1 /* $OpenBSD: kern_sig.c,v 1.263 2020/09/16 13:50:42 mpi 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 *retval = p->p_sigmask; 468 mask = SCARG(uap, mask) &~ sigcantmask; 469 470 switch (SCARG(uap, how)) { 471 case SIG_BLOCK: 472 atomic_setbits_int(&p->p_sigmask, mask); 473 break; 474 case SIG_UNBLOCK: 475 atomic_clearbits_int(&p->p_sigmask, mask); 476 break; 477 case SIG_SETMASK: 478 p->p_sigmask = mask; 479 break; 480 default: 481 error = EINVAL; 482 break; 483 } 484 return (error); 485 } 486 487 int 488 sys_sigpending(struct proc *p, void *v, register_t *retval) 489 { 490 491 *retval = p->p_siglist | p->p_p->ps_siglist; 492 return (0); 493 } 494 495 /* 496 * Temporarily replace calling proc's signal mask for the duration of a 497 * system call. Original signal mask will be restored by userret(). 498 */ 499 void 500 dosigsuspend(struct proc *p, sigset_t newmask) 501 { 502 KASSERT(p == curproc); 503 504 p->p_oldmask = p->p_sigmask; 505 atomic_setbits_int(&p->p_flag, P_SIGSUSPEND); 506 p->p_sigmask = newmask; 507 } 508 509 /* 510 * Suspend process until signal, providing mask to be set 511 * in the meantime. Note nonstandard calling convention: 512 * libc stub passes mask, not pointer, to save a copyin. 513 */ 514 int 515 sys_sigsuspend(struct proc *p, void *v, register_t *retval) 516 { 517 struct sys_sigsuspend_args /* { 518 syscallarg(int) mask; 519 } */ *uap = v; 520 struct process *pr = p->p_p; 521 struct sigacts *ps = pr->ps_sigacts; 522 523 dosigsuspend(p, SCARG(uap, mask) &~ sigcantmask); 524 while (tsleep_nsec(ps, PPAUSE|PCATCH, "pause", INFSLP) == 0) 525 /* void */; 526 /* always return EINTR rather than ERESTART... */ 527 return (EINTR); 528 } 529 530 int 531 sigonstack(size_t stack) 532 { 533 const struct sigaltstack *ss = &curproc->p_sigstk; 534 535 return (ss->ss_flags & SS_DISABLE ? 0 : 536 (stack - (size_t)ss->ss_sp < ss->ss_size)); 537 } 538 539 int 540 sys_sigaltstack(struct proc *p, void *v, register_t *retval) 541 { 542 struct sys_sigaltstack_args /* { 543 syscallarg(const struct sigaltstack *) nss; 544 syscallarg(struct sigaltstack *) oss; 545 } */ *uap = v; 546 struct sigaltstack ss; 547 const struct sigaltstack *nss; 548 struct sigaltstack *oss; 549 int onstack = sigonstack(PROC_STACK(p)); 550 int error; 551 552 nss = SCARG(uap, nss); 553 oss = SCARG(uap, oss); 554 555 if (oss != NULL) { 556 ss = p->p_sigstk; 557 if (onstack) 558 ss.ss_flags |= SS_ONSTACK; 559 if ((error = copyout(&ss, oss, sizeof(ss)))) 560 return (error); 561 } 562 if (nss == NULL) 563 return (0); 564 error = copyin(nss, &ss, sizeof(ss)); 565 if (error) 566 return (error); 567 if (onstack) 568 return (EPERM); 569 if (ss.ss_flags & ~SS_DISABLE) 570 return (EINVAL); 571 if (ss.ss_flags & SS_DISABLE) { 572 p->p_sigstk.ss_flags = ss.ss_flags; 573 return (0); 574 } 575 if (ss.ss_size < MINSIGSTKSZ) 576 return (ENOMEM); 577 578 error = uvm_map_remap_as_stack(p, (vaddr_t)ss.ss_sp, ss.ss_size); 579 if (error) 580 return (error); 581 582 p->p_sigstk = ss; 583 return (0); 584 } 585 586 int 587 sys_kill(struct proc *cp, void *v, register_t *retval) 588 { 589 struct sys_kill_args /* { 590 syscallarg(int) pid; 591 syscallarg(int) signum; 592 } */ *uap = v; 593 struct process *pr; 594 int pid = SCARG(uap, pid); 595 int signum = SCARG(uap, signum); 596 int error; 597 int zombie = 0; 598 599 if ((error = pledge_kill(cp, pid)) != 0) 600 return (error); 601 if (((u_int)signum) >= NSIG) 602 return (EINVAL); 603 if (pid > 0) { 604 if ((pr = prfind(pid)) == NULL) { 605 if ((pr = zombiefind(pid)) == NULL) 606 return (ESRCH); 607 else 608 zombie = 1; 609 } 610 if (!cansignal(cp, pr, signum)) 611 return (EPERM); 612 613 /* kill single process */ 614 if (signum && !zombie) 615 prsignal(pr, signum); 616 return (0); 617 } 618 switch (pid) { 619 case -1: /* broadcast signal */ 620 return (killpg1(cp, signum, 0, 1)); 621 case 0: /* signal own process group */ 622 return (killpg1(cp, signum, 0, 0)); 623 default: /* negative explicit process group */ 624 return (killpg1(cp, signum, -pid, 0)); 625 } 626 } 627 628 int 629 sys_thrkill(struct proc *cp, void *v, register_t *retval) 630 { 631 struct sys_thrkill_args /* { 632 syscallarg(pid_t) tid; 633 syscallarg(int) signum; 634 syscallarg(void *) tcb; 635 } */ *uap = v; 636 struct proc *p; 637 int tid = SCARG(uap, tid); 638 int signum = SCARG(uap, signum); 639 void *tcb; 640 641 if (((u_int)signum) >= NSIG) 642 return (EINVAL); 643 if (tid > THREAD_PID_OFFSET) { 644 if ((p = tfind(tid - THREAD_PID_OFFSET)) == NULL) 645 return (ESRCH); 646 647 /* can only kill threads in the same process */ 648 if (p->p_p != cp->p_p) 649 return (ESRCH); 650 } else if (tid == 0) 651 p = cp; 652 else 653 return (EINVAL); 654 655 /* optionally require the target thread to have the given tcb addr */ 656 tcb = SCARG(uap, tcb); 657 if (tcb != NULL && tcb != TCB_GET(p)) 658 return (ESRCH); 659 660 if (signum) 661 ptsignal(p, signum, STHREAD); 662 return (0); 663 } 664 665 /* 666 * Common code for kill process group/broadcast kill. 667 * cp is calling process. 668 */ 669 int 670 killpg1(struct proc *cp, int signum, int pgid, int all) 671 { 672 struct process *pr; 673 struct pgrp *pgrp; 674 int nfound = 0; 675 676 if (all) { 677 /* 678 * broadcast 679 */ 680 LIST_FOREACH(pr, &allprocess, ps_list) { 681 if (pr->ps_pid <= 1 || 682 pr->ps_flags & (PS_SYSTEM | PS_NOBROADCASTKILL) || 683 pr == cp->p_p || !cansignal(cp, pr, signum)) 684 continue; 685 nfound++; 686 if (signum) 687 prsignal(pr, signum); 688 } 689 } else { 690 if (pgid == 0) 691 /* 692 * zero pgid means send to my process group. 693 */ 694 pgrp = cp->p_p->ps_pgrp; 695 else { 696 pgrp = pgfind(pgid); 697 if (pgrp == NULL) 698 return (ESRCH); 699 } 700 LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) { 701 if (pr->ps_pid <= 1 || pr->ps_flags & PS_SYSTEM || 702 !cansignal(cp, pr, signum)) 703 continue; 704 nfound++; 705 if (signum) 706 prsignal(pr, signum); 707 } 708 } 709 return (nfound ? 0 : ESRCH); 710 } 711 712 #define CANDELIVER(uid, euid, pr) \ 713 (euid == 0 || \ 714 (uid) == (pr)->ps_ucred->cr_ruid || \ 715 (uid) == (pr)->ps_ucred->cr_svuid || \ 716 (uid) == (pr)->ps_ucred->cr_uid || \ 717 (euid) == (pr)->ps_ucred->cr_ruid || \ 718 (euid) == (pr)->ps_ucred->cr_svuid || \ 719 (euid) == (pr)->ps_ucred->cr_uid) 720 721 #define CANSIGIO(cr, pr) \ 722 CANDELIVER((cr)->cr_ruid, (cr)->cr_uid, (pr)) 723 724 /* 725 * Send a signal to a process group. If checktty is 1, 726 * limit to members which have a controlling terminal. 727 */ 728 void 729 pgsignal(struct pgrp *pgrp, int signum, int checkctty) 730 { 731 struct process *pr; 732 733 if (pgrp) 734 LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) 735 if (checkctty == 0 || pr->ps_flags & PS_CONTROLT) 736 prsignal(pr, signum); 737 } 738 739 /* 740 * Send a SIGIO or SIGURG signal to a process or process group using stored 741 * credentials rather than those of the current process. 742 */ 743 void 744 pgsigio(struct sigio_ref *sir, int sig, int checkctty) 745 { 746 struct process *pr; 747 struct sigio *sigio; 748 749 if (sir->sir_sigio == NULL) 750 return; 751 752 KERNEL_LOCK(); 753 mtx_enter(&sigio_lock); 754 sigio = sir->sir_sigio; 755 if (sigio == NULL) 756 goto out; 757 if (sigio->sio_pgid > 0) { 758 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc)) 759 prsignal(sigio->sio_proc, sig); 760 } else if (sigio->sio_pgid < 0) { 761 LIST_FOREACH(pr, &sigio->sio_pgrp->pg_members, ps_pglist) { 762 if (CANSIGIO(sigio->sio_ucred, pr) && 763 (checkctty == 0 || (pr->ps_flags & PS_CONTROLT))) 764 prsignal(pr, sig); 765 } 766 } 767 out: 768 mtx_leave(&sigio_lock); 769 KERNEL_UNLOCK(); 770 } 771 772 /* 773 * Recalculate the signal mask and reset the signal disposition after 774 * usermode frame for delivery is formed. 775 */ 776 void 777 postsig_done(struct proc *p, int signum, struct sigacts *ps) 778 { 779 int mask = sigmask(signum); 780 781 KERNEL_ASSERT_LOCKED(); 782 783 p->p_ru.ru_nsignals++; 784 atomic_setbits_int(&p->p_sigmask, ps->ps_catchmask[signum]); 785 if ((ps->ps_sigreset & mask) != 0) { 786 ps->ps_sigcatch &= ~mask; 787 if (signum != SIGCONT && sigprop[signum] & SA_IGNORE) 788 ps->ps_sigignore |= mask; 789 ps->ps_sigact[signum] = SIG_DFL; 790 } 791 } 792 793 /* 794 * Send a signal caused by a trap to the current thread 795 * If it will be caught immediately, deliver it with correct code. 796 * Otherwise, post it normally. 797 */ 798 void 799 trapsignal(struct proc *p, int signum, u_long trapno, int code, 800 union sigval sigval) 801 { 802 struct process *pr = p->p_p; 803 struct sigacts *ps = pr->ps_sigacts; 804 int mask; 805 806 KERNEL_LOCK(); 807 switch (signum) { 808 case SIGILL: 809 case SIGBUS: 810 case SIGSEGV: 811 pr->ps_acflag |= ATRAP; 812 break; 813 } 814 815 mask = sigmask(signum); 816 if ((pr->ps_flags & PS_TRACED) == 0 && 817 (ps->ps_sigcatch & mask) != 0 && 818 (p->p_sigmask & mask) == 0) { 819 siginfo_t si; 820 initsiginfo(&si, signum, trapno, code, sigval); 821 #ifdef KTRACE 822 if (KTRPOINT(p, KTR_PSIG)) { 823 ktrpsig(p, signum, ps->ps_sigact[signum], 824 p->p_sigmask, code, &si); 825 } 826 #endif 827 sendsig(ps->ps_sigact[signum], signum, p->p_sigmask, &si); 828 postsig_done(p, signum, ps); 829 } else { 830 p->p_sisig = signum; 831 p->p_sitrapno = trapno; /* XXX for core dump/debugger */ 832 p->p_sicode = code; 833 p->p_sigval = sigval; 834 835 /* 836 * Signals like SIGBUS and SIGSEGV should not, when 837 * generated by the kernel, be ignorable or blockable. 838 * If it is and we're not being traced, then just kill 839 * the process. 840 */ 841 if ((pr->ps_flags & PS_TRACED) == 0 && 842 (sigprop[signum] & SA_KILL) && 843 ((p->p_sigmask & mask) || (ps->ps_sigignore & mask))) 844 sigexit(p, signum); 845 ptsignal(p, signum, STHREAD); 846 } 847 KERNEL_UNLOCK(); 848 } 849 850 /* 851 * Send the signal to the process. If the signal has an action, the action 852 * is usually performed by the target process rather than the caller; we add 853 * the signal to the set of pending signals for the process. 854 * 855 * Exceptions: 856 * o When a stop signal is sent to a sleeping process that takes the 857 * default action, the process is stopped without awakening it. 858 * o SIGCONT restarts stopped processes (or puts them back to sleep) 859 * regardless of the signal action (eg, blocked or ignored). 860 * 861 * Other ignored signals are discarded immediately. 862 */ 863 void 864 psignal(struct proc *p, int signum) 865 { 866 ptsignal(p, signum, SPROCESS); 867 } 868 869 /* 870 * type = SPROCESS process signal, can be diverted (sigwait()) 871 * type = STHREAD thread signal, but should be propagated if unhandled 872 * type = SPROPAGATED propagated to this thread, so don't propagate again 873 */ 874 void 875 ptsignal(struct proc *p, int signum, enum signal_type type) 876 { 877 int s, prop; 878 sig_t action; 879 int mask; 880 int *siglist; 881 struct process *pr = p->p_p; 882 struct proc *q; 883 int wakeparent = 0; 884 885 KERNEL_ASSERT_LOCKED(); 886 887 #ifdef DIAGNOSTIC 888 if ((u_int)signum >= NSIG || signum == 0) 889 panic("psignal signal number"); 890 #endif 891 892 /* Ignore signal if the target process is exiting */ 893 if (pr->ps_flags & PS_EXITING) 894 return; 895 896 mask = sigmask(signum); 897 898 if (type == SPROCESS) { 899 /* Accept SIGKILL to coredumping processes */ 900 if (pr->ps_flags & PS_COREDUMP && signum == SIGKILL) { 901 atomic_setbits_int(&pr->ps_siglist, mask); 902 return; 903 } 904 905 /* 906 * If the current thread can process the signal 907 * immediately (it's unblocked) then have it take it. 908 */ 909 q = curproc; 910 if (q != NULL && q->p_p == pr && (q->p_flag & P_WEXIT) == 0 && 911 (q->p_sigmask & mask) == 0) 912 p = q; 913 else { 914 /* 915 * A process-wide signal can be diverted to a 916 * different thread that's in sigwait() for this 917 * signal. If there isn't such a thread, then 918 * pick a thread that doesn't have it blocked so 919 * that the stop/kill consideration isn't 920 * delayed. Otherwise, mark it pending on the 921 * main thread. 922 */ 923 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 924 /* ignore exiting threads */ 925 if (q->p_flag & P_WEXIT) 926 continue; 927 928 /* skip threads that have the signal blocked */ 929 if ((q->p_sigmask & mask) != 0) 930 continue; 931 932 /* okay, could send to this thread */ 933 p = q; 934 935 /* 936 * sigsuspend, sigwait, ppoll/pselect, etc? 937 * Definitely go to this thread, as it's 938 * already blocked in the kernel. 939 */ 940 if (q->p_flag & P_SIGSUSPEND) 941 break; 942 } 943 } 944 } 945 946 if (type != SPROPAGATED) 947 KNOTE(&pr->ps_klist, NOTE_SIGNAL | signum); 948 949 prop = sigprop[signum]; 950 951 /* 952 * If proc is traced, always give parent a chance. 953 */ 954 if (pr->ps_flags & PS_TRACED) { 955 action = SIG_DFL; 956 } else { 957 /* 958 * If the signal is being ignored, 959 * then we forget about it immediately. 960 * (Note: we don't set SIGCONT in ps_sigignore, 961 * and if it is set to SIG_IGN, 962 * action will be SIG_DFL here.) 963 */ 964 if (pr->ps_sigacts->ps_sigignore & mask) 965 return; 966 if (p->p_sigmask & mask) { 967 action = SIG_HOLD; 968 } else if (pr->ps_sigacts->ps_sigcatch & mask) { 969 action = SIG_CATCH; 970 } else { 971 action = SIG_DFL; 972 973 if (prop & SA_KILL && pr->ps_nice > NZERO) 974 pr->ps_nice = NZERO; 975 976 /* 977 * If sending a tty stop signal to a member of an 978 * orphaned process group, discard the signal here if 979 * the action is default; don't stop the process below 980 * if sleeping, and don't clear any pending SIGCONT. 981 */ 982 if (prop & SA_TTYSTOP && pr->ps_pgrp->pg_jobc == 0) 983 return; 984 } 985 } 986 /* 987 * If delivered to process, mark as pending there. Continue and stop 988 * signals will be propagated to all threads. So they are always 989 * marked at thread level. 990 */ 991 siglist = (type == SPROCESS) ? &pr->ps_siglist : &p->p_siglist; 992 if (prop & SA_CONT) { 993 siglist = &p->p_siglist; 994 atomic_clearbits_int(siglist, stopsigmask); 995 } 996 if (prop & SA_STOP) { 997 siglist = &p->p_siglist; 998 atomic_clearbits_int(siglist, contsigmask); 999 atomic_clearbits_int(&p->p_flag, P_CONTINUED); 1000 } 1001 atomic_setbits_int(siglist, mask); 1002 1003 /* 1004 * XXX delay processing of SA_STOP signals unless action == SIG_DFL? 1005 */ 1006 if (prop & (SA_CONT | SA_STOP) && type != SPROPAGATED) 1007 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) 1008 if (q != p) 1009 ptsignal(q, signum, SPROPAGATED); 1010 1011 /* 1012 * Defer further processing for signals which are held, 1013 * except that stopped processes must be continued by SIGCONT. 1014 */ 1015 if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) 1016 return; 1017 1018 SCHED_LOCK(s); 1019 1020 switch (p->p_stat) { 1021 1022 case SSLEEP: 1023 /* 1024 * If process is sleeping uninterruptibly 1025 * we can't interrupt the sleep... the signal will 1026 * be noticed when the process returns through 1027 * trap() or syscall(). 1028 */ 1029 if ((p->p_flag & P_SINTR) == 0) 1030 goto out; 1031 /* 1032 * Process is sleeping and traced... make it runnable 1033 * so it can discover the signal in issignal() and stop 1034 * for the parent. 1035 */ 1036 if (pr->ps_flags & PS_TRACED) 1037 goto run; 1038 /* 1039 * If SIGCONT is default (or ignored) and process is 1040 * asleep, we are finished; the process should not 1041 * be awakened. 1042 */ 1043 if ((prop & SA_CONT) && action == SIG_DFL) { 1044 atomic_clearbits_int(siglist, mask); 1045 goto out; 1046 } 1047 /* 1048 * When a sleeping process receives a stop 1049 * signal, process immediately if possible. 1050 */ 1051 if ((prop & SA_STOP) && action == SIG_DFL) { 1052 /* 1053 * If a child holding parent blocked, 1054 * stopping could cause deadlock. 1055 */ 1056 if (pr->ps_flags & PS_PPWAIT) 1057 goto out; 1058 atomic_clearbits_int(siglist, mask); 1059 pr->ps_xsig = signum; 1060 proc_stop(p, 0); 1061 goto out; 1062 } 1063 /* 1064 * All other (caught or default) signals 1065 * cause the process to run. 1066 */ 1067 goto runfast; 1068 /*NOTREACHED*/ 1069 1070 case SSTOP: 1071 /* 1072 * If traced process is already stopped, 1073 * then no further action is necessary. 1074 */ 1075 if (pr->ps_flags & PS_TRACED) 1076 goto out; 1077 1078 /* 1079 * Kill signal always sets processes running. 1080 */ 1081 if (signum == SIGKILL) { 1082 atomic_clearbits_int(&p->p_flag, P_SUSPSIG); 1083 goto runfast; 1084 } 1085 1086 if (prop & SA_CONT) { 1087 /* 1088 * If SIGCONT is default (or ignored), we continue the 1089 * process but don't leave the signal in p_siglist, as 1090 * it has no further action. If SIGCONT is held, we 1091 * continue the process and leave the signal in 1092 * p_siglist. If the process catches SIGCONT, let it 1093 * handle the signal itself. If it isn't waiting on 1094 * an event, then it goes back to run state. 1095 * Otherwise, process goes back to sleep state. 1096 */ 1097 atomic_setbits_int(&p->p_flag, P_CONTINUED); 1098 atomic_clearbits_int(&p->p_flag, P_SUSPSIG); 1099 wakeparent = 1; 1100 if (action == SIG_DFL) 1101 atomic_clearbits_int(siglist, mask); 1102 if (action == SIG_CATCH) 1103 goto runfast; 1104 if (p->p_wchan == 0) 1105 goto run; 1106 p->p_stat = SSLEEP; 1107 goto out; 1108 } 1109 1110 if (prop & SA_STOP) { 1111 /* 1112 * Already stopped, don't need to stop again. 1113 * (If we did the shell could get confused.) 1114 */ 1115 atomic_clearbits_int(siglist, mask); 1116 goto out; 1117 } 1118 1119 /* 1120 * If process is sleeping interruptibly, then simulate a 1121 * wakeup so that when it is continued, it will be made 1122 * runnable and can look at the signal. But don't make 1123 * the process runnable, leave it stopped. 1124 */ 1125 if (p->p_flag & P_SINTR) 1126 unsleep(p); 1127 goto out; 1128 1129 case SONPROC: 1130 signotify(p); 1131 /* FALLTHROUGH */ 1132 default: 1133 /* 1134 * SRUN, SIDL, SDEAD do nothing with the signal, 1135 * other than kicking ourselves if we are running. 1136 * It will either never be noticed, or noticed very soon. 1137 */ 1138 goto out; 1139 } 1140 /*NOTREACHED*/ 1141 1142 runfast: 1143 /* 1144 * Raise priority to at least PUSER. 1145 */ 1146 if (p->p_usrpri > PUSER) 1147 p->p_usrpri = PUSER; 1148 run: 1149 setrunnable(p); 1150 out: 1151 SCHED_UNLOCK(s); 1152 if (wakeparent) 1153 wakeup(pr->ps_pptr); 1154 } 1155 1156 /* 1157 * If the current process has received a signal (should be caught or cause 1158 * termination, should interrupt current syscall), return the signal number. 1159 * Stop signals with default action are processed immediately, then cleared; 1160 * they aren't returned. This is checked after each entry to the system for 1161 * a syscall or trap (though this can usually be done without calling issignal 1162 * by checking the pending signal masks in the CURSIG macro.) The normal call 1163 * sequence is 1164 * 1165 * while (signum = CURSIG(curproc)) 1166 * postsig(signum); 1167 * 1168 * Assumes that if the P_SINTR flag is set, we're holding both the 1169 * kernel and scheduler locks. 1170 */ 1171 int 1172 issignal(struct proc *p) 1173 { 1174 struct process *pr = p->p_p; 1175 int signum, mask, prop; 1176 int dolock = (p->p_flag & P_SINTR) == 0; 1177 int s; 1178 1179 for (;;) { 1180 mask = SIGPENDING(p); 1181 if (pr->ps_flags & PS_PPWAIT) 1182 mask &= ~stopsigmask; 1183 if (mask == 0) /* no signal to send */ 1184 return (0); 1185 signum = ffs((long)mask); 1186 mask = sigmask(signum); 1187 atomic_clearbits_int(&p->p_siglist, mask); 1188 atomic_clearbits_int(&pr->ps_siglist, mask); 1189 1190 /* 1191 * We should see pending but ignored signals 1192 * only if PS_TRACED was on when they were posted. 1193 */ 1194 if (mask & pr->ps_sigacts->ps_sigignore && 1195 (pr->ps_flags & PS_TRACED) == 0) 1196 continue; 1197 1198 /* 1199 * If traced, always stop, and stay stopped until released 1200 * by the debugger. If our parent process is waiting for 1201 * us, don't hang as we could deadlock. 1202 */ 1203 if (((pr->ps_flags & (PS_TRACED | PS_PPWAIT)) == PS_TRACED) && 1204 signum != SIGKILL) { 1205 pr->ps_xsig = signum; 1206 1207 if (dolock) 1208 KERNEL_LOCK(); 1209 single_thread_set(p, SINGLE_PTRACE, 0); 1210 if (dolock) 1211 KERNEL_UNLOCK(); 1212 1213 if (dolock) 1214 SCHED_LOCK(s); 1215 proc_stop(p, 1); 1216 if (dolock) 1217 SCHED_UNLOCK(s); 1218 1219 if (dolock) 1220 KERNEL_LOCK(); 1221 single_thread_clear(p, 0); 1222 if (dolock) 1223 KERNEL_UNLOCK(); 1224 1225 /* 1226 * If we are no longer being traced, or the parent 1227 * didn't give us a signal, look for more signals. 1228 */ 1229 if ((pr->ps_flags & PS_TRACED) == 0 || 1230 pr->ps_xsig == 0) 1231 continue; 1232 1233 /* 1234 * If the new signal is being masked, look for other 1235 * signals. 1236 */ 1237 signum = pr->ps_xsig; 1238 mask = sigmask(signum); 1239 if ((p->p_sigmask & mask) != 0) 1240 continue; 1241 1242 /* take the signal! */ 1243 atomic_clearbits_int(&p->p_siglist, mask); 1244 atomic_clearbits_int(&pr->ps_siglist, mask); 1245 } 1246 1247 prop = sigprop[signum]; 1248 1249 /* 1250 * Decide whether the signal should be returned. 1251 * Return the signal's number, or fall through 1252 * to clear it from the pending mask. 1253 */ 1254 switch ((long)pr->ps_sigacts->ps_sigact[signum]) { 1255 case (long)SIG_DFL: 1256 /* 1257 * Don't take default actions on system processes. 1258 */ 1259 if (pr->ps_pid <= 1) { 1260 #ifdef DIAGNOSTIC 1261 /* 1262 * Are you sure you want to ignore SIGSEGV 1263 * in init? XXX 1264 */ 1265 printf("Process (pid %d) got signal" 1266 " %d\n", pr->ps_pid, signum); 1267 #endif 1268 break; /* == ignore */ 1269 } 1270 /* 1271 * If there is a pending stop signal to process 1272 * with default action, stop here, 1273 * then clear the signal. However, 1274 * if process is member of an orphaned 1275 * process group, ignore tty stop signals. 1276 */ 1277 if (prop & SA_STOP) { 1278 if (pr->ps_flags & PS_TRACED || 1279 (pr->ps_pgrp->pg_jobc == 0 && 1280 prop & SA_TTYSTOP)) 1281 break; /* == ignore */ 1282 pr->ps_xsig = signum; 1283 if (dolock) 1284 SCHED_LOCK(s); 1285 proc_stop(p, 1); 1286 if (dolock) 1287 SCHED_UNLOCK(s); 1288 break; 1289 } else if (prop & SA_IGNORE) { 1290 /* 1291 * Except for SIGCONT, shouldn't get here. 1292 * Default action is to ignore; drop it. 1293 */ 1294 break; /* == ignore */ 1295 } else 1296 goto keep; 1297 /*NOTREACHED*/ 1298 case (long)SIG_IGN: 1299 /* 1300 * Masking above should prevent us ever trying 1301 * to take action on an ignored signal other 1302 * than SIGCONT, unless process is traced. 1303 */ 1304 if ((prop & SA_CONT) == 0 && 1305 (pr->ps_flags & PS_TRACED) == 0) 1306 printf("issignal\n"); 1307 break; /* == ignore */ 1308 default: 1309 /* 1310 * This signal has an action, let 1311 * postsig() process it. 1312 */ 1313 goto keep; 1314 } 1315 } 1316 /* NOTREACHED */ 1317 1318 keep: 1319 atomic_setbits_int(&p->p_siglist, mask); /*leave the signal for later */ 1320 return (signum); 1321 } 1322 1323 /* 1324 * Put the argument process into the stopped state and notify the parent 1325 * via wakeup. Signals are handled elsewhere. The process must not be 1326 * on the run queue. 1327 */ 1328 void 1329 proc_stop(struct proc *p, int sw) 1330 { 1331 struct process *pr = p->p_p; 1332 1333 #ifdef MULTIPROCESSOR 1334 SCHED_ASSERT_LOCKED(); 1335 #endif 1336 1337 p->p_stat = SSTOP; 1338 atomic_clearbits_int(&pr->ps_flags, PS_WAITED); 1339 atomic_setbits_int(&pr->ps_flags, PS_STOPPED); 1340 atomic_setbits_int(&p->p_flag, P_SUSPSIG); 1341 /* 1342 * We need this soft interrupt to be handled fast. 1343 * Extra calls to softclock don't hurt. 1344 */ 1345 softintr_schedule(proc_stop_si); 1346 if (sw) 1347 mi_switch(); 1348 } 1349 1350 /* 1351 * Called from a soft interrupt to send signals to the parents of stopped 1352 * processes. 1353 * We can't do this in proc_stop because it's called with nasty locks held 1354 * and we would need recursive scheduler lock to deal with that. 1355 */ 1356 void 1357 proc_stop_sweep(void *v) 1358 { 1359 struct process *pr; 1360 1361 LIST_FOREACH(pr, &allprocess, ps_list) { 1362 if ((pr->ps_flags & PS_STOPPED) == 0) 1363 continue; 1364 atomic_clearbits_int(&pr->ps_flags, PS_STOPPED); 1365 1366 if ((pr->ps_pptr->ps_sigacts->ps_sigflags & SAS_NOCLDSTOP) == 0) 1367 prsignal(pr->ps_pptr, SIGCHLD); 1368 wakeup(pr->ps_pptr); 1369 } 1370 } 1371 1372 /* 1373 * Take the action for the specified signal 1374 * from the current set of pending signals. 1375 */ 1376 void 1377 postsig(struct proc *p, int signum) 1378 { 1379 struct process *pr = p->p_p; 1380 struct sigacts *ps = pr->ps_sigacts; 1381 sig_t action; 1382 u_long trapno; 1383 int mask, returnmask; 1384 siginfo_t si; 1385 union sigval sigval; 1386 int s, code; 1387 1388 KASSERT(signum != 0); 1389 KERNEL_ASSERT_LOCKED(); 1390 1391 mask = sigmask(signum); 1392 atomic_clearbits_int(&p->p_siglist, mask); 1393 action = ps->ps_sigact[signum]; 1394 sigval.sival_ptr = 0; 1395 1396 if (p->p_sisig != signum) { 1397 trapno = 0; 1398 code = SI_USER; 1399 sigval.sival_ptr = 0; 1400 } else { 1401 trapno = p->p_sitrapno; 1402 code = p->p_sicode; 1403 sigval = p->p_sigval; 1404 } 1405 initsiginfo(&si, signum, trapno, code, sigval); 1406 1407 #ifdef KTRACE 1408 if (KTRPOINT(p, KTR_PSIG)) { 1409 ktrpsig(p, signum, action, p->p_flag & P_SIGSUSPEND ? 1410 p->p_oldmask : p->p_sigmask, code, &si); 1411 } 1412 #endif 1413 if (action == SIG_DFL) { 1414 /* 1415 * Default action, where the default is to kill 1416 * the process. (Other cases were ignored above.) 1417 */ 1418 sigexit(p, signum); 1419 /* NOTREACHED */ 1420 } else { 1421 /* 1422 * If we get here, the signal must be caught. 1423 */ 1424 #ifdef DIAGNOSTIC 1425 if (action == SIG_IGN || (p->p_sigmask & mask)) 1426 panic("postsig action"); 1427 #endif 1428 /* 1429 * Set the new mask value and also defer further 1430 * occurrences of this signal. 1431 * 1432 * Special case: user has done a sigpause. Here the 1433 * current mask is not of interest, but rather the 1434 * mask from before the sigpause is what we want 1435 * restored after the signal processing is completed. 1436 */ 1437 #ifdef MULTIPROCESSOR 1438 s = splsched(); 1439 #else 1440 s = splhigh(); 1441 #endif 1442 if (p->p_flag & P_SIGSUSPEND) { 1443 atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); 1444 returnmask = p->p_oldmask; 1445 } else { 1446 returnmask = p->p_sigmask; 1447 } 1448 if (p->p_sisig == signum) { 1449 p->p_sisig = 0; 1450 p->p_sitrapno = 0; 1451 p->p_sicode = SI_USER; 1452 p->p_sigval.sival_ptr = NULL; 1453 } 1454 1455 sendsig(action, signum, returnmask, &si); 1456 postsig_done(p, signum, ps); 1457 splx(s); 1458 } 1459 } 1460 1461 /* 1462 * Force the current process to exit with the specified signal, dumping core 1463 * if appropriate. We bypass the normal tests for masked and caught signals, 1464 * allowing unrecoverable failures to terminate the process without changing 1465 * signal state. Mark the accounting record with the signal termination. 1466 * If dumping core, save the signal number for the debugger. Calls exit and 1467 * does not return. 1468 */ 1469 void 1470 sigexit(struct proc *p, int signum) 1471 { 1472 /* Mark process as going away */ 1473 atomic_setbits_int(&p->p_flag, P_WEXIT); 1474 1475 p->p_p->ps_acflag |= AXSIG; 1476 if (sigprop[signum] & SA_CORE) { 1477 p->p_sisig = signum; 1478 1479 /* if there are other threads, pause them */ 1480 if (P_HASSIBLING(p)) 1481 single_thread_set(p, SINGLE_SUSPEND, 0); 1482 1483 if (coredump(p) == 0) 1484 signum |= WCOREFLAG; 1485 } 1486 exit1(p, 0, signum, EXIT_NORMAL); 1487 /* NOTREACHED */ 1488 } 1489 1490 /* 1491 * Send uncatchable SIGABRT for coredump. 1492 */ 1493 void 1494 sigabort(struct proc *p) 1495 { 1496 struct sigaction sa; 1497 1498 memset(&sa, 0, sizeof sa); 1499 sa.sa_handler = SIG_DFL; 1500 setsigvec(p, SIGABRT, &sa); 1501 atomic_clearbits_int(&p->p_sigmask, sigmask(SIGABRT)); 1502 psignal(p, SIGABRT); 1503 } 1504 1505 /* 1506 * Return 1 if `sig', a given signal, is ignored or masked for `p', a given 1507 * thread, and 0 otherwise. 1508 */ 1509 int 1510 sigismasked(struct proc *p, int sig) 1511 { 1512 struct process *pr = p->p_p; 1513 1514 if ((pr->ps_sigacts->ps_sigignore & sigmask(sig)) || 1515 (p->p_sigmask & sigmask(sig))) 1516 return 1; 1517 1518 return 0; 1519 } 1520 1521 int nosuidcoredump = 1; 1522 1523 struct coredump_iostate { 1524 struct proc *io_proc; 1525 struct vnode *io_vp; 1526 struct ucred *io_cred; 1527 off_t io_offset; 1528 }; 1529 1530 /* 1531 * Dump core, into a file named "progname.core", unless the process was 1532 * setuid/setgid. 1533 */ 1534 int 1535 coredump(struct proc *p) 1536 { 1537 #ifdef SMALL_KERNEL 1538 return EPERM; 1539 #else 1540 struct process *pr = p->p_p; 1541 struct vnode *vp; 1542 struct ucred *cred = p->p_ucred; 1543 struct vmspace *vm = p->p_vmspace; 1544 struct nameidata nd; 1545 struct vattr vattr; 1546 struct coredump_iostate io; 1547 int error, len, incrash = 0; 1548 char *name; 1549 const char *dir = "/var/crash"; 1550 1551 if (pr->ps_emul->e_coredump == NULL) 1552 return (EINVAL); 1553 1554 atomic_setbits_int(&pr->ps_flags, PS_COREDUMP); 1555 1556 /* Don't dump if will exceed file size limit. */ 1557 if (USPACE + ptoa(vm->vm_dsize + vm->vm_ssize) >= lim_cur(RLIMIT_CORE)) 1558 return (EFBIG); 1559 1560 name = pool_get(&namei_pool, PR_WAITOK); 1561 1562 /* 1563 * If the process has inconsistent uids, nosuidcoredump 1564 * determines coredump placement policy. 1565 */ 1566 if (((pr->ps_flags & PS_SUGID) && (error = suser(p))) || 1567 ((pr->ps_flags & PS_SUGID) && nosuidcoredump)) { 1568 if (nosuidcoredump == 3) { 1569 /* 1570 * If the program directory does not exist, dumps of 1571 * that core will silently fail. 1572 */ 1573 len = snprintf(name, MAXPATHLEN, "%s/%s/%u.core", 1574 dir, pr->ps_comm, pr->ps_pid); 1575 incrash = KERNELPATH; 1576 } else if (nosuidcoredump == 2) { 1577 len = snprintf(name, MAXPATHLEN, "%s/%s.core", 1578 dir, pr->ps_comm); 1579 incrash = KERNELPATH; 1580 } else { 1581 pool_put(&namei_pool, name); 1582 return (EPERM); 1583 } 1584 } else 1585 len = snprintf(name, MAXPATHLEN, "%s.core", pr->ps_comm); 1586 1587 if (len >= MAXPATHLEN) { 1588 pool_put(&namei_pool, name); 1589 return (EACCES); 1590 } 1591 1592 /* 1593 * Control the UID used to write out. The normal case uses 1594 * the real UID. If the sugid case is going to write into the 1595 * controlled directory, we do so as root. 1596 */ 1597 if (incrash == 0) { 1598 cred = crdup(cred); 1599 cred->cr_uid = cred->cr_ruid; 1600 cred->cr_gid = cred->cr_rgid; 1601 } else { 1602 if (p->p_fd->fd_rdir) { 1603 vrele(p->p_fd->fd_rdir); 1604 p->p_fd->fd_rdir = NULL; 1605 } 1606 p->p_ucred = crdup(p->p_ucred); 1607 crfree(cred); 1608 cred = p->p_ucred; 1609 crhold(cred); 1610 cred->cr_uid = 0; 1611 cred->cr_gid = 0; 1612 } 1613 1614 /* incrash should be 0 or KERNELPATH only */ 1615 NDINIT(&nd, 0, incrash, UIO_SYSSPACE, name, p); 1616 1617 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW | O_NONBLOCK, 1618 S_IRUSR | S_IWUSR); 1619 1620 if (error) 1621 goto out; 1622 1623 /* 1624 * Don't dump to non-regular files, files with links, or files 1625 * owned by someone else. 1626 */ 1627 vp = nd.ni_vp; 1628 if ((error = VOP_GETATTR(vp, &vattr, cred, p)) != 0) { 1629 VOP_UNLOCK(vp); 1630 vn_close(vp, FWRITE, cred, p); 1631 goto out; 1632 } 1633 if (vp->v_type != VREG || vattr.va_nlink != 1 || 1634 vattr.va_mode & ((VREAD | VWRITE) >> 3 | (VREAD | VWRITE) >> 6) || 1635 vattr.va_uid != cred->cr_uid) { 1636 error = EACCES; 1637 VOP_UNLOCK(vp); 1638 vn_close(vp, FWRITE, cred, p); 1639 goto out; 1640 } 1641 VATTR_NULL(&vattr); 1642 vattr.va_size = 0; 1643 VOP_SETATTR(vp, &vattr, cred, p); 1644 pr->ps_acflag |= ACORE; 1645 1646 io.io_proc = p; 1647 io.io_vp = vp; 1648 io.io_cred = cred; 1649 io.io_offset = 0; 1650 VOP_UNLOCK(vp); 1651 vref(vp); 1652 error = vn_close(vp, FWRITE, cred, p); 1653 if (error == 0) 1654 error = (*pr->ps_emul->e_coredump)(p, &io); 1655 vrele(vp); 1656 out: 1657 crfree(cred); 1658 pool_put(&namei_pool, name); 1659 return (error); 1660 #endif 1661 } 1662 1663 #ifndef SMALL_KERNEL 1664 int 1665 coredump_write(void *cookie, enum uio_seg segflg, const void *data, size_t len) 1666 { 1667 struct coredump_iostate *io = cookie; 1668 off_t coffset = 0; 1669 size_t csize; 1670 int chunk, error; 1671 1672 csize = len; 1673 do { 1674 if (sigmask(SIGKILL) & 1675 (io->io_proc->p_siglist | io->io_proc->p_p->ps_siglist)) 1676 return (EINTR); 1677 1678 /* Rest of the loop sleeps with lock held, so... */ 1679 yield(); 1680 1681 chunk = MIN(csize, MAXPHYS); 1682 error = vn_rdwr(UIO_WRITE, io->io_vp, 1683 (caddr_t)data + coffset, chunk, 1684 io->io_offset + coffset, segflg, 1685 IO_UNIT, io->io_cred, NULL, io->io_proc); 1686 if (error) { 1687 struct process *pr = io->io_proc->p_p; 1688 1689 if (error == ENOSPC) 1690 log(LOG_ERR, 1691 "coredump of %s(%d) failed, filesystem full\n", 1692 pr->ps_comm, pr->ps_pid); 1693 else 1694 log(LOG_ERR, 1695 "coredump of %s(%d), write failed: errno %d\n", 1696 pr->ps_comm, pr->ps_pid, error); 1697 return (error); 1698 } 1699 1700 coffset += chunk; 1701 csize -= chunk; 1702 } while (csize > 0); 1703 1704 io->io_offset += len; 1705 return (0); 1706 } 1707 1708 void 1709 coredump_unmap(void *cookie, vaddr_t start, vaddr_t end) 1710 { 1711 struct coredump_iostate *io = cookie; 1712 1713 uvm_unmap(&io->io_proc->p_vmspace->vm_map, start, end); 1714 } 1715 1716 #endif /* !SMALL_KERNEL */ 1717 1718 /* 1719 * Nonexistent system call-- signal process (may want to handle it). 1720 * Flag error in case process won't see signal immediately (blocked or ignored). 1721 */ 1722 int 1723 sys_nosys(struct proc *p, void *v, register_t *retval) 1724 { 1725 1726 ptsignal(p, SIGSYS, STHREAD); 1727 return (ENOSYS); 1728 } 1729 1730 int 1731 sys___thrsigdivert(struct proc *p, void *v, register_t *retval) 1732 { 1733 static int sigwaitsleep; 1734 struct sys___thrsigdivert_args /* { 1735 syscallarg(sigset_t) sigmask; 1736 syscallarg(siginfo_t *) info; 1737 syscallarg(const struct timespec *) timeout; 1738 } */ *uap = v; 1739 struct process *pr = p->p_p; 1740 sigset_t *m; 1741 sigset_t mask = SCARG(uap, sigmask) &~ sigcantmask; 1742 siginfo_t si; 1743 uint64_t nsecs = INFSLP; 1744 int timeinvalid = 0; 1745 int error = 0; 1746 1747 memset(&si, 0, sizeof(si)); 1748 1749 if (SCARG(uap, timeout) != NULL) { 1750 struct timespec ts; 1751 if ((error = copyin(SCARG(uap, timeout), &ts, sizeof(ts))) != 0) 1752 return (error); 1753 #ifdef KTRACE 1754 if (KTRPOINT(p, KTR_STRUCT)) 1755 ktrreltimespec(p, &ts); 1756 #endif 1757 if (!timespecisvalid(&ts)) 1758 timeinvalid = 1; 1759 else 1760 nsecs = TIMESPEC_TO_NSEC(&ts); 1761 } 1762 1763 dosigsuspend(p, p->p_sigmask &~ mask); 1764 for (;;) { 1765 si.si_signo = CURSIG(p); 1766 if (si.si_signo != 0) { 1767 sigset_t smask = sigmask(si.si_signo); 1768 if (smask & mask) { 1769 if (p->p_siglist & smask) 1770 m = &p->p_siglist; 1771 else if (pr->ps_siglist & smask) 1772 m = &pr->ps_siglist; 1773 else { 1774 /* signal got eaten by someone else? */ 1775 continue; 1776 } 1777 atomic_clearbits_int(m, smask); 1778 error = 0; 1779 break; 1780 } 1781 } 1782 1783 /* per-POSIX, delay this error until after the above */ 1784 if (timeinvalid) 1785 error = EINVAL; 1786 1787 if (SCARG(uap, timeout) != NULL && nsecs == INFSLP) 1788 error = EAGAIN; 1789 1790 if (error != 0) 1791 break; 1792 1793 error = tsleep_nsec(&sigwaitsleep, PPAUSE|PCATCH, "sigwait", 1794 nsecs); 1795 } 1796 1797 if (error == 0) { 1798 *retval = si.si_signo; 1799 if (SCARG(uap, info) != NULL) 1800 error = copyout(&si, SCARG(uap, info), sizeof(si)); 1801 } else if (error == ERESTART && SCARG(uap, timeout) != NULL) { 1802 /* 1803 * Restarting is wrong if there's a timeout, as it'll be 1804 * for the same interval again 1805 */ 1806 error = EINTR; 1807 } 1808 1809 return (error); 1810 } 1811 1812 void 1813 initsiginfo(siginfo_t *si, int sig, u_long trapno, int code, union sigval val) 1814 { 1815 memset(si, 0, sizeof(*si)); 1816 1817 si->si_signo = sig; 1818 si->si_code = code; 1819 if (code == SI_USER) { 1820 si->si_value = val; 1821 } else { 1822 switch (sig) { 1823 case SIGSEGV: 1824 case SIGILL: 1825 case SIGBUS: 1826 case SIGFPE: 1827 si->si_addr = val.sival_ptr; 1828 si->si_trapno = trapno; 1829 break; 1830 case SIGXFSZ: 1831 break; 1832 } 1833 } 1834 } 1835 1836 int 1837 filt_sigattach(struct knote *kn) 1838 { 1839 struct process *pr = curproc->p_p; 1840 int s; 1841 1842 if (kn->kn_id >= NSIG) 1843 return EINVAL; 1844 1845 kn->kn_ptr.p_process = pr; 1846 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1847 1848 s = splhigh(); 1849 klist_insert(&pr->ps_klist, kn); 1850 splx(s); 1851 1852 return (0); 1853 } 1854 1855 void 1856 filt_sigdetach(struct knote *kn) 1857 { 1858 struct process *pr = kn->kn_ptr.p_process; 1859 int s; 1860 1861 s = splhigh(); 1862 klist_remove(&pr->ps_klist, kn); 1863 splx(s); 1864 } 1865 1866 /* 1867 * signal knotes are shared with proc knotes, so we apply a mask to 1868 * the hint in order to differentiate them from process hints. This 1869 * could be avoided by using a signal-specific knote list, but probably 1870 * isn't worth the trouble. 1871 */ 1872 int 1873 filt_signal(struct knote *kn, long hint) 1874 { 1875 1876 if (hint & NOTE_SIGNAL) { 1877 hint &= ~NOTE_SIGNAL; 1878 1879 if (kn->kn_id == hint) 1880 kn->kn_data++; 1881 } 1882 return (kn->kn_data != 0); 1883 } 1884 1885 void 1886 userret(struct proc *p) 1887 { 1888 int signum; 1889 1890 /* send SIGPROF or SIGVTALRM if their timers interrupted this thread */ 1891 if (p->p_flag & P_PROFPEND) { 1892 atomic_clearbits_int(&p->p_flag, P_PROFPEND); 1893 KERNEL_LOCK(); 1894 psignal(p, SIGPROF); 1895 KERNEL_UNLOCK(); 1896 } 1897 if (p->p_flag & P_ALRMPEND) { 1898 atomic_clearbits_int(&p->p_flag, P_ALRMPEND); 1899 KERNEL_LOCK(); 1900 psignal(p, SIGVTALRM); 1901 KERNEL_UNLOCK(); 1902 } 1903 1904 if (SIGPENDING(p) != 0) { 1905 KERNEL_LOCK(); 1906 while ((signum = CURSIG(p)) != 0) 1907 postsig(p, signum); 1908 KERNEL_UNLOCK(); 1909 } 1910 1911 /* 1912 * If P_SIGSUSPEND is still set here, then we still need to restore 1913 * the original sigmask before returning to userspace. Also, this 1914 * might unmask some pending signals, so we need to check a second 1915 * time for signals to post. 1916 */ 1917 if (p->p_flag & P_SIGSUSPEND) { 1918 atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); 1919 p->p_sigmask = p->p_oldmask; 1920 1921 KERNEL_LOCK(); 1922 while ((signum = CURSIG(p)) != 0) 1923 postsig(p, signum); 1924 KERNEL_UNLOCK(); 1925 } 1926 1927 if (p->p_flag & P_SUSPSINGLE) 1928 single_thread_check(p, 0); 1929 1930 WITNESS_WARN(WARN_PANIC, NULL, "userret: returning"); 1931 1932 p->p_cpu->ci_schedstate.spc_curpriority = p->p_usrpri; 1933 } 1934 1935 int 1936 single_thread_check(struct proc *p, int deep) 1937 { 1938 struct process *pr = p->p_p; 1939 1940 if (pr->ps_single != NULL && pr->ps_single != p) { 1941 do { 1942 int s; 1943 1944 /* if we're in deep, we need to unwind to the edge */ 1945 if (deep) { 1946 if (pr->ps_flags & PS_SINGLEUNWIND) 1947 return (ERESTART); 1948 if (pr->ps_flags & PS_SINGLEEXIT) 1949 return (EINTR); 1950 } 1951 1952 SCHED_LOCK(s); 1953 if (pr->ps_single == NULL) { 1954 SCHED_UNLOCK(s); 1955 continue; 1956 } 1957 1958 if (atomic_dec_int_nv(&pr->ps_singlecount) == 0) 1959 wakeup(&pr->ps_singlecount); 1960 if (pr->ps_flags & PS_SINGLEEXIT) { 1961 SCHED_UNLOCK(s); 1962 KERNEL_LOCK(); 1963 exit1(p, 0, 0, EXIT_THREAD_NOCHECK); 1964 /* NOTREACHED */ 1965 } 1966 1967 /* not exiting and don't need to unwind, so suspend */ 1968 p->p_stat = SSTOP; 1969 mi_switch(); 1970 SCHED_UNLOCK(s); 1971 } while (pr->ps_single != NULL); 1972 } 1973 1974 return (0); 1975 } 1976 1977 /* 1978 * Stop other threads in the process. The mode controls how and 1979 * where the other threads should stop: 1980 * - SINGLE_SUSPEND: stop wherever they are, will later either be told to exit 1981 * (by setting to SINGLE_EXIT) or be released (via single_thread_clear()) 1982 * - SINGLE_PTRACE: stop wherever they are, will wait for them to stop 1983 * later (via single_thread_wait()) and released as with SINGLE_SUSPEND 1984 * - SINGLE_UNWIND: just unwind to kernel boundary, will be told to exit 1985 * or released as with SINGLE_SUSPEND 1986 * - SINGLE_EXIT: unwind to kernel boundary and exit 1987 */ 1988 int 1989 single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) 1990 { 1991 struct process *pr = p->p_p; 1992 struct proc *q; 1993 int error, s; 1994 1995 KERNEL_ASSERT_LOCKED(); 1996 KASSERT(curproc == p); 1997 1998 if ((error = single_thread_check(p, deep))) 1999 return error; 2000 2001 switch (mode) { 2002 case SINGLE_SUSPEND: 2003 case SINGLE_PTRACE: 2004 break; 2005 case SINGLE_UNWIND: 2006 atomic_setbits_int(&pr->ps_flags, PS_SINGLEUNWIND); 2007 break; 2008 case SINGLE_EXIT: 2009 atomic_setbits_int(&pr->ps_flags, PS_SINGLEEXIT); 2010 atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND); 2011 break; 2012 #ifdef DIAGNOSTIC 2013 default: 2014 panic("single_thread_mode = %d", mode); 2015 #endif 2016 } 2017 SCHED_LOCK(s); 2018 pr->ps_singlecount = 0; 2019 membar_producer(); 2020 pr->ps_single = p; 2021 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 2022 if (q == p) 2023 continue; 2024 if (q->p_flag & P_WEXIT) { 2025 if (mode == SINGLE_EXIT) { 2026 if (q->p_stat == SSTOP) { 2027 setrunnable(q); 2028 atomic_inc_int(&pr->ps_singlecount); 2029 } 2030 } 2031 continue; 2032 } 2033 atomic_setbits_int(&q->p_flag, P_SUSPSINGLE); 2034 switch (q->p_stat) { 2035 case SIDL: 2036 case SRUN: 2037 atomic_inc_int(&pr->ps_singlecount); 2038 break; 2039 case SSLEEP: 2040 /* if it's not interruptible, then just have to wait */ 2041 if (q->p_flag & P_SINTR) { 2042 /* merely need to suspend? just stop it */ 2043 if (mode == SINGLE_SUSPEND || 2044 mode == SINGLE_PTRACE) { 2045 q->p_stat = SSTOP; 2046 break; 2047 } 2048 /* need to unwind or exit, so wake it */ 2049 setrunnable(q); 2050 } 2051 atomic_inc_int(&pr->ps_singlecount); 2052 break; 2053 case SSTOP: 2054 if (mode == SINGLE_EXIT) { 2055 setrunnable(q); 2056 atomic_inc_int(&pr->ps_singlecount); 2057 } 2058 break; 2059 case SDEAD: 2060 break; 2061 case SONPROC: 2062 atomic_inc_int(&pr->ps_singlecount); 2063 signotify(q); 2064 break; 2065 } 2066 } 2067 SCHED_UNLOCK(s); 2068 2069 if (mode != SINGLE_PTRACE) 2070 single_thread_wait(pr, 1); 2071 2072 return 0; 2073 } 2074 2075 /* 2076 * Wait for other threads to stop. If recheck is false then the function 2077 * returns non-zero if the caller needs to restart the check else 0 is 2078 * returned. If recheck is true the return value is always 0. 2079 */ 2080 int 2081 single_thread_wait(struct process *pr, int recheck) 2082 { 2083 struct sleep_state sls; 2084 int wait; 2085 2086 /* wait until they're all suspended */ 2087 wait = pr->ps_singlecount > 0; 2088 while (wait) { 2089 sleep_setup(&sls, &pr->ps_singlecount, PWAIT, "suspend"); 2090 wait = pr->ps_singlecount > 0; 2091 sleep_finish(&sls, wait); 2092 if (!recheck) 2093 break; 2094 } 2095 2096 return wait; 2097 } 2098 2099 void 2100 single_thread_clear(struct proc *p, int flag) 2101 { 2102 struct process *pr = p->p_p; 2103 struct proc *q; 2104 int s; 2105 2106 KASSERT(pr->ps_single == p); 2107 KASSERT(curproc == p); 2108 KERNEL_ASSERT_LOCKED(); 2109 2110 SCHED_LOCK(s); 2111 pr->ps_single = NULL; 2112 atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND | PS_SINGLEEXIT); 2113 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 2114 if (q == p || (q->p_flag & P_SUSPSINGLE) == 0) 2115 continue; 2116 atomic_clearbits_int(&q->p_flag, P_SUSPSINGLE); 2117 2118 /* 2119 * if the thread was only stopped for single threading 2120 * then clearing that either makes it runnable or puts 2121 * it back into some sleep queue 2122 */ 2123 if (q->p_stat == SSTOP && (q->p_flag & flag) == 0) { 2124 if (q->p_wchan == 0) 2125 setrunnable(q); 2126 else 2127 q->p_stat = SSLEEP; 2128 } 2129 } 2130 SCHED_UNLOCK(s); 2131 } 2132 2133 void 2134 sigio_del(struct sigiolst *rmlist) 2135 { 2136 struct sigio *sigio; 2137 2138 while ((sigio = LIST_FIRST(rmlist)) != NULL) { 2139 LIST_REMOVE(sigio, sio_pgsigio); 2140 crfree(sigio->sio_ucred); 2141 free(sigio, M_SIGIO, sizeof(*sigio)); 2142 } 2143 } 2144 2145 void 2146 sigio_unlink(struct sigio_ref *sir, struct sigiolst *rmlist) 2147 { 2148 struct sigio *sigio; 2149 2150 MUTEX_ASSERT_LOCKED(&sigio_lock); 2151 2152 sigio = sir->sir_sigio; 2153 if (sigio != NULL) { 2154 KASSERT(sigio->sio_myref == sir); 2155 sir->sir_sigio = NULL; 2156 2157 if (sigio->sio_pgid > 0) 2158 sigio->sio_proc = NULL; 2159 else 2160 sigio->sio_pgrp = NULL; 2161 LIST_REMOVE(sigio, sio_pgsigio); 2162 2163 LIST_INSERT_HEAD(rmlist, sigio, sio_pgsigio); 2164 } 2165 } 2166 2167 void 2168 sigio_free(struct sigio_ref *sir) 2169 { 2170 struct sigiolst rmlist; 2171 2172 if (sir->sir_sigio == NULL) 2173 return; 2174 2175 LIST_INIT(&rmlist); 2176 2177 mtx_enter(&sigio_lock); 2178 sigio_unlink(sir, &rmlist); 2179 mtx_leave(&sigio_lock); 2180 2181 sigio_del(&rmlist); 2182 } 2183 2184 void 2185 sigio_freelist(struct sigiolst *sigiolst) 2186 { 2187 struct sigiolst rmlist; 2188 struct sigio *sigio; 2189 2190 if (LIST_EMPTY(sigiolst)) 2191 return; 2192 2193 LIST_INIT(&rmlist); 2194 2195 mtx_enter(&sigio_lock); 2196 while ((sigio = LIST_FIRST(sigiolst)) != NULL) 2197 sigio_unlink(sigio->sio_myref, &rmlist); 2198 mtx_leave(&sigio_lock); 2199 2200 sigio_del(&rmlist); 2201 } 2202 2203 int 2204 sigio_setown(struct sigio_ref *sir, u_long cmd, caddr_t data) 2205 { 2206 struct sigiolst rmlist; 2207 struct proc *p = curproc; 2208 struct pgrp *pgrp = NULL; 2209 struct process *pr = NULL; 2210 struct sigio *sigio; 2211 int error; 2212 pid_t pgid = *(int *)data; 2213 2214 if (pgid == 0) { 2215 sigio_free(sir); 2216 return (0); 2217 } 2218 2219 if (cmd == TIOCSPGRP) { 2220 if (pgid < 0) 2221 return (EINVAL); 2222 pgid = -pgid; 2223 } 2224 2225 sigio = malloc(sizeof(*sigio), M_SIGIO, M_WAITOK); 2226 sigio->sio_pgid = pgid; 2227 sigio->sio_ucred = crhold(p->p_ucred); 2228 sigio->sio_myref = sir; 2229 2230 LIST_INIT(&rmlist); 2231 2232 /* 2233 * The kernel lock, and not sleeping between prfind()/pgfind() and 2234 * linking of the sigio ensure that the process or process group does 2235 * not disappear unexpectedly. 2236 */ 2237 KERNEL_LOCK(); 2238 mtx_enter(&sigio_lock); 2239 2240 if (pgid > 0) { 2241 pr = prfind(pgid); 2242 if (pr == NULL) { 2243 error = ESRCH; 2244 goto fail; 2245 } 2246 2247 /* 2248 * Policy - Don't allow a process to FSETOWN a process 2249 * in another session. 2250 * 2251 * Remove this test to allow maximum flexibility or 2252 * restrict FSETOWN to the current process or process 2253 * group for maximum safety. 2254 */ 2255 if (pr->ps_session != p->p_p->ps_session) { 2256 error = EPERM; 2257 goto fail; 2258 } 2259 2260 if ((pr->ps_flags & PS_EXITING) != 0) { 2261 error = ESRCH; 2262 goto fail; 2263 } 2264 } else /* if (pgid < 0) */ { 2265 pgrp = pgfind(-pgid); 2266 if (pgrp == NULL) { 2267 error = ESRCH; 2268 goto fail; 2269 } 2270 2271 /* 2272 * Policy - Don't allow a process to FSETOWN a process 2273 * in another session. 2274 * 2275 * Remove this test to allow maximum flexibility or 2276 * restrict FSETOWN to the current process or process 2277 * group for maximum safety. 2278 */ 2279 if (pgrp->pg_session != p->p_p->ps_session) { 2280 error = EPERM; 2281 goto fail; 2282 } 2283 } 2284 2285 if (pgid > 0) { 2286 sigio->sio_proc = pr; 2287 LIST_INSERT_HEAD(&pr->ps_sigiolst, sigio, sio_pgsigio); 2288 } else { 2289 sigio->sio_pgrp = pgrp; 2290 LIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 2291 } 2292 2293 sigio_unlink(sir, &rmlist); 2294 sir->sir_sigio = sigio; 2295 2296 mtx_leave(&sigio_lock); 2297 KERNEL_UNLOCK(); 2298 2299 sigio_del(&rmlist); 2300 2301 return (0); 2302 2303 fail: 2304 mtx_leave(&sigio_lock); 2305 KERNEL_UNLOCK(); 2306 2307 crfree(sigio->sio_ucred); 2308 free(sigio, M_SIGIO, sizeof(*sigio)); 2309 2310 return (error); 2311 } 2312 2313 void 2314 sigio_getown(struct sigio_ref *sir, u_long cmd, caddr_t data) 2315 { 2316 struct sigio *sigio; 2317 pid_t pgid = 0; 2318 2319 mtx_enter(&sigio_lock); 2320 sigio = sir->sir_sigio; 2321 if (sigio != NULL) 2322 pgid = sigio->sio_pgid; 2323 mtx_leave(&sigio_lock); 2324 2325 if (cmd == TIOCGPGRP) 2326 pgid = -pgid; 2327 2328 *(int *)data = pgid; 2329 } 2330 2331 void 2332 sigio_copy(struct sigio_ref *dst, struct sigio_ref *src) 2333 { 2334 struct sigiolst rmlist; 2335 struct sigio *newsigio, *sigio; 2336 2337 sigio_free(dst); 2338 2339 if (src->sir_sigio == NULL) 2340 return; 2341 2342 newsigio = malloc(sizeof(*newsigio), M_SIGIO, M_WAITOK); 2343 LIST_INIT(&rmlist); 2344 2345 mtx_enter(&sigio_lock); 2346 2347 sigio = src->sir_sigio; 2348 if (sigio == NULL) { 2349 mtx_leave(&sigio_lock); 2350 free(newsigio, M_SIGIO, sizeof(*newsigio)); 2351 return; 2352 } 2353 2354 newsigio->sio_pgid = sigio->sio_pgid; 2355 newsigio->sio_ucred = crhold(sigio->sio_ucred); 2356 newsigio->sio_myref = dst; 2357 if (newsigio->sio_pgid > 0) { 2358 newsigio->sio_proc = sigio->sio_proc; 2359 LIST_INSERT_HEAD(&newsigio->sio_proc->ps_sigiolst, newsigio, 2360 sio_pgsigio); 2361 } else { 2362 newsigio->sio_pgrp = sigio->sio_pgrp; 2363 LIST_INSERT_HEAD(&newsigio->sio_pgrp->pg_sigiolst, newsigio, 2364 sio_pgsigio); 2365 } 2366 2367 sigio_unlink(dst, &rmlist); 2368 dst->sir_sigio = newsigio; 2369 2370 mtx_leave(&sigio_lock); 2371 2372 sigio_del(&rmlist); 2373 } 2374