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 * $FreeBSD$ 40 */ 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/sysproto.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/namei.h> 51 #include <sys/vnode.h> 52 #include <sys/event.h> 53 #include <sys/proc.h> 54 #include <sys/pioctl.h> 55 #include <sys/acct.h> 56 #include <sys/fcntl.h> 57 #include <sys/condvar.h> 58 #include <sys/lock.h> 59 #include <sys/mutex.h> 60 #include <sys/wait.h> 61 #include <sys/ktr.h> 62 #include <sys/ktrace.h> 63 #include <sys/resourcevar.h> 64 #include <sys/smp.h> 65 #include <sys/stat.h> 66 #include <sys/sx.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/syslog.h> 69 #include <sys/sysent.h> 70 #include <sys/sysctl.h> 71 #include <sys/malloc.h> 72 #include <sys/unistd.h> 73 74 #include <machine/cpu.h> 75 76 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 77 78 static int coredump(struct thread *); 79 static int do_sigprocmask(struct proc *p, int how, sigset_t *set, 80 sigset_t *oset, int old); 81 static char *expand_name(const char *, uid_t, pid_t); 82 static int killpg1(struct thread *td, int sig, int pgid, int all); 83 static int sig_ffs(sigset_t *set); 84 static int sigprop(int sig); 85 static void stop(struct proc *); 86 static void tdsignal(struct thread *td, int sig, sig_t action); 87 static int filt_sigattach(struct knote *kn); 88 static void filt_sigdetach(struct knote *kn); 89 static int filt_signal(struct knote *kn, long hint); 90 91 struct filterops sig_filtops = 92 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 93 94 static int kern_logsigexit = 1; 95 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 96 &kern_logsigexit, 0, 97 "Log processes quitting on abnormal signals to syslog(3)"); 98 99 /* 100 * Policy -- Can ucred cr1 send SIGIO to process cr2? 101 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 102 * in the right situations. 103 */ 104 #define CANSIGIO(cr1, cr2) \ 105 ((cr1)->cr_uid == 0 || \ 106 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 107 (cr1)->cr_uid == (cr2)->cr_ruid || \ 108 (cr1)->cr_ruid == (cr2)->cr_uid || \ 109 (cr1)->cr_uid == (cr2)->cr_uid) 110 111 int sugid_coredump; 112 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 113 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 114 115 static int do_coredump = 1; 116 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 117 &do_coredump, 0, "Enable/Disable coredumps"); 118 119 /* 120 * Signal properties and actions. 121 * The array below categorizes the signals and their default actions 122 * according to the following properties: 123 */ 124 #define SA_KILL 0x01 /* terminates process by default */ 125 #define SA_CORE 0x02 /* ditto and coredumps */ 126 #define SA_STOP 0x04 /* suspend process */ 127 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 128 #define SA_IGNORE 0x10 /* ignore by default */ 129 #define SA_CONT 0x20 /* continue if suspended */ 130 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 131 132 static int sigproptbl[NSIG] = { 133 SA_KILL, /* SIGHUP */ 134 SA_KILL, /* SIGINT */ 135 SA_KILL|SA_CORE, /* SIGQUIT */ 136 SA_KILL|SA_CORE, /* SIGILL */ 137 SA_KILL|SA_CORE, /* SIGTRAP */ 138 SA_KILL|SA_CORE, /* SIGABRT */ 139 SA_KILL|SA_CORE, /* SIGEMT */ 140 SA_KILL|SA_CORE, /* SIGFPE */ 141 SA_KILL, /* SIGKILL */ 142 SA_KILL|SA_CORE, /* SIGBUS */ 143 SA_KILL|SA_CORE, /* SIGSEGV */ 144 SA_KILL|SA_CORE, /* SIGSYS */ 145 SA_KILL, /* SIGPIPE */ 146 SA_KILL, /* SIGALRM */ 147 SA_KILL, /* SIGTERM */ 148 SA_IGNORE, /* SIGURG */ 149 SA_STOP, /* SIGSTOP */ 150 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 151 SA_IGNORE|SA_CONT, /* SIGCONT */ 152 SA_IGNORE, /* SIGCHLD */ 153 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 154 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 155 SA_IGNORE, /* SIGIO */ 156 SA_KILL, /* SIGXCPU */ 157 SA_KILL, /* SIGXFSZ */ 158 SA_KILL, /* SIGVTALRM */ 159 SA_KILL, /* SIGPROF */ 160 SA_IGNORE, /* SIGWINCH */ 161 SA_IGNORE, /* SIGINFO */ 162 SA_KILL, /* SIGUSR1 */ 163 SA_KILL, /* SIGUSR2 */ 164 }; 165 166 /* 167 * Determine signal that should be delivered to process p, the current 168 * process, 0 if none. If there is a pending stop signal with default 169 * action, the process stops in issignal(). 170 * XXXKSE the check for a pending stop is not done under KSE 171 * 172 * MP SAFE. 173 */ 174 int 175 cursig(struct thread *td) 176 { 177 struct proc *p = td->td_proc; 178 179 PROC_LOCK_ASSERT(p, MA_OWNED); 180 mtx_assert(&sched_lock, MA_NOTOWNED); 181 return (SIGPENDING(p) ? issignal(td) : 0); 182 } 183 184 /* 185 * Arrange for ast() to handle unmasked pending signals on return to user 186 * mode. This must be called whenever a signal is added to p_siglist or 187 * unmasked in p_sigmask. 188 */ 189 void 190 signotify(struct proc *p) 191 { 192 struct kse *ke; 193 struct ksegrp *kg; 194 195 PROC_LOCK_ASSERT(p, MA_OWNED); 196 mtx_lock_spin(&sched_lock); 197 if (SIGPENDING(p)) { 198 p->p_sflag |= PS_NEEDSIGCHK; 199 /* XXXKSE for now punish all KSEs */ 200 FOREACH_KSEGRP_IN_PROC(p, kg) { 201 FOREACH_KSE_IN_GROUP(kg, ke) { 202 ke->ke_flags |= KEF_ASTPENDING; 203 } 204 } 205 } 206 mtx_unlock_spin(&sched_lock); 207 } 208 209 static __inline int 210 sigprop(int sig) 211 { 212 213 if (sig > 0 && sig < NSIG) 214 return (sigproptbl[_SIG_IDX(sig)]); 215 return (0); 216 } 217 218 static __inline int 219 sig_ffs(sigset_t *set) 220 { 221 int i; 222 223 for (i = 0; i < _SIG_WORDS; i++) 224 if (set->__bits[i]) 225 return (ffs(set->__bits[i]) + (i * 32)); 226 return (0); 227 } 228 229 /* 230 * kern_sigaction 231 * sigaction 232 * osigaction 233 */ 234 int 235 kern_sigaction(td, sig, act, oact, old) 236 struct thread *td; 237 register int sig; 238 struct sigaction *act, *oact; 239 int old; 240 { 241 register struct sigacts *ps; 242 struct proc *p = td->td_proc; 243 244 if (!_SIG_VALID(sig)) 245 return (EINVAL); 246 247 PROC_LOCK(p); 248 ps = p->p_sigacts; 249 if (oact) { 250 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 251 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 252 oact->sa_flags = 0; 253 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 254 oact->sa_flags |= SA_ONSTACK; 255 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 256 oact->sa_flags |= SA_RESTART; 257 if (SIGISMEMBER(ps->ps_sigreset, sig)) 258 oact->sa_flags |= SA_RESETHAND; 259 if (SIGISMEMBER(ps->ps_signodefer, sig)) 260 oact->sa_flags |= SA_NODEFER; 261 if (SIGISMEMBER(ps->ps_siginfo, sig)) 262 oact->sa_flags |= SA_SIGINFO; 263 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 264 oact->sa_flags |= SA_NOCLDSTOP; 265 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 266 oact->sa_flags |= SA_NOCLDWAIT; 267 } 268 if (act) { 269 if ((sig == SIGKILL || sig == SIGSTOP) && 270 act->sa_handler != SIG_DFL) { 271 PROC_UNLOCK(p); 272 return (EINVAL); 273 } 274 275 /* 276 * Change setting atomically. 277 */ 278 279 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 280 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 281 if (act->sa_flags & SA_SIGINFO) { 282 ps->ps_sigact[_SIG_IDX(sig)] = 283 (__sighandler_t *)act->sa_sigaction; 284 SIGADDSET(ps->ps_siginfo, sig); 285 } else { 286 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 287 SIGDELSET(ps->ps_siginfo, sig); 288 } 289 if (!(act->sa_flags & SA_RESTART)) 290 SIGADDSET(ps->ps_sigintr, sig); 291 else 292 SIGDELSET(ps->ps_sigintr, sig); 293 if (act->sa_flags & SA_ONSTACK) 294 SIGADDSET(ps->ps_sigonstack, sig); 295 else 296 SIGDELSET(ps->ps_sigonstack, sig); 297 if (act->sa_flags & SA_RESETHAND) 298 SIGADDSET(ps->ps_sigreset, sig); 299 else 300 SIGDELSET(ps->ps_sigreset, sig); 301 if (act->sa_flags & SA_NODEFER) 302 SIGADDSET(ps->ps_signodefer, sig); 303 else 304 SIGDELSET(ps->ps_signodefer, sig); 305 #ifdef COMPAT_SUNOS 306 if (act->sa_flags & SA_USERTRAMP) 307 SIGADDSET(ps->ps_usertramp, sig); 308 else 309 SIGDELSET(ps->ps_usertramp, sig); 310 #endif 311 if (sig == SIGCHLD) { 312 if (act->sa_flags & SA_NOCLDSTOP) 313 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 314 else 315 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 316 if (act->sa_flags & SA_NOCLDWAIT) { 317 /* 318 * Paranoia: since SA_NOCLDWAIT is implemented 319 * by reparenting the dying child to PID 1 (and 320 * trust it to reap the zombie), PID 1 itself 321 * is forbidden to set SA_NOCLDWAIT. 322 */ 323 if (p->p_pid == 1) 324 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 325 else 326 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 327 } else 328 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 329 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 330 p->p_procsig->ps_flag |= PS_CLDSIGIGN; 331 else 332 p->p_procsig->ps_flag &= ~PS_CLDSIGIGN; 333 } 334 /* 335 * Set bit in p_sigignore for signals that are set to SIG_IGN, 336 * and for signals set to SIG_DFL where the default is to 337 * ignore. However, don't put SIGCONT in p_sigignore, as we 338 * have to restart the process. 339 */ 340 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 341 (sigprop(sig) & SA_IGNORE && 342 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 343 /* never to be seen again */ 344 SIGDELSET(p->p_siglist, sig); 345 if (sig != SIGCONT) 346 /* easier in psignal */ 347 SIGADDSET(p->p_sigignore, sig); 348 SIGDELSET(p->p_sigcatch, sig); 349 } else { 350 SIGDELSET(p->p_sigignore, sig); 351 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 352 SIGDELSET(p->p_sigcatch, sig); 353 else 354 SIGADDSET(p->p_sigcatch, sig); 355 } 356 #ifdef COMPAT_43 357 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 358 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) 359 SIGDELSET(ps->ps_osigset, sig); 360 else 361 SIGADDSET(ps->ps_osigset, sig); 362 #endif 363 } 364 PROC_UNLOCK(p); 365 return (0); 366 } 367 368 #ifndef _SYS_SYSPROTO_H_ 369 struct sigaction_args { 370 int sig; 371 struct sigaction *act; 372 struct sigaction *oact; 373 }; 374 #endif 375 /* 376 * MPSAFE 377 */ 378 /* ARGSUSED */ 379 int 380 sigaction(td, uap) 381 struct thread *td; 382 register struct sigaction_args *uap; 383 { 384 struct sigaction act, oact; 385 register struct sigaction *actp, *oactp; 386 int error; 387 388 mtx_lock(&Giant); 389 390 actp = (uap->act != NULL) ? &act : NULL; 391 oactp = (uap->oact != NULL) ? &oact : NULL; 392 if (actp) { 393 error = copyin(uap->act, actp, sizeof(act)); 394 if (error) 395 goto done2; 396 } 397 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 398 if (oactp && !error) { 399 error = copyout(oactp, uap->oact, sizeof(oact)); 400 } 401 done2: 402 mtx_unlock(&Giant); 403 return (error); 404 } 405 406 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 407 #ifndef _SYS_SYSPROTO_H_ 408 struct osigaction_args { 409 int signum; 410 struct osigaction *nsa; 411 struct osigaction *osa; 412 }; 413 #endif 414 /* 415 * MPSAFE 416 */ 417 /* ARGSUSED */ 418 int 419 osigaction(td, uap) 420 struct thread *td; 421 register struct osigaction_args *uap; 422 { 423 struct osigaction sa; 424 struct sigaction nsa, osa; 425 register struct sigaction *nsap, *osap; 426 int error; 427 428 if (uap->signum <= 0 || uap->signum >= ONSIG) 429 return (EINVAL); 430 431 nsap = (uap->nsa != NULL) ? &nsa : NULL; 432 osap = (uap->osa != NULL) ? &osa : NULL; 433 434 mtx_lock(&Giant); 435 436 if (nsap) { 437 error = copyin(uap->nsa, &sa, sizeof(sa)); 438 if (error) 439 goto done2; 440 nsap->sa_handler = sa.sa_handler; 441 nsap->sa_flags = sa.sa_flags; 442 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 443 } 444 error = kern_sigaction(td, uap->signum, nsap, osap, 1); 445 if (osap && !error) { 446 sa.sa_handler = osap->sa_handler; 447 sa.sa_flags = osap->sa_flags; 448 SIG2OSIG(osap->sa_mask, sa.sa_mask); 449 error = copyout(&sa, uap->osa, sizeof(sa)); 450 } 451 done2: 452 mtx_unlock(&Giant); 453 return (error); 454 } 455 #endif /* COMPAT_43 */ 456 457 /* 458 * Initialize signal state for process 0; 459 * set to ignore signals that are ignored by default. 460 */ 461 void 462 siginit(p) 463 struct proc *p; 464 { 465 register int i; 466 467 PROC_LOCK(p); 468 for (i = 1; i <= NSIG; i++) 469 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 470 SIGADDSET(p->p_sigignore, i); 471 PROC_UNLOCK(p); 472 } 473 474 /* 475 * Reset signals for an exec of the specified process. 476 */ 477 void 478 execsigs(p) 479 register struct proc *p; 480 { 481 register struct sigacts *ps; 482 register int sig; 483 484 /* 485 * Reset caught signals. Held signals remain held 486 * through p_sigmask (unless they were caught, 487 * and are now ignored by default). 488 */ 489 PROC_LOCK_ASSERT(p, MA_OWNED); 490 ps = p->p_sigacts; 491 while (SIGNOTEMPTY(p->p_sigcatch)) { 492 sig = sig_ffs(&p->p_sigcatch); 493 SIGDELSET(p->p_sigcatch, sig); 494 if (sigprop(sig) & SA_IGNORE) { 495 if (sig != SIGCONT) 496 SIGADDSET(p->p_sigignore, sig); 497 SIGDELSET(p->p_siglist, sig); 498 } 499 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 500 } 501 /* 502 * Reset stack state to the user stack. 503 * Clear set of signals caught on the signal stack. 504 */ 505 p->p_sigstk.ss_flags = SS_DISABLE; 506 p->p_sigstk.ss_size = 0; 507 p->p_sigstk.ss_sp = 0; 508 p->p_flag &= ~P_ALTSTACK; 509 /* 510 * Reset no zombies if child dies flag as Solaris does. 511 */ 512 p->p_procsig->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 513 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 514 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 515 } 516 517 /* 518 * do_sigprocmask() 519 * 520 * Manipulate signal mask. 521 */ 522 static int 523 do_sigprocmask(p, how, set, oset, old) 524 struct proc *p; 525 int how; 526 sigset_t *set, *oset; 527 int old; 528 { 529 int error; 530 531 PROC_LOCK(p); 532 if (oset != NULL) 533 *oset = p->p_sigmask; 534 535 error = 0; 536 if (set != NULL) { 537 switch (how) { 538 case SIG_BLOCK: 539 SIG_CANTMASK(*set); 540 SIGSETOR(p->p_sigmask, *set); 541 break; 542 case SIG_UNBLOCK: 543 SIGSETNAND(p->p_sigmask, *set); 544 signotify(p); 545 break; 546 case SIG_SETMASK: 547 SIG_CANTMASK(*set); 548 if (old) 549 SIGSETLO(p->p_sigmask, *set); 550 else 551 p->p_sigmask = *set; 552 signotify(p); 553 break; 554 default: 555 error = EINVAL; 556 break; 557 } 558 } 559 PROC_UNLOCK(p); 560 return (error); 561 } 562 563 /* 564 * sigprocmask() - MP SAFE (XXXKSE not under KSE it isn't) 565 */ 566 567 #ifndef _SYS_SYSPROTO_H_ 568 struct sigprocmask_args { 569 int how; 570 const sigset_t *set; 571 sigset_t *oset; 572 }; 573 #endif 574 int 575 sigprocmask(td, uap) 576 register struct thread *td; 577 struct sigprocmask_args *uap; 578 { 579 struct proc *p = td->td_proc; 580 sigset_t set, oset; 581 sigset_t *setp, *osetp; 582 int error; 583 584 setp = (uap->set != NULL) ? &set : NULL; 585 osetp = (uap->oset != NULL) ? &oset : NULL; 586 if (setp) { 587 error = copyin(uap->set, setp, sizeof(set)); 588 if (error) 589 return (error); 590 } 591 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 592 if (osetp && !error) { 593 error = copyout(osetp, uap->oset, sizeof(oset)); 594 } 595 return (error); 596 } 597 598 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 599 /* 600 * osigprocmask() - MP SAFE 601 */ 602 #ifndef _SYS_SYSPROTO_H_ 603 struct osigprocmask_args { 604 int how; 605 osigset_t mask; 606 }; 607 #endif 608 int 609 osigprocmask(td, uap) 610 register struct thread *td; 611 struct osigprocmask_args *uap; 612 { 613 struct proc *p = td->td_proc; 614 sigset_t set, oset; 615 int error; 616 617 OSIG2SIG(uap->mask, set); 618 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 619 SIG2OSIG(oset, td->td_retval[0]); 620 return (error); 621 } 622 #endif /* COMPAT_43 */ 623 624 #ifndef _SYS_SYSPROTO_H_ 625 struct sigpending_args { 626 sigset_t *set; 627 }; 628 #endif 629 /* 630 * MPSAFE 631 */ 632 /* ARGSUSED */ 633 int 634 sigpending(td, uap) 635 struct thread *td; 636 struct sigpending_args *uap; 637 { 638 struct proc *p = td->td_proc; 639 sigset_t siglist; 640 int error; 641 642 mtx_lock(&Giant); 643 PROC_LOCK(p); 644 siglist = p->p_siglist; 645 PROC_UNLOCK(p); 646 mtx_unlock(&Giant); 647 error = copyout(&siglist, uap->set, sizeof(sigset_t)); 648 return(error); 649 } 650 651 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 652 #ifndef _SYS_SYSPROTO_H_ 653 struct osigpending_args { 654 int dummy; 655 }; 656 #endif 657 /* 658 * MPSAFE 659 */ 660 /* ARGSUSED */ 661 int 662 osigpending(td, uap) 663 struct thread *td; 664 struct osigpending_args *uap; 665 { 666 struct proc *p = td->td_proc; 667 668 mtx_lock(&Giant); 669 PROC_LOCK(p); 670 SIG2OSIG(p->p_siglist, td->td_retval[0]); 671 PROC_UNLOCK(p); 672 mtx_unlock(&Giant); 673 return (0); 674 } 675 #endif /* COMPAT_43 */ 676 677 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 678 /* 679 * Generalized interface signal handler, 4.3-compatible. 680 */ 681 #ifndef _SYS_SYSPROTO_H_ 682 struct osigvec_args { 683 int signum; 684 struct sigvec *nsv; 685 struct sigvec *osv; 686 }; 687 #endif 688 /* 689 * MPSAFE 690 */ 691 /* ARGSUSED */ 692 int 693 osigvec(td, uap) 694 struct thread *td; 695 register struct osigvec_args *uap; 696 { 697 struct sigvec vec; 698 struct sigaction nsa, osa; 699 register struct sigaction *nsap, *osap; 700 int error; 701 702 if (uap->signum <= 0 || uap->signum >= ONSIG) 703 return (EINVAL); 704 nsap = (uap->nsv != NULL) ? &nsa : NULL; 705 osap = (uap->osv != NULL) ? &osa : NULL; 706 if (nsap) { 707 error = copyin(uap->nsv, &vec, sizeof(vec)); 708 if (error) 709 return (error); 710 nsap->sa_handler = vec.sv_handler; 711 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 712 nsap->sa_flags = vec.sv_flags; 713 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 714 #ifdef COMPAT_SUNOS 715 nsap->sa_flags |= SA_USERTRAMP; 716 #endif 717 } 718 mtx_lock(&Giant); 719 error = kern_sigaction(td, uap->signum, nsap, osap, 1); 720 mtx_unlock(&Giant); 721 if (osap && !error) { 722 vec.sv_handler = osap->sa_handler; 723 SIG2OSIG(osap->sa_mask, vec.sv_mask); 724 vec.sv_flags = osap->sa_flags; 725 vec.sv_flags &= ~SA_NOCLDWAIT; 726 vec.sv_flags ^= SA_RESTART; 727 #ifdef COMPAT_SUNOS 728 vec.sv_flags &= ~SA_NOCLDSTOP; 729 #endif 730 error = copyout(&vec, uap->osv, sizeof(vec)); 731 } 732 return (error); 733 } 734 735 #ifndef _SYS_SYSPROTO_H_ 736 struct osigblock_args { 737 int mask; 738 }; 739 #endif 740 /* 741 * MPSAFE 742 */ 743 int 744 osigblock(td, uap) 745 register struct thread *td; 746 struct osigblock_args *uap; 747 { 748 struct proc *p = td->td_proc; 749 sigset_t set; 750 751 OSIG2SIG(uap->mask, set); 752 SIG_CANTMASK(set); 753 mtx_lock(&Giant); 754 PROC_LOCK(p); 755 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 756 SIGSETOR(p->p_sigmask, set); 757 PROC_UNLOCK(p); 758 mtx_unlock(&Giant); 759 return (0); 760 } 761 762 #ifndef _SYS_SYSPROTO_H_ 763 struct osigsetmask_args { 764 int mask; 765 }; 766 #endif 767 /* 768 * MPSAFE 769 */ 770 int 771 osigsetmask(td, uap) 772 struct thread *td; 773 struct osigsetmask_args *uap; 774 { 775 struct proc *p = td->td_proc; 776 sigset_t set; 777 778 OSIG2SIG(uap->mask, set); 779 SIG_CANTMASK(set); 780 mtx_lock(&Giant); 781 PROC_LOCK(p); 782 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 783 SIGSETLO(p->p_sigmask, set); 784 signotify(p); 785 PROC_UNLOCK(p); 786 mtx_unlock(&Giant); 787 return (0); 788 } 789 #endif /* COMPAT_43 || COMPAT_SUNOS */ 790 791 /* 792 * Suspend process until signal, providing mask to be set 793 * in the meantime. Note nonstandard calling convention: 794 * libc stub passes mask, not pointer, to save a copyin. 795 ***** XXXKSE this doesn't make sense under KSE. 796 ***** Do we suspend the thread or all threads in the process? 797 ***** How do we suspend threads running NOW on another processor? 798 */ 799 #ifndef _SYS_SYSPROTO_H_ 800 struct sigsuspend_args { 801 const sigset_t *sigmask; 802 }; 803 #endif 804 /* 805 * MPSAFE 806 */ 807 /* ARGSUSED */ 808 int 809 sigsuspend(td, uap) 810 struct thread *td; 811 struct sigsuspend_args *uap; 812 { 813 sigset_t mask; 814 int error; 815 816 error = copyin(uap->sigmask, &mask, sizeof(mask)); 817 if (error) 818 return (error); 819 return (kern_sigsuspend(td, mask)); 820 } 821 822 int 823 kern_sigsuspend(struct thread *td, sigset_t mask) 824 { 825 struct proc *p = td->td_proc; 826 register struct sigacts *ps; 827 828 /* 829 * When returning from sigsuspend, we want 830 * the old mask to be restored after the 831 * signal handler has finished. Thus, we 832 * save it here and mark the sigacts structure 833 * to indicate this. 834 */ 835 mtx_lock(&Giant); 836 PROC_LOCK(p); 837 ps = p->p_sigacts; 838 p->p_oldsigmask = p->p_sigmask; 839 p->p_flag |= P_OLDMASK; 840 841 SIG_CANTMASK(mask); 842 p->p_sigmask = mask; 843 signotify(p); 844 while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 845 /* void */; 846 PROC_UNLOCK(p); 847 mtx_unlock(&Giant); 848 /* always return EINTR rather than ERESTART... */ 849 return (EINTR); 850 } 851 852 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 853 #ifndef _SYS_SYSPROTO_H_ 854 struct osigsuspend_args { 855 osigset_t mask; 856 }; 857 #endif 858 /* 859 * MPSAFE 860 */ 861 /* ARGSUSED */ 862 int 863 osigsuspend(td, uap) 864 struct thread *td; 865 struct osigsuspend_args *uap; 866 { 867 struct proc *p = td->td_proc; 868 sigset_t mask; 869 register struct sigacts *ps; 870 871 mtx_lock(&Giant); 872 PROC_LOCK(p); 873 ps = p->p_sigacts; 874 p->p_oldsigmask = p->p_sigmask; 875 p->p_flag |= P_OLDMASK; 876 OSIG2SIG(uap->mask, mask); 877 SIG_CANTMASK(mask); 878 SIGSETLO(p->p_sigmask, mask); 879 signotify(p); 880 while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 881 /* void */; 882 PROC_UNLOCK(p); 883 mtx_unlock(&Giant); 884 /* always return EINTR rather than ERESTART... */ 885 return (EINTR); 886 } 887 #endif /* COMPAT_43 */ 888 889 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 890 #ifndef _SYS_SYSPROTO_H_ 891 struct osigstack_args { 892 struct sigstack *nss; 893 struct sigstack *oss; 894 }; 895 #endif 896 /* 897 * MPSAFE 898 */ 899 /* ARGSUSED */ 900 int 901 osigstack(td, uap) 902 struct thread *td; 903 register struct osigstack_args *uap; 904 { 905 struct proc *p = td->td_proc; 906 struct sigstack ss; 907 int error = 0; 908 909 mtx_lock(&Giant); 910 911 if (uap->oss != NULL) { 912 PROC_LOCK(p); 913 ss.ss_sp = p->p_sigstk.ss_sp; 914 ss.ss_onstack = sigonstack(cpu_getstack(td)); 915 PROC_UNLOCK(p); 916 error = copyout(&ss, uap->oss, sizeof(struct sigstack)); 917 if (error) 918 goto done2; 919 } 920 921 if (uap->nss != NULL) { 922 if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0) 923 goto done2; 924 PROC_LOCK(p); 925 p->p_sigstk.ss_sp = ss.ss_sp; 926 p->p_sigstk.ss_size = 0; 927 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 928 p->p_flag |= P_ALTSTACK; 929 PROC_UNLOCK(p); 930 } 931 done2: 932 mtx_unlock(&Giant); 933 return (error); 934 } 935 #endif /* COMPAT_43 || COMPAT_SUNOS */ 936 937 #ifndef _SYS_SYSPROTO_H_ 938 struct sigaltstack_args { 939 stack_t *ss; 940 stack_t *oss; 941 }; 942 #endif 943 /* 944 * MPSAFE 945 */ 946 /* ARGSUSED */ 947 int 948 sigaltstack(td, uap) 949 struct thread *td; 950 register struct sigaltstack_args *uap; 951 { 952 stack_t ss, oss; 953 int error; 954 955 if (uap->ss != NULL) { 956 error = copyin(uap->ss, &ss, sizeof(ss)); 957 if (error) 958 return (error); 959 } 960 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 961 (uap->oss != NULL) ? &oss : NULL); 962 if (error) 963 return (error); 964 if (uap->oss != NULL) 965 error = copyout(&oss, uap->oss, sizeof(stack_t)); 966 return (error); 967 } 968 969 int 970 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 971 { 972 struct proc *p = td->td_proc; 973 int oonstack; 974 int error = 0; 975 976 mtx_lock(&Giant); 977 978 oonstack = sigonstack(cpu_getstack(td)); 979 980 if (oss != NULL) { 981 PROC_LOCK(p); 982 *oss = p->p_sigstk; 983 oss->ss_flags = (p->p_flag & P_ALTSTACK) 984 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 985 PROC_UNLOCK(p); 986 } 987 988 if (ss != NULL) { 989 if (oonstack) { 990 error = EPERM; 991 goto done2; 992 } 993 if ((ss->ss_flags & ~SS_DISABLE) != 0) { 994 error = EINVAL; 995 goto done2; 996 } 997 if (!(ss->ss_flags & SS_DISABLE)) { 998 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 999 error = ENOMEM; 1000 goto done2; 1001 } 1002 PROC_LOCK(p); 1003 p->p_sigstk = *ss; 1004 p->p_flag |= P_ALTSTACK; 1005 PROC_UNLOCK(p); 1006 } else { 1007 PROC_LOCK(p); 1008 p->p_flag &= ~P_ALTSTACK; 1009 PROC_UNLOCK(p); 1010 } 1011 } 1012 done2: 1013 mtx_unlock(&Giant); 1014 return (error); 1015 } 1016 1017 /* 1018 * Common code for kill process group/broadcast kill. 1019 * cp is calling process. 1020 */ 1021 static int 1022 killpg1(td, sig, pgid, all) 1023 register struct thread *td; 1024 int sig, pgid, all; 1025 { 1026 register struct proc *p; 1027 struct pgrp *pgrp; 1028 int nfound = 0; 1029 1030 if (all) { 1031 /* 1032 * broadcast 1033 */ 1034 sx_slock(&allproc_lock); 1035 LIST_FOREACH(p, &allproc, p_list) { 1036 PROC_LOCK(p); 1037 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1038 p == td->td_proc) { 1039 PROC_UNLOCK(p); 1040 continue; 1041 } 1042 if (p_cansignal(td, p, sig) == 0) { 1043 nfound++; 1044 if (sig) 1045 psignal(p, sig); 1046 } 1047 PROC_UNLOCK(p); 1048 } 1049 sx_sunlock(&allproc_lock); 1050 } else { 1051 sx_slock(&proctree_lock); 1052 if (pgid == 0) { 1053 /* 1054 * zero pgid means send to my process group. 1055 */ 1056 pgrp = td->td_proc->p_pgrp; 1057 PGRP_LOCK(pgrp); 1058 } else { 1059 pgrp = pgfind(pgid); 1060 if (pgrp == NULL) { 1061 sx_sunlock(&proctree_lock); 1062 return (ESRCH); 1063 } 1064 } 1065 sx_sunlock(&proctree_lock); 1066 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1067 PROC_LOCK(p); 1068 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1069 PROC_UNLOCK(p); 1070 continue; 1071 } 1072 if (p->p_state == PRS_ZOMBIE) { 1073 PROC_UNLOCK(p); 1074 continue; 1075 } 1076 if (p_cansignal(td, p, sig) == 0) { 1077 nfound++; 1078 if (sig) 1079 psignal(p, sig); 1080 } 1081 PROC_UNLOCK(p); 1082 } 1083 PGRP_UNLOCK(pgrp); 1084 } 1085 return (nfound ? 0 : ESRCH); 1086 } 1087 1088 #ifndef _SYS_SYSPROTO_H_ 1089 struct kill_args { 1090 int pid; 1091 int signum; 1092 }; 1093 #endif 1094 /* 1095 * MPSAFE 1096 */ 1097 /* ARGSUSED */ 1098 int 1099 kill(td, uap) 1100 register struct thread *td; 1101 register struct kill_args *uap; 1102 { 1103 register struct proc *p; 1104 int error = 0; 1105 1106 if ((u_int)uap->signum > _SIG_MAXSIG) 1107 return (EINVAL); 1108 1109 mtx_lock(&Giant); 1110 if (uap->pid > 0) { 1111 /* kill single process */ 1112 if ((p = pfind(uap->pid)) == NULL) { 1113 error = ESRCH; 1114 } else if ((error = p_cansignal(td, p, uap->signum)) != 0) { 1115 PROC_UNLOCK(p); 1116 } else { 1117 if (uap->signum) 1118 psignal(p, uap->signum); 1119 PROC_UNLOCK(p); 1120 error = 0; 1121 } 1122 } else { 1123 switch (uap->pid) { 1124 case -1: /* broadcast signal */ 1125 error = killpg1(td, uap->signum, 0, 1); 1126 break; 1127 case 0: /* signal own process group */ 1128 error = killpg1(td, uap->signum, 0, 0); 1129 break; 1130 default: /* negative explicit process group */ 1131 error = killpg1(td, uap->signum, -uap->pid, 0); 1132 break; 1133 } 1134 } 1135 mtx_unlock(&Giant); 1136 return(error); 1137 } 1138 1139 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1140 #ifndef _SYS_SYSPROTO_H_ 1141 struct okillpg_args { 1142 int pgid; 1143 int signum; 1144 }; 1145 #endif 1146 /* 1147 * MPSAFE 1148 */ 1149 /* ARGSUSED */ 1150 int 1151 okillpg(td, uap) 1152 struct thread *td; 1153 register struct okillpg_args *uap; 1154 { 1155 int error; 1156 1157 if ((u_int)uap->signum > _SIG_MAXSIG) 1158 return (EINVAL); 1159 mtx_lock(&Giant); 1160 error = killpg1(td, uap->signum, uap->pgid, 0); 1161 mtx_unlock(&Giant); 1162 return (error); 1163 } 1164 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1165 1166 /* 1167 * Send a signal to a process group. 1168 */ 1169 void 1170 gsignal(pgid, sig) 1171 int pgid, sig; 1172 { 1173 struct pgrp *pgrp; 1174 1175 if (pgid != 0) { 1176 sx_slock(&proctree_lock); 1177 pgrp = pgfind(pgid); 1178 sx_sunlock(&proctree_lock); 1179 if (pgrp != NULL) { 1180 pgsignal(pgrp, sig, 0); 1181 PGRP_UNLOCK(pgrp); 1182 } 1183 } 1184 } 1185 1186 /* 1187 * Send a signal to a process group. If checktty is 1, 1188 * limit to members which have a controlling terminal. 1189 */ 1190 void 1191 pgsignal(pgrp, sig, checkctty) 1192 struct pgrp *pgrp; 1193 int sig, checkctty; 1194 { 1195 register struct proc *p; 1196 1197 if (pgrp) { 1198 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1199 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1200 PROC_LOCK(p); 1201 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1202 psignal(p, sig); 1203 PROC_UNLOCK(p); 1204 } 1205 } 1206 } 1207 1208 /* 1209 * Send a signal caused by a trap to the current process. 1210 * If it will be caught immediately, deliver it with correct code. 1211 * Otherwise, post it normally. 1212 * 1213 * MPSAFE 1214 */ 1215 void 1216 trapsignal(p, sig, code) 1217 struct proc *p; 1218 register int sig; 1219 u_long code; 1220 { 1221 register struct sigacts *ps = p->p_sigacts; 1222 1223 PROC_LOCK(p); 1224 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 1225 !SIGISMEMBER(p->p_sigmask, sig)) { 1226 p->p_stats->p_ru.ru_nsignals++; 1227 #ifdef KTRACE 1228 if (KTRPOINT(curthread, KTR_PSIG)) 1229 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1230 &p->p_sigmask, code); 1231 #endif 1232 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 1233 &p->p_sigmask, code); 1234 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1235 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1236 SIGADDSET(p->p_sigmask, sig); 1237 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1238 /* 1239 * See kern_sigaction() for origin of this code. 1240 */ 1241 SIGDELSET(p->p_sigcatch, sig); 1242 if (sig != SIGCONT && 1243 sigprop(sig) & SA_IGNORE) 1244 SIGADDSET(p->p_sigignore, sig); 1245 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1246 } 1247 } else { 1248 p->p_code = code; /* XXX for core dump/debugger */ 1249 p->p_sig = sig; /* XXX to verify code */ 1250 psignal(p, sig); 1251 } 1252 PROC_UNLOCK(p); 1253 } 1254 1255 /* 1256 * Send the signal to the process. If the signal has an action, the action 1257 * is usually performed by the target process rather than the caller; we add 1258 * the signal to the set of pending signals for the process. 1259 * 1260 * Exceptions: 1261 * o When a stop signal is sent to a sleeping process that takes the 1262 * default action, the process is stopped without awakening it. 1263 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1264 * regardless of the signal action (eg, blocked or ignored). 1265 * 1266 * Other ignored signals are discarded immediately. 1267 */ 1268 void 1269 psignal(p, sig) 1270 register struct proc *p; 1271 register int sig; 1272 { 1273 register sig_t action; 1274 struct thread *td; 1275 register int prop; 1276 1277 1278 KASSERT(_SIG_VALID(sig), 1279 ("psignal(): invalid signal %d\n", sig)); 1280 1281 PROC_LOCK_ASSERT(p, MA_OWNED); 1282 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1283 1284 prop = sigprop(sig); 1285 /* 1286 * If proc is traced, always give parent a chance; 1287 * if signal event is tracked by procfs, give *that* 1288 * a chance, as well. 1289 */ 1290 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1291 action = SIG_DFL; 1292 } else { 1293 /* 1294 * If the signal is being ignored, 1295 * then we forget about it immediately. 1296 * (Note: we don't set SIGCONT in p_sigignore, 1297 * and if it is set to SIG_IGN, 1298 * action will be SIG_DFL here.) 1299 */ 1300 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1301 return; 1302 if (SIGISMEMBER(p->p_sigmask, sig)) 1303 action = SIG_HOLD; 1304 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1305 action = SIG_CATCH; 1306 else 1307 action = SIG_DFL; 1308 } 1309 1310 if (prop & SA_CONT) 1311 SIG_STOPSIGMASK(p->p_siglist); 1312 1313 if (prop & SA_STOP) { 1314 /* 1315 * If sending a tty stop signal to a member of an orphaned 1316 * process group, discard the signal here if the action 1317 * is default; don't stop the process below if sleeping, 1318 * and don't clear any pending SIGCONT. 1319 */ 1320 if ((prop & SA_TTYSTOP) && 1321 (p->p_pgrp->pg_jobc == 0) && 1322 (action == SIG_DFL)) 1323 return; 1324 SIG_CONTSIGMASK(p->p_siglist); 1325 p->p_flag &= ~P_CONTINUED; 1326 } 1327 SIGADDSET(p->p_siglist, sig); 1328 signotify(p); /* uses schedlock */ 1329 1330 /* 1331 * Some signals have a process-wide effect and a per-thread 1332 * component. Most processing occurs when the process next 1333 * tries to cross the user boundary, however there are some 1334 * times when processing needs to be done immediatly, such as 1335 * waking up threads so that they can cross the user boundary. 1336 * We try do the per-process part here. 1337 */ 1338 if (P_SHOULDSTOP(p)) { 1339 /* 1340 * The process is in stopped mode. All the threads should be 1341 * either winding down or already on the suspended queue. 1342 */ 1343 if (p->p_flag & P_TRACED) { 1344 /* 1345 * The traced process is already stopped, 1346 * so no further action is necessary. 1347 * No signal can restart us. 1348 */ 1349 goto out; 1350 } 1351 1352 if (sig == SIGKILL) { 1353 /* 1354 * SIGKILL sets process running. 1355 * It will die elsewhere. 1356 * All threads must be restarted. 1357 */ 1358 p->p_flag &= ~P_STOPPED; 1359 goto runfast; 1360 } 1361 1362 if (prop & SA_CONT) { 1363 /* 1364 * If SIGCONT is default (or ignored), we continue the 1365 * process but don't leave the signal in p_siglist as 1366 * it has no further action. If SIGCONT is held, we 1367 * continue the process and leave the signal in 1368 * p_siglist. If the process catches SIGCONT, let it 1369 * handle the signal itself. If it isn't waiting on 1370 * an event, it goes back to run state. 1371 * Otherwise, process goes back to sleep state. 1372 */ 1373 p->p_flag &= ~P_STOPPED_SIG; 1374 p->p_flag |= P_CONTINUED; 1375 if (action == SIG_DFL) { 1376 SIGDELSET(p->p_siglist, sig); 1377 } else if (action == SIG_CATCH) { 1378 /* 1379 * The process wants to catch it so it needs 1380 * to run at least one thread, but which one? 1381 * It would seem that the answer would be to 1382 * run an upcall in the next KSE to run, and 1383 * deliver the signal that way. In a NON KSE 1384 * process, we need to make sure that the 1385 * single thread is runnable asap. 1386 * XXXKSE for now however, make them all run. 1387 */ 1388 goto runfast; 1389 } 1390 /* 1391 * The signal is not ignored or caught. 1392 */ 1393 mtx_lock_spin(&sched_lock); 1394 thread_unsuspend(p); 1395 mtx_unlock_spin(&sched_lock); 1396 goto out; 1397 } 1398 1399 if (prop & SA_STOP) { 1400 /* 1401 * Already stopped, don't need to stop again 1402 * (If we did the shell could get confused). 1403 * Just make sure the signal STOP bit set. 1404 */ 1405 p->p_flag |= P_STOPPED_SIG; 1406 SIGDELSET(p->p_siglist, sig); 1407 goto out; 1408 } 1409 1410 /* 1411 * All other kinds of signals: 1412 * If a thread is sleeping interruptibly, simulate a 1413 * wakeup so that when it is continued it will be made 1414 * runnable and can look at the signal. However, don't make 1415 * the PROCESS runnable, leave it stopped. 1416 * It may run a bit until it hits a thread_suspend_check(). 1417 */ 1418 mtx_lock_spin(&sched_lock); 1419 FOREACH_THREAD_IN_PROC(p, td) { 1420 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) { 1421 if (td->td_flags & TDF_CVWAITQ) 1422 cv_abort(td); 1423 else 1424 abortsleep(td); 1425 } 1426 } 1427 mtx_unlock_spin(&sched_lock); 1428 goto out; 1429 /* 1430 * XXXKSE What about threads that are waiting on mutexes? 1431 * Shouldn't they abort too? 1432 * No, hopefully mutexes are short lived.. They'll 1433 * eventually hit thread_suspend_check(). 1434 */ 1435 } else if (p->p_state == PRS_NORMAL) { 1436 if (prop & SA_CONT) { 1437 /* 1438 * Already active, don't need to start again. 1439 */ 1440 SIGDELSET(p->p_siglist, sig); 1441 goto out; 1442 } 1443 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || 1444 !(prop & SA_STOP)) { 1445 mtx_lock_spin(&sched_lock); 1446 FOREACH_THREAD_IN_PROC(p, td) 1447 tdsignal(td, sig, action); 1448 mtx_unlock_spin(&sched_lock); 1449 goto out; 1450 } 1451 if (prop & SA_STOP) { 1452 if (p->p_flag & P_PPWAIT) 1453 goto out; 1454 mtx_lock_spin(&sched_lock); 1455 FOREACH_THREAD_IN_PROC(p, td) { 1456 if (TD_IS_SLEEPING(td) && 1457 (td->td_flags & TDF_SINTR)) 1458 thread_suspend_one(td); 1459 } 1460 if (p->p_suspcount == p->p_numthreads) { 1461 mtx_unlock_spin(&sched_lock); 1462 stop(p); 1463 p->p_xstat = sig; 1464 SIGDELSET(p->p_siglist, sig); 1465 PROC_LOCK(p->p_pptr); 1466 if ((p->p_pptr->p_procsig->ps_flag & 1467 PS_NOCLDSTOP) == 0) { 1468 psignal(p->p_pptr, SIGCHLD); 1469 } 1470 PROC_UNLOCK(p->p_pptr); 1471 } else { 1472 mtx_unlock_spin(&sched_lock); 1473 } 1474 goto out; 1475 } 1476 else 1477 goto runfast; 1478 /* NOTREACHED */ 1479 } else { 1480 /* Not in "NORMAL" state. discard the signal. */ 1481 SIGDELSET(p->p_siglist, sig); 1482 goto out; 1483 } 1484 1485 /* 1486 * The process is not stopped so we need to apply the signal to all the 1487 * running threads. 1488 */ 1489 1490 runfast: 1491 mtx_lock_spin(&sched_lock); 1492 FOREACH_THREAD_IN_PROC(p, td) 1493 tdsignal(td, sig, action); 1494 thread_unsuspend(p); 1495 mtx_unlock_spin(&sched_lock); 1496 out: 1497 /* If we jump here, sched_lock should not be owned. */ 1498 mtx_assert(&sched_lock, MA_NOTOWNED); 1499 } 1500 1501 /* 1502 * The force of a signal has been directed against a single 1503 * thread. We need to see what we can do about knocking it 1504 * out of any sleep it may be in etc. 1505 */ 1506 static void 1507 tdsignal(struct thread *td, int sig, sig_t action) 1508 { 1509 struct proc *p = td->td_proc; 1510 register int prop; 1511 1512 mtx_assert(&sched_lock, MA_OWNED); 1513 prop = sigprop(sig); 1514 /* 1515 * Bring the priority of a thread up if we want it to get 1516 * killed in this lifetime. 1517 */ 1518 if ((action == SIG_DFL) && (prop & SA_KILL)) { 1519 if (td->td_priority > PUSER) { 1520 td->td_priority = PUSER; 1521 } 1522 } 1523 1524 /* 1525 * Defer further processing for signals which are held, 1526 * except that stopped processes must be continued by SIGCONT. 1527 */ 1528 if (action == SIG_HOLD) { 1529 return; 1530 } 1531 if (TD_IS_SLEEPING(td)) { 1532 /* 1533 * If thread is sleeping uninterruptibly 1534 * we can't interrupt the sleep... the signal will 1535 * be noticed when the process returns through 1536 * trap() or syscall(). 1537 */ 1538 if ((td->td_flags & TDF_SINTR) == 0) { 1539 return; 1540 } 1541 /* 1542 * Process is sleeping and traced. Make it runnable 1543 * so it can discover the signal in issignal() and stop 1544 * for its parent. 1545 */ 1546 if (p->p_flag & P_TRACED) { 1547 p->p_flag &= ~P_STOPPED_TRACE; 1548 } else { 1549 1550 /* 1551 * If SIGCONT is default (or ignored) and process is 1552 * asleep, we are finished; the process should not 1553 * be awakened. 1554 */ 1555 if ((prop & SA_CONT) && action == SIG_DFL) { 1556 SIGDELSET(p->p_siglist, sig); 1557 return; 1558 } 1559 1560 /* 1561 * Raise priority to at least PUSER. 1562 */ 1563 if (td->td_priority > PUSER) { 1564 td->td_priority = PUSER; 1565 } 1566 } 1567 if (td->td_flags & TDF_CVWAITQ) 1568 cv_abort(td); 1569 else 1570 abortsleep(td); 1571 } 1572 #ifdef SMP 1573 else { 1574 /* 1575 * Other states do nothing with the signal immediatly, 1576 * other than kicking ourselves if we are running. 1577 * It will either never be noticed, or noticed very soon. 1578 */ 1579 if (TD_IS_RUNNING(td) && td != curthread) { 1580 forward_signal(td); 1581 } 1582 } 1583 #endif 1584 } 1585 1586 /* 1587 * If the current process has received a signal (should be caught or cause 1588 * termination, should interrupt current syscall), return the signal number. 1589 * Stop signals with default action are processed immediately, then cleared; 1590 * they aren't returned. This is checked after each entry to the system for 1591 * a syscall or trap (though this can usually be done without calling issignal 1592 * by checking the pending signal masks in cursig.) The normal call 1593 * sequence is 1594 * 1595 * while (sig = cursig(curthread)) 1596 * postsig(sig); 1597 */ 1598 int 1599 issignal(td) 1600 struct thread *td; 1601 { 1602 struct proc *p; 1603 sigset_t mask; 1604 register int sig, prop; 1605 1606 p = td->td_proc; 1607 PROC_LOCK_ASSERT(p, MA_OWNED); 1608 WITNESS_SLEEP(1, &p->p_mtx.mtx_object); 1609 for (;;) { 1610 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1611 1612 mask = p->p_siglist; 1613 SIGSETNAND(mask, p->p_sigmask); 1614 if (p->p_flag & P_PPWAIT) 1615 SIG_STOPSIGMASK(mask); 1616 if (SIGISEMPTY(mask)) /* no signal to send */ 1617 return (0); 1618 sig = sig_ffs(&mask); 1619 prop = sigprop(sig); 1620 1621 _STOPEVENT(p, S_SIG, sig); 1622 1623 /* 1624 * We should see pending but ignored signals 1625 * only if P_TRACED was on when they were posted. 1626 */ 1627 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1628 SIGDELSET(p->p_siglist, sig); 1629 continue; 1630 } 1631 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1632 /* 1633 * If traced, always stop. 1634 */ 1635 p->p_xstat = sig; 1636 PROC_LOCK(p->p_pptr); 1637 psignal(p->p_pptr, SIGCHLD); 1638 PROC_UNLOCK(p->p_pptr); 1639 mtx_lock_spin(&sched_lock); 1640 stop(p); /* uses schedlock too eventually */ 1641 thread_suspend_one(td); 1642 PROC_UNLOCK(p); 1643 DROP_GIANT(); 1644 p->p_stats->p_ru.ru_nivcsw++; 1645 mi_switch(); 1646 mtx_unlock_spin(&sched_lock); 1647 PICKUP_GIANT(); 1648 PROC_LOCK(p); 1649 1650 /* 1651 * If the traced bit got turned off, go back up 1652 * to the top to rescan signals. This ensures 1653 * that p_sig* and ps_sigact are consistent. 1654 */ 1655 if ((p->p_flag & P_TRACED) == 0) 1656 continue; 1657 1658 /* 1659 * If parent wants us to take the signal, 1660 * then it will leave it in p->p_xstat; 1661 * otherwise we just look for signals again. 1662 */ 1663 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1664 sig = p->p_xstat; 1665 if (sig == 0) 1666 continue; 1667 1668 /* 1669 * Put the new signal into p_siglist. If the 1670 * signal is being masked, look for other signals. 1671 */ 1672 SIGADDSET(p->p_siglist, sig); 1673 if (SIGISMEMBER(p->p_sigmask, sig)) 1674 continue; 1675 signotify(p); 1676 } 1677 1678 /* 1679 * Decide whether the signal should be returned. 1680 * Return the signal's number, or fall through 1681 * to clear it from the pending mask. 1682 */ 1683 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1684 1685 case (int)SIG_DFL: 1686 /* 1687 * Don't take default actions on system processes. 1688 */ 1689 if (p->p_pid <= 1) { 1690 #ifdef DIAGNOSTIC 1691 /* 1692 * Are you sure you want to ignore SIGSEGV 1693 * in init? XXX 1694 */ 1695 printf("Process (pid %lu) got signal %d\n", 1696 (u_long)p->p_pid, sig); 1697 #endif 1698 break; /* == ignore */ 1699 } 1700 /* 1701 * If there is a pending stop signal to process 1702 * with default action, stop here, 1703 * then clear the signal. However, 1704 * if process is member of an orphaned 1705 * process group, ignore tty stop signals. 1706 */ 1707 if (prop & SA_STOP) { 1708 if (p->p_flag & P_TRACED || 1709 (p->p_pgrp->pg_jobc == 0 && 1710 prop & SA_TTYSTOP)) 1711 break; /* == ignore */ 1712 p->p_xstat = sig; 1713 mtx_lock_spin(&sched_lock); 1714 if (p->p_suspcount+1 == p->p_numthreads) { 1715 mtx_unlock_spin(&sched_lock); 1716 PROC_LOCK(p->p_pptr); 1717 if ((p->p_pptr->p_procsig->ps_flag & 1718 PS_NOCLDSTOP) == 0) { 1719 psignal(p->p_pptr, SIGCHLD); 1720 } 1721 PROC_UNLOCK(p->p_pptr); 1722 mtx_lock_spin(&sched_lock); 1723 } 1724 stop(p); 1725 thread_suspend_one(td); 1726 PROC_UNLOCK(p); 1727 DROP_GIANT(); 1728 p->p_stats->p_ru.ru_nivcsw++; 1729 mi_switch(); 1730 mtx_unlock_spin(&sched_lock); 1731 PICKUP_GIANT(); 1732 PROC_LOCK(p); 1733 break; 1734 } else if (prop & SA_IGNORE) { 1735 /* 1736 * Except for SIGCONT, shouldn't get here. 1737 * Default action is to ignore; drop it. 1738 */ 1739 break; /* == ignore */ 1740 } else 1741 return (sig); 1742 /*NOTREACHED*/ 1743 1744 case (int)SIG_IGN: 1745 /* 1746 * Masking above should prevent us ever trying 1747 * to take action on an ignored signal other 1748 * than SIGCONT, unless process is traced. 1749 */ 1750 if ((prop & SA_CONT) == 0 && 1751 (p->p_flag & P_TRACED) == 0) 1752 printf("issignal\n"); 1753 break; /* == ignore */ 1754 1755 default: 1756 /* 1757 * This signal has an action, let 1758 * postsig() process it. 1759 */ 1760 return (sig); 1761 } 1762 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1763 } 1764 /* NOTREACHED */ 1765 } 1766 1767 /* 1768 * Put the argument process into the stopped state and notify the parent 1769 * via wakeup. Signals are handled elsewhere. The process must not be 1770 * on the run queue. Must be called with the proc p locked and the scheduler 1771 * lock held. 1772 */ 1773 static void 1774 stop(p) 1775 register struct proc *p; 1776 { 1777 1778 PROC_LOCK_ASSERT(p, MA_OWNED); 1779 p->p_flag |= P_STOPPED_SIG; 1780 p->p_flag &= ~P_WAITED; 1781 wakeup(p->p_pptr); 1782 } 1783 1784 /* 1785 * Take the action for the specified signal 1786 * from the current set of pending signals. 1787 */ 1788 void 1789 postsig(sig) 1790 register int sig; 1791 { 1792 struct thread *td = curthread; 1793 register struct proc *p = td->td_proc; 1794 struct sigacts *ps; 1795 sig_t action; 1796 sigset_t returnmask; 1797 int code; 1798 1799 KASSERT(sig != 0, ("postsig")); 1800 1801 PROC_LOCK_ASSERT(p, MA_OWNED); 1802 ps = p->p_sigacts; 1803 SIGDELSET(p->p_siglist, sig); 1804 action = ps->ps_sigact[_SIG_IDX(sig)]; 1805 #ifdef KTRACE 1806 if (KTRPOINT(td, KTR_PSIG)) 1807 ktrpsig(sig, action, p->p_flag & P_OLDMASK ? 1808 &p->p_oldsigmask : &p->p_sigmask, 0); 1809 #endif 1810 _STOPEVENT(p, S_SIG, sig); 1811 1812 if (action == SIG_DFL) { 1813 /* 1814 * Default action, where the default is to kill 1815 * the process. (Other cases were ignored above.) 1816 */ 1817 sigexit(td, sig); 1818 /* NOTREACHED */ 1819 } else { 1820 /* 1821 * If we get here, the signal must be caught. 1822 */ 1823 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1824 ("postsig action")); 1825 /* 1826 * Set the new mask value and also defer further 1827 * occurrences of this signal. 1828 * 1829 * Special case: user has done a sigsuspend. Here the 1830 * current mask is not of interest, but rather the 1831 * mask from before the sigsuspend is what we want 1832 * restored after the signal processing is completed. 1833 */ 1834 if (p->p_flag & P_OLDMASK) { 1835 returnmask = p->p_oldsigmask; 1836 p->p_flag &= ~P_OLDMASK; 1837 } else 1838 returnmask = p->p_sigmask; 1839 1840 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1841 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1842 SIGADDSET(p->p_sigmask, sig); 1843 1844 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1845 /* 1846 * See kern_sigaction() for origin of this code. 1847 */ 1848 SIGDELSET(p->p_sigcatch, sig); 1849 if (sig != SIGCONT && 1850 sigprop(sig) & SA_IGNORE) 1851 SIGADDSET(p->p_sigignore, sig); 1852 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1853 } 1854 p->p_stats->p_ru.ru_nsignals++; 1855 if (p->p_sig != sig) { 1856 code = 0; 1857 } else { 1858 code = p->p_code; 1859 p->p_code = 0; 1860 p->p_sig = 0; 1861 } 1862 if (p->p_flag & P_KSES) 1863 if (signal_upcall(p, sig)) 1864 return; 1865 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1866 } 1867 } 1868 1869 /* 1870 * Kill the current process for stated reason. 1871 */ 1872 void 1873 killproc(p, why) 1874 struct proc *p; 1875 char *why; 1876 { 1877 1878 PROC_LOCK_ASSERT(p, MA_OWNED); 1879 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 1880 p, p->p_pid, p->p_comm); 1881 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1882 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1883 psignal(p, SIGKILL); 1884 } 1885 1886 /* 1887 * Force the current process to exit with the specified signal, dumping core 1888 * if appropriate. We bypass the normal tests for masked and caught signals, 1889 * allowing unrecoverable failures to terminate the process without changing 1890 * signal state. Mark the accounting record with the signal termination. 1891 * If dumping core, save the signal number for the debugger. Calls exit and 1892 * does not return. 1893 */ 1894 void 1895 sigexit(td, sig) 1896 struct thread *td; 1897 int sig; 1898 { 1899 struct proc *p = td->td_proc; 1900 1901 PROC_LOCK_ASSERT(p, MA_OWNED); 1902 p->p_acflag |= AXSIG; 1903 if (sigprop(sig) & SA_CORE) { 1904 p->p_sig = sig; 1905 /* 1906 * Log signals which would cause core dumps 1907 * (Log as LOG_INFO to appease those who don't want 1908 * these messages.) 1909 * XXX : Todo, as well as euid, write out ruid too 1910 */ 1911 PROC_UNLOCK(p); 1912 if (!mtx_owned(&Giant)) 1913 mtx_lock(&Giant); 1914 if (coredump(td) == 0) 1915 sig |= WCOREFLAG; 1916 if (kern_logsigexit) 1917 log(LOG_INFO, 1918 "pid %d (%s), uid %d: exited on signal %d%s\n", 1919 p->p_pid, p->p_comm, 1920 td->td_ucred ? td->td_ucred->cr_uid : -1, 1921 sig &~ WCOREFLAG, 1922 sig & WCOREFLAG ? " (core dumped)" : ""); 1923 } else { 1924 PROC_UNLOCK(p); 1925 if (!mtx_owned(&Giant)) 1926 mtx_lock(&Giant); 1927 } 1928 exit1(td, W_EXITCODE(0, sig)); 1929 /* NOTREACHED */ 1930 } 1931 1932 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1933 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1934 sizeof(corefilename), "process corefile name format string"); 1935 1936 /* 1937 * expand_name(name, uid, pid) 1938 * Expand the name described in corefilename, using name, uid, and pid. 1939 * corefilename is a printf-like string, with three format specifiers: 1940 * %N name of process ("name") 1941 * %P process id (pid) 1942 * %U user id (uid) 1943 * For example, "%N.core" is the default; they can be disabled completely 1944 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1945 * This is controlled by the sysctl variable kern.corefile (see above). 1946 */ 1947 1948 static char * 1949 expand_name(name, uid, pid) 1950 const char *name; 1951 uid_t uid; 1952 pid_t pid; 1953 { 1954 const char *format, *appendstr; 1955 char *temp; 1956 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1957 size_t i, l, n; 1958 1959 format = corefilename; 1960 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 1961 if (temp == NULL) 1962 return (NULL); 1963 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1964 switch (format[i]) { 1965 case '%': /* Format character */ 1966 i++; 1967 switch (format[i]) { 1968 case '%': 1969 appendstr = "%"; 1970 break; 1971 case 'N': /* process name */ 1972 appendstr = name; 1973 break; 1974 case 'P': /* process id */ 1975 sprintf(buf, "%u", pid); 1976 appendstr = buf; 1977 break; 1978 case 'U': /* user id */ 1979 sprintf(buf, "%u", uid); 1980 appendstr = buf; 1981 break; 1982 default: 1983 appendstr = ""; 1984 log(LOG_ERR, 1985 "Unknown format character %c in `%s'\n", 1986 format[i], format); 1987 } 1988 l = strlen(appendstr); 1989 if ((n + l) >= MAXPATHLEN) 1990 goto toolong; 1991 memcpy(temp + n, appendstr, l); 1992 n += l; 1993 break; 1994 default: 1995 temp[n++] = format[i]; 1996 } 1997 } 1998 if (format[i] != '\0') 1999 goto toolong; 2000 return (temp); 2001 toolong: 2002 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2003 (long)pid, name, (u_long)uid); 2004 free(temp, M_TEMP); 2005 return (NULL); 2006 } 2007 2008 /* 2009 * Dump a process' core. The main routine does some 2010 * policy checking, and creates the name of the coredump; 2011 * then it passes on a vnode and a size limit to the process-specific 2012 * coredump routine if there is one; if there _is not_ one, it returns 2013 * ENOSYS; otherwise it returns the error from the process-specific routine. 2014 */ 2015 2016 static int 2017 coredump(struct thread *td) 2018 { 2019 struct proc *p = td->td_proc; 2020 register struct vnode *vp; 2021 register struct ucred *cred = td->td_ucred; 2022 struct flock lf; 2023 struct nameidata nd; 2024 struct vattr vattr; 2025 int error, error1, flags; 2026 struct mount *mp; 2027 char *name; /* name of corefile */ 2028 off_t limit; 2029 2030 PROC_LOCK(p); 2031 _STOPEVENT(p, S_CORE, 0); 2032 2033 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2034 PROC_UNLOCK(p); 2035 return (EFAULT); 2036 } 2037 2038 /* 2039 * Note that the bulk of limit checking is done after 2040 * the corefile is created. The exception is if the limit 2041 * for corefiles is 0, in which case we don't bother 2042 * creating the corefile at all. This layout means that 2043 * a corefile is truncated instead of not being created, 2044 * if it is larger than the limit. 2045 */ 2046 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2047 if (limit == 0) { 2048 PROC_UNLOCK(p); 2049 return 0; 2050 } 2051 PROC_UNLOCK(p); 2052 2053 restart: 2054 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2055 if (name == NULL) 2056 return (EINVAL); 2057 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2058 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2059 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); 2060 free(name, M_TEMP); 2061 if (error) 2062 return (error); 2063 NDFREE(&nd, NDF_ONLY_PNBUF); 2064 vp = nd.ni_vp; 2065 2066 /* Don't dump to non-regular files or files with links. */ 2067 if (vp->v_type != VREG || 2068 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2069 VOP_UNLOCK(vp, 0, td); 2070 error = EFAULT; 2071 goto out2; 2072 } 2073 2074 VOP_UNLOCK(vp, 0, td); 2075 lf.l_whence = SEEK_SET; 2076 lf.l_start = 0; 2077 lf.l_len = 0; 2078 lf.l_type = F_WRLCK; 2079 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 2080 if (error) 2081 goto out2; 2082 2083 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2084 lf.l_type = F_UNLCK; 2085 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2086 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2087 return (error); 2088 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2089 return (error); 2090 goto restart; 2091 } 2092 2093 VATTR_NULL(&vattr); 2094 vattr.va_size = 0; 2095 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2096 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2097 VOP_SETATTR(vp, &vattr, cred, td); 2098 VOP_UNLOCK(vp, 0, td); 2099 PROC_LOCK(p); 2100 p->p_acflag |= ACORE; 2101 PROC_UNLOCK(p); 2102 2103 error = p->p_sysent->sv_coredump ? 2104 p->p_sysent->sv_coredump(td, vp, limit) : 2105 ENOSYS; 2106 2107 lf.l_type = F_UNLCK; 2108 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2109 vn_finished_write(mp); 2110 out2: 2111 error1 = vn_close(vp, FWRITE, cred, td); 2112 if (error == 0) 2113 error = error1; 2114 return (error); 2115 } 2116 2117 /* 2118 * Nonexistent system call-- signal process (may want to handle it). 2119 * Flag error in case process won't see signal immediately (blocked or ignored). 2120 */ 2121 #ifndef _SYS_SYSPROTO_H_ 2122 struct nosys_args { 2123 int dummy; 2124 }; 2125 #endif 2126 /* 2127 * MPSAFE 2128 */ 2129 /* ARGSUSED */ 2130 int 2131 nosys(td, args) 2132 struct thread *td; 2133 struct nosys_args *args; 2134 { 2135 struct proc *p = td->td_proc; 2136 2137 mtx_lock(&Giant); 2138 PROC_LOCK(p); 2139 psignal(p, SIGSYS); 2140 PROC_UNLOCK(p); 2141 mtx_unlock(&Giant); 2142 return (ENOSYS); 2143 } 2144 2145 /* 2146 * Send a SIGIO or SIGURG signal to a process or process group using 2147 * stored credentials rather than those of the current process. 2148 */ 2149 void 2150 pgsigio(sigiop, sig, checkctty) 2151 struct sigio **sigiop; 2152 int sig, checkctty; 2153 { 2154 struct sigio *sigio; 2155 2156 SIGIO_LOCK(); 2157 sigio = *sigiop; 2158 if (sigio == NULL) { 2159 SIGIO_UNLOCK(); 2160 return; 2161 } 2162 if (sigio->sio_pgid > 0) { 2163 PROC_LOCK(sigio->sio_proc); 2164 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2165 psignal(sigio->sio_proc, sig); 2166 PROC_UNLOCK(sigio->sio_proc); 2167 } else if (sigio->sio_pgid < 0) { 2168 struct proc *p; 2169 2170 PGRP_LOCK(sigio->sio_pgrp); 2171 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2172 PROC_LOCK(p); 2173 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2174 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2175 psignal(p, sig); 2176 PROC_UNLOCK(p); 2177 } 2178 PGRP_UNLOCK(sigio->sio_pgrp); 2179 } 2180 SIGIO_UNLOCK(); 2181 } 2182 2183 static int 2184 filt_sigattach(struct knote *kn) 2185 { 2186 struct proc *p = curproc; 2187 2188 kn->kn_ptr.p_proc = p; 2189 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2190 2191 PROC_LOCK(p); 2192 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2193 PROC_UNLOCK(p); 2194 2195 return (0); 2196 } 2197 2198 static void 2199 filt_sigdetach(struct knote *kn) 2200 { 2201 struct proc *p = kn->kn_ptr.p_proc; 2202 2203 PROC_LOCK(p); 2204 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2205 PROC_UNLOCK(p); 2206 } 2207 2208 /* 2209 * signal knotes are shared with proc knotes, so we apply a mask to 2210 * the hint in order to differentiate them from process hints. This 2211 * could be avoided by using a signal-specific knote list, but probably 2212 * isn't worth the trouble. 2213 */ 2214 static int 2215 filt_signal(struct knote *kn, long hint) 2216 { 2217 2218 if (hint & NOTE_SIGNAL) { 2219 hint &= ~NOTE_SIGNAL; 2220 2221 if (kn->kn_id == hint) 2222 kn->kn_data++; 2223 } 2224 return (kn->kn_data != 0); 2225 } 2226