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/6.1/sys/kern/kern_sig.c 158179 2006-04-30 16:44:43Z cvs2svn $"); 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 *, int, sig_t, int); 89 static void sig_suspend_threads(struct thread *, struct proc *, int); 90 static int filt_sigattach(struct knote *kn); 91 static void filt_sigdetach(struct knote *kn); 92 static int filt_signal(struct knote *kn, long hint); 93 static struct thread *sigtd(struct proc *p, int sig, int prop); 94 static int kern_sigtimedwait(struct thread *td, sigset_t set, 95 siginfo_t *info, struct timespec *timeout); 96 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target); 97 98 struct filterops sig_filtops = 99 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 100 101 static int kern_logsigexit = 1; 102 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 103 &kern_logsigexit, 0, 104 "Log processes quitting on abnormal signals to syslog(3)"); 105 106 /* 107 * Policy -- Can ucred cr1 send SIGIO to process cr2? 108 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 109 * in the right situations. 110 */ 111 #define CANSIGIO(cr1, cr2) \ 112 ((cr1)->cr_uid == 0 || \ 113 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 114 (cr1)->cr_uid == (cr2)->cr_ruid || \ 115 (cr1)->cr_ruid == (cr2)->cr_uid || \ 116 (cr1)->cr_uid == (cr2)->cr_uid) 117 118 int sugid_coredump; 119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 121 122 static int do_coredump = 1; 123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 124 &do_coredump, 0, "Enable/Disable coredumps"); 125 126 static int set_core_nodump_flag = 0; 127 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 128 0, "Enable setting the NODUMP flag on coredump files"); 129 130 /* 131 * Signal properties and actions. 132 * The array below categorizes the signals and their default actions 133 * according to the following properties: 134 */ 135 #define SA_KILL 0x01 /* terminates process by default */ 136 #define SA_CORE 0x02 /* ditto and coredumps */ 137 #define SA_STOP 0x04 /* suspend process */ 138 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 139 #define SA_IGNORE 0x10 /* ignore by default */ 140 #define SA_CONT 0x20 /* continue if suspended */ 141 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 142 #define SA_PROC 0x80 /* deliverable to any thread */ 143 144 static int sigproptbl[NSIG] = { 145 SA_KILL|SA_PROC, /* SIGHUP */ 146 SA_KILL|SA_PROC, /* SIGINT */ 147 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 148 SA_KILL|SA_CORE, /* SIGILL */ 149 SA_KILL|SA_CORE, /* SIGTRAP */ 150 SA_KILL|SA_CORE, /* SIGABRT */ 151 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 152 SA_KILL|SA_CORE, /* SIGFPE */ 153 SA_KILL|SA_PROC, /* SIGKILL */ 154 SA_KILL|SA_CORE, /* SIGBUS */ 155 SA_KILL|SA_CORE, /* SIGSEGV */ 156 SA_KILL|SA_CORE, /* SIGSYS */ 157 SA_KILL|SA_PROC, /* SIGPIPE */ 158 SA_KILL|SA_PROC, /* SIGALRM */ 159 SA_KILL|SA_PROC, /* SIGTERM */ 160 SA_IGNORE|SA_PROC, /* SIGURG */ 161 SA_STOP|SA_PROC, /* SIGSTOP */ 162 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 163 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 164 SA_IGNORE|SA_PROC, /* SIGCHLD */ 165 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 166 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 167 SA_IGNORE|SA_PROC, /* SIGIO */ 168 SA_KILL, /* SIGXCPU */ 169 SA_KILL, /* SIGXFSZ */ 170 SA_KILL|SA_PROC, /* SIGVTALRM */ 171 SA_KILL|SA_PROC, /* SIGPROF */ 172 SA_IGNORE|SA_PROC, /* SIGWINCH */ 173 SA_IGNORE|SA_PROC, /* SIGINFO */ 174 SA_KILL|SA_PROC, /* SIGUSR1 */ 175 SA_KILL|SA_PROC, /* SIGUSR2 */ 176 }; 177 178 /* 179 * Determine signal that should be delivered to process p, the current 180 * process, 0 if none. If there is a pending stop signal with default 181 * action, the process stops in issignal(). 182 * XXXKSE the check for a pending stop is not done under KSE 183 * 184 * MP SAFE. 185 */ 186 int 187 cursig(struct thread *td) 188 { 189 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 190 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 191 mtx_assert(&sched_lock, MA_NOTOWNED); 192 return (SIGPENDING(td) ? issignal(td) : 0); 193 } 194 195 /* 196 * Arrange for ast() to handle unmasked pending signals on return to user 197 * mode. This must be called whenever a signal is added to td_siglist or 198 * unmasked in td_sigmask. 199 */ 200 void 201 signotify(struct thread *td) 202 { 203 struct proc *p; 204 sigset_t set, saved; 205 206 p = td->td_proc; 207 208 PROC_LOCK_ASSERT(p, MA_OWNED); 209 210 /* 211 * If our mask changed we may have to move signal that were 212 * previously masked by all threads to our siglist. 213 */ 214 set = p->p_siglist; 215 if (p->p_flag & P_SA) 216 saved = p->p_siglist; 217 SIGSETNAND(set, td->td_sigmask); 218 SIGSETNAND(p->p_siglist, set); 219 SIGSETOR(td->td_siglist, set); 220 221 if (SIGPENDING(td)) { 222 mtx_lock_spin(&sched_lock); 223 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 224 mtx_unlock_spin(&sched_lock); 225 } 226 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 227 if (!SIGSETEQ(saved, p->p_siglist)) { 228 /* pending set changed */ 229 p->p_flag |= P_SIGEVENT; 230 wakeup(&p->p_siglist); 231 } 232 } 233 } 234 235 int 236 sigonstack(size_t sp) 237 { 238 struct thread *td = curthread; 239 240 return ((td->td_pflags & TDP_ALTSTACK) ? 241 #if defined(COMPAT_43) 242 ((td->td_sigstk.ss_size == 0) ? 243 (td->td_sigstk.ss_flags & SS_ONSTACK) : 244 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 245 #else 246 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 247 #endif 248 : 0); 249 } 250 251 static __inline int 252 sigprop(int sig) 253 { 254 255 if (sig > 0 && sig < NSIG) 256 return (sigproptbl[_SIG_IDX(sig)]); 257 return (0); 258 } 259 260 int 261 sig_ffs(sigset_t *set) 262 { 263 int i; 264 265 for (i = 0; i < _SIG_WORDS; i++) 266 if (set->__bits[i]) 267 return (ffs(set->__bits[i]) + (i * 32)); 268 return (0); 269 } 270 271 /* 272 * kern_sigaction 273 * sigaction 274 * freebsd4_sigaction 275 * osigaction 276 * 277 * MPSAFE 278 */ 279 int 280 kern_sigaction(td, sig, act, oact, flags) 281 struct thread *td; 282 register int sig; 283 struct sigaction *act, *oact; 284 int flags; 285 { 286 struct sigacts *ps; 287 struct thread *td0; 288 struct proc *p = td->td_proc; 289 290 if (!_SIG_VALID(sig)) 291 return (EINVAL); 292 293 PROC_LOCK(p); 294 ps = p->p_sigacts; 295 mtx_lock(&ps->ps_mtx); 296 if (oact) { 297 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 298 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 299 oact->sa_flags = 0; 300 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 301 oact->sa_flags |= SA_ONSTACK; 302 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 303 oact->sa_flags |= SA_RESTART; 304 if (SIGISMEMBER(ps->ps_sigreset, sig)) 305 oact->sa_flags |= SA_RESETHAND; 306 if (SIGISMEMBER(ps->ps_signodefer, sig)) 307 oact->sa_flags |= SA_NODEFER; 308 if (SIGISMEMBER(ps->ps_siginfo, sig)) 309 oact->sa_flags |= SA_SIGINFO; 310 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 311 oact->sa_flags |= SA_NOCLDSTOP; 312 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 313 oact->sa_flags |= SA_NOCLDWAIT; 314 } 315 if (act) { 316 if ((sig == SIGKILL || sig == SIGSTOP) && 317 act->sa_handler != SIG_DFL) { 318 mtx_unlock(&ps->ps_mtx); 319 PROC_UNLOCK(p); 320 return (EINVAL); 321 } 322 323 /* 324 * Change setting atomically. 325 */ 326 327 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 328 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 329 if (act->sa_flags & SA_SIGINFO) { 330 ps->ps_sigact[_SIG_IDX(sig)] = 331 (__sighandler_t *)act->sa_sigaction; 332 SIGADDSET(ps->ps_siginfo, sig); 333 } else { 334 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 335 SIGDELSET(ps->ps_siginfo, sig); 336 } 337 if (!(act->sa_flags & SA_RESTART)) 338 SIGADDSET(ps->ps_sigintr, sig); 339 else 340 SIGDELSET(ps->ps_sigintr, sig); 341 if (act->sa_flags & SA_ONSTACK) 342 SIGADDSET(ps->ps_sigonstack, sig); 343 else 344 SIGDELSET(ps->ps_sigonstack, sig); 345 if (act->sa_flags & SA_RESETHAND) 346 SIGADDSET(ps->ps_sigreset, sig); 347 else 348 SIGDELSET(ps->ps_sigreset, sig); 349 if (act->sa_flags & SA_NODEFER) 350 SIGADDSET(ps->ps_signodefer, sig); 351 else 352 SIGDELSET(ps->ps_signodefer, sig); 353 if (sig == SIGCHLD) { 354 if (act->sa_flags & SA_NOCLDSTOP) 355 ps->ps_flag |= PS_NOCLDSTOP; 356 else 357 ps->ps_flag &= ~PS_NOCLDSTOP; 358 if (act->sa_flags & SA_NOCLDWAIT) { 359 /* 360 * Paranoia: since SA_NOCLDWAIT is implemented 361 * by reparenting the dying child to PID 1 (and 362 * trust it to reap the zombie), PID 1 itself 363 * is forbidden to set SA_NOCLDWAIT. 364 */ 365 if (p->p_pid == 1) 366 ps->ps_flag &= ~PS_NOCLDWAIT; 367 else 368 ps->ps_flag |= PS_NOCLDWAIT; 369 } else 370 ps->ps_flag &= ~PS_NOCLDWAIT; 371 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 372 ps->ps_flag |= PS_CLDSIGIGN; 373 else 374 ps->ps_flag &= ~PS_CLDSIGIGN; 375 } 376 /* 377 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 378 * and for signals set to SIG_DFL where the default is to 379 * ignore. However, don't put SIGCONT in ps_sigignore, as we 380 * have to restart the process. 381 */ 382 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 383 (sigprop(sig) & SA_IGNORE && 384 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 385 if ((p->p_flag & P_SA) && 386 SIGISMEMBER(p->p_siglist, sig)) { 387 p->p_flag |= P_SIGEVENT; 388 wakeup(&p->p_siglist); 389 } 390 /* never to be seen again */ 391 SIGDELSET(p->p_siglist, sig); 392 mtx_lock_spin(&sched_lock); 393 FOREACH_THREAD_IN_PROC(p, td0) 394 SIGDELSET(td0->td_siglist, sig); 395 mtx_unlock_spin(&sched_lock); 396 if (sig != SIGCONT) 397 /* easier in psignal */ 398 SIGADDSET(ps->ps_sigignore, sig); 399 SIGDELSET(ps->ps_sigcatch, sig); 400 } else { 401 SIGDELSET(ps->ps_sigignore, sig); 402 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 403 SIGDELSET(ps->ps_sigcatch, sig); 404 else 405 SIGADDSET(ps->ps_sigcatch, sig); 406 } 407 #ifdef COMPAT_FREEBSD4 408 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 409 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 410 (flags & KSA_FREEBSD4) == 0) 411 SIGDELSET(ps->ps_freebsd4, sig); 412 else 413 SIGADDSET(ps->ps_freebsd4, sig); 414 #endif 415 #ifdef COMPAT_43 416 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 417 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 418 (flags & KSA_OSIGSET) == 0) 419 SIGDELSET(ps->ps_osigset, sig); 420 else 421 SIGADDSET(ps->ps_osigset, sig); 422 #endif 423 } 424 mtx_unlock(&ps->ps_mtx); 425 PROC_UNLOCK(p); 426 return (0); 427 } 428 429 #ifndef _SYS_SYSPROTO_H_ 430 struct sigaction_args { 431 int sig; 432 struct sigaction *act; 433 struct sigaction *oact; 434 }; 435 #endif 436 /* 437 * MPSAFE 438 */ 439 int 440 sigaction(td, uap) 441 struct thread *td; 442 register struct sigaction_args *uap; 443 { 444 struct sigaction act, oact; 445 register struct sigaction *actp, *oactp; 446 int error; 447 448 actp = (uap->act != NULL) ? &act : NULL; 449 oactp = (uap->oact != NULL) ? &oact : NULL; 450 if (actp) { 451 error = copyin(uap->act, actp, sizeof(act)); 452 if (error) 453 return (error); 454 } 455 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 456 if (oactp && !error) 457 error = copyout(oactp, uap->oact, sizeof(oact)); 458 return (error); 459 } 460 461 #ifdef COMPAT_FREEBSD4 462 #ifndef _SYS_SYSPROTO_H_ 463 struct freebsd4_sigaction_args { 464 int sig; 465 struct sigaction *act; 466 struct sigaction *oact; 467 }; 468 #endif 469 /* 470 * MPSAFE 471 */ 472 int 473 freebsd4_sigaction(td, uap) 474 struct thread *td; 475 register struct freebsd4_sigaction_args *uap; 476 { 477 struct sigaction act, oact; 478 register struct sigaction *actp, *oactp; 479 int error; 480 481 482 actp = (uap->act != NULL) ? &act : NULL; 483 oactp = (uap->oact != NULL) ? &oact : NULL; 484 if (actp) { 485 error = copyin(uap->act, actp, sizeof(act)); 486 if (error) 487 return (error); 488 } 489 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 490 if (oactp && !error) 491 error = copyout(oactp, uap->oact, sizeof(oact)); 492 return (error); 493 } 494 #endif /* COMAPT_FREEBSD4 */ 495 496 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 497 #ifndef _SYS_SYSPROTO_H_ 498 struct osigaction_args { 499 int signum; 500 struct osigaction *nsa; 501 struct osigaction *osa; 502 }; 503 #endif 504 /* 505 * MPSAFE 506 */ 507 int 508 osigaction(td, uap) 509 struct thread *td; 510 register struct osigaction_args *uap; 511 { 512 struct osigaction sa; 513 struct sigaction nsa, osa; 514 register struct sigaction *nsap, *osap; 515 int error; 516 517 if (uap->signum <= 0 || uap->signum >= ONSIG) 518 return (EINVAL); 519 520 nsap = (uap->nsa != NULL) ? &nsa : NULL; 521 osap = (uap->osa != NULL) ? &osa : NULL; 522 523 if (nsap) { 524 error = copyin(uap->nsa, &sa, sizeof(sa)); 525 if (error) 526 return (error); 527 nsap->sa_handler = sa.sa_handler; 528 nsap->sa_flags = sa.sa_flags; 529 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 530 } 531 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 532 if (osap && !error) { 533 sa.sa_handler = osap->sa_handler; 534 sa.sa_flags = osap->sa_flags; 535 SIG2OSIG(osap->sa_mask, sa.sa_mask); 536 error = copyout(&sa, uap->osa, sizeof(sa)); 537 } 538 return (error); 539 } 540 541 #if !defined(__i386__) && !defined(__alpha__) 542 /* Avoid replicating the same stub everywhere */ 543 int 544 osigreturn(td, uap) 545 struct thread *td; 546 struct osigreturn_args *uap; 547 { 548 549 return (nosys(td, (struct nosys_args *)uap)); 550 } 551 #endif 552 #endif /* COMPAT_43 */ 553 554 /* 555 * Initialize signal state for process 0; 556 * set to ignore signals that are ignored by default. 557 */ 558 void 559 siginit(p) 560 struct proc *p; 561 { 562 register int i; 563 struct sigacts *ps; 564 565 PROC_LOCK(p); 566 ps = p->p_sigacts; 567 mtx_lock(&ps->ps_mtx); 568 for (i = 1; i <= NSIG; i++) 569 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 570 SIGADDSET(ps->ps_sigignore, i); 571 mtx_unlock(&ps->ps_mtx); 572 PROC_UNLOCK(p); 573 } 574 575 /* 576 * Reset signals for an exec of the specified process. 577 */ 578 void 579 execsigs(struct proc *p) 580 { 581 struct sigacts *ps; 582 int sig; 583 struct thread *td; 584 585 /* 586 * Reset caught signals. Held signals remain held 587 * through td_sigmask (unless they were caught, 588 * and are now ignored by default). 589 */ 590 PROC_LOCK_ASSERT(p, MA_OWNED); 591 td = FIRST_THREAD_IN_PROC(p); 592 ps = p->p_sigacts; 593 mtx_lock(&ps->ps_mtx); 594 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 595 sig = sig_ffs(&ps->ps_sigcatch); 596 SIGDELSET(ps->ps_sigcatch, sig); 597 if (sigprop(sig) & SA_IGNORE) { 598 if (sig != SIGCONT) 599 SIGADDSET(ps->ps_sigignore, sig); 600 SIGDELSET(p->p_siglist, sig); 601 /* 602 * There is only one thread at this point. 603 */ 604 SIGDELSET(td->td_siglist, sig); 605 } 606 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 607 } 608 /* 609 * Reset stack state to the user stack. 610 * Clear set of signals caught on the signal stack. 611 */ 612 td->td_sigstk.ss_flags = SS_DISABLE; 613 td->td_sigstk.ss_size = 0; 614 td->td_sigstk.ss_sp = 0; 615 td->td_pflags &= ~TDP_ALTSTACK; 616 /* 617 * Reset no zombies if child dies flag as Solaris does. 618 */ 619 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 620 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 621 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 622 mtx_unlock(&ps->ps_mtx); 623 } 624 625 /* 626 * kern_sigprocmask() 627 * 628 * Manipulate signal mask. 629 */ 630 int 631 kern_sigprocmask(td, how, set, oset, old) 632 struct thread *td; 633 int how; 634 sigset_t *set, *oset; 635 int old; 636 { 637 int error; 638 639 PROC_LOCK(td->td_proc); 640 if (oset != NULL) 641 *oset = td->td_sigmask; 642 643 error = 0; 644 if (set != NULL) { 645 switch (how) { 646 case SIG_BLOCK: 647 SIG_CANTMASK(*set); 648 SIGSETOR(td->td_sigmask, *set); 649 break; 650 case SIG_UNBLOCK: 651 SIGSETNAND(td->td_sigmask, *set); 652 signotify(td); 653 break; 654 case SIG_SETMASK: 655 SIG_CANTMASK(*set); 656 if (old) 657 SIGSETLO(td->td_sigmask, *set); 658 else 659 td->td_sigmask = *set; 660 signotify(td); 661 break; 662 default: 663 error = EINVAL; 664 break; 665 } 666 } 667 PROC_UNLOCK(td->td_proc); 668 return (error); 669 } 670 671 /* 672 * sigprocmask() - MP SAFE 673 */ 674 675 #ifndef _SYS_SYSPROTO_H_ 676 struct sigprocmask_args { 677 int how; 678 const sigset_t *set; 679 sigset_t *oset; 680 }; 681 #endif 682 int 683 sigprocmask(td, uap) 684 register struct thread *td; 685 struct sigprocmask_args *uap; 686 { 687 sigset_t set, oset; 688 sigset_t *setp, *osetp; 689 int error; 690 691 setp = (uap->set != NULL) ? &set : NULL; 692 osetp = (uap->oset != NULL) ? &oset : NULL; 693 if (setp) { 694 error = copyin(uap->set, setp, sizeof(set)); 695 if (error) 696 return (error); 697 } 698 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 699 if (osetp && !error) { 700 error = copyout(osetp, uap->oset, sizeof(oset)); 701 } 702 return (error); 703 } 704 705 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 706 /* 707 * osigprocmask() - MP SAFE 708 */ 709 #ifndef _SYS_SYSPROTO_H_ 710 struct osigprocmask_args { 711 int how; 712 osigset_t mask; 713 }; 714 #endif 715 int 716 osigprocmask(td, uap) 717 register struct thread *td; 718 struct osigprocmask_args *uap; 719 { 720 sigset_t set, oset; 721 int error; 722 723 OSIG2SIG(uap->mask, set); 724 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 725 SIG2OSIG(oset, td->td_retval[0]); 726 return (error); 727 } 728 #endif /* COMPAT_43 */ 729 730 #ifndef _SYS_SYSPROTO_H_ 731 struct sigpending_args { 732 sigset_t *set; 733 }; 734 #endif 735 /* 736 * MPSAFE 737 */ 738 int 739 sigwait(struct thread *td, struct sigwait_args *uap) 740 { 741 siginfo_t info; 742 sigset_t set; 743 int error; 744 745 error = copyin(uap->set, &set, sizeof(set)); 746 if (error) { 747 td->td_retval[0] = error; 748 return (0); 749 } 750 751 error = kern_sigtimedwait(td, set, &info, NULL); 752 if (error) { 753 if (error == ERESTART) 754 return (error); 755 td->td_retval[0] = error; 756 return (0); 757 } 758 759 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 760 /* Repost if we got an error. */ 761 if (error && info.si_signo) { 762 PROC_LOCK(td->td_proc); 763 tdsignal(td, info.si_signo, SIGTARGET_TD); 764 PROC_UNLOCK(td->td_proc); 765 } 766 td->td_retval[0] = error; 767 return (0); 768 } 769 /* 770 * MPSAFE 771 */ 772 int 773 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 774 { 775 struct timespec ts; 776 struct timespec *timeout; 777 sigset_t set; 778 siginfo_t info; 779 int error; 780 781 if (uap->timeout) { 782 error = copyin(uap->timeout, &ts, sizeof(ts)); 783 if (error) 784 return (error); 785 786 timeout = &ts; 787 } else 788 timeout = NULL; 789 790 error = copyin(uap->set, &set, sizeof(set)); 791 if (error) 792 return (error); 793 794 error = kern_sigtimedwait(td, set, &info, timeout); 795 if (error) 796 return (error); 797 798 if (uap->info) 799 error = copyout(&info, uap->info, sizeof(info)); 800 /* Repost if we got an error. */ 801 if (error && info.si_signo) { 802 PROC_LOCK(td->td_proc); 803 tdsignal(td, info.si_signo, SIGTARGET_TD); 804 PROC_UNLOCK(td->td_proc); 805 } else { 806 td->td_retval[0] = info.si_signo; 807 } 808 return (error); 809 } 810 811 /* 812 * MPSAFE 813 */ 814 int 815 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 816 { 817 siginfo_t info; 818 sigset_t set; 819 int error; 820 821 error = copyin(uap->set, &set, sizeof(set)); 822 if (error) 823 return (error); 824 825 error = kern_sigtimedwait(td, set, &info, NULL); 826 if (error) 827 return (error); 828 829 if (uap->info) 830 error = copyout(&info, uap->info, sizeof(info)); 831 /* Repost if we got an error. */ 832 if (error && info.si_signo) { 833 PROC_LOCK(td->td_proc); 834 tdsignal(td, info.si_signo, SIGTARGET_TD); 835 PROC_UNLOCK(td->td_proc); 836 } else { 837 td->td_retval[0] = info.si_signo; 838 } 839 return (error); 840 } 841 842 static int 843 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info, 844 struct timespec *timeout) 845 { 846 struct sigacts *ps; 847 sigset_t savedmask; 848 struct proc *p; 849 int error, sig, hz, i, timevalid = 0; 850 struct timespec rts, ets, ts; 851 struct timeval tv; 852 853 p = td->td_proc; 854 error = 0; 855 sig = 0; 856 SIG_CANTMASK(waitset); 857 858 PROC_LOCK(p); 859 ps = p->p_sigacts; 860 savedmask = td->td_sigmask; 861 if (timeout) { 862 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 863 timevalid = 1; 864 getnanouptime(&rts); 865 ets = rts; 866 timespecadd(&ets, timeout); 867 } 868 } 869 870 restart: 871 for (i = 1; i <= _SIG_MAXSIG; ++i) { 872 if (!SIGISMEMBER(waitset, i)) 873 continue; 874 if (!SIGISMEMBER(td->td_siglist, i)) { 875 if (SIGISMEMBER(p->p_siglist, i)) { 876 if (p->p_flag & P_SA) { 877 p->p_flag |= P_SIGEVENT; 878 wakeup(&p->p_siglist); 879 } 880 SIGDELSET(p->p_siglist, i); 881 SIGADDSET(td->td_siglist, i); 882 } else 883 continue; 884 } 885 886 SIGFILLSET(td->td_sigmask); 887 SIG_CANTMASK(td->td_sigmask); 888 SIGDELSET(td->td_sigmask, i); 889 mtx_lock(&ps->ps_mtx); 890 sig = cursig(td); 891 mtx_unlock(&ps->ps_mtx); 892 if (sig) 893 goto out; 894 else { 895 /* 896 * Because cursig() may have stopped current thread, 897 * after it is resumed, things may have already been 898 * changed, it should rescan any pending signals. 899 */ 900 goto restart; 901 } 902 } 903 if (error) 904 goto out; 905 906 /* 907 * POSIX says this must be checked after looking for pending 908 * signals. 909 */ 910 if (timeout) { 911 if (!timevalid) { 912 error = EINVAL; 913 goto out; 914 } 915 getnanouptime(&rts); 916 if (timespeccmp(&rts, &ets, >=)) { 917 error = EAGAIN; 918 goto out; 919 } 920 ts = ets; 921 timespecsub(&ts, &rts); 922 TIMESPEC_TO_TIMEVAL(&tv, &ts); 923 hz = tvtohz(&tv); 924 } else 925 hz = 0; 926 927 td->td_sigmask = savedmask; 928 SIGSETNAND(td->td_sigmask, waitset); 929 signotify(td); 930 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 931 if (timeout) { 932 if (error == ERESTART) { 933 /* timeout can not be restarted. */ 934 error = EINTR; 935 } else if (error == EAGAIN) { 936 /* will calculate timeout by ourself. */ 937 error = 0; 938 } 939 } 940 goto restart; 941 942 out: 943 td->td_sigmask = savedmask; 944 signotify(td); 945 if (sig) { 946 SIGDELSET(td->td_siglist, sig); 947 bzero(info, sizeof(*info)); 948 info->si_signo = sig; 949 info->si_code = 0; 950 error = 0; 951 952 #ifdef KTRACE 953 if (KTRPOINT(td, KTR_PSIG)) { 954 sig_t action; 955 956 mtx_lock(&ps->ps_mtx); 957 action = ps->ps_sigact[_SIG_IDX(sig)]; 958 mtx_unlock(&ps->ps_mtx); 959 ktrpsig(sig, action, &td->td_sigmask, 0); 960 } 961 #endif 962 _STOPEVENT(p, S_SIG, sig); 963 964 if (sig == SIGKILL) { 965 p->p_code = 0; 966 p->p_sig = sig; 967 sigexit(td, sig); 968 } 969 } 970 PROC_UNLOCK(p); 971 return (error); 972 } 973 974 /* 975 * MPSAFE 976 */ 977 int 978 sigpending(td, uap) 979 struct thread *td; 980 struct sigpending_args *uap; 981 { 982 struct proc *p = td->td_proc; 983 sigset_t siglist; 984 985 PROC_LOCK(p); 986 siglist = p->p_siglist; 987 SIGSETOR(siglist, td->td_siglist); 988 PROC_UNLOCK(p); 989 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 990 } 991 992 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 993 #ifndef _SYS_SYSPROTO_H_ 994 struct osigpending_args { 995 int dummy; 996 }; 997 #endif 998 /* 999 * MPSAFE 1000 */ 1001 int 1002 osigpending(td, uap) 1003 struct thread *td; 1004 struct osigpending_args *uap; 1005 { 1006 struct proc *p = td->td_proc; 1007 sigset_t siglist; 1008 1009 PROC_LOCK(p); 1010 siglist = p->p_siglist; 1011 SIGSETOR(siglist, td->td_siglist); 1012 PROC_UNLOCK(p); 1013 SIG2OSIG(siglist, td->td_retval[0]); 1014 return (0); 1015 } 1016 #endif /* COMPAT_43 */ 1017 1018 #if defined(COMPAT_43) 1019 /* 1020 * Generalized interface signal handler, 4.3-compatible. 1021 */ 1022 #ifndef _SYS_SYSPROTO_H_ 1023 struct osigvec_args { 1024 int signum; 1025 struct sigvec *nsv; 1026 struct sigvec *osv; 1027 }; 1028 #endif 1029 /* 1030 * MPSAFE 1031 */ 1032 /* ARGSUSED */ 1033 int 1034 osigvec(td, uap) 1035 struct thread *td; 1036 register struct osigvec_args *uap; 1037 { 1038 struct sigvec vec; 1039 struct sigaction nsa, osa; 1040 register struct sigaction *nsap, *osap; 1041 int error; 1042 1043 if (uap->signum <= 0 || uap->signum >= ONSIG) 1044 return (EINVAL); 1045 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1046 osap = (uap->osv != NULL) ? &osa : NULL; 1047 if (nsap) { 1048 error = copyin(uap->nsv, &vec, sizeof(vec)); 1049 if (error) 1050 return (error); 1051 nsap->sa_handler = vec.sv_handler; 1052 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1053 nsap->sa_flags = vec.sv_flags; 1054 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1055 } 1056 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1057 if (osap && !error) { 1058 vec.sv_handler = osap->sa_handler; 1059 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1060 vec.sv_flags = osap->sa_flags; 1061 vec.sv_flags &= ~SA_NOCLDWAIT; 1062 vec.sv_flags ^= SA_RESTART; 1063 error = copyout(&vec, uap->osv, sizeof(vec)); 1064 } 1065 return (error); 1066 } 1067 1068 #ifndef _SYS_SYSPROTO_H_ 1069 struct osigblock_args { 1070 int mask; 1071 }; 1072 #endif 1073 /* 1074 * MPSAFE 1075 */ 1076 int 1077 osigblock(td, uap) 1078 register struct thread *td; 1079 struct osigblock_args *uap; 1080 { 1081 struct proc *p = td->td_proc; 1082 sigset_t set; 1083 1084 OSIG2SIG(uap->mask, set); 1085 SIG_CANTMASK(set); 1086 PROC_LOCK(p); 1087 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1088 SIGSETOR(td->td_sigmask, set); 1089 PROC_UNLOCK(p); 1090 return (0); 1091 } 1092 1093 #ifndef _SYS_SYSPROTO_H_ 1094 struct osigsetmask_args { 1095 int mask; 1096 }; 1097 #endif 1098 /* 1099 * MPSAFE 1100 */ 1101 int 1102 osigsetmask(td, uap) 1103 struct thread *td; 1104 struct osigsetmask_args *uap; 1105 { 1106 struct proc *p = td->td_proc; 1107 sigset_t set; 1108 1109 OSIG2SIG(uap->mask, set); 1110 SIG_CANTMASK(set); 1111 PROC_LOCK(p); 1112 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1113 SIGSETLO(td->td_sigmask, set); 1114 signotify(td); 1115 PROC_UNLOCK(p); 1116 return (0); 1117 } 1118 #endif /* COMPAT_43 */ 1119 1120 /* 1121 * Suspend process until signal, providing mask to be set 1122 * in the meantime. 1123 ***** XXXKSE this doesn't make sense under KSE. 1124 ***** Do we suspend the thread or all threads in the process? 1125 ***** How do we suspend threads running NOW on another processor? 1126 */ 1127 #ifndef _SYS_SYSPROTO_H_ 1128 struct sigsuspend_args { 1129 const sigset_t *sigmask; 1130 }; 1131 #endif 1132 /* 1133 * MPSAFE 1134 */ 1135 /* ARGSUSED */ 1136 int 1137 sigsuspend(td, uap) 1138 struct thread *td; 1139 struct sigsuspend_args *uap; 1140 { 1141 sigset_t mask; 1142 int error; 1143 1144 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1145 if (error) 1146 return (error); 1147 return (kern_sigsuspend(td, mask)); 1148 } 1149 1150 int 1151 kern_sigsuspend(struct thread *td, sigset_t mask) 1152 { 1153 struct proc *p = td->td_proc; 1154 1155 /* 1156 * When returning from sigsuspend, we want 1157 * the old mask to be restored after the 1158 * signal handler has finished. Thus, we 1159 * save it here and mark the sigacts structure 1160 * to indicate this. 1161 */ 1162 PROC_LOCK(p); 1163 td->td_oldsigmask = td->td_sigmask; 1164 td->td_pflags |= TDP_OLDMASK; 1165 SIG_CANTMASK(mask); 1166 td->td_sigmask = mask; 1167 signotify(td); 1168 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1169 /* void */; 1170 PROC_UNLOCK(p); 1171 /* always return EINTR rather than ERESTART... */ 1172 return (EINTR); 1173 } 1174 1175 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1176 /* 1177 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1178 * convention: libc stub passes mask, not pointer, to save a copyin. 1179 */ 1180 #ifndef _SYS_SYSPROTO_H_ 1181 struct osigsuspend_args { 1182 osigset_t mask; 1183 }; 1184 #endif 1185 /* 1186 * MPSAFE 1187 */ 1188 /* ARGSUSED */ 1189 int 1190 osigsuspend(td, uap) 1191 struct thread *td; 1192 struct osigsuspend_args *uap; 1193 { 1194 struct proc *p = td->td_proc; 1195 sigset_t mask; 1196 1197 PROC_LOCK(p); 1198 td->td_oldsigmask = td->td_sigmask; 1199 td->td_pflags |= TDP_OLDMASK; 1200 OSIG2SIG(uap->mask, mask); 1201 SIG_CANTMASK(mask); 1202 SIGSETLO(td->td_sigmask, mask); 1203 signotify(td); 1204 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1205 /* void */; 1206 PROC_UNLOCK(p); 1207 /* always return EINTR rather than ERESTART... */ 1208 return (EINTR); 1209 } 1210 #endif /* COMPAT_43 */ 1211 1212 #if defined(COMPAT_43) 1213 #ifndef _SYS_SYSPROTO_H_ 1214 struct osigstack_args { 1215 struct sigstack *nss; 1216 struct sigstack *oss; 1217 }; 1218 #endif 1219 /* 1220 * MPSAFE 1221 */ 1222 /* ARGSUSED */ 1223 int 1224 osigstack(td, uap) 1225 struct thread *td; 1226 register struct osigstack_args *uap; 1227 { 1228 struct sigstack nss, oss; 1229 int error = 0; 1230 1231 if (uap->nss != NULL) { 1232 error = copyin(uap->nss, &nss, sizeof(nss)); 1233 if (error) 1234 return (error); 1235 } 1236 oss.ss_sp = td->td_sigstk.ss_sp; 1237 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1238 if (uap->nss != NULL) { 1239 td->td_sigstk.ss_sp = nss.ss_sp; 1240 td->td_sigstk.ss_size = 0; 1241 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1242 td->td_pflags |= TDP_ALTSTACK; 1243 } 1244 if (uap->oss != NULL) 1245 error = copyout(&oss, uap->oss, sizeof(oss)); 1246 1247 return (error); 1248 } 1249 #endif /* COMPAT_43 */ 1250 1251 #ifndef _SYS_SYSPROTO_H_ 1252 struct sigaltstack_args { 1253 stack_t *ss; 1254 stack_t *oss; 1255 }; 1256 #endif 1257 /* 1258 * MPSAFE 1259 */ 1260 /* ARGSUSED */ 1261 int 1262 sigaltstack(td, uap) 1263 struct thread *td; 1264 register struct sigaltstack_args *uap; 1265 { 1266 stack_t ss, oss; 1267 int error; 1268 1269 if (uap->ss != NULL) { 1270 error = copyin(uap->ss, &ss, sizeof(ss)); 1271 if (error) 1272 return (error); 1273 } 1274 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1275 (uap->oss != NULL) ? &oss : NULL); 1276 if (error) 1277 return (error); 1278 if (uap->oss != NULL) 1279 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1280 return (error); 1281 } 1282 1283 int 1284 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1285 { 1286 struct proc *p = td->td_proc; 1287 int oonstack; 1288 1289 oonstack = sigonstack(cpu_getstack(td)); 1290 1291 if (oss != NULL) { 1292 *oss = td->td_sigstk; 1293 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1294 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1295 } 1296 1297 if (ss != NULL) { 1298 if (oonstack) 1299 return (EPERM); 1300 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1301 return (EINVAL); 1302 if (!(ss->ss_flags & SS_DISABLE)) { 1303 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1304 return (ENOMEM); 1305 } 1306 td->td_sigstk = *ss; 1307 td->td_pflags |= TDP_ALTSTACK; 1308 } else { 1309 td->td_pflags &= ~TDP_ALTSTACK; 1310 } 1311 } 1312 return (0); 1313 } 1314 1315 /* 1316 * Common code for kill process group/broadcast kill. 1317 * cp is calling process. 1318 */ 1319 static int 1320 killpg1(td, sig, pgid, all) 1321 register struct thread *td; 1322 int sig, pgid, all; 1323 { 1324 register struct proc *p; 1325 struct pgrp *pgrp; 1326 int nfound = 0; 1327 1328 if (all) { 1329 /* 1330 * broadcast 1331 */ 1332 sx_slock(&allproc_lock); 1333 LIST_FOREACH(p, &allproc, p_list) { 1334 PROC_LOCK(p); 1335 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1336 p == td->td_proc) { 1337 PROC_UNLOCK(p); 1338 continue; 1339 } 1340 if (p_cansignal(td, p, sig) == 0) { 1341 nfound++; 1342 if (sig) 1343 psignal(p, sig); 1344 } 1345 PROC_UNLOCK(p); 1346 } 1347 sx_sunlock(&allproc_lock); 1348 } else { 1349 sx_slock(&proctree_lock); 1350 if (pgid == 0) { 1351 /* 1352 * zero pgid means send to my process group. 1353 */ 1354 pgrp = td->td_proc->p_pgrp; 1355 PGRP_LOCK(pgrp); 1356 } else { 1357 pgrp = pgfind(pgid); 1358 if (pgrp == NULL) { 1359 sx_sunlock(&proctree_lock); 1360 return (ESRCH); 1361 } 1362 } 1363 sx_sunlock(&proctree_lock); 1364 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1365 PROC_LOCK(p); 1366 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1367 PROC_UNLOCK(p); 1368 continue; 1369 } 1370 if (p_cansignal(td, p, sig) == 0) { 1371 nfound++; 1372 if (sig) 1373 psignal(p, sig); 1374 } 1375 PROC_UNLOCK(p); 1376 } 1377 PGRP_UNLOCK(pgrp); 1378 } 1379 return (nfound ? 0 : ESRCH); 1380 } 1381 1382 #ifndef _SYS_SYSPROTO_H_ 1383 struct kill_args { 1384 int pid; 1385 int signum; 1386 }; 1387 #endif 1388 /* 1389 * MPSAFE 1390 */ 1391 /* ARGSUSED */ 1392 int 1393 kill(td, uap) 1394 register struct thread *td; 1395 register struct kill_args *uap; 1396 { 1397 register struct proc *p; 1398 int error; 1399 1400 if ((u_int)uap->signum > _SIG_MAXSIG) 1401 return (EINVAL); 1402 1403 if (uap->pid > 0) { 1404 /* kill single process */ 1405 if ((p = pfind(uap->pid)) == NULL) { 1406 if ((p = zpfind(uap->pid)) == NULL) 1407 return (ESRCH); 1408 } 1409 error = p_cansignal(td, p, uap->signum); 1410 if (error == 0 && uap->signum) 1411 psignal(p, uap->signum); 1412 PROC_UNLOCK(p); 1413 return (error); 1414 } 1415 switch (uap->pid) { 1416 case -1: /* broadcast signal */ 1417 return (killpg1(td, uap->signum, 0, 1)); 1418 case 0: /* signal own process group */ 1419 return (killpg1(td, uap->signum, 0, 0)); 1420 default: /* negative explicit process group */ 1421 return (killpg1(td, uap->signum, -uap->pid, 0)); 1422 } 1423 /* NOTREACHED */ 1424 } 1425 1426 #if defined(COMPAT_43) 1427 #ifndef _SYS_SYSPROTO_H_ 1428 struct okillpg_args { 1429 int pgid; 1430 int signum; 1431 }; 1432 #endif 1433 /* 1434 * MPSAFE 1435 */ 1436 /* ARGSUSED */ 1437 int 1438 okillpg(td, uap) 1439 struct thread *td; 1440 register struct okillpg_args *uap; 1441 { 1442 1443 if ((u_int)uap->signum > _SIG_MAXSIG) 1444 return (EINVAL); 1445 return (killpg1(td, uap->signum, uap->pgid, 0)); 1446 } 1447 #endif /* COMPAT_43 */ 1448 1449 /* 1450 * Send a signal to a process group. 1451 */ 1452 void 1453 gsignal(pgid, sig) 1454 int pgid, sig; 1455 { 1456 struct pgrp *pgrp; 1457 1458 if (pgid != 0) { 1459 sx_slock(&proctree_lock); 1460 pgrp = pgfind(pgid); 1461 sx_sunlock(&proctree_lock); 1462 if (pgrp != NULL) { 1463 pgsignal(pgrp, sig, 0); 1464 PGRP_UNLOCK(pgrp); 1465 } 1466 } 1467 } 1468 1469 /* 1470 * Send a signal to a process group. If checktty is 1, 1471 * limit to members which have a controlling terminal. 1472 */ 1473 void 1474 pgsignal(pgrp, sig, checkctty) 1475 struct pgrp *pgrp; 1476 int sig, checkctty; 1477 { 1478 register struct proc *p; 1479 1480 if (pgrp) { 1481 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1482 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1483 PROC_LOCK(p); 1484 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1485 psignal(p, sig); 1486 PROC_UNLOCK(p); 1487 } 1488 } 1489 } 1490 1491 /* 1492 * Send a signal caused by a trap to the current thread. 1493 * If it will be caught immediately, deliver it with correct code. 1494 * Otherwise, post it normally. 1495 * 1496 * MPSAFE 1497 */ 1498 void 1499 trapsignal(struct thread *td, int sig, u_long code) 1500 { 1501 struct sigacts *ps; 1502 struct proc *p; 1503 siginfo_t siginfo; 1504 int error; 1505 1506 p = td->td_proc; 1507 if (td->td_pflags & TDP_SA) { 1508 if (td->td_mailbox == NULL) 1509 thread_user_enter(td); 1510 PROC_LOCK(p); 1511 SIGDELSET(td->td_sigmask, sig); 1512 mtx_lock_spin(&sched_lock); 1513 /* 1514 * Force scheduling an upcall, so UTS has chance to 1515 * process the signal before thread runs again in 1516 * userland. 1517 */ 1518 if (td->td_upcall) 1519 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1520 mtx_unlock_spin(&sched_lock); 1521 } else { 1522 PROC_LOCK(p); 1523 } 1524 ps = p->p_sigacts; 1525 mtx_lock(&ps->ps_mtx); 1526 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1527 !SIGISMEMBER(td->td_sigmask, sig)) { 1528 p->p_stats->p_ru.ru_nsignals++; 1529 #ifdef KTRACE 1530 if (KTRPOINT(curthread, KTR_PSIG)) 1531 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1532 &td->td_sigmask, code); 1533 #endif 1534 if (!(td->td_pflags & TDP_SA)) 1535 (*p->p_sysent->sv_sendsig)( 1536 ps->ps_sigact[_SIG_IDX(sig)], sig, 1537 &td->td_sigmask, code); 1538 else if (td->td_mailbox == NULL) { 1539 mtx_unlock(&ps->ps_mtx); 1540 /* UTS caused a sync signal */ 1541 p->p_code = code; /* XXX for core dump/debugger */ 1542 p->p_sig = sig; /* XXX to verify code */ 1543 sigexit(td, sig); 1544 } else { 1545 cpu_thread_siginfo(sig, code, &siginfo); 1546 mtx_unlock(&ps->ps_mtx); 1547 SIGADDSET(td->td_sigmask, sig); 1548 PROC_UNLOCK(p); 1549 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1550 sizeof(siginfo)); 1551 PROC_LOCK(p); 1552 /* UTS memory corrupted */ 1553 if (error) 1554 sigexit(td, SIGSEGV); 1555 mtx_lock(&ps->ps_mtx); 1556 } 1557 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1558 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1559 SIGADDSET(td->td_sigmask, sig); 1560 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1561 /* 1562 * See kern_sigaction() for origin of this code. 1563 */ 1564 SIGDELSET(ps->ps_sigcatch, sig); 1565 if (sig != SIGCONT && 1566 sigprop(sig) & SA_IGNORE) 1567 SIGADDSET(ps->ps_sigignore, sig); 1568 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1569 } 1570 mtx_unlock(&ps->ps_mtx); 1571 } else { 1572 mtx_unlock(&ps->ps_mtx); 1573 p->p_code = code; /* XXX for core dump/debugger */ 1574 p->p_sig = sig; /* XXX to verify code */ 1575 tdsignal(td, sig, SIGTARGET_TD); 1576 } 1577 PROC_UNLOCK(p); 1578 } 1579 1580 static struct thread * 1581 sigtd(struct proc *p, int sig, int prop) 1582 { 1583 struct thread *td, *signal_td; 1584 1585 PROC_LOCK_ASSERT(p, MA_OWNED); 1586 1587 /* 1588 * Check if current thread can handle the signal without 1589 * switching conetxt to another thread. 1590 */ 1591 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1592 return (curthread); 1593 signal_td = NULL; 1594 mtx_lock_spin(&sched_lock); 1595 FOREACH_THREAD_IN_PROC(p, td) { 1596 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1597 signal_td = td; 1598 break; 1599 } 1600 } 1601 if (signal_td == NULL) 1602 signal_td = FIRST_THREAD_IN_PROC(p); 1603 mtx_unlock_spin(&sched_lock); 1604 return (signal_td); 1605 } 1606 1607 /* 1608 * Send the signal to the process. If the signal has an action, the action 1609 * is usually performed by the target process rather than the caller; we add 1610 * the signal to the set of pending signals for the process. 1611 * 1612 * Exceptions: 1613 * o When a stop signal is sent to a sleeping process that takes the 1614 * default action, the process is stopped without awakening it. 1615 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1616 * regardless of the signal action (eg, blocked or ignored). 1617 * 1618 * Other ignored signals are discarded immediately. 1619 * 1620 * MPSAFE 1621 */ 1622 void 1623 psignal(struct proc *p, int sig) 1624 { 1625 struct thread *td; 1626 int prop; 1627 1628 if (!_SIG_VALID(sig)) 1629 panic("psignal(): invalid signal"); 1630 1631 PROC_LOCK_ASSERT(p, MA_OWNED); 1632 /* 1633 * IEEE Std 1003.1-2001: return success when killing a zombie. 1634 */ 1635 if (p->p_state == PRS_ZOMBIE) 1636 return; 1637 prop = sigprop(sig); 1638 1639 /* 1640 * Find a thread to deliver the signal to. 1641 */ 1642 td = sigtd(p, sig, prop); 1643 1644 tdsignal(td, sig, SIGTARGET_P); 1645 } 1646 1647 /* 1648 * MPSAFE 1649 */ 1650 void 1651 tdsignal(struct thread *td, int sig, sigtarget_t target) 1652 { 1653 sigset_t saved; 1654 struct proc *p = td->td_proc; 1655 1656 if (p->p_flag & P_SA) 1657 saved = p->p_siglist; 1658 do_tdsignal(td, sig, target); 1659 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1660 if (!SIGSETEQ(saved, p->p_siglist)) { 1661 /* pending set changed */ 1662 p->p_flag |= P_SIGEVENT; 1663 wakeup(&p->p_siglist); 1664 } 1665 } 1666 } 1667 1668 static void 1669 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1670 { 1671 struct proc *p; 1672 register sig_t action; 1673 sigset_t *siglist; 1674 struct thread *td0; 1675 register int prop; 1676 struct sigacts *ps; 1677 int intrval; 1678 1679 if (!_SIG_VALID(sig)) 1680 panic("do_tdsignal(): invalid signal"); 1681 1682 p = td->td_proc; 1683 ps = p->p_sigacts; 1684 1685 PROC_LOCK_ASSERT(p, MA_OWNED); 1686 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 1687 1688 prop = sigprop(sig); 1689 1690 /* 1691 * If the signal is blocked and not destined for this thread, then 1692 * assign it to the process so that we can find it later in the first 1693 * thread that unblocks it. Otherwise, assign it to this thread now. 1694 */ 1695 if (target == SIGTARGET_TD) { 1696 siglist = &td->td_siglist; 1697 } else { 1698 if (!SIGISMEMBER(td->td_sigmask, sig)) 1699 siglist = &td->td_siglist; 1700 else 1701 siglist = &p->p_siglist; 1702 } 1703 1704 /* 1705 * If the signal is being ignored, 1706 * then we forget about it immediately. 1707 * (Note: we don't set SIGCONT in ps_sigignore, 1708 * and if it is set to SIG_IGN, 1709 * action will be SIG_DFL here.) 1710 */ 1711 mtx_lock(&ps->ps_mtx); 1712 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1713 (p->p_flag & P_WEXIT)) { 1714 mtx_unlock(&ps->ps_mtx); 1715 return; 1716 } 1717 if (SIGISMEMBER(td->td_sigmask, sig)) 1718 action = SIG_HOLD; 1719 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1720 action = SIG_CATCH; 1721 else 1722 action = SIG_DFL; 1723 if (SIGISMEMBER(ps->ps_sigintr, sig)) 1724 intrval = EINTR; 1725 else 1726 intrval = ERESTART; 1727 mtx_unlock(&ps->ps_mtx); 1728 1729 if (prop & SA_CONT) { 1730 SIG_STOPSIGMASK(p->p_siglist); 1731 /* 1732 * XXX Should investigate leaving STOP and CONT sigs only in 1733 * the proc's siglist. 1734 */ 1735 mtx_lock_spin(&sched_lock); 1736 FOREACH_THREAD_IN_PROC(p, td0) 1737 SIG_STOPSIGMASK(td0->td_siglist); 1738 mtx_unlock_spin(&sched_lock); 1739 } 1740 1741 if (prop & SA_STOP) { 1742 /* 1743 * If sending a tty stop signal to a member of an orphaned 1744 * process group, discard the signal here if the action 1745 * is default; don't stop the process below if sleeping, 1746 * and don't clear any pending SIGCONT. 1747 */ 1748 if ((prop & SA_TTYSTOP) && 1749 (p->p_pgrp->pg_jobc == 0) && 1750 (action == SIG_DFL)) 1751 return; 1752 SIG_CONTSIGMASK(p->p_siglist); 1753 mtx_lock_spin(&sched_lock); 1754 FOREACH_THREAD_IN_PROC(p, td0) 1755 SIG_CONTSIGMASK(td0->td_siglist); 1756 mtx_unlock_spin(&sched_lock); 1757 p->p_flag &= ~P_CONTINUED; 1758 } 1759 1760 SIGADDSET(*siglist, sig); 1761 signotify(td); /* uses schedlock */ 1762 /* 1763 * Defer further processing for signals which are held, 1764 * except that stopped processes must be continued by SIGCONT. 1765 */ 1766 if (action == SIG_HOLD && 1767 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1768 return; 1769 /* 1770 * SIGKILL: Remove procfs STOPEVENTs. 1771 */ 1772 if (sig == SIGKILL) { 1773 /* from procfs_ioctl.c: PIOCBIC */ 1774 p->p_stops = 0; 1775 /* from procfs_ioctl.c: PIOCCONT */ 1776 p->p_step = 0; 1777 wakeup(&p->p_step); 1778 } 1779 /* 1780 * Some signals have a process-wide effect and a per-thread 1781 * component. Most processing occurs when the process next 1782 * tries to cross the user boundary, however there are some 1783 * times when processing needs to be done immediatly, such as 1784 * waking up threads so that they can cross the user boundary. 1785 * We try do the per-process part here. 1786 */ 1787 if (P_SHOULDSTOP(p)) { 1788 /* 1789 * The process is in stopped mode. All the threads should be 1790 * either winding down or already on the suspended queue. 1791 */ 1792 if (p->p_flag & P_TRACED) { 1793 /* 1794 * The traced process is already stopped, 1795 * so no further action is necessary. 1796 * No signal can restart us. 1797 */ 1798 goto out; 1799 } 1800 1801 if (sig == SIGKILL) { 1802 /* 1803 * SIGKILL sets process running. 1804 * It will die elsewhere. 1805 * All threads must be restarted. 1806 */ 1807 p->p_flag &= ~P_STOPPED_SIG; 1808 goto runfast; 1809 } 1810 1811 if (prop & SA_CONT) { 1812 /* 1813 * If SIGCONT is default (or ignored), we continue the 1814 * process but don't leave the signal in siglist as 1815 * it has no further action. If SIGCONT is held, we 1816 * continue the process and leave the signal in 1817 * siglist. If the process catches SIGCONT, let it 1818 * handle the signal itself. If it isn't waiting on 1819 * an event, it goes back to run state. 1820 * Otherwise, process goes back to sleep state. 1821 */ 1822 p->p_flag &= ~P_STOPPED_SIG; 1823 p->p_flag |= P_CONTINUED; 1824 if (action == SIG_DFL) { 1825 SIGDELSET(*siglist, sig); 1826 } else if (action == SIG_CATCH) { 1827 /* 1828 * The process wants to catch it so it needs 1829 * to run at least one thread, but which one? 1830 * It would seem that the answer would be to 1831 * run an upcall in the next KSE to run, and 1832 * deliver the signal that way. In a NON KSE 1833 * process, we need to make sure that the 1834 * single thread is runnable asap. 1835 * XXXKSE for now however, make them all run. 1836 */ 1837 goto runfast; 1838 } 1839 /* 1840 * The signal is not ignored or caught. 1841 */ 1842 mtx_lock_spin(&sched_lock); 1843 thread_unsuspend(p); 1844 mtx_unlock_spin(&sched_lock); 1845 goto out; 1846 } 1847 1848 if (prop & SA_STOP) { 1849 /* 1850 * Already stopped, don't need to stop again 1851 * (If we did the shell could get confused). 1852 * Just make sure the signal STOP bit set. 1853 */ 1854 p->p_flag |= P_STOPPED_SIG; 1855 SIGDELSET(*siglist, sig); 1856 goto out; 1857 } 1858 1859 /* 1860 * All other kinds of signals: 1861 * If a thread is sleeping interruptibly, simulate a 1862 * wakeup so that when it is continued it will be made 1863 * runnable and can look at the signal. However, don't make 1864 * the PROCESS runnable, leave it stopped. 1865 * It may run a bit until it hits a thread_suspend_check(). 1866 */ 1867 mtx_lock_spin(&sched_lock); 1868 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 1869 sleepq_abort(td, intrval); 1870 mtx_unlock_spin(&sched_lock); 1871 goto out; 1872 /* 1873 * Mutexes are short lived. Threads waiting on them will 1874 * hit thread_suspend_check() soon. 1875 */ 1876 } else if (p->p_state == PRS_NORMAL) { 1877 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 1878 mtx_lock_spin(&sched_lock); 1879 tdsigwakeup(td, sig, action, intrval); 1880 mtx_unlock_spin(&sched_lock); 1881 goto out; 1882 } 1883 1884 MPASS(action == SIG_DFL); 1885 1886 if (prop & SA_STOP) { 1887 if (p->p_flag & P_PPWAIT) 1888 goto out; 1889 p->p_flag |= P_STOPPED_SIG; 1890 p->p_xstat = sig; 1891 mtx_lock_spin(&sched_lock); 1892 sig_suspend_threads(td, p, 1); 1893 thread_stopped(p); 1894 if (p->p_numthreads == p->p_suspcount) { 1895 SIGDELSET(p->p_siglist, p->p_xstat); 1896 FOREACH_THREAD_IN_PROC(p, td0) 1897 SIGDELSET(td0->td_siglist, p->p_xstat); 1898 } 1899 mtx_unlock_spin(&sched_lock); 1900 goto out; 1901 } 1902 else 1903 goto runfast; 1904 /* NOTREACHED */ 1905 } else { 1906 /* Not in "NORMAL" state. discard the signal. */ 1907 SIGDELSET(*siglist, sig); 1908 goto out; 1909 } 1910 1911 /* 1912 * The process is not stopped so we need to apply the signal to all the 1913 * running threads. 1914 */ 1915 1916 runfast: 1917 mtx_lock_spin(&sched_lock); 1918 tdsigwakeup(td, sig, action, intrval); 1919 thread_unsuspend(p); 1920 mtx_unlock_spin(&sched_lock); 1921 out: 1922 /* If we jump here, sched_lock should not be owned. */ 1923 mtx_assert(&sched_lock, MA_NOTOWNED); 1924 } 1925 1926 /* 1927 * The force of a signal has been directed against a single 1928 * thread. We need to see what we can do about knocking it 1929 * out of any sleep it may be in etc. 1930 */ 1931 static void 1932 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 1933 { 1934 struct proc *p = td->td_proc; 1935 register int prop; 1936 1937 PROC_LOCK_ASSERT(p, MA_OWNED); 1938 mtx_assert(&sched_lock, MA_OWNED); 1939 prop = sigprop(sig); 1940 1941 /* 1942 * Bring the priority of a thread up if we want it to get 1943 * killed in this lifetime. 1944 */ 1945 if (action == SIG_DFL && (prop & SA_KILL)) { 1946 if (p->p_nice > 0) 1947 sched_nice(td->td_proc, 0); 1948 if (td->td_priority > PUSER) 1949 sched_prio(td, PUSER); 1950 } 1951 1952 if (TD_ON_SLEEPQ(td)) { 1953 /* 1954 * If thread is sleeping uninterruptibly 1955 * we can't interrupt the sleep... the signal will 1956 * be noticed when the process returns through 1957 * trap() or syscall(). 1958 */ 1959 if ((td->td_flags & TDF_SINTR) == 0) 1960 return; 1961 /* 1962 * If SIGCONT is default (or ignored) and process is 1963 * asleep, we are finished; the process should not 1964 * be awakened. 1965 */ 1966 if ((prop & SA_CONT) && action == SIG_DFL) { 1967 SIGDELSET(p->p_siglist, sig); 1968 /* 1969 * It may be on either list in this state. 1970 * Remove from both for now. 1971 */ 1972 SIGDELSET(td->td_siglist, sig); 1973 return; 1974 } 1975 1976 /* 1977 * Give low priority threads a better chance to run. 1978 */ 1979 if (td->td_priority > PUSER) 1980 sched_prio(td, PUSER); 1981 1982 sleepq_abort(td, intrval); 1983 } else { 1984 /* 1985 * Other states do nothing with the signal immediately, 1986 * other than kicking ourselves if we are running. 1987 * It will either never be noticed, or noticed very soon. 1988 */ 1989 #ifdef SMP 1990 if (TD_IS_RUNNING(td) && td != curthread) 1991 forward_signal(td); 1992 #endif 1993 } 1994 } 1995 1996 static void 1997 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 1998 { 1999 struct thread *td2; 2000 2001 PROC_LOCK_ASSERT(p, MA_OWNED); 2002 mtx_assert(&sched_lock, MA_OWNED); 2003 2004 FOREACH_THREAD_IN_PROC(p, td2) { 2005 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2006 (td2->td_flags & TDF_SINTR) && 2007 !TD_IS_SUSPENDED(td2)) { 2008 thread_suspend_one(td2); 2009 } else { 2010 if (sending || td != td2) 2011 td2->td_flags |= TDF_ASTPENDING; 2012 #ifdef SMP 2013 if (TD_IS_RUNNING(td2) && td2 != td) 2014 forward_signal(td2); 2015 #endif 2016 } 2017 } 2018 } 2019 2020 int 2021 ptracestop(struct thread *td, int sig) 2022 { 2023 struct proc *p = td->td_proc; 2024 2025 PROC_LOCK_ASSERT(p, MA_OWNED); 2026 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2027 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2028 2029 mtx_lock_spin(&sched_lock); 2030 td->td_flags |= TDF_XSIG; 2031 mtx_unlock_spin(&sched_lock); 2032 td->td_xsig = sig; 2033 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2034 if (p->p_flag & P_SINGLE_EXIT) { 2035 mtx_lock_spin(&sched_lock); 2036 td->td_flags &= ~TDF_XSIG; 2037 mtx_unlock_spin(&sched_lock); 2038 return (sig); 2039 } 2040 /* 2041 * Just make wait() to work, the last stopped thread 2042 * will win. 2043 */ 2044 p->p_xstat = sig; 2045 p->p_xthread = td; 2046 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2047 mtx_lock_spin(&sched_lock); 2048 sig_suspend_threads(td, p, 0); 2049 stopme: 2050 thread_stopped(p); 2051 thread_suspend_one(td); 2052 PROC_UNLOCK(p); 2053 DROP_GIANT(); 2054 mi_switch(SW_VOL, NULL); 2055 mtx_unlock_spin(&sched_lock); 2056 PICKUP_GIANT(); 2057 PROC_LOCK(p); 2058 if (!(p->p_flag & P_TRACED)) 2059 break; 2060 if (td->td_flags & TDF_DBSUSPEND) { 2061 if (p->p_flag & P_SINGLE_EXIT) 2062 break; 2063 mtx_lock_spin(&sched_lock); 2064 goto stopme; 2065 } 2066 } 2067 return (td->td_xsig); 2068 } 2069 2070 /* 2071 * If the current process has received a signal (should be caught or cause 2072 * termination, should interrupt current syscall), return the signal number. 2073 * Stop signals with default action are processed immediately, then cleared; 2074 * they aren't returned. This is checked after each entry to the system for 2075 * a syscall or trap (though this can usually be done without calling issignal 2076 * by checking the pending signal masks in cursig.) The normal call 2077 * sequence is 2078 * 2079 * while (sig = cursig(curthread)) 2080 * postsig(sig); 2081 */ 2082 static int 2083 issignal(td) 2084 struct thread *td; 2085 { 2086 struct proc *p; 2087 struct sigacts *ps; 2088 sigset_t sigpending; 2089 int sig, prop, newsig; 2090 2091 p = td->td_proc; 2092 ps = p->p_sigacts; 2093 mtx_assert(&ps->ps_mtx, MA_OWNED); 2094 PROC_LOCK_ASSERT(p, MA_OWNED); 2095 for (;;) { 2096 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2097 2098 sigpending = td->td_siglist; 2099 SIGSETNAND(sigpending, td->td_sigmask); 2100 2101 if (p->p_flag & P_PPWAIT) 2102 SIG_STOPSIGMASK(sigpending); 2103 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2104 return (0); 2105 sig = sig_ffs(&sigpending); 2106 2107 if (p->p_stops & S_SIG) { 2108 mtx_unlock(&ps->ps_mtx); 2109 stopevent(p, S_SIG, sig); 2110 mtx_lock(&ps->ps_mtx); 2111 } 2112 2113 /* 2114 * We should see pending but ignored signals 2115 * only if P_TRACED was on when they were posted. 2116 */ 2117 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2118 SIGDELSET(td->td_siglist, sig); 2119 if (td->td_pflags & TDP_SA) 2120 SIGADDSET(td->td_sigmask, sig); 2121 continue; 2122 } 2123 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2124 /* 2125 * If traced, always stop. 2126 */ 2127 mtx_unlock(&ps->ps_mtx); 2128 newsig = ptracestop(td, sig); 2129 mtx_lock(&ps->ps_mtx); 2130 2131 /* 2132 * If parent wants us to take the signal, 2133 * then it will leave it in p->p_xstat; 2134 * otherwise we just look for signals again. 2135 */ 2136 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2137 if (td->td_pflags & TDP_SA) 2138 SIGADDSET(td->td_sigmask, sig); 2139 if (newsig == 0) 2140 continue; 2141 sig = newsig; 2142 /* 2143 * If the traced bit got turned off, go back up 2144 * to the top to rescan signals. This ensures 2145 * that p_sig* and p_sigact are consistent. 2146 */ 2147 if ((p->p_flag & P_TRACED) == 0) 2148 continue; 2149 2150 /* 2151 * Put the new signal into td_siglist. If the 2152 * signal is being masked, look for other signals. 2153 */ 2154 SIGADDSET(td->td_siglist, sig); 2155 if (td->td_pflags & TDP_SA) 2156 SIGDELSET(td->td_sigmask, sig); 2157 if (SIGISMEMBER(td->td_sigmask, sig)) 2158 continue; 2159 signotify(td); 2160 } 2161 2162 prop = sigprop(sig); 2163 2164 /* 2165 * Decide whether the signal should be returned. 2166 * Return the signal's number, or fall through 2167 * to clear it from the pending mask. 2168 */ 2169 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2170 2171 case (intptr_t)SIG_DFL: 2172 /* 2173 * Don't take default actions on system processes. 2174 */ 2175 if (p->p_pid <= 1) { 2176 #ifdef DIAGNOSTIC 2177 /* 2178 * Are you sure you want to ignore SIGSEGV 2179 * in init? XXX 2180 */ 2181 printf("Process (pid %lu) got signal %d\n", 2182 (u_long)p->p_pid, sig); 2183 #endif 2184 break; /* == ignore */ 2185 } 2186 /* 2187 * If there is a pending stop signal to process 2188 * with default action, stop here, 2189 * then clear the signal. However, 2190 * if process is member of an orphaned 2191 * process group, ignore tty stop signals. 2192 */ 2193 if (prop & SA_STOP) { 2194 if (p->p_flag & P_TRACED || 2195 (p->p_pgrp->pg_jobc == 0 && 2196 prop & SA_TTYSTOP)) 2197 break; /* == ignore */ 2198 mtx_unlock(&ps->ps_mtx); 2199 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2200 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2201 p->p_flag |= P_STOPPED_SIG; 2202 p->p_xstat = sig; 2203 mtx_lock_spin(&sched_lock); 2204 sig_suspend_threads(td, p, 0); 2205 thread_stopped(p); 2206 thread_suspend_one(td); 2207 PROC_UNLOCK(p); 2208 DROP_GIANT(); 2209 mi_switch(SW_INVOL, NULL); 2210 mtx_unlock_spin(&sched_lock); 2211 PICKUP_GIANT(); 2212 PROC_LOCK(p); 2213 mtx_lock(&ps->ps_mtx); 2214 break; 2215 } else if (prop & SA_IGNORE) { 2216 /* 2217 * Except for SIGCONT, shouldn't get here. 2218 * Default action is to ignore; drop it. 2219 */ 2220 break; /* == ignore */ 2221 } else 2222 return (sig); 2223 /*NOTREACHED*/ 2224 2225 case (intptr_t)SIG_IGN: 2226 /* 2227 * Masking above should prevent us ever trying 2228 * to take action on an ignored signal other 2229 * than SIGCONT, unless process is traced. 2230 */ 2231 if ((prop & SA_CONT) == 0 && 2232 (p->p_flag & P_TRACED) == 0) 2233 printf("issignal\n"); 2234 break; /* == ignore */ 2235 2236 default: 2237 /* 2238 * This signal has an action, let 2239 * postsig() process it. 2240 */ 2241 return (sig); 2242 } 2243 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2244 } 2245 /* NOTREACHED */ 2246 } 2247 2248 /* 2249 * MPSAFE 2250 */ 2251 void 2252 thread_stopped(struct proc *p) 2253 { 2254 struct proc *p1 = curthread->td_proc; 2255 struct sigacts *ps; 2256 int n; 2257 2258 PROC_LOCK_ASSERT(p, MA_OWNED); 2259 mtx_assert(&sched_lock, MA_OWNED); 2260 n = p->p_suspcount; 2261 if (p == p1) 2262 n++; 2263 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2264 mtx_unlock_spin(&sched_lock); 2265 p->p_flag &= ~P_WAITED; 2266 PROC_LOCK(p->p_pptr); 2267 /* 2268 * Wake up parent sleeping in kern_wait(), also send 2269 * SIGCHLD to parent, but SIGCHLD does not guarantee 2270 * that parent will awake, because parent may masked 2271 * the signal. 2272 */ 2273 p->p_pptr->p_flag |= P_STATCHILD; 2274 wakeup(p->p_pptr); 2275 ps = p->p_pptr->p_sigacts; 2276 mtx_lock(&ps->ps_mtx); 2277 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2278 mtx_unlock(&ps->ps_mtx); 2279 psignal(p->p_pptr, SIGCHLD); 2280 } else 2281 mtx_unlock(&ps->ps_mtx); 2282 PROC_UNLOCK(p->p_pptr); 2283 mtx_lock_spin(&sched_lock); 2284 } 2285 } 2286 2287 /* 2288 * Take the action for the specified signal 2289 * from the current set of pending signals. 2290 */ 2291 void 2292 postsig(sig) 2293 register int sig; 2294 { 2295 struct thread *td = curthread; 2296 register struct proc *p = td->td_proc; 2297 struct sigacts *ps; 2298 sig_t action; 2299 sigset_t returnmask; 2300 int code; 2301 2302 KASSERT(sig != 0, ("postsig")); 2303 2304 PROC_LOCK_ASSERT(p, MA_OWNED); 2305 ps = p->p_sigacts; 2306 mtx_assert(&ps->ps_mtx, MA_OWNED); 2307 SIGDELSET(td->td_siglist, sig); 2308 action = ps->ps_sigact[_SIG_IDX(sig)]; 2309 #ifdef KTRACE 2310 if (KTRPOINT(td, KTR_PSIG)) 2311 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2312 &td->td_oldsigmask : &td->td_sigmask, 0); 2313 #endif 2314 if (p->p_stops & S_SIG) { 2315 mtx_unlock(&ps->ps_mtx); 2316 stopevent(p, S_SIG, sig); 2317 mtx_lock(&ps->ps_mtx); 2318 } 2319 2320 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2321 /* 2322 * Default action, where the default is to kill 2323 * the process. (Other cases were ignored above.) 2324 */ 2325 mtx_unlock(&ps->ps_mtx); 2326 sigexit(td, sig); 2327 /* NOTREACHED */ 2328 } else { 2329 if (td->td_pflags & TDP_SA) { 2330 if (sig == SIGKILL) { 2331 mtx_unlock(&ps->ps_mtx); 2332 sigexit(td, sig); 2333 } 2334 } 2335 2336 /* 2337 * If we get here, the signal must be caught. 2338 */ 2339 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2340 ("postsig action")); 2341 /* 2342 * Set the new mask value and also defer further 2343 * occurrences of this signal. 2344 * 2345 * Special case: user has done a sigsuspend. Here the 2346 * current mask is not of interest, but rather the 2347 * mask from before the sigsuspend is what we want 2348 * restored after the signal processing is completed. 2349 */ 2350 if (td->td_pflags & TDP_OLDMASK) { 2351 returnmask = td->td_oldsigmask; 2352 td->td_pflags &= ~TDP_OLDMASK; 2353 } else 2354 returnmask = td->td_sigmask; 2355 2356 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2357 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2358 SIGADDSET(td->td_sigmask, sig); 2359 2360 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2361 /* 2362 * See kern_sigaction() for origin of this code. 2363 */ 2364 SIGDELSET(ps->ps_sigcatch, sig); 2365 if (sig != SIGCONT && 2366 sigprop(sig) & SA_IGNORE) 2367 SIGADDSET(ps->ps_sigignore, sig); 2368 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2369 } 2370 p->p_stats->p_ru.ru_nsignals++; 2371 if (p->p_sig != sig) { 2372 code = 0; 2373 } else { 2374 code = p->p_code; 2375 p->p_code = 0; 2376 p->p_sig = 0; 2377 } 2378 if (td->td_pflags & TDP_SA) 2379 thread_signal_add(curthread, sig); 2380 else 2381 (*p->p_sysent->sv_sendsig)(action, sig, 2382 &returnmask, code); 2383 } 2384 } 2385 2386 /* 2387 * Kill the current process for stated reason. 2388 */ 2389 void 2390 killproc(p, why) 2391 struct proc *p; 2392 char *why; 2393 { 2394 2395 PROC_LOCK_ASSERT(p, MA_OWNED); 2396 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2397 p, p->p_pid, p->p_comm); 2398 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2399 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2400 psignal(p, SIGKILL); 2401 } 2402 2403 /* 2404 * Force the current process to exit with the specified signal, dumping core 2405 * if appropriate. We bypass the normal tests for masked and caught signals, 2406 * allowing unrecoverable failures to terminate the process without changing 2407 * signal state. Mark the accounting record with the signal termination. 2408 * If dumping core, save the signal number for the debugger. Calls exit and 2409 * does not return. 2410 * 2411 * MPSAFE 2412 */ 2413 void 2414 sigexit(td, sig) 2415 struct thread *td; 2416 int sig; 2417 { 2418 struct proc *p = td->td_proc; 2419 2420 PROC_LOCK_ASSERT(p, MA_OWNED); 2421 p->p_acflag |= AXSIG; 2422 /* 2423 * We must be single-threading to generate a core dump. This 2424 * ensures that the registers in the core file are up-to-date. 2425 * Also, the ELF dump handler assumes that the thread list doesn't 2426 * change out from under it. 2427 * 2428 * XXX If another thread attempts to single-thread before us 2429 * (e.g. via fork()), we won't get a dump at all. 2430 */ 2431 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2432 p->p_sig = sig; 2433 /* 2434 * Log signals which would cause core dumps 2435 * (Log as LOG_INFO to appease those who don't want 2436 * these messages.) 2437 * XXX : Todo, as well as euid, write out ruid too 2438 * Note that coredump() drops proc lock. 2439 */ 2440 if (coredump(td) == 0) 2441 sig |= WCOREFLAG; 2442 if (kern_logsigexit) 2443 log(LOG_INFO, 2444 "pid %d (%s), uid %d: exited on signal %d%s\n", 2445 p->p_pid, p->p_comm, 2446 td->td_ucred ? td->td_ucred->cr_uid : -1, 2447 sig &~ WCOREFLAG, 2448 sig & WCOREFLAG ? " (core dumped)" : ""); 2449 } else 2450 PROC_UNLOCK(p); 2451 exit1(td, W_EXITCODE(0, sig)); 2452 /* NOTREACHED */ 2453 } 2454 2455 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2456 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2457 sizeof(corefilename), "process corefile name format string"); 2458 2459 /* 2460 * expand_name(name, uid, pid) 2461 * Expand the name described in corefilename, using name, uid, and pid. 2462 * corefilename is a printf-like string, with three format specifiers: 2463 * %N name of process ("name") 2464 * %P process id (pid) 2465 * %U user id (uid) 2466 * For example, "%N.core" is the default; they can be disabled completely 2467 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2468 * This is controlled by the sysctl variable kern.corefile (see above). 2469 */ 2470 2471 static char * 2472 expand_name(name, uid, pid) 2473 const char *name; 2474 uid_t uid; 2475 pid_t pid; 2476 { 2477 const char *format, *appendstr; 2478 char *temp; 2479 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2480 size_t i, l, n; 2481 2482 format = corefilename; 2483 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2484 if (temp == NULL) 2485 return (NULL); 2486 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2487 switch (format[i]) { 2488 case '%': /* Format character */ 2489 i++; 2490 switch (format[i]) { 2491 case '%': 2492 appendstr = "%"; 2493 break; 2494 case 'N': /* process name */ 2495 appendstr = name; 2496 break; 2497 case 'P': /* process id */ 2498 sprintf(buf, "%u", pid); 2499 appendstr = buf; 2500 break; 2501 case 'U': /* user id */ 2502 sprintf(buf, "%u", uid); 2503 appendstr = buf; 2504 break; 2505 default: 2506 appendstr = ""; 2507 log(LOG_ERR, 2508 "Unknown format character %c in `%s'\n", 2509 format[i], format); 2510 } 2511 l = strlen(appendstr); 2512 if ((n + l) >= MAXPATHLEN) 2513 goto toolong; 2514 memcpy(temp + n, appendstr, l); 2515 n += l; 2516 break; 2517 default: 2518 temp[n++] = format[i]; 2519 } 2520 } 2521 if (format[i] != '\0') 2522 goto toolong; 2523 return (temp); 2524 toolong: 2525 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2526 (long)pid, name, (u_long)uid); 2527 free(temp, M_TEMP); 2528 return (NULL); 2529 } 2530 2531 /* 2532 * Dump a process' core. The main routine does some 2533 * policy checking, and creates the name of the coredump; 2534 * then it passes on a vnode and a size limit to the process-specific 2535 * coredump routine if there is one; if there _is not_ one, it returns 2536 * ENOSYS; otherwise it returns the error from the process-specific routine. 2537 */ 2538 2539 static int 2540 coredump(struct thread *td) 2541 { 2542 struct proc *p = td->td_proc; 2543 register struct vnode *vp; 2544 register struct ucred *cred = td->td_ucred; 2545 struct flock lf; 2546 struct nameidata nd; 2547 struct vattr vattr; 2548 int error, error1, flags, locked; 2549 struct mount *mp; 2550 char *name; /* name of corefile */ 2551 off_t limit; 2552 2553 PROC_LOCK_ASSERT(p, MA_OWNED); 2554 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 2555 _STOPEVENT(p, S_CORE, 0); 2556 2557 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2558 PROC_UNLOCK(p); 2559 return (EFAULT); 2560 } 2561 2562 /* 2563 * Note that the bulk of limit checking is done after 2564 * the corefile is created. The exception is if the limit 2565 * for corefiles is 0, in which case we don't bother 2566 * creating the corefile at all. This layout means that 2567 * a corefile is truncated instead of not being created, 2568 * if it is larger than the limit. 2569 */ 2570 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2571 PROC_UNLOCK(p); 2572 if (limit == 0) 2573 return (EFBIG); 2574 2575 mtx_lock(&Giant); 2576 restart: 2577 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2578 if (name == NULL) { 2579 mtx_unlock(&Giant); 2580 return (EINVAL); 2581 } 2582 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2583 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2584 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2585 free(name, M_TEMP); 2586 if (error) { 2587 mtx_unlock(&Giant); 2588 return (error); 2589 } 2590 NDFREE(&nd, NDF_ONLY_PNBUF); 2591 vp = nd.ni_vp; 2592 2593 /* Don't dump to non-regular files or files with links. */ 2594 if (vp->v_type != VREG || 2595 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2596 VOP_UNLOCK(vp, 0, td); 2597 error = EFAULT; 2598 goto out; 2599 } 2600 2601 VOP_UNLOCK(vp, 0, td); 2602 lf.l_whence = SEEK_SET; 2603 lf.l_start = 0; 2604 lf.l_len = 0; 2605 lf.l_type = F_WRLCK; 2606 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2607 2608 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2609 lf.l_type = F_UNLCK; 2610 if (locked) 2611 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2612 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2613 return (error); 2614 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2615 return (error); 2616 goto restart; 2617 } 2618 2619 VATTR_NULL(&vattr); 2620 vattr.va_size = 0; 2621 if (set_core_nodump_flag) 2622 vattr.va_flags = UF_NODUMP; 2623 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2624 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2625 VOP_SETATTR(vp, &vattr, cred, td); 2626 VOP_UNLOCK(vp, 0, td); 2627 PROC_LOCK(p); 2628 p->p_acflag |= ACORE; 2629 PROC_UNLOCK(p); 2630 2631 error = p->p_sysent->sv_coredump ? 2632 p->p_sysent->sv_coredump(td, vp, limit) : 2633 ENOSYS; 2634 2635 if (locked) { 2636 lf.l_type = F_UNLCK; 2637 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2638 } 2639 vn_finished_write(mp); 2640 out: 2641 error1 = vn_close(vp, FWRITE, cred, td); 2642 mtx_unlock(&Giant); 2643 if (error == 0) 2644 error = error1; 2645 return (error); 2646 } 2647 2648 /* 2649 * Nonexistent system call-- signal process (may want to handle it). 2650 * Flag error in case process won't see signal immediately (blocked or ignored). 2651 */ 2652 #ifndef _SYS_SYSPROTO_H_ 2653 struct nosys_args { 2654 int dummy; 2655 }; 2656 #endif 2657 /* 2658 * MPSAFE 2659 */ 2660 /* ARGSUSED */ 2661 int 2662 nosys(td, args) 2663 struct thread *td; 2664 struct nosys_args *args; 2665 { 2666 struct proc *p = td->td_proc; 2667 2668 PROC_LOCK(p); 2669 psignal(p, SIGSYS); 2670 PROC_UNLOCK(p); 2671 return (ENOSYS); 2672 } 2673 2674 /* 2675 * Send a SIGIO or SIGURG signal to a process or process group using 2676 * stored credentials rather than those of the current process. 2677 */ 2678 void 2679 pgsigio(sigiop, sig, checkctty) 2680 struct sigio **sigiop; 2681 int sig, checkctty; 2682 { 2683 struct sigio *sigio; 2684 2685 SIGIO_LOCK(); 2686 sigio = *sigiop; 2687 if (sigio == NULL) { 2688 SIGIO_UNLOCK(); 2689 return; 2690 } 2691 if (sigio->sio_pgid > 0) { 2692 PROC_LOCK(sigio->sio_proc); 2693 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2694 psignal(sigio->sio_proc, sig); 2695 PROC_UNLOCK(sigio->sio_proc); 2696 } else if (sigio->sio_pgid < 0) { 2697 struct proc *p; 2698 2699 PGRP_LOCK(sigio->sio_pgrp); 2700 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2701 PROC_LOCK(p); 2702 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2703 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2704 psignal(p, sig); 2705 PROC_UNLOCK(p); 2706 } 2707 PGRP_UNLOCK(sigio->sio_pgrp); 2708 } 2709 SIGIO_UNLOCK(); 2710 } 2711 2712 static int 2713 filt_sigattach(struct knote *kn) 2714 { 2715 struct proc *p = curproc; 2716 2717 kn->kn_ptr.p_proc = p; 2718 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2719 2720 knlist_add(&p->p_klist, kn, 0); 2721 2722 return (0); 2723 } 2724 2725 static void 2726 filt_sigdetach(struct knote *kn) 2727 { 2728 struct proc *p = kn->kn_ptr.p_proc; 2729 2730 knlist_remove(&p->p_klist, kn, 0); 2731 } 2732 2733 /* 2734 * signal knotes are shared with proc knotes, so we apply a mask to 2735 * the hint in order to differentiate them from process hints. This 2736 * could be avoided by using a signal-specific knote list, but probably 2737 * isn't worth the trouble. 2738 */ 2739 static int 2740 filt_signal(struct knote *kn, long hint) 2741 { 2742 2743 if (hint & NOTE_SIGNAL) { 2744 hint &= ~NOTE_SIGNAL; 2745 2746 if (kn->kn_id == hint) 2747 kn->kn_data++; 2748 } 2749 return (kn->kn_data != 0); 2750 } 2751 2752 struct sigacts * 2753 sigacts_alloc(void) 2754 { 2755 struct sigacts *ps; 2756 2757 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2758 ps->ps_refcnt = 1; 2759 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2760 return (ps); 2761 } 2762 2763 void 2764 sigacts_free(struct sigacts *ps) 2765 { 2766 2767 mtx_lock(&ps->ps_mtx); 2768 ps->ps_refcnt--; 2769 if (ps->ps_refcnt == 0) { 2770 mtx_destroy(&ps->ps_mtx); 2771 free(ps, M_SUBPROC); 2772 } else 2773 mtx_unlock(&ps->ps_mtx); 2774 } 2775 2776 struct sigacts * 2777 sigacts_hold(struct sigacts *ps) 2778 { 2779 mtx_lock(&ps->ps_mtx); 2780 ps->ps_refcnt++; 2781 mtx_unlock(&ps->ps_mtx); 2782 return (ps); 2783 } 2784 2785 void 2786 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2787 { 2788 2789 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2790 mtx_lock(&src->ps_mtx); 2791 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2792 mtx_unlock(&src->ps_mtx); 2793 } 2794 2795 int 2796 sigacts_shared(struct sigacts *ps) 2797 { 2798 int shared; 2799 2800 mtx_lock(&ps->ps_mtx); 2801 shared = ps->ps_refcnt > 1; 2802 mtx_unlock(&ps->ps_mtx); 2803 return (shared); 2804 }
Cache object: e9204ef680a3cc8d24c55eceb38f3e7d
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