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/signal2.h> 51 #include <sys/resourcevar.h> 52 #include <sys/vnode.h> 53 #include <sys/event.h> 54 #include <sys/proc.h> 55 #include <sys/nlookup.h> 56 #include <sys/pioctl.h> 57 #include <sys/systm.h> 58 #include <sys/acct.h> 59 #include <sys/fcntl.h> 60 #include <sys/lock.h> 61 #include <sys/wait.h> 62 #include <sys/ktrace.h> 63 #include <sys/syslog.h> 64 #include <sys/stat.h> 65 #include <sys/sysent.h> 66 #include <sys/sysctl.h> 67 #include <sys/malloc.h> 68 #include <sys/interrupt.h> 69 #include <sys/unistd.h> 70 #include <sys/kern_syscall.h> 71 #include <sys/vkernel.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 #ifdef SMP 83 static void signotify_remote(void *arg); 84 #endif 85 static int kern_sigtimedwait(sigset_t set, siginfo_t *info, 86 struct timespec *timeout); 87 88 static int filt_sigattach(struct knote *kn); 89 static void filt_sigdetach(struct knote *kn); 90 static int filt_signal(struct knote *kn, long hint); 91 92 struct filterops sig_filtops = 93 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 94 95 static int kern_logsigexit = 1; 96 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 97 &kern_logsigexit, 0, 98 "Log processes quitting on abnormal signals to syslog(3)"); 99 100 /* 101 * Can process p, with pcred pc, send the signal sig to process q? 102 */ 103 #define CANSIGNAL(q, sig) \ 104 (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \ 105 ((sig) == SIGCONT && (q)->p_session == curproc->p_session)) 106 107 /* 108 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 109 */ 110 #define CANSIGIO(ruid, uc, q) \ 111 ((uc)->cr_uid == 0 || \ 112 (ruid) == (q)->p_ucred->cr_ruid || \ 113 (uc)->cr_uid == (q)->p_ucred->cr_ruid || \ 114 (ruid) == (q)->p_ucred->cr_uid || \ 115 (uc)->cr_uid == (q)->p_ucred->cr_uid) 116 117 int sugid_coredump; 118 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 119 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 120 121 static int do_coredump = 1; 122 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 123 &do_coredump, 0, "Enable/Disable coredumps"); 124 125 /* 126 * Signal properties and actions. 127 * The array below categorizes the signals and their default actions 128 * according to the following properties: 129 */ 130 #define SA_KILL 0x01 /* terminates process by default */ 131 #define SA_CORE 0x02 /* ditto and coredumps */ 132 #define SA_STOP 0x04 /* suspend process */ 133 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 134 #define SA_IGNORE 0x10 /* ignore by default */ 135 #define SA_CONT 0x20 /* continue if suspended */ 136 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 137 #define SA_CKPT 0x80 /* checkpoint process */ 138 139 140 static int sigproptbl[NSIG] = { 141 SA_KILL, /* SIGHUP */ 142 SA_KILL, /* SIGINT */ 143 SA_KILL|SA_CORE, /* SIGQUIT */ 144 SA_KILL|SA_CORE, /* SIGILL */ 145 SA_KILL|SA_CORE, /* SIGTRAP */ 146 SA_KILL|SA_CORE, /* SIGABRT */ 147 SA_KILL|SA_CORE, /* SIGEMT */ 148 SA_KILL|SA_CORE, /* SIGFPE */ 149 SA_KILL, /* SIGKILL */ 150 SA_KILL|SA_CORE, /* SIGBUS */ 151 SA_KILL|SA_CORE, /* SIGSEGV */ 152 SA_KILL|SA_CORE, /* SIGSYS */ 153 SA_KILL, /* SIGPIPE */ 154 SA_KILL, /* SIGALRM */ 155 SA_KILL, /* SIGTERM */ 156 SA_IGNORE, /* SIGURG */ 157 SA_STOP, /* SIGSTOP */ 158 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 159 SA_IGNORE|SA_CONT, /* SIGCONT */ 160 SA_IGNORE, /* SIGCHLD */ 161 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 162 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 163 SA_IGNORE, /* SIGIO */ 164 SA_KILL, /* SIGXCPU */ 165 SA_KILL, /* SIGXFSZ */ 166 SA_KILL, /* SIGVTALRM */ 167 SA_KILL, /* SIGPROF */ 168 SA_IGNORE, /* SIGWINCH */ 169 SA_IGNORE, /* SIGINFO */ 170 SA_KILL, /* SIGUSR1 */ 171 SA_KILL, /* SIGUSR2 */ 172 SA_IGNORE, /* SIGTHR */ 173 SA_CKPT, /* SIGCKPT */ 174 SA_KILL|SA_CKPT, /* SIGCKPTEXIT */ 175 SA_IGNORE, 176 SA_IGNORE, 177 SA_IGNORE, 178 SA_IGNORE, 179 SA_IGNORE, 180 SA_IGNORE, 181 SA_IGNORE, 182 SA_IGNORE, 183 SA_IGNORE, 184 SA_IGNORE, 185 SA_IGNORE, 186 SA_IGNORE, 187 SA_IGNORE, 188 SA_IGNORE, 189 SA_IGNORE, 190 SA_IGNORE, 191 SA_IGNORE, 192 SA_IGNORE, 193 SA_IGNORE, 194 SA_IGNORE, 195 SA_IGNORE, 196 SA_IGNORE, 197 SA_IGNORE, 198 SA_IGNORE, 199 SA_IGNORE, 200 SA_IGNORE, 201 SA_IGNORE, 202 SA_IGNORE, 203 SA_IGNORE, 204 SA_IGNORE, 205 206 }; 207 208 static __inline int 209 sigprop(int sig) 210 { 211 212 if (sig > 0 && sig < NSIG) 213 return (sigproptbl[_SIG_IDX(sig)]); 214 return (0); 215 } 216 217 static __inline int 218 sig_ffs(sigset_t *set) 219 { 220 int i; 221 222 for (i = 0; i < _SIG_WORDS; i++) 223 if (set->__bits[i]) 224 return (ffs(set->__bits[i]) + (i * 32)); 225 return (0); 226 } 227 228 int 229 kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact) 230 { 231 struct thread *td = curthread; 232 struct proc *p = td->td_proc; 233 struct lwp *lp; 234 struct sigacts *ps = p->p_sigacts; 235 236 if (sig <= 0 || sig > _SIG_MAXSIG) 237 return (EINVAL); 238 239 if (oact) { 240 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 241 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 242 oact->sa_flags = 0; 243 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 244 oact->sa_flags |= SA_ONSTACK; 245 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 246 oact->sa_flags |= SA_RESTART; 247 if (SIGISMEMBER(ps->ps_sigreset, sig)) 248 oact->sa_flags |= SA_RESETHAND; 249 if (SIGISMEMBER(ps->ps_signodefer, sig)) 250 oact->sa_flags |= SA_NODEFER; 251 if (SIGISMEMBER(ps->ps_siginfo, sig)) 252 oact->sa_flags |= SA_SIGINFO; 253 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) 254 oact->sa_flags |= SA_MAILBOX; 255 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP) 256 oact->sa_flags |= SA_NOCLDSTOP; 257 if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT) 258 oact->sa_flags |= SA_NOCLDWAIT; 259 } 260 if (act) { 261 /* 262 * Check for invalid requests. KILL and STOP cannot be 263 * caught. 264 */ 265 if (sig == SIGKILL || sig == SIGSTOP) { 266 if (act->sa_handler != SIG_DFL) 267 return (EINVAL); 268 #if 0 269 /* (not needed, SIG_DFL forces action to occur) */ 270 if (act->sa_flags & SA_MAILBOX) 271 return (EINVAL); 272 #endif 273 } 274 275 /* 276 * Change setting atomically. 277 */ 278 crit_enter(); 279 280 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 281 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 282 if (act->sa_flags & SA_SIGINFO) { 283 ps->ps_sigact[_SIG_IDX(sig)] = 284 (__sighandler_t *)act->sa_sigaction; 285 SIGADDSET(ps->ps_siginfo, sig); 286 } else { 287 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 288 SIGDELSET(ps->ps_siginfo, sig); 289 } 290 if (!(act->sa_flags & SA_RESTART)) 291 SIGADDSET(ps->ps_sigintr, sig); 292 else 293 SIGDELSET(ps->ps_sigintr, sig); 294 if (act->sa_flags & SA_ONSTACK) 295 SIGADDSET(ps->ps_sigonstack, sig); 296 else 297 SIGDELSET(ps->ps_sigonstack, sig); 298 if (act->sa_flags & SA_RESETHAND) 299 SIGADDSET(ps->ps_sigreset, sig); 300 else 301 SIGDELSET(ps->ps_sigreset, sig); 302 if (act->sa_flags & SA_NODEFER) 303 SIGADDSET(ps->ps_signodefer, sig); 304 else 305 SIGDELSET(ps->ps_signodefer, sig); 306 if (act->sa_flags & SA_MAILBOX) 307 SIGADDSET(ps->ps_sigmailbox, sig); 308 else 309 SIGDELSET(ps->ps_sigmailbox, sig); 310 if (sig == SIGCHLD) { 311 if (act->sa_flags & SA_NOCLDSTOP) 312 p->p_sigacts->ps_flag |= PS_NOCLDSTOP; 313 else 314 p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP; 315 if (act->sa_flags & SA_NOCLDWAIT) { 316 /* 317 * Paranoia: since SA_NOCLDWAIT is implemented 318 * by reparenting the dying child to PID 1 (and 319 * trust it to reap the zombie), PID 1 itself 320 * is forbidden to set SA_NOCLDWAIT. 321 */ 322 if (p->p_pid == 1) 323 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 324 else 325 p->p_sigacts->ps_flag |= PS_NOCLDWAIT; 326 } else { 327 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 328 } 329 } 330 /* 331 * Set bit in p_sigignore for signals that are set to SIG_IGN, 332 * and for signals set to SIG_DFL where the default is to 333 * ignore. However, don't put SIGCONT in p_sigignore, as we 334 * have to restart the process. 335 */ 336 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 337 (sigprop(sig) & SA_IGNORE && 338 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 339 /* never to be seen again */ 340 SIGDELSET(p->p_siglist, sig); 341 /* 342 * Remove the signal also from the thread lists. 343 */ 344 FOREACH_LWP_IN_PROC(lp, p) { 345 SIGDELSET(lp->lwp_siglist, sig); 346 } 347 if (sig != SIGCONT) 348 /* easier in ksignal */ 349 SIGADDSET(p->p_sigignore, sig); 350 SIGDELSET(p->p_sigcatch, sig); 351 } else { 352 SIGDELSET(p->p_sigignore, sig); 353 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 354 SIGDELSET(p->p_sigcatch, sig); 355 else 356 SIGADDSET(p->p_sigcatch, sig); 357 } 358 359 crit_exit(); 360 } 361 return (0); 362 } 363 364 /* 365 * MPALMOSTSAFE 366 */ 367 int 368 sys_sigaction(struct sigaction_args *uap) 369 { 370 struct sigaction act, oact; 371 struct sigaction *actp, *oactp; 372 int error; 373 374 actp = (uap->act != NULL) ? &act : NULL; 375 oactp = (uap->oact != NULL) ? &oact : NULL; 376 if (actp) { 377 error = copyin(uap->act, actp, sizeof(act)); 378 if (error) 379 return (error); 380 } 381 get_mplock(); 382 error = kern_sigaction(uap->sig, actp, oactp); 383 rel_mplock(); 384 if (oactp && !error) { 385 error = copyout(oactp, uap->oact, sizeof(oact)); 386 } 387 return (error); 388 } 389 390 /* 391 * Initialize signal state for process 0; 392 * set to ignore signals that are ignored by default. 393 */ 394 void 395 siginit(struct proc *p) 396 { 397 int i; 398 399 for (i = 1; i <= NSIG; i++) 400 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 401 SIGADDSET(p->p_sigignore, i); 402 } 403 404 /* 405 * Reset signals for an exec of the specified process. 406 */ 407 void 408 execsigs(struct proc *p) 409 { 410 struct sigacts *ps = p->p_sigacts; 411 struct lwp *lp; 412 int sig; 413 414 lp = ONLY_LWP_IN_PROC(p); 415 416 /* 417 * Reset caught signals. Held signals remain held 418 * through p_sigmask (unless they were caught, 419 * and are now ignored by default). 420 */ 421 while (SIGNOTEMPTY(p->p_sigcatch)) { 422 sig = sig_ffs(&p->p_sigcatch); 423 SIGDELSET(p->p_sigcatch, sig); 424 if (sigprop(sig) & SA_IGNORE) { 425 if (sig != SIGCONT) 426 SIGADDSET(p->p_sigignore, sig); 427 SIGDELSET(p->p_siglist, sig); 428 SIGDELSET(lp->lwp_siglist, sig); 429 } 430 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 431 } 432 433 /* 434 * Reset stack state to the user stack. 435 * Clear set of signals caught on the signal stack. 436 */ 437 lp->lwp_sigstk.ss_flags = SS_DISABLE; 438 lp->lwp_sigstk.ss_size = 0; 439 lp->lwp_sigstk.ss_sp = 0; 440 lp->lwp_flag &= ~LWP_ALTSTACK; 441 /* 442 * Reset no zombies if child dies flag as Solaris does. 443 */ 444 p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; 445 } 446 447 /* 448 * kern_sigprocmask() - MP SAFE ONLY IF p == curproc 449 * 450 * Manipulate signal mask. This routine is MP SAFE *ONLY* if 451 * p == curproc. 452 */ 453 int 454 kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) 455 { 456 struct thread *td = curthread; 457 struct lwp *lp = td->td_lwp; 458 int error; 459 460 if (oset != NULL) 461 *oset = lp->lwp_sigmask; 462 463 error = 0; 464 if (set != NULL) { 465 switch (how) { 466 case SIG_BLOCK: 467 SIG_CANTMASK(*set); 468 SIGSETOR(lp->lwp_sigmask, *set); 469 break; 470 case SIG_UNBLOCK: 471 SIGSETNAND(lp->lwp_sigmask, *set); 472 break; 473 case SIG_SETMASK: 474 SIG_CANTMASK(*set); 475 lp->lwp_sigmask = *set; 476 break; 477 default: 478 error = EINVAL; 479 break; 480 } 481 } 482 return (error); 483 } 484 485 /* 486 * sigprocmask() 487 * 488 * MPSAFE 489 */ 490 int 491 sys_sigprocmask(struct sigprocmask_args *uap) 492 { 493 sigset_t set, oset; 494 sigset_t *setp, *osetp; 495 int error; 496 497 setp = (uap->set != NULL) ? &set : NULL; 498 osetp = (uap->oset != NULL) ? &oset : NULL; 499 if (setp) { 500 error = copyin(uap->set, setp, sizeof(set)); 501 if (error) 502 return (error); 503 } 504 error = kern_sigprocmask(uap->how, setp, osetp); 505 if (osetp && !error) { 506 error = copyout(osetp, uap->oset, sizeof(oset)); 507 } 508 return (error); 509 } 510 511 /* 512 * MPSAFE 513 */ 514 int 515 kern_sigpending(struct __sigset *set) 516 { 517 struct lwp *lp = curthread->td_lwp; 518 519 *set = lwp_sigpend(lp); 520 521 return (0); 522 } 523 524 /* 525 * MPSAFE 526 */ 527 int 528 sys_sigpending(struct sigpending_args *uap) 529 { 530 sigset_t set; 531 int error; 532 533 error = kern_sigpending(&set); 534 535 if (error == 0) 536 error = copyout(&set, uap->set, sizeof(set)); 537 return (error); 538 } 539 540 /* 541 * Suspend process until signal, providing mask to be set 542 * in the meantime. 543 * 544 * MPSAFE 545 */ 546 int 547 kern_sigsuspend(struct __sigset *set) 548 { 549 struct thread *td = curthread; 550 struct lwp *lp = td->td_lwp; 551 struct proc *p = td->td_proc; 552 struct sigacts *ps = p->p_sigacts; 553 554 /* 555 * When returning from sigsuspend, we want 556 * the old mask to be restored after the 557 * signal handler has finished. Thus, we 558 * save it here and mark the sigacts structure 559 * to indicate this. 560 */ 561 lp->lwp_oldsigmask = lp->lwp_sigmask; 562 lp->lwp_flag |= LWP_OLDMASK; 563 564 SIG_CANTMASK(*set); 565 lp->lwp_sigmask = *set; 566 while (tsleep(ps, PCATCH, "pause", 0) == 0) 567 /* void */; 568 /* always return EINTR rather than ERESTART... */ 569 return (EINTR); 570 } 571 572 /* 573 * Note nonstandard calling convention: libc stub passes mask, not 574 * pointer, to save a copyin. 575 * 576 * MPSAFE 577 */ 578 int 579 sys_sigsuspend(struct sigsuspend_args *uap) 580 { 581 sigset_t mask; 582 int error; 583 584 error = copyin(uap->sigmask, &mask, sizeof(mask)); 585 if (error) 586 return (error); 587 588 error = kern_sigsuspend(&mask); 589 590 return (error); 591 } 592 593 /* 594 * MPSAFE 595 */ 596 int 597 kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) 598 { 599 struct thread *td = curthread; 600 struct lwp *lp = td->td_lwp; 601 struct proc *p = td->td_proc; 602 603 if ((lp->lwp_flag & LWP_ALTSTACK) == 0) 604 lp->lwp_sigstk.ss_flags |= SS_DISABLE; 605 606 if (oss) 607 *oss = lp->lwp_sigstk; 608 609 if (ss) { 610 if (ss->ss_flags & SS_DISABLE) { 611 if (lp->lwp_sigstk.ss_flags & SS_ONSTACK) 612 return (EINVAL); 613 lp->lwp_flag &= ~LWP_ALTSTACK; 614 lp->lwp_sigstk.ss_flags = ss->ss_flags; 615 } else { 616 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 617 return (ENOMEM); 618 lp->lwp_flag |= LWP_ALTSTACK; 619 lp->lwp_sigstk = *ss; 620 } 621 } 622 623 return (0); 624 } 625 626 /* 627 * MPSAFE 628 */ 629 int 630 sys_sigaltstack(struct sigaltstack_args *uap) 631 { 632 stack_t ss, oss; 633 int error; 634 635 if (uap->ss) { 636 error = copyin(uap->ss, &ss, sizeof(ss)); 637 if (error) 638 return (error); 639 } 640 641 error = kern_sigaltstack(uap->ss ? &ss : NULL, 642 uap->oss ? &oss : NULL); 643 644 if (error == 0 && uap->oss) 645 error = copyout(&oss, uap->oss, sizeof(*uap->oss)); 646 return (error); 647 } 648 649 /* 650 * Common code for kill process group/broadcast kill. 651 * cp is calling process. 652 */ 653 struct killpg_info { 654 int nfound; 655 int sig; 656 }; 657 658 static int killpg_all_callback(struct proc *p, void *data); 659 660 static int 661 dokillpg(int sig, int pgid, int all) 662 { 663 struct killpg_info info; 664 struct proc *cp = curproc; 665 struct proc *p; 666 struct pgrp *pgrp; 667 668 info.nfound = 0; 669 info.sig = sig; 670 671 if (all) { 672 /* 673 * broadcast 674 */ 675 allproc_scan(killpg_all_callback, &info); 676 } else { 677 if (pgid == 0) { 678 /* 679 * zero pgid means send to my process group. 680 */ 681 pgrp = cp->p_pgrp; 682 } else { 683 pgrp = pgfind(pgid); 684 if (pgrp == NULL) 685 return (ESRCH); 686 } 687 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); 688 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 689 if (p->p_pid <= 1 || 690 p->p_stat == SZOMB || 691 (p->p_flag & P_SYSTEM) || 692 !CANSIGNAL(p, sig)) { 693 continue; 694 } 695 ++info.nfound; 696 if (sig) 697 ksignal(p, sig); 698 } 699 lockmgr(&pgrp->pg_lock, LK_RELEASE); 700 } 701 return (info.nfound ? 0 : ESRCH); 702 } 703 704 static int 705 killpg_all_callback(struct proc *p, void *data) 706 { 707 struct killpg_info *info = data; 708 709 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) || 710 p == curproc || !CANSIGNAL(p, info->sig)) { 711 return (0); 712 } 713 ++info->nfound; 714 if (info->sig) 715 ksignal(p, info->sig); 716 return(0); 717 } 718 719 /* 720 * Send a general signal to a process or LWPs within that process. Note 721 * that new signals cannot be sent if a process is exiting. 722 */ 723 int 724 kern_kill(int sig, pid_t pid, lwpid_t tid) 725 { 726 if ((u_int)sig > _SIG_MAXSIG) 727 return (EINVAL); 728 if (pid > 0) { 729 struct proc *p; 730 struct lwp *lp = NULL; 731 732 /* kill single process */ 733 if ((p = pfind(pid)) == NULL) 734 return (ESRCH); 735 if (!CANSIGNAL(p, sig)) 736 return (EPERM); 737 738 /* 739 * NOP if the process is exiting. Note that lwpsignal() is 740 * called directly with P_WEXIT set to kill individual LWPs 741 * during exit, which is allowed. 742 */ 743 if (p->p_flag & P_WEXIT) 744 return (0); 745 if (tid != -1) { 746 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid); 747 if (lp == NULL) 748 return (ESRCH); 749 } 750 if (sig) 751 lwpsignal(p, lp, sig); 752 return (0); 753 } 754 /* 755 * If we come here, pid is a special broadcast pid. 756 * This doesn't mix with a tid. 757 */ 758 if (tid != -1) 759 return (EINVAL); 760 switch (pid) { 761 case -1: /* broadcast signal */ 762 return (dokillpg(sig, 0, 1)); 763 case 0: /* signal own process group */ 764 return (dokillpg(sig, 0, 0)); 765 default: /* negative explicit process group */ 766 return (dokillpg(sig, -pid, 0)); 767 } 768 /* NOTREACHED */ 769 } 770 771 /* 772 * MPALMOSTSAFE 773 */ 774 int 775 sys_kill(struct kill_args *uap) 776 { 777 int error; 778 779 get_mplock(); 780 error = kern_kill(uap->signum, uap->pid, -1); 781 rel_mplock(); 782 return (error); 783 } 784 785 /* 786 * MPALMOSTSAFE 787 */ 788 int 789 sys_lwp_kill(struct lwp_kill_args *uap) 790 { 791 int error; 792 pid_t pid = uap->pid; 793 794 /* 795 * A tid is mandatory for lwp_kill(), otherwise 796 * you could simply use kill(). 797 */ 798 if (uap->tid == -1) 799 return (EINVAL); 800 801 /* 802 * To save on a getpid() function call for intra-process 803 * signals, pid == -1 means current process. 804 */ 805 if (pid == -1) 806 pid = curproc->p_pid; 807 808 get_mplock(); 809 error = kern_kill(uap->signum, pid, uap->tid); 810 rel_mplock(); 811 return (error); 812 } 813 814 /* 815 * Send a signal to a process group. 816 */ 817 void 818 gsignal(int pgid, int sig) 819 { 820 struct pgrp *pgrp; 821 822 if (pgid && (pgrp = pgfind(pgid))) 823 pgsignal(pgrp, sig, 0); 824 } 825 826 /* 827 * Send a signal to a process group. If checktty is 1, 828 * limit to members which have a controlling terminal. 829 * 830 * pg_lock interlocks against a fork that might be in progress, to 831 * ensure that the new child process picks up the signal. 832 */ 833 void 834 pgsignal(struct pgrp *pgrp, int sig, int checkctty) 835 { 836 struct proc *p; 837 838 if (pgrp) { 839 lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); 840 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 841 if (checkctty == 0 || p->p_flag & P_CONTROLT) 842 ksignal(p, sig); 843 } 844 lockmgr(&pgrp->pg_lock, LK_RELEASE); 845 } 846 } 847 848 /* 849 * Send a signal caused by a trap to the current lwp. If it will be caught 850 * immediately, deliver it with correct code. Otherwise, post it normally. 851 * 852 * These signals may ONLY be delivered to the specified lwp and may never 853 * be delivered to the process generically. 854 */ 855 void 856 trapsignal(struct lwp *lp, int sig, u_long code) 857 { 858 struct proc *p = lp->lwp_proc; 859 struct sigacts *ps = p->p_sigacts; 860 861 /* 862 * If we are a virtual kernel running an emulated user process 863 * context, switch back to the virtual kernel context before 864 * trying to post the signal. 865 */ 866 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { 867 struct trapframe *tf = lp->lwp_md.md_regs; 868 tf->tf_trapno = 0; 869 vkernel_trap(lp, tf); 870 } 871 872 873 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 874 !SIGISMEMBER(lp->lwp_sigmask, sig)) { 875 lp->lwp_ru.ru_nsignals++; 876 #ifdef KTRACE 877 if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) 878 ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)], 879 &lp->lwp_sigmask, code); 880 #endif 881 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 882 &lp->lwp_sigmask, code); 883 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 884 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 885 SIGADDSET(lp->lwp_sigmask, sig); 886 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 887 /* 888 * See kern_sigaction() for origin of this code. 889 */ 890 SIGDELSET(p->p_sigcatch, sig); 891 if (sig != SIGCONT && 892 sigprop(sig) & SA_IGNORE) 893 SIGADDSET(p->p_sigignore, sig); 894 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 895 } 896 } else { 897 lp->lwp_code = code; /* XXX for core dump/debugger */ 898 lp->lwp_sig = sig; /* XXX to verify code */ 899 lwpsignal(p, lp, sig); 900 } 901 } 902 903 /* 904 * Find a suitable lwp to deliver the signal to. 905 * 906 * Returns NULL if all lwps hold the signal blocked. 907 */ 908 static struct lwp * 909 find_lwp_for_signal(struct proc *p, int sig) 910 { 911 struct lwp *lp; 912 struct lwp *run, *sleep, *stop; 913 914 /* 915 * If the running/preempted thread belongs to the proc to which 916 * the signal is being delivered and this thread does not block 917 * the signal, then we can avoid a context switch by delivering 918 * the signal to this thread, because it will return to userland 919 * soon anyways. 920 */ 921 lp = lwkt_preempted_proc(); 922 if (lp != NULL && lp->lwp_proc == p && !SIGISMEMBER(lp->lwp_sigmask, sig)) 923 return (lp); 924 925 run = sleep = stop = NULL; 926 FOREACH_LWP_IN_PROC(lp, p) { 927 /* 928 * If the signal is being blocked by the lwp, then this 929 * lwp is not eligible for receiving the signal. 930 */ 931 if (SIGISMEMBER(lp->lwp_sigmask, sig)) 932 continue; 933 934 switch (lp->lwp_stat) { 935 case LSRUN: 936 run = lp; 937 break; 938 939 case LSSTOP: 940 stop = lp; 941 break; 942 943 case LSSLEEP: 944 if (lp->lwp_flag & LWP_SINTR) 945 sleep = lp; 946 break; 947 } 948 } 949 950 if (run != NULL) 951 return (run); 952 else if (sleep != NULL) 953 return (sleep); 954 else 955 return (stop); 956 } 957 958 /* 959 * Send the signal to the process. If the signal has an action, the action 960 * is usually performed by the target process rather than the caller; we add 961 * the signal to the set of pending signals for the process. 962 * 963 * Exceptions: 964 * o When a stop signal is sent to a sleeping process that takes the 965 * default action, the process is stopped without awakening it. 966 * o SIGCONT restarts stopped processes (or puts them back to sleep) 967 * regardless of the signal action (eg, blocked or ignored). 968 * 969 * Other ignored signals are discarded immediately. 970 */ 971 void 972 ksignal(struct proc *p, int sig) 973 { 974 lwpsignal(p, NULL, sig); 975 } 976 977 /* 978 * The core for ksignal. lp may be NULL, then a suitable thread 979 * will be chosen. If not, lp MUST be a member of p. 980 */ 981 void 982 lwpsignal(struct proc *p, struct lwp *lp, int sig) 983 { 984 int prop; 985 sig_t action; 986 987 if (sig > _SIG_MAXSIG || sig <= 0) { 988 kprintf("lwpsignal: signal %d\n", sig); 989 panic("lwpsignal signal number"); 990 } 991 992 KKASSERT(lp == NULL || lp->lwp_proc == p); 993 994 crit_enter(); 995 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 996 crit_exit(); 997 998 prop = sigprop(sig); 999 1000 /* 1001 * If proc is traced, always give parent a chance; 1002 * if signal event is tracked by procfs, give *that* 1003 * a chance, as well. 1004 */ 1005 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1006 action = SIG_DFL; 1007 } else { 1008 /* 1009 * Do not try to deliver signals to an exiting lwp. Note 1010 * that we must still deliver the signal if P_WEXIT is set 1011 * in the process flags. 1012 */ 1013 if (lp && (lp->lwp_flag & LWP_WEXIT)) 1014 return; 1015 1016 /* 1017 * If the signal is being ignored, then we forget about 1018 * it immediately. NOTE: We don't set SIGCONT in p_sigignore, 1019 * and if it is set to SIG_IGN, action will be SIG_DFL here. 1020 */ 1021 if (SIGISMEMBER(p->p_sigignore, sig)) 1022 return; 1023 if (SIGISMEMBER(p->p_sigcatch, sig)) 1024 action = SIG_CATCH; 1025 else 1026 action = SIG_DFL; 1027 } 1028 1029 /* 1030 * If continuing, clear any pending STOP signals. 1031 */ 1032 if (prop & SA_CONT) 1033 SIG_STOPSIGMASK(p->p_siglist); 1034 1035 if (prop & SA_STOP) { 1036 /* 1037 * If sending a tty stop signal to a member of an orphaned 1038 * process group, discard the signal here if the action 1039 * is default; don't stop the process below if sleeping, 1040 * and don't clear any pending SIGCONT. 1041 */ 1042 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1043 action == SIG_DFL) { 1044 return; 1045 } 1046 SIG_CONTSIGMASK(p->p_siglist); 1047 p->p_flag &= ~P_CONTINUED; 1048 } 1049 1050 crit_enter(); 1051 1052 if (p->p_stat == SSTOP) { 1053 /* 1054 * Nobody can handle this signal, add it to the lwp or 1055 * process pending list 1056 */ 1057 if (lp) 1058 SIGADDSET(lp->lwp_siglist, sig); 1059 else 1060 SIGADDSET(p->p_siglist, sig); 1061 1062 /* 1063 * If the process is stopped and is being traced, then no 1064 * further action is necessary. 1065 */ 1066 if (p->p_flag & P_TRACED) 1067 goto out; 1068 1069 /* 1070 * If the process is stopped and receives a KILL signal, 1071 * make the process runnable. 1072 */ 1073 if (sig == SIGKILL) { 1074 proc_unstop(p); 1075 goto active_process; 1076 } 1077 1078 /* 1079 * If the process is stopped and receives a CONT signal, 1080 * then try to make the process runnable again. 1081 */ 1082 if (prop & SA_CONT) { 1083 /* 1084 * If SIGCONT is default (or ignored), we continue the 1085 * process but don't leave the signal in p_siglist, as 1086 * it has no further action. If SIGCONT is held, we 1087 * continue the process and leave the signal in 1088 * p_siglist. If the process catches SIGCONT, let it 1089 * handle the signal itself. 1090 */ 1091 /* XXX what if the signal is being held blocked? */ 1092 p->p_flag |= P_CONTINUED; 1093 wakeup(p->p_pptr); 1094 if (action == SIG_DFL) 1095 SIGDELSET(p->p_siglist, sig); 1096 proc_unstop(p); 1097 if (action == SIG_CATCH) 1098 goto active_process; 1099 goto out; 1100 } 1101 1102 /* 1103 * If the process is stopped and receives another STOP 1104 * signal, we do not need to stop it again. If we did 1105 * the shell could get confused. 1106 * 1107 * However, if the current/preempted lwp is part of the 1108 * process receiving the signal, we need to keep it, 1109 * so that this lwp can stop in issignal() later, as 1110 * we don't want to wait until it reaches userret! 1111 */ 1112 if (prop & SA_STOP) { 1113 if (lwkt_preempted_proc() == NULL || 1114 lwkt_preempted_proc()->lwp_proc != p) 1115 SIGDELSET(p->p_siglist, sig); 1116 } 1117 1118 /* 1119 * Otherwise the process is stopped and it received some 1120 * signal, which does not change its stopped state. 1121 * 1122 * We have to select one thread to set LWP_BREAKTSLEEP, 1123 * so that the current signal will break the sleep 1124 * as soon as a SA_CONT signal will unstop the process. 1125 */ 1126 if (lp == NULL) 1127 lp = find_lwp_for_signal(p, sig); 1128 if (lp != NULL && 1129 (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP)) 1130 lp->lwp_flag |= LWP_BREAKTSLEEP; 1131 goto out; 1132 1133 /* NOTREACHED */ 1134 } 1135 /* else not stopped */ 1136 active_process: 1137 1138 /* 1139 * Never deliver a lwp-specific signal to a random lwp. 1140 */ 1141 if (lp == NULL) { 1142 lp = find_lwp_for_signal(p, sig); 1143 if (lp && SIGISMEMBER(lp->lwp_sigmask, sig)) 1144 lp = NULL; 1145 } 1146 1147 /* 1148 * Deliver to the process generically if (1) the signal is being 1149 * sent to any thread or (2) we could not find a thread to deliver 1150 * it to. 1151 */ 1152 if (lp == NULL) { 1153 SIGADDSET(p->p_siglist, sig); 1154 goto out; 1155 } 1156 1157 /* 1158 * Deliver to a specific LWP whether it masks it or not. It will 1159 * not be dispatched if masked but we must still deliver it. 1160 */ 1161 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1162 (p->p_flag & P_TRACED) == 0) { 1163 p->p_nice = NZERO; 1164 } 1165 1166 /* 1167 * If the process receives a STOP signal which indeed needs to 1168 * stop the process, do so. If the process chose to catch the 1169 * signal, it will be treated like any other signal. 1170 */ 1171 if ((prop & SA_STOP) && action == SIG_DFL) { 1172 /* 1173 * If a child holding parent blocked, stopping 1174 * could cause deadlock. Take no action at this 1175 * time. 1176 */ 1177 if (p->p_flag & P_PPWAIT) { 1178 SIGADDSET(p->p_siglist, sig); 1179 goto out; 1180 } 1181 1182 /* 1183 * Do not actually try to manipulate the process, but simply 1184 * stop it. Lwps will stop as soon as they safely can. 1185 */ 1186 p->p_xstat = sig; 1187 proc_stop(p); 1188 goto out; 1189 } 1190 1191 /* 1192 * If it is a CONT signal with default action, just ignore it. 1193 */ 1194 if ((prop & SA_CONT) && action == SIG_DFL) 1195 goto out; 1196 1197 /* 1198 * Mark signal pending at this specific thread. 1199 */ 1200 SIGADDSET(lp->lwp_siglist, sig); 1201 1202 lwp_signotify(lp); 1203 1204 out: 1205 crit_exit(); 1206 } 1207 1208 void 1209 lwp_signotify(struct lwp *lp) 1210 { 1211 crit_enter(); 1212 if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) { 1213 /* 1214 * Thread is in tsleep. 1215 */ 1216 1217 /* 1218 * If the thread is sleeping uninterruptibly 1219 * we can't interrupt the sleep... the signal will 1220 * be noticed when the lwp returns through 1221 * trap() or syscall(). 1222 * 1223 * Otherwise the signal can interrupt the sleep. 1224 * 1225 * If the process is traced, the lwp will handle the 1226 * tracing in issignal() when it returns to userland. 1227 */ 1228 if (lp->lwp_flag & LWP_SINTR) { 1229 /* 1230 * Make runnable and break out of any tsleep as well. 1231 */ 1232 lp->lwp_flag |= LWP_BREAKTSLEEP; 1233 setrunnable(lp); 1234 } 1235 } else { 1236 /* 1237 * Otherwise the thread is running 1238 * 1239 * LSRUN does nothing with the signal, other than kicking 1240 * ourselves if we are running. 1241 * SZOMB and SIDL mean that it will either never be noticed, 1242 * or noticed very soon. 1243 * 1244 * Note that lwp_thread may be NULL or may not be completely 1245 * initialized if the process is in the SIDL or SZOMB state. 1246 * 1247 * For SMP we may have to forward the request to another cpu. 1248 * YYY the MP lock prevents the target process from moving 1249 * to another cpu, see kern/kern_switch.c 1250 * 1251 * If the target thread is waiting on its message port, 1252 * wakeup the target thread so it can check (or ignore) 1253 * the new signal. YYY needs cleanup. 1254 */ 1255 if (lp == lwkt_preempted_proc()) { 1256 signotify(); 1257 } else if (lp->lwp_stat == LSRUN) { 1258 struct thread *td = lp->lwp_thread; 1259 struct proc *p __debugvar = lp->lwp_proc; 1260 1261 KASSERT(td != NULL, 1262 ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x", 1263 p->p_pid, lp->lwp_tid, lp->lwp_stat, 1264 p->p_flag, lp->lwp_flag)); 1265 1266 /* 1267 * To prevent a MP race with TDF_SINTR we must 1268 * schedule the thread on the correct cpu. 1269 */ 1270 #ifdef SMP 1271 if (td->td_gd != mycpu) { 1272 LWPHOLD(lp); 1273 lwkt_send_ipiq(td->td_gd, signotify_remote, lp); 1274 } else 1275 #endif 1276 if (td->td_flags & TDF_SINTR) 1277 lwkt_schedule(td); 1278 } 1279 } 1280 crit_exit(); 1281 } 1282 1283 #ifdef SMP 1284 1285 /* 1286 * This function is called via an IPI. We will be in a critical section but 1287 * the MP lock will NOT be held. Also note that by the time the ipi message 1288 * gets to us the process 'p' (arg) may no longer be scheduled or even valid. 1289 */ 1290 static void 1291 signotify_remote(void *arg) 1292 { 1293 struct lwp *lp = arg; 1294 1295 if (lp == lwkt_preempted_proc()) { 1296 signotify(); 1297 } else { 1298 struct thread *td = lp->lwp_thread; 1299 if (td->td_flags & TDF_SINTR) 1300 lwkt_schedule(td); 1301 } 1302 LWPRELE(lp); 1303 } 1304 1305 #endif 1306 1307 void 1308 proc_stop(struct proc *p) 1309 { 1310 struct lwp *lp; 1311 1312 /* If somebody raced us, be happy with it */ 1313 if (p->p_stat == SSTOP || p->p_stat == SZOMB) 1314 return; 1315 1316 crit_enter(); 1317 p->p_stat = SSTOP; 1318 1319 FOREACH_LWP_IN_PROC(lp, p) { 1320 switch (lp->lwp_stat) { 1321 case LSSTOP: 1322 /* 1323 * Do nothing, we are already counted in 1324 * p_nstopped. 1325 */ 1326 break; 1327 1328 case LSSLEEP: 1329 /* 1330 * We're sleeping, but we will stop before 1331 * returning to userspace, so count us 1332 * as stopped as well. We set LWP_WSTOP 1333 * to signal the lwp that it should not 1334 * increase p_nstopped when reaching tstop(). 1335 */ 1336 if ((lp->lwp_flag & LWP_WSTOP) == 0) { 1337 lp->lwp_flag |= LWP_WSTOP; 1338 ++p->p_nstopped; 1339 } 1340 break; 1341 1342 case LSRUN: 1343 /* 1344 * We might notify ourself, but that's not 1345 * a problem. 1346 */ 1347 lwp_signotify(lp); 1348 break; 1349 } 1350 } 1351 1352 if (p->p_nstopped == p->p_nthreads) { 1353 p->p_flag &= ~P_WAITED; 1354 wakeup(p->p_pptr); 1355 if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0) 1356 ksignal(p->p_pptr, SIGCHLD); 1357 } 1358 crit_exit(); 1359 } 1360 1361 void 1362 proc_unstop(struct proc *p) 1363 { 1364 struct lwp *lp; 1365 1366 if (p->p_stat != SSTOP) 1367 return; 1368 1369 crit_enter(); 1370 p->p_stat = SACTIVE; 1371 1372 FOREACH_LWP_IN_PROC(lp, p) { 1373 switch (lp->lwp_stat) { 1374 case LSRUN: 1375 /* 1376 * Uh? Not stopped? Well, I guess that's okay. 1377 */ 1378 if (bootverbose) 1379 kprintf("proc_unstop: lwp %d/%d not sleeping\n", 1380 p->p_pid, lp->lwp_tid); 1381 break; 1382 1383 case LSSLEEP: 1384 /* 1385 * Still sleeping. Don't bother waking it up. 1386 * However, if this thread was counted as 1387 * stopped, undo this. 1388 * 1389 * Nevertheless we call setrunnable() so that it 1390 * will wake up in case a signal or timeout arrived 1391 * in the meantime. 1392 */ 1393 if (lp->lwp_flag & LWP_WSTOP) { 1394 lp->lwp_flag &= ~LWP_WSTOP; 1395 --p->p_nstopped; 1396 } else { 1397 if (bootverbose) 1398 kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n", 1399 p->p_pid, lp->lwp_tid); 1400 } 1401 /* FALLTHROUGH */ 1402 1403 case LSSTOP: 1404 setrunnable(lp); 1405 break; 1406 1407 } 1408 } 1409 crit_exit(); 1410 } 1411 1412 static int 1413 kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout) 1414 { 1415 sigset_t savedmask, set; 1416 struct proc *p = curproc; 1417 struct lwp *lp = curthread->td_lwp; 1418 int error, sig, hz, timevalid = 0; 1419 struct timespec rts, ets, ts; 1420 struct timeval tv; 1421 1422 error = 0; 1423 sig = 0; 1424 ets.tv_sec = 0; /* silence compiler warning */ 1425 ets.tv_nsec = 0; /* silence compiler warning */ 1426 SIG_CANTMASK(waitset); 1427 savedmask = lp->lwp_sigmask; 1428 1429 if (timeout) { 1430 if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 && 1431 timeout->tv_nsec < 1000000000) { 1432 timevalid = 1; 1433 getnanouptime(&rts); 1434 ets = rts; 1435 timespecadd(&ets, timeout); 1436 } 1437 } 1438 1439 for (;;) { 1440 set = lwp_sigpend(lp); 1441 SIGSETAND(set, waitset); 1442 if ((sig = sig_ffs(&set)) != 0) { 1443 SIGFILLSET(lp->lwp_sigmask); 1444 SIGDELSET(lp->lwp_sigmask, sig); 1445 SIG_CANTMASK(lp->lwp_sigmask); 1446 sig = issignal(lp, 1); 1447 /* 1448 * It may be a STOP signal, in the case, issignal 1449 * returns 0, because we may stop there, and new 1450 * signal can come in, we should restart if we got 1451 * nothing. 1452 */ 1453 if (sig == 0) 1454 continue; 1455 else 1456 break; 1457 } 1458 1459 /* 1460 * Previous checking got nothing, and we retried but still 1461 * got nothing, we should return the error status. 1462 */ 1463 if (error) 1464 break; 1465 1466 /* 1467 * POSIX says this must be checked after looking for pending 1468 * signals. 1469 */ 1470 if (timeout) { 1471 if (timevalid == 0) { 1472 error = EINVAL; 1473 break; 1474 } 1475 getnanouptime(&rts); 1476 if (timespeccmp(&rts, &ets, >=)) { 1477 error = EAGAIN; 1478 break; 1479 } 1480 ts = ets; 1481 timespecsub(&ts, &rts); 1482 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1483 hz = tvtohz_high(&tv); 1484 } else 1485 hz = 0; 1486 1487 lp->lwp_sigmask = savedmask; 1488 SIGSETNAND(lp->lwp_sigmask, waitset); 1489 /* 1490 * We won't ever be woken up. Instead, our sleep will 1491 * be broken in lwpsignal(). 1492 */ 1493 error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz); 1494 if (timeout) { 1495 if (error == ERESTART) { 1496 /* can not restart a timeout wait. */ 1497 error = EINTR; 1498 } else if (error == EAGAIN) { 1499 /* will calculate timeout by ourself. */ 1500 error = 0; 1501 } 1502 } 1503 /* Retry ... */ 1504 } 1505 1506 lp->lwp_sigmask = savedmask; 1507 if (sig) { 1508 error = 0; 1509 bzero(info, sizeof(*info)); 1510 info->si_signo = sig; 1511 lwp_delsig(lp, sig); /* take the signal! */ 1512 1513 if (sig == SIGKILL) 1514 sigexit(lp, sig); 1515 } 1516 return (error); 1517 } 1518 1519 /* 1520 * MPALMOSTSAFE 1521 */ 1522 int 1523 sys_sigtimedwait(struct sigtimedwait_args *uap) 1524 { 1525 struct timespec ts; 1526 struct timespec *timeout; 1527 sigset_t set; 1528 siginfo_t info; 1529 int error; 1530 1531 if (uap->timeout) { 1532 error = copyin(uap->timeout, &ts, sizeof(ts)); 1533 if (error) 1534 return (error); 1535 timeout = &ts; 1536 } else { 1537 timeout = NULL; 1538 } 1539 error = copyin(uap->set, &set, sizeof(set)); 1540 if (error) 1541 return (error); 1542 get_mplock(); 1543 error = kern_sigtimedwait(set, &info, timeout); 1544 rel_mplock(); 1545 if (error) 1546 return (error); 1547 if (uap->info) 1548 error = copyout(&info, uap->info, sizeof(info)); 1549 /* Repost if we got an error. */ 1550 /* 1551 * XXX lwp 1552 * 1553 * This could transform a thread-specific signal to another 1554 * thread / process pending signal. 1555 */ 1556 if (error) { 1557 get_mplock(); 1558 ksignal(curproc, info.si_signo); 1559 rel_mplock(); 1560 } else { 1561 uap->sysmsg_result = info.si_signo; 1562 } 1563 return (error); 1564 } 1565 1566 /* 1567 * MPALMOSTSAFE 1568 */ 1569 int 1570 sys_sigwaitinfo(struct sigwaitinfo_args *uap) 1571 { 1572 siginfo_t info; 1573 sigset_t set; 1574 int error; 1575 1576 error = copyin(uap->set, &set, sizeof(set)); 1577 if (error) 1578 return (error); 1579 get_mplock(); 1580 error = kern_sigtimedwait(set, &info, NULL); 1581 rel_mplock(); 1582 if (error) 1583 return (error); 1584 if (uap->info) 1585 error = copyout(&info, uap->info, sizeof(info)); 1586 /* Repost if we got an error. */ 1587 /* 1588 * XXX lwp 1589 * 1590 * This could transform a thread-specific signal to another 1591 * thread / process pending signal. 1592 */ 1593 if (error) { 1594 get_mplock(); 1595 ksignal(curproc, info.si_signo); 1596 rel_mplock(); 1597 } else { 1598 uap->sysmsg_result = info.si_signo; 1599 } 1600 return (error); 1601 } 1602 1603 /* 1604 * If the current process has received a signal that would interrupt a 1605 * system call, return EINTR or ERESTART as appropriate. 1606 */ 1607 int 1608 iscaught(struct lwp *lp) 1609 { 1610 struct proc *p = lp->lwp_proc; 1611 int sig; 1612 1613 if (p) { 1614 if ((sig = CURSIG(lp)) != 0) { 1615 if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) 1616 return (EINTR); 1617 return (ERESTART); 1618 } 1619 } 1620 return(EWOULDBLOCK); 1621 } 1622 1623 /* 1624 * If the current process has received a signal (should be caught or cause 1625 * termination, should interrupt current syscall), return the signal number. 1626 * Stop signals with default action are processed immediately, then cleared; 1627 * they aren't returned. This is checked after each entry to the system for 1628 * a syscall or trap (though this can usually be done without calling issignal 1629 * by checking the pending signal masks in the CURSIG macro.) The normal call 1630 * sequence is 1631 * 1632 * This routine is called via CURSIG/__cursig and the MP lock might not be 1633 * held. Obtain the MP lock for the duration of the operation. 1634 * 1635 * while (sig = CURSIG(curproc)) 1636 * postsig(sig); 1637 */ 1638 int 1639 issignal(struct lwp *lp, int maytrace) 1640 { 1641 struct proc *p = lp->lwp_proc; 1642 sigset_t mask; 1643 int sig, prop; 1644 1645 get_mplock(); 1646 for (;;) { 1647 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1648 1649 /* 1650 * If this process is supposed to stop, stop this thread. 1651 */ 1652 if (p->p_stat == SSTOP) 1653 tstop(); 1654 1655 mask = lwp_sigpend(lp); 1656 SIGSETNAND(mask, lp->lwp_sigmask); 1657 if (p->p_flag & P_PPWAIT) 1658 SIG_STOPSIGMASK(mask); 1659 if (SIGISEMPTY(mask)) { /* no signal to send */ 1660 rel_mplock(); 1661 return (0); 1662 } 1663 sig = sig_ffs(&mask); 1664 1665 STOPEVENT(p, S_SIG, sig); 1666 1667 /* 1668 * We should see pending but ignored signals 1669 * only if P_TRACED was on when they were posted. 1670 */ 1671 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1672 lwp_delsig(lp, sig); 1673 continue; 1674 } 1675 if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) { 1676 /* 1677 * If traced, always stop, and stay stopped until 1678 * released by the parent. 1679 * 1680 * NOTE: SSTOP may get cleared during the loop, 1681 * but we do not re-notify the parent if we have 1682 * to loop several times waiting for the parent 1683 * to let us continue. 1684 * 1685 * XXX not sure if this is still true 1686 */ 1687 p->p_xstat = sig; 1688 proc_stop(p); 1689 do { 1690 tstop(); 1691 } while (!trace_req(p) && (p->p_flag & P_TRACED)); 1692 1693 /* 1694 * If parent wants us to take the signal, 1695 * then it will leave it in p->p_xstat; 1696 * otherwise we just look for signals again. 1697 */ 1698 lwp_delsig(lp, sig); /* clear old signal */ 1699 sig = p->p_xstat; 1700 if (sig == 0) 1701 continue; 1702 1703 /* 1704 * Put the new signal into p_siglist. If the 1705 * signal is being masked, look for other signals. 1706 * 1707 * XXX lwp might need a call to ksignal() 1708 */ 1709 SIGADDSET(p->p_siglist, sig); 1710 if (SIGISMEMBER(lp->lwp_sigmask, sig)) 1711 continue; 1712 1713 /* 1714 * If the traced bit got turned off, go back up 1715 * to the top to rescan signals. This ensures 1716 * that p_sig* and ps_sigact are consistent. 1717 */ 1718 if ((p->p_flag & P_TRACED) == 0) 1719 continue; 1720 } 1721 1722 prop = sigprop(sig); 1723 1724 /* 1725 * Decide whether the signal should be returned. 1726 * Return the signal's number, or fall through 1727 * to clear it from the pending mask. 1728 */ 1729 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1730 case (intptr_t)SIG_DFL: 1731 /* 1732 * Don't take default actions on system processes. 1733 */ 1734 if (p->p_pid <= 1) { 1735 #ifdef DIAGNOSTIC 1736 /* 1737 * Are you sure you want to ignore SIGSEGV 1738 * in init? XXX 1739 */ 1740 kprintf("Process (pid %lu) got signal %d\n", 1741 (u_long)p->p_pid, sig); 1742 #endif 1743 break; /* == ignore */ 1744 } 1745 1746 /* 1747 * Handle the in-kernel checkpoint action 1748 */ 1749 if (prop & SA_CKPT) { 1750 checkpoint_signal_handler(lp); 1751 break; 1752 } 1753 1754 /* 1755 * If there is a pending stop signal to process 1756 * with default action, stop here, 1757 * then clear the signal. However, 1758 * if process is member of an orphaned 1759 * process group, ignore tty stop signals. 1760 */ 1761 if (prop & SA_STOP) { 1762 if (p->p_flag & P_TRACED || 1763 (p->p_pgrp->pg_jobc == 0 && 1764 prop & SA_TTYSTOP)) 1765 break; /* == ignore */ 1766 p->p_xstat = sig; 1767 proc_stop(p); 1768 tstop(); 1769 break; 1770 } else if (prop & SA_IGNORE) { 1771 /* 1772 * Except for SIGCONT, shouldn't get here. 1773 * Default action is to ignore; drop it. 1774 */ 1775 break; /* == ignore */ 1776 } else { 1777 rel_mplock(); 1778 return (sig); 1779 } 1780 1781 /*NOTREACHED*/ 1782 1783 case (intptr_t)SIG_IGN: 1784 /* 1785 * Masking above should prevent us ever trying 1786 * to take action on an ignored signal other 1787 * than SIGCONT, unless process is traced. 1788 */ 1789 if ((prop & SA_CONT) == 0 && 1790 (p->p_flag & P_TRACED) == 0) 1791 kprintf("issignal\n"); 1792 break; /* == ignore */ 1793 1794 default: 1795 /* 1796 * This signal has an action, let 1797 * postsig() process it. 1798 */ 1799 rel_mplock(); 1800 return (sig); 1801 } 1802 lwp_delsig(lp, sig); /* take the signal! */ 1803 } 1804 /* NOTREACHED */ 1805 } 1806 1807 /* 1808 * Take the action for the specified signal 1809 * from the current set of pending signals. 1810 */ 1811 void 1812 postsig(int sig) 1813 { 1814 struct lwp *lp = curthread->td_lwp; 1815 struct proc *p = lp->lwp_proc; 1816 struct sigacts *ps = p->p_sigacts; 1817 sig_t action; 1818 sigset_t returnmask; 1819 int code; 1820 1821 KASSERT(sig != 0, ("postsig")); 1822 1823 /* 1824 * If we are a virtual kernel running an emulated user process 1825 * context, switch back to the virtual kernel context before 1826 * trying to post the signal. 1827 */ 1828 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { 1829 struct trapframe *tf = lp->lwp_md.md_regs; 1830 tf->tf_trapno = 0; 1831 vkernel_trap(lp, tf); 1832 } 1833 1834 lwp_delsig(lp, sig); 1835 action = ps->ps_sigact[_SIG_IDX(sig)]; 1836 #ifdef KTRACE 1837 if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) 1838 ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ? 1839 &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0); 1840 #endif 1841 STOPEVENT(p, S_SIG, sig); 1842 1843 if (action == SIG_DFL) { 1844 /* 1845 * Default action, where the default is to kill 1846 * the process. (Other cases were ignored above.) 1847 */ 1848 sigexit(lp, sig); 1849 /* NOTREACHED */ 1850 } else { 1851 /* 1852 * If we get here, the signal must be caught. 1853 */ 1854 KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig), 1855 ("postsig action")); 1856 1857 crit_enter(); 1858 1859 /* 1860 * Reset the signal handler if asked to 1861 */ 1862 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1863 /* 1864 * See kern_sigaction() for origin of this code. 1865 */ 1866 SIGDELSET(p->p_sigcatch, sig); 1867 if (sig != SIGCONT && 1868 sigprop(sig) & SA_IGNORE) 1869 SIGADDSET(p->p_sigignore, sig); 1870 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1871 } 1872 1873 /* 1874 * Handle the mailbox case. Copyout to the appropriate 1875 * location but do not generate a signal frame. The system 1876 * call simply returns EINTR and the user is responsible for 1877 * polling the mailbox. 1878 */ 1879 if (SIGISMEMBER(ps->ps_sigmailbox, sig)) { 1880 int sig_copy = sig; 1881 copyout(&sig_copy, (void *)action, sizeof(int)); 1882 curproc->p_flag |= P_MAILBOX; 1883 crit_exit(); 1884 goto done; 1885 } 1886 1887 /* 1888 * Set the signal mask and calculate the mask to restore 1889 * when the signal function returns. 1890 * 1891 * Special case: user has done a sigsuspend. Here the 1892 * current mask is not of interest, but rather the 1893 * mask from before the sigsuspend is what we want 1894 * restored after the signal processing is completed. 1895 */ 1896 if (lp->lwp_flag & LWP_OLDMASK) { 1897 returnmask = lp->lwp_oldsigmask; 1898 lp->lwp_flag &= ~LWP_OLDMASK; 1899 } else { 1900 returnmask = lp->lwp_sigmask; 1901 } 1902 1903 SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1904 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1905 SIGADDSET(lp->lwp_sigmask, sig); 1906 1907 crit_exit(); 1908 lp->lwp_ru.ru_nsignals++; 1909 if (lp->lwp_sig != sig) { 1910 code = 0; 1911 } else { 1912 code = lp->lwp_code; 1913 lp->lwp_code = 0; 1914 lp->lwp_sig = 0; 1915 } 1916 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1917 } 1918 done: 1919 ; 1920 } 1921 1922 /* 1923 * Kill the current process for stated reason. 1924 */ 1925 void 1926 killproc(struct proc *p, char *why) 1927 { 1928 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", 1929 p->p_pid, p->p_comm, 1930 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1931 ksignal(p, SIGKILL); 1932 } 1933 1934 /* 1935 * Force the current process to exit with the specified signal, dumping core 1936 * if appropriate. We bypass the normal tests for masked and caught signals, 1937 * allowing unrecoverable failures to terminate the process without changing 1938 * signal state. Mark the accounting record with the signal termination. 1939 * If dumping core, save the signal number for the debugger. Calls exit and 1940 * does not return. 1941 */ 1942 void 1943 sigexit(struct lwp *lp, int sig) 1944 { 1945 struct proc *p = lp->lwp_proc; 1946 1947 p->p_acflag |= AXSIG; 1948 if (sigprop(sig) & SA_CORE) { 1949 lp->lwp_sig = sig; 1950 /* 1951 * Log signals which would cause core dumps 1952 * (Log as LOG_INFO to appease those who don't want 1953 * these messages.) 1954 * XXX : Todo, as well as euid, write out ruid too 1955 */ 1956 if (coredump(lp, sig) == 0) 1957 sig |= WCOREFLAG; 1958 if (kern_logsigexit) 1959 log(LOG_INFO, 1960 "pid %d (%s), uid %d: exited on signal %d%s\n", 1961 p->p_pid, p->p_comm, 1962 p->p_ucred ? p->p_ucred->cr_uid : -1, 1963 sig &~ WCOREFLAG, 1964 sig & WCOREFLAG ? " (core dumped)" : ""); 1965 } 1966 exit1(W_EXITCODE(0, sig)); 1967 /* NOTREACHED */ 1968 } 1969 1970 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1971 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1972 sizeof(corefilename), "process corefile name format string"); 1973 1974 /* 1975 * expand_name(name, uid, pid) 1976 * Expand the name described in corefilename, using name, uid, and pid. 1977 * corefilename is a kprintf-like string, with three format specifiers: 1978 * %N name of process ("name") 1979 * %P process id (pid) 1980 * %U user id (uid) 1981 * For example, "%N.core" is the default; they can be disabled completely 1982 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1983 * This is controlled by the sysctl variable kern.corefile (see above). 1984 */ 1985 1986 static char * 1987 expand_name(const char *name, uid_t uid, pid_t pid) 1988 { 1989 char *temp; 1990 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1991 int i, n; 1992 char *format = corefilename; 1993 size_t namelen; 1994 1995 temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1996 if (temp == NULL) 1997 return NULL; 1998 namelen = strlen(name); 1999 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2000 int l; 2001 switch (format[i]) { 2002 case '%': /* Format character */ 2003 i++; 2004 switch (format[i]) { 2005 case '%': 2006 temp[n++] = '%'; 2007 break; 2008 case 'N': /* process name */ 2009 if ((n + namelen) > MAXPATHLEN) { 2010 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2011 pid, name, uid, temp, name); 2012 kfree(temp, M_TEMP); 2013 return NULL; 2014 } 2015 memcpy(temp+n, name, namelen); 2016 n += namelen; 2017 break; 2018 case 'P': /* process id */ 2019 l = ksprintf(buf, "%u", pid); 2020 if ((n + l) > MAXPATHLEN) { 2021 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2022 pid, name, uid, temp, name); 2023 kfree(temp, M_TEMP); 2024 return NULL; 2025 } 2026 memcpy(temp+n, buf, l); 2027 n += l; 2028 break; 2029 case 'U': /* user id */ 2030 l = ksprintf(buf, "%u", uid); 2031 if ((n + l) > MAXPATHLEN) { 2032 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 2033 pid, name, uid, temp, name); 2034 kfree(temp, M_TEMP); 2035 return NULL; 2036 } 2037 memcpy(temp+n, buf, l); 2038 n += l; 2039 break; 2040 default: 2041 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 2042 } 2043 break; 2044 default: 2045 temp[n++] = format[i]; 2046 } 2047 } 2048 temp[n] = '\0'; 2049 return temp; 2050 } 2051 2052 /* 2053 * Dump a process' core. The main routine does some 2054 * policy checking, and creates the name of the coredump; 2055 * then it passes on a vnode and a size limit to the process-specific 2056 * coredump routine if there is one; if there _is not_ one, it returns 2057 * ENOSYS; otherwise it returns the error from the process-specific routine. 2058 * 2059 * The parameter `lp' is the lwp which triggered the coredump. 2060 */ 2061 2062 static int 2063 coredump(struct lwp *lp, int sig) 2064 { 2065 struct proc *p = lp->lwp_proc; 2066 struct vnode *vp; 2067 struct ucred *cred = p->p_ucred; 2068 struct flock lf; 2069 struct nlookupdata nd; 2070 struct vattr vattr; 2071 int error, error1; 2072 char *name; /* name of corefile */ 2073 off_t limit; 2074 2075 STOPEVENT(p, S_CORE, 0); 2076 2077 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) 2078 return (EFAULT); 2079 2080 /* 2081 * Note that the bulk of limit checking is done after 2082 * the corefile is created. The exception is if the limit 2083 * for corefiles is 0, in which case we don't bother 2084 * creating the corefile at all. This layout means that 2085 * a corefile is truncated instead of not being created, 2086 * if it is larger than the limit. 2087 */ 2088 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 2089 if (limit == 0) 2090 return EFBIG; 2091 2092 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 2093 if (name == NULL) 2094 return (EINVAL); 2095 error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP); 2096 if (error == 0) 2097 error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 2098 kfree(name, M_TEMP); 2099 if (error) { 2100 nlookup_done(&nd); 2101 return (error); 2102 } 2103 vp = nd.nl_open_vp; 2104 nd.nl_open_vp = NULL; 2105 nlookup_done(&nd); 2106 2107 vn_unlock(vp); 2108 lf.l_whence = SEEK_SET; 2109 lf.l_start = 0; 2110 lf.l_len = 0; 2111 lf.l_type = F_WRLCK; 2112 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0); 2113 if (error) 2114 goto out2; 2115 2116 /* Don't dump to non-regular files or files with links. */ 2117 if (vp->v_type != VREG || 2118 VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) { 2119 error = EFAULT; 2120 goto out1; 2121 } 2122 2123 /* Don't dump to files current user does not own */ 2124 if (vattr.va_uid != p->p_ucred->cr_uid) { 2125 error = EFAULT; 2126 goto out1; 2127 } 2128 2129 VATTR_NULL(&vattr); 2130 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2131 vattr.va_size = 0; 2132 VOP_SETATTR(vp, &vattr, cred); 2133 p->p_acflag |= ACORE; 2134 vn_unlock(vp); 2135 2136 error = p->p_sysent->sv_coredump ? 2137 p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS; 2138 2139 out1: 2140 lf.l_type = F_UNLCK; 2141 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0); 2142 out2: 2143 error1 = vn_close(vp, FWRITE); 2144 if (error == 0) 2145 error = error1; 2146 return (error); 2147 } 2148 2149 /* 2150 * Nonexistent system call-- signal process (may want to handle it). 2151 * Flag error in case process won't see signal immediately (blocked or ignored). 2152 * 2153 * MPALMOSTSAFE 2154 */ 2155 /* ARGSUSED */ 2156 int 2157 sys_nosys(struct nosys_args *args) 2158 { 2159 get_mplock(); 2160 lwpsignal(curproc, curthread->td_lwp, SIGSYS); 2161 rel_mplock(); 2162 return (EINVAL); 2163 } 2164 2165 /* 2166 * Send a SIGIO or SIGURG signal to a process or process group using 2167 * stored credentials rather than those of the current process. 2168 */ 2169 void 2170 pgsigio(struct sigio *sigio, int sig, int checkctty) 2171 { 2172 if (sigio == NULL) 2173 return; 2174 2175 if (sigio->sio_pgid > 0) { 2176 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 2177 sigio->sio_proc)) 2178 ksignal(sigio->sio_proc, sig); 2179 } else if (sigio->sio_pgid < 0) { 2180 struct proc *p; 2181 2182 lockmgr(&sigio->sio_pgrp->pg_lock, LK_EXCLUSIVE); 2183 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2184 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 2185 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2186 ksignal(p, sig); 2187 } 2188 lockmgr(&sigio->sio_pgrp->pg_lock, LK_RELEASE); 2189 } 2190 } 2191 2192 static int 2193 filt_sigattach(struct knote *kn) 2194 { 2195 struct proc *p = curproc; 2196 2197 kn->kn_ptr.p_proc = p; 2198 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2199 2200 /* XXX lock the proc here while adding to the list? */ 2201 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2202 2203 return (0); 2204 } 2205 2206 static void 2207 filt_sigdetach(struct knote *kn) 2208 { 2209 struct proc *p = kn->kn_ptr.p_proc; 2210 2211 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2212 } 2213 2214 /* 2215 * signal knotes are shared with proc knotes, so we apply a mask to 2216 * the hint in order to differentiate them from process hints. This 2217 * could be avoided by using a signal-specific knote list, but probably 2218 * isn't worth the trouble. 2219 */ 2220 static int 2221 filt_signal(struct knote *kn, long hint) 2222 { 2223 if (hint & NOTE_SIGNAL) { 2224 hint &= ~NOTE_SIGNAL; 2225 2226 if (kn->kn_id == hint) 2227 kn->kn_data++; 2228 } 2229 return (kn->kn_data != 0); 2230 } 2231