipulate signal mask. 627 */ 628 int 629 kern_sigprocmask(td, how, set, oset, old) 630 struct thread *td; 631 int how; 632 sigset_t *set, *oset; 633 int old; 634 { 635 int error; 636 637 PROC_LOCK(td->td_proc); 638 if (oset != NULL) 639 *oset = td->td_sigmask; 640 641 error = 0; 642 if (set != NULL) { 643 switch (how) { 644 case SIG_BLOCK: 645 SIG_CANTMASK(*set); 646 SIGSETOR(td->td_sigmask, *set); 647 break; 648 case SIG_UNBLOCK: 649 SIGSETNAND(td->td_sigmask, *set); 650 signotify(td); 651 break; 652 case SIG_SETMASK: 653 SIG_CANTMASK(*set); 654 if (old) 655 SIGSETLO(td->td_sigmask, *set); 656 else 657 td->td_sigmask = *set; 658 signotify(td); 659 break; 660 default: 661 error = EINVAL; 662 break; 663 } 664 } 665 PROC_UNLOCK(td->td_proc); 666 return (error); 667 } 668 669 /* 670 * sigprocmask() - MP SAFE 671 */ 672 673 #ifndef _SYS_SYSPROTO_H_ 674 struct sigprocmask_args { 675 int how; 676 const sigset_t *set; 677 sigset_t *oset; 678 }; 679 #endif 680 int 681 sigprocmask(td, uap) 682 register struct thread *td; 683 struct sigprocmask_args *uap; 684 { 685 sigset_t set, oset; 686 sigset_t *setp, *osetp; 687 int error; 688 689 setp = (uap->set != NULL) ? &set : NULL; 690 osetp = (uap->oset != NULL) ? &oset : NULL; 691 if (setp) { 692 error = copyin(uap->set, setp, sizeof(set)); 693 if (error) 694 return (error); 695 } 696 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 697 if (osetp && !error) { 698 error = copyout(osetp, uap->oset, sizeof(oset)); 699 } 700 return (error); 701 } 702 703 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 704 /* 705 * osigprocmask() - MP SAFE 706 */ 707 #ifndef _SYS_SYSPROTO_H_ 708 struct osigprocmask_args { 709 int how; 710 osigset_t mask; 711 }; 712 #endif 713 int 714 osigprocmask(td, uap) 715 register struct thread *td; 716 struct osigprocmask_args *uap; 717 { 718 sigset_t set, oset; 719 int error; 720 721 OSIG2SIG(uap->mask, set); 722 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 723 SIG2OSIG(oset, td->td_retval[0]); 724 return (error); 725 } 726 #endif /* COMPAT_43 */ 727 728 #ifndef _SYS_SYSPROTO_H_ 729 struct sigpending_args { 730 sigset_t *set; 731 }; 732 #endif 733 /* 734 * MPSAFE 735 */ 736 int 737 sigwait(struct thread *td, struct sigwait_args *uap) 738 { 739 siginfo_t info; 740 sigset_t set; 741 int error; 742 743 error = copyin(uap->set, &set, sizeof(set)); 744 if (error) { 745 td->td_retval[0] = error; 746 return (0); 747 } 748 749 error = kern_sigtimedwait(td, set, &info, NULL); 750 if (error) { 751 if (error == ERESTART) 752 return (error); 753 td->td_retval[0] = error; 754 return (0); 755 } 756 757 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 758 /* Repost if we got an error. */ 759 if (error && info.si_signo) { 760 PROC_LOCK(td->td_proc); 761 tdsignal(td, info.si_signo, SIGTARGET_TD); 762 PROC_UNLOCK(td->td_proc); 763 } 764 td->td_retval[0] = error; 765 return (0); 766 } 767 /* 768 * MPSAFE 769 */ 770 int 771 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 772 { 773 struct timespec ts; 774 struct timespec *timeout; 775 sigset_t set; 776 siginfo_t info; 777 int error; 778 779 if (uap->timeout) { 780 error = copyin(uap->timeout, &ts, sizeof(ts)); 781 if (error) 782 return (error); 783 784 timeout = &ts; 785 } else 786 timeout = NULL; 787 788 error = copyin(uap->set, &set, sizeof(set)); 789 if (error) 790 return (error); 791 792 error = kern_sigtimedwait(td, set, &info, timeout); 793 if (error) 794 return (error); 795 796 if (uap->info) 797 error = copyout(&info, uap->info, sizeof(info)); 798 /* Repost if we got an error. */ 799 if (error && info.si_signo) { 800 PROC_LOCK(td->td_proc); 801 tdsignal(td, info.si_signo, SIGTARGET_TD); 802 PROC_UNLOCK(td->td_proc); 803 } else { 804 td->td_retval[0] = info.si_signo; 805 } 806 return (error); 807 } 808 809 /* 810 * MPSAFE 811 */ 812 int 813 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 814 { 815 siginfo_t info; 816 sigset_t set; 817 int error; 818 819 error = copyin(uap->set, &set, sizeof(set)); 820 if (error) 821 return (error); 822 823 error = kern_sigtimedwait(td, set, &info, NULL); 824 if (error) 825 return (error); 826 827 if (uap->info) 828 error = copyout(&info, uap->info, sizeof(info)); 829 /* Repost if we got an error. */ 830 if (error && info.si_signo) { 831 PROC_LOCK(td->td_proc); 832 tdsignal(td, info.si_signo, SIGTARGET_TD); 833 PROC_UNLOCK(td->td_proc); 834 } else { 835 td->td_retval[0] = info.si_signo; 836 } 837 return (error); 838 } 839 840 static int 841 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info, 842 struct timespec *timeout) 843 { 844 struct sigacts *ps; 845 sigset_t savedmask; 846 struct proc *p; 847 int error, sig, hz, i, timevalid = 0; 848 struct timespec rts, ets, ts; 849 struct timeval tv; 850 851 p = td->td_proc; 852 error = 0; 853 sig = 0; 854 SIG_CANTMASK(waitset); 855 856 PROC_LOCK(p); 857 ps = p->p_sigacts; 858 savedmask = td->td_sigmask; 859 if (timeout) { 860 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 861 timevalid = 1; 862 getnanouptime(&rts); 863 ets = rts; 864 timespecadd(&ets, timeout); 865 } 866 } 867 868 again: 869 for (i = 1; i <= _SIG_MAXSIG; ++i) { 870 if (!SIGISMEMBER(waitset, i)) 871 continue; 872 if (SIGISMEMBER(td->td_siglist, i)) { 873 SIGFILLSET(td->td_sigmask); 874 SIG_CANTMASK(td->td_sigmask); 875 SIGDELSET(td->td_sigmask, i); 876 mtx_lock(&ps->ps_mtx); 877 sig = cursig(td); 878 i = 0; 879 mtx_unlock(&ps->ps_mtx); 880 } else if (SIGISMEMBER(p->p_siglist, i)) { 881 if (p->p_flag & P_SA) { 882 p->p_flag |= P_SIGEVENT; 883 wakeup(&p->p_siglist); 884 } 885 SIGDELSET(p->p_siglist, i); 886 SIGADDSET(td->td_siglist, i); 887 SIGFILLSET(td->td_sigmask); 888 SIG_CANTMASK(td->td_sigmask); 889 SIGDELSET(td->td_sigmask, i); 890 mtx_lock(&ps->ps_mtx); 891 sig = cursig(td); 892 i = 0; 893 mtx_unlock(&ps->ps_mtx); 894 } 895 if (sig) 896 goto out; 897 } 898 if (error) 899 goto out; 900 901 /* 902 * POSIX says this must be checked after looking for pending 903 * signals. 904 */ 905 if (timeout) { 906 if (!timevalid) { 907 error = EINVAL; 908 goto out; 909 } 910 getnanouptime(&rts); 911 if (timespeccmp(&rts, &ets, >=)) { 912 error = EAGAIN; 913 goto out; 914 } 915 ts = ets; 916 timespecsub(&ts, &rts); 917 TIMESPEC_TO_TIMEVAL(&tv, &ts); 918 hz = tvtohz(&tv); 919 } else 920 hz = 0; 921 922 td->td_sigmask = savedmask; 923 SIGSETNAND(td->td_sigmask, waitset); 924 signotify(td); 925 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 926 if (timeout) { 927 if (error == ERESTART) { 928 /* timeout can not be restarted. */ 929 error = EINTR; 930 } else if (error == EAGAIN) { 931 /* will calculate timeout by ourself. */ 932 error = 0; 933 } 934 } 935 goto again; 936 937 out: 938 td->td_sigmask = savedmask; 939 signotify(td); 940 if (sig) { 941 sig_t action; 942 943 error = 0; 944 mtx_lock(&ps->ps_mtx); 945 action = ps->ps_sigact[_SIG_IDX(sig)]; 946 mtx_unlock(&ps->ps_mtx); 947 #ifdef KTRACE 948 if (KTRPOINT(td, KTR_PSIG)) 949 ktrpsig(sig, action, &td->td_sigmask, 0); 950 #endif 951 _STOPEVENT(p, S_SIG, sig); 952 953 SIGDELSET(td->td_siglist, sig); 954 bzero(info, sizeof(*info)); 955 info->si_signo = sig; 956 info->si_code = 0; 957 } 958 PROC_UNLOCK(p); 959 return (error); 960 } 961 962 /* 963 * MPSAFE 964 */ 965 int 966 sigpending(td, uap) 967 struct thread *td; 968 struct sigpending_args *uap; 969 { 970 struct proc *p = td->td_proc; 971 sigset_t siglist; 972 973 PROC_LOCK(p); 974 siglist = p->p_siglist; 975 SIGSETOR(siglist, td->td_siglist); 976 PROC_UNLOCK(p); 977 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 978 } 979 980 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 981 #ifndef _SYS_SYSPROTO_H_ 982 struct osigpending_args { 983 int dummy; 984 }; 985 #endif 986 /* 987 * MPSAFE 988 */ 989 int 990 osigpending(td, uap) 991 struct thread *td; 992 struct osigpending_args *uap; 993 { 994 struct proc *p = td->td_proc; 995 sigset_t siglist; 996 997 PROC_LOCK(p); 998 siglist = p->p_siglist; 999 SIGSETOR(siglist, td->td_siglist); 1000 PROC_UNLOCK(p); 1001 SIG2OSIG(siglist, td->td_retval[0]); 1002 return (0); 1003 } 1004 #endif /* COMPAT_43 */ 1005 1006 #if defined(COMPAT_43) 1007 /* 1008 * Generalized interface signal handler, 4.3-compatible. 1009 */ 1010 #ifndef _SYS_SYSPROTO_H_ 1011 struct osigvec_args { 1012 int signum; 1013 struct sigvec *nsv; 1014 struct sigvec *osv; 1015 }; 1016 #endif 1017 /* 1018 * MPSAFE 1019 */ 1020 /* ARGSUSED */ 1021 int 1022 osigvec(td, uap) 1023 struct thread *td; 1024 register struct osigvec_args *uap; 1025 { 1026 struct sigvec vec; 1027 struct sigaction nsa, osa; 1028 register struct sigaction *nsap, *osap; 1029 int error; 1030 1031 if (uap->signum <= 0 || uap->signum >= ONSIG) 1032 return (EINVAL); 1033 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1034 osap = (uap->osv != NULL) ? &osa : NULL; 1035 if (nsap) { 1036 error = copyin(uap->nsv, &vec, sizeof(vec)); 1037 if (error) 1038 return (error); 1039 nsap->sa_handler = vec.sv_handler; 1040 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1041 nsap->sa_flags = vec.sv_flags; 1042 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1043 } 1044 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1045 if (osap && !error) { 1046 vec.sv_handler = osap->sa_handler; 1047 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1048 vec.sv_flags = osap->sa_flags; 1049 vec.sv_flags &= ~SA_NOCLDWAIT; 1050 vec.sv_flags ^= SA_RESTART; 1051 error = copyout(&vec, uap->osv, sizeof(vec)); 1052 } 1053 return (error); 1054 } 1055 1056 #ifndef _SYS_SYSPROTO_H_ 1057 struct osigblock_args { 1058 int mask; 1059 }; 1060 #endif 1061 /* 1062 * MPSAFE 1063 */ 1064 int 1065 osigblock(td, uap) 1066 register struct thread *td; 1067 struct osigblock_args *uap; 1068 { 1069 struct proc *p = td->td_proc; 1070 sigset_t set; 1071 1072 OSIG2SIG(uap->mask, set); 1073 SIG_CANTMASK(set); 1074 PROC_LOCK(p); 1075 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1076 SIGSETOR(td->td_sigmask, set); 1077 PROC_UNLOCK(p); 1078 return (0); 1079 } 1080 1081 #ifndef _SYS_SYSPROTO_H_ 1082 struct osigsetmask_args { 1083 int mask; 1084 }; 1085 #endif 1086 /* 1087 * MPSAFE 1088 */ 1089 int 1090 osigsetmask(td, uap) 1091 struct thread *td; 1092 struct osigsetmask_args *uap; 1093 { 1094 struct proc *p = td->td_proc; 1095 sigset_t set; 1096 1097 OSIG2SIG(uap->mask, set); 1098 SIG_CANTMASK(set); 1099 PROC_LOCK(p); 1100 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1101 SIGSETLO(td->td_sigmask, set); 1102 signotify(td); 1103 PROC_UNLOCK(p); 1104 return (0); 1105 } 1106 #endif /* COMPAT_43 */ 1107 1108 /* 1109 * Suspend process until signal, providing mask to be set 1110 * in the meantime. 1111 ***** XXXKSE this doesn't make sense under KSE. 1112 ***** Do we suspend the thread or all threads in the process? 1113 ***** How do we suspend threads running NOW on another processor? 1114 */ 1115 #ifndef _SYS_SYSPROTO_H_ 1116 struct sigsuspend_args { 1117 const sigset_t *sigmask; 1118 }; 1119 #endif 1120 /* 1121 * MPSAFE 1122 */ 1123 /* ARGSUSED */ 1124 int 1125 sigsuspend(td, uap) 1126 struct thread *td; 1127 struct sigsuspend_args *uap; 1128 { 1129 sigset_t mask; 1130 int error; 1131 1132 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1133 if (error) 1134 return (error); 1135 return (kern_sigsuspend(td, mask)); 1136 } 1137 1138 int 1139 kern_sigsuspend(struct thread *td, sigset_t mask) 1140 { 1141 struct proc *p = td->td_proc; 1142 1143 /* 1144 * When returning from sigsuspend, we want 1145 * the old mask to be restored after the 1146 * signal handler has finished. Thus, we 1147 * save it here and mark the sigacts structure 1148 * to indicate this. 1149 */ 1150 PROC_LOCK(p); 1151 td->td_oldsigmask = td->td_sigmask; 1152 td->td_pflags |= TDP_OLDMASK; 1153 SIG_CANTMASK(mask); 1154 td->td_sigmask = mask; 1155 signotify(td); 1156 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1157 /* void */; 1158 PROC_UNLOCK(p); 1159 /* always return EINTR rather than ERESTART... */ 1160 return (EINTR); 1161 } 1162 1163 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1164 /* 1165 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1166 * convention: libc stub passes mask, not pointer, to save a copyin. 1167 */ 1168 #ifndef _SYS_SYSPROTO_H_ 1169 struct osigsuspend_args { 1170 osigset_t mask; 1171 }; 1172 #endif 1173 /* 1174 * MPSAFE 1175 */ 1176 /* ARGSUSED */ 1177 int 1178 osigsuspend(td, uap) 1179 struct thread *td; 1180 struct osigsuspend_args *uap; 1181 { 1182 struct proc *p = td->td_proc; 1183 sigset_t mask; 1184 1185 PROC_LOCK(p); 1186 td->td_oldsigmask = td->td_sigmask; 1187 td->td_pflags |= TDP_OLDMASK; 1188 OSIG2SIG(uap->mask, mask); 1189 SIG_CANTMASK(mask); 1190 SIGSETLO(td->td_sigmask, mask); 1191 signotify(td); 1192 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1193 /* void */; 1194 PROC_UNLOCK(p); 1195 /* always return EINTR rather than ERESTART... */ 1196 return (EINTR); 1197 } 1198 #endif /* COMPAT_43 */ 1199 1200 #if defined(COMPAT_43) 1201 #ifndef _SYS_SYSPROTO_H_ 1202 struct osigstack_args { 1203 struct sigstack *nss; 1204 struct sigstack *oss; 1205 }; 1206 #endif 1207 /* 1208 * MPSAFE 1209 */ 1210 /* ARGSUSED */ 1211 int 1212 osigstack(td, uap) 1213 struct thread *td; 1214 register struct osigstack_args *uap; 1215 { 1216 struct sigstack nss, oss; 1217 int error = 0; 1218 1219 if (uap->nss != NULL) { 1220 error = copyin(uap->nss, &nss, sizeof(nss)); 1221 if (error) 1222 return (error); 1223 } 1224 oss.ss_sp = td->td_sigstk.ss_sp; 1225 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1226 if (uap->nss != NULL) { 1227 td->td_sigstk.ss_sp = nss.ss_sp; 1228 td->td_sigstk.ss_size = 0; 1229 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1230 td->td_pflags |= TDP_ALTSTACK; 1231 } 1232 if (uap->oss != NULL) 1233 error = copyout(&oss, uap->oss, sizeof(oss)); 1234 1235 return (error); 1236 } 1237 #endif /* COMPAT_43 */ 1238 1239 #ifndef _SYS_SYSPROTO_H_ 1240 struct sigaltstack_args { 1241 stack_t *ss; 1242 stack_t *oss; 1243 }; 1244 #endif 1245 /* 1246 * MPSAFE 1247 */ 1248 /* ARGSUSED */ 1249 int 1250 sigaltstack(td, uap) 1251 struct thread *td; 1252 register struct sigaltstack_args *uap; 1253 { 1254 stack_t ss, oss; 1255 int error; 1256 1257 if (uap->ss != NULL) { 1258 error = copyin(uap->ss, &ss, sizeof(ss)); 1259 if (error) 1260 return (error); 1261 } 1262 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1263 (uap->oss != NULL) ? &oss : NULL); 1264 if (error) 1265 return (error); 1266 if (uap->oss != NULL) 1267 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1268 return (error); 1269 } 1270 1271 int 1272 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1273 { 1274 struct proc *p = td->td_proc; 1275 int oonstack; 1276 1277 oonstack = sigonstack(cpu_getstack(td)); 1278 1279 if (oss != NULL) { 1280 *oss = td->td_sigstk; 1281 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1282 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1283 } 1284 1285 if (ss != NULL) { 1286 if (oonstack) 1287 return (EPERM); 1288 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1289 return (EINVAL); 1290 if (!(ss->ss_flags & SS_DISABLE)) { 1291 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1292 return (ENOMEM); 1293 } 1294 td->td_sigstk = *ss; 1295 td->td_pflags |= TDP_ALTSTACK; 1296 } else { 1297 td->td_pflags &= ~TDP_ALTSTACK; 1298 } 1299 } 1300 return (0); 1301 } 1302 1303 /* 1304 * Common code for kill process group/broadcast kill. 1305 * cp is calling process. 1306 */ 1307 static int 1308 killpg1(td, sig, pgid, all) 1309 register struct thread *td; 1310 int sig, pgid, all; 1311 { 1312 register struct proc *p; 1313 struct pgrp *pgrp; 1314 int nfound = 0; 1315 1316 if (all) { 1317 /* 1318 * broadcast 1319 */ 1320 sx_slock(&allproc_lock); 1321 LIST_FOREACH(p, &allproc, p_list) { 1322 PROC_LOCK(p); 1323 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1324 p == td->td_proc) { 1325 PROC_UNLOCK(p); 1326 continue; 1327 } 1328 if (p_cansignal(td, p, sig) == 0) { 1329 nfound++; 1330 if (sig) 1331 psignal(p, sig); 1332 } 1333 PROC_UNLOCK(p); 1334 } 1335 sx_sunlock(&allproc_lock); 1336 } else { 1337 sx_slock(&proctree_lock); 1338 if (pgid == 0) { 1339 /* 1340 * zero pgid means send to my process group. 1341 */ 1342 pgrp = td->td_proc->p_pgrp; 1343 PGRP_LOCK(pgrp); 1344 } else { 1345 pgrp = pgfind(pgid); 1346 if (pgrp == NULL) { 1347 sx_sunlock(&proctree_lock); 1348 return (ESRCH); 1349 } 1350 } 1351 sx_sunlock(&proctree_lock); 1352 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1353 PROC_LOCK(p); 1354 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1355 PROC_UNLOCK(p); 1356 continue; 1357 } 1358 if (p_cansignal(td, p, sig) == 0) { 1359 nfound++; 1360 if (sig) 1361 psignal(p, sig); 1362 } 1363 PROC_UNLOCK(p); 1364 } 1365 PGRP_UNLOCK(pgrp); 1366 } 1367 return (nfound ? 0 : ESRCH); 1368 } 1369 1370 #ifndef _SYS_SYSPROTO_H_ 1371 struct kill_args { 1372 int pid; 1373 int signum; 1374 }; 1375 #endif 1376 /* 1377 * MPSAFE 1378 */ 1379 /* ARGSUSED */ 1380 int 1381 kill(td, uap) 1382 register struct thread *td; 1383 register struct kill_args *uap; 1384 { 1385 register struct proc *p; 1386 int error; 1387 1388 if ((u_int)uap->signum > _SIG_MAXSIG) 1389 return (EINVAL); 1390 1391 if (uap->pid > 0) { 1392 /* kill single process */ 1393 if ((p = pfind(uap->pid)) == NULL) { 1394 if ((p = zpfind(uap->pid)) == NULL) 1395 return (ESRCH); 1396 } 1397 error = p_cansignal(td, p, uap->signum); 1398 if (error == 0 && uap->signum) 1399 psignal(p, uap->signum); 1400 PROC_UNLOCK(p); 1401 return (error); 1402 } 1403 switch (uap->pid) { 1404 case -1: /* broadcast signal */ 1405 return (killpg1(td, uap->signum, 0, 1)); 1406 case 0: /* signal own process group */ 1407 return (killpg1(td, uap->signum, 0, 0)); 1408 default: /* negative explicit process group */ 1409 return (killpg1(td, uap->signum, -uap->pid, 0)); 1410 } 1411 /* NOTREACHED */ 1412 } 1413 1414 #if defined(COMPAT_43) 1415 #ifndef _SYS_SYSPROTO_H_ 1416 struct okillpg_args { 1417 int pgid; 1418 int signum; 1419 }; 1420 #endif 1421 /* 1422 * MPSAFE 1423 */ 1424 /* ARGSUSED */ 1425 int 1426 okillpg(td, uap) 1427 struct thread *td; 1428 register struct okillpg_args *uap; 1429 { 1430 1431 if ((u_int)uap->signum > _SIG_MAXSIG) 1432 return (EINVAL); 1433 return (killpg1(td, uap->signum, uap->pgid, 0)); 1434 } 1435 #endif /* COMPAT_43 */ 1436 1437 /* 1438 * Send a signal to a process group. 1439 */ 1440 void 1441 gsignal(pgid, sig) 1442 int pgid, sig; 1443 { 1444 struct pgrp *pgrp; 1445 1446 if (pgid != 0) { 1447 sx_slock(&proctree_lock); 1448 pgrp = pgfind(pgid); 1449 sx_sunlock(&proctree_lock); 1450 if (pgrp != NULL) { 1451 pgsignal(pgrp, sig, 0); 1452 PGRP_UNLOCK(pgrp); 1453 } 1454 } 1455 } 1456 1457 /* 1458 * Send a signal to a process group. If checktty is 1, 1459 * limit to members which have a controlling terminal. 1460 */ 1461 void 1462 pgsignal(pgrp, sig, checkctty) 1463 struct pgrp *pgrp; 1464 int sig, checkctty; 1465 { 1466 register struct proc *p; 1467 1468 if (pgrp) { 1469 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1470 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1471 PROC_LOCK(p); 1472 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1473 psignal(p, sig); 1474 PROC_UNLOCK(p); 1475 } 1476 } 1477 } 1478 1479 /* 1480 * Send a signal caused by a trap to the current thread. 1481 * If it will be caught immediately, deliver it with correct code. 1482 * Otherwise, post it normally. 1483 * 1484 * MPSAFE 1485 */ 1486 void 1487 trapsignal(struct thread *td, int sig, u_long code) 1488 { 1489 struct sigacts *ps; 1490 struct proc *p; 1491 siginfo_t siginfo; 1492 int error; 1493 1494 p = td->td_proc; 1495 if (td->td_pflags & TDP_SA) { 1496 if (td->td_mailbox == NULL) 1497 thread_user_enter(td); 1498 PROC_LOCK(p); 1499 SIGDELSET(td->td_sigmask, sig); 1500 mtx_lock_spin(&sched_lock); 1501 /* 1502 * Force scheduling an upcall, so UTS has chance to 1503 * process the signal before thread runs again in 1504 * userland. 1505 */ 1506 if (td->td_upcall) 1507 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1508 mtx_unlock_spin(&sched_lock); 1509 } else { 1510 PROC_LOCK(p); 1511 } 1512 ps = p->p_sigacts; 1513 mtx_lock(&ps->ps_mtx); 1514 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1515 !SIGISMEMBER(td->td_sigmask, sig)) { 1516 p->p_stats->p_ru.ru_nsignals++; 1517 #ifdef KTRACE 1518 if (KTRPOINT(curthread, KTR_PSIG)) 1519 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1520 &td->td_sigmask, code); 1521 #endif 1522 if (!(td->td_pflags & TDP_SA)) 1523 (*p->p_sysent->sv_sendsig)( 1524 ps->ps_sigact[_SIG_IDX(sig)], sig, 1525 &td->td_sigmask, code); 1526 else if (td->td_mailbox == NULL) { 1527 mtx_unlock(&ps->ps_mtx); 1528 /* UTS caused a sync signal */ 1529 p->p_code = code; /* XXX for core dump/debugger */ 1530 p->p_sig = sig; /* XXX to verify code */ 1531 sigexit(td, sig); 1532 } else { 1533 cpu_thread_siginfo(sig, code, &siginfo); 1534 mtx_unlock(&ps->ps_mtx); 1535 SIGADDSET(td->td_sigmask, sig); 1536 PROC_UNLOCK(p); 1537 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1538 sizeof(siginfo)); 1539 PROC_LOCK(p); 1540 /* UTS memory corrupted */ 1541 if (error) 1542 sigexit(td, SIGSEGV); 1543 mtx_lock(&ps->ps_mtx); 1544 } 1545 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1546 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1547 SIGADDSET(td->td_sigmask, sig); 1548 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1549 /* 1550 * See kern_sigaction() for origin of this code. 1551 */ 1552 SIGDELSET(ps->ps_sigcatch, sig); 1553 if (sig != SIGCONT && 1554 sigprop(sig) & SA_IGNORE) 1555 SIGADDSET(ps->ps_sigignore, sig); 1556 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1557 } 1558 mtx_unlock(&ps->ps_mtx); 1559 } else { 1560 mtx_unlock(&ps->ps_mtx); 1561 p->p_code = code; /* XXX for core dump/debugger */ 1562 p->p_sig = sig; /* XXX to verify code */ 1563 tdsignal(td, sig, SIGTARGET_TD); 1564 } 1565 PROC_UNLOCK(p); 1566 } 1567 1568 static struct thread * 1569 sigtd(struct proc *p, int sig, int prop) 1570 { 1571 struct thread *td, *signal_td; 1572 1573 PROC_LOCK_ASSERT(p, MA_OWNED); 1574 1575 /* 1576 * Check if current thread can handle the signal without 1577 * switching conetxt to another thread. 1578 */ 1579 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1580 return (curthread); 1581 signal_td = NULL; 1582 mtx_lock_spin(&sched_lock); 1583 FOREACH_THREAD_IN_PROC(p, td) { 1584 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1585 signal_td = td; 1586 break; 1587 } 1588 } 1589 if (signal_td == NULL) 1590 signal_td = FIRST_THREAD_IN_PROC(p); 1591 mtx_unlock_spin(&sched_lock); 1592 return (signal_td); 1593 } 1594 1595 /* 1596 * Send the signal to the process. If the signal has an action, the action 1597 * is usually performed by the target process rather than the caller; we add 1598 * the signal to the set of pending signals for the process. 1599 * 1600 * Exceptions: 1601 * o When a stop signal is sent to a sleeping process that takes the 1602 * default action, the process is stopped without awakening it. 1603 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1604 * regardless of the signal action (eg, blocked or ignored). 1605 * 1606 * Other ignored signals are discarded immediately. 1607 * 1608 * MPSAFE 1609 */ 1610 void 1611 psignal(struct proc *p, int sig) 1612 { 1613 struct thread *td; 1614 int prop; 1615 1616 if (!_SIG_VALID(sig)) 1617 panic("psignal(): invalid signal"); 1618 1619 PROC_LOCK_ASSERT(p, MA_OWNED); 1620 /* 1621 * IEEE Std 1003.1-2001: return success when killing a zombie. 1622 */ 1623 if (p->p_state == PRS_ZOMBIE) 1624 return; 1625 prop = sigprop(sig); 1626 1627 /* 1628 * Find a thread to deliver the signal to. 1629 */ 1630 td = sigtd(p, sig, prop); 1631 1632 tdsignal(td, sig, SIGTARGET_P); 1633 } 1634 1635 /* 1636 * MPSAFE 1637 */ 1638 void 1639 tdsignal(struct thread *td, int sig, sigtarget_t target) 1640 { 1641 sigset_t saved; 1642 struct proc *p = td->td_proc; 1643 1644 if (p->p_flag & P_SA) 1645 saved = p->p_siglist; 1646 do_tdsignal(td, sig, target); 1647 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1648 if (!SIGSETEQ(saved, p->p_siglist)) { 1649 /* pending set changed */ 1650 p->p_flag |= P_SIGEVENT; 1651 wakeup(&p->p_siglist); 1652 } 1653 } 1654 } 1655 1656 static void 1657 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1658 { 1659 struct proc *p; 1660 register sig_t action; 1661 sigset_t *siglist; 1662 struct thread *td0; 1663 register int prop; 1664 struct sigacts *ps; 1665 1666 if (!_SIG_VALID(sig)) 1667 panic("do_tdsignal(): invalid signal"); 1668 1669 p = td->td_proc; 1670 ps = p->p_sigacts; 1671 1672 PROC_LOCK_ASSERT(p, MA_OWNED); 1673 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 1674 1675 prop = sigprop(sig); 1676 1677 /* 1678 * If the signal is blocked and not destined for this thread, then 1679 * assign it to the process so that we can find it later in the first 1680 * thread that unblocks it. Otherwise, assign it to this thread now. 1681 */ 1682 if (target == SIGTARGET_TD) { 1683 siglist = &td->td_siglist; 1684 } else { 1685 if (!SIGISMEMBER(td->td_sigmask, sig)) 1686 siglist = &td->td_siglist; 1687 else 1688 siglist = &p->p_siglist; 1689 } 1690 1691 /* 1692 * If the signal is being ignored, 1693 * then we forget about it immediately. 1694 * (Note: we don't set SIGCONT in ps_sigignore, 1695 * and if it is set to SIG_IGN, 1696 * action will be SIG_DFL here.) 1697 */ 1698 mtx_lock(&ps->ps_mtx); 1699 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1700 (p->p_flag & P_WEXIT)) { 1701 mtx_unlock(&ps->ps_mtx); 1702 return; 1703 } 1704 if (SIGISMEMBER(td->td_sigmask, sig)) 1705 action = SIG_HOLD; 1706 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1707 action = SIG_CATCH; 1708 else 1709 action = SIG_DFL; 1710 mtx_unlock(&ps->ps_mtx); 1711 1712 if (prop & SA_CONT) { 1713 SIG_STOPSIGMASK(p->p_siglist); 1714 /* 1715 * XXX Should investigate leaving STOP and CONT sigs only in 1716 * the proc's siglist. 1717 */ 1718 mtx_lock_spin(&sched_lock); 1719 FOREACH_THREAD_IN_PROC(p, td0) 1720 SIG_STOPSIGMASK(td0->td_siglist); 1721 mtx_unlock_spin(&sched_lock); 1722 } 1723 1724 if (prop & SA_STOP) { 1725 /* 1726 * If sending a tty stop signal to a member of an orphaned 1727 * process group, discard the signal here if the action 1728 * is default; don't stop the process below if sleeping, 1729 * and don't clear any pending SIGCONT. 1730 */ 1731 if ((prop & SA_TTYSTOP) && 1732 (p->p_pgrp->pg_jobc == 0) && 1733 (action == SIG_DFL)) 1734 return; 1735 SIG_CONTSIGMASK(p->p_siglist); 1736 mtx_lock_spin(&sched_lock); 1737 FOREACH_THREAD_IN_PROC(p, td0) 1738 SIG_CONTSIGMASK(td0->td_siglist); 1739 mtx_unlock_spin(&sched_lock); 1740 p->p_flag &= ~P_CONTINUED; 1741 } 1742 1743 SIGADDSET(*siglist, sig); 1744 signotify(td); /* uses schedlock */ 1745 /* 1746 * Defer further processing for signals which are held, 1747 * except that stopped processes must be continued by SIGCONT. 1748 */ 1749 if (action == SIG_HOLD && 1750 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1751 return; 1752 /* 1753 * SIGKILL: Remove procfs STOPEVENTs. 1754 */ 1755 if (sig == SIGKILL) { 1756 /* from procfs_ioctl.c: PIOCBIC */ 1757 p->p_stops = 0; 1758 /* from procfs_ioctl.c: PIOCCONT */ 1759 p->p_step = 0; 1760 wakeup(&p->p_step); 1761 } 1762 /* 1763 * Some signals have a process-wide effect and a per-thread 1764 * component. Most processing occurs when the process next 1765 * tries to cross the user boundary, however there are some 1766 * times when processing needs to be done immediatly, such as 1767 * waking up threads so that they can cross the user boundary. 1768 * We try do the per-process part here. 1769 */ 1770 if (P_SHOULDSTOP(p)) { 1771 /* 1772 * The process is in stopped mode. All the threads should be 1773 * either winding down or already on the suspended queue. 1774 */ 1775 if (p->p_flag & P_TRACED) { 1776 /* 1777 * The traced process is already stopped, 1778 * so no further action is necessary. 1779 * No signal can restart us. 1780 */ 1781 goto out; 1782 } 1783 1784 if (sig == SIGKILL) { 1785 /* 1786 * SIGKILL sets process running. 1787 * It will die elsewhere. 1788 * All threads must be restarted. 1789 */ 1790 p->p_flag &= ~P_STOPPED_SIG; 1791 goto runfast; 1792 } 1793 1794 if (prop & SA_CONT) { 1795 /* 1796 * If SIGCONT is default (or ignored), we continue the 1797 * process but don't leave the signal in siglist as 1798 * it has no further action. If SIGCONT is held, we 1799 * continue the process and leave the signal in 1800 * siglist. If the process catches SIGCONT, let it 1801 * handle the signal itself. If it isn't waiting on 1802 * an event, it goes back to run state. 1803 * Otherwise, process goes back to sleep state. 1804 */ 1805 p->p_flag &= ~P_STOPPED_SIG; 1806 p->p_flag |= P_CONTINUED; 1807 if (action == SIG_DFL) { 1808 SIGDELSET(*siglist, sig); 1809 } else if (action == SIG_CATCH) { 1810 /* 1811 * The process wants to catch it so it needs 1812 * to run at least one thread, but which one? 1813 * It would seem that the answer would be to 1814 * run an upcall in the next KSE to run, and 1815 * deliver the signal that way. In a NON KSE 1816 * process, we need to make sure that the 1817 * single thread is runnable asap. 1818 * XXXKSE for now however, make them all run. 1819 */ 1820 goto runfast; 1821 } 1822 /* 1823 * The signal is not ignored or caught. 1824 */ 1825 mtx_lock_spin(&sched_lock); 1826 thread_unsuspend(p); 1827 mtx_unlock_spin(&sched_lock); 1828 goto out; 1829 } 1830 1831 if (prop & SA_STOP) { 1832 /* 1833 * Already stopped, don't need to stop again 1834 * (If we did the shell could get confused). 1835 * Just make sure the signal STOP bit set. 1836 */ 1837 p->p_flag |= P_STOPPED_SIG; 1838 SIGDELSET(*siglist, sig); 1839 goto out; 1840 } 1841 1842 /* 1843 * All other kinds of signals: 1844 * If a thread is sleeping interruptibly, simulate a 1845 * wakeup so that when it is continued it will be made 1846 * runnable and can look at the signal. However, don't make 1847 * the PROCESS runnable, leave it stopped. 1848 * It may run a bit until it hits a thread_suspend_check(). 1849 */ 1850 mtx_lock_spin(&sched_lock); 1851 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 1852 sleepq_abort(td); 1853 mtx_unlock_spin(&sched_lock); 1854 goto out; 1855 /* 1856 * Mutexes are short lived. Threads waiting on them will 1857 * hit thread_suspend_check() soon. 1858 */ 1859 } else if (p->p_state == PRS_NORMAL) { 1860 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 1861 mtx_lock_spin(&sched_lock); 1862 tdsigwakeup(td, sig, action); 1863 mtx_unlock_spin(&sched_lock); 1864 goto out; 1865 } 1866 1867 MPASS(action == SIG_DFL); 1868 1869 if (prop & SA_STOP) { 1870 if (p->p_flag & P_PPWAIT) 1871 goto out; 1872 p->p_flag |= P_STOPPED_SIG; 1873 p->p_xstat = sig; 1874 mtx_lock_spin(&sched_lock); 1875 FOREACH_THREAD_IN_PROC(p, td0) { 1876 if (TD_IS_SLEEPING(td0) && 1877 (td0->td_flags & TDF_SINTR) && 1878 !TD_IS_SUSPENDED(td0)) { 1879 thread_suspend_one(td0); 1880 } else if (td != td0) { 1881 td0->td_flags |= TDF_ASTPENDING; 1882 } 1883 } 1884 thread_stopped(p); 1885 if (p->p_numthreads == p->p_suspcount) { 1886 SIGDELSET(p->p_siglist, p->p_xstat); 1887 FOREACH_THREAD_IN_PROC(p, td0) 1888 SIGDELSET(td0->td_siglist, p->p_xstat); 1889 } 1890 mtx_unlock_spin(&sched_lock); 1891 goto out; 1892 } 1893 else 1894 goto runfast; 1895 /* NOTREACHED */ 1896 } else { 1897 /* Not in "NORMAL" state. discard the signal. */ 1898 SIGDELSET(*siglist, sig); 1899 goto out; 1900 } 1901 1902 /* 1903 * The process is not stopped so we need to apply the signal to all the 1904 * running threads. 1905 */ 1906 1907 runfast: 1908 mtx_lock_spin(&sched_lock); 1909 tdsigwakeup(td, sig, action); 1910 thread_unsuspend(p); 1911 mtx_unlock_spin(&sched_lock); 1912 out: 1913 /* If we jump here, sched_lock should not be owned. */ 1914 mtx_assert(&sched_lock, MA_NOTOWNED); 1915 } 1916 1917 /* 1918 * The force of a signal has been directed against a single 1919 * thread. We need to see what we can do about knocking it 1920 * out of any sleep it may be in etc. 1921 */ 1922 static void 1923 tdsigwakeup(struct thread *td, int sig, sig_t action) 1924 { 1925 struct proc *p = td->td_proc; 1926 register int prop; 1927 1928 PROC_LOCK_ASSERT(p, MA_OWNED); 1929 mtx_assert(&sched_lock, MA_OWNED); 1930 prop = sigprop(sig); 1931 1932 /* 1933 * Bring the priority of a thread up if we want it to get 1934 * killed in this lifetime. 1935 */ 1936 if (action == SIG_DFL && (prop & SA_KILL)) { 1937 if (td->td_priority > PUSER) 1938 td->td_priority = PUSER; 1939 } 1940 1941 if (TD_ON_SLEEPQ(td)) { 1942 /* 1943 * If thread is sleeping uninterruptibly 1944 * we can't interrupt the sleep... the signal will 1945 * be noticed when the process returns through 1946 * trap() or syscall(). 1947 */ 1948 if ((td->td_flags & TDF_SINTR) == 0) 1949 return; 1950 /* 1951 * If SIGCONT is default (or ignored) and process is 1952 * asleep, we are finished; the process should not 1953 * be awakened. 1954 */ 1955 if ((prop & SA_CONT) && action == SIG_DFL) { 1956 SIGDELSET(p->p_siglist, sig); 1957 /* 1958 * It may be on either list in this state. 1959 * Remove from both for now. 1960 */ 1961 SIGDELSET(td->td_siglist, sig); 1962 return; 1963 } 1964 1965 /* 1966 * Give low priority threads a better chance to run. 1967 */ 1968 if (td->td_priority > PUSER) 1969 td->td_priority = PUSER; 1970 1971 sleepq_abort(td); 1972 } else { 1973 /* 1974 * Other states do nothing with the signal immediately, 1975 * other than kicking ourselves if we are running. 1976 * It will either never be noticed, or noticed very soon. 1977 */ 1978 #ifdef SMP 1979 if (TD_IS_RUNNING(td) && td != curthread) 1980 forward_signal(td); 1981 #endif 1982 } 1983 } 1984 1985 int 1986 ptracestop(struct thread *td, int sig) 1987 { 1988 struct proc *p = td->td_proc; 1989 struct thread *td0; 1990 1991 PROC_LOCK_ASSERT(p, MA_OWNED); 1992 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 1993 &p->p_mtx.mtx_object, "Stopping for traced signal"); 1994 1995 mtx_lock_spin(&sched_lock); 1996 td->td_flags |= TDF_XSIG; 1997 mtx_unlock_spin(&sched_lock); 1998 td->td_xsig = sig; 1999 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2000 if (p->p_flag & P_SINGLE_EXIT) { 2001 mtx_lock_spin(&sched_lock); 2002 td->td_flags &= ~TDF_XSIG; 2003 mtx_unlock_spin(&sched_lock); 2004 return (sig); 2005 } 2006 /* 2007 * Just make wait() to work, the last stopped thread 2008 * will win. 2009 */ 2010 p->p_xstat = sig; 2011 p->p_xthread = td; 2012 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2013 mtx_lock_spin(&sched_lock); 2014 FOREACH_THREAD_IN_PROC(p, td0) { 2015 if (TD_IS_SLEEPING(td0) && 2016 (td0->td_flags & TDF_SINTR) && 2017 !TD_IS_SUSPENDED(td0)) { 2018 thread_suspend_one(td0); 2019 } else if (td != td0) { 2020 td0->td_flags |= TDF_ASTPENDING; 2021 } 2022 } 2023 stopme: 2024 thread_stopped(p); 2025 thread_suspend_one(td); 2026 PROC_UNLOCK(p); 2027 DROP_GIANT(); 2028 mi_switch(SW_VOL, NULL); 2029 mtx_unlock_spin(&sched_lock); 2030 PICKUP_GIANT(); 2031 PROC_LOCK(p); 2032 if (!(p->p_flag & P_TRACED)) 2033 break; 2034 if (td->td_flags & TDF_DBSUSPEND) { 2035 if (p->p_flag & P_SINGLE_EXIT) 2036 break; 2037 mtx_lock_spin(&sched_lock); 2038 goto stopme; 2039 } 2040 } 2041 return (td->td_xsig); 2042 } 2043 2044 /* 2045 * If the current process has received a signal (should be caught or cause 2046 * termination, should interrupt current syscall), return the signal number. 2047 * Stop signals with default action are processed immediately, then cleared; 2048 * they aren't returned. This is checked after each entry to the system for 2049 * a syscall or trap (though this can usually be done without calling issignal 2050 * by checking the pending signal masks in cursig.) The normal call 2051 * sequence is 2052 * 2053 * while (sig = cursig(curthread)) 2054 * postsig(sig); 2055 */ 2056 static int 2057 issignal(td) 2058 struct thread *td; 2059 { 2060 struct proc *p; 2061 struct sigacts *ps; 2062 sigset_t sigpending; 2063 int sig, prop, newsig; 2064 struct thread *td0; 2065 2066 p = td->td_proc; 2067 ps = p->p_sigacts; 2068 mtx_assert(&ps->ps_mtx, MA_OWNED); 2069 PROC_LOCK_ASSERT(p, MA_OWNED); 2070 for (;;) { 2071 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2072 2073 sigpending = td->td_siglist; 2074 SIGSETNAND(sigpending, td->td_sigmask); 2075 2076 if (p->p_flag & P_PPWAIT) 2077 SIG_STOPSIGMASK(sigpending); 2078 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2079 return (0); 2080 sig = sig_ffs(&sigpending); 2081 2082 if (p->p_stops & S_SIG) { 2083 mtx_unlock(&ps->ps_mtx); 2084 stopevent(p, S_SIG, sig); 2085 mtx_lock(&ps->ps_mtx); 2086 } 2087 2088 /* 2089 * We should see pending but ignored signals 2090 * only if P_TRACED was on when they were posted. 2091 */ 2092 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2093 SIGDELSET(td->td_siglist, sig); 2094 if (td->td_pflags & TDP_SA) 2095 SIGADDSET(td->td_sigmask, sig); 2096 continue; 2097 } 2098 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2099 /* 2100 * If traced, always stop. 2101 */ 2102 mtx_unlock(&ps->ps_mtx); 2103 newsig = ptracestop(td, sig); 2104 mtx_lock(&ps->ps_mtx); 2105 2106 /* 2107 * If parent wants us to take the signal, 2108 * then it will leave it in p->p_xstat; 2109 * otherwise we just look for signals again. 2110 */ 2111 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2112 if (td->td_pflags & TDP_SA) 2113 SIGADDSET(td->td_sigmask, sig); 2114 if (newsig == 0) 2115 continue; 2116 sig = newsig; 2117 /* 2118 * If the traced bit got turned off, go back up 2119 * to the top to rescan signals. This ensures 2120 * that p_sig* and p_sigact are consistent. 2121 */ 2122 if ((p->p_flag & P_TRACED) == 0) 2123 continue; 2124 2125 /* 2126 * Put the new signal into td_siglist. If the 2127 * signal is being masked, look for other signals. 2128 */ 2129 SIGADDSET(td->td_siglist, sig); 2130 if (td->td_pflags & TDP_SA) 2131 SIGDELSET(td->td_sigmask, sig); 2132 if (SIGISMEMBER(td->td_sigmask, sig)) 2133 continue; 2134 signotify(td); 2135 } 2136 2137 prop = sigprop(sig); 2138 2139 /* 2140 * Decide whether the signal should be returned. 2141 * Return the signal's number, or fall through 2142 * to clear it from the pending mask. 2143 */ 2144 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2145 2146 case (intptr_t)SIG_DFL: 2147 /* 2148 * Don't take default actions on system processes. 2149 */ 2150 if (p->p_pid <= 1) { 2151 #ifdef DIAGNOSTIC 2152 /* 2153 * Are you sure you want to ignore SIGSEGV 2154 * in init? XXX 2155 */ 2156 printf("Process (pid %lu) got signal %d\n", 2157 (u_long)p->p_pid, sig); 2158 #endif 2159 break; /* == ignore */ 2160 } 2161 /* 2162 * If there is a pending stop signal to process 2163 * with default action, stop here, 2164 * then clear the signal. However, 2165 * if process is member of an orphaned 2166 * process group, ignore tty stop signals. 2167 */ 2168 if (prop & SA_STOP) { 2169 if (p->p_flag & P_TRACED || 2170 (p->p_pgrp->pg_jobc == 0 && 2171 prop & SA_TTYSTOP)) 2172 break; /* == ignore */ 2173 mtx_unlock(&ps->ps_mtx); 2174 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2175 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2176 p->p_flag |= P_STOPPED_SIG; 2177 p->p_xstat = sig; 2178 mtx_lock_spin(&sched_lock); 2179 FOREACH_THREAD_IN_PROC(p, td0) { 2180 if (TD_IS_SLEEPING(td0) && 2181 (td0->td_flags & TDF_SINTR) && 2182 !TD_IS_SUSPENDED(td0)) { 2183 thread_suspend_one(td0); 2184 } else if (td != td0) { 2185 td0->td_flags |= TDF_ASTPENDING; 2186 } 2187 } 2188 thread_stopped(p); 2189 thread_suspend_one(td); 2190 PROC_UNLOCK(p); 2191 DROP_GIANT(); 2192 mi_switch(SW_INVOL, NULL); 2193 mtx_unlock_spin(&sched_lock); 2194 PICKUP_GIANT(); 2195 PROC_LOCK(p); 2196 mtx_lock(&ps->ps_mtx); 2197 break; 2198 } else if (prop & SA_IGNORE) { 2199 /* 2200 * Except for SIGCONT, shouldn't get here. 2201 * Default action is to ignore; drop it. 2202 */ 2203 break; /* == ignore */ 2204 } else 2205 return (sig); 2206 /*NOTREACHED*/ 2207 2208 case (intptr_t)SIG_IGN: 2209 /* 2210 * Masking above should prevent us ever trying 2211 * to take action on an ignored signal other 2212 * than SIGCONT, unless process is traced. 2213 */ 2214 if ((prop & SA_CONT) == 0 && 2215 (p->p_flag & P_TRACED) == 0) 2216 printf("issignal\n"); 2217 break; /* == ignore */ 2218 2219 default: 2220 /* 2221 * This signal has an action, let 2222 * postsig() process it. 2223 */ 2224 return (sig); 2225 } 2226 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2227 } 2228 /* NOTREACHED */ 2229 } 2230 2231 /* 2232 * MPSAFE 2233 */ 2234 void 2235 thread_stopped(struct proc *p) 2236 { 2237 struct proc *p1 = curthread->td_proc; 2238 struct sigacts *ps; 2239 int n; 2240 2241 PROC_LOCK_ASSERT(p, MA_OWNED); 2242 mtx_assert(&sched_lock, MA_OWNED); 2243 n = p->p_suspcount; 2244 if (p == p1) 2245 n++; 2246 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2247 mtx_unlock_spin(&sched_lock); 2248 p->p_flag &= ~P_WAITED; 2249 PROC_LOCK(p->p_pptr); 2250 /* 2251 * Wake up parent sleeping in kern_wait(), also send 2252 * SIGCHLD to parent, but SIGCHLD does not guarantee 2253 * that parent will awake, because parent may masked 2254 * the signal. 2255 */ 2256 p->p_pptr->p_flag |= P_STATCHILD; 2257 wakeup(p->p_pptr); 2258 ps = p->p_pptr->p_sigacts; 2259 mtx_lock(&ps->ps_mtx); 2260 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2261 mtx_unlock(&ps->ps_mtx); 2262 psignal(p->p_pptr, SIGCHLD); 2263 } else 2264 mtx_unlock(&ps->ps_mtx); 2265 PROC_UNLOCK(p->p_pptr); 2266 mtx_lock_spin(&sched_lock); 2267 } 2268 } 2269 2270 /* 2271 * Take the action for the specified signal 2272 * from the current set of pending signals. 2273 */ 2274 void 2275 postsig(sig) 2276 register int sig; 2277 { 2278 struct thread *td = curthread; 2279 register struct proc *p = td->td_proc; 2280 struct sigacts *ps; 2281 sig_t action; 2282 sigset_t returnmask; 2283 int code; 2284 2285 KASSERT(sig != 0, ("postsig")); 2286 2287 PROC_LOCK_ASSERT(p, MA_OWNED); 2288 ps = p->p_sigacts; 2289 mtx_assert(&ps->ps_mtx, MA_OWNED); 2290 SIGDELSET(td->td_siglist, sig); 2291 action = ps->ps_sigact[_SIG_IDX(sig)]; 2292 #ifdef KTRACE 2293 if (KTRPOINT(td, KTR_PSIG)) 2294 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2295 &td->td_oldsigmask : &td->td_sigmask, 0); 2296 #endif 2297 if (p->p_stops & S_SIG) { 2298 mtx_unlock(&ps->ps_mtx); 2299 stopevent(p, S_SIG, sig); 2300 mtx_lock(&ps->ps_mtx); 2301 } 2302 2303 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2304 /* 2305 * Default action, where the default is to kill 2306 * the process. (Other cases were ignored above.) 2307 */ 2308 mtx_unlock(&ps->ps_mtx); 2309 sigexit(td, sig); 2310 /* NOTREACHED */ 2311 } else { 2312 if (td->td_pflags & TDP_SA) { 2313 if (sig == SIGKILL) { 2314 mtx_unlock(&ps->ps_mtx); 2315 sigexit(td, sig); 2316 } 2317 } 2318 2319 /* 2320 * If we get here, the signal must be caught. 2321 */ 2322 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2323 ("postsig action")); 2324 /* 2325 * Set the new mask value and also defer further 2326 * occurrences of this signal. 2327 * 2328 * Special case: user has done a sigsuspend. Here the 2329 * current mask is not of interest, but rather the 2330 * mask from before the sigsuspend is what we want 2331 * restored after the signal processing is completed. 2332 */ 2333 if (td->td_pflags & TDP_OLDMASK) { 2334 returnmask = td->td_oldsigmask; 2335 td->td_pflags &= ~TDP_OLDMASK; 2336 } else 2337 returnmask = td->td_sigmask; 2338 2339 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2340 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2341 SIGADDSET(td->td_sigmask, sig); 2342 2343 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2344 /* 2345 * See kern_sigaction() for origin of this code. 2346 */ 2347 SIGDELSET(ps->ps_sigcatch, sig); 2348 if (sig != SIGCONT && 2349 sigprop(sig) & SA_IGNORE) 2350 SIGADDSET(ps->ps_sigignore, sig); 2351 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2352 } 2353 p->p_stats->p_ru.ru_nsignals++; 2354 if (p->p_sig != sig) { 2355 code = 0; 2356 } else { 2357 code = p->p_code; 2358 p->p_code = 0; 2359 p->p_sig = 0; 2360 } 2361 if (td->td_pflags & TDP_SA) 2362 thread_signal_add(curthread, sig); 2363 else 2364 (*p->p_sysent->sv_sendsig)(action, sig, 2365 &returnmask, code); 2366 } 2367 } 2368 2369 /* 2370 * Kill the current process for stated reason. 2371 */ 2372 void 2373 killproc(p, why) 2374 struct proc *p; 2375 char *why; 2376 { 2377 2378 PROC_LOCK_ASSERT(p, MA_OWNED); 2379 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2380 p, p->p_pid, p->p_comm); 2381 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2382 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2383 psignal(p, SIGKILL); 2384 } 2385 2386 /* 2387 * Force the current process to exit with the specified signal, dumping core 2388 * if appropriate. We bypass the normal tests for masked and caught signals, 2389 * allowing unrecoverable failures to terminate the process without changing 2390 * signal state. Mark the accounting record with the signal termination. 2391 * If dumping core, save the signal number for the debugger. Calls exit and 2392 * does not return. 2393 * 2394 * MPSAFE 2395 */ 2396 void 2397 sigexit(td, sig) 2398 struct thread *td; 2399 int sig; 2400 { 2401 struct proc *p = td->td_proc; 2402 2403 PROC_LOCK_ASSERT(p, MA_OWNED); 2404 p->p_acflag |= AXSIG; 2405 if (sigprop(sig) & SA_CORE) { 2406 p->p_sig = sig; 2407 /* 2408 * Log signals which would cause core dumps 2409 * (Log as LOG_INFO to appease those who don't want 2410 * these messages.) 2411 * XXX : Todo, as well as euid, write out ruid too 2412 * Note that coredump() drops proc lock. 2413 */ 2414 if (coredump(td) == 0) 2415 sig |= WCOREFLAG; 2416 if (kern_logsigexit) 2417 log(LOG_INFO, 2418 "pid %d (%s), uid %d: exited on signal %d%s\n", 2419 p->p_pid, p->p_comm, 2420 td->td_ucred ? td->td_ucred->cr_uid : -1, 2421 sig &~ WCOREFLAG, 2422 sig & WCOREFLAG ? " (core dumped)" : ""); 2423 } else 2424 PROC_UNLOCK(p); 2425 exit1(td, W_EXITCODE(0, sig)); 2426 /* NOTREACHED */ 2427 } 2428 2429 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2430 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2431 sizeof(corefilename), "process corefile name format string"); 2432 2433 /* 2434 * expand_name(name, uid, pid) 2435 * Expand the name described in corefilename, using name, uid, and pid. 2436 * corefilename is a printf-like string, with three format specifiers: 2437 * %N name of process ("name") 2438 * %P process id (pid) 2439 * %U user id (uid) 2440 * For example, "%N.core" is the default; they can be disabled completely 2441 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2442 * This is controlled by the sysctl variable kern.corefile (see above). 2443 */ 2444 2445 static char * 2446 expand_name(name, uid, pid) 2447 const char *name; 2448 uid_t uid; 2449 pid_t pid; 2450 { 2451 const char *format, *appendstr; 2452 char *temp; 2453 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2454 size_t i, l, n; 2455 2456 format = corefilename; 2457 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2458 if (temp == NULL) 2459 return (NULL); 2460 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2461 switch (format[i]) { 2462 case '%': /* Format character */ 2463 i++; 2464 switch (format[i]) { 2465 case '%': 2466 appendstr = "%"; 2467 break; 2468 case 'N': /* process name */ 2469 appendstr = name; 2470 break; 2471 case 'P': /* process id */ 2472 sprintf(buf, "%u", pid); 2473 appendstr = buf; 2474 break; 2475 case 'U': /* user id */ 2476 sprintf(buf, "%u", uid); 2477 appendstr = buf; 2478 break; 2479 default: 2480 appendstr = ""; 2481 log(LOG_ERR, 2482 "Unknown format character %c in `%s'\n", 2483 format[i], format); 2484 } 2485 l = strlen(appendstr); 2486 if ((n + l) >= MAXPATHLEN) 2487 goto toolong; 2488 memcpy(temp + n, appendstr, l); 2489 n += l; 2490 break; 2491 default: 2492 temp[n++] = format[i]; 2493 } 2494 } 2495 if (format[i] != '\0') 2496 goto toolong; 2497 return (temp); 2498 toolong: 2499 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2500 (long)pid, name, (u_long)uid); 2501 free(temp, M_TEMP); 2502 return (NULL); 2503 } 2504 2505 /* 2506 * Dump a process' core. The main routine does some 2507 * policy checking, and creates the name of the coredump; 2508 * then it passes on a vnode and a size limit to the process-specific 2509 * coredump routine if there is one; if there _is not_ one, it returns 2510 * ENOSYS; otherwise it returns the error from the process-specific routine. 2511 */ 2512 2513 static int 2514 coredump(struct thread *td) 2515 { 2516 struct proc *p = td->td_proc; 2517 register struct vnode *vp; 2518 register struct ucred *cred = td->td_ucred; 2519 struct flock lf; 2520 struct nameidata nd; 2521 struct vattr vattr; 2522 int error, error1, flags, locked; 2523 struct mount *mp; 2524 char *name; /* name of corefile */ 2525 off_t limit; 2526 2527 PROC_LOCK_ASSERT(p, MA_OWNED); 2528 _STOPEVENT(p, S_CORE, 0); 2529 2530 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2531 PROC_UNLOCK(p); 2532 return (EFAULT); 2533 } 2534 2535 /* 2536 * Note that the bulk of limit checking is done after 2537 * the corefile is created. The exception is if the limit 2538 * for corefiles is 0, in which case we don't bother 2539 * creating the corefile at all. This layout means that 2540 * a corefile is truncated instead of not being created, 2541 * if it is larger than the limit. 2542 */ 2543 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2544 PROC_UNLOCK(p); 2545 if (limit == 0) 2546 return (EFBIG); 2547 2548 mtx_lock(&Giant); 2549 restart: 2550 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2551 if (name == NULL) { 2552 mtx_unlock(&Giant); 2553 return (EINVAL); 2554 } 2555 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2556 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2557 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2558 free(name, M_TEMP); 2559 if (error) { 2560 mtx_unlock(&Giant); 2561 return (error); 2562 } 2563 NDFREE(&nd, NDF_ONLY_PNBUF); 2564 vp = nd.ni_vp; 2565 2566 /* Don't dump to non-regular files or files with links. */ 2567 if (vp->v_type != VREG || 2568 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2569 VOP_UNLOCK(vp, 0, td); 2570 error = EFAULT; 2571 goto out; 2572 } 2573 2574 VOP_UNLOCK(vp, 0, td); 2575 lf.l_whence = SEEK_SET; 2576 lf.l_start = 0; 2577 lf.l_len = 0; 2578 lf.l_type = F_WRLCK; 2579 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2580 2581 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2582 lf.l_type = F_UNLCK; 2583 if (locked) 2584 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2585 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2586 return (error); 2587 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2588 return (error); 2589 goto restart; 2590 } 2591 2592 VATTR_NULL(&vattr); 2593 vattr.va_size = 0; 2594 if (set_core_nodump_flag) 2595 vattr.va_flags = UF_NODUMP; 2596 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2597 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2598 VOP_SETATTR(vp, &vattr, cred, td); 2599 VOP_UNLOCK(vp, 0, td); 2600 PROC_LOCK(p); 2601 p->p_acflag |= ACORE; 2602 PROC_UNLOCK(p); 2603 2604 error = p->p_sysent->sv_coredump ? 2605 p->p_sysent->sv_coredump(td, vp, limit) : 2606 ENOSYS; 2607 2608 if (locked) { 2609 lf.l_type = F_UNLCK; 2610 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2611 } 2612 vn_finished_write(mp); 2613 out: 2614 error1 = vn_close(vp, FWRITE, cred, td); 2615 mtx_unlock(&Giant); 2616 if (error == 0) 2617 error = error1; 2618 return (error); 2619 } 2620 2621 /* 2622 * Nonexistent system call-- signal process (may want to handle it). 2623 * Flag error in case process won't see signal immediately (blocked or ignored). 2624 */ 2625 #ifndef _SYS_SYSPROTO_H_ 2626 struct nosys_args { 2627 int dummy; 2628 }; 2629 #endif 2630 /* 2631 * MPSAFE 2632 */ 2633 /* ARGSUSED */ 2634 int 2635 nosys(td, args) 2636 struct thread *td; 2637 struct nosys_args *args; 2638 { 2639 struct proc *p = td->td_proc; 2640 2641 PROC_LOCK(p); 2642 psignal(p, SIGSYS); 2643 PROC_UNLOCK(p); 2644 return (ENOSYS); 2645 } 2646 2647 /* 2648 * Send a SIGIO or SIGURG signal to a process or process group using 2649 * stored credentials rather than those of the current process. 2650 */ 2651 void 2652 pgsigio(sigiop, sig, checkctty) 2653 struct sigio **sigiop; 2654 int sig, checkctty; 2655 { 2656 struct sigio *sigio; 2657 2658 SIGIO_LOCK(); 2659 sigio = *sigiop; 2660 if (sigio == NULL) { 2661 SIGIO_UNLOCK(); 2662 return; 2663 } 2664 if (sigio->sio_pgid > 0) { 2665 PROC_LOCK(sigio->sio_proc); 2666 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2667 psignal(sigio->sio_proc, sig); 2668 PROC_UNLOCK(sigio->sio_proc); 2669 } else if (sigio->sio_pgid < 0) { 2670 struct proc *p; 2671 2672 PGRP_LOCK(sigio->sio_pgrp); 2673 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2674 PROC_LOCK(p); 2675 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2676 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2677 psignal(p, sig); 2678 PROC_UNLOCK(p); 2679 } 2680 PGRP_UNLOCK(sigio->sio_pgrp); 2681 } 2682 SIGIO_UNLOCK(); 2683 } 2684 2685 static int 2686 filt_sigattach(struct knote *kn) 2687 { 2688 struct proc *p = curproc; 2689 2690 kn->kn_ptr.p_proc = p; 2691 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2692 2693 knlist_add(&p->p_klist, kn, 0); 2694 2695 return (0); 2696 } 2697 2698 static void 2699 filt_sigdetach(struct knote *kn) 2700 { 2701 struct proc *p = kn->kn_ptr.p_proc; 2702 2703 knlist_remove(&p->p_klist, kn, 0); 2704 } 2705 2706 /* 2707 * signal knotes are shared with proc knotes, so we apply a mask to 2708 * the hint in order to differentiate them from process hints. This 2709 * could be avoided by using a signal-specific knote list, but probably 2710 * isn't worth the trouble. 2711 */ 2712 static int 2713 filt_signal(struct knote *kn, long hint) 2714 { 2715 2716 if (hint & NOTE_SIGNAL) { 2717 hint &= ~NOTE_SIGNAL; 2718 2719 if (kn->kn_id == hint) 2720 kn->kn_data++; 2721 } 2722 return (kn->kn_data != 0); 2723 } 2724 2725 struct sigacts * 2726 sigacts_alloc(void) 2727 { 2728 struct sigacts *ps; 2729 2730 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2731 ps->ps_refcnt = 1; 2732 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2733 return (ps); 2734 } 2735 2736 void 2737 sigacts_free(struct sigacts *ps) 2738 { 2739 2740 mtx_lock(&ps->ps_mtx); 2741 ps->ps_refcnt--; 2742 if (ps->ps_refcnt == 0) { 2743 mtx_destroy(&ps->ps_mtx); 2744 free(ps, M_SUBPROC); 2745 } else 2746 mtx_unlock(&ps->ps_mtx); 2747 } 2748 2749 struct sigacts * 2750 sigacts_hold(struct sigacts *ps) 2751 { 2752 mtx_lock(&ps->ps_mtx); 2753 ps->ps_refcnt++; 2754 mtx_unlock(&ps->ps_mtx); 2755 return (ps); 2756 } 2757 2758 void 2759 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2760 { 2761 2762 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2763 mtx_lock(&src->ps_mtx); 2764 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2765 mtx_unlock(&src->ps_mtx); 2766 } 2767 2768 int 2769 sigacts_shared(struct sigacts *ps) 2770 { 2771 int shared; 2772 2773 mtx_lock(&ps->ps_mtx); 2774 shared = ps->ps_refcnt > 1; 2775 mtx_unlock(&ps->ps_mtx); 2776 return (shared); 2777 }
Cache object: 913e91288e17353345a5112a61e1ba74
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