1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_compat.h" 45 #include "opt_ktrace.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 #include <sys/acct.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/kernel.h> 56 #include <sys/ktr.h> 57 #include <sys/ktrace.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mutex.h> 61 #include <sys/namei.h> 62 #include <sys/proc.h> 63 #include <sys/pioctl.h> 64 #include <sys/resourcevar.h> 65 #include <sys/smp.h> 66 #include <sys/stat.h> 67 #include <sys/sx.h> 68 #include <sys/syscallsubr.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysent.h> 71 #include <sys/syslog.h> 72 #include <sys/sysproto.h> 73 #include <sys/unistd.h> 74 #include <sys/wait.h> 75 76 #include <machine/cpu.h> 77 78 #if defined (__alpha__) && !defined(COMPAT_43) 79 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 80 #endif 81 82 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 83 84 static int coredump(struct thread *); 85 static char *expand_name(const char *, uid_t, pid_t); 86 static int killpg1(struct thread *td, int sig, int pgid, int all); 87 static int issignal(struct thread *p); 88 static int sigprop(int sig); 89 static void stop(struct proc *); 90 static void tdsigwakeup(struct thread *td, int sig, sig_t action); 91 static int filt_sigattach(struct knote *kn); 92 static void filt_sigdetach(struct knote *kn); 93 static int filt_signal(struct knote *kn, long hint); 94 static struct thread *sigtd(struct proc *p, int sig, int prop); 95 static int kern_sigtimedwait(struct thread *td, sigset_t set, 96 siginfo_t *info, struct timespec *timeout); 97 98 struct filterops sig_filtops = 99 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 100 101 static int kern_logsigexit = 1; 102 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 103 &kern_logsigexit, 0, 104 "Log processes quitting on abnormal signals to syslog(3)"); 105 106 /* 107 * Policy -- Can ucred cr1 send SIGIO to process cr2? 108 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 109 * in the right situations. 110 */ 111 #define CANSIGIO(cr1, cr2) \ 112 ((cr1)->cr_uid == 0 || \ 113 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 114 (cr1)->cr_uid == (cr2)->cr_ruid || \ 115 (cr1)->cr_ruid == (cr2)->cr_uid || \ 116 (cr1)->cr_uid == (cr2)->cr_uid) 117 118 int sugid_coredump; 119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 121 122 static int do_coredump = 1; 123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 124 &do_coredump, 0, "Enable/Disable coredumps"); 125 126 /* 127 * Signal properties and actions. 128 * The array below categorizes the signals and their default actions 129 * according to the following properties: 130 */ 131 #define SA_KILL 0x01 /* terminates process by default */ 132 #define SA_CORE 0x02 /* ditto and coredumps */ 133 #define SA_STOP 0x04 /* suspend process */ 134 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 135 #define SA_IGNORE 0x10 /* ignore by default */ 136 #define SA_CONT 0x20 /* continue if suspended */ 137 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 138 #define SA_PROC 0x80 /* deliverable to any thread */ 139 140 static int sigproptbl[NSIG] = { 141 SA_KILL|SA_PROC, /* SIGHUP */ 142 SA_KILL|SA_PROC, /* SIGINT */ 143 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 144 SA_KILL|SA_CORE, /* SIGILL */ 145 SA_KILL|SA_CORE, /* SIGTRAP */ 146 SA_KILL|SA_CORE, /* SIGABRT */ 147 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 148 SA_KILL|SA_CORE, /* SIGFPE */ 149 SA_KILL|SA_PROC, /* SIGKILL */ 150 SA_KILL|SA_CORE, /* SIGBUS */ 151 SA_KILL|SA_CORE, /* SIGSEGV */ 152 SA_KILL|SA_CORE, /* SIGSYS */ 153 SA_KILL|SA_PROC, /* SIGPIPE */ 154 SA_KILL|SA_PROC, /* SIGALRM */ 155 SA_KILL|SA_PROC, /* SIGTERM */ 156 SA_IGNORE|SA_PROC, /* SIGURG */ 157 SA_STOP|SA_PROC, /* SIGSTOP */ 158 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 159 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 160 SA_IGNORE|SA_PROC, /* SIGCHLD */ 161 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 162 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 163 SA_IGNORE|SA_PROC, /* SIGIO */ 164 SA_KILL, /* SIGXCPU */ 165 SA_KILL, /* SIGXFSZ */ 166 SA_KILL|SA_PROC, /* SIGVTALRM */ 167 SA_KILL|SA_PROC, /* SIGPROF */ 168 SA_IGNORE|SA_PROC, /* SIGWINCH */ 169 SA_IGNORE|SA_PROC, /* SIGINFO */ 170 SA_KILL|SA_PROC, /* SIGUSR1 */ 171 SA_KILL|SA_PROC, /* SIGUSR2 */ 172 }; 173 174 /* 175 * Determine signal that should be delivered to process p, the current 176 * process, 0 if none. If there is a pending stop signal with default 177 * action, the process stops in issignal(). 178 * XXXKSE the check for a pending stop is not done under KSE 179 * 180 * MP SAFE. 181 */ 182 int 183 cursig(struct thread *td) 184 { 185 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 186 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 187 mtx_assert(&sched_lock, MA_NOTOWNED); 188 return (SIGPENDING(td) ? issignal(td) : 0); 189 } 190 191 /* 192 * Arrange for ast() to handle unmasked pending signals on return to user 193 * mode. This must be called whenever a signal is added to td_siglist or 194 * unmasked in td_sigmask. 195 */ 196 void 197 signotify(struct thread *td) 198 { 199 struct proc *p; 200 sigset_t set; 201 202 p = td->td_proc; 203 204 PROC_LOCK_ASSERT(p, MA_OWNED); 205 206 /* 207 * If our mask changed we may have to move signal that were 208 * previously masked by all threads to our siglist. 209 */ 210 set = p->p_siglist; 211 SIGSETNAND(set, td->td_sigmask); 212 SIGSETNAND(p->p_siglist, set); 213 SIGSETOR(td->td_siglist, set); 214 215 if (SIGPENDING(td)) { 216 mtx_lock_spin(&sched_lock); 217 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 218 mtx_unlock_spin(&sched_lock); 219 } 220 } 221 222 int 223 sigonstack(size_t sp) 224 { 225 struct proc *p = curthread->td_proc; 226 227 PROC_LOCK_ASSERT(p, MA_OWNED); 228 return ((p->p_flag & P_ALTSTACK) ? 229 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 230 ((p->p_sigstk.ss_size == 0) ? (p->p_sigstk.ss_flags & SS_ONSTACK) : 231 ((sp - (size_t)p->p_sigstk.ss_sp) < p->p_sigstk.ss_size)) 232 #else 233 ((sp - (size_t)p->p_sigstk.ss_sp) < p->p_sigstk.ss_size) 234 #endif 235 : 0); 236 } 237 238 static __inline int 239 sigprop(int sig) 240 { 241 242 if (sig > 0 && sig < NSIG) 243 return (sigproptbl[_SIG_IDX(sig)]); 244 return (0); 245 } 246 247 int 248 sig_ffs(sigset_t *set) 249 { 250 int i; 251 252 for (i = 0; i < _SIG_WORDS; i++) 253 if (set->__bits[i]) 254 return (ffs(set->__bits[i]) + (i * 32)); 255 return (0); 256 } 257 258 /* 259 * kern_sigaction 260 * sigaction 261 * freebsd4_sigaction 262 * osigaction 263 * 264 * MPSAFE 265 */ 266 int 267 kern_sigaction(td, sig, act, oact, flags) 268 struct thread *td; 269 register int sig; 270 struct sigaction *act, *oact; 271 int flags; 272 { 273 struct sigacts *ps; 274 struct thread *td0; 275 struct proc *p = td->td_proc; 276 277 if (!_SIG_VALID(sig)) 278 return (EINVAL); 279 280 PROC_LOCK(p); 281 ps = p->p_sigacts; 282 mtx_lock(&ps->ps_mtx); 283 if (oact) { 284 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 285 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 286 oact->sa_flags = 0; 287 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 288 oact->sa_flags |= SA_ONSTACK; 289 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 290 oact->sa_flags |= SA_RESTART; 291 if (SIGISMEMBER(ps->ps_sigreset, sig)) 292 oact->sa_flags |= SA_RESETHAND; 293 if (SIGISMEMBER(ps->ps_signodefer, sig)) 294 oact->sa_flags |= SA_NODEFER; 295 if (SIGISMEMBER(ps->ps_siginfo, sig)) 296 oact->sa_flags |= SA_SIGINFO; 297 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 298 oact->sa_flags |= SA_NOCLDSTOP; 299 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 300 oact->sa_flags |= SA_NOCLDWAIT; 301 } 302 if (act) { 303 if ((sig == SIGKILL || sig == SIGSTOP) && 304 act->sa_handler != SIG_DFL) { 305 mtx_unlock(&ps->ps_mtx); 306 PROC_UNLOCK(p); 307 return (EINVAL); 308 } 309 310 /* 311 * Change setting atomically. 312 */ 313 314 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 315 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 316 if (act->sa_flags & SA_SIGINFO) { 317 ps->ps_sigact[_SIG_IDX(sig)] = 318 (__sighandler_t *)act->sa_sigaction; 319 SIGADDSET(ps->ps_siginfo, sig); 320 } else { 321 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 322 SIGDELSET(ps->ps_siginfo, sig); 323 } 324 if (!(act->sa_flags & SA_RESTART)) 325 SIGADDSET(ps->ps_sigintr, sig); 326 else 327 SIGDELSET(ps->ps_sigintr, sig); 328 if (act->sa_flags & SA_ONSTACK) 329 SIGADDSET(ps->ps_sigonstack, sig); 330 else 331 SIGDELSET(ps->ps_sigonstack, sig); 332 if (act->sa_flags & SA_RESETHAND) 333 SIGADDSET(ps->ps_sigreset, sig); 334 else 335 SIGDELSET(ps->ps_sigreset, sig); 336 if (act->sa_flags & SA_NODEFER) 337 SIGADDSET(ps->ps_signodefer, sig); 338 else 339 SIGDELSET(ps->ps_signodefer, sig); 340 #ifdef COMPAT_SUNOS 341 if (act->sa_flags & SA_USERTRAMP) 342 SIGADDSET(ps->ps_usertramp, sig); 343 else 344 SIGDELSET(ps->ps_usertramp, sig); 345 #endif 346 if (sig == SIGCHLD) { 347 if (act->sa_flags & SA_NOCLDSTOP) 348 ps->ps_flag |= PS_NOCLDSTOP; 349 else 350 ps->ps_flag &= ~PS_NOCLDSTOP; 351 if (act->sa_flags & SA_NOCLDWAIT) { 352 /* 353 * Paranoia: since SA_NOCLDWAIT is implemented 354 * by reparenting the dying child to PID 1 (and 355 * trust it to reap the zombie), PID 1 itself 356 * is forbidden to set SA_NOCLDWAIT. 357 */ 358 if (p->p_pid == 1) 359 ps->ps_flag &= ~PS_NOCLDWAIT; 360 else 361 ps->ps_flag |= PS_NOCLDWAIT; 362 } else 363 ps->ps_flag &= ~PS_NOCLDWAIT; 364 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 365 ps->ps_flag |= PS_CLDSIGIGN; 366 else 367 ps->ps_flag &= ~PS_CLDSIGIGN; 368 } 369 /* 370 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 371 * and for signals set to SIG_DFL where the default is to 372 * ignore. However, don't put SIGCONT in ps_sigignore, as we 373 * have to restart the process. 374 */ 375 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 376 (sigprop(sig) & SA_IGNORE && 377 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 378 /* never to be seen again */ 379 SIGDELSET(p->p_siglist, sig); 380 FOREACH_THREAD_IN_PROC(p, td0) 381 SIGDELSET(td0->td_siglist, sig); 382 if (sig != SIGCONT) 383 /* easier in psignal */ 384 SIGADDSET(ps->ps_sigignore, sig); 385 SIGDELSET(ps->ps_sigcatch, sig); 386 } else { 387 SIGDELSET(ps->ps_sigignore, sig); 388 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 389 SIGDELSET(ps->ps_sigcatch, sig); 390 else 391 SIGADDSET(ps->ps_sigcatch, sig); 392 } 393 #ifdef COMPAT_FREEBSD4 394 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 395 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 396 (flags & KSA_FREEBSD4) == 0) 397 SIGDELSET(ps->ps_freebsd4, sig); 398 else 399 SIGADDSET(ps->ps_freebsd4, sig); 400 #endif 401 #ifdef COMPAT_43 402 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 403 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 404 (flags & KSA_OSIGSET) == 0) 405 SIGDELSET(ps->ps_osigset, sig); 406 else 407 SIGADDSET(ps->ps_osigset, sig); 408 #endif 409 } 410 mtx_unlock(&ps->ps_mtx); 411 PROC_UNLOCK(p); 412 return (0); 413 } 414 415 #ifndef _SYS_SYSPROTO_H_ 416 struct sigaction_args { 417 int sig; 418 struct sigaction *act; 419 struct sigaction *oact; 420 }; 421 #endif 422 /* 423 * MPSAFE 424 */ 425 int 426 sigaction(td, uap) 427 struct thread *td; 428 register struct sigaction_args *uap; 429 { 430 struct sigaction act, oact; 431 register struct sigaction *actp, *oactp; 432 int error; 433 434 actp = (uap->act != NULL) ? &act : NULL; 435 oactp = (uap->oact != NULL) ? &oact : NULL; 436 if (actp) { 437 error = copyin(uap->act, actp, sizeof(act)); 438 if (error) 439 return (error); 440 } 441 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 442 if (oactp && !error) 443 error = copyout(oactp, uap->oact, sizeof(oact)); 444 return (error); 445 } 446 447 #ifdef COMPAT_FREEBSD4 448 #ifndef _SYS_SYSPROTO_H_ 449 struct freebsd4_sigaction_args { 450 int sig; 451 struct sigaction *act; 452 struct sigaction *oact; 453 }; 454 #endif 455 /* 456 * MPSAFE 457 */ 458 int 459 freebsd4_sigaction(td, uap) 460 struct thread *td; 461 register struct freebsd4_sigaction_args *uap; 462 { 463 struct sigaction act, oact; 464 register struct sigaction *actp, *oactp; 465 int error; 466 467 468 actp = (uap->act != NULL) ? &act : NULL; 469 oactp = (uap->oact != NULL) ? &oact : NULL; 470 if (actp) { 471 error = copyin(uap->act, actp, sizeof(act)); 472 if (error) 473 return (error); 474 } 475 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 476 if (oactp && !error) 477 error = copyout(oactp, uap->oact, sizeof(oact)); 478 return (error); 479 } 480 #endif /* COMAPT_FREEBSD4 */ 481 482 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 483 #ifndef _SYS_SYSPROTO_H_ 484 struct osigaction_args { 485 int signum; 486 struct osigaction *nsa; 487 struct osigaction *osa; 488 }; 489 #endif 490 /* 491 * MPSAFE 492 */ 493 int 494 osigaction(td, uap) 495 struct thread *td; 496 register struct osigaction_args *uap; 497 { 498 struct osigaction sa; 499 struct sigaction nsa, osa; 500 register struct sigaction *nsap, *osap; 501 int error; 502 503 if (uap->signum <= 0 || uap->signum >= ONSIG) 504 return (EINVAL); 505 506 nsap = (uap->nsa != NULL) ? &nsa : NULL; 507 osap = (uap->osa != NULL) ? &osa : NULL; 508 509 if (nsap) { 510 error = copyin(uap->nsa, &sa, sizeof(sa)); 511 if (error) 512 return (error); 513 nsap->sa_handler = sa.sa_handler; 514 nsap->sa_flags = sa.sa_flags; 515 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 516 } 517 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 518 if (osap && !error) { 519 sa.sa_handler = osap->sa_handler; 520 sa.sa_flags = osap->sa_flags; 521 SIG2OSIG(osap->sa_mask, sa.sa_mask); 522 error = copyout(&sa, uap->osa, sizeof(sa)); 523 } 524 return (error); 525 } 526 527 #if !defined(__i386__) && !defined(__alpha__) 528 /* Avoid replicating the same stub everywhere */ 529 int 530 osigreturn(td, uap) 531 struct thread *td; 532 struct osigreturn_args *uap; 533 { 534 535 return (nosys(td, (struct nosys_args *)uap)); 536 } 537 #endif 538 #endif /* COMPAT_43 */ 539 540 /* 541 * Initialize signal state for process 0; 542 * set to ignore signals that are ignored by default. 543 */ 544 void 545 siginit(p) 546 struct proc *p; 547 { 548 register int i; 549 struct sigacts *ps; 550 551 PROC_LOCK(p); 552 ps = p->p_sigacts; 553 mtx_lock(&ps->ps_mtx); 554 for (i = 1; i <= NSIG; i++) 555 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 556 SIGADDSET(ps->ps_sigignore, i); 557 mtx_unlock(&ps->ps_mtx); 558 PROC_UNLOCK(p); 559 } 560 561 /* 562 * Reset signals for an exec of the specified process. 563 */ 564 void 565 execsigs(p) 566 register struct proc *p; 567 { 568 register struct sigacts *ps; 569 register int sig; 570 571 /* 572 * Reset caught signals. Held signals remain held 573 * through td_sigmask (unless they were caught, 574 * and are now ignored by default). 575 */ 576 PROC_LOCK_ASSERT(p, MA_OWNED); 577 ps = p->p_sigacts; 578 mtx_lock(&ps->ps_mtx); 579 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 580 sig = sig_ffs(&ps->ps_sigcatch); 581 SIGDELSET(ps->ps_sigcatch, sig); 582 if (sigprop(sig) & SA_IGNORE) { 583 if (sig != SIGCONT) 584 SIGADDSET(ps->ps_sigignore, sig); 585 SIGDELSET(p->p_siglist, sig); 586 /* 587 * There is only one thread at this point. 588 */ 589 SIGDELSET(FIRST_THREAD_IN_PROC(p)->td_siglist, sig); 590 } 591 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 592 } 593 /* 594 * Clear out the td's sigmask. Normal processes use the proc sigmask. 595 */ 596 SIGEMPTYSET(FIRST_THREAD_IN_PROC(p)->td_sigmask); 597 /* 598 * Reset stack state to the user stack. 599 * Clear set of signals caught on the signal stack. 600 */ 601 p->p_sigstk.ss_flags = SS_DISABLE; 602 p->p_sigstk.ss_size = 0; 603 p->p_sigstk.ss_sp = 0; 604 p->p_flag &= ~P_ALTSTACK; 605 /* 606 * Reset no zombies if child dies flag as Solaris does. 607 */ 608 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 609 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 610 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 611 mtx_unlock(&ps->ps_mtx); 612 } 613 614 /* 615 * kern_sigprocmask() 616 * 617 * Manipulate signal mask. 618 */ 619 int 620 kern_sigprocmask(td, how, set, oset, old) 621 struct thread *td; 622 int how; 623 sigset_t *set, *oset; 624 int old; 625 { 626 int error; 627 628 PROC_LOCK(td->td_proc); 629 if (oset != NULL) 630 *oset = td->td_sigmask; 631 632 error = 0; 633 if (set != NULL) { 634 switch (how) { 635 case SIG_BLOCK: 636 SIG_CANTMASK(*set); 637 SIGSETOR(td->td_sigmask, *set); 638 break; 639 case SIG_UNBLOCK: 640 SIGSETNAND(td->td_sigmask, *set); 641 signotify(td); 642 break; 643 case SIG_SETMASK: 644 SIG_CANTMASK(*set); 645 if (old) 646 SIGSETLO(td->td_sigmask, *set); 647 else 648 td->td_sigmask = *set; 649 signotify(td); 650 break; 651 default: 652 error = EINVAL; 653 break; 654 } 655 } 656 PROC_UNLOCK(td->td_proc); 657 return (error); 658 } 659 660 /* 661 * sigprocmask() - MP SAFE 662 */ 663 664 #ifndef _SYS_SYSPROTO_H_ 665 struct sigprocmask_args { 666 int how; 667 const sigset_t *set; 668 sigset_t *oset; 669 }; 670 #endif 671 int 672 sigprocmask(td, uap) 673 register struct thread *td; 674 struct sigprocmask_args *uap; 675 { 676 sigset_t set, oset; 677 sigset_t *setp, *osetp; 678 int error; 679 680 setp = (uap->set != NULL) ? &set : NULL; 681 osetp = (uap->oset != NULL) ? &oset : NULL; 682 if (setp) { 683 error = copyin(uap->set, setp, sizeof(set)); 684 if (error) 685 return (error); 686 } 687 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 688 if (osetp && !error) { 689 error = copyout(osetp, uap->oset, sizeof(oset)); 690 } 691 return (error); 692 } 693 694 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 695 /* 696 * osigprocmask() - MP SAFE 697 */ 698 #ifndef _SYS_SYSPROTO_H_ 699 struct osigprocmask_args { 700 int how; 701 osigset_t mask; 702 }; 703 #endif 704 int 705 osigprocmask(td, uap) 706 register struct thread *td; 707 struct osigprocmask_args *uap; 708 { 709 sigset_t set, oset; 710 int error; 711 712 OSIG2SIG(uap->mask, set); 713 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 714 SIG2OSIG(oset, td->td_retval[0]); 715 return (error); 716 } 717 #endif /* COMPAT_43 */ 718 719 #ifndef _SYS_SYSPROTO_H_ 720 struct sigpending_args { 721 sigset_t *set; 722 }; 723 #endif 724 /* 725 * MPSAFE 726 */ 727 int 728 sigwait(struct thread *td, struct sigwait_args *uap) 729 { 730 siginfo_t info; 731 sigset_t set; 732 int error; 733 734 error = copyin(uap->set, &set, sizeof(set)); 735 if (error) 736 return (error); 737 738 error = kern_sigtimedwait(td, set, &info, NULL); 739 if (error) 740 return (error); 741 742 error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo)); 743 /* Repost if we got an error. */ 744 if (error && info.si_signo) { 745 PROC_LOCK(td->td_proc); 746 tdsignal(td, info.si_signo); 747 PROC_UNLOCK(td->td_proc); 748 } 749 return (error); 750 } 751 /* 752 * MPSAFE 753 */ 754 int 755 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 756 { 757 struct timespec ts; 758 struct timespec *timeout; 759 sigset_t set; 760 siginfo_t info; 761 int error; 762 763 if (uap->timeout) { 764 error = copyin(uap->timeout, &ts, sizeof(ts)); 765 if (error) 766 return (error); 767 768 timeout = &ts; 769 } else 770 timeout = NULL; 771 772 error = copyin(uap->set, &set, sizeof(set)); 773 if (error) 774 return (error); 775 776 error = kern_sigtimedwait(td, set, &info, timeout); 777 if (error) 778 return (error); 779 780 error = copyout(&info, uap->info, sizeof(info)); 781 /* Repost if we got an error. */ 782 if (error && info.si_signo) { 783 PROC_LOCK(td->td_proc); 784 tdsignal(td, info.si_signo); 785 PROC_UNLOCK(td->td_proc); 786 } 787 return (error); 788 } 789 790 /* 791 * MPSAFE 792 */ 793 int 794 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 795 { 796 siginfo_t info; 797 sigset_t set; 798 int error; 799 800 error = copyin(uap->set, &set, sizeof(set)); 801 if (error) 802 return (error); 803 804 error = kern_sigtimedwait(td, set, &info, NULL); 805 if (error) 806 return (error); 807 808 error = copyout(&info, uap->info, sizeof(info)); 809 /* Repost if we got an error. */ 810 if (error && info.si_signo) { 811 PROC_LOCK(td->td_proc); 812 tdsignal(td, info.si_signo); 813 PROC_UNLOCK(td->td_proc); 814 } 815 return (error); 816 } 817 818 static int 819 kern_sigtimedwait(struct thread *td, sigset_t set, siginfo_t *info, 820 struct timespec *timeout) 821 { 822 register struct sigacts *ps; 823 sigset_t oldmask; 824 struct proc *p; 825 int error; 826 int sig; 827 int hz; 828 829 p = td->td_proc; 830 error = 0; 831 sig = 0; 832 SIG_CANTMASK(set); 833 834 PROC_LOCK(p); 835 ps = p->p_sigacts; 836 oldmask = td->td_sigmask; 837 td->td_sigmask = set; 838 signotify(td); 839 840 mtx_lock(&ps->ps_mtx); 841 sig = cursig(td); 842 if (sig) 843 goto out; 844 845 /* 846 * POSIX says this must be checked after looking for pending 847 * signals. 848 */ 849 if (timeout) { 850 struct timeval tv; 851 852 if (timeout->tv_nsec > 1000000000) { 853 error = EINVAL; 854 goto out; 855 } 856 TIMESPEC_TO_TIMEVAL(&tv, timeout); 857 hz = tvtohz(&tv); 858 } else 859 hz = 0; 860 861 mtx_unlock(&ps->ps_mtx); 862 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "pause", hz); 863 mtx_lock(&ps->ps_mtx); 864 if (error == EINTR) 865 error = 0; 866 else if (error) 867 goto out; 868 869 sig = cursig(td); 870 out: 871 td->td_sigmask = oldmask; 872 if (sig) { 873 sig_t action; 874 875 action = ps->ps_sigact[_SIG_IDX(sig)]; 876 mtx_unlock(&ps->ps_mtx); 877 #ifdef KTRACE 878 if (KTRPOINT(td, KTR_PSIG)) 879 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 880 &td->td_oldsigmask : &td->td_sigmask, 0); 881 #endif 882 _STOPEVENT(p, S_SIG, sig); 883 884 if (action == SIG_DFL) 885 sigexit(td, sig); 886 /* NOTREACHED */ 887 888 SIGDELSET(td->td_siglist, sig); 889 info->si_signo = sig; 890 info->si_code = 0; 891 } else 892 mtx_unlock(&ps->ps_mtx); 893 PROC_UNLOCK(p); 894 return (error); 895 } 896 897 /* 898 * MPSAFE 899 */ 900 int 901 sigpending(td, uap) 902 struct thread *td; 903 struct sigpending_args *uap; 904 { 905 struct proc *p = td->td_proc; 906 sigset_t siglist; 907 908 PROC_LOCK(p); 909 siglist = p->p_siglist; 910 SIGSETOR(siglist, td->td_siglist); 911 PROC_UNLOCK(p); 912 return (copyout(&siglist, uap->set, sizeof(sigset_t))); 913 } 914 915 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 916 #ifndef _SYS_SYSPROTO_H_ 917 struct osigpending_args { 918 int dummy; 919 }; 920 #endif 921 /* 922 * MPSAFE 923 */ 924 int 925 osigpending(td, uap) 926 struct thread *td; 927 struct osigpending_args *uap; 928 { 929 struct proc *p = td->td_proc; 930 sigset_t siglist; 931 932 PROC_LOCK(p); 933 siglist = p->p_siglist; 934 SIGSETOR(siglist, td->td_siglist); 935 PROC_UNLOCK(p); 936 SIG2OSIG(siglist, td->td_retval[0]); 937 return (0); 938 } 939 #endif /* COMPAT_43 */ 940 941 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 942 /* 943 * Generalized interface signal handler, 4.3-compatible. 944 */ 945 #ifndef _SYS_SYSPROTO_H_ 946 struct osigvec_args { 947 int signum; 948 struct sigvec *nsv; 949 struct sigvec *osv; 950 }; 951 #endif 952 /* 953 * MPSAFE 954 */ 955 /* ARGSUSED */ 956 int 957 osigvec(td, uap) 958 struct thread *td; 959 register struct osigvec_args *uap; 960 { 961 struct sigvec vec; 962 struct sigaction nsa, osa; 963 register struct sigaction *nsap, *osap; 964 int error; 965 966 if (uap->signum <= 0 || uap->signum >= ONSIG) 967 return (EINVAL); 968 nsap = (uap->nsv != NULL) ? &nsa : NULL; 969 osap = (uap->osv != NULL) ? &osa : NULL; 970 if (nsap) { 971 error = copyin(uap->nsv, &vec, sizeof(vec)); 972 if (error) 973 return (error); 974 nsap->sa_handler = vec.sv_handler; 975 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 976 nsap->sa_flags = vec.sv_flags; 977 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 978 #ifdef COMPAT_SUNOS 979 nsap->sa_flags |= SA_USERTRAMP; 980 #endif 981 } 982 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 983 if (osap && !error) { 984 vec.sv_handler = osap->sa_handler; 985 SIG2OSIG(osap->sa_mask, vec.sv_mask); 986 vec.sv_flags = osap->sa_flags; 987 vec.sv_flags &= ~SA_NOCLDWAIT; 988 vec.sv_flags ^= SA_RESTART; 989 #ifdef COMPAT_SUNOS 990 vec.sv_flags &= ~SA_NOCLDSTOP; 991 #endif 992 error = copyout(&vec, uap->osv, sizeof(vec)); 993 } 994 return (error); 995 } 996 997 #ifndef _SYS_SYSPROTO_H_ 998 struct osigblock_args { 999 int mask; 1000 }; 1001 #endif 1002 /* 1003 * MPSAFE 1004 */ 1005 int 1006 osigblock(td, uap) 1007 register struct thread *td; 1008 struct osigblock_args *uap; 1009 { 1010 struct proc *p = td->td_proc; 1011 sigset_t set; 1012 1013 OSIG2SIG(uap->mask, set); 1014 SIG_CANTMASK(set); 1015 PROC_LOCK(p); 1016 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1017 SIGSETOR(td->td_sigmask, set); 1018 PROC_UNLOCK(p); 1019 return (0); 1020 } 1021 1022 #ifndef _SYS_SYSPROTO_H_ 1023 struct osigsetmask_args { 1024 int mask; 1025 }; 1026 #endif 1027 /* 1028 * MPSAFE 1029 */ 1030 int 1031 osigsetmask(td, uap) 1032 struct thread *td; 1033 struct osigsetmask_args *uap; 1034 { 1035 struct proc *p = td->td_proc; 1036 sigset_t set; 1037 1038 OSIG2SIG(uap->mask, set); 1039 SIG_CANTMASK(set); 1040 PROC_LOCK(p); 1041 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1042 SIGSETLO(td->td_sigmask, set); 1043 signotify(td); 1044 PROC_UNLOCK(p); 1045 return (0); 1046 } 1047 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1048 1049 /* 1050 * Suspend process until signal, providing mask to be set 1051 * in the meantime. Note nonstandard calling convention: 1052 * libc stub passes mask, not pointer, to save a copyin. 1053 ***** XXXKSE this doesn't make sense under KSE. 1054 ***** Do we suspend the thread or all threads in the process? 1055 ***** How do we suspend threads running NOW on another processor? 1056 */ 1057 #ifndef _SYS_SYSPROTO_H_ 1058 struct sigsuspend_args { 1059 const sigset_t *sigmask; 1060 }; 1061 #endif 1062 /* 1063 * MPSAFE 1064 */ 1065 /* ARGSUSED */ 1066 int 1067 sigsuspend(td, uap) 1068 struct thread *td; 1069 struct sigsuspend_args *uap; 1070 { 1071 sigset_t mask; 1072 int error; 1073 1074 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1075 if (error) 1076 return (error); 1077 return (kern_sigsuspend(td, mask)); 1078 } 1079 1080 int 1081 kern_sigsuspend(struct thread *td, sigset_t mask) 1082 { 1083 struct proc *p = td->td_proc; 1084 1085 /* 1086 * When returning from sigsuspend, we want 1087 * the old mask to be restored after the 1088 * signal handler has finished. Thus, we 1089 * save it here and mark the sigacts structure 1090 * to indicate this. 1091 */ 1092 PROC_LOCK(p); 1093 td->td_oldsigmask = td->td_sigmask; 1094 td->td_pflags |= TDP_OLDMASK; 1095 SIG_CANTMASK(mask); 1096 td->td_sigmask = mask; 1097 signotify(td); 1098 while (msleep(p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1099 /* void */; 1100 PROC_UNLOCK(p); 1101 /* always return EINTR rather than ERESTART... */ 1102 return (EINTR); 1103 } 1104 1105 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1106 #ifndef _SYS_SYSPROTO_H_ 1107 struct osigsuspend_args { 1108 osigset_t mask; 1109 }; 1110 #endif 1111 /* 1112 * MPSAFE 1113 */ 1114 /* ARGSUSED */ 1115 int 1116 osigsuspend(td, uap) 1117 struct thread *td; 1118 struct osigsuspend_args *uap; 1119 { 1120 struct proc *p = td->td_proc; 1121 sigset_t mask; 1122 1123 PROC_LOCK(p); 1124 td->td_oldsigmask = td->td_sigmask; 1125 td->td_pflags |= TDP_OLDMASK; 1126 OSIG2SIG(uap->mask, mask); 1127 SIG_CANTMASK(mask); 1128 SIGSETLO(td->td_sigmask, mask); 1129 signotify(td); 1130 while (msleep(p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1131 /* void */; 1132 PROC_UNLOCK(p); 1133 /* always return EINTR rather than ERESTART... */ 1134 return (EINTR); 1135 } 1136 #endif /* COMPAT_43 */ 1137 1138 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1139 #ifndef _SYS_SYSPROTO_H_ 1140 struct osigstack_args { 1141 struct sigstack *nss; 1142 struct sigstack *oss; 1143 }; 1144 #endif 1145 /* 1146 * MPSAFE 1147 */ 1148 /* ARGSUSED */ 1149 int 1150 osigstack(td, uap) 1151 struct thread *td; 1152 register struct osigstack_args *uap; 1153 { 1154 struct proc *p = td->td_proc; 1155 struct sigstack nss, oss; 1156 int error = 0; 1157 1158 if (uap->nss != NULL) { 1159 error = copyin(uap->nss, &nss, sizeof(nss)); 1160 if (error) 1161 return (error); 1162 } 1163 PROC_LOCK(p); 1164 oss.ss_sp = p->p_sigstk.ss_sp; 1165 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1166 if (uap->nss != NULL) { 1167 p->p_sigstk.ss_sp = nss.ss_sp; 1168 p->p_sigstk.ss_size = 0; 1169 p->p_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1170 p->p_flag |= P_ALTSTACK; 1171 } 1172 PROC_UNLOCK(p); 1173 if (uap->oss != NULL) 1174 error = copyout(&oss, uap->oss, sizeof(oss)); 1175 1176 return (error); 1177 } 1178 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1179 1180 #ifndef _SYS_SYSPROTO_H_ 1181 struct sigaltstack_args { 1182 stack_t *ss; 1183 stack_t *oss; 1184 }; 1185 #endif 1186 /* 1187 * MPSAFE 1188 */ 1189 /* ARGSUSED */ 1190 int 1191 sigaltstack(td, uap) 1192 struct thread *td; 1193 register struct sigaltstack_args *uap; 1194 { 1195 stack_t ss, oss; 1196 int error; 1197 1198 if (uap->ss != NULL) { 1199 error = copyin(uap->ss, &ss, sizeof(ss)); 1200 if (error) 1201 return (error); 1202 } 1203 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1204 (uap->oss != NULL) ? &oss : NULL); 1205 if (error) 1206 return (error); 1207 if (uap->oss != NULL) 1208 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1209 return (error); 1210 } 1211 1212 int 1213 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1214 { 1215 struct proc *p = td->td_proc; 1216 int oonstack; 1217 1218 PROC_LOCK(p); 1219 oonstack = sigonstack(cpu_getstack(td)); 1220 1221 if (oss != NULL) { 1222 *oss = p->p_sigstk; 1223 oss->ss_flags = (p->p_flag & P_ALTSTACK) 1224 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1225 } 1226 1227 if (ss != NULL) { 1228 if (oonstack) { 1229 PROC_UNLOCK(p); 1230 return (EPERM); 1231 } 1232 if ((ss->ss_flags & ~SS_DISABLE) != 0) { 1233 PROC_UNLOCK(p); 1234 return (EINVAL); 1235 } 1236 if (!(ss->ss_flags & SS_DISABLE)) { 1237 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1238 PROC_UNLOCK(p); 1239 return (ENOMEM); 1240 } 1241 p->p_sigstk = *ss; 1242 p->p_flag |= P_ALTSTACK; 1243 } else { 1244 p->p_flag &= ~P_ALTSTACK; 1245 } 1246 } 1247 PROC_UNLOCK(p); 1248 return (0); 1249 } 1250 1251 /* 1252 * Common code for kill process group/broadcast kill. 1253 * cp is calling process. 1254 */ 1255 static int 1256 killpg1(td, sig, pgid, all) 1257 register struct thread *td; 1258 int sig, pgid, all; 1259 { 1260 register struct proc *p; 1261 struct pgrp *pgrp; 1262 int nfound = 0; 1263 1264 if (all) { 1265 /* 1266 * broadcast 1267 */ 1268 sx_slock(&allproc_lock); 1269 LIST_FOREACH(p, &allproc, p_list) { 1270 PROC_LOCK(p); 1271 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1272 p == td->td_proc) { 1273 PROC_UNLOCK(p); 1274 continue; 1275 } 1276 if (p_cansignal(td, p, sig) == 0) { 1277 nfound++; 1278 if (sig) 1279 psignal(p, sig); 1280 } 1281 PROC_UNLOCK(p); 1282 } 1283 sx_sunlock(&allproc_lock); 1284 } else { 1285 sx_slock(&proctree_lock); 1286 if (pgid == 0) { 1287 /* 1288 * zero pgid means send to my process group. 1289 */ 1290 pgrp = td->td_proc->p_pgrp; 1291 PGRP_LOCK(pgrp); 1292 } else { 1293 pgrp = pgfind(pgid); 1294 if (pgrp == NULL) { 1295 sx_sunlock(&proctree_lock); 1296 return (ESRCH); 1297 } 1298 } 1299 sx_sunlock(&proctree_lock); 1300 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1301 PROC_LOCK(p); 1302 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1303 PROC_UNLOCK(p); 1304 continue; 1305 } 1306 if (p->p_state == PRS_ZOMBIE) { 1307 PROC_UNLOCK(p); 1308 continue; 1309 } 1310 if (p_cansignal(td, p, sig) == 0) { 1311 nfound++; 1312 if (sig) 1313 psignal(p, sig); 1314 } 1315 PROC_UNLOCK(p); 1316 } 1317 PGRP_UNLOCK(pgrp); 1318 } 1319 return (nfound ? 0 : ESRCH); 1320 } 1321 1322 #ifndef _SYS_SYSPROTO_H_ 1323 struct kill_args { 1324 int pid; 1325 int signum; 1326 }; 1327 #endif 1328 /* 1329 * MPSAFE 1330 */ 1331 /* ARGSUSED */ 1332 int 1333 kill(td, uap) 1334 register struct thread *td; 1335 register struct kill_args *uap; 1336 { 1337 register struct proc *p; 1338 int error; 1339 1340 if ((u_int)uap->signum > _SIG_MAXSIG) 1341 return (EINVAL); 1342 1343 if (uap->pid > 0) { 1344 /* kill single process */ 1345 if ((p = pfind(uap->pid)) == NULL) 1346 return (ESRCH); 1347 error = p_cansignal(td, p, uap->signum); 1348 if (error == 0 && uap->signum) 1349 psignal(p, uap->signum); 1350 PROC_UNLOCK(p); 1351 return (error); 1352 } 1353 switch (uap->pid) { 1354 case -1: /* broadcast signal */ 1355 return (killpg1(td, uap->signum, 0, 1)); 1356 case 0: /* signal own process group */ 1357 return (killpg1(td, uap->signum, 0, 0)); 1358 default: /* negative explicit process group */ 1359 return (killpg1(td, uap->signum, -uap->pid, 0)); 1360 } 1361 /* NOTREACHED */ 1362 } 1363 1364 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1365 #ifndef _SYS_SYSPROTO_H_ 1366 struct okillpg_args { 1367 int pgid; 1368 int signum; 1369 }; 1370 #endif 1371 /* 1372 * MPSAFE 1373 */ 1374 /* ARGSUSED */ 1375 int 1376 okillpg(td, uap) 1377 struct thread *td; 1378 register struct okillpg_args *uap; 1379 { 1380 1381 if ((u_int)uap->signum > _SIG_MAXSIG) 1382 return (EINVAL); 1383 return (killpg1(td, uap->signum, uap->pgid, 0)); 1384 } 1385 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1386 1387 /* 1388 * Send a signal to a process group. 1389 */ 1390 void 1391 gsignal(pgid, sig) 1392 int pgid, sig; 1393 { 1394 struct pgrp *pgrp; 1395 1396 if (pgid != 0) { 1397 sx_slock(&proctree_lock); 1398 pgrp = pgfind(pgid); 1399 sx_sunlock(&proctree_lock); 1400 if (pgrp != NULL) { 1401 pgsignal(pgrp, sig, 0); 1402 PGRP_UNLOCK(pgrp); 1403 } 1404 } 1405 } 1406 1407 /* 1408 * Send a signal to a process group. If checktty is 1, 1409 * limit to members which have a controlling terminal. 1410 */ 1411 void 1412 pgsignal(pgrp, sig, checkctty) 1413 struct pgrp *pgrp; 1414 int sig, checkctty; 1415 { 1416 register struct proc *p; 1417 1418 if (pgrp) { 1419 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1420 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1421 PROC_LOCK(p); 1422 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1423 psignal(p, sig); 1424 PROC_UNLOCK(p); 1425 } 1426 } 1427 } 1428 1429 /* 1430 * Send a signal caused by a trap to the current thread. 1431 * If it will be caught immediately, deliver it with correct code. 1432 * Otherwise, post it normally. 1433 * 1434 * MPSAFE 1435 */ 1436 void 1437 trapsignal(struct thread *td, int sig, u_long code) 1438 { 1439 struct sigacts *ps; 1440 struct proc *p; 1441 1442 p = td->td_proc; 1443 1444 PROC_LOCK(p); 1445 ps = p->p_sigacts; 1446 mtx_lock(&ps->ps_mtx); 1447 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1448 !SIGISMEMBER(td->td_sigmask, sig)) { 1449 p->p_stats->p_ru.ru_nsignals++; 1450 #ifdef KTRACE 1451 if (KTRPOINT(curthread, KTR_PSIG)) 1452 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1453 &td->td_sigmask, code); 1454 #endif 1455 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 1456 &td->td_sigmask, code); 1457 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1458 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1459 SIGADDSET(td->td_sigmask, sig); 1460 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1461 /* 1462 * See kern_sigaction() for origin of this code. 1463 */ 1464 SIGDELSET(ps->ps_sigcatch, sig); 1465 if (sig != SIGCONT && 1466 sigprop(sig) & SA_IGNORE) 1467 SIGADDSET(ps->ps_sigignore, sig); 1468 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1469 } 1470 mtx_unlock(&ps->ps_mtx); 1471 } else { 1472 mtx_unlock(&ps->ps_mtx); 1473 p->p_code = code; /* XXX for core dump/debugger */ 1474 p->p_sig = sig; /* XXX to verify code */ 1475 tdsignal(td, sig); 1476 } 1477 PROC_UNLOCK(p); 1478 } 1479 1480 static struct thread * 1481 sigtd(struct proc *p, int sig, int prop) 1482 { 1483 struct thread *td; 1484 1485 PROC_LOCK_ASSERT(p, MA_OWNED); 1486 1487 /* 1488 * If we know the signal is bound for a specific thread then we 1489 * assume that we are in that threads context. This is the case 1490 * for SIGXCPU, SIGILL, etc. Otherwise someone did a kill() from 1491 * userland and the real thread doesn't actually matter. 1492 */ 1493 if ((prop & SA_PROC) != 0 && curthread->td_proc == p) 1494 return (curthread); 1495 1496 /* 1497 * We should search for the first thread that is blocked in 1498 * sigsuspend with this signal unmasked. 1499 */ 1500 1501 /* XXX */ 1502 1503 /* 1504 * Find the first thread in the proc that doesn't have this signal 1505 * masked. 1506 */ 1507 FOREACH_THREAD_IN_PROC(p, td) 1508 if (!SIGISMEMBER(td->td_sigmask, sig)) 1509 return (td); 1510 1511 return (FIRST_THREAD_IN_PROC(p)); 1512 } 1513 1514 /* 1515 * Send the signal to the process. If the signal has an action, the action 1516 * is usually performed by the target process rather than the caller; we add 1517 * the signal to the set of pending signals for the process. 1518 * 1519 * Exceptions: 1520 * o When a stop signal is sent to a sleeping process that takes the 1521 * default action, the process is stopped without awakening it. 1522 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1523 * regardless of the signal action (eg, blocked or ignored). 1524 * 1525 * Other ignored signals are discarded immediately. 1526 * 1527 * MPSAFE 1528 */ 1529 void 1530 psignal(struct proc *p, int sig) 1531 { 1532 struct thread *td; 1533 int prop; 1534 1535 PROC_LOCK_ASSERT(p, MA_OWNED); 1536 prop = sigprop(sig); 1537 1538 /* 1539 * Find a thread to deliver the signal to. 1540 */ 1541 td = sigtd(p, sig, prop); 1542 1543 tdsignal(td, sig); 1544 } 1545 1546 /* 1547 * MPSAFE 1548 */ 1549 void 1550 tdsignal(struct thread *td, int sig) 1551 { 1552 struct proc *p; 1553 register sig_t action; 1554 sigset_t *siglist; 1555 struct thread *td0; 1556 register int prop; 1557 struct sigacts *ps; 1558 1559 KASSERT(_SIG_VALID(sig), 1560 ("tdsignal(): invalid signal %d\n", sig)); 1561 1562 p = td->td_proc; 1563 ps = p->p_sigacts; 1564 1565 PROC_LOCK_ASSERT(p, MA_OWNED); 1566 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1567 1568 prop = sigprop(sig); 1569 1570 /* 1571 * If this thread is blocking this signal then we'll leave it in the 1572 * proc so that we can find it in the first thread that unblocks it. 1573 */ 1574 if (SIGISMEMBER(td->td_sigmask, sig)) 1575 siglist = &p->p_siglist; 1576 else 1577 siglist = &td->td_siglist; 1578 1579 /* 1580 * If proc is traced, always give parent a chance; 1581 * if signal event is tracked by procfs, give *that* 1582 * a chance, as well. 1583 */ 1584 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1585 action = SIG_DFL; 1586 } else { 1587 /* 1588 * If the signal is being ignored, 1589 * then we forget about it immediately. 1590 * (Note: we don't set SIGCONT in ps_sigignore, 1591 * and if it is set to SIG_IGN, 1592 * action will be SIG_DFL here.) 1593 */ 1594 mtx_lock(&ps->ps_mtx); 1595 if (SIGISMEMBER(ps->ps_sigignore, sig) || 1596 (p->p_flag & P_WEXIT)) { 1597 mtx_unlock(&ps->ps_mtx); 1598 return; 1599 } 1600 if (SIGISMEMBER(td->td_sigmask, sig)) 1601 action = SIG_HOLD; 1602 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 1603 action = SIG_CATCH; 1604 else 1605 action = SIG_DFL; 1606 mtx_unlock(&ps->ps_mtx); 1607 } 1608 1609 if (prop & SA_CONT) { 1610 SIG_STOPSIGMASK(p->p_siglist); 1611 /* 1612 * XXX Should investigate leaving STOP and CONT sigs only in 1613 * the proc's siglist. 1614 */ 1615 FOREACH_THREAD_IN_PROC(p, td0) 1616 SIG_STOPSIGMASK(td0->td_siglist); 1617 } 1618 1619 if (prop & SA_STOP) { 1620 /* 1621 * If sending a tty stop signal to a member of an orphaned 1622 * process group, discard the signal here if the action 1623 * is default; don't stop the process below if sleeping, 1624 * and don't clear any pending SIGCONT. 1625 */ 1626 if ((prop & SA_TTYSTOP) && 1627 (p->p_pgrp->pg_jobc == 0) && 1628 (action == SIG_DFL)) 1629 return; 1630 SIG_CONTSIGMASK(p->p_siglist); 1631 FOREACH_THREAD_IN_PROC(p, td0) 1632 SIG_CONTSIGMASK(td0->td_siglist); 1633 p->p_flag &= ~P_CONTINUED; 1634 } 1635 SIGADDSET(*siglist, sig); 1636 signotify(td); /* uses schedlock */ 1637 /* 1638 * Defer further processing for signals which are held, 1639 * except that stopped processes must be continued by SIGCONT. 1640 */ 1641 if (action == SIG_HOLD && 1642 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 1643 return; 1644 /* 1645 * Some signals have a process-wide effect and a per-thread 1646 * component. Most processing occurs when the process next 1647 * tries to cross the user boundary, however there are some 1648 * times when processing needs to be done immediatly, such as 1649 * waking up threads so that they can cross the user boundary. 1650 * We try do the per-process part here. 1651 */ 1652 if (P_SHOULDSTOP(p)) { 1653 /* 1654 * The process is in stopped mode. All the threads should be 1655 * either winding down or already on the suspended queue. 1656 */ 1657 if (p->p_flag & P_TRACED) { 1658 /* 1659 * The traced process is already stopped, 1660 * so no further action is necessary. 1661 * No signal can restart us. 1662 */ 1663 goto out; 1664 } 1665 1666 if (sig == SIGKILL) { 1667 /* 1668 * SIGKILL sets process running. 1669 * It will die elsewhere. 1670 * All threads must be restarted. 1671 */ 1672 p->p_flag &= ~P_STOPPED; 1673 goto runfast; 1674 } 1675 1676 if (prop & SA_CONT) { 1677 /* 1678 * If SIGCONT is default (or ignored), we continue the 1679 * process but don't leave the signal in siglist as 1680 * it has no further action. If SIGCONT is held, we 1681 * continue the process and leave the signal in 1682 * siglist. If the process catches SIGCONT, let it 1683 * handle the signal itself. If it isn't waiting on 1684 * an event, it goes back to run state. 1685 * Otherwise, process goes back to sleep state. 1686 */ 1687 p->p_flag &= ~P_STOPPED_SIG; 1688 p->p_flag |= P_CONTINUED; 1689 if (action == SIG_DFL) { 1690 SIGDELSET(*siglist, sig); 1691 } else if (action == SIG_CATCH) { 1692 /* 1693 * The process wants to catch it so it needs 1694 * to run at least one thread, but which one? 1695 * It would seem that the answer would be to 1696 * run an upcall in the next KSE to run, and 1697 * deliver the signal that way. In a NON KSE 1698 * process, we need to make sure that the 1699 * single thread is runnable asap. 1700 * XXXKSE for now however, make them all run. 1701 */ 1702 goto runfast; 1703 } 1704 /* 1705 * The signal is not ignored or caught. 1706 */ 1707 mtx_lock_spin(&sched_lock); 1708 thread_unsuspend(p); 1709 mtx_unlock_spin(&sched_lock); 1710 goto out; 1711 } 1712 1713 if (prop & SA_STOP) { 1714 /* 1715 * Already stopped, don't need to stop again 1716 * (If we did the shell could get confused). 1717 * Just make sure the signal STOP bit set. 1718 */ 1719 p->p_flag |= P_STOPPED_SIG; 1720 SIGDELSET(*siglist, sig); 1721 goto out; 1722 } 1723 1724 /* 1725 * All other kinds of signals: 1726 * If a thread is sleeping interruptibly, simulate a 1727 * wakeup so that when it is continued it will be made 1728 * runnable and can look at the signal. However, don't make 1729 * the PROCESS runnable, leave it stopped. 1730 * It may run a bit until it hits a thread_suspend_check(). 1731 */ 1732 mtx_lock_spin(&sched_lock); 1733 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) { 1734 if (td->td_flags & TDF_CVWAITQ) 1735 cv_abort(td); 1736 else 1737 abortsleep(td); 1738 } 1739 mtx_unlock_spin(&sched_lock); 1740 goto out; 1741 /* 1742 * XXXKSE What about threads that are waiting on mutexes? 1743 * Shouldn't they abort too? 1744 * No, hopefully mutexes are short lived.. They'll 1745 * eventually hit thread_suspend_check(). 1746 */ 1747 } else if (p->p_state == PRS_NORMAL) { 1748 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || 1749 !(prop & SA_STOP)) { 1750 mtx_lock_spin(&sched_lock); 1751 tdsigwakeup(td, sig, action); 1752 mtx_unlock_spin(&sched_lock); 1753 goto out; 1754 } 1755 if (prop & SA_STOP) { 1756 if (p->p_flag & P_PPWAIT) 1757 goto out; 1758 p->p_flag |= P_STOPPED_SIG; 1759 p->p_xstat = sig; 1760 mtx_lock_spin(&sched_lock); 1761 FOREACH_THREAD_IN_PROC(p, td0) { 1762 if (TD_IS_SLEEPING(td0) && 1763 (td0->td_flags & TDF_SINTR) && 1764 !TD_IS_SUSPENDED(td0)) { 1765 thread_suspend_one(td0); 1766 } else if (td != td0) { 1767 td0->td_flags |= TDF_ASTPENDING; 1768 } 1769 } 1770 thread_stopped(p); 1771 if (p->p_numthreads == p->p_suspcount) { 1772 SIGDELSET(p->p_siglist, p->p_xstat); 1773 FOREACH_THREAD_IN_PROC(p, td0) 1774 SIGDELSET(td0->td_siglist, p->p_xstat); 1775 } 1776 mtx_unlock_spin(&sched_lock); 1777 goto out; 1778 } 1779 else 1780 goto runfast; 1781 /* NOTREACHED */ 1782 } else { 1783 /* Not in "NORMAL" state. discard the signal. */ 1784 SIGDELSET(*siglist, sig); 1785 goto out; 1786 } 1787 1788 /* 1789 * The process is not stopped so we need to apply the signal to all the 1790 * running threads. 1791 */ 1792 1793 runfast: 1794 mtx_lock_spin(&sched_lock); 1795 tdsigwakeup(td, sig, action); 1796 thread_unsuspend(p); 1797 mtx_unlock_spin(&sched_lock); 1798 out: 1799 /* If we jump here, sched_lock should not be owned. */ 1800 mtx_assert(&sched_lock, MA_NOTOWNED); 1801 } 1802 1803 /* 1804 * The force of a signal has been directed against a single 1805 * thread. We need to see what we can do about knocking it 1806 * out of any sleep it may be in etc. 1807 */ 1808 static void 1809 tdsigwakeup(struct thread *td, int sig, sig_t action) 1810 { 1811 struct proc *p = td->td_proc; 1812 register int prop; 1813 1814 PROC_LOCK_ASSERT(p, MA_OWNED); 1815 mtx_assert(&sched_lock, MA_OWNED); 1816 prop = sigprop(sig); 1817 /* 1818 * Bring the priority of a thread up if we want it to get 1819 * killed in this lifetime. 1820 */ 1821 if ((action == SIG_DFL) && (prop & SA_KILL)) { 1822 if (td->td_priority > PUSER) { 1823 td->td_priority = PUSER; 1824 } 1825 } 1826 if (TD_IS_SLEEPING(td)) { 1827 /* 1828 * If thread is sleeping uninterruptibly 1829 * we can't interrupt the sleep... the signal will 1830 * be noticed when the process returns through 1831 * trap() or syscall(). 1832 */ 1833 if ((td->td_flags & TDF_SINTR) == 0) { 1834 return; 1835 } 1836 /* 1837 * Process is sleeping and traced. Make it runnable 1838 * so it can discover the signal in issignal() and stop 1839 * for its parent. 1840 */ 1841 if (p->p_flag & P_TRACED) { 1842 p->p_flag &= ~P_STOPPED_TRACE; 1843 } else { 1844 1845 /* 1846 * If SIGCONT is default (or ignored) and process is 1847 * asleep, we are finished; the process should not 1848 * be awakened. 1849 */ 1850 if ((prop & SA_CONT) && action == SIG_DFL) { 1851 SIGDELSET(p->p_siglist, sig); 1852 /* 1853 * It may be on either list in this state. 1854 * Remove from both for now. 1855 */ 1856 SIGDELSET(td->td_siglist, sig); 1857 return; 1858 } 1859 1860 /* 1861 * Raise priority to at least PUSER. 1862 */ 1863 if (td->td_priority > PUSER) { 1864 td->td_priority = PUSER; 1865 } 1866 } 1867 if (td->td_flags & TDF_CVWAITQ) 1868 cv_abort(td); 1869 else 1870 abortsleep(td); 1871 } 1872 #ifdef SMP 1873 else { 1874 /* 1875 * Other states do nothing with the signal immediatly, 1876 * other than kicking ourselves if we are running. 1877 * It will either never be noticed, or noticed very soon. 1878 */ 1879 if (TD_IS_RUNNING(td) && td != curthread) { 1880 forward_signal(td); 1881 } 1882 } 1883 #endif 1884 } 1885 1886 /* 1887 * If the current process has received a signal (should be caught or cause 1888 * termination, should interrupt current syscall), return the signal number. 1889 * Stop signals with default action are processed immediately, then cleared; 1890 * they aren't returned. This is checked after each entry to the system for 1891 * a syscall or trap (though this can usually be done without calling issignal 1892 * by checking the pending signal masks in cursig.) The normal call 1893 * sequence is 1894 * 1895 * while (sig = cursig(curthread)) 1896 * postsig(sig); 1897 */ 1898 static int 1899 issignal(td) 1900 struct thread *td; 1901 { 1902 struct proc *p; 1903 struct sigacts *ps; 1904 sigset_t sigpending; 1905 int sig, prop; 1906 struct thread *td0; 1907 1908 p = td->td_proc; 1909 ps = p->p_sigacts; 1910 mtx_assert(&ps->ps_mtx, MA_OWNED); 1911 PROC_LOCK_ASSERT(p, MA_OWNED); 1912 for (;;) { 1913 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1914 1915 sigpending = td->td_siglist; 1916 SIGSETNAND(sigpending, td->td_sigmask); 1917 1918 if (p->p_flag & P_PPWAIT) 1919 SIG_STOPSIGMASK(sigpending); 1920 if (SIGISEMPTY(sigpending)) /* no signal to send */ 1921 return (0); 1922 sig = sig_ffs(&sigpending); 1923 1924 _STOPEVENT(p, S_SIG, sig); 1925 1926 /* 1927 * We should see pending but ignored signals 1928 * only if P_TRACED was on when they were posted. 1929 */ 1930 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 1931 SIGDELSET(td->td_siglist, sig); 1932 continue; 1933 } 1934 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1935 /* 1936 * If traced, always stop. 1937 */ 1938 mtx_unlock(&ps->ps_mtx); 1939 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 1940 &p->p_mtx.mtx_object, "Stopping for traced signal"); 1941 p->p_xstat = sig; 1942 PROC_LOCK(p->p_pptr); 1943 psignal(p->p_pptr, SIGCHLD); 1944 PROC_UNLOCK(p->p_pptr); 1945 mtx_lock_spin(&sched_lock); 1946 stop(p); /* uses schedlock too eventually */ 1947 thread_suspend_one(td); 1948 PROC_UNLOCK(p); 1949 DROP_GIANT(); 1950 p->p_stats->p_ru.ru_nivcsw++; 1951 mi_switch(); 1952 mtx_unlock_spin(&sched_lock); 1953 PICKUP_GIANT(); 1954 PROC_LOCK(p); 1955 mtx_lock(&ps->ps_mtx); 1956 1957 /* 1958 * If parent wants us to take the signal, 1959 * then it will leave it in p->p_xstat; 1960 * otherwise we just look for signals again. 1961 */ 1962 SIGDELSET(td->td_siglist, sig); /* clear old signal */ 1963 sig = p->p_xstat; 1964 if (sig == 0) 1965 continue; 1966 1967 /* 1968 * If the traced bit got turned off, go back up 1969 * to the top to rescan signals. This ensures 1970 * that p_sig* and p_sigact are consistent. 1971 */ 1972 if ((p->p_flag & P_TRACED) == 0) 1973 continue; 1974 1975 /* 1976 * Put the new signal into td_siglist. If the 1977 * signal is being masked, look for other signals. 1978 */ 1979 SIGADDSET(td->td_siglist, sig); 1980 if (SIGISMEMBER(td->td_sigmask, sig)) 1981 continue; 1982 signotify(td); 1983 } 1984 1985 prop = sigprop(sig); 1986 1987 /* 1988 * Decide whether the signal should be returned. 1989 * Return the signal's number, or fall through 1990 * to clear it from the pending mask. 1991 */ 1992 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1993 1994 case (intptr_t)SIG_DFL: 1995 /* 1996 * Don't take default actions on system processes. 1997 */ 1998 if (p->p_pid <= 1) { 1999 #ifdef DIAGNOSTIC 2000 /* 2001 * Are you sure you want to ignore SIGSEGV 2002 * in init? XXX 2003 */ 2004 printf("Process (pid %lu) got signal %d\n", 2005 (u_long)p->p_pid, sig); 2006 #endif 2007 break; /* == ignore */ 2008 } 2009 /* 2010 * If there is a pending stop signal to process 2011 * with default action, stop here, 2012 * then clear the signal. However, 2013 * if process is member of an orphaned 2014 * process group, ignore tty stop signals. 2015 */ 2016 if (prop & SA_STOP) { 2017 if (p->p_flag & P_TRACED || 2018 (p->p_pgrp->pg_jobc == 0 && 2019 prop & SA_TTYSTOP)) 2020 break; /* == ignore */ 2021 mtx_unlock(&ps->ps_mtx); 2022 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2023 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2024 p->p_flag |= P_STOPPED_SIG; 2025 p->p_xstat = sig; 2026 mtx_lock_spin(&sched_lock); 2027 FOREACH_THREAD_IN_PROC(p, td0) { 2028 if (TD_IS_SLEEPING(td0) && 2029 (td0->td_flags & TDF_SINTR) && 2030 !TD_IS_SUSPENDED(td0)) { 2031 thread_suspend_one(td0); 2032 } else if (td != td0) { 2033 td0->td_flags |= TDF_ASTPENDING; 2034 } 2035 } 2036 thread_stopped(p); 2037 thread_suspend_one(td); 2038 PROC_UNLOCK(p); 2039 DROP_GIANT(); 2040 p->p_stats->p_ru.ru_nivcsw++; 2041 mi_switch(); 2042 mtx_unlock_spin(&sched_lock); 2043 PICKUP_GIANT(); 2044 PROC_LOCK(p); 2045 mtx_lock(&ps->ps_mtx); 2046 break; 2047 } else if (prop & SA_IGNORE) { 2048 /* 2049 * Except for SIGCONT, shouldn't get here. 2050 * Default action is to ignore; drop it. 2051 */ 2052 break; /* == ignore */ 2053 } else 2054 return (sig); 2055 /*NOTREACHED*/ 2056 2057 case (intptr_t)SIG_IGN: 2058 /* 2059 * Masking above should prevent us ever trying 2060 * to take action on an ignored signal other 2061 * than SIGCONT, unless process is traced. 2062 */ 2063 if ((prop & SA_CONT) == 0 && 2064 (p->p_flag & P_TRACED) == 0) 2065 printf("issignal\n"); 2066 break; /* == ignore */ 2067 2068 default: 2069 /* 2070 * This signal has an action, let 2071 * postsig() process it. 2072 */ 2073 return (sig); 2074 } 2075 SIGDELSET(td->td_siglist, sig); /* take the signal! */ 2076 } 2077 /* NOTREACHED */ 2078 } 2079 2080 /* 2081 * Put the argument process into the stopped state and notify the parent 2082 * via wakeup. Signals are handled elsewhere. The process must not be 2083 * on the run queue. Must be called with the proc p locked and the scheduler 2084 * lock held. 2085 */ 2086 static void 2087 stop(struct proc *p) 2088 { 2089 2090 PROC_LOCK_ASSERT(p, MA_OWNED); 2091 p->p_flag |= P_STOPPED_SIG; 2092 p->p_flag &= ~P_WAITED; 2093 wakeup(p->p_pptr); 2094 } 2095 2096 /* 2097 * MPSAFE 2098 */ 2099 void 2100 thread_stopped(struct proc *p) 2101 { 2102 struct proc *p1 = curthread->td_proc; 2103 struct sigacts *ps; 2104 int n; 2105 2106 PROC_LOCK_ASSERT(p, MA_OWNED); 2107 mtx_assert(&sched_lock, MA_OWNED); 2108 n = p->p_suspcount; 2109 if (p == p1) 2110 n++; 2111 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2112 mtx_unlock_spin(&sched_lock); 2113 stop(p); 2114 PROC_LOCK(p->p_pptr); 2115 ps = p->p_pptr->p_sigacts; 2116 mtx_lock(&ps->ps_mtx); 2117 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2118 mtx_unlock(&ps->ps_mtx); 2119 psignal(p->p_pptr, SIGCHLD); 2120 } else 2121 mtx_unlock(&ps->ps_mtx); 2122 PROC_UNLOCK(p->p_pptr); 2123 mtx_lock_spin(&sched_lock); 2124 } 2125 } 2126 2127 /* 2128 * Take the action for the specified signal 2129 * from the current set of pending signals. 2130 */ 2131 void 2132 postsig(sig) 2133 register int sig; 2134 { 2135 struct thread *td = curthread; 2136 register struct proc *p = td->td_proc; 2137 struct sigacts *ps; 2138 sig_t action; 2139 sigset_t returnmask; 2140 int code; 2141 2142 KASSERT(sig != 0, ("postsig")); 2143 2144 PROC_LOCK_ASSERT(p, MA_OWNED); 2145 ps = p->p_sigacts; 2146 mtx_assert(&ps->ps_mtx, MA_OWNED); 2147 SIGDELSET(td->td_siglist, sig); 2148 action = ps->ps_sigact[_SIG_IDX(sig)]; 2149 #ifdef KTRACE 2150 if (KTRPOINT(td, KTR_PSIG)) 2151 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2152 &td->td_oldsigmask : &td->td_sigmask, 0); 2153 #endif 2154 _STOPEVENT(p, S_SIG, sig); 2155 2156 if (action == SIG_DFL) { 2157 /* 2158 * Default action, where the default is to kill 2159 * the process. (Other cases were ignored above.) 2160 */ 2161 mtx_unlock(&ps->ps_mtx); 2162 sigexit(td, sig); 2163 /* NOTREACHED */ 2164 } else { 2165 /* 2166 * If we get here, the signal must be caught. 2167 */ 2168 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2169 ("postsig action")); 2170 /* 2171 * Set the new mask value and also defer further 2172 * occurrences of this signal. 2173 * 2174 * Special case: user has done a sigsuspend. Here the 2175 * current mask is not of interest, but rather the 2176 * mask from before the sigsuspend is what we want 2177 * restored after the signal processing is completed. 2178 */ 2179 if (td->td_pflags & TDP_OLDMASK) { 2180 returnmask = td->td_oldsigmask; 2181 td->td_pflags &= ~TDP_OLDMASK; 2182 } else 2183 returnmask = td->td_sigmask; 2184 2185 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2186 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2187 SIGADDSET(td->td_sigmask, sig); 2188 2189 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2190 /* 2191 * See kern_sigaction() for origin of this code. 2192 */ 2193 SIGDELSET(ps->ps_sigcatch, sig); 2194 if (sig != SIGCONT && 2195 sigprop(sig) & SA_IGNORE) 2196 SIGADDSET(ps->ps_sigignore, sig); 2197 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2198 } 2199 p->p_stats->p_ru.ru_nsignals++; 2200 if (p->p_sig != sig) { 2201 code = 0; 2202 } else { 2203 code = p->p_code; 2204 p->p_code = 0; 2205 p->p_sig = 0; 2206 } 2207 if (td->td_flags & TDF_SA) 2208 thread_signal_add(curthread, sig); 2209 else 2210 (*p->p_sysent->sv_sendsig)(action, sig, 2211 &returnmask, code); 2212 } 2213 } 2214 2215 /* 2216 * Kill the current process for stated reason. 2217 */ 2218 void 2219 killproc(p, why) 2220 struct proc *p; 2221 char *why; 2222 { 2223 2224 PROC_LOCK_ASSERT(p, MA_OWNED); 2225 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2226 p, p->p_pid, p->p_comm); 2227 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2228 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2229 psignal(p, SIGKILL); 2230 } 2231 2232 /* 2233 * Force the current process to exit with the specified signal, dumping core 2234 * if appropriate. We bypass the normal tests for masked and caught signals, 2235 * allowing unrecoverable failures to terminate the process without changing 2236 * signal state. Mark the accounting record with the signal termination. 2237 * If dumping core, save the signal number for the debugger. Calls exit and 2238 * does not return. 2239 * 2240 * MPSAFE 2241 */ 2242 void 2243 sigexit(td, sig) 2244 struct thread *td; 2245 int sig; 2246 { 2247 struct proc *p = td->td_proc; 2248 2249 PROC_LOCK_ASSERT(p, MA_OWNED); 2250 p->p_acflag |= AXSIG; 2251 if (sigprop(sig) & SA_CORE) { 2252 p->p_sig = sig; 2253 /* 2254 * Log signals which would cause core dumps 2255 * (Log as LOG_INFO to appease those who don't want 2256 * these messages.) 2257 * XXX : Todo, as well as euid, write out ruid too 2258 */ 2259 PROC_UNLOCK(p); 2260 if (!mtx_owned(&Giant)) 2261 mtx_lock(&Giant); 2262 if (coredump(td) == 0) 2263 sig |= WCOREFLAG; 2264 if (kern_logsigexit) 2265 log(LOG_INFO, 2266 "pid %d (%s), uid %d: exited on signal %d%s\n", 2267 p->p_pid, p->p_comm, 2268 td->td_ucred ? td->td_ucred->cr_uid : -1, 2269 sig &~ WCOREFLAG, 2270 sig & WCOREFLAG ? " (core dumped)" : ""); 2271 } else { 2272 PROC_UNLOCK(p); 2273 if (!mtx_owned(&Giant)) 2274 mtx_lock(&Giant); 2275 } 2276 exit1(td, W_EXITCODE(0, sig)); 2277 /* NOTREACHED */ 2278 } 2279 2280 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2281 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2282 sizeof(corefilename), "process corefile name format string"); 2283 2284 /* 2285 * expand_name(name, uid, pid) 2286 * Expand the name described in corefilename, using name, uid, and pid. 2287 * corefilename is a printf-like string, with three format specifiers: 2288 * %N name of process ("name") 2289 * %P process id (pid) 2290 * %U user id (uid) 2291 * For example, "%N.core" is the default; they can be disabled completely 2292 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2293 * This is controlled by the sysctl variable kern.corefile (see above). 2294 */ 2295 2296 static char * 2297 expand_name(name, uid, pid) 2298 const char *name; 2299 uid_t uid; 2300 pid_t pid; 2301 { 2302 const char *format, *appendstr; 2303 char *temp; 2304 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2305 size_t i, l, n; 2306 2307 format = corefilename; 2308 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2309 if (temp == NULL) 2310 return (NULL); 2311 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2312 switch (format[i]) { 2313 case '%': /* Format character */ 2314 i++; 2315 switch (format[i]) { 2316 case '%': 2317 appendstr = "%"; 2318 break; 2319 case 'N': /* process name */ 2320 appendstr = name; 2321 break; 2322 case 'P': /* process id */ 2323 sprintf(buf, "%u", pid); 2324 appendstr = buf; 2325 break; 2326 case 'U': /* user id */ 2327 sprintf(buf, "%u", uid); 2328 appendstr = buf; 2329 break; 2330 default: 2331 appendstr = ""; 2332 log(LOG_ERR, 2333 "Unknown format character %c in `%s'\n", 2334 format[i], format); 2335 } 2336 l = strlen(appendstr); 2337 if ((n + l) >= MAXPATHLEN) 2338 goto toolong; 2339 memcpy(temp + n, appendstr, l); 2340 n += l; 2341 break; 2342 default: 2343 temp[n++] = format[i]; 2344 } 2345 } 2346 if (format[i] != '\0') 2347 goto toolong; 2348 return (temp); 2349 toolong: 2350 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2351 (long)pid, name, (u_long)uid); 2352 free(temp, M_TEMP); 2353 return (NULL); 2354 } 2355 2356 /* 2357 * Dump a process' core. The main routine does some 2358 * policy checking, and creates the name of the coredump; 2359 * then it passes on a vnode and a size limit to the process-specific 2360 * coredump routine if there is one; if there _is not_ one, it returns 2361 * ENOSYS; otherwise it returns the error from the process-specific routine. 2362 */ 2363 2364 static int 2365 coredump(struct thread *td) 2366 { 2367 struct proc *p = td->td_proc; 2368 register struct vnode *vp; 2369 register struct ucred *cred = td->td_ucred; 2370 struct flock lf; 2371 struct nameidata nd; 2372 struct vattr vattr; 2373 int error, error1, flags; 2374 struct mount *mp; 2375 char *name; /* name of corefile */ 2376 off_t limit; 2377 2378 PROC_LOCK(p); 2379 _STOPEVENT(p, S_CORE, 0); 2380 2381 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2382 PROC_UNLOCK(p); 2383 return (EFAULT); 2384 } 2385 2386 /* 2387 * Note that the bulk of limit checking is done after 2388 * the corefile is created. The exception is if the limit 2389 * for corefiles is 0, in which case we don't bother 2390 * creating the corefile at all. This layout means that 2391 * a corefile is truncated instead of not being created, 2392 * if it is larger than the limit. 2393 */ 2394 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2395 if (limit == 0) { 2396 PROC_UNLOCK(p); 2397 return 0; 2398 } 2399 PROC_UNLOCK(p); 2400 2401 restart: 2402 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2403 if (name == NULL) 2404 return (EINVAL); 2405 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2406 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2407 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); 2408 free(name, M_TEMP); 2409 if (error) 2410 return (error); 2411 NDFREE(&nd, NDF_ONLY_PNBUF); 2412 vp = nd.ni_vp; 2413 2414 /* Don't dump to non-regular files or files with links. */ 2415 if (vp->v_type != VREG || 2416 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2417 VOP_UNLOCK(vp, 0, td); 2418 error = EFAULT; 2419 goto out2; 2420 } 2421 2422 VOP_UNLOCK(vp, 0, td); 2423 lf.l_whence = SEEK_SET; 2424 lf.l_start = 0; 2425 lf.l_len = 0; 2426 lf.l_type = F_WRLCK; 2427 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 2428 if (error) 2429 goto out2; 2430 2431 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2432 lf.l_type = F_UNLCK; 2433 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2434 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2435 return (error); 2436 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2437 return (error); 2438 goto restart; 2439 } 2440 2441 VATTR_NULL(&vattr); 2442 vattr.va_size = 0; 2443 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2444 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2445 VOP_SETATTR(vp, &vattr, cred, td); 2446 VOP_UNLOCK(vp, 0, td); 2447 PROC_LOCK(p); 2448 p->p_acflag |= ACORE; 2449 PROC_UNLOCK(p); 2450 2451 error = p->p_sysent->sv_coredump ? 2452 p->p_sysent->sv_coredump(td, vp, limit) : 2453 ENOSYS; 2454 2455 lf.l_type = F_UNLCK; 2456 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2457 vn_finished_write(mp); 2458 out2: 2459 error1 = vn_close(vp, FWRITE, cred, td); 2460 if (error == 0) 2461 error = error1; 2462 return (error); 2463 } 2464 2465 /* 2466 * Nonexistent system call-- signal process (may want to handle it). 2467 * Flag error in case process won't see signal immediately (blocked or ignored). 2468 */ 2469 #ifndef _SYS_SYSPROTO_H_ 2470 struct nosys_args { 2471 int dummy; 2472 }; 2473 #endif 2474 /* 2475 * MPSAFE 2476 */ 2477 /* ARGSUSED */ 2478 int 2479 nosys(td, args) 2480 struct thread *td; 2481 struct nosys_args *args; 2482 { 2483 struct proc *p = td->td_proc; 2484 2485 PROC_LOCK(p); 2486 psignal(p, SIGSYS); 2487 PROC_UNLOCK(p); 2488 return (ENOSYS); 2489 } 2490 2491 /* 2492 * Send a SIGIO or SIGURG signal to a process or process group using 2493 * stored credentials rather than those of the current process. 2494 */ 2495 void 2496 pgsigio(sigiop, sig, checkctty) 2497 struct sigio **sigiop; 2498 int sig, checkctty; 2499 { 2500 struct sigio *sigio; 2501 2502 SIGIO_LOCK(); 2503 sigio = *sigiop; 2504 if (sigio == NULL) { 2505 SIGIO_UNLOCK(); 2506 return; 2507 } 2508 if (sigio->sio_pgid > 0) { 2509 PROC_LOCK(sigio->sio_proc); 2510 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2511 psignal(sigio->sio_proc, sig); 2512 PROC_UNLOCK(sigio->sio_proc); 2513 } else if (sigio->sio_pgid < 0) { 2514 struct proc *p; 2515 2516 PGRP_LOCK(sigio->sio_pgrp); 2517 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2518 PROC_LOCK(p); 2519 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2520 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2521 psignal(p, sig); 2522 PROC_UNLOCK(p); 2523 } 2524 PGRP_UNLOCK(sigio->sio_pgrp); 2525 } 2526 SIGIO_UNLOCK(); 2527 } 2528 2529 static int 2530 filt_sigattach(struct knote *kn) 2531 { 2532 struct proc *p = curproc; 2533 2534 kn->kn_ptr.p_proc = p; 2535 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2536 2537 PROC_LOCK(p); 2538 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2539 PROC_UNLOCK(p); 2540 2541 return (0); 2542 } 2543 2544 static void 2545 filt_sigdetach(struct knote *kn) 2546 { 2547 struct proc *p = kn->kn_ptr.p_proc; 2548 2549 PROC_LOCK(p); 2550 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2551 PROC_UNLOCK(p); 2552 } 2553 2554 /* 2555 * signal knotes are shared with proc knotes, so we apply a mask to 2556 * the hint in order to differentiate them from process hints. This 2557 * could be avoided by using a signal-specific knote list, but probably 2558 * isn't worth the trouble. 2559 */ 2560 static int 2561 filt_signal(struct knote *kn, long hint) 2562 { 2563 2564 if (hint & NOTE_SIGNAL) { 2565 hint &= ~NOTE_SIGNAL; 2566 2567 if (kn->kn_id == hint) 2568 kn->kn_data++; 2569 } 2570 return (kn->kn_data != 0); 2571 } 2572 2573 struct sigacts * 2574 sigacts_alloc(void) 2575 { 2576 struct sigacts *ps; 2577 2578 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 2579 ps->ps_refcnt = 1; 2580 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 2581 return (ps); 2582 } 2583 2584 void 2585 sigacts_free(struct sigacts *ps) 2586 { 2587 2588 mtx_lock(&ps->ps_mtx); 2589 ps->ps_refcnt--; 2590 if (ps->ps_refcnt == 0) { 2591 mtx_destroy(&ps->ps_mtx); 2592 free(ps, M_SUBPROC); 2593 } else 2594 mtx_unlock(&ps->ps_mtx); 2595 } 2596 2597 struct sigacts * 2598 sigacts_hold(struct sigacts *ps) 2599 { 2600 mtx_lock(&ps->ps_mtx); 2601 ps->ps_refcnt++; 2602 mtx_unlock(&ps->ps_mtx); 2603 return (ps); 2604 } 2605 2606 void 2607 sigacts_copy(struct sigacts *dest, struct sigacts *src) 2608 { 2609 2610 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 2611 mtx_lock(&src->ps_mtx); 2612 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 2613 mtx_unlock(&src->ps_mtx); 2614 } 2615 2616 int 2617 sigacts_shared(struct sigacts *ps) 2618 { 2619 int shared; 2620 2621 mtx_lock(&ps->ps_mtx); 2622 shared = ps->ps_refcnt > 1; 2623 mtx_unlock(&ps->ps_mtx); 2624 return (shared); 2625 } 2626