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 1.27 2004/03/01 06:33:17 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/namei.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 69 70 #include <machine/ipl.h> 71 #include <machine/cpu.h> 72 #include <machine/smp.h> 73 74 static int coredump (struct proc *); 75 static char *expand_name (const char *, uid_t, pid_t); 76 static int killpg (int sig, int pgid, int all); 77 static int sig_ffs (sigset_t *set); 78 static int sigprop (int sig); 79 static void stop (struct proc *); 80 #ifdef SMP 81 static void signotify_remote(void *arg); 82 #endif 83 84 static int filt_sigattach(struct knote *kn); 85 static void filt_sigdetach(struct knote *kn); 86 static int filt_signal(struct knote *kn, long hint); 87 88 struct filterops sig_filtops = 89 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 90 91 static int kern_logsigexit = 1; 92 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 93 &kern_logsigexit, 0, 94 "Log processes quitting on abnormal signals to syslog(3)"); 95 96 /* 97 * Can process p, with pcred pc, send the signal sig to process q? 98 */ 99 #define CANSIGNAL(q, sig) \ 100 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \ 101 ((sig) == SIGCONT && (q)->p_session == curproc->p_session)) 102 103 /* 104 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 105 */ 106 #define CANSIGIO(ruid, uc, q) \ 107 ((uc)->cr_uid == 0 || \ 108 (ruid) == (q)->p_ucred->cr_ruid || \ 109 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \ 110 (ruid) == (q)->p_ucred->cr_uid || \ 111 (uc)->cr_uid == (q)->p_ucred->cr_uid) 112 113 int sugid_coredump; 114 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 115 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 116 117 static int do_coredump = 1; 118 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 119 &do_coredump, 0, "Enable/Disable coredumps"); 120 121 /* 122 * Signal properties and actions. 123 * The array below categorizes the signals and their default actions 124 * according to the following properties: 125 */ 126 #define SA_KILL 0x01 /* terminates process by default */ 127 #define SA_CORE 0x02 /* ditto and coredumps */ 128 #define SA_STOP 0x04 /* suspend process */ 129 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 130 #define SA_IGNORE 0x10 /* ignore by default */ 131 #define SA_CONT 0x20 /* continue if suspended */ 132 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 133 #define SA_CKPT 0x80 /* checkpoint process */ 134 135 136 static int sigproptbl[NSIG] = { 137 SA_KILL, /* SIGHUP */ 138 SA_KILL, /* SIGINT */ 139 SA_KILL|SA_CORE, /* SIGQUIT */ 140 SA_KILL|SA_CORE, /* SIGILL */ 141 SA_KILL|SA_CORE, /* SIGTRAP */ 142 SA_KILL|SA_CORE, /* SIGABRT */ 143 SA_KILL|SA_CORE, /* SIGEMT */ 144 SA_KILL|SA_CORE, /* SIGFPE */ 145 SA_KILL, /* SIGKILL */ 146 SA_KILL|SA_CORE, /* SIGBUS */ 147 SA_KILL|SA_CORE, /* SIGSEGV */ 148 SA_KILL|SA_CORE, /* SIGSYS */ 149 SA_KILL, /* SIGPIPE */ 150 SA_KILL, /* SIGALRM */ 151 SA_KILL, /* SIGTERM */ 152 SA_IGNORE, /* SIGURG */ 153 SA_STOP, /* SIGSTOP */ 154 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 155 SA_IGNORE|SA_CONT, /* SIGCONT */ 156 SA_IGNORE, /* SIGCHLD */ 157 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 158 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 159 SA_IGNORE, /* SIGIO */ 160 SA_KILL, /* SIGXCPU */ 161 SA_KILL, /* SIGXFSZ */ 162 SA_KILL, /* SIGVTALRM */ 163 SA_KILL, /* SIGPROF */ 164 SA_IGNORE, /* SIGWINCH */ 165 SA_IGNORE, /* SIGINFO */ 166 SA_KILL, /* SIGUSR1 */ 167 SA_KILL, /* SIGUSR2 */ 168 SA_IGNORE, /* SIGTHR */ 169 SA_CKPT, /* SIGCKPT */ 170 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */ 171 SA_IGNORE, 172 SA_IGNORE, 173 SA_IGNORE, 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, 201 202 }; 203 204 static __inline int 205 sigprop(int sig) 206 { 207 208 if (sig > 0 && sig < NSIG) 209 return (sigproptbl[_SIG_IDX(sig)]); 210 return (0); 211 } 212 213 static __inline int 214 sig_ffs(sigset_t *set) 215 { 216 int i; 217 218 for (i = 0; i < _SIG_WORDS; i++) 219 if (set->__bits[i]) 220 return (ffs(set->__bits[i]) + (i * 32)); 221 return (0); 222 } 223 224 int 225 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact) 226 { 227 struct thread *td = curthread; 228 struct proc *p = td->td_proc; 229 struct sigacts *ps = p->p_sigacts; 230 231 if (sig <= 0 || sig > _SIG_MAXSIG) 232 return (EINVAL); 233 234 if (oact) { 235 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 236 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 237 oact->sa_flags = 0; 238 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 239 oact->sa_flags |= SA_ONSTACK; 240 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 241 oact->sa_flags |= SA_RESTART; 242 if (SIGISMEMBER(ps->ps_sigreset, sig)) 243 oact->sa_flags |= SA_RESETHAND; 244 if (SIGISMEMBER(ps->ps_signodefer, sig)) 245 oact->sa_flags |= SA_NODEFER; 246 if (SIGISMEMBER(ps->ps_siginfo, sig)) 247 oact->sa_flags |= SA_SIGINFO; 248 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 249 oact->sa_flags |= SA_NOCLDSTOP; 250 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 251 oact->sa_flags |= SA_NOCLDWAIT; 252 } 253 if (act) { 254 if ((sig == SIGKILL || sig == SIGSTOP) && 255 act->sa_handler != SIG_DFL) 256 return (EINVAL); 257 258 /* 259 * Change setting atomically. 260 */ 261 (void) splhigh(); 262 263 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 264 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 265 if (act->sa_flags & SA_SIGINFO) { 266 ps->ps_sigact[_SIG_IDX(sig)] = 267 (__sighandler_t *)act->sa_sigaction; 268 SIGADDSET(ps->ps_siginfo, sig); 269 } else { 270 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 271 SIGDELSET(ps->ps_siginfo, sig); 272 } 273 if (!(act->sa_flags & SA_RESTART)) 274 SIGADDSET(ps->ps_sigintr, sig); 275 else 276 SIGDELSET(ps->ps_sigintr, sig); 277 if (act->sa_flags & SA_ONSTACK) 278 SIGADDSET(ps->ps_sigonstack, sig); 279 else 280 SIGDELSET(ps->ps_sigonstack, sig); 281 if (act->sa_flags & SA_RESETHAND) 282 SIGADDSET(ps->ps_sigreset, sig); 283 else 284 SIGDELSET(ps->ps_sigreset, sig); 285 if (act->sa_flags & SA_NODEFER) 286 SIGADDSET(ps->ps_signodefer, sig); 287 else 288 SIGDELSET(ps->ps_signodefer, sig); 289 if (sig == SIGCHLD) { 290 if (act->sa_flags & SA_NOCLDSTOP) 291 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 292 else 293 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 294 if (act->sa_flags & SA_NOCLDWAIT) { 295 /* 296 * Paranoia: since SA_NOCLDWAIT is implemented 297 * by reparenting the dying child to PID 1 (and 298 * trust it to reap the zombie), PID 1 itself 299 * is forbidden to set SA_NOCLDWAIT. 300 */ 301 if (p->p_pid == 1) 302 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 303 else 304 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 305 } else 306 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 307 } 308 /* 309 * Set bit in p_sigignore for signals that are set to SIG_IGN, 310 * and for signals set to SIG_DFL where the default is to 311 * ignore. However, don't put SIGCONT in p_sigignore, as we 312 * have to restart the process. 313 */ 314 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 315 (sigprop(sig) & SA_IGNORE && 316 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 317 /* never to be seen again */ 318 SIGDELSET(p->p_siglist, sig); 319 if (sig != SIGCONT) 320 /* easier in psignal */ 321 SIGADDSET(p->p_sigignore, sig); 322 SIGDELSET(p->p_sigcatch, sig); 323 } else { 324 SIGDELSET(p->p_sigignore, sig); 325 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 326 SIGDELSET(p->p_sigcatch, sig); 327 else 328 SIGADDSET(p->p_sigcatch, sig); 329 } 330 331 (void) spl0(); 332 } 333 return (0); 334 } 335 336 int 337 sigaction(struct sigaction_args *uap) 338 { 339 struct sigaction act, oact; 340 struct sigaction *actp, *oactp; 341 int error; 342 343 actp = (uap->act != NULL) ? &act : NULL; 344 oactp = (uap->oact != NULL) ? &oact : NULL; 345 if (actp) { 346 error = copyin(uap->act, actp, sizeof(act)); 347 if (error) 348 return (error); 349 } 350 error = kern_sigaction(uap->sig, actp, oactp); 351 if (oactp && !error) { 352 error = copyout(oactp, uap->oact, sizeof(oact)); 353 } 354 return (error); 355 } 356 357 /* 358 * Initialize signal state for process 0; 359 * set to ignore signals that are ignored by default. 360 */ 361 void 362 siginit(p) 363 struct proc *p; 364 { 365 int i; 366 367 for (i = 1; i <= NSIG; i++) 368 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 369 SIGADDSET(p->p_sigignore, i); 370 } 371 372 /* 373 * Reset signals for an exec of the specified process. 374 */ 375 void 376 execsigs(p) 377 struct proc *p; 378 { 379 struct sigacts *ps = p->p_sigacts; 380 int sig; 381 382 /* 383 * Reset caught signals. Held signals remain held 384 * through p_sigmask (unless they were caught, 385 * and are now ignored by default). 386 */ 387 while (SIGNOTEMPTY(p->p_sigcatch)) { 388 sig = sig_ffs(&p->p_sigcatch); 389 SIGDELSET(p->p_sigcatch, sig); 390 if (sigprop(sig) & SA_IGNORE) { 391 if (sig != SIGCONT) 392 SIGADDSET(p->p_sigignore, sig); 393 SIGDELSET(p->p_siglist, sig); 394 } 395 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 396 } 397 /* 398 * Reset stack state to the user stack. 399 * Clear set of signals caught on the signal stack. 400 */ 401 p->p_sigstk.ss_flags = SS_DISABLE; 402 p->p_sigstk.ss_size = 0; 403 p->p_sigstk.ss_sp = 0; 404 p->p_flag &= ~P_ALTSTACK; 405 /* 406 * Reset no zombies if child dies flag as Solaris does. 407 */ 408 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 409 } 410 411 /* 412 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc 413 * 414 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 415 * p == curproc. Also remember that in order to remain MP SAFE 416 * no spl*() calls may be made. 417 */ 418 int 419 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) 420 { 421 struct thread *td = curthread; 422 struct proc *p = td->td_proc; 423 int error; 424 425 if (oset != NULL) 426 *oset = p->p_sigmask; 427 428 error = 0; 429 if (set != NULL) { 430 switch (how) { 431 case SIG_BLOCK: 432 SIG_CANTMASK(*set); 433 SIGSETOR(p->p_sigmask, *set); 434 break; 435 case SIG_UNBLOCK: 436 SIGSETNAND(p->p_sigmask, *set); 437 break; 438 case SIG_SETMASK: 439 SIG_CANTMASK(*set); 440 p->p_sigmask = *set; 441 break; 442 default: 443 error = EINVAL; 444 break; 445 } 446 } 447 return (error); 448 } 449 450 /* 451 * sigprocmask() - MP SAFE 452 */ 453 int 454 sigprocmask(struct sigprocmask_args *uap) 455 { 456 sigset_t set, oset; 457 sigset_t *setp, *osetp; 458 int error; 459 460 setp = (uap->set != NULL) ? &set : NULL; 461 osetp = (uap->oset != NULL) ? &oset : NULL; 462 if (setp) { 463 error = copyin(uap->set, setp, sizeof(set)); 464 if (error) 465 return (error); 466 } 467 error = kern_sigprocmask(uap->how, setp, osetp); 468 if (osetp && !error) { 469 error = copyout(osetp, uap->oset, sizeof(oset)); 470 } 471 return (error); 472 } 473 474 int 475 kern_sigpending(struct __sigset *set) 476 { 477 struct thread *td = curthread; 478 struct proc *p = td->td_proc; 479 480 *set = p->p_siglist; 481 482 return (0); 483 } 484 485 int 486 sigpending(struct sigpending_args *uap) 487 { 488 sigset_t set; 489 int error; 490 491 error = kern_sigpending(&set); 492 493 if (error == 0) 494 error = copyout(&set, uap->set, sizeof(set)); 495 return (error); 496 } 497 498 /* 499 * Suspend process until signal, providing mask to be set 500 * in the meantime. 501 */ 502 int 503 kern_sigsuspend(struct __sigset *set) 504 { 505 struct thread *td = curthread; 506 struct proc *p = td->td_proc; 507 struct sigacts *ps = p->p_sigacts; 508 509 /* 510 * When returning from sigsuspend, we want 511 * the old mask to be restored after the 512 * signal handler has finished. Thus, we 513 * save it here and mark the sigacts structure 514 * to indicate this. 515 */ 516 p->p_oldsigmask = p->p_sigmask; 517 p->p_flag |= P_OLDMASK; 518 519 SIG_CANTMASK(*set); 520 p->p_sigmask = *set; 521 while (tsleep(ps, PCATCH, "pause", 0) == 0) 522 /* void */; 523 /* always return EINTR rather than ERESTART... */ 524 return (EINTR); 525 } 526 527 /* 528 * Note nonstandard calling convention: libc stub passes mask, not 529 * pointer, to save a copyin. 530 */ 531 int 532 sigsuspend(struct sigsuspend_args *uap) 533 { 534 sigset_t mask; 535 int error; 536 537 error = copyin(uap->sigmask, &mask, sizeof(mask)); 538 if (error) 539 return (error); 540 541 error = kern_sigsuspend(&mask); 542 543 return (error); 544 } 545 546 int 547 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) 548 { 549 struct thread *td = curthread; 550 struct proc *p = td->td_proc; 551 552 if ((p->p_flag & P_ALTSTACK) == 0) 553 p->p_sigstk.ss_flags |= SS_DISABLE; 554 555 if (oss) 556 *oss = p->p_sigstk; 557 558 if (ss) { 559 if (ss->ss_flags & SS_DISABLE) { 560 if (p->p_sigstk.ss_flags & SS_ONSTACK) 561 return (EINVAL); 562 p->p_flag &= ~P_ALTSTACK; 563 p->p_sigstk.ss_flags = ss->ss_flags; 564 } else { 565 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 566 return (ENOMEM); 567 p->p_flag |= P_ALTSTACK; 568 p->p_sigstk = *ss; 569 } 570 } 571 572 return (0); 573 } 574 575 int 576 sigaltstack(struct sigaltstack_args *uap) 577 { 578 stack_t ss, oss; 579 int error; 580 581 if (uap->ss) { 582 error = copyin(uap->ss, &ss, sizeof(ss)); 583 if (error) 584 return (error); 585 } 586 587 error = kern_sigaltstack(uap->ss ? &ss : NULL, 588 uap->oss ? &oss : NULL); 589 590 if (error == 0 && uap->oss) 591 error = copyout(&oss, uap->oss, sizeof(*uap->oss)); 592 return (error); 593 } 594 595 /* 596 * Common code for kill process group/broadcast kill. 597 * cp is calling process. 598 */ 599 static int 600 killpg(int sig, int pgid, int all) 601 { 602 struct proc *cp = curproc; 603 struct proc *p; 604 struct pgrp *pgrp; 605 int nfound = 0; 606 607 if (all) 608 /* 609 * broadcast 610 */ 611 FOREACH_PROC_IN_SYSTEM(p) { 612 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 613 p == cp || !CANSIGNAL(p, sig)) 614 continue; 615 nfound++; 616 if (sig) 617 psignal(p, sig); 618 } 619 else { 620 if (pgid == 0) 621 /* 622 * zero pgid means send to my process group. 623 */ 624 pgrp = cp->p_pgrp; 625 else { 626 pgrp = pgfind(pgid); 627 if (pgrp == NULL) 628 return (ESRCH); 629 } 630 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 631 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 632 p->p_stat == SZOMB || 633 !CANSIGNAL(p, sig)) 634 continue; 635 nfound++; 636 if (sig) 637 psignal(p, sig); 638 } 639 } 640 return (nfound ? 0 : ESRCH); 641 } 642 643 int 644 kern_kill(int sig, int pid) 645 { 646 struct thread *td = curthread; 647 struct proc *p = td->td_proc; 648 649 if ((u_int)sig > _SIG_MAXSIG) 650 return (EINVAL); 651 if (pid > 0) { 652 /* kill single process */ 653 if ((p = pfind(pid)) == NULL) 654 return (ESRCH); 655 if (!CANSIGNAL(p, sig)) 656 return (EPERM); 657 if (sig) 658 psignal(p, sig); 659 return (0); 660 } 661 switch (pid) { 662 case -1: /* broadcast signal */ 663 return (killpg(sig, 0, 1)); 664 case 0: /* signal own process group */ 665 return (killpg(sig, 0, 0)); 666 default: /* negative explicit process group */ 667 return (killpg(sig, -pid, 0)); 668 } 669 /* NOTREACHED */ 670 } 671 672 int 673 kill(struct kill_args *uap) 674 { 675 int error; 676 677 error = kern_kill(uap->signum, uap->pid); 678 679 return (error); 680 } 681 682 /* 683 * Send a signal to a process group. 684 */ 685 void 686 gsignal(int pgid, int sig) 687 { 688 struct pgrp *pgrp; 689 690 if (pgid && (pgrp = pgfind(pgid))) 691 pgsignal(pgrp, sig, 0); 692 } 693 694 /* 695 * Send a signal to a process group. If checktty is 1, 696 * limit to members which have a controlling terminal. 697 */ 698 void 699 pgsignal(pgrp, sig, checkctty) 700 struct pgrp *pgrp; 701 int sig, checkctty; 702 { 703 struct proc *p; 704 705 if (pgrp) 706 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) 707 if (checkctty == 0 || p->p_flag & P_CONTROLT) 708 psignal(p, sig); 709 } 710 711 /* 712 * Send a signal caused by a trap to the current process. 713 * If it will be caught immediately, deliver it with correct code. 714 * Otherwise, post it normally. 715 */ 716 void 717 trapsignal(p, sig, code) 718 struct proc *p; 719 int sig; 720 u_long code; 721 { 722 struct sigacts *ps = p->p_sigacts; 723 724 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 725 !SIGISMEMBER(p->p_sigmask, sig)) { 726 p->p_stats->p_ru.ru_nsignals++; 727 #ifdef KTRACE 728 if (KTRPOINT(p->p_thread, KTR_PSIG)) 729 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 730 &p->p_sigmask, code); 731 #endif 732 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 733 &p->p_sigmask, code); 734 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 735 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 736 SIGADDSET(p->p_sigmask, sig); 737 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 738 /* 739 * See kern_sigaction() for origin of this code. 740 */ 741 SIGDELSET(p->p_sigcatch, sig); 742 if (sig != SIGCONT && 743 sigprop(sig) & SA_IGNORE) 744 SIGADDSET(p->p_sigignore, sig); 745 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 746 } 747 } else { 748 p->p_code = code; /* XXX for core dump/debugger */ 749 p->p_sig = sig; /* XXX to verify code */ 750 psignal(p, sig); 751 } 752 } 753 754 /* 755 * Send the signal to the process. If the signal has an action, the action 756 * is usually performed by the target process rather than the caller; we add 757 * the signal to the set of pending signals for the process. 758 * 759 * Exceptions: 760 * o When a stop signal is sent to a sleeping process that takes the 761 * default action, the process is stopped without awakening it. 762 * o SIGCONT restarts stopped processes (or puts them back to sleep) 763 * regardless of the signal action (eg, blocked or ignored). 764 * 765 * Other ignored signals are discarded immediately. 766 */ 767 768 /* 769 * temporary hack to allow checkpoint code to continue to 770 * be in a module for the moment 771 */ 772 773 static proc_func_t ckpt_func; 774 775 proc_func_t 776 register_ckpt_func(proc_func_t func) 777 { 778 proc_func_t old_func; 779 780 old_func = ckpt_func; 781 ckpt_func = func; 782 return (old_func); 783 } 784 785 void 786 psignal(p, sig) 787 struct proc *p; 788 int sig; 789 { 790 int s, prop; 791 sig_t action; 792 793 if (sig > _SIG_MAXSIG || sig <= 0) { 794 printf("psignal: signal %d\n", sig); 795 panic("psignal signal number"); 796 } 797 798 s = splhigh(); 799 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 800 splx(s); 801 802 prop = sigprop(sig); 803 804 /* 805 * If proc is traced, always give parent a chance; 806 * if signal event is tracked by procfs, give *that* 807 * a chance, as well. 808 */ 809 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) 810 action = SIG_DFL; 811 else { 812 /* 813 * If the signal is being ignored, 814 * then we forget about it immediately. 815 * (Note: we don't set SIGCONT in p_sigignore, 816 * and if it is set to SIG_IGN, 817 * action will be SIG_DFL here.) 818 */ 819 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 820 return; 821 if (SIGISMEMBER(p->p_sigmask, sig)) 822 action = SIG_HOLD; 823 else if (SIGISMEMBER(p->p_sigcatch, sig)) 824 action = SIG_CATCH; 825 else 826 action = SIG_DFL; 827 } 828 829 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 830 (p->p_flag & P_TRACED) == 0) 831 p->p_nice = NZERO; 832 833 if (prop & SA_CONT) 834 SIG_STOPSIGMASK(p->p_siglist); 835 836 837 if (prop & SA_STOP) { 838 /* 839 * If sending a tty stop signal to a member of an orphaned 840 * process group, discard the signal here if the action 841 * is default; don't stop the process below if sleeping, 842 * and don't clear any pending SIGCONT. 843 */ 844 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 845 action == SIG_DFL) 846 return; 847 SIG_CONTSIGMASK(p->p_siglist); 848 } 849 SIGADDSET(p->p_siglist, sig); 850 851 /* 852 * Defer further processing for signals which are held, 853 * except that stopped processes must be continued by SIGCONT. 854 */ 855 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) 856 return; 857 s = splhigh(); 858 switch (p->p_stat) { 859 860 case SSLEEP: 861 /* 862 * If process is sleeping uninterruptibly 863 * we can't interrupt the sleep... the signal will 864 * be noticed when the process returns through 865 * trap() or syscall(). 866 */ 867 if ((p->p_flag & P_SINTR) == 0) 868 goto out; 869 /* 870 * Process is sleeping and traced... make it runnable 871 * so it can discover the signal in issignal() and stop 872 * for the parent. 873 */ 874 if (p->p_flag & P_TRACED) 875 goto run; 876 /* 877 * If SIGCONT is default (or ignored) and process is 878 * asleep, we are finished; the process should not 879 * be awakened. 880 */ 881 if ((prop & SA_CONT) && action == SIG_DFL) { 882 SIGDELSET(p->p_siglist, sig); 883 goto out; 884 } 885 /* 886 * When a sleeping process receives a stop 887 * signal, process immediately if possible. 888 * All other (caught or default) signals 889 * cause the process to run. 890 */ 891 if (prop & SA_STOP) { 892 if (action != SIG_DFL) 893 goto run; 894 /* 895 * If a child holding parent blocked, 896 * stopping could cause deadlock. 897 */ 898 if (p->p_flag & P_PPWAIT) 899 goto out; 900 SIGDELSET(p->p_siglist, sig); 901 p->p_xstat = sig; 902 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 903 psignal(p->p_pptr, SIGCHLD); 904 stop(p); 905 goto out; 906 } else 907 goto run; 908 /*NOTREACHED*/ 909 910 case SSTOP: 911 /* 912 * If traced process is already stopped, 913 * then no further action is necessary. 914 */ 915 if (p->p_flag & P_TRACED) 916 goto out; 917 918 /* 919 * Kill signal always sets processes running. 920 */ 921 if (sig == SIGKILL) 922 goto run; 923 924 if (prop & SA_CONT) { 925 /* 926 * If SIGCONT is default (or ignored), we continue the 927 * process but don't leave the signal in p_siglist, as 928 * it has no further action. If SIGCONT is held, we 929 * continue the process and leave the signal in 930 * p_siglist. If the process catches SIGCONT, let it 931 * handle the signal itself. If it isn't waiting on 932 * an event, then it goes back to run state. 933 * Otherwise, process goes back to sleep state. 934 */ 935 if (action == SIG_DFL) 936 SIGDELSET(p->p_siglist, sig); 937 if (action == SIG_CATCH) 938 goto run; 939 if (p->p_wchan == 0) 940 goto run; 941 clrrunnable(p, SSLEEP); 942 goto out; 943 } 944 945 if (prop & SA_STOP) { 946 /* 947 * Already stopped, don't need to stop again. 948 * (If we did the shell could get confused.) 949 */ 950 SIGDELSET(p->p_siglist, sig); 951 goto out; 952 } 953 954 /* 955 * If process is sleeping interruptibly, then simulate a 956 * wakeup so that when it is continued, it will be made 957 * runnable and can look at the signal. But don't make 958 * the process runnable, leave it stopped. 959 */ 960 if (p->p_wchan && (p->p_flag & P_SINTR)) 961 unsleep(p->p_thread); 962 goto out; 963 964 default: 965 /* 966 * SRUN, SIDL, SZOMB do nothing with the signal, 967 * other than kicking ourselves if we are running. 968 * It will either never be noticed, or noticed very soon. 969 * 970 * For SMP we may have to forward the request to another cpu. 971 * YYY the MP lock prevents the target process from moving 972 * to another cpu, see kern/kern_switch.c 973 */ 974 #ifdef SMP 975 if (p == lwkt_preempted_proc()) { 976 signotify(); 977 } else { 978 struct thread *td = p->p_thread; 979 980 if (td->td_gd != mycpu) 981 lwkt_send_ipiq(td->td_gd, signotify_remote, p); 982 } 983 #else 984 if (p == lwkt_preempted_proc()) 985 signotify(); 986 #endif 987 goto out; 988 } 989 /*NOTREACHED*/ 990 run: 991 setrunnable(p); 992 out: 993 splx(s); 994 } 995 996 #ifdef SMP 997 998 /* 999 * This function is called via an IPI. We will be in a critical section but 1000 * the MP lock will NOT be held. Also note that by the time the ipi message 1001 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 1002 */ 1003 static void 1004 signotify_remote(void *arg) 1005 { 1006 struct proc *p = arg; 1007 if (p == lwkt_preempted_proc()) 1008 signotify(); 1009 } 1010 1011 #endif 1012 1013 /* 1014 * If the current process has received a signal that would interrupt a 1015 * system call, return EINTR or ERESTART as appropriate. 1016 */ 1017 int 1018 iscaught(struct proc *p) 1019 { 1020 int sig; 1021 1022 if (p) { 1023 if ((sig = CURSIG(p)) != 0) { 1024 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1025 return (EINTR); 1026 return (ERESTART); 1027 } 1028 } 1029 return(EWOULDBLOCK); 1030 } 1031 1032 /* 1033 * If the current process has received a signal (should be caught or cause 1034 * termination, should interrupt current syscall), return the signal number. 1035 * Stop signals with default action are processed immediately, then cleared; 1036 * they aren't returned. This is checked after each entry to the system for 1037 * a syscall or trap (though this can usually be done without calling issignal 1038 * by checking the pending signal masks in the CURSIG macro.) The normal call 1039 * sequence is 1040 * 1041 * while (sig = CURSIG(curproc)) 1042 * postsig(sig); 1043 */ 1044 int 1045 issignal(p) 1046 struct proc *p; 1047 { 1048 sigset_t mask; 1049 int sig, prop; 1050 1051 for (;;) { 1052 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1053 1054 mask = p->p_siglist; 1055 SIGSETNAND(mask, p->p_sigmask); 1056 if (p->p_flag & P_PPWAIT) 1057 SIG_STOPSIGMASK(mask); 1058 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1059 return (0); 1060 sig = sig_ffs(&mask); 1061 1062 STOPEVENT(p, S_SIG, sig); 1063 1064 /* 1065 * We should see pending but ignored signals 1066 * only if P_TRACED was on when they were posted. 1067 */ 1068 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1069 SIGDELSET(p->p_siglist, sig); 1070 continue; 1071 } 1072 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1073 /* 1074 * If traced, always stop, and stay 1075 * stopped until released by the parent. 1076 */ 1077 p->p_xstat = sig; 1078 psignal(p->p_pptr, SIGCHLD); 1079 do { 1080 stop(p); 1081 mi_switch(); 1082 } while (!trace_req(p) && p->p_flag & P_TRACED); 1083 1084 /* 1085 * If parent wants us to take the signal, 1086 * then it will leave it in p->p_xstat; 1087 * otherwise we just look for signals again. 1088 */ 1089 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1090 sig = p->p_xstat; 1091 if (sig == 0) 1092 continue; 1093 1094 /* 1095 * Put the new signal into p_siglist. If the 1096 * signal is being masked, look for other signals. 1097 */ 1098 SIGADDSET(p->p_siglist, sig); 1099 if (SIGISMEMBER(p->p_sigmask, sig)) 1100 continue; 1101 1102 /* 1103 * If the traced bit got turned off, go back up 1104 * to the top to rescan signals. This ensures 1105 * that p_sig* and ps_sigact are consistent. 1106 */ 1107 if ((p->p_flag & P_TRACED) == 0) 1108 continue; 1109 } 1110 1111 prop = sigprop(sig); 1112 1113 /* 1114 * Decide whether the signal should be returned. 1115 * Return the signal's number, or fall through 1116 * to clear it from the pending mask. 1117 */ 1118 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1119 1120 case (int)SIG_DFL: 1121 /* 1122 * Don't take default actions on system processes. 1123 */ 1124 if (p->p_pid <= 1) { 1125 #ifdef DIAGNOSTIC 1126 /* 1127 * Are you sure you want to ignore SIGSEGV 1128 * in init? XXX 1129 */ 1130 printf("Process (pid %lu) got signal %d\n", 1131 (u_long)p->p_pid, sig); 1132 #endif 1133 break; /* == ignore */ 1134 } 1135 1136 /* 1137 * Handle the in-kernel checkpoint action 1138 */ 1139 if (prop & SA_CKPT) { 1140 if (ckpt_func) 1141 ckpt_func(p); 1142 break; 1143 } 1144 1145 /* 1146 * If there is a pending stop signal to process 1147 * with default action, stop here, 1148 * then clear the signal. However, 1149 * if process is member of an orphaned 1150 * process group, ignore tty stop signals. 1151 */ 1152 if (prop & SA_STOP) { 1153 if (p->p_flag & P_TRACED || 1154 (p->p_pgrp->pg_jobc == 0 && 1155 prop & SA_TTYSTOP)) 1156 break; /* == ignore */ 1157 p->p_xstat = sig; 1158 stop(p); 1159 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1160 psignal(p->p_pptr, SIGCHLD); 1161 mi_switch(); 1162 break; 1163 } else if (prop & SA_IGNORE) { 1164 /* 1165 * Except for SIGCONT, shouldn't get here. 1166 * Default action is to ignore; drop it. 1167 */ 1168 break; /* == ignore */ 1169 } else 1170 return (sig); 1171 /*NOTREACHED*/ 1172 1173 case (int)SIG_IGN: 1174 /* 1175 * Masking above should prevent us ever trying 1176 * to take action on an ignored signal other 1177 * than SIGCONT, unless process is traced. 1178 */ 1179 if ((prop & SA_CONT) == 0 && 1180 (p->p_flag & P_TRACED) == 0) 1181 printf("issignal\n"); 1182 break; /* == ignore */ 1183 1184 default: 1185 /* 1186 * This signal has an action, let 1187 * postsig() process it. 1188 */ 1189 return (sig); 1190 } 1191 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1192 } 1193 /* NOTREACHED */ 1194 } 1195 1196 /* 1197 * Put the argument process into the stopped state and notify the parent 1198 * via wakeup. Signals are handled elsewhere. The process must not be 1199 * on the run queue. 1200 */ 1201 void 1202 stop(p) 1203 struct proc *p; 1204 { 1205 1206 p->p_stat = SSTOP; 1207 p->p_flag &= ~P_WAITED; 1208 wakeup((caddr_t)p->p_pptr); 1209 } 1210 1211 /* 1212 * Take the action for the specified signal 1213 * from the current set of pending signals. 1214 */ 1215 void 1216 postsig(sig) 1217 int sig; 1218 { 1219 struct proc *p = curproc; 1220 struct sigacts *ps = p->p_sigacts; 1221 sig_t action; 1222 sigset_t returnmask; 1223 int code; 1224 1225 KASSERT(sig != 0, ("postsig")); 1226 1227 SIGDELSET(p->p_siglist, sig); 1228 action = ps->ps_sigact[_SIG_IDX(sig)]; 1229 #ifdef KTRACE 1230 if (KTRPOINT(p->p_thread, KTR_PSIG)) 1231 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1232 &p->p_oldsigmask : &p->p_sigmask, 0); 1233 #endif 1234 STOPEVENT(p, S_SIG, sig); 1235 1236 if (action == SIG_DFL) { 1237 /* 1238 * Default action, where the default is to kill 1239 * the process. (Other cases were ignored above.) 1240 */ 1241 sigexit(p, sig); 1242 /* NOTREACHED */ 1243 } else { 1244 /* 1245 * If we get here, the signal must be caught. 1246 */ 1247 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1248 ("postsig action")); 1249 /* 1250 * Set the new mask value and also defer further 1251 * occurrences of this signal. 1252 * 1253 * Special case: user has done a sigsuspend. Here the 1254 * current mask is not of interest, but rather the 1255 * mask from before the sigsuspend is what we want 1256 * restored after the signal processing is completed. 1257 */ 1258 (void) splhigh(); 1259 if (p->p_flag & P_OLDMASK) { 1260 returnmask = p->p_oldsigmask; 1261 p->p_flag &= ~P_OLDMASK; 1262 } else 1263 returnmask = p->p_sigmask; 1264 1265 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1266 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1267 SIGADDSET(p->p_sigmask, sig); 1268 1269 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1270 /* 1271 * See kern_sigaction() for origin of this code. 1272 */ 1273 SIGDELSET(p->p_sigcatch, sig); 1274 if (sig != SIGCONT && 1275 sigprop(sig) & SA_IGNORE) 1276 SIGADDSET(p->p_sigignore, sig); 1277 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1278 } 1279 (void) spl0(); 1280 p->p_stats->p_ru.ru_nsignals++; 1281 if (p->p_sig != sig) { 1282 code = 0; 1283 } else { 1284 code = p->p_code; 1285 p->p_code = 0; 1286 p->p_sig = 0; 1287 } 1288 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1289 } 1290 } 1291 1292 /* 1293 * Kill the current process for stated reason. 1294 */ 1295 void 1296 killproc(p, why) 1297 struct proc *p; 1298 char *why; 1299 { 1300 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1301 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1302 psignal(p, SIGKILL); 1303 } 1304 1305 /* 1306 * Force the current process to exit with the specified signal, dumping core 1307 * if appropriate. We bypass the normal tests for masked and caught signals, 1308 * allowing unrecoverable failures to terminate the process without changing 1309 * signal state. Mark the accounting record with the signal termination. 1310 * If dumping core, save the signal number for the debugger. Calls exit and 1311 * does not return. 1312 */ 1313 void 1314 sigexit(struct proc *p, int sig) 1315 { 1316 p->p_acflag |= AXSIG; 1317 if (sigprop(sig) & SA_CORE) { 1318 p->p_sig = sig; 1319 /* 1320 * Log signals which would cause core dumps 1321 * (Log as LOG_INFO to appease those who don't want 1322 * these messages.) 1323 * XXX : Todo, as well as euid, write out ruid too 1324 */ 1325 if (coredump(p) == 0) 1326 sig |= WCOREFLAG; 1327 if (kern_logsigexit) 1328 log(LOG_INFO, 1329 "pid %d (%s), uid %d: exited on signal %d%s\n", 1330 p->p_pid, p->p_comm, 1331 p->p_ucred ? p->p_ucred->cr_uid : -1, 1332 sig &~ WCOREFLAG, 1333 sig & WCOREFLAG ? " (core dumped)" : ""); 1334 } 1335 exit1(W_EXITCODE(0, sig)); 1336 /* NOTREACHED */ 1337 } 1338 1339 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1340 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1341 sizeof(corefilename), "process corefile name format string"); 1342 1343 /* 1344 * expand_name(name, uid, pid) 1345 * Expand the name described in corefilename, using name, uid, and pid. 1346 * corefilename is a printf-like string, with three format specifiers: 1347 * %N name of process ("name") 1348 * %P process id (pid) 1349 * %U user id (uid) 1350 * For example, "%N.core" is the default; they can be disabled completely 1351 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1352 * This is controlled by the sysctl variable kern.corefile (see above). 1353 */ 1354 1355 static char * 1356 expand_name(name, uid, pid) 1357 const char *name; uid_t uid; pid_t pid; { 1358 char *temp; 1359 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1360 int i, n; 1361 char *format = corefilename; 1362 size_t namelen; 1363 1364 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1365 if (temp == NULL) 1366 return NULL; 1367 namelen = strlen(name); 1368 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1369 int l; 1370 switch (format[i]) { 1371 case '%': /* Format character */ 1372 i++; 1373 switch (format[i]) { 1374 case '%': 1375 temp[n++] = '%'; 1376 break; 1377 case 'N': /* process name */ 1378 if ((n + namelen) > MAXPATHLEN) { 1379 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1380 pid, name, uid, temp, name); 1381 free(temp, M_TEMP); 1382 return NULL; 1383 } 1384 memcpy(temp+n, name, namelen); 1385 n += namelen; 1386 break; 1387 case 'P': /* process id */ 1388 l = sprintf(buf, "%u", pid); 1389 if ((n + l) > MAXPATHLEN) { 1390 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1391 pid, name, uid, temp, name); 1392 free(temp, M_TEMP); 1393 return NULL; 1394 } 1395 memcpy(temp+n, buf, l); 1396 n += l; 1397 break; 1398 case 'U': /* user id */ 1399 l = sprintf(buf, "%u", uid); 1400 if ((n + l) > MAXPATHLEN) { 1401 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1402 pid, name, uid, temp, name); 1403 free(temp, M_TEMP); 1404 return NULL; 1405 } 1406 memcpy(temp+n, buf, l); 1407 n += l; 1408 break; 1409 default: 1410 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1411 } 1412 break; 1413 default: 1414 temp[n++] = format[i]; 1415 } 1416 } 1417 temp[n] = '\0'; 1418 return temp; 1419 } 1420 1421 /* 1422 * Dump a process' core. The main routine does some 1423 * policy checking, and creates the name of the coredump; 1424 * then it passes on a vnode and a size limit to the process-specific 1425 * coredump routine if there is one; if there _is not_ one, it returns 1426 * ENOSYS; otherwise it returns the error from the process-specific routine. 1427 */ 1428 1429 static int 1430 coredump(struct proc *p) 1431 { 1432 struct vnode *vp; 1433 struct ucred *cred = p->p_ucred; 1434 struct thread *td = p->p_thread; 1435 struct flock lf; 1436 struct nameidata nd; 1437 struct vattr vattr; 1438 int error, error1; 1439 char *name; /* name of corefile */ 1440 off_t limit; 1441 1442 STOPEVENT(p, S_CORE, 0); 1443 1444 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 1445 return (EFAULT); 1446 1447 /* 1448 * Note that the bulk of limit checking is done after 1449 * the corefile is created. The exception is if the limit 1450 * for corefiles is 0, in which case we don't bother 1451 * creating the corefile at all. This layout means that 1452 * a corefile is truncated instead of not being created, 1453 * if it is larger than the limit. 1454 */ 1455 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1456 if (limit == 0) 1457 return EFBIG; 1458 1459 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1460 if (name == NULL) 1461 return (EINVAL); 1462 NDINIT(&nd, NAMEI_LOOKUP, 0, UIO_SYSSPACE, name, td); 1463 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1464 free(name, M_TEMP); 1465 if (error) 1466 return (error); 1467 NDFREE(&nd, NDF_ONLY_PNBUF); 1468 vp = nd.ni_vp; 1469 1470 VOP_UNLOCK(vp, NULL, 0, td); 1471 lf.l_whence = SEEK_SET; 1472 lf.l_start = 0; 1473 lf.l_len = 0; 1474 lf.l_type = F_WRLCK; 1475 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 1476 if (error) 1477 goto out2; 1478 1479 /* Don't dump to non-regular files or files with links. */ 1480 if (vp->v_type != VREG || 1481 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) { 1482 error = EFAULT; 1483 goto out1; 1484 } 1485 1486 VATTR_NULL(&vattr); 1487 vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 1488 vattr.va_size = 0; 1489 VOP_LEASE(vp, td, cred, LEASE_WRITE); 1490 VOP_SETATTR(vp, &vattr, cred, td); 1491 p->p_acflag |= ACORE; 1492 VOP_UNLOCK(vp, NULL, 0, td); 1493 1494 error = p->p_sysent->sv_coredump ? 1495 p->p_sysent->sv_coredump(p, vp, limit) : 1496 ENOSYS; 1497 1498 out1: 1499 lf.l_type = F_UNLCK; 1500 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 1501 out2: 1502 error1 = vn_close(vp, FWRITE, td); 1503 if (error == 0) 1504 error = error1; 1505 return (error); 1506 } 1507 1508 /* 1509 * Nonexistent system call-- signal process (may want to handle it). 1510 * Flag error in case process won't see signal immediately (blocked or ignored). 1511 */ 1512 /* ARGSUSED */ 1513 int 1514 nosys(struct nosys_args *args) 1515 { 1516 psignal(curproc, SIGSYS); 1517 return (EINVAL); 1518 } 1519 1520 /* 1521 * Send a SIGIO or SIGURG signal to a process or process group using 1522 * stored credentials rather than those of the current process. 1523 */ 1524 void 1525 pgsigio(struct sigio *sigio, int sig, int checkctty) 1526 { 1527 if (sigio == NULL) 1528 return; 1529 1530 if (sigio->sio_pgid > 0) { 1531 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1532 sigio->sio_proc)) 1533 psignal(sigio->sio_proc, sig); 1534 } else if (sigio->sio_pgid < 0) { 1535 struct proc *p; 1536 1537 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) 1538 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1539 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1540 psignal(p, sig); 1541 } 1542 } 1543 1544 static int 1545 filt_sigattach(struct knote *kn) 1546 { 1547 struct proc *p = curproc; 1548 1549 kn->kn_ptr.p_proc = p; 1550 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1551 1552 /* XXX lock the proc here while adding to the list? */ 1553 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 1554 1555 return (0); 1556 } 1557 1558 static void 1559 filt_sigdetach(struct knote *kn) 1560 { 1561 struct proc *p = kn->kn_ptr.p_proc; 1562 1563 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 1564 } 1565 1566 /* 1567 * signal knotes are shared with proc knotes, so we apply a mask to 1568 * the hint in order to differentiate them from process hints. This 1569 * could be avoided by using a signal-specific knote list, but probably 1570 * isn't worth the trouble. 1571 */ 1572 static int 1573 filt_signal(struct knote *kn, long hint) 1574 { 1575 1576 if (hint & NOTE_SIGNAL) { 1577 hint &= ~NOTE_SIGNAL; 1578 1579 if (kn->kn_id == hint) 1580 kn->kn_data++; 1581 } 1582 return (kn->kn_data != 0); 1583 } 1584