1 /* $OpenBSD: kern_sig.c,v 1.284 2021/10/04 08:48:12 claudio 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 * After vfs_shutdown(9), init(8) cannot receive signals 846 * because new code pages of the signal handler cannot be 847 * mapped from halted storage. init(8) may not die or the 848 * kernel panics. Better loop between signal handler and 849 * page fault trap until the machine is halted. 850 */ 851 if ((pr->ps_flags & PS_TRACED) == 0 && 852 (sigprop[signum] & SA_KILL) && 853 ((p->p_sigmask & mask) || (ps->ps_sigignore & mask)) && 854 pr->ps_pid != 1) 855 sigexit(p, signum); 856 ptsignal(p, signum, STHREAD); 857 } 858 KERNEL_UNLOCK(); 859 } 860 861 /* 862 * Send the signal to the process. If the signal has an action, the action 863 * is usually performed by the target process rather than the caller; we add 864 * the signal to the set of pending signals for the process. 865 * 866 * Exceptions: 867 * o When a stop signal is sent to a sleeping process that takes the 868 * default action, the process is stopped without awakening it. 869 * o SIGCONT restarts stopped processes (or puts them back to sleep) 870 * regardless of the signal action (eg, blocked or ignored). 871 * 872 * Other ignored signals are discarded immediately. 873 */ 874 void 875 psignal(struct proc *p, int signum) 876 { 877 ptsignal(p, signum, SPROCESS); 878 } 879 880 /* 881 * type = SPROCESS process signal, can be diverted (sigwait()) 882 * type = STHREAD thread signal, but should be propagated if unhandled 883 * type = SPROPAGATED propagated to this thread, so don't propagate again 884 */ 885 void 886 ptsignal(struct proc *p, int signum, enum signal_type type) 887 { 888 int s, prop; 889 sig_t action; 890 int mask; 891 int *siglist; 892 struct process *pr = p->p_p; 893 struct proc *q; 894 int wakeparent = 0; 895 896 KERNEL_ASSERT_LOCKED(); 897 898 #ifdef DIAGNOSTIC 899 if ((u_int)signum >= NSIG || signum == 0) 900 panic("psignal signal number"); 901 #endif 902 903 /* Ignore signal if the target process is exiting */ 904 if (pr->ps_flags & PS_EXITING) 905 return; 906 907 mask = sigmask(signum); 908 909 if (type == SPROCESS) { 910 /* Accept SIGKILL to coredumping processes */ 911 if (pr->ps_flags & PS_COREDUMP && signum == SIGKILL) { 912 atomic_setbits_int(&pr->ps_siglist, mask); 913 return; 914 } 915 916 /* 917 * If the current thread can process the signal 918 * immediately (it's unblocked) then have it take it. 919 */ 920 q = curproc; 921 if (q != NULL && q->p_p == pr && (q->p_flag & P_WEXIT) == 0 && 922 (q->p_sigmask & mask) == 0) 923 p = q; 924 else { 925 /* 926 * A process-wide signal can be diverted to a 927 * different thread that's in sigwait() for this 928 * signal. If there isn't such a thread, then 929 * pick a thread that doesn't have it blocked so 930 * that the stop/kill consideration isn't 931 * delayed. Otherwise, mark it pending on the 932 * main thread. 933 */ 934 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 935 /* ignore exiting threads */ 936 if (q->p_flag & P_WEXIT) 937 continue; 938 939 /* skip threads that have the signal blocked */ 940 if ((q->p_sigmask & mask) != 0) 941 continue; 942 943 /* okay, could send to this thread */ 944 p = q; 945 946 /* 947 * sigsuspend, sigwait, ppoll/pselect, etc? 948 * Definitely go to this thread, as it's 949 * already blocked in the kernel. 950 */ 951 if (q->p_flag & P_SIGSUSPEND) 952 break; 953 } 954 } 955 } 956 957 if (type != SPROPAGATED) 958 KNOTE(&pr->ps_klist, NOTE_SIGNAL | signum); 959 960 prop = sigprop[signum]; 961 962 /* 963 * If proc is traced, always give parent a chance. 964 */ 965 if (pr->ps_flags & PS_TRACED) { 966 action = SIG_DFL; 967 } else { 968 /* 969 * If the signal is being ignored, 970 * then we forget about it immediately. 971 * (Note: we don't set SIGCONT in ps_sigignore, 972 * and if it is set to SIG_IGN, 973 * action will be SIG_DFL here.) 974 */ 975 if (pr->ps_sigacts->ps_sigignore & mask) 976 return; 977 if (p->p_sigmask & mask) { 978 action = SIG_HOLD; 979 } else if (pr->ps_sigacts->ps_sigcatch & mask) { 980 action = SIG_CATCH; 981 } else { 982 action = SIG_DFL; 983 984 if (prop & SA_KILL && pr->ps_nice > NZERO) 985 pr->ps_nice = NZERO; 986 987 /* 988 * If sending a tty stop signal to a member of an 989 * orphaned process group, discard the signal here if 990 * the action is default; don't stop the process below 991 * if sleeping, and don't clear any pending SIGCONT. 992 */ 993 if (prop & SA_TTYSTOP && pr->ps_pgrp->pg_jobc == 0) 994 return; 995 } 996 } 997 /* 998 * If delivered to process, mark as pending there. Continue and stop 999 * signals will be propagated to all threads. So they are always 1000 * marked at thread level. 1001 */ 1002 siglist = (type == SPROCESS) ? &pr->ps_siglist : &p->p_siglist; 1003 if (prop & SA_CONT) { 1004 siglist = &p->p_siglist; 1005 atomic_clearbits_int(siglist, STOPSIGMASK); 1006 } 1007 if (prop & SA_STOP) { 1008 siglist = &p->p_siglist; 1009 atomic_clearbits_int(siglist, CONTSIGMASK); 1010 atomic_clearbits_int(&p->p_flag, P_CONTINUED); 1011 } 1012 atomic_setbits_int(siglist, mask); 1013 1014 /* 1015 * XXX delay processing of SA_STOP signals unless action == SIG_DFL? 1016 */ 1017 if (prop & (SA_CONT | SA_STOP) && type != SPROPAGATED) 1018 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) 1019 if (q != p) 1020 ptsignal(q, signum, SPROPAGATED); 1021 1022 /* 1023 * Defer further processing for signals which are held, 1024 * except that stopped processes must be continued by SIGCONT. 1025 */ 1026 if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) 1027 return; 1028 1029 SCHED_LOCK(s); 1030 1031 switch (p->p_stat) { 1032 1033 case SSLEEP: 1034 /* 1035 * If process is sleeping uninterruptibly 1036 * we can't interrupt the sleep... the signal will 1037 * be noticed when the process returns through 1038 * trap() or syscall(). 1039 */ 1040 if ((p->p_flag & P_SINTR) == 0) 1041 goto out; 1042 /* 1043 * Process is sleeping and traced... make it runnable 1044 * so it can discover the signal in cursig() and stop 1045 * for the parent. 1046 */ 1047 if (pr->ps_flags & PS_TRACED) 1048 goto run; 1049 /* 1050 * If SIGCONT is default (or ignored) and process is 1051 * asleep, we are finished; the process should not 1052 * be awakened. 1053 */ 1054 if ((prop & SA_CONT) && action == SIG_DFL) { 1055 atomic_clearbits_int(siglist, mask); 1056 goto out; 1057 } 1058 /* 1059 * When a sleeping process receives a stop 1060 * signal, process immediately if possible. 1061 */ 1062 if ((prop & SA_STOP) && action == SIG_DFL) { 1063 /* 1064 * If a child holding parent blocked, 1065 * stopping could cause deadlock. 1066 */ 1067 if (pr->ps_flags & PS_PPWAIT) 1068 goto out; 1069 atomic_clearbits_int(siglist, mask); 1070 pr->ps_xsig = signum; 1071 proc_stop(p, 0); 1072 goto out; 1073 } 1074 /* 1075 * All other (caught or default) signals 1076 * cause the process to run. 1077 */ 1078 goto runfast; 1079 /*NOTREACHED*/ 1080 1081 case SSTOP: 1082 /* 1083 * If traced process is already stopped, 1084 * then no further action is necessary. 1085 */ 1086 if (pr->ps_flags & PS_TRACED) 1087 goto out; 1088 1089 /* 1090 * Kill signal always sets processes running. 1091 */ 1092 if (signum == SIGKILL) { 1093 atomic_clearbits_int(&p->p_flag, P_SUSPSIG); 1094 goto runfast; 1095 } 1096 1097 if (prop & SA_CONT) { 1098 /* 1099 * If SIGCONT is default (or ignored), we continue the 1100 * process but don't leave the signal in p_siglist, as 1101 * it has no further action. If SIGCONT is held, we 1102 * continue the process and leave the signal in 1103 * p_siglist. If the process catches SIGCONT, let it 1104 * handle the signal itself. If it isn't waiting on 1105 * an event, then it goes back to run state. 1106 * Otherwise, process goes back to sleep state. 1107 */ 1108 atomic_setbits_int(&p->p_flag, P_CONTINUED); 1109 atomic_clearbits_int(&p->p_flag, P_SUSPSIG); 1110 wakeparent = 1; 1111 if (action == SIG_DFL) 1112 atomic_clearbits_int(siglist, mask); 1113 if (action == SIG_CATCH) 1114 goto runfast; 1115 if (p->p_wchan == 0) 1116 goto run; 1117 p->p_stat = SSLEEP; 1118 goto out; 1119 } 1120 1121 if (prop & SA_STOP) { 1122 /* 1123 * Already stopped, don't need to stop again. 1124 * (If we did the shell could get confused.) 1125 */ 1126 atomic_clearbits_int(siglist, mask); 1127 goto out; 1128 } 1129 1130 /* 1131 * If process is sleeping interruptibly, then simulate a 1132 * wakeup so that when it is continued, it will be made 1133 * runnable and can look at the signal. But don't make 1134 * the process runnable, leave it stopped. 1135 */ 1136 if (p->p_flag & P_SINTR) 1137 unsleep(p); 1138 goto out; 1139 1140 case SONPROC: 1141 signotify(p); 1142 /* FALLTHROUGH */ 1143 default: 1144 /* 1145 * SRUN, SIDL, SDEAD do nothing with the signal, 1146 * other than kicking ourselves if we are running. 1147 * It will either never be noticed, or noticed very soon. 1148 */ 1149 goto out; 1150 } 1151 /*NOTREACHED*/ 1152 1153 runfast: 1154 /* 1155 * Raise priority to at least PUSER. 1156 */ 1157 if (p->p_usrpri > PUSER) 1158 p->p_usrpri = PUSER; 1159 run: 1160 setrunnable(p); 1161 out: 1162 SCHED_UNLOCK(s); 1163 if (wakeparent) 1164 wakeup(pr->ps_pptr); 1165 } 1166 1167 /* 1168 * Determine signal that should be delivered to process p, the current 1169 * process, 0 if none. 1170 * 1171 * If the current process has received a signal (should be caught or cause 1172 * termination, should interrupt current syscall), return the signal number. 1173 * Stop signals with default action are processed immediately, then cleared; 1174 * they aren't returned. This is checked after each entry to the system for 1175 * a syscall or trap. The normal call sequence is 1176 * 1177 * while (signum = cursig(curproc)) 1178 * postsig(signum); 1179 * 1180 * Assumes that if the P_SINTR flag is set, we're holding both the 1181 * kernel and scheduler locks. 1182 */ 1183 int 1184 cursig(struct proc *p) 1185 { 1186 struct process *pr = p->p_p; 1187 int sigpending, signum, mask, prop; 1188 int dolock = (p->p_flag & P_SINTR) == 0; 1189 int s; 1190 1191 KERNEL_ASSERT_LOCKED(); 1192 1193 sigpending = (p->p_siglist | pr->ps_siglist); 1194 if (sigpending == 0) 1195 return 0; 1196 1197 if (!ISSET(pr->ps_flags, PS_TRACED) && SIGPENDING(p) == 0) 1198 return 0; 1199 1200 for (;;) { 1201 mask = SIGPENDING(p); 1202 if (pr->ps_flags & PS_PPWAIT) 1203 mask &= ~STOPSIGMASK; 1204 if (mask == 0) /* no signal to send */ 1205 return (0); 1206 signum = ffs((long)mask); 1207 mask = sigmask(signum); 1208 atomic_clearbits_int(&p->p_siglist, mask); 1209 atomic_clearbits_int(&pr->ps_siglist, mask); 1210 1211 /* 1212 * We should see pending but ignored signals 1213 * only if PS_TRACED was on when they were posted. 1214 */ 1215 if (mask & pr->ps_sigacts->ps_sigignore && 1216 (pr->ps_flags & PS_TRACED) == 0) 1217 continue; 1218 1219 /* 1220 * If traced, always stop, and stay stopped until released 1221 * by the debugger. If our parent process is waiting for 1222 * us, don't hang as we could deadlock. 1223 */ 1224 if (((pr->ps_flags & (PS_TRACED | PS_PPWAIT)) == PS_TRACED) && 1225 signum != SIGKILL) { 1226 pr->ps_xsig = signum; 1227 1228 single_thread_set(p, SINGLE_SUSPEND, 0); 1229 1230 if (dolock) 1231 SCHED_LOCK(s); 1232 proc_stop(p, 1); 1233 if (dolock) 1234 SCHED_UNLOCK(s); 1235 1236 single_thread_clear(p, 0); 1237 1238 /* 1239 * If we are no longer being traced, or the parent 1240 * didn't give us a signal, look for more signals. 1241 */ 1242 if ((pr->ps_flags & PS_TRACED) == 0 || 1243 pr->ps_xsig == 0) 1244 continue; 1245 1246 /* 1247 * If the new signal is being masked, look for other 1248 * signals. 1249 */ 1250 signum = pr->ps_xsig; 1251 mask = sigmask(signum); 1252 if ((p->p_sigmask & mask) != 0) 1253 continue; 1254 1255 /* take the signal! */ 1256 atomic_clearbits_int(&p->p_siglist, mask); 1257 atomic_clearbits_int(&pr->ps_siglist, mask); 1258 } 1259 1260 prop = sigprop[signum]; 1261 1262 /* 1263 * Decide whether the signal should be returned. 1264 * Return the signal's number, or fall through 1265 * to clear it from the pending mask. 1266 */ 1267 switch ((long)pr->ps_sigacts->ps_sigact[signum]) { 1268 case (long)SIG_DFL: 1269 /* 1270 * Don't take default actions on system processes. 1271 */ 1272 if (pr->ps_pid <= 1) { 1273 #ifdef DIAGNOSTIC 1274 /* 1275 * Are you sure you want to ignore SIGSEGV 1276 * in init? XXX 1277 */ 1278 printf("Process (pid %d) got signal" 1279 " %d\n", pr->ps_pid, signum); 1280 #endif 1281 break; /* == ignore */ 1282 } 1283 /* 1284 * If there is a pending stop signal to process 1285 * with default action, stop here, 1286 * then clear the signal. However, 1287 * if process is member of an orphaned 1288 * process group, ignore tty stop signals. 1289 */ 1290 if (prop & SA_STOP) { 1291 if (pr->ps_flags & PS_TRACED || 1292 (pr->ps_pgrp->pg_jobc == 0 && 1293 prop & SA_TTYSTOP)) 1294 break; /* == ignore */ 1295 pr->ps_xsig = signum; 1296 if (dolock) 1297 SCHED_LOCK(s); 1298 proc_stop(p, 1); 1299 if (dolock) 1300 SCHED_UNLOCK(s); 1301 break; 1302 } else if (prop & SA_IGNORE) { 1303 /* 1304 * Except for SIGCONT, shouldn't get here. 1305 * Default action is to ignore; drop it. 1306 */ 1307 break; /* == ignore */ 1308 } else 1309 goto keep; 1310 /*NOTREACHED*/ 1311 case (long)SIG_IGN: 1312 /* 1313 * Masking above should prevent us ever trying 1314 * to take action on an ignored signal other 1315 * than SIGCONT, unless process is traced. 1316 */ 1317 if ((prop & SA_CONT) == 0 && 1318 (pr->ps_flags & PS_TRACED) == 0) 1319 printf("%s\n", __func__); 1320 break; /* == ignore */ 1321 default: 1322 /* 1323 * This signal has an action, let 1324 * postsig() process it. 1325 */ 1326 goto keep; 1327 } 1328 } 1329 /* NOTREACHED */ 1330 1331 keep: 1332 atomic_setbits_int(&p->p_siglist, mask); /*leave the signal for later */ 1333 return (signum); 1334 } 1335 1336 /* 1337 * Put the argument process into the stopped state and notify the parent 1338 * via wakeup. Signals are handled elsewhere. The process must not be 1339 * on the run queue. 1340 */ 1341 void 1342 proc_stop(struct proc *p, int sw) 1343 { 1344 struct process *pr = p->p_p; 1345 1346 #ifdef MULTIPROCESSOR 1347 SCHED_ASSERT_LOCKED(); 1348 #endif 1349 1350 p->p_stat = SSTOP; 1351 atomic_clearbits_int(&pr->ps_flags, PS_WAITED); 1352 atomic_setbits_int(&pr->ps_flags, PS_STOPPED); 1353 atomic_setbits_int(&p->p_flag, P_SUSPSIG); 1354 /* 1355 * We need this soft interrupt to be handled fast. 1356 * Extra calls to softclock don't hurt. 1357 */ 1358 softintr_schedule(proc_stop_si); 1359 if (sw) 1360 mi_switch(); 1361 } 1362 1363 /* 1364 * Called from a soft interrupt to send signals to the parents of stopped 1365 * processes. 1366 * We can't do this in proc_stop because it's called with nasty locks held 1367 * and we would need recursive scheduler lock to deal with that. 1368 */ 1369 void 1370 proc_stop_sweep(void *v) 1371 { 1372 struct process *pr; 1373 1374 LIST_FOREACH(pr, &allprocess, ps_list) { 1375 if ((pr->ps_flags & PS_STOPPED) == 0) 1376 continue; 1377 atomic_clearbits_int(&pr->ps_flags, PS_STOPPED); 1378 1379 if ((pr->ps_pptr->ps_sigacts->ps_sigflags & SAS_NOCLDSTOP) == 0) 1380 prsignal(pr->ps_pptr, SIGCHLD); 1381 wakeup(pr->ps_pptr); 1382 } 1383 } 1384 1385 /* 1386 * Take the action for the specified signal 1387 * from the current set of pending signals. 1388 */ 1389 void 1390 postsig(struct proc *p, int signum) 1391 { 1392 struct process *pr = p->p_p; 1393 struct sigacts *ps = pr->ps_sigacts; 1394 sig_t action; 1395 u_long trapno; 1396 int mask, returnmask; 1397 siginfo_t si; 1398 union sigval sigval; 1399 int s, code; 1400 1401 KASSERT(signum != 0); 1402 KERNEL_ASSERT_LOCKED(); 1403 1404 mask = sigmask(signum); 1405 atomic_clearbits_int(&p->p_siglist, mask); 1406 action = ps->ps_sigact[signum]; 1407 sigval.sival_ptr = 0; 1408 1409 if (p->p_sisig != signum) { 1410 trapno = 0; 1411 code = SI_USER; 1412 sigval.sival_ptr = 0; 1413 } else { 1414 trapno = p->p_sitrapno; 1415 code = p->p_sicode; 1416 sigval = p->p_sigval; 1417 } 1418 initsiginfo(&si, signum, trapno, code, sigval); 1419 1420 #ifdef KTRACE 1421 if (KTRPOINT(p, KTR_PSIG)) { 1422 ktrpsig(p, signum, action, p->p_flag & P_SIGSUSPEND ? 1423 p->p_oldmask : p->p_sigmask, code, &si); 1424 } 1425 #endif 1426 if (action == SIG_DFL) { 1427 /* 1428 * Default action, where the default is to kill 1429 * the process. (Other cases were ignored above.) 1430 */ 1431 sigexit(p, signum); 1432 /* NOTREACHED */ 1433 } else { 1434 /* 1435 * If we get here, the signal must be caught. 1436 */ 1437 #ifdef DIAGNOSTIC 1438 if (action == SIG_IGN || (p->p_sigmask & mask)) 1439 panic("postsig action"); 1440 #endif 1441 /* 1442 * Set the new mask value and also defer further 1443 * occurrences of this signal. 1444 * 1445 * Special case: user has done a sigpause. Here the 1446 * current mask is not of interest, but rather the 1447 * mask from before the sigpause is what we want 1448 * restored after the signal processing is completed. 1449 */ 1450 #ifdef MULTIPROCESSOR 1451 s = splsched(); 1452 #else 1453 s = splhigh(); 1454 #endif 1455 if (p->p_flag & P_SIGSUSPEND) { 1456 atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); 1457 returnmask = p->p_oldmask; 1458 } else { 1459 returnmask = p->p_sigmask; 1460 } 1461 if (p->p_sisig == signum) { 1462 p->p_sisig = 0; 1463 p->p_sitrapno = 0; 1464 p->p_sicode = SI_USER; 1465 p->p_sigval.sival_ptr = NULL; 1466 } 1467 1468 if (sendsig(action, signum, returnmask, &si)) { 1469 sigexit(p, SIGILL); 1470 /* NOTREACHED */ 1471 } 1472 postsig_done(p, signum, ps); 1473 splx(s); 1474 } 1475 } 1476 1477 /* 1478 * Force the current process to exit with the specified signal, dumping core 1479 * if appropriate. We bypass the normal tests for masked and caught signals, 1480 * allowing unrecoverable failures to terminate the process without changing 1481 * signal state. Mark the accounting record with the signal termination. 1482 * If dumping core, save the signal number for the debugger. Calls exit and 1483 * does not return. 1484 */ 1485 void 1486 sigexit(struct proc *p, int signum) 1487 { 1488 /* Mark process as going away */ 1489 atomic_setbits_int(&p->p_flag, P_WEXIT); 1490 1491 p->p_p->ps_acflag |= AXSIG; 1492 if (sigprop[signum] & SA_CORE) { 1493 p->p_sisig = signum; 1494 1495 /* if there are other threads, pause them */ 1496 if (P_HASSIBLING(p)) 1497 single_thread_set(p, SINGLE_SUSPEND, 1); 1498 1499 if (coredump(p) == 0) 1500 signum |= WCOREFLAG; 1501 } 1502 exit1(p, 0, signum, EXIT_NORMAL); 1503 /* NOTREACHED */ 1504 } 1505 1506 /* 1507 * Send uncatchable SIGABRT for coredump. 1508 */ 1509 void 1510 sigabort(struct proc *p) 1511 { 1512 struct sigaction sa; 1513 1514 memset(&sa, 0, sizeof sa); 1515 sa.sa_handler = SIG_DFL; 1516 setsigvec(p, SIGABRT, &sa); 1517 atomic_clearbits_int(&p->p_sigmask, sigmask(SIGABRT)); 1518 psignal(p, SIGABRT); 1519 } 1520 1521 /* 1522 * Return 1 if `sig', a given signal, is ignored or masked for `p', a given 1523 * thread, and 0 otherwise. 1524 */ 1525 int 1526 sigismasked(struct proc *p, int sig) 1527 { 1528 struct process *pr = p->p_p; 1529 1530 if ((pr->ps_sigacts->ps_sigignore & sigmask(sig)) || 1531 (p->p_sigmask & sigmask(sig))) 1532 return 1; 1533 1534 return 0; 1535 } 1536 1537 int nosuidcoredump = 1; 1538 1539 struct coredump_iostate { 1540 struct proc *io_proc; 1541 struct vnode *io_vp; 1542 struct ucred *io_cred; 1543 off_t io_offset; 1544 }; 1545 1546 /* 1547 * Dump core, into a file named "progname.core", unless the process was 1548 * setuid/setgid. 1549 */ 1550 int 1551 coredump(struct proc *p) 1552 { 1553 #ifdef SMALL_KERNEL 1554 return EPERM; 1555 #else 1556 struct process *pr = p->p_p; 1557 struct vnode *vp; 1558 struct ucred *cred = p->p_ucred; 1559 struct vmspace *vm = p->p_vmspace; 1560 struct nameidata nd; 1561 struct vattr vattr; 1562 struct coredump_iostate io; 1563 int error, len, incrash = 0; 1564 char *name; 1565 const char *dir = "/var/crash"; 1566 1567 if (pr->ps_emul->e_coredump == NULL) 1568 return (EINVAL); 1569 1570 atomic_setbits_int(&pr->ps_flags, PS_COREDUMP); 1571 1572 /* Don't dump if will exceed file size limit. */ 1573 if (USPACE + ptoa(vm->vm_dsize + vm->vm_ssize) >= lim_cur(RLIMIT_CORE)) 1574 return (EFBIG); 1575 1576 name = pool_get(&namei_pool, PR_WAITOK); 1577 1578 /* 1579 * If the process has inconsistent uids, nosuidcoredump 1580 * determines coredump placement policy. 1581 */ 1582 if (((pr->ps_flags & PS_SUGID) && (error = suser(p))) || 1583 ((pr->ps_flags & PS_SUGID) && nosuidcoredump)) { 1584 if (nosuidcoredump == 3) { 1585 /* 1586 * If the program directory does not exist, dumps of 1587 * that core will silently fail. 1588 */ 1589 len = snprintf(name, MAXPATHLEN, "%s/%s/%u.core", 1590 dir, pr->ps_comm, pr->ps_pid); 1591 incrash = KERNELPATH; 1592 } else if (nosuidcoredump == 2) { 1593 len = snprintf(name, MAXPATHLEN, "%s/%s.core", 1594 dir, pr->ps_comm); 1595 incrash = KERNELPATH; 1596 } else { 1597 pool_put(&namei_pool, name); 1598 return (EPERM); 1599 } 1600 } else 1601 len = snprintf(name, MAXPATHLEN, "%s.core", pr->ps_comm); 1602 1603 if (len >= MAXPATHLEN) { 1604 pool_put(&namei_pool, name); 1605 return (EACCES); 1606 } 1607 1608 /* 1609 * Control the UID used to write out. The normal case uses 1610 * the real UID. If the sugid case is going to write into the 1611 * controlled directory, we do so as root. 1612 */ 1613 if (incrash == 0) { 1614 cred = crdup(cred); 1615 cred->cr_uid = cred->cr_ruid; 1616 cred->cr_gid = cred->cr_rgid; 1617 } else { 1618 if (p->p_fd->fd_rdir) { 1619 vrele(p->p_fd->fd_rdir); 1620 p->p_fd->fd_rdir = NULL; 1621 } 1622 p->p_ucred = crdup(p->p_ucred); 1623 crfree(cred); 1624 cred = p->p_ucred; 1625 crhold(cred); 1626 cred->cr_uid = 0; 1627 cred->cr_gid = 0; 1628 } 1629 1630 /* incrash should be 0 or KERNELPATH only */ 1631 NDINIT(&nd, 0, incrash, UIO_SYSSPACE, name, p); 1632 1633 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW | O_NONBLOCK, 1634 S_IRUSR | S_IWUSR); 1635 1636 if (error) 1637 goto out; 1638 1639 /* 1640 * Don't dump to non-regular files, files with links, or files 1641 * owned by someone else. 1642 */ 1643 vp = nd.ni_vp; 1644 if ((error = VOP_GETATTR(vp, &vattr, cred, p)) != 0) { 1645 VOP_UNLOCK(vp); 1646 vn_close(vp, FWRITE, cred, p); 1647 goto out; 1648 } 1649 if (vp->v_type != VREG || vattr.va_nlink != 1 || 1650 vattr.va_mode & ((VREAD | VWRITE) >> 3 | (VREAD | VWRITE) >> 6) || 1651 vattr.va_uid != cred->cr_uid) { 1652 error = EACCES; 1653 VOP_UNLOCK(vp); 1654 vn_close(vp, FWRITE, cred, p); 1655 goto out; 1656 } 1657 VATTR_NULL(&vattr); 1658 vattr.va_size = 0; 1659 VOP_SETATTR(vp, &vattr, cred, p); 1660 pr->ps_acflag |= ACORE; 1661 1662 io.io_proc = p; 1663 io.io_vp = vp; 1664 io.io_cred = cred; 1665 io.io_offset = 0; 1666 VOP_UNLOCK(vp); 1667 vref(vp); 1668 error = vn_close(vp, FWRITE, cred, p); 1669 if (error == 0) 1670 error = (*pr->ps_emul->e_coredump)(p, &io); 1671 vrele(vp); 1672 out: 1673 crfree(cred); 1674 pool_put(&namei_pool, name); 1675 return (error); 1676 #endif 1677 } 1678 1679 #ifndef SMALL_KERNEL 1680 int 1681 coredump_write(void *cookie, enum uio_seg segflg, const void *data, size_t len) 1682 { 1683 struct coredump_iostate *io = cookie; 1684 off_t coffset = 0; 1685 size_t csize; 1686 int chunk, error; 1687 1688 csize = len; 1689 do { 1690 if (sigmask(SIGKILL) & 1691 (io->io_proc->p_siglist | io->io_proc->p_p->ps_siglist)) 1692 return (EINTR); 1693 1694 /* Rest of the loop sleeps with lock held, so... */ 1695 yield(); 1696 1697 chunk = MIN(csize, MAXPHYS); 1698 error = vn_rdwr(UIO_WRITE, io->io_vp, 1699 (caddr_t)data + coffset, chunk, 1700 io->io_offset + coffset, segflg, 1701 IO_UNIT, io->io_cred, NULL, io->io_proc); 1702 if (error) { 1703 struct process *pr = io->io_proc->p_p; 1704 1705 if (error == ENOSPC) 1706 log(LOG_ERR, 1707 "coredump of %s(%d) failed, filesystem full\n", 1708 pr->ps_comm, pr->ps_pid); 1709 else 1710 log(LOG_ERR, 1711 "coredump of %s(%d), write failed: errno %d\n", 1712 pr->ps_comm, pr->ps_pid, error); 1713 return (error); 1714 } 1715 1716 coffset += chunk; 1717 csize -= chunk; 1718 } while (csize > 0); 1719 1720 io->io_offset += len; 1721 return (0); 1722 } 1723 1724 void 1725 coredump_unmap(void *cookie, vaddr_t start, vaddr_t end) 1726 { 1727 struct coredump_iostate *io = cookie; 1728 1729 uvm_unmap(&io->io_proc->p_vmspace->vm_map, start, end); 1730 } 1731 1732 #endif /* !SMALL_KERNEL */ 1733 1734 /* 1735 * Nonexistent system call-- signal process (may want to handle it). 1736 * Flag error in case process won't see signal immediately (blocked or ignored). 1737 */ 1738 int 1739 sys_nosys(struct proc *p, void *v, register_t *retval) 1740 { 1741 1742 ptsignal(p, SIGSYS, STHREAD); 1743 return (ENOSYS); 1744 } 1745 1746 int 1747 sys___thrsigdivert(struct proc *p, void *v, register_t *retval) 1748 { 1749 static int sigwaitsleep; 1750 struct sys___thrsigdivert_args /* { 1751 syscallarg(sigset_t) sigmask; 1752 syscallarg(siginfo_t *) info; 1753 syscallarg(const struct timespec *) timeout; 1754 } */ *uap = v; 1755 sigset_t mask = SCARG(uap, sigmask) &~ sigcantmask; 1756 siginfo_t si; 1757 uint64_t nsecs = INFSLP; 1758 int timeinvalid = 0; 1759 int error = 0; 1760 1761 memset(&si, 0, sizeof(si)); 1762 1763 if (SCARG(uap, timeout) != NULL) { 1764 struct timespec ts; 1765 if ((error = copyin(SCARG(uap, timeout), &ts, sizeof(ts))) != 0) 1766 return (error); 1767 #ifdef KTRACE 1768 if (KTRPOINT(p, KTR_STRUCT)) 1769 ktrreltimespec(p, &ts); 1770 #endif 1771 if (!timespecisvalid(&ts)) 1772 timeinvalid = 1; 1773 else 1774 nsecs = TIMESPEC_TO_NSEC(&ts); 1775 } 1776 1777 dosigsuspend(p, p->p_sigmask &~ mask); 1778 for (;;) { 1779 si.si_signo = cursig(p); 1780 if (si.si_signo != 0) { 1781 sigset_t smask = sigmask(si.si_signo); 1782 if (smask & mask) { 1783 atomic_clearbits_int(&p->p_siglist, smask); 1784 error = 0; 1785 break; 1786 } 1787 } 1788 1789 /* per-POSIX, delay this error until after the above */ 1790 if (timeinvalid) 1791 error = EINVAL; 1792 /* per-POSIX, return immediatly if timeout is zero-valued */ 1793 if (nsecs == 0) 1794 error = EAGAIN; 1795 1796 if (error != 0) 1797 break; 1798 1799 error = tsleep_nsec(&sigwaitsleep, PPAUSE|PCATCH, "sigwait", 1800 nsecs); 1801 } 1802 1803 if (error == 0) { 1804 *retval = si.si_signo; 1805 if (SCARG(uap, info) != NULL) 1806 error = copyout(&si, SCARG(uap, info), sizeof(si)); 1807 } else if (error == ERESTART && SCARG(uap, timeout) != NULL) { 1808 /* 1809 * Restarting is wrong if there's a timeout, as it'll be 1810 * for the same interval again 1811 */ 1812 error = EINTR; 1813 } 1814 1815 return (error); 1816 } 1817 1818 void 1819 initsiginfo(siginfo_t *si, int sig, u_long trapno, int code, union sigval val) 1820 { 1821 memset(si, 0, sizeof(*si)); 1822 1823 si->si_signo = sig; 1824 si->si_code = code; 1825 if (code == SI_USER) { 1826 si->si_value = val; 1827 } else { 1828 switch (sig) { 1829 case SIGSEGV: 1830 case SIGILL: 1831 case SIGBUS: 1832 case SIGFPE: 1833 si->si_addr = val.sival_ptr; 1834 si->si_trapno = trapno; 1835 break; 1836 case SIGXFSZ: 1837 break; 1838 } 1839 } 1840 } 1841 1842 int 1843 filt_sigattach(struct knote *kn) 1844 { 1845 struct process *pr = curproc->p_p; 1846 int s; 1847 1848 if (kn->kn_id >= NSIG) 1849 return EINVAL; 1850 1851 kn->kn_ptr.p_process = pr; 1852 kn->kn_flags |= EV_CLEAR; /* automatically set */ 1853 1854 s = splhigh(); 1855 klist_insert_locked(&pr->ps_klist, kn); 1856 splx(s); 1857 1858 return (0); 1859 } 1860 1861 void 1862 filt_sigdetach(struct knote *kn) 1863 { 1864 struct process *pr = kn->kn_ptr.p_process; 1865 int s; 1866 1867 s = splhigh(); 1868 klist_remove_locked(&pr->ps_klist, kn); 1869 splx(s); 1870 } 1871 1872 /* 1873 * signal knotes are shared with proc knotes, so we apply a mask to 1874 * the hint in order to differentiate them from process hints. This 1875 * could be avoided by using a signal-specific knote list, but probably 1876 * isn't worth the trouble. 1877 */ 1878 int 1879 filt_signal(struct knote *kn, long hint) 1880 { 1881 1882 if (hint & NOTE_SIGNAL) { 1883 hint &= ~NOTE_SIGNAL; 1884 1885 if (kn->kn_id == hint) 1886 kn->kn_data++; 1887 } 1888 return (kn->kn_data != 0); 1889 } 1890 1891 void 1892 userret(struct proc *p) 1893 { 1894 int signum; 1895 1896 /* send SIGPROF or SIGVTALRM if their timers interrupted this thread */ 1897 if (p->p_flag & P_PROFPEND) { 1898 atomic_clearbits_int(&p->p_flag, P_PROFPEND); 1899 KERNEL_LOCK(); 1900 psignal(p, SIGPROF); 1901 KERNEL_UNLOCK(); 1902 } 1903 if (p->p_flag & P_ALRMPEND) { 1904 atomic_clearbits_int(&p->p_flag, P_ALRMPEND); 1905 KERNEL_LOCK(); 1906 psignal(p, SIGVTALRM); 1907 KERNEL_UNLOCK(); 1908 } 1909 1910 if (SIGPENDING(p) != 0) { 1911 KERNEL_LOCK(); 1912 while ((signum = cursig(p)) != 0) 1913 postsig(p, signum); 1914 KERNEL_UNLOCK(); 1915 } 1916 1917 /* 1918 * If P_SIGSUSPEND is still set here, then we still need to restore 1919 * the original sigmask before returning to userspace. Also, this 1920 * might unmask some pending signals, so we need to check a second 1921 * time for signals to post. 1922 */ 1923 if (p->p_flag & P_SIGSUSPEND) { 1924 atomic_clearbits_int(&p->p_flag, P_SIGSUSPEND); 1925 p->p_sigmask = p->p_oldmask; 1926 1927 KERNEL_LOCK(); 1928 while ((signum = cursig(p)) != 0) 1929 postsig(p, signum); 1930 KERNEL_UNLOCK(); 1931 } 1932 1933 if (p->p_flag & P_SUSPSINGLE) 1934 single_thread_check(p, 0); 1935 1936 WITNESS_WARN(WARN_PANIC, NULL, "userret: returning"); 1937 1938 p->p_cpu->ci_schedstate.spc_curpriority = p->p_usrpri; 1939 } 1940 1941 int 1942 single_thread_check_locked(struct proc *p, int deep, int s) 1943 { 1944 struct process *pr = p->p_p; 1945 1946 SCHED_ASSERT_LOCKED(); 1947 1948 if (pr->ps_single != NULL && pr->ps_single != p) { 1949 do { 1950 /* if we're in deep, we need to unwind to the edge */ 1951 if (deep) { 1952 if (pr->ps_flags & PS_SINGLEUNWIND) 1953 return (ERESTART); 1954 if (pr->ps_flags & PS_SINGLEEXIT) 1955 return (EINTR); 1956 } 1957 1958 if (pr->ps_single == NULL) 1959 continue; 1960 1961 if (atomic_dec_int_nv(&pr->ps_singlecount) == 0) 1962 wakeup(&pr->ps_singlecount); 1963 1964 if (pr->ps_flags & PS_SINGLEEXIT) { 1965 SCHED_UNLOCK(s); 1966 KERNEL_LOCK(); 1967 exit1(p, 0, 0, EXIT_THREAD_NOCHECK); 1968 /* NOTREACHED */ 1969 } 1970 1971 /* not exiting and don't need to unwind, so suspend */ 1972 p->p_stat = SSTOP; 1973 mi_switch(); 1974 } while (pr->ps_single != NULL); 1975 } 1976 1977 return (0); 1978 } 1979 1980 int 1981 single_thread_check(struct proc *p, int deep) 1982 { 1983 int s, error; 1984 1985 SCHED_LOCK(s); 1986 error = single_thread_check_locked(p, deep, s); 1987 SCHED_UNLOCK(s); 1988 1989 return error; 1990 } 1991 1992 /* 1993 * Stop other threads in the process. The mode controls how and 1994 * where the other threads should stop: 1995 * - SINGLE_SUSPEND: stop wherever they are, will later either be told to exit 1996 * (by setting to SINGLE_EXIT) or be released (via single_thread_clear()) 1997 * - SINGLE_UNWIND: just unwind to kernel boundary, will be told to exit 1998 * or released as with SINGLE_SUSPEND 1999 * - SINGLE_EXIT: unwind to kernel boundary and exit 2000 */ 2001 int 2002 single_thread_set(struct proc *p, enum single_thread_mode mode, int wait) 2003 { 2004 struct process *pr = p->p_p; 2005 struct proc *q; 2006 int error, s; 2007 2008 KASSERT(curproc == p); 2009 2010 SCHED_LOCK(s); 2011 error = single_thread_check_locked(p, (mode == SINGLE_UNWIND), s); 2012 if (error) { 2013 SCHED_UNLOCK(s); 2014 return error; 2015 } 2016 2017 switch (mode) { 2018 case SINGLE_SUSPEND: 2019 break; 2020 case SINGLE_UNWIND: 2021 atomic_setbits_int(&pr->ps_flags, PS_SINGLEUNWIND); 2022 break; 2023 case SINGLE_EXIT: 2024 atomic_setbits_int(&pr->ps_flags, PS_SINGLEEXIT); 2025 atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND); 2026 break; 2027 #ifdef DIAGNOSTIC 2028 default: 2029 panic("single_thread_mode = %d", mode); 2030 #endif 2031 } 2032 pr->ps_singlecount = 0; 2033 membar_producer(); 2034 pr->ps_single = p; 2035 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 2036 if (q == p) 2037 continue; 2038 if (q->p_flag & P_WEXIT) { 2039 if (mode == SINGLE_EXIT) { 2040 if (q->p_stat == SSTOP) { 2041 setrunnable(q); 2042 atomic_inc_int(&pr->ps_singlecount); 2043 } 2044 } 2045 continue; 2046 } 2047 atomic_setbits_int(&q->p_flag, P_SUSPSINGLE); 2048 switch (q->p_stat) { 2049 case SIDL: 2050 case SRUN: 2051 atomic_inc_int(&pr->ps_singlecount); 2052 break; 2053 case SSLEEP: 2054 /* if it's not interruptible, then just have to wait */ 2055 if (q->p_flag & P_SINTR) { 2056 /* merely need to suspend? just stop it */ 2057 if (mode == SINGLE_SUSPEND) { 2058 q->p_stat = SSTOP; 2059 break; 2060 } 2061 /* need to unwind or exit, so wake it */ 2062 setrunnable(q); 2063 } 2064 atomic_inc_int(&pr->ps_singlecount); 2065 break; 2066 case SSTOP: 2067 if (mode == SINGLE_EXIT) { 2068 setrunnable(q); 2069 atomic_inc_int(&pr->ps_singlecount); 2070 } 2071 break; 2072 case SDEAD: 2073 break; 2074 case SONPROC: 2075 atomic_inc_int(&pr->ps_singlecount); 2076 signotify(q); 2077 break; 2078 } 2079 } 2080 SCHED_UNLOCK(s); 2081 2082 if (wait) 2083 single_thread_wait(pr, 1); 2084 2085 return 0; 2086 } 2087 2088 /* 2089 * Wait for other threads to stop. If recheck is false then the function 2090 * returns non-zero if the caller needs to restart the check else 0 is 2091 * returned. If recheck is true the return value is always 0. 2092 */ 2093 int 2094 single_thread_wait(struct process *pr, int recheck) 2095 { 2096 struct sleep_state sls; 2097 int wait; 2098 2099 /* wait until they're all suspended */ 2100 wait = pr->ps_singlecount > 0; 2101 while (wait) { 2102 sleep_setup(&sls, &pr->ps_singlecount, PWAIT, "suspend", 0); 2103 wait = pr->ps_singlecount > 0; 2104 sleep_finish(&sls, wait); 2105 if (!recheck) 2106 break; 2107 } 2108 2109 return wait; 2110 } 2111 2112 void 2113 single_thread_clear(struct proc *p, int flag) 2114 { 2115 struct process *pr = p->p_p; 2116 struct proc *q; 2117 int s; 2118 2119 KASSERT(pr->ps_single == p); 2120 KASSERT(curproc == p); 2121 2122 SCHED_LOCK(s); 2123 pr->ps_single = NULL; 2124 atomic_clearbits_int(&pr->ps_flags, PS_SINGLEUNWIND | PS_SINGLEEXIT); 2125 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 2126 if (q == p || (q->p_flag & P_SUSPSINGLE) == 0) 2127 continue; 2128 atomic_clearbits_int(&q->p_flag, P_SUSPSINGLE); 2129 2130 /* 2131 * if the thread was only stopped for single threading 2132 * then clearing that either makes it runnable or puts 2133 * it back into some sleep queue 2134 */ 2135 if (q->p_stat == SSTOP && (q->p_flag & flag) == 0) { 2136 if (q->p_wchan == 0) 2137 setrunnable(q); 2138 else 2139 q->p_stat = SSLEEP; 2140 } 2141 } 2142 SCHED_UNLOCK(s); 2143 } 2144 2145 void 2146 sigio_del(struct sigiolst *rmlist) 2147 { 2148 struct sigio *sigio; 2149 2150 while ((sigio = LIST_FIRST(rmlist)) != NULL) { 2151 LIST_REMOVE(sigio, sio_pgsigio); 2152 crfree(sigio->sio_ucred); 2153 free(sigio, M_SIGIO, sizeof(*sigio)); 2154 } 2155 } 2156 2157 void 2158 sigio_unlink(struct sigio_ref *sir, struct sigiolst *rmlist) 2159 { 2160 struct sigio *sigio; 2161 2162 MUTEX_ASSERT_LOCKED(&sigio_lock); 2163 2164 sigio = sir->sir_sigio; 2165 if (sigio != NULL) { 2166 KASSERT(sigio->sio_myref == sir); 2167 sir->sir_sigio = NULL; 2168 2169 if (sigio->sio_pgid > 0) 2170 sigio->sio_proc = NULL; 2171 else 2172 sigio->sio_pgrp = NULL; 2173 LIST_REMOVE(sigio, sio_pgsigio); 2174 2175 LIST_INSERT_HEAD(rmlist, sigio, sio_pgsigio); 2176 } 2177 } 2178 2179 void 2180 sigio_free(struct sigio_ref *sir) 2181 { 2182 struct sigiolst rmlist; 2183 2184 if (sir->sir_sigio == NULL) 2185 return; 2186 2187 LIST_INIT(&rmlist); 2188 2189 mtx_enter(&sigio_lock); 2190 sigio_unlink(sir, &rmlist); 2191 mtx_leave(&sigio_lock); 2192 2193 sigio_del(&rmlist); 2194 } 2195 2196 void 2197 sigio_freelist(struct sigiolst *sigiolst) 2198 { 2199 struct sigiolst rmlist; 2200 struct sigio *sigio; 2201 2202 if (LIST_EMPTY(sigiolst)) 2203 return; 2204 2205 LIST_INIT(&rmlist); 2206 2207 mtx_enter(&sigio_lock); 2208 while ((sigio = LIST_FIRST(sigiolst)) != NULL) 2209 sigio_unlink(sigio->sio_myref, &rmlist); 2210 mtx_leave(&sigio_lock); 2211 2212 sigio_del(&rmlist); 2213 } 2214 2215 int 2216 sigio_setown(struct sigio_ref *sir, u_long cmd, caddr_t data) 2217 { 2218 struct sigiolst rmlist; 2219 struct proc *p = curproc; 2220 struct pgrp *pgrp = NULL; 2221 struct process *pr = NULL; 2222 struct sigio *sigio; 2223 int error; 2224 pid_t pgid = *(int *)data; 2225 2226 if (pgid == 0) { 2227 sigio_free(sir); 2228 return (0); 2229 } 2230 2231 if (cmd == TIOCSPGRP) { 2232 if (pgid < 0) 2233 return (EINVAL); 2234 pgid = -pgid; 2235 } 2236 2237 sigio = malloc(sizeof(*sigio), M_SIGIO, M_WAITOK); 2238 sigio->sio_pgid = pgid; 2239 sigio->sio_ucred = crhold(p->p_ucred); 2240 sigio->sio_myref = sir; 2241 2242 LIST_INIT(&rmlist); 2243 2244 /* 2245 * The kernel lock, and not sleeping between prfind()/pgfind() and 2246 * linking of the sigio ensure that the process or process group does 2247 * not disappear unexpectedly. 2248 */ 2249 KERNEL_LOCK(); 2250 mtx_enter(&sigio_lock); 2251 2252 if (pgid > 0) { 2253 pr = prfind(pgid); 2254 if (pr == NULL) { 2255 error = ESRCH; 2256 goto fail; 2257 } 2258 2259 /* 2260 * Policy - Don't allow a process to FSETOWN a process 2261 * in another session. 2262 * 2263 * Remove this test to allow maximum flexibility or 2264 * restrict FSETOWN to the current process or process 2265 * group for maximum safety. 2266 */ 2267 if (pr->ps_session != p->p_p->ps_session) { 2268 error = EPERM; 2269 goto fail; 2270 } 2271 2272 if ((pr->ps_flags & PS_EXITING) != 0) { 2273 error = ESRCH; 2274 goto fail; 2275 } 2276 } else /* if (pgid < 0) */ { 2277 pgrp = pgfind(-pgid); 2278 if (pgrp == NULL) { 2279 error = ESRCH; 2280 goto fail; 2281 } 2282 2283 /* 2284 * Policy - Don't allow a process to FSETOWN a process 2285 * in another session. 2286 * 2287 * Remove this test to allow maximum flexibility or 2288 * restrict FSETOWN to the current process or process 2289 * group for maximum safety. 2290 */ 2291 if (pgrp->pg_session != p->p_p->ps_session) { 2292 error = EPERM; 2293 goto fail; 2294 } 2295 } 2296 2297 if (pgid > 0) { 2298 sigio->sio_proc = pr; 2299 LIST_INSERT_HEAD(&pr->ps_sigiolst, sigio, sio_pgsigio); 2300 } else { 2301 sigio->sio_pgrp = pgrp; 2302 LIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 2303 } 2304 2305 sigio_unlink(sir, &rmlist); 2306 sir->sir_sigio = sigio; 2307 2308 mtx_leave(&sigio_lock); 2309 KERNEL_UNLOCK(); 2310 2311 sigio_del(&rmlist); 2312 2313 return (0); 2314 2315 fail: 2316 mtx_leave(&sigio_lock); 2317 KERNEL_UNLOCK(); 2318 2319 crfree(sigio->sio_ucred); 2320 free(sigio, M_SIGIO, sizeof(*sigio)); 2321 2322 return (error); 2323 } 2324 2325 void 2326 sigio_getown(struct sigio_ref *sir, u_long cmd, caddr_t data) 2327 { 2328 struct sigio *sigio; 2329 pid_t pgid = 0; 2330 2331 mtx_enter(&sigio_lock); 2332 sigio = sir->sir_sigio; 2333 if (sigio != NULL) 2334 pgid = sigio->sio_pgid; 2335 mtx_leave(&sigio_lock); 2336 2337 if (cmd == TIOCGPGRP) 2338 pgid = -pgid; 2339 2340 *(int *)data = pgid; 2341 } 2342 2343 void 2344 sigio_copy(struct sigio_ref *dst, struct sigio_ref *src) 2345 { 2346 struct sigiolst rmlist; 2347 struct sigio *newsigio, *sigio; 2348 2349 sigio_free(dst); 2350 2351 if (src->sir_sigio == NULL) 2352 return; 2353 2354 newsigio = malloc(sizeof(*newsigio), M_SIGIO, M_WAITOK); 2355 LIST_INIT(&rmlist); 2356 2357 mtx_enter(&sigio_lock); 2358 2359 sigio = src->sir_sigio; 2360 if (sigio == NULL) { 2361 mtx_leave(&sigio_lock); 2362 free(newsigio, M_SIGIO, sizeof(*newsigio)); 2363 return; 2364 } 2365 2366 newsigio->sio_pgid = sigio->sio_pgid; 2367 newsigio->sio_ucred = crhold(sigio->sio_ucred); 2368 newsigio->sio_myref = dst; 2369 if (newsigio->sio_pgid > 0) { 2370 newsigio->sio_proc = sigio->sio_proc; 2371 LIST_INSERT_HEAD(&newsigio->sio_proc->ps_sigiolst, newsigio, 2372 sio_pgsigio); 2373 } else { 2374 newsigio->sio_pgrp = sigio->sio_pgrp; 2375 LIST_INSERT_HEAD(&newsigio->sio_pgrp->pg_sigiolst, newsigio, 2376 sio_pgsigio); 2377 } 2378 2379 sigio_unlink(dst, &rmlist); 2380 dst->sir_sigio = newsigio; 2381 2382 mtx_leave(&sigio_lock); 2383 2384 sigio_del(&rmlist); 2385 } 2386