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 1.90 2008/06/09 04:33:08 dillon Exp $ 41 */ 42 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/sysproto.h> 49 #include <sys/signalvar.h> 50 #include <sys/resourcevar.h> 51 #include <sys/vnode.h> 52 #include <sys/event.h> 53 #include <sys/proc.h> 54 #include <sys/nlookup.h> 55 #include <sys/pioctl.h> 56 #include <sys/systm.h> 57 #include <sys/acct.h> 58 #include <sys/fcntl.h> 59 #include <sys/lock.h> 60 #include <sys/wait.h> 61 #include <sys/ktrace.h> 62 #include <sys/syslog.h> 63 #include <sys/stat.h> 64 #include <sys/sysent.h> 65 #include <sys/sysctl.h> 66 #include <sys/malloc.h> 67 #include <sys/interrupt.h> 68 #include <sys/unistd.h> 69 #include <sys/kern_syscall.h> 70 #include <sys/vkernel.h> 71 72 #include <sys/signal2.h> 73 #include <sys/thread2.h> 74 #include <sys/mplock2.h> 75 76 #include <machine/cpu.h> 77 #include <machine/smp.h> 78 79 static int coredump(struct lwp *, int); 80 static char *expand_name(const char *, uid_t, pid_t); 81 static int dokillpg(int sig, int pgid, int all); 82 static int sig_ffs(sigset_t *set); 83 static int sigprop(int sig); 84 #ifdef SMP 85 static void signotify_remote(void *arg); 86 #endif 87 static int kern_sigtimedwait(sigset_t set, siginfo_t *info, 88 struct timespec *timeout); 89 90 static int filt_sigattach(struct knote *kn); 91 static void filt_sigdetach(struct knote *kn); 92 static int filt_signal(struct knote *kn, long hint); 93 94 struct filterops sig_filtops = 95 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 96 97 static int kern_logsigexit = 1; 98 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 99 &kern_logsigexit, 0, 100 "Log processes quitting on abnormal signals to syslog(3)"); 101 102 /* 103 * Can process p, with pcred pc, send the signal sig to process q? 104 */ 105 #define CANSIGNAL(q, sig) \ 106 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \ 107 ((sig) == SIGCONT && (q)->p_session == curproc->p_session)) 108 109 /* 110 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 111 */ 112 #define CANSIGIO(ruid, uc, q) \ 113 ((uc)->cr_uid == 0 || \ 114 (ruid) == (q)->p_ucred->cr_ruid || \ 115 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \ 116 (ruid) == (q)->p_ucred->cr_uid || \ 117 (uc)->cr_uid == (q)->p_ucred->cr_uid) 118 119 int sugid_coredump; 120 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 121 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 122 123 static int do_coredump = 1; 124 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 125 &do_coredump, 0, "Enable/Disable coredumps"); 126 127 /* 128 * Signal properties and actions. 129 * The array below categorizes the signals and their default actions 130 * according to the following properties: 131 */ 132 #define SA_KILL 0x01 /* terminates process by default */ 133 #define SA_CORE 0x02 /* ditto and coredumps */ 134 #define SA_STOP 0x04 /* suspend process */ 135 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 136 #define SA_IGNORE 0x10 /* ignore by default */ 137 #define SA_CONT 0x20 /* continue if suspended */ 138 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 139 #define SA_CKPT 0x80 /* checkpoint process */ 140 141 142 static int sigproptbl[NSIG] = { 143 SA_KILL, /* SIGHUP */ 144 SA_KILL, /* SIGINT */ 145 SA_KILL|SA_CORE, /* SIGQUIT */ 146 SA_KILL|SA_CORE, /* SIGILL */ 147 SA_KILL|SA_CORE, /* SIGTRAP */ 148 SA_KILL|SA_CORE, /* SIGABRT */ 149 SA_KILL|SA_CORE, /* SIGEMT */ 150 SA_KILL|SA_CORE, /* SIGFPE */ 151 SA_KILL, /* SIGKILL */ 152 SA_KILL|SA_CORE, /* SIGBUS */ 153 SA_KILL|SA_CORE, /* SIGSEGV */ 154 SA_KILL|SA_CORE, /* SIGSYS */ 155 SA_KILL, /* SIGPIPE */ 156 SA_KILL, /* SIGALRM */ 157 SA_KILL, /* SIGTERM */ 158 SA_IGNORE, /* SIGURG */ 159 SA_STOP, /* SIGSTOP */ 160 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 161 SA_IGNORE|SA_CONT, /* SIGCONT */ 162 SA_IGNORE, /* SIGCHLD */ 163 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 164 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 165 SA_IGNORE, /* SIGIO */ 166 SA_KILL, /* SIGXCPU */ 167 SA_KILL, /* SIGXFSZ */ 168 SA_KILL, /* SIGVTALRM */ 169 SA_KILL, /* SIGPROF */ 170 SA_IGNORE, /* SIGWINCH */ 171 SA_IGNORE, /* SIGINFO */ 172 SA_KILL, /* SIGUSR1 */ 173 SA_KILL, /* SIGUSR2 */ 174 SA_IGNORE, /* SIGTHR */ 175 SA_CKPT, /* SIGCKPT */ 176 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */ 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 SA_IGNORE, 207 208 }; 209 210 static __inline int 211 sigprop(int sig) 212 { 213 214 if (sig > 0 && sig < NSIG) 215 return (sigproptbl[_SIG_IDX(sig)]); 216 return (0); 217 } 218 219 static __inline int 220 sig_ffs(sigset_t *set) 221 { 222 int i; 223 224 for (i = 0; i < _SIG_WORDS; i++) 225 if (set->__bits[i]) 226 return (ffs(set->__bits[i]) + (i * 32)); 227 return (0); 228 } 229 230 int 231 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact) 232 { 233 struct thread *td = curthread; 234 struct proc *p = td->td_proc; 235 struct lwp *lp; 236 struct sigacts *ps = p->p_sigacts; 237 238 if (sig <= 0 || sig > _SIG_MAXSIG) 239 return (EINVAL); 240 241 if (oact) { 242 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 243 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 244 oact->sa_flags = 0; 245 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 246 oact->sa_flags |= SA_ONSTACK; 247 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 248 oact->sa_flags |= SA_RESTART; 249 if (SIGISMEMBER(ps->ps_sigreset, sig)) 250 oact->sa_flags |= SA_RESETHAND; 251 if (SIGISMEMBER(ps->ps_signodefer, sig)) 252 oact->sa_flags |= SA_NODEFER; 253 if (SIGISMEMBER(ps->ps_siginfo, sig)) 254 oact->sa_flags |= SA_SIGINFO; 255 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) 256 oact->sa_flags |= SA_MAILBOX; 257 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP) 258 oact->sa_flags |= SA_NOCLDSTOP; 259 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT) 260 oact->sa_flags |= SA_NOCLDWAIT; 261 } 262 if (act) { 263 /* 264 * Check for invalid requests. KILL and STOP cannot be 265 * caught. 266 */ 267 if (sig == SIGKILL || sig == SIGSTOP) { 268 if (act->sa_handler != SIG_DFL) 269 return (EINVAL); 270 #if 0 271 /* (not needed, SIG_DFL forces action to occur) */ 272 if (act->sa_flags & SA_MAILBOX) 273 return (EINVAL); 274 #endif 275 } 276 277 /* 278 * Change setting atomically. 279 */ 280 crit_enter(); 281 282 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 283 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 284 if (act->sa_flags & SA_SIGINFO) { 285 ps->ps_sigact[_SIG_IDX(sig)] = 286 (__sighandler_t *)act->sa_sigaction; 287 SIGADDSET(ps->ps_siginfo, sig); 288 } else { 289 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 290 SIGDELSET(ps->ps_siginfo, sig); 291 } 292 if (!(act->sa_flags & SA_RESTART)) 293 SIGADDSET(ps->ps_sigintr, sig); 294 else 295 SIGDELSET(ps->ps_sigintr, sig); 296 if (act->sa_flags & SA_ONSTACK) 297 SIGADDSET(ps->ps_sigonstack, sig); 298 else 299 SIGDELSET(ps->ps_sigonstack, sig); 300 if (act->sa_flags & SA_RESETHAND) 301 SIGADDSET(ps->ps_sigreset, sig); 302 else 303 SIGDELSET(ps->ps_sigreset, sig); 304 if (act->sa_flags & SA_NODEFER) 305 SIGADDSET(ps->ps_signodefer, sig); 306 else 307 SIGDELSET(ps->ps_signodefer, sig); 308 if (act->sa_flags & SA_MAILBOX) 309 SIGADDSET(ps->ps_sigmailbox, sig); 310 else 311 SIGDELSET(ps->ps_sigmailbox, sig); 312 if (sig == SIGCHLD) { 313 if (act->sa_flags & SA_NOCLDSTOP) 314 p->p_sigacts->ps_flag |= PS_NOCLDSTOP; 315 else 316 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP; 317 if (act->sa_flags & SA_NOCLDWAIT) { 318 /* 319 * Paranoia: since SA_NOCLDWAIT is implemented 320 * by reparenting the dying child to PID 1 (and 321 * trust it to reap the zombie), PID 1 itself 322 * is forbidden to set SA_NOCLDWAIT. 323 */ 324 if (p->p_pid == 1) 325 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 326 else 327 p->p_sigacts->ps_flag |= PS_NOCLDWAIT; 328 } else { 329 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 330 } 331 } 332 /* 333 * Set bit in p_sigignore for signals that are set to SIG_IGN, 334 * and for signals set to SIG_DFL where the default is to 335 * ignore. However, don't put SIGCONT in p_sigignore, as we 336 * have to restart the process. 337 */ 338 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 339 (sigprop(sig) & SA_IGNORE && 340 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 341 /* never to be seen again */ 342 SIGDELSET(p->p_siglist, sig); 343 /* 344 * Remove the signal also from the thread lists. 345 */ 346 FOREACH_LWP_IN_PROC(lp, p) { 347 SIGDELSET(lp->lwp_siglist, sig); 348 } 349 if (sig != SIGCONT) 350 /* easier in ksignal */ 351 SIGADDSET(p->p_sigignore, sig); 352 SIGDELSET(p->p_sigcatch, sig); 353 } else { 354 SIGDELSET(p->p_sigignore, sig); 355 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 356 SIGDELSET(p->p_sigcatch, sig); 357 else 358 SIGADDSET(p->p_sigcatch, sig); 359 } 360 361 crit_exit(); 362 } 363 return (0); 364 } 365 366 /* 367 * MPALMOSTSAFE 368 */ 369 int 370 sys_sigaction(struct sigaction_args *uap) 371 { 372 struct sigaction act, oact; 373 struct sigaction *actp, *oactp; 374 int error; 375 376 actp = (uap->act != NULL) ? &act : NULL; 377 oactp = (uap->oact != NULL) ? &oact : NULL; 378 if (actp) { 379 error = copyin(uap->act, actp, sizeof(act)); 380 if (error) 381 return (error); 382 } 383 get_mplock(); 384 error = kern_sigaction(uap->sig, actp, oactp); 385 rel_mplock(); 386 if (oactp && !error) { 387 error = copyout(oactp, uap->oact, sizeof(oact)); 388 } 389 return (error); 390 } 391 392 /* 393 * Initialize signal state for process 0; 394 * set to ignore signals that are ignored by default. 395 */ 396 void 397 siginit(struct proc *p) 398 { 399 int i; 400 401 for (i = 1; i <= NSIG; i++) 402 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 403 SIGADDSET(p->p_sigignore, i); 404 } 405 406 /* 407 * Reset signals for an exec of the specified process. 408 */ 409 void 410 execsigs(struct proc *p) 411 { 412 struct sigacts *ps = p->p_sigacts; 413 struct lwp *lp; 414 int sig; 415 416 lp = ONLY_LWP_IN_PROC(p); 417 418 /* 419 * Reset caught signals. Held signals remain held 420 * through p_sigmask (unless they were caught, 421 * and are now ignored by default). 422 */ 423 while (SIGNOTEMPTY(p->p_sigcatch)) { 424 sig = sig_ffs(&p->p_sigcatch); 425 SIGDELSET(p->p_sigcatch, sig); 426 if (sigprop(sig) & SA_IGNORE) { 427 if (sig != SIGCONT) 428 SIGADDSET(p->p_sigignore, sig); 429 SIGDELSET(p->p_siglist, sig); 430 SIGDELSET(lp->lwp_siglist, sig); 431 } 432 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 433 } 434 435 /* 436 * Reset stack state to the user stack. 437 * Clear set of signals caught on the signal stack. 438 */ 439 lp->lwp_sigstk.ss_flags = SS_DISABLE; 440 lp->lwp_sigstk.ss_size = 0; 441 lp->lwp_sigstk.ss_sp = 0; 442 lp->lwp_flag &= ~LWP_ALTSTACK; 443 /* 444 * Reset no zombies if child dies flag as Solaris does. 445 */ 446 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 447 } 448 449 /* 450 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc 451 * 452 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 453 * p == curproc. 454 */ 455 int 456 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) 457 { 458 struct thread *td = curthread; 459 struct lwp *lp = td->td_lwp; 460 int error; 461 462 if (oset != NULL) 463 *oset = lp->lwp_sigmask; 464 465 error = 0; 466 if (set != NULL) { 467 switch (how) { 468 case SIG_BLOCK: 469 SIG_CANTMASK(*set); 470 SIGSETOR(lp->lwp_sigmask, *set); 471 break; 472 case SIG_UNBLOCK: 473 SIGSETNAND(lp->lwp_sigmask, *set); 474 break; 475 case SIG_SETMASK: 476 SIG_CANTMASK(*set); 477 lp->lwp_sigmask = *set; 478 break; 479 default: 480 error = EINVAL; 481 break; 482 } 483 } 484 return (error); 485 } 486 487 /* 488 * sigprocmask() 489 * 490 * MPSAFE 491 */ 492 int 493 sys_sigprocmask(struct sigprocmask_args *uap) 494 { 495 sigset_t set, oset; 496 sigset_t *setp, *osetp; 497 int error; 498 499 setp = (uap->set != NULL) ? &set : NULL; 500 osetp = (uap->oset != NULL) ? &oset : NULL; 501 if (setp) { 502 error = copyin(uap->set, setp, sizeof(set)); 503 if (error) 504 return (error); 505 } 506 error = kern_sigprocmask(uap->how, setp, osetp); 507 if (osetp && !error) { 508 error = copyout(osetp, uap->oset, sizeof(oset)); 509 } 510 return (error); 511 } 512 513 /* 514 * MPSAFE 515 */ 516 int 517 kern_sigpending(struct __sigset *set) 518 { 519 struct lwp *lp = curthread->td_lwp; 520 521 *set = lwp_sigpend(lp); 522 523 return (0); 524 } 525 526 /* 527 * MPSAFE 528 */ 529 int 530 sys_sigpending(struct sigpending_args *uap) 531 { 532 sigset_t set; 533 int error; 534 535 error = kern_sigpending(&set); 536 537 if (error == 0) 538 error = copyout(&set, uap->set, sizeof(set)); 539 return (error); 540 } 541 542 /* 543 * Suspend process until signal, providing mask to be set 544 * in the meantime. 545 * 546 * MPSAFE 547 */ 548 int 549 kern_sigsuspend(struct __sigset *set) 550 { 551 struct thread *td = curthread; 552 struct lwp *lp = td->td_lwp; 553 struct proc *p = td->td_proc; 554 struct sigacts *ps = p->p_sigacts; 555 556 /* 557 * When returning from sigsuspend, we want 558 * the old mask to be restored after the 559 * signal handler has finished. Thus, we 560 * save it here and mark the sigacts structure 561 * to indicate this. 562 */ 563 lp->lwp_oldsigmask = lp->lwp_sigmask; 564 lp->lwp_flag |= LWP_OLDMASK; 565 566 SIG_CANTMASK(*set); 567 lp->lwp_sigmask = *set; 568 while (tsleep(ps, PCATCH, "pause", 0) == 0) 569 /* void */; 570 /* always return EINTR rather than ERESTART... */ 571 return (EINTR); 572 } 573 574 /* 575 * Note nonstandard calling convention: libc stub passes mask, not 576 * pointer, to save a copyin. 577 * 578 * MPSAFE 579 */ 580 int 581 sys_sigsuspend(struct sigsuspend_args *uap) 582 { 583 sigset_t mask; 584 int error; 585 586 error = copyin(uap->sigmask, &mask, sizeof(mask)); 587 if (error) 588 return (error); 589 590 error = kern_sigsuspend(&mask); 591 592 return (error); 593 } 594 595 /* 596 * MPSAFE 597 */ 598 int 599 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) 600 { 601 struct thread *td = curthread; 602 struct lwp *lp = td->td_lwp; 603 struct proc *p = td->td_proc; 604 605 if ((lp->lwp_flag & LWP_ALTSTACK) == 0) 606 lp->lwp_sigstk.ss_flags |= SS_DISABLE; 607 608 if (oss) 609 *oss = lp->lwp_sigstk; 610 611 if (ss) { 612 if (ss->ss_flags & SS_DISABLE) { 613 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK) 614 return (EINVAL); 615 lp->lwp_flag &= ~LWP_ALTSTACK; 616 lp->lwp_sigstk.ss_flags = ss->ss_flags; 617 } else { 618 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 619 return (ENOMEM); 620 lp->lwp_flag |= LWP_ALTSTACK; 621 lp->lwp_sigstk = *ss; 622 } 623 } 624 625 return (0); 626 } 627 628 /* 629 * MPSAFE 630 */ 631 int 632 sys_sigaltstack(struct sigaltstack_args *uap) 633 { 634 stack_t ss, oss; 635 int error; 636 637 if (uap->ss) { 638 error = copyin(uap->ss, &ss, sizeof(ss)); 639 if (error) 640 return (error); 641 } 642 643 error = kern_sigaltstack(uap->ss ? &ss : NULL, 644 uap->oss ? &oss : NULL); 645 646 if (error == 0 && uap->oss) 647 error = copyout(&oss, uap->oss, sizeof(*uap->oss)); 648 return (error); 649 } 650 651 /* 652 * Common code for kill process group/broadcast kill. 653 * cp is calling process. 654 */ 655 struct killpg_info { 656 int nfound; 657 int sig; 658 }; 659 660 static int killpg_all_callback(struct proc *p, void *data); 661 662 static int 663 dokillpg(int sig, int pgid, int all) 664 { 665 struct killpg_info info; 666 struct proc *cp = curproc; 667 struct proc *p; 668 struct pgrp *pgrp; 669 670 info.nfound = 0; 671 info.sig = sig; 672 673 if (all) { 674 /* 675 * broadcast 676 */ 677 allproc_scan(killpg_all_callback, &info); 678 } else { 679 if (pgid == 0) { 680 /* 681 * zero pgid means send to my process group. 682 */ 683 pgrp = cp->p_pgrp; 684 } else { 685 pgrp = pgfind(pgid); 686 if (pgrp == NULL) 687 return (ESRCH); 688 } 689 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); 690 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 691 if (p->p_pid <= 1 || 692 p->p_stat == SZOMB || 693 (p->p_flag & P_SYSTEM) || 694 !CANSIGNAL(p, sig)) { 695 continue; 696 } 697 ++info.nfound; 698 if (sig) 699 ksignal(p, sig); 700 } 701 lockmgr(&pgrp->pg_lock, LK_RELEASE); 702 } 703 return (info.nfound ? 0 : ESRCH); 704 } 705 706 static int 707 killpg_all_callback(struct proc *p, void *data) 708 { 709 struct killpg_info *info = data; 710 711 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) || 712 p == curproc || !CANSIGNAL(p, info->sig)) { 713 return (0); 714 } 715 ++info->nfound; 716 if (info->sig) 717 ksignal(p, info->sig); 718 return(0); 719 } 720 721 /* 722 * Send a general signal to a process or LWPs within that process. Note 723 * that new signals cannot be sent if a process is exiting. 724 */ 725 int 726 kern_kill(int sig, pid_t pid, lwpid_t tid) 727 { 728 if ((u_int)sig > _SIG_MAXSIG) 729 return (EINVAL); 730 if (pid > 0) { 731 struct proc *p; 732 struct lwp *lp = NULL; 733 734 /* kill single process */ 735 if ((p = pfind(pid)) == NULL) 736 return (ESRCH); 737 if (!CANSIGNAL(p, sig)) 738 return (EPERM); 739 740 /* 741 * NOP if the process is exiting. Note that lwpsignal() is 742 * called directly with P_WEXIT set to kill individual LWPs 743 * during exit, which is allowed. 744 */ 745 if (p->p_flag & P_WEXIT) 746 return (0); 747 if (tid != -1) { 748 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid); 749 if (lp == NULL) 750 return (ESRCH); 751 } 752 if (sig) 753 lwpsignal(p, lp, sig); 754 return (0); 755 } 756 /* 757 * If we come here, pid is a special broadcast pid. 758 * This doesn't mix with a tid. 759 */ 760 if (tid != -1) 761 return (EINVAL); 762 switch (pid) { 763 case -1: /* broadcast signal */ 764 return (dokillpg(sig, 0, 1)); 765 case 0: /* signal own process group */ 766 return (dokillpg(sig, 0, 0)); 767 default: /* negative explicit process group */ 768 return (dokillpg(sig, -pid, 0)); 769 } 770 /* NOTREACHED */ 771 } 772 773 /* 774 * MPALMOSTSAFE 775 */ 776 int 777 sys_kill(struct kill_args *uap) 778 { 779 int error; 780 781 get_mplock(); 782 error = kern_kill(uap->signum, uap->pid, -1); 783 rel_mplock(); 784 return (error); 785 } 786 787 /* 788 * MPALMOSTSAFE 789 */ 790 int 791 sys_lwp_kill(struct lwp_kill_args *uap) 792 { 793 int error; 794 pid_t pid = uap->pid; 795 796 /* 797 * A tid is mandatory for lwp_kill(), otherwise 798 * you could simply use kill(). 799 */ 800 if (uap->tid == -1) 801 return (EINVAL); 802 803 /* 804 * To save on a getpid() function call for intra-process 805 * signals, pid == -1 means current process. 806 */ 807 if (pid == -1) 808 pid = curproc->p_pid; 809 810 get_mplock(); 811 error = kern_kill(uap->signum, pid, uap->tid); 812 rel_mplock(); 813 return (error); 814 } 815 816 /* 817 * Send a signal to a process group. 818 */ 819 void 820 gsignal(int pgid, int sig) 821 { 822 struct pgrp *pgrp; 823 824 if (pgid && (pgrp = pgfind(pgid))) 825 pgsignal(pgrp, sig, 0); 826 } 827 828 /* 829 * Send a signal to a process group. If checktty is 1, 830 * limit to members which have a controlling terminal. 831 * 832 * pg_lock interlocks against a fork that might be in progress, to 833 * ensure that the new child process picks up the signal. 834 */ 835 void 836 pgsignal(struct pgrp *pgrp, int sig, int checkctty) 837 { 838 struct proc *p; 839 840 if (pgrp) { 841 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); 842 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 843 if (checkctty == 0 || p->p_flag & P_CONTROLT) 844 ksignal(p, sig); 845 } 846 lockmgr(&pgrp->pg_lock, LK_RELEASE); 847 } 848 } 849 850 /* 851 * Send a signal caused by a trap to the current lwp. If it will be caught 852 * immediately, deliver it with correct code. Otherwise, post it normally. 853 * 854 * These signals may ONLY be delivered to the specified lwp and may never 855 * be delivered to the process generically. 856 */ 857 void 858 trapsignal(struct lwp *lp, int sig, u_long code) 859 { 860 struct proc *p = lp->lwp_proc; 861 struct sigacts *ps = p->p_sigacts; 862 863 /* 864 * If we are a virtual kernel running an emulated user process 865 * context, switch back to the virtual kernel context before 866 * trying to post the signal. 867 */ 868 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { 869 struct trapframe *tf = lp->lwp_md.md_regs; 870 tf->tf_trapno = 0; 871 vkernel_trap(lp, tf); 872 } 873 874 875 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 876 !SIGISMEMBER(lp->lwp_sigmask, sig)) { 877 lp->lwp_ru.ru_nsignals++; 878 #ifdef KTRACE 879 if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) 880 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)], 881 &lp->lwp_sigmask, code); 882 #endif 883 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 884 &lp->lwp_sigmask, code); 885 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 886 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 887 SIGADDSET(lp->lwp_sigmask, sig); 888 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 889 /* 890 * See kern_sigaction() for origin of this code. 891 */ 892 SIGDELSET(p->p_sigcatch, sig); 893 if (sig != SIGCONT && 894 sigprop(sig) & SA_IGNORE) 895 SIGADDSET(p->p_sigignore, sig); 896 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 897 } 898 } else { 899 lp->lwp_code = code; /* XXX for core dump/debugger */ 900 lp->lwp_sig = sig; /* XXX to verify code */ 901 lwpsignal(p, lp, sig); 902 } 903 } 904 905 /* 906 * Find a suitable lwp to deliver the signal to. 907 * 908 * Returns NULL if all lwps hold the signal blocked. 909 */ 910 static struct lwp * 911 find_lwp_for_signal(struct proc *p, int sig) 912 { 913 struct lwp *lp; 914 struct lwp *run, *sleep, *stop; 915 916 /* 917 * If the running/preempted thread belongs to the proc to which 918 * the signal is being delivered and this thread does not block 919 * the signal, then we can avoid a context switch by delivering 920 * the signal to this thread, because it will return to userland 921 * soon anyways. 922 */ 923 lp = lwkt_preempted_proc(); 924 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig)) 925 return (lp); 926 927 run = sleep = stop = NULL; 928 FOREACH_LWP_IN_PROC(lp, p) { 929 /* 930 * If the signal is being blocked by the lwp, then this 931 * lwp is not eligible for receiving the signal. 932 */ 933 if (SIGISMEMBER(lp->lwp_sigmask, sig)) 934 continue; 935 936 switch (lp->lwp_stat) { 937 case LSRUN: 938 run = lp; 939 break; 940 941 case LSSTOP: 942 stop = lp; 943 break; 944 945 case LSSLEEP: 946 if (lp->lwp_flag & LWP_SINTR) 947 sleep = lp; 948 break; 949 } 950 } 951 952 if (run != NULL) 953 return (run); 954 else if (sleep != NULL) 955 return (sleep); 956 else 957 return (stop); 958 } 959 960 /* 961 * Send the signal to the process. If the signal has an action, the action 962 * is usually performed by the target process rather than the caller; we add 963 * the signal to the set of pending signals for the process. 964 * 965 * Exceptions: 966 * o When a stop signal is sent to a sleeping process that takes the 967 * default action, the process is stopped without awakening it. 968 * o SIGCONT restarts stopped processes (or puts them back to sleep) 969 * regardless of the signal action (eg, blocked or ignored). 970 * 971 * Other ignored signals are discarded immediately. 972 */ 973 void 974 ksignal(struct proc *p, int sig) 975 { 976 lwpsignal(p, NULL, sig); 977 } 978 979 /* 980 * The core for ksignal. lp may be NULL, then a suitable thread 981 * will be chosen. If not, lp MUST be a member of p. 982 */ 983 void 984 lwpsignal(struct proc *p, struct lwp *lp, int sig) 985 { 986 int prop; 987 sig_t action; 988 989 if (sig > _SIG_MAXSIG || sig <= 0) { 990 kprintf("lwpsignal: signal %d\n", sig); 991 panic("lwpsignal signal number"); 992 } 993 994 KKASSERT(lp == NULL || lp->lwp_proc == p); 995 996 crit_enter(); 997 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 998 crit_exit(); 999 1000 prop = sigprop(sig); 1001 1002 /* 1003 * If proc is traced, always give parent a chance; 1004 * if signal event is tracked by procfs, give *that* 1005 * a chance, as well. 1006 */ 1007 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1008 action = SIG_DFL; 1009 } else { 1010 /* 1011 * Do not try to deliver signals to an exiting lwp. Note 1012 * that we must still deliver the signal if P_WEXIT is set 1013 * in the process flags. 1014 */ 1015 if (lp && (lp->lwp_flag & LWP_WEXIT)) 1016 return; 1017 1018 /* 1019 * If the signal is being ignored, then we forget about 1020 * it immediately. NOTE: We don't set SIGCONT in p_sigignore, 1021 * and if it is set to SIG_IGN, action will be SIG_DFL here. 1022 */ 1023 if (SIGISMEMBER(p->p_sigignore, sig)) 1024 return; 1025 if (SIGISMEMBER(p->p_sigcatch, sig)) 1026 action = SIG_CATCH; 1027 else 1028 action = SIG_DFL; 1029 } 1030 1031 /* 1032 * If continuing, clear any pending STOP signals. 1033 */ 1034 if (prop & SA_CONT) 1035 SIG_STOPSIGMASK(p->p_siglist); 1036 1037 if (prop & SA_STOP) { 1038 /* 1039 * If sending a tty stop signal to a member of an orphaned 1040 * process group, discard the signal here if the action 1041 * is default; don't stop the process below if sleeping, 1042 * and don't clear any pending SIGCONT. 1043 */ 1044 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1045 action == SIG_DFL) { 1046 return; 1047 } 1048 SIG_CONTSIGMASK(p->p_siglist); 1049 p->p_flag &= ~P_CONTINUED; 1050 } 1051 1052 crit_enter(); 1053 1054 if (p->p_stat == SSTOP) { 1055 /* 1056 * Nobody can handle this signal, add it to the lwp or 1057 * process pending list 1058 */ 1059 if (lp) 1060 SIGADDSET(lp->lwp_siglist, sig); 1061 else 1062 SIGADDSET(p->p_siglist, sig); 1063 1064 /* 1065 * If the process is stopped and is being traced, then no 1066 * further action is necessary. 1067 */ 1068 if (p->p_flag & P_TRACED) 1069 goto out; 1070 1071 /* 1072 * If the process is stopped and receives a KILL signal, 1073 * make the process runnable. 1074 */ 1075 if (sig == SIGKILL) { 1076 proc_unstop(p); 1077 goto active_process; 1078 } 1079 1080 /* 1081 * If the process is stopped and receives a CONT signal, 1082 * then try to make the process runnable again. 1083 */ 1084 if (prop & SA_CONT) { 1085 /* 1086 * If SIGCONT is default (or ignored), we continue the 1087 * process but don't leave the signal in p_siglist, as 1088 * it has no further action. If SIGCONT is held, we 1089 * continue the process and leave the signal in 1090 * p_siglist. If the process catches SIGCONT, let it 1091 * handle the signal itself. 1092 */ 1093 /* XXX what if the signal is being held blocked? */ 1094 p->p_flag |= P_CONTINUED; 1095 wakeup(p->p_pptr); 1096 if (action == SIG_DFL) 1097 SIGDELSET(p->p_siglist, sig); 1098 proc_unstop(p); 1099 if (action == SIG_CATCH) 1100 goto active_process; 1101 goto out; 1102 } 1103 1104 /* 1105 * If the process is stopped and receives another STOP 1106 * signal, we do not need to stop it again. If we did 1107 * the shell could get confused. 1108 * 1109 * However, if the current/preempted lwp is part of the 1110 * process receiving the signal, we need to keep it, 1111 * so that this lwp can stop in issignal() later, as 1112 * we don't want to wait until it reaches userret! 1113 */ 1114 if (prop & SA_STOP) { 1115 if (lwkt_preempted_proc() == NULL || 1116 lwkt_preempted_proc()->lwp_proc != p) 1117 SIGDELSET(p->p_siglist, sig); 1118 } 1119 1120 /* 1121 * Otherwise the process is stopped and it received some 1122 * signal, which does not change its stopped state. 1123 * 1124 * We have to select one thread to set LWP_BREAKTSLEEP, 1125 * so that the current signal will break the sleep 1126 * as soon as a SA_CONT signal will unstop the process. 1127 */ 1128 if (lp == NULL) 1129 lp = find_lwp_for_signal(p, sig); 1130 if (lp != NULL && 1131 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP)) 1132 lp->lwp_flag |= LWP_BREAKTSLEEP; 1133 goto out; 1134 1135 /* NOTREACHED */ 1136 } 1137 /* else not stopped */ 1138 active_process: 1139 1140 /* 1141 * Never deliver a lwp-specific signal to a random lwp. 1142 */ 1143 if (lp == NULL) { 1144 lp = find_lwp_for_signal(p, sig); 1145 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig)) 1146 lp = NULL; 1147 } 1148 1149 /* 1150 * Deliver to the process generically if (1) the signal is being 1151 * sent to any thread or (2) we could not find a thread to deliver 1152 * it to. 1153 */ 1154 if (lp == NULL) { 1155 SIGADDSET(p->p_siglist, sig); 1156 goto out; 1157 } 1158 1159 /* 1160 * Deliver to a specific LWP whether it masks it or not. It will 1161 * not be dispatched if masked but we must still deliver it. 1162 */ 1163 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1164 (p->p_flag & P_TRACED) == 0) { 1165 p->p_nice = NZERO; 1166 } 1167 1168 /* 1169 * If the process receives a STOP signal which indeed needs to 1170 * stop the process, do so. If the process chose to catch the 1171 * signal, it will be treated like any other signal. 1172 */ 1173 if ((prop & SA_STOP) && action == SIG_DFL) { 1174 /* 1175 * If a child holding parent blocked, stopping 1176 * could cause deadlock. Take no action at this 1177 * time. 1178 */ 1179 if (p->p_flag & P_PPWAIT) { 1180 SIGADDSET(p->p_siglist, sig); 1181 goto out; 1182 } 1183 1184 /* 1185 * Do not actually try to manipulate the process, but simply 1186 * stop it. Lwps will stop as soon as they safely can. 1187 */ 1188 p->p_xstat = sig; 1189 proc_stop(p); 1190 goto out; 1191 } 1192 1193 /* 1194 * If it is a CONT signal with default action, just ignore it. 1195 */ 1196 if ((prop & SA_CONT) && action == SIG_DFL) 1197 goto out; 1198 1199 /* 1200 * Mark signal pending at this specific thread. 1201 */ 1202 SIGADDSET(lp->lwp_siglist, sig); 1203 1204 lwp_signotify(lp); 1205 1206 out: 1207 crit_exit(); 1208 } 1209 1210 void 1211 lwp_signotify(struct lwp *lp) 1212 { 1213 crit_enter(); 1214 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) { 1215 /* 1216 * Thread is in tsleep. 1217 */ 1218 1219 /* 1220 * If the thread is sleeping uninterruptibly 1221 * we can't interrupt the sleep... the signal will 1222 * be noticed when the lwp returns through 1223 * trap() or syscall(). 1224 * 1225 * Otherwise the signal can interrupt the sleep. 1226 * 1227 * If the process is traced, the lwp will handle the 1228 * tracing in issignal() when it returns to userland. 1229 */ 1230 if (lp->lwp_flag & LWP_SINTR) { 1231 /* 1232 * Make runnable and break out of any tsleep as well. 1233 */ 1234 lp->lwp_flag |= LWP_BREAKTSLEEP; 1235 setrunnable(lp); 1236 } 1237 } else { 1238 /* 1239 * Otherwise the thread is running 1240 * 1241 * LSRUN does nothing with the signal, other than kicking 1242 * ourselves if we are running. 1243 * SZOMB and SIDL mean that it will either never be noticed, 1244 * or noticed very soon. 1245 * 1246 * Note that lwp_thread may be NULL or may not be completely 1247 * initialized if the process is in the SIDL or SZOMB state. 1248 * 1249 * For SMP we may have to forward the request to another cpu. 1250 * YYY the MP lock prevents the target process from moving 1251 * to another cpu, see kern/kern_switch.c 1252 * 1253 * If the target thread is waiting on its message port, 1254 * wakeup the target thread so it can check (or ignore) 1255 * the new signal. YYY needs cleanup. 1256 */ 1257 if (lp == lwkt_preempted_proc()) { 1258 signotify(); 1259 } else if (lp->lwp_stat == LSRUN) { 1260 struct thread *td = lp->lwp_thread; 1261 struct proc *p __debugvar = lp->lwp_proc; 1262 1263 KASSERT(td != NULL, 1264 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x", 1265 p->p_pid, lp->lwp_tid, lp->lwp_stat, 1266 p->p_flag, lp->lwp_flag)); 1267 1268 /* 1269 * To prevent a MP race with TDF_SINTR we must 1270 * schedule the thread on the correct cpu. 1271 */ 1272 #ifdef SMP 1273 if (td->td_gd != mycpu) { 1274 LWPHOLD(lp); 1275 lwkt_send_ipiq(td->td_gd, signotify_remote, lp); 1276 } else 1277 #endif 1278 if (td->td_flags & TDF_SINTR) 1279 lwkt_schedule(td); 1280 } 1281 } 1282 crit_exit(); 1283 } 1284 1285 #ifdef SMP 1286 1287 /* 1288 * This function is called via an IPI. We will be in a critical section but 1289 * the MP lock will NOT be held. Also note that by the time the ipi message 1290 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 1291 */ 1292 static void 1293 signotify_remote(void *arg) 1294 { 1295 struct lwp *lp = arg; 1296 1297 if (lp == lwkt_preempted_proc()) { 1298 signotify(); 1299 } else { 1300 struct thread *td = lp->lwp_thread; 1301 if (td->td_flags & TDF_SINTR) 1302 lwkt_schedule(td); 1303 } 1304 LWPRELE(lp); 1305 } 1306 1307 #endif 1308 1309 void 1310 proc_stop(struct proc *p) 1311 { 1312 struct lwp *lp; 1313 1314 /* If somebody raced us, be happy with it */ 1315 if (p->p_stat == SSTOP || p->p_stat == SZOMB) 1316 return; 1317 1318 crit_enter(); 1319 p->p_stat = SSTOP; 1320 1321 FOREACH_LWP_IN_PROC(lp, p) { 1322 switch (lp->lwp_stat) { 1323 case LSSTOP: 1324 /* 1325 * Do nothing, we are already counted in 1326 * p_nstopped. 1327 */ 1328 break; 1329 1330 case LSSLEEP: 1331 /* 1332 * We're sleeping, but we will stop before 1333 * returning to userspace, so count us 1334 * as stopped as well. We set LWP_WSTOP 1335 * to signal the lwp that it should not 1336 * increase p_nstopped when reaching tstop(). 1337 */ 1338 if ((lp->lwp_flag & LWP_WSTOP) == 0) { 1339 lp->lwp_flag |= LWP_WSTOP; 1340 ++p->p_nstopped; 1341 } 1342 break; 1343 1344 case LSRUN: 1345 /* 1346 * We might notify ourself, but that's not 1347 * a problem. 1348 */ 1349 lwp_signotify(lp); 1350 break; 1351 } 1352 } 1353 1354 if (p->p_nstopped == p->p_nthreads) { 1355 p->p_flag &= ~P_WAITED; 1356 wakeup(p->p_pptr); 1357 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0) 1358 ksignal(p->p_pptr, SIGCHLD); 1359 } 1360 crit_exit(); 1361 } 1362 1363 void 1364 proc_unstop(struct proc *p) 1365 { 1366 struct lwp *lp; 1367 1368 if (p->p_stat != SSTOP) 1369 return; 1370 1371 crit_enter(); 1372 p->p_stat = SACTIVE; 1373 1374 FOREACH_LWP_IN_PROC(lp, p) { 1375 switch (lp->lwp_stat) { 1376 case LSRUN: 1377 /* 1378 * Uh? Not stopped? Well, I guess that's okay. 1379 */ 1380 if (bootverbose) 1381 kprintf("proc_unstop: lwp %d/%d not sleeping\n", 1382 p->p_pid, lp->lwp_tid); 1383 break; 1384 1385 case LSSLEEP: 1386 /* 1387 * Still sleeping. Don't bother waking it up. 1388 * However, if this thread was counted as 1389 * stopped, undo this. 1390 * 1391 * Nevertheless we call setrunnable() so that it 1392 * will wake up in case a signal or timeout arrived 1393 * in the meantime. 1394 */ 1395 if (lp->lwp_flag & LWP_WSTOP) { 1396 lp->lwp_flag &= ~LWP_WSTOP; 1397 --p->p_nstopped; 1398 } else { 1399 if (bootverbose) 1400 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n", 1401 p->p_pid, lp->lwp_tid); 1402 } 1403 /* FALLTHROUGH */ 1404 1405 case LSSTOP: 1406 setrunnable(lp); 1407 break; 1408 1409 } 1410 } 1411 crit_exit(); 1412 } 1413 1414 static int 1415 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout) 1416 { 1417 sigset_t savedmask, set; 1418 struct proc *p = curproc; 1419 struct lwp *lp = curthread->td_lwp; 1420 int error, sig, hz, timevalid = 0; 1421 struct timespec rts, ets, ts; 1422 struct timeval tv; 1423 1424 error = 0; 1425 sig = 0; 1426 ets.tv_sec = 0; /* silence compiler warning */ 1427 ets.tv_nsec = 0; /* silence compiler warning */ 1428 SIG_CANTMASK(waitset); 1429 savedmask = lp->lwp_sigmask; 1430 1431 if (timeout) { 1432 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 && 1433 timeout->tv_nsec < 1000000000) { 1434 timevalid = 1; 1435 getnanouptime(&rts); 1436 ets = rts; 1437 timespecadd(&ets, timeout); 1438 } 1439 } 1440 1441 for (;;) { 1442 set = lwp_sigpend(lp); 1443 SIGSETAND(set, waitset); 1444 if ((sig = sig_ffs(&set)) != 0) { 1445 SIGFILLSET(lp->lwp_sigmask); 1446 SIGDELSET(lp->lwp_sigmask, sig); 1447 SIG_CANTMASK(lp->lwp_sigmask); 1448 sig = issignal(lp, 1); 1449 /* 1450 * It may be a STOP signal, in the case, issignal 1451 * returns 0, because we may stop there, and new 1452 * signal can come in, we should restart if we got 1453 * nothing. 1454 */ 1455 if (sig == 0) 1456 continue; 1457 else 1458 break; 1459 } 1460 1461 /* 1462 * Previous checking got nothing, and we retried but still 1463 * got nothing, we should return the error status. 1464 */ 1465 if (error) 1466 break; 1467 1468 /* 1469 * POSIX says this must be checked after looking for pending 1470 * signals. 1471 */ 1472 if (timeout) { 1473 if (timevalid == 0) { 1474 error = EINVAL; 1475 break; 1476 } 1477 getnanouptime(&rts); 1478 if (timespeccmp(&rts, &ets, >=)) { 1479 error = EAGAIN; 1480 break; 1481 } 1482 ts = ets; 1483 timespecsub(&ts, &rts); 1484 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1485 hz = tvtohz_high(&tv); 1486 } else 1487 hz = 0; 1488 1489 lp->lwp_sigmask = savedmask; 1490 SIGSETNAND(lp->lwp_sigmask, waitset); 1491 /* 1492 * We won't ever be woken up. Instead, our sleep will 1493 * be broken in lwpsignal(). 1494 */ 1495 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz); 1496 if (timeout) { 1497 if (error == ERESTART) { 1498 /* can not restart a timeout wait. */ 1499 error = EINTR; 1500 } else if (error == EAGAIN) { 1501 /* will calculate timeout by ourself. */ 1502 error = 0; 1503 } 1504 } 1505 /* Retry ... */ 1506 } 1507 1508 lp->lwp_sigmask = savedmask; 1509 if (sig) { 1510 error = 0; 1511 bzero(info, sizeof(*info)); 1512 info->si_signo = sig; 1513 lwp_delsig(lp, sig); /* take the signal! */ 1514 1515 if (sig == SIGKILL) 1516 sigexit(lp, sig); 1517 } 1518 return (error); 1519 } 1520 1521 /* 1522 * MPALMOSTSAFE 1523 */ 1524 int 1525 sys_sigtimedwait(struct sigtimedwait_args *uap) 1526 { 1527 struct timespec ts; 1528 struct timespec *timeout; 1529 sigset_t set; 1530 siginfo_t info; 1531 int error; 1532 1533 if (uap->timeout) { 1534 error = copyin(uap->timeout, &ts, sizeof(ts)); 1535 if (error) 1536 return (error); 1537 timeout = &ts; 1538 } else { 1539 timeout = NULL; 1540 } 1541 error = copyin(uap->set, &set, sizeof(set)); 1542 if (error) 1543 return (error); 1544 get_mplock(); 1545 error = kern_sigtimedwait(set, &info, timeout); 1546 rel_mplock(); 1547 if (error) 1548 return (error); 1549 if (uap->info) 1550 error = copyout(&info, uap->info, sizeof(info)); 1551 /* Repost if we got an error. */ 1552 /* 1553 * XXX lwp 1554 * 1555 * This could transform a thread-specific signal to another 1556 * thread / process pending signal. 1557 */ 1558 if (error) { 1559 get_mplock(); 1560 ksignal(curproc, info.si_signo); 1561 rel_mplock(); 1562 } else { 1563 uap->sysmsg_result = info.si_signo; 1564 } 1565 return (error); 1566 } 1567 1568 /* 1569 * MPALMOSTSAFE 1570 */ 1571 int 1572 sys_sigwaitinfo(struct sigwaitinfo_args *uap) 1573 { 1574 siginfo_t info; 1575 sigset_t set; 1576 int error; 1577 1578 error = copyin(uap->set, &set, sizeof(set)); 1579 if (error) 1580 return (error); 1581 get_mplock(); 1582 error = kern_sigtimedwait(set, &info, NULL); 1583 rel_mplock(); 1584 if (error) 1585 return (error); 1586 if (uap->info) 1587 error = copyout(&info, uap->info, sizeof(info)); 1588 /* Repost if we got an error. */ 1589 /* 1590 * XXX lwp 1591 * 1592 * This could transform a thread-specific signal to another 1593 * thread / process pending signal. 1594 */ 1595 if (error) { 1596 get_mplock(); 1597 ksignal(curproc, info.si_signo); 1598 rel_mplock(); 1599 } else { 1600 uap->sysmsg_result = info.si_signo; 1601 } 1602 return (error); 1603 } 1604 1605 /* 1606 * If the current process has received a signal that would interrupt a 1607 * system call, return EINTR or ERESTART as appropriate. 1608 */ 1609 int 1610 iscaught(struct lwp *lp) 1611 { 1612 struct proc *p = lp->lwp_proc; 1613 int sig; 1614 1615 if (p) { 1616 if ((sig = CURSIG(lp)) != 0) { 1617 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1618 return (EINTR); 1619 return (ERESTART); 1620 } 1621 } 1622 return(EWOULDBLOCK); 1623 } 1624 1625 /* 1626 * If the current process has received a signal (should be caught or cause 1627 * termination, should interrupt current syscall), return the signal number. 1628 * Stop signals with default action are processed immediately, then cleared; 1629 * they aren't returned. This is checked after each entry to the system for 1630 * a syscall or trap (though this can usually be done without calling issignal 1631 * by checking the pending signal masks in the CURSIG macro.) The normal call 1632 * sequence is 1633 * 1634 * This routine is called via CURSIG/__cursig and the MP lock might not be 1635 * held. Obtain the MP lock for the duration of the operation. 1636 * 1637 * while (sig = CURSIG(curproc)) 1638 * postsig(sig); 1639 */ 1640 int 1641 issignal(struct lwp *lp, int maytrace) 1642 { 1643 struct proc *p = lp->lwp_proc; 1644 sigset_t mask; 1645 int sig, prop; 1646 1647 get_mplock(); 1648 for (;;) { 1649 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1650 1651 /* 1652 * If this process is supposed to stop, stop this thread. 1653 */ 1654 if (p->p_stat == SSTOP) 1655 tstop(); 1656 1657 mask = lwp_sigpend(lp); 1658 SIGSETNAND(mask, lp->lwp_sigmask); 1659 if (p->p_flag & P_PPWAIT) 1660 SIG_STOPSIGMASK(mask); 1661 if (SIGISEMPTY(mask)) { /* no signal to send */ 1662 rel_mplock(); 1663 return (0); 1664 } 1665 sig = sig_ffs(&mask); 1666 1667 STOPEVENT(p, S_SIG, sig); 1668 1669 /* 1670 * We should see pending but ignored signals 1671 * only if P_TRACED was on when they were posted. 1672 */ 1673 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1674 lwp_delsig(lp, sig); 1675 continue; 1676 } 1677 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) { 1678 /* 1679 * If traced, always stop, and stay stopped until 1680 * released by the parent. 1681 * 1682 * NOTE: SSTOP may get cleared during the loop, 1683 * but we do not re-notify the parent if we have 1684 * to loop several times waiting for the parent 1685 * to let us continue. 1686 * 1687 * XXX not sure if this is still true 1688 */ 1689 p->p_xstat = sig; 1690 proc_stop(p); 1691 do { 1692 tstop(); 1693 } while (!trace_req(p) && (p->p_flag & P_TRACED)); 1694 1695 /* 1696 * If parent wants us to take the signal, 1697 * then it will leave it in p->p_xstat; 1698 * otherwise we just look for signals again. 1699 */ 1700 lwp_delsig(lp, sig); /* clear old signal */ 1701 sig = p->p_xstat; 1702 if (sig == 0) 1703 continue; 1704 1705 /* 1706 * Put the new signal into p_siglist. If the 1707 * signal is being masked, look for other signals. 1708 * 1709 * XXX lwp might need a call to ksignal() 1710 */ 1711 SIGADDSET(p->p_siglist, sig); 1712 if (SIGISMEMBER(lp->lwp_sigmask, sig)) 1713 continue; 1714 1715 /* 1716 * If the traced bit got turned off, go back up 1717 * to the top to rescan signals. This ensures 1718 * that p_sig* and ps_sigact are consistent. 1719 */ 1720 if ((p->p_flag & P_TRACED) == 0) 1721 continue; 1722 } 1723 1724 prop = sigprop(sig); 1725 1726 /* 1727 * Decide whether the signal should be returned. 1728 * Return the signal's number, or fall through 1729 * to clear it from the pending mask. 1730 */ 1731 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1732 case (intptr_t)SIG_DFL: 1733 /* 1734 * Don't take default actions on system processes. 1735 */ 1736 if (p->p_pid <= 1) { 1737 #ifdef DIAGNOSTIC 1738 /* 1739 * Are you sure you want to ignore SIGSEGV 1740 * in init? XXX 1741 */ 1742 kprintf("Process (pid %lu) got signal %d\n", 1743 (u_long)p->p_pid, sig); 1744 #endif 1745 break; /* == ignore */ 1746 } 1747 1748 /* 1749 * Handle the in-kernel checkpoint action 1750 */ 1751 if (prop & SA_CKPT) { 1752 checkpoint_signal_handler(lp); 1753 break; 1754 } 1755 1756 /* 1757 * If there is a pending stop signal to process 1758 * with default action, stop here, 1759 * then clear the signal. However, 1760 * if process is member of an orphaned 1761 * process group, ignore tty stop signals. 1762 */ 1763 if (prop & SA_STOP) { 1764 if (p->p_flag & P_TRACED || 1765 (p->p_pgrp->pg_jobc == 0 && 1766 prop & SA_TTYSTOP)) 1767 break; /* == ignore */ 1768 p->p_xstat = sig; 1769 proc_stop(p); 1770 tstop(); 1771 break; 1772 } else if (prop & SA_IGNORE) { 1773 /* 1774 * Except for SIGCONT, shouldn't get here. 1775 * Default action is to ignore; drop it. 1776 */ 1777 break; /* == ignore */ 1778 } else { 1779 rel_mplock(); 1780 return (sig); 1781 } 1782 1783 /*NOTREACHED*/ 1784 1785 case (intptr_t)SIG_IGN: 1786 /* 1787 * Masking above should prevent us ever trying 1788 * to take action on an ignored signal other 1789 * than SIGCONT, unless process is traced. 1790 */ 1791 if ((prop & SA_CONT) == 0 && 1792 (p->p_flag & P_TRACED) == 0) 1793 kprintf("issignal\n"); 1794 break; /* == ignore */ 1795 1796 default: 1797 /* 1798 * This signal has an action, let 1799 * postsig() process it. 1800 */ 1801 rel_mplock(); 1802 return (sig); 1803 } 1804 lwp_delsig(lp, sig); /* take the signal! */ 1805 } 1806 /* NOTREACHED */ 1807 } 1808 1809 /* 1810 * Take the action for the specified signal 1811 * from the current set of pending signals. 1812 */ 1813 void 1814 postsig(int sig) 1815 { 1816 struct lwp *lp = curthread->td_lwp; 1817 struct proc *p = lp->lwp_proc; 1818 struct sigacts *ps = p->p_sigacts; 1819 sig_t action; 1820 sigset_t returnmask; 1821 int code; 1822 1823 KASSERT(sig != 0, ("postsig")); 1824 1825 /* 1826 * If we are a virtual kernel running an emulated user process 1827 * context, switch back to the virtual kernel context before 1828 * trying to post the signal. 1829 */ 1830 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { 1831 struct trapframe *tf = lp->lwp_md.md_regs; 1832 tf->tf_trapno = 0; 1833 vkernel_trap(lp, tf); 1834 } 1835 1836 lwp_delsig(lp, sig); 1837 action = ps->ps_sigact[_SIG_IDX(sig)]; 1838 #ifdef KTRACE 1839 if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) 1840 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ? 1841 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0); 1842 #endif 1843 STOPEVENT(p, S_SIG, sig); 1844 1845 if (action == SIG_DFL) { 1846 /* 1847 * Default action, where the default is to kill 1848 * the process. (Other cases were ignored above.) 1849 */ 1850 sigexit(lp, sig); 1851 /* NOTREACHED */ 1852 } else { 1853 /* 1854 * If we get here, the signal must be caught. 1855 */ 1856 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig), 1857 ("postsig action")); 1858 1859 crit_enter(); 1860 1861 /* 1862 * Reset the signal handler if asked to 1863 */ 1864 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1865 /* 1866 * See kern_sigaction() for origin of this code. 1867 */ 1868 SIGDELSET(p->p_sigcatch, sig); 1869 if (sig != SIGCONT && 1870 sigprop(sig) & SA_IGNORE) 1871 SIGADDSET(p->p_sigignore, sig); 1872 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1873 } 1874 1875 /* 1876 * Handle the mailbox case. Copyout to the appropriate 1877 * location but do not generate a signal frame. The system 1878 * call simply returns EINTR and the user is responsible for 1879 * polling the mailbox. 1880 */ 1881 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) { 1882 int sig_copy = sig; 1883 copyout(&sig_copy, (void *)action, sizeof(int)); 1884 curproc->p_flag |= P_MAILBOX; 1885 crit_exit(); 1886 goto done; 1887 } 1888 1889 /* 1890 * Set the signal mask and calculate the mask to restore 1891 * when the signal function returns. 1892 * 1893 * Special case: user has done a sigsuspend. Here the 1894 * current mask is not of interest, but rather the 1895 * mask from before the sigsuspend is what we want 1896 * restored after the signal processing is completed. 1897 */ 1898 if (lp->lwp_flag & LWP_OLDMASK) { 1899 returnmask = lp->lwp_oldsigmask; 1900 lp->lwp_flag &= ~LWP_OLDMASK; 1901 } else { 1902 returnmask = lp->lwp_sigmask; 1903 } 1904 1905 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1906 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1907 SIGADDSET(lp->lwp_sigmask, sig); 1908 1909 crit_exit(); 1910 lp->lwp_ru.ru_nsignals++; 1911 if (lp->lwp_sig != sig) { 1912 code = 0; 1913 } else { 1914 code = lp->lwp_code; 1915 lp->lwp_code = 0; 1916 lp->lwp_sig = 0; 1917 } 1918 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1919 } 1920 done: 1921 ; 1922 } 1923 1924 /* 1925 * Kill the current process for stated reason. 1926 */ 1927 void 1928 killproc(struct proc *p, char *why) 1929 { 1930 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", 1931 p->p_pid, p->p_comm, 1932 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1933 ksignal(p, SIGKILL); 1934 } 1935 1936 /* 1937 * Force the current process to exit with the specified signal, dumping core 1938 * if appropriate. We bypass the normal tests for masked and caught signals, 1939 * allowing unrecoverable failures to terminate the process without changing 1940 * signal state. Mark the accounting record with the signal termination. 1941 * If dumping core, save the signal number for the debugger. Calls exit and 1942 * does not return. 1943 */ 1944 void 1945 sigexit(struct lwp *lp, int sig) 1946 { 1947 struct proc *p = lp->lwp_proc; 1948 1949 p->p_acflag |= AXSIG; 1950 if (sigprop(sig) & SA_CORE) { 1951 lp->lwp_sig = sig; 1952 /* 1953 * Log signals which would cause core dumps 1954 * (Log as LOG_INFO to appease those who don't want 1955 * these messages.) 1956 * XXX : Todo, as well as euid, write out ruid too 1957 */ 1958 if (coredump(lp, sig) == 0) 1959 sig |= WCOREFLAG; 1960 if (kern_logsigexit) 1961 log(LOG_INFO, 1962 "pid %d (%s), uid %d: exited on signal %d%s\n", 1963 p->p_pid, p->p_comm, 1964 p->p_ucred ? p->p_ucred->cr_uid : -1, 1965 sig &~ WCOREFLAG, 1966 sig & WCOREFLAG ? " (core dumped)" : ""); 1967 } 1968 exit1(W_EXITCODE(0, sig)); 1969 /* NOTREACHED */ 1970 } 1971 1972 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1973 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1974 sizeof(corefilename), "process corefile name format string"); 1975 1976 /* 1977 * expand_name(name, uid, pid) 1978 * Expand the name described in corefilename, using name, uid, and pid. 1979 * corefilename is a kprintf-like string, with three format specifiers: 1980 * %N name of process ("name") 1981 * %P process id (pid) 1982 * %U user id (uid) 1983 * For example, "%N.core" is the default; they can be disabled completely 1984 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1985 * This is controlled by the sysctl variable kern.corefile (see above). 1986 */ 1987 1988 static char * 1989 expand_name(const char *name, uid_t uid, pid_t pid) 1990 { 1991 char *temp; 1992 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1993 int i, n; 1994 char *format = corefilename; 1995 size_t namelen; 1996 1997 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1998 if (temp == NULL) 1999 return NULL; 2000 namelen = strlen(name); 2001 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2002 int l; 2003 switch (format[i]) { 2004 case '%': /* Format character */ 2005 i++; 2006 switch (format[i]) { 2007 case '%': 2008 temp[n++] = '%'; 2009 break; 2010 case 'N': /* process name */ 2011 if ((n + namelen) > MAXPATHLEN) { 2012 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2013 pid, name, uid, temp, name); 2014 kfree(temp, M_TEMP); 2015 return NULL; 2016 } 2017 memcpy(temp+n, name, namelen); 2018 n += namelen; 2019 break; 2020 case 'P': /* process id */ 2021 l = ksprintf(buf, "%u", pid); 2022 if ((n + l) > MAXPATHLEN) { 2023 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2024 pid, name, uid, temp, name); 2025 kfree(temp, M_TEMP); 2026 return NULL; 2027 } 2028 memcpy(temp+n, buf, l); 2029 n += l; 2030 break; 2031 case 'U': /* user id */ 2032 l = ksprintf(buf, "%u", uid); 2033 if ((n + l) > MAXPATHLEN) { 2034 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2035 pid, name, uid, temp, name); 2036 kfree(temp, M_TEMP); 2037 return NULL; 2038 } 2039 memcpy(temp+n, buf, l); 2040 n += l; 2041 break; 2042 default: 2043 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 2044 } 2045 break; 2046 default: 2047 temp[n++] = format[i]; 2048 } 2049 } 2050 temp[n] = '\0'; 2051 return temp; 2052 } 2053 2054 /* 2055 * Dump a process' core. The main routine does some 2056 * policy checking, and creates the name of the coredump; 2057 * then it passes on a vnode and a size limit to the process-specific 2058 * coredump routine if there is one; if there _is not_ one, it returns 2059 * ENOSYS; otherwise it returns the error from the process-specific routine. 2060 * 2061 * The parameter `lp' is the lwp which triggered the coredump. 2062 */ 2063 2064 static int 2065 coredump(struct lwp *lp, int sig) 2066 { 2067 struct proc *p = lp->lwp_proc; 2068 struct vnode *vp; 2069 struct ucred *cred = p->p_ucred; 2070 struct flock lf; 2071 struct nlookupdata nd; 2072 struct vattr vattr; 2073 int error, error1; 2074 char *name; /* name of corefile */ 2075 off_t limit; 2076 2077 STOPEVENT(p, S_CORE, 0); 2078 2079 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 2080 return (EFAULT); 2081 2082 /* 2083 * Note that the bulk of limit checking is done after 2084 * the corefile is created. The exception is if the limit 2085 * for corefiles is 0, in which case we don't bother 2086 * creating the corefile at all. This layout means that 2087 * a corefile is truncated instead of not being created, 2088 * if it is larger than the limit. 2089 */ 2090 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2091 if (limit == 0) 2092 return EFBIG; 2093 2094 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 2095 if (name == NULL) 2096 return (EINVAL); 2097 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP); 2098 if (error == 0) 2099 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 2100 kfree(name, M_TEMP); 2101 if (error) { 2102 nlookup_done(&nd); 2103 return (error); 2104 } 2105 vp = nd.nl_open_vp; 2106 nd.nl_open_vp = NULL; 2107 nlookup_done(&nd); 2108 2109 vn_unlock(vp); 2110 lf.l_whence = SEEK_SET; 2111 lf.l_start = 0; 2112 lf.l_len = 0; 2113 lf.l_type = F_WRLCK; 2114 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0); 2115 if (error) 2116 goto out2; 2117 2118 /* Don't dump to non-regular files or files with links. */ 2119 if (vp->v_type != VREG || 2120 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) { 2121 error = EFAULT; 2122 goto out1; 2123 } 2124 2125 /* Don't dump to files current user does not own */ 2126 if (vattr.va_uid != p->p_ucred->cr_uid) { 2127 error = EFAULT; 2128 goto out1; 2129 } 2130 2131 VATTR_NULL(&vattr); 2132 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2133 vattr.va_size = 0; 2134 VOP_SETATTR(vp, &vattr, cred); 2135 p->p_acflag |= ACORE; 2136 vn_unlock(vp); 2137 2138 error = p->p_sysent->sv_coredump ? 2139 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS; 2140 2141 out1: 2142 lf.l_type = F_UNLCK; 2143 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0); 2144 out2: 2145 error1 = vn_close(vp, FWRITE); 2146 if (error == 0) 2147 error = error1; 2148 return (error); 2149 } 2150 2151 /* 2152 * Nonexistent system call-- signal process (may want to handle it). 2153 * Flag error in case process won't see signal immediately (blocked or ignored). 2154 * 2155 * MPALMOSTSAFE 2156 */ 2157 /* ARGSUSED */ 2158 int 2159 sys_nosys(struct nosys_args *args) 2160 { 2161 get_mplock(); 2162 lwpsignal(curproc, curthread->td_lwp, SIGSYS); 2163 rel_mplock(); 2164 return (EINVAL); 2165 } 2166 2167 /* 2168 * Send a SIGIO or SIGURG signal to a process or process group using 2169 * stored credentials rather than those of the current process. 2170 */ 2171 void 2172 pgsigio(struct sigio *sigio, int sig, int checkctty) 2173 { 2174 if (sigio == NULL) 2175 return; 2176 2177 if (sigio->sio_pgid > 0) { 2178 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 2179 sigio->sio_proc)) 2180 ksignal(sigio->sio_proc, sig); 2181 } else if (sigio->sio_pgid < 0) { 2182 struct proc *p; 2183 2184 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE); 2185 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2186 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 2187 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2188 ksignal(p, sig); 2189 } 2190 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE); 2191 } 2192 } 2193 2194 static int 2195 filt_sigattach(struct knote *kn) 2196 { 2197 struct proc *p = curproc; 2198 2199 kn->kn_ptr.p_proc = p; 2200 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2201 2202 /* XXX lock the proc here while adding to the list? */ 2203 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2204 2205 return (0); 2206 } 2207 2208 static void 2209 filt_sigdetach(struct knote *kn) 2210 { 2211 struct proc *p = kn->kn_ptr.p_proc; 2212 2213 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2214 } 2215 2216 /* 2217 * signal knotes are shared with proc knotes, so we apply a mask to 2218 * the hint in order to differentiate them from process hints. This 2219 * could be avoided by using a signal-specific knote list, but probably 2220 * isn't worth the trouble. 2221 */ 2222 static int 2223 filt_signal(struct knote *kn, long hint) 2224 { 2225 if (hint & NOTE_SIGNAL) { 2226 hint &= ~NOTE_SIGNAL; 2227 2228 if (kn->kn_id == hint) 2229 kn->kn_data++; 2230 } 2231 return (kn->kn_data != 0); 2232 } 2233