1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/signalvar.h> 46 #include <sys/vnode.h> 47 #include <sys/acct.h> 48 #include <sys/condvar.h> 49 #include <sys/event.h> 50 #include <sys/fcntl.h> 51 #include <sys/kernel.h> 52 #include <sys/kse.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/pioctl.h> 61 #include <sys/resourcevar.h> 62 #include <sys/sleepqueue.h> 63 #include <sys/smp.h> 64 #include <sys/stat.h> 65 #include <sys/sx.h> 66 #include <sys/syscallsubr.h> 67 #include <sys/sysctl.h> 68 #include <sys/sysent.h> 69 #include <sys/syslog.h> 70 #include <sys/sysproto.h> 71 #include <sys/unistd.h> 72 #include <sys/wait.h> 73 74 #include <machine/cpu.h> 75 76 #if defined (__alpha__) && !defined(COMPAT_43) 77 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 78 #endif 79 80 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 81 82 static int coredump(struct thread *); 83 static char *expand_name(const char *, uid_t, pid_t); 84 static int killpg1(struct thread *td, int sig, int pgid, int all); 85 static int issignal(struct thread *p); 86 static int sigprop(int sig); 87 static void stop(struct proc *); 88 static void tdsigwakeup(struct thread *td, int sig, sig_t action); 89 static int filt_sigattach(struct knote *kn); 90 static void filt_sigdetach(struct knote *kn); 91 static int filt_signal(struct knote *kn, long hint); 92 static struct thread *sigtd(struct proc *p, int sig, int prop); 93 static int kern_sigtimedwait(struct thread *td, sigset_t set, 94 siginfo_t *info, struct timespec *timeout); 95 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target); 96 97 struct filterops sig_filtops = 98 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 99 100 static int kern_logsigexit = 1; 101 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 102 &kern_logsigexit, 0, 103 "Log processes quitting on abnormal signals to syslog(3)"); 104 105 /* 106 * Policy -- Can ucred cr1 send SIGIO to process cr2? 107 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 108 * in the right situations. 109 */ 110 #define CANSIGIO(cr1, cr2) \ 111 ((cr1)->cr_uid == 0 || \ 112 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 113 (cr1)->cr_uid == (cr2)->cr_ruid || \ 114 (cr1)->cr_ruid == (cr2)->cr_uid || \ 115 (cr1)->cr_uid == (cr2)->cr_uid) 116 117 int sugid_coredump; 118 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 119 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 120 121 static int do_coredump = 1; 122 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 123 &do_coredump, 0, "Enable/Disable coredumps"); 124 125 /* 126 * Signal properties and actions. 127 * The array below categorizes the signals and their default actions 128 * according to the following properties: 129 */ 130 #define SA_KILL 0x01 /* terminates process by default */ 131 #define SA_CORE 0x02 /* ditto and coredumps */ 132 #define SA_STOP 0x04 /* suspend process */ 133 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 134 #define SA_IGNORE 0x10 /* ignore by default */ 135 #define SA_CONT 0x20 /* continue if suspended */ 136 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 137 #define SA_PROC 0x80 /* deliverable to any thread */ 138 139 static int sigproptbl[NSIG] = { 140 SA_KILL|SA_PROC, /* SIGHUP */ 141 SA_KILL|SA_PROC, /* SIGINT */ 142 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 143 SA_KILL|SA_CORE, /* SIGILL */ 144 SA_KILL|SA_CORE, /* SIGTRAP */ 145 SA_KILL|SA_CORE, /* SIGABRT */ 146 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 147 SA_KILL|SA_CORE, /* SIGFPE */ 148 SA_KILL|SA_PROC, /* SIGKILL */ 149 SA_KILL|SA_CORE, /* SIGBUS */ 150 SA_KILL|SA_CORE, /* SIGSEGV */ 151 SA_KILL|SA_CORE, /* SIGSYS */ 152 SA_KILL|SA_PROC, /* SIGPIPE */ 153 SA_KILL|SA_PROC, /* SIGALRM */ 154 SA_KILL|SA_PROC, /* SIGTERM */ 155 SA_IGNORE|SA_PROC, /* SIGURG */ 156 SA_STOP|SA_PROC, /* SIGSTOP */ 157 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 158 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 159 SA_IGNORE|SA_PROC, /* SIGCHLD */ 160 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 161 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 162 SA_IGNORE|SA_PROC, /* SIGIO */ 163 SA_KILL, /* SIGXCPU */ 164 SA_KILL, /* SIGXFSZ */ 165 SA_KILL|SA_PROC, /* SIGVTALRM */ 166 SA_KILL|SA_PROC, /* SIGPROF */ 167 SA_IGNORE|SA_PROC, /* SIGWINCH */ 168 SA_IGNORE|SA_PROC, /* SIGINFO */ 169 SA_KILL|SA_PROC, /* SIGUSR1 */ 170 SA_KILL|SA_PROC, /* SIGUSR2 */ 171 }; 172 173 /* 174 * Determine signal that should be delivered to process p, the current 175 * process, 0 if none. If there is a pending stop signal with default 176 * action, the process stops in issignal(). 177 * XXXKSE the check for a pending stop is not done under KSE 178 * 179 * MP SAFE. 180 */ 181 int 182 cursig(struct thread *td) 183 { 184 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 185 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 186 mtx_assert(&sched_lock, MA_NOTOWNED); 187 return (SIGPENDING(td) ? issignal(td) : 0); 188 } 189 190 /* 191 * Arrange for ast() to handle unmasked pending signals on return to user 192 * mode. This must be called whenever a signal is added to td_siglist or 193 * unmasked in td_sigmask. 194 */ 195 void 196 signotify(struct thread *td) 197 { 198 struct proc *p; 199 sigset_t set, saved; 200 201 p = td->td_proc; 202 203 PROC_LOCK_ASSERT(p, MA_OWNED); 204 205 /* 206 * If our mask changed we may have to move signal that were 207 * previously masked by all threads to our siglist. 208 */ 209 set = p->p_siglist; 210 if (p->p_flag & P_SA) 211 saved = p->p_siglist; 212 SIGSETNAND(set, td->td_sigmask); 213 SIGSETNAND(p->p_siglist, set); 214 SIGSETOR(td->td_siglist, set); 215 216 if (SIGPENDING(td)) { 217 mtx_lock_spin(&sched_lock); 218 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 219 mtx_unlock_spin(&sched_lock); 220 } 221 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 222 if (!SIGSETEQ(saved, p->p_siglist)) { 223 /* pending set changed */ 224 p->p_flag |= P_SIGEVENT; 225 wakeup(&p->p_siglist); 226 } 227 } 228 } 229 230 int 231 sigonstack(size_t sp) 232 { 233 struct thread *td = curthread; 234 235 return ((td->td_pflags & TDP_ALTSTACK) ? 236 #if defined(COMPAT_43) 237 ((td->td_sigstk.ss_size == 0) ? 238 (td->td_sigstk.ss_flags & SS_ONSTACK) : 239 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 240 #else 241 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 242 #endif 243 : 0); 244 } 245 246 static __inline int 247 sigprop(int sig) 248 { 249 250 if (sig > 0 && sig < NSIG) 251 return (sigproptbl[_SIG_IDX(sig)]); 252 return (0); 253 } 254 255 int 256 sig_ffs(sigset_t *set) 257 { 258 int i; 259 260 for (i = 0; i < _SIG_WORDS; i++) 261 if (set->__bits[i]) 262 return (ffs(set->__bits[i]) + (i * 32)); 263 return (0); 264 } 265 266 /* 267 * kern_sigaction 268 * sigaction 269 * freebsd4_sigaction 270 * osigaction 271 * 272 * MPSAFE 273 */ 274 int 275 kern_sigaction(td, sig, act, oact, flags) 276 struct thread *td; 277 register int sig; 278 struct sigaction *act, *oact; 279 int flags; 280 { 281 struct sigacts *ps; 282 struct thread *td0; 283 struct proc *p = td->td_proc; 284 285 if (!_SIG_VALID(sig)) 286 return (EINVAL); 287 288 PROC_LOCK(p); 289 ps = p->p_sigacts; 290 mtx_lock(&ps->ps_mtx); 291 if (oact) { 292 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 293 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 294 oact->sa_flags = 0; 295 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 296 oact->sa_flags |= SA_ONSTACK; 297 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 298 oact->sa_flags |= SA_RESTART; 299 if (SIGISMEMBER(ps->ps_sigreset, sig)) 300 oact->sa_flags |= SA_RESETHAND; 301 if (SIGISMEMBER(ps->ps_signodefer, sig)) 302 oact->sa_flags |= SA_NODEFER; 303 if (SIGISMEMBER(ps->ps_siginfo, sig)) 304 oact->sa_flags |= SA_SIGINFO; 305 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 306 oact->sa_flags |= SA_NOCLDSTOP; 307 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 308 oact->sa_flags |= SA_NOCLDWAIT; 309 } 310 if (act) { 311 if ((sig == SIGKILL || sig == SIGSTOP) && 312 act->sa_handler != SIG_DFL) { 313 mtx_unlock(&ps->ps_mtx); 314 PROC_UNLOCK(p); 315 return (EINVAL); 316 } 317 318 /* 319 * Change setting atomically. 320 */ 321 322 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 323 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 324 if (act->sa_flags & SA_SIGINFO) { 325 ps->ps_sigact[_SIG_IDX(sig)] = 326 (__sighandler_t *)act->sa_sigaction; 327 SIGADDSET(ps->ps_siginfo, sig); 328 } else { 329 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 330 SIGDELSET(ps->ps_siginfo, sig); 331 } 332 if (!(act->sa_flags & SA_RESTART)) 333 SIGADDSET(ps->ps_sigintr, sig); 334 else 335 SIGDELSET(ps->ps_sigintr, sig); 336 if (act->sa_flags & SA_ONSTACK) 337 SIGADDSET(ps->ps_sigonstack, sig); 338 else 339 SIGDELSET(ps->ps_sigonstack, sig); 340 if (act->sa_flags & SA_RESETHAND) 341 SIGADDSET(ps->ps_sigreset, sig); 342 else 343 SIGDELSET(ps->ps_sigreset, sig); 344 if (act->sa_flags & SA_NODEFER) 345 SIGADDSET(ps->ps_signodefer, sig); 346 else 347 SIGDELSET(ps->ps_signodefer, sig); 348 if (sig == SIGCHLD) { 349 if (act->sa_flags & SA_NOCLDSTOP) 350 ps->ps_flag |= PS_NOCLDSTOP; 351 else 352 ps->ps_flag &= ~PS_NOCLDSTOP; 353 if (act->sa_flags & SA_NOCLDWAIT) { 354 /* 355 * Paranoia: since SA_NOCLDWAIT is implemented 356 * by reparenting the dying child to PID 1 (and 357 * trust it to reap the zombie), PID 1 itself 358 * is forbidden to set SA_NOCLDWAIT. 359 */ 360 if (p->p_pid == 1) 361 ps->ps_flag &= ~PS_NOCLDWAIT; 362 else 363 ps->ps_flag |= PS_NOCLDWAIT; 364 } else 365 ps->ps_flag &= ~PS_NOCLDWAIT; 366 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 367 ps->ps_flag |= PS_CLDSIGIGN; 368 else 369 ps->ps_flag &= ~PS_CLDSIGIGN; 370 } 371 /* 372 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 373 * and for signals set to SIG_DFL where the default is to 374 * ignore. However, don't put SIGCONT in ps_sigignore, as we 375 * have to restart the process. 376 */ 377 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 378 (sigprop(sig) & SA_IGNORE && 379 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 380 if ((p->p_flag & P_SA) && 381 SIGISMEMBER(p->p_siglist, sig)) { 382 p->p_flag |= P_SIGEVENT; 383 wakeup(&p->p_siglist); 384 } 385 /* never to be seen again */ 386 SIGDELSET(p->p_siglist, sig); 387 mtx_lock_spin(&sched_lock); 388 FOREACH_THREAD_IN_PROC(p, td0) 389 SIGDELSET(td0->td_siglist, sig); 390 mtx_unlock_spin(&sched_lock); 391 if (sig != SIGCONT) 392 /* easier in psignal */ 393 SIGADDSET(ps->ps_sigignore, sig); 394 SIGDELSET(ps->ps_sigcatch, sig); 395 } else { 396 SIGDELSET(ps->ps_sigignore, sig); 397 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 398 SIGDELSET(ps->ps_sigcatch, sig); 399 else 400 SIGADDSET(ps->ps_sigcatch, sig); 401 } 402 #ifdef COMPAT_FREEBSD4 403 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 404 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 405 (flags & KSA_FREEBSD4) == 0) 406 SIGDELSET(ps->ps_freebsd4, sig); 407 else 408 SIGADDSET(ps->ps_freebsd4, sig); 409 #endif 410 #ifdef COMPAT_43 411 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 412 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 413 (flags & KSA_OSIGSET) == 0) 414 SIGDELSET(ps->ps_osigset, sig); 415 else 416 SIGADDSET(ps->ps_osigset, sig); 417 #endif 418 } 419 mtx_unlock(&ps->ps_mtx); 420 PROC_UNLOCK(p); 421 return (0); 422 } 423 424 #ifndef _SYS_SYSPROTO_H_ 425 struct sigaction_args { 426 int sig; 427 struct sigaction *act; 428 struct sigaction *oact; 429 }; 430 #endif 431 /* 432 * MPSAFE 433 */ 434 int 435 sigaction(td, uap) 436 struct thread *td; 437 register struct sigaction_args *uap; 438 { 439 struct sigaction act, oact; 440 register struct sigaction *actp, *oactp; 441 int error; 442 443 actp = (uap->act != NULL) ? &act : NULL; 444 oactp = (uap->oact != NULL) ? &oact : NULL; 445 if (actp) { 446 error = copyin(uap->act, actp, sizeof(act)); 447 if (error) 448 return (error); 449 } 450 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 451 if (oactp && !error) 452 error = copyout(oactp, uap->oact, sizeof(oact)); 453 return (error); 454 } 455 456 #ifdef COMPAT_FREEBSD4 457 #ifndef _SYS_SYSPROTO_H_ 458 struct freebsd4_sigaction_args { 459 int sig; 460 struct sigaction *act; 461 struct sigaction *oact; 462 }; 463 #endif 464 /* 465 * MPSAFE 466 */ 467 int 468 freebsd4_sigaction(td, uap) 469 struct thread *td; 470 register struct freebsd4_sigaction_args *uap; 471 { 472 struct sigaction act, oact; 473 register struct sigaction *actp, *oactp; 474 int error; 475 476 477 actp = (uap->act != NULL) ? &act : NULL; 478 oactp = (uap->oact != NULL) ? &oact : NULL; 479 if (actp) { 480 error = copyin(uap->act, actp, sizeof(act)); 481 if (error) 482 return (error); 483 } 484 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 485 if (oactp && !error) 486 error = copyout(oactp, uap->oact, sizeof(oact)); 487 return (error); 488 } 489 #endif /* COMAPT_FREEBSD4 */ 490 491 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 492 #ifndef _SYS_SYSPROTO_H_ 493 struct osigaction_args { 494 int signum; 495 struct osigaction *nsa; 496 struct osigaction *osa; 497 }; 498 #endif 499 /* 500 * MPSAFE 501 */ 502 int 503 osigaction(td, uap) 504 struct thread *td; 505 register struct osigaction_args *uap; 506 { 507 struct osigaction sa; 508 struct sigaction nsa, osa; 509 register struct sigaction *nsap, *osap; 510 int error; 511 512 if (uap->signum <= 0 || uap->signum >= ONSIG) 513 return (EINVAL); 514 515 nsap = (uap->nsa != NULL) ? &nsa : NULL; 516 osap = (uap->osa != NULL) ? &osa : NULL; 517 518 if (nsap) { 519 error = copyin(uap->nsa, &sa, sizeof(sa)); 520 if (error) 521 return (error); 522 nsap->sa_handler = sa.sa_handler; 523 nsap->sa_flags = sa.sa_flags; 524 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 525 } 526 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 527 if (osap && !error) { 528 sa.sa_handler = osap->sa_handler; 529 sa.sa_flags = osap->sa_flags; 530 SIG2OSIG(osap->sa_mask, sa.sa_mask); 531 error = copyout(&sa, uap->osa, sizeof(sa)); 532 } 533 return (error); 534 } 535 536 #if !defined(__i386__) && !defined(__alpha__) 537 /* Avoid replicating the same stub everywhere */ 538 int 539 osigreturn(td, uap) 540 struct thread *td; 541 struct osigreturn_args *uap; 542 { 543 544 return (nosys(td, (struct nosys_args *)uap)); 545 } 546 #endif 547 #endif /* COMPAT_43 */ 548 549 /* 550 * Initialize signal state for process 0; 551 * set to ignore signals that are ignored by default. 552 */ 553 void 554 siginit(p) 555 struct proc *p; 556 { 557 register int i; 558 struct sigacts *ps; 559 560 PROC_LOCK(p); 561 ps = p->p_sigacts; 562 mtx_lock(&ps->ps_mtx); 563 for (i = 1; i <= NSIG; i++) 564 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 565 SIGADDSET(ps->ps_sigignore, i); 566 mtx_unlock(&ps->ps_mtx); 567 PROC_UNLOCK(p); 568 } 569 570 /* 571 * Reset signals for an exec of the specified process. 572 */ 573 void 574 execsigs(struct proc *p) 575 { 576 struct sigacts *ps; 577 int sig; 578 struct thread *td; 579 580 /* 581 * Reset caught signals. Held signals remain held 582 * through td_sigmask (unless they were caught, 583 * and are now ignored by default). 584 */ 585 PROC_LOCK_ASSERT(p, MA_OWNED); 586 td = FIRST_THREAD_IN_PROC(p); 587 ps = p->p_sigacts; 588 mtx_lock(&ps->ps_mtx); 589 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 590 sig = sig_ffs(&ps->ps_sigcatch); 591 SIGDELSET(ps->ps_sigcatch, sig); 592 if (sigprop(sig) & SA_IGNORE) { 593 if (sig != SIGCONT) 594 SIGADDSET(ps->ps_sigignore, sig); 595 SIGDELSET(p->p_siglist, sig); 596 /* 597 * There is only one thread at this point. 598 */ 599 SIGDELSET(td->td_siglist, sig); 600 } 601 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 602 } 603 /* 604 * Reset stack state to the user stack. 605 * Clear set of signals caught on the signal stack. 606 */ 607 td->td_sigstk.ss_flags = SS_DISABLE; 608 td->td_sigstk.ss_size = 0; 609 td->td_sigstk.ss_sp = 0; 610 td->td_pflags &= ~TDP_ALTSTACK; 611 /* 612 * Reset no zombies if child dies flag as Solaris does. 613 */ 614 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 615 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 616 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 617 mtx_unlock(&ps->ps_mtx); 618 } 619 620 /* 621 * kern_sigprocmask() 622 * 623 * Manipulate signal mask. 624 */ 625 int 626 kern_sigprocmask(td, how, set, oset, old) 627 struct thread *td; 628 int how; 629 sigset_t *set, *oset; 630 int old; 631 { 632 int error; 633 634 PROC_LOCK(td->td_proc); 635 if (oset != NULL) 636 *oset = td->td_sigmask; 637 638 error = 0; 639 if (set != NULL) { 640 switch (how) { 641 case SIG_BLOCK: 642 SIG_CANTMASK(*set); 643 SIGSETOR(td->td_sigmask, *set); 644 break; 645 case SIG_UNBLOCK: 646 SIGSETNAND(td->td_sigmask, *set); 647 signotify(td); 648 break; 649 case SIG_SETMASK: 650 SIG_CANTMASK(*set); 651 if (old) 652 SIGSETLO(td->td_sigmask, *set); 653 else 654 td->td_sigmask = *set; 655 signotify(td); 656 break; 657 default: 658 error = EINVAL; 659 break; 660 } 661 } 662 PROC_UNLOCK(td->td_proc); 663 return (error); 664 } 665 666 /* 667 * sigprocmask() - MP SAFE 668 */ 669 670 #ifndef _SYS_SYSPROTO_H_ 671 struct sigprocmask_args { 672 int how; 673 const sigset_t *set; 674 sigset_t *oset; 675 }; 676 #endif 677 int 678 sigprocmask(td, uap) 679 register struct thread *td; 680 struct sigprocmask_args *uap; 681 { 682 sigset_t set, oset; 683 sigset_t *setp, *osetp; 684 int error; 685 686 setp = (uap->set != NULL) ? &set : NULL; 687 osetp = (uap->oset != NULL) ? &oset : NULL; 688 if (setp) { 689 error = copyin(uap->set, setp, sizeof(set)); 690 if (error) 691 return (error); 692 } 693 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 694 if (osetp && !error) { 695 error = copyout(osetp, uap->oset, sizeof(oset)); 696 } 697 return (error); 698 } 699 700 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 701 /* 702 * osigprocmask() - MP SAFE 703 */ 704 #ifndef _SYS_SYSPROTO_H_ 705 struct osigprocmask_args { 706 int how; 707 osigset_t mask; 708 }; 709 #endif 710 int 711 osigprocmask(td, uap) 712 register struct thread *td; 713 struct osigprocmask_args *uap; 714 { 715 sigset_t set, oset; 716 int error; 717 718 OSIG2SIG(uap->mask, set); 719 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 720 SIG2OSIG(oset, td->td_retval[0]); 721 return (error); 722 } 723 #endif /* COMPAT_43 */ 724 725 #ifndef _SYS_SYSPROTO_H_ 726 struct sigpending_args { 727 sigset_t *set; 728 }; 729 #endif 730 /* 731 * MPSAFE 732 */ 733 int 734 sigwait(struct thread *td, struct sigwait_args *uap) 735 { 736 siginfo_t info; 737 sigset_t set; 738 int error; 739 740 error = copyin(uap->set, &set, sizeof(set)); 741 if (error) { 742 td->td_retval[0] = error; 743 return (0); 744 } 745 746 error = kern_sigtimedwait(td, set, &info, NULL); 747 if (error) { 748 if (error == ERESTART) 749 return (error); 750 td->td_retval[0] = error; 751 return (0); 752 } 753 754 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 755 /* Repost if we got an error. */ 756 if (error && info.si_signo) { 757 PROC_LOCK(td->td_proc); 758 tdsignal(td, info.si_signo, SIGTARGET_TD); 759 PROC_UNLOCK(td->td_proc); 760 } 761 td->td_retval[0] = error; 762 return (0); 763 } 764 /* 765 * MPSAFE 766 */ 767 int 768 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 769 { 770 struct timespec ts; 771 struct timespec *timeout; 772 sigset_t set; 773 siginfo_t info; 774 int error; 775 776 if (uap->timeout) { 777 error = copyin(uap->timeout, &ts, sizeof(ts)); 778 if (error) 779 return (error); 780 781 timeout = &ts; 782 } else 783 timeout = NULL; 784 785 error = copyin(uap->set, &set, sizeof(set)); 786 if (error) 787 return (error); 788 789 error = kern_sigtimedwait(td, set, &info, timeout); 790 if (error) 791 return (error); 792 793 if (uap->info) 794 error = copyout(&info, uap->info, sizeof(info)); 795 /* Repost if we got an error. */ 796 if (error && info.si_signo) { 797 PROC_LOCK(td->td_proc); 798 tdsignal(td, info.si_signo, SIGTARGET_TD); 799 PROC_UNLOCK(td->td_proc); 800 } else { 801 td->td_retval[0] = info.si_signo; 802 } 803 return (error); 804 } 805 806 /* 807 * MPSAFE 808 */ 809 int 810 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 811 { 812 siginfo_t info; 813 sigset_t set; 814 int error; 815 816 error = copyin(uap->set, &set, sizeof(set)); 817 if (error) 818 return (error); 819 820 error = kern_sigtimedwait(td, set, &info, NULL); 821 if (error) 822 return (error); 823 824 if (uap->info) 825 error = copyout(&info, uap->info, sizeof(info)); 826 /* Repost if we got an error. */ 827 if (error && info.si_signo) { 828 PROC_LOCK(td->td_proc); 829 tdsignal(td, info.si_signo, SIGTARGET_TD); 830 PROC_UNLOCK(td->td_proc); 831 } else { 832 td->td_retval[0] = info.si_signo; 833 } 834 return (error); 835 } 836 837 static int 838 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info, 839 struct timespec *timeout) 840 { 841 struct sigacts *ps; 842 sigset_t savedmask, sigset; 843 struct proc *p; 844 int error; 845 int sig; 846 int hz; 847 int i; 848 849 p = td->td_proc; 850 error = 0; 851 sig = 0; 852 SIG_CANTMASK(waitset); 853 854 PROC_LOCK(p); 855 ps = p->p_sigacts; 856 savedmask = td->td_sigmask; 857 858 again: 859 for (i = 1; i <= _SIG_MAXSIG; ++i) { 860 if (!SIGISMEMBER(waitset, i)) 861 continue; 862 if (SIGISMEMBER(td->td_siglist, i)) { 863 SIGFILLSET(td->td_sigmask); 864 SIG_CANTMASK(td->td_sigmask); 865 SIGDELSET(td->td_sigmask, i); 866 mtx_lock(&ps->ps_mtx); 867 sig = cursig(td); 868 i = 0; 869 mtx_unlock(&ps->ps_mtx); 870 } else if (SIGISMEMBER(p->p_siglist, i)) { 871 if (p->p_flag & P_SA) { 872 p->p_flag |= P_SIGEVENT; 873 wakeup(&p->p_siglist); 874 } 875 SIGDELSET(p->p_siglist, i); 876 SIGADDSET(td->td_siglist, i); 877 SIGFILLSET(td->td_sigmask); 878 SIG_CANTMASK(td->td_sigmask); 879 SIGDELSET(td->td_sigmask, i); 880 mtx_lock(&ps->ps_mtx); 881 sig = cursig(td); 882 i = 0; 883 mtx_unlock(&ps->ps_mtx); 884 } 885 if (sig) { 886 td->td_sigmask = savedmask; 887 signotify(td); 888 goto out; 889 } 890 } 891 if (error) 892 goto out; 893 894 td->td_sigmask = savedmask; 895 signotify(td); 896 sigset = td->td_siglist; 897 SIGSETOR(sigset, p->p_siglist); 898 SIGSETAND(sigset, waitset); 899 if (!SIGISEMPTY(sigset)) 900 goto again; 901 902 /* 903 * POSIX says this must be checked after looking for pending 904 * signals. 905 */ 906 if (timeout) { 907 struct timeval tv; 908 909 if (timeout->tv_nsec < 0 || timeout->tv_nsec > 1000000000) { 910 error = EINVAL; 911 goto out; 912 } 913 if (timeout->tv_sec == 0 && timeout->tv_nsec == 0) { 914 error = EAGAIN; 915 goto out; 916 } 917 TIMESPEC_TO_TIMEVAL(&tv, timeout); 918 hz = tvtohz(&tv); 919 } else 920 hz = 0; 921 922 td->td_waitset = &waitset; 923 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 924 td->td_waitset = NULL; 925 if (error == 0) /* surplus wakeup ? */ 926 error = EINTR; 927 goto again; 928 929 out: 930 if (sig) { 931 sig_t action; 932 933 error = 0; 934 mtx_lock(&ps->ps_mtx); 935 action = ps->ps_sigact[_SIG_IDX(sig)]; 936 mtx_unlock(&ps->ps_mtx); 937 #ifdef KTRACE 938 if (KTRPOINT(td, KTR_PSIG)) 939 ktrpsig(sig, action, &td->td_sigmask, 0); 940 #endif 941 _STOPEVENT(p, S_SIG, sig); 942 943 SIGDELSET(td->td_siglist, sig); 944 info->si_signo = sig; 945 info->si_code = 0; 946 } 947 PROC_UNLOCK(p); 948 return (error); 949 } 950 951 /* 952 * MPSAFE 953 */ 954 int 955 sigpending(td, uap) 956 struct thread *td; 957 struct sigpending_args *uap; 958 { 959 struct proc *p = td->td_proc; 960 sigset_t siglist; 961 962 PROC_LOCK(p); 963 siglist = p->p_siglist; 964 SIGSETOR(siglist, td->td_siglist); 965 PROC_UNLOCK(p); 966 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 967 } 968 969 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 970 #ifndef _SYS_SYSPROTO_H_ 971 struct osigpending_args { 972 int dummy; 973 }; 974 #endif 975 /* 976 * MPSAFE 977 */ 978 int 979 osigpending(td, uap) 980 struct thread *td; 981 struct osigpending_args *uap; 982 { 983 struct proc *p = td->td_proc; 984 sigset_t siglist; 985 986 PROC_LOCK(p); 987 siglist = p->p_siglist; 988 SIGSETOR(siglist, td->td_siglist); 989 PROC_UNLOCK(p); 990 SIG2OSIG(siglist, td->td_retval[0]); 991 return (0); 992 } 993 #endif /* COMPAT_43 */ 994 995 #if defined(COMPAT_43) 996 /* 997 * Generalized interface signal handler, 4.3-compatible. 998 */ 999 #ifndef _SYS_SYSPROTO_H_ 1000 struct osigvec_args { 1001 int signum; 1002 struct sigvec *nsv; 1003 struct sigvec *osv; 1004 }; 1005 #endif 1006 /* 1007 * MPSAFE 1008 */ 1009 /* ARGSUSED */ 1010 int 1011 osigvec(td, uap) 1012 struct thread *td; 1013 register struct osigvec_args *uap; 1014 { 1015 struct sigvec vec; 1016 struct sigaction nsa, osa; 1017 register struct sigaction *nsap, *osap; 1018 int error; 1019 1020 if (uap->signum <= 0 || uap->signum >= ONSIG) 1021 return (EINVAL); 1022 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1023 osap = (uap->osv != NULL) ? &osa : NULL; 1024 if (nsap) { 1025 error = copyin(uap->nsv, &vec, sizeof(vec)); 1026 if (error) 1027 return (error); 1028 nsap->sa_handler = vec.sv_handler; 1029 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1030 nsap->sa_flags = vec.sv_flags; 1031 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1032 } 1033 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1034 if (osap && !error) { 1035 vec.sv_handler = osap->sa_handler; 1036 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1037 vec.sv_flags = osap->sa_flags; 1038 vec.sv_flags &= ~SA_NOCLDWAIT; 1039 vec.sv_flags ^= SA_RESTART; 1040 error = copyout(&vec, uap->osv, sizeof(vec)); 1041 } 1042 return (error); 1043 } 1044 1045 #ifndef _SYS_SYSPROTO_H_ 1046 struct osigblock_args { 1047 int mask; 1048 }; 1049 #endif 1050 /* 1051 * MPSAFE 1052 */ 1053 int 1054 osigblock(td, uap) 1055 register struct thread *td; 1056 struct osigblock_args *uap; 1057 { 1058 struct proc *p = td->td_proc; 1059 sigset_t set; 1060 1061 OSIG2SIG(uap->mask, set); 1062 SIG_CANTMASK(set); 1063 PROC_LOCK(p); 1064 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1065 SIGSETOR(td->td_sigmask, set); 1066 PROC_UNLOCK(p); 1067 return (0); 1068 } 1069 1070 #ifndef _SYS_SYSPROTO_H_ 1071 struct osigsetmask_args { 1072 int mask; 1073 }; 1074 #endif 1075 /* 1076 * MPSAFE 1077 */ 1078 int 1079 osigsetmask(td, uap) 1080 struct thread *td; 1081 struct osigsetmask_args *uap; 1082 { 1083 struct proc *p = td->td_proc; 1084 sigset_t set; 1085 1086 OSIG2SIG(uap->mask, set); 1087 SIG_CANTMASK(set); 1088 PROC_LOCK(p); 1089 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1090 SIGSETLO(td->td_sigmask, set); 1091 signotify(td); 1092 PROC_UNLOCK(p); 1093 return (0); 1094 } 1095 #endif /* COMPAT_43 */ 1096 1097 /* 1098 * Suspend process until signal, providing mask to be set 1099 * in the meantime. 1100 ***** XXXKSE this doesn't make sense under KSE. 1101 ***** Do we suspend the thread or all threads in the process? 1102 ***** How do we suspend threads running NOW on another processor? 1103 */ 1104 #ifndef _SYS_SYSPROTO_H_ 1105 struct sigsuspend_args { 1106 const sigset_t *sigmask; 1107 }; 1108 #endif 1109 /* 1110 * MPSAFE 1111 */ 1112 /* ARGSUSED */ 1113 int 1114 sigsuspend(td, uap) 1115 struct thread *td; 1116 struct sigsuspend_args *uap; 1117 { 1118 sigset_t mask; 1119 int error; 1120 1121 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1122 if (error) 1123 return (error); 1124 return (kern_sigsuspend(td, mask)); 1125 } 1126 1127 int 1128 kern_sigsuspend(struct thread *td, sigset_t mask) 1129 { 1130 struct proc *p = td->td_proc; 1131 1132 /* 1133 * When returning from sigsuspend, we want 1134 * the old mask to be restored after the 1135 * signal handler has finished. Thus, we 1136 * save it here and mark the sigacts structure 1137 * to indicate this. 1138 */ 1139 PROC_LOCK(p); 1140 td->td_oldsigmask = td->td_sigmask; 1141 td->td_pflags |= TDP_OLDMASK; 1142 SIG_CANTMASK(mask); 1143 td->td_sigmask = mask; 1144 signotify(td); 1145 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1146 /* void */; 1147 PROC_UNLOCK(p); 1148 /* always return EINTR rather than ERESTART... */ 1149 return (EINTR); 1150 } 1151 1152 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1153 /* 1154 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1155 * convention: libc stub passes mask, not pointer, to save a copyin. 1156 */ 1157 #ifndef _SYS_SYSPROTO_H_ 1158 struct osigsuspend_args { 1159 osigset_t mask; 1160 }; 1161 #endif 1162 /* 1163 * MPSAFE 1164 */ 1165 /* ARGSUSED */ 1166 int 1167 osigsuspend(td, uap) 1168 struct thread *td; 1169 struct osigsuspend_args *uap; 1170 { 1171 struct proc *p = td->td_proc; 1172 sigset_t mask; 1173 1174 PROC_LOCK(p); 1175 td->td_oldsigmask = td->td_sigmask; 1176 td->td_pflags |= TDP_OLDMASK; 1177 OSIG2SIG(uap->mask, mask); 1178 SIG_CANTMASK(mask); 1179 SIGSETLO(td->td_sigmask, mask); 1180 signotify(td); 1181 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1182 /* void */; 1183 PROC_UNLOCK(p); 1184 /* always return EINTR rather than ERESTART... */ 1185 return (EINTR); 1186 } 1187 #endif /* COMPAT_43 */ 1188 1189 #if defined(COMPAT_43) 1190 #ifndef _SYS_SYSPROTO_H_ 1191 struct osigstack_args { 1192 struct sigstack *nss; 1193 struct sigstack *oss; 1194 }; 1195 #endif 1196 /* 1197 * MPSAFE 1198 */ 1199 /* ARGSUSED */ 1200 int 1201 osigstack(td, uap) 1202 struct thread *td; 1203 register struct osigstack_args *uap; 1204 { 1205 struct sigstack nss, oss; 1206 int error = 0; 1207 1208 if (uap->nss != NULL) { 1209 error = copyin(uap->nss, &nss, sizeof(nss)); 1210 if (error) 1211 return (error); 1212 } 1213 oss.ss_sp = td->td_sigstk.ss_sp; 1214 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1215 if (uap->nss != NULL) { 1216 td->td_sigstk.ss_sp = nss.ss_sp; 1217 td->td_sigstk.ss_size = 0; 1218 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1219 td->td_pflags |= TDP_ALTSTACK; 1220 } 1221 if (uap->oss != NULL) 1222 error = copyout(&oss, uap->oss, sizeof(oss)); 1223 1224 return (error); 1225 } 1226 #endif /* COMPAT_43 */ 1227 1228 #ifndef _SYS_SYSPROTO_H_ 1229 struct sigaltstack_args { 1230 stack_t *ss; 1231 stack_t *oss; 1232 }; 1233 #endif 1234 /* 1235 * MPSAFE 1236 */ 1237 /* ARGSUSED */ 1238 int 1239 sigaltstack(td, uap) 1240 struct thread *td; 1241 register struct sigaltstack_args *uap; 1242 { 1243 stack_t ss, oss; 1244 int error; 1245 1246 if (uap->ss != NULL) { 1247 error = copyin(uap->ss, &ss, sizeof(ss)); 1248 if (error) 1249 return (error); 1250 } 1251 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1252 (uap->oss != NULL) ? &oss : NULL); 1253 if (error) 1254 return (error); 1255 if (uap->oss != NULL) 1256 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1257 return (error); 1258 } 1259 1260 int 1261 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1262 { 1263 struct proc *p = td->td_proc; 1264 int oonstack; 1265 1266 oonstack = sigonstack(cpu_getstack(td)); 1267 1268 if (oss != NULL) { 1269 *oss = td->td_sigstk; 1270 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1271 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1272 } 1273 1274 if (ss != NULL) { 1275 if (oonstack) 1276 return (EPERM); 1277 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1278 return (EINVAL); 1279 if (!(ss->ss_flags & SS_DISABLE)) { 1280 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1281 return (ENOMEM); 1282 } 1283 td->td_sigstk = *ss; 1284 td->td_pflags |= TDP_ALTSTACK; 1285 } else { 1286 td->td_pflags &= ~TDP_ALTSTACK; 1287 } 1288 } 1289 return (0); 1290 } 1291 1292 /* 1293 * Common code for kill process group/broadcast kill. 1294 * cp is calling process. 1295 */ 1296 static int 1297 killpg1(td, sig, pgid, all) 1298 register struct thread *td; 1299 int sig, pgid, all; 1300 { 1301 register struct proc *p; 1302 struct pgrp *pgrp; 1303 int nfound = 0; 1304 1305 if (all) { 1306 /* 1307 * broadcast 1308 */ 1309 sx_slock(&allproc_lock); 1310 LIST_FOREACH(p, &allproc, p_list) { 1311 PROC_LOCK(p); 1312 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1313 p == td->td_proc) { 1314 PROC_UNLOCK(p); 1315 continue; 1316 } 1317 if (p_cansignal(td, p, sig) == 0) { 1318 nfound++; 1319 if (sig) 1320 psignal(p, sig); 1321 } 1322 PROC_UNLOCK(p); 1323 } 1324 sx_sunlock(&allproc_lock); 1325 } else { 1326 sx_slock(&proctree_lock); 1327 if (pgid == 0) { 1328 /* 1329 * zero pgid means send to my process group. 1330 */ 1331 pgrp = td->td_proc->p_pgrp; 1332 PGRP_LOCK(pgrp); 1333 } else { 1334 pgrp = pgfind(pgid); 1335 if (pgrp == NULL) { 1336 sx_sunlock(&proctree_lock); 1337 return (ESRCH); 1338 } 1339 } 1340 sx_sunlock(&proctree_lock); 1341 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1342 PROC_LOCK(p); 1343 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1344 PROC_UNLOCK(p); 1345 continue; 1346 } 1347 if (p->p_state == PRS_ZOMBIE) { 1348 PROC_UNLOCK(p); 1349 continue; 1350 } 1351 if (p_cansignal(td, p, sig) == 0) { 1352 nfound++; 1353 if (sig) 1354 psignal(p, sig); 1355 } 1356 PROC_UNLOCK(p); 1357 } 1358 PGRP_UNLOCK(pgrp); 1359 } 1360 return (nfound ? 0 : ESRCH); 1361 } 1362 1363 #ifndef _SYS_SYSPROTO_H_ 1364 struct kill_args { 1365 int pid; 1366 int signum; 1367 }; 1368 #endif 1369 /* 1370 * MPSAFE 1371 */ 1372 /* ARGSUSED */ 1373 int 1374 kill(td, uap) 1375 register struct thread *td; 1376 register struct kill_args *uap; 1377 { 1378 register struct proc *p; 1379 int error; 1380 1381 if ((u_int)uap->signum > _SIG_MAXSIG) 1382 return (EINVAL); 1383 1384 if (uap->pid > 0) { 1385 /* kill single process */ 1386 if ((p = pfind(uap->pid)) == NULL) 1387 return (ESRCH); 1388 error = p_cansignal(td, p, uap->signum); 1389 if (error == 0 && uap->signum) 1390 psignal(p, uap->signum); 1391 PROC_UNLOCK(p); 1392 return (error); 1393 } 1394 switch (uap->pid) { 1395 case -1: /* broadcast signal */ 1396 return (killpg1(td, uap->signum, 0, 1)); 1397 case 0: /* signal own process group */ 1398 return (killpg1(td, uap->signum, 0, 0)); 1399 default: /* negative explicit process group */ 1400 return (killpg1(td, uap->signum, -uap->pid, 0)); 1401 } 1402 /* NOTREACHED */ 1403 } 1404 1405 #if defined(COMPAT_43) 1406 #ifndef _SYS_SYSPROTO_H_ 1407 struct okillpg_args { 1408 int pgid; 1409 int signum; 1410 }; 1411 #endif 1412 /* 1413 * MPSAFE 1414 */ 1415 /* ARGSUSED */ 1416 int 1417 okillpg(td, uap) 1418 struct thread *td; 1419 register struct okillpg_args *uap; 1420 { 1421 1422 if ((u_int)uap->signum > _SIG_MAXSIG) 1423 return (EINVAL); 1424 return (killpg1(td, uap->signum, uap->pgid, 0)); 1425 } 1426 #endif /* COMPAT_43 */ 1427 1428 /* 1429 * Send a signal to a process group. 1430 */ 1431 void 1432 gsignal(pgid, sig) 1433 int pgid, sig; 1434 { 1435 struct pgrp *pgrp; 1436 1437 if (pgid != 0) { 1438 sx_slock(&proctree_lock); 1439 pgrp = pgfind(pgid); 1440 sx_sunlock(&proctree_lock); 1441 if (pgrp != NULL) { 1442 pgsignal(pgrp, sig, 0); 1443 PGRP_UNLOCK(pgrp); 1444 } 1445 } 1446 } 1447 1448 /* 1449 * Send a signal to a process group. If checktty is 1, 1450 * limit to members which have a controlling terminal. 1451 */ 1452 void 1453 pgsignal(pgrp, sig, checkctty) 1454 struct pgrp *pgrp; 1455 int sig, checkctty; 1456 { 1457 register struct proc *p; 1458 1459 if (pgrp) { 1460 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1461 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1462 PROC_LOCK(p); 1463 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1464 psignal(p, sig); 1465 PROC_UNLOCK(p); 1466 } 1467 } 1468 } 1469 1470 /* 1471 * Send a signal caused by a trap to the current thread. 1472 * If it will be caught immediately, deliver it with correct code. 1473 * Otherwise, post it normally. 1474 * 1475 * MPSAFE 1476 */ 1477 void 1478 trapsignal(struct thread *td, int sig, u_long code) 1479 { 1480 struct sigacts *ps; 1481 struct proc *p; 1482 siginfo_t siginfo; 1483 int error; 1484 1485 p = td->td_proc; 1486 if (td->td_pflags & TDP_SA) { 1487 if (td->td_mailbox == NULL) 1488 thread_user_enter(p, td); 1489 PROC_LOCK(p); 1490 SIGDELSET(td->td_sigmask, sig); 1491 mtx_lock_spin(&sched_lock); 1492 /* 1493 * Force scheduling an upcall, so UTS has chance to 1494 * process the signal before thread runs again in 1495 * userland. 1496 */ 1497 if (td->td_upcall) 1498 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1499 mtx_unlock_spin(&sched_lock); 1500 } else { 1501 PROC_LOCK(p); 1502 } 1503 ps = p->p_sigacts; 1504 mtx_lock(&ps->ps_mtx); 1505 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1506 !SIGISMEMBER(td->td_sigmask, sig)) { 1507 p->p_stats->p_ru.ru_nsignals++; 1508 #ifdef KTRACE 1509 if (KTRPOINT(curthread, KTR_PSIG)) 1510 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1511 &td->td_sigmask, code); 1512 #endif 1513 if (!(td->td_pflags & TDP_SA)) 1514 (*p->p_sysent->sv_sendsig)( 1515 ps->ps_sigact[_SIG_IDX(sig)], sig, 1516 &td->td_sigmask, code); 1517 else if (td->td_mailbox == NULL) { 1518 mtx_unlock(&ps->ps_mtx); 1519 /* UTS caused a sync signal */ 1520 p->p_code = code; /* XXX for core dump/debugger */ 1521 p->p_sig = sig; /* XXX to verify code */ 1522 sigexit(td, sig); 1523 } else { 1524 cpu_thread_siginfo(sig, code, &siginfo); 1525 mtx_unlock(&ps->ps_mtx); 1526 SIGADDSET(td->td_sigmask, sig); 1527 PROC_UNLOCK(p); 1528 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1529 sizeof(siginfo)); 1530 PROC_LOCK(p); 1531 /* UTS memory corrupted */ 1532 if (error) 1533 sigexit(td, SIGSEGV); 1534 mtx_lock(&ps->ps_mtx); 1535 } 1536 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1537 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1538 SIGADDSET(td->td_sigmask, sig); 1539 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1540 /* 1541 * See kern_sigaction() for origin of this code. 1542 */ 1543 SIGDELSET(ps->ps_sigcatch, sig); 1544 if (sig != SIGCONT && 1545 sigprop(sig) & SA_IGNORE) 1546 SIGADDSET(ps->ps_sigignore, sig); 1547 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1548 } 1549 mtx_unlock(&ps->ps_mtx); 1550 } else { 1551 mtx_unlock(&ps->ps_mtx); 1552 p->p_code = code; /* XXX for core dump/debugger */ 1553 p->p_sig = sig; /* XXX to verify code */ 1554 tdsignal(td, sig, SIGTARGET_TD); 1555 } 1556 PROC_UNLOCK(p); 1557 } 1558 1559 static struct thread * 1560 sigtd(struct proc *p, int sig, int prop) 1561 { 1562 struct thread *td, *signal_td; 1563 1564 PROC_LOCK_ASSERT(p, MA_OWNED); 1565 1566 /* 1567 * First find a thread in sigwait state and signal belongs to 1568 * its wait set. POSIX's arguments is that speed of delivering signal 1569 * to sigwait thread is faster than delivering signal to user stack. 1570 * If we can not find sigwait thread, then find the first thread in 1571 * the proc that doesn't have this signal masked, an exception is 1572 * if current thread is sending signal to its process, and it does not 1573 * mask the signal, it should get the signal, this is another fast 1574 * way to deliver signal. 1575 */ 1576 signal_td = NULL; 1577 mtx_lock_spin(&sched_lock); 1578 FOREACH_THREAD_IN_PROC(p, td) { 1579 if (td->td_waitset != NULL && 1580 SIGISMEMBER(*(td->td_waitset), sig)) { 1581 mtx_unlock_spin(&sched_lock); 1582 return (td); 1583 } 1584 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1585 if (td == curthread) 1586 signal_td = curthread; 1587 else if (signal_td == NULL) 1588 signal_td = td; 1589 } 1590 } 1591 if (signal_td == NULL) 1592 signal_td = FIRST_THREAD_IN_PROC(p); 1593 mtx_unlock_spin(&sched_lock); 1594 return (signal_td); 1595 } 1596 1597 /* 1598 * Send the signal to the process. If the signal has an action, the action 1599 * is usually performed by the target process rather than the caller; we add 1600 * the signal to the set of pending signals for the process. 1601 * 1602 * Exceptions: 1603 * o When a stop signal is sent to a sleeping process that takes the 1604 * default action, the process is stopped without awakening it. 1605 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1606 * regardless of the signal action (eg, blocked or ignored). 1607 * 1608 * Other ignored signals are discarded immediately. 1609 * 1610 * MPSAFE 1611 */ 1612 void 1613 psignal(struct proc *p, int sig) 1614 { 1615 struct thread *td; 1616 int prop; 1617 1618 if (!_SIG_VALID(sig)) 1619 panic("psignal(): invalid signal"); 1620 1621 PROC_LOCK_ASSERT(p, MA_OWNED); 1622 prop = sigprop(sig); 1623 1624 /* 1625 * Find a thread to deliver the signal to. 1626 */ 1627 td = sigtd(p, sig, prop); 1628 1629 tdsignal(td, sig, SIGTARGET_P); 1630 } 1631 1632 /* 1633 * MPSAFE 1634 */ 1635 void 1636 tdsignal(struct thread *td, int sig, sigtarget_t target) 1637 { 1638 sigset_t saved; 1639 struct proc *p = td->td_proc; 1640 1641 if (p->p_flag & P_SA) 1642 saved = p->p_siglist; 1643 do_tdsignal(td, sig, target); 1644 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1645 if (!SIGSETEQ(saved, p->p_siglist)) { 1646 /* pending set changed */ 1647 p->p_flag |= P_SIGEVENT; 1648 wakeup(&p->p_siglist); 1649 } 1650 } 1651 } 1652 1653 static void 1654 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1655 { 1656 struct proc *p; 1657 register sig_t action; 1658 sigset_t *siglist; 1659 struct thread *td0; 1660 register int prop; 1661 struct sigacts *ps; 1662 1663 if (!_SIG_VALID(sig)) 1664 panic("do_tdsignal(): invalid signal"); 1665 1666 p = td->td_proc; 1667 ps = p->p_sigacts; 1668 1669 PROC_LOCK_ASSERT(p, MA_OWNED); 1670 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1671 1672 prop = sigprop(sig); 1673 1674 /* 1675 * If the signal is blocked and not destined for this thread, then 1676 * assign it to the process so that we can find it later in the first 1677 * thread that unblocks it. Otherwise, assign it to this thread now. 1678 */ 1679 if (target == SIGTARGET_TD) { 1680 siglist = &td->td_siglist; 1681 } else { 1682 if (!SIGISMEMBER(td->td_sigmask, sig)) 1683 siglist = &td->td_siglist; 1684 else if (td->td_waitset != NULL && 1685 SIGISMEMBER(*(td->td_waitset), sig)) 1686 siglist = &td->td_siglist; 1687 else 1688 siglist = &p->p_siglist; 1689 } 1690 1691 /* 1692 * If proc is traced, always give parent a chance; 1693 * if signal event is tracked by procfs, give *that* 1694 * a chance, as well. 1695 */ 1696 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1697 action = SIG_DFL; 1698 } else { 1699 /* 1700 * If the signal is being ignored, 1701 * then we forget about it immediately. 1702 * (Note: we don't set SIGCONT in ps_sigignore, 1703 * and if it is set to SIG_IGN, 1704 * action will be SIG_DFL here.) 1705 */ 1706 mtx_lock(&ps->ps_mtx); 1707 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1708 (p->p_flag & P_WEXIT)) { 1709 mtx_unlock(&ps->ps_mtx); 1710 return; 1711 } 1712 if (((td->td_waitset == NULL) && 1713 SIGISMEMBER(td->td_sigmask, sig)) || 1714 ((td->td_waitset != NULL) && 1715 SIGISMEMBER(td->td_sigmask, sig) && 1716 !SIGISMEMBER(*(td->td_waitset), sig))) 1717 action = SIG_HOLD; 1718 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1719 action = SIG_CATCH; 1720 else 1721 action = SIG_DFL; 1722 mtx_unlock(&ps->ps_mtx); 1723 } 1724 1725 if (prop & SA_CONT) { 1726 SIG_STOPSIGMASK(p->p_siglist); 1727 /* 1728 * XXX Should investigate leaving STOP and CONT sigs only in 1729 * the proc's siglist. 1730 */ 1731 mtx_lock_spin(&sched_lock); 1732 FOREACH_THREAD_IN_PROC(p, td0) 1733 SIG_STOPSIGMASK(td0->td_siglist); 1734 mtx_unlock_spin(&sched_lock); 1735 } 1736 1737 if (prop & SA_STOP) { 1738 /* 1739 * If sending a tty stop signal to a member of an orphaned 1740 * process group, discard the signal here if the action 1741 * is default; don't stop the process below if sleeping, 1742 * and don't clear any pending SIGCONT. 1743 */ 1744 if ((prop & SA_TTYSTOP) && 1745 (p->p_pgrp->pg_jobc == 0) && 1746 (action == SIG_DFL)) 1747 return; 1748 SIG_CONTSIGMASK(p->p_siglist); 1749 mtx_lock_spin(&sched_lock); 1750 FOREACH_THREAD_IN_PROC(p, td0) 1751 SIG_CONTSIGMASK(td0->td_siglist); 1752 mtx_unlock_spin(&sched_lock); 1753 p->p_flag &= ~P_CONTINUED; 1754 } 1755 1756 SIGADDSET(*siglist, sig); 1757 signotify(td); /* uses schedlock */ 1758 if (siglist == &td->td_siglist && (td->td_waitset != NULL) && 1759 action != SIG_HOLD) { 1760 td->td_waitset = NULL; 1761 } 1762 1763 /* 1764 * Defer further processing for signals which are held, 1765 * except that stopped processes must be continued by SIGCONT. 1766 */ 1767 if (action == SIG_HOLD && 1768 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1769 return; 1770 /* 1771 * Some signals have a process-wide effect and a per-thread 1772 * component. Most processing occurs when the process next 1773 * tries to cross the user boundary, however there are some 1774 * times when processing needs to be done immediatly, such as 1775 * waking up threads so that they can cross the user boundary. 1776 * We try do the per-process part here. 1777 */ 1778 if (P_SHOULDSTOP(p)) { 1779 /* 1780 * The process is in stopped mode. All the threads should be 1781 * either winding down or already on the suspended queue. 1782 */ 1783 if (p->p_flag & P_TRACED) { 1784 /* 1785 * The traced process is already stopped, 1786 * so no further action is necessary. 1787 * No signal can restart us. 1788 */ 1789 goto out; 1790 } 1791 1792 if (sig == SIGKILL) { 1793 /* 1794 * SIGKILL sets process running. 1795 * It will die elsewhere. 1796 * All threads must be restarted. 1797 */ 1798 p->p_flag &= ~P_STOPPED; 1799 goto runfast; 1800 } 1801 1802 if (prop & SA_CONT) { 1803 /* 1804 * If SIGCONT is default (or ignored), we continue the 1805 * process but don't leave the signal in siglist as 1806 * it has no further action. If SIGCONT is held, we 1807 * continue the process and leave the signal in 1808 * siglist. If the process catches SIGCONT, let it 1809 * handle the signal itself. If it isn't waiting on 1810 * an event, it goes back to run state. 1811 * Otherwise, process goes back to sleep state. 1812 */ 1813 p->p_flag &= ~P_STOPPED_SIG; 1814 p->p_flag |= P_CONTINUED; 1815 if (action == SIG_DFL) { 1816 SIGDELSET(*siglist, sig); 1817 } else if (action == SIG_CATCH) { 1818 /* 1819 * The process wants to catch it so it needs 1820 * to run at least one thread, but which one? 1821 * It would seem that the answer would be to 1822 * run an upcall in the next KSE to run, and 1823 * deliver the signal that way. In a NON KSE 1824 * process, we need to make sure that the 1825 * single thread is runnable asap. 1826 * XXXKSE for now however, make them all run. 1827 */ 1828 goto runfast; 1829 } 1830 /* 1831 * The signal is not ignored or caught. 1832 */ 1833 mtx_lock_spin(&sched_lock); 1834 thread_unsuspend(p); 1835 mtx_unlock_spin(&sched_lock); 1836 goto out; 1837 } 1838 1839 if (prop & SA_STOP) { 1840 /* 1841 * Already stopped, don't need to stop again 1842 * (If we did the shell could get confused). 1843 * Just make sure the signal STOP bit set. 1844 */ 1845 p->p_flag |= P_STOPPED_SIG; 1846 SIGDELSET(*siglist, sig); 1847 goto out; 1848 } 1849 1850 /* 1851 * All other kinds of signals: 1852 * If a thread is sleeping interruptibly, simulate a 1853 * wakeup so that when it is continued it will be made 1854 * runnable and can look at the signal. However, don't make 1855 * the PROCESS runnable, leave it stopped. 1856 * It may run a bit until it hits a thread_suspend_check(). 1857 */ 1858 mtx_lock_spin(&sched_lock); 1859 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 1860 sleepq_abort(td); 1861 mtx_unlock_spin(&sched_lock); 1862 goto out; 1863 /* 1864 * Mutexes are short lived. Threads waiting on them will 1865 * hit thread_suspend_check() soon. 1866 */ 1867 } else if (p->p_state == PRS_NORMAL) { 1868 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || 1869 !(prop & SA_STOP)) { 1870 mtx_lock_spin(&sched_lock); 1871 tdsigwakeup(td, sig, action); 1872 mtx_unlock_spin(&sched_lock); 1873 goto out; 1874 } 1875 if (prop & SA_STOP) { 1876 if (p->p_flag & P_PPWAIT) 1877 goto out; 1878 p->p_flag |= P_STOPPED_SIG; 1879 p->p_xstat = sig; 1880 p->p_xthread = td; 1881 mtx_lock_spin(&sched_lock); 1882 FOREACH_THREAD_IN_PROC(p, td0) { 1883 if (TD_IS_SLEEPING(td0) && 1884 (td0->td_flags & TDF_SINTR) && 1885 !TD_IS_SUSPENDED(td0)) { 1886 thread_suspend_one(td0); 1887 } else if (td != td0) { 1888 td0->td_flags |= TDF_ASTPENDING; 1889 } 1890 } 1891 thread_stopped(p); 1892 if (p->p_numthreads == p->p_suspcount) { 1893 SIGDELSET(p->p_siglist, p->p_xstat); 1894 FOREACH_THREAD_IN_PROC(p, td0) 1895 SIGDELSET(td0->td_siglist, p->p_xstat); 1896 } 1897 mtx_unlock_spin(&sched_lock); 1898 goto out; 1899 } 1900 else 1901 goto runfast; 1902 /* NOTREACHED */ 1903 } else { 1904 /* Not in "NORMAL" state. discard the signal. */ 1905 SIGDELSET(*siglist, sig); 1906 goto out; 1907 } 1908 1909 /* 1910 * The process is not stopped so we need to apply the signal to all the 1911 * running threads. 1912 */ 1913 1914 runfast: 1915 mtx_lock_spin(&sched_lock); 1916 tdsigwakeup(td, sig, action); 1917 thread_unsuspend(p); 1918 mtx_unlock_spin(&sched_lock); 1919 out: 1920 /* If we jump here, sched_lock should not be owned. */ 1921 mtx_assert(&sched_lock, MA_NOTOWNED); 1922 } 1923 1924 /* 1925 * The force of a signal has been directed against a single 1926 * thread. We need to see what we can do about knocking it 1927 * out of any sleep it may be in etc. 1928 */ 1929 static void 1930 tdsigwakeup(struct thread *td, int sig, sig_t action) 1931 { 1932 struct proc *p = td->td_proc; 1933 register int prop; 1934 1935 PROC_LOCK_ASSERT(p, MA_OWNED); 1936 mtx_assert(&sched_lock, MA_OWNED); 1937 prop = sigprop(sig); 1938 1939 /* 1940 * Bring the priority of a thread up if we want it to get 1941 * killed in this lifetime. 1942 */ 1943 if (action == SIG_DFL && (prop & SA_KILL)) { 1944 if (td->td_priority > PUSER) 1945 td->td_priority = PUSER; 1946 } 1947 1948 if (TD_ON_SLEEPQ(td)) { 1949 /* 1950 * If thread is sleeping uninterruptibly 1951 * we can't interrupt the sleep... the signal will 1952 * be noticed when the process returns through 1953 * trap() or syscall(). 1954 */ 1955 if ((td->td_flags & TDF_SINTR) == 0) 1956 return; 1957 /* 1958 * Process is sleeping and traced. Make it runnable 1959 * so it can discover the signal in issignal() and stop 1960 * for its parent. 1961 */ 1962 if (p->p_flag & P_TRACED) { 1963 p->p_flag &= ~P_STOPPED_TRACE; 1964 } else { 1965 /* 1966 * If SIGCONT is default (or ignored) and process is 1967 * asleep, we are finished; the process should not 1968 * be awakened. 1969 */ 1970 if ((prop & SA_CONT) && action == SIG_DFL) { 1971 SIGDELSET(p->p_siglist, sig); 1972 /* 1973 * It may be on either list in this state. 1974 * Remove from both for now. 1975 */ 1976 SIGDELSET(td->td_siglist, sig); 1977 return; 1978 } 1979 1980 /* 1981 * Give low priority threads a better chance to run. 1982 */ 1983 if (td->td_priority > PUSER) 1984 td->td_priority = PUSER; 1985 } 1986 sleepq_abort(td); 1987 } else { 1988 /* 1989 * Other states do nothing with the signal immediately, 1990 * other than kicking ourselves if we are running. 1991 * It will either never be noticed, or noticed very soon. 1992 */ 1993 #ifdef SMP 1994 if (TD_IS_RUNNING(td) && td != curthread) 1995 forward_signal(td); 1996 #endif 1997 } 1998 } 1999 2000 int 2001 ptracestop(struct thread *td, int sig) 2002 { 2003 struct proc *p = td->td_proc; 2004 struct thread *td0; 2005 2006 PROC_LOCK_ASSERT(p, MA_OWNED); 2007 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2008 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2009 2010 mtx_lock_spin(&sched_lock); 2011 td->td_flags |= TDF_XSIG; 2012 mtx_unlock_spin(&sched_lock); 2013 td->td_xsig = sig; 2014 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2015 if (p->p_flag & P_SINGLE_EXIT) { 2016 mtx_lock_spin(&sched_lock); 2017 td->td_flags &= ~TDF_XSIG; 2018 mtx_unlock_spin(&sched_lock); 2019 return (sig); 2020 } 2021 /* 2022 * Just make wait() to work, the last stopped thread 2023 * will win. 2024 */ 2025 p->p_xstat = sig; 2026 p->p_xthread = td; 2027 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2028 mtx_lock_spin(&sched_lock); 2029 FOREACH_THREAD_IN_PROC(p, td0) { 2030 if (TD_IS_SLEEPING(td0) && 2031 (td0->td_flags & TDF_SINTR) && 2032 !TD_IS_SUSPENDED(td0)) { 2033 thread_suspend_one(td0); 2034 } else if (td != td0) { 2035 td0->td_flags |= TDF_ASTPENDING; 2036 } 2037 } 2038 stopme: 2039 thread_stopped(p); 2040 thread_suspend_one(td); 2041 PROC_UNLOCK(p); 2042 DROP_GIANT(); 2043 mi_switch(SW_VOL, NULL); 2044 mtx_unlock_spin(&sched_lock); 2045 PICKUP_GIANT(); 2046 PROC_LOCK(p); 2047 if (!(p->p_flag & P_TRACED)) 2048 break; 2049 if (td->td_flags & TDF_DBSUSPEND) { 2050 if (p->p_flag & P_SINGLE_EXIT) 2051 break; 2052 mtx_lock_spin(&sched_lock); 2053 goto stopme; 2054 } 2055 } 2056 return (td->td_xsig); 2057 } 2058 2059 /* 2060 * If the current process has received a signal (should be caught or cause 2061 * termination, should interrupt current syscall), return the signal number. 2062 * Stop signals with default action are processed immediately, then cleared; 2063 * they aren't returned. This is checked after each entry to the system for 2064 * a syscall or trap (though this can usually be done without calling issignal 2065 * by checking the pending signal masks in cursig.) The normal call 2066 * sequence is 2067 * 2068 * while (sig = cursig(curthread)) 2069 * postsig(sig); 2070 */ 2071 static int 2072 issignal(td) 2073 struct thread *td; 2074 { 2075 struct proc *p; 2076 struct sigacts *ps; 2077 sigset_t sigpending; 2078 int sig, prop, newsig; 2079 struct thread *td0; 2080 2081 p = td->td_proc; 2082 ps = p->p_sigacts; 2083 mtx_assert(&ps->ps_mtx, MA_OWNED); 2084 PROC_LOCK_ASSERT(p, MA_OWNED); 2085 for (;;) { 2086 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2087 2088 sigpending = td->td_siglist; 2089 SIGSETNAND(sigpending, td->td_sigmask); 2090 2091 if (p->p_flag & P_PPWAIT) 2092 SIG_STOPSIGMASK(sigpending); 2093 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2094 return (0); 2095 sig = sig_ffs(&sigpending); 2096 2097 if (p->p_stops & S_SIG) { 2098 mtx_unlock(&ps->ps_mtx); 2099 stopevent(p, S_SIG, sig); 2100 mtx_lock(&ps->ps_mtx); 2101 } 2102 2103 /* 2104 * We should see pending but ignored signals 2105 * only if P_TRACED was on when they were posted. 2106 */ 2107 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2108 SIGDELSET(td->td_siglist, sig); 2109 if (td->td_pflags & TDP_SA) 2110 SIGADDSET(td->td_sigmask, sig); 2111 continue; 2112 } 2113 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2114 /* 2115 * If traced, always stop. 2116 */ 2117 mtx_unlock(&ps->ps_mtx); 2118 newsig = ptracestop(td, sig); 2119 mtx_lock(&ps->ps_mtx); 2120 2121 /* 2122 * If parent wants us to take the signal, 2123 * then it will leave it in p->p_xstat; 2124 * otherwise we just look for signals again. 2125 */ 2126 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2127 if (td->td_pflags & TDP_SA) 2128 SIGADDSET(td->td_sigmask, sig); 2129 if (newsig == 0) 2130 continue; 2131 sig = newsig; 2132 /* 2133 * If the traced bit got turned off, go back up 2134 * to the top to rescan signals. This ensures 2135 * that p_sig* and p_sigact are consistent. 2136 */ 2137 if ((p->p_flag & P_TRACED) == 0) 2138 continue; 2139 2140 /* 2141 * Put the new signal into td_siglist. If the 2142 * signal is being masked, look for other signals. 2143 */ 2144 SIGADDSET(td->td_siglist, sig); 2145 if (td->td_pflags & TDP_SA) 2146 SIGDELSET(td->td_sigmask, sig); 2147 if (SIGISMEMBER(td->td_sigmask, sig)) 2148 continue; 2149 signotify(td); 2150 } 2151 2152 prop = sigprop(sig); 2153 2154 /* 2155 * Decide whether the signal should be returned. 2156 * Return the signal's number, or fall through 2157 * to clear it from the pending mask. 2158 */ 2159 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2160 2161 case (intptr_t)SIG_DFL: 2162 /* 2163 * Don't take default actions on system processes. 2164 */ 2165 if (p->p_pid <= 1) { 2166 #ifdef DIAGNOSTIC 2167 /* 2168 * Are you sure you want to ignore SIGSEGV 2169 * in init? XXX 2170 */ 2171 printf("Process (pid %lu) got signal %d\n", 2172 (u_long)p->p_pid, sig); 2173 #endif 2174 break; /* == ignore */ 2175 } 2176 /* 2177 * If there is a pending stop signal to process 2178 * with default action, stop here, 2179 * then clear the signal. However, 2180 * if process is member of an orphaned 2181 * process group, ignore tty stop signals. 2182 */ 2183 if (prop & SA_STOP) { 2184 if (p->p_flag & P_TRACED || 2185 (p->p_pgrp->pg_jobc == 0 && 2186 prop & SA_TTYSTOP)) 2187 break; /* == ignore */ 2188 mtx_unlock(&ps->ps_mtx); 2189 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2190 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2191 p->p_flag |= P_STOPPED_SIG; 2192 p->p_xstat = sig; 2193 p->p_xthread = td; 2194 mtx_lock_spin(&sched_lock); 2195 FOREACH_THREAD_IN_PROC(p, td0) { 2196 if (TD_IS_SLEEPING(td0) && 2197 (td0->td_flags & TDF_SINTR) && 2198 !TD_IS_SUSPENDED(td0)) { 2199 thread_suspend_one(td0); 2200 } else if (td != td0) { 2201 td0->td_flags |= TDF_ASTPENDING; 2202 } 2203 } 2204 thread_stopped(p); 2205 thread_suspend_one(td); 2206 PROC_UNLOCK(p); 2207 DROP_GIANT(); 2208 mi_switch(SW_INVOL, NULL); 2209 mtx_unlock_spin(&sched_lock); 2210 PICKUP_GIANT(); 2211 PROC_LOCK(p); 2212 mtx_lock(&ps->ps_mtx); 2213 break; 2214 } else if (prop & SA_IGNORE) { 2215 /* 2216 * Except for SIGCONT, shouldn't get here. 2217 * Default action is to ignore; drop it. 2218 */ 2219 break; /* == ignore */ 2220 } else 2221 return (sig); 2222 /*NOTREACHED*/ 2223 2224 case (intptr_t)SIG_IGN: 2225 /* 2226 * Masking above should prevent us ever trying 2227 * to take action on an ignored signal other 2228 * than SIGCONT, unless process is traced. 2229 */ 2230 if ((prop & SA_CONT) == 0 && 2231 (p->p_flag & P_TRACED) == 0) 2232 printf("issignal\n"); 2233 break; /* == ignore */ 2234 2235 default: 2236 /* 2237 * This signal has an action, let 2238 * postsig() process it. 2239 */ 2240 return (sig); 2241 } 2242 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2243 } 2244 /* NOTREACHED */ 2245 } 2246 2247 /* 2248 * Put the argument process into the stopped state and notify the parent 2249 * via wakeup. Signals are handled elsewhere. The process must not be 2250 * on the run queue. Must be called with the proc p locked. 2251 */ 2252 static void 2253 stop(struct proc *p) 2254 { 2255 2256 PROC_LOCK_ASSERT(p, MA_OWNED); 2257 p->p_flag |= P_STOPPED_SIG; 2258 p->p_flag &= ~P_WAITED; 2259 wakeup(p->p_pptr); 2260 } 2261 2262 /* 2263 * MPSAFE 2264 */ 2265 void 2266 thread_stopped(struct proc *p) 2267 { 2268 struct proc *p1 = curthread->td_proc; 2269 struct sigacts *ps; 2270 int n; 2271 2272 PROC_LOCK_ASSERT(p, MA_OWNED); 2273 mtx_assert(&sched_lock, MA_OWNED); 2274 n = p->p_suspcount; 2275 if (p == p1) 2276 n++; 2277 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2278 mtx_unlock_spin(&sched_lock); 2279 stop(p); 2280 PROC_LOCK(p->p_pptr); 2281 ps = p->p_pptr->p_sigacts; 2282 mtx_lock(&ps->ps_mtx); 2283 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2284 mtx_unlock(&ps->ps_mtx); 2285 psignal(p->p_pptr, SIGCHLD); 2286 } else 2287 mtx_unlock(&ps->ps_mtx); 2288 PROC_UNLOCK(p->p_pptr); 2289 mtx_lock_spin(&sched_lock); 2290 } 2291 } 2292 2293 /* 2294 * Take the action for the specified signal 2295 * from the current set of pending signals. 2296 */ 2297 void 2298 postsig(sig) 2299 register int sig; 2300 { 2301 struct thread *td = curthread; 2302 register struct proc *p = td->td_proc; 2303 struct sigacts *ps; 2304 sig_t action; 2305 sigset_t returnmask; 2306 int code; 2307 2308 KASSERT(sig != 0, ("postsig")); 2309 2310 PROC_LOCK_ASSERT(p, MA_OWNED); 2311 ps = p->p_sigacts; 2312 mtx_assert(&ps->ps_mtx, MA_OWNED); 2313 SIGDELSET(td->td_siglist, sig); 2314 action = ps->ps_sigact[_SIG_IDX(sig)]; 2315 #ifdef KTRACE 2316 if (KTRPOINT(td, KTR_PSIG)) 2317 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2318 &td->td_oldsigmask : &td->td_sigmask, 0); 2319 #endif 2320 if (p->p_stops & S_SIG) { 2321 mtx_unlock(&ps->ps_mtx); 2322 stopevent(p, S_SIG, sig); 2323 mtx_lock(&ps->ps_mtx); 2324 } 2325 2326 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2327 /* 2328 * Default action, where the default is to kill 2329 * the process. (Other cases were ignored above.) 2330 */ 2331 mtx_unlock(&ps->ps_mtx); 2332 sigexit(td, sig); 2333 /* NOTREACHED */ 2334 } else { 2335 if (td->td_pflags & TDP_SA) { 2336 if (sig == SIGKILL) { 2337 mtx_unlock(&ps->ps_mtx); 2338 sigexit(td, sig); 2339 } 2340 } 2341 2342 /* 2343 * If we get here, the signal must be caught. 2344 */ 2345 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2346 ("postsig action")); 2347 /* 2348 * Set the new mask value and also defer further 2349 * occurrences of this signal. 2350 * 2351 * Special case: user has done a sigsuspend. Here the 2352 * current mask is not of interest, but rather the 2353 * mask from before the sigsuspend is what we want 2354 * restored after the signal processing is completed. 2355 */ 2356 if (td->td_pflags & TDP_OLDMASK) { 2357 returnmask = td->td_oldsigmask; 2358 td->td_pflags &= ~TDP_OLDMASK; 2359 } else 2360 returnmask = td->td_sigmask; 2361 2362 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2363 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2364 SIGADDSET(td->td_sigmask, sig); 2365 2366 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2367 /* 2368 * See kern_sigaction() for origin of this code. 2369 */ 2370 SIGDELSET(ps->ps_sigcatch, sig); 2371 if (sig != SIGCONT && 2372 sigprop(sig) & SA_IGNORE) 2373 SIGADDSET(ps->ps_sigignore, sig); 2374 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2375 } 2376 p->p_stats->p_ru.ru_nsignals++; 2377 if (p->p_sig != sig) { 2378 code = 0; 2379 } else { 2380 code = p->p_code; 2381 p->p_code = 0; 2382 p->p_sig = 0; 2383 } 2384 if (td->td_pflags & TDP_SA) 2385 thread_signal_add(curthread, sig); 2386 else 2387 (*p->p_sysent->sv_sendsig)(action, sig, 2388 &returnmask, code); 2389 } 2390 } 2391 2392 /* 2393 * Kill the current process for stated reason. 2394 */ 2395 void 2396 killproc(p, why) 2397 struct proc *p; 2398 char *why; 2399 { 2400 2401 PROC_LOCK_ASSERT(p, MA_OWNED); 2402 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2403 p, p->p_pid, p->p_comm); 2404 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2405 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2406 psignal(p, SIGKILL); 2407 } 2408 2409 /* 2410 * Force the current process to exit with the specified signal, dumping core 2411 * if appropriate. We bypass the normal tests for masked and caught signals, 2412 * allowing unrecoverable failures to terminate the process without changing 2413 * signal state. Mark the accounting record with the signal termination. 2414 * If dumping core, save the signal number for the debugger. Calls exit and 2415 * does not return. 2416 * 2417 * MPSAFE 2418 */ 2419 void 2420 sigexit(td, sig) 2421 struct thread *td; 2422 int sig; 2423 { 2424 struct proc *p = td->td_proc; 2425 2426 PROC_LOCK_ASSERT(p, MA_OWNED); 2427 p->p_acflag |= AXSIG; 2428 if (sigprop(sig) & SA_CORE) { 2429 p->p_sig = sig; 2430 /* 2431 * Log signals which would cause core dumps 2432 * (Log as LOG_INFO to appease those who don't want 2433 * these messages.) 2434 * XXX : Todo, as well as euid, write out ruid too 2435 * Note that coredump() drops proc lock. 2436 */ 2437 if (coredump(td) == 0) 2438 sig |= WCOREFLAG; 2439 if (kern_logsigexit) 2440 log(LOG_INFO, 2441 "pid %d (%s), uid %d: exited on signal %d%s\n", 2442 p->p_pid, p->p_comm, 2443 td->td_ucred ? td->td_ucred->cr_uid : -1, 2444 sig &~ WCOREFLAG, 2445 sig & WCOREFLAG ? " (core dumped)" : ""); 2446 } else 2447 PROC_UNLOCK(p); 2448 exit1(td, W_EXITCODE(0, sig)); 2449 /* NOTREACHED */ 2450 } 2451 2452 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2453 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2454 sizeof(corefilename), "process corefile name format string"); 2455 2456 /* 2457 * expand_name(name, uid, pid) 2458 * Expand the name described in corefilename, using name, uid, and pid. 2459 * corefilename is a printf-like string, with three format specifiers: 2460 * %N name of process ("name") 2461 * %P process id (pid) 2462 * %U user id (uid) 2463 * For example, "%N.core" is the default; they can be disabled completely 2464 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2465 * This is controlled by the sysctl variable kern.corefile (see above). 2466 */ 2467 2468 static char * 2469 expand_name(name, uid, pid) 2470 const char *name; 2471 uid_t uid; 2472 pid_t pid; 2473 { 2474 const char *format, *appendstr; 2475 char *temp; 2476 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2477 size_t i, l, n; 2478 2479 format = corefilename; 2480 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2481 if (temp == NULL) 2482 return (NULL); 2483 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2484 switch (format[i]) { 2485 case '%': /* Format character */ 2486 i++; 2487 switch (format[i]) { 2488 case '%': 2489 appendstr = "%"; 2490 break; 2491 case 'N': /* process name */ 2492 appendstr = name; 2493 break; 2494 case 'P': /* process id */ 2495 sprintf(buf, "%u", pid); 2496 appendstr = buf; 2497 break; 2498 case 'U': /* user id */ 2499 sprintf(buf, "%u", uid); 2500 appendstr = buf; 2501 break; 2502 default: 2503 appendstr = ""; 2504 log(LOG_ERR, 2505 "Unknown format character %c in `%s'\n", 2506 format[i], format); 2507 } 2508 l = strlen(appendstr); 2509 if ((n + l) >= MAXPATHLEN) 2510 goto toolong; 2511 memcpy(temp + n, appendstr, l); 2512 n += l; 2513 break; 2514 default: 2515 temp[n++] = format[i]; 2516 } 2517 } 2518 if (format[i] != '\0') 2519 goto toolong; 2520 return (temp); 2521 toolong: 2522 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2523 (long)pid, name, (u_long)uid); 2524 free(temp, M_TEMP); 2525 return (NULL); 2526 } 2527 2528 /* 2529 * Dump a process' core. The main routine does some 2530 * policy checking, and creates the name of the coredump; 2531 * then it passes on a vnode and a size limit to the process-specific 2532 * coredump routine if there is one; if there _is not_ one, it returns 2533 * ENOSYS; otherwise it returns the error from the process-specific routine. 2534 */ 2535 2536 static int 2537 coredump(struct thread *td) 2538 { 2539 struct proc *p = td->td_proc; 2540 register struct vnode *vp; 2541 register struct ucred *cred = td->td_ucred; 2542 struct flock lf; 2543 struct nameidata nd; 2544 struct vattr vattr; 2545 int error, error1, flags, locked; 2546 struct mount *mp; 2547 char *name; /* name of corefile */ 2548 off_t limit; 2549 2550 PROC_LOCK_ASSERT(p, MA_OWNED); 2551 _STOPEVENT(p, S_CORE, 0); 2552 2553 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2554 PROC_UNLOCK(p); 2555 return (EFAULT); 2556 } 2557 2558 /* 2559 * Note that the bulk of limit checking is done after 2560 * the corefile is created. The exception is if the limit 2561 * for corefiles is 0, in which case we don't bother 2562 * creating the corefile at all. This layout means that 2563 * a corefile is truncated instead of not being created, 2564 * if it is larger than the limit. 2565 */ 2566 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2567 PROC_UNLOCK(p); 2568 if (limit == 0) 2569 return (EFBIG); 2570 2571 mtx_lock(&Giant); 2572 restart: 2573 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2574 if (name == NULL) { 2575 mtx_unlock(&Giant); 2576 return (EINVAL); 2577 } 2578 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2579 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2580 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2581 free(name, M_TEMP); 2582 if (error) { 2583 mtx_unlock(&Giant); 2584 return (error); 2585 } 2586 NDFREE(&nd, NDF_ONLY_PNBUF); 2587 vp = nd.ni_vp; 2588 2589 /* Don't dump to non-regular files or files with links. */ 2590 if (vp->v_type != VREG || 2591 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2592 VOP_UNLOCK(vp, 0, td); 2593 error = EFAULT; 2594 goto out; 2595 } 2596 2597 VOP_UNLOCK(vp, 0, td); 2598 lf.l_whence = SEEK_SET; 2599 lf.l_start = 0; 2600 lf.l_len = 0; 2601 lf.l_type = F_WRLCK; 2602 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2603 2604 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2605 lf.l_type = F_UNLCK; 2606 if (locked) 2607 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2608 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2609 return (error); 2610 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2611 return (error); 2612 goto restart; 2613 } 2614 2615 VATTR_NULL(&vattr); 2616 vattr.va_size = 0; 2617 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2618 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2619 VOP_SETATTR(vp, &vattr, cred, td); 2620 VOP_UNLOCK(vp, 0, td); 2621 PROC_LOCK(p); 2622 p->p_acflag |= ACORE; 2623 PROC_UNLOCK(p); 2624 2625 error = p->p_sysent->sv_coredump ? 2626 p->p_sysent->sv_coredump(td, vp, limit) : 2627 ENOSYS; 2628 2629 if (locked) { 2630 lf.l_type = F_UNLCK; 2631 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2632 } 2633 vn_finished_write(mp); 2634 out: 2635 error1 = vn_close(vp, FWRITE, cred, td); 2636 mtx_unlock(&Giant); 2637 if (error == 0) 2638 error = error1; 2639 return (error); 2640 } 2641 2642 /* 2643 * Nonexistent system call-- signal process (may want to handle it). 2644 * Flag error in case process won't see signal immediately (blocked or ignored). 2645 */ 2646 #ifndef _SYS_SYSPROTO_H_ 2647 struct nosys_args { 2648 int dummy; 2649 }; 2650 #endif 2651 /* 2652 * MPSAFE 2653 */ 2654 /* ARGSUSED */ 2655 int 2656 nosys(td, args) 2657 struct thread *td; 2658 struct nosys_args *args; 2659 { 2660 struct proc *p = td->td_proc; 2661 2662 PROC_LOCK(p); 2663 psignal(p, SIGSYS); 2664 PROC_UNLOCK(p); 2665 return (ENOSYS); 2666 } 2667 2668 /* 2669 * Send a SIGIO or SIGURG signal to a process or process group using 2670 * stored credentials rather than those of the current process. 2671 */ 2672 void 2673 pgsigio(sigiop, sig, checkctty) 2674 struct sigio **sigiop; 2675 int sig, checkctty; 2676 { 2677 struct sigio *sigio; 2678 2679 SIGIO_LOCK(); 2680 sigio = *sigiop; 2681 if (sigio == NULL) { 2682 SIGIO_UNLOCK(); 2683 return; 2684 } 2685 if (sigio->sio_pgid > 0) { 2686 PROC_LOCK(sigio->sio_proc); 2687 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2688 psignal(sigio->sio_proc, sig); 2689 PROC_UNLOCK(sigio->sio_proc); 2690 } else if (sigio->sio_pgid < 0) { 2691 struct proc *p; 2692 2693 PGRP_LOCK(sigio->sio_pgrp); 2694 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2695 PROC_LOCK(p); 2696 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2697 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2698 psignal(p, sig); 2699 PROC_UNLOCK(p); 2700 } 2701 PGRP_UNLOCK(sigio->sio_pgrp); 2702 } 2703 SIGIO_UNLOCK(); 2704 } 2705 2706 static int 2707 filt_sigattach(struct knote *kn) 2708 { 2709 struct proc *p = curproc; 2710 2711 kn->kn_ptr.p_proc = p; 2712 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2713 2714 PROC_LOCK(p); 2715 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2716 PROC_UNLOCK(p); 2717 2718 return (0); 2719 } 2720 2721 static void 2722 filt_sigdetach(struct knote *kn) 2723 { 2724 struct proc *p = kn->kn_ptr.p_proc; 2725 2726 PROC_LOCK(p); 2727 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2728 PROC_UNLOCK(p); 2729 } 2730 2731 /* 2732 * signal knotes are shared with proc knotes, so we apply a mask to 2733 * the hint in order to differentiate them from process hints. This 2734 * could be avoided by using a signal-specific knote list, but probably 2735 * isn't worth the trouble. 2736 */ 2737 static int 2738 filt_signal(struct knote *kn, long hint) 2739 { 2740 2741 if (hint & NOTE_SIGNAL) { 2742 hint &= ~NOTE_SIGNAL; 2743 2744 if (kn->kn_id == hint) 2745 kn->kn_data++; 2746 } 2747 return (kn->kn_data != 0); 2748 } 2749 2750 struct sigacts * 2751 sigacts_alloc(void) 2752 { 2753 struct sigacts *ps; 2754 2755 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2756 ps->ps_refcnt = 1; 2757 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2758 return (ps); 2759 } 2760 2761 void 2762 sigacts_free(struct sigacts *ps) 2763 { 2764 2765 mtx_lock(&ps->ps_mtx); 2766 ps->ps_refcnt--; 2767 if (ps->ps_refcnt == 0) { 2768 mtx_destroy(&ps->ps_mtx); 2769 free(ps, M_SUBPROC); 2770 } else 2771 mtx_unlock(&ps->ps_mtx); 2772 } 2773 2774 struct sigacts * 2775 sigacts_hold(struct sigacts *ps) 2776 { 2777 mtx_lock(&ps->ps_mtx); 2778 ps->ps_refcnt++; 2779 mtx_unlock(&ps->ps_mtx); 2780 return (ps); 2781 } 2782 2783 void 2784 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2785 { 2786 2787 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2788 mtx_lock(&src->ps_mtx); 2789 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2790 mtx_unlock(&src->ps_mtx); 2791 } 2792 2793 int 2794 sigacts_shared(struct sigacts *ps) 2795 { 2796 int shared; 2797 2798 mtx_lock(&ps->ps_mtx); 2799 shared = ps->ps_refcnt > 1; 2800 mtx_unlock(&ps->ps_mtx); 2801 return (shared); 2802 } 2803