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 1.30 2004/04/15 00:51:32 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 * If the target thread is waiting on its message port, 967 * wakeup the target thread so it can check (or ignore) 968 * the new signal. YYY needs cleanup. 969 */ 970 #ifdef SMP 971 if (p == lwkt_preempted_proc()) { 972 signotify(); 973 } else { 974 struct thread *td = p->p_thread; 975 976 if (td->td_gd != mycpu) 977 lwkt_send_ipiq(td->td_gd, signotify_remote, p); 978 else if (td->td_msgport.mp_flags & MSGPORTF_WAITING) 979 lwkt_schedule(td); 980 } 981 #else 982 if (p == lwkt_preempted_proc()) { 983 signotify(); 984 } else { 985 struct thread *td = p->p_thread; 986 if (td->td_msgport.mp_flags & MSGPORTF_WAITING) 987 lwkt_schedule(td); 988 } 989 #endif 990 goto out; 991 } 992 /*NOTREACHED*/ 993 run: 994 setrunnable(p); 995 out: 996 splx(s); 997 } 998 999 #ifdef SMP 1000 1001 /* 1002 * This function is called via an IPI. We will be in a critical section but 1003 * the MP lock will NOT be held. Also note that by the time the ipi message 1004 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 1005 */ 1006 static void 1007 signotify_remote(void *arg) 1008 { 1009 struct proc *p = arg; 1010 1011 if (p == lwkt_preempted_proc()) { 1012 signotify(); 1013 } else { 1014 struct thread *td = p->p_thread; 1015 if (td->td_msgport.mp_flags & MSGPORTF_WAITING) 1016 lwkt_schedule(td); 1017 } 1018 } 1019 1020 #endif 1021 1022 /* 1023 * If the current process has received a signal that would interrupt a 1024 * system call, return EINTR or ERESTART as appropriate. 1025 */ 1026 int 1027 iscaught(struct proc *p) 1028 { 1029 int sig; 1030 1031 if (p) { 1032 if ((sig = CURSIG(p)) != 0) { 1033 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1034 return (EINTR); 1035 return (ERESTART); 1036 } 1037 } 1038 return(EWOULDBLOCK); 1039 } 1040 1041 /* 1042 * If the current process has received a signal (should be caught or cause 1043 * termination, should interrupt current syscall), return the signal number. 1044 * Stop signals with default action are processed immediately, then cleared; 1045 * they aren't returned. This is checked after each entry to the system for 1046 * a syscall or trap (though this can usually be done without calling issignal 1047 * by checking the pending signal masks in the CURSIG macro.) The normal call 1048 * sequence is 1049 * 1050 * while (sig = CURSIG(curproc)) 1051 * postsig(sig); 1052 */ 1053 int 1054 issignal(struct proc *p) 1055 { 1056 sigset_t mask; 1057 int sig, prop; 1058 1059 for (;;) { 1060 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1061 1062 mask = p->p_siglist; 1063 SIGSETNAND(mask, p->p_sigmask); 1064 if (p->p_flag & P_PPWAIT) 1065 SIG_STOPSIGMASK(mask); 1066 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1067 return (0); 1068 sig = sig_ffs(&mask); 1069 1070 STOPEVENT(p, S_SIG, sig); 1071 1072 /* 1073 * We should see pending but ignored signals 1074 * only if P_TRACED was on when they were posted. 1075 */ 1076 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1077 SIGDELSET(p->p_siglist, sig); 1078 continue; 1079 } 1080 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1081 /* 1082 * If traced, always stop, and stay 1083 * stopped until released by the parent. 1084 */ 1085 p->p_xstat = sig; 1086 psignal(p->p_pptr, SIGCHLD); 1087 do { 1088 stop(p); 1089 mi_switch(p); 1090 } while (!trace_req(p) && p->p_flag & P_TRACED); 1091 1092 /* 1093 * If parent wants us to take the signal, 1094 * then it will leave it in p->p_xstat; 1095 * otherwise we just look for signals again. 1096 */ 1097 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1098 sig = p->p_xstat; 1099 if (sig == 0) 1100 continue; 1101 1102 /* 1103 * Put the new signal into p_siglist. If the 1104 * signal is being masked, look for other signals. 1105 */ 1106 SIGADDSET(p->p_siglist, sig); 1107 if (SIGISMEMBER(p->p_sigmask, sig)) 1108 continue; 1109 1110 /* 1111 * If the traced bit got turned off, go back up 1112 * to the top to rescan signals. This ensures 1113 * that p_sig* and ps_sigact are consistent. 1114 */ 1115 if ((p->p_flag & P_TRACED) == 0) 1116 continue; 1117 } 1118 1119 prop = sigprop(sig); 1120 1121 /* 1122 * Decide whether the signal should be returned. 1123 * Return the signal's number, or fall through 1124 * to clear it from the pending mask. 1125 */ 1126 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1127 1128 case (int)SIG_DFL: 1129 /* 1130 * Don't take default actions on system processes. 1131 */ 1132 if (p->p_pid <= 1) { 1133 #ifdef DIAGNOSTIC 1134 /* 1135 * Are you sure you want to ignore SIGSEGV 1136 * in init? XXX 1137 */ 1138 printf("Process (pid %lu) got signal %d\n", 1139 (u_long)p->p_pid, sig); 1140 #endif 1141 break; /* == ignore */ 1142 } 1143 1144 /* 1145 * Handle the in-kernel checkpoint action 1146 */ 1147 if (prop & SA_CKPT) { 1148 if (ckpt_func) 1149 ckpt_func(p); 1150 break; 1151 } 1152 1153 /* 1154 * If there is a pending stop signal to process 1155 * with default action, stop here, 1156 * then clear the signal. However, 1157 * if process is member of an orphaned 1158 * process group, ignore tty stop signals. 1159 */ 1160 if (prop & SA_STOP) { 1161 if (p->p_flag & P_TRACED || 1162 (p->p_pgrp->pg_jobc == 0 && 1163 prop & SA_TTYSTOP)) 1164 break; /* == ignore */ 1165 p->p_xstat = sig; 1166 stop(p); 1167 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1168 psignal(p->p_pptr, SIGCHLD); 1169 mi_switch(p); 1170 break; 1171 } else if (prop & SA_IGNORE) { 1172 /* 1173 * Except for SIGCONT, shouldn't get here. 1174 * Default action is to ignore; drop it. 1175 */ 1176 break; /* == ignore */ 1177 } else { 1178 return (sig); 1179 } 1180 1181 /*NOTREACHED*/ 1182 1183 case (int)SIG_IGN: 1184 /* 1185 * Masking above should prevent us ever trying 1186 * to take action on an ignored signal other 1187 * than SIGCONT, unless process is traced. 1188 */ 1189 if ((prop & SA_CONT) == 0 && 1190 (p->p_flag & P_TRACED) == 0) 1191 printf("issignal\n"); 1192 break; /* == ignore */ 1193 1194 default: 1195 /* 1196 * This signal has an action, let 1197 * postsig() process it. 1198 */ 1199 return (sig); 1200 } 1201 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1202 } 1203 /* NOTREACHED */ 1204 } 1205 1206 /* 1207 * Put the argument process into the stopped state and notify the parent 1208 * via wakeup. Signals are handled elsewhere. The process must not be 1209 * on the run queue. 1210 */ 1211 void 1212 stop(struct proc *p) 1213 { 1214 p->p_stat = SSTOP; 1215 p->p_flag &= ~P_WAITED; 1216 wakeup((caddr_t)p->p_pptr); 1217 } 1218 1219 /* 1220 * Take the action for the specified signal 1221 * from the current set of pending signals. 1222 */ 1223 void 1224 postsig(int sig) 1225 { 1226 struct proc *p = curproc; 1227 struct sigacts *ps = p->p_sigacts; 1228 sig_t action; 1229 sigset_t returnmask; 1230 int code; 1231 1232 KASSERT(sig != 0, ("postsig")); 1233 1234 SIGDELSET(p->p_siglist, sig); 1235 action = ps->ps_sigact[_SIG_IDX(sig)]; 1236 #ifdef KTRACE 1237 if (KTRPOINT(p->p_thread, KTR_PSIG)) 1238 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1239 &p->p_oldsigmask : &p->p_sigmask, 0); 1240 #endif 1241 STOPEVENT(p, S_SIG, sig); 1242 1243 if (action == SIG_DFL) { 1244 /* 1245 * Default action, where the default is to kill 1246 * the process. (Other cases were ignored above.) 1247 */ 1248 sigexit(p, sig); 1249 /* NOTREACHED */ 1250 } else { 1251 /* 1252 * If we get here, the signal must be caught. 1253 */ 1254 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1255 ("postsig action")); 1256 /* 1257 * Set the new mask value and also defer further 1258 * occurrences of this signal. 1259 * 1260 * Special case: user has done a sigsuspend. Here the 1261 * current mask is not of interest, but rather the 1262 * mask from before the sigsuspend is what we want 1263 * restored after the signal processing is completed. 1264 */ 1265 splhigh(); 1266 if (p->p_flag & P_OLDMASK) { 1267 returnmask = p->p_oldsigmask; 1268 p->p_flag &= ~P_OLDMASK; 1269 } else { 1270 returnmask = p->p_sigmask; 1271 } 1272 1273 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1274 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1275 SIGADDSET(p->p_sigmask, sig); 1276 1277 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1278 /* 1279 * See kern_sigaction() for origin of this code. 1280 */ 1281 SIGDELSET(p->p_sigcatch, sig); 1282 if (sig != SIGCONT && 1283 sigprop(sig) & SA_IGNORE) 1284 SIGADDSET(p->p_sigignore, sig); 1285 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1286 } 1287 spl0(); 1288 p->p_stats->p_ru.ru_nsignals++; 1289 if (p->p_sig != sig) { 1290 code = 0; 1291 } else { 1292 code = p->p_code; 1293 p->p_code = 0; 1294 p->p_sig = 0; 1295 } 1296 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1297 } 1298 } 1299 1300 /* 1301 * Kill the current process for stated reason. 1302 */ 1303 void 1304 killproc(struct proc *p, char *why) 1305 { 1306 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1307 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1308 psignal(p, SIGKILL); 1309 } 1310 1311 /* 1312 * Force the current process to exit with the specified signal, dumping core 1313 * if appropriate. We bypass the normal tests for masked and caught signals, 1314 * allowing unrecoverable failures to terminate the process without changing 1315 * signal state. Mark the accounting record with the signal termination. 1316 * If dumping core, save the signal number for the debugger. Calls exit and 1317 * does not return. 1318 */ 1319 void 1320 sigexit(struct proc *p, int sig) 1321 { 1322 p->p_acflag |= AXSIG; 1323 if (sigprop(sig) & SA_CORE) { 1324 p->p_sig = sig; 1325 /* 1326 * Log signals which would cause core dumps 1327 * (Log as LOG_INFO to appease those who don't want 1328 * these messages.) 1329 * XXX : Todo, as well as euid, write out ruid too 1330 */ 1331 if (coredump(p) == 0) 1332 sig |= WCOREFLAG; 1333 if (kern_logsigexit) 1334 log(LOG_INFO, 1335 "pid %d (%s), uid %d: exited on signal %d%s\n", 1336 p->p_pid, p->p_comm, 1337 p->p_ucred ? p->p_ucred->cr_uid : -1, 1338 sig &~ WCOREFLAG, 1339 sig & WCOREFLAG ? " (core dumped)" : ""); 1340 } 1341 exit1(W_EXITCODE(0, sig)); 1342 /* NOTREACHED */ 1343 } 1344 1345 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1346 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1347 sizeof(corefilename), "process corefile name format string"); 1348 1349 /* 1350 * expand_name(name, uid, pid) 1351 * Expand the name described in corefilename, using name, uid, and pid. 1352 * corefilename is a printf-like string, with three format specifiers: 1353 * %N name of process ("name") 1354 * %P process id (pid) 1355 * %U user id (uid) 1356 * For example, "%N.core" is the default; they can be disabled completely 1357 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1358 * This is controlled by the sysctl variable kern.corefile (see above). 1359 */ 1360 1361 static char * 1362 expand_name(const char *name, uid_t uid, pid_t pid) 1363 { 1364 char *temp; 1365 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1366 int i, n; 1367 char *format = corefilename; 1368 size_t namelen; 1369 1370 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1371 if (temp == NULL) 1372 return NULL; 1373 namelen = strlen(name); 1374 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1375 int l; 1376 switch (format[i]) { 1377 case '%': /* Format character */ 1378 i++; 1379 switch (format[i]) { 1380 case '%': 1381 temp[n++] = '%'; 1382 break; 1383 case 'N': /* process name */ 1384 if ((n + namelen) > MAXPATHLEN) { 1385 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1386 pid, name, uid, temp, name); 1387 free(temp, M_TEMP); 1388 return NULL; 1389 } 1390 memcpy(temp+n, name, namelen); 1391 n += namelen; 1392 break; 1393 case 'P': /* process id */ 1394 l = sprintf(buf, "%u", pid); 1395 if ((n + l) > MAXPATHLEN) { 1396 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1397 pid, name, uid, temp, name); 1398 free(temp, M_TEMP); 1399 return NULL; 1400 } 1401 memcpy(temp+n, buf, l); 1402 n += l; 1403 break; 1404 case 'U': /* user id */ 1405 l = sprintf(buf, "%u", uid); 1406 if ((n + l) > MAXPATHLEN) { 1407 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1408 pid, name, uid, temp, name); 1409 free(temp, M_TEMP); 1410 return NULL; 1411 } 1412 memcpy(temp+n, buf, l); 1413 n += l; 1414 break; 1415 default: 1416 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1417 } 1418 break; 1419 default: 1420 temp[n++] = format[i]; 1421 } 1422 } 1423 temp[n] = '\0'; 1424 return temp; 1425 } 1426 1427 /* 1428 * Dump a process' core. The main routine does some 1429 * policy checking, and creates the name of the coredump; 1430 * then it passes on a vnode and a size limit to the process-specific 1431 * coredump routine if there is one; if there _is not_ one, it returns 1432 * ENOSYS; otherwise it returns the error from the process-specific routine. 1433 */ 1434 1435 static int 1436 coredump(struct proc *p) 1437 { 1438 struct vnode *vp; 1439 struct ucred *cred = p->p_ucred; 1440 struct thread *td = p->p_thread; 1441 struct flock lf; 1442 struct nameidata nd; 1443 struct vattr vattr; 1444 int error, error1; 1445 char *name; /* name of corefile */ 1446 off_t limit; 1447 1448 STOPEVENT(p, S_CORE, 0); 1449 1450 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 1451 return (EFAULT); 1452 1453 /* 1454 * Note that the bulk of limit checking is done after 1455 * the corefile is created. The exception is if the limit 1456 * for corefiles is 0, in which case we don't bother 1457 * creating the corefile at all. This layout means that 1458 * a corefile is truncated instead of not being created, 1459 * if it is larger than the limit. 1460 */ 1461 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1462 if (limit == 0) 1463 return EFBIG; 1464 1465 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1466 if (name == NULL) 1467 return (EINVAL); 1468 NDINIT(&nd, NAMEI_LOOKUP, 0, UIO_SYSSPACE, name, td); 1469 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 1470 free(name, M_TEMP); 1471 if (error) 1472 return (error); 1473 NDFREE(&nd, NDF_ONLY_PNBUF); 1474 vp = nd.ni_vp; 1475 1476 VOP_UNLOCK(vp, NULL, 0, td); 1477 lf.l_whence = SEEK_SET; 1478 lf.l_start = 0; 1479 lf.l_len = 0; 1480 lf.l_type = F_WRLCK; 1481 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 1482 if (error) 1483 goto out2; 1484 1485 /* Don't dump to non-regular files or files with links. */ 1486 if (vp->v_type != VREG || 1487 VOP_GETATTR(vp, &vattr, td) || vattr.va_nlink != 1) { 1488 error = EFAULT; 1489 goto out1; 1490 } 1491 1492 VATTR_NULL(&vattr); 1493 vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 1494 vattr.va_size = 0; 1495 VOP_LEASE(vp, td, cred, LEASE_WRITE); 1496 VOP_SETATTR(vp, &vattr, cred, td); 1497 p->p_acflag |= ACORE; 1498 VOP_UNLOCK(vp, NULL, 0, td); 1499 1500 error = p->p_sysent->sv_coredump ? 1501 p->p_sysent->sv_coredump(p, vp, limit) : 1502 ENOSYS; 1503 1504 out1: 1505 lf.l_type = F_UNLCK; 1506 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 1507 out2: 1508 error1 = vn_close(vp, FWRITE, td); 1509 if (error == 0) 1510 error = error1; 1511 return (error); 1512 } 1513 1514 /* 1515 * Nonexistent system call-- signal process (may want to handle it). 1516 * Flag error in case process won't see signal immediately (blocked or ignored). 1517 */ 1518 /* ARGSUSED */ 1519 int 1520 nosys(struct nosys_args *args) 1521 { 1522 psignal(curproc, SIGSYS); 1523 return (EINVAL); 1524 } 1525 1526 /* 1527 * Send a SIGIO or SIGURG signal to a process or process group using 1528 * stored credentials rather than those of the current process. 1529 */ 1530 void 1531 pgsigio(struct sigio *sigio, int sig, int checkctty) 1532 { 1533 if (sigio == NULL) 1534 return; 1535 1536 if (sigio->sio_pgid > 0) { 1537 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1538 sigio->sio_proc)) 1539 psignal(sigio->sio_proc, sig); 1540 } else if (sigio->sio_pgid < 0) { 1541 struct proc *p; 1542 1543 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) 1544 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1545 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1546 psignal(p, sig); 1547 } 1548 } 1549 1550 static int 1551 filt_sigattach(struct knote *kn) 1552 { 1553 struct proc *p = curproc; 1554 1555 kn->kn_ptr.p_proc = p; 1556 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1557 1558 /* XXX lock the proc here while adding to the list? */ 1559 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 1560 1561 return (0); 1562 } 1563 1564 static void 1565 filt_sigdetach(struct knote *kn) 1566 { 1567 struct proc *p = kn->kn_ptr.p_proc; 1568 1569 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 1570 } 1571 1572 /* 1573 * signal knotes are shared with proc knotes, so we apply a mask to 1574 * the hint in order to differentiate them from process hints. This 1575 * could be avoided by using a signal-specific knote list, but probably 1576 * isn't worth the trouble. 1577 */ 1578 static int 1579 filt_signal(struct knote *kn, long hint) 1580 { 1581 if (hint & NOTE_SIGNAL) { 1582 hint &= ~NOTE_SIGNAL; 1583 1584 if (kn->kn_id == hint) 1585 kn->kn_data++; 1586 } 1587 return (kn->kn_data != 0); 1588 } 1589