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: releng/6.0/sys/kern/kern_sig.c 147046 2005-06-06 05:13:10Z davidxu $"); 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/sched.h> 63 #include <sys/sleepqueue.h> 64 #include <sys/smp.h> 65 #include <sys/stat.h> 66 #include <sys/sx.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysent.h> 70 #include <sys/syslog.h> 71 #include <sys/sysproto.h> 72 #include <sys/unistd.h> 73 #include <sys/wait.h> 74 75 #include <machine/cpu.h> 76 77 #if defined (__alpha__) && !defined(COMPAT_43) 78 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 79 #endif 80 81 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 82 83 static int coredump(struct thread *); 84 static char *expand_name(const char *, uid_t, pid_t); 85 static int killpg1(struct thread *td, int sig, int pgid, int all); 86 static int issignal(struct thread *p); 87 static int sigprop(int sig); 88 static void tdsigwakeup(struct thread *td, int sig, sig_t action); 89 static int filt_sigattach(struct knote *kn); 90 static void filt_sigdetach(struct knote *kn); 91 static int filt_signal(struct knote *kn, long hint); 92 static struct thread *sigtd(struct proc *p, int sig, int prop); 93 static int kern_sigtimedwait(struct thread *td, sigset_t set, 94 siginfo_t *info, struct timespec *timeout); 95 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target); 96 97 struct filterops sig_filtops = 98 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 99 100 static int kern_logsigexit = 1; 101 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 102 &kern_logsigexit, 0, 103 "Log processes quitting on abnormal signals to syslog(3)"); 104 105 /* 106 * Policy -- Can ucred cr1 send SIGIO to process cr2? 107 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 108 * in the right situations. 109 */ 110 #define CANSIGIO(cr1, cr2) \ 111 ((cr1)->cr_uid == 0 || \ 112 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 113 (cr1)->cr_uid == (cr2)->cr_ruid || \ 114 (cr1)->cr_ruid == (cr2)->cr_uid || \ 115 (cr1)->cr_uid == (cr2)->cr_uid) 116 117 int sugid_coredump; 118 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 119 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 120 121 static int do_coredump = 1; 122 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 123 &do_coredump, 0, "Enable/Disable coredumps"); 124 125 static int set_core_nodump_flag = 0; 126 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 127 0, "Enable setting the NODUMP flag on coredump files"); 128 129 /* 130 * Signal properties and actions. 131 * The array below categorizes the signals and their default actions 132 * according to the following properties: 133 */ 134 #define SA_KILL 0x01 /* terminates process by default */ 135 #define SA_CORE 0x02 /* ditto and coredumps */ 136 #define SA_STOP 0x04 /* suspend process */ 137 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 138 #define SA_IGNORE 0x10 /* ignore by default */ 139 #define SA_CONT 0x20 /* continue if suspended */ 140 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 141 #define SA_PROC 0x80 /* deliverable to any thread */ 142 143 static int sigproptbl[NSIG] = { 144 SA_KILL|SA_PROC, /* SIGHUP */ 145 SA_KILL|SA_PROC, /* SIGINT */ 146 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 147 SA_KILL|SA_CORE, /* SIGILL */ 148 SA_KILL|SA_CORE, /* SIGTRAP */ 149 SA_KILL|SA_CORE, /* SIGABRT */ 150 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 151 SA_KILL|SA_CORE, /* SIGFPE */ 152 SA_KILL|SA_PROC, /* SIGKILL */ 153 SA_KILL|SA_CORE, /* SIGBUS */ 154 SA_KILL|SA_CORE, /* SIGSEGV */ 155 SA_KILL|SA_CORE, /* SIGSYS */ 156 SA_KILL|SA_PROC, /* SIGPIPE */ 157 SA_KILL|SA_PROC, /* SIGALRM */ 158 SA_KILL|SA_PROC, /* SIGTERM */ 159 SA_IGNORE|SA_PROC, /* SIGURG */ 160 SA_STOP|SA_PROC, /* SIGSTOP */ 161 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 162 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 163 SA_IGNORE|SA_PROC, /* SIGCHLD */ 164 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 165 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 166 SA_IGNORE|SA_PROC, /* SIGIO */ 167 SA_KILL, /* SIGXCPU */ 168 SA_KILL, /* SIGXFSZ */ 169 SA_KILL|SA_PROC, /* SIGVTALRM */ 170 SA_KILL|SA_PROC, /* SIGPROF */ 171 SA_IGNORE|SA_PROC, /* SIGWINCH */ 172 SA_IGNORE|SA_PROC, /* SIGINFO */ 173 SA_KILL|SA_PROC, /* SIGUSR1 */ 174 SA_KILL|SA_PROC, /* SIGUSR2 */ 175 }; 176 177 /* 178 * Determine signal that should be delivered to process p, the current 179 * process, 0 if none. If there is a pending stop signal with default 180 * action, the process stops in issignal(). 181 * XXXKSE the check for a pending stop is not done under KSE 182 * 183 * MP SAFE. 184 */ 185 int 186 cursig(struct thread *td) 187 { 188 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 189 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 190 mtx_assert(&sched_lock, MA_NOTOWNED); 191 return (SIGPENDING(td) ? issignal(td) : 0); 192 } 193 194 /* 195 * Arrange for ast() to handle unmasked pending signals on return to user 196 * mode. This must be called whenever a signal is added to td_siglist or 197 * unmasked in td_sigmask. 198 */ 199 void 200 signotify(struct thread *td) 201 { 202 struct proc *p; 203 sigset_t set, saved; 204 205 p = td->td_proc; 206 207 PROC_LOCK_ASSERT(p, MA_OWNED); 208 209 /* 210 * If our mask changed we may have to move signal that were 211 * previously masked by all threads to our siglist. 212 */ 213 set = p->p_siglist; 214 if (p->p_flag & P_SA) 215 saved = p->p_siglist; 216 SIGSETNAND(set, td->td_sigmask); 217 SIGSETNAND(p->p_siglist, set); 218 SIGSETOR(td->td_siglist, set); 219 220 if (SIGPENDING(td)) { 221 mtx_lock_spin(&sched_lock); 222 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 223 mtx_unlock_spin(&sched_lock); 224 } 225 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 226 if (!SIGSETEQ(saved, p->p_siglist)) { 227 /* pending set changed */ 228 p->p_flag |= P_SIGEVENT; 229 wakeup(&p->p_siglist); 230 } 231 } 232 } 233 234 int 235 sigonstack(size_t sp) 236 { 237 struct thread *td = curthread; 238 239 return ((td->td_pflags & TDP_ALTSTACK) ? 240 #if defined(COMPAT_43) 241 ((td->td_sigstk.ss_size == 0) ? 242 (td->td_sigstk.ss_flags & SS_ONSTACK) : 243 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 244 #else 245 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 246 #endif 247 : 0); 248 } 249 250 static __inline int 251 sigprop(int sig) 252 { 253 254 if (sig > 0 && sig < NSIG) 255 return (sigproptbl[_SIG_IDX(sig)]); 256 return (0); 257 } 258 259 int 260 sig_ffs(sigset_t *set) 261 { 262 int i; 263 264 for (i = 0; i < _SIG_WORDS; i++) 265 if (set->__bits[i]) 266 return (ffs(set->__bits[i]) + (i * 32)); 267 return (0); 268 } 269 270 /* 271 * kern_sigaction 272 * sigaction 273 * freebsd4_sigaction 274 * osigaction 275 * 276 * MPSAFE 277 */ 278 int 279 kern_sigaction(td, sig, act, oact, flags) 280 struct thread *td; 281 register int sig; 282 struct sigaction *act, *oact; 283 int flags; 284 { 285 struct sigacts *ps; 286 struct thread *td0; 287 struct proc *p = td->td_proc; 288 289 if (!_SIG_VALID(sig)) 290 return (EINVAL); 291 292 PROC_LOCK(p); 293 ps = p->p_sigacts; 294 mtx_lock(&ps->ps_mtx); 295 if (oact) { 296 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 297 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 298 oact->sa_flags = 0; 299 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 300 oact->sa_flags |= SA_ONSTACK; 301 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 302 oact->sa_flags |= SA_RESTART; 303 if (SIGISMEMBER(ps->ps_sigreset, sig)) 304 oact->sa_flags |= SA_RESETHAND; 305 if (SIGISMEMBER(ps->ps_signodefer, sig)) 306 oact->sa_flags |= SA_NODEFER; 307 if (SIGISMEMBER(ps->ps_siginfo, sig)) 308 oact->sa_flags |= SA_SIGINFO; 309 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 310 oact->sa_flags |= SA_NOCLDSTOP; 311 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 312 oact->sa_flags |= SA_NOCLDWAIT; 313 } 314 if (act) { 315 if ((sig == SIGKILL || sig == SIGSTOP) && 316 act->sa_handler != SIG_DFL) { 317 mtx_unlock(&ps->ps_mtx); 318 PROC_UNLOCK(p); 319 return (EINVAL); 320 } 321 322 /* 323 * Change setting atomically. 324 */ 325 326 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 327 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 328 if (act->sa_flags & SA_SIGINFO) { 329 ps->ps_sigact[_SIG_IDX(sig)] = 330 (__sighandler_t *)act->sa_sigaction; 331 SIGADDSET(ps->ps_siginfo, sig); 332 } else { 333 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 334 SIGDELSET(ps->ps_siginfo, sig); 335 } 336 if (!(act->sa_flags & SA_RESTART)) 337 SIGADDSET(ps->ps_sigintr, sig); 338 else 339 SIGDELSET(ps->ps_sigintr, sig); 340 if (act->sa_flags & SA_ONSTACK) 341 SIGADDSET(ps->ps_sigonstack, sig); 342 else 343 SIGDELSET(ps->ps_sigonstack, sig); 344 if (act->sa_flags & SA_RESETHAND) 345 SIGADDSET(ps->ps_sigreset, sig); 346 else 347 SIGDELSET(ps->ps_sigreset, sig); 348 if (act->sa_flags & SA_NODEFER) 349 SIGADDSET(ps->ps_signodefer, sig); 350 else 351 SIGDELSET(ps->ps_signodefer, sig); 352 if (sig == SIGCHLD) { 353 if (act->sa_flags & SA_NOCLDSTOP) 354 ps->ps_flag |= PS_NOCLDSTOP; 355 else 356 ps->ps_flag &= ~PS_NOCLDSTOP; 357 if (act->sa_flags & SA_NOCLDWAIT) { 358 /* 359 * Paranoia: since SA_NOCLDWAIT is implemented 360 * by reparenting the dying child to PID 1 (and 361 * trust it to reap the zombie), PID 1 itself 362 * is forbidden to set SA_NOCLDWAIT. 363 */ 364 if (p->p_pid == 1) 365 ps->ps_flag &= ~PS_NOCLDWAIT; 366 else 367 ps->ps_flag |= PS_NOCLDWAIT; 368 } else 369 ps->ps_flag &= ~PS_NOCLDWAIT; 370 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 371 ps->ps_flag |= PS_CLDSIGIGN; 372 else 373 ps->ps_flag &= ~PS_CLDSIGIGN; 374 } 375 /* 376 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 377 * and for signals set to SIG_DFL where the default is to 378 * ignore. However, don't put SIGCONT in ps_sigignore, as we 379 * have to restart the process. 380 */ 381 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 382 (sigprop(sig) & SA_IGNORE && 383 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 384 if ((p->p_flag & P_SA) && 385 SIGISMEMBER(p->p_siglist, sig)) { 386 p->p_flag |= P_SIGEVENT; 387 wakeup(&p->p_siglist); 388 } 389 /* never to be seen again */ 390 SIGDELSET(p->p_siglist, sig); 391 mtx_lock_spin(&sched_lock); 392 FOREACH_THREAD_IN_PROC(p, td0) 393 SIGDELSET(td0->td_siglist, sig); 394 mtx_unlock_spin(&sched_lock); 395 if (sig != SIGCONT) 396 /* easier in psignal */ 397 SIGADDSET(ps->ps_sigignore, sig); 398 SIGDELSET(ps->ps_sigcatch, sig); 399 } else { 400 SIGDELSET(ps->ps_sigignore, sig); 401 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 402 SIGDELSET(ps->ps_sigcatch, sig); 403 else 404 SIGADDSET(ps->ps_sigcatch, sig); 405 } 406 #ifdef COMPAT_FREEBSD4 407 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 408 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 409 (flags & KSA_FREEBSD4) == 0) 410 SIGDELSET(ps->ps_freebsd4, sig); 411 else 412 SIGADDSET(ps->ps_freebsd4, sig); 413 #endif 414 #ifdef COMPAT_43 415 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 416 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 417 (flags & KSA_OSIGSET) == 0) 418 SIGDELSET(ps->ps_osigset, sig); 419 else 420 SIGADDSET(ps->ps_osigset, sig); 421 #endif 422 } 423 mtx_unlock(&ps->ps_mtx); 424 PROC_UNLOCK(p); 425 return (0); 426 } 427 428 #ifndef _SYS_SYSPROTO_H_ 429 struct sigaction_args { 430 int sig; 431 struct sigaction *act; 432 struct sigaction *oact; 433 }; 434 #endif 435 /* 436 * MPSAFE 437 */ 438 int 439 sigaction(td, uap) 440 struct thread *td; 441 register struct sigaction_args *uap; 442 { 443 struct sigaction act, oact; 444 register struct sigaction *actp, *oactp; 445 int error; 446 447 actp = (uap->act != NULL) ? &act : NULL; 448 oactp = (uap->oact != NULL) ? &oact : NULL; 449 if (actp) { 450 error = copyin(uap->act, actp, sizeof(act)); 451 if (error) 452 return (error); 453 } 454 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 455 if (oactp && !error) 456 error = copyout(oactp, uap->oact, sizeof(oact)); 457 return (error); 458 } 459 460 #ifdef COMPAT_FREEBSD4 461 #ifndef _SYS_SYSPROTO_H_ 462 struct freebsd4_sigaction_args { 463 int sig; 464 struct sigaction *act; 465 struct sigaction *oact; 466 }; 467 #endif 468 /* 469 * MPSAFE 470 */ 471 int 472 freebsd4_sigaction(td, uap) 473 struct thread *td; 474 register struct freebsd4_sigaction_args *uap; 475 { 476 struct sigaction act, oact; 477 register struct sigaction *actp, *oactp; 478 int error; 479 480 481 actp = (uap->act != NULL) ? &act : NULL; 482 oactp = (uap->oact != NULL) ? &oact : NULL; 483 if (actp) { 484 error = copyin(uap->act, actp, sizeof(act)); 485 if (error) 486 return (error); 487 } 488 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 489 if (oactp && !error) 490 error = copyout(oactp, uap->oact, sizeof(oact)); 491 return (error); 492 } 493 #endif /* COMAPT_FREEBSD4 */ 494 495 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 496 #ifndef _SYS_SYSPROTO_H_ 497 struct osigaction_args { 498 int signum; 499 struct osigaction *nsa; 500 struct osigaction *osa; 501 }; 502 #endif 503 /* 504 * MPSAFE 505 */ 506 int 507 osigaction(td, uap) 508 struct thread *td; 509 register struct osigaction_args *uap; 510 { 511 struct osigaction sa; 512 struct sigaction nsa, osa; 513 register struct sigaction *nsap, *osap; 514 int error; 515 516 if (uap->signum <= 0 || uap->signum >= ONSIG) 517 return (EINVAL); 518 519 nsap = (uap->nsa != NULL) ? &nsa : NULL; 520 osap = (uap->osa != NULL) ? &osa : NULL; 521 522 if (nsap) { 523 error = copyin(uap->nsa, &sa, sizeof(sa)); 524 if (error) 525 return (error); 526 nsap->sa_handler = sa.sa_handler; 527 nsap->sa_flags = sa.sa_flags; 528 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 529 } 530 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 531 if (osap && !error) { 532 sa.sa_handler = osap->sa_handler; 533 sa.sa_flags = osap->sa_flags; 534 SIG2OSIG(osap->sa_mask, sa.sa_mask); 535 error = copyout(&sa, uap->osa, sizeof(sa)); 536 } 537 return (error); 538 } 539 540 #if !defined(__i386__) && !defined(__alpha__) 541 /* Avoid replicating the same stub everywhere */ 542 int 543 osigreturn(td, uap) 544 struct thread *td; 545 struct osigreturn_args *uap; 546 { 547 548 return (nosys(td, (struct nosys_args *)uap)); 549 } 550 #endif 551 #endif /* COMPAT_43 */ 552 553 /* 554 * Initialize signal state for process 0; 555 * set to ignore signals that are ignored by default. 556 */ 557 void 558 siginit(p) 559 struct proc *p; 560 { 561 register int i; 562 struct sigacts *ps; 563 564 PROC_LOCK(p); 565 ps = p->p_sigacts; 566 mtx_lock(&ps->ps_mtx); 567 for (i = 1; i <= NSIG; i++) 568 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 569 SIGADDSET(ps->ps_sigignore, i); 570 mtx_unlock(&ps->ps_mtx); 571 PROC_UNLOCK(p); 572 } 573 574 /* 575 * Reset signals for an exec of the specified process. 576 */ 577 void 578 execsigs(struct proc *p) 579 { 580 struct sigacts *ps; 581 int sig; 582 struct thread *td; 583 584 /* 585 * Reset caught signals. Held signals remain held 586 * through td_sigmask (unless they were caught, 587 * and are now ignored by default). 588 */ 589 PROC_LOCK_ASSERT(p, MA_OWNED); 590 td = FIRST_THREAD_IN_PROC(p); 591 ps = p->p_sigacts; 592 mtx_lock(&ps->ps_mtx); 593 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 594 sig = sig_ffs(&ps->ps_sigcatch); 595 SIGDELSET(ps->ps_sigcatch, sig); 596 if (sigprop(sig) & SA_IGNORE) { 597 if (sig != SIGCONT) 598 SIGADDSET(ps->ps_sigignore, sig); 599 SIGDELSET(p->p_siglist, sig); 600 /* 601 * There is only one thread at this point. 602 */ 603 SIGDELSET(td->td_siglist, sig); 604 } 605 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 606 } 607 /* 608 * Reset stack state to the user stack. 609 * Clear set of signals caught on the signal stack. 610 */ 611 td->td_sigstk.ss_flags = SS_DISABLE; 612 td->td_sigstk.ss_size = 0; 613 td->td_sigstk.ss_sp = 0; 614 td->td_pflags &= ~TDP_ALTSTACK; 615 /* 616 * Reset no zombies if child dies flag as Solaris does. 617 */ 618 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 619 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 620 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 621 mtx_unlock(&ps->ps_mtx); 622 } 623 624 /* 625 * kern_sigprocmask() 626 * 627 * Manipulate signal mask. 628 */ 629 int 630 kern_sigprocmask(td, how, set, oset, old) 631 struct thread *td; 632 int how; 633 sigset_t *set, *oset; 634 int old; 635 { 636 int error; 637 638 PROC_LOCK(td->td_proc); 639 if (oset != NULL) 640 *oset = td->td_sigmask; 641 642 error = 0; 643 if (set != NULL) { 644 switch (how) { 645 case SIG_BLOCK: 646 SIG_CANTMASK(*set); 647 SIGSETOR(td->td_sigmask, *set); 648 break; 649 case SIG_UNBLOCK: 650 SIGSETNAND(td->td_sigmask, *set); 651 signotify(td); 652 break; 653 case SIG_SETMASK: 654 SIG_CANTMASK(*set); 655 if (old) 656 SIGSETLO(td->td_sigmask, *set); 657 else 658 td->td_sigmask = *set; 659 signotify(td); 660 break; 661 default: 662 error = EINVAL; 663 break; 664 } 665 } 666 PROC_UNLOCK(td->td_proc); 667 return (error); 668 } 669 670 /* 671 * sigprocmask() - MP SAFE 672 */ 673 674 #ifndef _SYS_SYSPROTO_H_ 675 struct sigprocmask_args { 676 int how; 677 const sigset_t *set; 678 sigset_t *oset; 679 }; 680 #endif 681 int 682 sigprocmask(td, uap) 683 register struct thread *td; 684 struct sigprocmask_args *uap; 685 { 686 sigset_t set, oset; 687 sigset_t *setp, *osetp; 688 int error; 689 690 setp = (uap->set != NULL) ? &set : NULL; 691 osetp = (uap->oset != NULL) ? &oset : NULL; 692 if (setp) { 693 error = copyin(uap->set, setp, sizeof(set)); 694 if (error) 695 return (error); 696 } 697 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 698 if (osetp && !error) { 699 error = copyout(osetp, uap->oset, sizeof(oset)); 700 } 701 return (error); 702 } 703 704 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 705 /* 706 * osigprocmask() - MP SAFE 707 */ 708 #ifndef _SYS_SYSPROTO_H_ 709 struct osigprocmask_args { 710 int how; 711 osigset_t mask; 712 }; 713 #endif 714 int 715 osigprocmask(td, uap) 716 register struct thread *td; 717 struct osigprocmask_args *uap; 718 { 719 sigset_t set, oset; 720 int error; 721 722 OSIG2SIG(uap->mask, set); 723 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 724 SIG2OSIG(oset, td->td_retval[0]); 725 return (error); 726 } 727 #endif /* COMPAT_43 */ 728 729 #ifndef _SYS_SYSPROTO_H_ 730 struct sigpending_args { 731 sigset_t *set; 732 }; 733 #endif 734 /* 735 * MPSAFE 736 */ 737 int 738 sigwait(struct thread *td, struct sigwait_args *uap) 739 { 740 siginfo_t info; 741 sigset_t set; 742 int error; 743 744 error = copyin(uap->set, &set, sizeof(set)); 745 if (error) { 746 td->td_retval[0] = error; 747 return (0); 748 } 749 750 error = kern_sigtimedwait(td, set, &info, NULL); 751 if (error) { 752 if (error == ERESTART) 753 return (error); 754 td->td_retval[0] = error; 755 return (0); 756 } 757 758 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 759 /* Repost if we got an error. */ 760 if (error && info.si_signo) { 761 PROC_LOCK(td->td_proc); 762 tdsignal(td, info.si_signo, SIGTARGET_TD); 763 PROC_UNLOCK(td->td_proc); 764 } 765 td->td_retval[0] = error; 766 return (0); 767 } 768 /* 769 * MPSAFE 770 */ 771 int 772 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 773 { 774 struct timespec ts; 775 struct timespec *timeout; 776 sigset_t set; 777 siginfo_t info; 778 int error; 779 780 if (uap->timeout) { 781 error = copyin(uap->timeout, &ts, sizeof(ts)); 782 if (error) 783 return (error); 784 785 timeout = &ts; 786 } else 787 timeout = NULL; 788 789 error = copyin(uap->set, &set, sizeof(set)); 790 if (error) 791 return (error); 792 793 error = kern_sigtimedwait(td, set, &info, timeout); 794 if (error) 795 return (error); 796 797 if (uap->info) 798 error = copyout(&info, uap->info, sizeof(info)); 799 /* Repost if we got an error. */ 800 if (error && info.si_signo) { 801 PROC_LOCK(td->td_proc); 802 tdsignal(td, info.si_signo, SIGTARGET_TD); 803 PROC_UNLOCK(td->td_proc); 804 } else { 805 td->td_retval[0] = info.si_signo; 806 } 807 return (error); 808 } 809 810 /* 811 * MPSAFE 812 */ 813 int 814 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 815 { 816 siginfo_t info; 817 sigset_t set; 818 int error; 819 820 error = copyin(uap->set, &set, sizeof(set)); 821 if (error) 822 return (error); 823 824 error = kern_sigtimedwait(td, set, &info, NULL); 825 if (error) 826 return (error); 827 828 if (uap->info) 829 error = copyout(&info, uap->info, sizeof(info)); 830 /* Repost if we got an error. */ 831 if (error && info.si_signo) { 832 PROC_LOCK(td->td_proc); 833 tdsignal(td, info.si_signo, SIGTARGET_TD); 834 PROC_UNLOCK(td->td_proc); 835 } else { 836 td->td_retval[0] = info.si_signo; 837 } 838 return (error); 839 } 840 841 static int 842 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info, 843 struct timespec *timeout) 844 { 845 struct sigacts *ps; 846 sigset_t savedmask; 847 struct proc *p; 848 int error, sig, hz, i, timevalid = 0; 849 struct timespec rts, ets, ts; 850 struct timeval tv; 851 852 p = td->td_proc; 853 error = 0; 854 sig = 0; 855 SIG_CANTMASK(waitset); 856 857 PROC_LOCK(p); 858 ps = p->p_sigacts; 859 savedmask = td->td_sigmask; 860 if (timeout) { 861 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 862 timevalid = 1; 863 getnanouptime(&rts); 864 ets = rts; 865 timespecadd(&ets, timeout); 866 } 867 } 868 869 again: 870 for (i = 1; i <= _SIG_MAXSIG; ++i) { 871 if (!SIGISMEMBER(waitset, i)) 872 continue; 873 if (SIGISMEMBER(td->td_siglist, i)) { 874 SIGFILLSET(td->td_sigmask); 875 SIG_CANTMASK(td->td_sigmask); 876 SIGDELSET(td->td_sigmask, i); 877 mtx_lock(&ps->ps_mtx); 878 sig = cursig(td); 879 i = 0; 880 mtx_unlock(&ps->ps_mtx); 881 } else if (SIGISMEMBER(p->p_siglist, i)) { 882 if (p->p_flag & P_SA) { 883 p->p_flag |= P_SIGEVENT; 884 wakeup(&p->p_siglist); 885 } 886 SIGDELSET(p->p_siglist, i); 887 SIGADDSET(td->td_siglist, i); 888 SIGFILLSET(td->td_sigmask); 889 SIG_CANTMASK(td->td_sigmask); 890 SIGDELSET(td->td_sigmask, i); 891 mtx_lock(&ps->ps_mtx); 892 sig = cursig(td); 893 i = 0; 894 mtx_unlock(&ps->ps_mtx); 895 } 896 if (sig) 897 goto out; 898 } 899 if (error) 900 goto out; 901 902 /* 903 * POSIX says this must be checked after looking for pending 904 * signals. 905 */ 906 if (timeout) { 907 if (!timevalid) { 908 error = EINVAL; 909 goto out; 910 } 911 getnanouptime(&rts); 912 if (timespeccmp(&rts, &ets, >=)) { 913 error = EAGAIN; 914 goto out; 915 } 916 ts = ets; 917 timespecsub(&ts, &rts); 918 TIMESPEC_TO_TIMEVAL(&tv, &ts); 919 hz = tvtohz(&tv); 920 } else 921 hz = 0; 922 923 td->td_sigmask = savedmask; 924 SIGSETNAND(td->td_sigmask, waitset); 925 signotify(td); 926 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 927 if (timeout) { 928 if (error == ERESTART) { 929 /* timeout can not be restarted. */ 930 error = EINTR; 931 } else if (error == EAGAIN) { 932 /* will calculate timeout by ourself. */ 933 error = 0; 934 } 935 } 936 goto again; 937 938 out: 939 td->td_sigmask = savedmask; 940 signotify(td); 941 if (sig) { 942 sig_t action; 943 944 error = 0; 945 mtx_lock(&ps->ps_mtx); 946 action = ps->ps_sigact[_SIG_IDX(sig)]; 947 mtx_unlock(&ps->ps_mtx); 948 #ifdef KTRACE 949 if (KTRPOINT(td, KTR_PSIG)) 950 ktrpsig(sig, action, &td->td_sigmask, 0); 951 #endif 952 _STOPEVENT(p, S_SIG, sig); 953 954 SIGDELSET(td->td_siglist, sig); 955 bzero(info, sizeof(*info)); 956 info->si_signo = sig; 957 info->si_code = 0; 958 } 959 PROC_UNLOCK(p); 960 return (error); 961 } 962 963 /* 964 * MPSAFE 965 */ 966 int 967 sigpending(td, uap) 968 struct thread *td; 969 struct sigpending_args *uap; 970 { 971 struct proc *p = td->td_proc; 972 sigset_t siglist; 973 974 PROC_LOCK(p); 975 siglist = p->p_siglist; 976 SIGSETOR(siglist, td->td_siglist); 977 PROC_UNLOCK(p); 978 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 979 } 980 981 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 982 #ifndef _SYS_SYSPROTO_H_ 983 struct osigpending_args { 984 int dummy; 985 }; 986 #endif 987 /* 988 * MPSAFE 989 */ 990 int 991 osigpending(td, uap) 992 struct thread *td; 993 struct osigpending_args *uap; 994 { 995 struct proc *p = td->td_proc; 996 sigset_t siglist; 997 998 PROC_LOCK(p); 999 siglist = p->p_siglist; 1000 SIGSETOR(siglist, td->td_siglist); 1001 PROC_UNLOCK(p); 1002 SIG2OSIG(siglist, td->td_retval[0]); 1003 return (0); 1004 } 1005 #endif /* COMPAT_43 */ 1006 1007 #if defined(COMPAT_43) 1008 /* 1009 * Generalized interface signal handler, 4.3-compatible. 1010 */ 1011 #ifndef _SYS_SYSPROTO_H_ 1012 struct osigvec_args { 1013 int signum; 1014 struct sigvec *nsv; 1015 struct sigvec *osv; 1016 }; 1017 #endif 1018 /* 1019 * MPSAFE 1020 */ 1021 /* ARGSUSED */ 1022 int 1023 osigvec(td, uap) 1024 struct thread *td; 1025 register struct osigvec_args *uap; 1026 { 1027 struct sigvec vec; 1028 struct sigaction nsa, osa; 1029 register struct sigaction *nsap, *osap; 1030 int error; 1031 1032 if (uap->signum <= 0 || uap->signum >= ONSIG) 1033 return (EINVAL); 1034 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1035 osap = (uap->osv != NULL) ? &osa : NULL; 1036 if (nsap) { 1037 error = copyin(uap->nsv, &vec, sizeof(vec)); 1038 if (error) 1039 return (error); 1040 nsap->sa_handler = vec.sv_handler; 1041 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1042 nsap->sa_flags = vec.sv_flags; 1043 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1044 } 1045 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1046 if (osap && !error) { 1047 vec.sv_handler = osap->sa_handler; 1048 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1049 vec.sv_flags = osap->sa_flags; 1050 vec.sv_flags &= ~SA_NOCLDWAIT; 1051 vec.sv_flags ^= SA_RESTART; 1052 error = copyout(&vec, uap->osv, sizeof(vec)); 1053 } 1054 return (error); 1055 } 1056 1057 #ifndef _SYS_SYSPROTO_H_ 1058 struct osigblock_args { 1059 int mask; 1060 }; 1061 #endif 1062 /* 1063 * MPSAFE 1064 */ 1065 int 1066 osigblock(td, uap) 1067 register struct thread *td; 1068 struct osigblock_args *uap; 1069 { 1070 struct proc *p = td->td_proc; 1071 sigset_t set; 1072 1073 OSIG2SIG(uap->mask, set); 1074 SIG_CANTMASK(set); 1075 PROC_LOCK(p); 1076 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1077 SIGSETOR(td->td_sigmask, set); 1078 PROC_UNLOCK(p); 1079 return (0); 1080 } 1081 1082 #ifndef _SYS_SYSPROTO_H_ 1083 struct osigsetmask_args { 1084 int mask; 1085 }; 1086 #endif 1087 /* 1088 * MPSAFE 1089 */ 1090 int 1091 osigsetmask(td, uap) 1092 struct thread *td; 1093 struct osigsetmask_args *uap; 1094 { 1095 struct proc *p = td->td_proc; 1096 sigset_t set; 1097 1098 OSIG2SIG(uap->mask, set); 1099 SIG_CANTMASK(set); 1100 PROC_LOCK(p); 1101 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1102 SIGSETLO(td->td_sigmask, set); 1103 signotify(td); 1104 PROC_UNLOCK(p); 1105 return (0); 1106 } 1107 #endif /* COMPAT_43 */ 1108 1109 /* 1110 * Suspend process until signal, providing mask to be set 1111 * in the meantime. 1112 ***** XXXKSE this doesn't make sense under KSE. 1113 ***** Do we suspend the thread or all threads in the process? 1114 ***** How do we suspend threads running NOW on another processor? 1115 */ 1116 #ifndef _SYS_SYSPROTO_H_ 1117 struct sigsuspend_args { 1118 const sigset_t *sigmask; 1119 }; 1120 #endif 1121 /* 1122 * MPSAFE 1123 */ 1124 /* ARGSUSED */ 1125 int 1126 sigsuspend(td, uap) 1127 struct thread *td; 1128 struct sigsuspend_args *uap; 1129 { 1130 sigset_t mask; 1131 int error; 1132 1133 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1134 if (error) 1135 return (error); 1136 return (kern_sigsuspend(td, mask)); 1137 } 1138 1139 int 1140 kern_sigsuspend(struct thread *td, sigset_t mask) 1141 { 1142 struct proc *p = td->td_proc; 1143 1144 /* 1145 * When returning from sigsuspend, we want 1146 * the old mask to be restored after the 1147 * signal handler has finished. Thus, we 1148 * save it here and mark the sigacts structure 1149 * to indicate this. 1150 */ 1151 PROC_LOCK(p); 1152 td->td_oldsigmask = td->td_sigmask; 1153 td->td_pflags |= TDP_OLDMASK; 1154 SIG_CANTMASK(mask); 1155 td->td_sigmask = mask; 1156 signotify(td); 1157 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1158 /* void */; 1159 PROC_UNLOCK(p); 1160 /* always return EINTR rather than ERESTART... */ 1161 return (EINTR); 1162 } 1163 1164 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1165 /* 1166 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1167 * convention: libc stub passes mask, not pointer, to save a copyin. 1168 */ 1169 #ifndef _SYS_SYSPROTO_H_ 1170 struct osigsuspend_args { 1171 osigset_t mask; 1172 }; 1173 #endif 1174 /* 1175 * MPSAFE 1176 */ 1177 /* ARGSUSED */ 1178 int 1179 osigsuspend(td, uap) 1180 struct thread *td; 1181 struct osigsuspend_args *uap; 1182 { 1183 struct proc *p = td->td_proc; 1184 sigset_t mask; 1185 1186 PROC_LOCK(p); 1187 td->td_oldsigmask = td->td_sigmask; 1188 td->td_pflags |= TDP_OLDMASK; 1189 OSIG2SIG(uap->mask, mask); 1190 SIG_CANTMASK(mask); 1191 SIGSETLO(td->td_sigmask, mask); 1192 signotify(td); 1193 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1194 /* void */; 1195 PROC_UNLOCK(p); 1196 /* always return EINTR rather than ERESTART... */ 1197 return (EINTR); 1198 } 1199 #endif /* COMPAT_43 */ 1200 1201 #if defined(COMPAT_43) 1202 #ifndef _SYS_SYSPROTO_H_ 1203 struct osigstack_args { 1204 struct sigstack *nss; 1205 struct sigstack *oss; 1206 }; 1207 #endif 1208 /* 1209 * MPSAFE 1210 */ 1211 /* ARGSUSED */ 1212 int 1213 osigstack(td, uap) 1214 struct thread *td; 1215 register struct osigstack_args *uap; 1216 { 1217 struct sigstack nss, oss; 1218 int error = 0; 1219 1220 if (uap->nss != NULL) { 1221 error = copyin(uap->nss, &nss, sizeof(nss)); 1222 if (error) 1223 return (error); 1224 } 1225 oss.ss_sp = td->td_sigstk.ss_sp; 1226 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1227 if (uap->nss != NULL) { 1228 td->td_sigstk.ss_sp = nss.ss_sp; 1229 td->td_sigstk.ss_size = 0; 1230 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1231 td->td_pflags |= TDP_ALTSTACK; 1232 } 1233 if (uap->oss != NULL) 1234 error = copyout(&oss, uap->oss, sizeof(oss)); 1235 1236 return (error); 1237 } 1238 #endif /* COMPAT_43 */ 1239 1240 #ifndef _SYS_SYSPROTO_H_ 1241 struct sigaltstack_args { 1242 stack_t *ss; 1243 stack_t *oss; 1244 }; 1245 #endif 1246 /* 1247 * MPSAFE 1248 */ 1249 /* ARGSUSED */ 1250 int 1251 sigaltstack(td, uap) 1252 struct thread *td; 1253 register struct sigaltstack_args *uap; 1254 { 1255 stack_t ss, oss; 1256 int error; 1257 1258 if (uap->ss != NULL) { 1259 error = copyin(uap->ss, &ss, sizeof(ss)); 1260 if (error) 1261 return (error); 1262 } 1263 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1264 (uap->oss != NULL) ? &oss : NULL); 1265 if (error) 1266 return (error); 1267 if (uap->oss != NULL) 1268 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1269 return (error); 1270 } 1271 1272 int 1273 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1274 { 1275 struct proc *p = td->td_proc; 1276 int oonstack; 1277 1278 oonstack = sigonstack(cpu_getstack(td)); 1279 1280 if (oss != NULL) { 1281 *oss = td->td_sigstk; 1282 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1283 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1284 } 1285 1286 if (ss != NULL) { 1287 if (oonstack) 1288 return (EPERM); 1289 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1290 return (EINVAL); 1291 if (!(ss->ss_flags & SS_DISABLE)) { 1292 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1293 return (ENOMEM); 1294 } 1295 td->td_sigstk = *ss; 1296 td->td_pflags |= TDP_ALTSTACK; 1297 } else { 1298 td->td_pflags &= ~TDP_ALTSTACK; 1299 } 1300 } 1301 return (0); 1302 } 1303 1304 /* 1305 * Common code for kill process group/broadcast kill. 1306 * cp is calling process. 1307 */ 1308 static int 1309 killpg1(td, sig, pgid, all) 1310 register struct thread *td; 1311 int sig, pgid, all; 1312 { 1313 register struct proc *p; 1314 struct pgrp *pgrp; 1315 int nfound = 0; 1316 1317 if (all) { 1318 /* 1319 * broadcast 1320 */ 1321 sx_slock(&allproc_lock); 1322 LIST_FOREACH(p, &allproc, p_list) { 1323 PROC_LOCK(p); 1324 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1325 p == td->td_proc) { 1326 PROC_UNLOCK(p); 1327 continue; 1328 } 1329 if (p_cansignal(td, p, sig) == 0) { 1330 nfound++; 1331 if (sig) 1332 psignal(p, sig); 1333 } 1334 PROC_UNLOCK(p); 1335 } 1336 sx_sunlock(&allproc_lock); 1337 } else { 1338 sx_slock(&proctree_lock); 1339 if (pgid == 0) { 1340 /* 1341 * zero pgid means send to my process group. 1342 */ 1343 pgrp = td->td_proc->p_pgrp; 1344 PGRP_LOCK(pgrp); 1345 } else { 1346 pgrp = pgfind(pgid); 1347 if (pgrp == NULL) { 1348 sx_sunlock(&proctree_lock); 1349 return (ESRCH); 1350 } 1351 } 1352 sx_sunlock(&proctree_lock); 1353 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1354 PROC_LOCK(p); 1355 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1356 PROC_UNLOCK(p); 1357 continue; 1358 } 1359 if (p_cansignal(td, p, sig) == 0) { 1360 nfound++; 1361 if (sig) 1362 psignal(p, sig); 1363 } 1364 PROC_UNLOCK(p); 1365 } 1366 PGRP_UNLOCK(pgrp); 1367 } 1368 return (nfound ? 0 : ESRCH); 1369 } 1370 1371 #ifndef _SYS_SYSPROTO_H_ 1372 struct kill_args { 1373 int pid; 1374 int signum; 1375 }; 1376 #endif 1377 /* 1378 * MPSAFE 1379 */ 1380 /* ARGSUSED */ 1381 int 1382 kill(td, uap) 1383 register struct thread *td; 1384 register struct kill_args *uap; 1385 { 1386 register struct proc *p; 1387 int error; 1388 1389 if ((u_int)uap->signum > _SIG_MAXSIG) 1390 return (EINVAL); 1391 1392 if (uap->pid > 0) { 1393 /* kill single process */ 1394 if ((p = pfind(uap->pid)) == NULL) { 1395 if ((p = zpfind(uap->pid)) == NULL) 1396 return (ESRCH); 1397 } 1398 error = p_cansignal(td, p, uap->signum); 1399 if (error == 0 && uap->signum) 1400 psignal(p, uap->signum); 1401 PROC_UNLOCK(p); 1402 return (error); 1403 } 1404 switch (uap->pid) { 1405 case -1: /* broadcast signal */ 1406 return (killpg1(td, uap->signum, 0, 1)); 1407 case 0: /* signal own process group */ 1408 return (killpg1(td, uap->signum, 0, 0)); 1409 default: /* negative explicit process group */ 1410 return (killpg1(td, uap->signum, -uap->pid, 0)); 1411 } 1412 /* NOTREACHED */ 1413 } 1414 1415 #if defined(COMPAT_43) 1416 #ifndef _SYS_SYSPROTO_H_ 1417 struct okillpg_args { 1418 int pgid; 1419 int signum; 1420 }; 1421 #endif 1422 /* 1423 * MPSAFE 1424 */ 1425 /* ARGSUSED */ 1426 int 1427 okillpg(td, uap) 1428 struct thread *td; 1429 register struct okillpg_args *uap; 1430 { 1431 1432 if ((u_int)uap->signum > _SIG_MAXSIG) 1433 return (EINVAL); 1434 return (killpg1(td, uap->signum, uap->pgid, 0)); 1435 } 1436 #endif /* COMPAT_43 */ 1437 1438 /* 1439 * Send a signal to a process group. 1440 */ 1441 void 1442 gsignal(pgid, sig) 1443 int pgid, sig; 1444 { 1445 struct pgrp *pgrp; 1446 1447 if (pgid != 0) { 1448 sx_slock(&proctree_lock); 1449 pgrp = pgfind(pgid); 1450 sx_sunlock(&proctree_lock); 1451 if (pgrp != NULL) { 1452 pgsignal(pgrp, sig, 0); 1453 PGRP_UNLOCK(pgrp); 1454 } 1455 } 1456 } 1457 1458 /* 1459 * Send a signal to a process group. If checktty is 1, 1460 * limit to members which have a controlling terminal. 1461 */ 1462 void 1463 pgsignal(pgrp, sig, checkctty) 1464 struct pgrp *pgrp; 1465 int sig, checkctty; 1466 { 1467 register struct proc *p; 1468 1469 if (pgrp) { 1470 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1471 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1472 PROC_LOCK(p); 1473 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1474 psignal(p, sig); 1475 PROC_UNLOCK(p); 1476 } 1477 } 1478 } 1479 1480 /* 1481 * Send a signal caused by a trap to the current thread. 1482 * If it will be caught immediately, deliver it with correct code. 1483 * Otherwise, post it normally. 1484 * 1485 * MPSAFE 1486 */ 1487 void 1488 trapsignal(struct thread *td, int sig, u_long code) 1489 { 1490 struct sigacts *ps; 1491 struct proc *p; 1492 siginfo_t siginfo; 1493 int error; 1494 1495 p = td->td_proc; 1496 if (td->td_pflags & TDP_SA) { 1497 if (td->td_mailbox == NULL) 1498 thread_user_enter(td); 1499 PROC_LOCK(p); 1500 SIGDELSET(td->td_sigmask, sig); 1501 mtx_lock_spin(&sched_lock); 1502 /* 1503 * Force scheduling an upcall, so UTS has chance to 1504 * process the signal before thread runs again in 1505 * userland. 1506 */ 1507 if (td->td_upcall) 1508 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1509 mtx_unlock_spin(&sched_lock); 1510 } else { 1511 PROC_LOCK(p); 1512 } 1513 ps = p->p_sigacts; 1514 mtx_lock(&ps->ps_mtx); 1515 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1516 !SIGISMEMBER(td->td_sigmask, sig)) { 1517 p->p_stats->p_ru.ru_nsignals++; 1518 #ifdef KTRACE 1519 if (KTRPOINT(curthread, KTR_PSIG)) 1520 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1521 &td->td_sigmask, code); 1522 #endif 1523 if (!(td->td_pflags & TDP_SA)) 1524 (*p->p_sysent->sv_sendsig)( 1525 ps->ps_sigact[_SIG_IDX(sig)], sig, 1526 &td->td_sigmask, code); 1527 else if (td->td_mailbox == NULL) { 1528 mtx_unlock(&ps->ps_mtx); 1529 /* UTS caused a sync signal */ 1530 p->p_code = code; /* XXX for core dump/debugger */ 1531 p->p_sig = sig; /* XXX to verify code */ 1532 sigexit(td, sig); 1533 } else { 1534 cpu_thread_siginfo(sig, code, &siginfo); 1535 mtx_unlock(&ps->ps_mtx); 1536 SIGADDSET(td->td_sigmask, sig); 1537 PROC_UNLOCK(p); 1538 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1539 sizeof(siginfo)); 1540 PROC_LOCK(p); 1541 /* UTS memory corrupted */ 1542 if (error) 1543 sigexit(td, SIGSEGV); 1544 mtx_lock(&ps->ps_mtx); 1545 } 1546 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1547 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1548 SIGADDSET(td->td_sigmask, sig); 1549 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1550 /* 1551 * See kern_sigaction() for origin of this code. 1552 */ 1553 SIGDELSET(ps->ps_sigcatch, sig); 1554 if (sig != SIGCONT && 1555 sigprop(sig) & SA_IGNORE) 1556 SIGADDSET(ps->ps_sigignore, sig); 1557 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1558 } 1559 mtx_unlock(&ps->ps_mtx); 1560 } else { 1561 mtx_unlock(&ps->ps_mtx); 1562 p->p_code = code; /* XXX for core dump/debugger */ 1563 p->p_sig = sig; /* XXX to verify code */ 1564 tdsignal(td, sig, SIGTARGET_TD); 1565 } 1566 PROC_UNLOCK(p); 1567 } 1568 1569 static struct thread * 1570 sigtd(struct proc *p, int sig, int prop) 1571 { 1572 struct thread *td, *signal_td; 1573 1574 PROC_LOCK_ASSERT(p, MA_OWNED); 1575 1576 /* 1577 * Check if current thread can handle the signal without 1578 * switching conetxt to another thread. 1579 */ 1580 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1581 return (curthread); 1582 signal_td = NULL; 1583 mtx_lock_spin(&sched_lock); 1584 FOREACH_THREAD_IN_PROC(p, td) { 1585 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1586 signal_td = td; 1587 break; 1588 } 1589 } 1590 if (signal_td == NULL) 1591 signal_td = FIRST_THREAD_IN_PROC(p); 1592 mtx_unlock_spin(&sched_lock); 1593 return (signal_td); 1594 } 1595 1596 /* 1597 * Send the signal to the process. If the signal has an action, the action 1598 * is usually performed by the target process rather than the caller; we add 1599 * the signal to the set of pending signals for the process. 1600 * 1601 * Exceptions: 1602 * o When a stop signal is sent to a sleeping process that takes the 1603 * default action, the process is stopped without awakening it. 1604 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1605 * regardless of the signal action (eg, blocked or ignored). 1606 * 1607 * Other ignored signals are discarded immediately. 1608 * 1609 * MPSAFE 1610 */ 1611 void 1612 psignal(struct proc *p, int sig) 1613 { 1614 struct thread *td; 1615 int prop; 1616 1617 if (!_SIG_VALID(sig)) 1618 panic("psignal(): invalid signal"); 1619 1620 PROC_LOCK_ASSERT(p, MA_OWNED); 1621 /* 1622 * IEEE Std 1003.1-2001: return success when killing a zombie. 1623 */ 1624 if (p->p_state == PRS_ZOMBIE) 1625 return; 1626 prop = sigprop(sig); 1627 1628 /* 1629 * Find a thread to deliver the signal to. 1630 */ 1631 td = sigtd(p, sig, prop); 1632 1633 tdsignal(td, sig, SIGTARGET_P); 1634 } 1635 1636 /* 1637 * MPSAFE 1638 */ 1639 void 1640 tdsignal(struct thread *td, int sig, sigtarget_t target) 1641 { 1642 sigset_t saved; 1643 struct proc *p = td->td_proc; 1644 1645 if (p->p_flag & P_SA) 1646 saved = p->p_siglist; 1647 do_tdsignal(td, sig, target); 1648 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1649 if (!SIGSETEQ(saved, p->p_siglist)) { 1650 /* pending set changed */ 1651 p->p_flag |= P_SIGEVENT; 1652 wakeup(&p->p_siglist); 1653 } 1654 } 1655 } 1656 1657 static void 1658 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1659 { 1660 struct proc *p; 1661 register sig_t action; 1662 sigset_t *siglist; 1663 struct thread *td0; 1664 register int prop; 1665 struct sigacts *ps; 1666 1667 if (!_SIG_VALID(sig)) 1668 panic("do_tdsignal(): invalid signal"); 1669 1670 p = td->td_proc; 1671 ps = p->p_sigacts; 1672 1673 PROC_LOCK_ASSERT(p, MA_OWNED); 1674 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 1675 1676 prop = sigprop(sig); 1677 1678 /* 1679 * If the signal is blocked and not destined for this thread, then 1680 * assign it to the process so that we can find it later in the first 1681 * thread that unblocks it. Otherwise, assign it to this thread now. 1682 */ 1683 if (target == SIGTARGET_TD) { 1684 siglist = &td->td_siglist; 1685 } else { 1686 if (!SIGISMEMBER(td->td_sigmask, sig)) 1687 siglist = &td->td_siglist; 1688 else 1689 siglist = &p->p_siglist; 1690 } 1691 1692 /* 1693 * If the signal is being ignored, 1694 * then we forget about it immediately. 1695 * (Note: we don't set SIGCONT in ps_sigignore, 1696 * and if it is set to SIG_IGN, 1697 * action will be SIG_DFL here.) 1698 */ 1699 mtx_lock(&ps->ps_mtx); 1700 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1701 (p->p_flag & P_WEXIT)) { 1702 mtx_unlock(&ps->ps_mtx); 1703 return; 1704 } 1705 if (SIGISMEMBER(td->td_sigmask, sig)) 1706 action = SIG_HOLD; 1707 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1708 action = SIG_CATCH; 1709 else 1710 action = SIG_DFL; 1711 mtx_unlock(&ps->ps_mtx); 1712 1713 if (prop & SA_CONT) { 1714 SIG_STOPSIGMASK(p->p_siglist); 1715 /* 1716 * XXX Should investigate leaving STOP and CONT sigs only in 1717 * the proc's siglist. 1718 */ 1719 mtx_lock_spin(&sched_lock); 1720 FOREACH_THREAD_IN_PROC(p, td0) 1721 SIG_STOPSIGMASK(td0->td_siglist); 1722 mtx_unlock_spin(&sched_lock); 1723 } 1724 1725 if (prop & SA_STOP) { 1726 /* 1727 * If sending a tty stop signal to a member of an orphaned 1728 * process group, discard the signal here if the action 1729 * is default; don't stop the process below if sleeping, 1730 * and don't clear any pending SIGCONT. 1731 */ 1732 if ((prop & SA_TTYSTOP) && 1733 (p->p_pgrp->pg_jobc == 0) && 1734 (action == SIG_DFL)) 1735 return; 1736 SIG_CONTSIGMASK(p->p_siglist); 1737 mtx_lock_spin(&sched_lock); 1738 FOREACH_THREAD_IN_PROC(p, td0) 1739 SIG_CONTSIGMASK(td0->td_siglist); 1740 mtx_unlock_spin(&sched_lock); 1741 p->p_flag &= ~P_CONTINUED; 1742 } 1743 1744 SIGADDSET(*siglist, sig); 1745 signotify(td); /* uses schedlock */ 1746 /* 1747 * Defer further processing for signals which are held, 1748 * except that stopped processes must be continued by SIGCONT. 1749 */ 1750 if (action == SIG_HOLD && 1751 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1752 return; 1753 /* 1754 * SIGKILL: Remove procfs STOPEVENTs. 1755 */ 1756 if (sig == SIGKILL) { 1757 /* from procfs_ioctl.c: PIOCBIC */ 1758 p->p_stops = 0; 1759 /* from procfs_ioctl.c: PIOCCONT */ 1760 p->p_step = 0; 1761 wakeup(&p->p_step); 1762 } 1763 /* 1764 * Some signals have a process-wide effect and a per-thread 1765 * component. Most processing occurs when the process next 1766 * tries to cross the user boundary, however there are some 1767 * times when processing needs to be done immediatly, such as 1768 * waking up threads so that they can cross the user boundary. 1769 * We try do the per-process part here. 1770 */ 1771 if (P_SHOULDSTOP(p)) { 1772 /* 1773 * The process is in stopped mode. All the threads should be 1774 * either winding down or already on the suspended queue. 1775 */ 1776 if (p->p_flag & P_TRACED) { 1777 /* 1778 * The traced process is already stopped, 1779 * so no further action is necessary. 1780 * No signal can restart us. 1781 */ 1782 goto out; 1783 } 1784 1785 if (sig == SIGKILL) { 1786 /* 1787 * SIGKILL sets process running. 1788 * It will die elsewhere. 1789 * All threads must be restarted. 1790 */ 1791 p->p_flag &= ~P_STOPPED_SIG; 1792 goto runfast; 1793 } 1794 1795 if (prop & SA_CONT) { 1796 /* 1797 * If SIGCONT is default (or ignored), we continue the 1798 * process but don't leave the signal in siglist as 1799 * it has no further action. If SIGCONT is held, we 1800 * continue the process and leave the signal in 1801 * siglist. If the process catches SIGCONT, let it 1802 * handle the signal itself. If it isn't waiting on 1803 * an event, it goes back to run state. 1804 * Otherwise, process goes back to sleep state. 1805 */ 1806 p->p_flag &= ~P_STOPPED_SIG; 1807 p->p_flag |= P_CONTINUED; 1808 if (action == SIG_DFL) { 1809 SIGDELSET(*siglist, sig); 1810 } else if (action == SIG_CATCH) { 1811 /* 1812 * The process wants to catch it so it needs 1813 * to run at least one thread, but which one? 1814 * It would seem that the answer would be to 1815 * run an upcall in the next KSE to run, and 1816 * deliver the signal that way. In a NON KSE 1817 * process, we need to make sure that the 1818 * single thread is runnable asap. 1819 * XXXKSE for now however, make them all run. 1820 */ 1821 goto runfast; 1822 } 1823 /* 1824 * The signal is not ignored or caught. 1825 */ 1826 mtx_lock_spin(&sched_lock); 1827 thread_unsuspend(p); 1828 mtx_unlock_spin(&sched_lock); 1829 goto out; 1830 } 1831 1832 if (prop & SA_STOP) { 1833 /* 1834 * Already stopped, don't need to stop again 1835 * (If we did the shell could get confused). 1836 * Just make sure the signal STOP bit set. 1837 */ 1838 p->p_flag |= P_STOPPED_SIG; 1839 SIGDELSET(*siglist, sig); 1840 goto out; 1841 } 1842 1843 /* 1844 * All other kinds of signals: 1845 * If a thread is sleeping interruptibly, simulate a 1846 * wakeup so that when it is continued it will be made 1847 * runnable and can look at the signal. However, don't make 1848 * the PROCESS runnable, leave it stopped. 1849 * It may run a bit until it hits a thread_suspend_check(). 1850 */ 1851 mtx_lock_spin(&sched_lock); 1852 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 1853 sleepq_abort(td); 1854 mtx_unlock_spin(&sched_lock); 1855 goto out; 1856 /* 1857 * Mutexes are short lived. Threads waiting on them will 1858 * hit thread_suspend_check() soon. 1859 */ 1860 } else if (p->p_state == PRS_NORMAL) { 1861 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 1862 mtx_lock_spin(&sched_lock); 1863 tdsigwakeup(td, sig, action); 1864 mtx_unlock_spin(&sched_lock); 1865 goto out; 1866 } 1867 1868 MPASS(action == SIG_DFL); 1869 1870 if (prop & SA_STOP) { 1871 if (p->p_flag & P_PPWAIT) 1872 goto out; 1873 p->p_flag |= P_STOPPED_SIG; 1874 p->p_xstat = sig; 1875 p->p_xthread = td; 1876 mtx_lock_spin(&sched_lock); 1877 FOREACH_THREAD_IN_PROC(p, td0) { 1878 if (TD_IS_SLEEPING(td0) && 1879 (td0->td_flags & TDF_SINTR) && 1880 !TD_IS_SUSPENDED(td0)) { 1881 thread_suspend_one(td0); 1882 } else if (td != td0) { 1883 td0->td_flags |= TDF_ASTPENDING; 1884 } 1885 } 1886 thread_stopped(p); 1887 if (p->p_numthreads == p->p_suspcount) { 1888 SIGDELSET(p->p_siglist, p->p_xstat); 1889 FOREACH_THREAD_IN_PROC(p, td0) 1890 SIGDELSET(td0->td_siglist, p->p_xstat); 1891 } 1892 mtx_unlock_spin(&sched_lock); 1893 goto out; 1894 } 1895 else 1896 goto runfast; 1897 /* NOTREACHED */ 1898 } else { 1899 /* Not in "NORMAL" state. discard the signal. */ 1900 SIGDELSET(*siglist, sig); 1901 goto out; 1902 } 1903 1904 /* 1905 * The process is not stopped so we need to apply the signal to all the 1906 * running threads. 1907 */ 1908 1909 runfast: 1910 mtx_lock_spin(&sched_lock); 1911 tdsigwakeup(td, sig, action); 1912 thread_unsuspend(p); 1913 mtx_unlock_spin(&sched_lock); 1914 out: 1915 /* If we jump here, sched_lock should not be owned. */ 1916 mtx_assert(&sched_lock, MA_NOTOWNED); 1917 } 1918 1919 /* 1920 * The force of a signal has been directed against a single 1921 * thread. We need to see what we can do about knocking it 1922 * out of any sleep it may be in etc. 1923 */ 1924 static void 1925 tdsigwakeup(struct thread *td, int sig, sig_t action) 1926 { 1927 struct proc *p = td->td_proc; 1928 register int prop; 1929 1930 PROC_LOCK_ASSERT(p, MA_OWNED); 1931 mtx_assert(&sched_lock, MA_OWNED); 1932 prop = sigprop(sig); 1933 1934 /* 1935 * Bring the priority of a thread up if we want it to get 1936 * killed in this lifetime. 1937 */ 1938 if (action == SIG_DFL && (prop & SA_KILL)) { 1939 if (p->p_nice > 0) 1940 sched_nice(td->td_proc, 0); 1941 if (td->td_priority > PUSER) 1942 sched_prio(td, PUSER); 1943 } 1944 1945 if (TD_ON_SLEEPQ(td)) { 1946 /* 1947 * If thread is sleeping uninterruptibly 1948 * we can't interrupt the sleep... the signal will 1949 * be noticed when the process returns through 1950 * trap() or syscall(). 1951 */ 1952 if ((td->td_flags & TDF_SINTR) == 0) 1953 return; 1954 /* 1955 * If SIGCONT is default (or ignored) and process is 1956 * asleep, we are finished; the process should not 1957 * be awakened. 1958 */ 1959 if ((prop & SA_CONT) && action == SIG_DFL) { 1960 SIGDELSET(p->p_siglist, sig); 1961 /* 1962 * It may be on either list in this state. 1963 * Remove from both for now. 1964 */ 1965 SIGDELSET(td->td_siglist, sig); 1966 return; 1967 } 1968 1969 /* 1970 * Give low priority threads a better chance to run. 1971 */ 1972 if (td->td_priority > PUSER) 1973 sched_prio(td, PUSER); 1974 1975 sleepq_abort(td); 1976 } else { 1977 /* 1978 * Other states do nothing with the signal immediately, 1979 * other than kicking ourselves if we are running. 1980 * It will either never be noticed, or noticed very soon. 1981 */ 1982 #ifdef SMP 1983 if (TD_IS_RUNNING(td) && td != curthread) 1984 forward_signal(td); 1985 #endif 1986 } 1987 } 1988 1989 int 1990 ptracestop(struct thread *td, int sig) 1991 { 1992 struct proc *p = td->td_proc; 1993 struct thread *td0; 1994 1995 PROC_LOCK_ASSERT(p, MA_OWNED); 1996 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 1997 &p->p_mtx.mtx_object, "Stopping for traced signal"); 1998 1999 mtx_lock_spin(&sched_lock); 2000 td->td_flags |= TDF_XSIG; 2001 mtx_unlock_spin(&sched_lock); 2002 td->td_xsig = sig; 2003 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2004 if (p->p_flag & P_SINGLE_EXIT) { 2005 mtx_lock_spin(&sched_lock); 2006 td->td_flags &= ~TDF_XSIG; 2007 mtx_unlock_spin(&sched_lock); 2008 return (sig); 2009 } 2010 /* 2011 * Just make wait() to work, the last stopped thread 2012 * will win. 2013 */ 2014 p->p_xstat = sig; 2015 p->p_xthread = td; 2016 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2017 mtx_lock_spin(&sched_lock); 2018 FOREACH_THREAD_IN_PROC(p, td0) { 2019 if (TD_IS_SLEEPING(td0) && 2020 (td0->td_flags & TDF_SINTR) && 2021 !TD_IS_SUSPENDED(td0)) { 2022 thread_suspend_one(td0); 2023 } else if (td != td0) { 2024 td0->td_flags |= TDF_ASTPENDING; 2025 } 2026 } 2027 stopme: 2028 thread_stopped(p); 2029 thread_suspend_one(td); 2030 PROC_UNLOCK(p); 2031 DROP_GIANT(); 2032 mi_switch(SW_VOL, NULL); 2033 mtx_unlock_spin(&sched_lock); 2034 PICKUP_GIANT(); 2035 PROC_LOCK(p); 2036 if (!(p->p_flag & P_TRACED)) 2037 break; 2038 if (td->td_flags & TDF_DBSUSPEND) { 2039 if (p->p_flag & P_SINGLE_EXIT) 2040 break; 2041 mtx_lock_spin(&sched_lock); 2042 goto stopme; 2043 } 2044 } 2045 return (td->td_xsig); 2046 } 2047 2048 /* 2049 * If the current process has received a signal (should be caught or cause 2050 * termination, should interrupt current syscall), return the signal number. 2051 * Stop signals with default action are processed immediately, then cleared; 2052 * they aren't returned. This is checked after each entry to the system for 2053 * a syscall or trap (though this can usually be done without calling issignal 2054 * by checking the pending signal masks in cursig.) The normal call 2055 * sequence is 2056 * 2057 * while (sig = cursig(curthread)) 2058 * postsig(sig); 2059 */ 2060 static int 2061 issignal(td) 2062 struct thread *td; 2063 { 2064 struct proc *p; 2065 struct sigacts *ps; 2066 sigset_t sigpending; 2067 int sig, prop, newsig; 2068 struct thread *td0; 2069 2070 p = td->td_proc; 2071 ps = p->p_sigacts; 2072 mtx_assert(&ps->ps_mtx, MA_OWNED); 2073 PROC_LOCK_ASSERT(p, MA_OWNED); 2074 for (;;) { 2075 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2076 2077 sigpending = td->td_siglist; 2078 SIGSETNAND(sigpending, td->td_sigmask); 2079 2080 if (p->p_flag & P_PPWAIT) 2081 SIG_STOPSIGMASK(sigpending); 2082 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2083 return (0); 2084 sig = sig_ffs(&sigpending); 2085 2086 if (p->p_stops & S_SIG) { 2087 mtx_unlock(&ps->ps_mtx); 2088 stopevent(p, S_SIG, sig); 2089 mtx_lock(&ps->ps_mtx); 2090 } 2091 2092 /* 2093 * We should see pending but ignored signals 2094 * only if P_TRACED was on when they were posted. 2095 */ 2096 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2097 SIGDELSET(td->td_siglist, sig); 2098 if (td->td_pflags & TDP_SA) 2099 SIGADDSET(td->td_sigmask, sig); 2100 continue; 2101 } 2102 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2103 /* 2104 * If traced, always stop. 2105 */ 2106 mtx_unlock(&ps->ps_mtx); 2107 newsig = ptracestop(td, sig); 2108 mtx_lock(&ps->ps_mtx); 2109 2110 /* 2111 * If parent wants us to take the signal, 2112 * then it will leave it in p->p_xstat; 2113 * otherwise we just look for signals again. 2114 */ 2115 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2116 if (td->td_pflags & TDP_SA) 2117 SIGADDSET(td->td_sigmask, sig); 2118 if (newsig == 0) 2119 continue; 2120 sig = newsig; 2121 /* 2122 * If the traced bit got turned off, go back up 2123 * to the top to rescan signals. This ensures 2124 * that p_sig* and p_sigact are consistent. 2125 */ 2126 if ((p->p_flag & P_TRACED) == 0) 2127 continue; 2128 2129 /* 2130 * Put the new signal into td_siglist. If the 2131 * signal is being masked, look for other signals. 2132 */ 2133 SIGADDSET(td->td_siglist, sig); 2134 if (td->td_pflags & TDP_SA) 2135 SIGDELSET(td->td_sigmask, sig); 2136 if (SIGISMEMBER(td->td_sigmask, sig)) 2137 continue; 2138 signotify(td); 2139 } 2140 2141 prop = sigprop(sig); 2142 2143 /* 2144 * Decide whether the signal should be returned. 2145 * Return the signal's number, or fall through 2146 * to clear it from the pending mask. 2147 */ 2148 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2149 2150 case (intptr_t)SIG_DFL: 2151 /* 2152 * Don't take default actions on system processes. 2153 */ 2154 if (p->p_pid <= 1) { 2155 #ifdef DIAGNOSTIC 2156 /* 2157 * Are you sure you want to ignore SIGSEGV 2158 * in init? XXX 2159 */ 2160 printf("Process (pid %lu) got signal %d\n", 2161 (u_long)p->p_pid, sig); 2162 #endif 2163 break; /* == ignore */ 2164 } 2165 /* 2166 * If there is a pending stop signal to process 2167 * with default action, stop here, 2168 * then clear the signal. However, 2169 * if process is member of an orphaned 2170 * process group, ignore tty stop signals. 2171 */ 2172 if (prop & SA_STOP) { 2173 if (p->p_flag & P_TRACED || 2174 (p->p_pgrp->pg_jobc == 0 && 2175 prop & SA_TTYSTOP)) 2176 break; /* == ignore */ 2177 mtx_unlock(&ps->ps_mtx); 2178 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2179 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2180 p->p_flag |= P_STOPPED_SIG; 2181 p->p_xstat = sig; 2182 p->p_xthread = td; 2183 mtx_lock_spin(&sched_lock); 2184 FOREACH_THREAD_IN_PROC(p, td0) { 2185 if (TD_IS_SLEEPING(td0) && 2186 (td0->td_flags & TDF_SINTR) && 2187 !TD_IS_SUSPENDED(td0)) { 2188 thread_suspend_one(td0); 2189 } else if (td != td0) { 2190 td0->td_flags |= TDF_ASTPENDING; 2191 } 2192 } 2193 thread_stopped(p); 2194 thread_suspend_one(td); 2195 PROC_UNLOCK(p); 2196 DROP_GIANT(); 2197 mi_switch(SW_INVOL, NULL); 2198 mtx_unlock_spin(&sched_lock); 2199 PICKUP_GIANT(); 2200 PROC_LOCK(p); 2201 mtx_lock(&ps->ps_mtx); 2202 break; 2203 } else if (prop & SA_IGNORE) { 2204 /* 2205 * Except for SIGCONT, shouldn't get here. 2206 * Default action is to ignore; drop it. 2207 */ 2208 break; /* == ignore */ 2209 } else 2210 return (sig); 2211 /*NOTREACHED*/ 2212 2213 case (intptr_t)SIG_IGN: 2214 /* 2215 * Masking above should prevent us ever trying 2216 * to take action on an ignored signal other 2217 * than SIGCONT, unless process is traced. 2218 */ 2219 if ((prop & SA_CONT) == 0 && 2220 (p->p_flag & P_TRACED) == 0) 2221 printf("issignal\n"); 2222 break; /* == ignore */ 2223 2224 default: 2225 /* 2226 * This signal has an action, let 2227 * postsig() process it. 2228 */ 2229 return (sig); 2230 } 2231 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2232 } 2233 /* NOTREACHED */ 2234 } 2235 2236 /* 2237 * MPSAFE 2238 */ 2239 void 2240 thread_stopped(struct proc *p) 2241 { 2242 struct proc *p1 = curthread->td_proc; 2243 struct sigacts *ps; 2244 int n; 2245 2246 PROC_LOCK_ASSERT(p, MA_OWNED); 2247 mtx_assert(&sched_lock, MA_OWNED); 2248 n = p->p_suspcount; 2249 if (p == p1) 2250 n++; 2251 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2252 mtx_unlock_spin(&sched_lock); 2253 p->p_flag &= ~P_WAITED; 2254 PROC_LOCK(p->p_pptr); 2255 /* 2256 * Wake up parent sleeping in kern_wait(), also send 2257 * SIGCHLD to parent, but SIGCHLD does not guarantee 2258 * that parent will awake, because parent may masked 2259 * the signal. 2260 */ 2261 p->p_pptr->p_flag |= P_STATCHILD; 2262 wakeup(p->p_pptr); 2263 ps = p->p_pptr->p_sigacts; 2264 mtx_lock(&ps->ps_mtx); 2265 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2266 mtx_unlock(&ps->ps_mtx); 2267 psignal(p->p_pptr, SIGCHLD); 2268 } else 2269 mtx_unlock(&ps->ps_mtx); 2270 PROC_UNLOCK(p->p_pptr); 2271 mtx_lock_spin(&sched_lock); 2272 } 2273 } 2274 2275 /* 2276 * Take the action for the specified signal 2277 * from the current set of pending signals. 2278 */ 2279 void 2280 postsig(sig) 2281 register int sig; 2282 { 2283 struct thread *td = curthread; 2284 register struct proc *p = td->td_proc; 2285 struct sigacts *ps; 2286 sig_t action; 2287 sigset_t returnmask; 2288 int code; 2289 2290 KASSERT(sig != 0, ("postsig")); 2291 2292 PROC_LOCK_ASSERT(p, MA_OWNED); 2293 ps = p->p_sigacts; 2294 mtx_assert(&ps->ps_mtx, MA_OWNED); 2295 SIGDELSET(td->td_siglist, sig); 2296 action = ps->ps_sigact[_SIG_IDX(sig)]; 2297 #ifdef KTRACE 2298 if (KTRPOINT(td, KTR_PSIG)) 2299 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2300 &td->td_oldsigmask : &td->td_sigmask, 0); 2301 #endif 2302 if (p->p_stops & S_SIG) { 2303 mtx_unlock(&ps->ps_mtx); 2304 stopevent(p, S_SIG, sig); 2305 mtx_lock(&ps->ps_mtx); 2306 } 2307 2308 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2309 /* 2310 * Default action, where the default is to kill 2311 * the process. (Other cases were ignored above.) 2312 */ 2313 mtx_unlock(&ps->ps_mtx); 2314 sigexit(td, sig); 2315 /* NOTREACHED */ 2316 } else { 2317 if (td->td_pflags & TDP_SA) { 2318 if (sig == SIGKILL) { 2319 mtx_unlock(&ps->ps_mtx); 2320 sigexit(td, sig); 2321 } 2322 } 2323 2324 /* 2325 * If we get here, the signal must be caught. 2326 */ 2327 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2328 ("postsig action")); 2329 /* 2330 * Set the new mask value and also defer further 2331 * occurrences of this signal. 2332 * 2333 * Special case: user has done a sigsuspend. Here the 2334 * current mask is not of interest, but rather the 2335 * mask from before the sigsuspend is what we want 2336 * restored after the signal processing is completed. 2337 */ 2338 if (td->td_pflags & TDP_OLDMASK) { 2339 returnmask = td->td_oldsigmask; 2340 td->td_pflags &= ~TDP_OLDMASK; 2341 } else 2342 returnmask = td->td_sigmask; 2343 2344 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2345 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2346 SIGADDSET(td->td_sigmask, sig); 2347 2348 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2349 /* 2350 * See kern_sigaction() for origin of this code. 2351 */ 2352 SIGDELSET(ps->ps_sigcatch, sig); 2353 if (sig != SIGCONT && 2354 sigprop(sig) & SA_IGNORE) 2355 SIGADDSET(ps->ps_sigignore, sig); 2356 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2357 } 2358 p->p_stats->p_ru.ru_nsignals++; 2359 if (p->p_sig != sig) { 2360 code = 0; 2361 } else { 2362 code = p->p_code; 2363 p->p_code = 0; 2364 p->p_sig = 0; 2365 } 2366 if (td->td_pflags & TDP_SA) 2367 thread_signal_add(curthread, sig); 2368 else 2369 (*p->p_sysent->sv_sendsig)(action, sig, 2370 &returnmask, code); 2371 } 2372 } 2373 2374 /* 2375 * Kill the current process for stated reason. 2376 */ 2377 void 2378 killproc(p, why) 2379 struct proc *p; 2380 char *why; 2381 { 2382 2383 PROC_LOCK_ASSERT(p, MA_OWNED); 2384 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2385 p, p->p_pid, p->p_comm); 2386 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2387 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2388 psignal(p, SIGKILL); 2389 } 2390 2391 /* 2392 * Force the current process to exit with the specified signal, dumping core 2393 * if appropriate. We bypass the normal tests for masked and caught signals, 2394 * allowing unrecoverable failures to terminate the process without changing 2395 * signal state. Mark the accounting record with the signal termination. 2396 * If dumping core, save the signal number for the debugger. Calls exit and 2397 * does not return. 2398 * 2399 * MPSAFE 2400 */ 2401 void 2402 sigexit(td, sig) 2403 struct thread *td; 2404 int sig; 2405 { 2406 struct proc *p = td->td_proc; 2407 2408 PROC_LOCK_ASSERT(p, MA_OWNED); 2409 p->p_acflag |= AXSIG; 2410 /* 2411 * We must be single-threading to generate a core dump. This 2412 * ensures that the registers in the core file are up-to-date. 2413 * Also, the ELF dump handler assumes that the thread list doesn't 2414 * change out from under it. 2415 * 2416 * XXX If another thread attempts to single-thread before us 2417 * (e.g. via fork()), we won't get a dump at all. 2418 */ 2419 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2420 p->p_sig = sig; 2421 /* 2422 * Log signals which would cause core dumps 2423 * (Log as LOG_INFO to appease those who don't want 2424 * these messages.) 2425 * XXX : Todo, as well as euid, write out ruid too 2426 * Note that coredump() drops proc lock. 2427 */ 2428 if (coredump(td) == 0) 2429 sig |= WCOREFLAG; 2430 if (kern_logsigexit) 2431 log(LOG_INFO, 2432 "pid %d (%s), uid %d: exited on signal %d%s\n", 2433 p->p_pid, p->p_comm, 2434 td->td_ucred ? td->td_ucred->cr_uid : -1, 2435 sig &~ WCOREFLAG, 2436 sig & WCOREFLAG ? " (core dumped)" : ""); 2437 } else 2438 PROC_UNLOCK(p); 2439 exit1(td, W_EXITCODE(0, sig)); 2440 /* NOTREACHED */ 2441 } 2442 2443 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2444 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2445 sizeof(corefilename), "process corefile name format string"); 2446 2447 /* 2448 * expand_name(name, uid, pid) 2449 * Expand the name described in corefilename, using name, uid, and pid. 2450 * corefilename is a printf-like string, with three format specifiers: 2451 * %N name of process ("name") 2452 * %P process id (pid) 2453 * %U user id (uid) 2454 * For example, "%N.core" is the default; they can be disabled completely 2455 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2456 * This is controlled by the sysctl variable kern.corefile (see above). 2457 */ 2458 2459 static char * 2460 expand_name(name, uid, pid) 2461 const char *name; 2462 uid_t uid; 2463 pid_t pid; 2464 { 2465 const char *format, *appendstr; 2466 char *temp; 2467 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2468 size_t i, l, n; 2469 2470 format = corefilename; 2471 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2472 if (temp == NULL) 2473 return (NULL); 2474 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2475 switch (format[i]) { 2476 case '%': /* Format character */ 2477 i++; 2478 switch (format[i]) { 2479 case '%': 2480 appendstr = "%"; 2481 break; 2482 case 'N': /* process name */ 2483 appendstr = name; 2484 break; 2485 case 'P': /* process id */ 2486 sprintf(buf, "%u", pid); 2487 appendstr = buf; 2488 break; 2489 case 'U': /* user id */ 2490 sprintf(buf, "%u", uid); 2491 appendstr = buf; 2492 break; 2493 default: 2494 appendstr = ""; 2495 log(LOG_ERR, 2496 "Unknown format character %c in `%s'\n", 2497 format[i], format); 2498 } 2499 l = strlen(appendstr); 2500 if ((n + l) >= MAXPATHLEN) 2501 goto toolong; 2502 memcpy(temp + n, appendstr, l); 2503 n += l; 2504 break; 2505 default: 2506 temp[n++] = format[i]; 2507 } 2508 } 2509 if (format[i] != '\0') 2510 goto toolong; 2511 return (temp); 2512 toolong: 2513 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2514 (long)pid, name, (u_long)uid); 2515 free(temp, M_TEMP); 2516 return (NULL); 2517 } 2518 2519 /* 2520 * Dump a process' core. The main routine does some 2521 * policy checking, and creates the name of the coredump; 2522 * then it passes on a vnode and a size limit to the process-specific 2523 * coredump routine if there is one; if there _is not_ one, it returns 2524 * ENOSYS; otherwise it returns the error from the process-specific routine. 2525 */ 2526 2527 static int 2528 coredump(struct thread *td) 2529 { 2530 struct proc *p = td->td_proc; 2531 register struct vnode *vp; 2532 register struct ucred *cred = td->td_ucred; 2533 struct flock lf; 2534 struct nameidata nd; 2535 struct vattr vattr; 2536 int error, error1, flags, locked; 2537 struct mount *mp; 2538 char *name; /* name of corefile */ 2539 off_t limit; 2540 2541 PROC_LOCK_ASSERT(p, MA_OWNED); 2542 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 2543 _STOPEVENT(p, S_CORE, 0); 2544 2545 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2546 PROC_UNLOCK(p); 2547 return (EFAULT); 2548 } 2549 2550 /* 2551 * Note that the bulk of limit checking is done after 2552 * the corefile is created. The exception is if the limit 2553 * for corefiles is 0, in which case we don't bother 2554 * creating the corefile at all. This layout means that 2555 * a corefile is truncated instead of not being created, 2556 * if it is larger than the limit. 2557 */ 2558 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2559 PROC_UNLOCK(p); 2560 if (limit == 0) 2561 return (EFBIG); 2562 2563 mtx_lock(&Giant); 2564 restart: 2565 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2566 if (name == NULL) { 2567 mtx_unlock(&Giant); 2568 return (EINVAL); 2569 } 2570 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2571 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2572 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2573 free(name, M_TEMP); 2574 if (error) { 2575 mtx_unlock(&Giant); 2576 return (error); 2577 } 2578 NDFREE(&nd, NDF_ONLY_PNBUF); 2579 vp = nd.ni_vp; 2580 2581 /* Don't dump to non-regular files or files with links. */ 2582 if (vp->v_type != VREG || 2583 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2584 VOP_UNLOCK(vp, 0, td); 2585 error = EFAULT; 2586 goto out; 2587 } 2588 2589 VOP_UNLOCK(vp, 0, td); 2590 lf.l_whence = SEEK_SET; 2591 lf.l_start = 0; 2592 lf.l_len = 0; 2593 lf.l_type = F_WRLCK; 2594 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2595 2596 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2597 lf.l_type = F_UNLCK; 2598 if (locked) 2599 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2600 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2601 return (error); 2602 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2603 return (error); 2604 goto restart; 2605 } 2606 2607 VATTR_NULL(&vattr); 2608 vattr.va_size = 0; 2609 if (set_core_nodump_flag) 2610 vattr.va_flags = UF_NODUMP; 2611 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2612 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2613 VOP_SETATTR(vp, &vattr, cred, td); 2614 VOP_UNLOCK(vp, 0, td); 2615 PROC_LOCK(p); 2616 p->p_acflag |= ACORE; 2617 PROC_UNLOCK(p); 2618 2619 error = p->p_sysent->sv_coredump ? 2620 p->p_sysent->sv_coredump(td, vp, limit) : 2621 ENOSYS; 2622 2623 if (locked) { 2624 lf.l_type = F_UNLCK; 2625 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2626 } 2627 vn_finished_write(mp); 2628 out: 2629 error1 = vn_close(vp, FWRITE, cred, td); 2630 mtx_unlock(&Giant); 2631 if (error == 0) 2632 error = error1; 2633 return (error); 2634 } 2635 2636 /* 2637 * Nonexistent system call-- signal process (may want to handle it). 2638 * Flag error in case process won't see signal immediately (blocked or ignored). 2639 */ 2640 #ifndef _SYS_SYSPROTO_H_ 2641 struct nosys_args { 2642 int dummy; 2643 }; 2644 #endif 2645 /* 2646 * MPSAFE 2647 */ 2648 /* ARGSUSED */ 2649 int 2650 nosys(td, args) 2651 struct thread *td; 2652 struct nosys_args *args; 2653 { 2654 struct proc *p = td->td_proc; 2655 2656 PROC_LOCK(p); 2657 psignal(p, SIGSYS); 2658 PROC_UNLOCK(p); 2659 return (ENOSYS); 2660 } 2661 2662 /* 2663 * Send a SIGIO or SIGURG signal to a process or process group using 2664 * stored credentials rather than those of the current process. 2665 */ 2666 void 2667 pgsigio(sigiop, sig, checkctty) 2668 struct sigio **sigiop; 2669 int sig, checkctty; 2670 { 2671 struct sigio *sigio; 2672 2673 SIGIO_LOCK(); 2674 sigio = *sigiop; 2675 if (sigio == NULL) { 2676 SIGIO_UNLOCK(); 2677 return; 2678 } 2679 if (sigio->sio_pgid > 0) { 2680 PROC_LOCK(sigio->sio_proc); 2681 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2682 psignal(sigio->sio_proc, sig); 2683 PROC_UNLOCK(sigio->sio_proc); 2684 } else if (sigio->sio_pgid < 0) { 2685 struct proc *p; 2686 2687 PGRP_LOCK(sigio->sio_pgrp); 2688 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2689 PROC_LOCK(p); 2690 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2691 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2692 psignal(p, sig); 2693 PROC_UNLOCK(p); 2694 } 2695 PGRP_UNLOCK(sigio->sio_pgrp); 2696 } 2697 SIGIO_UNLOCK(); 2698 } 2699 2700 static int 2701 filt_sigattach(struct knote *kn) 2702 { 2703 struct proc *p = curproc; 2704 2705 kn->kn_ptr.p_proc = p; 2706 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2707 2708 knlist_add(&p->p_klist, kn, 0); 2709 2710 return (0); 2711 } 2712 2713 static void 2714 filt_sigdetach(struct knote *kn) 2715 { 2716 struct proc *p = kn->kn_ptr.p_proc; 2717 2718 knlist_remove(&p->p_klist, kn, 0); 2719 } 2720 2721 /* 2722 * signal knotes are shared with proc knotes, so we apply a mask to 2723 * the hint in order to differentiate them from process hints. This 2724 * could be avoided by using a signal-specific knote list, but probably 2725 * isn't worth the trouble. 2726 */ 2727 static int 2728 filt_signal(struct knote *kn, long hint) 2729 { 2730 2731 if (hint & NOTE_SIGNAL) { 2732 hint &= ~NOTE_SIGNAL; 2733 2734 if (kn->kn_id == hint) 2735 kn->kn_data++; 2736 } 2737 return (kn->kn_data != 0); 2738 } 2739 2740 struct sigacts * 2741 sigacts_alloc(void) 2742 { 2743 struct sigacts *ps; 2744 2745 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2746 ps->ps_refcnt = 1; 2747 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2748 return (ps); 2749 } 2750 2751 void 2752 sigacts_free(struct sigacts *ps) 2753 { 2754 2755 mtx_lock(&ps->ps_mtx); 2756 ps->ps_refcnt--; 2757 if (ps->ps_refcnt == 0) { 2758 mtx_destroy(&ps->ps_mtx); 2759 free(ps, M_SUBPROC); 2760 } else 2761 mtx_unlock(&ps->ps_mtx); 2762 } 2763 2764 struct sigacts * 2765 sigacts_hold(struct sigacts *ps) 2766 { 2767 mtx_lock(&ps->ps_mtx); 2768 ps->ps_refcnt++; 2769 mtx_unlock(&ps->ps_mtx); 2770 return (ps); 2771 } 2772 2773 void 2774 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2775 { 2776 2777 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2778 mtx_lock(&src->ps_mtx); 2779 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2780 mtx_unlock(&src->ps_mtx); 2781 } 2782 2783 int 2784 sigacts_shared(struct sigacts *ps) 2785 { 2786 int shared; 2787 2788 mtx_lock(&ps->ps_mtx); 2789 shared = ps->ps_refcnt > 1; 2790 mtx_unlock(&ps->ps_mtx); 2791 return (shared); 2792 }
Cache object: b5e0171dd9a233ac0e71a6073433dbc4
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