1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 39 * $FreeBSD$ 40 */ 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/sysproto.h> 48 #include <sys/signalvar.h> 49 #include <sys/resourcevar.h> 50 #include <sys/namei.h> 51 #include <sys/vnode.h> 52 #include <sys/proc.h> 53 #include <sys/pioctl.h> 54 #include <sys/systm.h> 55 #include <sys/acct.h> 56 #include <sys/fcntl.h> 57 #include <sys/wait.h> 58 #include <sys/ktrace.h> 59 #include <sys/syslog.h> 60 #include <sys/stat.h> 61 #include <sys/sysent.h> 62 #include <sys/sysctl.h> 63 #include <sys/malloc.h> 64 65 #include <machine/cpu.h> 66 #ifdef SMP 67 #include <machine/smp.h> 68 #endif 69 70 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 71 72 static int coredump __P((struct proc *)); 73 static int do_sigaction __P((struct proc *p, int sig, struct sigaction *act, 74 struct sigaction *oact, int old)); 75 static int do_sigprocmask __P((struct proc *p, int how, sigset_t *set, 76 sigset_t *oset, int old)); 77 static char *expand_name __P((const char *, uid_t, pid_t)); 78 static int killpg1 __P((struct proc *cp, int sig, int pgid, int all)); 79 static int sig_ffs __P((sigset_t *set)); 80 static int sigprop __P((int sig)); 81 static void stop __P((struct proc *)); 82 83 static int kern_logsigexit = 1; 84 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 85 &kern_logsigexit, 0, 86 "Log processes quitting on abnormal signals to syslog(3)"); 87 88 /* 89 * Can process p, with pcred pc, send the signal sig to process q? 90 */ 91 #define CANSIGNAL(p, pc, q, sig) \ 92 (PRISON_CHECK(p, q) && ((pc)->pc_ucred->cr_uid == 0 || \ 93 (pc)->p_ruid == (q)->p_cred->p_ruid || \ 94 (pc)->pc_ucred->cr_uid == (q)->p_cred->p_ruid || \ 95 (pc)->p_ruid == (q)->p_ucred->cr_uid || \ 96 (pc)->pc_ucred->cr_uid == (q)->p_ucred->cr_uid || \ 97 ((sig) == SIGCONT && (q)->p_session == (p)->p_session))) 98 99 /* 100 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 101 */ 102 #define CANSIGIO(ruid, uc, q) \ 103 ((uc)->cr_uid == 0 || \ 104 (ruid) == (q)->p_cred->p_ruid || \ 105 (uc)->cr_uid == (q)->p_cred->p_ruid || \ 106 (ruid) == (q)->p_ucred->cr_uid || \ 107 (uc)->cr_uid == (q)->p_ucred->cr_uid) 108 109 int sugid_coredump; 110 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 111 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 112 113 /* 114 * Signal properties and actions. 115 * The array below categorizes the signals and their default actions 116 * according to the following properties: 117 */ 118 #define SA_KILL 0x01 /* terminates process by default */ 119 #define SA_CORE 0x02 /* ditto and coredumps */ 120 #define SA_STOP 0x04 /* suspend process */ 121 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 122 #define SA_IGNORE 0x10 /* ignore by default */ 123 #define SA_CONT 0x20 /* continue if suspended */ 124 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 125 126 static int sigproptbl[NSIG] = { 127 SA_KILL, /* SIGHUP */ 128 SA_KILL, /* SIGINT */ 129 SA_KILL|SA_CORE, /* SIGQUIT */ 130 SA_KILL|SA_CORE, /* SIGILL */ 131 SA_KILL|SA_CORE, /* SIGTRAP */ 132 SA_KILL|SA_CORE, /* SIGABRT */ 133 SA_KILL|SA_CORE, /* SIGEMT */ 134 SA_KILL|SA_CORE, /* SIGFPE */ 135 SA_KILL, /* SIGKILL */ 136 SA_KILL|SA_CORE, /* SIGBUS */ 137 SA_KILL|SA_CORE, /* SIGSEGV */ 138 SA_KILL|SA_CORE, /* SIGSYS */ 139 SA_KILL, /* SIGPIPE */ 140 SA_KILL, /* SIGALRM */ 141 SA_KILL, /* SIGTERM */ 142 SA_IGNORE, /* SIGURG */ 143 SA_STOP, /* SIGSTOP */ 144 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 145 SA_IGNORE|SA_CONT, /* SIGCONT */ 146 SA_IGNORE, /* SIGCHLD */ 147 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 148 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 149 SA_IGNORE, /* SIGIO */ 150 SA_KILL, /* SIGXCPU */ 151 SA_KILL, /* SIGXFSZ */ 152 SA_KILL, /* SIGVTALRM */ 153 SA_KILL, /* SIGPROF */ 154 SA_IGNORE, /* SIGWINCH */ 155 SA_IGNORE, /* SIGINFO */ 156 SA_KILL, /* SIGUSR1 */ 157 SA_KILL, /* SIGUSR2 */ 158 }; 159 160 static __inline int 161 sigprop(int sig) 162 { 163 164 if (sig > 0 && sig < NSIG) 165 return (sigproptbl[_SIG_IDX(sig)]); 166 return (0); 167 } 168 169 static __inline int 170 sig_ffs(sigset_t *set) 171 { 172 int i; 173 174 for (i = 0; i < _SIG_WORDS; i++) 175 if (set->__bits[i]) 176 return (ffs(set->__bits[i]) + (i * 32)); 177 return (0); 178 } 179 180 /* 181 * do_sigaction 182 * sigaction 183 * osigaction 184 */ 185 static int 186 do_sigaction(p, sig, act, oact, old) 187 struct proc *p; 188 register int sig; 189 struct sigaction *act, *oact; 190 int old; 191 { 192 register struct sigacts *ps = p->p_sigacts; 193 194 if (sig <= 0 || sig > _SIG_MAXSIG) 195 return (EINVAL); 196 197 if (oact) { 198 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 199 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 200 oact->sa_flags = 0; 201 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 202 oact->sa_flags |= SA_ONSTACK; 203 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 204 oact->sa_flags |= SA_RESTART; 205 if (SIGISMEMBER(ps->ps_sigreset, sig)) 206 oact->sa_flags |= SA_RESETHAND; 207 if (SIGISMEMBER(ps->ps_signodefer, sig)) 208 oact->sa_flags |= SA_NODEFER; 209 if (SIGISMEMBER(ps->ps_siginfo, sig)) 210 oact->sa_flags |= SA_SIGINFO; 211 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 212 oact->sa_flags |= SA_NOCLDSTOP; 213 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 214 oact->sa_flags |= SA_NOCLDWAIT; 215 } 216 if (act) { 217 if ((sig == SIGKILL || sig == SIGSTOP) && 218 act->sa_handler != SIG_DFL) 219 return (EINVAL); 220 221 /* 222 * Change setting atomically. 223 */ 224 (void) splhigh(); 225 226 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 227 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 228 if (act->sa_flags & SA_SIGINFO) { 229 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 230 SIGADDSET(ps->ps_siginfo, sig); 231 } else { 232 ps->ps_sigact[_SIG_IDX(sig)] = 233 (__sighandler_t *)act->sa_sigaction; 234 SIGDELSET(ps->ps_siginfo, sig); 235 } 236 if (!(act->sa_flags & SA_RESTART)) 237 SIGADDSET(ps->ps_sigintr, sig); 238 else 239 SIGDELSET(ps->ps_sigintr, sig); 240 if (act->sa_flags & SA_ONSTACK) 241 SIGADDSET(ps->ps_sigonstack, sig); 242 else 243 SIGDELSET(ps->ps_sigonstack, sig); 244 if (act->sa_flags & SA_RESETHAND) 245 SIGADDSET(ps->ps_sigreset, sig); 246 else 247 SIGDELSET(ps->ps_sigreset, sig); 248 if (act->sa_flags & SA_NODEFER) 249 SIGADDSET(ps->ps_signodefer, sig); 250 else 251 SIGDELSET(ps->ps_signodefer, sig); 252 #ifdef COMPAT_SUNOS 253 if (act->sa_flags & SA_USERTRAMP) 254 SIGADDSET(ps->ps_usertramp, sig); 255 else 256 SIGDELSET(ps->ps_usertramp, seg); 257 #endif 258 if (sig == SIGCHLD) { 259 if (act->sa_flags & SA_NOCLDSTOP) 260 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 261 else 262 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 263 if (act->sa_flags & SA_NOCLDWAIT) { 264 /* 265 * Paranoia: since SA_NOCLDWAIT is implemented 266 * by reparenting the dying child to PID 1 (and 267 * trust it to reap the zombie), PID 1 itself 268 * is forbidden to set SA_NOCLDWAIT. 269 */ 270 if (p->p_pid == 1) 271 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 272 else 273 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 274 } else 275 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 276 } 277 /* 278 * Set bit in p_sigignore for signals that are set to SIG_IGN, 279 * and for signals set to SIG_DFL where the default is to 280 * ignore. However, don't put SIGCONT in p_sigignore, as we 281 * have to restart the process. 282 */ 283 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 284 (sigprop(sig) & SA_IGNORE && 285 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 286 /* never to be seen again */ 287 SIGDELSET(p->p_siglist, sig); 288 if (sig != SIGCONT) 289 /* easier in psignal */ 290 SIGADDSET(p->p_sigignore, sig); 291 SIGDELSET(p->p_sigcatch, sig); 292 } else { 293 SIGDELSET(p->p_sigignore, sig); 294 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 295 SIGDELSET(p->p_sigcatch, sig); 296 else 297 SIGADDSET(p->p_sigcatch, sig); 298 } 299 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 300 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) 301 SIGDELSET(ps->ps_osigset, sig); 302 else 303 SIGADDSET(ps->ps_osigset, sig); 304 305 (void) spl0(); 306 } 307 return (0); 308 } 309 310 #ifndef _SYS_SYSPROTO_H_ 311 struct sigaction_args { 312 int sig; 313 struct sigaction *act; 314 struct sigaction *oact; 315 }; 316 #endif 317 /* ARGSUSED */ 318 int 319 sigaction(p, uap) 320 struct proc *p; 321 register struct sigaction_args *uap; 322 { 323 struct sigaction act, oact; 324 register struct sigaction *actp, *oactp; 325 int error; 326 327 actp = (uap->act != NULL) ? &act : NULL; 328 oactp = (uap->oact != NULL) ? &oact : NULL; 329 if (actp) { 330 error = copyin(uap->act, actp, sizeof(act)); 331 if (error) 332 return (error); 333 } 334 error = do_sigaction(p, uap->sig, actp, oactp, 0); 335 if (oactp && !error) { 336 error = copyout(oactp, uap->oact, sizeof(oact)); 337 } 338 return (error); 339 } 340 341 #ifndef _SYS_SYSPROTO_H_ 342 struct osigaction_args { 343 int signum; 344 struct osigaction *nsa; 345 struct osigaction *osa; 346 }; 347 #endif 348 /* ARGSUSED */ 349 int 350 osigaction(p, uap) 351 struct proc *p; 352 register struct osigaction_args *uap; 353 { 354 struct osigaction sa; 355 struct sigaction nsa, osa; 356 register struct sigaction *nsap, *osap; 357 int error; 358 359 if (uap->signum <= 0 || uap->signum >= ONSIG) 360 return (EINVAL); 361 nsap = (uap->nsa != NULL) ? &nsa : NULL; 362 osap = (uap->osa != NULL) ? &osa : NULL; 363 if (nsap) { 364 error = copyin(uap->nsa, &sa, sizeof(sa)); 365 if (error) 366 return (error); 367 nsap->sa_handler = sa.sa_handler; 368 nsap->sa_flags = sa.sa_flags; 369 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 370 } 371 error = do_sigaction(p, uap->signum, nsap, osap, 1); 372 if (osap && !error) { 373 sa.sa_handler = osap->sa_handler; 374 sa.sa_flags = osap->sa_flags; 375 SIG2OSIG(osap->sa_mask, sa.sa_mask); 376 error = copyout(&sa, uap->osa, sizeof(sa)); 377 } 378 return (error); 379 } 380 381 /* 382 * Initialize signal state for process 0; 383 * set to ignore signals that are ignored by default. 384 */ 385 void 386 siginit(p) 387 struct proc *p; 388 { 389 register int i; 390 391 for (i = 1; i <= NSIG; i++) 392 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 393 SIGADDSET(p->p_sigignore, i); 394 } 395 396 /* 397 * Reset signals for an exec of the specified process. 398 */ 399 void 400 execsigs(p) 401 register struct proc *p; 402 { 403 register struct sigacts *ps = p->p_sigacts; 404 register int sig; 405 406 /* 407 * Reset caught signals. Held signals remain held 408 * through p_sigmask (unless they were caught, 409 * and are now ignored by default). 410 */ 411 while (SIGNOTEMPTY(p->p_sigcatch)) { 412 sig = sig_ffs(&p->p_sigcatch); 413 SIGDELSET(p->p_sigcatch, sig); 414 if (sigprop(sig) & SA_IGNORE) { 415 if (sig != SIGCONT) 416 SIGADDSET(p->p_sigignore, sig); 417 SIGDELSET(p->p_siglist, sig); 418 } 419 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 420 } 421 /* 422 * Reset stack state to the user stack. 423 * Clear set of signals caught on the signal stack. 424 */ 425 p->p_sigstk.ss_flags = SS_DISABLE; 426 p->p_sigstk.ss_size = 0; 427 p->p_sigstk.ss_sp = 0; 428 /* 429 * Reset no zombies if child dies flag as Solaris does. 430 */ 431 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 432 } 433 434 /* 435 * Manipulate signal mask. 436 * Note that we receive new mask, not pointer, 437 * and return old mask as return value; 438 * the library stub does the rest. 439 */ 440 static int 441 do_sigprocmask(p, how, set, oset, old) 442 struct proc *p; 443 int how; 444 sigset_t *set, *oset; 445 int old; 446 { 447 int error; 448 449 if (oset != NULL) 450 *oset = p->p_sigmask; 451 452 error = 0; 453 if (set != NULL) { 454 (void) splhigh(); 455 switch (how) { 456 case SIG_BLOCK: 457 SIG_CANTMASK(*set); 458 SIGSETOR(p->p_sigmask, *set); 459 break; 460 case SIG_UNBLOCK: 461 SIGSETNAND(p->p_sigmask, *set); 462 break; 463 case SIG_SETMASK: 464 SIG_CANTMASK(*set); 465 if (old) 466 SIGSETLO(p->p_sigmask, *set); 467 else 468 p->p_sigmask = *set; 469 break; 470 default: 471 error = EINVAL; 472 break; 473 } 474 (void) spl0(); 475 } 476 return (error); 477 } 478 479 #ifndef _SYS_SYSPROTO_H_ 480 struct sigprocmask_args { 481 int how; 482 const sigset_t *set; 483 sigset_t *oset; 484 }; 485 #endif 486 int 487 sigprocmask(p, uap) 488 register struct proc *p; 489 struct sigprocmask_args *uap; 490 { 491 sigset_t set, oset; 492 sigset_t *setp, *osetp; 493 int error; 494 495 setp = (uap->set != NULL) ? &set : NULL; 496 osetp = (uap->oset != NULL) ? &oset : NULL; 497 if (setp) { 498 error = copyin(uap->set, setp, sizeof(set)); 499 if (error) 500 return (error); 501 } 502 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 503 if (osetp && !error) { 504 error = copyout(osetp, uap->oset, sizeof(oset)); 505 } 506 return (error); 507 } 508 509 #ifndef _SYS_SYSPROTO_H_ 510 struct osigprocmask_args { 511 int how; 512 osigset_t mask; 513 }; 514 #endif 515 int 516 osigprocmask(p, uap) 517 register struct proc *p; 518 struct osigprocmask_args *uap; 519 { 520 sigset_t set, oset; 521 int error; 522 523 OSIG2SIG(uap->mask, set); 524 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 525 SIG2OSIG(oset, p->p_retval[0]); 526 return (error); 527 } 528 529 #ifndef _SYS_SYSPROTO_H_ 530 struct sigpending_args { 531 sigset_t *set; 532 }; 533 #endif 534 /* ARGSUSED */ 535 int 536 sigpending(p, uap) 537 struct proc *p; 538 struct sigpending_args *uap; 539 { 540 541 return (copyout(&p->p_siglist, uap->set, sizeof(sigset_t))); 542 } 543 544 #ifndef _SYS_SYSPROTO_H_ 545 struct osigpending_args { 546 int dummy; 547 }; 548 #endif 549 /* ARGSUSED */ 550 int 551 osigpending(p, uap) 552 struct proc *p; 553 struct osigpending_args *uap; 554 { 555 556 SIG2OSIG(p->p_siglist, p->p_retval[0]); 557 return (0); 558 } 559 560 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 561 /* 562 * Generalized interface signal handler, 4.3-compatible. 563 */ 564 #ifndef _SYS_SYSPROTO_H_ 565 struct osigvec_args { 566 int signum; 567 struct sigvec *nsv; 568 struct sigvec *osv; 569 }; 570 #endif 571 /* ARGSUSED */ 572 int 573 osigvec(p, uap) 574 struct proc *p; 575 register struct osigvec_args *uap; 576 { 577 struct sigvec vec; 578 struct sigaction nsa, osa; 579 register struct sigaction *nsap, *osap; 580 int error; 581 582 if (uap->signum <= 0 || uap->signum >= ONSIG) 583 return (EINVAL); 584 nsap = (uap->nsv != NULL) ? &nsa : NULL; 585 osap = (uap->osv != NULL) ? &osa : NULL; 586 if (nsap) { 587 error = copyin(uap->nsv, &vec, sizeof(vec)); 588 if (error) 589 return (error); 590 nsap->sa_handler = vec.sv_handler; 591 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 592 nsap->sa_flags = vec.sv_flags; 593 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 594 #ifdef COMPAT_SUNOS 595 nsap->sa_flags |= SA_USERTRAMP; 596 #endif 597 } 598 error = do_sigaction(p, uap->signum, nsap, osap, 1); 599 if (osap && !error) { 600 vec.sv_handler = osap->sa_handler; 601 SIG2OSIG(osap->sa_mask, vec.sv_mask); 602 vec.sv_flags = osap->sa_flags; 603 vec.sv_flags &= ~SA_NOCLDWAIT; 604 vec.sv_flags ^= SA_RESTART; 605 #ifdef COMPAT_SUNOS 606 vec.sv_flags &= ~SA_NOCLDSTOP; 607 #endif 608 error = copyout(&vec, uap->osv, sizeof(vec)); 609 } 610 return (error); 611 } 612 613 #ifndef _SYS_SYSPROTO_H_ 614 struct osigblock_args { 615 int mask; 616 }; 617 #endif 618 int 619 osigblock(p, uap) 620 register struct proc *p; 621 struct osigblock_args *uap; 622 { 623 sigset_t set; 624 625 OSIG2SIG(uap->mask, set); 626 SIG_CANTMASK(set); 627 (void) splhigh(); 628 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 629 SIGSETOR(p->p_sigmask, set); 630 (void) spl0(); 631 return (0); 632 } 633 634 #ifndef _SYS_SYSPROTO_H_ 635 struct osigsetmask_args { 636 int mask; 637 }; 638 #endif 639 int 640 osigsetmask(p, uap) 641 struct proc *p; 642 struct osigsetmask_args *uap; 643 { 644 sigset_t set; 645 646 OSIG2SIG(uap->mask, set); 647 SIG_CANTMASK(set); 648 (void) splhigh(); 649 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 650 SIGSETLO(p->p_sigmask, set); 651 (void) spl0(); 652 return (0); 653 } 654 #endif /* COMPAT_43 || COMPAT_SUNOS */ 655 656 /* 657 * Suspend process until signal, providing mask to be set 658 * in the meantime. Note nonstandard calling convention: 659 * libc stub passes mask, not pointer, to save a copyin. 660 */ 661 #ifndef _SYS_SYSPROTO_H_ 662 struct sigsuspend_args { 663 const sigset_t *sigmask; 664 }; 665 #endif 666 /* ARGSUSED */ 667 int 668 sigsuspend(p, uap) 669 register struct proc *p; 670 struct sigsuspend_args *uap; 671 { 672 sigset_t mask; 673 register struct sigacts *ps = p->p_sigacts; 674 int error; 675 676 error = copyin(uap->sigmask, &mask, sizeof(mask)); 677 if (error) 678 return (error); 679 680 /* 681 * When returning from sigsuspend, we want 682 * the old mask to be restored after the 683 * signal handler has finished. Thus, we 684 * save it here and mark the sigacts structure 685 * to indicate this. 686 */ 687 p->p_oldsigmask = p->p_sigmask; 688 p->p_flag |= P_OLDMASK; 689 690 SIG_CANTMASK(mask); 691 p->p_sigmask = mask; 692 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0) 693 /* void */; 694 /* always return EINTR rather than ERESTART... */ 695 return (EINTR); 696 } 697 698 #ifndef _SYS_SYSPROTO_H_ 699 struct osigsuspend_args { 700 osigset_t mask; 701 }; 702 #endif 703 /* ARGSUSED */ 704 int 705 osigsuspend(p, uap) 706 register struct proc *p; 707 struct osigsuspend_args *uap; 708 { 709 sigset_t mask; 710 register struct sigacts *ps = p->p_sigacts; 711 712 p->p_oldsigmask = p->p_sigmask; 713 p->p_flag |= P_OLDMASK; 714 OSIG2SIG(uap->mask, mask); 715 SIG_CANTMASK(mask); 716 SIGSETLO(p->p_sigmask, mask); 717 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "opause", 0) == 0) 718 /* void */; 719 /* always return EINTR rather than ERESTART... */ 720 return (EINTR); 721 } 722 723 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 724 #ifndef _SYS_SYSPROTO_H_ 725 struct osigstack_args { 726 struct sigstack *nss; 727 struct sigstack *oss; 728 }; 729 #endif 730 /* ARGSUSED */ 731 int 732 osigstack(p, uap) 733 struct proc *p; 734 register struct osigstack_args *uap; 735 { 736 struct sigstack ss; 737 int error = 0; 738 739 ss.ss_sp = p->p_sigstk.ss_sp; 740 ss.ss_onstack = p->p_sigstk.ss_flags & SS_ONSTACK; 741 if (uap->oss && (error = copyout(&ss, uap->oss, 742 sizeof(struct sigstack)))) 743 return (error); 744 if (uap->nss && (error = copyin(uap->nss, &ss, sizeof(ss))) == 0) { 745 p->p_sigstk.ss_sp = ss.ss_sp; 746 p->p_sigstk.ss_size = 0; 747 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 748 p->p_flag |= P_ALTSTACK; 749 } 750 return (error); 751 } 752 #endif /* COMPAT_43 || COMPAT_SUNOS */ 753 754 #ifndef _SYS_SYSPROTO_H_ 755 struct sigaltstack_args { 756 stack_t *ss; 757 stack_t *oss; 758 }; 759 #endif 760 /* ARGSUSED */ 761 int 762 sigaltstack(p, uap) 763 struct proc *p; 764 register struct sigaltstack_args *uap; 765 { 766 stack_t ss; 767 int error; 768 769 if ((p->p_flag & P_ALTSTACK) == 0) 770 p->p_sigstk.ss_flags |= SS_DISABLE; 771 if (uap->oss && (error = copyout(&p->p_sigstk, uap->oss, 772 sizeof(stack_t)))) 773 return (error); 774 if (uap->ss == 0) 775 return (0); 776 if ((error = copyin(uap->ss, &ss, sizeof(ss)))) 777 return (error); 778 if (ss.ss_flags & SS_DISABLE) { 779 if (p->p_sigstk.ss_flags & SS_ONSTACK) 780 return (EINVAL); 781 p->p_flag &= ~P_ALTSTACK; 782 p->p_sigstk.ss_flags = ss.ss_flags; 783 return (0); 784 } 785 if (ss.ss_size < MINSIGSTKSZ) 786 return (ENOMEM); 787 p->p_flag |= P_ALTSTACK; 788 p->p_sigstk = ss; 789 return (0); 790 } 791 792 /* 793 * Common code for kill process group/broadcast kill. 794 * cp is calling process. 795 */ 796 int 797 killpg1(cp, sig, pgid, all) 798 register struct proc *cp; 799 int sig, pgid, all; 800 { 801 register struct proc *p; 802 register struct pcred *pc = cp->p_cred; 803 struct pgrp *pgrp; 804 int nfound = 0; 805 806 if (all) 807 /* 808 * broadcast 809 */ 810 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 811 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 812 p == cp || !CANSIGNAL(cp, pc, p, sig)) 813 continue; 814 nfound++; 815 if (sig) 816 psignal(p, sig); 817 } 818 else { 819 if (pgid == 0) 820 /* 821 * zero pgid means send to my process group. 822 */ 823 pgrp = cp->p_pgrp; 824 else { 825 pgrp = pgfind(pgid); 826 if (pgrp == NULL) 827 return (ESRCH); 828 } 829 for (p = pgrp->pg_members.lh_first; p != 0; 830 p = p->p_pglist.le_next) { 831 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 832 p->p_stat == SZOMB || 833 !CANSIGNAL(cp, pc, p, sig)) 834 continue; 835 nfound++; 836 if (sig) 837 psignal(p, sig); 838 } 839 } 840 return (nfound ? 0 : ESRCH); 841 } 842 843 #ifndef _SYS_SYSPROTO_H_ 844 struct kill_args { 845 int pid; 846 int signum; 847 }; 848 #endif 849 /* ARGSUSED */ 850 int 851 kill(cp, uap) 852 register struct proc *cp; 853 register struct kill_args *uap; 854 { 855 register struct proc *p; 856 register struct pcred *pc = cp->p_cred; 857 858 if ((u_int)uap->signum > _SIG_MAXSIG) 859 return (EINVAL); 860 if (uap->pid > 0) { 861 /* kill single process */ 862 if ((p = pfind(uap->pid)) == NULL) 863 return (ESRCH); 864 if (!CANSIGNAL(cp, pc, p, uap->signum)) 865 return (EPERM); 866 if (uap->signum) 867 psignal(p, uap->signum); 868 return (0); 869 } 870 switch (uap->pid) { 871 case -1: /* broadcast signal */ 872 return (killpg1(cp, uap->signum, 0, 1)); 873 case 0: /* signal own process group */ 874 return (killpg1(cp, uap->signum, 0, 0)); 875 default: /* negative explicit process group */ 876 return (killpg1(cp, uap->signum, -uap->pid, 0)); 877 } 878 /* NOTREACHED */ 879 } 880 881 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 882 #ifndef _SYS_SYSPROTO_H_ 883 struct okillpg_args { 884 int pgid; 885 int signum; 886 }; 887 #endif 888 /* ARGSUSED */ 889 int 890 okillpg(p, uap) 891 struct proc *p; 892 register struct okillpg_args *uap; 893 { 894 895 if ((u_int)uap->signum > _SIG_MAXSIG) 896 return (EINVAL); 897 return (killpg1(p, uap->signum, uap->pgid, 0)); 898 } 899 #endif /* COMPAT_43 || COMPAT_SUNOS */ 900 901 /* 902 * Send a signal to a process group. 903 */ 904 void 905 gsignal(pgid, sig) 906 int pgid, sig; 907 { 908 struct pgrp *pgrp; 909 910 if (pgid && (pgrp = pgfind(pgid))) 911 pgsignal(pgrp, sig, 0); 912 } 913 914 /* 915 * Send a signal to a process group. If checktty is 1, 916 * limit to members which have a controlling terminal. 917 */ 918 void 919 pgsignal(pgrp, sig, checkctty) 920 struct pgrp *pgrp; 921 int sig, checkctty; 922 { 923 register struct proc *p; 924 925 if (pgrp) 926 for (p = pgrp->pg_members.lh_first; p != 0; 927 p = p->p_pglist.le_next) 928 if (checkctty == 0 || p->p_flag & P_CONTROLT) 929 psignal(p, sig); 930 } 931 932 /* 933 * Send a signal caused by a trap to the current process. 934 * If it will be caught immediately, deliver it with correct code. 935 * Otherwise, post it normally. 936 */ 937 void 938 trapsignal(p, sig, code) 939 struct proc *p; 940 register int sig; 941 u_long code; 942 { 943 register struct sigacts *ps = p->p_sigacts; 944 945 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 946 SIGISMEMBER(p->p_sigmask, sig)) { 947 p->p_stats->p_ru.ru_nsignals++; 948 #ifdef KTRACE 949 if (KTRPOINT(p, KTR_PSIG)) 950 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 951 &p->p_sigmask, code); 952 #endif 953 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 954 &p->p_sigmask, code); 955 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 956 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 957 SIGADDSET(p->p_sigmask, sig); 958 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 959 /* 960 * See do_sigaction() for origin of this code. 961 */ 962 SIGDELSET(p->p_sigcatch, sig); 963 if (sig != SIGCONT && 964 sigprop(sig) & SA_IGNORE) 965 SIGADDSET(p->p_sigignore, sig); 966 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 967 } 968 } else { 969 p->p_code = code; /* XXX for core dump/debugger */ 970 p->p_sig = sig; /* XXX to verify code */ 971 psignal(p, sig); 972 } 973 } 974 975 /* 976 * Send the signal to the process. If the signal has an action, the action 977 * is usually performed by the target process rather than the caller; we add 978 * the signal to the set of pending signals for the process. 979 * 980 * Exceptions: 981 * o When a stop signal is sent to a sleeping process that takes the 982 * default action, the process is stopped without awakening it. 983 * o SIGCONT restarts stopped processes (or puts them back to sleep) 984 * regardless of the signal action (eg, blocked or ignored). 985 * 986 * Other ignored signals are discarded immediately. 987 */ 988 void 989 psignal(p, sig) 990 register struct proc *p; 991 register int sig; 992 { 993 register int s, prop; 994 register sig_t action; 995 996 if (sig > _SIG_MAXSIG || sig <= 0) { 997 printf("psignal: signal %d\n", sig); 998 panic("psignal signal number"); 999 } 1000 1001 prop = sigprop(sig); 1002 1003 /* 1004 * If proc is traced, always give parent a chance; 1005 * if signal event is tracked by procfs, give *that* 1006 * a chance, as well. 1007 */ 1008 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) 1009 action = SIG_DFL; 1010 else { 1011 /* 1012 * If the signal is being ignored, 1013 * then we forget about it immediately. 1014 * (Note: we don't set SIGCONT in p_sigignore, 1015 * and if it is set to SIG_IGN, 1016 * action will be SIG_DFL here.) 1017 */ 1018 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1019 return; 1020 if (SIGISMEMBER(p->p_sigmask, sig)) 1021 action = SIG_HOLD; 1022 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1023 action = SIG_CATCH; 1024 else 1025 action = SIG_DFL; 1026 } 1027 1028 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1029 (p->p_flag & P_TRACED) == 0) 1030 p->p_nice = NZERO; 1031 1032 if (prop & SA_CONT) 1033 SIG_STOPSIGMASK(p->p_siglist); 1034 1035 if (prop & SA_STOP) { 1036 /* 1037 * If sending a tty stop signal to a member of an orphaned 1038 * process group, discard the signal here if the action 1039 * is default; don't stop the process below if sleeping, 1040 * and don't clear any pending SIGCONT. 1041 */ 1042 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1043 action == SIG_DFL) 1044 return; 1045 SIG_CONTSIGMASK(p->p_siglist); 1046 } 1047 SIGADDSET(p->p_siglist, sig); 1048 1049 /* 1050 * Defer further processing for signals which are held, 1051 * except that stopped processes must be continued by SIGCONT. 1052 */ 1053 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) 1054 return; 1055 s = splhigh(); 1056 switch (p->p_stat) { 1057 1058 case SSLEEP: 1059 /* 1060 * If process is sleeping uninterruptibly 1061 * we can't interrupt the sleep... the signal will 1062 * be noticed when the process returns through 1063 * trap() or syscall(). 1064 */ 1065 if ((p->p_flag & P_SINTR) == 0) 1066 goto out; 1067 /* 1068 * Process is sleeping and traced... make it runnable 1069 * so it can discover the signal in issignal() and stop 1070 * for the parent. 1071 */ 1072 if (p->p_flag & P_TRACED) 1073 goto run; 1074 /* 1075 * If SIGCONT is default (or ignored) and process is 1076 * asleep, we are finished; the process should not 1077 * be awakened. 1078 */ 1079 if ((prop & SA_CONT) && action == SIG_DFL) { 1080 SIGDELSET(p->p_siglist, sig); 1081 goto out; 1082 } 1083 /* 1084 * When a sleeping process receives a stop 1085 * signal, process immediately if possible. 1086 * All other (caught or default) signals 1087 * cause the process to run. 1088 */ 1089 if (prop & SA_STOP) { 1090 if (action != SIG_DFL) 1091 goto runfast; 1092 /* 1093 * If a child holding parent blocked, 1094 * stopping could cause deadlock. 1095 */ 1096 if (p->p_flag & P_PPWAIT) 1097 goto out; 1098 SIGDELSET(p->p_siglist, sig); 1099 p->p_xstat = sig; 1100 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1101 psignal(p->p_pptr, SIGCHLD); 1102 stop(p); 1103 goto out; 1104 } else 1105 goto runfast; 1106 /*NOTREACHED*/ 1107 1108 case SSTOP: 1109 /* 1110 * If traced process is already stopped, 1111 * then no further action is necessary. 1112 */ 1113 if (p->p_flag & P_TRACED) 1114 goto out; 1115 1116 /* 1117 * Kill signal always sets processes running. 1118 */ 1119 if (sig == SIGKILL) 1120 goto runfast; 1121 1122 if (prop & SA_CONT) { 1123 /* 1124 * If SIGCONT is default (or ignored), we continue the 1125 * process but don't leave the signal in p_siglist, as 1126 * it has no further action. If SIGCONT is held, we 1127 * continue the process and leave the signal in 1128 * p_siglist. If the process catches SIGCONT, let it 1129 * handle the signal itself. If it isn't waiting on 1130 * an event, then it goes back to run state. 1131 * Otherwise, process goes back to sleep state. 1132 */ 1133 if (action == SIG_DFL) 1134 SIGDELSET(p->p_siglist, sig); 1135 if (action == SIG_CATCH) 1136 goto runfast; 1137 if (p->p_wchan == 0) 1138 goto run; 1139 p->p_stat = SSLEEP; 1140 goto out; 1141 } 1142 1143 if (prop & SA_STOP) { 1144 /* 1145 * Already stopped, don't need to stop again. 1146 * (If we did the shell could get confused.) 1147 */ 1148 SIGDELSET(p->p_siglist, sig); 1149 goto out; 1150 } 1151 1152 /* 1153 * If process is sleeping interruptibly, then simulate a 1154 * wakeup so that when it is continued, it will be made 1155 * runnable and can look at the signal. But don't make 1156 * the process runnable, leave it stopped. 1157 */ 1158 if (p->p_wchan && p->p_flag & P_SINTR) 1159 unsleep(p); 1160 goto out; 1161 1162 default: 1163 /* 1164 * SRUN, SIDL, SZOMB do nothing with the signal, 1165 * other than kicking ourselves if we are running. 1166 * It will either never be noticed, or noticed very soon. 1167 */ 1168 if (p == curproc) 1169 signotify(p); 1170 #ifdef SMP 1171 else if (p->p_stat == SRUN) 1172 forward_signal(p); 1173 #endif 1174 goto out; 1175 } 1176 /*NOTREACHED*/ 1177 1178 runfast: 1179 /* 1180 * Raise priority to at least PUSER. 1181 */ 1182 if (p->p_priority > PUSER) 1183 p->p_priority = PUSER; 1184 run: 1185 setrunnable(p); 1186 out: 1187 splx(s); 1188 } 1189 1190 /* 1191 * If the current process has received a signal (should be caught or cause 1192 * termination, should interrupt current syscall), return the signal number. 1193 * Stop signals with default action are processed immediately, then cleared; 1194 * they aren't returned. This is checked after each entry to the system for 1195 * a syscall or trap (though this can usually be done without calling issignal 1196 * by checking the pending signal masks in the CURSIG macro.) The normal call 1197 * sequence is 1198 * 1199 * while (sig = CURSIG(curproc)) 1200 * postsig(sig); 1201 */ 1202 int 1203 issignal(p) 1204 register struct proc *p; 1205 { 1206 sigset_t mask; 1207 register int sig, prop; 1208 1209 for (;;) { 1210 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1211 1212 mask = p->p_siglist; 1213 SIGSETNAND(mask, p->p_sigmask); 1214 if (p->p_flag & P_PPWAIT) 1215 SIG_STOPSIGMASK(mask); 1216 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1217 return (0); 1218 sig = sig_ffs(&mask); 1219 prop = sigprop(sig); 1220 1221 STOPEVENT(p, S_SIG, sig); 1222 1223 /* 1224 * We should see pending but ignored signals 1225 * only if P_TRACED was on when they were posted. 1226 */ 1227 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1228 SIGDELSET(p->p_siglist, sig); 1229 continue; 1230 } 1231 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1232 /* 1233 * If traced, always stop, and stay 1234 * stopped until released by the parent. 1235 */ 1236 p->p_xstat = sig; 1237 psignal(p->p_pptr, SIGCHLD); 1238 do { 1239 stop(p); 1240 mi_switch(); 1241 } while (!trace_req(p) 1242 && p->p_flag & P_TRACED); 1243 1244 /* 1245 * If the traced bit got turned off, go back up 1246 * to the top to rescan signals. This ensures 1247 * that p_sig* and ps_sigact are consistent. 1248 */ 1249 if ((p->p_flag & P_TRACED) == 0) 1250 continue; 1251 1252 /* 1253 * If parent wants us to take the signal, 1254 * then it will leave it in p->p_xstat; 1255 * otherwise we just look for signals again. 1256 */ 1257 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1258 sig = p->p_xstat; 1259 if (sig == 0) 1260 continue; 1261 1262 /* 1263 * Put the new signal into p_siglist. If the 1264 * signal is being masked, look for other signals. 1265 */ 1266 SIGADDSET(p->p_siglist, sig); 1267 if (SIGISMEMBER(p->p_sigmask, sig)) 1268 continue; 1269 } 1270 1271 /* 1272 * Decide whether the signal should be returned. 1273 * Return the signal's number, or fall through 1274 * to clear it from the pending mask. 1275 */ 1276 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1277 1278 case (int)SIG_DFL: 1279 /* 1280 * Don't take default actions on system processes. 1281 */ 1282 if (p->p_pid <= 1) { 1283 #ifdef DIAGNOSTIC 1284 /* 1285 * Are you sure you want to ignore SIGSEGV 1286 * in init? XXX 1287 */ 1288 printf("Process (pid %lu) got signal %d\n", 1289 (u_long)p->p_pid, sig); 1290 #endif 1291 break; /* == ignore */ 1292 } 1293 /* 1294 * If there is a pending stop signal to process 1295 * with default action, stop here, 1296 * then clear the signal. However, 1297 * if process is member of an orphaned 1298 * process group, ignore tty stop signals. 1299 */ 1300 if (prop & SA_STOP) { 1301 if (p->p_flag & P_TRACED || 1302 (p->p_pgrp->pg_jobc == 0 && 1303 prop & SA_TTYSTOP)) 1304 break; /* == ignore */ 1305 p->p_xstat = sig; 1306 stop(p); 1307 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1308 psignal(p->p_pptr, SIGCHLD); 1309 mi_switch(); 1310 break; 1311 } else if (prop & SA_IGNORE) { 1312 /* 1313 * Except for SIGCONT, shouldn't get here. 1314 * Default action is to ignore; drop it. 1315 */ 1316 break; /* == ignore */ 1317 } else 1318 return (sig); 1319 /*NOTREACHED*/ 1320 1321 case (int)SIG_IGN: 1322 /* 1323 * Masking above should prevent us ever trying 1324 * to take action on an ignored signal other 1325 * than SIGCONT, unless process is traced. 1326 */ 1327 if ((prop & SA_CONT) == 0 && 1328 (p->p_flag & P_TRACED) == 0) 1329 printf("issignal\n"); 1330 break; /* == ignore */ 1331 1332 default: 1333 /* 1334 * This signal has an action, let 1335 * postsig() process it. 1336 */ 1337 return (sig); 1338 } 1339 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1340 } 1341 /* NOTREACHED */ 1342 } 1343 1344 /* 1345 * Put the argument process into the stopped state and notify the parent 1346 * via wakeup. Signals are handled elsewhere. The process must not be 1347 * on the run queue. 1348 */ 1349 void 1350 stop(p) 1351 register struct proc *p; 1352 { 1353 1354 p->p_stat = SSTOP; 1355 p->p_flag &= ~P_WAITED; 1356 wakeup((caddr_t)p->p_pptr); 1357 } 1358 1359 /* 1360 * Take the action for the specified signal 1361 * from the current set of pending signals. 1362 */ 1363 void 1364 postsig(sig) 1365 register int sig; 1366 { 1367 register struct proc *p = curproc; 1368 struct sigacts *ps = p->p_sigacts; 1369 sig_t action; 1370 sigset_t returnmask; 1371 int code; 1372 1373 KASSERT(sig != 0, ("postsig")); 1374 1375 SIGDELSET(p->p_siglist, sig); 1376 action = ps->ps_sigact[_SIG_IDX(sig)]; 1377 #ifdef KTRACE 1378 if (KTRPOINT(p, KTR_PSIG)) 1379 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1380 &p->p_oldsigmask : &p->p_sigmask, 0); 1381 #endif 1382 STOPEVENT(p, S_SIG, sig); 1383 1384 if (action == SIG_DFL) { 1385 /* 1386 * Default action, where the default is to kill 1387 * the process. (Other cases were ignored above.) 1388 */ 1389 sigexit(p, sig); 1390 /* NOTREACHED */ 1391 } else { 1392 /* 1393 * If we get here, the signal must be caught. 1394 */ 1395 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1396 ("postsig action")); 1397 /* 1398 * Set the new mask value and also defer further 1399 * occurrences of this signal. 1400 * 1401 * Special case: user has done a sigsuspend. Here the 1402 * current mask is not of interest, but rather the 1403 * mask from before the sigsuspend is what we want 1404 * restored after the signal processing is completed. 1405 */ 1406 (void) splhigh(); 1407 if (p->p_flag & P_OLDMASK) { 1408 returnmask = p->p_oldsigmask; 1409 p->p_flag &= ~P_OLDMASK; 1410 } else 1411 returnmask = p->p_sigmask; 1412 1413 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1414 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1415 SIGADDSET(p->p_sigmask, sig); 1416 1417 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1418 /* 1419 * See do_sigaction() for origin of this code. 1420 */ 1421 SIGDELSET(p->p_sigcatch, sig); 1422 if (sig != SIGCONT && 1423 sigprop(sig) & SA_IGNORE) 1424 SIGADDSET(p->p_sigignore, sig); 1425 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1426 } 1427 (void) spl0(); 1428 p->p_stats->p_ru.ru_nsignals++; 1429 if (p->p_sig != sig) { 1430 code = 0; 1431 } else { 1432 code = p->p_code; 1433 p->p_code = 0; 1434 p->p_sig = 0; 1435 } 1436 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1437 } 1438 } 1439 1440 /* 1441 * Kill the current process for stated reason. 1442 */ 1443 void 1444 killproc(p, why) 1445 struct proc *p; 1446 char *why; 1447 { 1448 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1449 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1450 psignal(p, SIGKILL); 1451 } 1452 1453 /* 1454 * Force the current process to exit with the specified signal, dumping core 1455 * if appropriate. We bypass the normal tests for masked and caught signals, 1456 * allowing unrecoverable failures to terminate the process without changing 1457 * signal state. Mark the accounting record with the signal termination. 1458 * If dumping core, save the signal number for the debugger. Calls exit and 1459 * does not return. 1460 */ 1461 void 1462 sigexit(p, sig) 1463 register struct proc *p; 1464 int sig; 1465 { 1466 1467 p->p_acflag |= AXSIG; 1468 if (sigprop(sig) & SA_CORE) { 1469 p->p_sig = sig; 1470 /* 1471 * Log signals which would cause core dumps 1472 * (Log as LOG_INFO to appease those who don't want 1473 * these messages.) 1474 * XXX : Todo, as well as euid, write out ruid too 1475 */ 1476 if (coredump(p) == 0) 1477 sig |= WCOREFLAG; 1478 if (kern_logsigexit) 1479 log(LOG_INFO, 1480 "pid %d (%s), uid %d: exited on signal %d%s\n", 1481 p->p_pid, p->p_comm, 1482 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, 1483 sig &~ WCOREFLAG, 1484 sig & WCOREFLAG ? " (core dumped)" : ""); 1485 } 1486 exit1(p, W_EXITCODE(0, sig)); 1487 /* NOTREACHED */ 1488 } 1489 1490 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1491 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1492 sizeof(corefilename), "process corefile name format string"); 1493 1494 /* 1495 * expand_name(name, uid, pid) 1496 * Expand the name described in corefilename, using name, uid, and pid. 1497 * corefilename is a printf-like string, with three format specifiers: 1498 * %N name of process ("name") 1499 * %P process id (pid) 1500 * %U user id (uid) 1501 * For example, "%N.core" is the default; they can be disabled completely 1502 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1503 * This is controlled by the sysctl variable kern.corefile (see above). 1504 */ 1505 1506 static char * 1507 expand_name(name, uid, pid) 1508 const char *name; uid_t uid; pid_t pid; { 1509 char *temp; 1510 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1511 int i, n; 1512 char *format = corefilename; 1513 size_t namelen; 1514 1515 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1516 if (temp == NULL) 1517 return NULL; 1518 namelen = strlen(name); 1519 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1520 int l; 1521 switch (format[i]) { 1522 case '%': /* Format character */ 1523 i++; 1524 switch (format[i]) { 1525 case '%': 1526 temp[n++] = '%'; 1527 break; 1528 case 'N': /* process name */ 1529 if ((n + namelen) > MAXPATHLEN) { 1530 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1531 pid, name, uid, temp, name); 1532 free(temp, M_TEMP); 1533 return NULL; 1534 } 1535 memcpy(temp+n, name, namelen); 1536 n += namelen; 1537 break; 1538 case 'P': /* process id */ 1539 l = sprintf(buf, "%u", pid); 1540 if ((n + l) > MAXPATHLEN) { 1541 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1542 pid, name, uid, temp, name); 1543 free(temp, M_TEMP); 1544 return NULL; 1545 } 1546 memcpy(temp+n, buf, l); 1547 n += l; 1548 break; 1549 case 'U': /* user id */ 1550 l = sprintf(buf, "%u", uid); 1551 if ((n + l) > MAXPATHLEN) { 1552 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1553 pid, name, uid, temp, name); 1554 free(temp, M_TEMP); 1555 return NULL; 1556 } 1557 memcpy(temp+n, buf, l); 1558 n += l; 1559 break; 1560 default: 1561 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1562 } 1563 break; 1564 default: 1565 temp[n++] = format[i]; 1566 } 1567 } 1568 temp[n] = '\0'; 1569 return temp; 1570 } 1571 1572 /* 1573 * Dump a process' core. The main routine does some 1574 * policy checking, and creates the name of the coredump; 1575 * then it passes on a vnode and a size limit to the process-specific 1576 * coredump routine if there is one; if there _is not_ one, it returns 1577 * ENOSYS; otherwise it returns the error from the process-specific routine. 1578 */ 1579 1580 static int 1581 coredump(p) 1582 register struct proc *p; 1583 { 1584 register struct vnode *vp; 1585 register struct ucred *cred = p->p_cred->pc_ucred; 1586 struct nameidata nd; 1587 struct vattr vattr; 1588 int error, error1; 1589 char *name; /* name of corefile */ 1590 off_t limit; 1591 1592 STOPEVENT(p, S_CORE, 0); 1593 1594 if ((sugid_coredump == 0) && p->p_flag & P_SUGID) 1595 return (EFAULT); 1596 1597 /* 1598 * Note that the bulk of limit checking is done after 1599 * the corefile is created. The exception is if the limit 1600 * for corefiles is 0, in which case we don't bother 1601 * creating the corefile at all. This layout means that 1602 * a corefile is truncated instead of not being created, 1603 * if it is larger than the limit. 1604 */ 1605 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1606 if (limit == 0) 1607 return 0; 1608 1609 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1610 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p); 1611 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1612 free(name, M_TEMP); 1613 if (error) 1614 return (error); 1615 vp = nd.ni_vp; 1616 1617 /* Don't dump to non-regular files or files with links. */ 1618 if (vp->v_type != VREG || 1619 VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) { 1620 error = EFAULT; 1621 goto out; 1622 } 1623 VATTR_NULL(&vattr); 1624 vattr.va_size = 0; 1625 VOP_LEASE(vp, p, cred, LEASE_WRITE); 1626 VOP_SETATTR(vp, &vattr, cred, p); 1627 p->p_acflag |= ACORE; 1628 1629 error = p->p_sysent->sv_coredump ? 1630 p->p_sysent->sv_coredump(p, vp, limit) : 1631 ENOSYS; 1632 1633 out: 1634 VOP_UNLOCK(vp, 0, p); 1635 error1 = vn_close(vp, FWRITE, cred, p); 1636 if (error == 0) 1637 error = error1; 1638 return (error); 1639 } 1640 1641 /* 1642 * Nonexistent system call-- signal process (may want to handle it). 1643 * Flag error in case process won't see signal immediately (blocked or ignored). 1644 */ 1645 #ifndef _SYS_SYSPROTO_H_ 1646 struct nosys_args { 1647 int dummy; 1648 }; 1649 #endif 1650 /* ARGSUSED */ 1651 int 1652 nosys(p, args) 1653 struct proc *p; 1654 struct nosys_args *args; 1655 { 1656 1657 psignal(p, SIGSYS); 1658 return (EINVAL); 1659 } 1660 1661 /* 1662 * Send a signal to a SIGIO or SIGURG to a process or process group using 1663 * stored credentials rather than those of the current process. 1664 */ 1665 void 1666 pgsigio(sigio, sig, checkctty) 1667 struct sigio *sigio; 1668 int sig, checkctty; 1669 { 1670 if (sigio == NULL) 1671 return; 1672 1673 if (sigio->sio_pgid > 0) { 1674 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1675 sigio->sio_proc)) 1676 psignal(sigio->sio_proc, sig); 1677 } else if (sigio->sio_pgid < 0) { 1678 struct proc *p; 1679 1680 for (p = sigio->sio_pgrp->pg_members.lh_first; p != NULL; 1681 p = p->p_pglist.le_next) 1682 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1683 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1684 psignal(p, sig); 1685 } 1686 } 1687