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(COMPAT_FREEBSD4) && !defined(NO_COMPAT_FREEBSD4) 77 #error "You *really* want COMPAT_FREEBSD4 on -current for a while" 78 #endif 79 #if defined (__alpha__) && !defined(COMPAT_43) 80 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 81 #endif 82 83 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 84 85 static int coredump(struct thread *); 86 static int do_sigprocmask(struct proc *p, int how, sigset_t *set, 87 sigset_t *oset, int old); 88 static char *expand_name(const char *, uid_t, pid_t); 89 static int killpg1(struct thread *td, int sig, int pgid, int all); 90 static int sig_ffs(sigset_t *set); 91 static int sigprop(int sig); 92 static void stop(struct proc *); 93 static void tdsignal(struct thread *td, int sig, sig_t action); 94 static int filt_sigattach(struct knote *kn); 95 static void filt_sigdetach(struct knote *kn); 96 static int filt_signal(struct knote *kn, long hint); 97 98 struct filterops sig_filtops = 99 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 100 101 static int kern_logsigexit = 1; 102 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 103 &kern_logsigexit, 0, 104 "Log processes quitting on abnormal signals to syslog(3)"); 105 106 /* 107 * Policy -- Can ucred cr1 send SIGIO to process cr2? 108 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 109 * in the right situations. 110 */ 111 #define CANSIGIO(cr1, cr2) \ 112 ((cr1)->cr_uid == 0 || \ 113 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 114 (cr1)->cr_uid == (cr2)->cr_ruid || \ 115 (cr1)->cr_ruid == (cr2)->cr_uid || \ 116 (cr1)->cr_uid == (cr2)->cr_uid) 117 118 int sugid_coredump; 119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 121 122 static int do_coredump = 1; 123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 124 &do_coredump, 0, "Enable/Disable coredumps"); 125 126 /* 127 * Signal properties and actions. 128 * The array below categorizes the signals and their default actions 129 * according to the following properties: 130 */ 131 #define SA_KILL 0x01 /* terminates process by default */ 132 #define SA_CORE 0x02 /* ditto and coredumps */ 133 #define SA_STOP 0x04 /* suspend process */ 134 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 135 #define SA_IGNORE 0x10 /* ignore by default */ 136 #define SA_CONT 0x20 /* continue if suspended */ 137 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 138 139 static int sigproptbl[NSIG] = { 140 SA_KILL, /* SIGHUP */ 141 SA_KILL, /* SIGINT */ 142 SA_KILL|SA_CORE, /* SIGQUIT */ 143 SA_KILL|SA_CORE, /* SIGILL */ 144 SA_KILL|SA_CORE, /* SIGTRAP */ 145 SA_KILL|SA_CORE, /* SIGABRT */ 146 SA_KILL|SA_CORE, /* SIGEMT */ 147 SA_KILL|SA_CORE, /* SIGFPE */ 148 SA_KILL, /* SIGKILL */ 149 SA_KILL|SA_CORE, /* SIGBUS */ 150 SA_KILL|SA_CORE, /* SIGSEGV */ 151 SA_KILL|SA_CORE, /* SIGSYS */ 152 SA_KILL, /* SIGPIPE */ 153 SA_KILL, /* SIGALRM */ 154 SA_KILL, /* SIGTERM */ 155 SA_IGNORE, /* SIGURG */ 156 SA_STOP, /* SIGSTOP */ 157 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 158 SA_IGNORE|SA_CONT, /* SIGCONT */ 159 SA_IGNORE, /* SIGCHLD */ 160 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 161 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 162 SA_IGNORE, /* SIGIO */ 163 SA_KILL, /* SIGXCPU */ 164 SA_KILL, /* SIGXFSZ */ 165 SA_KILL, /* SIGVTALRM */ 166 SA_KILL, /* SIGPROF */ 167 SA_IGNORE, /* SIGWINCH */ 168 SA_IGNORE, /* SIGINFO */ 169 SA_KILL, /* SIGUSR1 */ 170 SA_KILL, /* SIGUSR2 */ 171 }; 172 173 /* 174 * Determine signal that should be delivered to process p, the current 175 * process, 0 if none. If there is a pending stop signal with default 176 * action, the process stops in issignal(). 177 * XXXKSE the check for a pending stop is not done under KSE 178 * 179 * MP SAFE. 180 */ 181 int 182 cursig(struct thread *td) 183 { 184 struct proc *p = td->td_proc; 185 186 PROC_LOCK_ASSERT(p, MA_OWNED); 187 mtx_assert(&sched_lock, MA_NOTOWNED); 188 return (SIGPENDING(p) ? issignal(td) : 0); 189 } 190 191 /* 192 * Arrange for ast() to handle unmasked pending signals on return to user 193 * mode. This must be called whenever a signal is added to p_siglist or 194 * unmasked in p_sigmask. 195 */ 196 void 197 signotify(struct proc *p) 198 { 199 struct kse *ke; 200 struct ksegrp *kg; 201 202 PROC_LOCK_ASSERT(p, MA_OWNED); 203 mtx_lock_spin(&sched_lock); 204 if (SIGPENDING(p)) { 205 p->p_sflag |= PS_NEEDSIGCHK; 206 /* XXXKSE for now punish all KSEs */ 207 FOREACH_KSEGRP_IN_PROC(p, kg) { 208 FOREACH_KSE_IN_GROUP(kg, ke) { 209 ke->ke_flags |= KEF_ASTPENDING; 210 } 211 } 212 } 213 mtx_unlock_spin(&sched_lock); 214 } 215 216 static __inline int 217 sigprop(int sig) 218 { 219 220 if (sig > 0 && sig < NSIG) 221 return (sigproptbl[_SIG_IDX(sig)]); 222 return (0); 223 } 224 225 static __inline int 226 sig_ffs(sigset_t *set) 227 { 228 int i; 229 230 for (i = 0; i < _SIG_WORDS; i++) 231 if (set->__bits[i]) 232 return (ffs(set->__bits[i]) + (i * 32)); 233 return (0); 234 } 235 236 /* 237 * kern_sigaction 238 * sigaction 239 * freebsd4_sigaction 240 * osigaction 241 */ 242 int 243 kern_sigaction(td, sig, act, oact, flags) 244 struct thread *td; 245 register int sig; 246 struct sigaction *act, *oact; 247 int flags; 248 { 249 register struct sigacts *ps; 250 struct proc *p = td->td_proc; 251 252 if (!_SIG_VALID(sig)) 253 return (EINVAL); 254 255 PROC_LOCK(p); 256 ps = p->p_sigacts; 257 if (oact) { 258 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 259 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 260 oact->sa_flags = 0; 261 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 262 oact->sa_flags |= SA_ONSTACK; 263 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 264 oact->sa_flags |= SA_RESTART; 265 if (SIGISMEMBER(ps->ps_sigreset, sig)) 266 oact->sa_flags |= SA_RESETHAND; 267 if (SIGISMEMBER(ps->ps_signodefer, sig)) 268 oact->sa_flags |= SA_NODEFER; 269 if (SIGISMEMBER(ps->ps_siginfo, sig)) 270 oact->sa_flags |= SA_SIGINFO; 271 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 272 oact->sa_flags |= SA_NOCLDSTOP; 273 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 274 oact->sa_flags |= SA_NOCLDWAIT; 275 } 276 if (act) { 277 if ((sig == SIGKILL || sig == SIGSTOP) && 278 act->sa_handler != SIG_DFL) { 279 PROC_UNLOCK(p); 280 return (EINVAL); 281 } 282 283 /* 284 * Change setting atomically. 285 */ 286 287 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 288 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 289 if (act->sa_flags & SA_SIGINFO) { 290 ps->ps_sigact[_SIG_IDX(sig)] = 291 (__sighandler_t *)act->sa_sigaction; 292 SIGADDSET(ps->ps_siginfo, sig); 293 } else { 294 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 295 SIGDELSET(ps->ps_siginfo, sig); 296 } 297 if (!(act->sa_flags & SA_RESTART)) 298 SIGADDSET(ps->ps_sigintr, sig); 299 else 300 SIGDELSET(ps->ps_sigintr, sig); 301 if (act->sa_flags & SA_ONSTACK) 302 SIGADDSET(ps->ps_sigonstack, sig); 303 else 304 SIGDELSET(ps->ps_sigonstack, sig); 305 if (act->sa_flags & SA_RESETHAND) 306 SIGADDSET(ps->ps_sigreset, sig); 307 else 308 SIGDELSET(ps->ps_sigreset, sig); 309 if (act->sa_flags & SA_NODEFER) 310 SIGADDSET(ps->ps_signodefer, sig); 311 else 312 SIGDELSET(ps->ps_signodefer, sig); 313 #ifdef COMPAT_SUNOS 314 if (act->sa_flags & SA_USERTRAMP) 315 SIGADDSET(ps->ps_usertramp, sig); 316 else 317 SIGDELSET(ps->ps_usertramp, sig); 318 #endif 319 if (sig == SIGCHLD) { 320 if (act->sa_flags & SA_NOCLDSTOP) 321 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 322 else 323 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 324 if (act->sa_flags & SA_NOCLDWAIT) { 325 /* 326 * Paranoia: since SA_NOCLDWAIT is implemented 327 * by reparenting the dying child to PID 1 (and 328 * trust it to reap the zombie), PID 1 itself 329 * is forbidden to set SA_NOCLDWAIT. 330 */ 331 if (p->p_pid == 1) 332 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 333 else 334 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 335 } else 336 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 337 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 338 p->p_procsig->ps_flag |= PS_CLDSIGIGN; 339 else 340 p->p_procsig->ps_flag &= ~PS_CLDSIGIGN; 341 } 342 /* 343 * Set bit in p_sigignore for signals that are set to SIG_IGN, 344 * and for signals set to SIG_DFL where the default is to 345 * ignore. However, don't put SIGCONT in p_sigignore, as we 346 * have to restart the process. 347 */ 348 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 349 (sigprop(sig) & SA_IGNORE && 350 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 351 /* never to be seen again */ 352 SIGDELSET(p->p_siglist, sig); 353 if (sig != SIGCONT) 354 /* easier in psignal */ 355 SIGADDSET(p->p_sigignore, sig); 356 SIGDELSET(p->p_sigcatch, sig); 357 } else { 358 SIGDELSET(p->p_sigignore, sig); 359 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 360 SIGDELSET(p->p_sigcatch, sig); 361 else 362 SIGADDSET(p->p_sigcatch, sig); 363 } 364 #ifdef COMPAT_FREEBSD4 365 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 366 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 367 (flags & KSA_FREEBSD4) == 0) 368 SIGDELSET(ps->ps_freebsd4, sig); 369 else 370 SIGADDSET(ps->ps_freebsd4, sig); 371 #endif 372 #ifdef COMPAT_43 373 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 374 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 375 (flags & KSA_OSIGSET) == 0) 376 SIGDELSET(ps->ps_osigset, sig); 377 else 378 SIGADDSET(ps->ps_osigset, sig); 379 #endif 380 } 381 PROC_UNLOCK(p); 382 return (0); 383 } 384 385 #ifndef _SYS_SYSPROTO_H_ 386 struct sigaction_args { 387 int sig; 388 struct sigaction *act; 389 struct sigaction *oact; 390 }; 391 #endif 392 /* 393 * MPSAFE 394 */ 395 /* ARGSUSED */ 396 int 397 sigaction(td, uap) 398 struct thread *td; 399 register struct sigaction_args *uap; 400 { 401 struct sigaction act, oact; 402 register struct sigaction *actp, *oactp; 403 int error; 404 405 mtx_lock(&Giant); 406 407 actp = (uap->act != NULL) ? &act : NULL; 408 oactp = (uap->oact != NULL) ? &oact : NULL; 409 if (actp) { 410 error = copyin(uap->act, actp, sizeof(act)); 411 if (error) 412 goto done2; 413 } 414 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 415 if (oactp && !error) { 416 error = copyout(oactp, uap->oact, sizeof(oact)); 417 } 418 done2: 419 mtx_unlock(&Giant); 420 return (error); 421 } 422 423 #ifdef COMPAT_FREEBSD4 424 #ifndef _SYS_SYSPROTO_H_ 425 struct freebsd4_sigaction_args { 426 int sig; 427 struct sigaction *act; 428 struct sigaction *oact; 429 }; 430 #endif 431 /* 432 * MPSAFE 433 */ 434 /* ARGSUSED */ 435 int 436 freebsd4_sigaction(td, uap) 437 struct thread *td; 438 register struct freebsd4_sigaction_args *uap; 439 { 440 struct sigaction act, oact; 441 register struct sigaction *actp, *oactp; 442 int error; 443 444 mtx_lock(&Giant); 445 446 actp = (uap->act != NULL) ? &act : NULL; 447 oactp = (uap->oact != NULL) ? &oact : NULL; 448 if (actp) { 449 error = copyin(uap->act, actp, sizeof(act)); 450 if (error) 451 goto done2; 452 } 453 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 454 if (oactp && !error) { 455 error = copyout(oactp, uap->oact, sizeof(oact)); 456 } 457 done2: 458 mtx_unlock(&Giant); 459 return (error); 460 } 461 #endif /* COMAPT_FREEBSD4 */ 462 463 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 464 #ifndef _SYS_SYSPROTO_H_ 465 struct osigaction_args { 466 int signum; 467 struct osigaction *nsa; 468 struct osigaction *osa; 469 }; 470 #endif 471 /* 472 * MPSAFE 473 */ 474 /* ARGSUSED */ 475 int 476 osigaction(td, uap) 477 struct thread *td; 478 register struct osigaction_args *uap; 479 { 480 struct osigaction sa; 481 struct sigaction nsa, osa; 482 register struct sigaction *nsap, *osap; 483 int error; 484 485 if (uap->signum <= 0 || uap->signum >= ONSIG) 486 return (EINVAL); 487 488 nsap = (uap->nsa != NULL) ? &nsa : NULL; 489 osap = (uap->osa != NULL) ? &osa : NULL; 490 491 mtx_lock(&Giant); 492 493 if (nsap) { 494 error = copyin(uap->nsa, &sa, sizeof(sa)); 495 if (error) 496 goto done2; 497 nsap->sa_handler = sa.sa_handler; 498 nsap->sa_flags = sa.sa_flags; 499 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 500 } 501 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 502 if (osap && !error) { 503 sa.sa_handler = osap->sa_handler; 504 sa.sa_flags = osap->sa_flags; 505 SIG2OSIG(osap->sa_mask, sa.sa_mask); 506 error = copyout(&sa, uap->osa, sizeof(sa)); 507 } 508 done2: 509 mtx_unlock(&Giant); 510 return (error); 511 } 512 513 #if !defined(__i386__) && !defined(__alpha__) 514 /* Avoid replicating the same stub everywhere */ 515 int 516 osigreturn(td, uap) 517 struct thread *td; 518 struct osigreturn_args *uap; 519 { 520 521 return (nosys(td, (struct nosys_args *)uap)); 522 } 523 #endif 524 #endif /* COMPAT_43 */ 525 526 /* 527 * Initialize signal state for process 0; 528 * set to ignore signals that are ignored by default. 529 */ 530 void 531 siginit(p) 532 struct proc *p; 533 { 534 register int i; 535 536 PROC_LOCK(p); 537 for (i = 1; i <= NSIG; i++) 538 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 539 SIGADDSET(p->p_sigignore, i); 540 PROC_UNLOCK(p); 541 } 542 543 /* 544 * Reset signals for an exec of the specified process. 545 */ 546 void 547 execsigs(p) 548 register struct proc *p; 549 { 550 register struct sigacts *ps; 551 register int sig; 552 553 /* 554 * Reset caught signals. Held signals remain held 555 * through p_sigmask (unless they were caught, 556 * and are now ignored by default). 557 */ 558 PROC_LOCK_ASSERT(p, MA_OWNED); 559 ps = p->p_sigacts; 560 while (SIGNOTEMPTY(p->p_sigcatch)) { 561 sig = sig_ffs(&p->p_sigcatch); 562 SIGDELSET(p->p_sigcatch, sig); 563 if (sigprop(sig) & SA_IGNORE) { 564 if (sig != SIGCONT) 565 SIGADDSET(p->p_sigignore, sig); 566 SIGDELSET(p->p_siglist, sig); 567 } 568 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 569 } 570 /* 571 * Reset stack state to the user stack. 572 * Clear set of signals caught on the signal stack. 573 */ 574 p->p_sigstk.ss_flags = SS_DISABLE; 575 p->p_sigstk.ss_size = 0; 576 p->p_sigstk.ss_sp = 0; 577 p->p_flag &= ~P_ALTSTACK; 578 /* 579 * Reset no zombies if child dies flag as Solaris does. 580 */ 581 p->p_procsig->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 582 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 583 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 584 } 585 586 /* 587 * do_sigprocmask() 588 * 589 * Manipulate signal mask. 590 */ 591 static int 592 do_sigprocmask(p, how, set, oset, old) 593 struct proc *p; 594 int how; 595 sigset_t *set, *oset; 596 int old; 597 { 598 int error; 599 600 PROC_LOCK(p); 601 if (oset != NULL) 602 *oset = p->p_sigmask; 603 604 error = 0; 605 if (set != NULL) { 606 switch (how) { 607 case SIG_BLOCK: 608 SIG_CANTMASK(*set); 609 SIGSETOR(p->p_sigmask, *set); 610 break; 611 case SIG_UNBLOCK: 612 SIGSETNAND(p->p_sigmask, *set); 613 signotify(p); 614 break; 615 case SIG_SETMASK: 616 SIG_CANTMASK(*set); 617 if (old) 618 SIGSETLO(p->p_sigmask, *set); 619 else 620 p->p_sigmask = *set; 621 signotify(p); 622 break; 623 default: 624 error = EINVAL; 625 break; 626 } 627 } 628 PROC_UNLOCK(p); 629 return (error); 630 } 631 632 /* 633 * sigprocmask() - MP SAFE (XXXKSE not under KSE it isn't) 634 */ 635 636 #ifndef _SYS_SYSPROTO_H_ 637 struct sigprocmask_args { 638 int how; 639 const sigset_t *set; 640 sigset_t *oset; 641 }; 642 #endif 643 int 644 sigprocmask(td, uap) 645 register struct thread *td; 646 struct sigprocmask_args *uap; 647 { 648 struct proc *p = td->td_proc; 649 sigset_t set, oset; 650 sigset_t *setp, *osetp; 651 int error; 652 653 setp = (uap->set != NULL) ? &set : NULL; 654 osetp = (uap->oset != NULL) ? &oset : NULL; 655 if (setp) { 656 error = copyin(uap->set, setp, sizeof(set)); 657 if (error) 658 return (error); 659 } 660 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 661 if (osetp && !error) { 662 error = copyout(osetp, uap->oset, sizeof(oset)); 663 } 664 return (error); 665 } 666 667 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 668 /* 669 * osigprocmask() - MP SAFE 670 */ 671 #ifndef _SYS_SYSPROTO_H_ 672 struct osigprocmask_args { 673 int how; 674 osigset_t mask; 675 }; 676 #endif 677 int 678 osigprocmask(td, uap) 679 register struct thread *td; 680 struct osigprocmask_args *uap; 681 { 682 struct proc *p = td->td_proc; 683 sigset_t set, oset; 684 int error; 685 686 OSIG2SIG(uap->mask, set); 687 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 688 SIG2OSIG(oset, td->td_retval[0]); 689 return (error); 690 } 691 #endif /* COMPAT_43 */ 692 693 #ifndef _SYS_SYSPROTO_H_ 694 struct sigpending_args { 695 sigset_t *set; 696 }; 697 #endif 698 /* 699 * MPSAFE 700 */ 701 /* ARGSUSED */ 702 int 703 sigpending(td, uap) 704 struct thread *td; 705 struct sigpending_args *uap; 706 { 707 struct proc *p = td->td_proc; 708 sigset_t siglist; 709 int error; 710 711 mtx_lock(&Giant); 712 PROC_LOCK(p); 713 siglist = p->p_siglist; 714 PROC_UNLOCK(p); 715 mtx_unlock(&Giant); 716 error = copyout(&siglist, uap->set, sizeof(sigset_t)); 717 return(error); 718 } 719 720 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 721 #ifndef _SYS_SYSPROTO_H_ 722 struct osigpending_args { 723 int dummy; 724 }; 725 #endif 726 /* 727 * MPSAFE 728 */ 729 /* ARGSUSED */ 730 int 731 osigpending(td, uap) 732 struct thread *td; 733 struct osigpending_args *uap; 734 { 735 struct proc *p = td->td_proc; 736 737 mtx_lock(&Giant); 738 PROC_LOCK(p); 739 SIG2OSIG(p->p_siglist, td->td_retval[0]); 740 PROC_UNLOCK(p); 741 mtx_unlock(&Giant); 742 return (0); 743 } 744 #endif /* COMPAT_43 */ 745 746 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 747 /* 748 * Generalized interface signal handler, 4.3-compatible. 749 */ 750 #ifndef _SYS_SYSPROTO_H_ 751 struct osigvec_args { 752 int signum; 753 struct sigvec *nsv; 754 struct sigvec *osv; 755 }; 756 #endif 757 /* 758 * MPSAFE 759 */ 760 /* ARGSUSED */ 761 int 762 osigvec(td, uap) 763 struct thread *td; 764 register struct osigvec_args *uap; 765 { 766 struct sigvec vec; 767 struct sigaction nsa, osa; 768 register struct sigaction *nsap, *osap; 769 int error; 770 771 if (uap->signum <= 0 || uap->signum >= ONSIG) 772 return (EINVAL); 773 nsap = (uap->nsv != NULL) ? &nsa : NULL; 774 osap = (uap->osv != NULL) ? &osa : NULL; 775 if (nsap) { 776 error = copyin(uap->nsv, &vec, sizeof(vec)); 777 if (error) 778 return (error); 779 nsap->sa_handler = vec.sv_handler; 780 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 781 nsap->sa_flags = vec.sv_flags; 782 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 783 #ifdef COMPAT_SUNOS 784 nsap->sa_flags |= SA_USERTRAMP; 785 #endif 786 } 787 mtx_lock(&Giant); 788 error = kern_sigaction(td, uap->signum, nsap, osap, 1); 789 mtx_unlock(&Giant); 790 if (osap && !error) { 791 vec.sv_handler = osap->sa_handler; 792 SIG2OSIG(osap->sa_mask, vec.sv_mask); 793 vec.sv_flags = osap->sa_flags; 794 vec.sv_flags &= ~SA_NOCLDWAIT; 795 vec.sv_flags ^= SA_RESTART; 796 #ifdef COMPAT_SUNOS 797 vec.sv_flags &= ~SA_NOCLDSTOP; 798 #endif 799 error = copyout(&vec, uap->osv, sizeof(vec)); 800 } 801 return (error); 802 } 803 804 #ifndef _SYS_SYSPROTO_H_ 805 struct osigblock_args { 806 int mask; 807 }; 808 #endif 809 /* 810 * MPSAFE 811 */ 812 int 813 osigblock(td, uap) 814 register struct thread *td; 815 struct osigblock_args *uap; 816 { 817 struct proc *p = td->td_proc; 818 sigset_t set; 819 820 OSIG2SIG(uap->mask, set); 821 SIG_CANTMASK(set); 822 mtx_lock(&Giant); 823 PROC_LOCK(p); 824 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 825 SIGSETOR(p->p_sigmask, set); 826 PROC_UNLOCK(p); 827 mtx_unlock(&Giant); 828 return (0); 829 } 830 831 #ifndef _SYS_SYSPROTO_H_ 832 struct osigsetmask_args { 833 int mask; 834 }; 835 #endif 836 /* 837 * MPSAFE 838 */ 839 int 840 osigsetmask(td, uap) 841 struct thread *td; 842 struct osigsetmask_args *uap; 843 { 844 struct proc *p = td->td_proc; 845 sigset_t set; 846 847 OSIG2SIG(uap->mask, set); 848 SIG_CANTMASK(set); 849 mtx_lock(&Giant); 850 PROC_LOCK(p); 851 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 852 SIGSETLO(p->p_sigmask, set); 853 signotify(p); 854 PROC_UNLOCK(p); 855 mtx_unlock(&Giant); 856 return (0); 857 } 858 #endif /* COMPAT_43 || COMPAT_SUNOS */ 859 860 /* 861 * Suspend process until signal, providing mask to be set 862 * in the meantime. Note nonstandard calling convention: 863 * libc stub passes mask, not pointer, to save a copyin. 864 ***** XXXKSE this doesn't make sense under KSE. 865 ***** Do we suspend the thread or all threads in the process? 866 ***** How do we suspend threads running NOW on another processor? 867 */ 868 #ifndef _SYS_SYSPROTO_H_ 869 struct sigsuspend_args { 870 const sigset_t *sigmask; 871 }; 872 #endif 873 /* 874 * MPSAFE 875 */ 876 /* ARGSUSED */ 877 int 878 sigsuspend(td, uap) 879 struct thread *td; 880 struct sigsuspend_args *uap; 881 { 882 sigset_t mask; 883 int error; 884 885 error = copyin(uap->sigmask, &mask, sizeof(mask)); 886 if (error) 887 return (error); 888 return (kern_sigsuspend(td, mask)); 889 } 890 891 int 892 kern_sigsuspend(struct thread *td, sigset_t mask) 893 { 894 struct proc *p = td->td_proc; 895 register struct sigacts *ps; 896 897 /* 898 * When returning from sigsuspend, we want 899 * the old mask to be restored after the 900 * signal handler has finished. Thus, we 901 * save it here and mark the sigacts structure 902 * to indicate this. 903 */ 904 mtx_lock(&Giant); 905 PROC_LOCK(p); 906 ps = p->p_sigacts; 907 p->p_oldsigmask = p->p_sigmask; 908 p->p_flag |= P_OLDMASK; 909 910 SIG_CANTMASK(mask); 911 p->p_sigmask = mask; 912 signotify(p); 913 while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 914 /* void */; 915 PROC_UNLOCK(p); 916 mtx_unlock(&Giant); 917 /* always return EINTR rather than ERESTART... */ 918 return (EINTR); 919 } 920 921 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 922 #ifndef _SYS_SYSPROTO_H_ 923 struct osigsuspend_args { 924 osigset_t mask; 925 }; 926 #endif 927 /* 928 * MPSAFE 929 */ 930 /* ARGSUSED */ 931 int 932 osigsuspend(td, uap) 933 struct thread *td; 934 struct osigsuspend_args *uap; 935 { 936 struct proc *p = td->td_proc; 937 sigset_t mask; 938 register struct sigacts *ps; 939 940 mtx_lock(&Giant); 941 PROC_LOCK(p); 942 ps = p->p_sigacts; 943 p->p_oldsigmask = p->p_sigmask; 944 p->p_flag |= P_OLDMASK; 945 OSIG2SIG(uap->mask, mask); 946 SIG_CANTMASK(mask); 947 SIGSETLO(p->p_sigmask, mask); 948 signotify(p); 949 while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 950 /* void */; 951 PROC_UNLOCK(p); 952 mtx_unlock(&Giant); 953 /* always return EINTR rather than ERESTART... */ 954 return (EINTR); 955 } 956 #endif /* COMPAT_43 */ 957 958 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 959 #ifndef _SYS_SYSPROTO_H_ 960 struct osigstack_args { 961 struct sigstack *nss; 962 struct sigstack *oss; 963 }; 964 #endif 965 /* 966 * MPSAFE 967 */ 968 /* ARGSUSED */ 969 int 970 osigstack(td, uap) 971 struct thread *td; 972 register struct osigstack_args *uap; 973 { 974 struct proc *p = td->td_proc; 975 struct sigstack ss; 976 int error = 0; 977 978 mtx_lock(&Giant); 979 980 if (uap->oss != NULL) { 981 PROC_LOCK(p); 982 ss.ss_sp = p->p_sigstk.ss_sp; 983 ss.ss_onstack = sigonstack(cpu_getstack(td)); 984 PROC_UNLOCK(p); 985 error = copyout(&ss, uap->oss, sizeof(struct sigstack)); 986 if (error) 987 goto done2; 988 } 989 990 if (uap->nss != NULL) { 991 if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0) 992 goto done2; 993 PROC_LOCK(p); 994 p->p_sigstk.ss_sp = ss.ss_sp; 995 p->p_sigstk.ss_size = 0; 996 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 997 p->p_flag |= P_ALTSTACK; 998 PROC_UNLOCK(p); 999 } 1000 done2: 1001 mtx_unlock(&Giant); 1002 return (error); 1003 } 1004 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1005 1006 #ifndef _SYS_SYSPROTO_H_ 1007 struct sigaltstack_args { 1008 stack_t *ss; 1009 stack_t *oss; 1010 }; 1011 #endif 1012 /* 1013 * MPSAFE 1014 */ 1015 /* ARGSUSED */ 1016 int 1017 sigaltstack(td, uap) 1018 struct thread *td; 1019 register struct sigaltstack_args *uap; 1020 { 1021 stack_t ss, oss; 1022 int error; 1023 1024 if (uap->ss != NULL) { 1025 error = copyin(uap->ss, &ss, sizeof(ss)); 1026 if (error) 1027 return (error); 1028 } 1029 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1030 (uap->oss != NULL) ? &oss : NULL); 1031 if (error) 1032 return (error); 1033 if (uap->oss != NULL) 1034 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1035 return (error); 1036 } 1037 1038 int 1039 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1040 { 1041 struct proc *p = td->td_proc; 1042 int oonstack; 1043 int error = 0; 1044 1045 mtx_lock(&Giant); 1046 1047 oonstack = sigonstack(cpu_getstack(td)); 1048 1049 if (oss != NULL) { 1050 PROC_LOCK(p); 1051 *oss = p->p_sigstk; 1052 oss->ss_flags = (p->p_flag & P_ALTSTACK) 1053 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1054 PROC_UNLOCK(p); 1055 } 1056 1057 if (ss != NULL) { 1058 if (oonstack) { 1059 error = EPERM; 1060 goto done2; 1061 } 1062 if ((ss->ss_flags & ~SS_DISABLE) != 0) { 1063 error = EINVAL; 1064 goto done2; 1065 } 1066 if (!(ss->ss_flags & SS_DISABLE)) { 1067 if (ss->ss_size < p->p_sysent->sv_minsigstksz) { 1068 error = ENOMEM; 1069 goto done2; 1070 } 1071 PROC_LOCK(p); 1072 p->p_sigstk = *ss; 1073 p->p_flag |= P_ALTSTACK; 1074 PROC_UNLOCK(p); 1075 } else { 1076 PROC_LOCK(p); 1077 p->p_flag &= ~P_ALTSTACK; 1078 PROC_UNLOCK(p); 1079 } 1080 } 1081 done2: 1082 mtx_unlock(&Giant); 1083 return (error); 1084 } 1085 1086 /* 1087 * Common code for kill process group/broadcast kill. 1088 * cp is calling process. 1089 */ 1090 static int 1091 killpg1(td, sig, pgid, all) 1092 register struct thread *td; 1093 int sig, pgid, all; 1094 { 1095 register struct proc *p; 1096 struct pgrp *pgrp; 1097 int nfound = 0; 1098 1099 if (all) { 1100 /* 1101 * broadcast 1102 */ 1103 sx_slock(&allproc_lock); 1104 LIST_FOREACH(p, &allproc, p_list) { 1105 PROC_LOCK(p); 1106 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1107 p == td->td_proc) { 1108 PROC_UNLOCK(p); 1109 continue; 1110 } 1111 if (p_cansignal(td, p, sig) == 0) { 1112 nfound++; 1113 if (sig) 1114 psignal(p, sig); 1115 } 1116 PROC_UNLOCK(p); 1117 } 1118 sx_sunlock(&allproc_lock); 1119 } else { 1120 sx_slock(&proctree_lock); 1121 if (pgid == 0) { 1122 /* 1123 * zero pgid means send to my process group. 1124 */ 1125 pgrp = td->td_proc->p_pgrp; 1126 PGRP_LOCK(pgrp); 1127 } else { 1128 pgrp = pgfind(pgid); 1129 if (pgrp == NULL) { 1130 sx_sunlock(&proctree_lock); 1131 return (ESRCH); 1132 } 1133 } 1134 sx_sunlock(&proctree_lock); 1135 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1136 PROC_LOCK(p); 1137 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1138 PROC_UNLOCK(p); 1139 continue; 1140 } 1141 if (p->p_state == PRS_ZOMBIE) { 1142 PROC_UNLOCK(p); 1143 continue; 1144 } 1145 if (p_cansignal(td, p, sig) == 0) { 1146 nfound++; 1147 if (sig) 1148 psignal(p, sig); 1149 } 1150 PROC_UNLOCK(p); 1151 } 1152 PGRP_UNLOCK(pgrp); 1153 } 1154 return (nfound ? 0 : ESRCH); 1155 } 1156 1157 #ifndef _SYS_SYSPROTO_H_ 1158 struct kill_args { 1159 int pid; 1160 int signum; 1161 }; 1162 #endif 1163 /* 1164 * MPSAFE 1165 */ 1166 /* ARGSUSED */ 1167 int 1168 kill(td, uap) 1169 register struct thread *td; 1170 register struct kill_args *uap; 1171 { 1172 register struct proc *p; 1173 int error = 0; 1174 1175 if ((u_int)uap->signum > _SIG_MAXSIG) 1176 return (EINVAL); 1177 1178 mtx_lock(&Giant); 1179 if (uap->pid > 0) { 1180 /* kill single process */ 1181 if ((p = pfind(uap->pid)) == NULL) { 1182 error = ESRCH; 1183 } else if ((error = p_cansignal(td, p, uap->signum)) != 0) { 1184 PROC_UNLOCK(p); 1185 } else { 1186 if (uap->signum) 1187 psignal(p, uap->signum); 1188 PROC_UNLOCK(p); 1189 error = 0; 1190 } 1191 } else { 1192 switch (uap->pid) { 1193 case -1: /* broadcast signal */ 1194 error = killpg1(td, uap->signum, 0, 1); 1195 break; 1196 case 0: /* signal own process group */ 1197 error = killpg1(td, uap->signum, 0, 0); 1198 break; 1199 default: /* negative explicit process group */ 1200 error = killpg1(td, uap->signum, -uap->pid, 0); 1201 break; 1202 } 1203 } 1204 mtx_unlock(&Giant); 1205 return(error); 1206 } 1207 1208 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1209 #ifndef _SYS_SYSPROTO_H_ 1210 struct okillpg_args { 1211 int pgid; 1212 int signum; 1213 }; 1214 #endif 1215 /* 1216 * MPSAFE 1217 */ 1218 /* ARGSUSED */ 1219 int 1220 okillpg(td, uap) 1221 struct thread *td; 1222 register struct okillpg_args *uap; 1223 { 1224 int error; 1225 1226 if ((u_int)uap->signum > _SIG_MAXSIG) 1227 return (EINVAL); 1228 mtx_lock(&Giant); 1229 error = killpg1(td, uap->signum, uap->pgid, 0); 1230 mtx_unlock(&Giant); 1231 return (error); 1232 } 1233 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1234 1235 /* 1236 * Send a signal to a process group. 1237 */ 1238 void 1239 gsignal(pgid, sig) 1240 int pgid, sig; 1241 { 1242 struct pgrp *pgrp; 1243 1244 if (pgid != 0) { 1245 sx_slock(&proctree_lock); 1246 pgrp = pgfind(pgid); 1247 sx_sunlock(&proctree_lock); 1248 if (pgrp != NULL) { 1249 pgsignal(pgrp, sig, 0); 1250 PGRP_UNLOCK(pgrp); 1251 } 1252 } 1253 } 1254 1255 /* 1256 * Send a signal to a process group. If checktty is 1, 1257 * limit to members which have a controlling terminal. 1258 */ 1259 void 1260 pgsignal(pgrp, sig, checkctty) 1261 struct pgrp *pgrp; 1262 int sig, checkctty; 1263 { 1264 register struct proc *p; 1265 1266 if (pgrp) { 1267 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1268 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1269 PROC_LOCK(p); 1270 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1271 psignal(p, sig); 1272 PROC_UNLOCK(p); 1273 } 1274 } 1275 } 1276 1277 /* 1278 * Send a signal caused by a trap to the current process. 1279 * If it will be caught immediately, deliver it with correct code. 1280 * Otherwise, post it normally. 1281 * 1282 * MPSAFE 1283 */ 1284 void 1285 trapsignal(p, sig, code) 1286 struct proc *p; 1287 register int sig; 1288 u_long code; 1289 { 1290 register struct sigacts *ps = p->p_sigacts; 1291 1292 PROC_LOCK(p); 1293 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 1294 !SIGISMEMBER(p->p_sigmask, sig)) { 1295 p->p_stats->p_ru.ru_nsignals++; 1296 #ifdef KTRACE 1297 if (KTRPOINT(curthread, KTR_PSIG)) 1298 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1299 &p->p_sigmask, code); 1300 #endif 1301 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 1302 &p->p_sigmask, code); 1303 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1304 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1305 SIGADDSET(p->p_sigmask, sig); 1306 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1307 /* 1308 * See kern_sigaction() for origin of this code. 1309 */ 1310 SIGDELSET(p->p_sigcatch, sig); 1311 if (sig != SIGCONT && 1312 sigprop(sig) & SA_IGNORE) 1313 SIGADDSET(p->p_sigignore, sig); 1314 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1315 } 1316 } else { 1317 p->p_code = code; /* XXX for core dump/debugger */ 1318 p->p_sig = sig; /* XXX to verify code */ 1319 psignal(p, sig); 1320 } 1321 PROC_UNLOCK(p); 1322 } 1323 1324 /* 1325 * Send the signal to the process. If the signal has an action, the action 1326 * is usually performed by the target process rather than the caller; we add 1327 * the signal to the set of pending signals for the process. 1328 * 1329 * Exceptions: 1330 * o When a stop signal is sent to a sleeping process that takes the 1331 * default action, the process is stopped without awakening it. 1332 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1333 * regardless of the signal action (eg, blocked or ignored). 1334 * 1335 * Other ignored signals are discarded immediately. 1336 */ 1337 void 1338 psignal(p, sig) 1339 register struct proc *p; 1340 register int sig; 1341 { 1342 register sig_t action; 1343 struct thread *td; 1344 register int prop; 1345 1346 1347 KASSERT(_SIG_VALID(sig), 1348 ("psignal(): invalid signal %d\n", sig)); 1349 1350 PROC_LOCK_ASSERT(p, MA_OWNED); 1351 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1352 1353 prop = sigprop(sig); 1354 /* 1355 * If proc is traced, always give parent a chance; 1356 * if signal event is tracked by procfs, give *that* 1357 * a chance, as well. 1358 */ 1359 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1360 action = SIG_DFL; 1361 } else { 1362 /* 1363 * If the signal is being ignored, 1364 * then we forget about it immediately. 1365 * (Note: we don't set SIGCONT in p_sigignore, 1366 * and if it is set to SIG_IGN, 1367 * action will be SIG_DFL here.) 1368 */ 1369 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1370 return; 1371 if (SIGISMEMBER(p->p_sigmask, sig)) 1372 action = SIG_HOLD; 1373 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1374 action = SIG_CATCH; 1375 else 1376 action = SIG_DFL; 1377 } 1378 1379 if (prop & SA_CONT) 1380 SIG_STOPSIGMASK(p->p_siglist); 1381 1382 if (prop & SA_STOP) { 1383 /* 1384 * If sending a tty stop signal to a member of an orphaned 1385 * process group, discard the signal here if the action 1386 * is default; don't stop the process below if sleeping, 1387 * and don't clear any pending SIGCONT. 1388 */ 1389 if ((prop & SA_TTYSTOP) && 1390 (p->p_pgrp->pg_jobc == 0) && 1391 (action == SIG_DFL)) 1392 return; 1393 SIG_CONTSIGMASK(p->p_siglist); 1394 p->p_flag &= ~P_CONTINUED; 1395 } 1396 SIGADDSET(p->p_siglist, sig); 1397 signotify(p); /* uses schedlock */ 1398 1399 /* 1400 * Some signals have a process-wide effect and a per-thread 1401 * component. Most processing occurs when the process next 1402 * tries to cross the user boundary, however there are some 1403 * times when processing needs to be done immediatly, such as 1404 * waking up threads so that they can cross the user boundary. 1405 * We try do the per-process part here. 1406 */ 1407 if (P_SHOULDSTOP(p)) { 1408 /* 1409 * The process is in stopped mode. All the threads should be 1410 * either winding down or already on the suspended queue. 1411 */ 1412 if (p->p_flag & P_TRACED) { 1413 /* 1414 * The traced process is already stopped, 1415 * so no further action is necessary. 1416 * No signal can restart us. 1417 */ 1418 goto out; 1419 } 1420 1421 if (sig == SIGKILL) { 1422 /* 1423 * SIGKILL sets process running. 1424 * It will die elsewhere. 1425 * All threads must be restarted. 1426 */ 1427 p->p_flag &= ~P_STOPPED; 1428 goto runfast; 1429 } 1430 1431 if (prop & SA_CONT) { 1432 /* 1433 * If SIGCONT is default (or ignored), we continue the 1434 * process but don't leave the signal in p_siglist as 1435 * it has no further action. If SIGCONT is held, we 1436 * continue the process and leave the signal in 1437 * p_siglist. If the process catches SIGCONT, let it 1438 * handle the signal itself. If it isn't waiting on 1439 * an event, it goes back to run state. 1440 * Otherwise, process goes back to sleep state. 1441 */ 1442 p->p_flag &= ~P_STOPPED_SIG; 1443 p->p_flag |= P_CONTINUED; 1444 if (action == SIG_DFL) { 1445 SIGDELSET(p->p_siglist, sig); 1446 } else if (action == SIG_CATCH) { 1447 /* 1448 * The process wants to catch it so it needs 1449 * to run at least one thread, but which one? 1450 * It would seem that the answer would be to 1451 * run an upcall in the next KSE to run, and 1452 * deliver the signal that way. In a NON KSE 1453 * process, we need to make sure that the 1454 * single thread is runnable asap. 1455 * XXXKSE for now however, make them all run. 1456 */ 1457 goto runfast; 1458 } 1459 /* 1460 * The signal is not ignored or caught. 1461 */ 1462 mtx_lock_spin(&sched_lock); 1463 thread_unsuspend(p); 1464 mtx_unlock_spin(&sched_lock); 1465 goto out; 1466 } 1467 1468 if (prop & SA_STOP) { 1469 /* 1470 * Already stopped, don't need to stop again 1471 * (If we did the shell could get confused). 1472 * Just make sure the signal STOP bit set. 1473 */ 1474 p->p_flag |= P_STOPPED_SIG; 1475 SIGDELSET(p->p_siglist, sig); 1476 goto out; 1477 } 1478 1479 /* 1480 * All other kinds of signals: 1481 * If a thread is sleeping interruptibly, simulate a 1482 * wakeup so that when it is continued it will be made 1483 * runnable and can look at the signal. However, don't make 1484 * the PROCESS runnable, leave it stopped. 1485 * It may run a bit until it hits a thread_suspend_check(). 1486 */ 1487 mtx_lock_spin(&sched_lock); 1488 FOREACH_THREAD_IN_PROC(p, td) { 1489 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) { 1490 if (td->td_flags & TDF_CVWAITQ) 1491 cv_abort(td); 1492 else 1493 abortsleep(td); 1494 } 1495 } 1496 mtx_unlock_spin(&sched_lock); 1497 goto out; 1498 /* 1499 * XXXKSE What about threads that are waiting on mutexes? 1500 * Shouldn't they abort too? 1501 * No, hopefully mutexes are short lived.. They'll 1502 * eventually hit thread_suspend_check(). 1503 */ 1504 } else if (p->p_state == PRS_NORMAL) { 1505 if (prop & SA_CONT) { 1506 /* 1507 * Already active, don't need to start again. 1508 */ 1509 SIGDELSET(p->p_siglist, sig); 1510 goto out; 1511 } 1512 if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || 1513 !(prop & SA_STOP)) { 1514 mtx_lock_spin(&sched_lock); 1515 FOREACH_THREAD_IN_PROC(p, td) 1516 tdsignal(td, sig, action); 1517 mtx_unlock_spin(&sched_lock); 1518 goto out; 1519 } 1520 if (prop & SA_STOP) { 1521 if (p->p_flag & P_PPWAIT) 1522 goto out; 1523 mtx_lock_spin(&sched_lock); 1524 FOREACH_THREAD_IN_PROC(p, td) { 1525 if (TD_IS_SLEEPING(td) && 1526 (td->td_flags & TDF_SINTR)) 1527 thread_suspend_one(td); 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 } 1641 #ifdef SMP 1642 else { 1643 /* 1644 * Other states do nothing with the signal immediatly, 1645 * other than kicking ourselves if we are running. 1646 * It will either never be noticed, or noticed very soon. 1647 */ 1648 if (TD_IS_RUNNING(td) && td != curthread) { 1649 forward_signal(td); 1650 } 1651 } 1652 #endif 1653 } 1654 1655 /* 1656 * If the current process has received a signal (should be caught or cause 1657 * termination, should interrupt current syscall), return the signal number. 1658 * Stop signals with default action are processed immediately, then cleared; 1659 * they aren't returned. This is checked after each entry to the system for 1660 * a syscall or trap (though this can usually be done without calling issignal 1661 * by checking the pending signal masks in cursig.) The normal call 1662 * sequence is 1663 * 1664 * while (sig = cursig(curthread)) 1665 * postsig(sig); 1666 */ 1667 int 1668 issignal(td) 1669 struct thread *td; 1670 { 1671 struct proc *p; 1672 sigset_t mask; 1673 register int sig, prop; 1674 1675 p = td->td_proc; 1676 PROC_LOCK_ASSERT(p, MA_OWNED); 1677 WITNESS_SLEEP(1, &p->p_mtx.mtx_object); 1678 for (;;) { 1679 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1680 1681 mask = p->p_siglist; 1682 SIGSETNAND(mask, p->p_sigmask); 1683 if (p->p_flag & P_PPWAIT) 1684 SIG_STOPSIGMASK(mask); 1685 if (SIGISEMPTY(mask)) /* no signal to send */ 1686 return (0); 1687 sig = sig_ffs(&mask); 1688 prop = sigprop(sig); 1689 1690 _STOPEVENT(p, S_SIG, sig); 1691 1692 /* 1693 * We should see pending but ignored signals 1694 * only if P_TRACED was on when they were posted. 1695 */ 1696 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1697 SIGDELSET(p->p_siglist, sig); 1698 continue; 1699 } 1700 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1701 /* 1702 * If traced, always stop. 1703 */ 1704 p->p_xstat = sig; 1705 PROC_LOCK(p->p_pptr); 1706 psignal(p->p_pptr, SIGCHLD); 1707 PROC_UNLOCK(p->p_pptr); 1708 mtx_lock_spin(&sched_lock); 1709 stop(p); /* uses schedlock too eventually */ 1710 thread_suspend_one(td); 1711 PROC_UNLOCK(p); 1712 DROP_GIANT(); 1713 p->p_stats->p_ru.ru_nivcsw++; 1714 mi_switch(); 1715 mtx_unlock_spin(&sched_lock); 1716 PICKUP_GIANT(); 1717 PROC_LOCK(p); 1718 1719 /* 1720 * If the traced bit got turned off, go back up 1721 * to the top to rescan signals. This ensures 1722 * that p_sig* and ps_sigact are consistent. 1723 */ 1724 if ((p->p_flag & P_TRACED) == 0) 1725 continue; 1726 1727 /* 1728 * If parent wants us to take the signal, 1729 * then it will leave it in p->p_xstat; 1730 * otherwise we just look for signals again. 1731 */ 1732 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1733 sig = p->p_xstat; 1734 if (sig == 0) 1735 continue; 1736 1737 /* 1738 * Put the new signal into p_siglist. If the 1739 * signal is being masked, look for other signals. 1740 */ 1741 SIGADDSET(p->p_siglist, sig); 1742 if (SIGISMEMBER(p->p_sigmask, sig)) 1743 continue; 1744 signotify(p); 1745 } 1746 1747 /* 1748 * Decide whether the signal should be returned. 1749 * Return the signal's number, or fall through 1750 * to clear it from the pending mask. 1751 */ 1752 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1753 1754 case (int)SIG_DFL: 1755 /* 1756 * Don't take default actions on system processes. 1757 */ 1758 if (p->p_pid <= 1) { 1759 #ifdef DIAGNOSTIC 1760 /* 1761 * Are you sure you want to ignore SIGSEGV 1762 * in init? XXX 1763 */ 1764 printf("Process (pid %lu) got signal %d\n", 1765 (u_long)p->p_pid, sig); 1766 #endif 1767 break; /* == ignore */ 1768 } 1769 /* 1770 * If there is a pending stop signal to process 1771 * with default action, stop here, 1772 * then clear the signal. However, 1773 * if process is member of an orphaned 1774 * process group, ignore tty stop signals. 1775 */ 1776 if (prop & SA_STOP) { 1777 if (p->p_flag & P_TRACED || 1778 (p->p_pgrp->pg_jobc == 0 && 1779 prop & SA_TTYSTOP)) 1780 break; /* == ignore */ 1781 p->p_xstat = sig; 1782 mtx_lock_spin(&sched_lock); 1783 if (p->p_suspcount+1 == p->p_numthreads) { 1784 mtx_unlock_spin(&sched_lock); 1785 PROC_LOCK(p->p_pptr); 1786 if ((p->p_pptr->p_procsig->ps_flag & 1787 PS_NOCLDSTOP) == 0) { 1788 psignal(p->p_pptr, SIGCHLD); 1789 } 1790 PROC_UNLOCK(p->p_pptr); 1791 mtx_lock_spin(&sched_lock); 1792 } 1793 stop(p); 1794 thread_suspend_one(td); 1795 PROC_UNLOCK(p); 1796 DROP_GIANT(); 1797 p->p_stats->p_ru.ru_nivcsw++; 1798 mi_switch(); 1799 mtx_unlock_spin(&sched_lock); 1800 PICKUP_GIANT(); 1801 PROC_LOCK(p); 1802 break; 1803 } else if (prop & SA_IGNORE) { 1804 /* 1805 * Except for SIGCONT, shouldn't get here. 1806 * Default action is to ignore; drop it. 1807 */ 1808 break; /* == ignore */ 1809 } else 1810 return (sig); 1811 /*NOTREACHED*/ 1812 1813 case (int)SIG_IGN: 1814 /* 1815 * Masking above should prevent us ever trying 1816 * to take action on an ignored signal other 1817 * than SIGCONT, unless process is traced. 1818 */ 1819 if ((prop & SA_CONT) == 0 && 1820 (p->p_flag & P_TRACED) == 0) 1821 printf("issignal\n"); 1822 break; /* == ignore */ 1823 1824 default: 1825 /* 1826 * This signal has an action, let 1827 * postsig() process it. 1828 */ 1829 return (sig); 1830 } 1831 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1832 } 1833 /* NOTREACHED */ 1834 } 1835 1836 /* 1837 * Put the argument process into the stopped state and notify the parent 1838 * via wakeup. Signals are handled elsewhere. The process must not be 1839 * on the run queue. Must be called with the proc p locked and the scheduler 1840 * lock held. 1841 */ 1842 static void 1843 stop(p) 1844 register struct proc *p; 1845 { 1846 1847 PROC_LOCK_ASSERT(p, MA_OWNED); 1848 p->p_flag |= P_STOPPED_SIG; 1849 p->p_flag &= ~P_WAITED; 1850 wakeup(p->p_pptr); 1851 } 1852 1853 /* 1854 * Take the action for the specified signal 1855 * from the current set of pending signals. 1856 */ 1857 void 1858 postsig(sig) 1859 register int sig; 1860 { 1861 struct thread *td = curthread; 1862 register struct proc *p = td->td_proc; 1863 struct sigacts *ps; 1864 sig_t action; 1865 sigset_t returnmask; 1866 int code; 1867 1868 KASSERT(sig != 0, ("postsig")); 1869 1870 PROC_LOCK_ASSERT(p, MA_OWNED); 1871 ps = p->p_sigacts; 1872 SIGDELSET(p->p_siglist, sig); 1873 action = ps->ps_sigact[_SIG_IDX(sig)]; 1874 #ifdef KTRACE 1875 if (KTRPOINT(td, KTR_PSIG)) 1876 ktrpsig(sig, action, p->p_flag & P_OLDMASK ? 1877 &p->p_oldsigmask : &p->p_sigmask, 0); 1878 #endif 1879 _STOPEVENT(p, S_SIG, sig); 1880 1881 if (action == SIG_DFL) { 1882 /* 1883 * Default action, where the default is to kill 1884 * the process. (Other cases were ignored above.) 1885 */ 1886 sigexit(td, sig); 1887 /* NOTREACHED */ 1888 } else { 1889 /* 1890 * If we get here, the signal must be caught. 1891 */ 1892 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1893 ("postsig action")); 1894 /* 1895 * Set the new mask value and also defer further 1896 * occurrences of this signal. 1897 * 1898 * Special case: user has done a sigsuspend. Here the 1899 * current mask is not of interest, but rather the 1900 * mask from before the sigsuspend is what we want 1901 * restored after the signal processing is completed. 1902 */ 1903 if (p->p_flag & P_OLDMASK) { 1904 returnmask = p->p_oldsigmask; 1905 p->p_flag &= ~P_OLDMASK; 1906 } else 1907 returnmask = p->p_sigmask; 1908 1909 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1910 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1911 SIGADDSET(p->p_sigmask, sig); 1912 1913 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1914 /* 1915 * See kern_sigaction() for origin of this code. 1916 */ 1917 SIGDELSET(p->p_sigcatch, sig); 1918 if (sig != SIGCONT && 1919 sigprop(sig) & SA_IGNORE) 1920 SIGADDSET(p->p_sigignore, sig); 1921 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1922 } 1923 p->p_stats->p_ru.ru_nsignals++; 1924 if (p->p_sig != sig) { 1925 code = 0; 1926 } else { 1927 code = p->p_code; 1928 p->p_code = 0; 1929 p->p_sig = 0; 1930 } 1931 if (p->p_flag & P_KSES) 1932 if (signal_upcall(p, sig)) 1933 return; 1934 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1935 } 1936 } 1937 1938 /* 1939 * Kill the current process for stated reason. 1940 */ 1941 void 1942 killproc(p, why) 1943 struct proc *p; 1944 char *why; 1945 { 1946 1947 PROC_LOCK_ASSERT(p, MA_OWNED); 1948 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 1949 p, p->p_pid, p->p_comm); 1950 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1951 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1952 psignal(p, SIGKILL); 1953 } 1954 1955 /* 1956 * Force the current process to exit with the specified signal, dumping core 1957 * if appropriate. We bypass the normal tests for masked and caught signals, 1958 * allowing unrecoverable failures to terminate the process without changing 1959 * signal state. Mark the accounting record with the signal termination. 1960 * If dumping core, save the signal number for the debugger. Calls exit and 1961 * does not return. 1962 */ 1963 void 1964 sigexit(td, sig) 1965 struct thread *td; 1966 int sig; 1967 { 1968 struct proc *p = td->td_proc; 1969 1970 PROC_LOCK_ASSERT(p, MA_OWNED); 1971 p->p_acflag |= AXSIG; 1972 if (sigprop(sig) & SA_CORE) { 1973 p->p_sig = sig; 1974 /* 1975 * Log signals which would cause core dumps 1976 * (Log as LOG_INFO to appease those who don't want 1977 * these messages.) 1978 * XXX : Todo, as well as euid, write out ruid too 1979 */ 1980 PROC_UNLOCK(p); 1981 if (!mtx_owned(&Giant)) 1982 mtx_lock(&Giant); 1983 if (coredump(td) == 0) 1984 sig |= WCOREFLAG; 1985 if (kern_logsigexit) 1986 log(LOG_INFO, 1987 "pid %d (%s), uid %d: exited on signal %d%s\n", 1988 p->p_pid, p->p_comm, 1989 td->td_ucred ? td->td_ucred->cr_uid : -1, 1990 sig &~ WCOREFLAG, 1991 sig & WCOREFLAG ? " (core dumped)" : ""); 1992 } else { 1993 PROC_UNLOCK(p); 1994 if (!mtx_owned(&Giant)) 1995 mtx_lock(&Giant); 1996 } 1997 exit1(td, W_EXITCODE(0, sig)); 1998 /* NOTREACHED */ 1999 } 2000 2001 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2002 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2003 sizeof(corefilename), "process corefile name format string"); 2004 2005 /* 2006 * expand_name(name, uid, pid) 2007 * Expand the name described in corefilename, using name, uid, and pid. 2008 * corefilename is a printf-like string, with three format specifiers: 2009 * %N name of process ("name") 2010 * %P process id (pid) 2011 * %U user id (uid) 2012 * For example, "%N.core" is the default; they can be disabled completely 2013 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2014 * This is controlled by the sysctl variable kern.corefile (see above). 2015 */ 2016 2017 static char * 2018 expand_name(name, uid, pid) 2019 const char *name; 2020 uid_t uid; 2021 pid_t pid; 2022 { 2023 const char *format, *appendstr; 2024 char *temp; 2025 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2026 size_t i, l, n; 2027 2028 format = corefilename; 2029 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2030 if (temp == NULL) 2031 return (NULL); 2032 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2033 switch (format[i]) { 2034 case '%': /* Format character */ 2035 i++; 2036 switch (format[i]) { 2037 case '%': 2038 appendstr = "%"; 2039 break; 2040 case 'N': /* process name */ 2041 appendstr = name; 2042 break; 2043 case 'P': /* process id */ 2044 sprintf(buf, "%u", pid); 2045 appendstr = buf; 2046 break; 2047 case 'U': /* user id */ 2048 sprintf(buf, "%u", uid); 2049 appendstr = buf; 2050 break; 2051 default: 2052 appendstr = ""; 2053 log(LOG_ERR, 2054 "Unknown format character %c in `%s'\n", 2055 format[i], format); 2056 } 2057 l = strlen(appendstr); 2058 if ((n + l) >= MAXPATHLEN) 2059 goto toolong; 2060 memcpy(temp + n, appendstr, l); 2061 n += l; 2062 break; 2063 default: 2064 temp[n++] = format[i]; 2065 } 2066 } 2067 if (format[i] != '\0') 2068 goto toolong; 2069 return (temp); 2070 toolong: 2071 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2072 (long)pid, name, (u_long)uid); 2073 free(temp, M_TEMP); 2074 return (NULL); 2075 } 2076 2077 /* 2078 * Dump a process' core. The main routine does some 2079 * policy checking, and creates the name of the coredump; 2080 * then it passes on a vnode and a size limit to the process-specific 2081 * coredump routine if there is one; if there _is not_ one, it returns 2082 * ENOSYS; otherwise it returns the error from the process-specific routine. 2083 */ 2084 2085 static int 2086 coredump(struct thread *td) 2087 { 2088 struct proc *p = td->td_proc; 2089 register struct vnode *vp; 2090 register struct ucred *cred = td->td_ucred; 2091 struct flock lf; 2092 struct nameidata nd; 2093 struct vattr vattr; 2094 int error, error1, flags; 2095 struct mount *mp; 2096 char *name; /* name of corefile */ 2097 off_t limit; 2098 2099 PROC_LOCK(p); 2100 _STOPEVENT(p, S_CORE, 0); 2101 2102 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2103 PROC_UNLOCK(p); 2104 return (EFAULT); 2105 } 2106 2107 /* 2108 * Note that the bulk of limit checking is done after 2109 * the corefile is created. The exception is if the limit 2110 * for corefiles is 0, in which case we don't bother 2111 * creating the corefile at all. This layout means that 2112 * a corefile is truncated instead of not being created, 2113 * if it is larger than the limit. 2114 */ 2115 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2116 if (limit == 0) { 2117 PROC_UNLOCK(p); 2118 return 0; 2119 } 2120 PROC_UNLOCK(p); 2121 2122 restart: 2123 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2124 if (name == NULL) 2125 return (EINVAL); 2126 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2127 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2128 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); 2129 free(name, M_TEMP); 2130 if (error) 2131 return (error); 2132 NDFREE(&nd, NDF_ONLY_PNBUF); 2133 vp = nd.ni_vp; 2134 2135 /* Don't dump to non-regular files or files with links. */ 2136 if (vp->v_type != VREG || 2137 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2138 VOP_UNLOCK(vp, 0, td); 2139 error = EFAULT; 2140 goto out2; 2141 } 2142 2143 VOP_UNLOCK(vp, 0, td); 2144 lf.l_whence = SEEK_SET; 2145 lf.l_start = 0; 2146 lf.l_len = 0; 2147 lf.l_type = F_WRLCK; 2148 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 2149 if (error) 2150 goto out2; 2151 2152 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2153 lf.l_type = F_UNLCK; 2154 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2155 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2156 return (error); 2157 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2158 return (error); 2159 goto restart; 2160 } 2161 2162 VATTR_NULL(&vattr); 2163 vattr.va_size = 0; 2164 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2165 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2166 VOP_SETATTR(vp, &vattr, cred, td); 2167 VOP_UNLOCK(vp, 0, td); 2168 PROC_LOCK(p); 2169 p->p_acflag |= ACORE; 2170 PROC_UNLOCK(p); 2171 2172 error = p->p_sysent->sv_coredump ? 2173 p->p_sysent->sv_coredump(td, vp, limit) : 2174 ENOSYS; 2175 2176 lf.l_type = F_UNLCK; 2177 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2178 vn_finished_write(mp); 2179 out2: 2180 error1 = vn_close(vp, FWRITE, cred, td); 2181 if (error == 0) 2182 error = error1; 2183 return (error); 2184 } 2185 2186 /* 2187 * Nonexistent system call-- signal process (may want to handle it). 2188 * Flag error in case process won't see signal immediately (blocked or ignored). 2189 */ 2190 #ifndef _SYS_SYSPROTO_H_ 2191 struct nosys_args { 2192 int dummy; 2193 }; 2194 #endif 2195 /* 2196 * MPSAFE 2197 */ 2198 /* ARGSUSED */ 2199 int 2200 nosys(td, args) 2201 struct thread *td; 2202 struct nosys_args *args; 2203 { 2204 struct proc *p = td->td_proc; 2205 2206 mtx_lock(&Giant); 2207 PROC_LOCK(p); 2208 psignal(p, SIGSYS); 2209 PROC_UNLOCK(p); 2210 mtx_unlock(&Giant); 2211 return (ENOSYS); 2212 } 2213 2214 /* 2215 * Send a SIGIO or SIGURG signal to a process or process group using 2216 * stored credentials rather than those of the current process. 2217 */ 2218 void 2219 pgsigio(sigiop, sig, checkctty) 2220 struct sigio **sigiop; 2221 int sig, checkctty; 2222 { 2223 struct sigio *sigio; 2224 2225 SIGIO_LOCK(); 2226 sigio = *sigiop; 2227 if (sigio == NULL) { 2228 SIGIO_UNLOCK(); 2229 return; 2230 } 2231 if (sigio->sio_pgid > 0) { 2232 PROC_LOCK(sigio->sio_proc); 2233 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2234 psignal(sigio->sio_proc, sig); 2235 PROC_UNLOCK(sigio->sio_proc); 2236 } else if (sigio->sio_pgid < 0) { 2237 struct proc *p; 2238 2239 PGRP_LOCK(sigio->sio_pgrp); 2240 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2241 PROC_LOCK(p); 2242 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2243 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2244 psignal(p, sig); 2245 PROC_UNLOCK(p); 2246 } 2247 PGRP_UNLOCK(sigio->sio_pgrp); 2248 } 2249 SIGIO_UNLOCK(); 2250 } 2251 2252 static int 2253 filt_sigattach(struct knote *kn) 2254 { 2255 struct proc *p = curproc; 2256 2257 kn->kn_ptr.p_proc = p; 2258 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2259 2260 PROC_LOCK(p); 2261 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2262 PROC_UNLOCK(p); 2263 2264 return (0); 2265 } 2266 2267 static void 2268 filt_sigdetach(struct knote *kn) 2269 { 2270 struct proc *p = kn->kn_ptr.p_proc; 2271 2272 PROC_LOCK(p); 2273 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2274 PROC_UNLOCK(p); 2275 } 2276 2277 /* 2278 * signal knotes are shared with proc knotes, so we apply a mask to 2279 * the hint in order to differentiate them from process hints. This 2280 * could be avoided by using a signal-specific knote list, but probably 2281 * isn't worth the trouble. 2282 */ 2283 static int 2284 filt_signal(struct knote *kn, long hint) 2285 { 2286 2287 if (hint & NOTE_SIGNAL) { 2288 hint &= ~NOTE_SIGNAL; 2289 2290 if (kn->kn_id == hint) 2291 kn->kn_data++; 2292 } 2293 return (kn->kn_data != 0); 2294 } 2295