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: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $ 40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.2 2003/06/17 04:28:41 dillon Exp $ 41 */ 42 43 #include "opt_compat.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/kernel.h> 48 #include <sys/sysproto.h> 49 #include <sys/signalvar.h> 50 #include <sys/resourcevar.h> 51 #include <sys/namei.h> 52 #include <sys/vnode.h> 53 #include <sys/event.h> 54 #include <sys/proc.h> 55 #include <sys/pioctl.h> 56 #include <sys/systm.h> 57 #include <sys/acct.h> 58 #include <sys/fcntl.h> 59 #include <sys/wait.h> 60 #include <sys/ktrace.h> 61 #include <sys/syslog.h> 62 #include <sys/stat.h> 63 #include <sys/sysent.h> 64 #include <sys/sysctl.h> 65 #include <sys/malloc.h> 66 #include <sys/unistd.h> 67 68 69 #include <machine/ipl.h> 70 #include <machine/cpu.h> 71 #include <machine/smp.h> 72 73 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 74 75 static int coredump __P((struct proc *)); 76 static int do_sigaction __P((struct proc *p, int sig, struct sigaction *act, 77 struct sigaction *oact, int old)); 78 static int do_sigprocmask __P((struct proc *p, int how, sigset_t *set, 79 sigset_t *oset, int old)); 80 static char *expand_name __P((const char *, uid_t, pid_t)); 81 static int killpg1 __P((struct proc *cp, int sig, int pgid, int all)); 82 static int sig_ffs __P((sigset_t *set)); 83 static int sigprop __P((int sig)); 84 static void stop __P((struct proc *)); 85 86 static int filt_sigattach(struct knote *kn); 87 static void filt_sigdetach(struct knote *kn); 88 static int filt_signal(struct knote *kn, long hint); 89 90 struct filterops sig_filtops = 91 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 92 93 static int kern_logsigexit = 1; 94 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 95 &kern_logsigexit, 0, 96 "Log processes quitting on abnormal signals to syslog(3)"); 97 98 /* 99 * Can process p, with pcred pc, send the signal sig to process q? 100 */ 101 #define CANSIGNAL(p, q, sig) \ 102 (!p_trespass(p, q) || \ 103 ((sig) == SIGCONT && (q)->p_session == (p)->p_session)) 104 105 /* 106 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 107 */ 108 #define CANSIGIO(ruid, uc, q) \ 109 ((uc)->cr_uid == 0 || \ 110 (ruid) == (q)->p_cred->p_ruid || \ 111 (uc)->cr_uid == (q)->p_cred->p_ruid || \ 112 (ruid) == (q)->p_ucred->cr_uid || \ 113 (uc)->cr_uid == (q)->p_ucred->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 static __inline int 171 sigprop(int sig) 172 { 173 174 if (sig > 0 && sig < NSIG) 175 return (sigproptbl[_SIG_IDX(sig)]); 176 return (0); 177 } 178 179 static __inline int 180 sig_ffs(sigset_t *set) 181 { 182 int i; 183 184 for (i = 0; i < _SIG_WORDS; i++) 185 if (set->__bits[i]) 186 return (ffs(set->__bits[i]) + (i * 32)); 187 return (0); 188 } 189 190 /* 191 * do_sigaction 192 * sigaction 193 * osigaction 194 */ 195 static int 196 do_sigaction(p, sig, act, oact, old) 197 struct proc *p; 198 register int sig; 199 struct sigaction *act, *oact; 200 int old; 201 { 202 register struct sigacts *ps = p->p_sigacts; 203 204 if (sig <= 0 || sig > _SIG_MAXSIG) 205 return (EINVAL); 206 207 if (oact) { 208 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 209 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 210 oact->sa_flags = 0; 211 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 212 oact->sa_flags |= SA_ONSTACK; 213 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 214 oact->sa_flags |= SA_RESTART; 215 if (SIGISMEMBER(ps->ps_sigreset, sig)) 216 oact->sa_flags |= SA_RESETHAND; 217 if (SIGISMEMBER(ps->ps_signodefer, sig)) 218 oact->sa_flags |= SA_NODEFER; 219 if (SIGISMEMBER(ps->ps_siginfo, sig)) 220 oact->sa_flags |= SA_SIGINFO; 221 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 222 oact->sa_flags |= SA_NOCLDSTOP; 223 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 224 oact->sa_flags |= SA_NOCLDWAIT; 225 } 226 if (act) { 227 if ((sig == SIGKILL || sig == SIGSTOP) && 228 act->sa_handler != SIG_DFL) 229 return (EINVAL); 230 231 /* 232 * Change setting atomically. 233 */ 234 (void) splhigh(); 235 236 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 237 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 238 if (act->sa_flags & SA_SIGINFO) { 239 ps->ps_sigact[_SIG_IDX(sig)] = 240 (__sighandler_t *)act->sa_sigaction; 241 SIGADDSET(ps->ps_siginfo, sig); 242 } else { 243 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 244 SIGDELSET(ps->ps_siginfo, sig); 245 } 246 if (!(act->sa_flags & SA_RESTART)) 247 SIGADDSET(ps->ps_sigintr, sig); 248 else 249 SIGDELSET(ps->ps_sigintr, sig); 250 if (act->sa_flags & SA_ONSTACK) 251 SIGADDSET(ps->ps_sigonstack, sig); 252 else 253 SIGDELSET(ps->ps_sigonstack, sig); 254 if (act->sa_flags & SA_RESETHAND) 255 SIGADDSET(ps->ps_sigreset, sig); 256 else 257 SIGDELSET(ps->ps_sigreset, sig); 258 if (act->sa_flags & SA_NODEFER) 259 SIGADDSET(ps->ps_signodefer, sig); 260 else 261 SIGDELSET(ps->ps_signodefer, sig); 262 #ifdef COMPAT_SUNOS 263 if (act->sa_flags & SA_USERTRAMP) 264 SIGADDSET(ps->ps_usertramp, sig); 265 else 266 SIGDELSET(ps->ps_usertramp, seg); 267 #endif 268 if (sig == SIGCHLD) { 269 if (act->sa_flags & SA_NOCLDSTOP) 270 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 271 else 272 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 273 if (act->sa_flags & SA_NOCLDWAIT) { 274 /* 275 * Paranoia: since SA_NOCLDWAIT is implemented 276 * by reparenting the dying child to PID 1 (and 277 * trust it to reap the zombie), PID 1 itself 278 * is forbidden to set SA_NOCLDWAIT. 279 */ 280 if (p->p_pid == 1) 281 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 282 else 283 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 284 } else 285 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 286 } 287 /* 288 * Set bit in p_sigignore for signals that are set to SIG_IGN, 289 * and for signals set to SIG_DFL where the default is to 290 * ignore. However, don't put SIGCONT in p_sigignore, as we 291 * have to restart the process. 292 */ 293 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 294 (sigprop(sig) & SA_IGNORE && 295 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 296 /* never to be seen again */ 297 SIGDELSET(p->p_siglist, sig); 298 if (sig != SIGCONT) 299 /* easier in psignal */ 300 SIGADDSET(p->p_sigignore, sig); 301 SIGDELSET(p->p_sigcatch, sig); 302 } else { 303 SIGDELSET(p->p_sigignore, sig); 304 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 305 SIGDELSET(p->p_sigcatch, sig); 306 else 307 SIGADDSET(p->p_sigcatch, sig); 308 } 309 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 310 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) 311 SIGDELSET(ps->ps_osigset, sig); 312 else 313 SIGADDSET(ps->ps_osigset, sig); 314 315 (void) spl0(); 316 } 317 return (0); 318 } 319 320 #ifndef _SYS_SYSPROTO_H_ 321 struct sigaction_args { 322 int sig; 323 struct sigaction *act; 324 struct sigaction *oact; 325 }; 326 #endif 327 /* ARGSUSED */ 328 int 329 sigaction(p, uap) 330 struct proc *p; 331 register struct sigaction_args *uap; 332 { 333 struct sigaction act, oact; 334 register struct sigaction *actp, *oactp; 335 int error; 336 337 actp = (uap->act != NULL) ? &act : NULL; 338 oactp = (uap->oact != NULL) ? &oact : NULL; 339 if (actp) { 340 error = copyin(uap->act, actp, sizeof(act)); 341 if (error) 342 return (error); 343 } 344 error = do_sigaction(p, uap->sig, actp, oactp, 0); 345 if (oactp && !error) { 346 error = copyout(oactp, uap->oact, sizeof(oact)); 347 } 348 return (error); 349 } 350 351 #ifndef _SYS_SYSPROTO_H_ 352 struct osigaction_args { 353 int signum; 354 struct osigaction *nsa; 355 struct osigaction *osa; 356 }; 357 #endif 358 /* ARGSUSED */ 359 int 360 osigaction(p, uap) 361 struct proc *p; 362 register struct osigaction_args *uap; 363 { 364 struct osigaction sa; 365 struct sigaction nsa, osa; 366 register struct sigaction *nsap, *osap; 367 int error; 368 369 if (uap->signum <= 0 || uap->signum >= ONSIG) 370 return (EINVAL); 371 nsap = (uap->nsa != NULL) ? &nsa : NULL; 372 osap = (uap->osa != NULL) ? &osa : NULL; 373 if (nsap) { 374 error = copyin(uap->nsa, &sa, sizeof(sa)); 375 if (error) 376 return (error); 377 nsap->sa_handler = sa.sa_handler; 378 nsap->sa_flags = sa.sa_flags; 379 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 380 } 381 error = do_sigaction(p, uap->signum, nsap, osap, 1); 382 if (osap && !error) { 383 sa.sa_handler = osap->sa_handler; 384 sa.sa_flags = osap->sa_flags; 385 SIG2OSIG(osap->sa_mask, sa.sa_mask); 386 error = copyout(&sa, uap->osa, sizeof(sa)); 387 } 388 return (error); 389 } 390 391 /* 392 * Initialize signal state for process 0; 393 * set to ignore signals that are ignored by default. 394 */ 395 void 396 siginit(p) 397 struct proc *p; 398 { 399 register int i; 400 401 for (i = 1; i <= NSIG; i++) 402 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 403 SIGADDSET(p->p_sigignore, i); 404 } 405 406 /* 407 * Reset signals for an exec of the specified process. 408 */ 409 void 410 execsigs(p) 411 register struct proc *p; 412 { 413 register struct sigacts *ps = p->p_sigacts; 414 register int sig; 415 416 /* 417 * Reset caught signals. Held signals remain held 418 * through p_sigmask (unless they were caught, 419 * and are now ignored by default). 420 */ 421 while (SIGNOTEMPTY(p->p_sigcatch)) { 422 sig = sig_ffs(&p->p_sigcatch); 423 SIGDELSET(p->p_sigcatch, sig); 424 if (sigprop(sig) & SA_IGNORE) { 425 if (sig != SIGCONT) 426 SIGADDSET(p->p_sigignore, sig); 427 SIGDELSET(p->p_siglist, sig); 428 } 429 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 430 } 431 /* 432 * Reset stack state to the user stack. 433 * Clear set of signals caught on the signal stack. 434 */ 435 p->p_sigstk.ss_flags = SS_DISABLE; 436 p->p_sigstk.ss_size = 0; 437 p->p_sigstk.ss_sp = 0; 438 p->p_flag &= ~P_ALTSTACK; 439 /* 440 * Reset no zombies if child dies flag as Solaris does. 441 */ 442 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 443 } 444 445 /* 446 * do_sigprocmask() - MP SAFE ONLY IF p == curproc 447 * 448 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 449 * p == curproc. Also remember that in order to remain MP SAFE 450 * no spl*() calls may be made. 451 */ 452 static int 453 do_sigprocmask(p, how, set, oset, old) 454 struct proc *p; 455 int how; 456 sigset_t *set, *oset; 457 int old; 458 { 459 int error; 460 461 if (oset != NULL) 462 *oset = p->p_sigmask; 463 464 error = 0; 465 if (set != NULL) { 466 switch (how) { 467 case SIG_BLOCK: 468 SIG_CANTMASK(*set); 469 SIGSETOR(p->p_sigmask, *set); 470 break; 471 case SIG_UNBLOCK: 472 SIGSETNAND(p->p_sigmask, *set); 473 break; 474 case SIG_SETMASK: 475 SIG_CANTMASK(*set); 476 if (old) 477 SIGSETLO(p->p_sigmask, *set); 478 else 479 p->p_sigmask = *set; 480 break; 481 default: 482 error = EINVAL; 483 break; 484 } 485 } 486 return (error); 487 } 488 489 /* 490 * sigprocmask() - MP SAFE 491 */ 492 493 #ifndef _SYS_SYSPROTO_H_ 494 struct sigprocmask_args { 495 int how; 496 const sigset_t *set; 497 sigset_t *oset; 498 }; 499 #endif 500 int 501 sigprocmask(p, uap) 502 register struct proc *p; 503 struct sigprocmask_args *uap; 504 { 505 sigset_t set, oset; 506 sigset_t *setp, *osetp; 507 int error; 508 509 setp = (uap->set != NULL) ? &set : NULL; 510 osetp = (uap->oset != NULL) ? &oset : NULL; 511 if (setp) { 512 error = copyin(uap->set, setp, sizeof(set)); 513 if (error) 514 return (error); 515 } 516 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 517 if (osetp && !error) { 518 error = copyout(osetp, uap->oset, sizeof(oset)); 519 } 520 return (error); 521 } 522 523 /* 524 * osigprocmask() - MP SAFE 525 */ 526 527 #ifndef _SYS_SYSPROTO_H_ 528 struct osigprocmask_args { 529 int how; 530 osigset_t mask; 531 }; 532 #endif 533 int 534 osigprocmask(p, uap) 535 register struct proc *p; 536 struct osigprocmask_args *uap; 537 { 538 sigset_t set, oset; 539 int error; 540 541 OSIG2SIG(uap->mask, set); 542 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 543 SIG2OSIG(oset, p->p_retval[0]); 544 return (error); 545 } 546 547 #ifndef _SYS_SYSPROTO_H_ 548 struct sigpending_args { 549 sigset_t *set; 550 }; 551 #endif 552 /* ARGSUSED */ 553 int 554 sigpending(p, uap) 555 struct proc *p; 556 struct sigpending_args *uap; 557 { 558 559 return (copyout(&p->p_siglist, uap->set, sizeof(sigset_t))); 560 } 561 562 #ifndef _SYS_SYSPROTO_H_ 563 struct osigpending_args { 564 int dummy; 565 }; 566 #endif 567 /* ARGSUSED */ 568 int 569 osigpending(p, uap) 570 struct proc *p; 571 struct osigpending_args *uap; 572 { 573 574 SIG2OSIG(p->p_siglist, p->p_retval[0]); 575 return (0); 576 } 577 578 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 579 /* 580 * Generalized interface signal handler, 4.3-compatible. 581 */ 582 #ifndef _SYS_SYSPROTO_H_ 583 struct osigvec_args { 584 int signum; 585 struct sigvec *nsv; 586 struct sigvec *osv; 587 }; 588 #endif 589 /* ARGSUSED */ 590 int 591 osigvec(p, uap) 592 struct proc *p; 593 register struct osigvec_args *uap; 594 { 595 struct sigvec vec; 596 struct sigaction nsa, osa; 597 register struct sigaction *nsap, *osap; 598 int error; 599 600 if (uap->signum <= 0 || uap->signum >= ONSIG) 601 return (EINVAL); 602 nsap = (uap->nsv != NULL) ? &nsa : NULL; 603 osap = (uap->osv != NULL) ? &osa : NULL; 604 if (nsap) { 605 error = copyin(uap->nsv, &vec, sizeof(vec)); 606 if (error) 607 return (error); 608 nsap->sa_handler = vec.sv_handler; 609 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 610 nsap->sa_flags = vec.sv_flags; 611 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 612 #ifdef COMPAT_SUNOS 613 nsap->sa_flags |= SA_USERTRAMP; 614 #endif 615 } 616 error = do_sigaction(p, uap->signum, nsap, osap, 1); 617 if (osap && !error) { 618 vec.sv_handler = osap->sa_handler; 619 SIG2OSIG(osap->sa_mask, vec.sv_mask); 620 vec.sv_flags = osap->sa_flags; 621 vec.sv_flags &= ~SA_NOCLDWAIT; 622 vec.sv_flags ^= SA_RESTART; 623 #ifdef COMPAT_SUNOS 624 vec.sv_flags &= ~SA_NOCLDSTOP; 625 #endif 626 error = copyout(&vec, uap->osv, sizeof(vec)); 627 } 628 return (error); 629 } 630 631 #ifndef _SYS_SYSPROTO_H_ 632 struct osigblock_args { 633 int mask; 634 }; 635 #endif 636 int 637 osigblock(p, uap) 638 register struct proc *p; 639 struct osigblock_args *uap; 640 { 641 sigset_t set; 642 643 OSIG2SIG(uap->mask, set); 644 SIG_CANTMASK(set); 645 (void) splhigh(); 646 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 647 SIGSETOR(p->p_sigmask, set); 648 (void) spl0(); 649 return (0); 650 } 651 652 #ifndef _SYS_SYSPROTO_H_ 653 struct osigsetmask_args { 654 int mask; 655 }; 656 #endif 657 int 658 osigsetmask(p, uap) 659 struct proc *p; 660 struct osigsetmask_args *uap; 661 { 662 sigset_t set; 663 664 OSIG2SIG(uap->mask, set); 665 SIG_CANTMASK(set); 666 (void) splhigh(); 667 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 668 SIGSETLO(p->p_sigmask, set); 669 (void) spl0(); 670 return (0); 671 } 672 #endif /* COMPAT_43 || COMPAT_SUNOS */ 673 674 /* 675 * Suspend process until signal, providing mask to be set 676 * in the meantime. Note nonstandard calling convention: 677 * libc stub passes mask, not pointer, to save a copyin. 678 */ 679 #ifndef _SYS_SYSPROTO_H_ 680 struct sigsuspend_args { 681 const sigset_t *sigmask; 682 }; 683 #endif 684 /* ARGSUSED */ 685 int 686 sigsuspend(p, uap) 687 register struct proc *p; 688 struct sigsuspend_args *uap; 689 { 690 sigset_t mask; 691 register struct sigacts *ps = p->p_sigacts; 692 int error; 693 694 error = copyin(uap->sigmask, &mask, sizeof(mask)); 695 if (error) 696 return (error); 697 698 /* 699 * When returning from sigsuspend, we want 700 * the old mask to be restored after the 701 * signal handler has finished. Thus, we 702 * save it here and mark the sigacts structure 703 * to indicate this. 704 */ 705 p->p_oldsigmask = p->p_sigmask; 706 p->p_flag |= P_OLDMASK; 707 708 SIG_CANTMASK(mask); 709 p->p_sigmask = mask; 710 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0) 711 /* void */; 712 /* always return EINTR rather than ERESTART... */ 713 return (EINTR); 714 } 715 716 #ifndef _SYS_SYSPROTO_H_ 717 struct osigsuspend_args { 718 osigset_t mask; 719 }; 720 #endif 721 /* ARGSUSED */ 722 int 723 osigsuspend(p, uap) 724 register struct proc *p; 725 struct osigsuspend_args *uap; 726 { 727 sigset_t mask; 728 register struct sigacts *ps = p->p_sigacts; 729 730 p->p_oldsigmask = p->p_sigmask; 731 p->p_flag |= P_OLDMASK; 732 OSIG2SIG(uap->mask, mask); 733 SIG_CANTMASK(mask); 734 SIGSETLO(p->p_sigmask, mask); 735 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "opause", 0) == 0) 736 /* void */; 737 /* always return EINTR rather than ERESTART... */ 738 return (EINTR); 739 } 740 741 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 742 #ifndef _SYS_SYSPROTO_H_ 743 struct osigstack_args { 744 struct sigstack *nss; 745 struct sigstack *oss; 746 }; 747 #endif 748 /* ARGSUSED */ 749 int 750 osigstack(p, uap) 751 struct proc *p; 752 register struct osigstack_args *uap; 753 { 754 struct sigstack ss; 755 int error = 0; 756 757 ss.ss_sp = p->p_sigstk.ss_sp; 758 ss.ss_onstack = p->p_sigstk.ss_flags & SS_ONSTACK; 759 if (uap->oss && (error = copyout(&ss, uap->oss, 760 sizeof(struct sigstack)))) 761 return (error); 762 if (uap->nss && (error = copyin(uap->nss, &ss, sizeof(ss))) == 0) { 763 p->p_sigstk.ss_sp = ss.ss_sp; 764 p->p_sigstk.ss_size = 0; 765 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 766 p->p_flag |= P_ALTSTACK; 767 } 768 return (error); 769 } 770 #endif /* COMPAT_43 || COMPAT_SUNOS */ 771 772 #ifndef _SYS_SYSPROTO_H_ 773 struct sigaltstack_args { 774 stack_t *ss; 775 stack_t *oss; 776 }; 777 #endif 778 /* ARGSUSED */ 779 int 780 sigaltstack(p, uap) 781 struct proc *p; 782 register struct sigaltstack_args *uap; 783 { 784 stack_t ss; 785 int error; 786 787 if ((p->p_flag & P_ALTSTACK) == 0) 788 p->p_sigstk.ss_flags |= SS_DISABLE; 789 if (uap->oss && (error = copyout(&p->p_sigstk, uap->oss, 790 sizeof(stack_t)))) 791 return (error); 792 if (uap->ss == 0) 793 return (0); 794 if ((error = copyin(uap->ss, &ss, sizeof(ss)))) 795 return (error); 796 if (ss.ss_flags & SS_DISABLE) { 797 if (p->p_sigstk.ss_flags & SS_ONSTACK) 798 return (EINVAL); 799 p->p_flag &= ~P_ALTSTACK; 800 p->p_sigstk.ss_flags = ss.ss_flags; 801 return (0); 802 } 803 if (ss.ss_size < p->p_sysent->sv_minsigstksz) 804 return (ENOMEM); 805 p->p_flag |= P_ALTSTACK; 806 p->p_sigstk = ss; 807 return (0); 808 } 809 810 /* 811 * Common code for kill process group/broadcast kill. 812 * cp is calling process. 813 */ 814 int 815 killpg1(cp, sig, pgid, all) 816 register struct proc *cp; 817 int sig, pgid, all; 818 { 819 register struct proc *p; 820 struct pgrp *pgrp; 821 int nfound = 0; 822 823 if (all) 824 /* 825 * broadcast 826 */ 827 LIST_FOREACH(p, &allproc, p_list) { 828 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 829 p == cp || !CANSIGNAL(cp, p, sig)) 830 continue; 831 nfound++; 832 if (sig) 833 psignal(p, sig); 834 } 835 else { 836 if (pgid == 0) 837 /* 838 * zero pgid means send to my process group. 839 */ 840 pgrp = cp->p_pgrp; 841 else { 842 pgrp = pgfind(pgid); 843 if (pgrp == NULL) 844 return (ESRCH); 845 } 846 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 847 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 848 p->p_stat == SZOMB || 849 !CANSIGNAL(cp, p, sig)) 850 continue; 851 nfound++; 852 if (sig) 853 psignal(p, sig); 854 } 855 } 856 return (nfound ? 0 : ESRCH); 857 } 858 859 #ifndef _SYS_SYSPROTO_H_ 860 struct kill_args { 861 int pid; 862 int signum; 863 }; 864 #endif 865 /* ARGSUSED */ 866 int 867 kill(cp, uap) 868 register struct proc *cp; 869 register struct kill_args *uap; 870 { 871 register struct proc *p; 872 873 if ((u_int)uap->signum > _SIG_MAXSIG) 874 return (EINVAL); 875 if (uap->pid > 0) { 876 /* kill single process */ 877 if ((p = pfind(uap->pid)) == NULL) 878 return (ESRCH); 879 if (!CANSIGNAL(cp, p, uap->signum)) 880 return (EPERM); 881 if (uap->signum) 882 psignal(p, uap->signum); 883 return (0); 884 } 885 switch (uap->pid) { 886 case -1: /* broadcast signal */ 887 return (killpg1(cp, uap->signum, 0, 1)); 888 case 0: /* signal own process group */ 889 return (killpg1(cp, uap->signum, 0, 0)); 890 default: /* negative explicit process group */ 891 return (killpg1(cp, uap->signum, -uap->pid, 0)); 892 } 893 /* NOTREACHED */ 894 } 895 896 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 897 #ifndef _SYS_SYSPROTO_H_ 898 struct okillpg_args { 899 int pgid; 900 int signum; 901 }; 902 #endif 903 /* ARGSUSED */ 904 int 905 okillpg(p, uap) 906 struct proc *p; 907 register struct okillpg_args *uap; 908 { 909 910 if ((u_int)uap->signum > _SIG_MAXSIG) 911 return (EINVAL); 912 return (killpg1(p, uap->signum, uap->pgid, 0)); 913 } 914 #endif /* COMPAT_43 || COMPAT_SUNOS */ 915 916 /* 917 * Send a signal to a process group. 918 */ 919 void 920 gsignal(pgid, sig) 921 int pgid, sig; 922 { 923 struct pgrp *pgrp; 924 925 if (pgid && (pgrp = pgfind(pgid))) 926 pgsignal(pgrp, sig, 0); 927 } 928 929 /* 930 * Send a signal to a process group. If checktty is 1, 931 * limit to members which have a controlling terminal. 932 */ 933 void 934 pgsignal(pgrp, sig, checkctty) 935 struct pgrp *pgrp; 936 int sig, checkctty; 937 { 938 register struct proc *p; 939 940 if (pgrp) 941 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) 942 if (checkctty == 0 || p->p_flag & P_CONTROLT) 943 psignal(p, sig); 944 } 945 946 /* 947 * Send a signal caused by a trap to the current process. 948 * If it will be caught immediately, deliver it with correct code. 949 * Otherwise, post it normally. 950 */ 951 void 952 trapsignal(p, sig, code) 953 struct proc *p; 954 register int sig; 955 u_long code; 956 { 957 register struct sigacts *ps = p->p_sigacts; 958 959 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 960 !SIGISMEMBER(p->p_sigmask, sig)) { 961 p->p_stats->p_ru.ru_nsignals++; 962 #ifdef KTRACE 963 if (KTRPOINT(p, KTR_PSIG)) 964 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 965 &p->p_sigmask, code); 966 #endif 967 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 968 &p->p_sigmask, code); 969 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 970 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 971 SIGADDSET(p->p_sigmask, sig); 972 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 973 /* 974 * See do_sigaction() for origin of this code. 975 */ 976 SIGDELSET(p->p_sigcatch, sig); 977 if (sig != SIGCONT && 978 sigprop(sig) & SA_IGNORE) 979 SIGADDSET(p->p_sigignore, sig); 980 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 981 } 982 } else { 983 p->p_code = code; /* XXX for core dump/debugger */ 984 p->p_sig = sig; /* XXX to verify code */ 985 psignal(p, sig); 986 } 987 } 988 989 /* 990 * Send the signal to the process. If the signal has an action, the action 991 * is usually performed by the target process rather than the caller; we add 992 * the signal to the set of pending signals for the process. 993 * 994 * Exceptions: 995 * o When a stop signal is sent to a sleeping process that takes the 996 * default action, the process is stopped without awakening it. 997 * o SIGCONT restarts stopped processes (or puts them back to sleep) 998 * regardless of the signal action (eg, blocked or ignored). 999 * 1000 * Other ignored signals are discarded immediately. 1001 */ 1002 void 1003 psignal(p, sig) 1004 register struct proc *p; 1005 register int sig; 1006 { 1007 register int s, prop; 1008 register sig_t action; 1009 1010 if (sig > _SIG_MAXSIG || sig <= 0) { 1011 printf("psignal: signal %d\n", sig); 1012 panic("psignal signal number"); 1013 } 1014 1015 s = splhigh(); 1016 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1017 splx(s); 1018 1019 prop = sigprop(sig); 1020 1021 /* 1022 * If proc is traced, always give parent a chance; 1023 * if signal event is tracked by procfs, give *that* 1024 * a chance, as well. 1025 */ 1026 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) 1027 action = SIG_DFL; 1028 else { 1029 /* 1030 * If the signal is being ignored, 1031 * then we forget about it immediately. 1032 * (Note: we don't set SIGCONT in p_sigignore, 1033 * and if it is set to SIG_IGN, 1034 * action will be SIG_DFL here.) 1035 */ 1036 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1037 return; 1038 if (SIGISMEMBER(p->p_sigmask, sig)) 1039 action = SIG_HOLD; 1040 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1041 action = SIG_CATCH; 1042 else 1043 action = SIG_DFL; 1044 } 1045 1046 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1047 (p->p_flag & P_TRACED) == 0) 1048 p->p_nice = NZERO; 1049 1050 if (prop & SA_CONT) 1051 SIG_STOPSIGMASK(p->p_siglist); 1052 1053 if (prop & SA_STOP) { 1054 /* 1055 * If sending a tty stop signal to a member of an orphaned 1056 * process group, discard the signal here if the action 1057 * is default; don't stop the process below if sleeping, 1058 * and don't clear any pending SIGCONT. 1059 */ 1060 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1061 action == SIG_DFL) 1062 return; 1063 SIG_CONTSIGMASK(p->p_siglist); 1064 } 1065 SIGADDSET(p->p_siglist, sig); 1066 1067 /* 1068 * Defer further processing for signals which are held, 1069 * except that stopped processes must be continued by SIGCONT. 1070 */ 1071 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) 1072 return; 1073 s = splhigh(); 1074 switch (p->p_stat) { 1075 1076 case SSLEEP: 1077 /* 1078 * If process is sleeping uninterruptibly 1079 * we can't interrupt the sleep... the signal will 1080 * be noticed when the process returns through 1081 * trap() or syscall(). 1082 */ 1083 if ((p->p_flag & P_SINTR) == 0) 1084 goto out; 1085 /* 1086 * Process is sleeping and traced... make it runnable 1087 * so it can discover the signal in issignal() and stop 1088 * for the parent. 1089 */ 1090 if (p->p_flag & P_TRACED) 1091 goto run; 1092 /* 1093 * If SIGCONT is default (or ignored) and process is 1094 * asleep, we are finished; the process should not 1095 * be awakened. 1096 */ 1097 if ((prop & SA_CONT) && action == SIG_DFL) { 1098 SIGDELSET(p->p_siglist, sig); 1099 goto out; 1100 } 1101 /* 1102 * When a sleeping process receives a stop 1103 * signal, process immediately if possible. 1104 * All other (caught or default) signals 1105 * cause the process to run. 1106 */ 1107 if (prop & SA_STOP) { 1108 if (action != SIG_DFL) 1109 goto runfast; 1110 /* 1111 * If a child holding parent blocked, 1112 * stopping could cause deadlock. 1113 */ 1114 if (p->p_flag & P_PPWAIT) 1115 goto out; 1116 SIGDELSET(p->p_siglist, sig); 1117 p->p_xstat = sig; 1118 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1119 psignal(p->p_pptr, SIGCHLD); 1120 stop(p); 1121 goto out; 1122 } else 1123 goto runfast; 1124 /*NOTREACHED*/ 1125 1126 case SSTOP: 1127 /* 1128 * If traced process is already stopped, 1129 * then no further action is necessary. 1130 */ 1131 if (p->p_flag & P_TRACED) 1132 goto out; 1133 1134 /* 1135 * Kill signal always sets processes running. 1136 */ 1137 if (sig == SIGKILL) 1138 goto runfast; 1139 1140 if (prop & SA_CONT) { 1141 /* 1142 * If SIGCONT is default (or ignored), we continue the 1143 * process but don't leave the signal in p_siglist, as 1144 * it has no further action. If SIGCONT is held, we 1145 * continue the process and leave the signal in 1146 * p_siglist. If the process catches SIGCONT, let it 1147 * handle the signal itself. If it isn't waiting on 1148 * an event, then it goes back to run state. 1149 * Otherwise, process goes back to sleep state. 1150 */ 1151 if (action == SIG_DFL) 1152 SIGDELSET(p->p_siglist, sig); 1153 if (action == SIG_CATCH) 1154 goto runfast; 1155 if (p->p_wchan == 0) 1156 goto run; 1157 p->p_stat = SSLEEP; 1158 goto out; 1159 } 1160 1161 if (prop & SA_STOP) { 1162 /* 1163 * Already stopped, don't need to stop again. 1164 * (If we did the shell could get confused.) 1165 */ 1166 SIGDELSET(p->p_siglist, sig); 1167 goto out; 1168 } 1169 1170 /* 1171 * If process is sleeping interruptibly, then simulate a 1172 * wakeup so that when it is continued, it will be made 1173 * runnable and can look at the signal. But don't make 1174 * the process runnable, leave it stopped. 1175 */ 1176 if (p->p_wchan && p->p_flag & P_SINTR) 1177 unsleep(p); 1178 goto out; 1179 1180 default: 1181 /* 1182 * SRUN, SIDL, SZOMB do nothing with the signal, 1183 * other than kicking ourselves if we are running. 1184 * It will either never be noticed, or noticed very soon. 1185 */ 1186 if (p == curproc) 1187 signotify(p); 1188 #ifdef SMP 1189 else if (p->p_stat == SRUN) 1190 forward_signal(p); 1191 #endif 1192 goto out; 1193 } 1194 /*NOTREACHED*/ 1195 1196 runfast: 1197 /* 1198 * Raise priority to at least PUSER. 1199 */ 1200 if (p->p_priority > PUSER) 1201 p->p_priority = PUSER; 1202 run: 1203 setrunnable(p); 1204 out: 1205 splx(s); 1206 } 1207 1208 /* 1209 * If the current process has received a signal (should be caught or cause 1210 * termination, should interrupt current syscall), return the signal number. 1211 * Stop signals with default action are processed immediately, then cleared; 1212 * they aren't returned. This is checked after each entry to the system for 1213 * a syscall or trap (though this can usually be done without calling issignal 1214 * by checking the pending signal masks in the CURSIG macro.) The normal call 1215 * sequence is 1216 * 1217 * while (sig = CURSIG(curproc)) 1218 * postsig(sig); 1219 */ 1220 int 1221 issignal(p) 1222 register struct proc *p; 1223 { 1224 sigset_t mask; 1225 register int sig, prop; 1226 1227 for (;;) { 1228 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1229 1230 mask = p->p_siglist; 1231 SIGSETNAND(mask, p->p_sigmask); 1232 if (p->p_flag & P_PPWAIT) 1233 SIG_STOPSIGMASK(mask); 1234 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1235 return (0); 1236 sig = sig_ffs(&mask); 1237 1238 STOPEVENT(p, S_SIG, sig); 1239 1240 /* 1241 * We should see pending but ignored signals 1242 * only if P_TRACED was on when they were posted. 1243 */ 1244 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1245 SIGDELSET(p->p_siglist, sig); 1246 continue; 1247 } 1248 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1249 /* 1250 * If traced, always stop, and stay 1251 * stopped until released by the parent. 1252 */ 1253 p->p_xstat = sig; 1254 psignal(p->p_pptr, SIGCHLD); 1255 do { 1256 stop(p); 1257 mi_switch(); 1258 } while (!trace_req(p) 1259 && p->p_flag & P_TRACED); 1260 1261 /* 1262 * If parent wants us to take the signal, 1263 * then it will leave it in p->p_xstat; 1264 * otherwise we just look for signals again. 1265 */ 1266 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1267 sig = p->p_xstat; 1268 if (sig == 0) 1269 continue; 1270 1271 /* 1272 * Put the new signal into p_siglist. If the 1273 * signal is being masked, look for other signals. 1274 */ 1275 SIGADDSET(p->p_siglist, sig); 1276 if (SIGISMEMBER(p->p_sigmask, sig)) 1277 continue; 1278 1279 /* 1280 * If the traced bit got turned off, go back up 1281 * to the top to rescan signals. This ensures 1282 * that p_sig* and ps_sigact are consistent. 1283 */ 1284 if ((p->p_flag & P_TRACED) == 0) 1285 continue; 1286 } 1287 1288 prop = sigprop(sig); 1289 1290 /* 1291 * Decide whether the signal should be returned. 1292 * Return the signal's number, or fall through 1293 * to clear it from the pending mask. 1294 */ 1295 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1296 1297 case (int)SIG_DFL: 1298 /* 1299 * Don't take default actions on system processes. 1300 */ 1301 if (p->p_pid <= 1) { 1302 #ifdef DIAGNOSTIC 1303 /* 1304 * Are you sure you want to ignore SIGSEGV 1305 * in init? XXX 1306 */ 1307 printf("Process (pid %lu) got signal %d\n", 1308 (u_long)p->p_pid, sig); 1309 #endif 1310 break; /* == ignore */ 1311 } 1312 /* 1313 * If there is a pending stop signal to process 1314 * with default action, stop here, 1315 * then clear the signal. However, 1316 * if process is member of an orphaned 1317 * process group, ignore tty stop signals. 1318 */ 1319 if (prop & SA_STOP) { 1320 if (p->p_flag & P_TRACED || 1321 (p->p_pgrp->pg_jobc == 0 && 1322 prop & SA_TTYSTOP)) 1323 break; /* == ignore */ 1324 p->p_xstat = sig; 1325 stop(p); 1326 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1327 psignal(p->p_pptr, SIGCHLD); 1328 mi_switch(); 1329 break; 1330 } else if (prop & SA_IGNORE) { 1331 /* 1332 * Except for SIGCONT, shouldn't get here. 1333 * Default action is to ignore; drop it. 1334 */ 1335 break; /* == ignore */ 1336 } else 1337 return (sig); 1338 /*NOTREACHED*/ 1339 1340 case (int)SIG_IGN: 1341 /* 1342 * Masking above should prevent us ever trying 1343 * to take action on an ignored signal other 1344 * than SIGCONT, unless process is traced. 1345 */ 1346 if ((prop & SA_CONT) == 0 && 1347 (p->p_flag & P_TRACED) == 0) 1348 printf("issignal\n"); 1349 break; /* == ignore */ 1350 1351 default: 1352 /* 1353 * This signal has an action, let 1354 * postsig() process it. 1355 */ 1356 return (sig); 1357 } 1358 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1359 } 1360 /* NOTREACHED */ 1361 } 1362 1363 /* 1364 * Put the argument process into the stopped state and notify the parent 1365 * via wakeup. Signals are handled elsewhere. The process must not be 1366 * on the run queue. 1367 */ 1368 void 1369 stop(p) 1370 register struct proc *p; 1371 { 1372 1373 p->p_stat = SSTOP; 1374 p->p_flag &= ~P_WAITED; 1375 wakeup((caddr_t)p->p_pptr); 1376 } 1377 1378 /* 1379 * Take the action for the specified signal 1380 * from the current set of pending signals. 1381 */ 1382 void 1383 postsig(sig) 1384 register int sig; 1385 { 1386 register struct proc *p = curproc; 1387 struct sigacts *ps = p->p_sigacts; 1388 sig_t action; 1389 sigset_t returnmask; 1390 int code; 1391 1392 KASSERT(sig != 0, ("postsig")); 1393 1394 SIGDELSET(p->p_siglist, sig); 1395 action = ps->ps_sigact[_SIG_IDX(sig)]; 1396 #ifdef KTRACE 1397 if (KTRPOINT(p, KTR_PSIG)) 1398 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1399 &p->p_oldsigmask : &p->p_sigmask, 0); 1400 #endif 1401 STOPEVENT(p, S_SIG, sig); 1402 1403 if (action == SIG_DFL) { 1404 /* 1405 * Default action, where the default is to kill 1406 * the process. (Other cases were ignored above.) 1407 */ 1408 sigexit(p, sig); 1409 /* NOTREACHED */ 1410 } else { 1411 /* 1412 * If we get here, the signal must be caught. 1413 */ 1414 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1415 ("postsig action")); 1416 /* 1417 * Set the new mask value and also defer further 1418 * occurrences of this signal. 1419 * 1420 * Special case: user has done a sigsuspend. Here the 1421 * current mask is not of interest, but rather the 1422 * mask from before the sigsuspend is what we want 1423 * restored after the signal processing is completed. 1424 */ 1425 (void) splhigh(); 1426 if (p->p_flag & P_OLDMASK) { 1427 returnmask = p->p_oldsigmask; 1428 p->p_flag &= ~P_OLDMASK; 1429 } else 1430 returnmask = p->p_sigmask; 1431 1432 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1433 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1434 SIGADDSET(p->p_sigmask, sig); 1435 1436 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1437 /* 1438 * See do_sigaction() for origin of this code. 1439 */ 1440 SIGDELSET(p->p_sigcatch, sig); 1441 if (sig != SIGCONT && 1442 sigprop(sig) & SA_IGNORE) 1443 SIGADDSET(p->p_sigignore, sig); 1444 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1445 } 1446 (void) spl0(); 1447 p->p_stats->p_ru.ru_nsignals++; 1448 if (p->p_sig != sig) { 1449 code = 0; 1450 } else { 1451 code = p->p_code; 1452 p->p_code = 0; 1453 p->p_sig = 0; 1454 } 1455 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1456 } 1457 } 1458 1459 /* 1460 * Kill the current process for stated reason. 1461 */ 1462 void 1463 killproc(p, why) 1464 struct proc *p; 1465 char *why; 1466 { 1467 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1468 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1469 psignal(p, SIGKILL); 1470 } 1471 1472 /* 1473 * Force the current process to exit with the specified signal, dumping core 1474 * if appropriate. We bypass the normal tests for masked and caught signals, 1475 * allowing unrecoverable failures to terminate the process without changing 1476 * signal state. Mark the accounting record with the signal termination. 1477 * If dumping core, save the signal number for the debugger. Calls exit and 1478 * does not return. 1479 */ 1480 void 1481 sigexit(p, sig) 1482 register struct proc *p; 1483 int sig; 1484 { 1485 1486 p->p_acflag |= AXSIG; 1487 if (sigprop(sig) & SA_CORE) { 1488 p->p_sig = sig; 1489 /* 1490 * Log signals which would cause core dumps 1491 * (Log as LOG_INFO to appease those who don't want 1492 * these messages.) 1493 * XXX : Todo, as well as euid, write out ruid too 1494 */ 1495 if (coredump(p) == 0) 1496 sig |= WCOREFLAG; 1497 if (kern_logsigexit) 1498 log(LOG_INFO, 1499 "pid %d (%s), uid %d: exited on signal %d%s\n", 1500 p->p_pid, p->p_comm, 1501 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, 1502 sig &~ WCOREFLAG, 1503 sig & WCOREFLAG ? " (core dumped)" : ""); 1504 } 1505 exit1(p, W_EXITCODE(0, sig)); 1506 /* NOTREACHED */ 1507 } 1508 1509 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1510 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1511 sizeof(corefilename), "process corefile name format string"); 1512 1513 /* 1514 * expand_name(name, uid, pid) 1515 * Expand the name described in corefilename, using name, uid, and pid. 1516 * corefilename is a printf-like string, with three format specifiers: 1517 * %N name of process ("name") 1518 * %P process id (pid) 1519 * %U user id (uid) 1520 * For example, "%N.core" is the default; they can be disabled completely 1521 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1522 * This is controlled by the sysctl variable kern.corefile (see above). 1523 */ 1524 1525 static char * 1526 expand_name(name, uid, pid) 1527 const char *name; uid_t uid; pid_t pid; { 1528 char *temp; 1529 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1530 int i, n; 1531 char *format = corefilename; 1532 size_t namelen; 1533 1534 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1535 if (temp == NULL) 1536 return NULL; 1537 namelen = strlen(name); 1538 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1539 int l; 1540 switch (format[i]) { 1541 case '%': /* Format character */ 1542 i++; 1543 switch (format[i]) { 1544 case '%': 1545 temp[n++] = '%'; 1546 break; 1547 case 'N': /* process name */ 1548 if ((n + namelen) > MAXPATHLEN) { 1549 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1550 pid, name, uid, temp, name); 1551 free(temp, M_TEMP); 1552 return NULL; 1553 } 1554 memcpy(temp+n, name, namelen); 1555 n += namelen; 1556 break; 1557 case 'P': /* process id */ 1558 l = sprintf(buf, "%u", pid); 1559 if ((n + l) > MAXPATHLEN) { 1560 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1561 pid, name, uid, temp, name); 1562 free(temp, M_TEMP); 1563 return NULL; 1564 } 1565 memcpy(temp+n, buf, l); 1566 n += l; 1567 break; 1568 case 'U': /* user id */ 1569 l = sprintf(buf, "%u", uid); 1570 if ((n + l) > MAXPATHLEN) { 1571 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1572 pid, name, uid, temp, name); 1573 free(temp, M_TEMP); 1574 return NULL; 1575 } 1576 memcpy(temp+n, buf, l); 1577 n += l; 1578 break; 1579 default: 1580 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1581 } 1582 break; 1583 default: 1584 temp[n++] = format[i]; 1585 } 1586 } 1587 temp[n] = '\0'; 1588 return temp; 1589 } 1590 1591 /* 1592 * Dump a process' core. The main routine does some 1593 * policy checking, and creates the name of the coredump; 1594 * then it passes on a vnode and a size limit to the process-specific 1595 * coredump routine if there is one; if there _is not_ one, it returns 1596 * ENOSYS; otherwise it returns the error from the process-specific routine. 1597 */ 1598 1599 static int 1600 coredump(p) 1601 register struct proc *p; 1602 { 1603 register struct vnode *vp; 1604 register struct ucred *cred = p->p_ucred; 1605 struct flock lf; 1606 struct nameidata nd; 1607 struct vattr vattr; 1608 int error, error1; 1609 char *name; /* name of corefile */ 1610 off_t limit; 1611 1612 STOPEVENT(p, S_CORE, 0); 1613 1614 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 1615 return (EFAULT); 1616 1617 /* 1618 * Note that the bulk of limit checking is done after 1619 * the corefile is created. The exception is if the limit 1620 * for corefiles is 0, in which case we don't bother 1621 * creating the corefile at all. This layout means that 1622 * a corefile is truncated instead of not being created, 1623 * if it is larger than the limit. 1624 */ 1625 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1626 if (limit == 0) 1627 return 0; 1628 1629 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1630 if (name == NULL) 1631 return (EINVAL); 1632 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p); 1633 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1634 free(name, M_TEMP); 1635 if (error) 1636 return (error); 1637 NDFREE(&nd, NDF_ONLY_PNBUF); 1638 vp = nd.ni_vp; 1639 1640 VOP_UNLOCK(vp, 0, p); 1641 lf.l_whence = SEEK_SET; 1642 lf.l_start = 0; 1643 lf.l_len = 0; 1644 lf.l_type = F_WRLCK; 1645 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 1646 if (error) 1647 goto out2; 1648 1649 /* Don't dump to non-regular files or files with links. */ 1650 if (vp->v_type != VREG || 1651 VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) { 1652 error = EFAULT; 1653 goto out1; 1654 } 1655 1656 VATTR_NULL(&vattr); 1657 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 1658 vattr.va_size = 0; 1659 VOP_LEASE(vp, p, cred, LEASE_WRITE); 1660 VOP_SETATTR(vp, &vattr, cred, p); 1661 p->p_acflag |= ACORE; 1662 VOP_UNLOCK(vp, 0, p); 1663 1664 error = p->p_sysent->sv_coredump ? 1665 p->p_sysent->sv_coredump(p, vp, limit) : 1666 ENOSYS; 1667 1668 out1: 1669 lf.l_type = F_UNLCK; 1670 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 1671 out2: 1672 error1 = vn_close(vp, FWRITE, cred, p); 1673 if (error == 0) 1674 error = error1; 1675 return (error); 1676 } 1677 1678 /* 1679 * Nonexistent system call-- signal process (may want to handle it). 1680 * Flag error in case process won't see signal immediately (blocked or ignored). 1681 */ 1682 #ifndef _SYS_SYSPROTO_H_ 1683 struct nosys_args { 1684 int dummy; 1685 }; 1686 #endif 1687 /* ARGSUSED */ 1688 int 1689 nosys(p, args) 1690 struct proc *p; 1691 struct nosys_args *args; 1692 { 1693 1694 psignal(p, SIGSYS); 1695 return (EINVAL); 1696 } 1697 1698 /* 1699 * Send a SIGIO or SIGURG signal to a process or process group using 1700 * stored credentials rather than those of the current process. 1701 */ 1702 void 1703 pgsigio(sigio, sig, checkctty) 1704 struct sigio *sigio; 1705 int sig, checkctty; 1706 { 1707 if (sigio == NULL) 1708 return; 1709 1710 if (sigio->sio_pgid > 0) { 1711 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1712 sigio->sio_proc)) 1713 psignal(sigio->sio_proc, sig); 1714 } else if (sigio->sio_pgid < 0) { 1715 struct proc *p; 1716 1717 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) 1718 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1719 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1720 psignal(p, sig); 1721 } 1722 } 1723 1724 static int 1725 filt_sigattach(struct knote *kn) 1726 { 1727 struct proc *p = curproc; 1728 1729 kn->kn_ptr.p_proc = p; 1730 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1731 1732 /* XXX lock the proc here while adding to the list? */ 1733 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 1734 1735 return (0); 1736 } 1737 1738 static void 1739 filt_sigdetach(struct knote *kn) 1740 { 1741 struct proc *p = kn->kn_ptr.p_proc; 1742 1743 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 1744 } 1745 1746 /* 1747 * signal knotes are shared with proc knotes, so we apply a mask to 1748 * the hint in order to differentiate them from process hints. This 1749 * could be avoided by using a signal-specific knote list, but probably 1750 * isn't worth the trouble. 1751 */ 1752 static int 1753 filt_signal(struct knote *kn, long hint) 1754 { 1755 1756 if (hint & NOTE_SIGNAL) { 1757 hint &= ~NOTE_SIGNAL; 1758 1759 if (kn->kn_id == hint) 1760 kn->kn_data++; 1761 } 1762 return (kn->kn_data != 0); 1763 } 1764