Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/6.2/sys/kern/kern_sig.c 164286 2006-11-14 20:42:41Z cvs2svn $"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/signalvar.h> 46 #include <sys/vnode.h> 47 #include <sys/acct.h> 48 #include <sys/condvar.h> 49 #include <sys/event.h> 50 #include <sys/fcntl.h> 51 #include <sys/kernel.h> 52 #include <sys/kse.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/pioctl.h> 61 #include <sys/resourcevar.h> 62 #include <sys/sched.h> 63 #include <sys/sleepqueue.h> 64 #include <sys/smp.h> 65 #include <sys/stat.h> 66 #include <sys/sx.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysent.h> 70 #include <sys/syslog.h> 71 #include <sys/sysproto.h> 72 #include <sys/unistd.h> 73 #include <sys/wait.h> 74 75 #include <machine/cpu.h> 76 77 #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_handler = ps->ps_sigact[_SIG_IDX(sig)]; 300 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 301 oact->sa_flags = 0; 302 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 303 oact->sa_flags |= SA_ONSTACK; 304 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 305 oact->sa_flags |= SA_RESTART; 306 if (SIGISMEMBER(ps->ps_sigreset, sig)) 307 oact->sa_flags |= SA_RESETHAND; 308 if (SIGISMEMBER(ps->ps_signodefer, sig)) 309 oact->sa_flags |= SA_NODEFER; 310 if (SIGISMEMBER(ps->ps_siginfo, sig)) 311 oact->sa_flags |= SA_SIGINFO; 312 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 313 oact->sa_flags |= SA_NOCLDSTOP; 314 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 315 oact->sa_flags |= SA_NOCLDWAIT; 316 } 317 if (act) { 318 if ((sig == SIGKILL || sig == SIGSTOP) && 319 act->sa_handler != SIG_DFL) { 320 mtx_unlock(&ps->ps_mtx); 321 PROC_UNLOCK(p); 322 return (EINVAL); 323 } 324 325 /* 326 * Change setting atomically. 327 */ 328 329 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 330 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 331 if (act->sa_flags & SA_SIGINFO) { 332 ps->ps_sigact[_SIG_IDX(sig)] = 333 (__sighandler_t *)act->sa_sigaction; 334 SIGADDSET(ps->ps_siginfo, sig); 335 } else { 336 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 337 SIGDELSET(ps->ps_siginfo, sig); 338 } 339 if (!(act->sa_flags & SA_RESTART)) 340 SIGADDSET(ps->ps_sigintr, sig); 341 else 342 SIGDELSET(ps->ps_sigintr, sig); 343 if (act->sa_flags & SA_ONSTACK) 344 SIGADDSET(ps->ps_sigonstack, sig); 345 else 346 SIGDELSET(ps->ps_sigonstack, sig); 347 if (act->sa_flags & SA_RESETHAND) 348 SIGADDSET(ps->ps_sigreset, sig); 349 else 350 SIGDELSET(ps->ps_sigreset, sig); 351 if (act->sa_flags & SA_NODEFER) 352 SIGADDSET(ps->ps_signodefer, sig); 353 else 354 SIGDELSET(ps->ps_signodefer, sig); 355 if (sig == SIGCHLD) { 356 if (act->sa_flags & SA_NOCLDSTOP) 357 ps->ps_flag |= PS_NOCLDSTOP; 358 else 359 ps->ps_flag &= ~PS_NOCLDSTOP; 360 if (act->sa_flags & SA_NOCLDWAIT) { 361 /* 362 * Paranoia: since SA_NOCLDWAIT is implemented 363 * by reparenting the dying child to PID 1 (and 364 * trust it to reap the zombie), PID 1 itself 365 * is forbidden to set SA_NOCLDWAIT. 366 */ 367 if (p->p_pid == 1) 368 ps->ps_flag &= ~PS_NOCLDWAIT; 369 else 370 ps->ps_flag |= PS_NOCLDWAIT; 371 } else 372 ps->ps_flag &= ~PS_NOCLDWAIT; 373 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 374 ps->ps_flag |= PS_CLDSIGIGN; 375 else 376 ps->ps_flag &= ~PS_CLDSIGIGN; 377 } 378 /* 379 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 380 * and for signals set to SIG_DFL where the default is to 381 * ignore. However, don't put SIGCONT in ps_sigignore, as we 382 * have to restart the process. 383 */ 384 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 385 (sigprop(sig) & SA_IGNORE && 386 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 387 if ((p->p_flag & P_SA) && 388 SIGISMEMBER(p->p_siglist, sig)) { 389 p->p_flag |= P_SIGEVENT; 390 wakeup(&p->p_siglist); 391 } 392 /* never to be seen again */ 393 SIGDELSET(p->p_siglist, sig); 394 mtx_lock_spin(&sched_lock); 395 FOREACH_THREAD_IN_PROC(p, td0) 396 SIGDELSET(td0->td_siglist, sig); 397 mtx_unlock_spin(&sched_lock); 398 if (sig != SIGCONT) 399 /* easier in psignal */ 400 SIGADDSET(ps->ps_sigignore, sig); 401 SIGDELSET(ps->ps_sigcatch, sig); 402 } else { 403 SIGDELSET(ps->ps_sigignore, sig); 404 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 405 SIGDELSET(ps->ps_sigcatch, sig); 406 else 407 SIGADDSET(ps->ps_sigcatch, sig); 408 } 409 #ifdef COMPAT_FREEBSD4 410 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 411 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 412 (flags & KSA_FREEBSD4) == 0) 413 SIGDELSET(ps->ps_freebsd4, sig); 414 else 415 SIGADDSET(ps->ps_freebsd4, sig); 416 #endif 417 #ifdef COMPAT_43 418 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 419 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 420 (flags & KSA_OSIGSET) == 0) 421 SIGDELSET(ps->ps_osigset, sig); 422 else 423 SIGADDSET(ps->ps_osigset, sig); 424 #endif 425 } 426 mtx_unlock(&ps->ps_mtx); 427 PROC_UNLOCK(p); 428 return (0); 429 } 430 431 #ifndef _SYS_SYSPROTO_H_ 432 struct sigaction_args { 433 int sig; 434 struct sigaction *act; 435 struct sigaction *oact; 436 }; 437 #endif 438 /* 439 * MPSAFE 440 */ 441 int 442 sigaction(td, uap) 443 struct thread *td; 444 register struct sigaction_args *uap; 445 { 446 struct sigaction act, oact; 447 register struct sigaction *actp, *oactp; 448 int error; 449 450 actp = (uap->act != NULL) ? &act : NULL; 451 oactp = (uap->oact != NULL) ? &oact : NULL; 452 if (actp) { 453 error = copyin(uap->act, actp, sizeof(act)); 454 if (error) 455 return (error); 456 } 457 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 458 if (oactp && !error) 459 error = copyout(oactp, uap->oact, sizeof(oact)); 460 return (error); 461 } 462 463 #ifdef COMPAT_FREEBSD4 464 #ifndef _SYS_SYSPROTO_H_ 465 struct freebsd4_sigaction_args { 466 int sig; 467 struct sigaction *act; 468 struct sigaction *oact; 469 }; 470 #endif 471 /* 472 * MPSAFE 473 */ 474 int 475 freebsd4_sigaction(td, uap) 476 struct thread *td; 477 register struct freebsd4_sigaction_args *uap; 478 { 479 struct sigaction act, oact; 480 register struct sigaction *actp, *oactp; 481 int error; 482 483 484 actp = (uap->act != NULL) ? &act : NULL; 485 oactp = (uap->oact != NULL) ? &oact : NULL; 486 if (actp) { 487 error = copyin(uap->act, actp, sizeof(act)); 488 if (error) 489 return (error); 490 } 491 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 492 if (oactp && !error) 493 error = copyout(oactp, uap->oact, sizeof(oact)); 494 return (error); 495 } 496 #endif /* COMAPT_FREEBSD4 */ 497 498 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 499 #ifndef _SYS_SYSPROTO_H_ 500 struct osigaction_args { 501 int signum; 502 struct osigaction *nsa; 503 struct osigaction *osa; 504 }; 505 #endif 506 /* 507 * MPSAFE 508 */ 509 int 510 osigaction(td, uap) 511 struct thread *td; 512 register struct osigaction_args *uap; 513 { 514 struct osigaction sa; 515 struct sigaction nsa, osa; 516 register struct sigaction *nsap, *osap; 517 int error; 518 519 if (uap->signum <= 0 || uap->signum >= ONSIG) 520 return (EINVAL); 521 522 nsap = (uap->nsa != NULL) ? &nsa : NULL; 523 osap = (uap->osa != NULL) ? &osa : NULL; 524 525 if (nsap) { 526 error = copyin(uap->nsa, &sa, sizeof(sa)); 527 if (error) 528 return (error); 529 nsap->sa_handler = sa.sa_handler; 530 nsap->sa_flags = sa.sa_flags; 531 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 532 } 533 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 534 if (osap && !error) { 535 sa.sa_handler = osap->sa_handler; 536 sa.sa_flags = osap->sa_flags; 537 SIG2OSIG(osap->sa_mask, sa.sa_mask); 538 error = copyout(&sa, uap->osa, sizeof(sa)); 539 } 540 return (error); 541 } 542 543 #if !defined(__i386__) && !defined(__alpha__) 544 /* Avoid replicating the same stub everywhere */ 545 int 546 osigreturn(td, uap) 547 struct thread *td; 548 struct osigreturn_args *uap; 549 { 550 551 return (nosys(td, (struct nosys_args *)uap)); 552 } 553 #endif 554 #endif /* COMPAT_43 */ 555 556 /* 557 * Initialize signal state for process 0; 558 * set to ignore signals that are ignored by default. 559 */ 560 void 561 siginit(p) 562 struct proc *p; 563 { 564 register int i; 565 struct sigacts *ps; 566 567 PROC_LOCK(p); 568 ps = p->p_sigacts; 569 mtx_lock(&ps->ps_mtx); 570 for (i = 1; i <= NSIG; i++) 571 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 572 SIGADDSET(ps->ps_sigignore, i); 573 mtx_unlock(&ps->ps_mtx); 574 PROC_UNLOCK(p); 575 } 576 577 /* 578 * Reset signals for an exec of the specified process. 579 */ 580 void 581 execsigs(struct proc *p) 582 { 583 struct sigacts *ps; 584 int sig; 585 struct thread *td; 586 587 /* 588 * Reset caught signals. Held signals remain held 589 * through td_sigmask (unless they were caught, 590 * and are now ignored by default). 591 */ 592 PROC_LOCK_ASSERT(p, MA_OWNED); 593 td = FIRST_THREAD_IN_PROC(p); 594 ps = p->p_sigacts; 595 mtx_lock(&ps->ps_mtx); 596 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 597 sig = sig_ffs(&ps->ps_sigcatch); 598 SIGDELSET(ps->ps_sigcatch, sig); 599 if (sigprop(sig) & SA_IGNORE) { 600 if (sig != SIGCONT) 601 SIGADDSET(ps->ps_sigignore, sig); 602 SIGDELSET(p->p_siglist, sig); 603 /* 604 * There is only one thread at this point. 605 */ 606 SIGDELSET(td->td_siglist, sig); 607 } 608 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 609 } 610 /* 611 * Reset stack state to the user stack. 612 * Clear set of signals caught on the signal stack. 613 */ 614 td->td_sigstk.ss_flags = SS_DISABLE; 615 td->td_sigstk.ss_size = 0; 616 td->td_sigstk.ss_sp = 0; 617 td->td_pflags &= ~TDP_ALTSTACK; 618 /* 619 * Reset no zombies if child dies flag as Solaris does. 620 */ 621 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 622 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 623 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 624 mtx_unlock(&ps->ps_mtx); 625 } 626 627 /* 628 * kern_sigprocmask() 629 * 630 * Manipulate signal mask. 631 */ 632 int 633 kern_sigprocmask(td, how, set, oset, old) 634 struct thread *td; 635 int how; 636 sigset_t *set, *oset; 637 int old; 638 { 639 int error; 640 641 PROC_LOCK(td->td_proc); 642 if (oset != NULL) 643 *oset = td->td_sigmask; 644 645 error = 0; 646 if (set != NULL) { 647 switch (how) { 648 case SIG_BLOCK: 649 SIG_CANTMASK(*set); 650 SIGSETOR(td->td_sigmask, *set); 651 break; 652 case SIG_UNBLOCK: 653 SIGSETNAND(td->td_sigmask, *set); 654 signotify(td); 655 break; 656 case SIG_SETMASK: 657 SIG_CANTMASK(*set); 658 if (old) 659 SIGSETLO(td->td_sigmask, *set); 660 else 661 td->td_sigmask = *set; 662 signotify(td); 663 break; 664 default: 665 error = EINVAL; 666 break; 667 } 668 } 669 PROC_UNLOCK(td->td_proc); 670 return (error); 671 } 672 673 /* 674 * sigprocmask() - MP SAFE 675 */ 676 677 #ifndef _SYS_SYSPROTO_H_ 678 struct sigprocmask_args { 679 int how; 680 const sigset_t *set; 681 sigset_t *oset; 682 }; 683 #endif 684 int 685 sigprocmask(td, uap) 686 register struct thread *td; 687 struct sigprocmask_args *uap; 688 { 689 sigset_t set, oset; 690 sigset_t *setp, *osetp; 691 int error; 692 693 setp = (uap->set != NULL) ? &set : NULL; 694 osetp = (uap->oset != NULL) ? &oset : NULL; 695 if (setp) { 696 error = copyin(uap->set, setp, sizeof(set)); 697 if (error) 698 return (error); 699 } 700 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 701 if (osetp && !error) { 702 error = copyout(osetp, uap->oset, sizeof(oset)); 703 } 704 return (error); 705 } 706 707 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 708 /* 709 * osigprocmask() - MP SAFE 710 */ 711 #ifndef _SYS_SYSPROTO_H_ 712 struct osigprocmask_args { 713 int how; 714 osigset_t mask; 715 }; 716 #endif 717 int 718 osigprocmask(td, uap) 719 register struct thread *td; 720 struct osigprocmask_args *uap; 721 { 722 sigset_t set, oset; 723 int error; 724 725 OSIG2SIG(uap->mask, set); 726 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 727 SIG2OSIG(oset, td->td_retval[0]); 728 return (error); 729 } 730 #endif /* COMPAT_43 */ 731 732 #ifndef _SYS_SYSPROTO_H_ 733 struct sigpending_args { 734 sigset_t *set; 735 }; 736 #endif 737 /* 738 * MPSAFE 739 */ 740 int 741 sigwait(struct thread *td, struct sigwait_args *uap) 742 { 743 siginfo_t info; 744 sigset_t set; 745 int error; 746 747 error = copyin(uap->set, &set, sizeof(set)); 748 if (error) { 749 td->td_retval[0] = error; 750 return (0); 751 } 752 753 error = kern_sigtimedwait(td, set, &info, NULL); 754 if (error) { 755 if (error == ERESTART) 756 return (error); 757 td->td_retval[0] = error; 758 return (0); 759 } 760 761 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 762 /* Repost if we got an error. */ 763 if (error && info.si_signo) { 764 PROC_LOCK(td->td_proc); 765 tdsignal(td, info.si_signo, SIGTARGET_TD); 766 PROC_UNLOCK(td->td_proc); 767 } 768 td->td_retval[0] = error; 769 return (0); 770 } 771 /* 772 * MPSAFE 773 */ 774 int 775 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 776 { 777 struct timespec ts; 778 struct timespec *timeout; 779 sigset_t set; 780 siginfo_t info; 781 int error; 782 783 if (uap->timeout) { 784 error = copyin(uap->timeout, &ts, sizeof(ts)); 785 if (error) 786 return (error); 787 788 timeout = &ts; 789 } else 790 timeout = NULL; 791 792 error = copyin(uap->set, &set, sizeof(set)); 793 if (error) 794 return (error); 795 796 error = kern_sigtimedwait(td, set, &info, timeout); 797 if (error) 798 return (error); 799 800 if (uap->info) 801 error = copyout(&info, uap->info, sizeof(info)); 802 /* Repost if we got an error. */ 803 if (error && info.si_signo) { 804 PROC_LOCK(td->td_proc); 805 tdsignal(td, info.si_signo, SIGTARGET_TD); 806 PROC_UNLOCK(td->td_proc); 807 } else { 808 td->td_retval[0] = info.si_signo; 809 } 810 return (error); 811 } 812 813 /* 814 * MPSAFE 815 */ 816 int 817 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 818 { 819 siginfo_t info; 820 sigset_t set; 821 int error; 822 823 error = copyin(uap->set, &set, sizeof(set)); 824 if (error) 825 return (error); 826 827 error = kern_sigtimedwait(td, set, &info, NULL); 828 if (error) 829 return (error); 830 831 if (uap->info) 832 error = copyout(&info, uap->info, sizeof(info)); 833 /* Repost if we got an error. */ 834 if (error && info.si_signo) { 835 PROC_LOCK(td->td_proc); 836 tdsignal(td, info.si_signo, SIGTARGET_TD); 837 PROC_UNLOCK(td->td_proc); 838 } else { 839 td->td_retval[0] = info.si_signo; 840 } 841 return (error); 842 } 843 844 static int 845 kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info, 846 struct timespec *timeout) 847 { 848 struct sigacts *ps; 849 sigset_t savedmask; 850 struct proc *p; 851 int error, sig, hz, i, timevalid = 0; 852 struct timespec rts, ets, ts; 853 struct timeval tv; 854 855 p = td->td_proc; 856 error = 0; 857 sig = 0; 858 SIG_CANTMASK(waitset); 859 860 PROC_LOCK(p); 861 ps = p->p_sigacts; 862 savedmask = td->td_sigmask; 863 if (timeout) { 864 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 865 timevalid = 1; 866 getnanouptime(&rts); 867 ets = rts; 868 timespecadd(&ets, timeout); 869 } 870 } 871 872 restart: 873 for (i = 1; i <= _SIG_MAXSIG; ++i) { 874 if (!SIGISMEMBER(waitset, i)) 875 continue; 876 if (!SIGISMEMBER(td->td_siglist, i)) { 877 if (SIGISMEMBER(p->p_siglist, i)) { 878 if (p->p_flag & P_SA) { 879 p->p_flag |= P_SIGEVENT; 880 wakeup(&p->p_siglist); 881 } 882 SIGDELSET(p->p_siglist, i); 883 SIGADDSET(td->td_siglist, i); 884 } else 885 continue; 886 } 887 888 SIGFILLSET(td->td_sigmask); 889 SIG_CANTMASK(td->td_sigmask); 890 SIGDELSET(td->td_sigmask, i); 891 mtx_lock(&ps->ps_mtx); 892 sig = cursig(td); 893 mtx_unlock(&ps->ps_mtx); 894 if (sig) 895 goto out; 896 else { 897 /* 898 * Because cursig() may have stopped current thread, 899 * after it is resumed, things may have already been 900 * changed, it should rescan any pending signals. 901 */ 902 goto restart; 903 } 904 } 905 if (error) 906 goto out; 907 908 /* 909 * POSIX says this must be checked after looking for pending 910 * signals. 911 */ 912 if (timeout) { 913 if (!timevalid) { 914 error = EINVAL; 915 goto out; 916 } 917 getnanouptime(&rts); 918 if (timespeccmp(&rts, &ets, >=)) { 919 error = EAGAIN; 920 goto out; 921 } 922 ts = ets; 923 timespecsub(&ts, &rts); 924 TIMESPEC_TO_TIMEVAL(&tv, &ts); 925 hz = tvtohz(&tv); 926 } else 927 hz = 0; 928 929 td->td_sigmask = savedmask; 930 SIGSETNAND(td->td_sigmask, waitset); 931 signotify(td); 932 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 933 if (timeout) { 934 if (error == ERESTART) { 935 /* timeout can not be restarted. */ 936 error = EINTR; 937 } else if (error == EAGAIN) { 938 /* will calculate timeout by ourself. */ 939 error = 0; 940 } 941 } 942 goto restart; 943 944 out: 945 td->td_sigmask = savedmask; 946 signotify(td); 947 if (sig) { 948 SIGDELSET(td->td_siglist, sig); 949 bzero(info, sizeof(*info)); 950 info->si_signo = sig; 951 info->si_code = 0; 952 error = 0; 953 954 #ifdef KTRACE 955 if (KTRPOINT(td, KTR_PSIG)) { 956 sig_t action; 957 958 mtx_lock(&ps->ps_mtx); 959 action = ps->ps_sigact[_SIG_IDX(sig)]; 960 mtx_unlock(&ps->ps_mtx); 961 ktrpsig(sig, action, &td->td_sigmask, 0); 962 } 963 #endif 964 _STOPEVENT(p, S_SIG, sig); 965 966 if (sig == SIGKILL) { 967 p->p_code = 0; 968 p->p_sig = sig; 969 sigexit(td, sig); 970 } 971 } 972 PROC_UNLOCK(p); 973 return (error); 974 } 975 976 /* 977 * MPSAFE 978 */ 979 int 980 sigpending(td, uap) 981 struct thread *td; 982 struct sigpending_args *uap; 983 { 984 struct proc *p = td->td_proc; 985 sigset_t siglist; 986 987 PROC_LOCK(p); 988 siglist = p->p_siglist; 989 SIGSETOR(siglist, td->td_siglist); 990 PROC_UNLOCK(p); 991 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 992 } 993 994 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 995 #ifndef _SYS_SYSPROTO_H_ 996 struct osigpending_args { 997 int dummy; 998 }; 999 #endif 1000 /* 1001 * MPSAFE 1002 */ 1003 int 1004 osigpending(td, uap) 1005 struct thread *td; 1006 struct osigpending_args *uap; 1007 { 1008 struct proc *p = td->td_proc; 1009 sigset_t siglist; 1010 1011 PROC_LOCK(p); 1012 siglist = p->p_siglist; 1013 SIGSETOR(siglist, td->td_siglist); 1014 PROC_UNLOCK(p); 1015 SIG2OSIG(siglist, td->td_retval[0]); 1016 return (0); 1017 } 1018 #endif /* COMPAT_43 */ 1019 1020 #if defined(COMPAT_43) 1021 /* 1022 * Generalized interface signal handler, 4.3-compatible. 1023 */ 1024 #ifndef _SYS_SYSPROTO_H_ 1025 struct osigvec_args { 1026 int signum; 1027 struct sigvec *nsv; 1028 struct sigvec *osv; 1029 }; 1030 #endif 1031 /* 1032 * MPSAFE 1033 */ 1034 /* ARGSUSED */ 1035 int 1036 osigvec(td, uap) 1037 struct thread *td; 1038 register struct osigvec_args *uap; 1039 { 1040 struct sigvec vec; 1041 struct sigaction nsa, osa; 1042 register struct sigaction *nsap, *osap; 1043 int error; 1044 1045 if (uap->signum <= 0 || uap->signum >= ONSIG) 1046 return (EINVAL); 1047 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1048 osap = (uap->osv != NULL) ? &osa : NULL; 1049 if (nsap) { 1050 error = copyin(uap->nsv, &vec, sizeof(vec)); 1051 if (error) 1052 return (error); 1053 nsap->sa_handler = vec.sv_handler; 1054 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1055 nsap->sa_flags = vec.sv_flags; 1056 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1057 } 1058 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1059 if (osap && !error) { 1060 vec.sv_handler = osap->sa_handler; 1061 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1062 vec.sv_flags = osap->sa_flags; 1063 vec.sv_flags &= ~SA_NOCLDWAIT; 1064 vec.sv_flags ^= SA_RESTART; 1065 error = copyout(&vec, uap->osv, sizeof(vec)); 1066 } 1067 return (error); 1068 } 1069 1070 #ifndef _SYS_SYSPROTO_H_ 1071 struct osigblock_args { 1072 int mask; 1073 }; 1074 #endif 1075 /* 1076 * MPSAFE 1077 */ 1078 int 1079 osigblock(td, uap) 1080 register struct thread *td; 1081 struct osigblock_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 SIGSETOR(td->td_sigmask, set); 1091 PROC_UNLOCK(p); 1092 return (0); 1093 } 1094 1095 #ifndef _SYS_SYSPROTO_H_ 1096 struct osigsetmask_args { 1097 int mask; 1098 }; 1099 #endif 1100 /* 1101 * MPSAFE 1102 */ 1103 int 1104 osigsetmask(td, uap) 1105 struct thread *td; 1106 struct osigsetmask_args *uap; 1107 { 1108 struct proc *p = td->td_proc; 1109 sigset_t set; 1110 1111 OSIG2SIG(uap->mask, set); 1112 SIG_CANTMASK(set); 1113 PROC_LOCK(p); 1114 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1115 SIGSETLO(td->td_sigmask, set); 1116 signotify(td); 1117 PROC_UNLOCK(p); 1118 return (0); 1119 } 1120 #endif /* COMPAT_43 */ 1121 1122 /* 1123 * Suspend process until signal, providing mask to be set 1124 * in the meantime. 1125 ***** XXXKSE this doesn't make sense under KSE. 1126 ***** Do we suspend the thread or all threads in the process? 1127 ***** How do we suspend threads running NOW on another processor? 1128 */ 1129 #ifndef _SYS_SYSPROTO_H_ 1130 struct sigsuspend_args { 1131 const sigset_t *sigmask; 1132 }; 1133 #endif 1134 /* 1135 * MPSAFE 1136 */ 1137 /* ARGSUSED */ 1138 int 1139 sigsuspend(td, uap) 1140 struct thread *td; 1141 struct sigsuspend_args *uap; 1142 { 1143 sigset_t mask; 1144 int error; 1145 1146 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1147 if (error) 1148 return (error); 1149 return (kern_sigsuspend(td, mask)); 1150 } 1151 1152 int 1153 kern_sigsuspend(struct thread *td, sigset_t mask) 1154 { 1155 struct proc *p = td->td_proc; 1156 1157 /* 1158 * When returning from sigsuspend, we want 1159 * the old mask to be restored after the 1160 * signal handler has finished. Thus, we 1161 * save it here and mark the sigacts structure 1162 * to indicate this. 1163 */ 1164 PROC_LOCK(p); 1165 td->td_oldsigmask = td->td_sigmask; 1166 td->td_pflags |= TDP_OLDMASK; 1167 SIG_CANTMASK(mask); 1168 td->td_sigmask = mask; 1169 signotify(td); 1170 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1171 /* void */; 1172 PROC_UNLOCK(p); 1173 /* always return EINTR rather than ERESTART... */ 1174 return (EINTR); 1175 } 1176 1177 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1178 /* 1179 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1180 * convention: libc stub passes mask, not pointer, to save a copyin. 1181 */ 1182 #ifndef _SYS_SYSPROTO_H_ 1183 struct osigsuspend_args { 1184 osigset_t mask; 1185 }; 1186 #endif 1187 /* 1188 * MPSAFE 1189 */ 1190 /* ARGSUSED */ 1191 int 1192 osigsuspend(td, uap) 1193 struct thread *td; 1194 struct osigsuspend_args *uap; 1195 { 1196 struct proc *p = td->td_proc; 1197 sigset_t mask; 1198 1199 PROC_LOCK(p); 1200 td->td_oldsigmask = td->td_sigmask; 1201 td->td_pflags |= TDP_OLDMASK; 1202 OSIG2SIG(uap->mask, mask); 1203 SIG_CANTMASK(mask); 1204 SIGSETLO(td->td_sigmask, mask); 1205 signotify(td); 1206 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1207 /* void */; 1208 PROC_UNLOCK(p); 1209 /* always return EINTR rather than ERESTART... */ 1210 return (EINTR); 1211 } 1212 #endif /* COMPAT_43 */ 1213 1214 #if defined(COMPAT_43) 1215 #ifndef _SYS_SYSPROTO_H_ 1216 struct osigstack_args { 1217 struct sigstack *nss; 1218 struct sigstack *oss; 1219 }; 1220 #endif 1221 /* 1222 * MPSAFE 1223 */ 1224 /* ARGSUSED */ 1225 int 1226 osigstack(td, uap) 1227 struct thread *td; 1228 register struct osigstack_args *uap; 1229 { 1230 struct sigstack nss, oss; 1231 int error = 0; 1232 1233 if (uap->nss != NULL) { 1234 error = copyin(uap->nss, &nss, sizeof(nss)); 1235 if (error) 1236 return (error); 1237 } 1238 oss.ss_sp = td->td_sigstk.ss_sp; 1239 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1240 if (uap->nss != NULL) { 1241 td->td_sigstk.ss_sp = nss.ss_sp; 1242 td->td_sigstk.ss_size = 0; 1243 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1244 td->td_pflags |= TDP_ALTSTACK; 1245 } 1246 if (uap->oss != NULL) 1247 error = copyout(&oss, uap->oss, sizeof(oss)); 1248 1249 return (error); 1250 } 1251 #endif /* COMPAT_43 */ 1252 1253 #ifndef _SYS_SYSPROTO_H_ 1254 struct sigaltstack_args { 1255 stack_t *ss; 1256 stack_t *oss; 1257 }; 1258 #endif 1259 /* 1260 * MPSAFE 1261 */ 1262 /* ARGSUSED */ 1263 int 1264 sigaltstack(td, uap) 1265 struct thread *td; 1266 register struct sigaltstack_args *uap; 1267 { 1268 stack_t ss, oss; 1269 int error; 1270 1271 if (uap->ss != NULL) { 1272 error = copyin(uap->ss, &ss, sizeof(ss)); 1273 if (error) 1274 return (error); 1275 } 1276 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1277 (uap->oss != NULL) ? &oss : NULL); 1278 if (error) 1279 return (error); 1280 if (uap->oss != NULL) 1281 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1282 return (error); 1283 } 1284 1285 int 1286 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1287 { 1288 struct proc *p = td->td_proc; 1289 int oonstack; 1290 1291 oonstack = sigonstack(cpu_getstack(td)); 1292 1293 if (oss != NULL) { 1294 *oss = td->td_sigstk; 1295 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1296 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1297 } 1298 1299 if (ss != NULL) { 1300 if (oonstack) 1301 return (EPERM); 1302 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1303 return (EINVAL); 1304 if (!(ss->ss_flags & SS_DISABLE)) { 1305 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1306 return (ENOMEM); 1307 } 1308 td->td_sigstk = *ss; 1309 td->td_pflags |= TDP_ALTSTACK; 1310 } else { 1311 td->td_pflags &= ~TDP_ALTSTACK; 1312 } 1313 } 1314 return (0); 1315 } 1316 1317 /* 1318 * Common code for kill process group/broadcast kill. 1319 * cp is calling process. 1320 */ 1321 static int 1322 killpg1(td, sig, pgid, all) 1323 register struct thread *td; 1324 int sig, pgid, all; 1325 { 1326 register struct proc *p; 1327 struct pgrp *pgrp; 1328 int nfound = 0; 1329 1330 if (all) { 1331 /* 1332 * broadcast 1333 */ 1334 sx_slock(&allproc_lock); 1335 LIST_FOREACH(p, &allproc, p_list) { 1336 PROC_LOCK(p); 1337 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1338 p == td->td_proc || p->p_state == PRS_NEW) { 1339 PROC_UNLOCK(p); 1340 continue; 1341 } 1342 if (p_cansignal(td, p, sig) == 0) { 1343 nfound++; 1344 if (sig) 1345 psignal(p, sig); 1346 } 1347 PROC_UNLOCK(p); 1348 } 1349 sx_sunlock(&allproc_lock); 1350 } else { 1351 sx_slock(&proctree_lock); 1352 if (pgid == 0) { 1353 /* 1354 * zero pgid means send to my process group. 1355 */ 1356 pgrp = td->td_proc->p_pgrp; 1357 PGRP_LOCK(pgrp); 1358 } else { 1359 pgrp = pgfind(pgid); 1360 if (pgrp == NULL) { 1361 sx_sunlock(&proctree_lock); 1362 return (ESRCH); 1363 } 1364 } 1365 sx_sunlock(&proctree_lock); 1366 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1367 PROC_LOCK(p); 1368 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1369 p->p_state == PRS_NEW ) { 1370 PROC_UNLOCK(p); 1371 continue; 1372 } 1373 if (p_cansignal(td, p, sig) == 0) { 1374 nfound++; 1375 if (sig) 1376 psignal(p, sig); 1377 } 1378 PROC_UNLOCK(p); 1379 } 1380 PGRP_UNLOCK(pgrp); 1381 } 1382 return (nfound ? 0 : ESRCH); 1383 } 1384 1385 #ifndef _SYS_SYSPROTO_H_ 1386 struct kill_args { 1387 int pid; 1388 int signum; 1389 }; 1390 #endif 1391 /* 1392 * MPSAFE 1393 */ 1394 /* ARGSUSED */ 1395 int 1396 kill(td, uap) 1397 register struct thread *td; 1398 register struct kill_args *uap; 1399 { 1400 register struct proc *p; 1401 int error; 1402 1403 AUDIT_ARG(signum, uap->signum); 1404 if ((u_int)uap->signum > _SIG_MAXSIG) 1405 return (EINVAL); 1406 1407 if (uap->pid > 0) { 1408 /* kill single process */ 1409 if ((p = pfind(uap->pid)) == NULL) { 1410 if ((p = zpfind(uap->pid)) == NULL) 1411 return (ESRCH); 1412 } 1413 AUDIT_ARG(process, p); 1414 error = p_cansignal(td, p, uap->signum); 1415 if (error == 0 && uap->signum) 1416 psignal(p, uap->signum); 1417 PROC_UNLOCK(p); 1418 return (error); 1419 } 1420 AUDIT_ARG(pid, uap->pid); 1421 switch (uap->pid) { 1422 case -1: /* broadcast signal */ 1423 return (killpg1(td, uap->signum, 0, 1)); 1424 case 0: /* signal own process group */ 1425 return (killpg1(td, uap->signum, 0, 0)); 1426 default: /* negative explicit process group */ 1427 return (killpg1(td, uap->signum, -uap->pid, 0)); 1428 } 1429 /* NOTREACHED */ 1430 } 1431 1432 #if defined(COMPAT_43) 1433 #ifndef _SYS_SYSPROTO_H_ 1434 struct okillpg_args { 1435 int pgid; 1436 int signum; 1437 }; 1438 #endif 1439 /* 1440 * MPSAFE 1441 */ 1442 /* ARGSUSED */ 1443 int 1444 okillpg(td, uap) 1445 struct thread *td; 1446 register struct okillpg_args *uap; 1447 { 1448 1449 AUDIT_ARG(signum, uap->signum); 1450 AUDIT_ARG(pid, uap->pgid); 1451 if ((u_int)uap->signum > _SIG_MAXSIG) 1452 return (EINVAL); 1453 return (killpg1(td, uap->signum, uap->pgid, 0)); 1454 } 1455 #endif /* COMPAT_43 */ 1456 1457 /* 1458 * Send a signal to a process group. 1459 */ 1460 void 1461 gsignal(pgid, sig) 1462 int pgid, sig; 1463 { 1464 struct pgrp *pgrp; 1465 1466 if (pgid != 0) { 1467 sx_slock(&proctree_lock); 1468 pgrp = pgfind(pgid); 1469 sx_sunlock(&proctree_lock); 1470 if (pgrp != NULL) { 1471 pgsignal(pgrp, sig, 0); 1472 PGRP_UNLOCK(pgrp); 1473 } 1474 } 1475 } 1476 1477 /* 1478 * Send a signal to a process group. If checktty is 1, 1479 * limit to members which have a controlling terminal. 1480 */ 1481 void 1482 pgsignal(pgrp, sig, checkctty) 1483 struct pgrp *pgrp; 1484 int sig, checkctty; 1485 { 1486 register struct proc *p; 1487 1488 if (pgrp) { 1489 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1490 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1491 PROC_LOCK(p); 1492 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1493 psignal(p, sig); 1494 PROC_UNLOCK(p); 1495 } 1496 } 1497 } 1498 1499 /* 1500 * Send a signal caused by a trap to the current thread. 1501 * If it will be caught immediately, deliver it with correct code. 1502 * Otherwise, post it normally. 1503 * 1504 * MPSAFE 1505 */ 1506 void 1507 trapsignal(struct thread *td, int sig, u_long code) 1508 { 1509 struct sigacts *ps; 1510 struct proc *p; 1511 siginfo_t siginfo; 1512 int error; 1513 1514 p = td->td_proc; 1515 if (td->td_pflags & TDP_SA) { 1516 if (td->td_mailbox == NULL) 1517 thread_user_enter(td); 1518 PROC_LOCK(p); 1519 SIGDELSET(td->td_sigmask, sig); 1520 mtx_lock_spin(&sched_lock); 1521 /* 1522 * Force scheduling an upcall, so UTS has chance to 1523 * process the signal before thread runs again in 1524 * userland. 1525 */ 1526 if (td->td_upcall) 1527 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1528 mtx_unlock_spin(&sched_lock); 1529 } else { 1530 PROC_LOCK(p); 1531 } 1532 ps = p->p_sigacts; 1533 mtx_lock(&ps->ps_mtx); 1534 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1535 !SIGISMEMBER(td->td_sigmask, sig)) { 1536 p->p_stats->p_ru.ru_nsignals++; 1537 #ifdef KTRACE 1538 if (KTRPOINT(curthread, KTR_PSIG)) 1539 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1540 &td->td_sigmask, code); 1541 #endif 1542 if (!(td->td_pflags & TDP_SA)) 1543 (*p->p_sysent->sv_sendsig)( 1544 ps->ps_sigact[_SIG_IDX(sig)], sig, 1545 &td->td_sigmask, code); 1546 else if (td->td_mailbox == NULL) { 1547 mtx_unlock(&ps->ps_mtx); 1548 /* UTS caused a sync signal */ 1549 p->p_code = code; /* XXX for core dump/debugger */ 1550 p->p_sig = sig; /* XXX to verify code */ 1551 sigexit(td, sig); 1552 } else { 1553 cpu_thread_siginfo(sig, code, &siginfo); 1554 mtx_unlock(&ps->ps_mtx); 1555 SIGADDSET(td->td_sigmask, sig); 1556 PROC_UNLOCK(p); 1557 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, 1558 sizeof(siginfo)); 1559 PROC_LOCK(p); 1560 /* UTS memory corrupted */ 1561 if (error) 1562 sigexit(td, SIGSEGV); 1563 mtx_lock(&ps->ps_mtx); 1564 } 1565 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1566 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1567 SIGADDSET(td->td_sigmask, sig); 1568 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1569 /* 1570 * See kern_sigaction() for origin of this code. 1571 */ 1572 SIGDELSET(ps->ps_sigcatch, sig); 1573 if (sig != SIGCONT && 1574 sigprop(sig) & SA_IGNORE) 1575 SIGADDSET(ps->ps_sigignore, sig); 1576 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1577 } 1578 mtx_unlock(&ps->ps_mtx); 1579 } else { 1580 mtx_unlock(&ps->ps_mtx); 1581 p->p_code = code; /* XXX for core dump/debugger */ 1582 p->p_sig = sig; /* XXX to verify code */ 1583 tdsignal(td, sig, SIGTARGET_TD); 1584 } 1585 PROC_UNLOCK(p); 1586 } 1587 1588 static struct thread * 1589 sigtd(struct proc *p, int sig, int prop) 1590 { 1591 struct thread *td, *signal_td; 1592 1593 PROC_LOCK_ASSERT(p, MA_OWNED); 1594 1595 /* 1596 * Check if current thread can handle the signal without 1597 * switching conetxt to another thread. 1598 */ 1599 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1600 return (curthread); 1601 signal_td = NULL; 1602 mtx_lock_spin(&sched_lock); 1603 FOREACH_THREAD_IN_PROC(p, td) { 1604 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1605 signal_td = td; 1606 break; 1607 } 1608 } 1609 if (signal_td == NULL) 1610 signal_td = FIRST_THREAD_IN_PROC(p); 1611 mtx_unlock_spin(&sched_lock); 1612 return (signal_td); 1613 } 1614 1615 /* 1616 * Send the signal to the process. If the signal has an action, the action 1617 * is usually performed by the target process rather than the caller; we add 1618 * the signal to the set of pending signals for the process. 1619 * 1620 * Exceptions: 1621 * o When a stop signal is sent to a sleeping process that takes the 1622 * default action, the process is stopped without awakening it. 1623 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1624 * regardless of the signal action (eg, blocked or ignored). 1625 * 1626 * Other ignored signals are discarded immediately. 1627 * 1628 * MPSAFE 1629 */ 1630 void 1631 psignal(struct proc *p, int sig) 1632 { 1633 struct thread *td; 1634 int prop; 1635 1636 if (!_SIG_VALID(sig)) 1637 panic("psignal(): invalid signal"); 1638 1639 PROC_LOCK_ASSERT(p, MA_OWNED); 1640 /* 1641 * IEEE Std 1003.1-2001: return success when killing a zombie. 1642 */ 1643 if (p->p_state == PRS_ZOMBIE) 1644 return; 1645 prop = sigprop(sig); 1646 1647 /* 1648 * Find a thread to deliver the signal to. 1649 */ 1650 td = sigtd(p, sig, prop); 1651 1652 tdsignal(td, sig, SIGTARGET_P); 1653 } 1654 1655 /* 1656 * MPSAFE 1657 */ 1658 void 1659 tdsignal(struct thread *td, int sig, sigtarget_t target) 1660 { 1661 sigset_t saved; 1662 struct proc *p = td->td_proc; 1663 1664 if (p->p_flag & P_SA) 1665 saved = p->p_siglist; 1666 do_tdsignal(td, sig, target); 1667 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1668 if (!SIGSETEQ(saved, p->p_siglist)) { 1669 /* pending set changed */ 1670 p->p_flag |= P_SIGEVENT; 1671 wakeup(&p->p_siglist); 1672 } 1673 } 1674 } 1675 1676 static void 1677 do_tdsignal(struct thread *td, int sig, sigtarget_t target) 1678 { 1679 struct proc *p; 1680 register sig_t action; 1681 sigset_t *siglist; 1682 struct thread *td0; 1683 register int prop; 1684 struct sigacts *ps; 1685 int intrval; 1686 1687 if (!_SIG_VALID(sig)) 1688 panic("do_tdsignal(): invalid signal"); 1689 1690 p = td->td_proc; 1691 ps = p->p_sigacts; 1692 1693 PROC_LOCK_ASSERT(p, MA_OWNED); 1694 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 1695 1696 prop = sigprop(sig); 1697 1698 /* 1699 * If the signal is blocked and not destined for this thread, then 1700 * assign it to the process so that we can find it later in the first 1701 * thread that unblocks it. Otherwise, assign it to this thread now. 1702 */ 1703 if (target == SIGTARGET_TD) { 1704 siglist = &td->td_siglist; 1705 } else { 1706 if (!SIGISMEMBER(td->td_sigmask, sig)) 1707 siglist = &td->td_siglist; 1708 else 1709 siglist = &p->p_siglist; 1710 } 1711 1712 /* 1713 * If the signal is being ignored, 1714 * then we forget about it immediately. 1715 * (Note: we don't set SIGCONT in ps_sigignore, 1716 * and if it is set to SIG_IGN, 1717 * action will be SIG_DFL here.) 1718 */ 1719 mtx_lock(&ps->ps_mtx); 1720 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1721 (p->p_flag & P_WEXIT)) { 1722 mtx_unlock(&ps->ps_mtx); 1723 return; 1724 } 1725 if (SIGISMEMBER(td->td_sigmask, sig)) 1726 action = SIG_HOLD; 1727 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1728 action = SIG_CATCH; 1729 else 1730 action = SIG_DFL; 1731 if (SIGISMEMBER(ps->ps_sigintr, sig)) 1732 intrval = EINTR; 1733 else 1734 intrval = ERESTART; 1735 mtx_unlock(&ps->ps_mtx); 1736 1737 if (prop & SA_CONT) { 1738 SIG_STOPSIGMASK(p->p_siglist); 1739 /* 1740 * XXX Should investigate leaving STOP and CONT sigs only in 1741 * the proc's siglist. 1742 */ 1743 mtx_lock_spin(&sched_lock); 1744 FOREACH_THREAD_IN_PROC(p, td0) 1745 SIG_STOPSIGMASK(td0->td_siglist); 1746 mtx_unlock_spin(&sched_lock); 1747 } 1748 1749 if (prop & SA_STOP) { 1750 /* 1751 * If sending a tty stop signal to a member of an orphaned 1752 * process group, discard the signal here if the action 1753 * is default; don't stop the process below if sleeping, 1754 * and don't clear any pending SIGCONT. 1755 */ 1756 if ((prop & SA_TTYSTOP) && 1757 (p->p_pgrp->pg_jobc == 0) && 1758 (action == SIG_DFL)) 1759 return; 1760 SIG_CONTSIGMASK(p->p_siglist); 1761 mtx_lock_spin(&sched_lock); 1762 FOREACH_THREAD_IN_PROC(p, td0) 1763 SIG_CONTSIGMASK(td0->td_siglist); 1764 mtx_unlock_spin(&sched_lock); 1765 p->p_flag &= ~P_CONTINUED; 1766 } 1767 1768 SIGADDSET(*siglist, sig); 1769 signotify(td); /* uses schedlock */ 1770 /* 1771 * Defer further processing for signals which are held, 1772 * except that stopped processes must be continued by SIGCONT. 1773 */ 1774 if (action == SIG_HOLD && 1775 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1776 return; 1777 /* 1778 * SIGKILL: Remove procfs STOPEVENTs. 1779 */ 1780 if (sig == SIGKILL) { 1781 /* from procfs_ioctl.c: PIOCBIC */ 1782 p->p_stops = 0; 1783 /* from procfs_ioctl.c: PIOCCONT */ 1784 p->p_step = 0; 1785 wakeup(&p->p_step); 1786 } 1787 /* 1788 * Some signals have a process-wide effect and a per-thread 1789 * component. Most processing occurs when the process next 1790 * tries to cross the user boundary, however there are some 1791 * times when processing needs to be done immediatly, such as 1792 * waking up threads so that they can cross the user boundary. 1793 * We try do the per-process part here. 1794 */ 1795 if (P_SHOULDSTOP(p)) { 1796 /* 1797 * The process is in stopped mode. All the threads should be 1798 * either winding down or already on the suspended queue. 1799 */ 1800 if (p->p_flag & P_TRACED) { 1801 /* 1802 * The traced process is already stopped, 1803 * so no further action is necessary. 1804 * No signal can restart us. 1805 */ 1806 goto out; 1807 } 1808 1809 if (sig == SIGKILL) { 1810 /* 1811 * SIGKILL sets process running. 1812 * It will die elsewhere. 1813 * All threads must be restarted. 1814 */ 1815 p->p_flag &= ~P_STOPPED_SIG; 1816 goto runfast; 1817 } 1818 1819 if (prop & SA_CONT) { 1820 /* 1821 * If SIGCONT is default (or ignored), we continue the 1822 * process but don't leave the signal in siglist as 1823 * it has no further action. If SIGCONT is held, we 1824 * continue the process and leave the signal in 1825 * siglist. If the process catches SIGCONT, let it 1826 * handle the signal itself. If it isn't waiting on 1827 * an event, it goes back to run state. 1828 * Otherwise, process goes back to sleep state. 1829 */ 1830 p->p_flag &= ~P_STOPPED_SIG; 1831 p->p_flag |= P_CONTINUED; 1832 if (action == SIG_DFL) { 1833 SIGDELSET(*siglist, sig); 1834 } else if (action == SIG_CATCH) { 1835 /* 1836 * The process wants to catch it so it needs 1837 * to run at least one thread, but which one? 1838 * It would seem that the answer would be to 1839 * run an upcall in the next KSE to run, and 1840 * deliver the signal that way. In a NON KSE 1841 * process, we need to make sure that the 1842 * single thread is runnable asap. 1843 * XXXKSE for now however, make them all run. 1844 */ 1845 goto runfast; 1846 } 1847 /* 1848 * The signal is not ignored or caught. 1849 */ 1850 mtx_lock_spin(&sched_lock); 1851 thread_unsuspend(p); 1852 mtx_unlock_spin(&sched_lock); 1853 goto out; 1854 } 1855 1856 if (prop & SA_STOP) { 1857 /* 1858 * Already stopped, don't need to stop again 1859 * (If we did the shell could get confused). 1860 * Just make sure the signal STOP bit set. 1861 */ 1862 p->p_flag |= P_STOPPED_SIG; 1863 SIGDELSET(*siglist, sig); 1864 goto out; 1865 } 1866 1867 /* 1868 * All other kinds of signals: 1869 * If a thread is sleeping interruptibly, simulate a 1870 * wakeup so that when it is continued it will be made 1871 * runnable and can look at the signal. However, don't make 1872 * the PROCESS runnable, leave it stopped. 1873 * It may run a bit until it hits a thread_suspend_check(). 1874 */ 1875 mtx_lock_spin(&sched_lock); 1876 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 1877 sleepq_abort(td, intrval); 1878 mtx_unlock_spin(&sched_lock); 1879 goto out; 1880 /* 1881 * Mutexes are short lived. Threads waiting on them will 1882 * hit thread_suspend_check() soon. 1883 */ 1884 } else if (p->p_state == PRS_NORMAL) { 1885 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 1886 mtx_lock_spin(&sched_lock); 1887 tdsigwakeup(td, sig, action, intrval); 1888 mtx_unlock_spin(&sched_lock); 1889 goto out; 1890 } 1891 1892 MPASS(action == SIG_DFL); 1893 1894 if (prop & SA_STOP) { 1895 if (p->p_flag & P_PPWAIT) 1896 goto out; 1897 p->p_flag |= P_STOPPED_SIG; 1898 p->p_xstat = sig; 1899 mtx_lock_spin(&sched_lock); 1900 sig_suspend_threads(td, p, 1); 1901 thread_stopped(p); 1902 if (p->p_numthreads == p->p_suspcount) { 1903 SIGDELSET(p->p_siglist, p->p_xstat); 1904 FOREACH_THREAD_IN_PROC(p, td0) 1905 SIGDELSET(td0->td_siglist, p->p_xstat); 1906 } 1907 mtx_unlock_spin(&sched_lock); 1908 goto out; 1909 } 1910 else 1911 goto runfast; 1912 /* NOTREACHED */ 1913 } else { 1914 /* Not in "NORMAL" state. discard the signal. */ 1915 SIGDELSET(*siglist, sig); 1916 goto out; 1917 } 1918 1919 /* 1920 * The process is not stopped so we need to apply the signal to all the 1921 * running threads. 1922 */ 1923 1924 runfast: 1925 mtx_lock_spin(&sched_lock); 1926 tdsigwakeup(td, sig, action, intrval); 1927 thread_unsuspend(p); 1928 mtx_unlock_spin(&sched_lock); 1929 out: 1930 /* If we jump here, sched_lock should not be owned. */ 1931 mtx_assert(&sched_lock, MA_NOTOWNED); 1932 } 1933 1934 /* 1935 * The force of a signal has been directed against a single 1936 * thread. We need to see what we can do about knocking it 1937 * out of any sleep it may be in etc. 1938 */ 1939 static void 1940 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 1941 { 1942 struct proc *p = td->td_proc; 1943 register int prop; 1944 1945 PROC_LOCK_ASSERT(p, MA_OWNED); 1946 mtx_assert(&sched_lock, MA_OWNED); 1947 prop = sigprop(sig); 1948 1949 /* 1950 * Bring the priority of a thread up if we want it to get 1951 * killed in this lifetime. 1952 */ 1953 if (action == SIG_DFL && (prop & SA_KILL)) { 1954 if (p->p_nice > 0) 1955 sched_nice(td->td_proc, 0); 1956 if (td->td_priority > PUSER) 1957 sched_prio(td, PUSER); 1958 } 1959 1960 if (TD_ON_SLEEPQ(td)) { 1961 /* 1962 * If thread is sleeping uninterruptibly 1963 * we can't interrupt the sleep... the signal will 1964 * be noticed when the process returns through 1965 * trap() or syscall(). 1966 */ 1967 if ((td->td_flags & TDF_SINTR) == 0) 1968 return; 1969 /* 1970 * If SIGCONT is default (or ignored) and process is 1971 * asleep, we are finished; the process should not 1972 * be awakened. 1973 */ 1974 if ((prop & SA_CONT) && action == SIG_DFL) { 1975 SIGDELSET(p->p_siglist, sig); 1976 /* 1977 * It may be on either list in this state. 1978 * Remove from both for now. 1979 */ 1980 SIGDELSET(td->td_siglist, sig); 1981 return; 1982 } 1983 1984 /* 1985 * Give low priority threads a better chance to run. 1986 */ 1987 if (td->td_priority > PUSER) 1988 sched_prio(td, PUSER); 1989 1990 sleepq_abort(td, intrval); 1991 } else { 1992 /* 1993 * Other states do nothing with the signal immediately, 1994 * other than kicking ourselves if we are running. 1995 * It will either never be noticed, or noticed very soon. 1996 */ 1997 #ifdef SMP 1998 if (TD_IS_RUNNING(td) && td != curthread) 1999 forward_signal(td); 2000 #endif 2001 } 2002 } 2003 2004 static void 2005 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2006 { 2007 struct thread *td2; 2008 2009 PROC_LOCK_ASSERT(p, MA_OWNED); 2010 mtx_assert(&sched_lock, MA_OWNED); 2011 2012 FOREACH_THREAD_IN_PROC(p, td2) { 2013 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2014 (td2->td_flags & TDF_SINTR) && 2015 !TD_IS_SUSPENDED(td2)) { 2016 thread_suspend_one(td2); 2017 } else { 2018 if (sending || td != td2) 2019 td2->td_flags |= TDF_ASTPENDING; 2020 #ifdef SMP 2021 if (TD_IS_RUNNING(td2) && td2 != td) 2022 forward_signal(td2); 2023 #endif 2024 } 2025 } 2026 } 2027 2028 int 2029 ptracestop(struct thread *td, int sig) 2030 { 2031 struct proc *p = td->td_proc; 2032 2033 PROC_LOCK_ASSERT(p, MA_OWNED); 2034 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2035 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2036 2037 mtx_lock_spin(&sched_lock); 2038 td->td_flags |= TDF_XSIG; 2039 mtx_unlock_spin(&sched_lock); 2040 td->td_xsig = sig; 2041 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2042 if (p->p_flag & P_SINGLE_EXIT) { 2043 mtx_lock_spin(&sched_lock); 2044 td->td_flags &= ~TDF_XSIG; 2045 mtx_unlock_spin(&sched_lock); 2046 return (sig); 2047 } 2048 /* 2049 * Just make wait() to work, the last stopped thread 2050 * will win. 2051 */ 2052 p->p_xstat = sig; 2053 p->p_xthread = td; 2054 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2055 mtx_lock_spin(&sched_lock); 2056 sig_suspend_threads(td, p, 0); 2057 stopme: 2058 thread_stopped(p); 2059 thread_suspend_one(td); 2060 PROC_UNLOCK(p); 2061 DROP_GIANT(); 2062 mi_switch(SW_VOL, NULL); 2063 mtx_unlock_spin(&sched_lock); 2064 PICKUP_GIANT(); 2065 PROC_LOCK(p); 2066 if (!(p->p_flag & P_TRACED)) 2067 break; 2068 if (td->td_flags & TDF_DBSUSPEND) { 2069 if (p->p_flag & P_SINGLE_EXIT) 2070 break; 2071 mtx_lock_spin(&sched_lock); 2072 goto stopme; 2073 } 2074 } 2075 return (td->td_xsig); 2076 } 2077 2078 /* 2079 * If the current process has received a signal (should be caught or cause 2080 * termination, should interrupt current syscall), return the signal number. 2081 * Stop signals with default action are processed immediately, then cleared; 2082 * they aren't returned. This is checked after each entry to the system for 2083 * a syscall or trap (though this can usually be done without calling issignal 2084 * by checking the pending signal masks in cursig.) The normal call 2085 * sequence is 2086 * 2087 * while (sig = cursig(curthread)) 2088 * postsig(sig); 2089 */ 2090 static int 2091 issignal(td) 2092 struct thread *td; 2093 { 2094 struct proc *p; 2095 struct sigacts *ps; 2096 sigset_t sigpending; 2097 int sig, prop, newsig; 2098 2099 p = td->td_proc; 2100 ps = p->p_sigacts; 2101 mtx_assert(&ps->ps_mtx, MA_OWNED); 2102 PROC_LOCK_ASSERT(p, MA_OWNED); 2103 for (;;) { 2104 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2105 2106 sigpending = td->td_siglist; 2107 SIGSETNAND(sigpending, td->td_sigmask); 2108 2109 if (p->p_flag & P_PPWAIT) 2110 SIG_STOPSIGMASK(sigpending); 2111 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2112 return (0); 2113 sig = sig_ffs(&sigpending); 2114 2115 if (p->p_stops & S_SIG) { 2116 mtx_unlock(&ps->ps_mtx); 2117 stopevent(p, S_SIG, sig); 2118 mtx_lock(&ps->ps_mtx); 2119 } 2120 2121 /* 2122 * We should see pending but ignored signals 2123 * only if P_TRACED was on when they were posted. 2124 */ 2125 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2126 SIGDELSET(td->td_siglist, sig); 2127 if (td->td_pflags & TDP_SA) 2128 SIGADDSET(td->td_sigmask, sig); 2129 continue; 2130 } 2131 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2132 /* 2133 * If traced, always stop. 2134 */ 2135 mtx_unlock(&ps->ps_mtx); 2136 newsig = ptracestop(td, sig); 2137 mtx_lock(&ps->ps_mtx); 2138 2139 /* 2140 * If parent wants us to take the signal, 2141 * then it will leave it in p->p_xstat; 2142 * otherwise we just look for signals again. 2143 */ 2144 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 2145 if (td->td_pflags & TDP_SA) 2146 SIGADDSET(td->td_sigmask, sig); 2147 if (newsig == 0) 2148 continue; 2149 sig = newsig; 2150 /* 2151 * If the traced bit got turned off, go back up 2152 * to the top to rescan signals. This ensures 2153 * that p_sig* and p_sigact are consistent. 2154 */ 2155 if ((p->p_flag & P_TRACED) == 0) 2156 continue; 2157 2158 /* 2159 * Put the new signal into td_siglist. If the 2160 * signal is being masked, look for other signals. 2161 */ 2162 SIGADDSET(td->td_siglist, sig); 2163 if (td->td_pflags & TDP_SA) 2164 SIGDELSET(td->td_sigmask, sig); 2165 if (SIGISMEMBER(td->td_sigmask, sig)) 2166 continue; 2167 signotify(td); 2168 } 2169 2170 prop = sigprop(sig); 2171 2172 /* 2173 * Decide whether the signal should be returned. 2174 * Return the signal's number, or fall through 2175 * to clear it from the pending mask. 2176 */ 2177 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2178 2179 case (intptr_t)SIG_DFL: 2180 /* 2181 * Don't take default actions on system processes. 2182 */ 2183 if (p->p_pid <= 1) { 2184 #ifdef DIAGNOSTIC 2185 /* 2186 * Are you sure you want to ignore SIGSEGV 2187 * in init? XXX 2188 */ 2189 printf("Process (pid %lu) got signal %d\n", 2190 (u_long)p->p_pid, sig); 2191 #endif 2192 break; /* == ignore */ 2193 } 2194 /* 2195 * If there is a pending stop signal to process 2196 * with default action, stop here, 2197 * then clear the signal. However, 2198 * if process is member of an orphaned 2199 * process group, ignore tty stop signals. 2200 */ 2201 if (prop & SA_STOP) { 2202 if (p->p_flag & P_TRACED || 2203 (p->p_pgrp->pg_jobc == 0 && 2204 prop & SA_TTYSTOP)) 2205 break; /* == ignore */ 2206 mtx_unlock(&ps->ps_mtx); 2207 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2208 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2209 p->p_flag |= P_STOPPED_SIG; 2210 p->p_xstat = sig; 2211 mtx_lock_spin(&sched_lock); 2212 sig_suspend_threads(td, p, 0); 2213 thread_stopped(p); 2214 thread_suspend_one(td); 2215 PROC_UNLOCK(p); 2216 DROP_GIANT(); 2217 mi_switch(SW_INVOL, NULL); 2218 mtx_unlock_spin(&sched_lock); 2219 PICKUP_GIANT(); 2220 PROC_LOCK(p); 2221 mtx_lock(&ps->ps_mtx); 2222 break; 2223 } else if (prop & SA_IGNORE) { 2224 /* 2225 * Except for SIGCONT, shouldn't get here. 2226 * Default action is to ignore; drop it. 2227 */ 2228 break; /* == ignore */ 2229 } else 2230 return (sig); 2231 /*NOTREACHED*/ 2232 2233 case (intptr_t)SIG_IGN: 2234 /* 2235 * Masking above should prevent us ever trying 2236 * to take action on an ignored signal other 2237 * than SIGCONT, unless process is traced. 2238 */ 2239 if ((prop & SA_CONT) == 0 && 2240 (p->p_flag & P_TRACED) == 0) 2241 printf("issignal\n"); 2242 break; /* == ignore */ 2243 2244 default: 2245 /* 2246 * This signal has an action, let 2247 * postsig() process it. 2248 */ 2249 return (sig); 2250 } 2251 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2252 } 2253 /* NOTREACHED */ 2254 } 2255 2256 /* 2257 * MPSAFE 2258 */ 2259 void 2260 thread_stopped(struct proc *p) 2261 { 2262 struct proc *p1 = curthread->td_proc; 2263 struct sigacts *ps; 2264 int n; 2265 2266 PROC_LOCK_ASSERT(p, MA_OWNED); 2267 mtx_assert(&sched_lock, MA_OWNED); 2268 n = p->p_suspcount; 2269 if (p == p1) 2270 n++; 2271 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2272 mtx_unlock_spin(&sched_lock); 2273 p->p_flag &= ~P_WAITED; 2274 PROC_LOCK(p->p_pptr); 2275 /* 2276 * Wake up parent sleeping in kern_wait(), also send 2277 * SIGCHLD to parent, but SIGCHLD does not guarantee 2278 * that parent will awake, because parent may masked 2279 * the signal. 2280 */ 2281 p->p_pptr->p_flag |= P_STATCHILD; 2282 wakeup(p->p_pptr); 2283 ps = p->p_pptr->p_sigacts; 2284 mtx_lock(&ps->ps_mtx); 2285 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2286 mtx_unlock(&ps->ps_mtx); 2287 psignal(p->p_pptr, SIGCHLD); 2288 } else 2289 mtx_unlock(&ps->ps_mtx); 2290 PROC_UNLOCK(p->p_pptr); 2291 mtx_lock_spin(&sched_lock); 2292 } 2293 } 2294 2295 /* 2296 * Take the action for the specified signal 2297 * from the current set of pending signals. 2298 */ 2299 void 2300 postsig(sig) 2301 register int sig; 2302 { 2303 struct thread *td = curthread; 2304 register struct proc *p = td->td_proc; 2305 struct sigacts *ps; 2306 sig_t action; 2307 sigset_t returnmask; 2308 int code; 2309 2310 KASSERT(sig != 0, ("postsig")); 2311 2312 PROC_LOCK_ASSERT(p, MA_OWNED); 2313 ps = p->p_sigacts; 2314 mtx_assert(&ps->ps_mtx, MA_OWNED); 2315 SIGDELSET(td->td_siglist, sig); 2316 action = ps->ps_sigact[_SIG_IDX(sig)]; 2317 #ifdef KTRACE 2318 if (KTRPOINT(td, KTR_PSIG)) 2319 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2320 &td->td_oldsigmask : &td->td_sigmask, 0); 2321 #endif 2322 if (p->p_stops & S_SIG) { 2323 mtx_unlock(&ps->ps_mtx); 2324 stopevent(p, S_SIG, sig); 2325 mtx_lock(&ps->ps_mtx); 2326 } 2327 2328 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2329 /* 2330 * Default action, where the default is to kill 2331 * the process. (Other cases were ignored above.) 2332 */ 2333 mtx_unlock(&ps->ps_mtx); 2334 sigexit(td, sig); 2335 /* NOTREACHED */ 2336 } else { 2337 if (td->td_pflags & TDP_SA) { 2338 if (sig == SIGKILL) { 2339 mtx_unlock(&ps->ps_mtx); 2340 sigexit(td, sig); 2341 } 2342 } 2343 2344 /* 2345 * If we get here, the signal must be caught. 2346 */ 2347 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2348 ("postsig action")); 2349 /* 2350 * Set the new mask value and also defer further 2351 * occurrences of this signal. 2352 * 2353 * Special case: user has done a sigsuspend. Here the 2354 * current mask is not of interest, but rather the 2355 * mask from before the sigsuspend is what we want 2356 * restored after the signal processing is completed. 2357 */ 2358 if (td->td_pflags & TDP_OLDMASK) { 2359 returnmask = td->td_oldsigmask; 2360 td->td_pflags &= ~TDP_OLDMASK; 2361 } else 2362 returnmask = td->td_sigmask; 2363 2364 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2365 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2366 SIGADDSET(td->td_sigmask, sig); 2367 2368 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2369 /* 2370 * See kern_sigaction() for origin of this code. 2371 */ 2372 SIGDELSET(ps->ps_sigcatch, sig); 2373 if (sig != SIGCONT && 2374 sigprop(sig) & SA_IGNORE) 2375 SIGADDSET(ps->ps_sigignore, sig); 2376 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2377 } 2378 p->p_stats->p_ru.ru_nsignals++; 2379 if (p->p_sig != sig) { 2380 code = 0; 2381 } else { 2382 code = p->p_code; 2383 p->p_code = 0; 2384 p->p_sig = 0; 2385 } 2386 if (td->td_pflags & TDP_SA) 2387 thread_signal_add(curthread, sig); 2388 else 2389 (*p->p_sysent->sv_sendsig)(action, sig, 2390 &returnmask, code); 2391 } 2392 } 2393 2394 /* 2395 * Kill the current process for stated reason. 2396 */ 2397 void 2398 killproc(p, why) 2399 struct proc *p; 2400 char *why; 2401 { 2402 2403 PROC_LOCK_ASSERT(p, MA_OWNED); 2404 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2405 p, p->p_pid, p->p_comm); 2406 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2407 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2408 psignal(p, SIGKILL); 2409 } 2410 2411 /* 2412 * Force the current process to exit with the specified signal, dumping core 2413 * if appropriate. We bypass the normal tests for masked and caught signals, 2414 * allowing unrecoverable failures to terminate the process without changing 2415 * signal state. Mark the accounting record with the signal termination. 2416 * If dumping core, save the signal number for the debugger. Calls exit and 2417 * does not return. 2418 * 2419 * MPSAFE 2420 */ 2421 void 2422 sigexit(td, sig) 2423 struct thread *td; 2424 int sig; 2425 { 2426 struct proc *p = td->td_proc; 2427 2428 PROC_LOCK_ASSERT(p, MA_OWNED); 2429 p->p_acflag |= AXSIG; 2430 /* 2431 * We must be single-threading to generate a core dump. This 2432 * ensures that the registers in the core file are up-to-date. 2433 * Also, the ELF dump handler assumes that the thread list doesn't 2434 * change out from under it. 2435 * 2436 * XXX If another thread attempts to single-thread before us 2437 * (e.g. via fork()), we won't get a dump at all. 2438 */ 2439 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2440 p->p_sig = sig; 2441 /* 2442 * Log signals which would cause core dumps 2443 * (Log as LOG_INFO to appease those who don't want 2444 * these messages.) 2445 * XXX : Todo, as well as euid, write out ruid too 2446 * Note that coredump() drops proc lock. 2447 */ 2448 if (coredump(td) == 0) 2449 sig |= WCOREFLAG; 2450 if (kern_logsigexit) 2451 log(LOG_INFO, 2452 "pid %d (%s), uid %d: exited on signal %d%s\n", 2453 p->p_pid, p->p_comm, 2454 td->td_ucred ? td->td_ucred->cr_uid : -1, 2455 sig &~ WCOREFLAG, 2456 sig & WCOREFLAG ? " (core dumped)" : ""); 2457 } else 2458 PROC_UNLOCK(p); 2459 exit1(td, W_EXITCODE(0, sig)); 2460 /* NOTREACHED */ 2461 } 2462 2463 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2464 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2465 sizeof(corefilename), "process corefile name format string"); 2466 2467 /* 2468 * expand_name(name, uid, pid) 2469 * Expand the name described in corefilename, using name, uid, and pid. 2470 * corefilename is a printf-like string, with three format specifiers: 2471 * %N name of process ("name") 2472 * %P process id (pid) 2473 * %U user id (uid) 2474 * For example, "%N.core" is the default; they can be disabled completely 2475 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2476 * This is controlled by the sysctl variable kern.corefile (see above). 2477 */ 2478 2479 static char * 2480 expand_name(name, uid, pid) 2481 const char *name; 2482 uid_t uid; 2483 pid_t pid; 2484 { 2485 const char *format, *appendstr; 2486 char *temp; 2487 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2488 size_t i, l, n; 2489 2490 format = corefilename; 2491 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2492 if (temp == NULL) 2493 return (NULL); 2494 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2495 switch (format[i]) { 2496 case '%': /* Format character */ 2497 i++; 2498 switch (format[i]) { 2499 case '%': 2500 appendstr = "%"; 2501 break; 2502 case 'N': /* process name */ 2503 appendstr = name; 2504 break; 2505 case 'P': /* process id */ 2506 sprintf(buf, "%u", pid); 2507 appendstr = buf; 2508 break; 2509 case 'U': /* user id */ 2510 sprintf(buf, "%u", uid); 2511 appendstr = buf; 2512 break; 2513 default: 2514 appendstr = ""; 2515 log(LOG_ERR, 2516 "Unknown format character %c in `%s'\n", 2517 format[i], format); 2518 } 2519 l = strlen(appendstr); 2520 if ((n + l) >= MAXPATHLEN) 2521 goto toolong; 2522 memcpy(temp + n, appendstr, l); 2523 n += l; 2524 break; 2525 default: 2526 temp[n++] = format[i]; 2527 } 2528 } 2529 if (format[i] != '\0') 2530 goto toolong; 2531 return (temp); 2532 toolong: 2533 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2534 (long)pid, name, (u_long)uid); 2535 free(temp, M_TEMP); 2536 return (NULL); 2537 } 2538 2539 /* 2540 * Dump a process' core. The main routine does some 2541 * policy checking, and creates the name of the coredump; 2542 * then it passes on a vnode and a size limit to the process-specific 2543 * coredump routine if there is one; if there _is not_ one, it returns 2544 * ENOSYS; otherwise it returns the error from the process-specific routine. 2545 */ 2546 2547 static int 2548 coredump(struct thread *td) 2549 { 2550 struct proc *p = td->td_proc; 2551 register struct vnode *vp; 2552 register struct ucred *cred = td->td_ucred; 2553 struct flock lf; 2554 struct nameidata nd; 2555 struct vattr vattr; 2556 int error, error1, flags, locked; 2557 struct mount *mp; 2558 char *name; /* name of corefile */ 2559 off_t limit; 2560 2561 PROC_LOCK_ASSERT(p, MA_OWNED); 2562 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 2563 _STOPEVENT(p, S_CORE, 0); 2564 2565 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2566 PROC_UNLOCK(p); 2567 return (EFAULT); 2568 } 2569 2570 /* 2571 * Note that the bulk of limit checking is done after 2572 * the corefile is created. The exception is if the limit 2573 * for corefiles is 0, in which case we don't bother 2574 * creating the corefile at all. This layout means that 2575 * a corefile is truncated instead of not being created, 2576 * if it is larger than the limit. 2577 */ 2578 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2579 PROC_UNLOCK(p); 2580 if (limit == 0) 2581 return (EFBIG); 2582 2583 mtx_lock(&Giant); 2584 restart: 2585 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2586 if (name == NULL) { 2587 mtx_unlock(&Giant); 2588 return (EINVAL); 2589 } 2590 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2591 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2592 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2593 free(name, M_TEMP); 2594 if (error) { 2595 mtx_unlock(&Giant); 2596 return (error); 2597 } 2598 NDFREE(&nd, NDF_ONLY_PNBUF); 2599 vp = nd.ni_vp; 2600 2601 /* Don't dump to non-regular files or files with links. */ 2602 if (vp->v_type != VREG || 2603 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2604 VOP_UNLOCK(vp, 0, td); 2605 error = EFAULT; 2606 goto out; 2607 } 2608 2609 VOP_UNLOCK(vp, 0, td); 2610 lf.l_whence = SEEK_SET; 2611 lf.l_start = 0; 2612 lf.l_len = 0; 2613 lf.l_type = F_WRLCK; 2614 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2615 2616 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2617 lf.l_type = F_UNLCK; 2618 if (locked) 2619 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2620 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2621 return (error); 2622 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2623 return (error); 2624 goto restart; 2625 } 2626 2627 VATTR_NULL(&vattr); 2628 vattr.va_size = 0; 2629 if (set_core_nodump_flag) 2630 vattr.va_flags = UF_NODUMP; 2631 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2632 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2633 VOP_SETATTR(vp, &vattr, cred, td); 2634 VOP_UNLOCK(vp, 0, td); 2635 vn_finished_write(mp); 2636 PROC_LOCK(p); 2637 p->p_acflag |= ACORE; 2638 PROC_UNLOCK(p); 2639 2640 error = p->p_sysent->sv_coredump ? 2641 p->p_sysent->sv_coredump(td, vp, limit) : 2642 ENOSYS; 2643 2644 if (locked) { 2645 lf.l_type = F_UNLCK; 2646 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2647 } 2648 out: 2649 error1 = vn_close(vp, FWRITE, cred, td); 2650 mtx_unlock(&Giant); 2651 if (error == 0) 2652 error = error1; 2653 return (error); 2654 } 2655 2656 /* 2657 * Nonexistent system call-- signal process (may want to handle it). 2658 * Flag error in case process won't see signal immediately (blocked or ignored). 2659 */ 2660 #ifndef _SYS_SYSPROTO_H_ 2661 struct nosys_args { 2662 int dummy; 2663 }; 2664 #endif 2665 /* 2666 * MPSAFE 2667 */ 2668 /* ARGSUSED */ 2669 int 2670 nosys(td, args) 2671 struct thread *td; 2672 struct nosys_args *args; 2673 { 2674 struct proc *p = td->td_proc; 2675 2676 PROC_LOCK(p); 2677 psignal(p, SIGSYS); 2678 PROC_UNLOCK(p); 2679 return (ENOSYS); 2680 } 2681 2682 /* 2683 * Send a SIGIO or SIGURG signal to a process or process group using 2684 * stored credentials rather than those of the current process. 2685 */ 2686 void 2687 pgsigio(sigiop, sig, checkctty) 2688 struct sigio **sigiop; 2689 int sig, checkctty; 2690 { 2691 struct sigio *sigio; 2692 2693 SIGIO_LOCK(); 2694 sigio = *sigiop; 2695 if (sigio == NULL) { 2696 SIGIO_UNLOCK(); 2697 return; 2698 } 2699 if (sigio->sio_pgid > 0) { 2700 PROC_LOCK(sigio->sio_proc); 2701 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2702 psignal(sigio->sio_proc, sig); 2703 PROC_UNLOCK(sigio->sio_proc); 2704 } else if (sigio->sio_pgid < 0) { 2705 struct proc *p; 2706 2707 PGRP_LOCK(sigio->sio_pgrp); 2708 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2709 PROC_LOCK(p); 2710 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2711 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2712 psignal(p, sig); 2713 PROC_UNLOCK(p); 2714 } 2715 PGRP_UNLOCK(sigio->sio_pgrp); 2716 } 2717 SIGIO_UNLOCK(); 2718 } 2719 2720 static int 2721 filt_sigattach(struct knote *kn) 2722 { 2723 struct proc *p = curproc; 2724 2725 kn->kn_ptr.p_proc = p; 2726 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2727 2728 knlist_add(&p->p_klist, kn, 0); 2729 2730 return (0); 2731 } 2732 2733 static void 2734 filt_sigdetach(struct knote *kn) 2735 { 2736 struct proc *p = kn->kn_ptr.p_proc; 2737 2738 knlist_remove(&p->p_klist, kn, 0); 2739 } 2740 2741 /* 2742 * signal knotes are shared with proc knotes, so we apply a mask to 2743 * the hint in order to differentiate them from process hints. This 2744 * could be avoided by using a signal-specific knote list, but probably 2745 * isn't worth the trouble. 2746 */ 2747 static int 2748 filt_signal(struct knote *kn, long hint) 2749 { 2750 2751 if (hint & NOTE_SIGNAL) { 2752 hint &= ~NOTE_SIGNAL; 2753 2754 if (kn->kn_id == hint) 2755 kn->kn_data++; 2756 } 2757 return (kn->kn_data != 0); 2758 } 2759 2760 struct sigacts * 2761 sigacts_alloc(void) 2762 { 2763 struct sigacts *ps; 2764 2765 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2766 ps->ps_refcnt = 1; 2767 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2768 return (ps); 2769 } 2770 2771 void 2772 sigacts_free(struct sigacts *ps) 2773 { 2774 2775 mtx_lock(&ps->ps_mtx); 2776 ps->ps_refcnt--; 2777 if (ps->ps_refcnt == 0) { 2778 mtx_destroy(&ps->ps_mtx); 2779 free(ps, M_SUBPROC); 2780 } else 2781 mtx_unlock(&ps->ps_mtx); 2782 } 2783 2784 struct sigacts * 2785 sigacts_hold(struct sigacts *ps) 2786 { 2787 mtx_lock(&ps->ps_mtx); 2788 ps->ps_refcnt++; 2789 mtx_unlock(&ps->ps_mtx); 2790 return (ps); 2791 } 2792 2793 void 2794 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2795 { 2796 2797 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2798 mtx_lock(&src->ps_mtx); 2799 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2800 mtx_unlock(&src->ps_mtx); 2801 } 2802 2803 int 2804 sigacts_shared(struct sigacts *ps) 2805 { 2806 int shared; 2807 2808 mtx_lock(&ps->ps_mtx); 2809 shared = ps->ps_refcnt > 1; 2810 mtx_unlock(&ps->ps_mtx); 2811 return (shared); 2812 }
Cache object: 984f578d1ee97e425e878e96bd83f1b8
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