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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_compat.h" 45 #include "opt_ktrace.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 #include <sys/acct.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/kernel.h> 56 #include <sys/kse.h> 57 #include <sys/ktr.h> 58 #include <sys/ktrace.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/proc.h> 64 #include <sys/pioctl.h> 65 #include <sys/resourcevar.h> 66 #include <sys/smp.h> 67 #include <sys/stat.h> 68 #include <sys/sx.h> 69 #include <sys/syscallsubr.h> 70 #include <sys/sysctl.h> 71 #include <sys/sysent.h> 72 #include <sys/syslog.h> 73 #include <sys/sysproto.h> 74 #include <sys/unistd.h> 75 #include <sys/wait.h> 76 77 #include <machine/cpu.h> 78 79 #if defined (__alpha__) && !defined(COMPAT_43) 80 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 81 #endif 82 83 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 84 85 static int coredump(struct thread *); 86 static char *expand_name(const char *, uid_t, pid_t); 87 static int killpg1(struct thread *td, int sig, int pgid, int all); 88 static int issignal(struct thread *p); 89 static int sigprop(int sig); 90 static void stop(struct proc *); 91 static void tdsigwakeup(struct thread *td, int sig, sig_t action); 92 static int filt_sigattach(struct knote *kn); 93 static void filt_sigdetach(struct knote *kn); 94 static int filt_signal(struct knote *kn, long hint); 95 static struct thread *sigtd(struct proc *p, int sig, int prop); 96 static int kern_sigtimedwait(struct thread *td, sigset_t set, 97 siginfo_t *info, struct timespec *timeout); 98 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target); 99 100 struct filterops sig_filtops = 101 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 102 103 static int kern_logsigexit = 1; 104 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 105 &kern_logsigexit, 0, 106 "Log processes quitting on abnormal signals to syslog(3)"); 107 108 /* 109 * Policy -- Can ucred cr1 send SIGIO to process cr2? 110 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 111 * in the right situations. 112 */ 113 #define CANSIGIO(cr1, cr2) \ 114 ((cr1)->cr_uid == 0 || \ 115 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 116 (cr1)->cr_uid == (cr2)->cr_ruid || \ 117 (cr1)->cr_ruid == (cr2)->cr_uid || \ 118 (cr1)->cr_uid == (cr2)->cr_uid) 119 120 int sugid_coredump; 121 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 122 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 123 124 static int do_coredump = 1; 125 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 126 &do_coredump, 0, "Enable/Disable coredumps"); 127 128 /* 129 * Signal properties and actions. 130 * The array below categorizes the signals and their default actions 131 * according to the following properties: 132 */ 133 #define SA_KILL 0x01 /* terminates process by default */ 134 #define SA_CORE 0x02 /* ditto and coredumps */ 135 #define SA_STOP 0x04 /* suspend process */ 136 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 137 #define SA_IGNORE 0x10 /* ignore by default */ 138 #define SA_CONT 0x20 /* continue if suspended */ 139 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 140 #define SA_PROC 0x80 /* deliverable to any thread */ 141 142 static int sigproptbl[NSIG] = { 143 SA_KILL|SA_PROC, /* SIGHUP */ 144 SA_KILL|SA_PROC, /* SIGINT */ 145 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 146 SA_KILL|SA_CORE, /* SIGILL */ 147 SA_KILL|SA_CORE, /* SIGTRAP */ 148 SA_KILL|SA_CORE, /* SIGABRT */ 149 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 150 SA_KILL|SA_CORE, /* SIGFPE */ 151 SA_KILL|SA_PROC, /* SIGKILL */ 152 SA_KILL|SA_CORE, /* SIGBUS */ 153 SA_KILL|SA_CORE, /* SIGSEGV */ 154 SA_KILL|SA_CORE, /* SIGSYS */ 155 SA_KILL|SA_PROC, /* SIGPIPE */ 156 SA_KILL|SA_PROC, /* SIGALRM */ 157 SA_KILL|SA_PROC, /* SIGTERM */ 158 SA_IGNORE|SA_PROC, /* SIGURG */ 159 SA_STOP|SA_PROC, /* SIGSTOP */ 160 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 161 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 162 SA_IGNORE|SA_PROC, /* SIGCHLD */ 163 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 164 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 165 SA_IGNORE|SA_PROC, /* SIGIO */ 166 SA_KILL, /* SIGXCPU */ 167 SA_KILL, /* SIGXFSZ */ 168 SA_KILL|SA_PROC, /* SIGVTALRM */ 169 SA_KILL|SA_PROC, /* SIGPROF */ 170 SA_IGNORE|SA_PROC, /* SIGWINCH */ 171 SA_IGNORE|SA_PROC, /* SIGINFO */ 172 SA_KILL|SA_PROC, /* SIGUSR1 */ 173 SA_KILL|SA_PROC, /* SIGUSR2 */ 174 }; 175 176 /* 177 * Determine signal that should be delivered to process p, the current 178 * process, 0 if none. If there is a pending stop signal with default 179 * action, the process stops in issignal(). 180 * XXXKSE the check for a pending stop is not done under KSE 181 * 182 * MP SAFE. 183 */ 184 int 185 cursig(struct thread *td) 186 { 187 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 188 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 189 mtx_assert(&sched_lock, MA_NOTOWNED); 190 return (SIGPENDING(td) ? issignal(td) : 0); 191 } 192 193 /* 194 * Arrange for ast() to handle unmasked pending signals on return to user 195 * mode. This must be called whenever a signal is added to td_siglist or 196 * unmasked in td_sigmask. 197 */ 198 void 199 signotify(struct thread *td) 200 { 201 struct proc *p; 202 sigset_t set, saved; 203 204 p = td->td_proc; 205 206 PROC_LOCK_ASSERT(p, MA_OWNED); 207 208 /* 209 * If our mask changed we may have to move signal that were 210 * previously masked by all threads to our siglist. 211 */ 212 set = p->p_siglist; 213 if (p->p_flag & P_SA) 214 saved = p->p_siglist; 215 SIGSETNAND(set, td->td_sigmask); 216 SIGSETNAND(p->p_siglist, set); 217 SIGSETOR(td->td_siglist, set); 218 219 if (SIGPENDING(td)) { 220 mtx_lock_spin(&sched_lock); 221 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 222 mtx_unlock_spin(&sched_lock); 223 } 224 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 225 if (SIGSETEQ(saved, p->p_siglist)) 226 return; 227 else { 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) || defined(COMPAT_SUNOS) 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 #ifdef COMPAT_SUNOS 354 if (act->sa_flags & SA_USERTRAMP) 355 SIGADDSET(ps->ps_usertramp, sig); 356 else 357 SIGDELSET(ps->ps_usertramp, sig); 358 #endif 359 if (sig == SIGCHLD) { 360 if (act->sa_flags & SA_NOCLDSTOP) 361 ps->ps_flag |= PS_NOCLDSTOP; 362 else 363 ps->ps_flag &= ~PS_NOCLDSTOP; 364 if (act->sa_flags & SA_NOCLDWAIT) { 365 /* 366 * Paranoia: since SA_NOCLDWAIT is implemented 367 * by reparenting the dying child to PID 1 (and 368 * trust it to reap the zombie), PID 1 itself 369 * is forbidden to set SA_NOCLDWAIT. 370 */ 371 if (p->p_pid == 1) 372 ps->ps_flag &= ~PS_NOCLDWAIT; 373 else 374 ps->ps_flag |= PS_NOCLDWAIT; 375 } else 376 ps->ps_flag &= ~PS_NOCLDWAIT; 377 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 378 ps->ps_flag |= PS_CLDSIGIGN; 379 else 380 ps->ps_flag &= ~PS_CLDSIGIGN; 381 } 382 /* 383 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 384 * and for signals set to SIG_DFL where the default is to 385 * ignore. However, don't put SIGCONT in ps_sigignore, as we 386 * have to restart the process. 387 */ 388 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 389 (sigprop(sig) & SA_IGNORE && 390 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 391 if ((p->p_flag & P_SA) && 392 SIGISMEMBER(p->p_siglist, sig)) { 393 p->p_flag |= P_SIGEVENT; 394 wakeup(&p->p_siglist); 395 } 396 /* never to be seen again */ 397 SIGDELSET(p->p_siglist, sig); 398 mtx_lock_spin(&sched_lock); 399 FOREACH_THREAD_IN_PROC(p, td0) 400 SIGDELSET(td0->td_siglist, sig); 401 mtx_unlock_spin(&sched_lock); 402 if (sig != SIGCONT) 403 /* easier in psignal */ 404 SIGADDSET(ps->ps_sigignore, sig); 405 SIGDELSET(ps->ps_sigcatch, sig); 406 } else { 407 SIGDELSET(ps->ps_sigignore, sig); 408 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 409 SIGDELSET(ps->ps_sigcatch, sig); 410 else 411 SIGADDSET(ps->ps_sigcatch, sig); 412 } 413 #ifdef COMPAT_FREEBSD4 414 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 415 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 416 (flags & KSA_FREEBSD4) == 0) 417 SIGDELSET(ps->ps_freebsd4, sig); 418 else 419 SIGADDSET(ps->ps_freebsd4, sig); 420 #endif 421 #ifdef COMPAT_43 422 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 423 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 424 (flags & KSA_OSIGSET) == 0) 425 SIGDELSET(ps->ps_osigset, sig); 426 else 427 SIGADDSET(ps->ps_osigset, sig); 428 #endif 429 } 430 mtx_unlock(&ps->ps_mtx); 431 PROC_UNLOCK(p); 432 return (0); 433 } 434 435 #ifndef _SYS_SYSPROTO_H_ 436 struct sigaction_args { 437 int sig; 438 struct sigaction *act; 439 struct sigaction *oact; 440 }; 441 #endif 442 /* 443 * MPSAFE 444 */ 445 int 446 sigaction(td, uap) 447 struct thread *td; 448 register struct sigaction_args *uap; 449 { 450 struct sigaction act, oact; 451 register struct sigaction *actp, *oactp; 452 int error; 453 454 actp = (uap->act != NULL) ? &act : NULL; 455 oactp = (uap->oact != NULL) ? &oact : NULL; 456 if (actp) { 457 error = copyin(uap->act, actp, sizeof(act)); 458 if (error) 459 return (error); 460 } 461 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 462 if (oactp && !error) 463 error = copyout(oactp, uap->oact, sizeof(oact)); 464 return (error); 465 } 466 467 #ifdef COMPAT_FREEBSD4 468 #ifndef _SYS_SYSPROTO_H_ 469 struct freebsd4_sigaction_args { 470 int sig; 471 struct sigaction *act; 472 struct sigaction *oact; 473 }; 474 #endif 475 /* 476 * MPSAFE 477 */ 478 int 479 freebsd4_sigaction(td, uap) 480 struct thread *td; 481 register struct freebsd4_sigaction_args *uap; 482 { 483 struct sigaction act, oact; 484 register struct sigaction *actp, *oactp; 485 int error; 486 487 488 actp = (uap->act != NULL) ? &act : NULL; 489 oactp = (uap->oact != NULL) ? &oact : NULL; 490 if (actp) { 491 error = copyin(uap->act, actp, sizeof(act)); 492 if (error) 493 return (error); 494 } 495 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 496 if (oactp && !error) 497 error = copyout(oactp, uap->oact, sizeof(oact)); 498 return (error); 499 } 500 #endif /* COMAPT_FREEBSD4 */ 501 502 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 503 #ifndef _SYS_SYSPROTO_H_ 504 struct osigaction_args { 505 int signum; 506 struct osigaction *nsa; 507 struct osigaction *osa; 508 }; 509 #endif 510 /* 511 * MPSAFE 512 */ 513 int 514 osigaction(td, uap) 515 struct thread *td; 516 register struct osigaction_args *uap; 517 { 518 struct osigaction sa; 519 struct sigaction nsa, osa; 520 register struct sigaction *nsap, *osap; 521 int error; 522 523 if (uap->signum <= 0 || uap->signum >= ONSIG) 524 return (EINVAL); 525 526 nsap = (uap->nsa != NULL) ? &nsa : NULL; 527 osap = (uap->osa != NULL) ? &osa : NULL; 528 529 if (nsap) { 530 error = copyin(uap->nsa, &sa, sizeof(sa)); 531 if (error) 532 return (error); 533 nsap->sa_handler = sa.sa_handler; 534 nsap->sa_flags = sa.sa_flags; 535 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 536 } 537 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 538 if (osap && !error) { 539 sa.sa_handler = osap->sa_handler; 540 sa.sa_flags = osap->sa_flags; 541 SIG2OSIG(osap->sa_mask, sa.sa_mask); 542 error = copyout(&sa, uap->osa, sizeof(sa)); 543 } 544 return (error); 545 } 546 547 #if !defined(__i386__) && !defined(__alpha__) 548 /* Avoid replicating the same stub everywhere */ 549 int 550 osigreturn(td, uap) 551 struct thread *td; 552 struct osigreturn_args *uap; 553 { 554 555 return (nosys(td, (struct nosys_args *)uap)); 556 } 557 #endif 558 #endif /* COMPAT_43 */ 559 560 /* 561 * Initialize signal state for process 0; 562 * set to ignore signals that are ignored by default. 563 */ 564 void 565 siginit(p) 566 struct proc *p; 567 { 568 register int i; 569 struct sigacts *ps; 570 571 PROC_LOCK(p); 572 ps = p->p_sigacts; 573 mtx_lock(&ps->ps_mtx); 574 for (i = 1; i <= NSIG; i++) 575 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 576 SIGADDSET(ps->ps_sigignore, i); 577 mtx_unlock(&ps->ps_mtx); 578 PROC_UNLOCK(p); 579 } 580 581 /* 582 * Reset signals for an exec of the specified process. 583 */ 584 void 585 execsigs(struct proc *p) 586 { 587 struct sigacts *ps; 588 int sig; 589 struct thread *td; 590 591 /* 592 * Reset caught signals. Held signals remain held 593 * through td_sigmask (unless they were caught, 594 * and are now ignored by default). 595 */ 596 PROC_LOCK_ASSERT(p, MA_OWNED); 597 td = FIRST_THREAD_IN_PROC(p); 598 ps = p->p_sigacts; 599 mtx_lock(&ps->ps_mtx); 600 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 601 sig = sig_ffs(&ps->ps_sigcatch); 602 SIGDELSET(ps->ps_sigcatch, sig); 603 if (sigprop(sig) & SA_IGNORE) { 604 if (sig != SIGCONT) 605 SIGADDSET(ps->ps_sigignore, sig); 606 SIGDELSET(p->p_siglist, sig); 607 /* 608 * There is only one thread at this point. 609 */ 610 SIGDELSET(td->td_siglist, sig); 611 } 612 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 613 } 614 /* 615 * Reset stack state to the user stack. 616 * Clear set of signals caught on the signal stack. 617 */ 618 td->td_sigstk.ss_flags = SS_DISABLE; 619 td->td_sigstk.ss_size = 0; 620 td->td_sigstk.ss_sp = 0; 621 td->td_pflags &= ~TDP_ALTSTACK; 622 /* 623 * Reset no zombies if child dies flag as Solaris does. 624 */ 625 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 626 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 627 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 628 mtx_unlock(&ps->ps_mtx); 629 } 630 631 /* 632 * kern_sigprocmask() 633 * 634 * Manipulate signal mask. 635 */ 636 int 637 kern_sigprocmask(td, how, set, oset, old) 638 struct thread *td; 639 int how; 640 sigset_t *set, *oset; 641 int old; 642 { 643 int error; 644 645 PROC_LOCK(td->td_proc); 646 if (oset != NULL) 647 *oset = td->td_sigmask; 648 649 error = 0; 650 if (set != NULL) { 651 switch (how) { 652 case SIG_BLOCK: 653 SIG_CANTMASK(*set); 654 SIGSETOR(td->td_sigmask, *set); 655 break; 656 case SIG_UNBLOCK: 657 SIGSETNAND(td->td_sigmask, *set); 658 signotify(td); 659 break; 660 case SIG_SETMASK: 661 SIG_CANTMASK(*set); 662 if (old) 663 SIGSETLO(td->td_sigmask, *set); 664 else 665 td->td_sigmask = *set; 666 signotify(td); 667 break; 668 default: 669 error = EINVAL; 670 break; 671 } 672 } 673 PROC_UNLOCK(td->td_proc); 674 return (error); 675 } 676 677 /* 678 * sigprocmask() - MP SAFE 679 */ 680 681 #ifndef _SYS_SYSPROTO_H_ 682 struct sigprocmask_args { 683 int how; 684 const sigset_t *set; 685 sigset_t *oset; 686 }; 687 #endif 688 int 689 sigprocmask(td, uap) 690 register struct thread *td; 691 struct sigprocmask_args *uap; 692 { 693 sigset_t set, oset; 694 sigset_t *setp, *osetp; 695 int error; 696 697 setp = (uap->set != NULL) ? &set : NULL; 698 osetp = (uap->oset != NULL) ? &oset : NULL; 699 if (setp) { 700 error = copyin(uap->set, setp, sizeof(set)); 701 if (error) 702 return (error); 703 } 704 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 705 if (osetp && !error) { 706 error = copyout(osetp, uap->oset, sizeof(oset)); 707 } 708 return (error); 709 } 710 711 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 712 /* 713 * osigprocmask() - MP SAFE 714 */ 715 #ifndef _SYS_SYSPROTO_H_ 716 struct osigprocmask_args { 717 int how; 718 osigset_t mask; 719 }; 720 #endif 721 int 722 osigprocmask(td, uap) 723 register struct thread *td; 724 struct osigprocmask_args *uap; 725 { 726 sigset_t set, oset; 727 int error; 728 729 OSIG2SIG(uap->mask, set); 730 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 731 SIG2OSIG(oset, td->td_retval[0]); 732 return (error); 733 } 734 #endif /* COMPAT_43 */ 735 736 #ifndef _SYS_SYSPROTO_H_ 737 struct sigpending_args { 738 sigset_t *set; 739 }; 740 #endif 741 /* 742 * MPSAFE 743 */ 744 int 745 sigwait(struct thread *td, struct sigwait_args *uap) 746 { 747 siginfo_t info; 748 sigset_t set; 749 int error; 750 751 error = copyin(uap->set, &set, sizeof(set)); 752 if (error) 753 return (error); 754 755 error = kern_sigtimedwait(td, set, &info, NULL); 756 if (error) 757 return (error); 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 return (error); 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, sigset; 847 struct proc *p; 848 int error; 849 int sig; 850 int hz; 851 int i; 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; 861 862 again: 863 for (i = 1; i <= _SIG_MAXSIG; ++i) { 864 if (!SIGISMEMBER(waitset, i)) 865 continue; 866 if (SIGISMEMBER(td->td_siglist, i)) { 867 SIGFILLSET(td->td_sigmask); 868 SIG_CANTMASK(td->td_sigmask); 869 SIGDELSET(td->td_sigmask, i); 870 mtx_lock(&ps->ps_mtx); 871 sig = cursig(td); 872 i = 0; 873 mtx_unlock(&ps->ps_mtx); 874 } else if (SIGISMEMBER(p->p_siglist, i)) { 875 if (p->p_flag & P_SA) { 876 p->p_flag |= P_SIGEVENT; 877 wakeup(&p->p_siglist); 878 } 879 SIGDELSET(p->p_siglist, i); 880 SIGADDSET(td->td_siglist, i); 881 SIGFILLSET(td->td_sigmask); 882 SIG_CANTMASK(td->td_sigmask); 883 SIGDELSET(td->td_sigmask, i); 884 mtx_lock(&ps->ps_mtx); 885 sig = cursig(td); 886 i = 0; 887 mtx_unlock(&ps->ps_mtx); 888 } 889 if (sig) { 890 td->td_sigmask = savedmask; 891 signotify(td); 892 goto out; 893 } 894 } 895 if (error) 896 goto out; 897 898 td->td_sigmask = savedmask; 899 signotify(td); 900 sigset = td->td_siglist; 901 SIGSETOR(sigset, p->p_siglist); 902 SIGSETAND(sigset, waitset); 903 if (!SIGISEMPTY(sigset)) 904 goto again; 905 906 /* 907 * POSIX says this must be checked after looking for pending 908 * signals. 909 */ 910 if (timeout) { 911 struct timeval tv; 912 913 if (timeout->tv_nsec < 0 || timeout->tv_nsec > 1000000000) { 914 error = EINVAL; 915 goto out; 916 } 917 if (timeout->tv_sec == 0 && timeout->tv_nsec == 0) { 918 error = EAGAIN; 919 goto out; 920 } 921 TIMESPEC_TO_TIMEVAL(&tv, timeout); 922 hz = tvtohz(&tv); 923 } else 924 hz = 0; 925 926 td->td_waitset = &waitset; 927 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 928 td->td_waitset = NULL; 929 if (error == 0) /* surplus wakeup ? */ 930 error = EINTR; 931 goto again; 932 933 out: 934 if (sig) { 935 sig_t action; 936 937 error = 0; 938 mtx_lock(&ps->ps_mtx); 939 action = ps->ps_sigact[_SIG_IDX(sig)]; 940 mtx_unlock(&ps->ps_mtx); 941 #ifdef KTRACE 942 if (KTRPOINT(td, KTR_PSIG)) 943 ktrpsig(sig, action, &td->td_sigmask, 0); 944 #endif 945 _STOPEVENT(p, S_SIG, sig); 946 947 SIGDELSET(td->td_siglist, sig); 948 info->si_signo = sig; 949 info->si_code = 0; 950 } 951 PROC_UNLOCK(p); 952 return (error); 953 } 954 955 /* 956 * MPSAFE 957 */ 958 int 959 sigpending(td, uap) 960 struct thread *td; 961 struct sigpending_args *uap; 962 { 963 struct proc *p = td->td_proc; 964 sigset_t siglist; 965 966 PROC_LOCK(p); 967 siglist = p->p_siglist; 968 SIGSETOR(siglist, td->td_siglist); 969 PROC_UNLOCK(p); 970 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 971 } 972 973 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 974 #ifndef _SYS_SYSPROTO_H_ 975 struct osigpending_args { 976 int dummy; 977 }; 978 #endif 979 /* 980 * MPSAFE 981 */ 982 int 983 osigpending(td, uap) 984 struct thread *td; 985 struct osigpending_args *uap; 986 { 987 struct proc *p = td->td_proc; 988 sigset_t siglist; 989 990 PROC_LOCK(p); 991 siglist = p->p_siglist; 992 SIGSETOR(siglist, td->td_siglist); 993 PROC_UNLOCK(p); 994 SIG2OSIG(siglist, td->td_retval[0]); 995 return (0); 996 } 997 #endif /* COMPAT_43 */ 998 999 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1000 /* 1001 * Generalized interface signal handler, 4.3-compatible. 1002 */ 1003 #ifndef _SYS_SYSPROTO_H_ 1004 struct osigvec_args { 1005 int signum; 1006 struct sigvec *nsv; 1007 struct sigvec *osv; 1008 }; 1009 #endif 1010 /* 1011 * MPSAFE 1012 */ 1013 /* ARGSUSED */ 1014 int 1015 osigvec(td, uap) 1016 struct thread *td; 1017 register struct osigvec_args *uap; 1018 { 1019 struct sigvec vec; 1020 struct sigaction nsa, osa; 1021 register struct sigaction *nsap, *osap; 1022 int error; 1023 1024 if (uap->signum <= 0 || uap->signum >= ONSIG) 1025 return (EINVAL); 1026 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1027 osap = (uap->osv != NULL) ? &osa : NULL; 1028 if (nsap) { 1029 error = copyin(uap->nsv, &vec, sizeof(vec)); 1030 if (error) 1031 return (error); 1032 nsap->sa_handler = vec.sv_handler; 1033 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1034 nsap->sa_flags = vec.sv_flags; 1035 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1036 #ifdef COMPAT_SUNOS 1037 nsap->sa_flags |= SA_USERTRAMP; 1038 #endif 1039 } 1040 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1041 if (osap && !error) { 1042 vec.sv_handler = osap->sa_handler; 1043 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1044 vec.sv_flags = osap->sa_flags; 1045 vec.sv_flags &= ~SA_NOCLDWAIT; 1046 vec.sv_flags ^= SA_RESTART; 1047 #ifdef COMPAT_SUNOS 1048 vec.sv_flags &= ~SA_NOCLDSTOP; 1049 #endif 1050 error = copyout(&vec, uap->osv, sizeof(vec)); 1051 } 1052 return (error); 1053 } 1054 1055 #ifndef _SYS_SYSPROTO_H_ 1056 struct osigblock_args { 1057 int mask; 1058 }; 1059 #endif 1060 /* 1061 * MPSAFE 1062 */ 1063 int 1064 osigblock(td, uap) 1065 register struct thread *td; 1066 struct osigblock_args *uap; 1067 { 1068 struct proc *p = td->td_proc; 1069 sigset_t set; 1070 1071 OSIG2SIG(uap->mask, set); 1072 SIG_CANTMASK(set); 1073 PROC_LOCK(p); 1074 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1075 SIGSETOR(td->td_sigmask, set); 1076 PROC_UNLOCK(p); 1077 return (0); 1078 } 1079 1080 #ifndef _SYS_SYSPROTO_H_ 1081 struct osigsetmask_args { 1082 int mask; 1083 }; 1084 #endif 1085 /* 1086 * MPSAFE 1087 */ 1088 int 1089 osigsetmask(td, uap) 1090 struct thread *td; 1091 struct osigsetmask_args *uap; 1092 { 1093 struct proc *p = td->td_proc; 1094 sigset_t set; 1095 1096 OSIG2SIG(uap->mask, set); 1097 SIG_CANTMASK(set); 1098 PROC_LOCK(p); 1099 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1100 SIGSETLO(td->td_sigmask, set); 1101 signotify(td); 1102 PROC_UNLOCK(p); 1103 return (0); 1104 } 1105 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1106 1107 /* 1108 * Suspend process until signal, providing mask to be set 1109 * in the meantime. Note nonstandard calling convention: 1110 * libc stub passes mask, not pointer, to save a copyin. 1111 ***** XXXKSE this doesn't make sense under KSE. 1112 ***** Do we suspend the thread or all threads in the process? 1113 ***** How do we suspend threads running NOW on another processor? 1114 */ 1115 #ifndef _SYS_SYSPROTO_H_ 1116 struct sigsuspend_args { 1117 const sigset_t *sigmask; 1118 }; 1119 #endif 1120 /* 1121 * MPSAFE 1122 */ 1123 /* ARGSUSED */ 1124 int 1125 sigsuspend(td, uap) 1126 struct thread *td; 1127 struct sigsuspend_args *uap; 1128 { 1129 sigset_t mask; 1130 int error; 1131 1132 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1133 if (error) 1134 return (error); 1135 return (kern_sigsuspend(td, mask)); 1136 } 1137 1138 int 1139 kern_sigsuspend(struct thread *td, sigset_t mask) 1140 { 1141 struct proc *p = td->td_proc; 1142 1143 /* 1144 * When returning from sigsuspend, we want 1145 * the old mask to be restored after the 1146 * signal handler has finished. Thus, we 1147 * save it here and mark the sigacts structure 1148 * to indicate this. 1149 */ 1150 PROC_LOCK(p); 1151 td->td_oldsigmask = td->td_sigmask; 1152 td->td_pflags |= TDP_OLDMASK; 1153 SIG_CANTMASK(mask); 1154 td->td_sigmask = mask; 1155 signotify(td); 1156 while (msleep(p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1157 /* void */; 1158 PROC_UNLOCK(p); 1159 /* always return EINTR rather than ERESTART... */ 1160 return (EINTR); 1161 } 1162 1163 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1164 #ifndef _SYS_SYSPROTO_H_ 1165 struct osigsuspend_args { 1166 osigset_t mask; 1167 }; 1168 #endif 1169 /* 1170 * MPSAFE 1171 */ 1172 /* ARGSUSED */ 1173 int 1174 osigsuspend(td, uap) 1175 struct thread *td; 1176 struct osigsuspend_args *uap; 1177 { 1178 struct proc *p = td->td_proc; 1179 sigset_t mask; 1180 1181 PROC_LOCK(p); 1182 td->td_oldsigmask = td->td_sigmask; 1183 td->td_pflags |= TDP_OLDMASK; 1184 OSIG2SIG(uap->mask, mask); 1185 SIG_CANTMASK(mask); 1186 SIGSETLO(td->td_sigmask, mask); 1187 signotify(td); 1188 while (msleep(p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1189 /* void */; 1190 PROC_UNLOCK(p); 1191 /* always return EINTR rather than ERESTART... */ 1192 return (EINTR); 1193 } 1194 #endif /* COMPAT_43 */ 1195 1196 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1197 #ifndef _SYS_SYSPROTO_H_ 1198 struct osigstack_args { 1199 struct sigstack *nss; 1200 struct sigstack *oss; 1201 }; 1202 #endif 1203 /* 1204 * MPSAFE 1205 */ 1206 /* ARGSUSED */ 1207 int 1208 osigstack(td, uap) 1209 struct thread *td; 1210 register struct osigstack_args *uap; 1211 { 1212 struct sigstack nss, oss; 1213 int error = 0; 1214 1215 if (uap->nss != NULL) { 1216 error = copyin(uap->nss, &nss, sizeof(nss)); 1217 if (error) 1218 return (error); 1219 } 1220 oss.ss_sp = td->td_sigstk.ss_sp; 1221 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1222 if (uap->nss != NULL) { 1223 td->td_sigstk.ss_sp = nss.ss_sp; 1224 td->td_sigstk.ss_size = 0; 1225 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1226 td->td_pflags |= TDP_ALTSTACK; 1227 } 1228 if (uap->oss != NULL) 1229 error = copyout(&oss, uap->oss, sizeof(oss)); 1230 1231 return (error); 1232 } 1233 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1234 1235 #ifndef _SYS_SYSPROTO_H_ 1236 struct sigaltstack_args { 1237 stack_t *ss; 1238 stack_t *oss; 1239 }; 1240 #endif 1241 /* 1242 * MPSAFE 1243 */ 1244 /* ARGSUSED */ 1245 int 1246 sigaltstack(td, uap) 1247 struct thread *td; 1248 register struct sigaltstack_args *uap; 1249 { 1250 stack_t ss, oss; 1251 int error; 1252 1253 if (uap->ss != NULL) { 1254 error = copyin(uap->ss, &ss, sizeof(ss)); 1255 if (error) 1256 return (error); 1257 } 1258 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1259 (uap->oss != NULL) ? &oss : NULL); 1260 if (error) 1261 return (error); 1262 if (uap->oss != NULL) 1263 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1264 return (error); 1265 } 1266 1267 int 1268 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1269 { 1270 struct proc *p = td->td_proc; 1271 int oonstack; 1272 1273 oonstack = sigonstack(cpu_getstack(td)); 1274 1275 if (oss != NULL) { 1276 *oss = td->td_sigstk; 1277 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1278 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1279 } 1280 1281 if (ss != NULL) { 1282 if (oonstack) 1283 return (EPERM); 1284 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1285 return (EINVAL); 1286 if (!(ss->ss_flags & SS_DISABLE)) { 1287 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1288 return (ENOMEM); 1289 } 1290 td->td_sigstk = *ss; 1291 td->td_pflags |= TDP_ALTSTACK; 1292 } else { 1293 td->td_pflags &= ~TDP_ALTSTACK; 1294 } 1295 } 1296 return (0); 1297 } 1298 1299 /* 1300 * Common code for kill process group/broadcast kill. 1301 * cp is calling process. 1302 */ 1303 static int 1304 killpg1(td, sig, pgid, all) 1305 register struct thread *td; 1306 int sig, pgid, all; 1307 { 1308 register struct proc *p; 1309 struct pgrp *pgrp; 1310 int nfound = 0; 1311 1312 if (all) { 1313 /* 1314 * broadcast 1315 */ 1316 sx_slock(&allproc_lock); 1317 LIST_FOREACH(p, &allproc, p_list) { 1318 PROC_LOCK(p); 1319 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1320 p == td->td_proc) { 1321 PROC_UNLOCK(p); 1322 continue; 1323 } 1324 if (p_cansignal(td, p, sig) == 0) { 1325 nfound++; 1326 if (sig) 1327 psignal(p, sig); 1328 } 1329 PROC_UNLOCK(p); 1330 } 1331 sx_sunlock(&allproc_lock); 1332 } else { 1333 sx_slock(&proctree_lock); 1334 if (pgid == 0) { 1335 /* 1336 * zero pgid means send to my process group. 1337 */ 1338 pgrp = td->td_proc->p_pgrp; 1339 PGRP_LOCK(pgrp); 1340 } else { 1341 pgrp = pgfind(pgid); 1342 if (pgrp == NULL) { 1343 sx_sunlock(&proctree_lock); 1344 return (ESRCH); 1345 } 1346 } 1347 sx_sunlock(&proctree_lock); 1348 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1349 PROC_LOCK(p); 1350 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1351 PROC_UNLOCK(p); 1352 continue; 1353 } 1354 if (p->p_state == PRS_ZOMBIE) { 1355 PROC_UNLOCK(p); 1356 continue; 1357 } 1358 if (p_cansignal(td, p, sig) == 0) { 1359 nfound++; 1360 if (sig) 1361 psignal(p, sig); 1362 } 1363 PROC_UNLOCK(p); 1364 } 1365 PGRP_UNLOCK(pgrp); 1366 } 1367 return (nfound ? 0 : ESRCH); 1368 } 1369 1370 #ifndef _SYS_SYSPROTO_H_ 1371 struct kill_args { 1372 int pid; 1373 int signum; 1374 }; 1375 #endif 1376 /* 1377 * MPSAFE 1378 */ 1379 /* ARGSUSED */ 1380 int 1381 kill(td, uap) 1382 register struct thread *td; 1383 register struct kill_args *uap; 1384 { 1385 register struct proc *p; 1386 int error; 1387 1388 if ((u_int)uap->signum > _SIG_MAXSIG) 1389 return (EINVAL); 1390 1391 if (uap->pid > 0) { 1392 /* kill single process */ 1393 if ((p = pfind(uap->pid)) == NULL) 1394 return (ESRCH); 1395 error = p_cansignal(td, p, uap->signum); 1396 if (error == 0 && uap->signum) 1397 psignal(p, uap->signum); 1398 PROC_UNLOCK(p); 1399 return (error); 1400 } 1401 switch (uap->pid) { 1402 case -1: /* broadcast signal */ 1403 return (killpg1(td, uap->signum, 0, 1)); 1404 case 0: /* signal own process group */ 1405 return (killpg1(td, uap->signum, 0, 0)); 1406 default: /* negative explicit process group */ 1407 return (killpg1(td, uap->signum, -uap->pid, 0)); 1408 } 1409 /* NOTREACHED */ 1410 } 1411 1412 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1413 #ifndef _SYS_SYSPROTO_H_ 1414 struct okillpg_args { 1415 int pgid; 1416 int signum; 1417 }; 1418 #endif 1419 /* 1420 * MPSAFE 1421 */ 1422 /* ARGSUSED */ 1423 int 1424 okillpg(td, uap) 1425 struct thread *td; 1426 register struct okillpg_args *uap; 1427 { 1428 1429 if ((u_int)uap->signum > _SIG_MAXSIG) 1430 return (EINVAL); 1431 return (killpg1(td, uap->signum, uap->pgid, 0)); 1432 } 1433 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1434 1435 /* 1436 * Send a signal to a process group. 1437 */ 1438 void 1439 gsignal(pgid, sig) 1440 int pgid, sig; 1441 { 1442 struct pgrp *pgrp; 1443 1444 if (pgid != 0) { 1445 sx_slock(&proctree_lock); 1446 pgrp = pgfind(pgid); 1447 sx_sunlock(&proctree_lock); 1448 if (pgrp != NULL) { 1449 pgsignal(pgrp, sig, 0); 1450 PGRP_UNLOCK(pgrp); 1451 } 1452 } 1453 } 1454 1455 /* 1456 * Send a signal to a process group. If checktty is 1, 1457 * limit to members which have a controlling terminal. 1458 */ 1459 void 1460 pgsignal(pgrp, sig, checkctty) 1461 struct pgrp *pgrp; 1462 int sig, checkctty; 1463 { 1464 register struct proc *p; 1465 1466 if (pgrp) { 1467 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1468 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1469 PROC_LOCK(p); 1470 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1471 psignal(p, sig); 1472 PROC_UNLOCK(p); 1473 } 1474 } 1475 } 1476 1477 /* 1478 * Send a signal caused by a trap to the current thread. 1479 * If it will be caught immediately, deliver it with correct code. 1480 * Otherwise, post it normally. 1481 * 1482 * MPSAFE 1483 */ 1484 void 1485 trapsignal(struct thread *td, int sig, u_long code) 1486 { 1487 struct sigacts *ps; 1488 struct proc *p; 1489 siginfo_t siginfo; 1490 int error; 1491 1492 p = td->td_proc; 1493 if (td->td_flags & TDF_SA) { 1494 if (td->td_mailbox == NULL) 1495 thread_user_enter(p, td); 1496 PROC_LOCK(p); 1497 if (td->td_mailbox) { 1498 SIGDELSET(td->td_sigmask, sig); 1499 mtx_lock_spin(&sched_lock); 1500 /* 1501 * Force scheduling an upcall, so UTS has chance to 1502 * process the signal before thread runs again in 1503 * userland. 1504 */ 1505 if (td->td_upcall) 1506 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1507 mtx_unlock_spin(&sched_lock); 1508 } else { 1509 /* UTS caused a sync signal */ 1510 p->p_code = code; /* XXX for core dump/debugger */ 1511 p->p_sig = sig; /* XXX to verify code */ 1512 sigexit(td, sig); 1513 } 1514 } else { 1515 PROC_LOCK(p); 1516 } 1517 ps = p->p_sigacts; 1518 mtx_lock(&ps->ps_mtx); 1519 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1520 !SIGISMEMBER(td->td_sigmask, sig)) { 1521 p->p_stats->p_ru.ru_nsignals++; 1522 #ifdef KTRACE 1523 if (KTRPOINT(curthread, KTR_PSIG)) 1524 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1525 &td->td_sigmask, code); 1526 #endif 1527 if (!(td->td_flags & TDF_SA)) 1528 (*p->p_sysent->sv_sendsig)( 1529 ps->ps_sigact[_SIG_IDX(sig)], sig, 1530 &td->td_sigmask, code); 1531 else { 1532 cpu_thread_siginfo(sig, code, &siginfo); 1533 mtx_unlock(&ps->ps_mtx); 1534 PROC_UNLOCK(p); 1535 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1536 sizeof(siginfo)); 1537 PROC_LOCK(p); 1538 /* UTS memory corrupted */ 1539 if (error) 1540 sigexit(td, SIGILL); 1541 SIGADDSET(td->td_sigmask, sig); 1542 mtx_lock(&ps->ps_mtx); 1543 } 1544 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1545 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1546 SIGADDSET(td->td_sigmask, sig); 1547 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1548 /* 1549 * See kern_sigaction() for origin of this code. 1550 */ 1551 SIGDELSET(ps->ps_sigcatch, sig); 1552 if (sig != SIGCONT && 1553 sigprop(sig) & SA_IGNORE) 1554 SIGADDSET(ps->ps_sigignore, sig); 1555 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1556 } 1557 mtx_unlock(&ps->ps_mtx); 1558 } else { 1559 mtx_unlock(&ps->ps_mtx); 1560 p->p_code = code; /* XXX for core dump/debugger */ 1561 p->p_sig = sig; /* XXX to verify code */ 1562 tdsignal(td, sig, SIGTARGET_TD); 1563 } 1564 PROC_UNLOCK(p); 1565 } 1566 1567 static struct thread * 1568 sigtd(struct proc *p, int sig, int prop) 1569 { 1570 struct thread *td, *signal_td; 1571 1572 PROC_LOCK_ASSERT(p, MA_OWNED); 1573 1574 /* 1575 * First find a thread in sigwait state and signal belongs to 1576 * its wait set. POSIX's arguments is that speed of delivering signal 1577 * to sigwait thread is faster than delivering signal to user stack. 1578 * If we can not find sigwait thread, then find the first thread in 1579 * the proc that doesn't have this signal masked, an exception is 1580 * if current thread is sending signal to its process, and it does not 1581 * mask the signal, it should get the signal, this is another fast 1582 * way to deliver signal. 1583 */ 1584 signal_td = NULL; 1585 mtx_lock_spin(&sched_lock); 1586 FOREACH_THREAD_IN_PROC(p, td) { 1587 if (td->td_waitset != NULL && 1588 SIGISMEMBER(*(td->td_waitset), sig)) { 1589 mtx_unlock_spin(&sched_lock); 1590 return (td); 1591 } 1592 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1593 if (td == curthread) 1594 signal_td = curthread; 1595 else if (signal_td == NULL) 1596 signal_td = td; 1597 } 1598 } 1599 if (signal_td == NULL) 1600 signal_td = FIRST_THREAD_IN_PROC(p); 1601 mtx_unlock_spin(&sched_lock); 1602 return (signal_td); 1603 } 1604 1605 /* 1606 * Send the signal to the process. If the signal has an action, the action 1607 * is usually performed by the target process rather than the caller; we add 1608 * the signal to the set of pending signals for the process. 1609 * 1610 * Exceptions: 1611 * o When a stop signal is sent to a sleeping process that takes the 1612 * default action, the process is stopped without awakening it. 1613 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1614 * regardless of the signal action (eg, blocked or ignored). 1615 * 1616 * Other ignored signals are discarded immediately. 1617 * 1618 * MPSAFE 1619 */ 1620 void 1621 psignal(struct proc *p, int sig) 1622 { 1623 struct thread *td; 1624 int prop; 1625 1626 if (!_SIG_VALID(sig)) 1627 panic("psignal(): invalid signal"); 1628 1629 PROC_LOCK_ASSERT(p, MA_OWNED); 1630 prop = sigprop(sig); 1631 1632 /* 1633 * Find a thread to deliver the signal to. 1634 */ 1635 td = sigtd(p, sig, prop); 1636 1637 tdsignal(td, sig, SIGTARGET_P); 1638 } 1639 1640 /* 1641 * MPSAFE 1642 */ 1643 void 1644 tdsignal(struct thread *td, int sig, sigtarget_t target) 1645 { 1646 sigset_t saved; 1647 struct proc *p = td->td_proc; 1648 1649 if (p->p_flag & P_SA) 1650 saved = p->p_siglist; 1651 do_tdsignal(td, sig, target); 1652 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1653 if (SIGSETEQ(saved, p->p_siglist)) 1654 return; 1655 else { 1656 /* pending set changed */ 1657 p->p_flag |= P_SIGEVENT; 1658 wakeup(&p->p_siglist); 1659 } 1660 } 1661 } 1662 1663 static void 1664 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1665 { 1666 struct proc *p; 1667 register sig_t action; 1668 sigset_t *siglist; 1669 struct thread *td0; 1670 register int prop; 1671 struct sigacts *ps; 1672 1673 if (!_SIG_VALID(sig)) 1674 panic("do_tdsignal(): invalid signal"); 1675 1676 p = td->td_proc; 1677 ps = p->p_sigacts; 1678 1679 PROC_LOCK_ASSERT(p, MA_OWNED); 1680 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1681 1682 prop = sigprop(sig); 1683 1684 /* 1685 * If the signal is blocked and not destined for this thread, then 1686 * assign it to the process so that we can find it later in the first 1687 * thread that unblocks it. Otherwise, assign it to this thread now. 1688 */ 1689 if (target == SIGTARGET_TD) { 1690 siglist = &td->td_siglist; 1691 } else { 1692 if (!SIGISMEMBER(td->td_sigmask, sig)) 1693 siglist = &td->td_siglist; 1694 else if (td->td_waitset != NULL && 1695 SIGISMEMBER(*(td->td_waitset), sig)) 1696 siglist = &td->td_siglist; 1697 else 1698 siglist = &p->p_siglist; 1699 } 1700 1701 /* 1702 * If proc is traced, always give parent a chance; 1703 * if signal event is tracked by procfs, give *that* 1704 * a chance, as well. 1705 */ 1706 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1707 action = SIG_DFL; 1708 } else { 1709 /* 1710 * If the signal is being ignored, 1711 * then we forget about it immediately. 1712 * (Note: we don't set SIGCONT in ps_sigignore, 1713 * and if it is set to SIG_IGN, 1714 * action will be SIG_DFL here.) 1715 */ 1716 mtx_lock(&ps->ps_mtx); 1717 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1718 (p->p_flag & P_WEXIT)) { 1719 mtx_unlock(&ps->ps_mtx); 1720 return; 1721 } 1722 if (((td->td_waitset == NULL) && 1723 SIGISMEMBER(td->td_sigmask, sig)) || 1724 ((td->td_waitset != NULL) && 1725 SIGISMEMBER(td->td_sigmask, sig) && 1726 !SIGISMEMBER(*(td->td_waitset), sig))) 1727 action = SIG_HOLD; 1728 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1729 action = SIG_CATCH; 1730 else 1731 action = SIG_DFL; 1732 mtx_unlock(&ps->ps_mtx); 1733 } 1734 1735 if (prop & SA_CONT) { 1736 SIG_STOPSIGMASK(p->p_siglist); 1737 /* 1738 * XXX Should investigate leaving STOP and CONT sigs only in 1739 * the proc's siglist. 1740 */ 1741 mtx_lock_spin(&sched_lock); 1742 FOREACH_THREAD_IN_PROC(p, td0) 1743 SIG_STOPSIGMASK(td0->td_siglist); 1744 mtx_unlock_spin(&sched_lock); 1745 } 1746 1747 if (prop & SA_STOP) { 1748 /* 1749 * If sending a tty stop signal to a member of an orphaned 1750 * process group, discard the signal here if the action 1751 * is default; don't stop the process below if sleeping, 1752 * and don't clear any pending SIGCONT. 1753 */ 1754 if ((prop & SA_TTYSTOP) && 1755 (p->p_pgrp->pg_jobc == 0) && 1756 (action == SIG_DFL)) 1757 return; 1758 SIG_CONTSIGMASK(p->p_siglist); 1759 mtx_lock_spin(&sched_lock); 1760 FOREACH_THREAD_IN_PROC(p, td0) 1761 SIG_CONTSIGMASK(td0->td_siglist); 1762 mtx_unlock_spin(&sched_lock); 1763 p->p_flag &= ~P_CONTINUED; 1764 } 1765 1766 SIGADDSET(*siglist, sig); 1767 signotify(td); /* uses schedlock */ 1768 if (siglist == &td->td_siglist && (td->td_waitset != NULL) && 1769 action != SIG_HOLD) { 1770 td->td_waitset = NULL; 1771 } 1772 1773 /* 1774 * Defer further processing for signals which are held, 1775 * except that stopped processes must be continued by SIGCONT. 1776 */ 1777 if (action == SIG_HOLD && 1778 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1779 return; 1780 /* 1781 * Some signals have a process-wide effect and a per-thread 1782 * component. Most processing occurs when the process next 1783 * tries to cross the user boundary, however there are some 1784 * times when processing needs to be done immediatly, such as 1785 * waking up threads so that they can cross the user boundary. 1786 * We try do the per-process part here. 1787 */ 1788 if (P_SHOULDSTOP(p)) { 1789 /* 1790 * The process is in stopped mode. All the threads should be 1791 * either winding down or already on the suspended queue. 1792 */ 1793 if (p->p_flag & P_TRACED) { 1794 /* 1795 * The traced process is already stopped, 1796 * so no further action is necessary. 1797 * No signal can restart us. 1798 */ 1799 goto out; 1800 } 1801 1802 if (sig == SIGKILL) { 1803 /* 1804 * SIGKILL sets process running. 1805 * It will die elsewhere. 1806 * All threads must be restarted. 1807 */ 1808 p->p_flag &= ~P_STOPPED; 1809 goto runfast; 1810 } 1811 1812 if (prop & SA_CONT) { 1813 /* 1814 * If SIGCONT is default (or ignored), we continue the 1815 * process but don't leave the signal in siglist as 1816 * it has no further action. If SIGCONT is held, we 1817 * continue the process and leave the signal in 1818 * siglist. If the process catches SIGCONT, let it 1819 * handle the signal itself. If it isn't waiting on 1820 * an event, it goes back to run state. 1821 * Otherwise, process goes back to sleep state. 1822 */ 1823 p->p_flag &= ~P_STOPPED_SIG; 1824 p->p_flag |= P_CONTINUED; 1825 if (action == SIG_DFL) { 1826 SIGDELSET(*siglist, sig); 1827 } else if (action == SIG_CATCH) { 1828 /* 1829 * The process wants to catch it so it needs 1830 * to run at least one thread, but which one? 1831 * It would seem that the answer would be to 1832 * run an upcall in the next KSE to run, and 1833 * deliver the signal that way. In a NON KSE 1834 * process, we need to make sure that the 1835 * single thread is runnable asap. 1836 * XXXKSE for now however, make them all run. 1837 */ 1838 goto runfast; 1839 } 1840 /* 1841 * The signal is not ignored or caught. 1842 */ 1843 mtx_lock_spin(&sched_lock); 1844 thread_unsuspend(p); 1845 mtx_unlock_spin(&sched_lock); 1846 goto out; 1847 } 1848 1849 if (prop & SA_STOP) { 1850 /* 1851 * Already stopped, don't need to stop again 1852 * (If we did the shell could get confused). 1853 * Just make sure the signal STOP bit set. 1854 */ 1855 p->p_flag |= P_STOPPED_SIG; 1856 SIGDELSET(*siglist, sig); 1857 goto out; 1858 } 1859 1860 /* 1861 * All other kinds of signals: 1862 * If a thread is sleeping interruptibly, simulate a 1863 * wakeup so that when it is continued it will be made 1864 * runnable and can look at the signal. However, don't make 1865 * the PROCESS runnable, leave it stopped. 1866 * It may run a bit until it hits a thread_suspend_check(). 1867 */ 1868 mtx_lock_spin(&sched_lock); 1869 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) { 1870 if (td->td_flags & TDF_CVWAITQ) 1871 cv_abort(td); 1872 else 1873 abortsleep(td); 1874 } 1875 mtx_unlock_spin(&sched_lock); 1876 goto out; 1877 /* 1878 * XXXKSE What about threads that are waiting on mutexes? 1879 * Shouldn't they abort too? 1880 * No, hopefully mutexes are short lived.. They'll 1881 * eventually hit thread_suspend_check(). 1882 */ 1883 } else if (p->p_state == PRS_NORMAL) { 1884 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || 1885 !(prop & SA_STOP)) { 1886 mtx_lock_spin(&sched_lock); 1887 tdsigwakeup(td, sig, action); 1888 mtx_unlock_spin(&sched_lock); 1889 goto out; 1890 } 1891 if (prop & SA_STOP) { 1892 if (p->p_flag & P_PPWAIT) 1893 goto out; 1894 p->p_flag |= P_STOPPED_SIG; 1895 p->p_xstat = sig; 1896 mtx_lock_spin(&sched_lock); 1897 FOREACH_THREAD_IN_PROC(p, td0) { 1898 if (TD_IS_SLEEPING(td0) && 1899 (td0->td_flags & TDF_SINTR) && 1900 !TD_IS_SUSPENDED(td0)) { 1901 thread_suspend_one(td0); 1902 } else if (td != td0) { 1903 td0->td_flags |= TDF_ASTPENDING; 1904 } 1905 } 1906 thread_stopped(p); 1907 if (p->p_numthreads == p->p_suspcount) { 1908 SIGDELSET(p->p_siglist, p->p_xstat); 1909 FOREACH_THREAD_IN_PROC(p, td0) 1910 SIGDELSET(td0->td_siglist, p->p_xstat); 1911 } 1912 mtx_unlock_spin(&sched_lock); 1913 goto out; 1914 } 1915 else 1916 goto runfast; 1917 /* NOTREACHED */ 1918 } else { 1919 /* Not in "NORMAL" state. discard the signal. */ 1920 SIGDELSET(*siglist, sig); 1921 goto out; 1922 } 1923 1924 /* 1925 * The process is not stopped so we need to apply the signal to all the 1926 * running threads. 1927 */ 1928 1929 runfast: 1930 mtx_lock_spin(&sched_lock); 1931 tdsigwakeup(td, sig, action); 1932 thread_unsuspend(p); 1933 mtx_unlock_spin(&sched_lock); 1934 out: 1935 /* If we jump here, sched_lock should not be owned. */ 1936 mtx_assert(&sched_lock, MA_NOTOWNED); 1937 } 1938 1939 /* 1940 * The force of a signal has been directed against a single 1941 * thread. We need to see what we can do about knocking it 1942 * out of any sleep it may be in etc. 1943 */ 1944 static void 1945 tdsigwakeup(struct thread *td, int sig, sig_t action) 1946 { 1947 struct proc *p = td->td_proc; 1948 register int prop; 1949 1950 PROC_LOCK_ASSERT(p, MA_OWNED); 1951 mtx_assert(&sched_lock, MA_OWNED); 1952 prop = sigprop(sig); 1953 /* 1954 * Bring the priority of a thread up if we want it to get 1955 * killed in this lifetime. 1956 */ 1957 if ((action == SIG_DFL) && (prop & SA_KILL)) { 1958 if (td->td_priority > PUSER) { 1959 td->td_priority = PUSER; 1960 } 1961 } 1962 if (TD_IS_SLEEPING(td)) { 1963 /* 1964 * If thread is sleeping uninterruptibly 1965 * we can't interrupt the sleep... the signal will 1966 * be noticed when the process returns through 1967 * trap() or syscall(). 1968 */ 1969 if ((td->td_flags & TDF_SINTR) == 0) { 1970 return; 1971 } 1972 /* 1973 * Process is sleeping and traced. Make it runnable 1974 * so it can discover the signal in issignal() and stop 1975 * for its parent. 1976 */ 1977 if (p->p_flag & P_TRACED) { 1978 p->p_flag &= ~P_STOPPED_TRACE; 1979 } else { 1980 1981 /* 1982 * If SIGCONT is default (or ignored) and process is 1983 * asleep, we are finished; the process should not 1984 * be awakened. 1985 */ 1986 if ((prop & SA_CONT) && action == SIG_DFL) { 1987 SIGDELSET(p->p_siglist, sig); 1988 /* 1989 * It may be on either list in this state. 1990 * Remove from both for now. 1991 */ 1992 SIGDELSET(td->td_siglist, sig); 1993 return; 1994 } 1995 1996 /* 1997 * Raise priority to at least PUSER. 1998 */ 1999 if (td->td_priority > PUSER) { 2000 td->td_priority = PUSER; 2001 } 2002 } 2003 if (td->td_flags & TDF_CVWAITQ) 2004 cv_abort(td); 2005 else 2006 abortsleep(td); 2007 } 2008 #ifdef SMP 2009 else { 2010 /* 2011 * Other states do nothing with the signal immediatly, 2012 * other than kicking ourselves if we are running. 2013 * It will either never be noticed, or noticed very soon. 2014 */ 2015 if (TD_IS_RUNNING(td) && td != curthread) { 2016 forward_signal(td); 2017 } 2018 } 2019 #endif 2020 } 2021 2022 void 2023 ptracestop(struct thread *td, int sig) 2024 { 2025 struct proc *p = td->td_proc; 2026 2027 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2028 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2029 2030 p->p_xstat = sig; 2031 PROC_LOCK(p->p_pptr); 2032 psignal(p->p_pptr, SIGCHLD); 2033 PROC_UNLOCK(p->p_pptr); 2034 mtx_lock_spin(&sched_lock); 2035 stop(p); /* uses schedlock too eventually */ 2036 thread_suspend_one(td); 2037 PROC_UNLOCK(p); 2038 DROP_GIANT(); 2039 p->p_stats->p_ru.ru_nivcsw++; 2040 mi_switch(); 2041 mtx_unlock_spin(&sched_lock); 2042 PICKUP_GIANT(); 2043 } 2044 2045 /* 2046 * If the current process has received a signal (should be caught or cause 2047 * termination, should interrupt current syscall), return the signal number. 2048 * Stop signals with default action are processed immediately, then cleared; 2049 * they aren't returned. This is checked after each entry to the system for 2050 * a syscall or trap (though this can usually be done without calling issignal 2051 * by checking the pending signal masks in cursig.) The normal call 2052 * sequence is 2053 * 2054 * while (sig = cursig(curthread)) 2055 * postsig(sig); 2056 */ 2057 static int 2058 issignal(td) 2059 struct thread *td; 2060 { 2061 struct proc *p; 2062 struct sigacts *ps; 2063 sigset_t sigpending; 2064 int sig, prop; 2065 struct thread *td0; 2066 2067 p = td->td_proc; 2068 ps = p->p_sigacts; 2069 mtx_assert(&ps->ps_mtx, MA_OWNED); 2070 PROC_LOCK_ASSERT(p, MA_OWNED); 2071 for (;;) { 2072 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2073 2074 sigpending = td->td_siglist; 2075 SIGSETNAND(sigpending, td->td_sigmask); 2076 2077 if (p->p_flag & P_PPWAIT) 2078 SIG_STOPSIGMASK(sigpending); 2079 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2080 return (0); 2081 sig = sig_ffs(&sigpending); 2082 2083 if (p->p_stops & S_SIG) { 2084 mtx_unlock(&ps->ps_mtx); 2085 stopevent(p, S_SIG, sig); 2086 mtx_lock(&ps->ps_mtx); 2087 } 2088 2089 /* 2090 * We should see pending but ignored signals 2091 * only if P_TRACED was on when they were posted. 2092 */ 2093 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2094 SIGDELSET(td->td_siglist, sig); 2095 continue; 2096 } 2097 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2098 /* 2099 * If traced, always stop. 2100 */ 2101 mtx_unlock(&ps->ps_mtx); 2102 ptracestop(td, sig); 2103 PROC_LOCK(p); 2104 mtx_lock(&ps->ps_mtx); 2105 2106 /* 2107 * If parent wants us to take the signal, 2108 * then it will leave it in p->p_xstat; 2109 * otherwise we just look for signals again. 2110 */ 2111 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2112 sig = p->p_xstat; 2113 if (sig == 0) 2114 continue; 2115 2116 /* 2117 * If the traced bit got turned off, go back up 2118 * to the top to rescan signals. This ensures 2119 * that p_sig* and p_sigact are consistent. 2120 */ 2121 if ((p->p_flag & P_TRACED) == 0) 2122 continue; 2123 2124 /* 2125 * Put the new signal into td_siglist. If the 2126 * signal is being masked, look for other signals. 2127 */ 2128 SIGADDSET(td->td_siglist, sig); 2129 if (SIGISMEMBER(td->td_sigmask, sig)) 2130 continue; 2131 signotify(td); 2132 } 2133 2134 prop = sigprop(sig); 2135 2136 /* 2137 * Decide whether the signal should be returned. 2138 * Return the signal's number, or fall through 2139 * to clear it from the pending mask. 2140 */ 2141 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2142 2143 case (intptr_t)SIG_DFL: 2144 /* 2145 * Don't take default actions on system processes. 2146 */ 2147 if (p->p_pid <= 1) { 2148 #ifdef DIAGNOSTIC 2149 /* 2150 * Are you sure you want to ignore SIGSEGV 2151 * in init? XXX 2152 */ 2153 printf("Process (pid %lu) got signal %d\n", 2154 (u_long)p->p_pid, sig); 2155 #endif 2156 break; /* == ignore */ 2157 } 2158 /* 2159 * If there is a pending stop signal to process 2160 * with default action, stop here, 2161 * then clear the signal. However, 2162 * if process is member of an orphaned 2163 * process group, ignore tty stop signals. 2164 */ 2165 if (prop & SA_STOP) { 2166 if (p->p_flag & P_TRACED || 2167 (p->p_pgrp->pg_jobc == 0 && 2168 prop & SA_TTYSTOP)) 2169 break; /* == ignore */ 2170 mtx_unlock(&ps->ps_mtx); 2171 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2172 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2173 p->p_flag |= P_STOPPED_SIG; 2174 p->p_xstat = sig; 2175 mtx_lock_spin(&sched_lock); 2176 FOREACH_THREAD_IN_PROC(p, td0) { 2177 if (TD_IS_SLEEPING(td0) && 2178 (td0->td_flags & TDF_SINTR) && 2179 !TD_IS_SUSPENDED(td0)) { 2180 thread_suspend_one(td0); 2181 } else if (td != td0) { 2182 td0->td_flags |= TDF_ASTPENDING; 2183 } 2184 } 2185 thread_stopped(p); 2186 thread_suspend_one(td); 2187 PROC_UNLOCK(p); 2188 DROP_GIANT(); 2189 p->p_stats->p_ru.ru_nivcsw++; 2190 mi_switch(); 2191 mtx_unlock_spin(&sched_lock); 2192 PICKUP_GIANT(); 2193 PROC_LOCK(p); 2194 mtx_lock(&ps->ps_mtx); 2195 break; 2196 } else if (prop & SA_IGNORE) { 2197 /* 2198 * Except for SIGCONT, shouldn't get here. 2199 * Default action is to ignore; drop it. 2200 */ 2201 break; /* == ignore */ 2202 } else 2203 return (sig); 2204 /*NOTREACHED*/ 2205 2206 case (intptr_t)SIG_IGN: 2207 /* 2208 * Masking above should prevent us ever trying 2209 * to take action on an ignored signal other 2210 * than SIGCONT, unless process is traced. 2211 */ 2212 if ((prop & SA_CONT) == 0 && 2213 (p->p_flag & P_TRACED) == 0) 2214 printf("issignal\n"); 2215 break; /* == ignore */ 2216 2217 default: 2218 /* 2219 * This signal has an action, let 2220 * postsig() process it. 2221 */ 2222 return (sig); 2223 } 2224 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2225 } 2226 /* NOTREACHED */ 2227 } 2228 2229 /* 2230 * Put the argument process into the stopped state and notify the parent 2231 * via wakeup. Signals are handled elsewhere. The process must not be 2232 * on the run queue. Must be called with the proc p locked and the scheduler 2233 * lock held. 2234 */ 2235 static void 2236 stop(struct proc *p) 2237 { 2238 2239 PROC_LOCK_ASSERT(p, MA_OWNED); 2240 p->p_flag |= P_STOPPED_SIG; 2241 p->p_flag &= ~P_WAITED; 2242 wakeup(p->p_pptr); 2243 } 2244 2245 /* 2246 * MPSAFE 2247 */ 2248 void 2249 thread_stopped(struct proc *p) 2250 { 2251 struct proc *p1 = curthread->td_proc; 2252 struct sigacts *ps; 2253 int n; 2254 2255 PROC_LOCK_ASSERT(p, MA_OWNED); 2256 mtx_assert(&sched_lock, MA_OWNED); 2257 n = p->p_suspcount; 2258 if (p == p1) 2259 n++; 2260 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2261 mtx_unlock_spin(&sched_lock); 2262 stop(p); 2263 PROC_LOCK(p->p_pptr); 2264 ps = p->p_pptr->p_sigacts; 2265 mtx_lock(&ps->ps_mtx); 2266 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2267 mtx_unlock(&ps->ps_mtx); 2268 psignal(p->p_pptr, SIGCHLD); 2269 } else 2270 mtx_unlock(&ps->ps_mtx); 2271 PROC_UNLOCK(p->p_pptr); 2272 mtx_lock_spin(&sched_lock); 2273 } 2274 } 2275 2276 /* 2277 * Take the action for the specified signal 2278 * from the current set of pending signals. 2279 */ 2280 void 2281 postsig(sig) 2282 register int sig; 2283 { 2284 struct thread *td = curthread; 2285 register struct proc *p = td->td_proc; 2286 struct sigacts *ps; 2287 sig_t action; 2288 sigset_t returnmask; 2289 int code; 2290 2291 KASSERT(sig != 0, ("postsig")); 2292 2293 PROC_LOCK_ASSERT(p, MA_OWNED); 2294 ps = p->p_sigacts; 2295 mtx_assert(&ps->ps_mtx, MA_OWNED); 2296 SIGDELSET(td->td_siglist, sig); 2297 action = ps->ps_sigact[_SIG_IDX(sig)]; 2298 #ifdef KTRACE 2299 if (KTRPOINT(td, KTR_PSIG)) 2300 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2301 &td->td_oldsigmask : &td->td_sigmask, 0); 2302 #endif 2303 if (p->p_stops & S_SIG) { 2304 mtx_unlock(&ps->ps_mtx); 2305 stopevent(p, S_SIG, sig); 2306 mtx_lock(&ps->ps_mtx); 2307 } 2308 2309 if (!(td->td_flags & TDF_SA && td->td_mailbox) && 2310 action == SIG_DFL) { 2311 /* 2312 * Default action, where the default is to kill 2313 * the process. (Other cases were ignored above.) 2314 */ 2315 mtx_unlock(&ps->ps_mtx); 2316 sigexit(td, sig); 2317 /* NOTREACHED */ 2318 } else { 2319 if (td->td_flags & TDF_SA && td->td_mailbox) { 2320 if (sig == SIGKILL) { 2321 mtx_unlock(&ps->ps_mtx); 2322 sigexit(td, sig); 2323 } 2324 } 2325 2326 /* 2327 * If we get here, the signal must be caught. 2328 */ 2329 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2330 ("postsig action")); 2331 /* 2332 * Set the new mask value and also defer further 2333 * occurrences of this signal. 2334 * 2335 * Special case: user has done a sigsuspend. Here the 2336 * current mask is not of interest, but rather the 2337 * mask from before the sigsuspend is what we want 2338 * restored after the signal processing is completed. 2339 */ 2340 if (td->td_pflags & TDP_OLDMASK) { 2341 returnmask = td->td_oldsigmask; 2342 td->td_pflags &= ~TDP_OLDMASK; 2343 } else 2344 returnmask = td->td_sigmask; 2345 2346 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2347 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2348 SIGADDSET(td->td_sigmask, sig); 2349 2350 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2351 /* 2352 * See kern_sigaction() for origin of this code. 2353 */ 2354 SIGDELSET(ps->ps_sigcatch, sig); 2355 if (sig != SIGCONT && 2356 sigprop(sig) & SA_IGNORE) 2357 SIGADDSET(ps->ps_sigignore, sig); 2358 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2359 } 2360 p->p_stats->p_ru.ru_nsignals++; 2361 if (p->p_sig != sig) { 2362 code = 0; 2363 } else { 2364 code = p->p_code; 2365 p->p_code = 0; 2366 p->p_sig = 0; 2367 } 2368 if (td->td_flags & TDF_SA && td->td_mailbox) 2369 thread_signal_add(curthread, sig); 2370 else 2371 (*p->p_sysent->sv_sendsig)(action, sig, 2372 &returnmask, code); 2373 } 2374 } 2375 2376 /* 2377 * Kill the current process for stated reason. 2378 */ 2379 void 2380 killproc(p, why) 2381 struct proc *p; 2382 char *why; 2383 { 2384 2385 PROC_LOCK_ASSERT(p, MA_OWNED); 2386 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2387 p, p->p_pid, p->p_comm); 2388 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2389 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2390 psignal(p, SIGKILL); 2391 } 2392 2393 /* 2394 * Force the current process to exit with the specified signal, dumping core 2395 * if appropriate. We bypass the normal tests for masked and caught signals, 2396 * allowing unrecoverable failures to terminate the process without changing 2397 * signal state. Mark the accounting record with the signal termination. 2398 * If dumping core, save the signal number for the debugger. Calls exit and 2399 * does not return. 2400 * 2401 * MPSAFE 2402 */ 2403 void 2404 sigexit(td, sig) 2405 struct thread *td; 2406 int sig; 2407 { 2408 struct proc *p = td->td_proc; 2409 2410 PROC_LOCK_ASSERT(p, MA_OWNED); 2411 p->p_acflag |= AXSIG; 2412 if (sigprop(sig) & SA_CORE) { 2413 p->p_sig = sig; 2414 /* 2415 * Log signals which would cause core dumps 2416 * (Log as LOG_INFO to appease those who don't want 2417 * these messages.) 2418 * XXX : Todo, as well as euid, write out ruid too 2419 */ 2420 PROC_UNLOCK(p); 2421 if (!mtx_owned(&Giant)) 2422 mtx_lock(&Giant); 2423 if (coredump(td) == 0) 2424 sig |= WCOREFLAG; 2425 if (kern_logsigexit) 2426 log(LOG_INFO, 2427 "pid %d (%s), uid %d: exited on signal %d%s\n", 2428 p->p_pid, p->p_comm, 2429 td->td_ucred ? td->td_ucred->cr_uid : -1, 2430 sig &~ WCOREFLAG, 2431 sig & WCOREFLAG ? " (core dumped)" : ""); 2432 } else { 2433 PROC_UNLOCK(p); 2434 if (!mtx_owned(&Giant)) 2435 mtx_lock(&Giant); 2436 } 2437 exit1(td, W_EXITCODE(0, sig)); 2438 /* NOTREACHED */ 2439 } 2440 2441 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2442 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2443 sizeof(corefilename), "process corefile name format string"); 2444 2445 /* 2446 * expand_name(name, uid, pid) 2447 * Expand the name described in corefilename, using name, uid, and pid. 2448 * corefilename is a printf-like string, with three format specifiers: 2449 * %N name of process ("name") 2450 * %P process id (pid) 2451 * %U user id (uid) 2452 * For example, "%N.core" is the default; they can be disabled completely 2453 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2454 * This is controlled by the sysctl variable kern.corefile (see above). 2455 */ 2456 2457 static char * 2458 expand_name(name, uid, pid) 2459 const char *name; 2460 uid_t uid; 2461 pid_t pid; 2462 { 2463 const char *format, *appendstr; 2464 char *temp; 2465 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2466 size_t i, l, n; 2467 2468 format = corefilename; 2469 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2470 if (temp == NULL) 2471 return (NULL); 2472 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2473 switch (format[i]) { 2474 case '%': /* Format character */ 2475 i++; 2476 switch (format[i]) { 2477 case '%': 2478 appendstr = "%"; 2479 break; 2480 case 'N': /* process name */ 2481 appendstr = name; 2482 break; 2483 case 'P': /* process id */ 2484 sprintf(buf, "%u", pid); 2485 appendstr = buf; 2486 break; 2487 case 'U': /* user id */ 2488 sprintf(buf, "%u", uid); 2489 appendstr = buf; 2490 break; 2491 default: 2492 appendstr = ""; 2493 log(LOG_ERR, 2494 "Unknown format character %c in `%s'\n", 2495 format[i], format); 2496 } 2497 l = strlen(appendstr); 2498 if ((n + l) >= MAXPATHLEN) 2499 goto toolong; 2500 memcpy(temp + n, appendstr, l); 2501 n += l; 2502 break; 2503 default: 2504 temp[n++] = format[i]; 2505 } 2506 } 2507 if (format[i] != '\0') 2508 goto toolong; 2509 return (temp); 2510 toolong: 2511 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2512 (long)pid, name, (u_long)uid); 2513 free(temp, M_TEMP); 2514 return (NULL); 2515 } 2516 2517 /* 2518 * Dump a process' core. The main routine does some 2519 * policy checking, and creates the name of the coredump; 2520 * then it passes on a vnode and a size limit to the process-specific 2521 * coredump routine if there is one; if there _is not_ one, it returns 2522 * ENOSYS; otherwise it returns the error from the process-specific routine. 2523 */ 2524 2525 static int 2526 coredump(struct thread *td) 2527 { 2528 struct proc *p = td->td_proc; 2529 register struct vnode *vp; 2530 register struct ucred *cred = td->td_ucred; 2531 struct flock lf; 2532 struct nameidata nd; 2533 struct vattr vattr; 2534 int error, error1, flags, locked; 2535 struct mount *mp; 2536 char *name; /* name of corefile */ 2537 off_t limit; 2538 2539 PROC_LOCK(p); 2540 _STOPEVENT(p, S_CORE, 0); 2541 2542 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2543 PROC_UNLOCK(p); 2544 return (EFAULT); 2545 } 2546 2547 /* 2548 * Note that the bulk of limit checking is done after 2549 * the corefile is created. The exception is if the limit 2550 * for corefiles is 0, in which case we don't bother 2551 * creating the corefile at all. This layout means that 2552 * a corefile is truncated instead of not being created, 2553 * if it is larger than the limit. 2554 */ 2555 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2556 if (limit == 0) { 2557 PROC_UNLOCK(p); 2558 return EFBIG; 2559 } 2560 PROC_UNLOCK(p); 2561 2562 restart: 2563 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2564 if (name == NULL) 2565 return (EINVAL); 2566 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2567 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2568 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2569 free(name, M_TEMP); 2570 if (error) 2571 return (error); 2572 NDFREE(&nd, NDF_ONLY_PNBUF); 2573 vp = nd.ni_vp; 2574 2575 /* Don't dump to non-regular files or files with links. */ 2576 if (vp->v_type != VREG || 2577 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2578 VOP_UNLOCK(vp, 0, td); 2579 error = EFAULT; 2580 goto out2; 2581 } 2582 2583 VOP_UNLOCK(vp, 0, td); 2584 lf.l_whence = SEEK_SET; 2585 lf.l_start = 0; 2586 lf.l_len = 0; 2587 lf.l_type = F_WRLCK; 2588 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2589 2590 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2591 lf.l_type = F_UNLCK; 2592 if (locked) 2593 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2594 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2595 return (error); 2596 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2597 return (error); 2598 goto restart; 2599 } 2600 2601 VATTR_NULL(&vattr); 2602 vattr.va_size = 0; 2603 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2604 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2605 VOP_SETATTR(vp, &vattr, cred, td); 2606 VOP_UNLOCK(vp, 0, td); 2607 PROC_LOCK(p); 2608 p->p_acflag |= ACORE; 2609 PROC_UNLOCK(p); 2610 2611 error = p->p_sysent->sv_coredump ? 2612 p->p_sysent->sv_coredump(td, vp, limit) : 2613 ENOSYS; 2614 2615 if (locked) { 2616 lf.l_type = F_UNLCK; 2617 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2618 } 2619 vn_finished_write(mp); 2620 out2: 2621 error1 = vn_close(vp, FWRITE, cred, td); 2622 if (error == 0) 2623 error = error1; 2624 return (error); 2625 } 2626 2627 /* 2628 * Nonexistent system call-- signal process (may want to handle it). 2629 * Flag error in case process won't see signal immediately (blocked or ignored). 2630 */ 2631 #ifndef _SYS_SYSPROTO_H_ 2632 struct nosys_args { 2633 int dummy; 2634 }; 2635 #endif 2636 /* 2637 * MPSAFE 2638 */ 2639 /* ARGSUSED */ 2640 int 2641 nosys(td, args) 2642 struct thread *td; 2643 struct nosys_args *args; 2644 { 2645 struct proc *p = td->td_proc; 2646 2647 PROC_LOCK(p); 2648 psignal(p, SIGSYS); 2649 PROC_UNLOCK(p); 2650 return (ENOSYS); 2651 } 2652 2653 /* 2654 * Send a SIGIO or SIGURG signal to a process or process group using 2655 * stored credentials rather than those of the current process. 2656 */ 2657 void 2658 pgsigio(sigiop, sig, checkctty) 2659 struct sigio **sigiop; 2660 int sig, checkctty; 2661 { 2662 struct sigio *sigio; 2663 2664 SIGIO_LOCK(); 2665 sigio = *sigiop; 2666 if (sigio == NULL) { 2667 SIGIO_UNLOCK(); 2668 return; 2669 } 2670 if (sigio->sio_pgid > 0) { 2671 PROC_LOCK(sigio->sio_proc); 2672 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2673 psignal(sigio->sio_proc, sig); 2674 PROC_UNLOCK(sigio->sio_proc); 2675 } else if (sigio->sio_pgid < 0) { 2676 struct proc *p; 2677 2678 PGRP_LOCK(sigio->sio_pgrp); 2679 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2680 PROC_LOCK(p); 2681 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2682 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2683 psignal(p, sig); 2684 PROC_UNLOCK(p); 2685 } 2686 PGRP_UNLOCK(sigio->sio_pgrp); 2687 } 2688 SIGIO_UNLOCK(); 2689 } 2690 2691 static int 2692 filt_sigattach(struct knote *kn) 2693 { 2694 struct proc *p = curproc; 2695 2696 kn->kn_ptr.p_proc = p; 2697 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2698 2699 PROC_LOCK(p); 2700 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2701 PROC_UNLOCK(p); 2702 2703 return (0); 2704 } 2705 2706 static void 2707 filt_sigdetach(struct knote *kn) 2708 { 2709 struct proc *p = kn->kn_ptr.p_proc; 2710 2711 PROC_LOCK(p); 2712 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2713 PROC_UNLOCK(p); 2714 } 2715 2716 /* 2717 * signal knotes are shared with proc knotes, so we apply a mask to 2718 * the hint in order to differentiate them from process hints. This 2719 * could be avoided by using a signal-specific knote list, but probably 2720 * isn't worth the trouble. 2721 */ 2722 static int 2723 filt_signal(struct knote *kn, long hint) 2724 { 2725 2726 if (hint & NOTE_SIGNAL) { 2727 hint &= ~NOTE_SIGNAL; 2728 2729 if (kn->kn_id == hint) 2730 kn->kn_data++; 2731 } 2732 return (kn->kn_data != 0); 2733 } 2734 2735 struct sigacts * 2736 sigacts_alloc(void) 2737 { 2738 struct sigacts *ps; 2739 2740 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2741 ps->ps_refcnt = 1; 2742 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2743 return (ps); 2744 } 2745 2746 void 2747 sigacts_free(struct sigacts *ps) 2748 { 2749 2750 mtx_lock(&ps->ps_mtx); 2751 ps->ps_refcnt--; 2752 if (ps->ps_refcnt == 0) { 2753 mtx_destroy(&ps->ps_mtx); 2754 free(ps, M_SUBPROC); 2755 } else 2756 mtx_unlock(&ps->ps_mtx); 2757 } 2758 2759 struct sigacts * 2760 sigacts_hold(struct sigacts *ps) 2761 { 2762 mtx_lock(&ps->ps_mtx); 2763 ps->ps_refcnt++; 2764 mtx_unlock(&ps->ps_mtx); 2765 return (ps); 2766 } 2767 2768 void 2769 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2770 { 2771 2772 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2773 mtx_lock(&src->ps_mtx); 2774 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2775 mtx_unlock(&src->ps_mtx); 2776 } 2777 2778 int 2779 sigacts_shared(struct sigacts *ps) 2780 { 2781 int shared; 2782 2783 mtx_lock(&ps->ps_mtx); 2784 shared = ps->ps_refcnt > 1; 2785 mtx_unlock(&ps->ps_mtx); 2786 return (shared); 2787 } 2788