1 /* $OpenBSD: kern_sig.c,v 1.270 2020/12/25 12:59:52 visa Exp $ */ 2 /* $NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1997 Theo de Raadt. All rights reserved. 6 * Copyright (c) 1982, 1986, 1989, 1991, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. 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 */ 40 41 #include <sys/param.h> 42 #include <sys/signalvar.h> 43 #include <sys/resourcevar.h> 44 #include <sys/queue.h> 45 #include <sys/namei.h> 46 #include <sys/vnode.h> 47 #include <sys/event.h> 48 #include <sys/proc.h> 49 #include <sys/systm.h> 50 #include <sys/acct.h> 51 #include <sys/fcntl.h> 52 #include <sys/filedesc.h> 53 #include <sys/kernel.h> 54 #include <sys/wait.h> 55 #include <sys/ktrace.h> 56 #include <sys/stat.h> 57 #include <sys/core.h> 58 #include <sys/malloc.h> 59 #include <sys/pool.h> 60 #include <sys/ptrace.h> 61 #include <sys/sched.h> 62 #include <sys/user.h> 63 #include <sys/syslog.h> 64 #include <sys/ttycom.h> 65 #include <sys/pledge.h> 66 #include <sys/witness.h> 67 68 #include <sys/mount.h> 69 #include <sys/syscallargs.h> 70 71 #include <uvm/uvm_extern.h> 72 #include <machine/tcb.h> 73 74 int filt_sigattach(struct knote *kn); 75 void filt_sigdetach(struct knote *kn); 76 int filt_signal(struct knote *kn, long hint); 77 78 const struct filterops sig_filtops = { 79 .f_flags = 0, 80 .f_attach = filt_sigattach, 81 .f_detach = filt_sigdetach, 82 .f_event = filt_signal, 83 }; 84 85 const int sigprop[NSIG + 1] = { 86 0, /* unused */ 87 SA_KILL, /* SIGHUP */ 88 SA_KILL, /* SIGINT */ 89 SA_KILL|SA_CORE, /* SIGQUIT */ 90 SA_KILL|SA_CORE, /* SIGILL */ 91 SA_KILL|SA_CORE, /* SIGTRAP */ 92 SA_KILL|SA_CORE, /* SIGABRT */ 93 SA_KILL|SA_CORE, /* SIGEMT */ 94 SA_KILL|SA_CORE, /* SIGFPE */ 95 SA_KILL, /* SIGKILL */ 96 SA_KILL|SA_CORE, /* SIGBUS */ 97 SA_KILL|SA_CORE, /* SIGSEGV */ 98 SA_KILL|SA_CORE, /* SIGSYS */ 99 SA_KILL, /* SIGPIPE */ 100 SA_KILL, /* SIGALRM */ 101 SA_KILL, /* SIGTERM */ 102 SA_IGNORE, /* SIGURG */ 103 SA_STOP, /* SIGSTOP */ 104 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 105 SA_IGNORE|SA_CONT, /* SIGCONT */ 106 SA_IGNORE, /* SIGCHLD */ 107 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 108 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 109 SA_IGNORE, /* SIGIO */ 110 SA_KILL, /* SIGXCPU */ 111 SA_KILL, /* SIGXFSZ */ 112 SA_KILL, /* SIGVTALRM */ 113 SA_KILL, /* SIGPROF */ 114 SA_IGNORE, /* SIGWINCH */ 115 SA_IGNORE, /* SIGINFO */ 116 SA_KILL, /* SIGUSR1 */ 117 SA_KILL, /* SIGUSR2 */ 118 SA_IGNORE, /* SIGTHR */ 119 }; 120 121 #define contsigmask (sigmask(SIGCONT)) 122 #define stopsigmask (sigmask(SIGSTOP) | sigmask(SIGTSTP) | \ 123 sigmask(SIGTTIN) | sigmask(SIGTTOU)) 124 125 void setsigvec(struct proc *, int, struct sigaction *); 126 127 void proc_stop(struct proc *p, int); 128 void proc_stop_sweep(void *); 129 void *proc_stop_si; 130 131 void postsig(struct proc *, int); 132 int cansignal(struct proc *, struct process *, int); 133 134 struct pool sigacts_pool; /* memory pool for sigacts structures */ 135 136 void sigio_del(struct sigiolst *); 137 void sigio_unlink(struct sigio_ref *, struct sigiolst *); 138 struct mutex sigio_lock = MUTEX_INITIALIZER(IPL_HIGH); 139 140 /* 141 * Can thread p, send the signal signum to process qr? 142 */ 143 int 144 cansignal(struct proc *p, struct process *qr, int signum) 145 { 146 struct process *pr = p->p_p; 147 struct ucred *uc = p->p_ucred; 148 struct ucred *quc = qr->ps_ucred; 149 150 if (uc->cr_uid == 0) 151 return (1); /* root can always signal */ 152 153 if (pr == qr) 154 return (1); /* process can always signal itself */ 155 156 /* optimization: if the same creds then the tests below will pass */ 157 if (uc == quc) 158 return (1); 159 160 if (signum == SIGCONT && qr->ps_session == pr->ps_session) 161 return (1); /* SIGCONT in session */ 162 163 /* 164 * Using kill(), only certain signals can be sent to setugid 165 * child processes 166 */ 167 if (qr->ps_flags & PS_SUGID) { 168 switch (signum) { 169 case 0: 170 case SIGKILL: 171 case SIGINT: 172 case SIGTERM: 173 case SIGALRM: 174 case SIGSTOP: 175 case SIGTTIN: 176 case SIGTTOU: 177 case SIGTSTP: 178 case SIGHUP: 179 case SIGUSR1: 180 case SIGUSR2: 181 if (uc->cr_ruid == quc->cr_ruid || 182 uc->cr_uid == quc->cr_ruid) 183 return (1); 184 } 185 return (0); 186 } 187 188 if (uc->cr_ruid == quc->cr_ruid || 189 uc->cr_ruid == quc->cr_svuid || 190 uc->cr_uid == quc->cr_ruid || 191 uc->cr_uid == quc->cr_svuid) 192 return (1); 193 return (0); 194 } 195 196 /* 197 * Initialize signal-related data structures. 198 */ 199 void 200 signal_init(void) 201 { 202 proc_stop_si = softintr_establish(IPL_SOFTCLOCK, proc_stop_sweep, 203 NULL); 204 if (proc_stop_si == NULL) 205 panic("signal_init failed to register softintr"); 206 207 pool_init(&sigacts_pool, sizeof(struct sigacts), 0, IPL_NONE, 208 PR_WAITOK, "sigapl", NULL); 209 } 210 211 /* 212 * Create an initial sigacts structure, using the same signal state 213 * as pr. 214 */ 215 struct sigacts * 216 sigactsinit(struct process *pr) 217 { 218 struct sigacts *ps; 219 220 ps = pool_get(&sigacts_pool, PR_WAITOK); 221 memcpy(ps, pr->ps_sigacts, sizeof(struct sigacts)); 222 return (ps); 223 } 224 225 /* 226 * Initialize a new sigaltstack structure. 227 */ 228 void 229 sigstkinit(struct sigaltstack *ss) 230 { 231 ss->ss_flags = SS_DISABLE; 232 ss->ss_size = 0; 233 ss->ss_sp = 0; 234 } 235 236 /* 237 * Release a sigacts structure. 238 */ 239 void 240 sigactsfree(struct process *pr) 241 { 242 struct sigacts *ps = pr->ps_sigacts; 243 244 pr->ps_sigacts = NULL; 245 246 pool_put(&sigacts_pool, ps); 247 } 248 249 int 250 sys_sigaction(struct proc *p, void *v, register_t *retval) 251 { 252 struct sys_sigaction_args /* { 253 syscallarg(int) signum; 254 syscallarg(const struct sigaction *) nsa; 255 syscallarg(struct sigaction *) osa; 256 } */ *uap = v; 257 struct sigaction vec; 258 #ifdef KTRACE 259 struct sigaction ovec; 260 #endif 261 struct sigaction *sa; 262 const struct sigaction *nsa; 263 struct sigaction *osa; 264 struct sigacts *ps = p->p_p->ps_sigacts; 265 int signum; 266 int bit, error; 267 268 signum = SCARG(uap, signum); 269 nsa = SCARG(uap, nsa); 270 osa = SCARG(uap, osa); 271 272 if (signum <= 0 || signum >= NSIG || 273 (nsa && (signum == SIGKILL || signum == SIGSTOP))) 274 return (EINVAL); 275 sa = &vec; 276 if (osa) { 277 sa->sa_handler = ps->ps_sigact[signum]; 278 sa->sa_mask = ps->ps_catchmask[signum]; 279 bit = sigmask(signum); 280 sa->sa_flags = 0; 281 if ((ps->ps_sigonstack & bit) != 0) 282 sa->sa_flags |= SA_ONSTACK; 283 if ((ps->ps_sigintr & bit) == 0) 284 sa->sa_flags |= SA_RESTART; 285 if ((ps->ps_sigreset & bit) != 0) 286 sa->sa_flags |= SA_RESETHAND; 287 if ((ps->ps_siginfo & bit) != 0) 288 sa->sa_flags |= SA_SIGINFO; 289 if (signum == SIGCHLD) { 290 if ((ps->ps_sigflags & SAS_NOCLDSTOP) != 0) 291 sa->sa_flags |= SA_NOCLDSTOP; 292 if ((ps->ps_sigflags & SAS_NOCLDWAIT) != 0) 293 sa->sa_flags |= SA_NOCLDWAIT; 294 } 295 if ((sa->sa_mask & bit) == 0) 296 sa->sa_flags |= SA_NODEFER; 297 sa->sa_mask &= ~bit; 298 error = copyout(sa, osa, sizeof (vec)); 299 if (error) 300 return (error); 301 #ifdef KTRACE 302 if (KTRPOINT(p, KTR_STRUCT)) 303 ovec = vec; 304 #endif 305 } 306 if (nsa) { 307 error = copyin(nsa, sa, sizeof (vec)); 308 if (error) 309 return (error); 310 #ifdef KTRACE 311 if (KTRPOINT(p, KTR_STRUCT)) 312 ktrsigaction(p, sa); 313 #endif 314 setsigvec(p, signum, sa); 315 } 316 #ifdef KTRACE 317 if (osa && KTRPOINT(p, KTR_STRUCT)) 318 ktrsigaction(p, &ovec); 319 #endif 320 return (0); 321 } 322 323 void 324 setsigvec(struct proc *p, int signum, struct sigaction *sa) 325 { 326 struct sigacts *ps = p->p_p->ps_sigacts; 327 int bit; 328 int s; 329 330 bit = sigmask(signum); 331 /* 332 * Change setting atomically. 333 */ 334 s = splhigh(); 335 ps->ps_sigact[signum] = sa->sa_handler; 336 if ((sa->sa_flags & SA_NODEFER) == 0) 337 sa->sa_mask |= sigmask(signum); 338 ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask; 339 if (signum == SIGCHLD) { 340 if (sa->sa_flags & SA_NOCLDSTOP) 341 atomic_setbits_int(&ps->ps_sigflags, SAS_NOCLDSTOP); 342 else 343 atomic_clearbits_int(&ps->ps_sigflags, SAS_NOCLDSTOP); 344 /* 345 * If the SA_NOCLDWAIT flag is set or the handler 346 * is SIG_IGN we reparent the dying child to PID 1 347 * (init) which will reap the zombie. Because we use 348 * init to do our dirty work we never set SAS_NOCLDWAIT 349 * for PID 1. 350 * XXX exit1 rework means this is unnecessary? 351 */ 352 if (initprocess->ps_sigacts != ps && 353 ((sa->sa_flags & SA_NOCLDWAIT) || 354 sa->sa_handler == SIG_IGN)) 355 atomic_setbits_int(&ps->ps_sigflags, SAS_NOCLDWAIT); 356 else 357 atomic_clearbits_int(&ps->ps_sigflags, SAS_NOCLDWAIT); 358 } 359 if ((sa->sa_flags & SA_RESETHAND) != 0) 360 ps->ps_sigreset |= bit; 361 else 362 ps->ps_sigreset &= ~bit; 363 if ((sa->sa_flags & SA_SIGINFO) != 0) 364 ps->ps_siginfo |= bit; 365 else 366 ps->ps_siginfo &= ~bit; 367 if ((sa->sa_flags & SA_RESTART) == 0) 368 ps->ps_sigintr |= bit; 369 else 370 ps->ps_sigintr &= ~bit; 371 if ((sa->sa_flags & SA_ONSTACK) != 0) 372 ps->ps_sigonstack |= bit; 373 else 374 ps->ps_sigonstack &= ~bit; 375 /* 376 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 377 * and for signals set to SIG_DFL where the default is to ignore. 378 * However, don't put SIGCONT in ps_sigignore, 379 * as we have to restart the process. 380 */ 381 if (sa->sa_handler == SIG_IGN || 382 (sigprop[signum] & SA_IGNORE && sa->sa_handler == SIG_DFL)) { 383 atomic_clearbits_int(&p->p_siglist, bit); 384 atomic_clearbits_int(&p->p_p->ps_siglist, bit); 385 if (signum != SIGCONT) 386 ps->ps_sigignore |= bit; /* easier in psignal */ 387 ps->ps_sigcatch &= ~bit; 388 } else { 389 ps->ps_sigignore &= ~bit; 390 if (sa->sa_handler == SIG_DFL) 391 ps->ps_sigcatch &= ~bit; 392 else 393 ps->ps_sigcatch |= bit; 394 } 395 splx(s); 396 } 397 398 /* 399 * Initialize signal state for process 0; 400 * set to ignore signals that are ignored by default. 401 */ 402 void 403 siginit(struct sigacts *ps) 404 { 405 int i; 406 407 for (i = 0; i < NSIG; i++) 408 if (sigprop[i] & SA_IGNORE && i != SIGCONT) 409 ps->ps_sigignore |= sigmask(i); 410 ps->ps_sigflags = SAS_NOCLDWAIT | SAS_NOCLDSTOP; 411 } 412 413 /* 414 * Reset signals for an exec by the specified thread. 415 */ 416 void 417 execsigs(struct proc *p) 418 { 419 struct sigacts *ps; 420 int nc, mask; 421 422 ps = p->p_p->ps_sigacts; 423 424 /* 425 * Reset caught signals. Held signals remain held 426 * through p_sigmask (unless they were caught, 427 * and are now ignored by default). 428 */ 429 while (ps->ps_sigcatch) { 430 nc = ffs((long)ps->ps_sigcatch); 431 mask = sigmask(nc); 432 ps->ps_sigcatch &= ~mask; 433 if (sigprop[nc] & SA_IGNORE) { 434 if (nc != SIGCONT) 435 ps->ps_sigignore |= mask; 436 atomic_clearbits_int(&p->p_siglist, mask); 437 atomic_clearbits_int(&p->p_p->ps_siglist, mask); 438 } 439 ps->ps_sigact[nc] = SIG_DFL; 440 } 441 /* 442 * Reset stack state to the user stack. 443 * Clear set of signals caught on the signal stack. 444 */ 445 sigstkinit(&p->p_sigstk); 446 atomic_clearbits_int(&ps->ps_sigflags, SAS_NOCLDWAIT); 447 if (ps->ps_sigact[SIGCHLD] == SIG_IGN) 448 ps->ps_sigact[SIGCHLD] = SIG_DFL; 449 } 450 451 /* 452 * Manipulate signal mask. 453 * Note that we receive new mask, not pointer, 454 * and return old mask as return value; 455 * the library stub does the rest. 456 */ 457 int 458 sys_sigprocmask(struct proc *p, void *v, register_t *retval) 459 { 460 struct sys_sigprocmask_args /* { 461 syscallarg(int) how; 462 syscallarg(sigset_t) mask; 463 } */ *uap = v; 464 int error = 0; 465 sigset_t mask; 466 467 KASSERT(p == curproc); 468 469 *retval = p->p_sigmask; 470 mask = SCARG(uap, mask) &~ sigcantmask; 471 472 switch (SCARG(uap, how)) { 473 case SIG_BLOCK: 474 atomic_setbits_int(&p->p_sigmask, mask); 475 break; 476 case SIG_UNBLOCK: 477 atomic_clearbits_int(&p->p_sigmask, mask); 478 break; 479 case SIG_SETMASK: 480 p->p_sigmask = mask; 481 break; 482 default: 483 error = EINVAL; 484 break; 485 } 486 return (error); 487 } 488 489 int 490 sys_sigpending(struct proc *p, void *v, register_t *retval) 491 { 492 493 *retval = p->p_siglist | p->p_p->ps_siglist; 494 return (0); 495 } 496 497 /* 498 * Temporarily replace calling proc's signal mask for the duration of a 499 * system call. Original signal mask will be restored by userret(). 500 */ 501 void 502 dosigsuspend(struct proc *p, sigset_t newmask) 503 { 504 KASSERT(p == curproc); 505 506 p->p_oldmask = p->p_sigmask; 507 atomic_setbits_int(&p->p_flag, P_SIGSUSPEND); 508 p->p_sigmask = newmask; 509 } 510 511 /* 512 * Suspend process until signal, providing mask to be set 513 * in the meantime. Note nonstandard calling convention: 514 * libc stub passes mask, not pointer, to save a copyin. 515 */ 516 int 517 sys_sigsuspend(struct proc *p, void *v, register_t *retval) 518 { 519 struct sys_sigsuspend_args /* { 520 syscallarg(int) mask; 521 } */ *uap = v; 522 struct process *pr = p->p_p; 523 struct sigacts *ps = pr->ps_sigacts; 524 525 dosigsuspend(p, SCARG(uap, mask) &~ sigcantmask); 526 while (tsleep_nsec(ps, PPAUSE|PCATCH, "sigsusp", INFSLP) == 0) 527 /* void */; 528 /* always return EINTR rather than ERESTART... */ 529 return (EINTR); 530 } 531 532 int 533 sigonstack(size_t stack) 534 { 535 const struct sigaltstack *ss = &curproc->p_sigstk; 536 537 return (ss->ss_flags & SS_DISABLE ? 0 : 538 (stack - (size_t)ss->ss_sp < ss->ss_size)); 539 } 540 541 int 542 sys_sigaltstack(struct proc *p, void *v, register_t *retval) 543 { 544 struct sys_sigaltstack_args /* { 545 syscallarg(const struct sigaltstack *) nss; 546 syscallarg(struct sigaltstack *) oss; 547 } */ *uap = v; 548 struct sigaltstack ss; 549 const struct sigaltstack *nss; 550 struct sigaltstack *oss; 551 int onstack = sigonstack(PROC_STACK(p)); 552 int error; 553 554 nss = SCARG(uap, nss); 555 oss = SCARG(uap, oss); 556 557 if (oss != NULL) { 558 ss = p->p_sigstk; 559 if (onstack) 560 ss.ss_flags |= SS_ONSTACK; 561 if ((error = copyout(&ss, oss, sizeof(ss)))) 562 return (error); 563 } 564 if (nss == NULL) 565 return (0); 566 error = copyin(nss, &ss, sizeof(ss)); 567 if (error) 568 return (error); 569 if (onstack) 570 return (EPERM); 571 if (ss.ss_flags & ~SS_DISABLE) 572 return (EINVAL); 573 if (ss.ss_flags & SS_DISABLE) { 574 p->p_sigstk.ss_flags = ss.ss_flags; 575 return (0); 576 } 577 if (ss.ss_size < MINSIGSTKSZ) 578 return (ENOMEM); 579 580 error = uvm_map_remap_as_stack(p, (vaddr_t)ss.ss_sp, ss.ss_size); 581 if (error) 582 return (error); 583 584 p->p_sigstk = ss; 585 return (0); 586 } 587 588 int 589 sys_kill(struct proc *cp, void *v, register_t *retval) 590 { 591 struct sys_kill_args /* { 592 syscallarg(int) pid; 593 syscallarg(int) signum; 594 } */ *uap = v; 595 struct process *pr; 596 int pid = SCARG(uap, pid); 597 int signum = SCARG(uap, signum); 598 int error; 599 int zombie = 0; 600 601 if ((error = pledge_kill(cp, pid)) != 0) 602 return (error); 603 if (((u_int)signum) >= NSIG) 604 return (EINVAL); 605 if (pid > 0) { 606 if ((pr = prfind(pid)) == NULL) { 607 if ((pr = zombiefind(pid)) == NULL) 608 return (ESRCH); 609 else 610 zombie = 1; 611 } 612 if (!cansignal(cp, pr, signum)) 613 return (EPERM); 614 615 /* kill single process */ 616 if (signum && !zombie) 617 prsignal(pr, signum); 618 return (0); 619 } 620 switch (pid) { 621 case -1: /* broadcast signal */ 622 return (killpg1(cp, signum, 0, 1)); 623 case 0: /* signal own process group */ 624 return (killpg1(cp, signum, 0, 0)); 625 default: /* negative explicit process group */ 626 return (killpg1(cp, signum, -pid, 0)); 627 } 628 } 629 630 int 631 sys_thrkill(struct proc *cp, void *v, register_t *retval) 632 { 633 struct sys_thrkill_args /* { 634 syscallarg(pid_t) tid; 635 syscallarg(int) signum; 636 syscallarg(void *) tcb; 637 } */ *uap = v; 638 struct proc *p; 639 int tid = SCARG(uap, tid); 640 int signum = SCARG(uap, signum); 641 void *tcb; 642 643 if (((u_int)signum) >= NSIG) 644 return (EINVAL); 645 if (tid > THREAD_PID_OFFSET) { 646 if ((p = tfind(tid - THREAD_PID_OFFSET)) == NULL) 647 return (ESRCH); 648 649 /* can only kill threads in the same process */ 650 if (p->p_p != cp->p_p) 651 return (ESRCH); 652 } else if (tid == 0) 653 p = cp; 654 else 655 return (EINVAL); 656 657 /* optionally require the target thread to have the given tcb addr */ 658 tcb = SCARG(uap, tcb); 659 if (tcb != NULL && tcb != TCB_GET(p)) 660 return (ESRCH); 661 662 if (signum) 663 ptsignal(p, signum, STHREAD); 664 return (0); 665 } 666 667 /* 668 * Common code for kill process group/broadcast kill. 669 * cp is calling process. 670 */ 671 int 672 killpg1(struct proc *cp, int signum, int pgid, int all) 673 { 674 struct process *pr; 675 struct pgrp *pgrp; 676 int nfound = 0; 677 678 if (all) { 679 /* 680 * broadcast 681 */ 682 LIST_FOREACH(pr, &allprocess, ps_list) { 683 if (pr->ps_pid <= 1 || 684 pr->ps_flags & (PS_SYSTEM | PS_NOBROADCASTKILL) || 685 pr == cp->p_p || !cansignal(cp, pr, signum)) 686 continue; 687 nfound++; 688 if (signum) 689 prsignal(pr, signum); 690 } 691 } else { 692 if (pgid == 0) 693 /* 694 * zero pgid means send to my process group. 695 */ 696 pgrp = cp->p_p->ps_pgrp; 697 else { 698 pgrp = pgfind(pgid); 699 if (pgrp == NULL) 700 return (ESRCH); 701 } 702 LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) { 703 if (pr->ps_pid <= 1 || pr->ps_flags & PS_SYSTEM || 704 !cansignal(cp, pr, signum)) 705 continue; 706 nfound++; 707 if (signum) 708 prsignal(pr, signum); 709 } 710 } 711 return (nfound ? 0 : ESRCH); 712 } 713 714 #define CANDELIVER(uid, euid, pr) \ 715 (euid == 0 || \ 716 (uid) == (pr)->ps_ucred->cr_ruid || \ 717 (uid) == (pr)->ps_ucred->cr_svuid || \ 718 (uid) == (pr)->ps_ucred->cr_uid || \ 719 (euid) == (pr)->ps_ucred->cr_ruid || \ 720 (euid) == (pr)->ps_ucred->cr_svuid || \ 721 (euid) == (pr)->ps_ucred->cr_uid) 722 723 #define CANSIGIO(cr, pr) \ 724 CANDELIVER((cr)->cr_ruid, (cr)->cr_uid, (pr)) 725 726 /* 727 * Send a signal to a process group. If checktty is 1, 728 * limit to members which have a controlling terminal. 729 */ 730 void 731 pgsignal(struct pgrp *pgrp, int signum, int checkctty) 732 { 733 struct process *pr; 734 735 if (pgrp) 736 LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) 737 if (checkctty == 0 || pr->ps_flags & PS_CONTROLT) 738 prsignal(pr, signum); 739 } 740 741 /* 742 * Send a SIGIO or SIGURG signal to a process or process group using stored 743 * credentials rather than those of the current process. 744 */ 745 void 746 pgsigio(struct sigio_ref *sir, int sig, int checkctty) 747 { 748 struct process *pr; 749 struct sigio *sigio; 750 751 if (sir->sir_sigio == NULL) 752 return; 753 754 KERNEL_LOCK(); 755 mtx_enter(&sigio_lock); 756 sigio = sir->sir_sigio; 757 if (sigio == NULL) 758 goto out; 759 if (sigio->sio_pgid > 0) { 760 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc)) 761 prsignal(sigio->sio_proc, sig); 762 } else if (sigio->sio_pgid < 0) { 763 LIST_FOREACH(pr, &sigio->sio_pgrp->pg_members, ps_pglist) { 764 if (CANSIGIO(sigio->sio_ucred, pr) && 765 (checkctty == 0 || (pr->ps_flags & PS_CONTROLT))) 766 prsignal(pr, sig); 767 } 768 } 769 out: 770 mtx_leave(&sigio_lock); 771 KERNEL_UNLOCK(); 772 } 773 774 /* 775 * Recalculate the signal mask and reset the signal disposition after 776 * usermode frame for delivery is formed. 777 */ 778 void 779 postsig_done(struct proc *p, int signum, struct sigacts *ps) 780 { 781 int mask = sigmask(signum); 782 783 KERNEL_ASSERT_LOCKED(); 784 785 p->p_ru.ru_nsignals++; 786 atomic_setbits_int(&p->p_sigmask, ps->ps_catchmask[signum]); 787 if ((ps->ps_sigreset & mask) != 0) { 788 ps->ps_sigcatch &= ~mask; 789 if (signum != SIGCONT && sigprop[signum] & SA_IGNORE) 790 ps->ps_sigignore |= mask; 791 ps->ps_sigact[signum] = SIG_DFL; 792 } 793 } 794 795 /* 796 * Send a signal caused by a trap to the current thread 797 * If it will be caught immediately, deliver it with correct code. 798 * Otherwise, post it normally. 799 */ 800 void 801 trapsignal(struct proc *p, int signum, u_long trapno, int code, 802 union sigval sigval) 803 { 804 struct process *pr = p->p_p; 805 struct sigacts *ps = pr->ps_sigacts; 806 int mask; 807 808 KERNEL_LOCK(); 809 switch (signum) { 810 case SIGILL: 811 case SIGBUS: 812 case SIGSEGV: 813 pr->ps_acflag |= ATRAP; 814 break; 815 } 816 817 mask = sigmask(signum); 818 if ((pr->ps_flags & PS_TRACED) == 0 && 819 (ps->ps_sigcatch & mask) != 0 && 820 (p->p_sigmask & mask) == 0) { 821 siginfo_t si; 822 initsiginfo(&si, signum, trapno, code, sigval); 823 #ifdef KTRACE 824 if (KTRPOINT(p, KTR_PSIG)) { 825 ktrpsig(p, signum, ps->ps_sigact[signum], 826 p->p_sigmask, code, &si); 827 } 828 #endif 829 if (sendsig(ps->ps_sigact[signum], signum, p->p_sigmask, &si)) { 830 sigexit(p, SIGILL); 831 /* NOTREACHED */ 832 } 833 postsig_done(p, signum, ps); 834 } else { 835 p->p_sisig = signum; 836 p->p_sitrapno = trapno; /* XXX for core dump/debugger */ 837 p->p_sicode = code; 838 p->p_sigval = sigval; 839 840 /* 841 * Signals like SIGBUS and SIGSEGV should not, when 842 * generated by the kernel, be ignorable or blockable. 843 * If it is and we're not being traced, then just kill 844 * the process. 845 */ 846 if ((pr->ps_flags & PS_TRACED) == 0 && 847 (sigprop[signum] & SA_KILL) && 848 ((p->p_sigmask & mask) || (ps->ps_sigignore & mask))) 849 sigexit(p, signum); 850 ptsignal(p, signum, STHREAD); 851 } 852 KERNEL_UNLOCK(); 853 } 854 855 /* 856 * Send the signal to the process. If the signal has an action, the action 857 * is usually performed by the target process rather than the caller; we add 858 * the signal to the set of pending signals for the process. 859 * 860 * Exceptions: 861 * o When a stop signal is sent to a sleeping process that takes the 862 * default action, the process is stopped without awakening it. 863 * o SIGCONT restarts stopped processes (or puts them back to sleep) 864 * regardless of the signal action (eg, blocked or ignored). 865 * 866 * Other ignored signals are discarded immediately. 867 */ 868 void 869 psignal(struct proc *p, int signum) 870 { 871 ptsignal(p, signum, SPROCESS); 872 } 873 874 /* 875 * type = SPROCESS process signal, can be diverted (sigwait()) 876 * type = STHREAD thread signal, but should be propagated if unhandled 877 * type = SPROPAGATED propagated to this thread, so don't propagate again 878 */ 879 void 880 ptsignal(struct proc *p, int signum, enum signal_type type) 881 { 882 int s, prop; 883 sig_t action; 884 int mask; 885 int *siglist; 886 struct process *pr = p->p_p; 887 struct proc *q; 888 int wakeparent = 0; 889 890 KERNEL_ASSERT_LOCKED(); 891 892 #ifdef DIAGNOSTIC 893 if ((u_int)signum >= NSIG || signum == 0) 894 panic("psignal signal number"); 895 #endif 896 897 /* Ignore signal if the target process is exiting */ 898 if (pr->ps_flags & PS_EXITING) 899 return; 900 901 mask = sigmask(signum); 902 903 if (type == SPROCESS) { 904 /* Accept SIGKILL to coredumping processes */ 905 if (pr->ps_flags & PS_COREDUMP && signum == SIGKILL) { 906 atomic_setbits_int(&pr->ps_siglist, mask); 907 return; 908 } 909 910 /* 911 * If the current thread can process the signal 912 * immediately (it's unblocked) then have it take it. 913 */ 914 q = curproc; 915 if (q != NULL && q->p_p == pr && (q->p_flag & P_WEXIT) == 0 && 916 (q->p_sigmask & mask) == 0) 917 p = q; 918 else { 919 /* 920 * A process-wide signal can be diverted to a 921 * different thread that's in sigwait() for this 922 * signal. If there isn't such a thread, then 923 * pick a thread that doesn't have it blocked so 924 * that the stop/kill consideration isn't 925 * delayed. Otherwise, mark it pending on the 926 * main thread. 927 */ 928 SMR_TAILQ_FOREACH_LOCKED(q, &pr->ps_threads, p_thr_link) { 929 /* ignore exiting threads */ 930 if (q->p_flag & P_WEXIT) 931 continue; 932 933 /* skip threads that have the signal blocked */ 934 if ((q->p_sigmask & mask) != 0) 935 continue; 936 937 /* okay, could send to this thread */ 938 p = q; 939 940 /* 941 * sigsuspend, sigwait, ppoll/pselect, etc? 942 * Definitely go to this thread, as it's 943 * already blocked in the kernel. 944 */ 945 if (q->p_flag & P_SIGSUSPEND) 946 break; 947 } 948 } 949 } 950 951 if (type != SPROPAGATED) 952 KNOTE(&pr->ps_klist, NOTE_SIGNAL | signum); 953 954 prop = sigprop[signum]; 955 956 /* 957 * If proc is traced, always give parent a chance. 958 */ 959 if (pr->ps_flags & PS_TRACED) { 960 action = SIG_DFL; 961 } else { 962 /* 963 * If the signal is being ignored, 964 * then we forget about it immediately. 965 * (Note: we don't set SIGCONT in ps_sigignore, 966 * and if it is set to SIG_IGN, 967 * action will be SIG_DFL here.) 968 */ 969 if (pr->ps_sigacts->ps_sigignore & mask) 970 return; 971 if (p->p_sigmask & mask) { 972 action = SIG_HOLD; 973 } else if (pr->ps_sigacts->ps_sigcatch & mask) { 974 action = SIG_CATCH; 975 } else { 976 action = SIG_DFL; 977 978 if (prop & SA_KILL && pr->ps_nice > NZERO) 979 pr->ps_nice = NZERO; 980 981 /* 982 * If sending a tty stop signal to a member of an 983 * orphaned process group, discard the signal here if 984 * the action is default; don't stop the process below 985 * if sleeping, and don't clear any pending SIGCONT. 986 */ 987 if (prop & SA_TTYSTOP && pr->ps_pgrp->pg_jobc == 0) 988 return; 989 } 990 } 991 /* 992 * If delivered to process, mark as pending there. Continue and stop 993 * signals will be propagated to all threads. So they are always 994 * marked at thread level. 995 */ 996 siglist = (type == SPROCESS) ? &pr->ps_siglist : &p->p_siglist; 997 if (prop & SA_CONT) { 998 siglist = &p->p_siglist; 999 atomic_clearbits_int(siglist, stopsigmask); 1000 } 1001 if (prop & SA_STOP) { 1002 siglist = &p->p_siglist; 1003 atomic_clearbits_int(siglist, contsigmask); 1004 atomic_clearbits_int(&p->p_flag, P_CONTINUED); 1005 } 1006 atomic_setbits_int(siglist, mask); 1007 1008 /* 1009 * XXX delay processing of SA_STOP signals unless action == SIG_DFL? 1010 */ 1011 if (prop & (SA_CONT | SA_STOP) && type != SPROPAGATED) 1012 SMR_TAILQ_FOREACH_LOCKED(q, &pr->ps_threads, p_thr_link) 1013 if (q != p) 1014 ptsignal(q, signum, SPROPAGATED); 1015 1016 /* 1017 * Defer further processing for signals which are held, 1018 * except that stopped processes must be continued by SIGCONT. 1019 */ 1020 if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) 1021 return; 1022 1023 SCHED_LOCK(s); 1024 1025 switch (p->p_stat) { 1026 1027 case SSLEEP: 1028 /* 1029 * If process is sleeping uninterruptibly 1030 * we can't interrupt the sleep... the signal will 1031 * be noticed when the process returns through 1032 * trap() or syscall(). 1033 */ 1034 if ((p->p_flag & P_SINTR) == 0) 1035 goto out; 1036 /* 1037 * Process is sleeping and traced... make it runnable 1038 * so it can discover the signal in issignal() and stop 1039 * for the parent. 1040 */ 1041 if (pr->ps_flags & PS_TRACED) 1042 goto run; 1043 /* 1044 * If SIGCONT is default (or ignored) and process is 1045 * asleep, we are finished; the process should not 1046 * be awakened. 1047 */ 1048 if ((prop & SA_CONT) && action == SIG_DFL) { 1049 atomic_clearbits_int(siglist, mask); 1050 goto out; 1051 } 1052 /* 1053 * When a sleeping process receives a stop 1054 * signal, process immediately if possible. 1055 */ 1056 if ((prop & SA_STOP) && action == SIG_DFL) { 1057 /* 1058 * If a child holding parent blocked, 1059 * stopping could cause deadlock. 1060 */ 1061 if (pr->ps_flags & PS_PPWAIT) 1062 goto out; 1063 atomic_clearbits_int(siglist, mask); 1064 pr->ps_xsig = signum; 1065 proc_stop(p, 0); 1066 goto out; 1067 } 1068 /* 1069 * All other (caught or default) signals 1070 * cause the process to run. 1071 */ 1072 goto runfast; 1073 /*NOTREACHED*/ 1074 1075 case SSTOP: 1076 /* 1077 * If traced process is already stopped, 1078 * then no further action is necessary. 1079 */ 1080 if (pr->ps_flags & PS_TRACED) 1081 goto out; 1082 1083 /* 1084 * Kill signal always sets processes running. 1085 */ 1086 if (signum == SIGKILL) { 1087 atomic_clearbits_int(&p->p_flag, P_SUSPSIG); 1088 goto runfast; 1089 } 1090 1091 if (prop & SA_CONT) { 1092 /* 1093 * If SIGCONT is default (or ignored), we continue the 1094 * process but don't leave the signal in p_siglist, as 1095 * it has no further action. If SIGCONT is held, we 1096 * continue the process and leave the signal in 1097 * p_siglist. If the process catches SIGCONT, let it 1098 * handle the signal itself. If it isn't waiting on 1099 * an event, then it goes back to run state. 1100 * Otherwise, process goes back to sleep state. 1101 */ 1102 atomic_setbits_int(&p->p_flag, P_CONTINUED); 1103 atomic_clearbits_int(&p->p_flag, P_SUSPSIG); 1104 wakeparent = 1; 1105 if (action == SIG_DFL) 1106 atomic_clearbits_int(siglist, mask); 1107 if (action == SIG_CATCH) 1108 goto runfast; 1109 if (p->p_wchan == 0) 1110 goto run; 1111 p->p_stat = SSLEEP; 1112 goto out; 1113 } 1114 1115 if (prop & SA_STOP) { 1116 /* 1117 * Already stopped, don't need to stop again. 1118 * (If we did the shell could get confused.) 1119 */ 1120 atomic_clearbits_int(siglist, mask); 1121 goto out; 1122 } 1123 1124 /* 1125 * If process is sleeping interruptibly, then simulate a 1126 * wakeup so that when it is continued, it will be made 1127 * runnable and can look at the signal. But don't make 1128 * the process runnable, leave it stopped. 1129 */ 1130 if (p->p_flag & P_SINTR) 1131 unsleep(p); 1132 goto out; 1133 1134 case SONPROC: 1135 signotify(p); 1136 /* FALLTHROUGH */ 1137 default: 1138 /* 1139 * SRUN, SIDL, SDEAD do nothing with the signal, 1140 * other than kicking ourselves if we are running. 1141 * It will either never be noticed, or noticed very soon. 1142 */ 1143 goto out; 1144 } 1145 /*NOTREACHED*/ 1146 1147 runfast: 1148 /* 1149 * Raise priority to at least PUSER. 1150 */ 1151 if (p->p_usrpri > PUSER) 1152 p->p_usrpri = PUSER; 1153 run: 1154 setrunnable(p); 1155 out: 1156 SCHED_UNLOCK(s); 1157 if (wakeparent) 1158 wakeup(pr->ps_pptr); 1159 } 1160 1161 /* 1162 * If the current process has received a signal (should be caught or cause 1163 * termination, should interrupt current syscall), return the signal number. 1164 * Stop signals with default action are processed immediately, then cleared; 1165 * they aren't returned. This is checked after each entry to the system for 1166 * a syscall or trap (though this can usually be done without calling issignal 1167 * by checking the pending signal masks in the CURSIG macro.) The normal call 1168 * sequence is 1169 * 1170 * while (signum = CURSIG(curproc)) 1171 * postsig(signum); 1172 * 1173 * Assumes that if the P_SINTR flag is set, we're holding both the 1174 * kernel and scheduler locks. 1175 */ 1176 int 1177 issignal(struct proc *p) 1178 { 1179 struct process *pr = p->p_p; 1180 int signum, mask, prop; 1181 int dolock = (p->p_flag & P_SINTR) == 0; 1182 int s; 1183 1184 for (;;) { 1185 mask = SIGPENDING(p); 1186 if (pr->ps_flags & PS_PPWAIT) 1187 mask &= ~stopsigmask; 1188 if (mask == 0) /* no signal to send */ 1189 return (0); 1190 signum = ffs((long)mask); 1191 mask = sigmask(signum); 1192 atomic_clearbits_int(&p->p_siglist, mask); 1193 atomic_clearbits_int(&pr->ps_siglist, mask); 1194 1195 /* 1196 * We should see pending but ignored signals 1197 * only if PS_TRACED was on when they were posted. 1198 */ 1199 if (mask & pr->ps_sigacts->ps_sigignore && 1200 (pr->ps_flags & PS_TRACED) == 0) 1201 continue; 1202 1203 /* 1204 * If traced, always stop, and stay stopped until released 1205 * by the debugger. If our parent process is waiting for 1206 * us, don't hang as we could deadlock. 1207 */ 1208 if (((pr->ps_flags & (PS_TRACED | PS_PPWAIT)) == PS_TRACED) && 1209 signum != SIGKILL) { 1210 pr->ps_xsig = signum; 1211 1212 if (dolock) 1213 KERNEL_LOCK(); 1214 single_thread_set(p, SINGLE_PTRACE, 0); 1215 if (dolock) 1216 KERNEL_UNLOCK(); 1217 1218 if (dolock) 1219 SCHED_LOCK(s); 1220 proc_stop(p, 1); 1221 if (dolock) 1222 SCHED_UNLOCK(s); 1223 1224 if (dolock) 1225 KERNEL_LOCK(); 1226 single_thread_clear(p, 0); 1227 if (dolock) 1228 KERNEL_UNLOCK(); 1229 1230 /* 1231 * If we are no longer being traced, or the parent 1232 * didn't give us a signal, look for more signals. 1233 */ 1234 if ((pr->ps_flags & PS_TRACED) == 0 || 1235 pr->ps_xsig == 0) 1236 continue; 1237 1238 /* 1239 * If the new signal is being masked, look for other 1240 * signals. 1241 */ 1242 signum = pr->ps_xsig; 1243 mask = sigmask(signum); 1244 if ((p->p_sigmask & mask) != 0) 1245 continue; 1246 1247 /* take the signal! */ 1248 atomic_clearbits_int(&p->p_siglist, mask); 1249 atomic_clearbits_int(&pr->ps_siglist, mask); 1250 } 1251 1252 prop = sigprop[signum]; 1253 1254 /* 1255 * Decide whether the signal should be returned. 1256 * Return the signal's number, or fall through 1257 * to clear it from the pending mask. 1258 */ 1259 switch ((long)pr->ps_sigacts->ps_sigact[signum]) { 1260 case (long)SIG_DFL: 1261 /* 1262 * Don't take default actions on system processes. 1263 */ 1264 if (pr->ps_pid <= 1) { 1265 #ifdef DIAGNOSTIC 1266 /* 1267 * Are you sure you want to ignore SIGSEGV 1268 * in init? XXX 1269 */ 1270 printf("Process (pid %d) got signal" 1271 " %d\n", pr->ps_pid, signum); 1272 #endif 1273 break; /* == ignore */ 1274 } 1275 /* 1276 * If there is a pending stop signal to process 1277 * with default action, stop here, 1278 * then clear the signal. However, 1279 * if process is member of an orphaned 1280 * process group, ignore tty stop signals. 1281 */ 1282 if (prop & SA_STOP) { 1283 if (pr->ps_flags & PS_TRACED || 1284 (pr->ps_pgrp->pg_jobc == 0 && 1285 prop & SA_TTYSTOP)) 1286 break; /* == ignore */ 1287 pr->ps_xsig = signum; 1288 if (dolock) 1289 SCHED_LOCK(s); 1290 proc_stop(p, 1); 1291 if (dolock) 1292 SCHED_UNLOCK(s); 1293 break; 1294 } else if (prop & SA_IGNORE) { 1295 /* 1296 * Except for SIGCONT, shouldn't get here. 1297 * Default action is to ignore; drop it. 1298 */ 1299 break; /* == ignore */ 1300 } else 1301 goto keep; 1302 /*NOTREACHED*/ 1303 case (long)SIG_IGN: 1304 /* 1305 * Masking above should prevent us ever trying 1306 * to take action on an ignored signal other 1307 * than SIGCONT, unless process is traced. 1308 */ 1309 if ((prop & SA_CONT) == 0 && 1310 (pr->ps_flags & PS_TRACED) == 0) 1311 printf("issignal\n"); 1312 break; /* == ignore */ 1313 default: 1314 /* 1315 * This signal has an action, let 1316 * postsig() process it. 1317 */ 1318 goto keep; 1319 } 1320 } 1321 /* NOTREACHED */ 1322 1323 keep: 1324 atomic_setbits_int(&p->p_siglist, mask); /*leave the signal for later */ 1325 return (signum); 1326 } 1327 1328 /* 1329 * Put the argument process into the stopped state and notify the parent 1330 * via wakeup. Signals are handled elsewhere. The process must not be 1331 * on the run queue. 1332 */ 1333 void 1334 proc_stop(struct proc *p, int sw) 1335 { 1336 struct process *pr = p->p_p; 1337 1338 #ifdef MULTIPROCESSOR 1339 SCHED_ASSERT_LOCKED(); 1340 #endif 1341 1342 p->p_stat = SSTOP; 1343 atomic_clearbits_int(&pr->ps_flags, PS_WAITED); 1344 atomic_setbits_int(&pr->ps_flags, PS_STOPPED); 1345 atomic_setbits_int(&p->p_flag, P_SUSPSIG); 1346 /* 1347 * We need this soft interrupt to be handled fast. 1348 * Extra calls to softclock don't hurt. 1349 */ 1350 softintr_schedule(proc_stop_si); 1351 if (sw) 1352 mi_switch(); 1353 } 1354 1355 /* 1356 * Called from a soft interrupt to send signals to the parents of stopped 1357 * processes. 1358 * We can't do this in proc_stop because it's called with nasty locks held 1359 * and we would need recursive scheduler lock to deal with that. 1360 */ 1361 void 1362 proc_stop_sweep(void *v) 1363 { 1364 struct process *pr; 1365 1366 LIST_FOREACH(pr, &allprocess, ps_list) { 1367 if ((pr->ps_flags & PS_STOPPED) == 0) 1368 continue; 1369 atomic_clearbits_int(&pr->ps_flags, PS_STOPPED); 1370 1371 if ((pr->ps_pptr->ps_sigacts->ps_sigflags & SAS_NOCLDSTOP) == 0) 1372 prsignal(pr->ps_pptr, SIGCHLD); 1373 wakeup(pr->ps_pptr); 1374 } 1375 } 1376 1377 /* 1378 * Take the action for the specified signal 1379 * from the current set of pending signals. 1380 */ 1381 void 1382 postsig(struct proc *p, int signum) 1383 { 1384 struct process *pr = p->p_p; 1385 struct sigacts *ps = pr->ps_sigacts; 1386 sig_t action; 1387 u_long trapno; 1388 int mask, returnmask; 1389 siginfo_t si; 1390 union sigval sigval; 1391 int s, code; 1392 1393 KASSERT(signum != 0); 1394 KERNEL_ASSERT_LOCKED(); 1395 1396 mask = sigmask(signum); 1397 atomic_clearbits_int(&p->p_siglist, mask); 1398 action = ps->ps_sigact[signum]; 1399 sigval.sival_ptr = 0; 1400 1401 if (p->p_sisig != signum) { 1402 trapno = 0; 1403 code = SI_USER; 1404 sigval.sival_ptr = 0; 1405 } else { 1406 trapno = p->p_sitrapno; 1407 code = p->p_sicode; 1408 sigval = p->p_sigval; 1409 } 1410 initsiginfo(&si, signum, trapno, code, sigval); 1411 1412 #ifdef KTRACE 1413 if (KTRPOINT(p, KTR_PSIG)) { 1414 ktrpsig(p, signum, action, p->p_flag & P_SIGSUSPEND ? 1415 p->p_oldmask : p->p_sigmask, code, &si); 1416 } 1417 #endif 1418 if (action == SIG_DFL) { 1419 /* 1420 * Default action, where the default is to kill 1421 * the process. (Other cases were ignored above.) 1422 */ 1423 sigexit(p, signum); 1424 /* NOTREACHED */ 1425 } else { 1426 /* 1427 * If we get here, the signal must be caught. 1428 */ 1429 #ifdef DIAGNOSTIC 1430 if (action == SIG_IGN || (p->p_sigmask & mask)) 1431 panic("postsig action"); 1432 #endif 1433 /* 1434 * Set the new mask value and also defer further 1435 * occurrences of this signal. 1436 * 1437 * Special case: user has done a sigpause. Here the 1438 * current mask is not of interest, but rather the 1439 * mask from before the sigpause is what we want 1440 * restored after the signal processing is completed. 1441 */ 1442 #ifdef MULTIPROCESSOR 1443 s = splsched(); 1444 #else 1445 s = splhigh(); 1446 #endif 1447 if (p->p_flag & P_SIGSUSPEND) { 1448 atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); 1449 returnmask = p->p_oldmask; 1450 } else { 1451 returnmask = p->p_sigmask; 1452 } 1453 if (p->p_sisig == signum) { 1454 p->p_sisig = 0; 1455 p->p_sitrapno = 0; 1456 p->p_sicode = SI_USER; 1457 p->p_sigval.sival_ptr = NULL; 1458 } 1459 1460 if (sendsig(action, signum, returnmask, &si)) { 1461 sigexit(p, SIGILL); 1462 /* NOTREACHED */ 1463 } 1464 postsig_done(p, signum, ps); 1465 splx(s); 1466 } 1467 } 1468 1469 /* 1470 * Force the current process to exit with the specified signal, dumping core 1471 * if appropriate. We bypass the normal tests for masked and caught signals, 1472 * allowing unrecoverable failures to terminate the process without changing 1473 * signal state. Mark the accounting record with the signal termination. 1474 * If dumping core, save the signal number for the debugger. Calls exit and 1475 * does not return. 1476 */ 1477 void 1478 sigexit(struct proc *p, int signum) 1479 { 1480 /* Mark process as going away */ 1481 atomic_setbits_int(&p->p_flag, P_WEXIT); 1482 1483 p->p_p->ps_acflag |= AXSIG; 1484 if (sigprop[signum] & SA_CORE) { 1485 p->p_sisig = signum; 1486 1487 /* if there are other threads, pause them */ 1488 if (P_HASSIBLING(p)) 1489 single_thread_set(p, SINGLE_SUSPEND, 0); 1490 1491 if (coredump(p) == 0) 1492 signum |= WCOREFLAG; 1493 } 1494 exit1(p, 0, signum, EXIT_NORMAL); 1495 /* NOTREACHED */ 1496 } 1497 1498 /* 1499 * Send uncatchable SIGABRT for coredump. 1500 */ 1501 void 1502 sigabort(struct proc *p) 1503 { 1504 struct sigaction sa; 1505 1506 memset(&sa, 0, sizeof sa); 1507 sa.sa_handler = SIG_DFL; 1508 setsigvec(p, SIGABRT, &sa); 1509 atomic_clearbits_int(&p->p_sigmask, sigmask(SIGABRT)); 1510 psignal(p, SIGABRT); 1511 } 1512 1513 /* 1514 * Return 1 if `sig', a given signal, is ignored or masked for `p', a given 1515 * thread, and 0 otherwise. 1516 */ 1517 int 1518 sigismasked(struct proc *p, int sig) 1519 { 1520 struct process *pr = p->p_p; 1521 1522 if ((pr->ps_sigacts->ps_sigignore & sigmask(sig)) || 1523 (p->p_sigmask & sigmask(sig))) 1524 return 1; 1525 1526 return 0; 1527 } 1528 1529 int nosuidcoredump = 1; 1530 1531 struct coredump_iostate { 1532 struct proc *io_proc; 1533 struct vnode *io_vp; 1534 struct ucred *io_cred; 1535 off_t io_offset; 1536 }; 1537 1538 /* 1539 * Dump core, into a file named "progname.core", unless the process was 1540 * setuid/setgid. 1541 */ 1542 int 1543 coredump(struct proc *p) 1544 { 1545 #ifdef SMALL_KERNEL 1546 return EPERM; 1547 #else 1548 struct process *pr = p->p_p; 1549 struct vnode *vp; 1550 struct ucred *cred = p->p_ucred; 1551 struct vmspace *vm = p->p_vmspace; 1552 struct nameidata nd; 1553 struct vattr vattr; 1554 struct coredump_iostate io; 1555 int error, len, incrash = 0; 1556 char *name; 1557 const char *dir = "/var/crash"; 1558 1559 if (pr->ps_emul->e_coredump == NULL) 1560 return (EINVAL); 1561 1562 atomic_setbits_int(&pr->ps_flags, PS_COREDUMP); 1563 1564 /* Don't dump if will exceed file size limit. */ 1565 if (USPACE + ptoa(vm->vm_dsize + vm->vm_ssize) >= lim_cur(RLIMIT_CORE)) 1566 return (EFBIG); 1567 1568 name = pool_get(&namei_pool, PR_WAITOK); 1569 1570 /* 1571 * If the process has inconsistent uids, nosuidcoredump 1572 * determines coredump placement policy. 1573 */ 1574 if (((pr->ps_flags & PS_SUGID) && (error = suser(p))) || 1575 ((pr->ps_flags & PS_SUGID) && nosuidcoredump)) { 1576 if (nosuidcoredump == 3) { 1577 /* 1578 * If the program directory does not exist, dumps of 1579 * that core will silently fail. 1580 */ 1581 len = snprintf(name, MAXPATHLEN, "%s/%s/%u.core", 1582 dir, pr->ps_comm, pr->ps_pid); 1583 incrash = KERNELPATH; 1584 } else if (nosuidcoredump == 2) { 1585 len = snprintf(name, MAXPATHLEN, "%s/%s.core", 1586 dir, pr->ps_comm); 1587 incrash = KERNELPATH; 1588 } else { 1589 pool_put(&namei_pool, name); 1590 return (EPERM); 1591 } 1592 } else 1593 len = snprintf(name, MAXPATHLEN, "%s.core", pr->ps_comm); 1594 1595 if (len >= MAXPATHLEN) { 1596 pool_put(&namei_pool, name); 1597 return (EACCES); 1598 } 1599 1600 /* 1601 * Control the UID used to write out. The normal case uses 1602 * the real UID. If the sugid case is going to write into the 1603 * controlled directory, we do so as root. 1604 */ 1605 if (incrash == 0) { 1606 cred = crdup(cred); 1607 cred->cr_uid = cred->cr_ruid; 1608 cred->cr_gid = cred->cr_rgid; 1609 } else { 1610 if (p->p_fd->fd_rdir) { 1611 vrele(p->p_fd->fd_rdir); 1612 p->p_fd->fd_rdir = NULL; 1613 } 1614 p->p_ucred = crdup(p->p_ucred); 1615 crfree(cred); 1616 cred = p->p_ucred; 1617 crhold(cred); 1618 cred->cr_uid = 0; 1619 cred->cr_gid = 0; 1620 } 1621 1622 /* incrash should be 0 or KERNELPATH only */ 1623 NDINIT(&nd, 0, incrash, UIO_SYSSPACE, name, p); 1624 1625 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW | O_NONBLOCK, 1626 S_IRUSR | S_IWUSR); 1627 1628 if (error) 1629 goto out; 1630 1631 /* 1632 * Don't dump to non-regular files, files with links, or files 1633 * owned by someone else. 1634 */ 1635 vp = nd.ni_vp; 1636 if ((error = VOP_GETATTR(vp, &vattr, cred, p)) != 0) { 1637 VOP_UNLOCK(vp); 1638 vn_close(vp, FWRITE, cred, p); 1639 goto out; 1640 } 1641 if (vp->v_type != VREG || vattr.va_nlink != 1 || 1642 vattr.va_mode & ((VREAD | VWRITE) >> 3 | (VREAD | VWRITE) >> 6) || 1643 vattr.va_uid != cred->cr_uid) { 1644 error = EACCES; 1645 VOP_UNLOCK(vp); 1646 vn_close(vp, FWRITE, cred, p); 1647 goto out; 1648 } 1649 VATTR_NULL(&vattr); 1650 vattr.va_size = 0; 1651 VOP_SETATTR(vp, &vattr, cred, p); 1652 pr->ps_acflag |= ACORE; 1653 1654 io.io_proc = p; 1655 io.io_vp = vp; 1656 io.io_cred = cred; 1657 io.io_offset = 0; 1658 VOP_UNLOCK(vp); 1659 vref(vp); 1660 error = vn_close(vp, FWRITE, cred, p); 1661 if (error == 0) 1662 error = (*pr->ps_emul->e_coredump)(p, &io); 1663 vrele(vp); 1664 out: 1665 crfree(cred); 1666 pool_put(&namei_pool, name); 1667 return (error); 1668 #endif 1669 } 1670 1671 #ifndef SMALL_KERNEL 1672 int 1673 coredump_write(void *cookie, enum uio_seg segflg, const void *data, size_t len) 1674 { 1675 struct coredump_iostate *io = cookie; 1676 off_t coffset = 0; 1677 size_t csize; 1678 int chunk, error; 1679 1680 csize = len; 1681 do { 1682 if (sigmask(SIGKILL) & 1683 (io->io_proc->p_siglist | io->io_proc->p_p->ps_siglist)) 1684 return (EINTR); 1685 1686 /* Rest of the loop sleeps with lock held, so... */ 1687 yield(); 1688 1689 chunk = MIN(csize, MAXPHYS); 1690 error = vn_rdwr(UIO_WRITE, io->io_vp, 1691 (caddr_t)data + coffset, chunk, 1692 io->io_offset + coffset, segflg, 1693 IO_UNIT, io->io_cred, NULL, io->io_proc); 1694 if (error) { 1695 struct process *pr = io->io_proc->p_p; 1696 1697 if (error == ENOSPC) 1698 log(LOG_ERR, 1699 "coredump of %s(%d) failed, filesystem full\n", 1700 pr->ps_comm, pr->ps_pid); 1701 else 1702 log(LOG_ERR, 1703 "coredump of %s(%d), write failed: errno %d\n", 1704 pr->ps_comm, pr->ps_pid, error); 1705 return (error); 1706 } 1707 1708 coffset += chunk; 1709 csize -= chunk; 1710 } while (csize > 0); 1711 1712 io->io_offset += len; 1713 return (0); 1714 } 1715 1716 void 1717 coredump_unmap(void *cookie, vaddr_t start, vaddr_t end) 1718 { 1719 struct coredump_iostate *io = cookie; 1720 1721 uvm_unmap(&io->io_proc->p_vmspace->vm_map, start, end); 1722 } 1723 1724 #endif /* !SMALL_KERNEL */ 1725 1726 /* 1727 * Nonexistent system call-- signal process (may want to handle it). 1728 * Flag error in case process won't see signal immediately (blocked or ignored). 1729 */ 1730 int 1731 sys_nosys(struct proc *p, void *v, register_t *retval) 1732 { 1733 1734 ptsignal(p, SIGSYS, STHREAD); 1735 return (ENOSYS); 1736 } 1737 1738 int 1739 sys___thrsigdivert(struct proc *p, void *v, register_t *retval) 1740 { 1741 static int sigwaitsleep; 1742 struct sys___thrsigdivert_args /* { 1743 syscallarg(sigset_t) sigmask; 1744 syscallarg(siginfo_t *) info; 1745 syscallarg(const struct timespec *) timeout; 1746 } */ *uap = v; 1747 struct process *pr = p->p_p; 1748 sigset_t *m; 1749 sigset_t mask = SCARG(uap, sigmask) &~ sigcantmask; 1750 siginfo_t si; 1751 uint64_t nsecs = INFSLP; 1752 int timeinvalid = 0; 1753 int error = 0; 1754 1755 memset(&si, 0, sizeof(si)); 1756 1757 if (SCARG(uap, timeout) != NULL) { 1758 struct timespec ts; 1759 if ((error = copyin(SCARG(uap, timeout), &ts, sizeof(ts))) != 0) 1760 return (error); 1761 #ifdef KTRACE 1762 if (KTRPOINT(p, KTR_STRUCT)) 1763 ktrreltimespec(p, &ts); 1764 #endif 1765 if (!timespecisvalid(&ts)) 1766 timeinvalid = 1; 1767 else 1768 nsecs = TIMESPEC_TO_NSEC(&ts); 1769 } 1770 1771 dosigsuspend(p, p->p_sigmask &~ mask); 1772 for (;;) { 1773 si.si_signo = CURSIG(p); 1774 if (si.si_signo != 0) { 1775 sigset_t smask = sigmask(si.si_signo); 1776 if (smask & mask) { 1777 if (p->p_siglist & smask) 1778 m = &p->p_siglist; 1779 else if (pr->ps_siglist & smask) 1780 m = &pr->ps_siglist; 1781 else { 1782 /* signal got eaten by someone else? */ 1783 continue; 1784 } 1785 atomic_clearbits_int(m, smask); 1786 error = 0; 1787 break; 1788 } 1789 } 1790 1791 /* per-POSIX, delay this error until after the above */ 1792 if (timeinvalid) 1793 error = EINVAL; 1794 1795 if (SCARG(uap, timeout) != NULL && nsecs == INFSLP) 1796 error = EAGAIN; 1797 1798 if (error != 0) 1799 break; 1800 1801 error = tsleep_nsec(&sigwaitsleep, PPAUSE|PCATCH, "sigwait", 1802 nsecs); 1803 } 1804 1805 if (error == 0) { 1806 *retval = si.si_signo; 1807 if (SCARG(uap, info) != NULL) 1808 error = copyout(&si, SCARG(uap, info), sizeof(si)); 1809 } else if (error == ERESTART && SCARG(uap, timeout) != NULL) { 1810 /* 1811 * Restarting is wrong if there's a timeout, as it'll be 1812 * for the same interval again 1813 */ 1814 error = EINTR; 1815 } 1816 1817 return (error); 1818 } 1819 1820 void 1821 initsiginfo(siginfo_t *si, int sig, u_long trapno, int code, union sigval val) 1822 { 1823 memset(si, 0, sizeof(*si)); 1824 1825 si->si_signo = sig; 1826 si->si_code = code; 1827 if (code == SI_USER) { 1828 si->si_value = val; 1829 } else { 1830 switch (sig) { 1831 case SIGSEGV: 1832 case SIGILL: 1833 case SIGBUS: 1834 case SIGFPE: 1835 si->si_addr = val.sival_ptr; 1836 si->si_trapno = trapno; 1837 break; 1838 case SIGXFSZ: 1839 break; 1840 } 1841 } 1842 } 1843 1844 int 1845 filt_sigattach(struct knote *kn) 1846 { 1847 struct process *pr = curproc->p_p; 1848 int s; 1849 1850 if (kn->kn_id >= NSIG) 1851 return EINVAL; 1852 1853 kn->kn_ptr.p_process = pr; 1854 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1855 1856 s = splhigh(); 1857 klist_insert_locked(&pr->ps_klist, kn); 1858 splx(s); 1859 1860 return (0); 1861 } 1862 1863 void 1864 filt_sigdetach(struct knote *kn) 1865 { 1866 struct process *pr = kn->kn_ptr.p_process; 1867 int s; 1868 1869 s = splhigh(); 1870 klist_remove_locked(&pr->ps_klist, kn); 1871 splx(s); 1872 } 1873 1874 /* 1875 * signal knotes are shared with proc knotes, so we apply a mask to 1876 * the hint in order to differentiate them from process hints. This 1877 * could be avoided by using a signal-specific knote list, but probably 1878 * isn't worth the trouble. 1879 */ 1880 int 1881 filt_signal(struct knote *kn, long hint) 1882 { 1883 1884 if (hint & NOTE_SIGNAL) { 1885 hint &= ~NOTE_SIGNAL; 1886 1887 if (kn->kn_id == hint) 1888 kn->kn_data++; 1889 } 1890 return (kn->kn_data != 0); 1891 } 1892 1893 void 1894 userret(struct proc *p) 1895 { 1896 int signum; 1897 1898 /* send SIGPROF or SIGVTALRM if their timers interrupted this thread */ 1899 if (p->p_flag & P_PROFPEND) { 1900 atomic_clearbits_int(&p->p_flag, P_PROFPEND); 1901 KERNEL_LOCK(); 1902 psignal(p, SIGPROF); 1903 KERNEL_UNLOCK(); 1904 } 1905 if (p->p_flag & P_ALRMPEND) { 1906 atomic_clearbits_int(&p->p_flag, P_ALRMPEND); 1907 KERNEL_LOCK(); 1908 psignal(p, SIGVTALRM); 1909 KERNEL_UNLOCK(); 1910 } 1911 1912 if (SIGPENDING(p) != 0) { 1913 KERNEL_LOCK(); 1914 while ((signum = CURSIG(p)) != 0) 1915 postsig(p, signum); 1916 KERNEL_UNLOCK(); 1917 } 1918 1919 /* 1920 * If P_SIGSUSPEND is still set here, then we still need to restore 1921 * the original sigmask before returning to userspace. Also, this 1922 * might unmask some pending signals, so we need to check a second 1923 * time for signals to post. 1924 */ 1925 if (p->p_flag & P_SIGSUSPEND) { 1926 atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); 1927 p->p_sigmask = p->p_oldmask; 1928 1929 KERNEL_LOCK(); 1930 while ((signum = CURSIG(p)) != 0) 1931 postsig(p, signum); 1932 KERNEL_UNLOCK(); 1933 } 1934 1935 if (p->p_flag & P_SUSPSINGLE) 1936 single_thread_check(p, 0); 1937 1938 WITNESS_WARN(WARN_PANIC, NULL, "userret: returning"); 1939 1940 p->p_cpu->ci_schedstate.spc_curpriority = p->p_usrpri; 1941 } 1942 1943 int 1944 single_thread_check_locked(struct proc *p, int deep, int s) 1945 { 1946 struct process *pr = p->p_p; 1947 1948 SCHED_ASSERT_LOCKED(); 1949 1950 if (pr->ps_single != NULL && pr->ps_single != p) { 1951 do { 1952 /* if we're in deep, we need to unwind to the edge */ 1953 if (deep) { 1954 if (pr->ps_flags & PS_SINGLEUNWIND) 1955 return (ERESTART); 1956 if (pr->ps_flags & PS_SINGLEEXIT) 1957 return (EINTR); 1958 } 1959 1960 if (pr->ps_single == NULL) 1961 continue; 1962 1963 if (atomic_dec_int_nv(&pr->ps_singlecount) == 0) 1964 wakeup(&pr->ps_singlecount); 1965 1966 if (pr->ps_flags & PS_SINGLEEXIT) { 1967 SCHED_UNLOCK(s); 1968 KERNEL_LOCK(); 1969 exit1(p, 0, 0, EXIT_THREAD_NOCHECK); 1970 /* NOTREACHED */ 1971 } 1972 1973 /* not exiting and don't need to unwind, so suspend */ 1974 p->p_stat = SSTOP; 1975 mi_switch(); 1976 } while (pr->ps_single != NULL); 1977 } 1978 1979 return (0); 1980 } 1981 1982 int 1983 single_thread_check(struct proc *p, int deep) 1984 { 1985 int s, error; 1986 1987 SCHED_LOCK(s); 1988 error = single_thread_check_locked(p, deep, s); 1989 SCHED_UNLOCK(s); 1990 1991 return error; 1992 } 1993 1994 /* 1995 * Stop other threads in the process. The mode controls how and 1996 * where the other threads should stop: 1997 * - SINGLE_SUSPEND: stop wherever they are, will later either be told to exit 1998 * (by setting to SINGLE_EXIT) or be released (via single_thread_clear()) 1999 * - SINGLE_PTRACE: stop wherever they are, will wait for them to stop 2000 * later (via single_thread_wait()) and released as with SINGLE_SUSPEND 2001 * - SINGLE_UNWIND: just unwind to kernel boundary, will be told to exit 2002 * or released as with SINGLE_SUSPEND 2003 * - SINGLE_EXIT: unwind to kernel boundary and exit 2004 */ 2005 int 2006 single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) 2007 { 2008 struct process *pr = p->p_p; 2009 struct proc *q; 2010 int error, s; 2011 2012 KERNEL_ASSERT_LOCKED(); 2013 KASSERT(curproc == p); 2014 2015 SCHED_LOCK(s); 2016 error = single_thread_check_locked(p, deep, s); 2017 if (error) { 2018 SCHED_UNLOCK(s); 2019 return error; 2020 } 2021 2022 switch (mode) { 2023 case SINGLE_SUSPEND: 2024 case SINGLE_PTRACE: 2025 break; 2026 case SINGLE_UNWIND: 2027 atomic_setbits_int(&pr->ps_flags, PS_SINGLEUNWIND); 2028 break; 2029 case SINGLE_EXIT: 2030 atomic_setbits_int(&pr->ps_flags, PS_SINGLEEXIT); 2031 atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND); 2032 break; 2033 #ifdef DIAGNOSTIC 2034 default: 2035 panic("single_thread_mode = %d", mode); 2036 #endif 2037 } 2038 pr->ps_singlecount = 0; 2039 membar_producer(); 2040 pr->ps_single = p; 2041 SMR_TAILQ_FOREACH_LOCKED(q, &pr->ps_threads, p_thr_link) { 2042 if (q == p) 2043 continue; 2044 if (q->p_flag & P_WEXIT) { 2045 if (mode == SINGLE_EXIT) { 2046 if (q->p_stat == SSTOP) { 2047 setrunnable(q); 2048 atomic_inc_int(&pr->ps_singlecount); 2049 } 2050 } 2051 continue; 2052 } 2053 atomic_setbits_int(&q->p_flag, P_SUSPSINGLE); 2054 switch (q->p_stat) { 2055 case SIDL: 2056 case SRUN: 2057 atomic_inc_int(&pr->ps_singlecount); 2058 break; 2059 case SSLEEP: 2060 /* if it's not interruptible, then just have to wait */ 2061 if (q->p_flag & P_SINTR) { 2062 /* merely need to suspend? just stop it */ 2063 if (mode == SINGLE_SUSPEND || 2064 mode == SINGLE_PTRACE) { 2065 q->p_stat = SSTOP; 2066 break; 2067 } 2068 /* need to unwind or exit, so wake it */ 2069 setrunnable(q); 2070 } 2071 atomic_inc_int(&pr->ps_singlecount); 2072 break; 2073 case SSTOP: 2074 if (mode == SINGLE_EXIT) { 2075 setrunnable(q); 2076 atomic_inc_int(&pr->ps_singlecount); 2077 } 2078 break; 2079 case SDEAD: 2080 break; 2081 case SONPROC: 2082 atomic_inc_int(&pr->ps_singlecount); 2083 signotify(q); 2084 break; 2085 } 2086 } 2087 SCHED_UNLOCK(s); 2088 2089 if (mode != SINGLE_PTRACE) 2090 single_thread_wait(pr, 1); 2091 2092 return 0; 2093 } 2094 2095 /* 2096 * Wait for other threads to stop. If recheck is false then the function 2097 * returns non-zero if the caller needs to restart the check else 0 is 2098 * returned. If recheck is true the return value is always 0. 2099 */ 2100 int 2101 single_thread_wait(struct process *pr, int recheck) 2102 { 2103 struct sleep_state sls; 2104 int wait; 2105 2106 /* wait until they're all suspended */ 2107 wait = pr->ps_singlecount > 0; 2108 while (wait) { 2109 sleep_setup(&sls, &pr->ps_singlecount, PWAIT, "suspend"); 2110 wait = pr->ps_singlecount > 0; 2111 sleep_finish(&sls, wait); 2112 if (!recheck) 2113 break; 2114 } 2115 2116 return wait; 2117 } 2118 2119 void 2120 single_thread_clear(struct proc *p, int flag) 2121 { 2122 struct process *pr = p->p_p; 2123 struct proc *q; 2124 int s; 2125 2126 KASSERT(pr->ps_single == p); 2127 KASSERT(curproc == p); 2128 KERNEL_ASSERT_LOCKED(); 2129 2130 SCHED_LOCK(s); 2131 pr->ps_single = NULL; 2132 atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND | PS_SINGLEEXIT); 2133 SMR_TAILQ_FOREACH_LOCKED(q, &pr->ps_threads, p_thr_link) { 2134 if (q == p || (q->p_flag & P_SUSPSINGLE) == 0) 2135 continue; 2136 atomic_clearbits_int(&q->p_flag, P_SUSPSINGLE); 2137 2138 /* 2139 * if the thread was only stopped for single threading 2140 * then clearing that either makes it runnable or puts 2141 * it back into some sleep queue 2142 */ 2143 if (q->p_stat == SSTOP && (q->p_flag & flag) == 0) { 2144 if (q->p_wchan == 0) 2145 setrunnable(q); 2146 else 2147 q->p_stat = SSLEEP; 2148 } 2149 } 2150 SCHED_UNLOCK(s); 2151 } 2152 2153 void 2154 sigio_del(struct sigiolst *rmlist) 2155 { 2156 struct sigio *sigio; 2157 2158 while ((sigio = LIST_FIRST(rmlist)) != NULL) { 2159 LIST_REMOVE(sigio, sio_pgsigio); 2160 crfree(sigio->sio_ucred); 2161 free(sigio, M_SIGIO, sizeof(*sigio)); 2162 } 2163 } 2164 2165 void 2166 sigio_unlink(struct sigio_ref *sir, struct sigiolst *rmlist) 2167 { 2168 struct sigio *sigio; 2169 2170 MUTEX_ASSERT_LOCKED(&sigio_lock); 2171 2172 sigio = sir->sir_sigio; 2173 if (sigio != NULL) { 2174 KASSERT(sigio->sio_myref == sir); 2175 sir->sir_sigio = NULL; 2176 2177 if (sigio->sio_pgid > 0) 2178 sigio->sio_proc = NULL; 2179 else 2180 sigio->sio_pgrp = NULL; 2181 LIST_REMOVE(sigio, sio_pgsigio); 2182 2183 LIST_INSERT_HEAD(rmlist, sigio, sio_pgsigio); 2184 } 2185 } 2186 2187 void 2188 sigio_free(struct sigio_ref *sir) 2189 { 2190 struct sigiolst rmlist; 2191 2192 if (sir->sir_sigio == NULL) 2193 return; 2194 2195 LIST_INIT(&rmlist); 2196 2197 mtx_enter(&sigio_lock); 2198 sigio_unlink(sir, &rmlist); 2199 mtx_leave(&sigio_lock); 2200 2201 sigio_del(&rmlist); 2202 } 2203 2204 void 2205 sigio_freelist(struct sigiolst *sigiolst) 2206 { 2207 struct sigiolst rmlist; 2208 struct sigio *sigio; 2209 2210 if (LIST_EMPTY(sigiolst)) 2211 return; 2212 2213 LIST_INIT(&rmlist); 2214 2215 mtx_enter(&sigio_lock); 2216 while ((sigio = LIST_FIRST(sigiolst)) != NULL) 2217 sigio_unlink(sigio->sio_myref, &rmlist); 2218 mtx_leave(&sigio_lock); 2219 2220 sigio_del(&rmlist); 2221 } 2222 2223 int 2224 sigio_setown(struct sigio_ref *sir, u_long cmd, caddr_t data) 2225 { 2226 struct sigiolst rmlist; 2227 struct proc *p = curproc; 2228 struct pgrp *pgrp = NULL; 2229 struct process *pr = NULL; 2230 struct sigio *sigio; 2231 int error; 2232 pid_t pgid = *(int *)data; 2233 2234 if (pgid == 0) { 2235 sigio_free(sir); 2236 return (0); 2237 } 2238 2239 if (cmd == TIOCSPGRP) { 2240 if (pgid < 0) 2241 return (EINVAL); 2242 pgid = -pgid; 2243 } 2244 2245 sigio = malloc(sizeof(*sigio), M_SIGIO, M_WAITOK); 2246 sigio->sio_pgid = pgid; 2247 sigio->sio_ucred = crhold(p->p_ucred); 2248 sigio->sio_myref = sir; 2249 2250 LIST_INIT(&rmlist); 2251 2252 /* 2253 * The kernel lock, and not sleeping between prfind()/pgfind() and 2254 * linking of the sigio ensure that the process or process group does 2255 * not disappear unexpectedly. 2256 */ 2257 KERNEL_LOCK(); 2258 mtx_enter(&sigio_lock); 2259 2260 if (pgid > 0) { 2261 pr = prfind(pgid); 2262 if (pr == NULL) { 2263 error = ESRCH; 2264 goto fail; 2265 } 2266 2267 /* 2268 * Policy - Don't allow a process to FSETOWN a process 2269 * in another session. 2270 * 2271 * Remove this test to allow maximum flexibility or 2272 * restrict FSETOWN to the current process or process 2273 * group for maximum safety. 2274 */ 2275 if (pr->ps_session != p->p_p->ps_session) { 2276 error = EPERM; 2277 goto fail; 2278 } 2279 2280 if ((pr->ps_flags & PS_EXITING) != 0) { 2281 error = ESRCH; 2282 goto fail; 2283 } 2284 } else /* if (pgid < 0) */ { 2285 pgrp = pgfind(-pgid); 2286 if (pgrp == NULL) { 2287 error = ESRCH; 2288 goto fail; 2289 } 2290 2291 /* 2292 * Policy - Don't allow a process to FSETOWN a process 2293 * in another session. 2294 * 2295 * Remove this test to allow maximum flexibility or 2296 * restrict FSETOWN to the current process or process 2297 * group for maximum safety. 2298 */ 2299 if (pgrp->pg_session != p->p_p->ps_session) { 2300 error = EPERM; 2301 goto fail; 2302 } 2303 } 2304 2305 if (pgid > 0) { 2306 sigio->sio_proc = pr; 2307 LIST_INSERT_HEAD(&pr->ps_sigiolst, sigio, sio_pgsigio); 2308 } else { 2309 sigio->sio_pgrp = pgrp; 2310 LIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 2311 } 2312 2313 sigio_unlink(sir, &rmlist); 2314 sir->sir_sigio = sigio; 2315 2316 mtx_leave(&sigio_lock); 2317 KERNEL_UNLOCK(); 2318 2319 sigio_del(&rmlist); 2320 2321 return (0); 2322 2323 fail: 2324 mtx_leave(&sigio_lock); 2325 KERNEL_UNLOCK(); 2326 2327 crfree(sigio->sio_ucred); 2328 free(sigio, M_SIGIO, sizeof(*sigio)); 2329 2330 return (error); 2331 } 2332 2333 void 2334 sigio_getown(struct sigio_ref *sir, u_long cmd, caddr_t data) 2335 { 2336 struct sigio *sigio; 2337 pid_t pgid = 0; 2338 2339 mtx_enter(&sigio_lock); 2340 sigio = sir->sir_sigio; 2341 if (sigio != NULL) 2342 pgid = sigio->sio_pgid; 2343 mtx_leave(&sigio_lock); 2344 2345 if (cmd == TIOCGPGRP) 2346 pgid = -pgid; 2347 2348 *(int *)data = pgid; 2349 } 2350 2351 void 2352 sigio_copy(struct sigio_ref *dst, struct sigio_ref *src) 2353 { 2354 struct sigiolst rmlist; 2355 struct sigio *newsigio, *sigio; 2356 2357 sigio_free(dst); 2358 2359 if (src->sir_sigio == NULL) 2360 return; 2361 2362 newsigio = malloc(sizeof(*newsigio), M_SIGIO, M_WAITOK); 2363 LIST_INIT(&rmlist); 2364 2365 mtx_enter(&sigio_lock); 2366 2367 sigio = src->sir_sigio; 2368 if (sigio == NULL) { 2369 mtx_leave(&sigio_lock); 2370 free(newsigio, M_SIGIO, sizeof(*newsigio)); 2371 return; 2372 } 2373 2374 newsigio->sio_pgid = sigio->sio_pgid; 2375 newsigio->sio_ucred = crhold(sigio->sio_ucred); 2376 newsigio->sio_myref = dst; 2377 if (newsigio->sio_pgid > 0) { 2378 newsigio->sio_proc = sigio->sio_proc; 2379 LIST_INSERT_HEAD(&newsigio->sio_proc->ps_sigiolst, newsigio, 2380 sio_pgsigio); 2381 } else { 2382 newsigio->sio_pgrp = sigio->sio_pgrp; 2383 LIST_INSERT_HEAD(&newsigio->sio_pgrp->pg_sigiolst, newsigio, 2384 sio_pgsigio); 2385 } 2386 2387 sigio_unlink(dst, &rmlist); 2388 dst->sir_sigio = newsigio; 2389 2390 mtx_leave(&sigio_lock); 2391 2392 sigio_del(&rmlist); 2393 } 2394