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 * XXX what to do now that sparc64 is gone... remove if? 221 */ 222 if (p == initproc && rebooting == 0) { 223 printf("init died (signal %d, exit %d)\n", signo, rval); 224 panic("Going nowhere without my init!"); 225 } 226 227 /* 228 * Deref SU mp, since the thread does not return to userspace. 229 */ 230 td_softdep_cleanup(td); 231 232 /* 233 * MUST abort all other threads before proceeding past here. 234 */ 235 PROC_LOCK(p); 236 /* 237 * First check if some other thread or external request got 238 * here before us. If so, act appropriately: exit or suspend. 239 * We must ensure that stop requests are handled before we set 240 * P_WEXIT. 241 */ 242 thread_suspend_check(0); 243 while (p->p_flag & P_HADTHREADS) { 244 /* 245 * Kill off the other threads. This requires 246 * some co-operation from other parts of the kernel 247 * so it may not be instantaneous. With this state set 248 * any thread entering the kernel from userspace will 249 * thread_exit() in trap(). Any thread attempting to 250 * sleep will return immediately with EINTR or EWOULDBLOCK 251 * which will hopefully force them to back out to userland 252 * freeing resources as they go. Any thread attempting 253 * to return to userland will thread_exit() from userret(). 254 * thread_exit() will unsuspend us when the last of the 255 * other threads exits. 256 * If there is already a thread singler after resumption, 257 * calling thread_single will fail; in that case, we just 258 * re-check all suspension request, the thread should 259 * either be suspended there or exit. 260 */ 261 if (!thread_single(p, SINGLE_EXIT)) 262 /* 263 * All other activity in this process is now 264 * stopped. Threading support has been turned 265 * off. 266 */ 267 break; 268 /* 269 * Recheck for new stop or suspend requests which 270 * might appear while process lock was dropped in 271 * thread_single(). 272 */ 273 thread_suspend_check(0); 274 } 275 KASSERT(p->p_numthreads == 1, 276 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 277 racct_sub(p, RACCT_NTHR, 1); 278 279 /* Let event handler change exit status */ 280 p->p_xexit = rval; 281 p->p_xsig = signo; 282 283 /* 284 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold 285 * on our vmspace, so we should block below until they have 286 * released their reference to us. Note that if they have 287 * requested S_EXIT stops we will block here until they ack 288 * via PIOCCONT. 289 */ 290 _STOPEVENT(p, S_EXIT, 0); 291 292 /* 293 * Ignore any pending request to stop due to a stop signal. 294 * Once P_WEXIT is set, future requests will be ignored as 295 * well. 296 */ 297 p->p_flag &= ~P_STOPPED_SIG; 298 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 299 300 /* 301 * Note that we are exiting and do another wakeup of anyone in 302 * PIOCWAIT in case they aren't listening for S_EXIT stops or 303 * decided to wait again after we told them we are exiting. 304 */ 305 p->p_flag |= P_WEXIT; 306 wakeup(&p->p_stype); 307 308 /* 309 * Wait for any processes that have a hold on our vmspace to 310 * release their reference. 311 */ 312 while (p->p_lock > 0) 313 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 314 315 PROC_UNLOCK(p); 316 /* Drain the limit callout while we don't have the proc locked */ 317 callout_drain(&p->p_limco); 318 319 #ifdef AUDIT 320 /* 321 * The Sun BSM exit token contains two components: an exit status as 322 * passed to exit(), and a return value to indicate what sort of exit 323 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 324 * what the return value is. 325 */ 326 AUDIT_ARG_EXIT(rval, 0); 327 AUDIT_SYSCALL_EXIT(0, td); 328 #endif 329 330 /* Are we a task leader with peers? */ 331 if (p->p_peers != NULL && p == p->p_leader) { 332 mtx_lock(&ppeers_lock); 333 q = p->p_peers; 334 while (q != NULL) { 335 PROC_LOCK(q); 336 kern_psignal(q, SIGKILL); 337 PROC_UNLOCK(q); 338 q = q->p_peers; 339 } 340 while (p->p_peers != NULL) 341 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 342 mtx_unlock(&ppeers_lock); 343 } 344 345 /* 346 * Check if any loadable modules need anything done at process exit. 347 * E.g. SYSV IPC stuff. 348 * Event handler could change exit status. 349 * XXX what if one of these generates an error? 350 */ 351 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 352 353 /* 354 * If parent is waiting for us to exit or exec, 355 * P_PPWAIT is set; we will wakeup the parent below. 356 */ 357 PROC_LOCK(p); 358 stopprofclock(p); 359 p->p_ptevents = 0; 360 361 /* 362 * Stop the real interval timer. If the handler is currently 363 * executing, prevent it from rearming itself and let it finish. 364 */ 365 if (timevalisset(&p->p_realtimer.it_value) && 366 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 367 timevalclear(&p->p_realtimer.it_interval); 368 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 369 KASSERT(!timevalisset(&p->p_realtimer.it_value), 370 ("realtime timer is still armed")); 371 } 372 373 PROC_UNLOCK(p); 374 375 umtx_thread_exit(td); 376 377 /* 378 * Reset any sigio structures pointing to us as a result of 379 * F_SETOWN with our pid. 380 */ 381 funsetownlst(&p->p_sigiolst); 382 383 /* 384 * If this process has an nlminfo data area (for lockd), release it 385 */ 386 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL) 387 (*nlminfo_release_p)(p); 388 389 /* 390 * Close open files and release open-file table. 391 * This may block! 392 */ 393 fdescfree(td); 394 395 /* 396 * If this thread tickled GEOM, we need to wait for the giggling to 397 * stop before we return to userland 398 */ 399 if (td->td_pflags & TDP_GEOM) 400 g_waitidle(); 401 402 /* 403 * Remove ourself from our leader's peer list and wake our leader. 404 */ 405 if (p->p_leader->p_peers != NULL) { 406 mtx_lock(&ppeers_lock); 407 if (p->p_leader->p_peers != NULL) { 408 q = p->p_leader; 409 while (q->p_peers != p) 410 q = q->p_peers; 411 q->p_peers = p->p_peers; 412 wakeup(p->p_leader); 413 } 414 mtx_unlock(&ppeers_lock); 415 } 416 417 vmspace_exit(td); 418 killjobc(); 419 (void)acct_process(td); 420 421 #ifdef KTRACE 422 ktrprocexit(td); 423 #endif 424 /* 425 * Release reference to text vnode 426 */ 427 if (p->p_textvp != NULL) { 428 vrele(p->p_textvp); 429 p->p_textvp = NULL; 430 } 431 432 /* 433 * Release our limits structure. 434 */ 435 lim_free(p->p_limit); 436 p->p_limit = NULL; 437 438 tidhash_remove(td); 439 440 /* 441 * Call machine-dependent code to release any 442 * machine-dependent resources other than the address space. 443 * The address space is released by "vmspace_exitfree(p)" in 444 * vm_waitproc(). 445 */ 446 cpu_exit(td); 447 448 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 449 450 /* 451 * Remove from allproc. It still sits in the hash. 452 */ 453 sx_xlock(&allproc_lock); 454 LIST_REMOVE(p, p_list); 455 sx_xunlock(&allproc_lock); 456 457 sx_xlock(&proctree_lock); 458 PROC_LOCK(p); 459 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 460 PROC_UNLOCK(p); 461 462 /* 463 * Reparent all children processes: 464 * - traced ones to the original parent (or init if we are that parent) 465 * - the rest to init 466 */ 467 q = LIST_FIRST(&p->p_children); 468 if (q != NULL) /* only need this if any child is S_ZOMB */ 469 wakeup(q->p_reaper); 470 for (; q != NULL; q = nq) { 471 nq = LIST_NEXT(q, p_sibling); 472 ksi = ksiginfo_alloc(TRUE); 473 PROC_LOCK(q); 474 q->p_sigparent = SIGCHLD; 475 476 if ((q->p_flag & P_TRACED) == 0) { 477 proc_reparent(q, q->p_reaper, true); 478 if (q->p_state == PRS_ZOMBIE) { 479 /* 480 * Inform reaper about the reparented 481 * zombie, since wait(2) has something 482 * new to report. Guarantee queueing 483 * of the SIGCHLD signal, similar to 484 * the _exit() behaviour, by providing 485 * our ksiginfo. Ksi is freed by the 486 * signal delivery. 487 */ 488 if (q->p_ksi == NULL) { 489 ksi1 = NULL; 490 } else { 491 ksiginfo_copy(q->p_ksi, ksi); 492 ksi->ksi_flags |= KSI_INS; 493 ksi1 = ksi; 494 ksi = NULL; 495 } 496 PROC_LOCK(q->p_reaper); 497 pksignal(q->p_reaper, SIGCHLD, ksi1); 498 PROC_UNLOCK(q->p_reaper); 499 } else if (q->p_pdeathsig > 0) { 500 /* 501 * The child asked to received a signal 502 * when we exit. 503 */ 504 kern_psignal(q, q->p_pdeathsig); 505 } 506 } else { 507 /* 508 * Traced processes are killed since their existence 509 * means someone is screwing up. 510 */ 511 t = proc_realparent(q); 512 if (t == p) { 513 proc_reparent(q, q->p_reaper, true); 514 } else { 515 PROC_LOCK(t); 516 proc_reparent(q, t, true); 517 PROC_UNLOCK(t); 518 } 519 /* 520 * Since q was found on our children list, the 521 * proc_reparent() call moved q to the orphan 522 * list due to present P_TRACED flag. Clear 523 * orphan link for q now while q is locked. 524 */ 525 proc_clear_orphan(q); 526 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 527 q->p_flag2 &= ~P2_PTRACE_FSTP; 528 q->p_ptevents = 0; 529 FOREACH_THREAD_IN_PROC(q, tdt) { 530 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 531 TDB_FSTP); 532 } 533 kern_psignal(q, SIGKILL); 534 } 535 PROC_UNLOCK(q); 536 if (ksi != NULL) 537 ksiginfo_free(ksi); 538 } 539 540 /* 541 * Also get rid of our orphans. 542 */ 543 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 544 PROC_LOCK(q); 545 KASSERT(q->p_oppid == p->p_pid, 546 ("orphan %p of %p has unexpected oppid %d", q, p, 547 q->p_oppid)); 548 q->p_oppid = q->p_reaper->p_pid; 549 550 /* 551 * If we are the real parent of this process 552 * but it has been reparented to a debugger, then 553 * check if it asked for a signal when we exit. 554 */ 555 if (q->p_pdeathsig > 0) 556 kern_psignal(q, q->p_pdeathsig); 557 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 558 q->p_pid); 559 proc_clear_orphan(q); 560 PROC_UNLOCK(q); 561 } 562 563 #ifdef KDTRACE_HOOKS 564 if (SDT_PROBES_ENABLED()) { 565 int reason = CLD_EXITED; 566 if (WCOREDUMP(signo)) 567 reason = CLD_DUMPED; 568 else if (WIFSIGNALED(signo)) 569 reason = CLD_KILLED; 570 SDT_PROBE1(proc, , , exit, reason); 571 } 572 #endif 573 574 /* Save exit status. */ 575 PROC_LOCK(p); 576 p->p_xthread = td; 577 578 #ifdef KDTRACE_HOOKS 579 /* 580 * Tell the DTrace fasttrap provider about the exit if it 581 * has declared an interest. 582 */ 583 if (dtrace_fasttrap_exit) 584 dtrace_fasttrap_exit(p); 585 #endif 586 587 /* 588 * Notify interested parties of our demise. 589 */ 590 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 591 592 /* 593 * If this is a process with a descriptor, we may not need to deliver 594 * a signal to the parent. proctree_lock is held over 595 * procdesc_exit() to serialize concurrent calls to close() and 596 * exit(). 597 */ 598 signal_parent = 0; 599 if (p->p_procdesc == NULL || procdesc_exit(p)) { 600 /* 601 * Notify parent that we're gone. If parent has the 602 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 603 * notify process 1 instead (and hope it will handle this 604 * situation). 605 */ 606 PROC_LOCK(p->p_pptr); 607 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 608 if (p->p_pptr->p_sigacts->ps_flag & 609 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 610 struct proc *pp; 611 612 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 613 pp = p->p_pptr; 614 PROC_UNLOCK(pp); 615 proc_reparent(p, p->p_reaper, true); 616 p->p_sigparent = SIGCHLD; 617 PROC_LOCK(p->p_pptr); 618 619 /* 620 * Notify parent, so in case he was wait(2)ing or 621 * executing waitpid(2) with our pid, he will 622 * continue. 623 */ 624 wakeup(pp); 625 } else 626 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 627 628 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 629 signal_parent = 1; 630 } else if (p->p_sigparent != 0) { 631 if (p->p_sigparent == SIGCHLD) { 632 signal_parent = 1; 633 } else { /* LINUX thread */ 634 signal_parent = 2; 635 } 636 } 637 } else 638 PROC_LOCK(p->p_pptr); 639 sx_xunlock(&proctree_lock); 640 641 if (signal_parent == 1) { 642 childproc_exited(p); 643 } else if (signal_parent == 2) { 644 kern_psignal(p->p_pptr, p->p_sigparent); 645 } 646 647 /* Tell the prison that we are gone. */ 648 prison_proc_free(p->p_ucred->cr_prison); 649 650 /* 651 * The state PRS_ZOMBIE prevents other proesses from sending 652 * signal to the process, to avoid memory leak, we free memory 653 * for signal queue at the time when the state is set. 654 */ 655 sigqueue_flush(&p->p_sigqueue); 656 sigqueue_flush(&td->td_sigqueue); 657 658 /* 659 * We have to wait until after acquiring all locks before 660 * changing p_state. We need to avoid all possible context 661 * switches (including ones from blocking on a mutex) while 662 * marked as a zombie. We also have to set the zombie state 663 * before we release the parent process' proc lock to avoid 664 * a lost wakeup. So, we first call wakeup, then we grab the 665 * sched lock, update the state, and release the parent process' 666 * proc lock. 667 */ 668 wakeup(p->p_pptr); 669 cv_broadcast(&p->p_pwait); 670 sched_exit(p->p_pptr, td); 671 PROC_SLOCK(p); 672 p->p_state = PRS_ZOMBIE; 673 PROC_UNLOCK(p->p_pptr); 674 675 /* 676 * Save our children's rusage information in our exit rusage. 677 */ 678 PROC_STATLOCK(p); 679 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 680 PROC_STATUNLOCK(p); 681 682 /* 683 * Make sure the scheduler takes this thread out of its tables etc. 684 * This will also release this thread's reference to the ucred. 685 * Other thread parts to release include pcb bits and such. 686 */ 687 thread_exit(); 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 #ifdef COMPAT_43 767 /* 768 * The dirty work is handled by kern_wait(). 769 */ 770 int 771 owait(struct thread *td, struct owait_args *uap __unused) 772 { 773 int error, status; 774 775 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 776 if (error == 0) 777 td->td_retval[1] = status; 778 return (error); 779 } 780 #endif /* COMPAT_43 */ 781 782 /* 783 * The dirty work is handled by kern_wait(). 784 */ 785 int 786 sys_wait4(struct thread *td, struct wait4_args *uap) 787 { 788 struct rusage ru, *rup; 789 int error, status; 790 791 if (uap->rusage != NULL) 792 rup = &ru; 793 else 794 rup = NULL; 795 error = kern_wait(td, uap->pid, &status, uap->options, rup); 796 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 797 error = copyout(&status, uap->status, sizeof(status)); 798 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 799 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 800 return (error); 801 } 802 803 int 804 sys_wait6(struct thread *td, struct wait6_args *uap) 805 { 806 struct __wrusage wru, *wrup; 807 siginfo_t si, *sip; 808 idtype_t idtype; 809 id_t id; 810 int error, status; 811 812 idtype = uap->idtype; 813 id = uap->id; 814 815 if (uap->wrusage != NULL) 816 wrup = &wru; 817 else 818 wrup = NULL; 819 820 if (uap->info != NULL) { 821 sip = &si; 822 bzero(sip, sizeof(*sip)); 823 } else 824 sip = NULL; 825 826 /* 827 * We expect all callers of wait6() to know about WEXITED and 828 * WTRAPPED. 829 */ 830 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 831 832 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 833 error = copyout(&status, uap->status, sizeof(status)); 834 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 835 error = copyout(&wru, uap->wrusage, sizeof(wru)); 836 if (uap->info != NULL && error == 0) 837 error = copyout(&si, uap->info, sizeof(si)); 838 return (error); 839 } 840 841 /* 842 * Reap the remains of a zombie process and optionally return status and 843 * rusage. Asserts and will release both the proctree_lock and the process 844 * lock as part of its work. 845 */ 846 void 847 proc_reap(struct thread *td, struct proc *p, int *status, int options) 848 { 849 struct proc *q, *t; 850 851 sx_assert(&proctree_lock, SA_XLOCKED); 852 PROC_LOCK_ASSERT(p, MA_OWNED); 853 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 854 855 mtx_spin_wait_unlocked(&p->p_slock); 856 857 q = td->td_proc; 858 859 if (status) 860 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 861 if (options & WNOWAIT) { 862 /* 863 * Only poll, returning the status. Caller does not wish to 864 * release the proc struct just yet. 865 */ 866 PROC_UNLOCK(p); 867 sx_xunlock(&proctree_lock); 868 return; 869 } 870 871 PROC_LOCK(q); 872 sigqueue_take(p->p_ksi); 873 PROC_UNLOCK(q); 874 875 /* 876 * If we got the child via a ptrace 'attach', we need to give it back 877 * to the old parent. 878 */ 879 if (p->p_oppid != p->p_pptr->p_pid) { 880 PROC_UNLOCK(p); 881 t = proc_realparent(p); 882 PROC_LOCK(t); 883 PROC_LOCK(p); 884 CTR2(KTR_PTRACE, 885 "wait: traced child %d moved back to parent %d", p->p_pid, 886 t->p_pid); 887 proc_reparent(p, t, false); 888 PROC_UNLOCK(p); 889 pksignal(t, SIGCHLD, p->p_ksi); 890 wakeup(t); 891 cv_broadcast(&p->p_pwait); 892 PROC_UNLOCK(t); 893 sx_xunlock(&proctree_lock); 894 return; 895 } 896 PROC_UNLOCK(p); 897 898 /* 899 * Remove other references to this process to ensure we have an 900 * exclusive reference. 901 */ 902 sx_xlock(PIDHASHLOCK(p->p_pid)); 903 LIST_REMOVE(p, p_hash); 904 sx_xunlock(PIDHASHLOCK(p->p_pid)); 905 LIST_REMOVE(p, p_sibling); 906 reaper_abandon_children(p, true); 907 reaper_clear(p); 908 PROC_LOCK(p); 909 proc_clear_orphan(p); 910 PROC_UNLOCK(p); 911 leavepgrp(p); 912 if (p->p_procdesc != NULL) 913 procdesc_reap(p); 914 sx_xunlock(&proctree_lock); 915 916 proc_id_clear(PROC_ID_PID, p->p_pid); 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 (p->p_pptr == td->td_proc && 997 (p->p_flag & P_TRACED) != 0)) { 998 break; 999 } 1000 1001 PROC_UNLOCK(p); 1002 return (0); 1003 case P_PID: 1004 if (p->p_pid != (pid_t)id) { 1005 PROC_UNLOCK(p); 1006 return (0); 1007 } 1008 break; 1009 case P_PGID: 1010 if (p->p_pgid != (pid_t)id) { 1011 PROC_UNLOCK(p); 1012 return (0); 1013 } 1014 break; 1015 case P_SID: 1016 if (p->p_session->s_sid != (pid_t)id) { 1017 PROC_UNLOCK(p); 1018 return (0); 1019 } 1020 break; 1021 case P_UID: 1022 if (p->p_ucred->cr_uid != (uid_t)id) { 1023 PROC_UNLOCK(p); 1024 return (0); 1025 } 1026 break; 1027 case P_GID: 1028 if (p->p_ucred->cr_gid != (gid_t)id) { 1029 PROC_UNLOCK(p); 1030 return (0); 1031 } 1032 break; 1033 case P_JAILID: 1034 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1035 PROC_UNLOCK(p); 1036 return (0); 1037 } 1038 break; 1039 /* 1040 * It seems that the thread structures get zeroed out 1041 * at process exit. This makes it impossible to 1042 * support P_SETID, P_CID or P_CPUID. 1043 */ 1044 default: 1045 PROC_UNLOCK(p); 1046 return (0); 1047 } 1048 1049 if (p_canwait(td, p)) { 1050 PROC_UNLOCK(p); 1051 return (0); 1052 } 1053 1054 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1055 PROC_UNLOCK(p); 1056 return (0); 1057 } 1058 1059 /* 1060 * This special case handles a kthread spawned by linux_clone 1061 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1062 * functions need to be able to distinguish between waiting 1063 * on a process and waiting on a thread. It is a thread if 1064 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1065 * signifies we want to wait for threads and not processes. 1066 */ 1067 if ((p->p_sigparent != SIGCHLD) ^ 1068 ((options & WLINUXCLONE) != 0)) { 1069 PROC_UNLOCK(p); 1070 return (0); 1071 } 1072 1073 if (siginfo != NULL) { 1074 bzero(siginfo, sizeof(*siginfo)); 1075 siginfo->si_errno = 0; 1076 1077 /* 1078 * SUSv4 requires that the si_signo value is always 1079 * SIGCHLD. Obey it despite the rfork(2) interface 1080 * allows to request other signal for child exit 1081 * notification. 1082 */ 1083 siginfo->si_signo = SIGCHLD; 1084 1085 /* 1086 * This is still a rough estimate. We will fix the 1087 * cases TRAPPED, STOPPED, and CONTINUED later. 1088 */ 1089 if (WCOREDUMP(p->p_xsig)) { 1090 siginfo->si_code = CLD_DUMPED; 1091 siginfo->si_status = WTERMSIG(p->p_xsig); 1092 } else if (WIFSIGNALED(p->p_xsig)) { 1093 siginfo->si_code = CLD_KILLED; 1094 siginfo->si_status = WTERMSIG(p->p_xsig); 1095 } else { 1096 siginfo->si_code = CLD_EXITED; 1097 siginfo->si_status = p->p_xexit; 1098 } 1099 1100 siginfo->si_pid = p->p_pid; 1101 siginfo->si_uid = p->p_ucred->cr_uid; 1102 1103 /* 1104 * The si_addr field would be useful additional 1105 * detail, but apparently the PC value may be lost 1106 * when we reach this point. bzero() above sets 1107 * siginfo->si_addr to NULL. 1108 */ 1109 } 1110 1111 /* 1112 * There should be no reason to limit resources usage info to 1113 * exited processes only. A snapshot about any resources used 1114 * by a stopped process may be exactly what is needed. 1115 */ 1116 if (wrusage != NULL) { 1117 rup = &wrusage->wru_self; 1118 *rup = p->p_ru; 1119 PROC_STATLOCK(p); 1120 calcru(p, &rup->ru_utime, &rup->ru_stime); 1121 PROC_STATUNLOCK(p); 1122 1123 rup = &wrusage->wru_children; 1124 *rup = p->p_stats->p_cru; 1125 calccru(p, &rup->ru_utime, &rup->ru_stime); 1126 } 1127 1128 if (p->p_state == PRS_ZOMBIE && !check_only) { 1129 proc_reap(td, p, status, options); 1130 return (-1); 1131 } 1132 return (1); 1133 } 1134 1135 int 1136 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1137 struct rusage *rusage) 1138 { 1139 struct __wrusage wru, *wrup; 1140 idtype_t idtype; 1141 id_t id; 1142 int ret; 1143 1144 /* 1145 * Translate the special pid values into the (idtype, pid) 1146 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1147 * kern_wait6() on its own. 1148 */ 1149 if (pid == WAIT_ANY) { 1150 idtype = P_ALL; 1151 id = 0; 1152 } else if (pid < 0) { 1153 idtype = P_PGID; 1154 id = (id_t)-pid; 1155 } else { 1156 idtype = P_PID; 1157 id = (id_t)pid; 1158 } 1159 1160 if (rusage != NULL) 1161 wrup = &wru; 1162 else 1163 wrup = NULL; 1164 1165 /* 1166 * For backward compatibility we implicitly add flags WEXITED 1167 * and WTRAPPED here. 1168 */ 1169 options |= WEXITED | WTRAPPED; 1170 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1171 if (rusage != NULL) 1172 *rusage = wru.wru_self; 1173 return (ret); 1174 } 1175 1176 static void 1177 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1178 int *status, int options, int si_code) 1179 { 1180 bool cont; 1181 1182 PROC_LOCK_ASSERT(p, MA_OWNED); 1183 sx_assert(&proctree_lock, SA_XLOCKED); 1184 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1185 si_code == CLD_CONTINUED); 1186 1187 cont = si_code == CLD_CONTINUED; 1188 if ((options & WNOWAIT) == 0) { 1189 if (cont) 1190 p->p_flag &= ~P_CONTINUED; 1191 else 1192 p->p_flag |= P_WAITED; 1193 PROC_LOCK(td->td_proc); 1194 sigqueue_take(p->p_ksi); 1195 PROC_UNLOCK(td->td_proc); 1196 } 1197 sx_xunlock(&proctree_lock); 1198 if (siginfo != NULL) { 1199 siginfo->si_code = si_code; 1200 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1201 } 1202 if (status != NULL) 1203 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1204 PROC_UNLOCK(p); 1205 td->td_retval[0] = p->p_pid; 1206 } 1207 1208 int 1209 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1210 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1211 { 1212 struct proc *p, *q; 1213 pid_t pid; 1214 int error, nfound, ret; 1215 bool report; 1216 1217 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1218 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1219 AUDIT_ARG_VALUE(options); 1220 1221 q = td->td_proc; 1222 1223 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1224 PROC_LOCK(q); 1225 id = (id_t)q->p_pgid; 1226 PROC_UNLOCK(q); 1227 idtype = P_PGID; 1228 } 1229 1230 /* If we don't know the option, just return. */ 1231 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1232 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1233 return (EINVAL); 1234 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1235 /* 1236 * We will be unable to find any matching processes, 1237 * because there are no known events to look for. 1238 * Prefer to return error instead of blocking 1239 * indefinitely. 1240 */ 1241 return (EINVAL); 1242 } 1243 1244 loop: 1245 if (q->p_flag & P_STATCHILD) { 1246 PROC_LOCK(q); 1247 q->p_flag &= ~P_STATCHILD; 1248 PROC_UNLOCK(q); 1249 } 1250 sx_xlock(&proctree_lock); 1251 loop_locked: 1252 nfound = 0; 1253 LIST_FOREACH(p, &q->p_children, p_sibling) { 1254 pid = p->p_pid; 1255 ret = proc_to_reap(td, p, idtype, id, status, options, 1256 wrusage, siginfo, 0); 1257 if (ret == 0) 1258 continue; 1259 else if (ret != 1) { 1260 td->td_retval[0] = pid; 1261 return (0); 1262 } 1263 1264 nfound++; 1265 PROC_LOCK_ASSERT(p, MA_OWNED); 1266 1267 if ((options & WTRAPPED) != 0 && 1268 (p->p_flag & P_TRACED) != 0) { 1269 PROC_SLOCK(p); 1270 report = 1271 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1272 p->p_suspcount == p->p_numthreads && 1273 (p->p_flag & P_WAITED) == 0); 1274 PROC_SUNLOCK(p); 1275 if (report) { 1276 CTR4(KTR_PTRACE, 1277 "wait: returning trapped pid %d status %#x " 1278 "(xstat %d) xthread %d", 1279 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1280 p->p_xthread != NULL ? 1281 p->p_xthread->td_tid : -1); 1282 report_alive_proc(td, p, siginfo, status, 1283 options, CLD_TRAPPED); 1284 return (0); 1285 } 1286 } 1287 if ((options & WUNTRACED) != 0 && 1288 (p->p_flag & P_STOPPED_SIG) != 0) { 1289 PROC_SLOCK(p); 1290 report = (p->p_suspcount == p->p_numthreads && 1291 ((p->p_flag & P_WAITED) == 0)); 1292 PROC_SUNLOCK(p); 1293 if (report) { 1294 report_alive_proc(td, p, siginfo, status, 1295 options, CLD_STOPPED); 1296 return (0); 1297 } 1298 } 1299 if ((options & WCONTINUED) != 0 && 1300 (p->p_flag & P_CONTINUED) != 0) { 1301 report_alive_proc(td, p, siginfo, status, options, 1302 CLD_CONTINUED); 1303 return (0); 1304 } 1305 PROC_UNLOCK(p); 1306 } 1307 1308 /* 1309 * Look in the orphans list too, to allow the parent to 1310 * collect it's child exit status even if child is being 1311 * debugged. 1312 * 1313 * Debugger detaches from the parent upon successful 1314 * switch-over from parent to child. At this point due to 1315 * re-parenting the parent loses the child to debugger and a 1316 * wait4(2) call would report that it has no children to wait 1317 * for. By maintaining a list of orphans we allow the parent 1318 * to successfully wait until the child becomes a zombie. 1319 */ 1320 if (nfound == 0) { 1321 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1322 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1323 NULL, NULL, 1); 1324 if (ret != 0) { 1325 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1326 (int)td->td_retval[0])); 1327 PROC_UNLOCK(p); 1328 nfound++; 1329 break; 1330 } 1331 } 1332 } 1333 if (nfound == 0) { 1334 sx_xunlock(&proctree_lock); 1335 return (ECHILD); 1336 } 1337 if (options & WNOHANG) { 1338 sx_xunlock(&proctree_lock); 1339 td->td_retval[0] = 0; 1340 return (0); 1341 } 1342 PROC_LOCK(q); 1343 if (q->p_flag & P_STATCHILD) { 1344 q->p_flag &= ~P_STATCHILD; 1345 PROC_UNLOCK(q); 1346 goto loop_locked; 1347 } 1348 sx_xunlock(&proctree_lock); 1349 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1350 if (error) 1351 return (error); 1352 goto loop; 1353 } 1354 1355 void 1356 proc_add_orphan(struct proc *child, struct proc *parent) 1357 { 1358 1359 sx_assert(&proctree_lock, SX_XLOCKED); 1360 KASSERT((child->p_flag & P_TRACED) != 0, 1361 ("proc_add_orphan: not traced")); 1362 1363 if (LIST_EMPTY(&parent->p_orphans)) { 1364 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1365 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1366 } else { 1367 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1368 child, p_orphan); 1369 } 1370 child->p_treeflag |= P_TREE_ORPHANED; 1371 } 1372 1373 /* 1374 * Make process 'parent' the new parent of process 'child'. 1375 * Must be called with an exclusive hold of proctree lock. 1376 */ 1377 void 1378 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1379 { 1380 1381 sx_assert(&proctree_lock, SX_XLOCKED); 1382 PROC_LOCK_ASSERT(child, MA_OWNED); 1383 if (child->p_pptr == parent) 1384 return; 1385 1386 PROC_LOCK(child->p_pptr); 1387 sigqueue_take(child->p_ksi); 1388 PROC_UNLOCK(child->p_pptr); 1389 LIST_REMOVE(child, p_sibling); 1390 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1391 1392 proc_clear_orphan(child); 1393 if ((child->p_flag & P_TRACED) != 0) { 1394 proc_add_orphan(child, child->p_pptr); 1395 } 1396 1397 child->p_pptr = parent; 1398 if (set_oppid) 1399 child->p_oppid = parent->p_pid; 1400 } 1401