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 1.29 2004/04/10 20:55:23 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 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 /* 310 * Set bit in p_sigignore for signals that are set to SIG_IGN, 311 * and for signals set to SIG_DFL where the default is to 312 * ignore. However, don't put SIGCONT in p_sigignore, as we 313 * have to restart the process. 314 */ 315 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 316 (sigprop(sig) & SA_IGNORE && 317 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 318 /* never to be seen again */ 319 SIGDELSET(p->p_siglist, sig); 320 if (sig != SIGCONT) 321 /* easier in psignal */ 322 SIGADDSET(p->p_sigignore, sig); 323 SIGDELSET(p->p_sigcatch, sig); 324 } else { 325 SIGDELSET(p->p_sigignore, sig); 326 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 327 SIGDELSET(p->p_sigcatch, sig); 328 else 329 SIGADDSET(p->p_sigcatch, sig); 330 } 331 332 spl0(); 333 } 334 return (0); 335 } 336 337 int 338 sigaction(struct sigaction_args *uap) 339 { 340 struct sigaction act, oact; 341 struct sigaction *actp, *oactp; 342 int error; 343 344 actp = (uap->act != NULL) ? &act : NULL; 345 oactp = (uap->oact != NULL) ? &oact : NULL; 346 if (actp) { 347 error = copyin(uap->act, actp, sizeof(act)); 348 if (error) 349 return (error); 350 } 351 error = kern_sigaction(uap->sig, actp, oactp); 352 if (oactp && !error) { 353 error = copyout(oactp, uap->oact, sizeof(oact)); 354 } 355 return (error); 356 } 357 358 /* 359 * Initialize signal state for process 0; 360 * set to ignore signals that are ignored by default. 361 */ 362 void 363 siginit(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(struct proc *p) 377 { 378 struct sigacts *ps = p->p_sigacts; 379 int sig; 380 381 /* 382 * Reset caught signals. Held signals remain held 383 * through p_sigmask (unless they were caught, 384 * and are now ignored by default). 385 */ 386 while (SIGNOTEMPTY(p->p_sigcatch)) { 387 sig = sig_ffs(&p->p_sigcatch); 388 SIGDELSET(p->p_sigcatch, sig); 389 if (sigprop(sig) & SA_IGNORE) { 390 if (sig != SIGCONT) 391 SIGADDSET(p->p_sigignore, sig); 392 SIGDELSET(p->p_siglist, sig); 393 } 394 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 395 } 396 /* 397 * Reset stack state to the user stack. 398 * Clear set of signals caught on the signal stack. 399 */ 400 p->p_sigstk.ss_flags = SS_DISABLE; 401 p->p_sigstk.ss_size = 0; 402 p->p_sigstk.ss_sp = 0; 403 p->p_flag &= ~P_ALTSTACK; 404 /* 405 * Reset no zombies if child dies flag as Solaris does. 406 */ 407 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 408 } 409 410 /* 411 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc 412 * 413 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 414 * p == curproc. Also remember that in order to remain MP SAFE 415 * no spl*() calls may be made. 416 */ 417 int 418 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) 419 { 420 struct thread *td = curthread; 421 struct proc *p = td->td_proc; 422 int error; 423 424 if (oset != NULL) 425 *oset = p->p_sigmask; 426 427 error = 0; 428 if (set != NULL) { 429 switch (how) { 430 case SIG_BLOCK: 431 SIG_CANTMASK(*set); 432 SIGSETOR(p->p_sigmask, *set); 433 break; 434 case SIG_UNBLOCK: 435 SIGSETNAND(p->p_sigmask, *set); 436 break; 437 case SIG_SETMASK: 438 SIG_CANTMASK(*set); 439 p->p_sigmask = *set; 440 break; 441 default: 442 error = EINVAL; 443 break; 444 } 445 } 446 return (error); 447 } 448 449 /* 450 * sigprocmask() - MP SAFE 451 */ 452 int 453 sigprocmask(struct sigprocmask_args *uap) 454 { 455 sigset_t set, oset; 456 sigset_t *setp, *osetp; 457 int error; 458 459 setp = (uap->set != NULL) ? &set : NULL; 460 osetp = (uap->oset != NULL) ? &oset : NULL; 461 if (setp) { 462 error = copyin(uap->set, setp, sizeof(set)); 463 if (error) 464 return (error); 465 } 466 error = kern_sigprocmask(uap->how, setp, osetp); 467 if (osetp && !error) { 468 error = copyout(osetp, uap->oset, sizeof(oset)); 469 } 470 return (error); 471 } 472 473 int 474 kern_sigpending(struct __sigset *set) 475 { 476 struct thread *td = curthread; 477 struct proc *p = td->td_proc; 478 479 *set = p->p_siglist; 480 481 return (0); 482 } 483 484 int 485 sigpending(struct sigpending_args *uap) 486 { 487 sigset_t set; 488 int error; 489 490 error = kern_sigpending(&set); 491 492 if (error == 0) 493 error = copyout(&set, uap->set, sizeof(set)); 494 return (error); 495 } 496 497 /* 498 * Suspend process until signal, providing mask to be set 499 * in the meantime. 500 */ 501 int 502 kern_sigsuspend(struct __sigset *set) 503 { 504 struct thread *td = curthread; 505 struct proc *p = td->td_proc; 506 struct sigacts *ps = p->p_sigacts; 507 508 /* 509 * When returning from sigsuspend, we want 510 * the old mask to be restored after the 511 * signal handler has finished. Thus, we 512 * save it here and mark the sigacts structure 513 * to indicate this. 514 */ 515 p->p_oldsigmask = p->p_sigmask; 516 p->p_flag |= P_OLDMASK; 517 518 SIG_CANTMASK(*set); 519 p->p_sigmask = *set; 520 while (tsleep(ps, PCATCH, "pause", 0) == 0) 521 /* void */; 522 /* always return EINTR rather than ERESTART... */ 523 return (EINTR); 524 } 525 526 /* 527 * Note nonstandard calling convention: libc stub passes mask, not 528 * pointer, to save a copyin. 529 */ 530 int 531 sigsuspend(struct sigsuspend_args *uap) 532 { 533 sigset_t mask; 534 int error; 535 536 error = copyin(uap->sigmask, &mask, sizeof(mask)); 537 if (error) 538 return (error); 539 540 error = kern_sigsuspend(&mask); 541 542 return (error); 543 } 544 545 int 546 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) 547 { 548 struct thread *td = curthread; 549 struct proc *p = td->td_proc; 550 551 if ((p->p_flag & P_ALTSTACK) == 0) 552 p->p_sigstk.ss_flags |= SS_DISABLE; 553 554 if (oss) 555 *oss = p->p_sigstk; 556 557 if (ss) { 558 if (ss->ss_flags & SS_DISABLE) { 559 if (p->p_sigstk.ss_flags & SS_ONSTACK) 560 return (EINVAL); 561 p->p_flag &= ~P_ALTSTACK; 562 p->p_sigstk.ss_flags = ss->ss_flags; 563 } else { 564 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 565 return (ENOMEM); 566 p->p_flag |= P_ALTSTACK; 567 p->p_sigstk = *ss; 568 } 569 } 570 571 return (0); 572 } 573 574 int 575 sigaltstack(struct sigaltstack_args *uap) 576 { 577 stack_t ss, oss; 578 int error; 579 580 if (uap->ss) { 581 error = copyin(uap->ss, &ss, sizeof(ss)); 582 if (error) 583 return (error); 584 } 585 586 error = kern_sigaltstack(uap->ss ? &ss : NULL, 587 uap->oss ? &oss : NULL); 588 589 if (error == 0 && uap->oss) 590 error = copyout(&oss, uap->oss, sizeof(*uap->oss)); 591 return (error); 592 } 593 594 /* 595 * Common code for kill process group/broadcast kill. 596 * cp is calling process. 597 */ 598 static int 599 killpg(int sig, int pgid, int all) 600 { 601 struct proc *cp = curproc; 602 struct proc *p; 603 struct pgrp *pgrp; 604 int nfound = 0; 605 606 if (all) { 607 /* 608 * broadcast 609 */ 610 FOREACH_PROC_IN_SYSTEM(p) { 611 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 612 p == cp || !CANSIGNAL(p, sig)) 613 continue; 614 nfound++; 615 if (sig) 616 psignal(p, sig); 617 } 618 } else { 619 if (pgid == 0) { 620 /* 621 * zero pgid means send to my process group. 622 */ 623 pgrp = cp->p_pgrp; 624 } else { 625 pgrp = pgfind(pgid); 626 if (pgrp == NULL) 627 return (ESRCH); 628 } 629 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 630 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 631 p->p_stat == SZOMB || 632 !CANSIGNAL(p, sig)) 633 continue; 634 nfound++; 635 if (sig) 636 psignal(p, sig); 637 } 638 } 639 return (nfound ? 0 : ESRCH); 640 } 641 642 int 643 kern_kill(int sig, int pid) 644 { 645 struct thread *td = curthread; 646 struct proc *p = td->td_proc; 647 648 if ((u_int)sig > _SIG_MAXSIG) 649 return (EINVAL); 650 if (pid > 0) { 651 /* kill single process */ 652 if ((p = pfind(pid)) == NULL) 653 return (ESRCH); 654 if (!CANSIGNAL(p, sig)) 655 return (EPERM); 656 if (sig) 657 psignal(p, sig); 658 return (0); 659 } 660 switch (pid) { 661 case -1: /* broadcast signal */ 662 return (killpg(sig, 0, 1)); 663 case 0: /* signal own process group */ 664 return (killpg(sig, 0, 0)); 665 default: /* negative explicit process group */ 666 return (killpg(sig, -pid, 0)); 667 } 668 /* NOTREACHED */ 669 } 670 671 int 672 kill(struct kill_args *uap) 673 { 674 int error; 675 676 error = kern_kill(uap->signum, uap->pid); 677 678 return (error); 679 } 680 681 /* 682 * Send a signal to a process group. 683 */ 684 void 685 gsignal(int pgid, int sig) 686 { 687 struct pgrp *pgrp; 688 689 if (pgid && (pgrp = pgfind(pgid))) 690 pgsignal(pgrp, sig, 0); 691 } 692 693 /* 694 * Send a signal to a process group. If checktty is 1, 695 * limit to members which have a controlling terminal. 696 */ 697 void 698 pgsignal(struct pgrp *pgrp, int sig, int checkctty) 699 { 700 struct proc *p; 701 702 if (pgrp) 703 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) 704 if (checkctty == 0 || p->p_flag & P_CONTROLT) 705 psignal(p, sig); 706 } 707 708 /* 709 * Send a signal caused by a trap to the current process. 710 * If it will be caught immediately, deliver it with correct code. 711 * Otherwise, post it normally. 712 */ 713 void 714 trapsignal(struct proc *p, int sig, u_long code) 715 { 716 struct sigacts *ps = p->p_sigacts; 717 718 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 719 !SIGISMEMBER(p->p_sigmask, sig)) { 720 p->p_stats->p_ru.ru_nsignals++; 721 #ifdef KTRACE 722 if (KTRPOINT(p->p_thread, KTR_PSIG)) 723 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 724 &p->p_sigmask, code); 725 #endif 726 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 727 &p->p_sigmask, code); 728 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 729 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 730 SIGADDSET(p->p_sigmask, sig); 731 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 732 /* 733 * See kern_sigaction() for origin of this code. 734 */ 735 SIGDELSET(p->p_sigcatch, sig); 736 if (sig != SIGCONT && 737 sigprop(sig) & SA_IGNORE) 738 SIGADDSET(p->p_sigignore, sig); 739 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 740 } 741 } else { 742 p->p_code = code; /* XXX for core dump/debugger */ 743 p->p_sig = sig; /* XXX to verify code */ 744 psignal(p, sig); 745 } 746 } 747 748 /* 749 * Send the signal to the process. If the signal has an action, the action 750 * is usually performed by the target process rather than the caller; we add 751 * the signal to the set of pending signals for the process. 752 * 753 * Exceptions: 754 * o When a stop signal is sent to a sleeping process that takes the 755 * default action, the process is stopped without awakening it. 756 * o SIGCONT restarts stopped processes (or puts them back to sleep) 757 * regardless of the signal action (eg, blocked or ignored). 758 * 759 * Other ignored signals are discarded immediately. 760 */ 761 762 /* 763 * temporary hack to allow checkpoint code to continue to 764 * be in a module for the moment 765 */ 766 767 static proc_func_t ckpt_func; 768 769 proc_func_t 770 register_ckpt_func(proc_func_t func) 771 { 772 proc_func_t old_func; 773 774 old_func = ckpt_func; 775 ckpt_func = func; 776 return (old_func); 777 } 778 779 void 780 psignal(struct proc *p, int sig) 781 { 782 int s, prop; 783 sig_t action; 784 785 if (sig > _SIG_MAXSIG || sig <= 0) { 786 printf("psignal: signal %d\n", sig); 787 panic("psignal signal number"); 788 } 789 790 s = splhigh(); 791 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 792 splx(s); 793 794 prop = sigprop(sig); 795 796 /* 797 * If proc is traced, always give parent a chance; 798 * if signal event is tracked by procfs, give *that* 799 * a chance, as well. 800 */ 801 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 802 action = SIG_DFL; 803 } else { 804 /* 805 * If the signal is being ignored, 806 * then we forget about it immediately. 807 * (Note: we don't set SIGCONT in p_sigignore, 808 * and if it is set to SIG_IGN, 809 * action will be SIG_DFL here.) 810 */ 811 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 812 return; 813 if (SIGISMEMBER(p->p_sigmask, sig)) 814 action = SIG_HOLD; 815 else if (SIGISMEMBER(p->p_sigcatch, sig)) 816 action = SIG_CATCH; 817 else 818 action = SIG_DFL; 819 } 820 821 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 822 (p->p_flag & P_TRACED) == 0) { 823 p->p_nice = NZERO; 824 } 825 826 if (prop & SA_CONT) 827 SIG_STOPSIGMASK(p->p_siglist); 828 829 830 if (prop & SA_STOP) { 831 /* 832 * If sending a tty stop signal to a member of an orphaned 833 * process group, discard the signal here if the action 834 * is default; don't stop the process below if sleeping, 835 * and don't clear any pending SIGCONT. 836 */ 837 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 838 action == SIG_DFL) { 839 return; 840 } 841 SIG_CONTSIGMASK(p->p_siglist); 842 } 843 SIGADDSET(p->p_siglist, sig); 844 845 /* 846 * Defer further processing for signals which are held, 847 * except that stopped processes must be continued by SIGCONT. 848 */ 849 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) 850 return; 851 s = splhigh(); 852 switch (p->p_stat) { 853 case SSLEEP: 854 /* 855 * If process is sleeping uninterruptibly 856 * we can't interrupt the sleep... the signal will 857 * be noticed when the process returns through 858 * trap() or syscall(). 859 */ 860 if ((p->p_flag & P_SINTR) == 0) 861 goto out; 862 /* 863 * Process is sleeping and traced... make it runnable 864 * so it can discover the signal in issignal() and stop 865 * for the parent. 866 */ 867 if (p->p_flag & P_TRACED) 868 goto run; 869 /* 870 * If SIGCONT is default (or ignored) and process is 871 * asleep, we are finished; the process should not 872 * be awakened. 873 */ 874 if ((prop & SA_CONT) && action == SIG_DFL) { 875 SIGDELSET(p->p_siglist, sig); 876 goto out; 877 } 878 /* 879 * When a sleeping process receives a stop 880 * signal, process immediately if possible. 881 * All other (caught or default) signals 882 * cause the process to run. 883 */ 884 if (prop & SA_STOP) { 885 if (action != SIG_DFL) 886 goto run; 887 /* 888 * If a child holding parent blocked, 889 * stopping could cause deadlock. 890 */ 891 if (p->p_flag & P_PPWAIT) 892 goto out; 893 SIGDELSET(p->p_siglist, sig); 894 p->p_xstat = sig; 895 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 896 psignal(p->p_pptr, SIGCHLD); 897 stop(p); 898 goto out; 899 } else { 900 goto run; 901 } 902 /*NOTREACHED*/ 903 case SSTOP: 904 /* 905 * If traced process is already stopped, 906 * then no further action is necessary. 907 */ 908 if (p->p_flag & P_TRACED) 909 goto out; 910 911 /* 912 * Kill signal always sets processes running. 913 */ 914 if (sig == SIGKILL) 915 goto run; 916 917 if (prop & SA_CONT) { 918 /* 919 * If SIGCONT is default (or ignored), we continue the 920 * process but don't leave the signal in p_siglist, as 921 * it has no further action. If SIGCONT is held, we 922 * continue the process and leave the signal in 923 * p_siglist. If the process catches SIGCONT, let it 924 * handle the signal itself. If it isn't waiting on 925 * an event, then it goes back to run state. 926 * Otherwise, process goes back to sleep state. 927 */ 928 if (action == SIG_DFL) 929 SIGDELSET(p->p_siglist, sig); 930 if (action == SIG_CATCH) 931 goto run; 932 if (p->p_wchan == 0) 933 goto run; 934 clrrunnable(p, SSLEEP); 935 goto out; 936 } 937 938 if (prop & SA_STOP) { 939 /* 940 * Already stopped, don't need to stop again. 941 * (If we did the shell could get confused.) 942 */ 943 SIGDELSET(p->p_siglist, sig); 944 goto out; 945 } 946 947 /* 948 * If process is sleeping interruptibly, then simulate a 949 * wakeup so that when it is continued, it will be made 950 * runnable and can look at the signal. But don't make 951 * the process runnable, leave it stopped. 952 */ 953 if (p->p_wchan && (p->p_flag & P_SINTR)) 954 unsleep(p->p_thread); 955 goto out; 956 default: 957 /* 958 * SRUN, SIDL, SZOMB do nothing with the signal, 959 * other than kicking ourselves if we are running. 960 * It will either never be noticed, or noticed very soon. 961 * 962 * For SMP we may have to forward the request to another cpu. 963 * YYY the MP lock prevents the target process from moving 964 * to another cpu, see kern/kern_switch.c 965 */ 966 #ifdef SMP 967 if (p == lwkt_preempted_proc()) { 968 signotify(); 969 } else { 970 struct thread *td = p->p_thread; 971 972 if (td->td_gd != mycpu) 973 lwkt_send_ipiq(td->td_gd, signotify_remote, p); 974 } 975 #else 976 if (p == lwkt_preempted_proc()) 977 signotify(); 978 #endif 979 goto out; 980 } 981 /*NOTREACHED*/ 982 run: 983 setrunnable(p); 984 out: 985 splx(s); 986 } 987 988 #ifdef SMP 989 990 /* 991 * This function is called via an IPI. We will be in a critical section but 992 * the MP lock will NOT be held. Also note that by the time the ipi message 993 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 994 */ 995 static void 996 signotify_remote(void *arg) 997 { 998 struct proc *p = arg; 999 if (p == lwkt_preempted_proc()) 1000 signotify(); 1001 } 1002 1003 #endif 1004 1005 /* 1006 * If the current process has received a signal that would interrupt a 1007 * system call, return EINTR or ERESTART as appropriate. 1008 */ 1009 int 1010 iscaught(struct proc *p) 1011 { 1012 int sig; 1013 1014 if (p) { 1015 if ((sig = CURSIG(p)) != 0) { 1016 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1017 return (EINTR); 1018 return (ERESTART); 1019 } 1020 } 1021 return(EWOULDBLOCK); 1022 } 1023 1024 /* 1025 * If the current process has received a signal (should be caught or cause 1026 * termination, should interrupt current syscall), return the signal number. 1027 * Stop signals with default action are processed immediately, then cleared; 1028 * they aren't returned. This is checked after each entry to the system for 1029 * a syscall or trap (though this can usually be done without calling issignal 1030 * by checking the pending signal masks in the CURSIG macro.) The normal call 1031 * sequence is 1032 * 1033 * while (sig = CURSIG(curproc)) 1034 * postsig(sig); 1035 */ 1036 int 1037 issignal(struct proc *p) 1038 { 1039 sigset_t mask; 1040 int sig, prop; 1041 1042 for (;;) { 1043 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1044 1045 mask = p->p_siglist; 1046 SIGSETNAND(mask, p->p_sigmask); 1047 if (p->p_flag & P_PPWAIT) 1048 SIG_STOPSIGMASK(mask); 1049 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1050 return (0); 1051 sig = sig_ffs(&mask); 1052 1053 STOPEVENT(p, S_SIG, sig); 1054 1055 /* 1056 * We should see pending but ignored signals 1057 * only if P_TRACED was on when they were posted. 1058 */ 1059 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1060 SIGDELSET(p->p_siglist, sig); 1061 continue; 1062 } 1063 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1064 /* 1065 * If traced, always stop, and stay 1066 * stopped until released by the parent. 1067 */ 1068 p->p_xstat = sig; 1069 psignal(p->p_pptr, SIGCHLD); 1070 do { 1071 stop(p); 1072 mi_switch(p); 1073 } while (!trace_req(p) && p->p_flag & P_TRACED); 1074 1075 /* 1076 * If parent wants us to take the signal, 1077 * then it will leave it in p->p_xstat; 1078 * otherwise we just look for signals again. 1079 */ 1080 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1081 sig = p->p_xstat; 1082 if (sig == 0) 1083 continue; 1084 1085 /* 1086 * Put the new signal into p_siglist. If the 1087 * signal is being masked, look for other signals. 1088 */ 1089 SIGADDSET(p->p_siglist, sig); 1090 if (SIGISMEMBER(p->p_sigmask, sig)) 1091 continue; 1092 1093 /* 1094 * If the traced bit got turned off, go back up 1095 * to the top to rescan signals. This ensures 1096 * that p_sig* and ps_sigact are consistent. 1097 */ 1098 if ((p->p_flag & P_TRACED) == 0) 1099 continue; 1100 } 1101 1102 prop = sigprop(sig); 1103 1104 /* 1105 * Decide whether the signal should be returned. 1106 * Return the signal's number, or fall through 1107 * to clear it from the pending mask. 1108 */ 1109 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1110 1111 case (int)SIG_DFL: 1112 /* 1113 * Don't take default actions on system processes. 1114 */ 1115 if (p->p_pid <= 1) { 1116 #ifdef DIAGNOSTIC 1117 /* 1118 * Are you sure you want to ignore SIGSEGV 1119 * in init? XXX 1120 */ 1121 printf("Process (pid %lu) got signal %d\n", 1122 (u_long)p->p_pid, sig); 1123 #endif 1124 break; /* == ignore */ 1125 } 1126 1127 /* 1128 * Handle the in-kernel checkpoint action 1129 */ 1130 if (prop & SA_CKPT) { 1131 if (ckpt_func) 1132 ckpt_func(p); 1133 break; 1134 } 1135 1136 /* 1137 * If there is a pending stop signal to process 1138 * with default action, stop here, 1139 * then clear the signal. However, 1140 * if process is member of an orphaned 1141 * process group, ignore tty stop signals. 1142 */ 1143 if (prop & SA_STOP) { 1144 if (p->p_flag & P_TRACED || 1145 (p->p_pgrp->pg_jobc == 0 && 1146 prop & SA_TTYSTOP)) 1147 break; /* == ignore */ 1148 p->p_xstat = sig; 1149 stop(p); 1150 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1151 psignal(p->p_pptr, SIGCHLD); 1152 mi_switch(p); 1153 break; 1154 } else if (prop & SA_IGNORE) { 1155 /* 1156 * Except for SIGCONT, shouldn't get here. 1157 * Default action is to ignore; drop it. 1158 */ 1159 break; /* == ignore */ 1160 } else { 1161 return (sig); 1162 } 1163 1164 /*NOTREACHED*/ 1165 1166 case (int)SIG_IGN: 1167 /* 1168 * Masking above should prevent us ever trying 1169 * to take action on an ignored signal other 1170 * than SIGCONT, unless process is traced. 1171 */ 1172 if ((prop & SA_CONT) == 0 && 1173 (p->p_flag & P_TRACED) == 0) 1174 printf("issignal\n"); 1175 break; /* == ignore */ 1176 1177 default: 1178 /* 1179 * This signal has an action, let 1180 * postsig() process it. 1181 */ 1182 return (sig); 1183 } 1184 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1185 } 1186 /* NOTREACHED */ 1187 } 1188 1189 /* 1190 * Put the argument process into the stopped state and notify the parent 1191 * via wakeup. Signals are handled elsewhere. The process must not be 1192 * on the run queue. 1193 */ 1194 void 1195 stop(struct proc *p) 1196 { 1197 p->p_stat = SSTOP; 1198 p->p_flag &= ~P_WAITED; 1199 wakeup((caddr_t)p->p_pptr); 1200 } 1201 1202 /* 1203 * Take the action for the specified signal 1204 * from the current set of pending signals. 1205 */ 1206 void 1207 postsig(int sig) 1208 { 1209 struct proc *p = curproc; 1210 struct sigacts *ps = p->p_sigacts; 1211 sig_t action; 1212 sigset_t returnmask; 1213 int code; 1214 1215 KASSERT(sig != 0, ("postsig")); 1216 1217 SIGDELSET(p->p_siglist, sig); 1218 action = ps->ps_sigact[_SIG_IDX(sig)]; 1219 #ifdef KTRACE 1220 if (KTRPOINT(p->p_thread, KTR_PSIG)) 1221 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1222 &p->p_oldsigmask : &p->p_sigmask, 0); 1223 #endif 1224 STOPEVENT(p, S_SIG, sig); 1225 1226 if (action == SIG_DFL) { 1227 /* 1228 * Default action, where the default is to kill 1229 * the process. (Other cases were ignored above.) 1230 */ 1231 sigexit(p, sig); 1232 /* NOTREACHED */ 1233 } else { 1234 /* 1235 * If we get here, the signal must be caught. 1236 */ 1237 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1238 ("postsig action")); 1239 /* 1240 * Set the new mask value and also defer further 1241 * occurrences of this signal. 1242 * 1243 * Special case: user has done a sigsuspend. Here the 1244 * current mask is not of interest, but rather the 1245 * mask from before the sigsuspend is what we want 1246 * restored after the signal processing is completed. 1247 */ 1248 splhigh(); 1249 if (p->p_flag & P_OLDMASK) { 1250 returnmask = p->p_oldsigmask; 1251 p->p_flag &= ~P_OLDMASK; 1252 } else { 1253 returnmask = p->p_sigmask; 1254 } 1255 1256 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1257 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1258 SIGADDSET(p->p_sigmask, sig); 1259 1260 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1261 /* 1262 * See kern_sigaction() for origin of this code. 1263 */ 1264 SIGDELSET(p->p_sigcatch, sig); 1265 if (sig != SIGCONT && 1266 sigprop(sig) & SA_IGNORE) 1267 SIGADDSET(p->p_sigignore, sig); 1268 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1269 } 1270 spl0(); 1271 p->p_stats->p_ru.ru_nsignals++; 1272 if (p->p_sig != sig) { 1273 code = 0; 1274 } else { 1275 code = p->p_code; 1276 p->p_code = 0; 1277 p->p_sig = 0; 1278 } 1279 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1280 } 1281 } 1282 1283 /* 1284 * Kill the current process for stated reason. 1285 */ 1286 void 1287 killproc(struct proc *p, char *why) 1288 { 1289 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1290 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1291 psignal(p, SIGKILL); 1292 } 1293 1294 /* 1295 * Force the current process to exit with the specified signal, dumping core 1296 * if appropriate. We bypass the normal tests for masked and caught signals, 1297 * allowing unrecoverable failures to terminate the process without changing 1298 * signal state. Mark the accounting record with the signal termination. 1299 * If dumping core, save the signal number for the debugger. Calls exit and 1300 * does not return. 1301 */ 1302 void 1303 sigexit(struct proc *p, int sig) 1304 { 1305 p->p_acflag |= AXSIG; 1306 if (sigprop(sig) & SA_CORE) { 1307 p->p_sig = sig; 1308 /* 1309 * Log signals which would cause core dumps 1310 * (Log as LOG_INFO to appease those who don't want 1311 * these messages.) 1312 * XXX : Todo, as well as euid, write out ruid too 1313 */ 1314 if (coredump(p) == 0) 1315 sig |= WCOREFLAG; 1316 if (kern_logsigexit) 1317 log(LOG_INFO, 1318 "pid %d (%s), uid %d: exited on signal %d%s\n", 1319 p->p_pid, p->p_comm, 1320 p->p_ucred ? p->p_ucred->cr_uid : -1, 1321 sig &~ WCOREFLAG, 1322 sig & WCOREFLAG ? " (core dumped)" : ""); 1323 } 1324 exit1(W_EXITCODE(0, sig)); 1325 /* NOTREACHED */ 1326 } 1327 1328 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1329 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1330 sizeof(corefilename), "process corefile name format string"); 1331 1332 /* 1333 * expand_name(name, uid, pid) 1334 * Expand the name described in corefilename, using name, uid, and pid. 1335 * corefilename is a printf-like string, with three format specifiers: 1336 * %N name of process ("name") 1337 * %P process id (pid) 1338 * %U user id (uid) 1339 * For example, "%N.core" is the default; they can be disabled completely 1340 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1341 * This is controlled by the sysctl variable kern.corefile (see above). 1342 */ 1343 1344 static char * 1345 expand_name(const char *name, uid_t uid, pid_t pid) 1346 { 1347 char *temp; 1348 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1349 int i, n; 1350 char *format = corefilename; 1351 size_t namelen; 1352 1353 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1354 if (temp == NULL) 1355 return NULL; 1356 namelen = strlen(name); 1357 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1358 int l; 1359 switch (format[i]) { 1360 case '%': /* Format character */ 1361 i++; 1362 switch (format[i]) { 1363 case '%': 1364 temp[n++] = '%'; 1365 break; 1366 case 'N': /* process name */ 1367 if ((n + namelen) > MAXPATHLEN) { 1368 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1369 pid, name, uid, temp, name); 1370 free(temp, M_TEMP); 1371 return NULL; 1372 } 1373 memcpy(temp+n, name, namelen); 1374 n += namelen; 1375 break; 1376 case 'P': /* process id */ 1377 l = sprintf(buf, "%u", pid); 1378 if ((n + l) > 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, buf, l); 1385 n += l; 1386 break; 1387 case 'U': /* user id */ 1388 l = sprintf(buf, "%u", uid); 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 default: 1399 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1400 } 1401 break; 1402 default: 1403 temp[n++] = format[i]; 1404 } 1405 } 1406 temp[n] = '\0'; 1407 return temp; 1408 } 1409 1410 /* 1411 * Dump a process' core. The main routine does some 1412 * policy checking, and creates the name of the coredump; 1413 * then it passes on a vnode and a size limit to the process-specific 1414 * coredump routine if there is one; if there _is not_ one, it returns 1415 * ENOSYS; otherwise it returns the error from the process-specific routine. 1416 */ 1417 1418 static int 1419 coredump(struct proc *p) 1420 { 1421 struct vnode *vp; 1422 struct ucred *cred = p->p_ucred; 1423 struct thread *td = p->p_thread; 1424 struct flock lf; 1425 struct nameidata nd; 1426 struct vattr vattr; 1427 int error, error1; 1428 char *name; /* name of corefile */ 1429 off_t limit; 1430 1431 STOPEVENT(p, S_CORE, 0); 1432 1433 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 1434 return (EFAULT); 1435 1436 /* 1437 * Note that the bulk of limit checking is done after 1438 * the corefile is created. The exception is if the limit 1439 * for corefiles is 0, in which case we don't bother 1440 * creating the corefile at all. This layout means that 1441 * a corefile is truncated instead of not being created, 1442 * if it is larger than the limit. 1443 */ 1444 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1445 if (limit == 0) 1446 return EFBIG; 1447 1448 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1449 if (name == NULL) 1450 return (EINVAL); 1451 NDINIT(&nd, NAMEI_LOOKUP, 0, UIO_SYSSPACE, name, td); 1452 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1453 free(name, M_TEMP); 1454 if (error) 1455 return (error); 1456 NDFREE(&nd, NDF_ONLY_PNBUF); 1457 vp = nd.ni_vp; 1458 1459 VOP_UNLOCK(vp, NULL, 0, td); 1460 lf.l_whence = SEEK_SET; 1461 lf.l_start = 0; 1462 lf.l_len = 0; 1463 lf.l_type = F_WRLCK; 1464 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 1465 if (error) 1466 goto out2; 1467 1468 /* Don't dump to non-regular files or files with links. */ 1469 if (vp->v_type != VREG || 1470 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) { 1471 error = EFAULT; 1472 goto out1; 1473 } 1474 1475 VATTR_NULL(&vattr); 1476 vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 1477 vattr.va_size = 0; 1478 VOP_LEASE(vp, td, cred, LEASE_WRITE); 1479 VOP_SETATTR(vp, &vattr, cred, td); 1480 p->p_acflag |= ACORE; 1481 VOP_UNLOCK(vp, NULL, 0, td); 1482 1483 error = p->p_sysent->sv_coredump ? 1484 p->p_sysent->sv_coredump(p, vp, limit) : 1485 ENOSYS; 1486 1487 out1: 1488 lf.l_type = F_UNLCK; 1489 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 1490 out2: 1491 error1 = vn_close(vp, FWRITE, td); 1492 if (error == 0) 1493 error = error1; 1494 return (error); 1495 } 1496 1497 /* 1498 * Nonexistent system call-- signal process (may want to handle it). 1499 * Flag error in case process won't see signal immediately (blocked or ignored). 1500 */ 1501 /* ARGSUSED */ 1502 int 1503 nosys(struct nosys_args *args) 1504 { 1505 psignal(curproc, SIGSYS); 1506 return (EINVAL); 1507 } 1508 1509 /* 1510 * Send a SIGIO or SIGURG signal to a process or process group using 1511 * stored credentials rather than those of the current process. 1512 */ 1513 void 1514 pgsigio(struct sigio *sigio, int sig, int checkctty) 1515 { 1516 if (sigio == NULL) 1517 return; 1518 1519 if (sigio->sio_pgid > 0) { 1520 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1521 sigio->sio_proc)) 1522 psignal(sigio->sio_proc, sig); 1523 } else if (sigio->sio_pgid < 0) { 1524 struct proc *p; 1525 1526 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) 1527 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1528 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1529 psignal(p, sig); 1530 } 1531 } 1532 1533 static int 1534 filt_sigattach(struct knote *kn) 1535 { 1536 struct proc *p = curproc; 1537 1538 kn->kn_ptr.p_proc = p; 1539 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1540 1541 /* XXX lock the proc here while adding to the list? */ 1542 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 1543 1544 return (0); 1545 } 1546 1547 static void 1548 filt_sigdetach(struct knote *kn) 1549 { 1550 struct proc *p = kn->kn_ptr.p_proc; 1551 1552 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 1553 } 1554 1555 /* 1556 * signal knotes are shared with proc knotes, so we apply a mask to 1557 * the hint in order to differentiate them from process hints. This 1558 * could be avoided by using a signal-specific knote list, but probably 1559 * isn't worth the trouble. 1560 */ 1561 static int 1562 filt_signal(struct knote *kn, long hint) 1563 { 1564 if (hint & NOTE_SIGNAL) { 1565 hint &= ~NOTE_SIGNAL; 1566 1567 if (kn->kn_id == hint) 1568 kn->kn_data++; 1569 } 1570 return (kn->kn_data != 0); 1571 } 1572