1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/capsicum.h> 48 #include <sys/eventhandler.h> 49 #include <sys/kernel.h> 50 #include <sys/ktr.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 #include <sys/umtx.h> 77 #ifdef KTRACE 78 #include <sys/ktrace.h> 79 #endif 80 81 #include <security/audit/audit.h> 82 #include <security/mac/mac_framework.h> 83 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/vm_param.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_page.h> 90 #include <vm/uma.h> 91 92 #ifdef KDTRACE_HOOKS 93 #include <sys/dtrace_bsd.h> 94 dtrace_execexit_func_t dtrace_fasttrap_exit; 95 #endif 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE1(proc, , , exit, "int"); 99 100 /* Hook for NFS teardown procedure. */ 101 void (*nlminfo_release_p)(struct proc *p); 102 103 struct proc * 104 proc_realparent(struct proc *child) 105 { 106 struct proc *p, *parent; 107 108 sx_assert(&proctree_lock, SX_LOCKED); 109 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) 110 return (child->p_pptr->p_pid == child->p_oppid ? 111 child->p_pptr : initproc); 112 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) { 113 /* Cannot use LIST_PREV(), since the list head is not known. */ 114 p = __containerof(p->p_orphan.le_prev, struct proc, 115 p_orphan.le_next); 116 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0, 117 ("missing P_ORPHAN %p", p)); 118 } 119 parent = __containerof(p->p_orphan.le_prev, struct proc, 120 p_orphans.lh_first); 121 return (parent); 122 } 123 124 void 125 reaper_abandon_children(struct proc *p, bool exiting) 126 { 127 struct proc *p1, *p2, *ptmp; 128 129 sx_assert(&proctree_lock, SX_LOCKED); 130 KASSERT(p != initproc, ("reaper_abandon_children for initproc")); 131 if ((p->p_treeflag & P_TREE_REAPER) == 0) 132 return; 133 p1 = p->p_reaper; 134 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) { 135 LIST_REMOVE(p2, p_reapsibling); 136 p2->p_reaper = p1; 137 p2->p_reapsubtree = p->p_reapsubtree; 138 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling); 139 if (exiting && p2->p_pptr == p) { 140 PROC_LOCK(p2); 141 proc_reparent(p2, p1, true); 142 PROC_UNLOCK(p2); 143 } 144 } 145 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty")); 146 p->p_treeflag &= ~P_TREE_REAPER; 147 } 148 149 static void 150 reaper_clear(struct proc *p) 151 { 152 struct proc *p1; 153 bool clear; 154 155 sx_assert(&proctree_lock, SX_LOCKED); 156 LIST_REMOVE(p, p_reapsibling); 157 if (p->p_reapsubtree == 1) 158 return; 159 clear = true; 160 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) { 161 if (p1->p_reapsubtree == p->p_reapsubtree) { 162 clear = false; 163 break; 164 } 165 } 166 if (clear) 167 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree); 168 } 169 170 void 171 proc_clear_orphan(struct proc *p) 172 { 173 struct proc *p1; 174 175 sx_assert(&proctree_lock, SA_XLOCKED); 176 if ((p->p_treeflag & P_TREE_ORPHANED) == 0) 177 return; 178 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) { 179 p1 = LIST_NEXT(p, p_orphan); 180 if (p1 != NULL) 181 p1->p_treeflag |= P_TREE_FIRST_ORPHAN; 182 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN; 183 } 184 LIST_REMOVE(p, p_orphan); 185 p->p_treeflag &= ~P_TREE_ORPHANED; 186 } 187 188 /* 189 * exit -- death of process. 190 */ 191 void 192 sys_sys_exit(struct thread *td, struct sys_exit_args *uap) 193 { 194 195 exit1(td, uap->rval, 0); 196 /* NOTREACHED */ 197 } 198 199 /* 200 * Exit: deallocate address space and other resources, change proc state to 201 * zombie, and unlink proc from allproc and parent's lists. Save exit status 202 * and rusage for wait(). Check for child processes and orphan them. 203 */ 204 void 205 exit1(struct thread *td, int rval, int signo) 206 { 207 struct proc *p, *nq, *q, *t; 208 struct thread *tdt; 209 ksiginfo_t *ksi, *ksi1; 210 int signal_parent; 211 212 mtx_assert(&Giant, MA_NOTOWNED); 213 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo)); 214 215 p = td->td_proc; 216 /* 217 * XXX in case we're rebooting we just let init die in order to 218 * work around an unsolved stack overflow seen very late during 219 * shutdown on sparc64 when the gmirror worker process exists. 220 */ 221 if (p == initproc && rebooting == 0) { 222 printf("init died (signal %d, exit %d)\n", signo, rval); 223 panic("Going nowhere without my init!"); 224 } 225 226 /* 227 * Deref SU mp, since the thread does not return to userspace. 228 */ 229 td_softdep_cleanup(td); 230 231 /* 232 * MUST abort all other threads before proceeding past here. 233 */ 234 PROC_LOCK(p); 235 /* 236 * First check if some other thread or external request got 237 * here before us. If so, act appropriately: exit or suspend. 238 * We must ensure that stop requests are handled before we set 239 * P_WEXIT. 240 */ 241 thread_suspend_check(0); 242 while (p->p_flag & P_HADTHREADS) { 243 /* 244 * Kill off the other threads. This requires 245 * some co-operation from other parts of the kernel 246 * so it may not be instantaneous. With this state set 247 * any thread entering the kernel from userspace will 248 * thread_exit() in trap(). Any thread attempting to 249 * sleep will return immediately with EINTR or EWOULDBLOCK 250 * which will hopefully force them to back out to userland 251 * freeing resources as they go. Any thread attempting 252 * to return to userland will thread_exit() from userret(). 253 * thread_exit() will unsuspend us when the last of the 254 * other threads exits. 255 * If there is already a thread singler after resumption, 256 * calling thread_single will fail; in that case, we just 257 * re-check all suspension request, the thread should 258 * either be suspended there or exit. 259 */ 260 if (!thread_single(p, SINGLE_EXIT)) 261 /* 262 * All other activity in this process is now 263 * stopped. Threading support has been turned 264 * off. 265 */ 266 break; 267 /* 268 * Recheck for new stop or suspend requests which 269 * might appear while process lock was dropped in 270 * thread_single(). 271 */ 272 thread_suspend_check(0); 273 } 274 KASSERT(p->p_numthreads == 1, 275 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 276 racct_sub(p, RACCT_NTHR, 1); 277 278 /* Let event handler change exit status */ 279 p->p_xexit = rval; 280 p->p_xsig = signo; 281 282 /* 283 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold 284 * on our vmspace, so we should block below until they have 285 * released their reference to us. Note that if they have 286 * requested S_EXIT stops we will block here until they ack 287 * via PIOCCONT. 288 */ 289 _STOPEVENT(p, S_EXIT, 0); 290 291 /* 292 * Ignore any pending request to stop due to a stop signal. 293 * Once P_WEXIT is set, future requests will be ignored as 294 * well. 295 */ 296 p->p_flag &= ~P_STOPPED_SIG; 297 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 298 299 /* 300 * Note that we are exiting and do another wakeup of anyone in 301 * PIOCWAIT in case they aren't listening for S_EXIT stops or 302 * decided to wait again after we told them we are exiting. 303 */ 304 p->p_flag |= P_WEXIT; 305 wakeup(&p->p_stype); 306 307 /* 308 * Wait for any processes that have a hold on our vmspace to 309 * release their reference. 310 */ 311 while (p->p_lock > 0) 312 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 313 314 PROC_UNLOCK(p); 315 /* Drain the limit callout while we don't have the proc locked */ 316 callout_drain(&p->p_limco); 317 318 #ifdef AUDIT 319 /* 320 * The Sun BSM exit token contains two components: an exit status as 321 * passed to exit(), and a return value to indicate what sort of exit 322 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 323 * what the return value is. 324 */ 325 AUDIT_ARG_EXIT(rval, 0); 326 AUDIT_SYSCALL_EXIT(0, td); 327 #endif 328 329 /* Are we a task leader with peers? */ 330 if (p->p_peers != NULL && p == p->p_leader) { 331 mtx_lock(&ppeers_lock); 332 q = p->p_peers; 333 while (q != NULL) { 334 PROC_LOCK(q); 335 kern_psignal(q, SIGKILL); 336 PROC_UNLOCK(q); 337 q = q->p_peers; 338 } 339 while (p->p_peers != NULL) 340 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 341 mtx_unlock(&ppeers_lock); 342 } 343 344 /* 345 * Check if any loadable modules need anything done at process exit. 346 * E.g. SYSV IPC stuff. 347 * Event handler could change exit status. 348 * XXX what if one of these generates an error? 349 */ 350 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 351 352 /* 353 * If parent is waiting for us to exit or exec, 354 * P_PPWAIT is set; we will wakeup the parent below. 355 */ 356 PROC_LOCK(p); 357 stopprofclock(p); 358 p->p_ptevents = 0; 359 360 /* 361 * Stop the real interval timer. If the handler is currently 362 * executing, prevent it from rearming itself and let it finish. 363 */ 364 if (timevalisset(&p->p_realtimer.it_value) && 365 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 366 timevalclear(&p->p_realtimer.it_interval); 367 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 368 KASSERT(!timevalisset(&p->p_realtimer.it_value), 369 ("realtime timer is still armed")); 370 } 371 372 PROC_UNLOCK(p); 373 374 umtx_thread_exit(td); 375 376 /* 377 * Reset any sigio structures pointing to us as a result of 378 * F_SETOWN with our pid. 379 */ 380 funsetownlst(&p->p_sigiolst); 381 382 /* 383 * If this process has an nlminfo data area (for lockd), release it 384 */ 385 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL) 386 (*nlminfo_release_p)(p); 387 388 /* 389 * Close open files and release open-file table. 390 * This may block! 391 */ 392 fdescfree(td); 393 394 /* 395 * If this thread tickled GEOM, we need to wait for the giggling to 396 * stop before we return to userland 397 */ 398 if (td->td_pflags & TDP_GEOM) 399 g_waitidle(); 400 401 /* 402 * Remove ourself from our leader's peer list and wake our leader. 403 */ 404 if (p->p_leader->p_peers != NULL) { 405 mtx_lock(&ppeers_lock); 406 if (p->p_leader->p_peers != NULL) { 407 q = p->p_leader; 408 while (q->p_peers != p) 409 q = q->p_peers; 410 q->p_peers = p->p_peers; 411 wakeup(p->p_leader); 412 } 413 mtx_unlock(&ppeers_lock); 414 } 415 416 vmspace_exit(td); 417 killjobc(); 418 (void)acct_process(td); 419 420 #ifdef KTRACE 421 ktrprocexit(td); 422 #endif 423 /* 424 * Release reference to text vnode 425 */ 426 if (p->p_textvp != NULL) { 427 vrele(p->p_textvp); 428 p->p_textvp = NULL; 429 } 430 431 /* 432 * Release our limits structure. 433 */ 434 lim_free(p->p_limit); 435 p->p_limit = NULL; 436 437 tidhash_remove(td); 438 439 /* 440 * Call machine-dependent code to release any 441 * machine-dependent resources other than the address space. 442 * The address space is released by "vmspace_exitfree(p)" in 443 * vm_waitproc(). 444 */ 445 cpu_exit(td); 446 447 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 448 449 /* 450 * Remove from allproc. It still sits in the hash. 451 */ 452 sx_xlock(&allproc_lock); 453 LIST_REMOVE(p, p_list); 454 sx_xunlock(&allproc_lock); 455 456 sx_xlock(&proctree_lock); 457 PROC_LOCK(p); 458 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 459 PROC_UNLOCK(p); 460 461 /* 462 * Reparent all children processes: 463 * - traced ones to the original parent (or init if we are that parent) 464 * - the rest to init 465 */ 466 q = LIST_FIRST(&p->p_children); 467 if (q != NULL) /* only need this if any child is S_ZOMB */ 468 wakeup(q->p_reaper); 469 for (; q != NULL; q = nq) { 470 nq = LIST_NEXT(q, p_sibling); 471 ksi = ksiginfo_alloc(TRUE); 472 PROC_LOCK(q); 473 q->p_sigparent = SIGCHLD; 474 475 if ((q->p_flag & P_TRACED) == 0) { 476 proc_reparent(q, q->p_reaper, true); 477 if (q->p_state == PRS_ZOMBIE) { 478 /* 479 * Inform reaper about the reparented 480 * zombie, since wait(2) has something 481 * new to report. Guarantee queueing 482 * of the SIGCHLD signal, similar to 483 * the _exit() behaviour, by providing 484 * our ksiginfo. Ksi is freed by the 485 * signal delivery. 486 */ 487 if (q->p_ksi == NULL) { 488 ksi1 = NULL; 489 } else { 490 ksiginfo_copy(q->p_ksi, ksi); 491 ksi->ksi_flags |= KSI_INS; 492 ksi1 = ksi; 493 ksi = NULL; 494 } 495 PROC_LOCK(q->p_reaper); 496 pksignal(q->p_reaper, SIGCHLD, ksi1); 497 PROC_UNLOCK(q->p_reaper); 498 } else if (q->p_pdeathsig > 0) { 499 /* 500 * The child asked to received a signal 501 * when we exit. 502 */ 503 kern_psignal(q, q->p_pdeathsig); 504 } 505 } else { 506 /* 507 * Traced processes are killed since their existence 508 * means someone is screwing up. 509 */ 510 t = proc_realparent(q); 511 if (t == p) { 512 proc_reparent(q, q->p_reaper, true); 513 } else { 514 PROC_LOCK(t); 515 proc_reparent(q, t, true); 516 PROC_UNLOCK(t); 517 } 518 /* 519 * Since q was found on our children list, the 520 * proc_reparent() call moved q to the orphan 521 * list due to present P_TRACED flag. Clear 522 * orphan link for q now while q is locked. 523 */ 524 proc_clear_orphan(q); 525 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 526 q->p_flag2 &= ~P2_PTRACE_FSTP; 527 q->p_ptevents = 0; 528 FOREACH_THREAD_IN_PROC(q, tdt) { 529 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 530 TDB_FSTP); 531 } 532 kern_psignal(q, SIGKILL); 533 } 534 PROC_UNLOCK(q); 535 if (ksi != NULL) 536 ksiginfo_free(ksi); 537 } 538 539 /* 540 * Also get rid of our orphans. 541 */ 542 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 543 PROC_LOCK(q); 544 KASSERT(q->p_oppid == p->p_pid, 545 ("orphan %p of %p has unexpected oppid %d", q, p, 546 q->p_oppid)); 547 q->p_oppid = q->p_reaper->p_pid; 548 549 /* 550 * If we are the real parent of this process 551 * but it has been reparented to a debugger, then 552 * check if it asked for a signal when we exit. 553 */ 554 if (q->p_pdeathsig > 0) 555 kern_psignal(q, q->p_pdeathsig); 556 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 557 q->p_pid); 558 proc_clear_orphan(q); 559 PROC_UNLOCK(q); 560 } 561 562 #ifdef KDTRACE_HOOKS 563 if (SDT_PROBES_ENABLED()) { 564 int reason = CLD_EXITED; 565 if (WCOREDUMP(signo)) 566 reason = CLD_DUMPED; 567 else if (WIFSIGNALED(signo)) 568 reason = CLD_KILLED; 569 SDT_PROBE1(proc, , , exit, reason); 570 } 571 #endif 572 573 /* Save exit status. */ 574 PROC_LOCK(p); 575 p->p_xthread = td; 576 577 #ifdef KDTRACE_HOOKS 578 /* 579 * Tell the DTrace fasttrap provider about the exit if it 580 * has declared an interest. 581 */ 582 if (dtrace_fasttrap_exit) 583 dtrace_fasttrap_exit(p); 584 #endif 585 586 /* 587 * Notify interested parties of our demise. 588 */ 589 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 590 591 /* 592 * If this is a process with a descriptor, we may not need to deliver 593 * a signal to the parent. proctree_lock is held over 594 * procdesc_exit() to serialize concurrent calls to close() and 595 * exit(). 596 */ 597 signal_parent = 0; 598 if (p->p_procdesc == NULL || procdesc_exit(p)) { 599 /* 600 * Notify parent that we're gone. If parent has the 601 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 602 * notify process 1 instead (and hope it will handle this 603 * situation). 604 */ 605 PROC_LOCK(p->p_pptr); 606 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 607 if (p->p_pptr->p_sigacts->ps_flag & 608 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 609 struct proc *pp; 610 611 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 612 pp = p->p_pptr; 613 PROC_UNLOCK(pp); 614 proc_reparent(p, p->p_reaper, true); 615 p->p_sigparent = SIGCHLD; 616 PROC_LOCK(p->p_pptr); 617 618 /* 619 * Notify parent, so in case he was wait(2)ing or 620 * executing waitpid(2) with our pid, he will 621 * continue. 622 */ 623 wakeup(pp); 624 } else 625 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 626 627 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 628 signal_parent = 1; 629 } else if (p->p_sigparent != 0) { 630 if (p->p_sigparent == SIGCHLD) { 631 signal_parent = 1; 632 } else { /* LINUX thread */ 633 signal_parent = 2; 634 } 635 } 636 } else 637 PROC_LOCK(p->p_pptr); 638 sx_xunlock(&proctree_lock); 639 640 if (signal_parent == 1) { 641 childproc_exited(p); 642 } else if (signal_parent == 2) { 643 kern_psignal(p->p_pptr, p->p_sigparent); 644 } 645 646 /* Tell the prison that we are gone. */ 647 prison_proc_free(p->p_ucred->cr_prison); 648 649 /* 650 * The state PRS_ZOMBIE prevents other proesses from sending 651 * signal to the process, to avoid memory leak, we free memory 652 * for signal queue at the time when the state is set. 653 */ 654 sigqueue_flush(&p->p_sigqueue); 655 sigqueue_flush(&td->td_sigqueue); 656 657 /* 658 * We have to wait until after acquiring all locks before 659 * changing p_state. We need to avoid all possible context 660 * switches (including ones from blocking on a mutex) while 661 * marked as a zombie. We also have to set the zombie state 662 * before we release the parent process' proc lock to avoid 663 * a lost wakeup. So, we first call wakeup, then we grab the 664 * sched lock, update the state, and release the parent process' 665 * proc lock. 666 */ 667 wakeup(p->p_pptr); 668 cv_broadcast(&p->p_pwait); 669 sched_exit(p->p_pptr, td); 670 PROC_SLOCK(p); 671 p->p_state = PRS_ZOMBIE; 672 PROC_UNLOCK(p->p_pptr); 673 674 /* 675 * Save our children's rusage information in our exit rusage. 676 */ 677 PROC_STATLOCK(p); 678 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 679 PROC_STATUNLOCK(p); 680 681 /* 682 * Make sure the scheduler takes this thread out of its tables etc. 683 * This will also release this thread's reference to the ucred. 684 * Other thread parts to release include pcb bits and such. 685 */ 686 thread_exit(); 687 } 688 689 690 #ifndef _SYS_SYSPROTO_H_ 691 struct abort2_args { 692 char *why; 693 int nargs; 694 void **args; 695 }; 696 #endif 697 698 int 699 sys_abort2(struct thread *td, struct abort2_args *uap) 700 { 701 struct proc *p = td->td_proc; 702 struct sbuf *sb; 703 void *uargs[16]; 704 int error, i, sig; 705 706 /* 707 * Do it right now so we can log either proper call of abort2(), or 708 * note, that invalid argument was passed. 512 is big enough to 709 * handle 16 arguments' descriptions with additional comments. 710 */ 711 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 712 sbuf_clear(sb); 713 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 714 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 715 /* 716 * Since we can't return from abort2(), send SIGKILL in cases, where 717 * abort2() was called improperly 718 */ 719 sig = SIGKILL; 720 /* Prevent from DoSes from user-space. */ 721 if (uap->nargs < 0 || uap->nargs > 16) 722 goto out; 723 if (uap->nargs > 0) { 724 if (uap->args == NULL) 725 goto out; 726 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 727 if (error != 0) 728 goto out; 729 } 730 /* 731 * Limit size of 'reason' string to 128. Will fit even when 732 * maximal number of arguments was chosen to be logged. 733 */ 734 if (uap->why != NULL) { 735 error = sbuf_copyin(sb, uap->why, 128); 736 if (error < 0) 737 goto out; 738 } else { 739 sbuf_printf(sb, "(null)"); 740 } 741 if (uap->nargs > 0) { 742 sbuf_printf(sb, "("); 743 for (i = 0;i < uap->nargs; i++) 744 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 745 sbuf_printf(sb, ")"); 746 } 747 /* 748 * Final stage: arguments were proper, string has been 749 * successfully copied from userspace, and copying pointers 750 * from user-space succeed. 751 */ 752 sig = SIGABRT; 753 out: 754 if (sig == SIGKILL) { 755 sbuf_trim(sb); 756 sbuf_printf(sb, " (Reason text inaccessible)"); 757 } 758 sbuf_cat(sb, "\n"); 759 sbuf_finish(sb); 760 log(LOG_INFO, "%s", sbuf_data(sb)); 761 sbuf_delete(sb); 762 exit1(td, 0, sig); 763 return (0); 764 } 765 766 767 #ifdef COMPAT_43 768 /* 769 * The dirty work is handled by kern_wait(). 770 */ 771 int 772 owait(struct thread *td, struct owait_args *uap __unused) 773 { 774 int error, status; 775 776 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 777 if (error == 0) 778 td->td_retval[1] = status; 779 return (error); 780 } 781 #endif /* COMPAT_43 */ 782 783 /* 784 * The dirty work is handled by kern_wait(). 785 */ 786 int 787 sys_wait4(struct thread *td, struct wait4_args *uap) 788 { 789 struct rusage ru, *rup; 790 int error, status; 791 792 if (uap->rusage != NULL) 793 rup = &ru; 794 else 795 rup = NULL; 796 error = kern_wait(td, uap->pid, &status, uap->options, rup); 797 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 798 error = copyout(&status, uap->status, sizeof(status)); 799 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 800 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 801 return (error); 802 } 803 804 int 805 sys_wait6(struct thread *td, struct wait6_args *uap) 806 { 807 struct __wrusage wru, *wrup; 808 siginfo_t si, *sip; 809 idtype_t idtype; 810 id_t id; 811 int error, status; 812 813 idtype = uap->idtype; 814 id = uap->id; 815 816 if (uap->wrusage != NULL) 817 wrup = &wru; 818 else 819 wrup = NULL; 820 821 if (uap->info != NULL) { 822 sip = &si; 823 bzero(sip, sizeof(*sip)); 824 } else 825 sip = NULL; 826 827 /* 828 * We expect all callers of wait6() to know about WEXITED and 829 * WTRAPPED. 830 */ 831 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 832 833 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 834 error = copyout(&status, uap->status, sizeof(status)); 835 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 836 error = copyout(&wru, uap->wrusage, sizeof(wru)); 837 if (uap->info != NULL && error == 0) 838 error = copyout(&si, uap->info, sizeof(si)); 839 return (error); 840 } 841 842 /* 843 * Reap the remains of a zombie process and optionally return status and 844 * rusage. Asserts and will release both the proctree_lock and the process 845 * lock as part of its work. 846 */ 847 void 848 proc_reap(struct thread *td, struct proc *p, int *status, int options) 849 { 850 struct proc *q, *t; 851 852 sx_assert(&proctree_lock, SA_XLOCKED); 853 PROC_LOCK_ASSERT(p, MA_OWNED); 854 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 855 856 mtx_spin_wait_unlocked(&p->p_slock); 857 858 q = td->td_proc; 859 860 if (status) 861 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 862 if (options & WNOWAIT) { 863 /* 864 * Only poll, returning the status. Caller does not wish to 865 * release the proc struct just yet. 866 */ 867 PROC_UNLOCK(p); 868 sx_xunlock(&proctree_lock); 869 return; 870 } 871 872 PROC_LOCK(q); 873 sigqueue_take(p->p_ksi); 874 PROC_UNLOCK(q); 875 876 /* 877 * If we got the child via a ptrace 'attach', we need to give it back 878 * to the old parent. 879 */ 880 if (p->p_oppid != p->p_pptr->p_pid) { 881 PROC_UNLOCK(p); 882 t = proc_realparent(p); 883 PROC_LOCK(t); 884 PROC_LOCK(p); 885 CTR2(KTR_PTRACE, 886 "wait: traced child %d moved back to parent %d", p->p_pid, 887 t->p_pid); 888 proc_reparent(p, t, false); 889 PROC_UNLOCK(p); 890 pksignal(t, SIGCHLD, p->p_ksi); 891 wakeup(t); 892 cv_broadcast(&p->p_pwait); 893 PROC_UNLOCK(t); 894 sx_xunlock(&proctree_lock); 895 return; 896 } 897 PROC_UNLOCK(p); 898 899 /* 900 * Remove other references to this process to ensure we have an 901 * exclusive reference. 902 */ 903 sx_xlock(PIDHASHLOCK(p->p_pid)); 904 LIST_REMOVE(p, p_hash); 905 sx_xunlock(PIDHASHLOCK(p->p_pid)); 906 LIST_REMOVE(p, p_sibling); 907 reaper_abandon_children(p, true); 908 reaper_clear(p); 909 proc_id_clear(PROC_ID_PID, p->p_pid); 910 PROC_LOCK(p); 911 proc_clear_orphan(p); 912 PROC_UNLOCK(p); 913 leavepgrp(p); 914 if (p->p_procdesc != NULL) 915 procdesc_reap(p); 916 sx_xunlock(&proctree_lock); 917 918 PROC_LOCK(p); 919 knlist_detach(p->p_klist); 920 p->p_klist = NULL; 921 PROC_UNLOCK(p); 922 923 /* 924 * Removal from allproc list and process group list paired with 925 * PROC_LOCK which was executed during that time should guarantee 926 * nothing can reach this process anymore. As such further locking 927 * is unnecessary. 928 */ 929 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 930 931 PROC_LOCK(q); 932 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 933 PROC_UNLOCK(q); 934 935 /* 936 * Decrement the count of procs running with this uid. 937 */ 938 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 939 940 /* 941 * Destroy resource accounting information associated with the process. 942 */ 943 #ifdef RACCT 944 if (racct_enable) { 945 PROC_LOCK(p); 946 racct_sub(p, RACCT_NPROC, 1); 947 PROC_UNLOCK(p); 948 } 949 #endif 950 racct_proc_exit(p); 951 952 /* 953 * Free credentials, arguments, and sigacts. 954 */ 955 crfree(p->p_ucred); 956 proc_set_cred(p, NULL); 957 pargs_drop(p->p_args); 958 p->p_args = NULL; 959 sigacts_free(p->p_sigacts); 960 p->p_sigacts = NULL; 961 962 /* 963 * Do any thread-system specific cleanups. 964 */ 965 thread_wait(p); 966 967 /* 968 * Give vm and machine-dependent layer a chance to free anything that 969 * cpu_exit couldn't release while still running in process context. 970 */ 971 vm_waitproc(p); 972 #ifdef MAC 973 mac_proc_destroy(p); 974 #endif 975 976 KASSERT(FIRST_THREAD_IN_PROC(p), 977 ("proc_reap: no residual thread!")); 978 uma_zfree(proc_zone, p); 979 atomic_add_int(&nprocs, -1); 980 } 981 982 static int 983 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 984 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 985 int check_only) 986 { 987 struct rusage *rup; 988 989 sx_assert(&proctree_lock, SA_XLOCKED); 990 991 PROC_LOCK(p); 992 993 switch (idtype) { 994 case P_ALL: 995 if (p->p_procdesc != NULL) { 996 PROC_UNLOCK(p); 997 return (0); 998 } 999 break; 1000 case P_PID: 1001 if (p->p_pid != (pid_t)id) { 1002 PROC_UNLOCK(p); 1003 return (0); 1004 } 1005 break; 1006 case P_PGID: 1007 if (p->p_pgid != (pid_t)id) { 1008 PROC_UNLOCK(p); 1009 return (0); 1010 } 1011 break; 1012 case P_SID: 1013 if (p->p_session->s_sid != (pid_t)id) { 1014 PROC_UNLOCK(p); 1015 return (0); 1016 } 1017 break; 1018 case P_UID: 1019 if (p->p_ucred->cr_uid != (uid_t)id) { 1020 PROC_UNLOCK(p); 1021 return (0); 1022 } 1023 break; 1024 case P_GID: 1025 if (p->p_ucred->cr_gid != (gid_t)id) { 1026 PROC_UNLOCK(p); 1027 return (0); 1028 } 1029 break; 1030 case P_JAILID: 1031 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1032 PROC_UNLOCK(p); 1033 return (0); 1034 } 1035 break; 1036 /* 1037 * It seems that the thread structures get zeroed out 1038 * at process exit. This makes it impossible to 1039 * support P_SETID, P_CID or P_CPUID. 1040 */ 1041 default: 1042 PROC_UNLOCK(p); 1043 return (0); 1044 } 1045 1046 if (p_canwait(td, p)) { 1047 PROC_UNLOCK(p); 1048 return (0); 1049 } 1050 1051 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1052 PROC_UNLOCK(p); 1053 return (0); 1054 } 1055 1056 /* 1057 * This special case handles a kthread spawned by linux_clone 1058 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1059 * functions need to be able to distinguish between waiting 1060 * on a process and waiting on a thread. It is a thread if 1061 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1062 * signifies we want to wait for threads and not processes. 1063 */ 1064 if ((p->p_sigparent != SIGCHLD) ^ 1065 ((options & WLINUXCLONE) != 0)) { 1066 PROC_UNLOCK(p); 1067 return (0); 1068 } 1069 1070 if (siginfo != NULL) { 1071 bzero(siginfo, sizeof(*siginfo)); 1072 siginfo->si_errno = 0; 1073 1074 /* 1075 * SUSv4 requires that the si_signo value is always 1076 * SIGCHLD. Obey it despite the rfork(2) interface 1077 * allows to request other signal for child exit 1078 * notification. 1079 */ 1080 siginfo->si_signo = SIGCHLD; 1081 1082 /* 1083 * This is still a rough estimate. We will fix the 1084 * cases TRAPPED, STOPPED, and CONTINUED later. 1085 */ 1086 if (WCOREDUMP(p->p_xsig)) { 1087 siginfo->si_code = CLD_DUMPED; 1088 siginfo->si_status = WTERMSIG(p->p_xsig); 1089 } else if (WIFSIGNALED(p->p_xsig)) { 1090 siginfo->si_code = CLD_KILLED; 1091 siginfo->si_status = WTERMSIG(p->p_xsig); 1092 } else { 1093 siginfo->si_code = CLD_EXITED; 1094 siginfo->si_status = p->p_xexit; 1095 } 1096 1097 siginfo->si_pid = p->p_pid; 1098 siginfo->si_uid = p->p_ucred->cr_uid; 1099 1100 /* 1101 * The si_addr field would be useful additional 1102 * detail, but apparently the PC value may be lost 1103 * when we reach this point. bzero() above sets 1104 * siginfo->si_addr to NULL. 1105 */ 1106 } 1107 1108 /* 1109 * There should be no reason to limit resources usage info to 1110 * exited processes only. A snapshot about any resources used 1111 * by a stopped process may be exactly what is needed. 1112 */ 1113 if (wrusage != NULL) { 1114 rup = &wrusage->wru_self; 1115 *rup = p->p_ru; 1116 PROC_STATLOCK(p); 1117 calcru(p, &rup->ru_utime, &rup->ru_stime); 1118 PROC_STATUNLOCK(p); 1119 1120 rup = &wrusage->wru_children; 1121 *rup = p->p_stats->p_cru; 1122 calccru(p, &rup->ru_utime, &rup->ru_stime); 1123 } 1124 1125 if (p->p_state == PRS_ZOMBIE && !check_only) { 1126 proc_reap(td, p, status, options); 1127 return (-1); 1128 } 1129 return (1); 1130 } 1131 1132 int 1133 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1134 struct rusage *rusage) 1135 { 1136 struct __wrusage wru, *wrup; 1137 idtype_t idtype; 1138 id_t id; 1139 int ret; 1140 1141 /* 1142 * Translate the special pid values into the (idtype, pid) 1143 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1144 * kern_wait6() on its own. 1145 */ 1146 if (pid == WAIT_ANY) { 1147 idtype = P_ALL; 1148 id = 0; 1149 } else if (pid < 0) { 1150 idtype = P_PGID; 1151 id = (id_t)-pid; 1152 } else { 1153 idtype = P_PID; 1154 id = (id_t)pid; 1155 } 1156 1157 if (rusage != NULL) 1158 wrup = &wru; 1159 else 1160 wrup = NULL; 1161 1162 /* 1163 * For backward compatibility we implicitly add flags WEXITED 1164 * and WTRAPPED here. 1165 */ 1166 options |= WEXITED | WTRAPPED; 1167 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1168 if (rusage != NULL) 1169 *rusage = wru.wru_self; 1170 return (ret); 1171 } 1172 1173 static void 1174 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1175 int *status, int options, int si_code) 1176 { 1177 bool cont; 1178 1179 PROC_LOCK_ASSERT(p, MA_OWNED); 1180 sx_assert(&proctree_lock, SA_XLOCKED); 1181 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1182 si_code == CLD_CONTINUED); 1183 1184 cont = si_code == CLD_CONTINUED; 1185 if ((options & WNOWAIT) == 0) { 1186 if (cont) 1187 p->p_flag &= ~P_CONTINUED; 1188 else 1189 p->p_flag |= P_WAITED; 1190 PROC_LOCK(td->td_proc); 1191 sigqueue_take(p->p_ksi); 1192 PROC_UNLOCK(td->td_proc); 1193 } 1194 sx_xunlock(&proctree_lock); 1195 if (siginfo != NULL) { 1196 siginfo->si_code = si_code; 1197 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1198 } 1199 if (status != NULL) 1200 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1201 PROC_UNLOCK(p); 1202 td->td_retval[0] = p->p_pid; 1203 } 1204 1205 int 1206 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1207 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1208 { 1209 struct proc *p, *q; 1210 pid_t pid; 1211 int error, nfound, ret; 1212 bool report; 1213 1214 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1215 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1216 AUDIT_ARG_VALUE(options); 1217 1218 q = td->td_proc; 1219 1220 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1221 PROC_LOCK(q); 1222 id = (id_t)q->p_pgid; 1223 PROC_UNLOCK(q); 1224 idtype = P_PGID; 1225 } 1226 1227 /* If we don't know the option, just return. */ 1228 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1229 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1230 return (EINVAL); 1231 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1232 /* 1233 * We will be unable to find any matching processes, 1234 * because there are no known events to look for. 1235 * Prefer to return error instead of blocking 1236 * indefinitely. 1237 */ 1238 return (EINVAL); 1239 } 1240 1241 loop: 1242 if (q->p_flag & P_STATCHILD) { 1243 PROC_LOCK(q); 1244 q->p_flag &= ~P_STATCHILD; 1245 PROC_UNLOCK(q); 1246 } 1247 sx_xlock(&proctree_lock); 1248 loop_locked: 1249 nfound = 0; 1250 LIST_FOREACH(p, &q->p_children, p_sibling) { 1251 pid = p->p_pid; 1252 ret = proc_to_reap(td, p, idtype, id, status, options, 1253 wrusage, siginfo, 0); 1254 if (ret == 0) 1255 continue; 1256 else if (ret != 1) { 1257 td->td_retval[0] = pid; 1258 return (0); 1259 } 1260 1261 nfound++; 1262 PROC_LOCK_ASSERT(p, MA_OWNED); 1263 1264 if ((options & WTRAPPED) != 0 && 1265 (p->p_flag & P_TRACED) != 0) { 1266 PROC_SLOCK(p); 1267 report = 1268 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1269 p->p_suspcount == p->p_numthreads && 1270 (p->p_flag & P_WAITED) == 0); 1271 PROC_SUNLOCK(p); 1272 if (report) { 1273 CTR4(KTR_PTRACE, 1274 "wait: returning trapped pid %d status %#x " 1275 "(xstat %d) xthread %d", 1276 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1277 p->p_xthread != NULL ? 1278 p->p_xthread->td_tid : -1); 1279 report_alive_proc(td, p, siginfo, status, 1280 options, CLD_TRAPPED); 1281 return (0); 1282 } 1283 } 1284 if ((options & WUNTRACED) != 0 && 1285 (p->p_flag & P_STOPPED_SIG) != 0) { 1286 PROC_SLOCK(p); 1287 report = (p->p_suspcount == p->p_numthreads && 1288 ((p->p_flag & P_WAITED) == 0)); 1289 PROC_SUNLOCK(p); 1290 if (report) { 1291 report_alive_proc(td, p, siginfo, status, 1292 options, CLD_STOPPED); 1293 return (0); 1294 } 1295 } 1296 if ((options & WCONTINUED) != 0 && 1297 (p->p_flag & P_CONTINUED) != 0) { 1298 report_alive_proc(td, p, siginfo, status, options, 1299 CLD_CONTINUED); 1300 return (0); 1301 } 1302 PROC_UNLOCK(p); 1303 } 1304 1305 /* 1306 * Look in the orphans list too, to allow the parent to 1307 * collect it's child exit status even if child is being 1308 * debugged. 1309 * 1310 * Debugger detaches from the parent upon successful 1311 * switch-over from parent to child. At this point due to 1312 * re-parenting the parent loses the child to debugger and a 1313 * wait4(2) call would report that it has no children to wait 1314 * for. By maintaining a list of orphans we allow the parent 1315 * to successfully wait until the child becomes a zombie. 1316 */ 1317 if (nfound == 0) { 1318 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1319 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1320 NULL, NULL, 1); 1321 if (ret != 0) { 1322 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1323 (int)td->td_retval[0])); 1324 PROC_UNLOCK(p); 1325 nfound++; 1326 break; 1327 } 1328 } 1329 } 1330 if (nfound == 0) { 1331 sx_xunlock(&proctree_lock); 1332 return (ECHILD); 1333 } 1334 if (options & WNOHANG) { 1335 sx_xunlock(&proctree_lock); 1336 td->td_retval[0] = 0; 1337 return (0); 1338 } 1339 PROC_LOCK(q); 1340 if (q->p_flag & P_STATCHILD) { 1341 q->p_flag &= ~P_STATCHILD; 1342 PROC_UNLOCK(q); 1343 goto loop_locked; 1344 } 1345 sx_xunlock(&proctree_lock); 1346 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1347 if (error) 1348 return (error); 1349 goto loop; 1350 } 1351 1352 void 1353 proc_add_orphan(struct proc *child, struct proc *parent) 1354 { 1355 1356 sx_assert(&proctree_lock, SX_XLOCKED); 1357 KASSERT((child->p_flag & P_TRACED) != 0, 1358 ("proc_add_orphan: not traced")); 1359 1360 if (LIST_EMPTY(&parent->p_orphans)) { 1361 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1362 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1363 } else { 1364 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1365 child, p_orphan); 1366 } 1367 child->p_treeflag |= P_TREE_ORPHANED; 1368 } 1369 1370 /* 1371 * Make process 'parent' the new parent of process 'child'. 1372 * Must be called with an exclusive hold of proctree lock. 1373 */ 1374 void 1375 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1376 { 1377 1378 sx_assert(&proctree_lock, SX_XLOCKED); 1379 PROC_LOCK_ASSERT(child, MA_OWNED); 1380 if (child->p_pptr == parent) 1381 return; 1382 1383 PROC_LOCK(child->p_pptr); 1384 sigqueue_take(child->p_ksi); 1385 PROC_UNLOCK(child->p_pptr); 1386 LIST_REMOVE(child, p_sibling); 1387 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1388 1389 proc_clear_orphan(child); 1390 if ((child->p_flag & P_TRACED) != 0) { 1391 proc_add_orphan(child, child->p_pptr); 1392 } 1393 1394 child->p_pptr = parent; 1395 if (set_oppid) 1396 child->p_oppid = parent->p_pid; 1397 } 1398