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 */ 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/sysproto.h> 48 #include <sys/signalvar.h> 49 #include <sys/resourcevar.h> 50 #include <sys/vnode.h> 51 #include <sys/event.h> 52 #include <sys/proc.h> 53 #include <sys/nlookup.h> 54 #include <sys/pioctl.h> 55 #include <sys/systm.h> 56 #include <sys/acct.h> 57 #include <sys/fcntl.h> 58 #include <sys/lock.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/interrupt.h> 67 #include <sys/unistd.h> 68 #include <sys/kern_syscall.h> 69 #include <sys/vkernel.h> 70 71 #include <sys/signal2.h> 72 #include <sys/thread2.h> 73 74 #include <machine/cpu.h> 75 #include <machine/smp.h> 76 77 static int coredump(struct lwp *, int); 78 static char *expand_name(const char *, uid_t, pid_t); 79 static int dokillpg(int sig, int pgid, int all); 80 static int sig_ffs(sigset_t *set); 81 static int sigprop(int sig); 82 static void lwp_signotify(struct lwp *lp); 83 #ifdef SMP 84 static void signotify_remote(void *arg); 85 #endif 86 static int kern_sigtimedwait(sigset_t set, siginfo_t *info, 87 struct timespec *timeout); 88 89 static int filt_sigattach(struct knote *kn); 90 static void filt_sigdetach(struct knote *kn); 91 static int filt_signal(struct knote *kn, long hint); 92 93 struct filterops sig_filtops = 94 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 95 96 static int kern_logsigexit = 1; 97 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 98 &kern_logsigexit, 0, 99 "Log processes quitting on abnormal signals to syslog(3)"); 100 101 /* 102 * Can process p, with pcred pc, send the signal sig to process q? 103 */ 104 #define CANSIGNAL(q, sig) \ 105 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \ 106 ((sig) == SIGCONT && (q)->p_session == curproc->p_session)) 107 108 /* 109 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 110 */ 111 #define CANSIGIO(ruid, uc, q) \ 112 ((uc)->cr_uid == 0 || \ 113 (ruid) == (q)->p_ucred->cr_ruid || \ 114 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \ 115 (ruid) == (q)->p_ucred->cr_uid || \ 116 (uc)->cr_uid == (q)->p_ucred->cr_uid) 117 118 int sugid_coredump; 119 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 120 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 121 122 static int do_coredump = 1; 123 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 124 &do_coredump, 0, "Enable/Disable coredumps"); 125 126 /* 127 * Signal properties and actions. 128 * The array below categorizes the signals and their default actions 129 * according to the following properties: 130 */ 131 #define SA_KILL 0x01 /* terminates process by default */ 132 #define SA_CORE 0x02 /* ditto and coredumps */ 133 #define SA_STOP 0x04 /* suspend process */ 134 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 135 #define SA_IGNORE 0x10 /* ignore by default */ 136 #define SA_CONT 0x20 /* continue if suspended */ 137 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 138 #define SA_CKPT 0x80 /* checkpoint process */ 139 140 141 static int sigproptbl[NSIG] = { 142 SA_KILL, /* SIGHUP */ 143 SA_KILL, /* SIGINT */ 144 SA_KILL|SA_CORE, /* SIGQUIT */ 145 SA_KILL|SA_CORE, /* SIGILL */ 146 SA_KILL|SA_CORE, /* SIGTRAP */ 147 SA_KILL|SA_CORE, /* SIGABRT */ 148 SA_KILL|SA_CORE, /* SIGEMT */ 149 SA_KILL|SA_CORE, /* SIGFPE */ 150 SA_KILL, /* SIGKILL */ 151 SA_KILL|SA_CORE, /* SIGBUS */ 152 SA_KILL|SA_CORE, /* SIGSEGV */ 153 SA_KILL|SA_CORE, /* SIGSYS */ 154 SA_KILL, /* SIGPIPE */ 155 SA_KILL, /* SIGALRM */ 156 SA_KILL, /* SIGTERM */ 157 SA_IGNORE, /* SIGURG */ 158 SA_STOP, /* SIGSTOP */ 159 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 160 SA_IGNORE|SA_CONT, /* SIGCONT */ 161 SA_IGNORE, /* SIGCHLD */ 162 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 163 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 164 SA_IGNORE, /* SIGIO */ 165 SA_KILL, /* SIGXCPU */ 166 SA_KILL, /* SIGXFSZ */ 167 SA_KILL, /* SIGVTALRM */ 168 SA_KILL, /* SIGPROF */ 169 SA_IGNORE, /* SIGWINCH */ 170 SA_IGNORE, /* SIGINFO */ 171 SA_KILL, /* SIGUSR1 */ 172 SA_KILL, /* SIGUSR2 */ 173 SA_IGNORE, /* SIGTHR */ 174 SA_CKPT, /* SIGCKPT */ 175 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */ 176 SA_IGNORE, 177 SA_IGNORE, 178 SA_IGNORE, 179 SA_IGNORE, 180 SA_IGNORE, 181 SA_IGNORE, 182 SA_IGNORE, 183 SA_IGNORE, 184 SA_IGNORE, 185 SA_IGNORE, 186 SA_IGNORE, 187 SA_IGNORE, 188 SA_IGNORE, 189 SA_IGNORE, 190 SA_IGNORE, 191 SA_IGNORE, 192 SA_IGNORE, 193 SA_IGNORE, 194 SA_IGNORE, 195 SA_IGNORE, 196 SA_IGNORE, 197 SA_IGNORE, 198 SA_IGNORE, 199 SA_IGNORE, 200 SA_IGNORE, 201 SA_IGNORE, 202 SA_IGNORE, 203 SA_IGNORE, 204 SA_IGNORE, 205 SA_IGNORE, 206 207 }; 208 209 static __inline int 210 sigprop(int sig) 211 { 212 213 if (sig > 0 && sig < NSIG) 214 return (sigproptbl[_SIG_IDX(sig)]); 215 return (0); 216 } 217 218 static __inline int 219 sig_ffs(sigset_t *set) 220 { 221 int i; 222 223 for (i = 0; i < _SIG_WORDS; i++) 224 if (set->__bits[i]) 225 return (ffs(set->__bits[i]) + (i * 32)); 226 return (0); 227 } 228 229 /* 230 * No requirements. 231 */ 232 int 233 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact) 234 { 235 struct thread *td = curthread; 236 struct proc *p = td->td_proc; 237 struct lwp *lp; 238 struct sigacts *ps = p->p_sigacts; 239 240 if (sig <= 0 || sig > _SIG_MAXSIG) 241 return (EINVAL); 242 243 lwkt_gettoken(&proc_token); 244 245 if (oact) { 246 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 247 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 248 oact->sa_flags = 0; 249 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 250 oact->sa_flags |= SA_ONSTACK; 251 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 252 oact->sa_flags |= SA_RESTART; 253 if (SIGISMEMBER(ps->ps_sigreset, sig)) 254 oact->sa_flags |= SA_RESETHAND; 255 if (SIGISMEMBER(ps->ps_signodefer, sig)) 256 oact->sa_flags |= SA_NODEFER; 257 if (SIGISMEMBER(ps->ps_siginfo, sig)) 258 oact->sa_flags |= SA_SIGINFO; 259 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) 260 oact->sa_flags |= SA_MAILBOX; 261 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP) 262 oact->sa_flags |= SA_NOCLDSTOP; 263 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT) 264 oact->sa_flags |= SA_NOCLDWAIT; 265 } 266 if (act) { 267 /* 268 * Check for invalid requests. KILL and STOP cannot be 269 * caught. 270 */ 271 if (sig == SIGKILL || sig == SIGSTOP) { 272 if (act->sa_handler != SIG_DFL) { 273 lwkt_reltoken(&proc_token); 274 return (EINVAL); 275 } 276 #if 0 277 /* (not needed, SIG_DFL forces action to occur) */ 278 if (act->sa_flags & SA_MAILBOX) 279 return (EINVAL); 280 #endif 281 } 282 283 /* 284 * Change setting atomically. 285 */ 286 crit_enter(); 287 288 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 289 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 290 if (act->sa_flags & SA_SIGINFO) { 291 ps->ps_sigact[_SIG_IDX(sig)] = 292 (__sighandler_t *)act->sa_sigaction; 293 SIGADDSET(ps->ps_siginfo, sig); 294 } else { 295 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 296 SIGDELSET(ps->ps_siginfo, sig); 297 } 298 if (!(act->sa_flags & SA_RESTART)) 299 SIGADDSET(ps->ps_sigintr, sig); 300 else 301 SIGDELSET(ps->ps_sigintr, sig); 302 if (act->sa_flags & SA_ONSTACK) 303 SIGADDSET(ps->ps_sigonstack, sig); 304 else 305 SIGDELSET(ps->ps_sigonstack, sig); 306 if (act->sa_flags & SA_RESETHAND) 307 SIGADDSET(ps->ps_sigreset, sig); 308 else 309 SIGDELSET(ps->ps_sigreset, sig); 310 if (act->sa_flags & SA_NODEFER) 311 SIGADDSET(ps->ps_signodefer, sig); 312 else 313 SIGDELSET(ps->ps_signodefer, sig); 314 if (act->sa_flags & SA_MAILBOX) 315 SIGADDSET(ps->ps_sigmailbox, sig); 316 else 317 SIGDELSET(ps->ps_sigmailbox, sig); 318 if (sig == SIGCHLD) { 319 if (act->sa_flags & SA_NOCLDSTOP) 320 p->p_sigacts->ps_flag |= PS_NOCLDSTOP; 321 else 322 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP; 323 if (act->sa_flags & SA_NOCLDWAIT) { 324 /* 325 * Paranoia: since SA_NOCLDWAIT is implemented 326 * by reparenting the dying child to PID 1 (and 327 * trust it to reap the zombie), PID 1 itself 328 * is forbidden to set SA_NOCLDWAIT. 329 */ 330 if (p->p_pid == 1) 331 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 332 else 333 p->p_sigacts->ps_flag |= PS_NOCLDWAIT; 334 } else { 335 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 336 } 337 } 338 /* 339 * Set bit in p_sigignore for signals that are set to SIG_IGN, 340 * and for signals set to SIG_DFL where the default is to 341 * ignore. However, don't put SIGCONT in p_sigignore, as we 342 * have to restart the process. 343 */ 344 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 345 (sigprop(sig) & SA_IGNORE && 346 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 347 /* never to be seen again */ 348 SIGDELSET(p->p_siglist, sig); 349 /* 350 * Remove the signal also from the thread lists. 351 */ 352 FOREACH_LWP_IN_PROC(lp, p) { 353 SIGDELSET(lp->lwp_siglist, sig); 354 } 355 if (sig != SIGCONT) 356 /* easier in ksignal */ 357 SIGADDSET(p->p_sigignore, sig); 358 SIGDELSET(p->p_sigcatch, sig); 359 } else { 360 SIGDELSET(p->p_sigignore, sig); 361 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 362 SIGDELSET(p->p_sigcatch, sig); 363 else 364 SIGADDSET(p->p_sigcatch, sig); 365 } 366 367 crit_exit(); 368 } 369 lwkt_reltoken(&proc_token); 370 return (0); 371 } 372 373 int 374 sys_sigaction(struct sigaction_args *uap) 375 { 376 struct sigaction act, oact; 377 struct sigaction *actp, *oactp; 378 int error; 379 380 actp = (uap->act != NULL) ? &act : NULL; 381 oactp = (uap->oact != NULL) ? &oact : NULL; 382 if (actp) { 383 error = copyin(uap->act, actp, sizeof(act)); 384 if (error) 385 return (error); 386 } 387 error = kern_sigaction(uap->sig, actp, oactp); 388 if (oactp && !error) { 389 error = copyout(oactp, uap->oact, sizeof(oact)); 390 } 391 return (error); 392 } 393 394 /* 395 * Initialize signal state for process 0; 396 * set to ignore signals that are ignored by default. 397 */ 398 void 399 siginit(struct proc *p) 400 { 401 int i; 402 403 for (i = 1; i <= NSIG; i++) 404 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 405 SIGADDSET(p->p_sigignore, i); 406 } 407 408 /* 409 * Reset signals for an exec of the specified process. 410 */ 411 void 412 execsigs(struct proc *p) 413 { 414 struct sigacts *ps = p->p_sigacts; 415 struct lwp *lp; 416 int sig; 417 418 lp = ONLY_LWP_IN_PROC(p); 419 420 /* 421 * Reset caught signals. Held signals remain held 422 * through p_sigmask (unless they were caught, 423 * and are now ignored by default). 424 */ 425 while (SIGNOTEMPTY(p->p_sigcatch)) { 426 sig = sig_ffs(&p->p_sigcatch); 427 SIGDELSET(p->p_sigcatch, sig); 428 if (sigprop(sig) & SA_IGNORE) { 429 if (sig != SIGCONT) 430 SIGADDSET(p->p_sigignore, sig); 431 SIGDELSET(p->p_siglist, sig); 432 SIGDELSET(lp->lwp_siglist, sig); 433 } 434 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 435 } 436 437 /* 438 * Reset stack state to the user stack. 439 * Clear set of signals caught on the signal stack. 440 */ 441 lp->lwp_sigstk.ss_flags = SS_DISABLE; 442 lp->lwp_sigstk.ss_size = 0; 443 lp->lwp_sigstk.ss_sp = 0; 444 lp->lwp_flag &= ~LWP_ALTSTACK; 445 /* 446 * Reset no zombies if child dies flag as Solaris does. 447 */ 448 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 449 } 450 451 /* 452 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc 453 * 454 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 455 * p == curproc. 456 */ 457 int 458 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) 459 { 460 struct thread *td = curthread; 461 struct lwp *lp = td->td_lwp; 462 int error; 463 464 lwkt_gettoken(&proc_token); 465 466 if (oset != NULL) 467 *oset = lp->lwp_sigmask; 468 469 error = 0; 470 if (set != NULL) { 471 switch (how) { 472 case SIG_BLOCK: 473 SIG_CANTMASK(*set); 474 SIGSETOR(lp->lwp_sigmask, *set); 475 break; 476 case SIG_UNBLOCK: 477 SIGSETNAND(lp->lwp_sigmask, *set); 478 break; 479 case SIG_SETMASK: 480 SIG_CANTMASK(*set); 481 lp->lwp_sigmask = *set; 482 break; 483 default: 484 error = EINVAL; 485 break; 486 } 487 } 488 489 lwkt_reltoken(&proc_token); 490 491 return (error); 492 } 493 494 /* 495 * sigprocmask() 496 * 497 * MPSAFE 498 */ 499 int 500 sys_sigprocmask(struct sigprocmask_args *uap) 501 { 502 sigset_t set, oset; 503 sigset_t *setp, *osetp; 504 int error; 505 506 setp = (uap->set != NULL) ? &set : NULL; 507 osetp = (uap->oset != NULL) ? &oset : NULL; 508 if (setp) { 509 error = copyin(uap->set, setp, sizeof(set)); 510 if (error) 511 return (error); 512 } 513 error = kern_sigprocmask(uap->how, setp, osetp); 514 if (osetp && !error) { 515 error = copyout(osetp, uap->oset, sizeof(oset)); 516 } 517 return (error); 518 } 519 520 /* 521 * MPSAFE 522 */ 523 int 524 kern_sigpending(struct __sigset *set) 525 { 526 struct lwp *lp = curthread->td_lwp; 527 528 *set = lwp_sigpend(lp); 529 530 return (0); 531 } 532 533 /* 534 * MPSAFE 535 */ 536 int 537 sys_sigpending(struct sigpending_args *uap) 538 { 539 sigset_t set; 540 int error; 541 542 error = kern_sigpending(&set); 543 544 if (error == 0) 545 error = copyout(&set, uap->set, sizeof(set)); 546 return (error); 547 } 548 549 /* 550 * Suspend process until signal, providing mask to be set 551 * in the meantime. 552 * 553 * MPSAFE 554 */ 555 int 556 kern_sigsuspend(struct __sigset *set) 557 { 558 struct thread *td = curthread; 559 struct lwp *lp = td->td_lwp; 560 struct proc *p = td->td_proc; 561 struct sigacts *ps = p->p_sigacts; 562 563 /* 564 * When returning from sigsuspend, we want 565 * the old mask to be restored after the 566 * signal handler has finished. Thus, we 567 * save it here and mark the sigacts structure 568 * to indicate this. 569 */ 570 lp->lwp_oldsigmask = lp->lwp_sigmask; 571 lp->lwp_flag |= LWP_OLDMASK; 572 573 SIG_CANTMASK(*set); 574 lp->lwp_sigmask = *set; 575 while (tsleep(ps, PCATCH, "pause", 0) == 0) 576 /* void */; 577 /* always return EINTR rather than ERESTART... */ 578 return (EINTR); 579 } 580 581 /* 582 * Note nonstandard calling convention: libc stub passes mask, not 583 * pointer, to save a copyin. 584 * 585 * MPSAFE 586 */ 587 int 588 sys_sigsuspend(struct sigsuspend_args *uap) 589 { 590 sigset_t mask; 591 int error; 592 593 error = copyin(uap->sigmask, &mask, sizeof(mask)); 594 if (error) 595 return (error); 596 597 error = kern_sigsuspend(&mask); 598 599 return (error); 600 } 601 602 /* 603 * MPSAFE 604 */ 605 int 606 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) 607 { 608 struct thread *td = curthread; 609 struct lwp *lp = td->td_lwp; 610 struct proc *p = td->td_proc; 611 612 if ((lp->lwp_flag & LWP_ALTSTACK) == 0) 613 lp->lwp_sigstk.ss_flags |= SS_DISABLE; 614 615 if (oss) 616 *oss = lp->lwp_sigstk; 617 618 if (ss) { 619 if (ss->ss_flags & SS_DISABLE) { 620 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK) 621 return (EINVAL); 622 lp->lwp_flag &= ~LWP_ALTSTACK; 623 lp->lwp_sigstk.ss_flags = ss->ss_flags; 624 } else { 625 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 626 return (ENOMEM); 627 lp->lwp_flag |= LWP_ALTSTACK; 628 lp->lwp_sigstk = *ss; 629 } 630 } 631 632 return (0); 633 } 634 635 /* 636 * MPSAFE 637 */ 638 int 639 sys_sigaltstack(struct sigaltstack_args *uap) 640 { 641 stack_t ss, oss; 642 int error; 643 644 if (uap->ss) { 645 error = copyin(uap->ss, &ss, sizeof(ss)); 646 if (error) 647 return (error); 648 } 649 650 error = kern_sigaltstack(uap->ss ? &ss : NULL, 651 uap->oss ? &oss : NULL); 652 653 if (error == 0 && uap->oss) 654 error = copyout(&oss, uap->oss, sizeof(*uap->oss)); 655 return (error); 656 } 657 658 /* 659 * Common code for kill process group/broadcast kill. 660 * cp is calling process. 661 */ 662 struct killpg_info { 663 int nfound; 664 int sig; 665 }; 666 667 static int killpg_all_callback(struct proc *p, void *data); 668 669 static int 670 dokillpg(int sig, int pgid, int all) 671 { 672 struct killpg_info info; 673 struct proc *cp = curproc; 674 struct proc *p; 675 struct pgrp *pgrp; 676 677 info.nfound = 0; 678 info.sig = sig; 679 680 if (all) { 681 /* 682 * broadcast 683 */ 684 allproc_scan(killpg_all_callback, &info); 685 } else { 686 if (pgid == 0) { 687 /* 688 * zero pgid means send to my process group. 689 */ 690 pgrp = cp->p_pgrp; 691 } else { 692 pgrp = pgfind(pgid); 693 if (pgrp == NULL) 694 return (ESRCH); 695 } 696 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); 697 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 698 if (p->p_pid <= 1 || 699 p->p_stat == SZOMB || 700 (p->p_flag & P_SYSTEM) || 701 !CANSIGNAL(p, sig)) { 702 continue; 703 } 704 ++info.nfound; 705 if (sig) 706 ksignal(p, sig); 707 } 708 lockmgr(&pgrp->pg_lock, LK_RELEASE); 709 } 710 return (info.nfound ? 0 : ESRCH); 711 } 712 713 static int 714 killpg_all_callback(struct proc *p, void *data) 715 { 716 struct killpg_info *info = data; 717 718 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) || 719 p == curproc || !CANSIGNAL(p, info->sig)) { 720 return (0); 721 } 722 ++info->nfound; 723 if (info->sig) 724 ksignal(p, info->sig); 725 return(0); 726 } 727 728 /* 729 * Send a general signal to a process or LWPs within that process. Note 730 * that new signals cannot be sent if a process is exiting. 731 * 732 * No requirements. 733 */ 734 int 735 kern_kill(int sig, pid_t pid, lwpid_t tid) 736 { 737 int t; 738 739 if ((u_int)sig > _SIG_MAXSIG) 740 return (EINVAL); 741 742 lwkt_gettoken(&proc_token); 743 744 if (pid > 0) { 745 struct proc *p; 746 struct lwp *lp = NULL; 747 748 /* kill single process */ 749 if ((p = pfind(pid)) == NULL) { 750 lwkt_reltoken(&proc_token); 751 return (ESRCH); 752 } 753 if (!CANSIGNAL(p, sig)) { 754 lwkt_reltoken(&proc_token); 755 return (EPERM); 756 } 757 758 /* 759 * NOP if the process is exiting. Note that lwpsignal() is 760 * called directly with P_WEXIT set to kill individual LWPs 761 * during exit, which is allowed. 762 */ 763 if (p->p_flag & P_WEXIT) { 764 lwkt_reltoken(&proc_token); 765 return (0); 766 } 767 if (tid != -1) { 768 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid); 769 if (lp == NULL) { 770 lwkt_reltoken(&proc_token); 771 return (ESRCH); 772 } 773 } 774 if (sig) 775 lwpsignal(p, lp, sig); 776 lwkt_reltoken(&proc_token); 777 return (0); 778 } 779 /* 780 * If we come here, pid is a special broadcast pid. 781 * This doesn't mix with a tid. 782 */ 783 if (tid != -1) { 784 lwkt_reltoken(&proc_token); 785 return (EINVAL); 786 } 787 switch (pid) { 788 case -1: /* broadcast signal */ 789 t = (dokillpg(sig, 0, 1)); 790 break; 791 case 0: /* signal own process group */ 792 t = (dokillpg(sig, 0, 0)); 793 break; 794 default: /* negative explicit process group */ 795 t = (dokillpg(sig, -pid, 0)); 796 break; 797 } 798 lwkt_reltoken(&proc_token); 799 return t; 800 } 801 802 int 803 sys_kill(struct kill_args *uap) 804 { 805 int error; 806 807 error = kern_kill(uap->signum, uap->pid, -1); 808 return (error); 809 } 810 811 int 812 sys_lwp_kill(struct lwp_kill_args *uap) 813 { 814 int error; 815 pid_t pid = uap->pid; 816 817 /* 818 * A tid is mandatory for lwp_kill(), otherwise 819 * you could simply use kill(). 820 */ 821 if (uap->tid == -1) 822 return (EINVAL); 823 824 /* 825 * To save on a getpid() function call for intra-process 826 * signals, pid == -1 means current process. 827 */ 828 if (pid == -1) 829 pid = curproc->p_pid; 830 831 error = kern_kill(uap->signum, pid, uap->tid); 832 return (error); 833 } 834 835 /* 836 * Send a signal to a process group. 837 */ 838 void 839 gsignal(int pgid, int sig) 840 { 841 struct pgrp *pgrp; 842 843 if (pgid && (pgrp = pgfind(pgid))) 844 pgsignal(pgrp, sig, 0); 845 } 846 847 /* 848 * Send a signal to a process group. If checktty is 1, 849 * limit to members which have a controlling terminal. 850 * 851 * pg_lock interlocks against a fork that might be in progress, to 852 * ensure that the new child process picks up the signal. 853 */ 854 void 855 pgsignal(struct pgrp *pgrp, int sig, int checkctty) 856 { 857 struct proc *p; 858 859 if (pgrp) { 860 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); 861 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 862 if (checkctty == 0 || p->p_flag & P_CONTROLT) 863 ksignal(p, sig); 864 } 865 lockmgr(&pgrp->pg_lock, LK_RELEASE); 866 } 867 } 868 869 /* 870 * Send a signal caused by a trap to the current lwp. If it will be caught 871 * immediately, deliver it with correct code. Otherwise, post it normally. 872 * 873 * These signals may ONLY be delivered to the specified lwp and may never 874 * be delivered to the process generically. 875 */ 876 void 877 trapsignal(struct lwp *lp, int sig, u_long code) 878 { 879 struct proc *p = lp->lwp_proc; 880 struct sigacts *ps = p->p_sigacts; 881 882 /* 883 * If we are a virtual kernel running an emulated user process 884 * context, switch back to the virtual kernel context before 885 * trying to post the signal. 886 */ 887 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { 888 struct trapframe *tf = lp->lwp_md.md_regs; 889 tf->tf_trapno = 0; 890 vkernel_trap(lp, tf); 891 } 892 893 894 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 895 !SIGISMEMBER(lp->lwp_sigmask, sig)) { 896 lp->lwp_ru.ru_nsignals++; 897 #ifdef KTRACE 898 if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) 899 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)], 900 &lp->lwp_sigmask, code); 901 #endif 902 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 903 &lp->lwp_sigmask, code); 904 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 905 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 906 SIGADDSET(lp->lwp_sigmask, sig); 907 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 908 /* 909 * See kern_sigaction() for origin of this code. 910 */ 911 SIGDELSET(p->p_sigcatch, sig); 912 if (sig != SIGCONT && 913 sigprop(sig) & SA_IGNORE) 914 SIGADDSET(p->p_sigignore, sig); 915 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 916 } 917 } else { 918 lp->lwp_code = code; /* XXX for core dump/debugger */ 919 lp->lwp_sig = sig; /* XXX to verify code */ 920 lwpsignal(p, lp, sig); 921 } 922 } 923 924 /* 925 * Find a suitable lwp to deliver the signal to. 926 * 927 * Returns NULL if all lwps hold the signal blocked. 928 */ 929 static struct lwp * 930 find_lwp_for_signal(struct proc *p, int sig) 931 { 932 struct lwp *lp; 933 struct lwp *run, *sleep, *stop; 934 935 /* 936 * If the running/preempted thread belongs to the proc to which 937 * the signal is being delivered and this thread does not block 938 * the signal, then we can avoid a context switch by delivering 939 * the signal to this thread, because it will return to userland 940 * soon anyways. 941 */ 942 lp = lwkt_preempted_proc(); 943 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig)) 944 return (lp); 945 946 run = sleep = stop = NULL; 947 FOREACH_LWP_IN_PROC(lp, p) { 948 /* 949 * If the signal is being blocked by the lwp, then this 950 * lwp is not eligible for receiving the signal. 951 */ 952 if (SIGISMEMBER(lp->lwp_sigmask, sig)) 953 continue; 954 955 switch (lp->lwp_stat) { 956 case LSRUN: 957 run = lp; 958 break; 959 960 case LSSTOP: 961 stop = lp; 962 break; 963 964 case LSSLEEP: 965 if (lp->lwp_flag & LWP_SINTR) 966 sleep = lp; 967 break; 968 } 969 } 970 971 if (run != NULL) 972 return (run); 973 else if (sleep != NULL) 974 return (sleep); 975 else 976 return (stop); 977 } 978 979 /* 980 * Send the signal to the process. If the signal has an action, the action 981 * is usually performed by the target process rather than the caller; we add 982 * the signal to the set of pending signals for the process. 983 * 984 * Exceptions: 985 * o When a stop signal is sent to a sleeping process that takes the 986 * default action, the process is stopped without awakening it. 987 * o SIGCONT restarts stopped processes (or puts them back to sleep) 988 * regardless of the signal action (eg, blocked or ignored). 989 * 990 * Other ignored signals are discarded immediately. 991 * 992 * No requirements. 993 */ 994 void 995 ksignal(struct proc *p, int sig) 996 { 997 lwpsignal(p, NULL, sig); 998 } 999 1000 /* 1001 * The core for ksignal. lp may be NULL, then a suitable thread 1002 * will be chosen. If not, lp MUST be a member of p. 1003 * 1004 * No requirements. 1005 */ 1006 void 1007 lwpsignal(struct proc *p, struct lwp *lp, int sig) 1008 { 1009 int prop; 1010 sig_t action; 1011 1012 if (sig > _SIG_MAXSIG || sig <= 0) { 1013 kprintf("lwpsignal: signal %d\n", sig); 1014 panic("lwpsignal signal number"); 1015 } 1016 1017 KKASSERT(lp == NULL || lp->lwp_proc == p); 1018 1019 lwkt_gettoken(&proc_token); 1020 1021 prop = sigprop(sig); 1022 1023 /* 1024 * If proc is traced, always give parent a chance; 1025 * if signal event is tracked by procfs, give *that* 1026 * a chance, as well. 1027 */ 1028 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1029 action = SIG_DFL; 1030 } else { 1031 /* 1032 * Do not try to deliver signals to an exiting lwp. Note 1033 * that we must still deliver the signal if P_WEXIT is set 1034 * in the process flags. 1035 */ 1036 if (lp && (lp->lwp_flag & LWP_WEXIT)) { 1037 lwkt_reltoken(&proc_token); 1038 return; 1039 } 1040 1041 /* 1042 * If the signal is being ignored, then we forget about 1043 * it immediately. NOTE: We don't set SIGCONT in p_sigignore, 1044 * and if it is set to SIG_IGN, action will be SIG_DFL here. 1045 */ 1046 if (SIGISMEMBER(p->p_sigignore, sig)) { 1047 lwkt_reltoken(&proc_token); 1048 return; 1049 } 1050 if (SIGISMEMBER(p->p_sigcatch, sig)) 1051 action = SIG_CATCH; 1052 else 1053 action = SIG_DFL; 1054 } 1055 1056 /* 1057 * If continuing, clear any pending STOP signals. 1058 */ 1059 if (prop & SA_CONT) 1060 SIG_STOPSIGMASK(p->p_siglist); 1061 1062 if (prop & SA_STOP) { 1063 /* 1064 * If sending a tty stop signal to a member of an orphaned 1065 * process group, discard the signal here if the action 1066 * is default; don't stop the process below if sleeping, 1067 * and don't clear any pending SIGCONT. 1068 */ 1069 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1070 action == SIG_DFL) { 1071 lwkt_reltoken(&proc_token); 1072 return; 1073 } 1074 SIG_CONTSIGMASK(p->p_siglist); 1075 p->p_flag &= ~P_CONTINUED; 1076 } 1077 1078 crit_enter(); 1079 1080 if (p->p_stat == SSTOP) { 1081 /* 1082 * Nobody can handle this signal, add it to the lwp or 1083 * process pending list 1084 */ 1085 if (lp) 1086 SIGADDSET(lp->lwp_siglist, sig); 1087 else 1088 SIGADDSET(p->p_siglist, sig); 1089 1090 /* 1091 * If the process is stopped and is being traced, then no 1092 * further action is necessary. 1093 */ 1094 if (p->p_flag & P_TRACED) 1095 goto out; 1096 1097 /* 1098 * If the process is stopped and receives a KILL signal, 1099 * make the process runnable. 1100 */ 1101 if (sig == SIGKILL) { 1102 proc_unstop(p); 1103 goto active_process; 1104 } 1105 1106 /* 1107 * If the process is stopped and receives a CONT signal, 1108 * then try to make the process runnable again. 1109 */ 1110 if (prop & SA_CONT) { 1111 /* 1112 * If SIGCONT is default (or ignored), we continue the 1113 * process but don't leave the signal in p_siglist, as 1114 * it has no further action. If SIGCONT is held, we 1115 * continue the process and leave the signal in 1116 * p_siglist. If the process catches SIGCONT, let it 1117 * handle the signal itself. 1118 */ 1119 /* XXX what if the signal is being held blocked? */ 1120 p->p_flag |= P_CONTINUED; 1121 wakeup(p->p_pptr); 1122 if (action == SIG_DFL) 1123 SIGDELSET(p->p_siglist, sig); 1124 proc_unstop(p); 1125 if (action == SIG_CATCH) 1126 goto active_process; 1127 goto out; 1128 } 1129 1130 /* 1131 * If the process is stopped and receives another STOP 1132 * signal, we do not need to stop it again. If we did 1133 * the shell could get confused. 1134 * 1135 * However, if the current/preempted lwp is part of the 1136 * process receiving the signal, we need to keep it, 1137 * so that this lwp can stop in issignal() later, as 1138 * we don't want to wait until it reaches userret! 1139 */ 1140 if (prop & SA_STOP) { 1141 if (lwkt_preempted_proc() == NULL || 1142 lwkt_preempted_proc()->lwp_proc != p) 1143 SIGDELSET(p->p_siglist, sig); 1144 } 1145 1146 /* 1147 * Otherwise the process is stopped and it received some 1148 * signal, which does not change its stopped state. 1149 * 1150 * We have to select one thread to set LWP_BREAKTSLEEP, 1151 * so that the current signal will break the sleep 1152 * as soon as a SA_CONT signal will unstop the process. 1153 */ 1154 if (lp == NULL) 1155 lp = find_lwp_for_signal(p, sig); 1156 if (lp != NULL && 1157 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP)) 1158 lp->lwp_flag |= LWP_BREAKTSLEEP; 1159 goto out; 1160 1161 /* NOTREACHED */ 1162 } 1163 /* else not stopped */ 1164 active_process: 1165 1166 /* 1167 * Never deliver a lwp-specific signal to a random lwp. 1168 */ 1169 if (lp == NULL) { 1170 lp = find_lwp_for_signal(p, sig); 1171 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig)) 1172 lp = NULL; 1173 } 1174 1175 /* 1176 * Deliver to the process generically if (1) the signal is being 1177 * sent to any thread or (2) we could not find a thread to deliver 1178 * it to. 1179 */ 1180 if (lp == NULL) { 1181 SIGADDSET(p->p_siglist, sig); 1182 goto out; 1183 } 1184 1185 /* 1186 * Deliver to a specific LWP whether it masks it or not. It will 1187 * not be dispatched if masked but we must still deliver it. 1188 */ 1189 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1190 (p->p_flag & P_TRACED) == 0) { 1191 p->p_nice = NZERO; 1192 } 1193 1194 /* 1195 * If the process receives a STOP signal which indeed needs to 1196 * stop the process, do so. If the process chose to catch the 1197 * signal, it will be treated like any other signal. 1198 */ 1199 if ((prop & SA_STOP) && action == SIG_DFL) { 1200 /* 1201 * If a child holding parent blocked, stopping 1202 * could cause deadlock. Take no action at this 1203 * time. 1204 */ 1205 if (p->p_flag & P_PPWAIT) { 1206 SIGADDSET(p->p_siglist, sig); 1207 goto out; 1208 } 1209 1210 /* 1211 * Do not actually try to manipulate the process, but simply 1212 * stop it. Lwps will stop as soon as they safely can. 1213 */ 1214 p->p_xstat = sig; 1215 proc_stop(p); 1216 goto out; 1217 } 1218 1219 /* 1220 * If it is a CONT signal with default action, just ignore it. 1221 */ 1222 if ((prop & SA_CONT) && action == SIG_DFL) 1223 goto out; 1224 1225 /* 1226 * Mark signal pending at this specific thread. 1227 */ 1228 SIGADDSET(lp->lwp_siglist, sig); 1229 1230 lwp_signotify(lp); 1231 1232 out: 1233 lwkt_reltoken(&proc_token); 1234 crit_exit(); 1235 } 1236 1237 /* 1238 * proc_token must be held 1239 */ 1240 static void 1241 lwp_signotify(struct lwp *lp) 1242 { 1243 ASSERT_LWKT_TOKEN_HELD(&proc_token); 1244 crit_enter(); 1245 1246 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) { 1247 /* 1248 * Thread is in tsleep. 1249 */ 1250 1251 /* 1252 * If the thread is sleeping uninterruptibly 1253 * we can't interrupt the sleep... the signal will 1254 * be noticed when the lwp returns through 1255 * trap() or syscall(). 1256 * 1257 * Otherwise the signal can interrupt the sleep. 1258 * 1259 * If the process is traced, the lwp will handle the 1260 * tracing in issignal() when it returns to userland. 1261 */ 1262 if (lp->lwp_flag & LWP_SINTR) { 1263 /* 1264 * Make runnable and break out of any tsleep as well. 1265 */ 1266 lp->lwp_flag |= LWP_BREAKTSLEEP; 1267 setrunnable(lp); 1268 } 1269 } else { 1270 /* 1271 * Otherwise the thread is running 1272 * 1273 * LSRUN does nothing with the signal, other than kicking 1274 * ourselves if we are running. 1275 * SZOMB and SIDL mean that it will either never be noticed, 1276 * or noticed very soon. 1277 * 1278 * Note that lwp_thread may be NULL or may not be completely 1279 * initialized if the process is in the SIDL or SZOMB state. 1280 * 1281 * For SMP we may have to forward the request to another cpu. 1282 * YYY the MP lock prevents the target process from moving 1283 * to another cpu, see kern/kern_switch.c 1284 * 1285 * If the target thread is waiting on its message port, 1286 * wakeup the target thread so it can check (or ignore) 1287 * the new signal. YYY needs cleanup. 1288 */ 1289 if (lp == lwkt_preempted_proc()) { 1290 signotify(); 1291 } else if (lp->lwp_stat == LSRUN) { 1292 struct thread *td = lp->lwp_thread; 1293 struct proc *p __debugvar = lp->lwp_proc; 1294 1295 KASSERT(td != NULL, 1296 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x", 1297 p->p_pid, lp->lwp_tid, lp->lwp_stat, 1298 p->p_flag, lp->lwp_flag)); 1299 1300 /* 1301 * To prevent a MP race with TDF_SINTR we must 1302 * schedule the thread on the correct cpu. 1303 */ 1304 #ifdef SMP 1305 if (td->td_gd != mycpu) { 1306 LWPHOLD(lp); 1307 lwkt_send_ipiq(td->td_gd, signotify_remote, lp); 1308 } else 1309 #endif 1310 if (td->td_flags & TDF_SINTR) 1311 lwkt_schedule(td); 1312 } 1313 } 1314 crit_exit(); 1315 } 1316 1317 #ifdef SMP 1318 1319 /* 1320 * This function is called via an IPI. We will be in a critical section but 1321 * the MP lock will NOT be held. Also note that by the time the ipi message 1322 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 1323 */ 1324 static void 1325 signotify_remote(void *arg) 1326 { 1327 struct lwp *lp = arg; 1328 1329 if (lp == lwkt_preempted_proc()) { 1330 signotify(); 1331 } else { 1332 struct thread *td = lp->lwp_thread; 1333 if (td->td_flags & TDF_SINTR) 1334 lwkt_schedule(td); 1335 } 1336 LWPRELE(lp); 1337 } 1338 1339 #endif 1340 1341 /* 1342 * Caller must hold proc_token 1343 */ 1344 void 1345 proc_stop(struct proc *p) 1346 { 1347 struct lwp *lp; 1348 1349 ASSERT_LWKT_TOKEN_HELD(&proc_token); 1350 crit_enter(); 1351 1352 /* If somebody raced us, be happy with it */ 1353 if (p->p_stat == SSTOP || p->p_stat == SZOMB) { 1354 crit_exit(); 1355 return; 1356 } 1357 p->p_stat = SSTOP; 1358 1359 FOREACH_LWP_IN_PROC(lp, p) { 1360 switch (lp->lwp_stat) { 1361 case LSSTOP: 1362 /* 1363 * Do nothing, we are already counted in 1364 * p_nstopped. 1365 */ 1366 break; 1367 1368 case LSSLEEP: 1369 /* 1370 * We're sleeping, but we will stop before 1371 * returning to userspace, so count us 1372 * as stopped as well. We set LWP_WSTOP 1373 * to signal the lwp that it should not 1374 * increase p_nstopped when reaching tstop(). 1375 */ 1376 if ((lp->lwp_flag & LWP_WSTOP) == 0) { 1377 lp->lwp_flag |= LWP_WSTOP; 1378 ++p->p_nstopped; 1379 } 1380 break; 1381 1382 case LSRUN: 1383 /* 1384 * We might notify ourself, but that's not 1385 * a problem. 1386 */ 1387 lwp_signotify(lp); 1388 break; 1389 } 1390 } 1391 1392 if (p->p_nstopped == p->p_nthreads) { 1393 p->p_flag &= ~P_WAITED; 1394 wakeup(p->p_pptr); 1395 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0) 1396 ksignal(p->p_pptr, SIGCHLD); 1397 } 1398 crit_exit(); 1399 } 1400 1401 /* 1402 * Caller must hold proc_token 1403 */ 1404 void 1405 proc_unstop(struct proc *p) 1406 { 1407 struct lwp *lp; 1408 1409 ASSERT_LWKT_TOKEN_HELD(&proc_token); 1410 crit_enter(); 1411 1412 if (p->p_stat != SSTOP) { 1413 crit_exit(); 1414 return; 1415 } 1416 1417 p->p_stat = SACTIVE; 1418 1419 FOREACH_LWP_IN_PROC(lp, p) { 1420 switch (lp->lwp_stat) { 1421 case LSRUN: 1422 /* 1423 * Uh? Not stopped? Well, I guess that's okay. 1424 */ 1425 if (bootverbose) 1426 kprintf("proc_unstop: lwp %d/%d not sleeping\n", 1427 p->p_pid, lp->lwp_tid); 1428 break; 1429 1430 case LSSLEEP: 1431 /* 1432 * Still sleeping. Don't bother waking it up. 1433 * However, if this thread was counted as 1434 * stopped, undo this. 1435 * 1436 * Nevertheless we call setrunnable() so that it 1437 * will wake up in case a signal or timeout arrived 1438 * in the meantime. 1439 */ 1440 if (lp->lwp_flag & LWP_WSTOP) { 1441 lp->lwp_flag &= ~LWP_WSTOP; 1442 --p->p_nstopped; 1443 } else { 1444 if (bootverbose) 1445 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n", 1446 p->p_pid, lp->lwp_tid); 1447 } 1448 /* FALLTHROUGH */ 1449 1450 case LSSTOP: 1451 setrunnable(lp); 1452 break; 1453 1454 } 1455 } 1456 crit_exit(); 1457 } 1458 1459 /* 1460 * No requirements. 1461 * 1462 * XXX: Holds the proc_token for longer than it probably needs to. 1463 */ 1464 static int 1465 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout) 1466 { 1467 sigset_t savedmask, set; 1468 struct proc *p = curproc; 1469 struct lwp *lp = curthread->td_lwp; 1470 int error, sig, hz, timevalid = 0; 1471 struct timespec rts, ets, ts; 1472 struct timeval tv; 1473 1474 lwkt_gettoken(&proc_token); 1475 1476 error = 0; 1477 sig = 0; 1478 ets.tv_sec = 0; /* silence compiler warning */ 1479 ets.tv_nsec = 0; /* silence compiler warning */ 1480 SIG_CANTMASK(waitset); 1481 savedmask = lp->lwp_sigmask; 1482 1483 if (timeout) { 1484 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 && 1485 timeout->tv_nsec < 1000000000) { 1486 timevalid = 1; 1487 getnanouptime(&rts); 1488 ets = rts; 1489 timespecadd(&ets, timeout); 1490 } 1491 } 1492 1493 for (;;) { 1494 set = lwp_sigpend(lp); 1495 SIGSETAND(set, waitset); 1496 if ((sig = sig_ffs(&set)) != 0) { 1497 SIGFILLSET(lp->lwp_sigmask); 1498 SIGDELSET(lp->lwp_sigmask, sig); 1499 SIG_CANTMASK(lp->lwp_sigmask); 1500 sig = issignal(lp, 1); 1501 /* 1502 * It may be a STOP signal, in the case, issignal 1503 * returns 0, because we may stop there, and new 1504 * signal can come in, we should restart if we got 1505 * nothing. 1506 */ 1507 if (sig == 0) 1508 continue; 1509 else 1510 break; 1511 } 1512 1513 /* 1514 * Previous checking got nothing, and we retried but still 1515 * got nothing, we should return the error status. 1516 */ 1517 if (error) 1518 break; 1519 1520 /* 1521 * POSIX says this must be checked after looking for pending 1522 * signals. 1523 */ 1524 if (timeout) { 1525 if (timevalid == 0) { 1526 error = EINVAL; 1527 break; 1528 } 1529 getnanouptime(&rts); 1530 if (timespeccmp(&rts, &ets, >=)) { 1531 error = EAGAIN; 1532 break; 1533 } 1534 ts = ets; 1535 timespecsub(&ts, &rts); 1536 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1537 hz = tvtohz_high(&tv); 1538 } else 1539 hz = 0; 1540 1541 lp->lwp_sigmask = savedmask; 1542 SIGSETNAND(lp->lwp_sigmask, waitset); 1543 /* 1544 * We won't ever be woken up. Instead, our sleep will 1545 * be broken in lwpsignal(). 1546 */ 1547 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz); 1548 if (timeout) { 1549 if (error == ERESTART) { 1550 /* can not restart a timeout wait. */ 1551 error = EINTR; 1552 } else if (error == EAGAIN) { 1553 /* will calculate timeout by ourself. */ 1554 error = 0; 1555 } 1556 } 1557 /* Retry ... */ 1558 } 1559 1560 lp->lwp_sigmask = savedmask; 1561 if (sig) { 1562 error = 0; 1563 bzero(info, sizeof(*info)); 1564 info->si_signo = sig; 1565 lwp_delsig(lp, sig); /* take the signal! */ 1566 1567 if (sig == SIGKILL) 1568 sigexit(lp, sig); 1569 } 1570 1571 lwkt_reltoken(&proc_token); 1572 1573 return (error); 1574 } 1575 1576 /* 1577 * MPALMOSTSAFE 1578 */ 1579 int 1580 sys_sigtimedwait(struct sigtimedwait_args *uap) 1581 { 1582 struct timespec ts; 1583 struct timespec *timeout; 1584 sigset_t set; 1585 siginfo_t info; 1586 int error; 1587 1588 if (uap->timeout) { 1589 error = copyin(uap->timeout, &ts, sizeof(ts)); 1590 if (error) 1591 return (error); 1592 timeout = &ts; 1593 } else { 1594 timeout = NULL; 1595 } 1596 error = copyin(uap->set, &set, sizeof(set)); 1597 if (error) 1598 return (error); 1599 error = kern_sigtimedwait(set, &info, timeout); 1600 if (error) 1601 return (error); 1602 if (uap->info) 1603 error = copyout(&info, uap->info, sizeof(info)); 1604 /* Repost if we got an error. */ 1605 /* 1606 * XXX lwp 1607 * 1608 * This could transform a thread-specific signal to another 1609 * thread / process pending signal. 1610 */ 1611 if (error) { 1612 ksignal(curproc, info.si_signo); 1613 } else { 1614 uap->sysmsg_result = info.si_signo; 1615 } 1616 return (error); 1617 } 1618 1619 /* 1620 * MPALMOSTSAFE 1621 */ 1622 int 1623 sys_sigwaitinfo(struct sigwaitinfo_args *uap) 1624 { 1625 siginfo_t info; 1626 sigset_t set; 1627 int error; 1628 1629 error = copyin(uap->set, &set, sizeof(set)); 1630 if (error) 1631 return (error); 1632 error = kern_sigtimedwait(set, &info, NULL); 1633 if (error) 1634 return (error); 1635 if (uap->info) 1636 error = copyout(&info, uap->info, sizeof(info)); 1637 /* Repost if we got an error. */ 1638 /* 1639 * XXX lwp 1640 * 1641 * This could transform a thread-specific signal to another 1642 * thread / process pending signal. 1643 */ 1644 if (error) { 1645 ksignal(curproc, info.si_signo); 1646 } else { 1647 uap->sysmsg_result = info.si_signo; 1648 } 1649 return (error); 1650 } 1651 1652 /* 1653 * If the current process has received a signal that would interrupt a 1654 * system call, return EINTR or ERESTART as appropriate. 1655 */ 1656 int 1657 iscaught(struct lwp *lp) 1658 { 1659 struct proc *p = lp->lwp_proc; 1660 int sig; 1661 1662 if (p) { 1663 if ((sig = CURSIG(lp)) != 0) { 1664 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1665 return (EINTR); 1666 return (ERESTART); 1667 } 1668 } 1669 return(EWOULDBLOCK); 1670 } 1671 1672 /* 1673 * If the current process has received a signal (should be caught or cause 1674 * termination, should interrupt current syscall), return the signal number. 1675 * Stop signals with default action are processed immediately, then cleared; 1676 * they aren't returned. This is checked after each entry to the system for 1677 * a syscall or trap (though this can usually be done without calling issignal 1678 * by checking the pending signal masks in the CURSIG macro.) The normal call 1679 * sequence is 1680 * 1681 * This routine is called via CURSIG/__cursig and the MP lock might not be 1682 * held. Obtain the MP lock for the duration of the operation. 1683 * 1684 * while (sig = CURSIG(curproc)) 1685 * postsig(sig); 1686 */ 1687 int 1688 issignal(struct lwp *lp, int maytrace) 1689 { 1690 struct proc *p = lp->lwp_proc; 1691 sigset_t mask; 1692 int sig, prop; 1693 1694 lwkt_gettoken(&proc_token); 1695 1696 for (;;) { 1697 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1698 1699 /* 1700 * If this process is supposed to stop, stop this thread. 1701 */ 1702 if (p->p_stat == SSTOP) 1703 tstop(); 1704 1705 mask = lwp_sigpend(lp); 1706 SIGSETNAND(mask, lp->lwp_sigmask); 1707 if (p->p_flag & P_PPWAIT) 1708 SIG_STOPSIGMASK(mask); 1709 if (SIGISEMPTY(mask)) { /* no signal to send */ 1710 lwkt_reltoken(&proc_token); 1711 return (0); 1712 } 1713 sig = sig_ffs(&mask); 1714 1715 STOPEVENT(p, S_SIG, sig); 1716 1717 /* 1718 * We should see pending but ignored signals 1719 * only if P_TRACED was on when they were posted. 1720 */ 1721 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1722 lwp_delsig(lp, sig); 1723 continue; 1724 } 1725 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) { 1726 /* 1727 * If traced, always stop, and stay stopped until 1728 * released by the parent. 1729 * 1730 * NOTE: SSTOP may get cleared during the loop, 1731 * but we do not re-notify the parent if we have 1732 * to loop several times waiting for the parent 1733 * to let us continue. 1734 * 1735 * XXX not sure if this is still true 1736 */ 1737 p->p_xstat = sig; 1738 proc_stop(p); 1739 do { 1740 tstop(); 1741 } while (!trace_req(p) && (p->p_flag & P_TRACED)); 1742 1743 /* 1744 * If parent wants us to take the signal, 1745 * then it will leave it in p->p_xstat; 1746 * otherwise we just look for signals again. 1747 */ 1748 lwp_delsig(lp, sig); /* clear old signal */ 1749 sig = p->p_xstat; 1750 if (sig == 0) 1751 continue; 1752 1753 /* 1754 * Put the new signal into p_siglist. If the 1755 * signal is being masked, look for other signals. 1756 * 1757 * XXX lwp might need a call to ksignal() 1758 */ 1759 SIGADDSET(p->p_siglist, sig); 1760 if (SIGISMEMBER(lp->lwp_sigmask, sig)) 1761 continue; 1762 1763 /* 1764 * If the traced bit got turned off, go back up 1765 * to the top to rescan signals. This ensures 1766 * that p_sig* and ps_sigact are consistent. 1767 */ 1768 if ((p->p_flag & P_TRACED) == 0) 1769 continue; 1770 } 1771 1772 prop = sigprop(sig); 1773 1774 /* 1775 * Decide whether the signal should be returned. 1776 * Return the signal's number, or fall through 1777 * to clear it from the pending mask. 1778 */ 1779 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1780 case (intptr_t)SIG_DFL: 1781 /* 1782 * Don't take default actions on system processes. 1783 */ 1784 if (p->p_pid <= 1) { 1785 #ifdef DIAGNOSTIC 1786 /* 1787 * Are you sure you want to ignore SIGSEGV 1788 * in init? XXX 1789 */ 1790 kprintf("Process (pid %lu) got signal %d\n", 1791 (u_long)p->p_pid, sig); 1792 #endif 1793 break; /* == ignore */ 1794 } 1795 1796 /* 1797 * Handle the in-kernel checkpoint action 1798 */ 1799 if (prop & SA_CKPT) { 1800 checkpoint_signal_handler(lp); 1801 break; 1802 } 1803 1804 /* 1805 * If there is a pending stop signal to process 1806 * with default action, stop here, 1807 * then clear the signal. However, 1808 * if process is member of an orphaned 1809 * process group, ignore tty stop signals. 1810 */ 1811 if (prop & SA_STOP) { 1812 if (p->p_flag & P_TRACED || 1813 (p->p_pgrp->pg_jobc == 0 && 1814 prop & SA_TTYSTOP)) 1815 break; /* == ignore */ 1816 p->p_xstat = sig; 1817 proc_stop(p); 1818 tstop(); 1819 break; 1820 } else if (prop & SA_IGNORE) { 1821 /* 1822 * Except for SIGCONT, shouldn't get here. 1823 * Default action is to ignore; drop it. 1824 */ 1825 break; /* == ignore */ 1826 } else { 1827 lwkt_reltoken(&proc_token); 1828 return (sig); 1829 } 1830 1831 /*NOTREACHED*/ 1832 1833 case (intptr_t)SIG_IGN: 1834 /* 1835 * Masking above should prevent us ever trying 1836 * to take action on an ignored signal other 1837 * than SIGCONT, unless process is traced. 1838 */ 1839 if ((prop & SA_CONT) == 0 && 1840 (p->p_flag & P_TRACED) == 0) 1841 kprintf("issignal\n"); 1842 break; /* == ignore */ 1843 1844 default: 1845 /* 1846 * This signal has an action, let 1847 * postsig() process it. 1848 */ 1849 lwkt_reltoken(&proc_token); 1850 return (sig); 1851 } 1852 lwp_delsig(lp, sig); /* take the signal! */ 1853 } 1854 /* NOTREACHED */ 1855 } 1856 1857 /* 1858 * Take the action for the specified signal 1859 * from the current set of pending signals. 1860 */ 1861 void 1862 postsig(int sig) 1863 { 1864 struct lwp *lp = curthread->td_lwp; 1865 struct proc *p = lp->lwp_proc; 1866 struct sigacts *ps = p->p_sigacts; 1867 sig_t action; 1868 sigset_t returnmask; 1869 int code; 1870 1871 KASSERT(sig != 0, ("postsig")); 1872 1873 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1874 1875 /* 1876 * If we are a virtual kernel running an emulated user process 1877 * context, switch back to the virtual kernel context before 1878 * trying to post the signal. 1879 */ 1880 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { 1881 struct trapframe *tf = lp->lwp_md.md_regs; 1882 tf->tf_trapno = 0; 1883 vkernel_trap(lp, tf); 1884 } 1885 1886 lwp_delsig(lp, sig); 1887 action = ps->ps_sigact[_SIG_IDX(sig)]; 1888 #ifdef KTRACE 1889 if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) 1890 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ? 1891 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0); 1892 #endif 1893 STOPEVENT(p, S_SIG, sig); 1894 1895 if (action == SIG_DFL) { 1896 /* 1897 * Default action, where the default is to kill 1898 * the process. (Other cases were ignored above.) 1899 */ 1900 sigexit(lp, sig); 1901 /* NOTREACHED */ 1902 } else { 1903 /* 1904 * If we get here, the signal must be caught. 1905 */ 1906 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig), 1907 ("postsig action")); 1908 1909 crit_enter(); 1910 1911 /* 1912 * Reset the signal handler if asked to 1913 */ 1914 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1915 /* 1916 * See kern_sigaction() for origin of this code. 1917 */ 1918 SIGDELSET(p->p_sigcatch, sig); 1919 if (sig != SIGCONT && 1920 sigprop(sig) & SA_IGNORE) 1921 SIGADDSET(p->p_sigignore, sig); 1922 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1923 } 1924 1925 /* 1926 * Handle the mailbox case. Copyout to the appropriate 1927 * location but do not generate a signal frame. The system 1928 * call simply returns EINTR and the user is responsible for 1929 * polling the mailbox. 1930 */ 1931 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) { 1932 int sig_copy = sig; 1933 copyout(&sig_copy, (void *)action, sizeof(int)); 1934 curproc->p_flag |= P_MAILBOX; 1935 crit_exit(); 1936 goto done; 1937 } 1938 1939 /* 1940 * Set the signal mask and calculate the mask to restore 1941 * when the signal function returns. 1942 * 1943 * Special case: user has done a sigsuspend. Here the 1944 * current mask is not of interest, but rather the 1945 * mask from before the sigsuspend is what we want 1946 * restored after the signal processing is completed. 1947 */ 1948 if (lp->lwp_flag & LWP_OLDMASK) { 1949 returnmask = lp->lwp_oldsigmask; 1950 lp->lwp_flag &= ~LWP_OLDMASK; 1951 } else { 1952 returnmask = lp->lwp_sigmask; 1953 } 1954 1955 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1956 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1957 SIGADDSET(lp->lwp_sigmask, sig); 1958 1959 crit_exit(); 1960 lp->lwp_ru.ru_nsignals++; 1961 if (lp->lwp_sig != sig) { 1962 code = 0; 1963 } else { 1964 code = lp->lwp_code; 1965 lp->lwp_code = 0; 1966 lp->lwp_sig = 0; 1967 } 1968 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1969 } 1970 done: 1971 ; 1972 } 1973 1974 /* 1975 * Kill the current process for stated reason. 1976 */ 1977 void 1978 killproc(struct proc *p, char *why) 1979 { 1980 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", 1981 p->p_pid, p->p_comm, 1982 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1983 ksignal(p, SIGKILL); 1984 } 1985 1986 /* 1987 * Force the current process to exit with the specified signal, dumping core 1988 * if appropriate. We bypass the normal tests for masked and caught signals, 1989 * allowing unrecoverable failures to terminate the process without changing 1990 * signal state. Mark the accounting record with the signal termination. 1991 * If dumping core, save the signal number for the debugger. Calls exit and 1992 * does not return. 1993 */ 1994 void 1995 sigexit(struct lwp *lp, int sig) 1996 { 1997 struct proc *p = lp->lwp_proc; 1998 1999 p->p_acflag |= AXSIG; 2000 if (sigprop(sig) & SA_CORE) { 2001 lp->lwp_sig = sig; 2002 /* 2003 * Log signals which would cause core dumps 2004 * (Log as LOG_INFO to appease those who don't want 2005 * these messages.) 2006 * XXX : Todo, as well as euid, write out ruid too 2007 */ 2008 if (coredump(lp, sig) == 0) 2009 sig |= WCOREFLAG; 2010 if (kern_logsigexit) 2011 log(LOG_INFO, 2012 "pid %d (%s), uid %d: exited on signal %d%s\n", 2013 p->p_pid, p->p_comm, 2014 p->p_ucred ? p->p_ucred->cr_uid : -1, 2015 sig &~ WCOREFLAG, 2016 sig & WCOREFLAG ? " (core dumped)" : ""); 2017 } 2018 exit1(W_EXITCODE(0, sig)); 2019 /* NOTREACHED */ 2020 } 2021 2022 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 2023 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2024 sizeof(corefilename), "process corefile name format string"); 2025 2026 /* 2027 * expand_name(name, uid, pid) 2028 * Expand the name described in corefilename, using name, uid, and pid. 2029 * corefilename is a kprintf-like string, with three format specifiers: 2030 * %N name of process ("name") 2031 * %P process id (pid) 2032 * %U user id (uid) 2033 * For example, "%N.core" is the default; they can be disabled completely 2034 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2035 * This is controlled by the sysctl variable kern.corefile (see above). 2036 */ 2037 2038 static char * 2039 expand_name(const char *name, uid_t uid, pid_t pid) 2040 { 2041 char *temp; 2042 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2043 int i, n; 2044 char *format = corefilename; 2045 size_t namelen; 2046 2047 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 2048 if (temp == NULL) 2049 return NULL; 2050 namelen = strlen(name); 2051 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2052 int l; 2053 switch (format[i]) { 2054 case '%': /* Format character */ 2055 i++; 2056 switch (format[i]) { 2057 case '%': 2058 temp[n++] = '%'; 2059 break; 2060 case 'N': /* process name */ 2061 if ((n + namelen) > MAXPATHLEN) { 2062 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2063 pid, name, uid, temp, name); 2064 kfree(temp, M_TEMP); 2065 return NULL; 2066 } 2067 memcpy(temp+n, name, namelen); 2068 n += namelen; 2069 break; 2070 case 'P': /* process id */ 2071 l = ksprintf(buf, "%u", pid); 2072 if ((n + l) > MAXPATHLEN) { 2073 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2074 pid, name, uid, temp, name); 2075 kfree(temp, M_TEMP); 2076 return NULL; 2077 } 2078 memcpy(temp+n, buf, l); 2079 n += l; 2080 break; 2081 case 'U': /* user id */ 2082 l = ksprintf(buf, "%u", uid); 2083 if ((n + l) > MAXPATHLEN) { 2084 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2085 pid, name, uid, temp, name); 2086 kfree(temp, M_TEMP); 2087 return NULL; 2088 } 2089 memcpy(temp+n, buf, l); 2090 n += l; 2091 break; 2092 default: 2093 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 2094 } 2095 break; 2096 default: 2097 temp[n++] = format[i]; 2098 } 2099 } 2100 temp[n] = '\0'; 2101 return temp; 2102 } 2103 2104 /* 2105 * Dump a process' core. The main routine does some 2106 * policy checking, and creates the name of the coredump; 2107 * then it passes on a vnode and a size limit to the process-specific 2108 * coredump routine if there is one; if there _is not_ one, it returns 2109 * ENOSYS; otherwise it returns the error from the process-specific routine. 2110 * 2111 * The parameter `lp' is the lwp which triggered the coredump. 2112 */ 2113 2114 static int 2115 coredump(struct lwp *lp, int sig) 2116 { 2117 struct proc *p = lp->lwp_proc; 2118 struct vnode *vp; 2119 struct ucred *cred = p->p_ucred; 2120 struct flock lf; 2121 struct nlookupdata nd; 2122 struct vattr vattr; 2123 int error, error1; 2124 char *name; /* name of corefile */ 2125 off_t limit; 2126 2127 STOPEVENT(p, S_CORE, 0); 2128 2129 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 2130 return (EFAULT); 2131 2132 /* 2133 * Note that the bulk of limit checking is done after 2134 * the corefile is created. The exception is if the limit 2135 * for corefiles is 0, in which case we don't bother 2136 * creating the corefile at all. This layout means that 2137 * a corefile is truncated instead of not being created, 2138 * if it is larger than the limit. 2139 */ 2140 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2141 if (limit == 0) 2142 return EFBIG; 2143 2144 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 2145 if (name == NULL) 2146 return (EINVAL); 2147 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP); 2148 if (error == 0) 2149 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 2150 kfree(name, M_TEMP); 2151 if (error) { 2152 nlookup_done(&nd); 2153 return (error); 2154 } 2155 vp = nd.nl_open_vp; 2156 nd.nl_open_vp = NULL; 2157 nlookup_done(&nd); 2158 2159 vn_unlock(vp); 2160 lf.l_whence = SEEK_SET; 2161 lf.l_start = 0; 2162 lf.l_len = 0; 2163 lf.l_type = F_WRLCK; 2164 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0); 2165 if (error) 2166 goto out2; 2167 2168 /* Don't dump to non-regular files or files with links. */ 2169 if (vp->v_type != VREG || 2170 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) { 2171 error = EFAULT; 2172 goto out1; 2173 } 2174 2175 /* Don't dump to files current user does not own */ 2176 if (vattr.va_uid != p->p_ucred->cr_uid) { 2177 error = EFAULT; 2178 goto out1; 2179 } 2180 2181 VATTR_NULL(&vattr); 2182 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2183 vattr.va_size = 0; 2184 VOP_SETATTR(vp, &vattr, cred); 2185 p->p_acflag |= ACORE; 2186 vn_unlock(vp); 2187 2188 error = p->p_sysent->sv_coredump ? 2189 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS; 2190 2191 out1: 2192 lf.l_type = F_UNLCK; 2193 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0); 2194 out2: 2195 error1 = vn_close(vp, FWRITE); 2196 if (error == 0) 2197 error = error1; 2198 return (error); 2199 } 2200 2201 /* 2202 * Nonexistent system call-- signal process (may want to handle it). 2203 * Flag error in case process won't see signal immediately (blocked or ignored). 2204 * 2205 * MPALMOSTSAFE 2206 */ 2207 /* ARGSUSED */ 2208 int 2209 sys_nosys(struct nosys_args *args) 2210 { 2211 lwpsignal(curproc, curthread->td_lwp, SIGSYS); 2212 return (EINVAL); 2213 } 2214 2215 /* 2216 * Send a SIGIO or SIGURG signal to a process or process group using 2217 * stored credentials rather than those of the current process. 2218 */ 2219 void 2220 pgsigio(struct sigio *sigio, int sig, int checkctty) 2221 { 2222 if (sigio == NULL) 2223 return; 2224 2225 if (sigio->sio_pgid > 0) { 2226 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 2227 sigio->sio_proc)) 2228 ksignal(sigio->sio_proc, sig); 2229 } else if (sigio->sio_pgid < 0) { 2230 struct proc *p; 2231 2232 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE); 2233 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2234 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 2235 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2236 ksignal(p, sig); 2237 } 2238 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE); 2239 } 2240 } 2241 2242 static int 2243 filt_sigattach(struct knote *kn) 2244 { 2245 struct proc *p = curproc; 2246 2247 kn->kn_ptr.p_proc = p; 2248 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2249 2250 /* XXX lock the proc here while adding to the list? */ 2251 knote_insert(&p->p_klist, kn); 2252 2253 return (0); 2254 } 2255 2256 static void 2257 filt_sigdetach(struct knote *kn) 2258 { 2259 struct proc *p = kn->kn_ptr.p_proc; 2260 2261 knote_remove(&p->p_klist, kn); 2262 } 2263 2264 /* 2265 * signal knotes are shared with proc knotes, so we apply a mask to 2266 * the hint in order to differentiate them from process hints. This 2267 * could be avoided by using a signal-specific knote list, but probably 2268 * isn't worth the trouble. 2269 */ 2270 static int 2271 filt_signal(struct knote *kn, long hint) 2272 { 2273 if (hint & NOTE_SIGNAL) { 2274 hint &= ~NOTE_SIGNAL; 2275 2276 if (kn->kn_id == hint) 2277 kn->kn_data++; 2278 } 2279 return (kn->kn_data != 0); 2280 } 2281