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 */ 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/signalvar.h> 49 #include <sys/resourcevar.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/systm.h> 56 #include <sys/acct.h> 57 #include <sys/fcntl.h> 58 #include <sys/wait.h> 59 #include <sys/ktrace.h> 60 #include <sys/syslog.h> 61 #include <sys/stat.h> 62 #include <sys/sysent.h> 63 #include <sys/sysctl.h> 64 #include <sys/malloc.h> 65 #include <sys/unistd.h> 66 67 68 #include <machine/ipl.h> 69 #include <machine/cpu.h> 70 #include <machine/smp.h> 71 72 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 73 74 static int coredump __P((struct proc *)); 75 static int do_sigaction __P((struct proc *p, int sig, struct sigaction *act, 76 struct sigaction *oact, int old)); 77 static int do_sigprocmask __P((struct proc *p, int how, sigset_t *set, 78 sigset_t *oset, int old)); 79 static char *expand_name __P((const char *, uid_t, pid_t)); 80 static int killpg1 __P((struct proc *cp, int sig, int pgid, int all)); 81 static int sig_ffs __P((sigset_t *set)); 82 static int sigprop __P((int sig)); 83 static void stop __P((struct proc *)); 84 85 static int filt_sigattach(struct knote *kn); 86 static void filt_sigdetach(struct knote *kn); 87 static int filt_signal(struct knote *kn, long hint); 88 89 struct filterops sig_filtops = 90 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 91 92 static int kern_logsigexit = 1; 93 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 94 &kern_logsigexit, 0, 95 "Log processes quitting on abnormal signals to syslog(3)"); 96 97 /* 98 * Can process p, with pcred pc, send the signal sig to process q? 99 */ 100 #define CANSIGNAL(p, q, sig) \ 101 (!p_trespass(p, q) || \ 102 ((sig) == SIGCONT && (q)->p_session == (p)->p_session)) 103 104 /* 105 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 106 */ 107 #define CANSIGIO(ruid, uc, q) \ 108 ((uc)->cr_uid == 0 || \ 109 (ruid) == (q)->p_cred->p_ruid || \ 110 (uc)->cr_uid == (q)->p_cred->p_ruid || \ 111 (ruid) == (q)->p_ucred->cr_uid || \ 112 (uc)->cr_uid == (q)->p_ucred->cr_uid) 113 114 int sugid_coredump; 115 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 116 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 117 118 static int do_coredump = 1; 119 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 120 &do_coredump, 0, "Enable/Disable coredumps"); 121 122 /* 123 * Signal properties and actions. 124 * The array below categorizes the signals and their default actions 125 * according to the following properties: 126 */ 127 #define SA_KILL 0x01 /* terminates process by default */ 128 #define SA_CORE 0x02 /* ditto and coredumps */ 129 #define SA_STOP 0x04 /* suspend process */ 130 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 131 #define SA_IGNORE 0x10 /* ignore by default */ 132 #define SA_CONT 0x20 /* continue if suspended */ 133 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 134 135 static int sigproptbl[NSIG] = { 136 SA_KILL, /* SIGHUP */ 137 SA_KILL, /* SIGINT */ 138 SA_KILL|SA_CORE, /* SIGQUIT */ 139 SA_KILL|SA_CORE, /* SIGILL */ 140 SA_KILL|SA_CORE, /* SIGTRAP */ 141 SA_KILL|SA_CORE, /* SIGABRT */ 142 SA_KILL|SA_CORE, /* SIGEMT */ 143 SA_KILL|SA_CORE, /* SIGFPE */ 144 SA_KILL, /* SIGKILL */ 145 SA_KILL|SA_CORE, /* SIGBUS */ 146 SA_KILL|SA_CORE, /* SIGSEGV */ 147 SA_KILL|SA_CORE, /* SIGSYS */ 148 SA_KILL, /* SIGPIPE */ 149 SA_KILL, /* SIGALRM */ 150 SA_KILL, /* SIGTERM */ 151 SA_IGNORE, /* SIGURG */ 152 SA_STOP, /* SIGSTOP */ 153 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 154 SA_IGNORE|SA_CONT, /* SIGCONT */ 155 SA_IGNORE, /* SIGCHLD */ 156 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 157 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 158 SA_IGNORE, /* SIGIO */ 159 SA_KILL, /* SIGXCPU */ 160 SA_KILL, /* SIGXFSZ */ 161 SA_KILL, /* SIGVTALRM */ 162 SA_KILL, /* SIGPROF */ 163 SA_IGNORE, /* SIGWINCH */ 164 SA_IGNORE, /* SIGINFO */ 165 SA_KILL, /* SIGUSR1 */ 166 SA_KILL, /* SIGUSR2 */ 167 }; 168 169 static __inline int 170 sigprop(int sig) 171 { 172 173 if (sig > 0 && sig < NSIG) 174 return (sigproptbl[_SIG_IDX(sig)]); 175 return (0); 176 } 177 178 static __inline int 179 sig_ffs(sigset_t *set) 180 { 181 int i; 182 183 for (i = 0; i < _SIG_WORDS; i++) 184 if (set->__bits[i]) 185 return (ffs(set->__bits[i]) + (i * 32)); 186 return (0); 187 } 188 189 /* 190 * do_sigaction 191 * sigaction 192 * osigaction 193 */ 194 static int 195 do_sigaction(p, sig, act, oact, old) 196 struct proc *p; 197 register int sig; 198 struct sigaction *act, *oact; 199 int old; 200 { 201 register struct sigacts *ps = p->p_sigacts; 202 203 if (sig <= 0 || sig > _SIG_MAXSIG) 204 return (EINVAL); 205 206 if (oact) { 207 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 208 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 209 oact->sa_flags = 0; 210 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 211 oact->sa_flags |= SA_ONSTACK; 212 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 213 oact->sa_flags |= SA_RESTART; 214 if (SIGISMEMBER(ps->ps_sigreset, sig)) 215 oact->sa_flags |= SA_RESETHAND; 216 if (SIGISMEMBER(ps->ps_signodefer, sig)) 217 oact->sa_flags |= SA_NODEFER; 218 if (SIGISMEMBER(ps->ps_siginfo, sig)) 219 oact->sa_flags |= SA_SIGINFO; 220 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 221 oact->sa_flags |= SA_NOCLDSTOP; 222 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 223 oact->sa_flags |= SA_NOCLDWAIT; 224 } 225 if (act) { 226 if ((sig == SIGKILL || sig == SIGSTOP) && 227 act->sa_handler != SIG_DFL) 228 return (EINVAL); 229 230 /* 231 * Change setting atomically. 232 */ 233 (void) splhigh(); 234 235 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 236 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 237 if (act->sa_flags & SA_SIGINFO) { 238 ps->ps_sigact[_SIG_IDX(sig)] = 239 (__sighandler_t *)act->sa_sigaction; 240 SIGADDSET(ps->ps_siginfo, sig); 241 } else { 242 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 243 SIGDELSET(ps->ps_siginfo, sig); 244 } 245 if (!(act->sa_flags & SA_RESTART)) 246 SIGADDSET(ps->ps_sigintr, sig); 247 else 248 SIGDELSET(ps->ps_sigintr, sig); 249 if (act->sa_flags & SA_ONSTACK) 250 SIGADDSET(ps->ps_sigonstack, sig); 251 else 252 SIGDELSET(ps->ps_sigonstack, sig); 253 if (act->sa_flags & SA_RESETHAND) 254 SIGADDSET(ps->ps_sigreset, sig); 255 else 256 SIGDELSET(ps->ps_sigreset, sig); 257 if (act->sa_flags & SA_NODEFER) 258 SIGADDSET(ps->ps_signodefer, sig); 259 else 260 SIGDELSET(ps->ps_signodefer, sig); 261 #ifdef COMPAT_SUNOS 262 if (act->sa_flags & SA_USERTRAMP) 263 SIGADDSET(ps->ps_usertramp, sig); 264 else 265 SIGDELSET(ps->ps_usertramp, seg); 266 #endif 267 if (sig == SIGCHLD) { 268 if (act->sa_flags & SA_NOCLDSTOP) 269 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 270 else 271 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 272 if (act->sa_flags & SA_NOCLDWAIT) { 273 /* 274 * Paranoia: since SA_NOCLDWAIT is implemented 275 * by reparenting the dying child to PID 1 (and 276 * trust it to reap the zombie), PID 1 itself 277 * is forbidden to set SA_NOCLDWAIT. 278 */ 279 if (p->p_pid == 1) 280 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 281 else 282 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 283 } else 284 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 285 } 286 /* 287 * Set bit in p_sigignore for signals that are set to SIG_IGN, 288 * and for signals set to SIG_DFL where the default is to 289 * ignore. However, don't put SIGCONT in p_sigignore, as we 290 * have to restart the process. 291 */ 292 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 293 (sigprop(sig) & SA_IGNORE && 294 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 295 /* never to be seen again */ 296 SIGDELSET(p->p_siglist, sig); 297 if (sig != SIGCONT) 298 /* easier in psignal */ 299 SIGADDSET(p->p_sigignore, sig); 300 SIGDELSET(p->p_sigcatch, sig); 301 } else { 302 SIGDELSET(p->p_sigignore, sig); 303 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 304 SIGDELSET(p->p_sigcatch, sig); 305 else 306 SIGADDSET(p->p_sigcatch, sig); 307 } 308 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 309 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) 310 SIGDELSET(ps->ps_osigset, sig); 311 else 312 SIGADDSET(ps->ps_osigset, sig); 313 314 (void) spl0(); 315 } 316 return (0); 317 } 318 319 #ifndef _SYS_SYSPROTO_H_ 320 struct sigaction_args { 321 int sig; 322 struct sigaction *act; 323 struct sigaction *oact; 324 }; 325 #endif 326 /* ARGSUSED */ 327 int 328 sigaction(p, uap) 329 struct proc *p; 330 register struct sigaction_args *uap; 331 { 332 struct sigaction act, oact; 333 register struct sigaction *actp, *oactp; 334 int error; 335 336 actp = (uap->act != NULL) ? &act : NULL; 337 oactp = (uap->oact != NULL) ? &oact : NULL; 338 if (actp) { 339 error = copyin(uap->act, actp, sizeof(act)); 340 if (error) 341 return (error); 342 } 343 error = do_sigaction(p, uap->sig, actp, oactp, 0); 344 if (oactp && !error) { 345 error = copyout(oactp, uap->oact, sizeof(oact)); 346 } 347 return (error); 348 } 349 350 #ifndef _SYS_SYSPROTO_H_ 351 struct osigaction_args { 352 int signum; 353 struct osigaction *nsa; 354 struct osigaction *osa; 355 }; 356 #endif 357 /* ARGSUSED */ 358 int 359 osigaction(p, uap) 360 struct proc *p; 361 register struct osigaction_args *uap; 362 { 363 struct osigaction sa; 364 struct sigaction nsa, osa; 365 register struct sigaction *nsap, *osap; 366 int error; 367 368 if (uap->signum <= 0 || uap->signum >= ONSIG) 369 return (EINVAL); 370 nsap = (uap->nsa != NULL) ? &nsa : NULL; 371 osap = (uap->osa != NULL) ? &osa : NULL; 372 if (nsap) { 373 error = copyin(uap->nsa, &sa, sizeof(sa)); 374 if (error) 375 return (error); 376 nsap->sa_handler = sa.sa_handler; 377 nsap->sa_flags = sa.sa_flags; 378 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 379 } 380 error = do_sigaction(p, uap->signum, nsap, osap, 1); 381 if (osap && !error) { 382 sa.sa_handler = osap->sa_handler; 383 sa.sa_flags = osap->sa_flags; 384 SIG2OSIG(osap->sa_mask, sa.sa_mask); 385 error = copyout(&sa, uap->osa, sizeof(sa)); 386 } 387 return (error); 388 } 389 390 /* 391 * Initialize signal state for process 0; 392 * set to ignore signals that are ignored by default. 393 */ 394 void 395 siginit(p) 396 struct proc *p; 397 { 398 register int i; 399 400 for (i = 1; i <= NSIG; i++) 401 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 402 SIGADDSET(p->p_sigignore, i); 403 } 404 405 /* 406 * Reset signals for an exec of the specified process. 407 */ 408 void 409 execsigs(p) 410 register struct proc *p; 411 { 412 register struct sigacts *ps = p->p_sigacts; 413 register int sig; 414 415 /* 416 * Reset caught signals. Held signals remain held 417 * through p_sigmask (unless they were caught, 418 * and are now ignored by default). 419 */ 420 while (SIGNOTEMPTY(p->p_sigcatch)) { 421 sig = sig_ffs(&p->p_sigcatch); 422 SIGDELSET(p->p_sigcatch, sig); 423 if (sigprop(sig) & SA_IGNORE) { 424 if (sig != SIGCONT) 425 SIGADDSET(p->p_sigignore, sig); 426 SIGDELSET(p->p_siglist, sig); 427 } 428 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 429 } 430 /* 431 * Reset stack state to the user stack. 432 * Clear set of signals caught on the signal stack. 433 */ 434 p->p_sigstk.ss_flags = SS_DISABLE; 435 p->p_sigstk.ss_size = 0; 436 p->p_sigstk.ss_sp = 0; 437 p->p_flag &= ~P_ALTSTACK; 438 /* 439 * Reset no zombies if child dies flag as Solaris does. 440 */ 441 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 442 } 443 444 /* 445 * do_sigprocmask() - MP SAFE ONLY IF p == curproc 446 * 447 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 448 * p == curproc. Also remember that in order to remain MP SAFE 449 * no spl*() calls may be made. 450 */ 451 static int 452 do_sigprocmask(p, how, set, oset, old) 453 struct proc *p; 454 int how; 455 sigset_t *set, *oset; 456 int old; 457 { 458 int error; 459 460 if (oset != NULL) 461 *oset = p->p_sigmask; 462 463 error = 0; 464 if (set != NULL) { 465 switch (how) { 466 case SIG_BLOCK: 467 SIG_CANTMASK(*set); 468 SIGSETOR(p->p_sigmask, *set); 469 break; 470 case SIG_UNBLOCK: 471 SIGSETNAND(p->p_sigmask, *set); 472 break; 473 case SIG_SETMASK: 474 SIG_CANTMASK(*set); 475 if (old) 476 SIGSETLO(p->p_sigmask, *set); 477 else 478 p->p_sigmask = *set; 479 break; 480 default: 481 error = EINVAL; 482 break; 483 } 484 } 485 return (error); 486 } 487 488 /* 489 * sigprocmask() - MP SAFE 490 */ 491 492 #ifndef _SYS_SYSPROTO_H_ 493 struct sigprocmask_args { 494 int how; 495 const sigset_t *set; 496 sigset_t *oset; 497 }; 498 #endif 499 int 500 sigprocmask(p, uap) 501 register struct proc *p; 502 struct sigprocmask_args *uap; 503 { 504 sigset_t set, oset; 505 sigset_t *setp, *osetp; 506 int error; 507 508 setp = (uap->set != NULL) ? &set : NULL; 509 osetp = (uap->oset != NULL) ? &oset : NULL; 510 if (setp) { 511 error = copyin(uap->set, setp, sizeof(set)); 512 if (error) 513 return (error); 514 } 515 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 516 if (osetp && !error) { 517 error = copyout(osetp, uap->oset, sizeof(oset)); 518 } 519 return (error); 520 } 521 522 /* 523 * osigprocmask() - MP SAFE 524 */ 525 526 #ifndef _SYS_SYSPROTO_H_ 527 struct osigprocmask_args { 528 int how; 529 osigset_t mask; 530 }; 531 #endif 532 int 533 osigprocmask(p, uap) 534 register struct proc *p; 535 struct osigprocmask_args *uap; 536 { 537 sigset_t set, oset; 538 int error; 539 540 OSIG2SIG(uap->mask, set); 541 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 542 SIG2OSIG(oset, p->p_retval[0]); 543 return (error); 544 } 545 546 #ifndef _SYS_SYSPROTO_H_ 547 struct sigpending_args { 548 sigset_t *set; 549 }; 550 #endif 551 /* ARGSUSED */ 552 int 553 sigpending(p, uap) 554 struct proc *p; 555 struct sigpending_args *uap; 556 { 557 558 return (copyout(&p->p_siglist, uap->set, sizeof(sigset_t))); 559 } 560 561 #ifndef _SYS_SYSPROTO_H_ 562 struct osigpending_args { 563 int dummy; 564 }; 565 #endif 566 /* ARGSUSED */ 567 int 568 osigpending(p, uap) 569 struct proc *p; 570 struct osigpending_args *uap; 571 { 572 573 SIG2OSIG(p->p_siglist, p->p_retval[0]); 574 return (0); 575 } 576 577 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 578 /* 579 * Generalized interface signal handler, 4.3-compatible. 580 */ 581 #ifndef _SYS_SYSPROTO_H_ 582 struct osigvec_args { 583 int signum; 584 struct sigvec *nsv; 585 struct sigvec *osv; 586 }; 587 #endif 588 /* ARGSUSED */ 589 int 590 osigvec(p, uap) 591 struct proc *p; 592 register struct osigvec_args *uap; 593 { 594 struct sigvec vec; 595 struct sigaction nsa, osa; 596 register struct sigaction *nsap, *osap; 597 int error; 598 599 if (uap->signum <= 0 || uap->signum >= ONSIG) 600 return (EINVAL); 601 nsap = (uap->nsv != NULL) ? &nsa : NULL; 602 osap = (uap->osv != NULL) ? &osa : NULL; 603 if (nsap) { 604 error = copyin(uap->nsv, &vec, sizeof(vec)); 605 if (error) 606 return (error); 607 nsap->sa_handler = vec.sv_handler; 608 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 609 nsap->sa_flags = vec.sv_flags; 610 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 611 #ifdef COMPAT_SUNOS 612 nsap->sa_flags |= SA_USERTRAMP; 613 #endif 614 } 615 error = do_sigaction(p, uap->signum, nsap, osap, 1); 616 if (osap && !error) { 617 vec.sv_handler = osap->sa_handler; 618 SIG2OSIG(osap->sa_mask, vec.sv_mask); 619 vec.sv_flags = osap->sa_flags; 620 vec.sv_flags &= ~SA_NOCLDWAIT; 621 vec.sv_flags ^= SA_RESTART; 622 #ifdef COMPAT_SUNOS 623 vec.sv_flags &= ~SA_NOCLDSTOP; 624 #endif 625 error = copyout(&vec, uap->osv, sizeof(vec)); 626 } 627 return (error); 628 } 629 630 #ifndef _SYS_SYSPROTO_H_ 631 struct osigblock_args { 632 int mask; 633 }; 634 #endif 635 int 636 osigblock(p, uap) 637 register struct proc *p; 638 struct osigblock_args *uap; 639 { 640 sigset_t set; 641 642 OSIG2SIG(uap->mask, set); 643 SIG_CANTMASK(set); 644 (void) splhigh(); 645 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 646 SIGSETOR(p->p_sigmask, set); 647 (void) spl0(); 648 return (0); 649 } 650 651 #ifndef _SYS_SYSPROTO_H_ 652 struct osigsetmask_args { 653 int mask; 654 }; 655 #endif 656 int 657 osigsetmask(p, uap) 658 struct proc *p; 659 struct osigsetmask_args *uap; 660 { 661 sigset_t set; 662 663 OSIG2SIG(uap->mask, set); 664 SIG_CANTMASK(set); 665 (void) splhigh(); 666 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 667 SIGSETLO(p->p_sigmask, set); 668 (void) spl0(); 669 return (0); 670 } 671 #endif /* COMPAT_43 || COMPAT_SUNOS */ 672 673 /* 674 * Suspend process until signal, providing mask to be set 675 * in the meantime. Note nonstandard calling convention: 676 * libc stub passes mask, not pointer, to save a copyin. 677 */ 678 #ifndef _SYS_SYSPROTO_H_ 679 struct sigsuspend_args { 680 const sigset_t *sigmask; 681 }; 682 #endif 683 /* ARGSUSED */ 684 int 685 sigsuspend(p, uap) 686 register struct proc *p; 687 struct sigsuspend_args *uap; 688 { 689 sigset_t mask; 690 register struct sigacts *ps = p->p_sigacts; 691 int error; 692 693 error = copyin(uap->sigmask, &mask, sizeof(mask)); 694 if (error) 695 return (error); 696 697 /* 698 * When returning from sigsuspend, we want 699 * the old mask to be restored after the 700 * signal handler has finished. Thus, we 701 * save it here and mark the sigacts structure 702 * to indicate this. 703 */ 704 p->p_oldsigmask = p->p_sigmask; 705 p->p_flag |= P_OLDMASK; 706 707 SIG_CANTMASK(mask); 708 p->p_sigmask = mask; 709 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0) 710 /* void */; 711 /* always return EINTR rather than ERESTART... */ 712 return (EINTR); 713 } 714 715 #ifndef _SYS_SYSPROTO_H_ 716 struct osigsuspend_args { 717 osigset_t mask; 718 }; 719 #endif 720 /* ARGSUSED */ 721 int 722 osigsuspend(p, uap) 723 register struct proc *p; 724 struct osigsuspend_args *uap; 725 { 726 sigset_t mask; 727 register struct sigacts *ps = p->p_sigacts; 728 729 p->p_oldsigmask = p->p_sigmask; 730 p->p_flag |= P_OLDMASK; 731 OSIG2SIG(uap->mask, mask); 732 SIG_CANTMASK(mask); 733 SIGSETLO(p->p_sigmask, mask); 734 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "opause", 0) == 0) 735 /* void */; 736 /* always return EINTR rather than ERESTART... */ 737 return (EINTR); 738 } 739 740 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 741 #ifndef _SYS_SYSPROTO_H_ 742 struct osigstack_args { 743 struct sigstack *nss; 744 struct sigstack *oss; 745 }; 746 #endif 747 /* ARGSUSED */ 748 int 749 osigstack(p, uap) 750 struct proc *p; 751 register struct osigstack_args *uap; 752 { 753 struct sigstack ss; 754 int error = 0; 755 756 ss.ss_sp = p->p_sigstk.ss_sp; 757 ss.ss_onstack = p->p_sigstk.ss_flags & SS_ONSTACK; 758 if (uap->oss && (error = copyout(&ss, uap->oss, 759 sizeof(struct sigstack)))) 760 return (error); 761 if (uap->nss && (error = copyin(uap->nss, &ss, sizeof(ss))) == 0) { 762 p->p_sigstk.ss_sp = ss.ss_sp; 763 p->p_sigstk.ss_size = 0; 764 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 765 p->p_flag |= P_ALTSTACK; 766 } 767 return (error); 768 } 769 #endif /* COMPAT_43 || COMPAT_SUNOS */ 770 771 #ifndef _SYS_SYSPROTO_H_ 772 struct sigaltstack_args { 773 stack_t *ss; 774 stack_t *oss; 775 }; 776 #endif 777 /* ARGSUSED */ 778 int 779 sigaltstack(p, uap) 780 struct proc *p; 781 register struct sigaltstack_args *uap; 782 { 783 stack_t ss; 784 int error; 785 786 if ((p->p_flag & P_ALTSTACK) == 0) 787 p->p_sigstk.ss_flags |= SS_DISABLE; 788 if (uap->oss && (error = copyout(&p->p_sigstk, uap->oss, 789 sizeof(stack_t)))) 790 return (error); 791 if (uap->ss == 0) 792 return (0); 793 if ((error = copyin(uap->ss, &ss, sizeof(ss)))) 794 return (error); 795 if (ss.ss_flags & SS_DISABLE) { 796 if (p->p_sigstk.ss_flags & SS_ONSTACK) 797 return (EINVAL); 798 p->p_flag &= ~P_ALTSTACK; 799 p->p_sigstk.ss_flags = ss.ss_flags; 800 return (0); 801 } 802 if (ss.ss_size < p->p_sysent->sv_minsigstksz) 803 return (ENOMEM); 804 p->p_flag |= P_ALTSTACK; 805 p->p_sigstk = ss; 806 return (0); 807 } 808 809 /* 810 * Common code for kill process group/broadcast kill. 811 * cp is calling process. 812 */ 813 int 814 killpg1(cp, sig, pgid, all) 815 register struct proc *cp; 816 int sig, pgid, all; 817 { 818 register struct proc *p; 819 struct pgrp *pgrp; 820 int nfound = 0; 821 822 if (all) 823 /* 824 * broadcast 825 */ 826 LIST_FOREACH(p, &allproc, p_list) { 827 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 828 p == cp || !CANSIGNAL(cp, p, sig)) 829 continue; 830 nfound++; 831 if (sig) 832 psignal(p, sig); 833 } 834 else { 835 if (pgid == 0) 836 /* 837 * zero pgid means send to my process group. 838 */ 839 pgrp = cp->p_pgrp; 840 else { 841 pgrp = pgfind(pgid); 842 if (pgrp == NULL) 843 return (ESRCH); 844 } 845 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 846 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 847 p->p_stat == SZOMB || 848 !CANSIGNAL(cp, p, sig)) 849 continue; 850 nfound++; 851 if (sig) 852 psignal(p, sig); 853 } 854 } 855 return (nfound ? 0 : ESRCH); 856 } 857 858 #ifndef _SYS_SYSPROTO_H_ 859 struct kill_args { 860 int pid; 861 int signum; 862 }; 863 #endif 864 /* ARGSUSED */ 865 int 866 kill(cp, uap) 867 register struct proc *cp; 868 register struct kill_args *uap; 869 { 870 register struct proc *p; 871 872 if ((u_int)uap->signum > _SIG_MAXSIG) 873 return (EINVAL); 874 if (uap->pid > 0) { 875 /* kill single process */ 876 if ((p = pfind(uap->pid)) == NULL) 877 return (ESRCH); 878 if (!CANSIGNAL(cp, p, uap->signum)) 879 return (EPERM); 880 if (uap->signum) 881 psignal(p, uap->signum); 882 return (0); 883 } 884 switch (uap->pid) { 885 case -1: /* broadcast signal */ 886 return (killpg1(cp, uap->signum, 0, 1)); 887 case 0: /* signal own process group */ 888 return (killpg1(cp, uap->signum, 0, 0)); 889 default: /* negative explicit process group */ 890 return (killpg1(cp, uap->signum, -uap->pid, 0)); 891 } 892 /* NOTREACHED */ 893 } 894 895 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 896 #ifndef _SYS_SYSPROTO_H_ 897 struct okillpg_args { 898 int pgid; 899 int signum; 900 }; 901 #endif 902 /* ARGSUSED */ 903 int 904 okillpg(p, uap) 905 struct proc *p; 906 register struct okillpg_args *uap; 907 { 908 909 if ((u_int)uap->signum > _SIG_MAXSIG) 910 return (EINVAL); 911 return (killpg1(p, uap->signum, uap->pgid, 0)); 912 } 913 #endif /* COMPAT_43 || COMPAT_SUNOS */ 914 915 /* 916 * Send a signal to a process group. 917 */ 918 void 919 gsignal(pgid, sig) 920 int pgid, sig; 921 { 922 struct pgrp *pgrp; 923 924 if (pgid && (pgrp = pgfind(pgid))) 925 pgsignal(pgrp, sig, 0); 926 } 927 928 /* 929 * Send a signal to a process group. If checktty is 1, 930 * limit to members which have a controlling terminal. 931 */ 932 void 933 pgsignal(pgrp, sig, checkctty) 934 struct pgrp *pgrp; 935 int sig, checkctty; 936 { 937 register struct proc *p; 938 939 if (pgrp) 940 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) 941 if (checkctty == 0 || p->p_flag & P_CONTROLT) 942 psignal(p, sig); 943 } 944 945 /* 946 * Send a signal caused by a trap to the current process. 947 * If it will be caught immediately, deliver it with correct code. 948 * Otherwise, post it normally. 949 */ 950 void 951 trapsignal(p, sig, code) 952 struct proc *p; 953 register int sig; 954 u_long code; 955 { 956 register struct sigacts *ps = p->p_sigacts; 957 958 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 959 !SIGISMEMBER(p->p_sigmask, sig)) { 960 p->p_stats->p_ru.ru_nsignals++; 961 #ifdef KTRACE 962 if (KTRPOINT(p, KTR_PSIG)) 963 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 964 &p->p_sigmask, code); 965 #endif 966 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 967 &p->p_sigmask, code); 968 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 969 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 970 SIGADDSET(p->p_sigmask, sig); 971 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 972 /* 973 * See do_sigaction() for origin of this code. 974 */ 975 SIGDELSET(p->p_sigcatch, sig); 976 if (sig != SIGCONT && 977 sigprop(sig) & SA_IGNORE) 978 SIGADDSET(p->p_sigignore, sig); 979 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 980 } 981 } else { 982 p->p_code = code; /* XXX for core dump/debugger */ 983 p->p_sig = sig; /* XXX to verify code */ 984 psignal(p, sig); 985 } 986 } 987 988 /* 989 * Send the signal to the process. If the signal has an action, the action 990 * is usually performed by the target process rather than the caller; we add 991 * the signal to the set of pending signals for the process. 992 * 993 * Exceptions: 994 * o When a stop signal is sent to a sleeping process that takes the 995 * default action, the process is stopped without awakening it. 996 * o SIGCONT restarts stopped processes (or puts them back to sleep) 997 * regardless of the signal action (eg, blocked or ignored). 998 * 999 * Other ignored signals are discarded immediately. 1000 */ 1001 void 1002 psignal(p, sig) 1003 register struct proc *p; 1004 register int sig; 1005 { 1006 register int s, prop; 1007 register sig_t action; 1008 1009 if (sig > _SIG_MAXSIG || sig <= 0) { 1010 printf("psignal: signal %d\n", sig); 1011 panic("psignal signal number"); 1012 } 1013 1014 s = splhigh(); 1015 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1016 splx(s); 1017 1018 prop = sigprop(sig); 1019 1020 /* 1021 * If proc is traced, always give parent a chance; 1022 * if signal event is tracked by procfs, give *that* 1023 * a chance, as well. 1024 */ 1025 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) 1026 action = SIG_DFL; 1027 else { 1028 /* 1029 * If the signal is being ignored, 1030 * then we forget about it immediately. 1031 * (Note: we don't set SIGCONT in p_sigignore, 1032 * and if it is set to SIG_IGN, 1033 * action will be SIG_DFL here.) 1034 */ 1035 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1036 return; 1037 if (SIGISMEMBER(p->p_sigmask, sig)) 1038 action = SIG_HOLD; 1039 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1040 action = SIG_CATCH; 1041 else 1042 action = SIG_DFL; 1043 } 1044 1045 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1046 (p->p_flag & P_TRACED) == 0) 1047 p->p_nice = NZERO; 1048 1049 if (prop & SA_CONT) 1050 SIG_STOPSIGMASK(p->p_siglist); 1051 1052 if (prop & SA_STOP) { 1053 /* 1054 * If sending a tty stop signal to a member of an orphaned 1055 * process group, discard the signal here if the action 1056 * is default; don't stop the process below if sleeping, 1057 * and don't clear any pending SIGCONT. 1058 */ 1059 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1060 action == SIG_DFL) 1061 return; 1062 SIG_CONTSIGMASK(p->p_siglist); 1063 } 1064 SIGADDSET(p->p_siglist, sig); 1065 1066 /* 1067 * Defer further processing for signals which are held, 1068 * except that stopped processes must be continued by SIGCONT. 1069 */ 1070 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) 1071 return; 1072 s = splhigh(); 1073 switch (p->p_stat) { 1074 1075 case SSLEEP: 1076 /* 1077 * If process is sleeping uninterruptibly 1078 * we can't interrupt the sleep... the signal will 1079 * be noticed when the process returns through 1080 * trap() or syscall(). 1081 */ 1082 if ((p->p_flag & P_SINTR) == 0) 1083 goto out; 1084 /* 1085 * Process is sleeping and traced... make it runnable 1086 * so it can discover the signal in issignal() and stop 1087 * for the parent. 1088 */ 1089 if (p->p_flag & P_TRACED) 1090 goto run; 1091 /* 1092 * If SIGCONT is default (or ignored) and process is 1093 * asleep, we are finished; the process should not 1094 * be awakened. 1095 */ 1096 if ((prop & SA_CONT) && action == SIG_DFL) { 1097 SIGDELSET(p->p_siglist, sig); 1098 goto out; 1099 } 1100 /* 1101 * When a sleeping process receives a stop 1102 * signal, process immediately if possible. 1103 * All other (caught or default) signals 1104 * cause the process to run. 1105 */ 1106 if (prop & SA_STOP) { 1107 if (action != SIG_DFL) 1108 goto runfast; 1109 /* 1110 * If a child holding parent blocked, 1111 * stopping could cause deadlock. 1112 */ 1113 if (p->p_flag & P_PPWAIT) 1114 goto out; 1115 SIGDELSET(p->p_siglist, sig); 1116 p->p_xstat = sig; 1117 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1118 psignal(p->p_pptr, SIGCHLD); 1119 stop(p); 1120 goto out; 1121 } else 1122 goto runfast; 1123 /*NOTREACHED*/ 1124 1125 case SSTOP: 1126 /* 1127 * If traced process is already stopped, 1128 * then no further action is necessary. 1129 */ 1130 if (p->p_flag & P_TRACED) 1131 goto out; 1132 1133 /* 1134 * Kill signal always sets processes running. 1135 */ 1136 if (sig == SIGKILL) 1137 goto runfast; 1138 1139 if (prop & SA_CONT) { 1140 /* 1141 * If SIGCONT is default (or ignored), we continue the 1142 * process but don't leave the signal in p_siglist, as 1143 * it has no further action. If SIGCONT is held, we 1144 * continue the process and leave the signal in 1145 * p_siglist. If the process catches SIGCONT, let it 1146 * handle the signal itself. If it isn't waiting on 1147 * an event, then it goes back to run state. 1148 * Otherwise, process goes back to sleep state. 1149 */ 1150 if (action == SIG_DFL) 1151 SIGDELSET(p->p_siglist, sig); 1152 if (action == SIG_CATCH) 1153 goto runfast; 1154 if (p->p_wchan == 0) 1155 goto run; 1156 p->p_stat = SSLEEP; 1157 goto out; 1158 } 1159 1160 if (prop & SA_STOP) { 1161 /* 1162 * Already stopped, don't need to stop again. 1163 * (If we did the shell could get confused.) 1164 */ 1165 SIGDELSET(p->p_siglist, sig); 1166 goto out; 1167 } 1168 1169 /* 1170 * If process is sleeping interruptibly, then simulate a 1171 * wakeup so that when it is continued, it will be made 1172 * runnable and can look at the signal. But don't make 1173 * the process runnable, leave it stopped. 1174 */ 1175 if (p->p_wchan && p->p_flag & P_SINTR) 1176 unsleep(p); 1177 goto out; 1178 1179 default: 1180 /* 1181 * SRUN, SIDL, SZOMB do nothing with the signal, 1182 * other than kicking ourselves if we are running. 1183 * It will either never be noticed, or noticed very soon. 1184 */ 1185 if (p == curproc) 1186 signotify(p); 1187 #ifdef SMP 1188 else if (p->p_stat == SRUN) 1189 forward_signal(p); 1190 #endif 1191 goto out; 1192 } 1193 /*NOTREACHED*/ 1194 1195 runfast: 1196 /* 1197 * Raise priority to at least PUSER. 1198 */ 1199 if (p->p_priority > PUSER) 1200 p->p_priority = PUSER; 1201 run: 1202 setrunnable(p); 1203 out: 1204 splx(s); 1205 } 1206 1207 /* 1208 * If the current process has received a signal (should be caught or cause 1209 * termination, should interrupt current syscall), return the signal number. 1210 * Stop signals with default action are processed immediately, then cleared; 1211 * they aren't returned. This is checked after each entry to the system for 1212 * a syscall or trap (though this can usually be done without calling issignal 1213 * by checking the pending signal masks in the CURSIG macro.) The normal call 1214 * sequence is 1215 * 1216 * while (sig = CURSIG(curproc)) 1217 * postsig(sig); 1218 */ 1219 int 1220 issignal(p) 1221 register struct proc *p; 1222 { 1223 sigset_t mask; 1224 register int sig, prop; 1225 1226 for (;;) { 1227 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1228 1229 mask = p->p_siglist; 1230 SIGSETNAND(mask, p->p_sigmask); 1231 if (p->p_flag & P_PPWAIT) 1232 SIG_STOPSIGMASK(mask); 1233 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1234 return (0); 1235 sig = sig_ffs(&mask); 1236 1237 STOPEVENT(p, S_SIG, sig); 1238 1239 /* 1240 * We should see pending but ignored signals 1241 * only if P_TRACED was on when they were posted. 1242 */ 1243 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1244 SIGDELSET(p->p_siglist, sig); 1245 continue; 1246 } 1247 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1248 /* 1249 * If traced, always stop, and stay 1250 * stopped until released by the parent. 1251 */ 1252 p->p_xstat = sig; 1253 psignal(p->p_pptr, SIGCHLD); 1254 do { 1255 stop(p); 1256 mi_switch(); 1257 } while (!trace_req(p) 1258 && p->p_flag & P_TRACED); 1259 1260 /* 1261 * If parent wants us to take the signal, 1262 * then it will leave it in p->p_xstat; 1263 * otherwise we just look for signals again. 1264 */ 1265 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1266 sig = p->p_xstat; 1267 if (sig == 0) 1268 continue; 1269 1270 /* 1271 * Put the new signal into p_siglist. If the 1272 * signal is being masked, look for other signals. 1273 */ 1274 SIGADDSET(p->p_siglist, sig); 1275 if (SIGISMEMBER(p->p_sigmask, sig)) 1276 continue; 1277 1278 /* 1279 * If the traced bit got turned off, go back up 1280 * to the top to rescan signals. This ensures 1281 * that p_sig* and ps_sigact are consistent. 1282 */ 1283 if ((p->p_flag & P_TRACED) == 0) 1284 continue; 1285 } 1286 1287 prop = sigprop(sig); 1288 1289 /* 1290 * Decide whether the signal should be returned. 1291 * Return the signal's number, or fall through 1292 * to clear it from the pending mask. 1293 */ 1294 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1295 1296 case (int)SIG_DFL: 1297 /* 1298 * Don't take default actions on system processes. 1299 */ 1300 if (p->p_pid <= 1) { 1301 #ifdef DIAGNOSTIC 1302 /* 1303 * Are you sure you want to ignore SIGSEGV 1304 * in init? XXX 1305 */ 1306 printf("Process (pid %lu) got signal %d\n", 1307 (u_long)p->p_pid, sig); 1308 #endif 1309 break; /* == ignore */ 1310 } 1311 /* 1312 * If there is a pending stop signal to process 1313 * with default action, stop here, 1314 * then clear the signal. However, 1315 * if process is member of an orphaned 1316 * process group, ignore tty stop signals. 1317 */ 1318 if (prop & SA_STOP) { 1319 if (p->p_flag & P_TRACED || 1320 (p->p_pgrp->pg_jobc == 0 && 1321 prop & SA_TTYSTOP)) 1322 break; /* == ignore */ 1323 p->p_xstat = sig; 1324 stop(p); 1325 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1326 psignal(p->p_pptr, SIGCHLD); 1327 mi_switch(); 1328 break; 1329 } else if (prop & SA_IGNORE) { 1330 /* 1331 * Except for SIGCONT, shouldn't get here. 1332 * Default action is to ignore; drop it. 1333 */ 1334 break; /* == ignore */ 1335 } else 1336 return (sig); 1337 /*NOTREACHED*/ 1338 1339 case (int)SIG_IGN: 1340 /* 1341 * Masking above should prevent us ever trying 1342 * to take action on an ignored signal other 1343 * than SIGCONT, unless process is traced. 1344 */ 1345 if ((prop & SA_CONT) == 0 && 1346 (p->p_flag & P_TRACED) == 0) 1347 printf("issignal\n"); 1348 break; /* == ignore */ 1349 1350 default: 1351 /* 1352 * This signal has an action, let 1353 * postsig() process it. 1354 */ 1355 return (sig); 1356 } 1357 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1358 } 1359 /* NOTREACHED */ 1360 } 1361 1362 /* 1363 * Put the argument process into the stopped state and notify the parent 1364 * via wakeup. Signals are handled elsewhere. The process must not be 1365 * on the run queue. 1366 */ 1367 void 1368 stop(p) 1369 register struct proc *p; 1370 { 1371 1372 p->p_stat = SSTOP; 1373 p->p_flag &= ~P_WAITED; 1374 wakeup((caddr_t)p->p_pptr); 1375 } 1376 1377 /* 1378 * Take the action for the specified signal 1379 * from the current set of pending signals. 1380 */ 1381 void 1382 postsig(sig) 1383 register int sig; 1384 { 1385 register struct proc *p = curproc; 1386 struct sigacts *ps = p->p_sigacts; 1387 sig_t action; 1388 sigset_t returnmask; 1389 int code; 1390 1391 KASSERT(sig != 0, ("postsig")); 1392 1393 SIGDELSET(p->p_siglist, sig); 1394 action = ps->ps_sigact[_SIG_IDX(sig)]; 1395 #ifdef KTRACE 1396 if (KTRPOINT(p, KTR_PSIG)) 1397 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1398 &p->p_oldsigmask : &p->p_sigmask, 0); 1399 #endif 1400 STOPEVENT(p, S_SIG, sig); 1401 1402 if (action == SIG_DFL) { 1403 /* 1404 * Default action, where the default is to kill 1405 * the process. (Other cases were ignored above.) 1406 */ 1407 sigexit(p, sig); 1408 /* NOTREACHED */ 1409 } else { 1410 /* 1411 * If we get here, the signal must be caught. 1412 */ 1413 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1414 ("postsig action")); 1415 /* 1416 * Set the new mask value and also defer further 1417 * occurrences of this signal. 1418 * 1419 * Special case: user has done a sigsuspend. Here the 1420 * current mask is not of interest, but rather the 1421 * mask from before the sigsuspend is what we want 1422 * restored after the signal processing is completed. 1423 */ 1424 (void) splhigh(); 1425 if (p->p_flag & P_OLDMASK) { 1426 returnmask = p->p_oldsigmask; 1427 p->p_flag &= ~P_OLDMASK; 1428 } else 1429 returnmask = p->p_sigmask; 1430 1431 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1432 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1433 SIGADDSET(p->p_sigmask, sig); 1434 1435 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1436 /* 1437 * See do_sigaction() for origin of this code. 1438 */ 1439 SIGDELSET(p->p_sigcatch, sig); 1440 if (sig != SIGCONT && 1441 sigprop(sig) & SA_IGNORE) 1442 SIGADDSET(p->p_sigignore, sig); 1443 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1444 } 1445 (void) spl0(); 1446 p->p_stats->p_ru.ru_nsignals++; 1447 if (p->p_sig != sig) { 1448 code = 0; 1449 } else { 1450 code = p->p_code; 1451 p->p_code = 0; 1452 p->p_sig = 0; 1453 } 1454 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1455 } 1456 } 1457 1458 /* 1459 * Kill the current process for stated reason. 1460 */ 1461 void 1462 killproc(p, why) 1463 struct proc *p; 1464 char *why; 1465 { 1466 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1467 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1468 psignal(p, SIGKILL); 1469 } 1470 1471 /* 1472 * Force the current process to exit with the specified signal, dumping core 1473 * if appropriate. We bypass the normal tests for masked and caught signals, 1474 * allowing unrecoverable failures to terminate the process without changing 1475 * signal state. Mark the accounting record with the signal termination. 1476 * If dumping core, save the signal number for the debugger. Calls exit and 1477 * does not return. 1478 */ 1479 void 1480 sigexit(p, sig) 1481 register struct proc *p; 1482 int sig; 1483 { 1484 1485 p->p_acflag |= AXSIG; 1486 if (sigprop(sig) & SA_CORE) { 1487 p->p_sig = sig; 1488 /* 1489 * Log signals which would cause core dumps 1490 * (Log as LOG_INFO to appease those who don't want 1491 * these messages.) 1492 * XXX : Todo, as well as euid, write out ruid too 1493 */ 1494 if (coredump(p) == 0) 1495 sig |= WCOREFLAG; 1496 if (kern_logsigexit) 1497 log(LOG_INFO, 1498 "pid %d (%s), uid %d: exited on signal %d%s\n", 1499 p->p_pid, p->p_comm, 1500 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, 1501 sig &~ WCOREFLAG, 1502 sig & WCOREFLAG ? " (core dumped)" : ""); 1503 } 1504 exit1(p, W_EXITCODE(0, sig)); 1505 /* NOTREACHED */ 1506 } 1507 1508 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1509 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1510 sizeof(corefilename), "process corefile name format string"); 1511 1512 /* 1513 * expand_name(name, uid, pid) 1514 * Expand the name described in corefilename, using name, uid, and pid. 1515 * corefilename is a printf-like string, with three format specifiers: 1516 * %N name of process ("name") 1517 * %P process id (pid) 1518 * %U user id (uid) 1519 * For example, "%N.core" is the default; they can be disabled completely 1520 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1521 * This is controlled by the sysctl variable kern.corefile (see above). 1522 */ 1523 1524 static char * 1525 expand_name(name, uid, pid) 1526 const char *name; uid_t uid; pid_t pid; { 1527 char *temp; 1528 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1529 int i, n; 1530 char *format = corefilename; 1531 size_t namelen; 1532 1533 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1534 if (temp == NULL) 1535 return NULL; 1536 namelen = strlen(name); 1537 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1538 int l; 1539 switch (format[i]) { 1540 case '%': /* Format character */ 1541 i++; 1542 switch (format[i]) { 1543 case '%': 1544 temp[n++] = '%'; 1545 break; 1546 case 'N': /* process name */ 1547 if ((n + namelen) > MAXPATHLEN) { 1548 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1549 pid, name, uid, temp, name); 1550 free(temp, M_TEMP); 1551 return NULL; 1552 } 1553 memcpy(temp+n, name, namelen); 1554 n += namelen; 1555 break; 1556 case 'P': /* process id */ 1557 l = sprintf(buf, "%u", pid); 1558 if ((n + l) > MAXPATHLEN) { 1559 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1560 pid, name, uid, temp, name); 1561 free(temp, M_TEMP); 1562 return NULL; 1563 } 1564 memcpy(temp+n, buf, l); 1565 n += l; 1566 break; 1567 case 'U': /* user id */ 1568 l = sprintf(buf, "%u", uid); 1569 if ((n + l) > MAXPATHLEN) { 1570 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1571 pid, name, uid, temp, name); 1572 free(temp, M_TEMP); 1573 return NULL; 1574 } 1575 memcpy(temp+n, buf, l); 1576 n += l; 1577 break; 1578 default: 1579 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1580 } 1581 break; 1582 default: 1583 temp[n++] = format[i]; 1584 } 1585 } 1586 temp[n] = '\0'; 1587 return temp; 1588 } 1589 1590 /* 1591 * Dump a process' core. The main routine does some 1592 * policy checking, and creates the name of the coredump; 1593 * then it passes on a vnode and a size limit to the process-specific 1594 * coredump routine if there is one; if there _is not_ one, it returns 1595 * ENOSYS; otherwise it returns the error from the process-specific routine. 1596 */ 1597 1598 static int 1599 coredump(p) 1600 register struct proc *p; 1601 { 1602 register struct vnode *vp; 1603 register struct ucred *cred = p->p_ucred; 1604 struct flock lf; 1605 struct nameidata nd; 1606 struct vattr vattr; 1607 int error, error1; 1608 char *name; /* name of corefile */ 1609 off_t limit; 1610 1611 STOPEVENT(p, S_CORE, 0); 1612 1613 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 1614 return (EFAULT); 1615 1616 /* 1617 * Note that the bulk of limit checking is done after 1618 * the corefile is created. The exception is if the limit 1619 * for corefiles is 0, in which case we don't bother 1620 * creating the corefile at all. This layout means that 1621 * a corefile is truncated instead of not being created, 1622 * if it is larger than the limit. 1623 */ 1624 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1625 if (limit == 0) 1626 return 0; 1627 1628 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1629 if (name == NULL) 1630 return (EINVAL); 1631 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p); 1632 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1633 free(name, M_TEMP); 1634 if (error) 1635 return (error); 1636 NDFREE(&nd, NDF_ONLY_PNBUF); 1637 vp = nd.ni_vp; 1638 1639 VOP_UNLOCK(vp, 0, p); 1640 lf.l_whence = SEEK_SET; 1641 lf.l_start = 0; 1642 lf.l_len = 0; 1643 lf.l_type = F_WRLCK; 1644 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 1645 if (error) 1646 goto out2; 1647 1648 /* Don't dump to non-regular files or files with links. */ 1649 if (vp->v_type != VREG || 1650 VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) { 1651 error = EFAULT; 1652 goto out1; 1653 } 1654 1655 VATTR_NULL(&vattr); 1656 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 1657 vattr.va_size = 0; 1658 VOP_LEASE(vp, p, cred, LEASE_WRITE); 1659 VOP_SETATTR(vp, &vattr, cred, p); 1660 p->p_acflag |= ACORE; 1661 VOP_UNLOCK(vp, 0, p); 1662 1663 error = p->p_sysent->sv_coredump ? 1664 p->p_sysent->sv_coredump(p, vp, limit) : 1665 ENOSYS; 1666 1667 out1: 1668 lf.l_type = F_UNLCK; 1669 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 1670 out2: 1671 error1 = vn_close(vp, FWRITE, cred, p); 1672 if (error == 0) 1673 error = error1; 1674 return (error); 1675 } 1676 1677 /* 1678 * Nonexistent system call-- signal process (may want to handle it). 1679 * Flag error in case process won't see signal immediately (blocked or ignored). 1680 */ 1681 #ifndef _SYS_SYSPROTO_H_ 1682 struct nosys_args { 1683 int dummy; 1684 }; 1685 #endif 1686 /* ARGSUSED */ 1687 int 1688 nosys(p, args) 1689 struct proc *p; 1690 struct nosys_args *args; 1691 { 1692 1693 psignal(p, SIGSYS); 1694 return (EINVAL); 1695 } 1696 1697 /* 1698 * Send a SIGIO or SIGURG signal to a process or process group using 1699 * stored credentials rather than those of the current process. 1700 */ 1701 void 1702 pgsigio(sigio, sig, checkctty) 1703 struct sigio *sigio; 1704 int sig, checkctty; 1705 { 1706 if (sigio == NULL) 1707 return; 1708 1709 if (sigio->sio_pgid > 0) { 1710 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1711 sigio->sio_proc)) 1712 psignal(sigio->sio_proc, sig); 1713 } else if (sigio->sio_pgid < 0) { 1714 struct proc *p; 1715 1716 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) 1717 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1718 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1719 psignal(p, sig); 1720 } 1721 } 1722 1723 static int 1724 filt_sigattach(struct knote *kn) 1725 { 1726 struct proc *p = curproc; 1727 1728 kn->kn_ptr.p_proc = p; 1729 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1730 1731 /* XXX lock the proc here while adding to the list? */ 1732 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 1733 1734 return (0); 1735 } 1736 1737 static void 1738 filt_sigdetach(struct knote *kn) 1739 { 1740 struct proc *p = kn->kn_ptr.p_proc; 1741 1742 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 1743 } 1744 1745 /* 1746 * signal knotes are shared with proc knotes, so we apply a mask to 1747 * the hint in order to differentiate them from process hints. This 1748 * could be avoided by using a signal-specific knote list, but probably 1749 * isn't worth the trouble. 1750 */ 1751 static int 1752 filt_signal(struct knote *kn, long hint) 1753 { 1754 1755 if (hint & NOTE_SIGNAL) { 1756 hint &= ~NOTE_SIGNAL; 1757 1758 if (kn->kn_id == hint) 1759 kn->kn_data++; 1760 } 1761 return (kn->kn_data != 0); 1762 } 1763