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 72 #include <machine/cpu.h> 73 74 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 75 76 static int coredump __P((struct proc *)); 77 static int do_sigaction __P((struct proc *p, int sig, struct sigaction *act, 78 struct sigaction *oact, int old)); 79 static int do_sigprocmask __P((struct proc *p, int how, sigset_t *set, 80 sigset_t *oset, int old)); 81 static char *expand_name __P((const char *, uid_t, pid_t)); 82 static int killpg1 __P((struct proc *cp, int sig, int pgid, int all)); 83 static int sig_ffs __P((sigset_t *set)); 84 static int sigprop __P((int sig)); 85 static void stop __P((struct proc *)); 86 87 static int filt_sigattach(struct knote *kn); 88 static void filt_sigdetach(struct knote *kn); 89 static int filt_signal(struct knote *kn, long hint); 90 91 struct filterops sig_filtops = 92 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 93 94 static int kern_logsigexit = 1; 95 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 96 &kern_logsigexit, 0, 97 "Log processes quitting on abnormal signals to syslog(3)"); 98 99 /* 100 * Policy -- Can ucred cr1 send SIGIO to process cr2? 101 */ 102 #define CANSIGIO(cr1, cr2) \ 103 ((cr1)->cr_uid == 0 || \ 104 (cr2)->cr_ruid == (cr2)->cr_ruid || \ 105 (cr2)->cr_uid == (cr2)->cr_ruid || \ 106 (cr2)->cr_ruid == (cr2)->cr_uid || \ 107 (cr2)->cr_uid == (cr2)->cr_uid) 108 109 int sugid_coredump; 110 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 111 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 112 113 static int do_coredump = 1; 114 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 115 &do_coredump, 0, "Enable/Disable coredumps"); 116 117 /* 118 * Signal properties and actions. 119 * The array below categorizes the signals and their default actions 120 * according to the following properties: 121 */ 122 #define SA_KILL 0x01 /* terminates process by default */ 123 #define SA_CORE 0x02 /* ditto and coredumps */ 124 #define SA_STOP 0x04 /* suspend process */ 125 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 126 #define SA_IGNORE 0x10 /* ignore by default */ 127 #define SA_CONT 0x20 /* continue if suspended */ 128 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 129 130 static int sigproptbl[NSIG] = { 131 SA_KILL, /* SIGHUP */ 132 SA_KILL, /* SIGINT */ 133 SA_KILL|SA_CORE, /* SIGQUIT */ 134 SA_KILL|SA_CORE, /* SIGILL */ 135 SA_KILL|SA_CORE, /* SIGTRAP */ 136 SA_KILL|SA_CORE, /* SIGABRT */ 137 SA_KILL|SA_CORE, /* SIGEMT */ 138 SA_KILL|SA_CORE, /* SIGFPE */ 139 SA_KILL, /* SIGKILL */ 140 SA_KILL|SA_CORE, /* SIGBUS */ 141 SA_KILL|SA_CORE, /* SIGSEGV */ 142 SA_KILL|SA_CORE, /* SIGSYS */ 143 SA_KILL, /* SIGPIPE */ 144 SA_KILL, /* SIGALRM */ 145 SA_KILL, /* SIGTERM */ 146 SA_IGNORE, /* SIGURG */ 147 SA_STOP, /* SIGSTOP */ 148 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 149 SA_IGNORE|SA_CONT, /* SIGCONT */ 150 SA_IGNORE, /* SIGCHLD */ 151 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 152 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 153 SA_IGNORE, /* SIGIO */ 154 SA_KILL, /* SIGXCPU */ 155 SA_KILL, /* SIGXFSZ */ 156 SA_KILL, /* SIGVTALRM */ 157 SA_KILL, /* SIGPROF */ 158 SA_IGNORE, /* SIGWINCH */ 159 SA_IGNORE, /* SIGINFO */ 160 SA_KILL, /* SIGUSR1 */ 161 SA_KILL, /* SIGUSR2 */ 162 }; 163 164 /* 165 * Determine signal that should be delivered to process p, the current 166 * process, 0 if none. If there is a pending stop signal with default 167 * action, the process stops in issignal(). 168 * 169 * MP SAFE. 170 */ 171 int 172 CURSIG(struct proc *p) 173 { 174 sigset_t tmpset; 175 176 PROC_LOCK_ASSERT(p, MA_OWNED); 177 if (SIGISEMPTY(p->p_siglist)) 178 return (0); 179 tmpset = p->p_siglist; 180 SIGSETNAND(tmpset, p->p_sigmask); 181 if (SIGISEMPTY(tmpset) && (p->p_flag & P_TRACED) == 0) 182 return (0); 183 return (issignal(p)); 184 } 185 186 static __inline int 187 sigprop(int sig) 188 { 189 190 if (sig > 0 && sig < NSIG) 191 return (sigproptbl[_SIG_IDX(sig)]); 192 return (0); 193 } 194 195 static __inline int 196 sig_ffs(sigset_t *set) 197 { 198 int i; 199 200 for (i = 0; i < _SIG_WORDS; i++) 201 if (set->__bits[i]) 202 return (ffs(set->__bits[i]) + (i * 32)); 203 return (0); 204 } 205 206 /* 207 * do_sigaction 208 * sigaction 209 * osigaction 210 */ 211 static int 212 do_sigaction(p, sig, act, oact, old) 213 struct proc *p; 214 register int sig; 215 struct sigaction *act, *oact; 216 int old; 217 { 218 register struct sigacts *ps; 219 220 if (sig <= 0 || sig > _SIG_MAXSIG) 221 return (EINVAL); 222 223 PROC_LOCK(p); 224 ps = p->p_sigacts; 225 if (oact) { 226 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 227 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 228 oact->sa_flags = 0; 229 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 230 oact->sa_flags |= SA_ONSTACK; 231 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 232 oact->sa_flags |= SA_RESTART; 233 if (SIGISMEMBER(ps->ps_sigreset, sig)) 234 oact->sa_flags |= SA_RESETHAND; 235 if (SIGISMEMBER(ps->ps_signodefer, sig)) 236 oact->sa_flags |= SA_NODEFER; 237 if (SIGISMEMBER(ps->ps_siginfo, sig)) 238 oact->sa_flags |= SA_SIGINFO; 239 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) 240 oact->sa_flags |= SA_NOCLDSTOP; 241 if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) 242 oact->sa_flags |= SA_NOCLDWAIT; 243 } 244 if (act) { 245 if ((sig == SIGKILL || sig == SIGSTOP) && 246 act->sa_handler != SIG_DFL) { 247 PROC_UNLOCK(p); 248 return (EINVAL); 249 } 250 251 /* 252 * Change setting atomically. 253 */ 254 255 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 256 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 257 if (act->sa_flags & SA_SIGINFO) { 258 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 259 SIGADDSET(ps->ps_siginfo, sig); 260 } else { 261 ps->ps_sigact[_SIG_IDX(sig)] = 262 (__sighandler_t *)act->sa_sigaction; 263 SIGDELSET(ps->ps_siginfo, sig); 264 } 265 if (!(act->sa_flags & SA_RESTART)) 266 SIGADDSET(ps->ps_sigintr, sig); 267 else 268 SIGDELSET(ps->ps_sigintr, sig); 269 if (act->sa_flags & SA_ONSTACK) 270 SIGADDSET(ps->ps_sigonstack, sig); 271 else 272 SIGDELSET(ps->ps_sigonstack, sig); 273 if (act->sa_flags & SA_RESETHAND) 274 SIGADDSET(ps->ps_sigreset, sig); 275 else 276 SIGDELSET(ps->ps_sigreset, sig); 277 if (act->sa_flags & SA_NODEFER) 278 SIGADDSET(ps->ps_signodefer, sig); 279 else 280 SIGDELSET(ps->ps_signodefer, sig); 281 #ifdef COMPAT_SUNOS 282 if (act->sa_flags & SA_USERTRAMP) 283 SIGADDSET(ps->ps_usertramp, sig); 284 else 285 SIGDELSET(ps->ps_usertramp, seg); 286 #endif 287 if (sig == SIGCHLD) { 288 if (act->sa_flags & SA_NOCLDSTOP) 289 p->p_procsig->ps_flag |= PS_NOCLDSTOP; 290 else 291 p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; 292 if ((act->sa_flags & SA_NOCLDWAIT) || 293 ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) { 294 /* 295 * Paranoia: since SA_NOCLDWAIT is implemented 296 * by reparenting the dying child to PID 1 (and 297 * trust it to reap the zombie), PID 1 itself 298 * is forbidden to set SA_NOCLDWAIT. 299 */ 300 if (p->p_pid == 1) 301 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 302 else 303 p->p_procsig->ps_flag |= PS_NOCLDWAIT; 304 } else 305 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 306 } 307 /* 308 * Set bit in p_sigignore for signals that are set to SIG_IGN, 309 * and for signals set to SIG_DFL where the default is to 310 * ignore. However, don't put SIGCONT in p_sigignore, as we 311 * have to restart the process. 312 */ 313 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 314 (sigprop(sig) & SA_IGNORE && 315 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 316 /* never to be seen again */ 317 SIGDELSET(p->p_siglist, sig); 318 if (sig != SIGCONT) 319 /* easier in psignal */ 320 SIGADDSET(p->p_sigignore, sig); 321 SIGDELSET(p->p_sigcatch, sig); 322 } else { 323 SIGDELSET(p->p_sigignore, sig); 324 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 325 SIGDELSET(p->p_sigcatch, sig); 326 else 327 SIGADDSET(p->p_sigcatch, sig); 328 } 329 #ifdef COMPAT_43 330 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 331 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) 332 SIGDELSET(ps->ps_osigset, sig); 333 else 334 SIGADDSET(ps->ps_osigset, sig); 335 #endif 336 } 337 PROC_UNLOCK(p); 338 return (0); 339 } 340 341 #ifndef _SYS_SYSPROTO_H_ 342 struct sigaction_args { 343 int sig; 344 struct sigaction *act; 345 struct sigaction *oact; 346 }; 347 #endif 348 /* 349 * MPSAFE 350 */ 351 /* ARGSUSED */ 352 int 353 sigaction(p, uap) 354 struct proc *p; 355 register struct sigaction_args *uap; 356 { 357 struct sigaction act, oact; 358 register struct sigaction *actp, *oactp; 359 int error; 360 361 mtx_lock(&Giant); 362 363 actp = (uap->act != NULL) ? &act : NULL; 364 oactp = (uap->oact != NULL) ? &oact : NULL; 365 if (actp) { 366 error = copyin(uap->act, actp, sizeof(act)); 367 if (error) 368 goto done2; 369 } 370 error = do_sigaction(p, uap->sig, actp, oactp, 0); 371 if (oactp && !error) { 372 error = copyout(oactp, uap->oact, sizeof(oact)); 373 } 374 done2: 375 mtx_unlock(&Giant); 376 return (error); 377 } 378 379 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 380 #ifndef _SYS_SYSPROTO_H_ 381 struct osigaction_args { 382 int signum; 383 struct osigaction *nsa; 384 struct osigaction *osa; 385 }; 386 #endif 387 /* 388 * MPSAFE 389 */ 390 /* ARGSUSED */ 391 int 392 osigaction(p, uap) 393 struct proc *p; 394 register struct osigaction_args *uap; 395 { 396 struct osigaction sa; 397 struct sigaction nsa, osa; 398 register struct sigaction *nsap, *osap; 399 int error; 400 401 if (uap->signum <= 0 || uap->signum >= ONSIG) 402 return (EINVAL); 403 404 nsap = (uap->nsa != NULL) ? &nsa : NULL; 405 osap = (uap->osa != NULL) ? &osa : NULL; 406 407 mtx_lock(&Giant); 408 409 if (nsap) { 410 error = copyin(uap->nsa, &sa, sizeof(sa)); 411 if (error) 412 goto done2; 413 nsap->sa_handler = sa.sa_handler; 414 nsap->sa_flags = sa.sa_flags; 415 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 416 } 417 error = do_sigaction(p, uap->signum, nsap, osap, 1); 418 if (osap && !error) { 419 sa.sa_handler = osap->sa_handler; 420 sa.sa_flags = osap->sa_flags; 421 SIG2OSIG(osap->sa_mask, sa.sa_mask); 422 error = copyout(&sa, uap->osa, sizeof(sa)); 423 } 424 done2: 425 mtx_unlock(&Giant); 426 return (error); 427 } 428 #endif /* COMPAT_43 */ 429 430 /* 431 * Initialize signal state for process 0; 432 * set to ignore signals that are ignored by default. 433 */ 434 void 435 siginit(p) 436 struct proc *p; 437 { 438 register int i; 439 440 PROC_LOCK(p); 441 for (i = 1; i <= NSIG; i++) 442 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 443 SIGADDSET(p->p_sigignore, i); 444 PROC_UNLOCK(p); 445 } 446 447 /* 448 * Reset signals for an exec of the specified process. 449 */ 450 void 451 execsigs(p) 452 register struct proc *p; 453 { 454 register struct sigacts *ps; 455 register int sig; 456 457 /* 458 * Reset caught signals. Held signals remain held 459 * through p_sigmask (unless they were caught, 460 * and are now ignored by default). 461 */ 462 PROC_LOCK(p); 463 ps = p->p_sigacts; 464 while (SIGNOTEMPTY(p->p_sigcatch)) { 465 sig = sig_ffs(&p->p_sigcatch); 466 SIGDELSET(p->p_sigcatch, sig); 467 if (sigprop(sig) & SA_IGNORE) { 468 if (sig != SIGCONT) 469 SIGADDSET(p->p_sigignore, sig); 470 SIGDELSET(p->p_siglist, sig); 471 } 472 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 473 } 474 /* 475 * Reset stack state to the user stack. 476 * Clear set of signals caught on the signal stack. 477 */ 478 p->p_sigstk.ss_flags = SS_DISABLE; 479 p->p_sigstk.ss_size = 0; 480 p->p_sigstk.ss_sp = 0; 481 p->p_flag &= ~P_ALTSTACK; 482 /* 483 * Reset no zombies if child dies flag as Solaris does. 484 */ 485 p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; 486 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 487 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 488 PROC_UNLOCK(p); 489 } 490 491 /* 492 * do_sigprocmask() 493 * 494 * Manipulate signal mask. 495 */ 496 static int 497 do_sigprocmask(p, how, set, oset, old) 498 struct proc *p; 499 int how; 500 sigset_t *set, *oset; 501 int old; 502 { 503 int error; 504 505 PROC_LOCK(p); 506 if (oset != NULL) 507 *oset = p->p_sigmask; 508 509 error = 0; 510 if (set != NULL) { 511 switch (how) { 512 case SIG_BLOCK: 513 SIG_CANTMASK(*set); 514 SIGSETOR(p->p_sigmask, *set); 515 break; 516 case SIG_UNBLOCK: 517 SIGSETNAND(p->p_sigmask, *set); 518 break; 519 case SIG_SETMASK: 520 SIG_CANTMASK(*set); 521 if (old) 522 SIGSETLO(p->p_sigmask, *set); 523 else 524 p->p_sigmask = *set; 525 break; 526 default: 527 error = EINVAL; 528 break; 529 } 530 } 531 PROC_UNLOCK(p); 532 return (error); 533 } 534 535 /* 536 * sigprocmask() - MP SAFE 537 */ 538 539 #ifndef _SYS_SYSPROTO_H_ 540 struct sigprocmask_args { 541 int how; 542 const sigset_t *set; 543 sigset_t *oset; 544 }; 545 #endif 546 int 547 sigprocmask(p, uap) 548 register struct proc *p; 549 struct sigprocmask_args *uap; 550 { 551 sigset_t set, oset; 552 sigset_t *setp, *osetp; 553 int error; 554 555 setp = (uap->set != NULL) ? &set : NULL; 556 osetp = (uap->oset != NULL) ? &oset : NULL; 557 if (setp) { 558 error = copyin(uap->set, setp, sizeof(set)); 559 if (error) 560 return (error); 561 } 562 error = do_sigprocmask(p, uap->how, setp, osetp, 0); 563 if (osetp && !error) { 564 error = copyout(osetp, uap->oset, sizeof(oset)); 565 } 566 return (error); 567 } 568 569 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 570 /* 571 * osigprocmask() - MP SAFE 572 */ 573 #ifndef _SYS_SYSPROTO_H_ 574 struct osigprocmask_args { 575 int how; 576 osigset_t mask; 577 }; 578 #endif 579 int 580 osigprocmask(p, uap) 581 register struct proc *p; 582 struct osigprocmask_args *uap; 583 { 584 sigset_t set, oset; 585 int error; 586 587 OSIG2SIG(uap->mask, set); 588 error = do_sigprocmask(p, uap->how, &set, &oset, 1); 589 SIG2OSIG(oset, p->p_retval[0]); 590 return (error); 591 } 592 #endif /* COMPAT_43 */ 593 594 #ifndef _SYS_SYSPROTO_H_ 595 struct sigpending_args { 596 sigset_t *set; 597 }; 598 #endif 599 /* 600 * MPSAFE 601 */ 602 /* ARGSUSED */ 603 int 604 sigpending(p, uap) 605 struct proc *p; 606 struct sigpending_args *uap; 607 { 608 sigset_t siglist; 609 int error; 610 611 mtx_lock(&Giant); 612 PROC_LOCK(p); 613 siglist = p->p_siglist; 614 PROC_UNLOCK(p); 615 mtx_unlock(&Giant); 616 error = copyout(&siglist, uap->set, sizeof(sigset_t)); 617 return(error); 618 } 619 620 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 621 #ifndef _SYS_SYSPROTO_H_ 622 struct osigpending_args { 623 int dummy; 624 }; 625 #endif 626 /* 627 * MPSAFE 628 */ 629 /* ARGSUSED */ 630 int 631 osigpending(p, uap) 632 struct proc *p; 633 struct osigpending_args *uap; 634 { 635 mtx_lock(&Giant); 636 PROC_LOCK(p); 637 SIG2OSIG(p->p_siglist, p->p_retval[0]); 638 PROC_UNLOCK(p); 639 mtx_unlock(&Giant); 640 return (0); 641 } 642 #endif /* COMPAT_43 */ 643 644 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 645 /* 646 * Generalized interface signal handler, 4.3-compatible. 647 */ 648 #ifndef _SYS_SYSPROTO_H_ 649 struct osigvec_args { 650 int signum; 651 struct sigvec *nsv; 652 struct sigvec *osv; 653 }; 654 #endif 655 /* 656 * MPSAFE 657 */ 658 /* ARGSUSED */ 659 int 660 osigvec(p, uap) 661 struct proc *p; 662 register struct osigvec_args *uap; 663 { 664 struct sigvec vec; 665 struct sigaction nsa, osa; 666 register struct sigaction *nsap, *osap; 667 int error; 668 669 if (uap->signum <= 0 || uap->signum >= ONSIG) 670 return (EINVAL); 671 nsap = (uap->nsv != NULL) ? &nsa : NULL; 672 osap = (uap->osv != NULL) ? &osa : NULL; 673 if (nsap) { 674 error = copyin(uap->nsv, &vec, sizeof(vec)); 675 if (error) 676 return (error); 677 nsap->sa_handler = vec.sv_handler; 678 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 679 nsap->sa_flags = vec.sv_flags; 680 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 681 #ifdef COMPAT_SUNOS 682 nsap->sa_flags |= SA_USERTRAMP; 683 #endif 684 } 685 mtx_lock(&Giant); 686 error = do_sigaction(p, uap->signum, nsap, osap, 1); 687 mtx_unlock(&Giant); 688 if (osap && !error) { 689 vec.sv_handler = osap->sa_handler; 690 SIG2OSIG(osap->sa_mask, vec.sv_mask); 691 vec.sv_flags = osap->sa_flags; 692 vec.sv_flags &= ~SA_NOCLDWAIT; 693 vec.sv_flags ^= SA_RESTART; 694 #ifdef COMPAT_SUNOS 695 vec.sv_flags &= ~SA_NOCLDSTOP; 696 #endif 697 error = copyout(&vec, uap->osv, sizeof(vec)); 698 } 699 return (error); 700 } 701 702 #ifndef _SYS_SYSPROTO_H_ 703 struct osigblock_args { 704 int mask; 705 }; 706 #endif 707 /* 708 * MPSAFE 709 */ 710 int 711 osigblock(p, uap) 712 register struct proc *p; 713 struct osigblock_args *uap; 714 { 715 sigset_t set; 716 717 OSIG2SIG(uap->mask, set); 718 SIG_CANTMASK(set); 719 mtx_lock(&Giant); 720 PROC_LOCK(p); 721 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 722 SIGSETOR(p->p_sigmask, set); 723 PROC_UNLOCK(p); 724 mtx_unlock(&Giant); 725 return (0); 726 } 727 728 #ifndef _SYS_SYSPROTO_H_ 729 struct osigsetmask_args { 730 int mask; 731 }; 732 #endif 733 /* 734 * MPSAFE 735 */ 736 int 737 osigsetmask(p, uap) 738 struct proc *p; 739 struct osigsetmask_args *uap; 740 { 741 sigset_t set; 742 743 OSIG2SIG(uap->mask, set); 744 SIG_CANTMASK(set); 745 mtx_lock(&Giant); 746 PROC_LOCK(p); 747 SIG2OSIG(p->p_sigmask, p->p_retval[0]); 748 SIGSETLO(p->p_sigmask, set); 749 PROC_UNLOCK(p); 750 mtx_unlock(&Giant); 751 return (0); 752 } 753 #endif /* COMPAT_43 || COMPAT_SUNOS */ 754 755 /* 756 * Suspend process until signal, providing mask to be set 757 * in the meantime. Note nonstandard calling convention: 758 * libc stub passes mask, not pointer, to save a copyin. 759 */ 760 #ifndef _SYS_SYSPROTO_H_ 761 struct sigsuspend_args { 762 const sigset_t *sigmask; 763 }; 764 #endif 765 /* 766 * MPSAFE 767 */ 768 /* ARGSUSED */ 769 int 770 sigsuspend(p, uap) 771 register struct proc *p; 772 struct sigsuspend_args *uap; 773 { 774 sigset_t mask; 775 register struct sigacts *ps; 776 int error; 777 778 error = copyin(uap->sigmask, &mask, sizeof(mask)); 779 if (error) 780 return (error); 781 782 /* 783 * When returning from sigsuspend, we want 784 * the old mask to be restored after the 785 * signal handler has finished. Thus, we 786 * save it here and mark the sigacts structure 787 * to indicate this. 788 */ 789 mtx_lock(&Giant); 790 PROC_LOCK(p); 791 ps = p->p_sigacts; 792 p->p_oldsigmask = p->p_sigmask; 793 p->p_flag |= P_OLDMASK; 794 795 SIG_CANTMASK(mask); 796 p->p_sigmask = mask; 797 while (msleep((caddr_t) ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 798 /* void */; 799 PROC_UNLOCK(p); 800 mtx_unlock(&Giant); 801 /* always return EINTR rather than ERESTART... */ 802 return (EINTR); 803 } 804 805 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 806 #ifndef _SYS_SYSPROTO_H_ 807 struct osigsuspend_args { 808 osigset_t mask; 809 }; 810 #endif 811 /* 812 * MPSAFE 813 */ 814 /* ARGSUSED */ 815 int 816 osigsuspend(p, uap) 817 register struct proc *p; 818 struct osigsuspend_args *uap; 819 { 820 sigset_t mask; 821 register struct sigacts *ps; 822 823 mtx_lock(&Giant); 824 PROC_LOCK(p); 825 ps = p->p_sigacts; 826 p->p_oldsigmask = p->p_sigmask; 827 p->p_flag |= P_OLDMASK; 828 OSIG2SIG(uap->mask, mask); 829 SIG_CANTMASK(mask); 830 SIGSETLO(p->p_sigmask, mask); 831 while (msleep((caddr_t) ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 832 /* void */; 833 PROC_UNLOCK(p); 834 mtx_unlock(&Giant); 835 /* always return EINTR rather than ERESTART... */ 836 return (EINTR); 837 } 838 #endif /* COMPAT_43 */ 839 840 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 841 #ifndef _SYS_SYSPROTO_H_ 842 struct osigstack_args { 843 struct sigstack *nss; 844 struct sigstack *oss; 845 }; 846 #endif 847 /* 848 * MPSAFE 849 */ 850 /* ARGSUSED */ 851 int 852 osigstack(p, uap) 853 struct proc *p; 854 register struct osigstack_args *uap; 855 { 856 struct sigstack ss; 857 int error = 0; 858 859 mtx_lock(&Giant); 860 861 if (uap->oss != NULL) { 862 PROC_LOCK(p); 863 ss.ss_sp = p->p_sigstk.ss_sp; 864 ss.ss_onstack = sigonstack(cpu_getstack(p)); 865 PROC_UNLOCK(p); 866 error = copyout(&ss, uap->oss, sizeof(struct sigstack)); 867 if (error) 868 goto done2; 869 } 870 871 if (uap->nss != NULL) { 872 if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0) 873 goto done2; 874 PROC_LOCK(p); 875 p->p_sigstk.ss_sp = ss.ss_sp; 876 p->p_sigstk.ss_size = 0; 877 p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 878 p->p_flag |= P_ALTSTACK; 879 PROC_UNLOCK(p); 880 } 881 done2: 882 mtx_unlock(&Giant); 883 return (error); 884 } 885 #endif /* COMPAT_43 || COMPAT_SUNOS */ 886 887 #ifndef _SYS_SYSPROTO_H_ 888 struct sigaltstack_args { 889 stack_t *ss; 890 stack_t *oss; 891 }; 892 #endif 893 /* 894 * MPSAFE 895 */ 896 /* ARGSUSED */ 897 int 898 sigaltstack(p, uap) 899 struct proc *p; 900 register struct sigaltstack_args *uap; 901 { 902 stack_t ss; 903 int oonstack; 904 int error = 0; 905 906 mtx_lock(&Giant); 907 908 oonstack = sigonstack(cpu_getstack(p)); 909 910 if (uap->oss != NULL) { 911 PROC_LOCK(p); 912 ss = p->p_sigstk; 913 ss.ss_flags = (p->p_flag & P_ALTSTACK) 914 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 915 PROC_UNLOCK(p); 916 if ((error = copyout(&ss, uap->oss, sizeof(stack_t))) != 0) 917 goto done2; 918 } 919 920 if (uap->ss != NULL) { 921 if (oonstack) { 922 error = EPERM; 923 goto done2; 924 } 925 if ((error = copyin(uap->ss, &ss, sizeof(ss))) != 0) 926 goto done2; 927 if ((ss.ss_flags & ~SS_DISABLE) != 0) { 928 error = EINVAL; 929 goto done2; 930 } 931 if (!(ss.ss_flags & SS_DISABLE)) { 932 if (ss.ss_size < p->p_sysent->sv_minsigstksz) { 933 error = ENOMEM; 934 goto done2; 935 } 936 PROC_LOCK(p); 937 p->p_sigstk = ss; 938 p->p_flag |= P_ALTSTACK; 939 PROC_UNLOCK(p); 940 } else { 941 PROC_LOCK(p); 942 p->p_flag &= ~P_ALTSTACK; 943 PROC_UNLOCK(p); 944 } 945 } 946 done2: 947 mtx_unlock(&Giant); 948 return (error); 949 } 950 951 /* 952 * Common code for kill process group/broadcast kill. 953 * cp is calling process. 954 */ 955 int 956 killpg1(cp, sig, pgid, all) 957 register struct proc *cp; 958 int sig, pgid, all; 959 { 960 register struct proc *p; 961 struct pgrp *pgrp; 962 int nfound = 0; 963 964 if (all) { 965 /* 966 * broadcast 967 */ 968 sx_slock(&allproc_lock); 969 LIST_FOREACH(p, &allproc, p_list) { 970 PROC_LOCK(p); 971 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || p == cp) { 972 PROC_UNLOCK(p); 973 continue; 974 } 975 if (p_cansignal(cp, p, sig) == 0) { 976 nfound++; 977 if (sig) 978 psignal(p, sig); 979 } 980 PROC_UNLOCK(p); 981 } 982 sx_sunlock(&allproc_lock); 983 } else { 984 if (pgid == 0) 985 /* 986 * zero pgid means send to my process group. 987 */ 988 pgrp = cp->p_pgrp; 989 else { 990 pgrp = pgfind(pgid); 991 if (pgrp == NULL) 992 return (ESRCH); 993 } 994 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 995 PROC_LOCK(p); 996 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 997 PROC_UNLOCK(p); 998 continue; 999 } 1000 mtx_lock_spin(&sched_lock); 1001 if (p->p_stat == SZOMB) { 1002 mtx_unlock_spin(&sched_lock); 1003 PROC_UNLOCK(p); 1004 continue; 1005 } 1006 mtx_unlock_spin(&sched_lock); 1007 if (p_cansignal(cp, p, sig) == 0) { 1008 nfound++; 1009 if (sig) 1010 psignal(p, sig); 1011 } 1012 PROC_UNLOCK(p); 1013 } 1014 } 1015 return (nfound ? 0 : ESRCH); 1016 } 1017 1018 #ifndef _SYS_SYSPROTO_H_ 1019 struct kill_args { 1020 int pid; 1021 int signum; 1022 }; 1023 #endif 1024 /* 1025 * MPSAFE 1026 */ 1027 /* ARGSUSED */ 1028 int 1029 kill(cp, uap) 1030 register struct proc *cp; 1031 register struct kill_args *uap; 1032 { 1033 register struct proc *p; 1034 int error = 0; 1035 1036 if ((u_int)uap->signum > _SIG_MAXSIG) 1037 return (EINVAL); 1038 1039 mtx_lock(&Giant); 1040 if (uap->pid > 0) { 1041 /* kill single process */ 1042 if ((p = pfind(uap->pid)) == NULL) { 1043 error = ESRCH; 1044 } else if (p_cansignal(cp, p, uap->signum)) { 1045 PROC_UNLOCK(p); 1046 error = EPERM; 1047 } else { 1048 if (uap->signum) 1049 psignal(p, uap->signum); 1050 PROC_UNLOCK(p); 1051 error = 0; 1052 } 1053 } else { 1054 switch (uap->pid) { 1055 case -1: /* broadcast signal */ 1056 error = killpg1(cp, uap->signum, 0, 1); 1057 break; 1058 case 0: /* signal own process group */ 1059 error = killpg1(cp, uap->signum, 0, 0); 1060 break; 1061 default: /* negative explicit process group */ 1062 error = killpg1(cp, uap->signum, -uap->pid, 0); 1063 break; 1064 } 1065 } 1066 mtx_unlock(&Giant); 1067 return(error); 1068 } 1069 1070 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 1071 #ifndef _SYS_SYSPROTO_H_ 1072 struct okillpg_args { 1073 int pgid; 1074 int signum; 1075 }; 1076 #endif 1077 /* 1078 * MPSAFE 1079 */ 1080 /* ARGSUSED */ 1081 int 1082 okillpg(p, uap) 1083 struct proc *p; 1084 register struct okillpg_args *uap; 1085 { 1086 int error; 1087 1088 if ((u_int)uap->signum > _SIG_MAXSIG) 1089 return (EINVAL); 1090 mtx_lock(&Giant); 1091 error = killpg1(p, uap->signum, uap->pgid, 0); 1092 mtx_unlock(&Giant); 1093 return (error); 1094 } 1095 #endif /* COMPAT_43 || COMPAT_SUNOS */ 1096 1097 /* 1098 * Send a signal to a process group. 1099 */ 1100 void 1101 gsignal(pgid, sig) 1102 int pgid, sig; 1103 { 1104 struct pgrp *pgrp; 1105 1106 if (pgid && (pgrp = pgfind(pgid))) 1107 pgsignal(pgrp, sig, 0); 1108 } 1109 1110 /* 1111 * Send a signal to a process group. If checktty is 1, 1112 * limit to members which have a controlling terminal. 1113 */ 1114 void 1115 pgsignal(pgrp, sig, checkctty) 1116 struct pgrp *pgrp; 1117 int sig, checkctty; 1118 { 1119 register struct proc *p; 1120 1121 if (pgrp) { 1122 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1123 PROC_LOCK(p); 1124 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1125 psignal(p, sig); 1126 PROC_UNLOCK(p); 1127 } 1128 } 1129 } 1130 1131 /* 1132 * Send a signal caused by a trap to the current process. 1133 * If it will be caught immediately, deliver it with correct code. 1134 * Otherwise, post it normally. 1135 * 1136 * MPSAFE 1137 */ 1138 void 1139 trapsignal(p, sig, code) 1140 struct proc *p; 1141 register int sig; 1142 u_long code; 1143 { 1144 register struct sigacts *ps = p->p_sigacts; 1145 1146 mtx_lock(&Giant); 1147 PROC_LOCK(p); 1148 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && 1149 !SIGISMEMBER(p->p_sigmask, sig)) { 1150 p->p_stats->p_ru.ru_nsignals++; 1151 #ifdef KTRACE 1152 if (KTRPOINT(p, KTR_PSIG)) 1153 ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)], 1154 &p->p_sigmask, code); 1155 #endif 1156 PROC_UNLOCK(p); /* XXX ??? */ 1157 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, 1158 &p->p_sigmask, code); 1159 PROC_LOCK(p); 1160 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1161 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1162 SIGADDSET(p->p_sigmask, sig); 1163 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1164 /* 1165 * See do_sigaction() for origin of this code. 1166 */ 1167 SIGDELSET(p->p_sigcatch, sig); 1168 if (sig != SIGCONT && 1169 sigprop(sig) & SA_IGNORE) 1170 SIGADDSET(p->p_sigignore, sig); 1171 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1172 } 1173 } else { 1174 p->p_code = code; /* XXX for core dump/debugger */ 1175 p->p_sig = sig; /* XXX to verify code */ 1176 psignal(p, sig); 1177 } 1178 PROC_UNLOCK(p); 1179 mtx_unlock(&Giant); 1180 } 1181 1182 /* 1183 * Send the signal to the process. If the signal has an action, the action 1184 * is usually performed by the target process rather than the caller; we add 1185 * the signal to the set of pending signals for the process. 1186 * 1187 * Exceptions: 1188 * o When a stop signal is sent to a sleeping process that takes the 1189 * default action, the process is stopped without awakening it. 1190 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1191 * regardless of the signal action (eg, blocked or ignored). 1192 * 1193 * Other ignored signals are discarded immediately. 1194 */ 1195 void 1196 psignal(p, sig) 1197 register struct proc *p; 1198 register int sig; 1199 { 1200 register int prop; 1201 register sig_t action; 1202 1203 if (sig > _SIG_MAXSIG || sig <= 0) { 1204 printf("psignal: signal %d\n", sig); 1205 panic("psignal signal number"); 1206 } 1207 1208 PROC_LOCK_ASSERT(p, MA_OWNED); 1209 KNOTE(&p->p_klist, NOTE_SIGNAL | sig); 1210 1211 prop = sigprop(sig); 1212 1213 /* 1214 * If proc is traced, always give parent a chance; 1215 * if signal event is tracked by procfs, give *that* 1216 * a chance, as well. 1217 */ 1218 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) 1219 action = SIG_DFL; 1220 else { 1221 /* 1222 * If the signal is being ignored, 1223 * then we forget about it immediately. 1224 * (Note: we don't set SIGCONT in p_sigignore, 1225 * and if it is set to SIG_IGN, 1226 * action will be SIG_DFL here.) 1227 */ 1228 if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) 1229 return; 1230 if (SIGISMEMBER(p->p_sigmask, sig)) 1231 action = SIG_HOLD; 1232 else if (SIGISMEMBER(p->p_sigcatch, sig)) 1233 action = SIG_CATCH; 1234 else 1235 action = SIG_DFL; 1236 } 1237 1238 mtx_lock_spin(&sched_lock); 1239 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 1240 (p->p_flag & P_TRACED) == 0) 1241 p->p_nice = NZERO; 1242 mtx_unlock_spin(&sched_lock); 1243 1244 if (prop & SA_CONT) 1245 SIG_STOPSIGMASK(p->p_siglist); 1246 1247 if (prop & SA_STOP) { 1248 /* 1249 * If sending a tty stop signal to a member of an orphaned 1250 * process group, discard the signal here if the action 1251 * is default; don't stop the process below if sleeping, 1252 * and don't clear any pending SIGCONT. 1253 */ 1254 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 1255 action == SIG_DFL) 1256 return; 1257 SIG_CONTSIGMASK(p->p_siglist); 1258 } 1259 SIGADDSET(p->p_siglist, sig); 1260 1261 /* 1262 * Defer further processing for signals which are held, 1263 * except that stopped processes must be continued by SIGCONT. 1264 */ 1265 mtx_lock_spin(&sched_lock); 1266 if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) { 1267 mtx_unlock_spin(&sched_lock); 1268 return; 1269 } 1270 switch (p->p_stat) { 1271 1272 case SSLEEP: 1273 /* 1274 * If process is sleeping uninterruptibly 1275 * we can't interrupt the sleep... the signal will 1276 * be noticed when the process returns through 1277 * trap() or syscall(). 1278 */ 1279 if ((p->p_sflag & PS_SINTR) == 0) { 1280 mtx_unlock_spin(&sched_lock); 1281 goto out; 1282 } 1283 /* 1284 * Process is sleeping and traced... make it runnable 1285 * so it can discover the signal in issignal() and stop 1286 * for the parent. 1287 */ 1288 if (p->p_flag & P_TRACED) 1289 goto run; 1290 mtx_unlock_spin(&sched_lock); 1291 /* 1292 * If SIGCONT is default (or ignored) and process is 1293 * asleep, we are finished; the process should not 1294 * be awakened. 1295 */ 1296 if ((prop & SA_CONT) && action == SIG_DFL) { 1297 SIGDELSET(p->p_siglist, sig); 1298 goto out; 1299 } 1300 /* 1301 * When a sleeping process receives a stop 1302 * signal, process immediately if possible. 1303 * All other (caught or default) signals 1304 * cause the process to run. 1305 */ 1306 if (prop & SA_STOP) { 1307 if (action != SIG_DFL) 1308 goto runfast; 1309 /* 1310 * If a child holding parent blocked, 1311 * stopping could cause deadlock. 1312 */ 1313 if (p->p_flag & P_PPWAIT) 1314 goto out; 1315 SIGDELSET(p->p_siglist, sig); 1316 p->p_xstat = sig; 1317 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) { 1318 PROC_LOCK(p->p_pptr); 1319 psignal(p->p_pptr, SIGCHLD); 1320 PROC_UNLOCK(p->p_pptr); 1321 } 1322 mtx_lock_spin(&sched_lock); 1323 stop(p); 1324 mtx_unlock_spin(&sched_lock); 1325 goto out; 1326 } else 1327 goto runfast; 1328 /* NOTREACHED */ 1329 1330 case SSTOP: 1331 mtx_unlock_spin(&sched_lock); 1332 /* 1333 * If traced process is already stopped, 1334 * then no further action is necessary. 1335 */ 1336 if (p->p_flag & P_TRACED) 1337 goto out; 1338 1339 /* 1340 * Kill signal always sets processes running. 1341 */ 1342 if (sig == SIGKILL) 1343 goto runfast; 1344 1345 if (prop & SA_CONT) { 1346 /* 1347 * If SIGCONT is default (or ignored), we continue the 1348 * process but don't leave the signal in p_siglist, as 1349 * it has no further action. If SIGCONT is held, we 1350 * continue the process and leave the signal in 1351 * p_siglist. If the process catches SIGCONT, let it 1352 * handle the signal itself. If it isn't waiting on 1353 * an event, then it goes back to run state. 1354 * Otherwise, process goes back to sleep state. 1355 */ 1356 if (action == SIG_DFL) 1357 SIGDELSET(p->p_siglist, sig); 1358 if (action == SIG_CATCH) 1359 goto runfast; 1360 mtx_lock_spin(&sched_lock); 1361 if (p->p_wchan == NULL) 1362 goto run; 1363 p->p_stat = SSLEEP; 1364 mtx_unlock_spin(&sched_lock); 1365 goto out; 1366 } 1367 1368 if (prop & SA_STOP) { 1369 /* 1370 * Already stopped, don't need to stop again. 1371 * (If we did the shell could get confused.) 1372 */ 1373 SIGDELSET(p->p_siglist, sig); 1374 goto out; 1375 } 1376 1377 /* 1378 * If process is sleeping interruptibly, then simulate a 1379 * wakeup so that when it is continued, it will be made 1380 * runnable and can look at the signal. But don't make 1381 * the process runnable, leave it stopped. 1382 */ 1383 mtx_lock_spin(&sched_lock); 1384 if (p->p_wchan && p->p_sflag & PS_SINTR) { 1385 if (p->p_sflag & PS_CVWAITQ) 1386 cv_waitq_remove(p); 1387 else 1388 unsleep(p); 1389 } 1390 mtx_unlock_spin(&sched_lock); 1391 goto out; 1392 1393 default: 1394 /* 1395 * SRUN, SIDL, SZOMB do nothing with the signal, 1396 * other than kicking ourselves if we are running. 1397 * It will either never be noticed, or noticed very soon. 1398 */ 1399 if (p->p_stat == SRUN) { 1400 signotify(p); 1401 #ifdef SMP 1402 forward_signal(p); 1403 #endif 1404 } 1405 mtx_unlock_spin(&sched_lock); 1406 goto out; 1407 } 1408 /*NOTREACHED*/ 1409 1410 runfast: 1411 /* 1412 * Raise priority to at least PUSER. 1413 */ 1414 mtx_lock_spin(&sched_lock); 1415 if (p->p_pri.pri_level > PUSER) 1416 p->p_pri.pri_level = PUSER; 1417 run: 1418 /* If we jump here, sched_lock has to be owned. */ 1419 mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED); 1420 setrunnable(p); 1421 mtx_unlock_spin(&sched_lock); 1422 out: 1423 /* If we jump here, sched_lock should not be owned. */ 1424 mtx_assert(&sched_lock, MA_NOTOWNED); 1425 } 1426 1427 /* 1428 * If the current process has received a signal (should be caught or cause 1429 * termination, should interrupt current syscall), return the signal number. 1430 * Stop signals with default action are processed immediately, then cleared; 1431 * they aren't returned. This is checked after each entry to the system for 1432 * a syscall or trap (though this can usually be done without calling issignal 1433 * by checking the pending signal masks in the CURSIG macro.) The normal call 1434 * sequence is 1435 * 1436 * while (sig = CURSIG(curproc)) 1437 * postsig(sig); 1438 */ 1439 int 1440 issignal(p) 1441 register struct proc *p; 1442 { 1443 sigset_t mask; 1444 register int sig, prop; 1445 1446 PROC_LOCK_ASSERT(p, MA_OWNED); 1447 for (;;) { 1448 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 1449 1450 mask = p->p_siglist; 1451 SIGSETNAND(mask, p->p_sigmask); 1452 if (p->p_flag & P_PPWAIT) 1453 SIG_STOPSIGMASK(mask); 1454 if (!SIGNOTEMPTY(mask)) /* no signal to send */ 1455 return (0); 1456 sig = sig_ffs(&mask); 1457 prop = sigprop(sig); 1458 1459 _STOPEVENT(p, S_SIG, sig); 1460 1461 /* 1462 * We should see pending but ignored signals 1463 * only if P_TRACED was on when they were posted. 1464 */ 1465 if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { 1466 SIGDELSET(p->p_siglist, sig); 1467 continue; 1468 } 1469 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1470 /* 1471 * If traced, always stop, and stay 1472 * stopped until released by the parent. 1473 */ 1474 p->p_xstat = sig; 1475 PROC_LOCK(p->p_pptr); 1476 psignal(p->p_pptr, SIGCHLD); 1477 PROC_UNLOCK(p->p_pptr); 1478 do { 1479 mtx_lock_spin(&sched_lock); 1480 stop(p); 1481 PROC_UNLOCK_NOSWITCH(p); 1482 DROP_GIANT_NOSWITCH(); 1483 p->p_stats->p_ru.ru_nivcsw++; 1484 mi_switch(); 1485 mtx_unlock_spin(&sched_lock); 1486 PICKUP_GIANT(); 1487 PROC_LOCK(p); 1488 } while (!trace_req(p) 1489 && p->p_flag & P_TRACED); 1490 1491 /* 1492 * If the traced bit got turned off, go back up 1493 * to the top to rescan signals. This ensures 1494 * that p_sig* and ps_sigact are consistent. 1495 */ 1496 if ((p->p_flag & P_TRACED) == 0) 1497 continue; 1498 1499 /* 1500 * If parent wants us to take the signal, 1501 * then it will leave it in p->p_xstat; 1502 * otherwise we just look for signals again. 1503 */ 1504 SIGDELSET(p->p_siglist, sig); /* clear old signal */ 1505 sig = p->p_xstat; 1506 if (sig == 0) 1507 continue; 1508 1509 /* 1510 * Put the new signal into p_siglist. If the 1511 * signal is being masked, look for other signals. 1512 */ 1513 SIGADDSET(p->p_siglist, sig); 1514 if (SIGISMEMBER(p->p_sigmask, sig)) 1515 continue; 1516 } 1517 1518 /* 1519 * Decide whether the signal should be returned. 1520 * Return the signal's number, or fall through 1521 * to clear it from the pending mask. 1522 */ 1523 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 1524 1525 case (int)SIG_DFL: 1526 /* 1527 * Don't take default actions on system processes. 1528 */ 1529 if (p->p_pid <= 1) { 1530 #ifdef DIAGNOSTIC 1531 /* 1532 * Are you sure you want to ignore SIGSEGV 1533 * in init? XXX 1534 */ 1535 printf("Process (pid %lu) got signal %d\n", 1536 (u_long)p->p_pid, sig); 1537 #endif 1538 break; /* == ignore */ 1539 } 1540 /* 1541 * If there is a pending stop signal to process 1542 * with default action, stop here, 1543 * then clear the signal. However, 1544 * if process is member of an orphaned 1545 * process group, ignore tty stop signals. 1546 */ 1547 if (prop & SA_STOP) { 1548 if (p->p_flag & P_TRACED || 1549 (p->p_pgrp->pg_jobc == 0 && 1550 prop & SA_TTYSTOP)) 1551 break; /* == ignore */ 1552 p->p_xstat = sig; 1553 if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) { 1554 PROC_LOCK(p->p_pptr); 1555 psignal(p->p_pptr, SIGCHLD); 1556 PROC_UNLOCK(p->p_pptr); 1557 } 1558 mtx_lock_spin(&sched_lock); 1559 stop(p); 1560 PROC_UNLOCK_NOSWITCH(p); 1561 DROP_GIANT_NOSWITCH(); 1562 p->p_stats->p_ru.ru_nivcsw++; 1563 mi_switch(); 1564 mtx_unlock_spin(&sched_lock); 1565 PICKUP_GIANT(); 1566 PROC_LOCK(p); 1567 break; 1568 } else if (prop & SA_IGNORE) { 1569 /* 1570 * Except for SIGCONT, shouldn't get here. 1571 * Default action is to ignore; drop it. 1572 */ 1573 break; /* == ignore */ 1574 } else 1575 return (sig); 1576 /*NOTREACHED*/ 1577 1578 case (int)SIG_IGN: 1579 /* 1580 * Masking above should prevent us ever trying 1581 * to take action on an ignored signal other 1582 * than SIGCONT, unless process is traced. 1583 */ 1584 if ((prop & SA_CONT) == 0 && 1585 (p->p_flag & P_TRACED) == 0) 1586 printf("issignal\n"); 1587 break; /* == ignore */ 1588 1589 default: 1590 /* 1591 * This signal has an action, let 1592 * postsig() process it. 1593 */ 1594 return (sig); 1595 } 1596 SIGDELSET(p->p_siglist, sig); /* take the signal! */ 1597 } 1598 /* NOTREACHED */ 1599 } 1600 1601 /* 1602 * Put the argument process into the stopped state and notify the parent 1603 * via wakeup. Signals are handled elsewhere. The process must not be 1604 * on the run queue. Must be called with the proc p locked and the scheduler 1605 * lock held. 1606 */ 1607 static void 1608 stop(p) 1609 register struct proc *p; 1610 { 1611 1612 PROC_LOCK_ASSERT(p, MA_OWNED); 1613 mtx_assert(&sched_lock, MA_OWNED); 1614 p->p_stat = SSTOP; 1615 p->p_flag &= ~P_WAITED; 1616 wakeup((caddr_t)p->p_pptr); 1617 } 1618 1619 /* 1620 * Take the action for the specified signal 1621 * from the current set of pending signals. 1622 */ 1623 void 1624 postsig(sig) 1625 register int sig; 1626 { 1627 register struct proc *p = curproc; 1628 struct sigacts *ps; 1629 sig_t action; 1630 sigset_t returnmask; 1631 int code; 1632 1633 KASSERT(sig != 0, ("postsig")); 1634 1635 PROC_LOCK_ASSERT(p, MA_OWNED); 1636 ps = p->p_sigacts; 1637 SIGDELSET(p->p_siglist, sig); 1638 action = ps->ps_sigact[_SIG_IDX(sig)]; 1639 #ifdef KTRACE 1640 if (KTRPOINT(p, KTR_PSIG)) 1641 ktrpsig(p->p_tracep, sig, action, p->p_flag & P_OLDMASK ? 1642 &p->p_oldsigmask : &p->p_sigmask, 0); 1643 #endif 1644 _STOPEVENT(p, S_SIG, sig); 1645 1646 if (action == SIG_DFL) { 1647 /* 1648 * Default action, where the default is to kill 1649 * the process. (Other cases were ignored above.) 1650 */ 1651 sigexit(p, sig); 1652 /* NOTREACHED */ 1653 } else { 1654 /* 1655 * If we get here, the signal must be caught. 1656 */ 1657 KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), 1658 ("postsig action")); 1659 /* 1660 * Set the new mask value and also defer further 1661 * occurrences of this signal. 1662 * 1663 * Special case: user has done a sigsuspend. Here the 1664 * current mask is not of interest, but rather the 1665 * mask from before the sigsuspend is what we want 1666 * restored after the signal processing is completed. 1667 */ 1668 if (p->p_flag & P_OLDMASK) { 1669 returnmask = p->p_oldsigmask; 1670 p->p_flag &= ~P_OLDMASK; 1671 } else 1672 returnmask = p->p_sigmask; 1673 1674 SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1675 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1676 SIGADDSET(p->p_sigmask, sig); 1677 1678 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1679 /* 1680 * See do_sigaction() for origin of this code. 1681 */ 1682 SIGDELSET(p->p_sigcatch, sig); 1683 if (sig != SIGCONT && 1684 sigprop(sig) & SA_IGNORE) 1685 SIGADDSET(p->p_sigignore, sig); 1686 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1687 } 1688 p->p_stats->p_ru.ru_nsignals++; 1689 if (p->p_sig != sig) { 1690 code = 0; 1691 } else { 1692 code = p->p_code; 1693 p->p_code = 0; 1694 p->p_sig = 0; 1695 } 1696 PROC_UNLOCK(p); 1697 (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); 1698 PROC_LOCK(p); 1699 } 1700 } 1701 1702 /* 1703 * Kill the current process for stated reason. 1704 */ 1705 void 1706 killproc(p, why) 1707 struct proc *p; 1708 char *why; 1709 { 1710 1711 PROC_LOCK_ASSERT(p, MA_OWNED); 1712 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 1713 p, p->p_pid, p->p_comm); 1714 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1715 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1716 psignal(p, SIGKILL); 1717 } 1718 1719 /* 1720 * Force the current process to exit with the specified signal, dumping core 1721 * if appropriate. We bypass the normal tests for masked and caught signals, 1722 * allowing unrecoverable failures to terminate the process without changing 1723 * signal state. Mark the accounting record with the signal termination. 1724 * If dumping core, save the signal number for the debugger. Calls exit and 1725 * does not return. 1726 */ 1727 void 1728 sigexit(p, sig) 1729 register struct proc *p; 1730 int sig; 1731 { 1732 1733 PROC_LOCK_ASSERT(p, MA_OWNED); 1734 p->p_acflag |= AXSIG; 1735 if (sigprop(sig) & SA_CORE) { 1736 p->p_sig = sig; 1737 /* 1738 * Log signals which would cause core dumps 1739 * (Log as LOG_INFO to appease those who don't want 1740 * these messages.) 1741 * XXX : Todo, as well as euid, write out ruid too 1742 */ 1743 PROC_UNLOCK(p); 1744 if (!mtx_owned(&Giant)) 1745 mtx_lock(&Giant); 1746 if (coredump(p) == 0) 1747 sig |= WCOREFLAG; 1748 if (kern_logsigexit) 1749 log(LOG_INFO, 1750 "pid %d (%s), uid %d: exited on signal %d%s\n", 1751 p->p_pid, p->p_comm, 1752 p->p_ucred ? p->p_ucred->cr_uid : -1, 1753 sig &~ WCOREFLAG, 1754 sig & WCOREFLAG ? " (core dumped)" : ""); 1755 } else { 1756 PROC_UNLOCK(p); 1757 if (!mtx_owned(&Giant)) 1758 mtx_lock(&Giant); 1759 } 1760 exit1(p, W_EXITCODE(0, sig)); 1761 /* NOTREACHED */ 1762 } 1763 1764 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1765 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1766 sizeof(corefilename), "process corefile name format string"); 1767 1768 /* 1769 * expand_name(name, uid, pid) 1770 * Expand the name described in corefilename, using name, uid, and pid. 1771 * corefilename is a printf-like string, with three format specifiers: 1772 * %N name of process ("name") 1773 * %P process id (pid) 1774 * %U user id (uid) 1775 * For example, "%N.core" is the default; they can be disabled completely 1776 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1777 * This is controlled by the sysctl variable kern.corefile (see above). 1778 */ 1779 1780 static char * 1781 expand_name(name, uid, pid) 1782 const char *name; uid_t uid; pid_t pid; { 1783 char *temp; 1784 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1785 int i, n; 1786 char *format = corefilename; 1787 size_t namelen; 1788 1789 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1790 if (temp == NULL) 1791 return NULL; 1792 namelen = strlen(name); 1793 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1794 int l; 1795 switch (format[i]) { 1796 case '%': /* Format character */ 1797 i++; 1798 switch (format[i]) { 1799 case '%': 1800 temp[n++] = '%'; 1801 break; 1802 case 'N': /* process name */ 1803 if ((n + namelen) > MAXPATHLEN) { 1804 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1805 pid, name, uid, temp, name); 1806 free(temp, M_TEMP); 1807 return NULL; 1808 } 1809 memcpy(temp+n, name, namelen); 1810 n += namelen; 1811 break; 1812 case 'P': /* process id */ 1813 l = sprintf(buf, "%u", pid); 1814 if ((n + l) > MAXPATHLEN) { 1815 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1816 pid, name, uid, temp, name); 1817 free(temp, M_TEMP); 1818 return NULL; 1819 } 1820 memcpy(temp+n, buf, l); 1821 n += l; 1822 break; 1823 case 'U': /* user id */ 1824 l = sprintf(buf, "%u", uid); 1825 if ((n + l) > MAXPATHLEN) { 1826 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1827 pid, name, uid, temp, name); 1828 free(temp, M_TEMP); 1829 return NULL; 1830 } 1831 memcpy(temp+n, buf, l); 1832 n += l; 1833 break; 1834 default: 1835 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1836 } 1837 break; 1838 default: 1839 temp[n++] = format[i]; 1840 } 1841 } 1842 temp[n] = '\0'; 1843 return temp; 1844 } 1845 1846 /* 1847 * Dump a process' core. The main routine does some 1848 * policy checking, and creates the name of the coredump; 1849 * then it passes on a vnode and a size limit to the process-specific 1850 * coredump routine if there is one; if there _is not_ one, it returns 1851 * ENOSYS; otherwise it returns the error from the process-specific routine. 1852 */ 1853 1854 static int 1855 coredump(p) 1856 register struct proc *p; 1857 { 1858 register struct vnode *vp; 1859 register struct ucred *cred = p->p_ucred; 1860 struct nameidata nd; 1861 struct vattr vattr; 1862 int error, error1, flags; 1863 struct mount *mp; 1864 char *name; /* name of corefile */ 1865 off_t limit; 1866 1867 PROC_LOCK(p); 1868 _STOPEVENT(p, S_CORE, 0); 1869 1870 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 1871 PROC_UNLOCK(p); 1872 return (EFAULT); 1873 } 1874 1875 /* 1876 * Note that the bulk of limit checking is done after 1877 * the corefile is created. The exception is if the limit 1878 * for corefiles is 0, in which case we don't bother 1879 * creating the corefile at all. This layout means that 1880 * a corefile is truncated instead of not being created, 1881 * if it is larger than the limit. 1882 */ 1883 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 1884 if (limit == 0) { 1885 PROC_UNLOCK(p); 1886 return 0; 1887 } 1888 PROC_UNLOCK(p); 1889 1890 restart: 1891 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 1892 if (name == NULL) 1893 return (EINVAL); 1894 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p); 1895 flags = O_CREAT | FWRITE | O_NOFOLLOW; 1896 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); 1897 free(name, M_TEMP); 1898 if (error) 1899 return (error); 1900 NDFREE(&nd, NDF_ONLY_PNBUF); 1901 vp = nd.ni_vp; 1902 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1903 VOP_UNLOCK(vp, 0, p); 1904 if ((error = vn_close(vp, FWRITE, cred, p)) != 0) 1905 return (error); 1906 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 1907 return (error); 1908 goto restart; 1909 } 1910 1911 /* Don't dump to non-regular files or files with links. */ 1912 if (vp->v_type != VREG || 1913 VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) { 1914 error = EFAULT; 1915 goto out; 1916 } 1917 VATTR_NULL(&vattr); 1918 vattr.va_size = 0; 1919 VOP_LEASE(vp, p, cred, LEASE_WRITE); 1920 VOP_SETATTR(vp, &vattr, cred, p); 1921 PROC_LOCK(p); 1922 p->p_acflag |= ACORE; 1923 PROC_UNLOCK(p); 1924 1925 error = p->p_sysent->sv_coredump ? 1926 p->p_sysent->sv_coredump(p, vp, limit) : 1927 ENOSYS; 1928 1929 out: 1930 VOP_UNLOCK(vp, 0, p); 1931 vn_finished_write(mp); 1932 error1 = vn_close(vp, FWRITE, cred, p); 1933 if (error == 0) 1934 error = error1; 1935 return (error); 1936 } 1937 1938 /* 1939 * Nonexistent system call-- signal process (may want to handle it). 1940 * Flag error in case process won't see signal immediately (blocked or ignored). 1941 */ 1942 #ifndef _SYS_SYSPROTO_H_ 1943 struct nosys_args { 1944 int dummy; 1945 }; 1946 #endif 1947 /* 1948 * MPSAFE 1949 */ 1950 /* ARGSUSED */ 1951 int 1952 nosys(p, args) 1953 struct proc *p; 1954 struct nosys_args *args; 1955 { 1956 mtx_lock(&Giant); 1957 PROC_LOCK(p); 1958 psignal(p, SIGSYS); 1959 PROC_UNLOCK(p); 1960 mtx_unlock(&Giant); 1961 return (EINVAL); 1962 } 1963 1964 /* 1965 * Send a signal to a SIGIO or SIGURG to a process or process group using 1966 * stored credentials rather than those of the current process. 1967 */ 1968 void 1969 pgsigio(sigio, sig, checkctty) 1970 struct sigio *sigio; 1971 int sig, checkctty; 1972 { 1973 if (sigio == NULL) 1974 return; 1975 1976 if (sigio->sio_pgid > 0) { 1977 PROC_LOCK(sigio->sio_proc); 1978 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 1979 psignal(sigio->sio_proc, sig); 1980 PROC_UNLOCK(sigio->sio_proc); 1981 } else if (sigio->sio_pgid < 0) { 1982 struct proc *p; 1983 1984 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 1985 PROC_LOCK(p); 1986 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 1987 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1988 psignal(p, sig); 1989 PROC_UNLOCK(p); 1990 } 1991 } 1992 } 1993 1994 static int 1995 filt_sigattach(struct knote *kn) 1996 { 1997 struct proc *p = curproc; 1998 1999 kn->kn_ptr.p_proc = p; 2000 kn->kn_flags |= EV_CLEAR; /* automatically set */ 2001 2002 PROC_LOCK(p); 2003 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 2004 PROC_UNLOCK(p); 2005 2006 return (0); 2007 } 2008 2009 static void 2010 filt_sigdetach(struct knote *kn) 2011 { 2012 struct proc *p = kn->kn_ptr.p_proc; 2013 2014 PROC_LOCK(p); 2015 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 2016 PROC_UNLOCK(p); 2017 } 2018 2019 /* 2020 * signal knotes are shared with proc knotes, so we apply a mask to 2021 * the hint in order to differentiate them from process hints. This 2022 * could be avoided by using a signal-specific knote list, but probably 2023 * isn't worth the trouble. 2024 */ 2025 static int 2026 filt_signal(struct knote *kn, long hint) 2027 { 2028 2029 if (hint & NOTE_SIGNAL) { 2030 hint &= ~NOTE_SIGNAL; 2031 2032 if (kn->kn_id == hint) 2033 kn->kn_data++; 2034 } 2035 return (kn->kn_data != 0); 2036 } 2037