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