Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/signalvar.h> 46 #include <sys/vnode.h> 47 #include <sys/acct.h> 48 #include <sys/condvar.h> 49 #include <sys/event.h> 50 #include <sys/fcntl.h> 51 #include <sys/kernel.h> 52 #include <sys/kse.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/pioctl.h> 61 #include <sys/resourcevar.h> 62 #include <sys/sched.h> 63 #include <sys/sleepqueue.h> 64 #include <sys/smp.h> 65 #include <sys/stat.h> 66 #include <sys/sx.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysent.h> 70 #include <sys/syslog.h> 71 #include <sys/sysproto.h> 72 #include <sys/unistd.h> 73 #include <sys/wait.h> 74 75 #include <machine/cpu.h> 76 77 #include <security/audit/audit.h> 78 79 #if defined (__alpha__) && !defined(COMPAT_43) 80 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 81 #endif 82 83 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 84 85 static int coredump(struct thread *); 86 static char *expand_name(const char *, uid_t, pid_t); 87 static int killpg1(struct thread *td, int sig, int pgid, int all); 88 static int issignal(struct thread *p); 89 static int sigprop(int sig); 90 static void tdsigwakeup(struct thread *, int, sig_t, int); 91 static void sig_suspend_threads(struct thread *, struct proc *, int); 92 static int filt_sigattach(struct knote *kn); 93 static void filt_sigdetach(struct knote *kn); 94 static int filt_signal(struct knote *kn, long hint); 95 static struct thread *sigtd(struct proc *p, int sig, int prop); 96 static int kern_sigtimedwait(struct thread *td, sigset_t set, 97 siginfo_t *info, struct timespec *timeout); 98 static void do_tdsignal(struct thread *td, int sig, sigtarget_t target); 99 100 struct filterops sig_filtops = 101 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 102 103 static int kern_logsigexit = 1; 104 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 105 &kern_logsigexit, 0, 106 "Log processes quitting on abnormal signals to syslog(3)"); 107 108 /* 109 * Policy -- Can ucred cr1 send SIGIO to process cr2? 110 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 111 * in the right situations. 112 */ 113 #define CANSIGIO(cr1, cr2) \ 114 ((cr1)->cr_uid == 0 || \ 115 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 116 (cr1)->cr_uid == (cr2)->cr_ruid || \ 117 (cr1)->cr_ruid == (cr2)->cr_uid || \ 118 (cr1)->cr_uid == (cr2)->cr_uid) 119 120 int sugid_coredump; 121 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 122 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 123 124 static int do_coredump = 1; 125 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 126 &do_coredump, 0, "Enable/Disable coredumps"); 127 128 static int set_core_nodump_flag = 0; 129 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 130 0, "Enable setting the NODUMP flag on coredump files"); 131 132 /* 133 * Signal properties and actions. 134 * The array below categorizes the signals and their default actions 135 * according to the following properties: 136 */ 137 #define SA_KILL 0x01 /* terminates process by default */ 138 #define SA_CORE 0x02 /* ditto and coredumps */ 139 #define SA_STOP 0x04 /* suspend process */ 140 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 141 #define SA_IGNORE 0x10 /* ignore by default */ 142 #define SA_CONT 0x20 /* continue if suspended */ 143 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 144 #define SA_PROC 0x80 /* deliverable to any thread */ 145 146 static int sigproptbl[NSIG] = { 147 SA_KILL|SA_PROC, /* SIGHUP */ 148 SA_KILL|SA_PROC, /* SIGINT */ 149 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 150 SA_KILL|SA_CORE, /* SIGILL */ 151 SA_KILL|SA_CORE, /* SIGTRAP */ 152 SA_KILL|SA_CORE, /* SIGABRT */ 153 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 154 SA_KILL|SA_CORE, /* SIGFPE */ 155 SA_KILL|SA_PROC, /* SIGKILL */ 156 SA_KILL|SA_CORE, /* SIGBUS */ 157 SA_KILL|SA_CORE, /* SIGSEGV */ 158 SA_KILL|SA_CORE, /* SIGSYS */ 159 SA_KILL|SA_PROC, /* SIGPIPE */ 160 SA_KILL|SA_PROC, /* SIGALRM */ 161 SA_KILL|SA_PROC, /* SIGTERM */ 162 SA_IGNORE|SA_PROC, /* SIGURG */ 163 SA_STOP|SA_PROC, /* SIGSTOP */ 164 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 165 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 166 SA_IGNORE|SA_PROC, /* SIGCHLD */ 167 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 168 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 169 SA_IGNORE|SA_PROC, /* SIGIO */ 170 SA_KILL, /* SIGXCPU */ 171 SA_KILL, /* SIGXFSZ */ 172 SA_KILL|SA_PROC, /* SIGVTALRM */ 173 SA_KILL|SA_PROC, /* SIGPROF */ 174 SA_IGNORE|SA_PROC, /* SIGWINCH */ 175 SA_IGNORE|SA_PROC, /* SIGINFO */ 176 SA_KILL|SA_PROC, /* SIGUSR1 */ 177 SA_KILL|SA_PROC, /* SIGUSR2 */ 178 }; 179 180 /* 181 * Determine signal that should be delivered to process p, the current 182 * process, 0 if none. If there is a pending stop signal with default 183 * action, the process stops in issignal(). 184 * XXXKSE the check for a pending stop is not done under KSE 185 * 186 * MP SAFE. 187 */ 188 int 189 cursig(struct thread *td) 190 { 191 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 192 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 193 mtx_assert(&sched_lock, MA_NOTOWNED); 194 return (SIGPENDING(td) ? issignal(td) : 0); 195 } 196 197 /* 198 * Arrange for ast() to handle unmasked pending signals on return to user 199 * mode. This must be called whenever a signal is added to td_siglist or 200 * unmasked in td_sigmask. 201 */ 202 void 203 signotify(struct thread *td) 204 { 205 struct proc *p; 206 sigset_t set, saved; 207 208 p = td->td_proc; 209 210 PROC_LOCK_ASSERT(p, MA_OWNED); 211 212 /* 213 * If our mask changed we may have to move signal that were 214 * previously masked by all threads to our siglist. 215 */ 216 set = p->p_siglist; 217 if (p->p_flag & P_SA) 218 saved = p->p_siglist; 219 SIGSETNAND(set, td->td_sigmask); 220 SIGSETNAND(p->p_siglist, set); 221 SIGSETOR(td->td_siglist, set); 222 223 if (SIGPENDING(td)) { 224 mtx_lock_spin(&sched_lock); 225 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 226 mtx_unlock_spin(&sched_lock); 227 } 228 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 229 if (!SIGSETEQ(saved, p->p_siglist)) { 230 /* pending set changed */ 231 p->p_flag |= P_SIGEVENT; 232 wakeup(&p->p_siglist); 233 } 234 } 235 } 236 237 int 238 sigonstack(size_t sp) 239 { 240 struct thread *td = curthread; 241 242 return ((td->td_pflags & TDP_ALTSTACK) ? 243 #if defined(COMPAT_43) 244 ((td->td_sigstk.ss_size == 0) ? 245 (td->td_sigstk.ss_flags & SS_ONSTACK) : 246 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 247 #else 248 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 249 #endif 250 : 0); 251 } 252 253 static __inline int 254 sigprop(int sig) 255 { 256 257 if (sig > 0 && sig < NSIG) 258 return (sigproptbl[_SIG_IDX(sig)]); 259 return (0); 260 } 261 262 int 263 sig_ffs(sigset_t *set) 264 { 265 int i; 266 267 for (i = 0; i < _SIG_WORDS; i++) 268 if (set->__bits[i]) 269 return (ffs(set->__bits[i]) + (i * 32)); 270 return (0); 271 } 272 273 /* 274 * kern_sigaction 275 * sigaction 276 * freebsd4_sigaction 277 * osigaction 278 * 279 * MPSAFE 280 */ 281 int 282 kern_sigaction(td, sig, act, oact, flags) 283 struct thread *td; 284 register int sig; 285 struct sigaction *act, *oact; 286 int flags; 287 { 288 struct sigacts *ps; 289 struct thread *td0; 290 struct proc *p = td->td_proc; 291 292 if (!_SIG_VALID(sig)) 293 return (EINVAL); 294 295 PROC_LOCK(p); 296 ps = p->p_sigacts; 297 mtx_lock(&ps->ps_mtx); 298 if (oact) { 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 oact->sa_sigaction = 312 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 313 } else 314 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 315 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 316 oact->sa_flags |= SA_NOCLDSTOP; 317 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 318 oact->sa_flags |= SA_NOCLDWAIT; 319 } 320 if (act) { 321 if ((sig == SIGKILL || sig == SIGSTOP) && 322 act->sa_handler != SIG_DFL) { 323 mtx_unlock(&ps->ps_mtx); 324 PROC_UNLOCK(p); 325 return (EINVAL); 326 } 327 328 /* 329 * Change setting atomically. 330 */ 331 332 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 333 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 334 if (act->sa_flags & SA_SIGINFO) { 335 ps->ps_sigact[_SIG_IDX(sig)] = 336 (__sighandler_t *)act->sa_sigaction; 337 SIGADDSET(ps->ps_siginfo, sig); 338 } else { 339 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 340 SIGDELSET(ps->ps_siginfo, sig); 341 } 342 if (!(act->sa_flags & SA_RESTART)) 343 SIGADDSET(ps->ps_sigintr, sig); 344 else 345 SIGDELSET(ps->ps_sigintr, sig); 346 if (act->sa_flags & SA_ONSTACK) 347 SIGADDSET(ps->ps_sigonstack, sig); 348 else 349 SIGDELSET(ps->ps_sigonstack, sig); 350 if (act->sa_flags & SA_RESETHAND) 351 SIGADDSET(ps->ps_sigreset, sig); 352 else 353 SIGDELSET(ps->ps_sigreset, sig); 354 if (act->sa_flags & SA_NODEFER) 355 SIGADDSET(ps->ps_signodefer, sig); 356 else 357 SIGDELSET(ps->ps_signodefer, sig); 358 if (sig == SIGCHLD) { 359 if (act->sa_flags & SA_NOCLDSTOP) 360 ps->ps_flag |= PS_NOCLDSTOP; 361 else 362 ps->ps_flag &= ~PS_NOCLDSTOP; 363 if (act->sa_flags & SA_NOCLDWAIT) { 364 /* 365 * Paranoia: since SA_NOCLDWAIT is implemented 366 * by reparenting the dying child to PID 1 (and 367 * trust it to reap the zombie), PID 1 itself 368 * is forbidden to set SA_NOCLDWAIT. 369 */ 370 if (p->p_pid == 1) 371 ps->ps_flag &= ~PS_NOCLDWAIT; 372 else 373 ps->ps_flag |= PS_NOCLDWAIT; 374 } else 375 ps->ps_flag &= ~PS_NOCLDWAIT; 376 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 377 ps->ps_flag |= PS_CLDSIGIGN; 378 else 379 ps->ps_flag &= ~PS_CLDSIGIGN; 380 } 381 /* 382 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 383 * and for signals set to SIG_DFL where the default is to 384 * ignore. However, don't put SIGCONT in ps_sigignore, as we 385 * have to restart the process. 386 */ 387 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 388 (sigprop(sig) & SA_IGNORE && 389 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 390 if ((p->p_flag & P_SA) && 391 SIGISMEMBER(p->p_siglist, sig)) { 392 p->p_flag |= P_SIGEVENT; 393 wakeup(&p->p_siglist); 394 } 395 /* never to be seen again */ 396 SIGDELSET(p->p_siglist, sig); 397 mtx_lock_spin(&sched_lock); 398 FOREACH_THREAD_IN_PROC(p, td0) 399 SIGDELSET(td0->td_siglist, sig); 400 mtx_unlock_spin(&sched_lock); 401 if (sig != SIGCONT) 402 /* easier in psignal */ 403 SIGADDSET(ps->ps_sigignore, sig); 404 SIGDELSET(ps->ps_sigcatch, sig); 405 } else { 406 SIGDELSET(ps->ps_sigignore, sig); 407 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 408 SIGDELSET(ps->ps_sigcatch, sig); 409 else 410 SIGADDSET(ps->ps_sigcatch, sig); 411 } 412 #ifdef COMPAT_FREEBSD4 413 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 414 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 415 (flags & KSA_FREEBSD4) == 0) 416 SIGDELSET(ps->ps_freebsd4, sig); 417 else 418 SIGADDSET(ps->ps_freebsd4, sig); 419 #endif 420 #ifdef COMPAT_43 421 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 422 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 423 (flags & KSA_OSIGSET) == 0) 424 SIGDELSET(ps->ps_osigset, sig); 425 else 426 SIGADDSET(ps->ps_osigset, sig); 427 #endif 428 } 429 mtx_unlock(&ps->ps_mtx); 430 PROC_UNLOCK(p); 431 return (0); 432 } 433 434 #ifndef _SYS_SYSPROTO_H_ 435 struct sigaction_args { 436 int sig; 437 struct sigaction *act; 438 struct sigaction *oact; 439 }; 440 #endif 441 /* 442 * MPSAFE 443 */ 444 int 445 sigaction(td, uap) 446 struct thread *td; 447 register struct sigaction_args *uap; 448 { 449 struct sigaction act, oact; 450 register struct sigaction *actp, *oactp; 451 int error; 452 453 actp = (uap->act != NULL) ? &act : NULL; 454 oactp = (uap->oact != NULL) ? &oact : NULL; 455 if (actp) { 456 error = copyin(uap->act, actp, sizeof(act)); 457 if (error) 458 return (error); 459 } 460 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 461 if (oactp && !error) 462 error = copyout(oactp, uap->oact, sizeof(oact)); 463 return (error); 464 } 465 466 #ifdef COMPAT_FREEBSD4 467 #ifndef _SYS_SYSPROTO_H_ 468 struct freebsd4_sigaction_args { 469 int sig; 470 struct sigaction *act; 471 struct sigaction *oact; 472 }; 473 #endif 474 /* 475 * MPSAFE 476 */ 477 int 478 freebsd4_sigaction(td, uap) 479 struct thread *td; 480 register struct freebsd4_sigaction_args *uap; 481 { 482 struct sigaction act, oact; 483 register struct sigaction *actp, *oactp; 484 int error; 485 486 487 actp = (uap->act != NULL) ? &act : NULL; 488 oactp = (uap->oact != NULL) ? &oact : NULL; 489 if (actp) { 490 error = copyin(uap->act, actp, sizeof(act)); 491 if (error) 492 return (error); 493 } 494 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 495 if (oactp && !error) 496 error = copyout(oactp, uap->oact, sizeof(oact)); 497 return (error); 498 } 499 #endif /* COMAPT_FREEBSD4 */ 500 501 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 502 #ifndef _SYS_SYSPROTO_H_ 503 struct osigaction_args { 504 int signum; 505 struct osigaction *nsa; 506 struct osigaction *osa; 507 }; 508 #endif 509 /* 510 * MPSAFE 511 */ 512 int 513 osigaction(td, uap) 514 struct thread *td; 515 register struct osigaction_args *uap; 516 { 517 struct osigaction sa; 518 struct sigaction nsa, osa; 519 register struct sigaction *nsap, *osap; 520 int error; 521 522 if (uap->signum <= 0 || uap->signum >= ONSIG) 523 return (EINVAL); 524 525 nsap = (uap->nsa != NULL) ? &nsa : NULL; 526 osap = (uap->osa != NULL) ? &osa : NULL; 527 528 if (nsap) { 529 error = copyin(uap->nsa, &sa, sizeof(sa)); 530 if (error) 531 return (error); 532 nsap->sa_handler = sa.sa_handler; 533 nsap->sa_flags = sa.sa_flags; 534 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 535 } 536 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 537 if (osap && !error) { 538 sa.sa_handler = osap->sa_handler; 539 sa.sa_flags = osap->sa_flags; 540 SIG2OSIG(osap->sa_mask, sa.sa_mask); 541 error = copyout(&sa, uap->osa, sizeof(sa)); 542 } 543 return (error); 544 } 545 546 #if !defined(__i386__) && !defined(__alpha__) 547 /* Avoid replicating the same stub everywhere */ 548 int 549 osigreturn(td, uap) 550 struct thread *td; 551 struct osigreturn_args *uap; 552 { 553 554 return (nosys(td, (struct nosys_args *)uap)); 555 } 556 #endif 557 #endif /* COMPAT_43 */ 558 559 /* 560 * Initialize signal state for process 0; 561 * set to ignore signals that are ignored by default. 562 */ 563 void 564 siginit(p) 565 struct proc *p; 566 { 567 register int i; 568 struct sigacts *ps; 569 570 PROC_LOCK(p); 571 ps = p->p_sigacts; 572 mtx_lock(&ps->ps_mtx); 573 for (i = 1; i <= NSIG; i++) 574 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 575 SIGADDSET(ps->ps_sigignore, i); 576 mtx_unlock(&ps->ps_mtx); 577 PROC_UNLOCK(p); 578 } 579 580 /* 581 * Reset signals for an exec of the specified process. 582 */ 583 void 584 execsigs(struct proc *p) 585 { 586 struct sigacts *ps; 587 int sig; 588 struct thread *td; 589 590 /* 591 * Reset caught signals. Held signals remain held 592 * through td_sigmask (unless they were caught, 593 * and are now ignored by default). 594 */ 595 PROC_LOCK_ASSERT(p, MA_OWNED); 596 td = FIRST_THREAD_IN_PROC(p); 597 ps = p->p_sigacts; 598 mtx_lock(&ps->ps_mtx); 599 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 600 sig = sig_ffs(&ps->ps_sigcatch); 601 SIGDELSET(ps->ps_sigcatch, sig); 602 if (sigprop(sig) & SA_IGNORE) { 603 if (sig != SIGCONT) 604 SIGADDSET(ps->ps_sigignore, sig); 605 SIGDELSET(p->p_siglist, sig); 606 /* 607 * There is only one thread at this point. 608 */ 609 SIGDELSET(td->td_siglist, sig); 610 } 611 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 612 } 613 /* 614 * Reset stack state to the user stack. 615 * Clear set of signals caught on the signal stack. 616 */ 617 td->td_sigstk.ss_flags = SS_DISABLE; 618 td->td_sigstk.ss_size = 0; 619 td->td_sigstk.ss_sp = 0; 620 td->td_pflags &= ~TDP_ALTSTACK; 621 /* 622 * Reset no zombies if child dies flag as Solaris does. 623 */ 624 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 625 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 626 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 627 mtx_unlock(&ps->ps_mtx); 628 } 629 630 /* 631 * kern_sigprocmask() 632 * 633 * Manipulate signal mask. 634 */ 635 int 636 kern_sigprocmask(td, how, set, oset, old) 637 struct thread *td; 638 int how; 639 sigset_t *set, *oset; 640 int old; 641 { 642 int error; 643 644 PROC_LOCK(td->td_proc); 645 if (oset != NULL) 646 *oset = td->td_sigmask; 647 648 error = 0; 649 if (set != NULL) { 650 switch (how) { 651 case SIG_BLOCK: 652 SIG_CANTMASK(*set); 653 SIGSETOR(td->td_sigmask, *set); 654 break; 655 case SIG_UNBLOCK: 656 SIGSETNAND(td->td_sigmask, *set); 657 signotify(td); 658 break; 659 case SIG_SETMASK: 660 SIG_CANTMASK(*set); 661 if (old) 662 SIGSETLO(td->td_sigmask, *set); 663 else 664 td->td_sigmask = *set; 665 signotify(td); 666 break; 667 default: 668 error = EINVAL; 669 break; 670 } 671 } 672 PROC_UNLOCK(td->td_proc); 673 return (error); 674 } 675 676 /* 677 * sigprocmask() - MP SAFE 678 */ 679 680 #ifndef _SYS_SYSPROTO_H_ 681 struct sigprocmask_args { 682 int how; 683 const sigset_t *set; 684 sigset_t *oset; 685 }; 686 #endif 687 int 688 sigprocmask(td, uap) 689 register struct thread *td; 690 struct sigprocmask_args *uap; 691 { 692 sigset_t set, oset; 693 sigset_t *setp, *osetp; 694 int error; 695 696 setp = (uap->set != NULL) ? &set : NULL; 697 osetp = (uap->oset != NULL) ? &oset : NULL; 698 if (setp) { 699 error = copyin(uap->set, setp, sizeof(set)); 700 if (error) 701 return (error); 702 } 703 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 704 if (osetp && !error) { 705 error = copyout(osetp, uap->oset, sizeof(oset)); 706 } 707 return (error); 708 } 709 710 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 711 /* 712 * osigprocmask() - MP SAFE 713 */ 714 #ifndef _SYS_SYSPROTO_H_ 715 struct osigprocmask_args { 716 int how; 717 osigset_t mask; 718 }; 719 #endif 720 int 721 osigprocmask(td, uap) 722 register struct thread *td; 723 struct osigprocmask_args *uap; 724 { 725 sigset_t set, oset; 726 int error; 727 728 OSIG2SIG(uap->mask, set); 729 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 730 SIG2OSIG(oset, td->td_retval[0]); 731 return (error); 732 } 733 #endif /* COMPAT_43 */ 734 735 #ifndef _SYS_SYSPROTO_H_ 736 struct sigpending_args { 737 sigset_t *set; 738 }; 739 #endif 740 /* 741 * MPSAFE 742 */ 743 int 744 sigwait(struct thread *td, struct sigwait_args *uap) 745 { 746 siginfo_t info; 747 sigset_t set; 748 int error; 749 750 error = copyin(uap->set, &set, sizeof(set)); 751 if (error) { 752 td->td_retval[0] = error; 753 return (0); 754 } 755 756 error = kern_sigtimedwait(td, set, &info, NULL); 757 if (error) { 758 if (error == ERESTART) 759 return (error); 760 td->td_retval[0] = error; 761 return (0); 762 } 763 764 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 765 /* Repost if we got an error. */ 766 if (error && info.si_signo) { 767 PROC_LOCK(td->td_proc); 768 tdsignal(td, info.si_signo, SIGTARGET_TD); 769 PROC_UNLOCK(td->td_proc); 770 } 771 td->td_retval[0] = error; 772 return (0); 773 } 774 /* 775 * MPSAFE 776 */ 777 int 778 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 779 { 780 struct timespec ts; 781 struct timespec *timeout; 782 sigset_t set; 783 siginfo_t info; 784 int error; 785 786 if (uap->timeout) { 787 error = copyin(uap->timeout, &ts, sizeof(ts)); 788 if (error) 789 return (error); 790 791 timeout = &ts; 792 } else 793 timeout = NULL; 794 795 error = copyin(uap->set, &set, sizeof(set)); 796 if (error) 797 return (error); 798 799 error = kern_sigtimedwait(td, set, &info, timeout); 800 if (error) 801 return (error); 802 803 if (uap->info) 804 error = copyout(&info, uap->info, sizeof(info)); 805 /* Repost if we got an error. */ 806 if (error && info.si_signo) { 807 PROC_LOCK(td->td_proc); 808 tdsignal(td, info.si_signo, SIGTARGET_TD); 809 PROC_UNLOCK(td->td_proc); 810 } else { 811 td->td_retval[0] = info.si_signo; 812 } 813 return (error); 814 } 815 816 /* 817 * MPSAFE 818 */ 819 int 820 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 821 { 822 siginfo_t info; 823 sigset_t set; 824 int error; 825 826 error = copyin(uap->set, &set, sizeof(set)); 827 if (error) 828 return (error); 829 830 error = kern_sigtimedwait(td, set, &info, NULL); 831 if (error) 832 return (error); 833 834 if (uap->info) 835 error = copyout(&info, uap->info, sizeof(info)); 836 /* Repost if we got an error. */ 837 if (error && info.si_signo) { 838 PROC_LOCK(td->td_proc); 839 tdsignal(td, info.si_signo, SIGTARGET_TD); 840 PROC_UNLOCK(td->td_proc); 841 } else { 842 td->td_retval[0] = info.si_signo; 843 } 844 return (error); 845 } 846 847 static int 848 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info, 849 struct timespec *timeout) 850 { 851 struct sigacts *ps; 852 sigset_t savedmask; 853 struct proc *p; 854 int error, sig, hz, i, timevalid = 0; 855 struct timespec rts, ets, ts; 856 struct timeval tv; 857 858 p = td->td_proc; 859 error = 0; 860 sig = 0; 861 SIG_CANTMASK(waitset); 862 863 PROC_LOCK(p); 864 ps = p->p_sigacts; 865 savedmask = td->td_sigmask; 866 if (timeout) { 867 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 868 timevalid = 1; 869 getnanouptime(&rts); 870 ets = rts; 871 timespecadd(&ets, timeout); 872 } 873 } 874 875 restart: 876 for (i = 1; i <= _SIG_MAXSIG; ++i) { 877 if (!SIGISMEMBER(waitset, i)) 878 continue; 879 if (!SIGISMEMBER(td->td_siglist, i)) { 880 if (SIGISMEMBER(p->p_siglist, i)) { 881 if (p->p_flag & P_SA) { 882 p->p_flag |= P_SIGEVENT; 883 wakeup(&p->p_siglist); 884 } 885 SIGDELSET(p->p_siglist, i); 886 SIGADDSET(td->td_siglist, i); 887 } else 888 continue; 889 } 890 891 SIGFILLSET(td->td_sigmask); 892 SIG_CANTMASK(td->td_sigmask); 893 SIGDELSET(td->td_sigmask, i); 894 mtx_lock(&ps->ps_mtx); 895 sig = cursig(td); 896 mtx_unlock(&ps->ps_mtx); 897 if (sig) 898 goto out; 899 else { 900 /* 901 * Because cursig() may have stopped current thread, 902 * after it is resumed, things may have already been 903 * changed, it should rescan any pending signals. 904 */ 905 goto restart; 906 } 907 } 908 if (error) 909 goto out; 910 911 /* 912 * POSIX says this must be checked after looking for pending 913 * signals. 914 */ 915 if (timeout) { 916 if (!timevalid) { 917 error = EINVAL; 918 goto out; 919 } 920 getnanouptime(&rts); 921 if (timespeccmp(&rts, &ets, >=)) { 922 error = EAGAIN; 923 goto out; 924 } 925 ts = ets; 926 timespecsub(&ts, &rts); 927 TIMESPEC_TO_TIMEVAL(&tv, &ts); 928 hz = tvtohz(&tv); 929 } else 930 hz = 0; 931 932 td->td_sigmask = savedmask; 933 SIGSETNAND(td->td_sigmask, waitset); 934 signotify(td); 935 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 936 if (timeout) { 937 if (error == ERESTART) { 938 /* timeout can not be restarted. */ 939 error = EINTR; 940 } else if (error == EAGAIN) { 941 /* will calculate timeout by ourself. */ 942 error = 0; 943 } 944 } 945 goto restart; 946 947 out: 948 td->td_sigmask = savedmask; 949 signotify(td); 950 if (sig) { 951 SIGDELSET(td->td_siglist, sig); 952 bzero(info, sizeof(*info)); 953 info->si_signo = sig; 954 info->si_code = 0; 955 error = 0; 956 957 #ifdef KTRACE 958 if (KTRPOINT(td, KTR_PSIG)) { 959 sig_t action; 960 961 mtx_lock(&ps->ps_mtx); 962 action = ps->ps_sigact[_SIG_IDX(sig)]; 963 mtx_unlock(&ps->ps_mtx); 964 ktrpsig(sig, action, &td->td_sigmask, 0); 965 } 966 #endif 967 _STOPEVENT(p, S_SIG, sig); 968 969 if (sig == SIGKILL) { 970 p->p_code = 0; 971 p->p_sig = sig; 972 sigexit(td, sig); 973 } 974 } 975 PROC_UNLOCK(p); 976 return (error); 977 } 978 979 /* 980 * MPSAFE 981 */ 982 int 983 sigpending(td, uap) 984 struct thread *td; 985 struct sigpending_args *uap; 986 { 987 struct proc *p = td->td_proc; 988 sigset_t siglist; 989 990 PROC_LOCK(p); 991 siglist = p->p_siglist; 992 SIGSETOR(siglist, td->td_siglist); 993 PROC_UNLOCK(p); 994 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 995 } 996 997 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 998 #ifndef _SYS_SYSPROTO_H_ 999 struct osigpending_args { 1000 int dummy; 1001 }; 1002 #endif 1003 /* 1004 * MPSAFE 1005 */ 1006 int 1007 osigpending(td, uap) 1008 struct thread *td; 1009 struct osigpending_args *uap; 1010 { 1011 struct proc *p = td->td_proc; 1012 sigset_t siglist; 1013 1014 PROC_LOCK(p); 1015 siglist = p->p_siglist; 1016 SIGSETOR(siglist, td->td_siglist); 1017 PROC_UNLOCK(p); 1018 SIG2OSIG(siglist, td->td_retval[0]); 1019 return (0); 1020 } 1021 #endif /* COMPAT_43 */ 1022 1023 #if defined(COMPAT_43) 1024 /* 1025 * Generalized interface signal handler, 4.3-compatible. 1026 */ 1027 #ifndef _SYS_SYSPROTO_H_ 1028 struct osigvec_args { 1029 int signum; 1030 struct sigvec *nsv; 1031 struct sigvec *osv; 1032 }; 1033 #endif 1034 /* 1035 * MPSAFE 1036 */ 1037 /* ARGSUSED */ 1038 int 1039 osigvec(td, uap) 1040 struct thread *td; 1041 register struct osigvec_args *uap; 1042 { 1043 struct sigvec vec; 1044 struct sigaction nsa, osa; 1045 register struct sigaction *nsap, *osap; 1046 int error; 1047 1048 if (uap->signum <= 0 || uap->signum >= ONSIG) 1049 return (EINVAL); 1050 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1051 osap = (uap->osv != NULL) ? &osa : NULL; 1052 if (nsap) { 1053 error = copyin(uap->nsv, &vec, sizeof(vec)); 1054 if (error) 1055 return (error); 1056 nsap->sa_handler = vec.sv_handler; 1057 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1058 nsap->sa_flags = vec.sv_flags; 1059 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1060 } 1061 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1062 if (osap && !error) { 1063 vec.sv_handler = osap->sa_handler; 1064 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1065 vec.sv_flags = osap->sa_flags; 1066 vec.sv_flags &= ~SA_NOCLDWAIT; 1067 vec.sv_flags ^= SA_RESTART; 1068 error = copyout(&vec, uap->osv, sizeof(vec)); 1069 } 1070 return (error); 1071 } 1072 1073 #ifndef _SYS_SYSPROTO_H_ 1074 struct osigblock_args { 1075 int mask; 1076 }; 1077 #endif 1078 /* 1079 * MPSAFE 1080 */ 1081 int 1082 osigblock(td, uap) 1083 register struct thread *td; 1084 struct osigblock_args *uap; 1085 { 1086 struct proc *p = td->td_proc; 1087 sigset_t set; 1088 1089 OSIG2SIG(uap->mask, set); 1090 SIG_CANTMASK(set); 1091 PROC_LOCK(p); 1092 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1093 SIGSETOR(td->td_sigmask, set); 1094 PROC_UNLOCK(p); 1095 return (0); 1096 } 1097 1098 #ifndef _SYS_SYSPROTO_H_ 1099 struct osigsetmask_args { 1100 int mask; 1101 }; 1102 #endif 1103 /* 1104 * MPSAFE 1105 */ 1106 int 1107 osigsetmask(td, uap) 1108 struct thread *td; 1109 struct osigsetmask_args *uap; 1110 { 1111 struct proc *p = td->td_proc; 1112 sigset_t set; 1113 1114 OSIG2SIG(uap->mask, set); 1115 SIG_CANTMASK(set); 1116 PROC_LOCK(p); 1117 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1118 SIGSETLO(td->td_sigmask, set); 1119 signotify(td); 1120 PROC_UNLOCK(p); 1121 return (0); 1122 } 1123 #endif /* COMPAT_43 */ 1124 1125 /* 1126 * Suspend process until signal, providing mask to be set 1127 * in the meantime. 1128 ***** XXXKSE this doesn't make sense under KSE. 1129 ***** Do we suspend the thread or all threads in the process? 1130 ***** How do we suspend threads running NOW on another processor? 1131 */ 1132 #ifndef _SYS_SYSPROTO_H_ 1133 struct sigsuspend_args { 1134 const sigset_t *sigmask; 1135 }; 1136 #endif 1137 /* 1138 * MPSAFE 1139 */ 1140 /* ARGSUSED */ 1141 int 1142 sigsuspend(td, uap) 1143 struct thread *td; 1144 struct sigsuspend_args *uap; 1145 { 1146 sigset_t mask; 1147 int error; 1148 1149 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1150 if (error) 1151 return (error); 1152 return (kern_sigsuspend(td, mask)); 1153 } 1154 1155 int 1156 kern_sigsuspend(struct thread *td, sigset_t mask) 1157 { 1158 struct proc *p = td->td_proc; 1159 1160 /* 1161 * When returning from sigsuspend, we want 1162 * the old mask to be restored after the 1163 * signal handler has finished. Thus, we 1164 * save it here and mark the sigacts structure 1165 * to indicate this. 1166 */ 1167 PROC_LOCK(p); 1168 td->td_oldsigmask = td->td_sigmask; 1169 td->td_pflags |= TDP_OLDMASK; 1170 SIG_CANTMASK(mask); 1171 td->td_sigmask = mask; 1172 signotify(td); 1173 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1174 /* void */; 1175 PROC_UNLOCK(p); 1176 /* always return EINTR rather than ERESTART... */ 1177 return (EINTR); 1178 } 1179 1180 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1181 /* 1182 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1183 * convention: libc stub passes mask, not pointer, to save a copyin. 1184 */ 1185 #ifndef _SYS_SYSPROTO_H_ 1186 struct osigsuspend_args { 1187 osigset_t mask; 1188 }; 1189 #endif 1190 /* 1191 * MPSAFE 1192 */ 1193 /* ARGSUSED */ 1194 int 1195 osigsuspend(td, uap) 1196 struct thread *td; 1197 struct osigsuspend_args *uap; 1198 { 1199 struct proc *p = td->td_proc; 1200 sigset_t mask; 1201 1202 PROC_LOCK(p); 1203 td->td_oldsigmask = td->td_sigmask; 1204 td->td_pflags |= TDP_OLDMASK; 1205 OSIG2SIG(uap->mask, mask); 1206 SIG_CANTMASK(mask); 1207 SIGSETLO(td->td_sigmask, mask); 1208 signotify(td); 1209 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1210 /* void */; 1211 PROC_UNLOCK(p); 1212 /* always return EINTR rather than ERESTART... */ 1213 return (EINTR); 1214 } 1215 #endif /* COMPAT_43 */ 1216 1217 #if defined(COMPAT_43) 1218 #ifndef _SYS_SYSPROTO_H_ 1219 struct osigstack_args { 1220 struct sigstack *nss; 1221 struct sigstack *oss; 1222 }; 1223 #endif 1224 /* 1225 * MPSAFE 1226 */ 1227 /* ARGSUSED */ 1228 int 1229 osigstack(td, uap) 1230 struct thread *td; 1231 register struct osigstack_args *uap; 1232 { 1233 struct sigstack nss, oss; 1234 int error = 0; 1235 1236 if (uap->nss != NULL) { 1237 error = copyin(uap->nss, &nss, sizeof(nss)); 1238 if (error) 1239 return (error); 1240 } 1241 oss.ss_sp = td->td_sigstk.ss_sp; 1242 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1243 if (uap->nss != NULL) { 1244 td->td_sigstk.ss_sp = nss.ss_sp; 1245 td->td_sigstk.ss_size = 0; 1246 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1247 td->td_pflags |= TDP_ALTSTACK; 1248 } 1249 if (uap->oss != NULL) 1250 error = copyout(&oss, uap->oss, sizeof(oss)); 1251 1252 return (error); 1253 } 1254 #endif /* COMPAT_43 */ 1255 1256 #ifndef _SYS_SYSPROTO_H_ 1257 struct sigaltstack_args { 1258 stack_t *ss; 1259 stack_t *oss; 1260 }; 1261 #endif 1262 /* 1263 * MPSAFE 1264 */ 1265 /* ARGSUSED */ 1266 int 1267 sigaltstack(td, uap) 1268 struct thread *td; 1269 register struct sigaltstack_args *uap; 1270 { 1271 stack_t ss, oss; 1272 int error; 1273 1274 if (uap->ss != NULL) { 1275 error = copyin(uap->ss, &ss, sizeof(ss)); 1276 if (error) 1277 return (error); 1278 } 1279 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1280 (uap->oss != NULL) ? &oss : NULL); 1281 if (error) 1282 return (error); 1283 if (uap->oss != NULL) 1284 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1285 return (error); 1286 } 1287 1288 int 1289 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1290 { 1291 struct proc *p = td->td_proc; 1292 int oonstack; 1293 1294 oonstack = sigonstack(cpu_getstack(td)); 1295 1296 if (oss != NULL) { 1297 *oss = td->td_sigstk; 1298 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1299 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1300 } 1301 1302 if (ss != NULL) { 1303 if (oonstack) 1304 return (EPERM); 1305 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1306 return (EINVAL); 1307 if (!(ss->ss_flags & SS_DISABLE)) { 1308 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1309 return (ENOMEM); 1310 } 1311 td->td_sigstk = *ss; 1312 td->td_pflags |= TDP_ALTSTACK; 1313 } else { 1314 td->td_pflags &= ~TDP_ALTSTACK; 1315 } 1316 } 1317 return (0); 1318 } 1319 1320 /* 1321 * Common code for kill process group/broadcast kill. 1322 * cp is calling process. 1323 */ 1324 static int 1325 killpg1(td, sig, pgid, all) 1326 register struct thread *td; 1327 int sig, pgid, all; 1328 { 1329 register struct proc *p; 1330 struct pgrp *pgrp; 1331 int nfound = 0; 1332 1333 if (all) { 1334 /* 1335 * broadcast 1336 */ 1337 sx_slock(&allproc_lock); 1338 LIST_FOREACH(p, &allproc, p_list) { 1339 PROC_LOCK(p); 1340 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1341 p == td->td_proc || p->p_state == PRS_NEW) { 1342 PROC_UNLOCK(p); 1343 continue; 1344 } 1345 if (p_cansignal(td, p, sig) == 0) { 1346 nfound++; 1347 if (sig) 1348 psignal(p, sig); 1349 } 1350 PROC_UNLOCK(p); 1351 } 1352 sx_sunlock(&allproc_lock); 1353 } else { 1354 sx_slock(&proctree_lock); 1355 if (pgid == 0) { 1356 /* 1357 * zero pgid means send to my process group. 1358 */ 1359 pgrp = td->td_proc->p_pgrp; 1360 PGRP_LOCK(pgrp); 1361 } else { 1362 pgrp = pgfind(pgid); 1363 if (pgrp == NULL) { 1364 sx_sunlock(&proctree_lock); 1365 return (ESRCH); 1366 } 1367 } 1368 sx_sunlock(&proctree_lock); 1369 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1370 PROC_LOCK(p); 1371 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1372 p->p_state == PRS_NEW ) { 1373 PROC_UNLOCK(p); 1374 continue; 1375 } 1376 if (p_cansignal(td, p, sig) == 0) { 1377 nfound++; 1378 if (sig) 1379 psignal(p, sig); 1380 } 1381 PROC_UNLOCK(p); 1382 } 1383 PGRP_UNLOCK(pgrp); 1384 } 1385 return (nfound ? 0 : ESRCH); 1386 } 1387 1388 #ifndef _SYS_SYSPROTO_H_ 1389 struct kill_args { 1390 int pid; 1391 int signum; 1392 }; 1393 #endif 1394 /* 1395 * MPSAFE 1396 */ 1397 /* ARGSUSED */ 1398 int 1399 kill(td, uap) 1400 register struct thread *td; 1401 register struct kill_args *uap; 1402 { 1403 register struct proc *p; 1404 int error; 1405 1406 AUDIT_ARG(signum, uap->signum); 1407 AUDIT_ARG(pid, uap->pid); 1408 if ((u_int)uap->signum > _SIG_MAXSIG) 1409 return (EINVAL); 1410 1411 if (uap->pid > 0) { 1412 /* kill single process */ 1413 if ((p = pfind(uap->pid)) == NULL) { 1414 if ((p = zpfind(uap->pid)) == NULL) 1415 return (ESRCH); 1416 } 1417 AUDIT_ARG(process, p); 1418 error = p_cansignal(td, p, uap->signum); 1419 if (error == 0 && uap->signum) 1420 psignal(p, uap->signum); 1421 PROC_UNLOCK(p); 1422 return (error); 1423 } 1424 switch (uap->pid) { 1425 case -1: /* broadcast signal */ 1426 return (killpg1(td, uap->signum, 0, 1)); 1427 case 0: /* signal own process group */ 1428 return (killpg1(td, uap->signum, 0, 0)); 1429 default: /* negative explicit process group */ 1430 return (killpg1(td, uap->signum, -uap->pid, 0)); 1431 } 1432 /* NOTREACHED */ 1433 } 1434 1435 #if defined(COMPAT_43) 1436 #ifndef _SYS_SYSPROTO_H_ 1437 struct okillpg_args { 1438 int pgid; 1439 int signum; 1440 }; 1441 #endif 1442 /* 1443 * MPSAFE 1444 */ 1445 /* ARGSUSED */ 1446 int 1447 okillpg(td, uap) 1448 struct thread *td; 1449 register struct okillpg_args *uap; 1450 { 1451 1452 AUDIT_ARG(signum, uap->signum); 1453 AUDIT_ARG(pid, uap->pgid); 1454 if ((u_int)uap->signum > _SIG_MAXSIG) 1455 return (EINVAL); 1456 return (killpg1(td, uap->signum, uap->pgid, 0)); 1457 } 1458 #endif /* COMPAT_43 */ 1459 1460 /* 1461 * Send a signal to a process group. 1462 */ 1463 void 1464 gsignal(pgid, sig) 1465 int pgid, sig; 1466 { 1467 struct pgrp *pgrp; 1468 1469 if (pgid != 0) { 1470 sx_slock(&proctree_lock); 1471 pgrp = pgfind(pgid); 1472 sx_sunlock(&proctree_lock); 1473 if (pgrp != NULL) { 1474 pgsignal(pgrp, sig, 0); 1475 PGRP_UNLOCK(pgrp); 1476 } 1477 } 1478 } 1479 1480 /* 1481 * Send a signal to a process group. If checktty is 1, 1482 * limit to members which have a controlling terminal. 1483 */ 1484 void 1485 pgsignal(pgrp, sig, checkctty) 1486 struct pgrp *pgrp; 1487 int sig, checkctty; 1488 { 1489 register struct proc *p; 1490 1491 if (pgrp) { 1492 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1493 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1494 PROC_LOCK(p); 1495 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1496 psignal(p, sig); 1497 PROC_UNLOCK(p); 1498 } 1499 } 1500 } 1501 1502 /* 1503 * Send a signal caused by a trap to the current thread. 1504 * If it will be caught immediately, deliver it with correct code. 1505 * Otherwise, post it normally. 1506 * 1507 * MPSAFE 1508 */ 1509 void 1510 trapsignal(struct thread *td, int sig, u_long code) 1511 { 1512 struct sigacts *ps; 1513 struct proc *p; 1514 siginfo_t siginfo; 1515 int error; 1516 1517 p = td->td_proc; 1518 if (td->td_pflags & TDP_SA) { 1519 if (td->td_mailbox == NULL) 1520 thread_user_enter(td); 1521 PROC_LOCK(p); 1522 SIGDELSET(td->td_sigmask, sig); 1523 mtx_lock_spin(&sched_lock); 1524 /* 1525 * Force scheduling an upcall, so UTS has chance to 1526 * process the signal before thread runs again in 1527 * userland. 1528 */ 1529 if (td->td_upcall) 1530 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1531 mtx_unlock_spin(&sched_lock); 1532 } else { 1533 PROC_LOCK(p); 1534 } 1535 ps = p->p_sigacts; 1536 mtx_lock(&ps->ps_mtx); 1537 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1538 !SIGISMEMBER(td->td_sigmask, sig)) { 1539 p->p_stats->p_ru.ru_nsignals++; 1540 #ifdef KTRACE 1541 if (KTRPOINT(curthread, KTR_PSIG)) 1542 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1543 &td->td_sigmask, code); 1544 #endif 1545 if (!(td->td_pflags & TDP_SA)) 1546 (*p->p_sysent->sv_sendsig)( 1547 ps->ps_sigact[_SIG_IDX(sig)], sig, 1548 &td->td_sigmask, code); 1549 else if (td->td_mailbox == NULL) { 1550 mtx_unlock(&ps->ps_mtx); 1551 /* UTS caused a sync signal */ 1552 p->p_code = code; /* XXX for core dump/debugger */ 1553 p->p_sig = sig; /* XXX to verify code */ 1554 sigexit(td, sig); 1555 } else { 1556 cpu_thread_siginfo(sig, code, &siginfo); 1557 mtx_unlock(&ps->ps_mtx); 1558 SIGADDSET(td->td_sigmask, sig); 1559 PROC_UNLOCK(p); 1560 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1561 sizeof(siginfo)); 1562 PROC_LOCK(p); 1563 /* UTS memory corrupted */ 1564 if (error) 1565 sigexit(td, SIGSEGV); 1566 mtx_lock(&ps->ps_mtx); 1567 } 1568 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1569 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1570 SIGADDSET(td->td_sigmask, sig); 1571 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1572 /* 1573 * See kern_sigaction() for origin of this code. 1574 */ 1575 SIGDELSET(ps->ps_sigcatch, sig); 1576 if (sig != SIGCONT && 1577 sigprop(sig) & SA_IGNORE) 1578 SIGADDSET(ps->ps_sigignore, sig); 1579 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1580 } 1581 mtx_unlock(&ps->ps_mtx); 1582 } else { 1583 mtx_unlock(&ps->ps_mtx); 1584 p->p_code = code; /* XXX for core dump/debugger */ 1585 p->p_sig = sig; /* XXX to verify code */ 1586 tdsignal(td, sig, SIGTARGET_TD); 1587 } 1588 PROC_UNLOCK(p); 1589 } 1590 1591 static struct thread * 1592 sigtd(struct proc *p, int sig, int prop) 1593 { 1594 struct thread *td, *signal_td; 1595 1596 PROC_LOCK_ASSERT(p, MA_OWNED); 1597 1598 /* 1599 * Check if current thread can handle the signal without 1600 * switching conetxt to another thread. 1601 */ 1602 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1603 return (curthread); 1604 signal_td = NULL; 1605 mtx_lock_spin(&sched_lock); 1606 FOREACH_THREAD_IN_PROC(p, td) { 1607 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1608 signal_td = td; 1609 break; 1610 } 1611 } 1612 if (signal_td == NULL) 1613 signal_td = FIRST_THREAD_IN_PROC(p); 1614 mtx_unlock_spin(&sched_lock); 1615 return (signal_td); 1616 } 1617 1618 /* 1619 * Send the signal to the process. If the signal has an action, the action 1620 * is usually performed by the target process rather than the caller; we add 1621 * the signal to the set of pending signals for the process. 1622 * 1623 * Exceptions: 1624 * o When a stop signal is sent to a sleeping process that takes the 1625 * default action, the process is stopped without awakening it. 1626 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1627 * regardless of the signal action (eg, blocked or ignored). 1628 * 1629 * Other ignored signals are discarded immediately. 1630 * 1631 * MPSAFE 1632 */ 1633 void 1634 psignal(struct proc *p, int sig) 1635 { 1636 struct thread *td; 1637 int prop; 1638 1639 if (!_SIG_VALID(sig)) 1640 panic("psignal(): invalid signal"); 1641 1642 PROC_LOCK_ASSERT(p, MA_OWNED); 1643 /* 1644 * IEEE Std 1003.1-2001: return success when killing a zombie. 1645 */ 1646 if (p->p_state == PRS_ZOMBIE) 1647 return; 1648 prop = sigprop(sig); 1649 1650 /* 1651 * Find a thread to deliver the signal to. 1652 */ 1653 td = sigtd(p, sig, prop); 1654 1655 tdsignal(td, sig, SIGTARGET_P); 1656 } 1657 1658 /* 1659 * MPSAFE 1660 */ 1661 void 1662 tdsignal(struct thread *td, int sig, sigtarget_t target) 1663 { 1664 sigset_t saved; 1665 struct proc *p = td->td_proc; 1666 1667 if (p->p_flag & P_SA) 1668 saved = p->p_siglist; 1669 do_tdsignal(td, sig, target); 1670 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1671 if (!SIGSETEQ(saved, p->p_siglist)) { 1672 /* pending set changed */ 1673 p->p_flag |= P_SIGEVENT; 1674 wakeup(&p->p_siglist); 1675 } 1676 } 1677 } 1678 1679 static void 1680 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1681 { 1682 struct proc *p; 1683 register sig_t action; 1684 sigset_t *siglist; 1685 struct thread *td0; 1686 register int prop; 1687 struct sigacts *ps; 1688 int intrval; 1689 1690 if (!_SIG_VALID(sig)) 1691 panic("do_tdsignal(): invalid signal"); 1692 1693 p = td->td_proc; 1694 ps = p->p_sigacts; 1695 1696 PROC_LOCK_ASSERT(p, MA_OWNED); 1697 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 1698 1699 prop = sigprop(sig); 1700 1701 /* 1702 * If the signal is blocked and not destined for this thread, then 1703 * assign it to the process so that we can find it later in the first 1704 * thread that unblocks it. Otherwise, assign it to this thread now. 1705 */ 1706 if (target == SIGTARGET_TD) { 1707 siglist = &td->td_siglist; 1708 } else { 1709 if (!SIGISMEMBER(td->td_sigmask, sig)) 1710 siglist = &td->td_siglist; 1711 else 1712 siglist = &p->p_siglist; 1713 } 1714 1715 /* 1716 * If the signal is being ignored, 1717 * then we forget about it immediately. 1718 * (Note: we don't set SIGCONT in ps_sigignore, 1719 * and if it is set to SIG_IGN, 1720 * action will be SIG_DFL here.) 1721 */ 1722 mtx_lock(&ps->ps_mtx); 1723 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1724 (p->p_flag & P_WEXIT)) { 1725 mtx_unlock(&ps->ps_mtx); 1726 return; 1727 } 1728 if (SIGISMEMBER(td->td_sigmask, sig)) 1729 action = SIG_HOLD; 1730 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1731 action = SIG_CATCH; 1732 else 1733 action = SIG_DFL; 1734 if (SIGISMEMBER(ps->ps_sigintr, sig)) 1735 intrval = EINTR; 1736 else 1737 intrval = ERESTART; 1738 mtx_unlock(&ps->ps_mtx); 1739 1740 if (prop & SA_CONT) { 1741 SIG_STOPSIGMASK(p->p_siglist); 1742 /* 1743 * XXX Should investigate leaving STOP and CONT sigs only in 1744 * the proc's siglist. 1745 */ 1746 mtx_lock_spin(&sched_lock); 1747 FOREACH_THREAD_IN_PROC(p, td0) 1748 SIG_STOPSIGMASK(td0->td_siglist); 1749 mtx_unlock_spin(&sched_lock); 1750 } 1751 1752 if (prop & SA_STOP) { 1753 /* 1754 * If sending a tty stop signal to a member of an orphaned 1755 * process group, discard the signal here if the action 1756 * is default; don't stop the process below if sleeping, 1757 * and don't clear any pending SIGCONT. 1758 */ 1759 if ((prop & SA_TTYSTOP) && 1760 (p->p_pgrp->pg_jobc == 0) && 1761 (action == SIG_DFL)) 1762 return; 1763 SIG_CONTSIGMASK(p->p_siglist); 1764 mtx_lock_spin(&sched_lock); 1765 FOREACH_THREAD_IN_PROC(p, td0) 1766 SIG_CONTSIGMASK(td0->td_siglist); 1767 mtx_unlock_spin(&sched_lock); 1768 p->p_flag &= ~P_CONTINUED; 1769 } 1770 1771 SIGADDSET(*siglist, sig); 1772 signotify(td); /* uses schedlock */ 1773 /* 1774 * Defer further processing for signals which are held, 1775 * except that stopped processes must be continued by SIGCONT. 1776 */ 1777 if (action == SIG_HOLD && 1778 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1779 return; 1780 /* 1781 * SIGKILL: Remove procfs STOPEVENTs. 1782 */ 1783 if (sig == SIGKILL) { 1784 /* from procfs_ioctl.c: PIOCBIC */ 1785 p->p_stops = 0; 1786 /* from procfs_ioctl.c: PIOCCONT */ 1787 p->p_step = 0; 1788 wakeup(&p->p_step); 1789 } 1790 /* 1791 * Some signals have a process-wide effect and a per-thread 1792 * component. Most processing occurs when the process next 1793 * tries to cross the user boundary, however there are some 1794 * times when processing needs to be done immediatly, such as 1795 * waking up threads so that they can cross the user boundary. 1796 * We try do the per-process part here. 1797 */ 1798 if (P_SHOULDSTOP(p)) { 1799 /* 1800 * The process is in stopped mode. All the threads should be 1801 * either winding down or already on the suspended queue. 1802 */ 1803 if (p->p_flag & P_TRACED) { 1804 /* 1805 * The traced process is already stopped, 1806 * so no further action is necessary. 1807 * No signal can restart us. 1808 */ 1809 goto out; 1810 } 1811 1812 if (sig == SIGKILL) { 1813 /* 1814 * SIGKILL sets process running. 1815 * It will die elsewhere. 1816 * All threads must be restarted. 1817 */ 1818 p->p_flag &= ~P_STOPPED_SIG; 1819 goto runfast; 1820 } 1821 1822 if (prop & SA_CONT) { 1823 /* 1824 * If SIGCONT is default (or ignored), we continue the 1825 * process but don't leave the signal in siglist as 1826 * it has no further action. If SIGCONT is held, we 1827 * continue the process and leave the signal in 1828 * siglist. If the process catches SIGCONT, let it 1829 * handle the signal itself. If it isn't waiting on 1830 * an event, it goes back to run state. 1831 * Otherwise, process goes back to sleep state. 1832 */ 1833 p->p_flag &= ~P_STOPPED_SIG; 1834 p->p_flag |= P_CONTINUED; 1835 if (action == SIG_DFL) { 1836 SIGDELSET(*siglist, sig); 1837 } else if (action == SIG_CATCH) { 1838 /* 1839 * The process wants to catch it so it needs 1840 * to run at least one thread, but which one? 1841 * It would seem that the answer would be to 1842 * run an upcall in the next KSE to run, and 1843 * deliver the signal that way. In a NON KSE 1844 * process, we need to make sure that the 1845 * single thread is runnable asap. 1846 * XXXKSE for now however, make them all run. 1847 */ 1848 goto runfast; 1849 } 1850 /* 1851 * The signal is not ignored or caught. 1852 */ 1853 mtx_lock_spin(&sched_lock); 1854 thread_unsuspend(p); 1855 mtx_unlock_spin(&sched_lock); 1856 goto out; 1857 } 1858 1859 if (prop & SA_STOP) { 1860 /* 1861 * Already stopped, don't need to stop again 1862 * (If we did the shell could get confused). 1863 * Just make sure the signal STOP bit set. 1864 */ 1865 p->p_flag |= P_STOPPED_SIG; 1866 SIGDELSET(*siglist, sig); 1867 goto out; 1868 } 1869 1870 /* 1871 * All other kinds of signals: 1872 * If a thread is sleeping interruptibly, simulate a 1873 * wakeup so that when it is continued it will be made 1874 * runnable and can look at the signal. However, don't make 1875 * the PROCESS runnable, leave it stopped. 1876 * It may run a bit until it hits a thread_suspend_check(). 1877 */ 1878 mtx_lock_spin(&sched_lock); 1879 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 1880 sleepq_abort(td, intrval); 1881 mtx_unlock_spin(&sched_lock); 1882 goto out; 1883 /* 1884 * Mutexes are short lived. Threads waiting on them will 1885 * hit thread_suspend_check() soon. 1886 */ 1887 } else if (p->p_state == PRS_NORMAL) { 1888 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 1889 mtx_lock_spin(&sched_lock); 1890 tdsigwakeup(td, sig, action, intrval); 1891 mtx_unlock_spin(&sched_lock); 1892 goto out; 1893 } 1894 1895 MPASS(action == SIG_DFL); 1896 1897 if (prop & SA_STOP) { 1898 if (p->p_flag & P_PPWAIT) 1899 goto out; 1900 p->p_flag |= P_STOPPED_SIG; 1901 p->p_xstat = sig; 1902 mtx_lock_spin(&sched_lock); 1903 sig_suspend_threads(td, p, 1); 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, intrval); 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, int intrval) 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 /* 1953 * Bring the priority of a thread up if we want it to get 1954 * killed in this lifetime. 1955 */ 1956 if (action == SIG_DFL && (prop & SA_KILL)) { 1957 if (p->p_nice > 0) 1958 sched_nice(td->td_proc, 0); 1959 if (td->td_priority > PUSER) 1960 sched_prio(td, PUSER); 1961 } 1962 1963 if (TD_ON_SLEEPQ(td)) { 1964 /* 1965 * If thread is sleeping uninterruptibly 1966 * we can't interrupt the sleep... the signal will 1967 * be noticed when the process returns through 1968 * trap() or syscall(). 1969 */ 1970 if ((td->td_flags & TDF_SINTR) == 0) 1971 return; 1972 /* 1973 * If SIGCONT is default (or ignored) and process is 1974 * asleep, we are finished; the process should not 1975 * be awakened. 1976 */ 1977 if ((prop & SA_CONT) && action == SIG_DFL) { 1978 SIGDELSET(p->p_siglist, sig); 1979 /* 1980 * It may be on either list in this state. 1981 * Remove from both for now. 1982 */ 1983 SIGDELSET(td->td_siglist, sig); 1984 return; 1985 } 1986 1987 /* 1988 * Give low priority threads a better chance to run. 1989 */ 1990 if (td->td_priority > PUSER) 1991 sched_prio(td, PUSER); 1992 1993 sleepq_abort(td, intrval); 1994 } else { 1995 /* 1996 * Other states do nothing with the signal immediately, 1997 * other than kicking ourselves if we are running. 1998 * It will either never be noticed, or noticed very soon. 1999 */ 2000 #ifdef SMP 2001 if (TD_IS_RUNNING(td) && td != curthread) 2002 forward_signal(td); 2003 #endif 2004 } 2005 } 2006 2007 static void 2008 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2009 { 2010 struct thread *td2; 2011 2012 PROC_LOCK_ASSERT(p, MA_OWNED); 2013 mtx_assert(&sched_lock, MA_OWNED); 2014 2015 FOREACH_THREAD_IN_PROC(p, td2) { 2016 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2017 (td2->td_flags & TDF_SINTR) && 2018 !TD_IS_SUSPENDED(td2)) { 2019 thread_suspend_one(td2); 2020 } else { 2021 if (sending || td != td2) 2022 td2->td_flags |= TDF_ASTPENDING; 2023 #ifdef SMP 2024 if (TD_IS_RUNNING(td2) && td2 != td) 2025 forward_signal(td2); 2026 #endif 2027 } 2028 } 2029 } 2030 2031 int 2032 ptracestop(struct thread *td, int sig) 2033 { 2034 struct proc *p = td->td_proc; 2035 2036 PROC_LOCK_ASSERT(p, MA_OWNED); 2037 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2038 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2039 2040 mtx_lock_spin(&sched_lock); 2041 td->td_flags |= TDF_XSIG; 2042 mtx_unlock_spin(&sched_lock); 2043 td->td_xsig = sig; 2044 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2045 if (p->p_flag & P_SINGLE_EXIT) { 2046 mtx_lock_spin(&sched_lock); 2047 td->td_flags &= ~TDF_XSIG; 2048 mtx_unlock_spin(&sched_lock); 2049 return (sig); 2050 } 2051 /* 2052 * Just make wait() to work, the last stopped thread 2053 * will win. 2054 */ 2055 p->p_xstat = sig; 2056 p->p_xthread = td; 2057 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2058 mtx_lock_spin(&sched_lock); 2059 sig_suspend_threads(td, p, 0); 2060 stopme: 2061 thread_stopped(p); 2062 thread_suspend_one(td); 2063 PROC_UNLOCK(p); 2064 DROP_GIANT(); 2065 mi_switch(SW_VOL, NULL); 2066 mtx_unlock_spin(&sched_lock); 2067 PICKUP_GIANT(); 2068 PROC_LOCK(p); 2069 if (!(p->p_flag & P_TRACED)) 2070 break; 2071 if (td->td_flags & TDF_DBSUSPEND) { 2072 if (p->p_flag & P_SINGLE_EXIT) 2073 break; 2074 mtx_lock_spin(&sched_lock); 2075 goto stopme; 2076 } 2077 } 2078 return (td->td_xsig); 2079 } 2080 2081 /* 2082 * If the current process has received a signal (should be caught or cause 2083 * termination, should interrupt current syscall), return the signal number. 2084 * Stop signals with default action are processed immediately, then cleared; 2085 * they aren't returned. This is checked after each entry to the system for 2086 * a syscall or trap (though this can usually be done without calling issignal 2087 * by checking the pending signal masks in cursig.) The normal call 2088 * sequence is 2089 * 2090 * while (sig = cursig(curthread)) 2091 * postsig(sig); 2092 */ 2093 static int 2094 issignal(td) 2095 struct thread *td; 2096 { 2097 struct proc *p; 2098 struct sigacts *ps; 2099 sigset_t sigpending; 2100 int sig, prop, newsig; 2101 2102 p = td->td_proc; 2103 ps = p->p_sigacts; 2104 mtx_assert(&ps->ps_mtx, MA_OWNED); 2105 PROC_LOCK_ASSERT(p, MA_OWNED); 2106 for (;;) { 2107 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2108 2109 sigpending = td->td_siglist; 2110 SIGSETNAND(sigpending, td->td_sigmask); 2111 2112 if (p->p_flag & P_PPWAIT) 2113 SIG_STOPSIGMASK(sigpending); 2114 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2115 return (0); 2116 sig = sig_ffs(&sigpending); 2117 2118 if (p->p_stops & S_SIG) { 2119 mtx_unlock(&ps->ps_mtx); 2120 stopevent(p, S_SIG, sig); 2121 mtx_lock(&ps->ps_mtx); 2122 } 2123 2124 /* 2125 * We should see pending but ignored signals 2126 * only if P_TRACED was on when they were posted. 2127 */ 2128 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2129 SIGDELSET(td->td_siglist, sig); 2130 if (td->td_pflags & TDP_SA) 2131 SIGADDSET(td->td_sigmask, sig); 2132 continue; 2133 } 2134 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2135 /* 2136 * If traced, always stop. 2137 */ 2138 mtx_unlock(&ps->ps_mtx); 2139 newsig = ptracestop(td, sig); 2140 mtx_lock(&ps->ps_mtx); 2141 2142 /* 2143 * If parent wants us to take the signal, 2144 * then it will leave it in p->p_xstat; 2145 * otherwise we just look for signals again. 2146 */ 2147 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2148 if (td->td_pflags & TDP_SA) 2149 SIGADDSET(td->td_sigmask, sig); 2150 if (newsig == 0) 2151 continue; 2152 sig = newsig; 2153 /* 2154 * If the traced bit got turned off, go back up 2155 * to the top to rescan signals. This ensures 2156 * that p_sig* and p_sigact are consistent. 2157 */ 2158 if ((p->p_flag & P_TRACED) == 0) 2159 continue; 2160 2161 /* 2162 * Put the new signal into td_siglist. If the 2163 * signal is being masked, look for other signals. 2164 */ 2165 SIGADDSET(td->td_siglist, sig); 2166 if (td->td_pflags & TDP_SA) 2167 SIGDELSET(td->td_sigmask, sig); 2168 if (SIGISMEMBER(td->td_sigmask, sig)) 2169 continue; 2170 signotify(td); 2171 } 2172 2173 prop = sigprop(sig); 2174 2175 /* 2176 * Decide whether the signal should be returned. 2177 * Return the signal's number, or fall through 2178 * to clear it from the pending mask. 2179 */ 2180 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2181 2182 case (intptr_t)SIG_DFL: 2183 /* 2184 * Don't take default actions on system processes. 2185 */ 2186 if (p->p_pid <= 1) { 2187 #ifdef DIAGNOSTIC 2188 /* 2189 * Are you sure you want to ignore SIGSEGV 2190 * in init? XXX 2191 */ 2192 printf("Process (pid %lu) got signal %d\n", 2193 (u_long)p->p_pid, sig); 2194 #endif 2195 break; /* == ignore */ 2196 } 2197 /* 2198 * If there is a pending stop signal to process 2199 * with default action, stop here, 2200 * then clear the signal. However, 2201 * if process is member of an orphaned 2202 * process group, ignore tty stop signals. 2203 */ 2204 if (prop & SA_STOP) { 2205 if (p->p_flag & P_TRACED || 2206 (p->p_pgrp->pg_jobc == 0 && 2207 prop & SA_TTYSTOP)) 2208 break; /* == ignore */ 2209 mtx_unlock(&ps->ps_mtx); 2210 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2211 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2212 p->p_flag |= P_STOPPED_SIG; 2213 p->p_xstat = sig; 2214 mtx_lock_spin(&sched_lock); 2215 sig_suspend_threads(td, p, 0); 2216 thread_stopped(p); 2217 thread_suspend_one(td); 2218 PROC_UNLOCK(p); 2219 DROP_GIANT(); 2220 mi_switch(SW_INVOL, NULL); 2221 mtx_unlock_spin(&sched_lock); 2222 PICKUP_GIANT(); 2223 PROC_LOCK(p); 2224 mtx_lock(&ps->ps_mtx); 2225 break; 2226 } else if (prop & SA_IGNORE) { 2227 /* 2228 * Except for SIGCONT, shouldn't get here. 2229 * Default action is to ignore; drop it. 2230 */ 2231 break; /* == ignore */ 2232 } else 2233 return (sig); 2234 /*NOTREACHED*/ 2235 2236 case (intptr_t)SIG_IGN: 2237 /* 2238 * Masking above should prevent us ever trying 2239 * to take action on an ignored signal other 2240 * than SIGCONT, unless process is traced. 2241 */ 2242 if ((prop & SA_CONT) == 0 && 2243 (p->p_flag & P_TRACED) == 0) 2244 printf("issignal\n"); 2245 break; /* == ignore */ 2246 2247 default: 2248 /* 2249 * This signal has an action, let 2250 * postsig() process it. 2251 */ 2252 return (sig); 2253 } 2254 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2255 } 2256 /* NOTREACHED */ 2257 } 2258 2259 /* 2260 * MPSAFE 2261 */ 2262 void 2263 thread_stopped(struct proc *p) 2264 { 2265 struct proc *p1 = curthread->td_proc; 2266 struct sigacts *ps; 2267 int n; 2268 2269 PROC_LOCK_ASSERT(p, MA_OWNED); 2270 mtx_assert(&sched_lock, MA_OWNED); 2271 n = p->p_suspcount; 2272 if (p == p1) 2273 n++; 2274 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2275 mtx_unlock_spin(&sched_lock); 2276 p->p_flag &= ~P_WAITED; 2277 PROC_LOCK(p->p_pptr); 2278 /* 2279 * Wake up parent sleeping in kern_wait(), also send 2280 * SIGCHLD to parent, but SIGCHLD does not guarantee 2281 * that parent will awake, because parent may masked 2282 * the signal. 2283 */ 2284 p->p_pptr->p_flag |= P_STATCHILD; 2285 wakeup(p->p_pptr); 2286 ps = p->p_pptr->p_sigacts; 2287 mtx_lock(&ps->ps_mtx); 2288 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2289 mtx_unlock(&ps->ps_mtx); 2290 psignal(p->p_pptr, SIGCHLD); 2291 } else 2292 mtx_unlock(&ps->ps_mtx); 2293 PROC_UNLOCK(p->p_pptr); 2294 mtx_lock_spin(&sched_lock); 2295 } 2296 } 2297 2298 /* 2299 * Take the action for the specified signal 2300 * from the current set of pending signals. 2301 */ 2302 void 2303 postsig(sig) 2304 register int sig; 2305 { 2306 struct thread *td = curthread; 2307 register struct proc *p = td->td_proc; 2308 struct sigacts *ps; 2309 sig_t action; 2310 sigset_t returnmask; 2311 int code; 2312 2313 KASSERT(sig != 0, ("postsig")); 2314 2315 PROC_LOCK_ASSERT(p, MA_OWNED); 2316 ps = p->p_sigacts; 2317 mtx_assert(&ps->ps_mtx, MA_OWNED); 2318 SIGDELSET(td->td_siglist, sig); 2319 action = ps->ps_sigact[_SIG_IDX(sig)]; 2320 #ifdef KTRACE 2321 if (KTRPOINT(td, KTR_PSIG)) 2322 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2323 &td->td_oldsigmask : &td->td_sigmask, 0); 2324 #endif 2325 if (p->p_stops & S_SIG) { 2326 mtx_unlock(&ps->ps_mtx); 2327 stopevent(p, S_SIG, sig); 2328 mtx_lock(&ps->ps_mtx); 2329 } 2330 2331 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2332 /* 2333 * Default action, where the default is to kill 2334 * the process. (Other cases were ignored above.) 2335 */ 2336 mtx_unlock(&ps->ps_mtx); 2337 sigexit(td, sig); 2338 /* NOTREACHED */ 2339 } else { 2340 if (td->td_pflags & TDP_SA) { 2341 if (sig == SIGKILL) { 2342 mtx_unlock(&ps->ps_mtx); 2343 sigexit(td, sig); 2344 } 2345 } 2346 2347 /* 2348 * If we get here, the signal must be caught. 2349 */ 2350 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2351 ("postsig action")); 2352 /* 2353 * Set the new mask value and also defer further 2354 * occurrences of this signal. 2355 * 2356 * Special case: user has done a sigsuspend. Here the 2357 * current mask is not of interest, but rather the 2358 * mask from before the sigsuspend is what we want 2359 * restored after the signal processing is completed. 2360 */ 2361 if (td->td_pflags & TDP_OLDMASK) { 2362 returnmask = td->td_oldsigmask; 2363 td->td_pflags &= ~TDP_OLDMASK; 2364 } else 2365 returnmask = td->td_sigmask; 2366 2367 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2368 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2369 SIGADDSET(td->td_sigmask, sig); 2370 2371 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2372 /* 2373 * See kern_sigaction() for origin of this code. 2374 */ 2375 SIGDELSET(ps->ps_sigcatch, sig); 2376 if (sig != SIGCONT && 2377 sigprop(sig) & SA_IGNORE) 2378 SIGADDSET(ps->ps_sigignore, sig); 2379 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2380 } 2381 p->p_stats->p_ru.ru_nsignals++; 2382 if (p->p_sig != sig) { 2383 code = 0; 2384 } else { 2385 code = p->p_code; 2386 p->p_code = 0; 2387 p->p_sig = 0; 2388 } 2389 if (td->td_pflags & TDP_SA) 2390 thread_signal_add(curthread, sig); 2391 else 2392 (*p->p_sysent->sv_sendsig)(action, sig, 2393 &returnmask, code); 2394 } 2395 } 2396 2397 /* 2398 * Kill the current process for stated reason. 2399 */ 2400 void 2401 killproc(p, why) 2402 struct proc *p; 2403 char *why; 2404 { 2405 2406 PROC_LOCK_ASSERT(p, MA_OWNED); 2407 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2408 p, p->p_pid, p->p_comm); 2409 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2410 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2411 p->p_flag |= P_WKILLED; 2412 psignal(p, SIGKILL); 2413 } 2414 2415 /* 2416 * Force the current process to exit with the specified signal, dumping core 2417 * if appropriate. We bypass the normal tests for masked and caught signals, 2418 * allowing unrecoverable failures to terminate the process without changing 2419 * signal state. Mark the accounting record with the signal termination. 2420 * If dumping core, save the signal number for the debugger. Calls exit and 2421 * does not return. 2422 * 2423 * MPSAFE 2424 */ 2425 void 2426 sigexit(td, sig) 2427 struct thread *td; 2428 int sig; 2429 { 2430 struct proc *p = td->td_proc; 2431 2432 PROC_LOCK_ASSERT(p, MA_OWNED); 2433 p->p_acflag |= AXSIG; 2434 /* 2435 * We must be single-threading to generate a core dump. This 2436 * ensures that the registers in the core file are up-to-date. 2437 * Also, the ELF dump handler assumes that the thread list doesn't 2438 * change out from under it. 2439 * 2440 * XXX If another thread attempts to single-thread before us 2441 * (e.g. via fork()), we won't get a dump at all. 2442 */ 2443 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2444 p->p_sig = sig; 2445 /* 2446 * Log signals which would cause core dumps 2447 * (Log as LOG_INFO to appease those who don't want 2448 * these messages.) 2449 * XXX : Todo, as well as euid, write out ruid too 2450 * Note that coredump() drops proc lock. 2451 */ 2452 if (coredump(td) == 0) 2453 sig |= WCOREFLAG; 2454 if (kern_logsigexit) 2455 log(LOG_INFO, 2456 "pid %d (%s), uid %d: exited on signal %d%s\n", 2457 p->p_pid, p->p_comm, 2458 td->td_ucred ? td->td_ucred->cr_uid : -1, 2459 sig &~ WCOREFLAG, 2460 sig & WCOREFLAG ? " (core dumped)" : ""); 2461 } else 2462 PROC_UNLOCK(p); 2463 exit1(td, W_EXITCODE(0, sig)); 2464 /* NOTREACHED */ 2465 } 2466 2467 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2468 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2469 sizeof(corefilename), "process corefile name format string"); 2470 2471 /* 2472 * expand_name(name, uid, pid) 2473 * Expand the name described in corefilename, using name, uid, and pid. 2474 * corefilename is a printf-like string, with three format specifiers: 2475 * %N name of process ("name") 2476 * %P process id (pid) 2477 * %U user id (uid) 2478 * For example, "%N.core" is the default; they can be disabled completely 2479 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2480 * This is controlled by the sysctl variable kern.corefile (see above). 2481 */ 2482 2483 static char * 2484 expand_name(name, uid, pid) 2485 const char *name; 2486 uid_t uid; 2487 pid_t pid; 2488 { 2489 const char *format, *appendstr; 2490 char *temp; 2491 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2492 size_t i, l, n; 2493 2494 format = corefilename; 2495 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2496 if (temp == NULL) 2497 return (NULL); 2498 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2499 switch (format[i]) { 2500 case '%': /* Format character */ 2501 i++; 2502 switch (format[i]) { 2503 case '%': 2504 appendstr = "%"; 2505 break; 2506 case 'N': /* process name */ 2507 appendstr = name; 2508 break; 2509 case 'P': /* process id */ 2510 sprintf(buf, "%u", pid); 2511 appendstr = buf; 2512 break; 2513 case 'U': /* user id */ 2514 sprintf(buf, "%u", uid); 2515 appendstr = buf; 2516 break; 2517 default: 2518 appendstr = ""; 2519 log(LOG_ERR, 2520 "Unknown format character %c in `%s'\n", 2521 format[i], format); 2522 } 2523 l = strlen(appendstr); 2524 if ((n + l) >= MAXPATHLEN) 2525 goto toolong; 2526 memcpy(temp + n, appendstr, l); 2527 n += l; 2528 break; 2529 default: 2530 temp[n++] = format[i]; 2531 } 2532 } 2533 if (format[i] != '\0') 2534 goto toolong; 2535 return (temp); 2536 toolong: 2537 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2538 (long)pid, name, (u_long)uid); 2539 free(temp, M_TEMP); 2540 return (NULL); 2541 } 2542 2543 /* 2544 * Dump a process' core. The main routine does some 2545 * policy checking, and creates the name of the coredump; 2546 * then it passes on a vnode and a size limit to the process-specific 2547 * coredump routine if there is one; if there _is not_ one, it returns 2548 * ENOSYS; otherwise it returns the error from the process-specific routine. 2549 */ 2550 2551 static int 2552 coredump(struct thread *td) 2553 { 2554 struct proc *p = td->td_proc; 2555 register struct vnode *vp; 2556 register struct ucred *cred = td->td_ucred; 2557 struct flock lf; 2558 struct nameidata nd; 2559 struct vattr vattr; 2560 int error, error1, flags, locked; 2561 struct mount *mp; 2562 char *name; /* name of corefile */ 2563 off_t limit; 2564 2565 PROC_LOCK_ASSERT(p, MA_OWNED); 2566 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 2567 _STOPEVENT(p, S_CORE, 0); 2568 2569 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2570 PROC_UNLOCK(p); 2571 return (EFAULT); 2572 } 2573 2574 /* 2575 * Note that the bulk of limit checking is done after 2576 * the corefile is created. The exception is if the limit 2577 * for corefiles is 0, in which case we don't bother 2578 * creating the corefile at all. This layout means that 2579 * a corefile is truncated instead of not being created, 2580 * if it is larger than the limit. 2581 */ 2582 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2583 PROC_UNLOCK(p); 2584 if (limit == 0) 2585 return (EFBIG); 2586 2587 mtx_lock(&Giant); 2588 restart: 2589 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2590 if (name == NULL) { 2591 mtx_unlock(&Giant); 2592 return (EINVAL); 2593 } 2594 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2595 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2596 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2597 free(name, M_TEMP); 2598 if (error) { 2599 mtx_unlock(&Giant); 2600 return (error); 2601 } 2602 NDFREE(&nd, NDF_ONLY_PNBUF); 2603 vp = nd.ni_vp; 2604 2605 /* Don't dump to non-regular files or files with links. */ 2606 if (vp->v_type != VREG || 2607 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2608 VOP_UNLOCK(vp, 0, td); 2609 error = EFAULT; 2610 goto out; 2611 } 2612 2613 VOP_UNLOCK(vp, 0, td); 2614 lf.l_whence = SEEK_SET; 2615 lf.l_start = 0; 2616 lf.l_len = 0; 2617 lf.l_type = F_WRLCK; 2618 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2619 2620 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2621 lf.l_type = F_UNLCK; 2622 if (locked) 2623 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2624 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2625 return (error); 2626 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2627 return (error); 2628 goto restart; 2629 } 2630 2631 VATTR_NULL(&vattr); 2632 vattr.va_size = 0; 2633 if (set_core_nodump_flag) 2634 vattr.va_flags = UF_NODUMP; 2635 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2636 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2637 VOP_SETATTR(vp, &vattr, cred, td); 2638 VOP_UNLOCK(vp, 0, td); 2639 vn_finished_write(mp); 2640 PROC_LOCK(p); 2641 p->p_acflag |= ACORE; 2642 PROC_UNLOCK(p); 2643 2644 error = p->p_sysent->sv_coredump ? 2645 p->p_sysent->sv_coredump(td, vp, limit) : 2646 ENOSYS; 2647 2648 if (locked) { 2649 lf.l_type = F_UNLCK; 2650 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2651 } 2652 out: 2653 error1 = vn_close(vp, FWRITE, cred, td); 2654 mtx_unlock(&Giant); 2655 if (error == 0) 2656 error = error1; 2657 return (error); 2658 } 2659 2660 /* 2661 * Nonexistent system call-- signal process (may want to handle it). 2662 * Flag error in case process won't see signal immediately (blocked or ignored). 2663 */ 2664 #ifndef _SYS_SYSPROTO_H_ 2665 struct nosys_args { 2666 int dummy; 2667 }; 2668 #endif 2669 /* 2670 * MPSAFE 2671 */ 2672 /* ARGSUSED */ 2673 int 2674 nosys(td, args) 2675 struct thread *td; 2676 struct nosys_args *args; 2677 { 2678 struct proc *p = td->td_proc; 2679 2680 PROC_LOCK(p); 2681 psignal(p, SIGSYS); 2682 PROC_UNLOCK(p); 2683 return (ENOSYS); 2684 } 2685 2686 /* 2687 * Send a SIGIO or SIGURG signal to a process or process group using 2688 * stored credentials rather than those of the current process. 2689 */ 2690 void 2691 pgsigio(sigiop, sig, checkctty) 2692 struct sigio **sigiop; 2693 int sig, checkctty; 2694 { 2695 struct sigio *sigio; 2696 2697 SIGIO_LOCK(); 2698 sigio = *sigiop; 2699 if (sigio == NULL) { 2700 SIGIO_UNLOCK(); 2701 return; 2702 } 2703 if (sigio->sio_pgid > 0) { 2704 PROC_LOCK(sigio->sio_proc); 2705 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2706 psignal(sigio->sio_proc, sig); 2707 PROC_UNLOCK(sigio->sio_proc); 2708 } else if (sigio->sio_pgid < 0) { 2709 struct proc *p; 2710 2711 PGRP_LOCK(sigio->sio_pgrp); 2712 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2713 PROC_LOCK(p); 2714 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2715 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2716 psignal(p, sig); 2717 PROC_UNLOCK(p); 2718 } 2719 PGRP_UNLOCK(sigio->sio_pgrp); 2720 } 2721 SIGIO_UNLOCK(); 2722 } 2723 2724 static int 2725 filt_sigattach(struct knote *kn) 2726 { 2727 struct proc *p = curproc; 2728 2729 kn->kn_ptr.p_proc = p; 2730 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2731 2732 knlist_add(&p->p_klist, kn, 0); 2733 2734 return (0); 2735 } 2736 2737 static void 2738 filt_sigdetach(struct knote *kn) 2739 { 2740 struct proc *p = kn->kn_ptr.p_proc; 2741 2742 knlist_remove(&p->p_klist, kn, 0); 2743 } 2744 2745 /* 2746 * signal knotes are shared with proc knotes, so we apply a mask to 2747 * the hint in order to differentiate them from process hints. This 2748 * could be avoided by using a signal-specific knote list, but probably 2749 * isn't worth the trouble. 2750 */ 2751 static int 2752 filt_signal(struct knote *kn, long hint) 2753 { 2754 2755 if (hint & NOTE_SIGNAL) { 2756 hint &= ~NOTE_SIGNAL; 2757 2758 if (kn->kn_id == hint) 2759 kn->kn_data++; 2760 } 2761 return (kn->kn_data != 0); 2762 } 2763 2764 struct sigacts * 2765 sigacts_alloc(void) 2766 { 2767 struct sigacts *ps; 2768 2769 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2770 ps->ps_refcnt = 1; 2771 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2772 return (ps); 2773 } 2774 2775 void 2776 sigacts_free(struct sigacts *ps) 2777 { 2778 2779 mtx_lock(&ps->ps_mtx); 2780 ps->ps_refcnt--; 2781 if (ps->ps_refcnt == 0) { 2782 mtx_destroy(&ps->ps_mtx); 2783 free(ps, M_SUBPROC); 2784 } else 2785 mtx_unlock(&ps->ps_mtx); 2786 } 2787 2788 struct sigacts * 2789 sigacts_hold(struct sigacts *ps) 2790 { 2791 mtx_lock(&ps->ps_mtx); 2792 ps->ps_refcnt++; 2793 mtx_unlock(&ps->ps_mtx); 2794 return (ps); 2795 } 2796 2797 void 2798 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2799 { 2800 2801 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2802 mtx_lock(&src->ps_mtx); 2803 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2804 mtx_unlock(&src->ps_mtx); 2805 } 2806 2807 int 2808 sigacts_shared(struct sigacts *ps) 2809 { 2810 int shared; 2811 2812 mtx_lock(&ps->ps_mtx); 2813 shared = ps->ps_refcnt > 1; 2814 mtx_unlock(&ps->ps_mtx); 2815 return (shared); 2816 }
Cache object: 8cee8b7aaeaebce1084d9223c41b0c4d
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