Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exit.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/10.1/sys/kern/kern_exit.c 271423 2014-09-11 11:25:10Z kib $"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 #include "opt_procdesc.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sysproto.h> 48 #include <sys/capability.h> 49 #include <sys/eventhandler.h> 50 #include <sys/kernel.h> 51 #include <sys/malloc.h> 52 #include <sys/lock.h> 53 #include <sys/mutex.h> 54 #include <sys/proc.h> 55 #include <sys/procdesc.h> 56 #include <sys/pioctl.h> 57 #include <sys/jail.h> 58 #include <sys/tty.h> 59 #include <sys/wait.h> 60 #include <sys/vmmeter.h> 61 #include <sys/vnode.h> 62 #include <sys/racct.h> 63 #include <sys/resourcevar.h> 64 #include <sys/sbuf.h> 65 #include <sys/signalvar.h> 66 #include <sys/sched.h> 67 #include <sys/sx.h> 68 #include <sys/syscallsubr.h> 69 #include <sys/syslog.h> 70 #include <sys/ptrace.h> 71 #include <sys/acct.h> /* for acct_process() function prototype */ 72 #include <sys/filedesc.h> 73 #include <sys/sdt.h> 74 #include <sys/shm.h> 75 #include <sys/sem.h> 76 #ifdef KTRACE 77 #include <sys/ktrace.h> 78 #endif 79 80 #include <security/audit/audit.h> 81 #include <security/mac/mac_framework.h> 82 83 #include <vm/vm.h> 84 #include <vm/vm_extern.h> 85 #include <vm/vm_param.h> 86 #include <vm/pmap.h> 87 #include <vm/vm_map.h> 88 #include <vm/vm_page.h> 89 #include <vm/uma.h> 90 91 #ifdef KDTRACE_HOOKS 92 #include <sys/dtrace_bsd.h> 93 dtrace_execexit_func_t dtrace_fasttrap_exit; 94 #endif 95 96 SDT_PROVIDER_DECLARE(proc); 97 SDT_PROBE_DEFINE1(proc, kernel, , exit, "int"); 98 99 /* Hook for NFS teardown procedure. */ 100 void (*nlminfo_release_p)(struct proc *p); 101 102 struct proc * 103 proc_realparent(struct proc *child) 104 { 105 struct proc *p, *parent; 106 107 sx_assert(&proctree_lock, SX_LOCKED); 108 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) { 109 if (child->p_oppid == 0 || 110 child->p_pptr->p_pid == child->p_oppid) 111 parent = child->p_pptr; 112 else 113 parent = initproc; 114 return (parent); 115 } 116 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) { 117 /* Cannot use LIST_PREV(), since the list head is not known. */ 118 p = __containerof(p->p_orphan.le_prev, struct proc, 119 p_orphan.le_next); 120 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0, 121 ("missing P_ORPHAN %p", p)); 122 } 123 parent = __containerof(p->p_orphan.le_prev, struct proc, 124 p_orphans.lh_first); 125 return (parent); 126 } 127 128 static void 129 clear_orphan(struct proc *p) 130 { 131 struct proc *p1; 132 133 sx_assert(&proctree_lock, SA_XLOCKED); 134 if ((p->p_treeflag & P_TREE_ORPHANED) == 0) 135 return; 136 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) { 137 p1 = LIST_NEXT(p, p_orphan); 138 if (p1 != NULL) 139 p1->p_treeflag |= P_TREE_FIRST_ORPHAN; 140 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN; 141 } 142 LIST_REMOVE(p, p_orphan); 143 p->p_treeflag &= ~P_TREE_ORPHANED; 144 } 145 146 /* 147 * exit -- death of process. 148 */ 149 void 150 sys_sys_exit(struct thread *td, struct sys_exit_args *uap) 151 { 152 153 exit1(td, W_EXITCODE(uap->rval, 0)); 154 /* NOTREACHED */ 155 } 156 157 /* 158 * Exit: deallocate address space and other resources, change proc state to 159 * zombie, and unlink proc from allproc and parent's lists. Save exit status 160 * and rusage for wait(). Check for child processes and orphan them. 161 */ 162 void 163 exit1(struct thread *td, int rv) 164 { 165 struct proc *p, *nq, *q; 166 struct vnode *ttyvp = NULL; 167 168 mtx_assert(&Giant, MA_NOTOWNED); 169 170 p = td->td_proc; 171 /* 172 * XXX in case we're rebooting we just let init die in order to 173 * work around an unsolved stack overflow seen very late during 174 * shutdown on sparc64 when the gmirror worker process exists. 175 */ 176 if (p == initproc && rebooting == 0) { 177 printf("init died (signal %d, exit %d)\n", 178 WTERMSIG(rv), WEXITSTATUS(rv)); 179 panic("Going nowhere without my init!"); 180 } 181 182 /* 183 * MUST abort all other threads before proceeding past here. 184 */ 185 PROC_LOCK(p); 186 while (p->p_flag & P_HADTHREADS) { 187 /* 188 * First check if some other thread got here before us. 189 * If so, act appropriately: exit or suspend. 190 */ 191 thread_suspend_check(0); 192 193 /* 194 * Kill off the other threads. This requires 195 * some co-operation from other parts of the kernel 196 * so it may not be instantaneous. With this state set 197 * any thread entering the kernel from userspace will 198 * thread_exit() in trap(). Any thread attempting to 199 * sleep will return immediately with EINTR or EWOULDBLOCK 200 * which will hopefully force them to back out to userland 201 * freeing resources as they go. Any thread attempting 202 * to return to userland will thread_exit() from userret(). 203 * thread_exit() will unsuspend us when the last of the 204 * other threads exits. 205 * If there is already a thread singler after resumption, 206 * calling thread_single will fail; in that case, we just 207 * re-check all suspension request, the thread should 208 * either be suspended there or exit. 209 */ 210 if (!thread_single(SINGLE_EXIT)) 211 break; 212 213 /* 214 * All other activity in this process is now stopped. 215 * Threading support has been turned off. 216 */ 217 } 218 KASSERT(p->p_numthreads == 1, 219 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 220 racct_sub(p, RACCT_NTHR, 1); 221 /* 222 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold 223 * on our vmspace, so we should block below until they have 224 * released their reference to us. Note that if they have 225 * requested S_EXIT stops we will block here until they ack 226 * via PIOCCONT. 227 */ 228 _STOPEVENT(p, S_EXIT, rv); 229 230 /* 231 * Ignore any pending request to stop due to a stop signal. 232 * Once P_WEXIT is set, future requests will be ignored as 233 * well. 234 */ 235 p->p_flag &= ~P_STOPPED_SIG; 236 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 237 238 /* 239 * Note that we are exiting and do another wakeup of anyone in 240 * PIOCWAIT in case they aren't listening for S_EXIT stops or 241 * decided to wait again after we told them we are exiting. 242 */ 243 p->p_flag |= P_WEXIT; 244 wakeup(&p->p_stype); 245 246 /* 247 * Wait for any processes that have a hold on our vmspace to 248 * release their reference. 249 */ 250 while (p->p_lock > 0) 251 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 252 253 p->p_xstat = rv; /* Let event handler change exit status */ 254 PROC_UNLOCK(p); 255 /* Drain the limit callout while we don't have the proc locked */ 256 callout_drain(&p->p_limco); 257 258 #ifdef AUDIT 259 /* 260 * The Sun BSM exit token contains two components: an exit status as 261 * passed to exit(), and a return value to indicate what sort of exit 262 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 263 * what the return value is. 264 */ 265 AUDIT_ARG_EXIT(WEXITSTATUS(rv), 0); 266 AUDIT_SYSCALL_EXIT(0, td); 267 #endif 268 269 /* Are we a task leader? */ 270 if (p == p->p_leader) { 271 mtx_lock(&ppeers_lock); 272 q = p->p_peers; 273 while (q != NULL) { 274 PROC_LOCK(q); 275 kern_psignal(q, SIGKILL); 276 PROC_UNLOCK(q); 277 q = q->p_peers; 278 } 279 while (p->p_peers != NULL) 280 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 281 mtx_unlock(&ppeers_lock); 282 } 283 284 /* 285 * Check if any loadable modules need anything done at process exit. 286 * E.g. SYSV IPC stuff 287 * XXX what if one of these generates an error? 288 */ 289 EVENTHANDLER_INVOKE(process_exit, p); 290 291 /* 292 * If parent is waiting for us to exit or exec, 293 * P_PPWAIT is set; we will wakeup the parent below. 294 */ 295 PROC_LOCK(p); 296 rv = p->p_xstat; /* Event handler could change exit status */ 297 stopprofclock(p); 298 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 299 300 /* 301 * Stop the real interval timer. If the handler is currently 302 * executing, prevent it from rearming itself and let it finish. 303 */ 304 if (timevalisset(&p->p_realtimer.it_value) && 305 callout_stop(&p->p_itcallout) == 0) { 306 timevalclear(&p->p_realtimer.it_interval); 307 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 308 KASSERT(!timevalisset(&p->p_realtimer.it_value), 309 ("realtime timer is still armed")); 310 } 311 PROC_UNLOCK(p); 312 313 /* 314 * Reset any sigio structures pointing to us as a result of 315 * F_SETOWN with our pid. 316 */ 317 funsetownlst(&p->p_sigiolst); 318 319 /* 320 * If this process has an nlminfo data area (for lockd), release it 321 */ 322 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL) 323 (*nlminfo_release_p)(p); 324 325 /* 326 * Close open files and release open-file table. 327 * This may block! 328 */ 329 fdescfree(td); 330 331 /* 332 * If this thread tickled GEOM, we need to wait for the giggling to 333 * stop before we return to userland 334 */ 335 if (td->td_pflags & TDP_GEOM) 336 g_waitidle(); 337 338 /* 339 * Remove ourself from our leader's peer list and wake our leader. 340 */ 341 mtx_lock(&ppeers_lock); 342 if (p->p_leader->p_peers) { 343 q = p->p_leader; 344 while (q->p_peers != p) 345 q = q->p_peers; 346 q->p_peers = p->p_peers; 347 wakeup(p->p_leader); 348 } 349 mtx_unlock(&ppeers_lock); 350 351 vmspace_exit(td); 352 353 sx_xlock(&proctree_lock); 354 if (SESS_LEADER(p)) { 355 struct session *sp = p->p_session; 356 struct tty *tp; 357 358 /* 359 * s_ttyp is not zero'd; we use this to indicate that 360 * the session once had a controlling terminal. (for 361 * logging and informational purposes) 362 */ 363 SESS_LOCK(sp); 364 ttyvp = sp->s_ttyvp; 365 tp = sp->s_ttyp; 366 sp->s_ttyvp = NULL; 367 sp->s_ttydp = NULL; 368 sp->s_leader = NULL; 369 SESS_UNLOCK(sp); 370 371 /* 372 * Signal foreground pgrp and revoke access to 373 * controlling terminal if it has not been revoked 374 * already. 375 * 376 * Because the TTY may have been revoked in the mean 377 * time and could already have a new session associated 378 * with it, make sure we don't send a SIGHUP to a 379 * foreground process group that does not belong to this 380 * session. 381 */ 382 383 if (tp != NULL) { 384 tty_lock(tp); 385 if (tp->t_session == sp) 386 tty_signal_pgrp(tp, SIGHUP); 387 tty_unlock(tp); 388 } 389 390 if (ttyvp != NULL) { 391 sx_xunlock(&proctree_lock); 392 if (vn_lock(ttyvp, LK_EXCLUSIVE) == 0) { 393 VOP_REVOKE(ttyvp, REVOKEALL); 394 VOP_UNLOCK(ttyvp, 0); 395 } 396 sx_xlock(&proctree_lock); 397 } 398 } 399 fixjobc(p, p->p_pgrp, 0); 400 sx_xunlock(&proctree_lock); 401 (void)acct_process(td); 402 403 /* Release the TTY now we've unlocked everything. */ 404 if (ttyvp != NULL) 405 vrele(ttyvp); 406 #ifdef KTRACE 407 ktrprocexit(td); 408 #endif 409 /* 410 * Release reference to text vnode 411 */ 412 if (p->p_textvp != NULL) { 413 vrele(p->p_textvp); 414 p->p_textvp = NULL; 415 } 416 417 /* 418 * Release our limits structure. 419 */ 420 lim_free(p->p_limit); 421 p->p_limit = NULL; 422 423 tidhash_remove(td); 424 425 /* 426 * Remove proc from allproc queue and pidhash chain. 427 * Place onto zombproc. Unlink from parent's child list. 428 */ 429 sx_xlock(&allproc_lock); 430 LIST_REMOVE(p, p_list); 431 LIST_INSERT_HEAD(&zombproc, p, p_list); 432 LIST_REMOVE(p, p_hash); 433 sx_xunlock(&allproc_lock); 434 435 /* 436 * Call machine-dependent code to release any 437 * machine-dependent resources other than the address space. 438 * The address space is released by "vmspace_exitfree(p)" in 439 * vm_waitproc(). 440 */ 441 cpu_exit(td); 442 443 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 444 445 /* 446 * Reparent all of our children to init. 447 */ 448 sx_xlock(&proctree_lock); 449 q = LIST_FIRST(&p->p_children); 450 if (q != NULL) /* only need this if any child is S_ZOMB */ 451 wakeup(initproc); 452 for (; q != NULL; q = nq) { 453 nq = LIST_NEXT(q, p_sibling); 454 PROC_LOCK(q); 455 proc_reparent(q, initproc); 456 q->p_sigparent = SIGCHLD; 457 /* 458 * Traced processes are killed 459 * since their existence means someone is screwing up. 460 */ 461 if (q->p_flag & P_TRACED) { 462 struct thread *temp; 463 464 /* 465 * Since q was found on our children list, the 466 * proc_reparent() call moved q to the orphan 467 * list due to present P_TRACED flag. Clear 468 * orphan link for q now while q is locked. 469 */ 470 clear_orphan(q); 471 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 472 FOREACH_THREAD_IN_PROC(q, temp) 473 temp->td_dbgflags &= ~TDB_SUSPEND; 474 kern_psignal(q, SIGKILL); 475 } 476 PROC_UNLOCK(q); 477 } 478 479 /* 480 * Also get rid of our orphans. 481 */ 482 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 483 PROC_LOCK(q); 484 clear_orphan(q); 485 PROC_UNLOCK(q); 486 } 487 488 /* Save exit status. */ 489 PROC_LOCK(p); 490 p->p_xthread = td; 491 492 /* Tell the prison that we are gone. */ 493 prison_proc_free(p->p_ucred->cr_prison); 494 495 #ifdef KDTRACE_HOOKS 496 /* 497 * Tell the DTrace fasttrap provider about the exit if it 498 * has declared an interest. 499 */ 500 if (dtrace_fasttrap_exit) 501 dtrace_fasttrap_exit(p); 502 #endif 503 504 /* 505 * Notify interested parties of our demise. 506 */ 507 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT); 508 509 #ifdef KDTRACE_HOOKS 510 int reason = CLD_EXITED; 511 if (WCOREDUMP(rv)) 512 reason = CLD_DUMPED; 513 else if (WIFSIGNALED(rv)) 514 reason = CLD_KILLED; 515 SDT_PROBE(proc, kernel, , exit, reason, 0, 0, 0, 0); 516 #endif 517 518 /* 519 * Just delete all entries in the p_klist. At this point we won't 520 * report any more events, and there are nasty race conditions that 521 * can beat us if we don't. 522 */ 523 knlist_clear(&p->p_klist, 1); 524 525 /* 526 * If this is a process with a descriptor, we may not need to deliver 527 * a signal to the parent. proctree_lock is held over 528 * procdesc_exit() to serialize concurrent calls to close() and 529 * exit(). 530 */ 531 #ifdef PROCDESC 532 if (p->p_procdesc == NULL || procdesc_exit(p)) { 533 #endif 534 /* 535 * Notify parent that we're gone. If parent has the 536 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 537 * notify process 1 instead (and hope it will handle this 538 * situation). 539 */ 540 PROC_LOCK(p->p_pptr); 541 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 542 if (p->p_pptr->p_sigacts->ps_flag & 543 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 544 struct proc *pp; 545 546 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 547 pp = p->p_pptr; 548 PROC_UNLOCK(pp); 549 proc_reparent(p, initproc); 550 p->p_sigparent = SIGCHLD; 551 PROC_LOCK(p->p_pptr); 552 553 /* 554 * Notify parent, so in case he was wait(2)ing or 555 * executing waitpid(2) with our pid, he will 556 * continue. 557 */ 558 wakeup(pp); 559 } else 560 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 561 562 if (p->p_pptr == initproc) 563 kern_psignal(p->p_pptr, SIGCHLD); 564 else if (p->p_sigparent != 0) { 565 if (p->p_sigparent == SIGCHLD) 566 childproc_exited(p); 567 else /* LINUX thread */ 568 kern_psignal(p->p_pptr, p->p_sigparent); 569 } 570 #ifdef PROCDESC 571 } else 572 PROC_LOCK(p->p_pptr); 573 #endif 574 sx_xunlock(&proctree_lock); 575 576 /* 577 * The state PRS_ZOMBIE prevents other proesses from sending 578 * signal to the process, to avoid memory leak, we free memory 579 * for signal queue at the time when the state is set. 580 */ 581 sigqueue_flush(&p->p_sigqueue); 582 sigqueue_flush(&td->td_sigqueue); 583 584 /* 585 * We have to wait until after acquiring all locks before 586 * changing p_state. We need to avoid all possible context 587 * switches (including ones from blocking on a mutex) while 588 * marked as a zombie. We also have to set the zombie state 589 * before we release the parent process' proc lock to avoid 590 * a lost wakeup. So, we first call wakeup, then we grab the 591 * sched lock, update the state, and release the parent process' 592 * proc lock. 593 */ 594 wakeup(p->p_pptr); 595 cv_broadcast(&p->p_pwait); 596 sched_exit(p->p_pptr, td); 597 PROC_SLOCK(p); 598 p->p_state = PRS_ZOMBIE; 599 PROC_UNLOCK(p->p_pptr); 600 601 /* 602 * Hopefully no one will try to deliver a signal to the process this 603 * late in the game. 604 */ 605 knlist_destroy(&p->p_klist); 606 607 /* 608 * Save our children's rusage information in our exit rusage. 609 */ 610 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 611 612 /* 613 * Make sure the scheduler takes this thread out of its tables etc. 614 * This will also release this thread's reference to the ucred. 615 * Other thread parts to release include pcb bits and such. 616 */ 617 thread_exit(); 618 } 619 620 621 #ifndef _SYS_SYSPROTO_H_ 622 struct abort2_args { 623 char *why; 624 int nargs; 625 void **args; 626 }; 627 #endif 628 629 int 630 sys_abort2(struct thread *td, struct abort2_args *uap) 631 { 632 struct proc *p = td->td_proc; 633 struct sbuf *sb; 634 void *uargs[16]; 635 int error, i, sig; 636 637 /* 638 * Do it right now so we can log either proper call of abort2(), or 639 * note, that invalid argument was passed. 512 is big enough to 640 * handle 16 arguments' descriptions with additional comments. 641 */ 642 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 643 sbuf_clear(sb); 644 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 645 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 646 /* 647 * Since we can't return from abort2(), send SIGKILL in cases, where 648 * abort2() was called improperly 649 */ 650 sig = SIGKILL; 651 /* Prevent from DoSes from user-space. */ 652 if (uap->nargs < 0 || uap->nargs > 16) 653 goto out; 654 if (uap->nargs > 0) { 655 if (uap->args == NULL) 656 goto out; 657 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 658 if (error != 0) 659 goto out; 660 } 661 /* 662 * Limit size of 'reason' string to 128. Will fit even when 663 * maximal number of arguments was chosen to be logged. 664 */ 665 if (uap->why != NULL) { 666 error = sbuf_copyin(sb, uap->why, 128); 667 if (error < 0) 668 goto out; 669 } else { 670 sbuf_printf(sb, "(null)"); 671 } 672 if (uap->nargs > 0) { 673 sbuf_printf(sb, "("); 674 for (i = 0;i < uap->nargs; i++) 675 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 676 sbuf_printf(sb, ")"); 677 } 678 /* 679 * Final stage: arguments were proper, string has been 680 * successfully copied from userspace, and copying pointers 681 * from user-space succeed. 682 */ 683 sig = SIGABRT; 684 out: 685 if (sig == SIGKILL) { 686 sbuf_trim(sb); 687 sbuf_printf(sb, " (Reason text inaccessible)"); 688 } 689 sbuf_cat(sb, "\n"); 690 sbuf_finish(sb); 691 log(LOG_INFO, "%s", sbuf_data(sb)); 692 sbuf_delete(sb); 693 exit1(td, W_EXITCODE(0, sig)); 694 return (0); 695 } 696 697 698 #ifdef COMPAT_43 699 /* 700 * The dirty work is handled by kern_wait(). 701 */ 702 int 703 owait(struct thread *td, struct owait_args *uap __unused) 704 { 705 int error, status; 706 707 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 708 if (error == 0) 709 td->td_retval[1] = status; 710 return (error); 711 } 712 #endif /* COMPAT_43 */ 713 714 /* 715 * The dirty work is handled by kern_wait(). 716 */ 717 int 718 sys_wait4(struct thread *td, struct wait4_args *uap) 719 { 720 struct rusage ru, *rup; 721 int error, status; 722 723 if (uap->rusage != NULL) 724 rup = &ru; 725 else 726 rup = NULL; 727 error = kern_wait(td, uap->pid, &status, uap->options, rup); 728 if (uap->status != NULL && error == 0) 729 error = copyout(&status, uap->status, sizeof(status)); 730 if (uap->rusage != NULL && error == 0) 731 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 732 return (error); 733 } 734 735 int 736 sys_wait6(struct thread *td, struct wait6_args *uap) 737 { 738 struct __wrusage wru, *wrup; 739 siginfo_t si, *sip; 740 idtype_t idtype; 741 id_t id; 742 int error, status; 743 744 idtype = uap->idtype; 745 id = uap->id; 746 747 if (uap->wrusage != NULL) 748 wrup = &wru; 749 else 750 wrup = NULL; 751 752 if (uap->info != NULL) { 753 sip = &si; 754 bzero(sip, sizeof(*sip)); 755 } else 756 sip = NULL; 757 758 /* 759 * We expect all callers of wait6() to know about WEXITED and 760 * WTRAPPED. 761 */ 762 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 763 764 if (uap->status != NULL && error == 0) 765 error = copyout(&status, uap->status, sizeof(status)); 766 if (uap->wrusage != NULL && error == 0) 767 error = copyout(&wru, uap->wrusage, sizeof(wru)); 768 if (uap->info != NULL && error == 0) 769 error = copyout(&si, uap->info, sizeof(si)); 770 return (error); 771 } 772 773 /* 774 * Reap the remains of a zombie process and optionally return status and 775 * rusage. Asserts and will release both the proctree_lock and the process 776 * lock as part of its work. 777 */ 778 void 779 proc_reap(struct thread *td, struct proc *p, int *status, int options) 780 { 781 struct proc *q, *t; 782 783 sx_assert(&proctree_lock, SA_XLOCKED); 784 PROC_LOCK_ASSERT(p, MA_OWNED); 785 PROC_SLOCK_ASSERT(p, MA_OWNED); 786 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 787 788 q = td->td_proc; 789 790 PROC_SUNLOCK(p); 791 td->td_retval[0] = p->p_pid; 792 if (status) 793 *status = p->p_xstat; /* convert to int */ 794 if (options & WNOWAIT) { 795 /* 796 * Only poll, returning the status. Caller does not wish to 797 * release the proc struct just yet. 798 */ 799 PROC_UNLOCK(p); 800 sx_xunlock(&proctree_lock); 801 return; 802 } 803 804 PROC_LOCK(q); 805 sigqueue_take(p->p_ksi); 806 PROC_UNLOCK(q); 807 PROC_UNLOCK(p); 808 809 /* 810 * If we got the child via a ptrace 'attach', we need to give it back 811 * to the old parent. 812 */ 813 if (p->p_oppid != 0) { 814 t = proc_realparent(p); 815 PROC_LOCK(t); 816 PROC_LOCK(p); 817 proc_reparent(p, t); 818 p->p_oppid = 0; 819 PROC_UNLOCK(p); 820 pksignal(t, SIGCHLD, p->p_ksi); 821 wakeup(t); 822 cv_broadcast(&p->p_pwait); 823 PROC_UNLOCK(t); 824 sx_xunlock(&proctree_lock); 825 return; 826 } 827 828 /* 829 * Remove other references to this process to ensure we have an 830 * exclusive reference. 831 */ 832 sx_xlock(&allproc_lock); 833 LIST_REMOVE(p, p_list); /* off zombproc */ 834 sx_xunlock(&allproc_lock); 835 LIST_REMOVE(p, p_sibling); 836 PROC_LOCK(p); 837 clear_orphan(p); 838 PROC_UNLOCK(p); 839 leavepgrp(p); 840 #ifdef PROCDESC 841 if (p->p_procdesc != NULL) 842 procdesc_reap(p); 843 #endif 844 sx_xunlock(&proctree_lock); 845 846 /* 847 * As a side effect of this lock, we know that all other writes to 848 * this proc are visible now, so no more locking is needed for p. 849 */ 850 PROC_LOCK(p); 851 p->p_xstat = 0; /* XXX: why? */ 852 PROC_UNLOCK(p); 853 PROC_LOCK(q); 854 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 855 PROC_UNLOCK(q); 856 857 /* 858 * Decrement the count of procs running with this uid. 859 */ 860 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 861 862 /* 863 * Destroy resource accounting information associated with the process. 864 */ 865 #ifdef RACCT 866 PROC_LOCK(p); 867 racct_sub(p, RACCT_NPROC, 1); 868 PROC_UNLOCK(p); 869 #endif 870 racct_proc_exit(p); 871 872 /* 873 * Free credentials, arguments, and sigacts. 874 */ 875 crfree(p->p_ucred); 876 p->p_ucred = NULL; 877 pargs_drop(p->p_args); 878 p->p_args = NULL; 879 sigacts_free(p->p_sigacts); 880 p->p_sigacts = NULL; 881 882 /* 883 * Do any thread-system specific cleanups. 884 */ 885 thread_wait(p); 886 887 /* 888 * Give vm and machine-dependent layer a chance to free anything that 889 * cpu_exit couldn't release while still running in process context. 890 */ 891 vm_waitproc(p); 892 #ifdef MAC 893 mac_proc_destroy(p); 894 #endif 895 KASSERT(FIRST_THREAD_IN_PROC(p), 896 ("proc_reap: no residual thread!")); 897 uma_zfree(proc_zone, p); 898 sx_xlock(&allproc_lock); 899 nprocs--; 900 sx_xunlock(&allproc_lock); 901 } 902 903 static int 904 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 905 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo) 906 { 907 struct proc *q; 908 struct rusage *rup; 909 910 sx_assert(&proctree_lock, SA_XLOCKED); 911 912 q = td->td_proc; 913 PROC_LOCK(p); 914 915 switch (idtype) { 916 case P_ALL: 917 break; 918 case P_PID: 919 if (p->p_pid != (pid_t)id) { 920 PROC_UNLOCK(p); 921 return (0); 922 } 923 break; 924 case P_PGID: 925 if (p->p_pgid != (pid_t)id) { 926 PROC_UNLOCK(p); 927 return (0); 928 } 929 break; 930 case P_SID: 931 if (p->p_session->s_sid != (pid_t)id) { 932 PROC_UNLOCK(p); 933 return (0); 934 } 935 break; 936 case P_UID: 937 if (p->p_ucred->cr_uid != (uid_t)id) { 938 PROC_UNLOCK(p); 939 return (0); 940 } 941 break; 942 case P_GID: 943 if (p->p_ucred->cr_gid != (gid_t)id) { 944 PROC_UNLOCK(p); 945 return (0); 946 } 947 break; 948 case P_JAILID: 949 if (p->p_ucred->cr_prison->pr_id != (int)id) { 950 PROC_UNLOCK(p); 951 return (0); 952 } 953 break; 954 /* 955 * It seems that the thread structures get zeroed out 956 * at process exit. This makes it impossible to 957 * support P_SETID, P_CID or P_CPUID. 958 */ 959 default: 960 PROC_UNLOCK(p); 961 return (0); 962 } 963 964 if (p_canwait(td, p)) { 965 PROC_UNLOCK(p); 966 return (0); 967 } 968 969 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 970 PROC_UNLOCK(p); 971 return (0); 972 } 973 974 /* 975 * This special case handles a kthread spawned by linux_clone 976 * (see linux_misc.c). The linux_wait4 and linux_waitpid 977 * functions need to be able to distinguish between waiting 978 * on a process and waiting on a thread. It is a thread if 979 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 980 * signifies we want to wait for threads and not processes. 981 */ 982 if ((p->p_sigparent != SIGCHLD) ^ 983 ((options & WLINUXCLONE) != 0)) { 984 PROC_UNLOCK(p); 985 return (0); 986 } 987 988 PROC_SLOCK(p); 989 990 if (siginfo != NULL) { 991 bzero(siginfo, sizeof(*siginfo)); 992 siginfo->si_errno = 0; 993 994 /* 995 * SUSv4 requires that the si_signo value is always 996 * SIGCHLD. Obey it despite the rfork(2) interface 997 * allows to request other signal for child exit 998 * notification. 999 */ 1000 siginfo->si_signo = SIGCHLD; 1001 1002 /* 1003 * This is still a rough estimate. We will fix the 1004 * cases TRAPPED, STOPPED, and CONTINUED later. 1005 */ 1006 if (WCOREDUMP(p->p_xstat)) { 1007 siginfo->si_code = CLD_DUMPED; 1008 siginfo->si_status = WTERMSIG(p->p_xstat); 1009 } else if (WIFSIGNALED(p->p_xstat)) { 1010 siginfo->si_code = CLD_KILLED; 1011 siginfo->si_status = WTERMSIG(p->p_xstat); 1012 } else { 1013 siginfo->si_code = CLD_EXITED; 1014 siginfo->si_status = WEXITSTATUS(p->p_xstat); 1015 } 1016 1017 siginfo->si_pid = p->p_pid; 1018 siginfo->si_uid = p->p_ucred->cr_uid; 1019 1020 /* 1021 * The si_addr field would be useful additional 1022 * detail, but apparently the PC value may be lost 1023 * when we reach this point. bzero() above sets 1024 * siginfo->si_addr to NULL. 1025 */ 1026 } 1027 1028 /* 1029 * There should be no reason to limit resources usage info to 1030 * exited processes only. A snapshot about any resources used 1031 * by a stopped process may be exactly what is needed. 1032 */ 1033 if (wrusage != NULL) { 1034 rup = &wrusage->wru_self; 1035 *rup = p->p_ru; 1036 calcru(p, &rup->ru_utime, &rup->ru_stime); 1037 1038 rup = &wrusage->wru_children; 1039 *rup = p->p_stats->p_cru; 1040 calccru(p, &rup->ru_utime, &rup->ru_stime); 1041 } 1042 1043 if (p->p_state == PRS_ZOMBIE) { 1044 proc_reap(td, p, status, options); 1045 return (-1); 1046 } 1047 PROC_SUNLOCK(p); 1048 PROC_UNLOCK(p); 1049 return (1); 1050 } 1051 1052 int 1053 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1054 struct rusage *rusage) 1055 { 1056 struct __wrusage wru, *wrup; 1057 idtype_t idtype; 1058 id_t id; 1059 int ret; 1060 1061 /* 1062 * Translate the special pid values into the (idtype, pid) 1063 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1064 * kern_wait6() on its own. 1065 */ 1066 if (pid == WAIT_ANY) { 1067 idtype = P_ALL; 1068 id = 0; 1069 } else if (pid < 0) { 1070 idtype = P_PGID; 1071 id = (id_t)-pid; 1072 } else { 1073 idtype = P_PID; 1074 id = (id_t)pid; 1075 } 1076 1077 if (rusage != NULL) 1078 wrup = &wru; 1079 else 1080 wrup = NULL; 1081 1082 /* 1083 * For backward compatibility we implicitly add flags WEXITED 1084 * and WTRAPPED here. 1085 */ 1086 options |= WEXITED | WTRAPPED; 1087 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1088 if (rusage != NULL) 1089 *rusage = wru.wru_self; 1090 return (ret); 1091 } 1092 1093 int 1094 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1095 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1096 { 1097 struct proc *p, *q; 1098 int error, nfound, ret; 1099 1100 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1101 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1102 AUDIT_ARG_VALUE(options); 1103 1104 q = td->td_proc; 1105 1106 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1107 PROC_LOCK(q); 1108 id = (id_t)q->p_pgid; 1109 PROC_UNLOCK(q); 1110 idtype = P_PGID; 1111 } 1112 1113 /* If we don't know the option, just return. */ 1114 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1115 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1116 return (EINVAL); 1117 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1118 /* 1119 * We will be unable to find any matching processes, 1120 * because there are no known events to look for. 1121 * Prefer to return error instead of blocking 1122 * indefinitely. 1123 */ 1124 return (EINVAL); 1125 } 1126 1127 loop: 1128 if (q->p_flag & P_STATCHILD) { 1129 PROC_LOCK(q); 1130 q->p_flag &= ~P_STATCHILD; 1131 PROC_UNLOCK(q); 1132 } 1133 nfound = 0; 1134 sx_xlock(&proctree_lock); 1135 LIST_FOREACH(p, &q->p_children, p_sibling) { 1136 ret = proc_to_reap(td, p, idtype, id, status, options, 1137 wrusage, siginfo); 1138 if (ret == 0) 1139 continue; 1140 else if (ret == 1) 1141 nfound++; 1142 else 1143 return (0); 1144 1145 PROC_LOCK(p); 1146 PROC_SLOCK(p); 1147 1148 if ((options & WTRAPPED) != 0 && 1149 (p->p_flag & P_TRACED) != 0 && 1150 (p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) != 0 && 1151 (p->p_suspcount == p->p_numthreads) && 1152 ((p->p_flag & P_WAITED) == 0)) { 1153 PROC_SUNLOCK(p); 1154 if ((options & WNOWAIT) == 0) 1155 p->p_flag |= P_WAITED; 1156 sx_xunlock(&proctree_lock); 1157 td->td_retval[0] = p->p_pid; 1158 1159 if (status != NULL) 1160 *status = W_STOPCODE(p->p_xstat); 1161 if (siginfo != NULL) { 1162 siginfo->si_status = p->p_xstat; 1163 siginfo->si_code = CLD_TRAPPED; 1164 } 1165 if ((options & WNOWAIT) == 0) { 1166 PROC_LOCK(q); 1167 sigqueue_take(p->p_ksi); 1168 PROC_UNLOCK(q); 1169 } 1170 1171 PROC_UNLOCK(p); 1172 return (0); 1173 } 1174 if ((options & WUNTRACED) != 0 && 1175 (p->p_flag & P_STOPPED_SIG) != 0 && 1176 (p->p_suspcount == p->p_numthreads) && 1177 ((p->p_flag & P_WAITED) == 0)) { 1178 PROC_SUNLOCK(p); 1179 if ((options & WNOWAIT) == 0) 1180 p->p_flag |= P_WAITED; 1181 sx_xunlock(&proctree_lock); 1182 td->td_retval[0] = p->p_pid; 1183 1184 if (status != NULL) 1185 *status = W_STOPCODE(p->p_xstat); 1186 if (siginfo != NULL) { 1187 siginfo->si_status = p->p_xstat; 1188 siginfo->si_code = CLD_STOPPED; 1189 } 1190 if ((options & WNOWAIT) == 0) { 1191 PROC_LOCK(q); 1192 sigqueue_take(p->p_ksi); 1193 PROC_UNLOCK(q); 1194 } 1195 1196 PROC_UNLOCK(p); 1197 return (0); 1198 } 1199 PROC_SUNLOCK(p); 1200 if ((options & WCONTINUED) != 0 && 1201 (p->p_flag & P_CONTINUED) != 0) { 1202 sx_xunlock(&proctree_lock); 1203 td->td_retval[0] = p->p_pid; 1204 if ((options & WNOWAIT) == 0) { 1205 p->p_flag &= ~P_CONTINUED; 1206 PROC_LOCK(q); 1207 sigqueue_take(p->p_ksi); 1208 PROC_UNLOCK(q); 1209 } 1210 PROC_UNLOCK(p); 1211 1212 if (status != NULL) 1213 *status = SIGCONT; 1214 if (siginfo != NULL) { 1215 siginfo->si_status = SIGCONT; 1216 siginfo->si_code = CLD_CONTINUED; 1217 } 1218 return (0); 1219 } 1220 PROC_UNLOCK(p); 1221 } 1222 1223 /* 1224 * Look in the orphans list too, to allow the parent to 1225 * collect it's child exit status even if child is being 1226 * debugged. 1227 * 1228 * Debugger detaches from the parent upon successful 1229 * switch-over from parent to child. At this point due to 1230 * re-parenting the parent loses the child to debugger and a 1231 * wait4(2) call would report that it has no children to wait 1232 * for. By maintaining a list of orphans we allow the parent 1233 * to successfully wait until the child becomes a zombie. 1234 */ 1235 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1236 ret = proc_to_reap(td, p, idtype, id, status, options, 1237 wrusage, siginfo); 1238 if (ret == 0) 1239 continue; 1240 else if (ret == 1) 1241 nfound++; 1242 else 1243 return (0); 1244 } 1245 if (nfound == 0) { 1246 sx_xunlock(&proctree_lock); 1247 return (ECHILD); 1248 } 1249 if (options & WNOHANG) { 1250 sx_xunlock(&proctree_lock); 1251 td->td_retval[0] = 0; 1252 return (0); 1253 } 1254 PROC_LOCK(q); 1255 sx_xunlock(&proctree_lock); 1256 if (q->p_flag & P_STATCHILD) { 1257 q->p_flag &= ~P_STATCHILD; 1258 error = 0; 1259 } else 1260 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 1261 PROC_UNLOCK(q); 1262 if (error) 1263 return (error); 1264 goto loop; 1265 } 1266 1267 /* 1268 * Make process 'parent' the new parent of process 'child'. 1269 * Must be called with an exclusive hold of proctree lock. 1270 */ 1271 void 1272 proc_reparent(struct proc *child, struct proc *parent) 1273 { 1274 1275 sx_assert(&proctree_lock, SX_XLOCKED); 1276 PROC_LOCK_ASSERT(child, MA_OWNED); 1277 if (child->p_pptr == parent) 1278 return; 1279 1280 PROC_LOCK(child->p_pptr); 1281 sigqueue_take(child->p_ksi); 1282 PROC_UNLOCK(child->p_pptr); 1283 LIST_REMOVE(child, p_sibling); 1284 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1285 1286 clear_orphan(child); 1287 if (child->p_flag & P_TRACED) { 1288 if (LIST_EMPTY(&child->p_pptr->p_orphans)) { 1289 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1290 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child, 1291 p_orphan); 1292 } else { 1293 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans), 1294 child, p_orphan); 1295 } 1296 child->p_treeflag |= P_TREE_ORPHANED; 1297 } 1298 1299 child->p_pptr = parent; 1300 }
Cache object: 0308017bd7a2aa8a2685f3ae5f8e1de9
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