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