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 #if defined (__alpha__) && !defined(COMPAT_43) 77 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 78 #endif 79 80 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 81 82 static int coredump(struct thread *); 83 static int do_sigprocmask(struct proc *p, int how, sigset_t *set, 84 sigset_t *oset, int old); 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 sig_ffs(sigset_t *set); 88 static int sigprop(int sig); 89 static void stop(struct proc *); 90 static void tdsignal(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 95 struct filterops sig_filtops = 96 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 97 98 static int kern_logsigexit = 1; 99 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 100 &kern_logsigexit, 0, 101 "Log processes quitting on abnormal signals to syslog(3)"); 102 103 /* 104 * Policy -- Can ucred cr1 send SIGIO to process cr2? 105 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 106 * in the right situations. 107 */ 108 #define CANSIGIO(cr1, cr2) \ 109 ((cr1)->cr_uid == 0 || \ 110 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 111 (cr1)->cr_uid == (cr2)->cr_ruid || \ 112 (cr1)->cr_ruid == (cr2)->cr_uid || \ 113 (cr1)->cr_uid == (cr2)->cr_uid) 114 115 int sugid_coredump; 116 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 117 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 118 119 static int do_coredump = 1; 120 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 121 &do_coredump, 0, "Enable/Disable coredumps"); 122 123 /* 124 * Signal properties and actions. 125 * The array below categorizes the signals and their default actions 126 * according to the following properties: 127 */ 128 #define SA_KILL 0x01 /* terminates process by default */ 129 #define SA_CORE 0x02 /* ditto and coredumps */ 130 #define SA_STOP 0x04 /* suspend process */ 131 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 132 #define SA_IGNORE 0x10 /* ignore by default */ 133 #define SA_CONT 0x20 /* continue if suspended */ 134 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 135 136 static int sigproptbl[NSIG] = { 137 SA_KILL, /* SIGHUP */ 138 SA_KILL, /* SIGINT */ 139 SA_KILL|SA_CORE, /* SIGQUIT */ 140 SA_KILL|SA_CORE, /* SIGILL */ 141 SA_KILL|SA_CORE, /* SIGTRAP */ 142 SA_KILL|SA_CORE, /* SIGABRT */ 143 SA_KILL|SA_CORE, /* SIGEMT */ 144 SA_KILL|SA_CORE, /* SIGFPE */ 145 SA_KILL, /* SIGKILL */ 146 SA_KILL|SA_CORE, /* SIGBUS */ 147 SA_KILL|SA_CORE, /* SIGSEGV */ 148 SA_KILL|SA_CORE, /* SIGSYS */ 149 SA_KILL, /* SIGPIPE */ 150 SA_KILL, /* SIGALRM */ 151 SA_KILL, /* SIGTERM */ 152 SA_IGNORE, /* SIGURG */ 153 SA_STOP, /* SIGSTOP */ 154 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 155 SA_IGNORE|SA_CONT, /* SIGCONT */ 156 SA_IGNORE, /* SIGCHLD */ 157 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 158 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 159 SA_IGNORE, /* SIGIO */ 160 SA_KILL, /* SIGXCPU */ 161 SA_KILL, /* SIGXFSZ */ 162 SA_KILL, /* SIGVTALRM */ 163 SA_KILL, /* SIGPROF */ 164 SA_IGNORE, /* SIGWINCH */ 165 SA_IGNORE, /* SIGINFO */ 166 SA_KILL, /* SIGUSR1 */ 167 SA_KILL, /* SIGUSR2 */ 168 }; 169 170 /* 171 * Determine signal that should be delivered to process p, the current 172 * process, 0 if none. If there is a pending stop signal with default 173 * action, the process stops in issignal(). 174 * XXXKSE the check for a pending stop is not done under KSE 175 * 176 * MP SAFE. 177 */ 178 int 179 cursig(struct thread *td) 180 { 181 struct proc *p = td->td_proc; 182 183 PROC_LOCK_ASSERT(p, MA_OWNED); 184 mtx_assert(&sched_lock, MA_NOTOWNED); 185 return (SIGPENDING(p) ? issignal(td) : 0); 186 } 187 188 /* 189 * Arrange for ast() to handle unmasked pending signals on return to user 190 * mode. This must be called whenever a signal is added to p_siglist or 191 * unmasked in p_sigmask. 192 */ 193 void 194 signotify(struct proc *p) 195 { 196 struct kse *ke; 197 struct ksegrp *kg; 198 199 PROC_LOCK_ASSERT(p, MA_OWNED); 200 mtx_lock_spin(&sched_lock); 201 if (SIGPENDING(p)) { 202 p->p_sflag |= PS_NEEDSIGCHK; 203 /* XXXKSE for now punish all KSEs */ 204 FOREACH_KSEGRP_IN_PROC(p, kg) { 205 FOREACH_KSE_IN_GROUP(kg, ke) { 206 ke->ke_flags |= KEF_ASTPENDING; 207 } 208 } 209 } 210 mtx_unlock_spin(&sched_lock); 211 } 212 213 static __inline int 214 sigprop(int sig) 215 { 216 217 if (sig > 0 && sig < NSIG) 218 return (sigproptbl[_SIG_IDX(sig)]); 219 return (0); 220 } 221 222 static __inline int 223 sig_ffs(sigset_t *set) 224 { 225 int i; 226 227 for (i = 0; i < _SIG_WORDS; i++) 228 if (set->__bits[i]) 229 return (ffs(set->__bits[i]) + (i * 32)); 230 return (0); 231 } 232 233 /* 234 * kern_sigaction 235 * sigaction 236 * freebsd4_sigaction 237 * osigaction 238 */ 239 int 240 kern_sigaction(td, sig, act, oact, flags) 241 struct thread *td; 242 register int sig; 243 struct sigaction *act, *oact; 244 int flags; 245 { 246 register struct sigacts *ps; 247 struct proc *p = td->td_proc; 248 249 if (!_SIG_VALID(sig)) 250 return (EINVAL); 251 252 PROC_LOCK(p); 253 ps = p->p_sigacts; 254 if (oact) { 255 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 256 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 257 oact->sa_flags = 0; 258 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 259 oact->sa_flags |= SA_ONSTACK; 260 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 261 oact->sa_flags |= SA_RESTART; 262 if (SIGISMEMBER(ps->ps_sigreset, sig)) 263 oact->sa_flags |= SA_RESETHAND; 264 if (SIGISMEMBER(ps->ps_signodefer, sig)) 265 oact->sa_flags |= SA_NODEFER; 266 if (SIGISMEMBER(ps->ps_siginfo, sig)) 267 oact->sa_flags |= SA_SIGINFO; 268 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 269 oact->sa_flags |= SA_NOCLDSTOP; 270 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 271 oact->sa_flags |= SA_NOCLDWAIT; 272 } 273 if (act) { 274 if ((sig == SIGKILL || sig == SIGSTOP) && 275 act->sa_handler != SIG_DFL) { 276 PROC_UNLOCK(p); 277 return (EINVAL); 278 } 279 280 /* 281 * Change setting atomically. 282 */ 283 284 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 285 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 286 if (act->sa_flags & SA_SIGINFO) { 287 ps->ps_sigact[_SIG_IDX(sig)] = 288 (__sighandler_t *)act->sa_sigaction; 289 SIGADDSET(ps->ps_siginfo, sig); 290 } else { 291 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 292 SIGDELSET(ps->ps_siginfo, sig); 293 } 294 if (!(act->sa_flags & SA_RESTART)) 295 SIGADDSET(ps->ps_sigintr, sig); 296 else 297 SIGDELSET(ps->ps_sigintr, sig); 298 if (act->sa_flags & SA_ONSTACK) 299 SIGADDSET(ps->ps_sigonstack, sig); 300 else 301 SIGDELSET(ps->ps_sigonstack, sig); 302 if (act->sa_flags & SA_RESETHAND) 303 SIGADDSET(ps->ps_sigreset, sig); 304 else 305 SIGDELSET(ps->ps_sigreset, sig); 306 if (act->sa_flags & SA_NODEFER) 307 SIGADDSET(ps->ps_signodefer, sig); 308 else 309 SIGDELSET(ps->ps_signodefer, sig); 310 #ifdef COMPAT_SUNOS 311 if (act->sa_flags & SA_USERTRAMP) 312 SIGADDSET(ps->ps_usertramp, sig); 313 else 314 SIGDELSET(ps->ps_usertramp, sig); 315 #endif 316 if (sig == SIGCHLD) { 317 if (act->sa_flags & SA_NOCLDSTOP) 318 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 319 else 320 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 321 if (act->sa_flags & SA_NOCLDWAIT) { 322 /* 323 * Paranoia: since SA_NOCLDWAIT is implemented 324 * by reparenting the dying child to PID 1 (and 325 * trust it to reap the zombie), PID 1 itself 326 * is forbidden to set SA_NOCLDWAIT. 327 */ 328 if (p->p_pid == 1) 329 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 330 else 331 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 332 } else 333 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 334 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 335 p->p_procsig->ps_flag |= PS_CLDSIGIGN; 336 else 337 p->p_procsig->ps_flag &= ~PS_CLDSIGIGN; 338 } 339 /* 340 * Set bit in p_sigignore for signals that are set to SIG_IGN, 341 * and for signals set to SIG_DFL where the default is to 342 * ignore. However, don't put SIGCONT in p_sigignore, as we 343 * have to restart the process. 344 */ 345 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 346 (sigprop(sig) & SA_IGNORE && 347 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 348 /* never to be seen again */ 349 SIGDELSET(p->p_siglist, sig); 350 if (sig != SIGCONT) 351 /* easier in psignal */ 352 SIGADDSET(p->p_sigignore, sig); 353 SIGDELSET(p->p_sigcatch, sig); 354 } else { 355 SIGDELSET(p->p_sigignore, sig); 356 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 357 SIGDELSET(p->p_sigcatch, sig); 358 else 359 SIGADDSET(p->p_sigcatch, sig); 360 } 361 #ifdef COMPAT_FREEBSD4 362 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 363 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 364 (flags & KSA_FREEBSD4) == 0) 365 SIGDELSET(ps->ps_freebsd4, sig); 366 else 367 SIGADDSET(ps->ps_freebsd4, sig); 368 #endif 369 #ifdef COMPAT_43 370 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 371 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 372 (flags & KSA_OSIGSET) == 0) 373 SIGDELSET(ps->ps_osigset, sig); 374 else 375 SIGADDSET(ps->ps_osigset, sig); 376 #endif 377 } 378 PROC_UNLOCK(p); 379 return (0); 380 } 381 382 #ifndef _SYS_SYSPROTO_H_ 383 struct sigaction_args { 384 int sig; 385 struct sigaction *act; 386 struct sigaction *oact; 387 }; 388 #endif 389 /* 390 * MPSAFE 391 */ 392 /* ARGSUSED */ 393 int 394 sigaction(td, uap) 395 struct thread *td; 396 register struct sigaction_args *uap; 397 { 398 struct sigaction act, oact; 399 register struct sigaction *actp, *oactp; 400 int error; 401 402 mtx_lock(&Giant); 403 404 actp = (uap->act != NULL) ? &act : NULL; 405 oactp = (uap->oact != NULL) ? &oact : NULL; 406 if (actp) { 407 error = copyin(uap->act, actp, sizeof(act)); 408 if (error) 409 goto done2; 410 } 411 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 412 if (oactp && !error) { 413 error = copyout(oactp, uap->oact, sizeof(oact)); 414 } 415 done2: 416 mtx_unlock(&Giant); 417 return (error); 418 } 419 420 #ifdef COMPAT_FREEBSD4 421 #ifndef _SYS_SYSPROTO_H_ 422 struct freebsd4_sigaction_args { 423 int sig; 424 struct sigaction *act; 425 struct sigaction *oact; 426 }; 427 #endif 428 /* 429 * MPSAFE 430 */ 431 /* ARGSUSED */ 432 int 433 freebsd4_sigaction(td, uap) 434 struct thread *td; 435 register struct freebsd4_sigaction_args *uap; 436 { 437 struct sigaction act, oact; 438 register struct sigaction *actp, *oactp; 439 int error; 440 441 mtx_lock(&Giant); 442 443 actp = (uap->act != NULL) ? &act : NULL; 444 oactp = (uap->oact != NULL) ? &oact : NULL; 445 if (actp) { 446 error = copyin(uap->act, actp, sizeof(act)); 447 if (error) 448 goto done2; 449 } 450 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 451 if (oactp && !error) { 452 error = copyout(oactp, uap->oact, sizeof(oact)); 453 } 454 done2: 455 mtx_unlock(&Giant); 456 return (error); 457 } 458 #endif /* COMAPT_FREEBSD4 */ 459 460 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 461 #ifndef _SYS_SYSPROTO_H_ 462 struct osigaction_args { 463 int signum; 464 struct osigaction *nsa; 465 struct osigaction *osa; 466 }; 467 #endif 468 /* 469 * MPSAFE 470 */ 471 /* ARGSUSED */ 472 int 473 osigaction(td, uap) 474 struct thread *td; 475 register struct osigaction_args *uap; 476 { 477 struct osigaction sa; 478 struct sigaction nsa, osa; 479 register struct sigaction *nsap, *osap; 480 int error; 481 482 if (uap->signum <= 0 || uap->signum >= ONSIG) 483 return (EINVAL); 484 485 nsap = (uap->nsa != NULL) ? &nsa : NULL; 486 osap = (uap->osa != NULL) ? &osa : NULL; 487 488 mtx_lock(&Giant); 489 490 if (nsap) { 491 error = copyin(uap->nsa, &sa, sizeof(sa)); 492 if (error) 493 goto done2; 494 nsap->sa_handler = sa.sa_handler; 495 nsap->sa_flags = sa.sa_flags; 496 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 497 } 498 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 499 if (osap && !error) { 500 sa.sa_handler = osap->sa_handler; 501 sa.sa_flags = osap->sa_flags; 502 SIG2OSIG(osap->sa_mask, sa.sa_mask); 503 error = copyout(&sa, uap->osa, sizeof(sa)); 504 } 505 done2: 506 mtx_unlock(&Giant); 507 return (error); 508 } 509 510 #if !defined(__i386__) && !defined(__alpha__) 511 /* Avoid replicating the same stub everywhere */ 512 int 513 osigreturn(td, uap) 514 struct thread *td; 515 struct osigreturn_args *uap; 516 { 517 518 return (nosys(td, (struct nosys_args *)uap)); 519 } 520 #endif 521 #endif /* COMPAT_43 */ 522 523 /* 524 * Initialize signal state for process 0; 525 * set to ignore signals that are ignored by default. 526 */ 527 void 528 siginit(p) 529 struct proc *p; 530 { 531 register int i; 532 533 PROC_LOCK(p); 534 for (i = 1; i <= NSIG; i++) 535 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 536 SIGADDSET(p->p_sigignore, i); 537 PROC_UNLOCK(p); 538 } 539 540 /* 541 * Reset signals for an exec of the specified process. 542 */ 543 void 544 execsigs(p) 545 register struct proc *p; 546 { 547 register struct sigacts *ps; 548 register int sig; 549 550 /* 551 * Reset caught signals. Held signals remain held 552 * through p_sigmask (unless they were caught, 553 * and are now ignored by default). 554 */ 555 PROC_LOCK_ASSERT(p, MA_OWNED); 556 ps = p->p_sigacts; 557 while (SIGNOTEMPTY(p->p_sigcatch)) { 558 sig = sig_ffs(&p->p_sigcatch); 559 SIGDELSET(p->p_sigcatch, sig); 560 if (sigprop(sig) & SA_IGNORE) { 561 if (sig != SIGCONT) 562 SIGADDSET(p->p_sigignore, sig); 563 SIGDELSET(p->p_siglist, sig); 564 } 565 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 566 } 567 /* 568 * Reset stack state to the user stack. 569 * Clear set of signals caught on the signal stack. 570 */ 571 p->p_sigstk.ss_flags = SS_DISABLE; 572 p->p_sigstk.ss_size = 0; 573 p->p_sigstk.ss_sp = 0; 574 p->p_flag &= ~P_ALTSTACK; 575 /* 576 * Reset no zombies if child dies flag as Solaris does. 577 */ 578 p->p_procsig->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 579 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 580 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 581 } 582 583 /* 584 * do_sigprocmask() 585 * 586 * Manipulate signal mask. 587 */ 588 static int 589 do_sigprocmask(p, how, set, oset, old) 590 struct proc *p; 591 int how; 592 sigset_t *set, *oset; 593 int old; 594 { 595 int error; 596 597 PROC_LOCK(p); 598 if (oset != NULL) 599 *oset = p->p_sigmask; 600 601 error = 0; 602 if (set != NULL) { 603 switch (how) { 604 case SIG_BLOCK: 605 SIG_CANTMASK(*set); 606 SIGSETOR(p->p_sigmask, *set); 607 break; 608 case SIG_UNBLOCK: 609 SIGSETNAND(p->p_sigmask, *set); 610 signotify(p); 611 break; 612 case SIG_SETMASK: 613 SIG_CANTMASK(*set); 614 if (old) 615 SIGSETLO(p->p_sigmask, *set); 616 else 617 p->p_sigmask = *set; 618 signotify(p); 619 break; 620 default: 621 error = EINVAL; 622 break; 623 } 624 } 625 PROC_UNLOCK(p); 626 return (error); 627 } 628 629 /* 630 * sigprocmask() - MP SAFE (XXXKSE not under KSE it isn't) 631 */ 632 633 #ifndef _SYS_SYSPROTO_H_ 634 struct sigprocmask_args { 635 int how; 636 const sigset_t *set; 637 sigset_t *oset; 638 }; 639 #endif 640 int 641 sigprocmask(td, uap) 642 register struct thread *td; 643 struct sigprocmask_args *uap; 644 { 645 struct proc *p = td->td_proc; 646 sigset_t set, oset; 647 sigset_t *setp, *osetp; 648 int error; 649 650 setp = (uap->set != NULL) ? &set : NULL; 651 osetp = (uap->oset != NULL) ? &oset : NULL; 652 if (setp) { 653 error = copyin(uap->set, setp, sizeof(set)); 654 if (error) 655 return (error); 656 } 657 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 658 if (osetp && !error) { 659 error = copyout(osetp, uap->oset, sizeof(oset)); 660 } 661 return (error); 662 } 663 664 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 665 /* 666 * osigprocmask() - MP SAFE 667 */ 668 #ifndef _SYS_SYSPROTO_H_ 669 struct osigprocmask_args { 670 int how; 671 osigset_t mask; 672 }; 673 #endif 674 int 675 osigprocmask(td, uap) 676 register struct thread *td; 677 struct osigprocmask_args *uap; 678 { 679 struct proc *p = td->td_proc; 680 sigset_t set, oset; 681 int error; 682 683 OSIG2SIG(uap->mask, set); 684 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 685 SIG2OSIG(oset, td->td_retval[0]); 686 return (error); 687 } 688 #endif /* COMPAT_43 */ 689 690 #ifndef _SYS_SYSPROTO_H_ 691 struct sigpending_args { 692 sigset_t *set; 693 }; 694 #endif 695 /* 696 * MPSAFE 697 */ 698 /* ARGSUSED */ 699 int 700 sigpending(td, uap) 701 struct thread *td; 702 struct sigpending_args *uap; 703 { 704 struct proc *p = td->td_proc; 705 sigset_t siglist; 706 int error; 707 708 mtx_lock(&Giant); 709 PROC_LOCK(p); 710 siglist = p->p_siglist; 711 PROC_UNLOCK(p); 712 mtx_unlock(&Giant); 713 error = copyout(&siglist, uap->set, sizeof(sigset_t)); 714 return(error); 715 } 716 717 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 718 #ifndef _SYS_SYSPROTO_H_ 719 struct osigpending_args { 720 int dummy; 721 }; 722 #endif 723 /* 724 * MPSAFE 725 */ 726 /* ARGSUSED */ 727 int 728 osigpending(td, uap) 729 struct thread *td; 730 struct osigpending_args *uap; 731 { 732 struct proc *p = td->td_proc; 733 734 mtx_lock(&Giant); 735 PROC_LOCK(p); 736 SIG2OSIG(p->p_siglist, td->td_retval[0]); 737 PROC_UNLOCK(p); 738 mtx_unlock(&Giant); 739 return (0); 740 } 741 #endif /* COMPAT_43 */ 742 743 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 744 /* 745 * Generalized interface signal handler, 4.3-compatible. 746 */ 747 #ifndef _SYS_SYSPROTO_H_ 748 struct osigvec_args { 749 int signum; 750 struct sigvec *nsv; 751 struct sigvec *osv; 752 }; 753 #endif 754 /* 755 * MPSAFE 756 */ 757 /* ARGSUSED */ 758 int 759 osigvec(td, uap) 760 struct thread *td; 761 register struct osigvec_args *uap; 762 { 763 struct sigvec vec; 764 struct sigaction nsa, osa; 765 register struct sigaction *nsap, *osap; 766 int error; 767 768 if (uap->signum <= 0 || uap->signum >= ONSIG) 769 return (EINVAL); 770 nsap = (uap->nsv != NULL) ? &nsa : NULL; 771 osap = (uap->osv != NULL) ? &osa : NULL; 772 if (nsap) { 773 error = copyin(uap->nsv, &vec, sizeof(vec)); 774 if (error) 775 return (error); 776 nsap->sa_handler = vec.sv_handler; 777 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 778 nsap->sa_flags = vec.sv_flags; 779 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 780 #ifdef COMPAT_SUNOS 781 nsap->sa_flags |= SA_USERTRAMP; 782 #endif 783 } 784 mtx_lock(&Giant); 785 error = kern_sigaction(td, uap->signum, nsap, osap, 1); 786 mtx_unlock(&Giant); 787 if (osap && !error) { 788 vec.sv_handler = osap->sa_handler; 789 SIG2OSIG(osap->sa_mask, vec.sv_mask); 790 vec.sv_flags = osap->sa_flags; 791 vec.sv_flags &= ~SA_NOCLDWAIT; 792 vec.sv_flags ^= SA_RESTART; 793 #ifdef COMPAT_SUNOS 794 vec.sv_flags &= ~SA_NOCLDSTOP; 795 #endif 796 error = copyout(&vec, uap->osv, sizeof(vec)); 797 } 798 return (error); 799 } 800 801 #ifndef _SYS_SYSPROTO_H_ 802 struct osigblock_args { 803 int mask; 804 }; 805 #endif 806 /* 807 * MPSAFE 808 */ 809 int 810 osigblock(td, uap) 811 register struct thread *td; 812 struct osigblock_args *uap; 813 { 814 struct proc *p = td->td_proc; 815 sigset_t set; 816 817 OSIG2SIG(uap->mask, set); 818 SIG_CANTMASK(set); 819 mtx_lock(&Giant); 820 PROC_LOCK(p); 821 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 822 SIGSETOR(p->p_sigmask, set); 823 PROC_UNLOCK(p); 824 mtx_unlock(&Giant); 825 return (0); 826 } 827 828 #ifndef _SYS_SYSPROTO_H_ 829 struct osigsetmask_args { 830 int mask; 831 }; 832 #endif 833 /* 834 * MPSAFE 835 */ 836 int 837 osigsetmask(td, uap) 838 struct thread *td; 839 struct osigsetmask_args *uap; 840 { 841 struct proc *p = td->td_proc; 842 sigset_t set; 843 844 OSIG2SIG(uap->mask, set); 845 SIG_CANTMASK(set); 846 mtx_lock(&Giant); 847 PROC_LOCK(p); 848 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 849 SIGSETLO(p->p_sigmask, set); 850 signotify(p); 851 PROC_UNLOCK(p); 852 mtx_unlock(&Giant); 853 return (0); 854 } 855 #endif /* COMPAT_43 || COMPAT_SUNOS */ 856 857 /* 858 * Suspend process until signal, providing mask to be set 859 * in the meantime. Note nonstandard calling convention: 860 * libc stub passes mask, not pointer, to save a copyin. 861 ***** XXXKSE this doesn't make sense under KSE. 862 ***** Do we suspend the thread or all threads in the process? 863 ***** How do we suspend threads running NOW on another processor? 864 */ 865 #ifndef _SYS_SYSPROTO_H_ 866 struct sigsuspend_args { 867 const sigset_t *sigmask; 868 }; 869 #endif 870 /* 871 * MPSAFE 872 */ 873 /* ARGSUSED */ 874 int 875 sigsuspend(td, uap) 876 struct thread *td; 877 struct sigsuspend_args *uap; 878 { 879 sigset_t mask; 880 int error; 881 882 error = copyin(uap->sigmask, &mask, sizeof(mask)); 883 if (error) 884 return (error); 885 return (kern_sigsuspend(td, mask)); 886 } 887 888 int 889 kern_sigsuspend(struct thread *td, sigset_t mask) 890 { 891 struct proc *p = td->td_proc; 892 register struct sigacts *ps; 893 894 /* 895 * When returning from sigsuspend, we want 896 * the old mask to be restored after the 897 * signal handler has finished. Thus, we 898 * save it here and mark the sigacts structure 899 * to indicate this. 900 */ 901 mtx_lock(&Giant); 902 PROC_LOCK(p); 903 ps = p->p_sigacts; 904 p->p_oldsigmask = p->p_sigmask; 905 p->p_flag |= P_OLDMASK; 906 907 SIG_CANTMASK(mask); 908 p->p_sigmask = mask; 909 signotify(p); 910 while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 911 /* void */; 912 PROC_UNLOCK(p); 913 mtx_unlock(&Giant); 914 /* always return EINTR rather than ERESTART... */ 915 return (EINTR); 916 } 917 918 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 919 #ifndef _SYS_SYSPROTO_H_ 920 struct osigsuspend_args { 921 osigset_t mask; 922 }; 923 #endif 924 /* 925 * MPSAFE 926 */ 927 /* ARGSUSED */ 928 int 929 osigsuspend(td, uap) 930 struct thread *td; 931 struct osigsuspend_args *uap; 932 { 933 struct proc *p = td->td_proc; 934 sigset_t mask; 935 register struct sigacts *ps; 936 937 mtx_lock(&Giant); 938 PROC_LOCK(p); 939 ps = p->p_sigacts; 940 p->p_oldsigmask = p->p_sigmask; 941 p->p_flag |= P_OLDMASK; 942 OSIG2SIG(uap->mask, mask); 943 SIG_CANTMASK(mask); 944 SIGSETLO(p->p_sigmask, mask); 945 signotify(p); 946 while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 947 /* void */; 948 PROC_UNLOCK(p); 949 mtx_unlock(&Giant); 950 /* always return EINTR rather than ERESTART... */ 951 return (EINTR); 952 } 953 #endif /* COMPAT_43 */ 954 955 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 956 #ifndef _SYS_SYSPROTO_H_ 957 struct osigstack_args { 958 struct sigstack *nss; 959 struct sigstack *oss; 960 }; 961 #endif 962 /* 963 * MPSAFE 964 */ 965 /* ARGSUSED */ 966 int 967 osigstack(td, uap) 968 struct thread *td; 969 register struct osigstack_args *uap; 970 { 971 struct proc *p = td->td_proc; 972 struct sigstack ss; 973 int error = 0; 974 975 mtx_lock(&Giant); 976 977 if (uap->oss != NULL) { 978 PROC_LOCK(p); 979 ss.ss_sp = p->p_sigstk.ss_sp; 980 ss.ss_onstack = sigonstack(cpu_getstack(td)); 981 PROC_UNLOCK(p); 982 error = copyout(&ss, uap->oss, sizeof(struct sigstack)); 983 if (error) 984 goto done2; 985 } 986 987 if (uap->nss != NULL) { 988 if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0) 989 goto done2; 990 PROC_LOCK(p); 991 p->p_sigstk.ss_sp = ss.ss_sp; 992 p->p_sigstk.ss_size = 0; 993 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 994 p->p_flag |= P_ALTSTACK; 995 PROC_UNLOCK(p); 996 } 997 done2: 998 mtx_unlock(&Giant); 999 return (error); 1000 } 1001 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1002 1003 #ifndef _SYS_SYSPROTO_H_ 1004 struct sigaltstack_args { 1005 stack_t *ss; 1006 stack_t *oss; 1007 }; 1008 #endif 1009 /* 1010 * MPSAFE 1011 */ 1012 /* ARGSUSED */ 1013 int 1014 sigaltstack(td, uap) 1015 struct thread *td; 1016 register struct sigaltstack_args *uap; 1017 { 1018 stack_t ss, oss; 1019 int error; 1020 1021 if (uap->ss != NULL) { 1022 error = copyin(uap->ss, &ss, sizeof(ss)); 1023 if (error) 1024 return (error); 1025 } 1026 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1027 (uap->oss != NULL) ? &oss : NULL); 1028 if (error) 1029 return (error); 1030 if (uap->oss != NULL) 1031 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1032 return (error); 1033 } 1034 1035 int 1036 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1037 { 1038 struct proc *p = td->td_proc; 1039 int oonstack; 1040 int error = 0; 1041 1042 mtx_lock(&Giant); 1043 1044 oonstack = sigonstack(cpu_getstack(td)); 1045 1046 if (oss != NULL) { 1047 PROC_LOCK(p); 1048 *oss = p->p_sigstk; 1049 oss->ss_flags = (p->p_flag & P_ALTSTACK) 1050 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1051 PROC_UNLOCK(p); 1052 } 1053 1054 if (ss != NULL) { 1055 if (oonstack) { 1056 error = EPERM; 1057 goto done2; 1058 } 1059 if ((ss->ss_flags & ~SS_DISABLE) != 0) { 1060 error = EINVAL; 1061 goto done2; 1062 } 1063 if (!(ss->ss_flags & SS_DISABLE)) { 1064 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1065 error = ENOMEM; 1066 goto done2; 1067 } 1068 PROC_LOCK(p); 1069 p->p_sigstk = *ss; 1070 p->p_flag |= P_ALTSTACK; 1071 PROC_UNLOCK(p); 1072 } else { 1073 PROC_LOCK(p); 1074 p->p_flag &= ~P_ALTSTACK; 1075 PROC_UNLOCK(p); 1076 } 1077 } 1078 done2: 1079 mtx_unlock(&Giant); 1080 return (error); 1081 } 1082 1083 /* 1084 * Common code for kill process group/broadcast kill. 1085 * cp is calling process. 1086 */ 1087 static int 1088 killpg1(td, sig, pgid, all) 1089 register struct thread *td; 1090 int sig, pgid, all; 1091 { 1092 register struct proc *p; 1093 struct pgrp *pgrp; 1094 int nfound = 0; 1095 1096 if (all) { 1097 /* 1098 * broadcast 1099 */ 1100 sx_slock(&allproc_lock); 1101 LIST_FOREACH(p, &allproc, p_list) { 1102 PROC_LOCK(p); 1103 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1104 p == td->td_proc) { 1105 PROC_UNLOCK(p); 1106 continue; 1107 } 1108 if (p_cansignal(td, p, sig) == 0) { 1109 nfound++; 1110 if (sig) 1111 psignal(p, sig); 1112 } 1113 PROC_UNLOCK(p); 1114 } 1115 sx_sunlock(&allproc_lock); 1116 } else { 1117 sx_slock(&proctree_lock); 1118 if (pgid == 0) { 1119 /* 1120 * zero pgid means send to my process group. 1121 */ 1122 pgrp = td->td_proc->p_pgrp; 1123 PGRP_LOCK(pgrp); 1124 } else { 1125 pgrp = pgfind(pgid); 1126 if (pgrp == NULL) { 1127 sx_sunlock(&proctree_lock); 1128 return (ESRCH); 1129 } 1130 } 1131 sx_sunlock(&proctree_lock); 1132 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1133 PROC_LOCK(p); 1134 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1135 PROC_UNLOCK(p); 1136 continue; 1137 } 1138 if (p->p_state == PRS_ZOMBIE) { 1139 PROC_UNLOCK(p); 1140 continue; 1141 } 1142 if (p_cansignal(td, p, sig) == 0) { 1143 nfound++; 1144 if (sig) 1145 psignal(p, sig); 1146 } 1147 PROC_UNLOCK(p); 1148 } 1149 PGRP_UNLOCK(pgrp); 1150 } 1151 return (nfound ? 0 : ESRCH); 1152 } 1153 1154 #ifndef _SYS_SYSPROTO_H_ 1155 struct kill_args { 1156 int pid; 1157 int signum; 1158 }; 1159 #endif 1160 /* 1161 * MPSAFE 1162 */ 1163 /* ARGSUSED */ 1164 int 1165 kill(td, uap) 1166 register struct thread *td; 1167 register struct kill_args *uap; 1168 { 1169 register struct proc *p; 1170 int error = 0; 1171 1172 if ((u_int)uap->signum > _SIG_MAXSIG) 1173 return (EINVAL); 1174 1175 mtx_lock(&Giant); 1176 if (uap->pid > 0) { 1177 /* kill single process */ 1178 if ((p = pfind(uap->pid)) == NULL) { 1179 error = ESRCH; 1180 } else if ((error = p_cansignal(td, p, uap->signum)) != 0) { 1181 PROC_UNLOCK(p); 1182 } else { 1183 if (uap->signum) 1184 psignal(p, uap->signum); 1185 PROC_UNLOCK(p); 1186 error = 0; 1187 } 1188 } else { 1189 switch (uap->pid) { 1190 case -1: /* broadcast signal */ 1191 error = killpg1(td, uap->signum, 0, 1); 1192 break; 1193 case 0: /* signal own process group */ 1194 error = killpg1(td, uap->signum, 0, 0); 1195 break; 1196 default: /* negative explicit process group */ 1197 error = killpg1(td, uap->signum, -uap->pid, 0); 1198 break; 1199 } 1200 } 1201 mtx_unlock(&Giant); 1202 return(error); 1203 } 1204 1205 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1206 #ifndef _SYS_SYSPROTO_H_ 1207 struct okillpg_args { 1208 int pgid; 1209 int signum; 1210 }; 1211 #endif 1212 /* 1213 * MPSAFE 1214 */ 1215 /* ARGSUSED */ 1216 int 1217 okillpg(td, uap) 1218 struct thread *td; 1219 register struct okillpg_args *uap; 1220 { 1221 int error; 1222 1223 if ((u_int)uap->signum > _SIG_MAXSIG) 1224 return (EINVAL); 1225 mtx_lock(&Giant); 1226 error = killpg1(td, uap->signum, uap->pgid, 0); 1227 mtx_unlock(&Giant); 1228 return (error); 1229 } 1230 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1231 1232 /* 1233 * Send a signal to a process group. 1234 */ 1235 void 1236 gsignal(pgid, sig) 1237 int pgid, sig; 1238 { 1239 struct pgrp *pgrp; 1240 1241 if (pgid != 0) { 1242 sx_slock(&proctree_lock); 1243 pgrp = pgfind(pgid); 1244 sx_sunlock(&proctree_lock); 1245 if (pgrp != NULL) { 1246 pgsignal(pgrp, sig, 0); 1247 PGRP_UNLOCK(pgrp); 1248 } 1249 } 1250 } 1251 1252 /* 1253 * Send a signal to a process group. If checktty is 1, 1254 * limit to members which have a controlling terminal. 1255 */ 1256 void 1257 pgsignal(pgrp, sig, checkctty) 1258 struct pgrp *pgrp; 1259 int sig, checkctty; 1260 { 1261 register struct proc *p; 1262 1263 if (pgrp) { 1264 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1265 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1266 PROC_LOCK(p); 1267 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1268 psignal(p, sig); 1269 PROC_UNLOCK(p); 1270 } 1271 } 1272 } 1273 1274 /* 1275 * Send a signal caused by a trap to the current process. 1276 * If it will be caught immediately, deliver it with correct code. 1277 * Otherwise, post it normally. 1278 * 1279 * MPSAFE 1280 */ 1281 void 1282 trapsignal(p, sig, code) 1283 struct proc *p; 1284 register int sig; 1285 u_long code; 1286 { 1287 register struct sigacts *ps = p->p_sigacts; 1288 1289 PROC_LOCK(p); 1290 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 1291 !SIGISMEMBER(p->p_sigmask, sig)) { 1292 p->p_stats->p_ru.ru_nsignals++; 1293 #ifdef KTRACE 1294 if (KTRPOINT(curthread, KTR_PSIG)) 1295 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1296 &p->p_sigmask, code); 1297 #endif 1298 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 1299 &p->p_sigmask, code); 1300 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1301 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1302 SIGADDSET(p->p_sigmask, sig); 1303 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1304 /* 1305 * See kern_sigaction() for origin of this code. 1306 */ 1307 SIGDELSET(p->p_sigcatch, sig); 1308 if (sig != SIGCONT && 1309 sigprop(sig) & SA_IGNORE) 1310 SIGADDSET(p->p_sigignore, sig); 1311 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1312 } 1313 } else { 1314 p->p_code = code; /* XXX for core dump/debugger */ 1315 p->p_sig = sig; /* XXX to verify code */ 1316 psignal(p, sig); 1317 } 1318 PROC_UNLOCK(p); 1319 } 1320 1321 /* 1322 * Send the signal to the process. If the signal has an action, the action 1323 * is usually performed by the target process rather than the caller; we add 1324 * the signal to the set of pending signals for the process. 1325 * 1326 * Exceptions: 1327 * o When a stop signal is sent to a sleeping process that takes the 1328 * default action, the process is stopped without awakening it. 1329 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1330 * regardless of the signal action (eg, blocked or ignored). 1331 * 1332 * Other ignored signals are discarded immediately. 1333 */ 1334 void 1335 psignal(p, sig) 1336 register struct proc *p; 1337 register int sig; 1338 { 1339 register sig_t action; 1340 struct thread *td; 1341 register int prop; 1342 1343 1344 KASSERT(_SIG_VALID(sig), 1345 ("psignal(): invalid signal %d\n", sig)); 1346 1347 PROC_LOCK_ASSERT(p, MA_OWNED); 1348 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1349 1350 prop = sigprop(sig); 1351 /* 1352 * If proc is traced, always give parent a chance; 1353 * if signal event is tracked by procfs, give *that* 1354 * a chance, as well. 1355 */ 1356 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1357 action = SIG_DFL; 1358 } else { 1359 /* 1360 * If the signal is being ignored, 1361 * then we forget about it immediately. 1362 * (Note: we don't set SIGCONT in p_sigignore, 1363 * and if it is set to SIG_IGN, 1364 * action will be SIG_DFL here.) 1365 */ 1366 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1367 return; 1368 if (SIGISMEMBER(p->p_sigmask, sig)) 1369 action = SIG_HOLD; 1370 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1371 action = SIG_CATCH; 1372 else 1373 action = SIG_DFL; 1374 } 1375 1376 if (prop & SA_CONT) 1377 SIG_STOPSIGMASK(p->p_siglist); 1378 1379 if (prop & SA_STOP) { 1380 /* 1381 * If sending a tty stop signal to a member of an orphaned 1382 * process group, discard the signal here if the action 1383 * is default; don't stop the process below if sleeping, 1384 * and don't clear any pending SIGCONT. 1385 */ 1386 if ((prop & SA_TTYSTOP) && 1387 (p->p_pgrp->pg_jobc == 0) && 1388 (action == SIG_DFL)) 1389 return; 1390 SIG_CONTSIGMASK(p->p_siglist); 1391 p->p_flag &= ~P_CONTINUED; 1392 } 1393 SIGADDSET(p->p_siglist, sig); 1394 signotify(p); /* uses schedlock */ 1395 1396 /* 1397 * Some signals have a process-wide effect and a per-thread 1398 * component. Most processing occurs when the process next 1399 * tries to cross the user boundary, however there are some 1400 * times when processing needs to be done immediatly, such as 1401 * waking up threads so that they can cross the user boundary. 1402 * We try do the per-process part here. 1403 */ 1404 if (P_SHOULDSTOP(p)) { 1405 /* 1406 * The process is in stopped mode. All the threads should be 1407 * either winding down or already on the suspended queue. 1408 */ 1409 if (p->p_flag & P_TRACED) { 1410 /* 1411 * The traced process is already stopped, 1412 * so no further action is necessary. 1413 * No signal can restart us. 1414 */ 1415 goto out; 1416 } 1417 1418 if (sig == SIGKILL) { 1419 /* 1420 * SIGKILL sets process running. 1421 * It will die elsewhere. 1422 * All threads must be restarted. 1423 */ 1424 p->p_flag &= ~P_STOPPED; 1425 goto runfast; 1426 } 1427 1428 if (prop & SA_CONT) { 1429 /* 1430 * If SIGCONT is default (or ignored), we continue the 1431 * process but don't leave the signal in p_siglist as 1432 * it has no further action. If SIGCONT is held, we 1433 * continue the process and leave the signal in 1434 * p_siglist. If the process catches SIGCONT, let it 1435 * handle the signal itself. If it isn't waiting on 1436 * an event, it goes back to run state. 1437 * Otherwise, process goes back to sleep state. 1438 */ 1439 p->p_flag &= ~P_STOPPED_SIG; 1440 p->p_flag |= P_CONTINUED; 1441 if (action == SIG_DFL) { 1442 SIGDELSET(p->p_siglist, sig); 1443 } else if (action == SIG_CATCH) { 1444 /* 1445 * The process wants to catch it so it needs 1446 * to run at least one thread, but which one? 1447 * It would seem that the answer would be to 1448 * run an upcall in the next KSE to run, and 1449 * deliver the signal that way. In a NON KSE 1450 * process, we need to make sure that the 1451 * single thread is runnable asap. 1452 * XXXKSE for now however, make them all run. 1453 */ 1454 goto runfast; 1455 } 1456 /* 1457 * The signal is not ignored or caught. 1458 */ 1459 mtx_lock_spin(&sched_lock); 1460 thread_unsuspend(p); 1461 mtx_unlock_spin(&sched_lock); 1462 goto out; 1463 } 1464 1465 if (prop & SA_STOP) { 1466 /* 1467 * Already stopped, don't need to stop again 1468 * (If we did the shell could get confused). 1469 * Just make sure the signal STOP bit set. 1470 */ 1471 p->p_flag |= P_STOPPED_SIG; 1472 SIGDELSET(p->p_siglist, sig); 1473 goto out; 1474 } 1475 1476 /* 1477 * All other kinds of signals: 1478 * If a thread is sleeping interruptibly, simulate a 1479 * wakeup so that when it is continued it will be made 1480 * runnable and can look at the signal. However, don't make 1481 * the PROCESS runnable, leave it stopped. 1482 * It may run a bit until it hits a thread_suspend_check(). 1483 */ 1484 mtx_lock_spin(&sched_lock); 1485 FOREACH_THREAD_IN_PROC(p, td) { 1486 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) { 1487 if (td->td_flags & TDF_CVWAITQ) 1488 cv_abort(td); 1489 else 1490 abortsleep(td); 1491 } 1492 } 1493 mtx_unlock_spin(&sched_lock); 1494 goto out; 1495 /* 1496 * XXXKSE What about threads that are waiting on mutexes? 1497 * Shouldn't they abort too? 1498 * No, hopefully mutexes are short lived.. They'll 1499 * eventually hit thread_suspend_check(). 1500 */ 1501 } else if (p->p_state == PRS_NORMAL) { 1502 if (prop & SA_CONT) { 1503 /* 1504 * Already active, don't need to start again. 1505 */ 1506 SIGDELSET(p->p_siglist, sig); 1507 goto out; 1508 } 1509 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || 1510 !(prop & SA_STOP)) { 1511 mtx_lock_spin(&sched_lock); 1512 FOREACH_THREAD_IN_PROC(p, td) 1513 tdsignal(td, sig, action); 1514 mtx_unlock_spin(&sched_lock); 1515 goto out; 1516 } 1517 if (prop & SA_STOP) { 1518 if (p->p_flag & P_PPWAIT) 1519 goto out; 1520 mtx_lock_spin(&sched_lock); 1521 FOREACH_THREAD_IN_PROC(p, td) { 1522 if (TD_IS_SLEEPING(td) && 1523 (td->td_flags & TDF_SINTR)) 1524 thread_suspend_one(td); 1525 else if (TD_IS_IDLE(td)) { 1526 thread_suspend_one(td); 1527 } 1528 } 1529 if (p->p_suspcount == p->p_numthreads) { 1530 mtx_unlock_spin(&sched_lock); 1531 stop(p); 1532 p->p_xstat = sig; 1533 SIGDELSET(p->p_siglist, sig); 1534 PROC_LOCK(p->p_pptr); 1535 if ((p->p_pptr->p_procsig->ps_flag & 1536 PS_NOCLDSTOP) == 0) { 1537 psignal(p->p_pptr, SIGCHLD); 1538 } 1539 PROC_UNLOCK(p->p_pptr); 1540 } else { 1541 mtx_unlock_spin(&sched_lock); 1542 } 1543 goto out; 1544 } 1545 else 1546 goto runfast; 1547 /* NOTREACHED */ 1548 } else { 1549 /* Not in "NORMAL" state. discard the signal. */ 1550 SIGDELSET(p->p_siglist, sig); 1551 goto out; 1552 } 1553 1554 /* 1555 * The process is not stopped so we need to apply the signal to all the 1556 * running threads. 1557 */ 1558 1559 runfast: 1560 mtx_lock_spin(&sched_lock); 1561 FOREACH_THREAD_IN_PROC(p, td) 1562 tdsignal(td, sig, action); 1563 thread_unsuspend(p); 1564 mtx_unlock_spin(&sched_lock); 1565 out: 1566 /* If we jump here, sched_lock should not be owned. */ 1567 mtx_assert(&sched_lock, MA_NOTOWNED); 1568 } 1569 1570 /* 1571 * The force of a signal has been directed against a single 1572 * thread. We need to see what we can do about knocking it 1573 * out of any sleep it may be in etc. 1574 */ 1575 static void 1576 tdsignal(struct thread *td, int sig, sig_t action) 1577 { 1578 struct proc *p = td->td_proc; 1579 register int prop; 1580 1581 mtx_assert(&sched_lock, MA_OWNED); 1582 prop = sigprop(sig); 1583 /* 1584 * Bring the priority of a thread up if we want it to get 1585 * killed in this lifetime. 1586 */ 1587 if ((action == SIG_DFL) && (prop & SA_KILL)) { 1588 if (td->td_priority > PUSER) { 1589 td->td_priority = PUSER; 1590 } 1591 } 1592 1593 /* 1594 * Defer further processing for signals which are held, 1595 * except that stopped processes must be continued by SIGCONT. 1596 */ 1597 if (action == SIG_HOLD) { 1598 return; 1599 } 1600 if (TD_IS_SLEEPING(td)) { 1601 /* 1602 * If thread is sleeping uninterruptibly 1603 * we can't interrupt the sleep... the signal will 1604 * be noticed when the process returns through 1605 * trap() or syscall(). 1606 */ 1607 if ((td->td_flags & TDF_SINTR) == 0) { 1608 return; 1609 } 1610 /* 1611 * Process is sleeping and traced. Make it runnable 1612 * so it can discover the signal in issignal() and stop 1613 * for its parent. 1614 */ 1615 if (p->p_flag & P_TRACED) { 1616 p->p_flag &= ~P_STOPPED_TRACE; 1617 } else { 1618 1619 /* 1620 * If SIGCONT is default (or ignored) and process is 1621 * asleep, we are finished; the process should not 1622 * be awakened. 1623 */ 1624 if ((prop & SA_CONT) && action == SIG_DFL) { 1625 SIGDELSET(p->p_siglist, sig); 1626 return; 1627 } 1628 1629 /* 1630 * Raise priority to at least PUSER. 1631 */ 1632 if (td->td_priority > PUSER) { 1633 td->td_priority = PUSER; 1634 } 1635 } 1636 if (td->td_flags & TDF_CVWAITQ) 1637 cv_abort(td); 1638 else 1639 abortsleep(td); 1640 } else if (TD_IS_IDLE(td)) { 1641 TD_CLR_IDLE(td); 1642 setrunnable(td); 1643 } 1644 #ifdef SMP 1645 else { 1646 /* 1647 * Other states do nothing with the signal immediatly, 1648 * other than kicking ourselves if we are running. 1649 * It will either never be noticed, or noticed very soon. 1650 */ 1651 if (TD_IS_RUNNING(td) && td != curthread) { 1652 forward_signal(td); 1653 } 1654 } 1655 #endif 1656 } 1657 1658 /* 1659 * If the current process has received a signal (should be caught or cause 1660 * termination, should interrupt current syscall), return the signal number. 1661 * Stop signals with default action are processed immediately, then cleared; 1662 * they aren't returned. This is checked after each entry to the system for 1663 * a syscall or trap (though this can usually be done without calling issignal 1664 * by checking the pending signal masks in cursig.) The normal call 1665 * sequence is 1666 * 1667 * while (sig = cursig(curthread)) 1668 * postsig(sig); 1669 */ 1670 int 1671 issignal(td) 1672 struct thread *td; 1673 { 1674 struct proc *p; 1675 sigset_t mask; 1676 register int sig, prop; 1677 1678 p = td->td_proc; 1679 PROC_LOCK_ASSERT(p, MA_OWNED); 1680 WITNESS_SLEEP(1, &p->p_mtx.mtx_object); 1681 for (;;) { 1682 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1683 1684 mask = p->p_siglist; 1685 SIGSETNAND(mask, p->p_sigmask); 1686 if (p->p_flag & P_PPWAIT) 1687 SIG_STOPSIGMASK(mask); 1688 if (SIGISEMPTY(mask)) /* no signal to send */ 1689 return (0); 1690 sig = sig_ffs(&mask); 1691 prop = sigprop(sig); 1692 1693 _STOPEVENT(p, S_SIG, sig); 1694 1695 /* 1696 * We should see pending but ignored signals 1697 * only if P_TRACED was on when they were posted. 1698 */ 1699 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1700 SIGDELSET(p->p_siglist, sig); 1701 continue; 1702 } 1703 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1704 /* 1705 * If traced, always stop. 1706 */ 1707 p->p_xstat = sig; 1708 PROC_LOCK(p->p_pptr); 1709 psignal(p->p_pptr, SIGCHLD); 1710 PROC_UNLOCK(p->p_pptr); 1711 mtx_lock_spin(&sched_lock); 1712 stop(p); /* uses schedlock too eventually */ 1713 thread_suspend_one(td); 1714 PROC_UNLOCK(p); 1715 DROP_GIANT(); 1716 p->p_stats->p_ru.ru_nivcsw++; 1717 mi_switch(); 1718 mtx_unlock_spin(&sched_lock); 1719 PICKUP_GIANT(); 1720 PROC_LOCK(p); 1721 1722 /* 1723 * If the traced bit got turned off, go back up 1724 * to the top to rescan signals. This ensures 1725 * that p_sig* and ps_sigact are consistent. 1726 */ 1727 if ((p->p_flag & P_TRACED) == 0) 1728 continue; 1729 1730 /* 1731 * If parent wants us to take the signal, 1732 * then it will leave it in p->p_xstat; 1733 * otherwise we just look for signals again. 1734 */ 1735 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1736 sig = p->p_xstat; 1737 if (sig == 0) 1738 continue; 1739 1740 /* 1741 * Put the new signal into p_siglist. If the 1742 * signal is being masked, look for other signals. 1743 */ 1744 SIGADDSET(p->p_siglist, sig); 1745 if (SIGISMEMBER(p->p_sigmask, sig)) 1746 continue; 1747 signotify(p); 1748 } 1749 1750 /* 1751 * Decide whether the signal should be returned. 1752 * Return the signal's number, or fall through 1753 * to clear it from the pending mask. 1754 */ 1755 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1756 1757 case (intptr_t)SIG_DFL: 1758 /* 1759 * Don't take default actions on system processes. 1760 */ 1761 if (p->p_pid <= 1) { 1762 #ifdef DIAGNOSTIC 1763 /* 1764 * Are you sure you want to ignore SIGSEGV 1765 * in init? XXX 1766 */ 1767 printf("Process (pid %lu) got signal %d\n", 1768 (u_long)p->p_pid, sig); 1769 #endif 1770 break; /* == ignore */ 1771 } 1772 /* 1773 * If there is a pending stop signal to process 1774 * with default action, stop here, 1775 * then clear the signal. However, 1776 * if process is member of an orphaned 1777 * process group, ignore tty stop signals. 1778 */ 1779 if (prop & SA_STOP) { 1780 if (p->p_flag & P_TRACED || 1781 (p->p_pgrp->pg_jobc == 0 && 1782 prop & SA_TTYSTOP)) 1783 break; /* == ignore */ 1784 p->p_xstat = sig; 1785 mtx_lock_spin(&sched_lock); 1786 if (p->p_suspcount+1 == p->p_numthreads) { 1787 mtx_unlock_spin(&sched_lock); 1788 PROC_LOCK(p->p_pptr); 1789 if ((p->p_pptr->p_procsig->ps_flag & 1790 PS_NOCLDSTOP) == 0) { 1791 psignal(p->p_pptr, SIGCHLD); 1792 } 1793 PROC_UNLOCK(p->p_pptr); 1794 mtx_lock_spin(&sched_lock); 1795 } 1796 stop(p); 1797 thread_suspend_one(td); 1798 PROC_UNLOCK(p); 1799 DROP_GIANT(); 1800 p->p_stats->p_ru.ru_nivcsw++; 1801 mi_switch(); 1802 mtx_unlock_spin(&sched_lock); 1803 PICKUP_GIANT(); 1804 PROC_LOCK(p); 1805 break; 1806 } else if (prop & SA_IGNORE) { 1807 /* 1808 * Except for SIGCONT, shouldn't get here. 1809 * Default action is to ignore; drop it. 1810 */ 1811 break; /* == ignore */ 1812 } else 1813 return (sig); 1814 /*NOTREACHED*/ 1815 1816 case (intptr_t)SIG_IGN: 1817 /* 1818 * Masking above should prevent us ever trying 1819 * to take action on an ignored signal other 1820 * than SIGCONT, unless process is traced. 1821 */ 1822 if ((prop & SA_CONT) == 0 && 1823 (p->p_flag & P_TRACED) == 0) 1824 printf("issignal\n"); 1825 break; /* == ignore */ 1826 1827 default: 1828 /* 1829 * This signal has an action, let 1830 * postsig() process it. 1831 */ 1832 return (sig); 1833 } 1834 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1835 } 1836 /* NOTREACHED */ 1837 } 1838 1839 /* 1840 * Put the argument process into the stopped state and notify the parent 1841 * via wakeup. Signals are handled elsewhere. The process must not be 1842 * on the run queue. Must be called with the proc p locked and the scheduler 1843 * lock held. 1844 */ 1845 static void 1846 stop(p) 1847 register struct proc *p; 1848 { 1849 1850 PROC_LOCK_ASSERT(p, MA_OWNED); 1851 p->p_flag |= P_STOPPED_SIG; 1852 p->p_flag &= ~P_WAITED; 1853 wakeup(p->p_pptr); 1854 } 1855 1856 /* 1857 * Take the action for the specified signal 1858 * from the current set of pending signals. 1859 */ 1860 void 1861 postsig(sig) 1862 register int sig; 1863 { 1864 struct thread *td = curthread; 1865 register struct proc *p = td->td_proc; 1866 struct sigacts *ps; 1867 sig_t action; 1868 sigset_t returnmask; 1869 int code; 1870 1871 KASSERT(sig != 0, ("postsig")); 1872 1873 PROC_LOCK_ASSERT(p, MA_OWNED); 1874 ps = p->p_sigacts; 1875 SIGDELSET(p->p_siglist, sig); 1876 action = ps->ps_sigact[_SIG_IDX(sig)]; 1877 #ifdef KTRACE 1878 if (KTRPOINT(td, KTR_PSIG)) 1879 ktrpsig(sig, action, p->p_flag & P_OLDMASK ? 1880 &p->p_oldsigmask : &p->p_sigmask, 0); 1881 #endif 1882 _STOPEVENT(p, S_SIG, sig); 1883 1884 if (action == SIG_DFL) { 1885 /* 1886 * Default action, where the default is to kill 1887 * the process. (Other cases were ignored above.) 1888 */ 1889 sigexit(td, sig); 1890 /* NOTREACHED */ 1891 } else { 1892 /* 1893 * If we get here, the signal must be caught. 1894 */ 1895 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1896 ("postsig action")); 1897 /* 1898 * Set the new mask value and also defer further 1899 * occurrences of this signal. 1900 * 1901 * Special case: user has done a sigsuspend. Here the 1902 * current mask is not of interest, but rather the 1903 * mask from before the sigsuspend is what we want 1904 * restored after the signal processing is completed. 1905 */ 1906 if (p->p_flag & P_OLDMASK) { 1907 returnmask = p->p_oldsigmask; 1908 p->p_flag &= ~P_OLDMASK; 1909 } else 1910 returnmask = p->p_sigmask; 1911 1912 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1913 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1914 SIGADDSET(p->p_sigmask, sig); 1915 1916 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1917 /* 1918 * See kern_sigaction() for origin of this code. 1919 */ 1920 SIGDELSET(p->p_sigcatch, sig); 1921 if (sig != SIGCONT && 1922 sigprop(sig) & SA_IGNORE) 1923 SIGADDSET(p->p_sigignore, sig); 1924 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1925 } 1926 p->p_stats->p_ru.ru_nsignals++; 1927 if (p->p_sig != sig) { 1928 code = 0; 1929 } else { 1930 code = p->p_code; 1931 p->p_code = 0; 1932 p->p_sig = 0; 1933 } 1934 if (p->p_flag & P_KSES) 1935 if (signal_upcall(p, sig)) 1936 return; 1937 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1938 } 1939 } 1940 1941 /* 1942 * Kill the current process for stated reason. 1943 */ 1944 void 1945 killproc(p, why) 1946 struct proc *p; 1947 char *why; 1948 { 1949 1950 PROC_LOCK_ASSERT(p, MA_OWNED); 1951 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 1952 p, p->p_pid, p->p_comm); 1953 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1954 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1955 psignal(p, SIGKILL); 1956 } 1957 1958 /* 1959 * Force the current process to exit with the specified signal, dumping core 1960 * if appropriate. We bypass the normal tests for masked and caught signals, 1961 * allowing unrecoverable failures to terminate the process without changing 1962 * signal state. Mark the accounting record with the signal termination. 1963 * If dumping core, save the signal number for the debugger. Calls exit and 1964 * does not return. 1965 */ 1966 void 1967 sigexit(td, sig) 1968 struct thread *td; 1969 int sig; 1970 { 1971 struct proc *p = td->td_proc; 1972 1973 PROC_LOCK_ASSERT(p, MA_OWNED); 1974 p->p_acflag |= AXSIG; 1975 if (sigprop(sig) & SA_CORE) { 1976 p->p_sig = sig; 1977 /* 1978 * Log signals which would cause core dumps 1979 * (Log as LOG_INFO to appease those who don't want 1980 * these messages.) 1981 * XXX : Todo, as well as euid, write out ruid too 1982 */ 1983 PROC_UNLOCK(p); 1984 if (!mtx_owned(&Giant)) 1985 mtx_lock(&Giant); 1986 if (coredump(td) == 0) 1987 sig |= WCOREFLAG; 1988 if (kern_logsigexit) 1989 log(LOG_INFO, 1990 "pid %d (%s), uid %d: exited on signal %d%s\n", 1991 p->p_pid, p->p_comm, 1992 td->td_ucred ? td->td_ucred->cr_uid : -1, 1993 sig &~ WCOREFLAG, 1994 sig & WCOREFLAG ? " (core dumped)" : ""); 1995 } else { 1996 PROC_UNLOCK(p); 1997 if (!mtx_owned(&Giant)) 1998 mtx_lock(&Giant); 1999 } 2000 exit1(td, W_EXITCODE(0, sig)); 2001 /* NOTREACHED */ 2002 } 2003 2004 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2005 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2006 sizeof(corefilename), "process corefile name format string"); 2007 2008 /* 2009 * expand_name(name, uid, pid) 2010 * Expand the name described in corefilename, using name, uid, and pid. 2011 * corefilename is a printf-like string, with three format specifiers: 2012 * %N name of process ("name") 2013 * %P process id (pid) 2014 * %U user id (uid) 2015 * For example, "%N.core" is the default; they can be disabled completely 2016 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2017 * This is controlled by the sysctl variable kern.corefile (see above). 2018 */ 2019 2020 static char * 2021 expand_name(name, uid, pid) 2022 const char *name; 2023 uid_t uid; 2024 pid_t pid; 2025 { 2026 const char *format, *appendstr; 2027 char *temp; 2028 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2029 size_t i, l, n; 2030 2031 format = corefilename; 2032 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2033 if (temp == NULL) 2034 return (NULL); 2035 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2036 switch (format[i]) { 2037 case '%': /* Format character */ 2038 i++; 2039 switch (format[i]) { 2040 case '%': 2041 appendstr = "%"; 2042 break; 2043 case 'N': /* process name */ 2044 appendstr = name; 2045 break; 2046 case 'P': /* process id */ 2047 sprintf(buf, "%u", pid); 2048 appendstr = buf; 2049 break; 2050 case 'U': /* user id */ 2051 sprintf(buf, "%u", uid); 2052 appendstr = buf; 2053 break; 2054 default: 2055 appendstr = ""; 2056 log(LOG_ERR, 2057 "Unknown format character %c in `%s'\n", 2058 format[i], format); 2059 } 2060 l = strlen(appendstr); 2061 if ((n + l) >= MAXPATHLEN) 2062 goto toolong; 2063 memcpy(temp + n, appendstr, l); 2064 n += l; 2065 break; 2066 default: 2067 temp[n++] = format[i]; 2068 } 2069 } 2070 if (format[i] != '\0') 2071 goto toolong; 2072 return (temp); 2073 toolong: 2074 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2075 (long)pid, name, (u_long)uid); 2076 free(temp, M_TEMP); 2077 return (NULL); 2078 } 2079 2080 /* 2081 * Dump a process' core. The main routine does some 2082 * policy checking, and creates the name of the coredump; 2083 * then it passes on a vnode and a size limit to the process-specific 2084 * coredump routine if there is one; if there _is not_ one, it returns 2085 * ENOSYS; otherwise it returns the error from the process-specific routine. 2086 */ 2087 2088 static int 2089 coredump(struct thread *td) 2090 { 2091 struct proc *p = td->td_proc; 2092 register struct vnode *vp; 2093 register struct ucred *cred = td->td_ucred; 2094 struct flock lf; 2095 struct nameidata nd; 2096 struct vattr vattr; 2097 int error, error1, flags; 2098 struct mount *mp; 2099 char *name; /* name of corefile */ 2100 off_t limit; 2101 2102 PROC_LOCK(p); 2103 _STOPEVENT(p, S_CORE, 0); 2104 2105 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2106 PROC_UNLOCK(p); 2107 return (EFAULT); 2108 } 2109 2110 /* 2111 * Note that the bulk of limit checking is done after 2112 * the corefile is created. The exception is if the limit 2113 * for corefiles is 0, in which case we don't bother 2114 * creating the corefile at all. This layout means that 2115 * a corefile is truncated instead of not being created, 2116 * if it is larger than the limit. 2117 */ 2118 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2119 if (limit == 0) { 2120 PROC_UNLOCK(p); 2121 return 0; 2122 } 2123 PROC_UNLOCK(p); 2124 2125 restart: 2126 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2127 if (name == NULL) 2128 return (EINVAL); 2129 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2130 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2131 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); 2132 free(name, M_TEMP); 2133 if (error) 2134 return (error); 2135 NDFREE(&nd, NDF_ONLY_PNBUF); 2136 vp = nd.ni_vp; 2137 2138 /* Don't dump to non-regular files or files with links. */ 2139 if (vp->v_type != VREG || 2140 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2141 VOP_UNLOCK(vp, 0, td); 2142 error = EFAULT; 2143 goto out2; 2144 } 2145 2146 VOP_UNLOCK(vp, 0, td); 2147 lf.l_whence = SEEK_SET; 2148 lf.l_start = 0; 2149 lf.l_len = 0; 2150 lf.l_type = F_WRLCK; 2151 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 2152 if (error) 2153 goto out2; 2154 2155 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2156 lf.l_type = F_UNLCK; 2157 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2158 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2159 return (error); 2160 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2161 return (error); 2162 goto restart; 2163 } 2164 2165 VATTR_NULL(&vattr); 2166 vattr.va_size = 0; 2167 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2168 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2169 VOP_SETATTR(vp, &vattr, cred, td); 2170 VOP_UNLOCK(vp, 0, td); 2171 PROC_LOCK(p); 2172 p->p_acflag |= ACORE; 2173 PROC_UNLOCK(p); 2174 2175 error = p->p_sysent->sv_coredump ? 2176 p->p_sysent->sv_coredump(td, vp, limit) : 2177 ENOSYS; 2178 2179 lf.l_type = F_UNLCK; 2180 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2181 vn_finished_write(mp); 2182 out2: 2183 error1 = vn_close(vp, FWRITE, cred, td); 2184 if (error == 0) 2185 error = error1; 2186 return (error); 2187 } 2188 2189 /* 2190 * Nonexistent system call-- signal process (may want to handle it). 2191 * Flag error in case process won't see signal immediately (blocked or ignored). 2192 */ 2193 #ifndef _SYS_SYSPROTO_H_ 2194 struct nosys_args { 2195 int dummy; 2196 }; 2197 #endif 2198 /* 2199 * MPSAFE 2200 */ 2201 /* ARGSUSED */ 2202 int 2203 nosys(td, args) 2204 struct thread *td; 2205 struct nosys_args *args; 2206 { 2207 struct proc *p = td->td_proc; 2208 2209 mtx_lock(&Giant); 2210 PROC_LOCK(p); 2211 psignal(p, SIGSYS); 2212 PROC_UNLOCK(p); 2213 mtx_unlock(&Giant); 2214 return (ENOSYS); 2215 } 2216 2217 /* 2218 * Send a SIGIO or SIGURG signal to a process or process group using 2219 * stored credentials rather than those of the current process. 2220 */ 2221 void 2222 pgsigio(sigiop, sig, checkctty) 2223 struct sigio **sigiop; 2224 int sig, checkctty; 2225 { 2226 struct sigio *sigio; 2227 2228 SIGIO_LOCK(); 2229 sigio = *sigiop; 2230 if (sigio == NULL) { 2231 SIGIO_UNLOCK(); 2232 return; 2233 } 2234 if (sigio->sio_pgid > 0) { 2235 PROC_LOCK(sigio->sio_proc); 2236 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2237 psignal(sigio->sio_proc, sig); 2238 PROC_UNLOCK(sigio->sio_proc); 2239 } else if (sigio->sio_pgid < 0) { 2240 struct proc *p; 2241 2242 PGRP_LOCK(sigio->sio_pgrp); 2243 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2244 PROC_LOCK(p); 2245 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2246 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2247 psignal(p, sig); 2248 PROC_UNLOCK(p); 2249 } 2250 PGRP_UNLOCK(sigio->sio_pgrp); 2251 } 2252 SIGIO_UNLOCK(); 2253 } 2254 2255 static int 2256 filt_sigattach(struct knote *kn) 2257 { 2258 struct proc *p = curproc; 2259 2260 kn->kn_ptr.p_proc = p; 2261 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2262 2263 PROC_LOCK(p); 2264 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2265 PROC_UNLOCK(p); 2266 2267 return (0); 2268 } 2269 2270 static void 2271 filt_sigdetach(struct knote *kn) 2272 { 2273 struct proc *p = kn->kn_ptr.p_proc; 2274 2275 PROC_LOCK(p); 2276 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2277 PROC_UNLOCK(p); 2278 } 2279 2280 /* 2281 * signal knotes are shared with proc knotes, so we apply a mask to 2282 * the hint in order to differentiate them from process hints. This 2283 * could be avoided by using a signal-specific knote list, but probably 2284 * isn't worth the trouble. 2285 */ 2286 static int 2287 filt_signal(struct knote *kn, long hint) 2288 { 2289 2290 if (hint & NOTE_SIGNAL) { 2291 hint &= ~NOTE_SIGNAL; 2292 2293 if (kn->kn_id == hint) 2294 kn->kn_data++; 2295 } 2296 return (kn->kn_data != 0); 2297 } 2298