1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 39 * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $ 40 * $DragonFly: src/sys/kern/kern_sig.c,v 1.37 2005/06/06 15:02:28 dillon Exp $ 41 */ 42 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/sysproto.h> 49 #include <sys/signalvar.h> 50 #include <sys/resourcevar.h> 51 #include <sys/vnode.h> 52 #include <sys/event.h> 53 #include <sys/proc.h> 54 #include <sys/nlookup.h> 55 #include <sys/pioctl.h> 56 #include <sys/systm.h> 57 #include <sys/acct.h> 58 #include <sys/fcntl.h> 59 #include <sys/wait.h> 60 #include <sys/ktrace.h> 61 #include <sys/syslog.h> 62 #include <sys/stat.h> 63 #include <sys/sysent.h> 64 #include <sys/sysctl.h> 65 #include <sys/malloc.h> 66 #include <sys/unistd.h> 67 #include <sys/kern_syscall.h> 68 #include <sys/thread2.h> 69 70 71 #include <machine/ipl.h> 72 #include <machine/cpu.h> 73 #include <machine/smp.h> 74 75 static int coredump(struct proc *); 76 static char *expand_name(const char *, uid_t, pid_t); 77 static int killpg(int sig, int pgid, int all); 78 static int sig_ffs(sigset_t *set); 79 static int sigprop(int sig); 80 static void stop(struct proc *); 81 #ifdef SMP 82 static void signotify_remote(void *arg); 83 #endif 84 static int kern_sigtimedwait(sigset_t set, siginfo_t *info, 85 struct timespec *timeout); 86 87 static int filt_sigattach(struct knote *kn); 88 static void filt_sigdetach(struct knote *kn); 89 static int filt_signal(struct knote *kn, long hint); 90 91 struct filterops sig_filtops = 92 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 93 94 static int kern_logsigexit = 1; 95 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 96 &kern_logsigexit, 0, 97 "Log processes quitting on abnormal signals to syslog(3)"); 98 99 /* 100 * Can process p, with pcred pc, send the signal sig to process q? 101 */ 102 #define CANSIGNAL(q, sig) \ 103 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \ 104 ((sig) == SIGCONT && (q)->p_session == curproc->p_session)) 105 106 /* 107 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 108 */ 109 #define CANSIGIO(ruid, uc, q) \ 110 ((uc)->cr_uid == 0 || \ 111 (ruid) == (q)->p_ucred->cr_ruid || \ 112 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \ 113 (ruid) == (q)->p_ucred->cr_uid || \ 114 (uc)->cr_uid == (q)->p_ucred->cr_uid) 115 116 int sugid_coredump; 117 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 118 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 119 120 static int do_coredump = 1; 121 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 122 &do_coredump, 0, "Enable/Disable coredumps"); 123 124 /* 125 * Signal properties and actions. 126 * The array below categorizes the signals and their default actions 127 * according to the following properties: 128 */ 129 #define SA_KILL 0x01 /* terminates process by default */ 130 #define SA_CORE 0x02 /* ditto and coredumps */ 131 #define SA_STOP 0x04 /* suspend process */ 132 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 133 #define SA_IGNORE 0x10 /* ignore by default */ 134 #define SA_CONT 0x20 /* continue if suspended */ 135 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 136 #define SA_CKPT 0x80 /* checkpoint process */ 137 138 139 static int sigproptbl[NSIG] = { 140 SA_KILL, /* SIGHUP */ 141 SA_KILL, /* SIGINT */ 142 SA_KILL|SA_CORE, /* SIGQUIT */ 143 SA_KILL|SA_CORE, /* SIGILL */ 144 SA_KILL|SA_CORE, /* SIGTRAP */ 145 SA_KILL|SA_CORE, /* SIGABRT */ 146 SA_KILL|SA_CORE, /* SIGEMT */ 147 SA_KILL|SA_CORE, /* SIGFPE */ 148 SA_KILL, /* SIGKILL */ 149 SA_KILL|SA_CORE, /* SIGBUS */ 150 SA_KILL|SA_CORE, /* SIGSEGV */ 151 SA_KILL|SA_CORE, /* SIGSYS */ 152 SA_KILL, /* SIGPIPE */ 153 SA_KILL, /* SIGALRM */ 154 SA_KILL, /* SIGTERM */ 155 SA_IGNORE, /* SIGURG */ 156 SA_STOP, /* SIGSTOP */ 157 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 158 SA_IGNORE|SA_CONT, /* SIGCONT */ 159 SA_IGNORE, /* SIGCHLD */ 160 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 161 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 162 SA_IGNORE, /* SIGIO */ 163 SA_KILL, /* SIGXCPU */ 164 SA_KILL, /* SIGXFSZ */ 165 SA_KILL, /* SIGVTALRM */ 166 SA_KILL, /* SIGPROF */ 167 SA_IGNORE, /* SIGWINCH */ 168 SA_IGNORE, /* SIGINFO */ 169 SA_KILL, /* SIGUSR1 */ 170 SA_KILL, /* SIGUSR2 */ 171 SA_IGNORE, /* SIGTHR */ 172 SA_CKPT, /* SIGCKPT */ 173 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */ 174 SA_IGNORE, 175 SA_IGNORE, 176 SA_IGNORE, 177 SA_IGNORE, 178 SA_IGNORE, 179 SA_IGNORE, 180 SA_IGNORE, 181 SA_IGNORE, 182 SA_IGNORE, 183 SA_IGNORE, 184 SA_IGNORE, 185 SA_IGNORE, 186 SA_IGNORE, 187 SA_IGNORE, 188 SA_IGNORE, 189 SA_IGNORE, 190 SA_IGNORE, 191 SA_IGNORE, 192 SA_IGNORE, 193 SA_IGNORE, 194 SA_IGNORE, 195 SA_IGNORE, 196 SA_IGNORE, 197 SA_IGNORE, 198 SA_IGNORE, 199 SA_IGNORE, 200 SA_IGNORE, 201 SA_IGNORE, 202 SA_IGNORE, 203 SA_IGNORE, 204 205 }; 206 207 static __inline int 208 sigprop(int sig) 209 { 210 211 if (sig > 0 && sig < NSIG) 212 return (sigproptbl[_SIG_IDX(sig)]); 213 return (0); 214 } 215 216 static __inline int 217 sig_ffs(sigset_t *set) 218 { 219 int i; 220 221 for (i = 0; i < _SIG_WORDS; i++) 222 if (set->__bits[i]) 223 return (ffs(set->__bits[i]) + (i * 32)); 224 return (0); 225 } 226 227 int 228 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact) 229 { 230 struct thread *td = curthread; 231 struct proc *p = td->td_proc; 232 struct sigacts *ps = p->p_sigacts; 233 234 if (sig <= 0 || sig > _SIG_MAXSIG) 235 return (EINVAL); 236 237 if (oact) { 238 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 239 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 240 oact->sa_flags = 0; 241 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 242 oact->sa_flags |= SA_ONSTACK; 243 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 244 oact->sa_flags |= SA_RESTART; 245 if (SIGISMEMBER(ps->ps_sigreset, sig)) 246 oact->sa_flags |= SA_RESETHAND; 247 if (SIGISMEMBER(ps->ps_signodefer, sig)) 248 oact->sa_flags |= SA_NODEFER; 249 if (SIGISMEMBER(ps->ps_siginfo, sig)) 250 oact->sa_flags |= SA_SIGINFO; 251 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 252 oact->sa_flags |= SA_NOCLDSTOP; 253 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 254 oact->sa_flags |= SA_NOCLDWAIT; 255 } 256 if (act) { 257 if ((sig == SIGKILL || sig == SIGSTOP) && 258 act->sa_handler != SIG_DFL) 259 return (EINVAL); 260 261 /* 262 * Change setting atomically. 263 */ 264 crit_enter(); 265 266 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 267 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 268 if (act->sa_flags & SA_SIGINFO) { 269 ps->ps_sigact[_SIG_IDX(sig)] = 270 (__sighandler_t *)act->sa_sigaction; 271 SIGADDSET(ps->ps_siginfo, sig); 272 } else { 273 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 274 SIGDELSET(ps->ps_siginfo, sig); 275 } 276 if (!(act->sa_flags & SA_RESTART)) 277 SIGADDSET(ps->ps_sigintr, sig); 278 else 279 SIGDELSET(ps->ps_sigintr, sig); 280 if (act->sa_flags & SA_ONSTACK) 281 SIGADDSET(ps->ps_sigonstack, sig); 282 else 283 SIGDELSET(ps->ps_sigonstack, sig); 284 if (act->sa_flags & SA_RESETHAND) 285 SIGADDSET(ps->ps_sigreset, sig); 286 else 287 SIGDELSET(ps->ps_sigreset, sig); 288 if (act->sa_flags & SA_NODEFER) 289 SIGADDSET(ps->ps_signodefer, sig); 290 else 291 SIGDELSET(ps->ps_signodefer, sig); 292 if (sig == SIGCHLD) { 293 if (act->sa_flags & SA_NOCLDSTOP) 294 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 295 else 296 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 297 if (act->sa_flags & SA_NOCLDWAIT) { 298 /* 299 * Paranoia: since SA_NOCLDWAIT is implemented 300 * by reparenting the dying child to PID 1 (and 301 * trust it to reap the zombie), PID 1 itself 302 * is forbidden to set SA_NOCLDWAIT. 303 */ 304 if (p->p_pid == 1) 305 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 306 else 307 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 308 } else { 309 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 310 } 311 } 312 /* 313 * Set bit in p_sigignore for signals that are set to SIG_IGN, 314 * and for signals set to SIG_DFL where the default is to 315 * ignore. However, don't put SIGCONT in p_sigignore, as we 316 * have to restart the process. 317 */ 318 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 319 (sigprop(sig) & SA_IGNORE && 320 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 321 /* never to be seen again */ 322 SIGDELSET(p->p_siglist, sig); 323 if (sig != SIGCONT) 324 /* easier in psignal */ 325 SIGADDSET(p->p_sigignore, sig); 326 SIGDELSET(p->p_sigcatch, sig); 327 } else { 328 SIGDELSET(p->p_sigignore, sig); 329 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 330 SIGDELSET(p->p_sigcatch, sig); 331 else 332 SIGADDSET(p->p_sigcatch, sig); 333 } 334 335 crit_exit(); 336 } 337 return (0); 338 } 339 340 int 341 sigaction(struct sigaction_args *uap) 342 { 343 struct sigaction act, oact; 344 struct sigaction *actp, *oactp; 345 int error; 346 347 actp = (uap->act != NULL) ? &act : NULL; 348 oactp = (uap->oact != NULL) ? &oact : NULL; 349 if (actp) { 350 error = copyin(uap->act, actp, sizeof(act)); 351 if (error) 352 return (error); 353 } 354 error = kern_sigaction(uap->sig, actp, oactp); 355 if (oactp && !error) { 356 error = copyout(oactp, uap->oact, sizeof(oact)); 357 } 358 return (error); 359 } 360 361 /* 362 * Initialize signal state for process 0; 363 * set to ignore signals that are ignored by default. 364 */ 365 void 366 siginit(struct proc *p) 367 { 368 int i; 369 370 for (i = 1; i <= NSIG; i++) 371 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 372 SIGADDSET(p->p_sigignore, i); 373 } 374 375 /* 376 * Reset signals for an exec of the specified process. 377 */ 378 void 379 execsigs(struct proc *p) 380 { 381 struct sigacts *ps = p->p_sigacts; 382 int sig; 383 384 /* 385 * Reset caught signals. Held signals remain held 386 * through p_sigmask (unless they were caught, 387 * and are now ignored by default). 388 */ 389 while (SIGNOTEMPTY(p->p_sigcatch)) { 390 sig = sig_ffs(&p->p_sigcatch); 391 SIGDELSET(p->p_sigcatch, sig); 392 if (sigprop(sig) & SA_IGNORE) { 393 if (sig != SIGCONT) 394 SIGADDSET(p->p_sigignore, sig); 395 SIGDELSET(p->p_siglist, sig); 396 } 397 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 398 } 399 /* 400 * Reset stack state to the user stack. 401 * Clear set of signals caught on the signal stack. 402 */ 403 p->p_sigstk.ss_flags = SS_DISABLE; 404 p->p_sigstk.ss_size = 0; 405 p->p_sigstk.ss_sp = 0; 406 p->p_flag &= ~P_ALTSTACK; 407 /* 408 * Reset no zombies if child dies flag as Solaris does. 409 */ 410 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 411 } 412 413 /* 414 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc 415 * 416 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 417 * p == curproc. 418 */ 419 int 420 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) 421 { 422 struct thread *td = curthread; 423 struct proc *p = td->td_proc; 424 int error; 425 426 if (oset != NULL) 427 *oset = p->p_sigmask; 428 429 error = 0; 430 if (set != NULL) { 431 switch (how) { 432 case SIG_BLOCK: 433 SIG_CANTMASK(*set); 434 SIGSETOR(p->p_sigmask, *set); 435 break; 436 case SIG_UNBLOCK: 437 SIGSETNAND(p->p_sigmask, *set); 438 break; 439 case SIG_SETMASK: 440 SIG_CANTMASK(*set); 441 p->p_sigmask = *set; 442 break; 443 default: 444 error = EINVAL; 445 break; 446 } 447 } 448 return (error); 449 } 450 451 /* 452 * sigprocmask() - MP SAFE 453 */ 454 int 455 sigprocmask(struct sigprocmask_args *uap) 456 { 457 sigset_t set, oset; 458 sigset_t *setp, *osetp; 459 int error; 460 461 setp = (uap->set != NULL) ? &set : NULL; 462 osetp = (uap->oset != NULL) ? &oset : NULL; 463 if (setp) { 464 error = copyin(uap->set, setp, sizeof(set)); 465 if (error) 466 return (error); 467 } 468 error = kern_sigprocmask(uap->how, setp, osetp); 469 if (osetp && !error) { 470 error = copyout(osetp, uap->oset, sizeof(oset)); 471 } 472 return (error); 473 } 474 475 int 476 kern_sigpending(struct __sigset *set) 477 { 478 struct thread *td = curthread; 479 struct proc *p = td->td_proc; 480 481 *set = p->p_siglist; 482 483 return (0); 484 } 485 486 int 487 sigpending(struct sigpending_args *uap) 488 { 489 sigset_t set; 490 int error; 491 492 error = kern_sigpending(&set); 493 494 if (error == 0) 495 error = copyout(&set, uap->set, sizeof(set)); 496 return (error); 497 } 498 499 /* 500 * Suspend process until signal, providing mask to be set 501 * in the meantime. 502 */ 503 int 504 kern_sigsuspend(struct __sigset *set) 505 { 506 struct thread *td = curthread; 507 struct proc *p = td->td_proc; 508 struct sigacts *ps = p->p_sigacts; 509 510 /* 511 * When returning from sigsuspend, we want 512 * the old mask to be restored after the 513 * signal handler has finished. Thus, we 514 * save it here and mark the sigacts structure 515 * to indicate this. 516 */ 517 p->p_oldsigmask = p->p_sigmask; 518 p->p_flag |= P_OLDMASK; 519 520 SIG_CANTMASK(*set); 521 p->p_sigmask = *set; 522 while (tsleep(ps, PCATCH, "pause", 0) == 0) 523 /* void */; 524 /* always return EINTR rather than ERESTART... */ 525 return (EINTR); 526 } 527 528 /* 529 * Note nonstandard calling convention: libc stub passes mask, not 530 * pointer, to save a copyin. 531 */ 532 int 533 sigsuspend(struct sigsuspend_args *uap) 534 { 535 sigset_t mask; 536 int error; 537 538 error = copyin(uap->sigmask, &mask, sizeof(mask)); 539 if (error) 540 return (error); 541 542 error = kern_sigsuspend(&mask); 543 544 return (error); 545 } 546 547 int 548 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) 549 { 550 struct thread *td = curthread; 551 struct proc *p = td->td_proc; 552 553 if ((p->p_flag & P_ALTSTACK) == 0) 554 p->p_sigstk.ss_flags |= SS_DISABLE; 555 556 if (oss) 557 *oss = p->p_sigstk; 558 559 if (ss) { 560 if (ss->ss_flags & SS_DISABLE) { 561 if (p->p_sigstk.ss_flags & SS_ONSTACK) 562 return (EINVAL); 563 p->p_flag &= ~P_ALTSTACK; 564 p->p_sigstk.ss_flags = ss->ss_flags; 565 } else { 566 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 567 return (ENOMEM); 568 p->p_flag |= P_ALTSTACK; 569 p->p_sigstk = *ss; 570 } 571 } 572 573 return (0); 574 } 575 576 int 577 sigaltstack(struct sigaltstack_args *uap) 578 { 579 stack_t ss, oss; 580 int error; 581 582 if (uap->ss) { 583 error = copyin(uap->ss, &ss, sizeof(ss)); 584 if (error) 585 return (error); 586 } 587 588 error = kern_sigaltstack(uap->ss ? &ss : NULL, 589 uap->oss ? &oss : NULL); 590 591 if (error == 0 && uap->oss) 592 error = copyout(&oss, uap->oss, sizeof(*uap->oss)); 593 return (error); 594 } 595 596 /* 597 * Common code for kill process group/broadcast kill. 598 * cp is calling process. 599 */ 600 static int 601 killpg(int sig, int pgid, int all) 602 { 603 struct proc *cp = curproc; 604 struct proc *p; 605 struct pgrp *pgrp; 606 int nfound = 0; 607 608 if (all) { 609 /* 610 * broadcast 611 */ 612 FOREACH_PROC_IN_SYSTEM(p) { 613 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 614 p == cp || !CANSIGNAL(p, sig)) 615 continue; 616 nfound++; 617 if (sig) 618 psignal(p, sig); 619 } 620 } else { 621 if (pgid == 0) { 622 /* 623 * zero pgid means send to my process group. 624 */ 625 pgrp = cp->p_pgrp; 626 } else { 627 pgrp = pgfind(pgid); 628 if (pgrp == NULL) 629 return (ESRCH); 630 } 631 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 632 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 633 p->p_stat == SZOMB || 634 !CANSIGNAL(p, sig)) 635 continue; 636 nfound++; 637 if (sig) 638 psignal(p, sig); 639 } 640 } 641 return (nfound ? 0 : ESRCH); 642 } 643 644 int 645 kern_kill(int sig, int pid) 646 { 647 struct thread *td = curthread; 648 struct proc *p = td->td_proc; 649 650 if ((u_int)sig > _SIG_MAXSIG) 651 return (EINVAL); 652 if (pid > 0) { 653 /* kill single process */ 654 if ((p = pfind(pid)) == NULL) 655 return (ESRCH); 656 if (!CANSIGNAL(p, sig)) 657 return (EPERM); 658 if (sig) 659 psignal(p, sig); 660 return (0); 661 } 662 switch (pid) { 663 case -1: /* broadcast signal */ 664 return (killpg(sig, 0, 1)); 665 case 0: /* signal own process group */ 666 return (killpg(sig, 0, 0)); 667 default: /* negative explicit process group */ 668 return (killpg(sig, -pid, 0)); 669 } 670 /* NOTREACHED */ 671 } 672 673 int 674 kill(struct kill_args *uap) 675 { 676 int error; 677 678 error = kern_kill(uap->signum, uap->pid); 679 680 return (error); 681 } 682 683 /* 684 * Send a signal to a process group. 685 */ 686 void 687 gsignal(int pgid, int sig) 688 { 689 struct pgrp *pgrp; 690 691 if (pgid && (pgrp = pgfind(pgid))) 692 pgsignal(pgrp, sig, 0); 693 } 694 695 /* 696 * Send a signal to a process group. If checktty is 1, 697 * limit to members which have a controlling terminal. 698 */ 699 void 700 pgsignal(struct pgrp *pgrp, int sig, int checkctty) 701 { 702 struct proc *p; 703 704 if (pgrp) 705 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) 706 if (checkctty == 0 || p->p_flag & P_CONTROLT) 707 psignal(p, sig); 708 } 709 710 /* 711 * Send a signal caused by a trap to the current process. 712 * If it will be caught immediately, deliver it with correct code. 713 * Otherwise, post it normally. 714 */ 715 void 716 trapsignal(struct proc *p, int sig, u_long code) 717 { 718 struct sigacts *ps = p->p_sigacts; 719 720 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 721 !SIGISMEMBER(p->p_sigmask, sig)) { 722 p->p_stats->p_ru.ru_nsignals++; 723 #ifdef KTRACE 724 if (KTRPOINT(p->p_thread, KTR_PSIG)) 725 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 726 &p->p_sigmask, code); 727 #endif 728 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 729 &p->p_sigmask, code); 730 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 731 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 732 SIGADDSET(p->p_sigmask, sig); 733 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 734 /* 735 * See kern_sigaction() for origin of this code. 736 */ 737 SIGDELSET(p->p_sigcatch, sig); 738 if (sig != SIGCONT && 739 sigprop(sig) & SA_IGNORE) 740 SIGADDSET(p->p_sigignore, sig); 741 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 742 } 743 } else { 744 p->p_code = code; /* XXX for core dump/debugger */ 745 p->p_sig = sig; /* XXX to verify code */ 746 psignal(p, sig); 747 } 748 } 749 750 /* 751 * Send the signal to the process. If the signal has an action, the action 752 * is usually performed by the target process rather than the caller; we add 753 * the signal to the set of pending signals for the process. 754 * 755 * Exceptions: 756 * o When a stop signal is sent to a sleeping process that takes the 757 * default action, the process is stopped without awakening it. 758 * o SIGCONT restarts stopped processes (or puts them back to sleep) 759 * regardless of the signal action (eg, blocked or ignored). 760 * 761 * Other ignored signals are discarded immediately. 762 */ 763 764 /* 765 * temporary hack to allow checkpoint code to continue to 766 * be in a module for the moment 767 */ 768 769 void 770 psignal(struct proc *p, int sig) 771 { 772 int prop; 773 sig_t action; 774 775 if (sig > _SIG_MAXSIG || sig <= 0) { 776 printf("psignal: signal %d\n", sig); 777 panic("psignal signal number"); 778 } 779 780 crit_enter(); 781 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 782 crit_exit(); 783 784 prop = sigprop(sig); 785 786 /* 787 * If proc is traced, always give parent a chance; 788 * if signal event is tracked by procfs, give *that* 789 * a chance, as well. 790 */ 791 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 792 action = SIG_DFL; 793 } else { 794 /* 795 * If the signal is being ignored, 796 * then we forget about it immediately. 797 * (Note: we don't set SIGCONT in p_sigignore, 798 * and if it is set to SIG_IGN, 799 * action will be SIG_DFL here.) 800 */ 801 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 802 return; 803 if (SIGISMEMBER(p->p_sigmask, sig)) 804 action = SIG_HOLD; 805 else if (SIGISMEMBER(p->p_sigcatch, sig)) 806 action = SIG_CATCH; 807 else 808 action = SIG_DFL; 809 } 810 811 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 812 (p->p_flag & P_TRACED) == 0) { 813 p->p_nice = NZERO; 814 } 815 816 if (prop & SA_CONT) 817 SIG_STOPSIGMASK(p->p_siglist); 818 819 820 if (prop & SA_STOP) { 821 /* 822 * If sending a tty stop signal to a member of an orphaned 823 * process group, discard the signal here if the action 824 * is default; don't stop the process below if sleeping, 825 * and don't clear any pending SIGCONT. 826 */ 827 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 828 action == SIG_DFL) { 829 return; 830 } 831 SIG_CONTSIGMASK(p->p_siglist); 832 } 833 SIGADDSET(p->p_siglist, sig); 834 835 /* 836 * Defer further processing for signals which are held, 837 * except that stopped processes must be continued by SIGCONT. 838 */ 839 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) 840 return; 841 842 crit_enter(); 843 844 switch (p->p_stat) { 845 case SSLEEP: 846 /* 847 * If process is sleeping uninterruptibly 848 * we can't interrupt the sleep... the signal will 849 * be noticed when the process returns through 850 * trap() or syscall(). 851 */ 852 if ((p->p_flag & P_SINTR) == 0) 853 goto out; 854 /* 855 * Process is sleeping and traced... make it runnable 856 * so it can discover the signal in issignal() and stop 857 * for the parent. 858 */ 859 if (p->p_flag & P_TRACED) 860 goto run; 861 /* 862 * If SIGCONT is default (or ignored) and process is 863 * asleep, we are finished; the process should not 864 * be awakened. 865 */ 866 if ((prop & SA_CONT) && action == SIG_DFL) { 867 SIGDELSET(p->p_siglist, sig); 868 goto out; 869 } 870 /* 871 * When a sleeping process receives a stop 872 * signal, process immediately if possible. 873 * All other (caught or default) signals 874 * cause the process to run. 875 */ 876 if (prop & SA_STOP) { 877 if (action != SIG_DFL) 878 goto run; 879 /* 880 * If a child holding parent blocked, 881 * stopping could cause deadlock. 882 */ 883 if (p->p_flag & P_PPWAIT) 884 goto out; 885 SIGDELSET(p->p_siglist, sig); 886 p->p_xstat = sig; 887 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 888 psignal(p->p_pptr, SIGCHLD); 889 stop(p); 890 goto out; 891 } else { 892 goto run; 893 } 894 /*NOTREACHED*/ 895 case SSTOP: 896 /* 897 * If traced process is already stopped, 898 * then no further action is necessary. 899 */ 900 if (p->p_flag & P_TRACED) 901 goto out; 902 903 /* 904 * Kill signal always sets processes running. 905 */ 906 if (sig == SIGKILL) 907 goto run; 908 909 if (prop & SA_CONT) { 910 /* 911 * If SIGCONT is default (or ignored), we continue the 912 * process but don't leave the signal in p_siglist, as 913 * it has no further action. If SIGCONT is held, we 914 * continue the process and leave the signal in 915 * p_siglist. If the process catches SIGCONT, let it 916 * handle the signal itself. If it isn't waiting on 917 * an event, then it goes back to run state. 918 * Otherwise, process goes back to sleep state. 919 */ 920 if (action == SIG_DFL) 921 SIGDELSET(p->p_siglist, sig); 922 if (action == SIG_CATCH) 923 goto run; 924 if (p->p_wchan == 0) 925 goto run; 926 clrrunnable(p, SSLEEP); 927 goto out; 928 } 929 930 if (prop & SA_STOP) { 931 /* 932 * Already stopped, don't need to stop again. 933 * (If we did the shell could get confused.) 934 */ 935 SIGDELSET(p->p_siglist, sig); 936 goto out; 937 } 938 939 /* 940 * If process is sleeping interruptibly, then simulate a 941 * wakeup so that when it is continued, it will be made 942 * runnable and can look at the signal. But don't make 943 * the process runnable, leave it stopped. 944 */ 945 if (p->p_wchan && (p->p_flag & P_SINTR)) 946 unsleep(p->p_thread); 947 goto out; 948 default: 949 /* 950 * SRUN, SIDL, SZOMB do nothing with the signal, 951 * other than kicking ourselves if we are running. 952 * It will either never be noticed, or noticed very soon. 953 * 954 * Note that p_thread may be NULL or may not be completely 955 * initialized if the process is in the SIDL or SZOMB state. 956 * 957 * For SMP we may have to forward the request to another cpu. 958 * YYY the MP lock prevents the target process from moving 959 * to another cpu, see kern/kern_switch.c 960 * 961 * If the target thread is waiting on its message port, 962 * wakeup the target thread so it can check (or ignore) 963 * the new signal. YYY needs cleanup. 964 */ 965 #ifdef SMP 966 if (p == lwkt_preempted_proc()) { 967 signotify(); 968 } else if (p->p_stat == SRUN) { 969 struct thread *td = p->p_thread; 970 971 KASSERT(td != NULL, 972 ("pid %d NULL p_thread stat %d flags %08x", 973 p->p_pid, p->p_stat, p->p_flag)); 974 975 if (td->td_gd != mycpu) 976 lwkt_send_ipiq(td->td_gd, signotify_remote, p); 977 else if (td->td_msgport.mp_flags & MSGPORTF_WAITING) 978 lwkt_schedule(td); 979 } 980 #else 981 if (p == lwkt_preempted_proc()) { 982 signotify(); 983 } else if (p->p_stat == SRUN) { 984 struct thread *td = p->p_thread; 985 986 KASSERT(td != NULL, 987 ("pid %d NULL p_thread stat %d flags %08x", 988 p->p_pid, p->p_stat, p->p_flag)); 989 990 if (td->td_msgport.mp_flags & MSGPORTF_WAITING) 991 lwkt_schedule(td); 992 } 993 #endif 994 goto out; 995 } 996 /*NOTREACHED*/ 997 run: 998 setrunnable(p); 999 out: 1000 crit_exit(); 1001 } 1002 1003 #ifdef SMP 1004 1005 /* 1006 * This function is called via an IPI. We will be in a critical section but 1007 * the MP lock will NOT be held. Also note that by the time the ipi message 1008 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 1009 */ 1010 static void 1011 signotify_remote(void *arg) 1012 { 1013 struct proc *p = arg; 1014 1015 if (p == lwkt_preempted_proc()) { 1016 signotify(); 1017 } else { 1018 struct thread *td = p->p_thread; 1019 if (td->td_msgport.mp_flags & MSGPORTF_WAITING) 1020 lwkt_schedule(td); 1021 } 1022 } 1023 1024 #endif 1025 1026 static int 1027 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout) 1028 { 1029 sigset_t savedmask, set; 1030 struct proc *p = curproc; 1031 int error, sig, hz, timevalid = 0; 1032 struct timespec rts, ets, ts; 1033 struct timeval tv; 1034 1035 error = 0; 1036 sig = 0; 1037 SIG_CANTMASK(waitset); 1038 savedmask = p->p_sigmask; 1039 1040 if (timeout) { 1041 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 && 1042 timeout->tv_nsec < 1000000000) { 1043 timevalid = 1; 1044 getnanouptime(&rts); 1045 ets = rts; 1046 timespecadd(&ets, timeout); 1047 } 1048 } 1049 1050 for (;;) { 1051 set = p->p_siglist; 1052 SIGSETAND(set, waitset); 1053 if ((sig = sig_ffs(&set)) != 0) { 1054 SIGFILLSET(p->p_sigmask); 1055 SIGDELSET(p->p_sigmask, sig); 1056 SIG_CANTMASK(p->p_sigmask); 1057 sig = issignal(p); 1058 /* 1059 * It may be a STOP signal, in the case, issignal 1060 * returns 0, because we may stop there, and new 1061 * signal can come in, we should restart if we got 1062 * nothing. 1063 */ 1064 if (sig == 0) 1065 continue; 1066 else 1067 break; 1068 } 1069 1070 /* 1071 * Previous checking got nothing, and we retried but still 1072 * got nothing, we should return the error status. 1073 */ 1074 if (error) 1075 break; 1076 1077 /* 1078 * POSIX says this must be checked after looking for pending 1079 * signals. 1080 */ 1081 if (timeout) { 1082 if (!timevalid) { 1083 error = EINVAL; 1084 break; 1085 } 1086 getnanouptime(&rts); 1087 if (timespeccmp(&rts, &ets, >=)) { 1088 error = EAGAIN; 1089 break; 1090 } 1091 ts = ets; 1092 timespecsub(&ts, &rts); 1093 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1094 hz = tvtohz_high(&tv); 1095 } else 1096 hz = 0; 1097 1098 p->p_sigmask = savedmask; 1099 SIGSETNAND(p->p_sigmask, waitset); 1100 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz); 1101 if (timeout) { 1102 if (error == ERESTART) { 1103 /* can not restart a timeout wait. */ 1104 error = EINTR; 1105 } else if (error == EAGAIN) { 1106 /* will calculate timeout by ourself. */ 1107 error = 0; 1108 } 1109 } 1110 /* Retry ... */ 1111 } 1112 1113 p->p_sigmask = savedmask; 1114 if (sig) { 1115 error = 0; 1116 bzero(info, sizeof(*info)); 1117 info->si_signo = sig; 1118 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1119 } 1120 return (error); 1121 } 1122 1123 int 1124 sigtimedwait(struct sigtimedwait_args *uap) 1125 { 1126 struct timespec ts; 1127 struct timespec *timeout; 1128 sigset_t set; 1129 siginfo_t info; 1130 int error; 1131 1132 if (uap->timeout) { 1133 error = copyin(uap->timeout, &ts, sizeof(ts)); 1134 if (error) 1135 return (error); 1136 timeout = &ts; 1137 } else { 1138 timeout = NULL; 1139 } 1140 error = copyin(uap->set, &set, sizeof(set)); 1141 if (error) 1142 return (error); 1143 error = kern_sigtimedwait(set, &info, timeout); 1144 if (error) 1145 return (error); 1146 if (uap->info) 1147 error = copyout(&info, uap->info, sizeof(info)); 1148 /* Repost if we got an error. */ 1149 if (error) 1150 psignal(curproc, info.si_signo); 1151 else 1152 uap->sysmsg_result = info.si_signo; 1153 return (error); 1154 } 1155 1156 int 1157 sigwaitinfo(struct sigwaitinfo_args *uap) 1158 { 1159 siginfo_t info; 1160 sigset_t set; 1161 int error; 1162 1163 error = copyin(uap->set, &set, sizeof(set)); 1164 if (error) 1165 return (error); 1166 error = kern_sigtimedwait(set, &info, NULL); 1167 if (error) 1168 return (error); 1169 if (uap->info) 1170 error = copyout(&info, uap->info, sizeof(info)); 1171 /* Repost if we got an error. */ 1172 if (error) 1173 psignal(curproc, info.si_signo); 1174 else 1175 uap->sysmsg_result = info.si_signo; 1176 return (error); 1177 } 1178 1179 /* 1180 * If the current process has received a signal that would interrupt a 1181 * system call, return EINTR or ERESTART as appropriate. 1182 */ 1183 int 1184 iscaught(struct proc *p) 1185 { 1186 int sig; 1187 1188 if (p) { 1189 if ((sig = CURSIG(p)) != 0) { 1190 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1191 return (EINTR); 1192 return (ERESTART); 1193 } 1194 } 1195 return(EWOULDBLOCK); 1196 } 1197 1198 /* 1199 * If the current process has received a signal (should be caught or cause 1200 * termination, should interrupt current syscall), return the signal number. 1201 * Stop signals with default action are processed immediately, then cleared; 1202 * they aren't returned. This is checked after each entry to the system for 1203 * a syscall or trap (though this can usually be done without calling issignal 1204 * by checking the pending signal masks in the CURSIG macro.) The normal call 1205 * sequence is 1206 * 1207 * while (sig = CURSIG(curproc)) 1208 * postsig(sig); 1209 */ 1210 int 1211 issignal(struct proc *p) 1212 { 1213 sigset_t mask; 1214 int sig, prop; 1215 1216 for (;;) { 1217 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1218 1219 mask = p->p_siglist; 1220 SIGSETNAND(mask, p->p_sigmask); 1221 if (p->p_flag & P_PPWAIT) 1222 SIG_STOPSIGMASK(mask); 1223 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1224 return (0); 1225 sig = sig_ffs(&mask); 1226 1227 STOPEVENT(p, S_SIG, sig); 1228 1229 /* 1230 * We should see pending but ignored signals 1231 * only if P_TRACED was on when they were posted. 1232 */ 1233 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1234 SIGDELSET(p->p_siglist, sig); 1235 continue; 1236 } 1237 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1238 /* 1239 * If traced, always stop, and stay 1240 * stopped until released by the parent. 1241 */ 1242 p->p_xstat = sig; 1243 psignal(p->p_pptr, SIGCHLD); 1244 do { 1245 stop(p); 1246 mi_switch(p); 1247 } while (!trace_req(p) && p->p_flag & P_TRACED); 1248 1249 /* 1250 * If parent wants us to take the signal, 1251 * then it will leave it in p->p_xstat; 1252 * otherwise we just look for signals again. 1253 */ 1254 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1255 sig = p->p_xstat; 1256 if (sig == 0) 1257 continue; 1258 1259 /* 1260 * Put the new signal into p_siglist. If the 1261 * signal is being masked, look for other signals. 1262 */ 1263 SIGADDSET(p->p_siglist, sig); 1264 if (SIGISMEMBER(p->p_sigmask, sig)) 1265 continue; 1266 1267 /* 1268 * If the traced bit got turned off, go back up 1269 * to the top to rescan signals. This ensures 1270 * that p_sig* and ps_sigact are consistent. 1271 */ 1272 if ((p->p_flag & P_TRACED) == 0) 1273 continue; 1274 } 1275 1276 prop = sigprop(sig); 1277 1278 /* 1279 * Decide whether the signal should be returned. 1280 * Return the signal's number, or fall through 1281 * to clear it from the pending mask. 1282 */ 1283 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1284 1285 case (int)SIG_DFL: 1286 /* 1287 * Don't take default actions on system processes. 1288 */ 1289 if (p->p_pid <= 1) { 1290 #ifdef DIAGNOSTIC 1291 /* 1292 * Are you sure you want to ignore SIGSEGV 1293 * in init? XXX 1294 */ 1295 printf("Process (pid %lu) got signal %d\n", 1296 (u_long)p->p_pid, sig); 1297 #endif 1298 break; /* == ignore */ 1299 } 1300 1301 /* 1302 * Handle the in-kernel checkpoint action 1303 */ 1304 if (prop & SA_CKPT) { 1305 checkpoint_signal_handler(p); 1306 break; 1307 } 1308 1309 /* 1310 * If there is a pending stop signal to process 1311 * with default action, stop here, 1312 * then clear the signal. However, 1313 * if process is member of an orphaned 1314 * process group, ignore tty stop signals. 1315 */ 1316 if (prop & SA_STOP) { 1317 if (p->p_flag & P_TRACED || 1318 (p->p_pgrp->pg_jobc == 0 && 1319 prop & SA_TTYSTOP)) 1320 break; /* == ignore */ 1321 p->p_xstat = sig; 1322 stop(p); 1323 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1324 psignal(p->p_pptr, SIGCHLD); 1325 mi_switch(p); 1326 break; 1327 } else if (prop & SA_IGNORE) { 1328 /* 1329 * Except for SIGCONT, shouldn't get here. 1330 * Default action is to ignore; drop it. 1331 */ 1332 break; /* == ignore */ 1333 } else { 1334 return (sig); 1335 } 1336 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(struct proc *p) 1369 { 1370 p->p_stat = SSTOP; 1371 p->p_flag &= ~P_WAITED; 1372 wakeup((caddr_t)p->p_pptr); 1373 } 1374 1375 /* 1376 * Take the action for the specified signal 1377 * from the current set of pending signals. 1378 */ 1379 void 1380 postsig(int sig) 1381 { 1382 struct proc *p = curproc; 1383 struct sigacts *ps = p->p_sigacts; 1384 sig_t action; 1385 sigset_t returnmask; 1386 int code; 1387 1388 KASSERT(sig != 0, ("postsig")); 1389 1390 SIGDELSET(p->p_siglist, sig); 1391 action = ps->ps_sigact[_SIG_IDX(sig)]; 1392 #ifdef KTRACE 1393 if (KTRPOINT(p->p_thread, KTR_PSIG)) 1394 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1395 &p->p_oldsigmask : &p->p_sigmask, 0); 1396 #endif 1397 STOPEVENT(p, S_SIG, sig); 1398 1399 if (action == SIG_DFL) { 1400 /* 1401 * Default action, where the default is to kill 1402 * the process. (Other cases were ignored above.) 1403 */ 1404 sigexit(p, sig); 1405 /* NOTREACHED */ 1406 } else { 1407 /* 1408 * If we get here, the signal must be caught. 1409 */ 1410 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1411 ("postsig action")); 1412 /* 1413 * Set the new mask value and also defer further 1414 * occurrences of this signal. 1415 * 1416 * Special case: user has done a sigsuspend. Here the 1417 * current mask is not of interest, but rather the 1418 * mask from before the sigsuspend is what we want 1419 * restored after the signal processing is completed. 1420 */ 1421 crit_enter(); 1422 if (p->p_flag & P_OLDMASK) { 1423 returnmask = p->p_oldsigmask; 1424 p->p_flag &= ~P_OLDMASK; 1425 } else { 1426 returnmask = p->p_sigmask; 1427 } 1428 1429 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1430 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1431 SIGADDSET(p->p_sigmask, sig); 1432 1433 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1434 /* 1435 * See kern_sigaction() for origin of this code. 1436 */ 1437 SIGDELSET(p->p_sigcatch, sig); 1438 if (sig != SIGCONT && 1439 sigprop(sig) & SA_IGNORE) 1440 SIGADDSET(p->p_sigignore, sig); 1441 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1442 } 1443 crit_exit(); 1444 p->p_stats->p_ru.ru_nsignals++; 1445 if (p->p_sig != sig) { 1446 code = 0; 1447 } else { 1448 code = p->p_code; 1449 p->p_code = 0; 1450 p->p_sig = 0; 1451 } 1452 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1453 } 1454 } 1455 1456 /* 1457 * Kill the current process for stated reason. 1458 */ 1459 void 1460 killproc(struct proc *p, char *why) 1461 { 1462 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1463 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1464 psignal(p, SIGKILL); 1465 } 1466 1467 /* 1468 * Force the current process to exit with the specified signal, dumping core 1469 * if appropriate. We bypass the normal tests for masked and caught signals, 1470 * allowing unrecoverable failures to terminate the process without changing 1471 * signal state. Mark the accounting record with the signal termination. 1472 * If dumping core, save the signal number for the debugger. Calls exit and 1473 * does not return. 1474 */ 1475 void 1476 sigexit(struct proc *p, int sig) 1477 { 1478 p->p_acflag |= AXSIG; 1479 if (sigprop(sig) & SA_CORE) { 1480 p->p_sig = sig; 1481 /* 1482 * Log signals which would cause core dumps 1483 * (Log as LOG_INFO to appease those who don't want 1484 * these messages.) 1485 * XXX : Todo, as well as euid, write out ruid too 1486 */ 1487 if (coredump(p) == 0) 1488 sig |= WCOREFLAG; 1489 if (kern_logsigexit) 1490 log(LOG_INFO, 1491 "pid %d (%s), uid %d: exited on signal %d%s\n", 1492 p->p_pid, p->p_comm, 1493 p->p_ucred ? p->p_ucred->cr_uid : -1, 1494 sig &~ WCOREFLAG, 1495 sig & WCOREFLAG ? " (core dumped)" : ""); 1496 } 1497 exit1(W_EXITCODE(0, sig)); 1498 /* NOTREACHED */ 1499 } 1500 1501 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1502 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1503 sizeof(corefilename), "process corefile name format string"); 1504 1505 /* 1506 * expand_name(name, uid, pid) 1507 * Expand the name described in corefilename, using name, uid, and pid. 1508 * corefilename is a printf-like string, with three format specifiers: 1509 * %N name of process ("name") 1510 * %P process id (pid) 1511 * %U user id (uid) 1512 * For example, "%N.core" is the default; they can be disabled completely 1513 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1514 * This is controlled by the sysctl variable kern.corefile (see above). 1515 */ 1516 1517 static char * 1518 expand_name(const char *name, uid_t uid, pid_t pid) 1519 { 1520 char *temp; 1521 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1522 int i, n; 1523 char *format = corefilename; 1524 size_t namelen; 1525 1526 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1527 if (temp == NULL) 1528 return NULL; 1529 namelen = strlen(name); 1530 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1531 int l; 1532 switch (format[i]) { 1533 case '%': /* Format character */ 1534 i++; 1535 switch (format[i]) { 1536 case '%': 1537 temp[n++] = '%'; 1538 break; 1539 case 'N': /* process name */ 1540 if ((n + namelen) > 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, name, namelen); 1547 n += namelen; 1548 break; 1549 case 'P': /* process id */ 1550 l = sprintf(buf, "%u", pid); 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 case 'U': /* user id */ 1561 l = sprintf(buf, "%u", uid); 1562 if ((n + l) > MAXPATHLEN) { 1563 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1564 pid, name, uid, temp, name); 1565 free(temp, M_TEMP); 1566 return NULL; 1567 } 1568 memcpy(temp+n, buf, l); 1569 n += l; 1570 break; 1571 default: 1572 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1573 } 1574 break; 1575 default: 1576 temp[n++] = format[i]; 1577 } 1578 } 1579 temp[n] = '\0'; 1580 return temp; 1581 } 1582 1583 /* 1584 * Dump a process' core. The main routine does some 1585 * policy checking, and creates the name of the coredump; 1586 * then it passes on a vnode and a size limit to the process-specific 1587 * coredump routine if there is one; if there _is not_ one, it returns 1588 * ENOSYS; otherwise it returns the error from the process-specific routine. 1589 */ 1590 1591 static int 1592 coredump(struct proc *p) 1593 { 1594 struct vnode *vp; 1595 struct ucred *cred = p->p_ucred; 1596 struct thread *td = p->p_thread; 1597 struct flock lf; 1598 struct nlookupdata nd; 1599 struct vattr vattr; 1600 int error, error1; 1601 char *name; /* name of corefile */ 1602 off_t limit; 1603 1604 STOPEVENT(p, S_CORE, 0); 1605 1606 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 1607 return (EFAULT); 1608 1609 /* 1610 * Note that the bulk of limit checking is done after 1611 * the corefile is created. The exception is if the limit 1612 * for corefiles is 0, in which case we don't bother 1613 * creating the corefile at all. This layout means that 1614 * a corefile is truncated instead of not being created, 1615 * if it is larger than the limit. 1616 */ 1617 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1618 if (limit == 0) 1619 return EFBIG; 1620 1621 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1622 if (name == NULL) 1623 return (EINVAL); 1624 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP); 1625 if (error == 0) 1626 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1627 free(name, M_TEMP); 1628 if (error) { 1629 nlookup_done(&nd); 1630 return (error); 1631 } 1632 vp = nd.nl_open_vp; 1633 nd.nl_open_vp = NULL; 1634 nlookup_done(&nd); 1635 1636 VOP_UNLOCK(vp, 0, td); 1637 lf.l_whence = SEEK_SET; 1638 lf.l_start = 0; 1639 lf.l_len = 0; 1640 lf.l_type = F_WRLCK; 1641 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 1642 if (error) 1643 goto out2; 1644 1645 /* Don't dump to non-regular files or files with links. */ 1646 if (vp->v_type != VREG || 1647 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) { 1648 error = EFAULT; 1649 goto out1; 1650 } 1651 1652 VATTR_NULL(&vattr); 1653 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1654 vattr.va_size = 0; 1655 VOP_LEASE(vp, td, cred, LEASE_WRITE); 1656 VOP_SETATTR(vp, &vattr, cred, td); 1657 p->p_acflag |= ACORE; 1658 VOP_UNLOCK(vp, 0, td); 1659 1660 error = p->p_sysent->sv_coredump ? 1661 p->p_sysent->sv_coredump(p, vp, limit) : ENOSYS; 1662 1663 out1: 1664 lf.l_type = F_UNLCK; 1665 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 1666 out2: 1667 error1 = vn_close(vp, FWRITE, td); 1668 if (error == 0) 1669 error = error1; 1670 return (error); 1671 } 1672 1673 /* 1674 * Nonexistent system call-- signal process (may want to handle it). 1675 * Flag error in case process won't see signal immediately (blocked or ignored). 1676 */ 1677 /* ARGSUSED */ 1678 int 1679 nosys(struct nosys_args *args) 1680 { 1681 psignal(curproc, SIGSYS); 1682 return (EINVAL); 1683 } 1684 1685 /* 1686 * Send a SIGIO or SIGURG signal to a process or process group using 1687 * stored credentials rather than those of the current process. 1688 */ 1689 void 1690 pgsigio(struct sigio *sigio, int sig, int checkctty) 1691 { 1692 if (sigio == NULL) 1693 return; 1694 1695 if (sigio->sio_pgid > 0) { 1696 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1697 sigio->sio_proc)) 1698 psignal(sigio->sio_proc, sig); 1699 } else if (sigio->sio_pgid < 0) { 1700 struct proc *p; 1701 1702 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) 1703 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1704 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1705 psignal(p, sig); 1706 } 1707 } 1708 1709 static int 1710 filt_sigattach(struct knote *kn) 1711 { 1712 struct proc *p = curproc; 1713 1714 kn->kn_ptr.p_proc = p; 1715 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1716 1717 /* XXX lock the proc here while adding to the list? */ 1718 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 1719 1720 return (0); 1721 } 1722 1723 static void 1724 filt_sigdetach(struct knote *kn) 1725 { 1726 struct proc *p = kn->kn_ptr.p_proc; 1727 1728 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 1729 } 1730 1731 /* 1732 * signal knotes are shared with proc knotes, so we apply a mask to 1733 * the hint in order to differentiate them from process hints. This 1734 * could be avoided by using a signal-specific knote list, but probably 1735 * isn't worth the trouble. 1736 */ 1737 static int 1738 filt_signal(struct knote *kn, long hint) 1739 { 1740 if (hint & NOTE_SIGNAL) { 1741 hint &= ~NOTE_SIGNAL; 1742 1743 if (kn->kn_id == hint) 1744 kn->kn_data++; 1745 } 1746 return (kn->kn_data != 0); 1747 } 1748