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 * $FreeBSD$ 40 */ 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/sysproto.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/namei.h> 51 #include <sys/vnode.h> 52 #include <sys/event.h> 53 #include <sys/proc.h> 54 #include <sys/pioctl.h> 55 #include <sys/acct.h> 56 #include <sys/fcntl.h> 57 #include <sys/condvar.h> 58 #include <sys/lock.h> 59 #include <sys/mutex.h> 60 #include <sys/wait.h> 61 #include <sys/ktr.h> 62 #include <sys/ktrace.h> 63 #include <sys/resourcevar.h> 64 #include <sys/smp.h> 65 #include <sys/stat.h> 66 #include <sys/sx.h> 67 #include <sys/syslog.h> 68 #include <sys/sysent.h> 69 #include <sys/sysctl.h> 70 #include <sys/malloc.h> 71 #include <sys/unistd.h> 72 73 #include <machine/cpu.h> 74 75 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 76 77 static int coredump (struct thread *); 78 static int do_sigaction(struct proc *p, int sig, struct sigaction *act, 79 struct sigaction *oact, int old); 80 static int do_sigprocmask(struct proc *p, int how, sigset_t *set, 81 sigset_t *oset, int old); 82 static char *expand_name(const char *, uid_t, pid_t); 83 static int killpg1 (struct proc *cp, int sig, int pgid, int all); 84 static int sig_ffs (sigset_t *set); 85 static int sigprop (int sig); 86 static void stop (struct proc *); 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 * Policy -- Can ucred cr1 send SIGIO to process cr2? 102 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 103 * in the right situations. 104 */ 105 #define CANSIGIO(cr1, cr2) \ 106 ((cr1)->cr_uid == 0 || \ 107 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 108 (cr1)->cr_uid == (cr2)->cr_ruid || \ 109 (cr1)->cr_ruid == (cr2)->cr_uid || \ 110 (cr1)->cr_uid == (cr2)->cr_uid) 111 112 int sugid_coredump; 113 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 114 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 115 116 static int do_coredump = 1; 117 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 118 &do_coredump, 0, "Enable/Disable coredumps"); 119 120 /* 121 * Signal properties and actions. 122 * The array below categorizes the signals and their default actions 123 * according to the following properties: 124 */ 125 #define SA_KILL 0x01 /* terminates process by default */ 126 #define SA_CORE 0x02 /* ditto and coredumps */ 127 #define SA_STOP 0x04 /* suspend process */ 128 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 129 #define SA_IGNORE 0x10 /* ignore by default */ 130 #define SA_CONT 0x20 /* continue if suspended */ 131 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 132 133 static int sigproptbl[NSIG] = { 134 SA_KILL, /* SIGHUP */ 135 SA_KILL, /* SIGINT */ 136 SA_KILL|SA_CORE, /* SIGQUIT */ 137 SA_KILL|SA_CORE, /* SIGILL */ 138 SA_KILL|SA_CORE, /* SIGTRAP */ 139 SA_KILL|SA_CORE, /* SIGABRT */ 140 SA_KILL|SA_CORE, /* SIGEMT */ 141 SA_KILL|SA_CORE, /* SIGFPE */ 142 SA_KILL, /* SIGKILL */ 143 SA_KILL|SA_CORE, /* SIGBUS */ 144 SA_KILL|SA_CORE, /* SIGSEGV */ 145 SA_KILL|SA_CORE, /* SIGSYS */ 146 SA_KILL, /* SIGPIPE */ 147 SA_KILL, /* SIGALRM */ 148 SA_KILL, /* SIGTERM */ 149 SA_IGNORE, /* SIGURG */ 150 SA_STOP, /* SIGSTOP */ 151 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 152 SA_IGNORE|SA_CONT, /* SIGCONT */ 153 SA_IGNORE, /* SIGCHLD */ 154 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 155 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 156 SA_IGNORE, /* SIGIO */ 157 SA_KILL, /* SIGXCPU */ 158 SA_KILL, /* SIGXFSZ */ 159 SA_KILL, /* SIGVTALRM */ 160 SA_KILL, /* SIGPROF */ 161 SA_IGNORE, /* SIGWINCH */ 162 SA_IGNORE, /* SIGINFO */ 163 SA_KILL, /* SIGUSR1 */ 164 SA_KILL, /* SIGUSR2 */ 165 }; 166 167 /* 168 * Determine signal that should be delivered to process p, the current 169 * process, 0 if none. If there is a pending stop signal with default 170 * action, the process stops in issignal(). 171 * 172 * MP SAFE. 173 */ 174 int 175 CURSIG(struct proc *p) 176 { 177 sigset_t tmpset; 178 179 PROC_LOCK_ASSERT(p, MA_OWNED); 180 if (SIGISEMPTY(p->p_siglist)) 181 return (0); 182 tmpset = p->p_siglist; 183 SIGSETNAND(tmpset, p->p_sigmask); 184 if (SIGISEMPTY(tmpset) && (p->p_flag & P_TRACED) == 0) 185 return (0); 186 return (issignal(p)); 187 } 188 189 static __inline int 190 sigprop(int sig) 191 { 192 193 if (sig > 0 && sig < NSIG) 194 return (sigproptbl[_SIG_IDX(sig)]); 195 return (0); 196 } 197 198 static __inline int 199 sig_ffs(sigset_t *set) 200 { 201 int i; 202 203 for (i = 0; i < _SIG_WORDS; i++) 204 if (set->__bits[i]) 205 return (ffs(set->__bits[i]) + (i * 32)); 206 return (0); 207 } 208 209 /* 210 * do_sigaction 211 * sigaction 212 * osigaction 213 */ 214 static int 215 do_sigaction(p, sig, act, oact, old) 216 struct proc *p; 217 register int sig; 218 struct sigaction *act, *oact; 219 int old; 220 { 221 register struct sigacts *ps; 222 223 if (!_SIG_VALID(sig)) 224 return (EINVAL); 225 226 PROC_LOCK(p); 227 ps = p->p_sigacts; 228 if (oact) { 229 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 230 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 231 oact->sa_flags = 0; 232 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 233 oact->sa_flags |= SA_ONSTACK; 234 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 235 oact->sa_flags |= SA_RESTART; 236 if (SIGISMEMBER(ps->ps_sigreset, sig)) 237 oact->sa_flags |= SA_RESETHAND; 238 if (SIGISMEMBER(ps->ps_signodefer, sig)) 239 oact->sa_flags |= SA_NODEFER; 240 if (SIGISMEMBER(ps->ps_siginfo, sig)) 241 oact->sa_flags |= SA_SIGINFO; 242 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 243 oact->sa_flags |= SA_NOCLDSTOP; 244 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 245 oact->sa_flags |= SA_NOCLDWAIT; 246 } 247 if (act) { 248 if ((sig == SIGKILL || sig == SIGSTOP) && 249 act->sa_handler != SIG_DFL) { 250 PROC_UNLOCK(p); 251 return (EINVAL); 252 } 253 254 /* 255 * Change setting atomically. 256 */ 257 258 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 259 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 260 if (act->sa_flags & SA_SIGINFO) { 261 ps->ps_sigact[_SIG_IDX(sig)] = 262 (__sighandler_t *)act->sa_sigaction; 263 SIGADDSET(ps->ps_siginfo, sig); 264 } else { 265 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 266 SIGDELSET(ps->ps_siginfo, sig); 267 } 268 if (!(act->sa_flags & SA_RESTART)) 269 SIGADDSET(ps->ps_sigintr, sig); 270 else 271 SIGDELSET(ps->ps_sigintr, sig); 272 if (act->sa_flags & SA_ONSTACK) 273 SIGADDSET(ps->ps_sigonstack, sig); 274 else 275 SIGDELSET(ps->ps_sigonstack, sig); 276 if (act->sa_flags & SA_RESETHAND) 277 SIGADDSET(ps->ps_sigreset, sig); 278 else 279 SIGDELSET(ps->ps_sigreset, sig); 280 if (act->sa_flags & SA_NODEFER) 281 SIGADDSET(ps->ps_signodefer, sig); 282 else 283 SIGDELSET(ps->ps_signodefer, sig); 284 #ifdef COMPAT_SUNOS 285 if (act->sa_flags & SA_USERTRAMP) 286 SIGADDSET(ps->ps_usertramp, sig); 287 else 288 SIGDELSET(ps->ps_usertramp, sig); 289 #endif 290 if (sig == SIGCHLD) { 291 if (act->sa_flags & SA_NOCLDSTOP) 292 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 293 else 294 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 295 if ((act->sa_flags & SA_NOCLDWAIT) || 296 ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) { 297 /* 298 * Paranoia: since SA_NOCLDWAIT is implemented 299 * by reparenting the dying child to PID 1 (and 300 * trust it to reap the zombie), PID 1 itself 301 * is forbidden to set SA_NOCLDWAIT. 302 */ 303 if (p->p_pid == 1) 304 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 305 else 306 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 307 } else 308 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 309 } 310 /* 311 * Set bit in p_sigignore for signals that are set to SIG_IGN, 312 * and for signals set to SIG_DFL where the default is to 313 * ignore. However, don't put SIGCONT in p_sigignore, as we 314 * have to restart the process. 315 */ 316 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 317 (sigprop(sig) & SA_IGNORE && 318 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 319 /* never to be seen again */ 320 SIGDELSET(p->p_siglist, sig); 321 if (sig != SIGCONT) 322 /* easier in psignal */ 323 SIGADDSET(p->p_sigignore, sig); 324 SIGDELSET(p->p_sigcatch, sig); 325 } else { 326 SIGDELSET(p->p_sigignore, sig); 327 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 328 SIGDELSET(p->p_sigcatch, sig); 329 else 330 SIGADDSET(p->p_sigcatch, sig); 331 } 332 #ifdef COMPAT_43 333 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 334 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) 335 SIGDELSET(ps->ps_osigset, sig); 336 else 337 SIGADDSET(ps->ps_osigset, sig); 338 #endif 339 } 340 PROC_UNLOCK(p); 341 return (0); 342 } 343 344 #ifndef _SYS_SYSPROTO_H_ 345 struct sigaction_args { 346 int sig; 347 struct sigaction *act; 348 struct sigaction *oact; 349 }; 350 #endif 351 /* 352 * MPSAFE 353 */ 354 /* ARGSUSED */ 355 int 356 sigaction(td, uap) 357 struct thread *td; 358 register struct sigaction_args *uap; 359 { 360 struct proc *p = td->td_proc; 361 struct sigaction act, oact; 362 register struct sigaction *actp, *oactp; 363 int error; 364 365 mtx_lock(&Giant); 366 367 actp = (uap->act != NULL) ? &act : NULL; 368 oactp = (uap->oact != NULL) ? &oact : NULL; 369 if (actp) { 370 error = copyin(uap->act, actp, sizeof(act)); 371 if (error) 372 goto done2; 373 } 374 error = do_sigaction(p, uap->sig, actp, oactp, 0); 375 if (oactp && !error) { 376 error = copyout(oactp, uap->oact, sizeof(oact)); 377 } 378 done2: 379 mtx_unlock(&Giant); 380 return (error); 381 } 382 383 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 384 #ifndef _SYS_SYSPROTO_H_ 385 struct osigaction_args { 386 int signum; 387 struct osigaction *nsa; 388 struct osigaction *osa; 389 }; 390 #endif 391 /* 392 * MPSAFE 393 */ 394 /* ARGSUSED */ 395 int 396 osigaction(td, uap) 397 struct thread *td; 398 register struct osigaction_args *uap; 399 { 400 struct proc *p = td->td_proc; 401 struct osigaction sa; 402 struct sigaction nsa, osa; 403 register struct sigaction *nsap, *osap; 404 int error; 405 406 if (uap->signum <= 0 || uap->signum >= ONSIG) 407 return (EINVAL); 408 409 nsap = (uap->nsa != NULL) ? &nsa : NULL; 410 osap = (uap->osa != NULL) ? &osa : NULL; 411 412 mtx_lock(&Giant); 413 414 if (nsap) { 415 error = copyin(uap->nsa, &sa, sizeof(sa)); 416 if (error) 417 goto done2; 418 nsap->sa_handler = sa.sa_handler; 419 nsap->sa_flags = sa.sa_flags; 420 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 421 } 422 error = do_sigaction(p, uap->signum, nsap, osap, 1); 423 if (osap && !error) { 424 sa.sa_handler = osap->sa_handler; 425 sa.sa_flags = osap->sa_flags; 426 SIG2OSIG(osap->sa_mask, sa.sa_mask); 427 error = copyout(&sa, uap->osa, sizeof(sa)); 428 } 429 done2: 430 mtx_unlock(&Giant); 431 return (error); 432 } 433 #endif /* COMPAT_43 */ 434 435 /* 436 * Initialize signal state for process 0; 437 * set to ignore signals that are ignored by default. 438 */ 439 void 440 siginit(p) 441 struct proc *p; 442 { 443 register int i; 444 445 PROC_LOCK(p); 446 for (i = 1; i <= NSIG; i++) 447 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 448 SIGADDSET(p->p_sigignore, i); 449 PROC_UNLOCK(p); 450 } 451 452 /* 453 * Reset signals for an exec of the specified process. 454 */ 455 void 456 execsigs(p) 457 register struct proc *p; 458 { 459 register struct sigacts *ps; 460 register int sig; 461 462 /* 463 * Reset caught signals. Held signals remain held 464 * through p_sigmask (unless they were caught, 465 * and are now ignored by default). 466 */ 467 PROC_LOCK(p); 468 ps = p->p_sigacts; 469 while (SIGNOTEMPTY(p->p_sigcatch)) { 470 sig = sig_ffs(&p->p_sigcatch); 471 SIGDELSET(p->p_sigcatch, sig); 472 if (sigprop(sig) & SA_IGNORE) { 473 if (sig != SIGCONT) 474 SIGADDSET(p->p_sigignore, sig); 475 SIGDELSET(p->p_siglist, sig); 476 } 477 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 478 } 479 /* 480 * Reset stack state to the user stack. 481 * Clear set of signals caught on the signal stack. 482 */ 483 p->p_sigstk.ss_flags = SS_DISABLE; 484 p->p_sigstk.ss_size = 0; 485 p->p_sigstk.ss_sp = 0; 486 p->p_flag &= ~P_ALTSTACK; 487 /* 488 * Reset no zombies if child dies flag as Solaris does. 489 */ 490 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 491 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 492 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 493 PROC_UNLOCK(p); 494 } 495 496 /* 497 * do_sigprocmask() 498 * 499 * Manipulate signal mask. 500 */ 501 static int 502 do_sigprocmask(p, how, set, oset, old) 503 struct proc *p; 504 int how; 505 sigset_t *set, *oset; 506 int old; 507 { 508 int error; 509 510 PROC_LOCK(p); 511 if (oset != NULL) 512 *oset = p->p_sigmask; 513 514 error = 0; 515 if (set != NULL) { 516 switch (how) { 517 case SIG_BLOCK: 518 SIG_CANTMASK(*set); 519 SIGSETOR(p->p_sigmask, *set); 520 break; 521 case SIG_UNBLOCK: 522 SIGSETNAND(p->p_sigmask, *set); 523 break; 524 case SIG_SETMASK: 525 SIG_CANTMASK(*set); 526 if (old) 527 SIGSETLO(p->p_sigmask, *set); 528 else 529 p->p_sigmask = *set; 530 break; 531 default: 532 error = EINVAL; 533 break; 534 } 535 } 536 PROC_UNLOCK(p); 537 return (error); 538 } 539 540 /* 541 * sigprocmask() - MP SAFE (XXXKSE not under KSE it isn't) 542 */ 543 544 #ifndef _SYS_SYSPROTO_H_ 545 struct sigprocmask_args { 546 int how; 547 const sigset_t *set; 548 sigset_t *oset; 549 }; 550 #endif 551 int 552 sigprocmask(td, uap) 553 register struct thread *td; 554 struct sigprocmask_args *uap; 555 { 556 struct proc *p = td->td_proc; 557 sigset_t set, oset; 558 sigset_t *setp, *osetp; 559 int error; 560 561 setp = (uap->set != NULL) ? &set : NULL; 562 osetp = (uap->oset != NULL) ? &oset : NULL; 563 if (setp) { 564 error = copyin(uap->set, setp, sizeof(set)); 565 if (error) 566 return (error); 567 } 568 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 569 if (osetp && !error) { 570 error = copyout(osetp, uap->oset, sizeof(oset)); 571 } 572 return (error); 573 } 574 575 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 576 /* 577 * osigprocmask() - MP SAFE 578 */ 579 #ifndef _SYS_SYSPROTO_H_ 580 struct osigprocmask_args { 581 int how; 582 osigset_t mask; 583 }; 584 #endif 585 int 586 osigprocmask(td, uap) 587 register struct thread *td; 588 struct osigprocmask_args *uap; 589 { 590 struct proc *p = td->td_proc; 591 sigset_t set, oset; 592 int error; 593 594 OSIG2SIG(uap->mask, set); 595 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 596 SIG2OSIG(oset, td->td_retval[0]); 597 return (error); 598 } 599 #endif /* COMPAT_43 */ 600 601 #ifndef _SYS_SYSPROTO_H_ 602 struct sigpending_args { 603 sigset_t *set; 604 }; 605 #endif 606 /* 607 * MPSAFE 608 */ 609 /* ARGSUSED */ 610 int 611 sigpending(td, uap) 612 struct thread *td; 613 struct sigpending_args *uap; 614 { 615 struct proc *p = td->td_proc; 616 sigset_t siglist; 617 int error; 618 619 mtx_lock(&Giant); 620 PROC_LOCK(p); 621 siglist = p->p_siglist; 622 PROC_UNLOCK(p); 623 mtx_unlock(&Giant); 624 error = copyout(&siglist, uap->set, sizeof(sigset_t)); 625 return(error); 626 } 627 628 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 629 #ifndef _SYS_SYSPROTO_H_ 630 struct osigpending_args { 631 int dummy; 632 }; 633 #endif 634 /* 635 * MPSAFE 636 */ 637 /* ARGSUSED */ 638 int 639 osigpending(td, uap) 640 struct thread *td; 641 struct osigpending_args *uap; 642 { 643 struct proc *p = td->td_proc; 644 645 mtx_lock(&Giant); 646 PROC_LOCK(p); 647 SIG2OSIG(p->p_siglist, td->td_retval[0]); 648 PROC_UNLOCK(p); 649 mtx_unlock(&Giant); 650 return (0); 651 } 652 #endif /* COMPAT_43 */ 653 654 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 655 /* 656 * Generalized interface signal handler, 4.3-compatible. 657 */ 658 #ifndef _SYS_SYSPROTO_H_ 659 struct osigvec_args { 660 int signum; 661 struct sigvec *nsv; 662 struct sigvec *osv; 663 }; 664 #endif 665 /* 666 * MPSAFE 667 */ 668 /* ARGSUSED */ 669 int 670 osigvec(td, uap) 671 struct thread *td; 672 register struct osigvec_args *uap; 673 { 674 struct proc *p = td->td_proc; 675 struct sigvec vec; 676 struct sigaction nsa, osa; 677 register struct sigaction *nsap, *osap; 678 int error; 679 680 if (uap->signum <= 0 || uap->signum >= ONSIG) 681 return (EINVAL); 682 nsap = (uap->nsv != NULL) ? &nsa : NULL; 683 osap = (uap->osv != NULL) ? &osa : NULL; 684 if (nsap) { 685 error = copyin(uap->nsv, &vec, sizeof(vec)); 686 if (error) 687 return (error); 688 nsap->sa_handler = vec.sv_handler; 689 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 690 nsap->sa_flags = vec.sv_flags; 691 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 692 #ifdef COMPAT_SUNOS 693 nsap->sa_flags |= SA_USERTRAMP; 694 #endif 695 } 696 mtx_lock(&Giant); 697 error = do_sigaction(p, uap->signum, nsap, osap, 1); 698 mtx_unlock(&Giant); 699 if (osap && !error) { 700 vec.sv_handler = osap->sa_handler; 701 SIG2OSIG(osap->sa_mask, vec.sv_mask); 702 vec.sv_flags = osap->sa_flags; 703 vec.sv_flags &= ~SA_NOCLDWAIT; 704 vec.sv_flags ^= SA_RESTART; 705 #ifdef COMPAT_SUNOS 706 vec.sv_flags &= ~SA_NOCLDSTOP; 707 #endif 708 error = copyout(&vec, uap->osv, sizeof(vec)); 709 } 710 return (error); 711 } 712 713 #ifndef _SYS_SYSPROTO_H_ 714 struct osigblock_args { 715 int mask; 716 }; 717 #endif 718 /* 719 * MPSAFE 720 */ 721 int 722 osigblock(td, uap) 723 register struct thread *td; 724 struct osigblock_args *uap; 725 { 726 struct proc *p = td->td_proc; 727 sigset_t set; 728 729 OSIG2SIG(uap->mask, set); 730 SIG_CANTMASK(set); 731 mtx_lock(&Giant); 732 PROC_LOCK(p); 733 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 734 SIGSETOR(p->p_sigmask, set); 735 PROC_UNLOCK(p); 736 mtx_unlock(&Giant); 737 return (0); 738 } 739 740 #ifndef _SYS_SYSPROTO_H_ 741 struct osigsetmask_args { 742 int mask; 743 }; 744 #endif 745 /* 746 * MPSAFE 747 */ 748 int 749 osigsetmask(td, uap) 750 struct thread *td; 751 struct osigsetmask_args *uap; 752 { 753 struct proc *p = td->td_proc; 754 sigset_t set; 755 756 OSIG2SIG(uap->mask, set); 757 SIG_CANTMASK(set); 758 mtx_lock(&Giant); 759 PROC_LOCK(p); 760 SIG2OSIG(p->p_sigmask, td->td_retval[0]); 761 SIGSETLO(p->p_sigmask, set); 762 PROC_UNLOCK(p); 763 mtx_unlock(&Giant); 764 return (0); 765 } 766 #endif /* COMPAT_43 || COMPAT_SUNOS */ 767 768 /* 769 * Suspend process until signal, providing mask to be set 770 * in the meantime. Note nonstandard calling convention: 771 * libc stub passes mask, not pointer, to save a copyin. 772 ***** XXXKSE this doesn't make sense under KSE. 773 ***** Do we suspend the thread or all threads in the process? 774 ***** How do we suspend threads running NOW on another processor? 775 */ 776 #ifndef _SYS_SYSPROTO_H_ 777 struct sigsuspend_args { 778 const sigset_t *sigmask; 779 }; 780 #endif 781 /* 782 * MPSAFE 783 */ 784 /* ARGSUSED */ 785 int 786 sigsuspend(td, uap) 787 struct thread *td; 788 struct sigsuspend_args *uap; 789 { 790 struct proc *p = td->td_proc; 791 sigset_t mask; 792 register struct sigacts *ps; 793 int error; 794 795 error = copyin(uap->sigmask, &mask, sizeof(mask)); 796 if (error) 797 return (error); 798 799 /* 800 * When returning from sigsuspend, we want 801 * the old mask to be restored after the 802 * signal handler has finished. Thus, we 803 * save it here and mark the sigacts structure 804 * to indicate this. 805 */ 806 mtx_lock(&Giant); 807 PROC_LOCK(p); 808 ps = p->p_sigacts; 809 p->p_oldsigmask = p->p_sigmask; 810 p->p_flag |= P_OLDMASK; 811 812 SIG_CANTMASK(mask); 813 p->p_sigmask = mask; 814 while (msleep((caddr_t) ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 815 /* void */; 816 PROC_UNLOCK(p); 817 mtx_unlock(&Giant); 818 /* always return EINTR rather than ERESTART... */ 819 return (EINTR); 820 } 821 822 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 823 #ifndef _SYS_SYSPROTO_H_ 824 struct osigsuspend_args { 825 osigset_t mask; 826 }; 827 #endif 828 /* 829 * MPSAFE 830 */ 831 /* ARGSUSED */ 832 int 833 osigsuspend(td, uap) 834 struct thread *td; 835 struct osigsuspend_args *uap; 836 { 837 struct proc *p = td->td_proc; 838 sigset_t mask; 839 register struct sigacts *ps; 840 841 mtx_lock(&Giant); 842 PROC_LOCK(p); 843 ps = p->p_sigacts; 844 p->p_oldsigmask = p->p_sigmask; 845 p->p_flag |= P_OLDMASK; 846 OSIG2SIG(uap->mask, mask); 847 SIG_CANTMASK(mask); 848 SIGSETLO(p->p_sigmask, mask); 849 while (msleep((caddr_t) ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 850 /* void */; 851 PROC_UNLOCK(p); 852 mtx_unlock(&Giant); 853 /* always return EINTR rather than ERESTART... */ 854 return (EINTR); 855 } 856 #endif /* COMPAT_43 */ 857 858 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 859 #ifndef _SYS_SYSPROTO_H_ 860 struct osigstack_args { 861 struct sigstack *nss; 862 struct sigstack *oss; 863 }; 864 #endif 865 /* 866 * MPSAFE 867 */ 868 /* ARGSUSED */ 869 int 870 osigstack(td, uap) 871 struct thread *td; 872 register struct osigstack_args *uap; 873 { 874 struct proc *p = td->td_proc; 875 struct sigstack ss; 876 int error = 0; 877 878 mtx_lock(&Giant); 879 880 if (uap->oss != NULL) { 881 PROC_LOCK(p); 882 ss.ss_sp = p->p_sigstk.ss_sp; 883 ss.ss_onstack = sigonstack(cpu_getstack(td)); 884 PROC_UNLOCK(p); 885 error = copyout(&ss, uap->oss, sizeof(struct sigstack)); 886 if (error) 887 goto done2; 888 } 889 890 if (uap->nss != NULL) { 891 if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0) 892 goto done2; 893 PROC_LOCK(p); 894 p->p_sigstk.ss_sp = ss.ss_sp; 895 p->p_sigstk.ss_size = 0; 896 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 897 p->p_flag |= P_ALTSTACK; 898 PROC_UNLOCK(p); 899 } 900 done2: 901 mtx_unlock(&Giant); 902 return (error); 903 } 904 #endif /* COMPAT_43 || COMPAT_SUNOS */ 905 906 #ifndef _SYS_SYSPROTO_H_ 907 struct sigaltstack_args { 908 stack_t *ss; 909 stack_t *oss; 910 }; 911 #endif 912 /* 913 * MPSAFE 914 */ 915 /* ARGSUSED */ 916 int 917 sigaltstack(td, uap) 918 struct thread *td; 919 register struct sigaltstack_args *uap; 920 { 921 struct proc *p = td->td_proc; 922 stack_t ss; 923 int oonstack; 924 int error = 0; 925 926 mtx_lock(&Giant); 927 928 oonstack = sigonstack(cpu_getstack(td)); 929 930 if (uap->oss != NULL) { 931 PROC_LOCK(p); 932 ss = p->p_sigstk; 933 ss.ss_flags = (p->p_flag & P_ALTSTACK) 934 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 935 PROC_UNLOCK(p); 936 if ((error = copyout(&ss, uap->oss, sizeof(stack_t))) != 0) 937 goto done2; 938 } 939 940 if (uap->ss != NULL) { 941 if (oonstack) { 942 error = EPERM; 943 goto done2; 944 } 945 if ((error = copyin(uap->ss, &ss, sizeof(ss))) != 0) 946 goto done2; 947 if ((ss.ss_flags & ~SS_DISABLE) != 0) { 948 error = EINVAL; 949 goto done2; 950 } 951 if (!(ss.ss_flags & SS_DISABLE)) { 952 if (ss.ss_size < p->p_sysent->sv_minsigstksz) { 953 error = ENOMEM; 954 goto done2; 955 } 956 PROC_LOCK(p); 957 p->p_sigstk = ss; 958 p->p_flag |= P_ALTSTACK; 959 PROC_UNLOCK(p); 960 } else { 961 PROC_LOCK(p); 962 p->p_flag &= ~P_ALTSTACK; 963 PROC_UNLOCK(p); 964 } 965 } 966 done2: 967 mtx_unlock(&Giant); 968 return (error); 969 } 970 971 /* 972 * Common code for kill process group/broadcast kill. 973 * cp is calling process. 974 */ 975 int 976 killpg1(cp, sig, pgid, all) 977 register struct proc *cp; 978 int sig, pgid, all; 979 { 980 register struct proc *p; 981 struct pgrp *pgrp; 982 int nfound = 0; 983 984 if (all) { 985 /* 986 * broadcast 987 */ 988 sx_slock(&allproc_lock); 989 LIST_FOREACH(p, &allproc, p_list) { 990 PROC_LOCK(p); 991 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || p == cp) { 992 PROC_UNLOCK(p); 993 continue; 994 } 995 if (p_cansignal(cp, p, sig) == 0) { 996 nfound++; 997 if (sig) 998 psignal(p, sig); 999 } 1000 PROC_UNLOCK(p); 1001 } 1002 sx_sunlock(&allproc_lock); 1003 } else { 1004 PGRPSESS_SLOCK(); 1005 if (pgid == 0) { 1006 /* 1007 * zero pgid means send to my process group. 1008 */ 1009 pgrp = cp->p_pgrp; 1010 PGRP_LOCK(pgrp); 1011 } else { 1012 pgrp = pgfind(pgid); 1013 if (pgrp == NULL) { 1014 PGRPSESS_SUNLOCK(); 1015 return (ESRCH); 1016 } 1017 } 1018 PGRPSESS_SUNLOCK(); 1019 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1020 PROC_LOCK(p); 1021 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1022 PROC_UNLOCK(p); 1023 continue; 1024 } 1025 mtx_lock_spin(&sched_lock); 1026 if (p->p_stat == SZOMB) { 1027 mtx_unlock_spin(&sched_lock); 1028 PROC_UNLOCK(p); 1029 continue; 1030 } 1031 mtx_unlock_spin(&sched_lock); 1032 if (p_cansignal(cp, p, sig) == 0) { 1033 nfound++; 1034 if (sig) 1035 psignal(p, sig); 1036 } 1037 PROC_UNLOCK(p); 1038 } 1039 PGRP_UNLOCK(pgrp); 1040 } 1041 return (nfound ? 0 : ESRCH); 1042 } 1043 1044 #ifndef _SYS_SYSPROTO_H_ 1045 struct kill_args { 1046 int pid; 1047 int signum; 1048 }; 1049 #endif 1050 /* 1051 * MPSAFE 1052 */ 1053 /* ARGSUSED */ 1054 int 1055 kill(td, uap) 1056 register struct thread *td; 1057 register struct kill_args *uap; 1058 { 1059 register struct proc *cp = td->td_proc; 1060 register struct proc *p; 1061 int error = 0; 1062 1063 if ((u_int)uap->signum > _SIG_MAXSIG) 1064 return (EINVAL); 1065 1066 mtx_lock(&Giant); 1067 if (uap->pid > 0) { 1068 /* kill single process */ 1069 if ((p = pfind(uap->pid)) == NULL) { 1070 error = ESRCH; 1071 } else if (p_cansignal(cp, p, uap->signum)) { 1072 PROC_UNLOCK(p); 1073 error = EPERM; 1074 } else { 1075 if (uap->signum) 1076 psignal(p, uap->signum); 1077 PROC_UNLOCK(p); 1078 error = 0; 1079 } 1080 } else { 1081 switch (uap->pid) { 1082 case -1: /* broadcast signal */ 1083 error = killpg1(cp, uap->signum, 0, 1); 1084 break; 1085 case 0: /* signal own process group */ 1086 error = killpg1(cp, uap->signum, 0, 0); 1087 break; 1088 default: /* negative explicit process group */ 1089 error = killpg1(cp, uap->signum, -uap->pid, 0); 1090 break; 1091 } 1092 } 1093 mtx_unlock(&Giant); 1094 return(error); 1095 } 1096 1097 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1098 #ifndef _SYS_SYSPROTO_H_ 1099 struct okillpg_args { 1100 int pgid; 1101 int signum; 1102 }; 1103 #endif 1104 /* 1105 * MPSAFE 1106 */ 1107 /* ARGSUSED */ 1108 int 1109 okillpg(td, uap) 1110 struct thread *td; 1111 register struct okillpg_args *uap; 1112 { 1113 int error; 1114 1115 if ((u_int)uap->signum > _SIG_MAXSIG) 1116 return (EINVAL); 1117 mtx_lock(&Giant); 1118 error = killpg1(td->td_proc, uap->signum, uap->pgid, 0); 1119 mtx_unlock(&Giant); 1120 return (error); 1121 } 1122 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1123 1124 /* 1125 * Send a signal to a process group. 1126 */ 1127 void 1128 gsignal(pgid, sig) 1129 int pgid, sig; 1130 { 1131 struct pgrp *pgrp; 1132 1133 if (pgid != 0) { 1134 PGRPSESS_SLOCK(); 1135 pgrp = pgfind(pgid); 1136 PGRPSESS_SUNLOCK(); 1137 if (pgrp != NULL) { 1138 pgsignal(pgrp, sig, 0); 1139 PGRP_UNLOCK(pgrp); 1140 } 1141 } 1142 } 1143 1144 /* 1145 * Send a signal to a process group. If checktty is 1, 1146 * limit to members which have a controlling terminal. 1147 */ 1148 void 1149 pgsignal(pgrp, sig, checkctty) 1150 struct pgrp *pgrp; 1151 int sig, checkctty; 1152 { 1153 register struct proc *p; 1154 1155 if (pgrp) { 1156 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1157 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1158 PROC_LOCK(p); 1159 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1160 psignal(p, sig); 1161 PROC_UNLOCK(p); 1162 } 1163 } 1164 } 1165 1166 /* 1167 * Send a signal caused by a trap to the current process. 1168 * If it will be caught immediately, deliver it with correct code. 1169 * Otherwise, post it normally. 1170 * 1171 * MPSAFE 1172 */ 1173 void 1174 trapsignal(p, sig, code) 1175 struct proc *p; 1176 register int sig; 1177 u_long code; 1178 { 1179 register struct sigacts *ps = p->p_sigacts; 1180 1181 mtx_lock(&Giant); 1182 PROC_LOCK(p); 1183 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 1184 !SIGISMEMBER(p->p_sigmask, sig)) { 1185 p->p_stats->p_ru.ru_nsignals++; 1186 #ifdef KTRACE 1187 if (KTRPOINT(p, KTR_PSIG)) 1188 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 1189 &p->p_sigmask, code); 1190 #endif 1191 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 1192 &p->p_sigmask, code); 1193 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1194 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1195 SIGADDSET(p->p_sigmask, sig); 1196 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1197 /* 1198 * See do_sigaction() for origin of this code. 1199 */ 1200 SIGDELSET(p->p_sigcatch, sig); 1201 if (sig != SIGCONT && 1202 sigprop(sig) & SA_IGNORE) 1203 SIGADDSET(p->p_sigignore, sig); 1204 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1205 } 1206 } else { 1207 p->p_code = code; /* XXX for core dump/debugger */ 1208 p->p_sig = sig; /* XXX to verify code */ 1209 psignal(p, sig); 1210 } 1211 PROC_UNLOCK(p); 1212 mtx_unlock(&Giant); 1213 } 1214 1215 /* 1216 * Send the signal to the process. If the signal has an action, the action 1217 * is usually performed by the target process rather than the caller; we add 1218 * the signal to the set of pending signals for the process. 1219 * 1220 * Exceptions: 1221 * o When a stop signal is sent to a sleeping process that takes the 1222 * default action, the process is stopped without awakening it. 1223 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1224 * regardless of the signal action (eg, blocked or ignored). 1225 * 1226 * Other ignored signals are discarded immediately. 1227 */ 1228 void 1229 psignal(p, sig) 1230 register struct proc *p; 1231 register int sig; 1232 { 1233 register int prop; 1234 register sig_t action; 1235 struct thread *td; 1236 #ifdef SMP 1237 struct ksegrp *kg; 1238 #endif 1239 1240 KASSERT(_SIG_VALID(sig), 1241 ("psignal(): invalid signal %d\n", sig)); 1242 1243 PROC_LOCK_ASSERT(p, MA_OWNED); 1244 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1245 1246 prop = sigprop(sig); 1247 1248 /* 1249 * If proc is traced, always give parent a chance; 1250 * if signal event is tracked by procfs, give *that* 1251 * a chance, as well. 1252 */ 1253 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { 1254 action = SIG_DFL; 1255 } else { 1256 /* 1257 * If the signal is being ignored, 1258 * then we forget about it immediately. 1259 * (Note: we don't set SIGCONT in p_sigignore, 1260 * and if it is set to SIG_IGN, 1261 * action will be SIG_DFL here.) 1262 */ 1263 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1264 return; 1265 if (SIGISMEMBER(p->p_sigmask, sig)) 1266 action = SIG_HOLD; 1267 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1268 action = SIG_CATCH; 1269 else 1270 action = SIG_DFL; 1271 } 1272 1273 /* 1274 * bring the priority of a process up if we want it to get 1275 * killed in this lifetime. 1276 * XXXKSE think if a better way to do this. 1277 * 1278 * What we need to do is see if there is a thread that will 1279 * be able to accept the signal. e.g. 1280 * FOREACH_THREAD_IN_PROC() { 1281 * if runnable, we're done 1282 * else pick one at random. 1283 * } 1284 */ 1285 /* XXXKSE 1286 * For now there is one thread per proc. 1287 * Effectively select one sucker thread.. 1288 */ 1289 td = FIRST_THREAD_IN_PROC(p); 1290 mtx_lock_spin(&sched_lock); 1291 if ((p->p_ksegrp.kg_nice > NZERO) && (action == SIG_DFL) && 1292 (prop & SA_KILL) && ((p->p_flag & P_TRACED) == 0)) 1293 p->p_ksegrp.kg_nice = NZERO; /* XXXKSE */ 1294 mtx_unlock_spin(&sched_lock); 1295 1296 if (prop & SA_CONT) 1297 SIG_STOPSIGMASK(p->p_siglist); 1298 1299 if (prop & SA_STOP) { 1300 /* 1301 * If sending a tty stop signal to a member of an orphaned 1302 * process group, discard the signal here if the action 1303 * is default; don't stop the process below if sleeping, 1304 * and don't clear any pending SIGCONT. 1305 */ 1306 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1307 action == SIG_DFL) 1308 return; 1309 SIG_CONTSIGMASK(p->p_siglist); 1310 } 1311 SIGADDSET(p->p_siglist, sig); 1312 1313 /* 1314 * Defer further processing for signals which are held, 1315 * except that stopped processes must be continued by SIGCONT. 1316 */ 1317 mtx_lock_spin(&sched_lock); 1318 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) { 1319 mtx_unlock_spin(&sched_lock); 1320 return; 1321 } 1322 1323 switch (p->p_stat) { 1324 1325 case SSLEEP: 1326 /* 1327 * If process is sleeping uninterruptibly 1328 * we can't interrupt the sleep... the signal will 1329 * be noticed when the process returns through 1330 * trap() or syscall(). 1331 */ 1332 if ((td->td_flags & TDF_SINTR) == 0) { 1333 mtx_unlock_spin(&sched_lock); 1334 goto out; 1335 } 1336 /* 1337 * Process is sleeping and traced... make it runnable 1338 * so it can discover the signal in issignal() and stop 1339 * for the parent. 1340 */ 1341 if (p->p_flag & P_TRACED) 1342 goto run; 1343 mtx_unlock_spin(&sched_lock); 1344 /* 1345 * If SIGCONT is default (or ignored) and process is 1346 * asleep, we are finished; the process should not 1347 * be awakened. 1348 */ 1349 if ((prop & SA_CONT) && action == SIG_DFL) { 1350 SIGDELSET(p->p_siglist, sig); 1351 goto out; 1352 } 1353 /* 1354 * When a sleeping process receives a stop 1355 * signal, process immediately if possible. 1356 * All other (caught or default) signals 1357 * cause the process to run. 1358 */ 1359 if (prop & SA_STOP) { 1360 if (action != SIG_DFL) 1361 goto runfast; 1362 /* 1363 * If a child holding parent blocked, 1364 * stopping could cause deadlock. 1365 */ 1366 if (p->p_flag & P_PPWAIT) 1367 goto out; 1368 SIGDELSET(p->p_siglist, sig); 1369 p->p_xstat = sig; 1370 PROC_LOCK(p->p_pptr); 1371 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1372 psignal(p->p_pptr, SIGCHLD); 1373 PROC_UNLOCK(p->p_pptr); 1374 mtx_lock_spin(&sched_lock); 1375 stop(p); 1376 mtx_unlock_spin(&sched_lock); 1377 goto out; 1378 } else 1379 goto runfast; 1380 /* NOTREACHED */ 1381 1382 case SSTOP: 1383 mtx_unlock_spin(&sched_lock); 1384 /* 1385 * If traced process is already stopped, 1386 * then no further action is necessary. 1387 */ 1388 if (p->p_flag & P_TRACED) 1389 goto out; 1390 1391 /* 1392 * Kill signal always sets processes running. 1393 */ 1394 if (sig == SIGKILL) 1395 goto runfast; 1396 1397 if (prop & SA_CONT) { 1398 /* 1399 * If SIGCONT is default (or ignored), we continue the 1400 * process but don't leave the signal in p_siglist, as 1401 * it has no further action. If SIGCONT is held, we 1402 * continue the process and leave the signal in 1403 * p_siglist. If the process catches SIGCONT, let it 1404 * handle the signal itself. If it isn't waiting on 1405 * an event, then it goes back to run state. 1406 * Otherwise, process goes back to sleep state. 1407 */ 1408 if (action == SIG_DFL) 1409 SIGDELSET(p->p_siglist, sig); 1410 if (action == SIG_CATCH) 1411 goto runfast; 1412 mtx_lock_spin(&sched_lock); 1413 /* 1414 * XXXKSE 1415 * do this for each thread. 1416 */ 1417 if (p->p_flag & P_KSES) { 1418 mtx_assert(&sched_lock, 1419 MA_OWNED | MA_NOTRECURSED); 1420 FOREACH_THREAD_IN_PROC(p, td) { 1421 if (td->td_wchan == NULL) { 1422 setrunnable(td); /* XXXKSE */ 1423 } else { 1424 /* mark it as sleeping */ 1425 } 1426 } 1427 mtx_unlock_spin(&sched_lock); 1428 } else { 1429 if (td->td_wchan == NULL) 1430 goto run; 1431 p->p_stat = SSLEEP; 1432 mtx_unlock_spin(&sched_lock); 1433 } 1434 goto out; 1435 } 1436 1437 if (prop & SA_STOP) { 1438 /* 1439 * Already stopped, don't need to stop again. 1440 * (If we did the shell could get confused.) 1441 */ 1442 SIGDELSET(p->p_siglist, sig); 1443 goto out; 1444 } 1445 1446 /* 1447 * If process is sleeping interruptibly, then simulate a 1448 * wakeup so that when it is continued, it will be made 1449 * runnable and can look at the signal. But don't make 1450 * the process runnable, leave it stopped. 1451 * XXXKSE should we wake ALL blocked threads? 1452 */ 1453 mtx_lock_spin(&sched_lock); 1454 if (p->p_flag & P_KSES) { 1455 FOREACH_THREAD_IN_PROC(p, td) { 1456 if (td->td_wchan && (td->td_flags & TDF_SINTR)){ 1457 if (td->td_flags & TDF_CVWAITQ) 1458 cv_waitq_remove(td); 1459 else 1460 unsleep(td); /* XXXKSE */ 1461 } 1462 } 1463 } else { 1464 if (td->td_wchan && td->td_flags & TDF_SINTR) { 1465 if (td->td_flags & TDF_CVWAITQ) 1466 cv_waitq_remove(td); 1467 else 1468 unsleep(td); /* XXXKSE */ 1469 } 1470 } 1471 mtx_unlock_spin(&sched_lock); 1472 goto out; 1473 1474 default: 1475 /* 1476 * SRUN, SIDL, SZOMB do nothing with the signal, 1477 * other than kicking ourselves if we are running. 1478 * It will either never be noticed, or noticed very soon. 1479 */ 1480 if (p->p_stat == SRUN) { 1481 #ifdef SMP 1482 struct kse *ke; 1483 struct thread *td = curthread; 1484 signotify(&p->p_kse); /* XXXKSE */ 1485 /* we should only deliver to one thread.. but which one? */ 1486 FOREACH_KSEGRP_IN_PROC(p, kg) { 1487 FOREACH_KSE_IN_GROUP(kg, ke) { 1488 if (ke->ke_thread == td) { 1489 continue; 1490 } 1491 forward_signal(ke->ke_thread); 1492 } 1493 } 1494 #else 1495 signotify(&p->p_kse); /* XXXKSE */ 1496 #endif 1497 } 1498 mtx_unlock_spin(&sched_lock); 1499 goto out; 1500 } 1501 /*NOTREACHED*/ 1502 1503 runfast: 1504 /* 1505 * Raise priority to at least PUSER. 1506 * XXXKSE Should we make them all run fast? 1507 * Maybe just one would be enough? 1508 */ 1509 mtx_lock_spin(&sched_lock); 1510 1511 if (FIRST_THREAD_IN_PROC(p)->td_priority > PUSER) { 1512 FIRST_THREAD_IN_PROC(p)->td_priority = PUSER; 1513 } 1514 run: 1515 /* If we jump here, sched_lock has to be owned. */ 1516 mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED); 1517 setrunnable(td); /* XXXKSE */ 1518 mtx_unlock_spin(&sched_lock); 1519 out: 1520 /* If we jump here, sched_lock should not be owned. */ 1521 mtx_assert(&sched_lock, MA_NOTOWNED); 1522 } 1523 1524 /* 1525 * If the current process has received a signal (should be caught or cause 1526 * termination, should interrupt current syscall), return the signal number. 1527 * Stop signals with default action are processed immediately, then cleared; 1528 * they aren't returned. This is checked after each entry to the system for 1529 * a syscall or trap (though this can usually be done without calling issignal 1530 * by checking the pending signal masks in the CURSIG macro.) The normal call 1531 * sequence is 1532 * 1533 * while (sig = CURSIG(curproc)) 1534 * postsig(sig); 1535 */ 1536 int 1537 issignal(p) 1538 register struct proc *p; 1539 { 1540 sigset_t mask; 1541 register int sig, prop; 1542 1543 PROC_LOCK_ASSERT(p, MA_OWNED); 1544 for (;;) { 1545 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1546 1547 mask = p->p_siglist; 1548 SIGSETNAND(mask, p->p_sigmask); 1549 if (p->p_flag & P_PPWAIT) 1550 SIG_STOPSIGMASK(mask); 1551 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1552 return (0); 1553 sig = sig_ffs(&mask); 1554 prop = sigprop(sig); 1555 1556 _STOPEVENT(p, S_SIG, sig); 1557 1558 /* 1559 * We should see pending but ignored signals 1560 * only if P_TRACED was on when they were posted. 1561 */ 1562 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1563 SIGDELSET(p->p_siglist, sig); 1564 continue; 1565 } 1566 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1567 /* 1568 * If traced, always stop, and stay 1569 * stopped until released by the parent. 1570 */ 1571 p->p_xstat = sig; 1572 PROC_LOCK(p->p_pptr); 1573 psignal(p->p_pptr, SIGCHLD); 1574 PROC_UNLOCK(p->p_pptr); 1575 do { 1576 mtx_lock_spin(&sched_lock); 1577 stop(p); 1578 PROC_UNLOCK(p); 1579 DROP_GIANT(); 1580 p->p_stats->p_ru.ru_nivcsw++; 1581 mi_switch(); 1582 mtx_unlock_spin(&sched_lock); 1583 PICKUP_GIANT(); 1584 PROC_LOCK(p); 1585 } while (!trace_req(p) 1586 && p->p_flag & P_TRACED); 1587 1588 /* 1589 * If the traced bit got turned off, go back up 1590 * to the top to rescan signals. This ensures 1591 * that p_sig* and ps_sigact are consistent. 1592 */ 1593 if ((p->p_flag & P_TRACED) == 0) 1594 continue; 1595 1596 /* 1597 * If parent wants us to take the signal, 1598 * then it will leave it in p->p_xstat; 1599 * otherwise we just look for signals again. 1600 */ 1601 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1602 sig = p->p_xstat; 1603 if (sig == 0) 1604 continue; 1605 1606 /* 1607 * Put the new signal into p_siglist. If the 1608 * signal is being masked, look for other signals. 1609 */ 1610 SIGADDSET(p->p_siglist, sig); 1611 if (SIGISMEMBER(p->p_sigmask, sig)) 1612 continue; 1613 } 1614 1615 /* 1616 * Decide whether the signal should be returned. 1617 * Return the signal's number, or fall through 1618 * to clear it from the pending mask. 1619 */ 1620 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1621 1622 case (int)SIG_DFL: 1623 /* 1624 * Don't take default actions on system processes. 1625 */ 1626 if (p->p_pid <= 1) { 1627 #ifdef DIAGNOSTIC 1628 /* 1629 * Are you sure you want to ignore SIGSEGV 1630 * in init? XXX 1631 */ 1632 printf("Process (pid %lu) got signal %d\n", 1633 (u_long)p->p_pid, sig); 1634 #endif 1635 break; /* == ignore */ 1636 } 1637 /* 1638 * If there is a pending stop signal to process 1639 * with default action, stop here, 1640 * then clear the signal. However, 1641 * if process is member of an orphaned 1642 * process group, ignore tty stop signals. 1643 */ 1644 if (prop & SA_STOP) { 1645 if (p->p_flag & P_TRACED || 1646 (p->p_pgrp->pg_jobc == 0 && 1647 prop & SA_TTYSTOP)) 1648 break; /* == ignore */ 1649 p->p_xstat = sig; 1650 PROC_LOCK(p->p_pptr); 1651 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) 1652 psignal(p->p_pptr, SIGCHLD); 1653 PROC_UNLOCK(p->p_pptr); 1654 mtx_lock_spin(&sched_lock); 1655 stop(p); 1656 PROC_UNLOCK(p); 1657 DROP_GIANT(); 1658 p->p_stats->p_ru.ru_nivcsw++; 1659 mi_switch(); 1660 mtx_unlock_spin(&sched_lock); 1661 PICKUP_GIANT(); 1662 PROC_LOCK(p); 1663 break; 1664 } else if (prop & SA_IGNORE) { 1665 /* 1666 * Except for SIGCONT, shouldn't get here. 1667 * Default action is to ignore; drop it. 1668 */ 1669 break; /* == ignore */ 1670 } else 1671 return (sig); 1672 /*NOTREACHED*/ 1673 1674 case (int)SIG_IGN: 1675 /* 1676 * Masking above should prevent us ever trying 1677 * to take action on an ignored signal other 1678 * than SIGCONT, unless process is traced. 1679 */ 1680 if ((prop & SA_CONT) == 0 && 1681 (p->p_flag & P_TRACED) == 0) 1682 printf("issignal\n"); 1683 break; /* == ignore */ 1684 1685 default: 1686 /* 1687 * This signal has an action, let 1688 * postsig() process it. 1689 */ 1690 return (sig); 1691 } 1692 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1693 } 1694 /* NOTREACHED */ 1695 } 1696 1697 /* 1698 * Put the argument process into the stopped state and notify the parent 1699 * via wakeup. Signals are handled elsewhere. The process must not be 1700 * on the run queue. Must be called with the proc p locked and the scheduler 1701 * lock held. 1702 */ 1703 static void 1704 stop(p) 1705 register struct proc *p; 1706 { 1707 1708 PROC_LOCK_ASSERT(p, MA_OWNED); 1709 mtx_assert(&sched_lock, MA_OWNED); 1710 p->p_stat = SSTOP; 1711 p->p_flag &= ~P_WAITED; 1712 wakeup((caddr_t)p->p_pptr); 1713 } 1714 1715 /* 1716 * Take the action for the specified signal 1717 * from the current set of pending signals. 1718 */ 1719 void 1720 postsig(sig) 1721 register int sig; 1722 { 1723 struct thread *td = curthread; 1724 register struct proc *p = td->td_proc; 1725 struct sigacts *ps; 1726 sig_t action; 1727 sigset_t returnmask; 1728 int code; 1729 1730 KASSERT(sig != 0, ("postsig")); 1731 1732 PROC_LOCK_ASSERT(p, MA_OWNED); 1733 ps = p->p_sigacts; 1734 SIGDELSET(p->p_siglist, sig); 1735 action = ps->ps_sigact[_SIG_IDX(sig)]; 1736 #ifdef KTRACE 1737 if (KTRPOINT(p, KTR_PSIG)) 1738 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1739 &p->p_oldsigmask : &p->p_sigmask, 0); 1740 #endif 1741 _STOPEVENT(p, S_SIG, sig); 1742 1743 if (action == SIG_DFL) { 1744 /* 1745 * Default action, where the default is to kill 1746 * the process. (Other cases were ignored above.) 1747 */ 1748 sigexit(td, sig); 1749 /* NOTREACHED */ 1750 } else { 1751 /* 1752 * If we get here, the signal must be caught. 1753 */ 1754 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1755 ("postsig action")); 1756 /* 1757 * Set the new mask value and also defer further 1758 * occurrences of this signal. 1759 * 1760 * Special case: user has done a sigsuspend. Here the 1761 * current mask is not of interest, but rather the 1762 * mask from before the sigsuspend is what we want 1763 * restored after the signal processing is completed. 1764 */ 1765 if (p->p_flag & P_OLDMASK) { 1766 returnmask = p->p_oldsigmask; 1767 p->p_flag &= ~P_OLDMASK; 1768 } else 1769 returnmask = p->p_sigmask; 1770 1771 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1772 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1773 SIGADDSET(p->p_sigmask, sig); 1774 1775 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1776 /* 1777 * See do_sigaction() for origin of this code. 1778 */ 1779 SIGDELSET(p->p_sigcatch, sig); 1780 if (sig != SIGCONT && 1781 sigprop(sig) & SA_IGNORE) 1782 SIGADDSET(p->p_sigignore, sig); 1783 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1784 } 1785 p->p_stats->p_ru.ru_nsignals++; 1786 if (p->p_sig != sig) { 1787 code = 0; 1788 } else { 1789 code = p->p_code; 1790 p->p_code = 0; 1791 p->p_sig = 0; 1792 } 1793 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1794 } 1795 } 1796 1797 /* 1798 * Kill the current process for stated reason. 1799 */ 1800 void 1801 killproc(p, why) 1802 struct proc *p; 1803 char *why; 1804 { 1805 1806 PROC_LOCK_ASSERT(p, MA_OWNED); 1807 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 1808 p, p->p_pid, p->p_comm); 1809 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1810 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1811 psignal(p, SIGKILL); 1812 } 1813 1814 /* 1815 * Force the current process to exit with the specified signal, dumping core 1816 * if appropriate. We bypass the normal tests for masked and caught signals, 1817 * allowing unrecoverable failures to terminate the process without changing 1818 * signal state. Mark the accounting record with the signal termination. 1819 * If dumping core, save the signal number for the debugger. Calls exit and 1820 * does not return. 1821 */ 1822 void 1823 sigexit(td, sig) 1824 struct thread *td; 1825 int sig; 1826 { 1827 struct proc *p = td->td_proc; 1828 1829 PROC_LOCK_ASSERT(p, MA_OWNED); 1830 p->p_acflag |= AXSIG; 1831 if (sigprop(sig) & SA_CORE) { 1832 p->p_sig = sig; 1833 /* 1834 * Log signals which would cause core dumps 1835 * (Log as LOG_INFO to appease those who don't want 1836 * these messages.) 1837 * XXX : Todo, as well as euid, write out ruid too 1838 */ 1839 PROC_UNLOCK(p); 1840 if (!mtx_owned(&Giant)) 1841 mtx_lock(&Giant); 1842 if (coredump(td) == 0) 1843 sig |= WCOREFLAG; 1844 if (kern_logsigexit) 1845 log(LOG_INFO, 1846 "pid %d (%s), uid %d: exited on signal %d%s\n", 1847 p->p_pid, p->p_comm, 1848 p->p_ucred ? p->p_ucred->cr_uid : -1, 1849 sig &~ WCOREFLAG, 1850 sig & WCOREFLAG ? " (core dumped)" : ""); 1851 } else { 1852 PROC_UNLOCK(p); 1853 if (!mtx_owned(&Giant)) 1854 mtx_lock(&Giant); 1855 } 1856 exit1(td, W_EXITCODE(0, sig)); 1857 /* NOTREACHED */ 1858 } 1859 1860 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1861 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1862 sizeof(corefilename), "process corefile name format string"); 1863 1864 /* 1865 * expand_name(name, uid, pid) 1866 * Expand the name described in corefilename, using name, uid, and pid. 1867 * corefilename is a printf-like string, with three format specifiers: 1868 * %N name of process ("name") 1869 * %P process id (pid) 1870 * %U user id (uid) 1871 * For example, "%N.core" is the default; they can be disabled completely 1872 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1873 * This is controlled by the sysctl variable kern.corefile (see above). 1874 */ 1875 1876 static char * 1877 expand_name(name, uid, pid) 1878 const char *name; uid_t uid; pid_t pid; { 1879 char *temp; 1880 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1881 int i, n; 1882 char *format = corefilename; 1883 size_t namelen; 1884 1885 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1886 if (temp == NULL) 1887 return NULL; 1888 namelen = strlen(name); 1889 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1890 int l; 1891 switch (format[i]) { 1892 case '%': /* Format character */ 1893 i++; 1894 switch (format[i]) { 1895 case '%': 1896 temp[n++] = '%'; 1897 break; 1898 case 'N': /* process name */ 1899 if ((n + namelen) > MAXPATHLEN) { 1900 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1901 pid, name, uid, temp, name); 1902 free(temp, M_TEMP); 1903 return NULL; 1904 } 1905 memcpy(temp+n, name, namelen); 1906 n += namelen; 1907 break; 1908 case 'P': /* process id */ 1909 l = sprintf(buf, "%u", pid); 1910 if ((n + l) > MAXPATHLEN) { 1911 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1912 pid, name, uid, temp, name); 1913 free(temp, M_TEMP); 1914 return NULL; 1915 } 1916 memcpy(temp+n, buf, l); 1917 n += l; 1918 break; 1919 case 'U': /* user id */ 1920 l = sprintf(buf, "%u", uid); 1921 if ((n + l) > MAXPATHLEN) { 1922 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1923 pid, name, uid, temp, name); 1924 free(temp, M_TEMP); 1925 return NULL; 1926 } 1927 memcpy(temp+n, buf, l); 1928 n += l; 1929 break; 1930 default: 1931 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1932 } 1933 break; 1934 default: 1935 temp[n++] = format[i]; 1936 } 1937 } 1938 temp[n] = '\0'; 1939 return temp; 1940 } 1941 1942 /* 1943 * Dump a process' core. The main routine does some 1944 * policy checking, and creates the name of the coredump; 1945 * then it passes on a vnode and a size limit to the process-specific 1946 * coredump routine if there is one; if there _is not_ one, it returns 1947 * ENOSYS; otherwise it returns the error from the process-specific routine. 1948 * 1949 * XXX: VOP_GETATTR() here requires holding the vnode lock. 1950 */ 1951 1952 static int 1953 coredump(struct thread *td) 1954 { 1955 struct proc *p = td->td_proc; 1956 register struct vnode *vp; 1957 register struct ucred *cred = p->p_ucred; 1958 struct flock lf; 1959 struct nameidata nd; 1960 struct vattr vattr; 1961 int error, error1, flags; 1962 struct mount *mp; 1963 char *name; /* name of corefile */ 1964 off_t limit; 1965 1966 PROC_LOCK(p); 1967 _STOPEVENT(p, S_CORE, 0); 1968 1969 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 1970 PROC_UNLOCK(p); 1971 return (EFAULT); 1972 } 1973 1974 /* 1975 * Note that the bulk of limit checking is done after 1976 * the corefile is created. The exception is if the limit 1977 * for corefiles is 0, in which case we don't bother 1978 * creating the corefile at all. This layout means that 1979 * a corefile is truncated instead of not being created, 1980 * if it is larger than the limit. 1981 */ 1982 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1983 if (limit == 0) { 1984 PROC_UNLOCK(p); 1985 return 0; 1986 } 1987 PROC_UNLOCK(p); 1988 1989 restart: 1990 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1991 if (name == NULL) 1992 return (EINVAL); 1993 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 1994 flags = O_CREAT | FWRITE | O_NOFOLLOW; 1995 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); 1996 free(name, M_TEMP); 1997 if (error) 1998 return (error); 1999 NDFREE(&nd, NDF_ONLY_PNBUF); 2000 vp = nd.ni_vp; 2001 2002 VOP_UNLOCK(vp, 0, td); 2003 lf.l_whence = SEEK_SET; 2004 lf.l_start = 0; 2005 lf.l_len = 0; 2006 lf.l_type = F_WRLCK; 2007 error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); 2008 if (error) 2009 goto out2; 2010 2011 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2012 lf.l_type = F_UNLCK; 2013 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2014 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2015 return (error); 2016 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2017 return (error); 2018 goto restart; 2019 } 2020 2021 /* Don't dump to non-regular files or files with links. */ 2022 if (vp->v_type != VREG || 2023 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2024 error = EFAULT; 2025 goto out1; 2026 } 2027 VATTR_NULL(&vattr); 2028 vattr.va_size = 0; 2029 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2030 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2031 VOP_SETATTR(vp, &vattr, cred, td); 2032 VOP_UNLOCK(vp, 0, td); 2033 PROC_LOCK(p); 2034 p->p_acflag |= ACORE; 2035 PROC_UNLOCK(p); 2036 2037 error = p->p_sysent->sv_coredump ? 2038 p->p_sysent->sv_coredump(td, vp, limit) : 2039 ENOSYS; 2040 2041 out1: 2042 lf.l_type = F_UNLCK; 2043 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2044 vn_finished_write(mp); 2045 out2: 2046 error1 = vn_close(vp, FWRITE, cred, td); 2047 if (error == 0) 2048 error = error1; 2049 return (error); 2050 } 2051 2052 /* 2053 * Nonexistent system call-- signal process (may want to handle it). 2054 * Flag error in case process won't see signal immediately (blocked or ignored). 2055 */ 2056 #ifndef _SYS_SYSPROTO_H_ 2057 struct nosys_args { 2058 int dummy; 2059 }; 2060 #endif 2061 /* 2062 * MPSAFE 2063 */ 2064 /* ARGSUSED */ 2065 int 2066 nosys(td, args) 2067 struct thread *td; 2068 struct nosys_args *args; 2069 { 2070 struct proc *p = td->td_proc; 2071 2072 mtx_lock(&Giant); 2073 PROC_LOCK(p); 2074 psignal(p, SIGSYS); 2075 PROC_UNLOCK(p); 2076 mtx_unlock(&Giant); 2077 return (EINVAL); 2078 } 2079 2080 /* 2081 * Send a SIGIO or SIGURG signal to a process or process group using 2082 * stored credentials rather than those of the current process. 2083 */ 2084 void 2085 pgsigio(sigio, sig, checkctty) 2086 struct sigio *sigio; 2087 int sig, checkctty; 2088 { 2089 if (sigio == NULL) 2090 return; 2091 2092 if (sigio->sio_pgid > 0) { 2093 PROC_LOCK(sigio->sio_proc); 2094 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 2095 psignal(sigio->sio_proc, sig); 2096 PROC_UNLOCK(sigio->sio_proc); 2097 } else if (sigio->sio_pgid < 0) { 2098 struct proc *p; 2099 2100 PGRP_LOCK(sigio->sio_pgrp); 2101 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 2102 PROC_LOCK(p); 2103 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 2104 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 2105 psignal(p, sig); 2106 PROC_UNLOCK(p); 2107 } 2108 PGRP_UNLOCK(sigio->sio_pgrp); 2109 } 2110 } 2111 2112 static int 2113 filt_sigattach(struct knote *kn) 2114 { 2115 struct proc *p = curproc; 2116 2117 kn->kn_ptr.p_proc = p; 2118 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2119 2120 PROC_LOCK(p); 2121 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2122 PROC_UNLOCK(p); 2123 2124 return (0); 2125 } 2126 2127 static void 2128 filt_sigdetach(struct knote *kn) 2129 { 2130 struct proc *p = kn->kn_ptr.p_proc; 2131 2132 PROC_LOCK(p); 2133 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2134 PROC_UNLOCK(p); 2135 } 2136 2137 /* 2138 * signal knotes are shared with proc knotes, so we apply a mask to 2139 * the hint in order to differentiate them from process hints. This 2140 * could be avoided by using a signal-specific knote list, but probably 2141 * isn't worth the trouble. 2142 */ 2143 static int 2144 filt_signal(struct knote *kn, long hint) 2145 { 2146 2147 if (hint & NOTE_SIGNAL) { 2148 hint &= ~NOTE_SIGNAL; 2149 2150 if (kn->kn_id == hint) 2151 kn->kn_data++; 2152 } 2153 return (kn->kn_data != 0); 2154 } 2155