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 * Move proc from allproc queue to zombproc. 451 */ 452 sx_xlock(&allproc_lock); 453 sx_xlock(&zombproc_lock); 454 LIST_REMOVE(p, p_list); 455 LIST_INSERT_HEAD(&zombproc, p, p_list); 456 sx_xunlock(&zombproc_lock); 457 sx_xunlock(&allproc_lock); 458 459 sx_xlock(&proctree_lock); 460 PROC_LOCK(p); 461 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 462 PROC_UNLOCK(p); 463 464 /* 465 * Reparent all children processes: 466 * - traced ones to the original parent (or init if we are that parent) 467 * - the rest to init 468 */ 469 q = LIST_FIRST(&p->p_children); 470 if (q != NULL) /* only need this if any child is S_ZOMB */ 471 wakeup(q->p_reaper); 472 for (; q != NULL; q = nq) { 473 nq = LIST_NEXT(q, p_sibling); 474 ksi = ksiginfo_alloc(TRUE); 475 PROC_LOCK(q); 476 q->p_sigparent = SIGCHLD; 477 478 if ((q->p_flag & P_TRACED) == 0) { 479 proc_reparent(q, q->p_reaper, true); 480 if (q->p_state == PRS_ZOMBIE) { 481 /* 482 * Inform reaper about the reparented 483 * zombie, since wait(2) has something 484 * new to report. Guarantee queueing 485 * of the SIGCHLD signal, similar to 486 * the _exit() behaviour, by providing 487 * our ksiginfo. Ksi is freed by the 488 * signal delivery. 489 */ 490 if (q->p_ksi == NULL) { 491 ksi1 = NULL; 492 } else { 493 ksiginfo_copy(q->p_ksi, ksi); 494 ksi->ksi_flags |= KSI_INS; 495 ksi1 = ksi; 496 ksi = NULL; 497 } 498 PROC_LOCK(q->p_reaper); 499 pksignal(q->p_reaper, SIGCHLD, ksi1); 500 PROC_UNLOCK(q->p_reaper); 501 } else if (q->p_pdeathsig > 0) { 502 /* 503 * The child asked to received a signal 504 * when we exit. 505 */ 506 kern_psignal(q, q->p_pdeathsig); 507 } 508 } else { 509 /* 510 * Traced processes are killed since their existence 511 * means someone is screwing up. 512 */ 513 t = proc_realparent(q); 514 if (t == p) { 515 proc_reparent(q, q->p_reaper, true); 516 } else { 517 PROC_LOCK(t); 518 proc_reparent(q, t, true); 519 PROC_UNLOCK(t); 520 } 521 /* 522 * Since q was found on our children list, the 523 * proc_reparent() call moved q to the orphan 524 * list due to present P_TRACED flag. Clear 525 * orphan link for q now while q is locked. 526 */ 527 proc_clear_orphan(q); 528 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 529 q->p_flag2 &= ~P2_PTRACE_FSTP; 530 q->p_ptevents = 0; 531 FOREACH_THREAD_IN_PROC(q, tdt) { 532 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 533 TDB_FSTP); 534 } 535 kern_psignal(q, SIGKILL); 536 } 537 PROC_UNLOCK(q); 538 if (ksi != NULL) 539 ksiginfo_free(ksi); 540 } 541 542 /* 543 * Also get rid of our orphans. 544 */ 545 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 546 PROC_LOCK(q); 547 KASSERT(q->p_oppid == p->p_pid, 548 ("orphan %p of %p has unexpected oppid %d", q, p, 549 q->p_oppid)); 550 q->p_oppid = q->p_reaper->p_pid; 551 552 /* 553 * If we are the real parent of this process 554 * but it has been reparented to a debugger, then 555 * check if it asked for a signal when we exit. 556 */ 557 if (q->p_pdeathsig > 0) 558 kern_psignal(q, q->p_pdeathsig); 559 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 560 q->p_pid); 561 proc_clear_orphan(q); 562 PROC_UNLOCK(q); 563 } 564 565 #ifdef KDTRACE_HOOKS 566 if (SDT_PROBES_ENABLED()) { 567 int reason = CLD_EXITED; 568 if (WCOREDUMP(signo)) 569 reason = CLD_DUMPED; 570 else if (WIFSIGNALED(signo)) 571 reason = CLD_KILLED; 572 SDT_PROBE1(proc, , , exit, reason); 573 } 574 #endif 575 576 /* Save exit status. */ 577 PROC_LOCK(p); 578 p->p_xthread = td; 579 580 #ifdef KDTRACE_HOOKS 581 /* 582 * Tell the DTrace fasttrap provider about the exit if it 583 * has declared an interest. 584 */ 585 if (dtrace_fasttrap_exit) 586 dtrace_fasttrap_exit(p); 587 #endif 588 589 /* 590 * Notify interested parties of our demise. 591 */ 592 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 593 594 /* 595 * If this is a process with a descriptor, we may not need to deliver 596 * a signal to the parent. proctree_lock is held over 597 * procdesc_exit() to serialize concurrent calls to close() and 598 * exit(). 599 */ 600 signal_parent = 0; 601 if (p->p_procdesc == NULL || procdesc_exit(p)) { 602 /* 603 * Notify parent that we're gone. If parent has the 604 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 605 * notify process 1 instead (and hope it will handle this 606 * situation). 607 */ 608 PROC_LOCK(p->p_pptr); 609 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 610 if (p->p_pptr->p_sigacts->ps_flag & 611 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 612 struct proc *pp; 613 614 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 615 pp = p->p_pptr; 616 PROC_UNLOCK(pp); 617 proc_reparent(p, p->p_reaper, true); 618 p->p_sigparent = SIGCHLD; 619 PROC_LOCK(p->p_pptr); 620 621 /* 622 * Notify parent, so in case he was wait(2)ing or 623 * executing waitpid(2) with our pid, he will 624 * continue. 625 */ 626 wakeup(pp); 627 } else 628 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 629 630 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 631 signal_parent = 1; 632 } else if (p->p_sigparent != 0) { 633 if (p->p_sigparent == SIGCHLD) { 634 signal_parent = 1; 635 } else { /* LINUX thread */ 636 signal_parent = 2; 637 } 638 } 639 } else 640 PROC_LOCK(p->p_pptr); 641 sx_xunlock(&proctree_lock); 642 643 if (signal_parent == 1) { 644 childproc_exited(p); 645 } else if (signal_parent == 2) { 646 kern_psignal(p->p_pptr, p->p_sigparent); 647 } 648 649 /* Tell the prison that we are gone. */ 650 prison_proc_free(p->p_ucred->cr_prison); 651 652 /* 653 * The state PRS_ZOMBIE prevents other proesses from sending 654 * signal to the process, to avoid memory leak, we free memory 655 * for signal queue at the time when the state is set. 656 */ 657 sigqueue_flush(&p->p_sigqueue); 658 sigqueue_flush(&td->td_sigqueue); 659 660 /* 661 * We have to wait until after acquiring all locks before 662 * changing p_state. We need to avoid all possible context 663 * switches (including ones from blocking on a mutex) while 664 * marked as a zombie. We also have to set the zombie state 665 * before we release the parent process' proc lock to avoid 666 * a lost wakeup. So, we first call wakeup, then we grab the 667 * sched lock, update the state, and release the parent process' 668 * proc lock. 669 */ 670 wakeup(p->p_pptr); 671 cv_broadcast(&p->p_pwait); 672 sched_exit(p->p_pptr, td); 673 PROC_SLOCK(p); 674 p->p_state = PRS_ZOMBIE; 675 PROC_UNLOCK(p->p_pptr); 676 677 /* 678 * Save our children's rusage information in our exit rusage. 679 */ 680 PROC_STATLOCK(p); 681 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 682 PROC_STATUNLOCK(p); 683 684 /* 685 * Make sure the scheduler takes this thread out of its tables etc. 686 * This will also release this thread's reference to the ucred. 687 * Other thread parts to release include pcb bits and such. 688 */ 689 thread_exit(); 690 } 691 692 693 #ifndef _SYS_SYSPROTO_H_ 694 struct abort2_args { 695 char *why; 696 int nargs; 697 void **args; 698 }; 699 #endif 700 701 int 702 sys_abort2(struct thread *td, struct abort2_args *uap) 703 { 704 struct proc *p = td->td_proc; 705 struct sbuf *sb; 706 void *uargs[16]; 707 int error, i, sig; 708 709 /* 710 * Do it right now so we can log either proper call of abort2(), or 711 * note, that invalid argument was passed. 512 is big enough to 712 * handle 16 arguments' descriptions with additional comments. 713 */ 714 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 715 sbuf_clear(sb); 716 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 717 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 718 /* 719 * Since we can't return from abort2(), send SIGKILL in cases, where 720 * abort2() was called improperly 721 */ 722 sig = SIGKILL; 723 /* Prevent from DoSes from user-space. */ 724 if (uap->nargs < 0 || uap->nargs > 16) 725 goto out; 726 if (uap->nargs > 0) { 727 if (uap->args == NULL) 728 goto out; 729 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 730 if (error != 0) 731 goto out; 732 } 733 /* 734 * Limit size of 'reason' string to 128. Will fit even when 735 * maximal number of arguments was chosen to be logged. 736 */ 737 if (uap->why != NULL) { 738 error = sbuf_copyin(sb, uap->why, 128); 739 if (error < 0) 740 goto out; 741 } else { 742 sbuf_printf(sb, "(null)"); 743 } 744 if (uap->nargs > 0) { 745 sbuf_printf(sb, "("); 746 for (i = 0;i < uap->nargs; i++) 747 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 748 sbuf_printf(sb, ")"); 749 } 750 /* 751 * Final stage: arguments were proper, string has been 752 * successfully copied from userspace, and copying pointers 753 * from user-space succeed. 754 */ 755 sig = SIGABRT; 756 out: 757 if (sig == SIGKILL) { 758 sbuf_trim(sb); 759 sbuf_printf(sb, " (Reason text inaccessible)"); 760 } 761 sbuf_cat(sb, "\n"); 762 sbuf_finish(sb); 763 log(LOG_INFO, "%s", sbuf_data(sb)); 764 sbuf_delete(sb); 765 exit1(td, 0, sig); 766 return (0); 767 } 768 769 770 #ifdef COMPAT_43 771 /* 772 * The dirty work is handled by kern_wait(). 773 */ 774 int 775 owait(struct thread *td, struct owait_args *uap __unused) 776 { 777 int error, status; 778 779 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 780 if (error == 0) 781 td->td_retval[1] = status; 782 return (error); 783 } 784 #endif /* COMPAT_43 */ 785 786 /* 787 * The dirty work is handled by kern_wait(). 788 */ 789 int 790 sys_wait4(struct thread *td, struct wait4_args *uap) 791 { 792 struct rusage ru, *rup; 793 int error, status; 794 795 if (uap->rusage != NULL) 796 rup = &ru; 797 else 798 rup = NULL; 799 error = kern_wait(td, uap->pid, &status, uap->options, rup); 800 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 801 error = copyout(&status, uap->status, sizeof(status)); 802 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 803 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 804 return (error); 805 } 806 807 int 808 sys_wait6(struct thread *td, struct wait6_args *uap) 809 { 810 struct __wrusage wru, *wrup; 811 siginfo_t si, *sip; 812 idtype_t idtype; 813 id_t id; 814 int error, status; 815 816 idtype = uap->idtype; 817 id = uap->id; 818 819 if (uap->wrusage != NULL) 820 wrup = &wru; 821 else 822 wrup = NULL; 823 824 if (uap->info != NULL) { 825 sip = &si; 826 bzero(sip, sizeof(*sip)); 827 } else 828 sip = NULL; 829 830 /* 831 * We expect all callers of wait6() to know about WEXITED and 832 * WTRAPPED. 833 */ 834 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 835 836 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 837 error = copyout(&status, uap->status, sizeof(status)); 838 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 839 error = copyout(&wru, uap->wrusage, sizeof(wru)); 840 if (uap->info != NULL && error == 0) 841 error = copyout(&si, uap->info, sizeof(si)); 842 return (error); 843 } 844 845 /* 846 * Reap the remains of a zombie process and optionally return status and 847 * rusage. Asserts and will release both the proctree_lock and the process 848 * lock as part of its work. 849 */ 850 void 851 proc_reap(struct thread *td, struct proc *p, int *status, int options) 852 { 853 struct proc *q, *t; 854 855 sx_assert(&proctree_lock, SA_XLOCKED); 856 PROC_LOCK_ASSERT(p, MA_OWNED); 857 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 858 859 mtx_spin_wait_unlocked(&p->p_slock); 860 861 q = td->td_proc; 862 863 if (status) 864 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 865 if (options & WNOWAIT) { 866 /* 867 * Only poll, returning the status. Caller does not wish to 868 * release the proc struct just yet. 869 */ 870 PROC_UNLOCK(p); 871 sx_xunlock(&proctree_lock); 872 return; 873 } 874 875 PROC_LOCK(q); 876 sigqueue_take(p->p_ksi); 877 PROC_UNLOCK(q); 878 879 /* 880 * If we got the child via a ptrace 'attach', we need to give it back 881 * to the old parent. 882 */ 883 if (p->p_oppid != p->p_pptr->p_pid) { 884 PROC_UNLOCK(p); 885 t = proc_realparent(p); 886 PROC_LOCK(t); 887 PROC_LOCK(p); 888 CTR2(KTR_PTRACE, 889 "wait: traced child %d moved back to parent %d", p->p_pid, 890 t->p_pid); 891 proc_reparent(p, t, false); 892 PROC_UNLOCK(p); 893 pksignal(t, SIGCHLD, p->p_ksi); 894 wakeup(t); 895 cv_broadcast(&p->p_pwait); 896 PROC_UNLOCK(t); 897 sx_xunlock(&proctree_lock); 898 return; 899 } 900 PROC_UNLOCK(p); 901 902 /* 903 * Remove other references to this process to ensure we have an 904 * exclusive reference. 905 */ 906 sx_xlock(&zombproc_lock); 907 LIST_REMOVE(p, p_list); /* off zombproc */ 908 sx_xunlock(&zombproc_lock); 909 sx_xlock(PIDHASHLOCK(p->p_pid)); 910 LIST_REMOVE(p, p_hash); 911 sx_xunlock(PIDHASHLOCK(p->p_pid)); 912 LIST_REMOVE(p, p_sibling); 913 reaper_abandon_children(p, true); 914 reaper_clear(p); 915 proc_id_clear(PROC_ID_PID, p->p_pid); 916 PROC_LOCK(p); 917 proc_clear_orphan(p); 918 PROC_UNLOCK(p); 919 leavepgrp(p); 920 if (p->p_procdesc != NULL) 921 procdesc_reap(p); 922 sx_xunlock(&proctree_lock); 923 924 PROC_LOCK(p); 925 knlist_detach(p->p_klist); 926 p->p_klist = NULL; 927 PROC_UNLOCK(p); 928 929 /* 930 * Removal from allproc list and process group list paired with 931 * PROC_LOCK which was executed during that time should guarantee 932 * nothing can reach this process anymore. As such further locking 933 * is unnecessary. 934 */ 935 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 936 937 PROC_LOCK(q); 938 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 939 PROC_UNLOCK(q); 940 941 /* 942 * Decrement the count of procs running with this uid. 943 */ 944 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 945 946 /* 947 * Destroy resource accounting information associated with the process. 948 */ 949 #ifdef RACCT 950 if (racct_enable) { 951 PROC_LOCK(p); 952 racct_sub(p, RACCT_NPROC, 1); 953 PROC_UNLOCK(p); 954 } 955 #endif 956 racct_proc_exit(p); 957 958 /* 959 * Free credentials, arguments, and sigacts. 960 */ 961 crfree(p->p_ucred); 962 proc_set_cred(p, NULL); 963 pargs_drop(p->p_args); 964 p->p_args = NULL; 965 sigacts_free(p->p_sigacts); 966 p->p_sigacts = NULL; 967 968 /* 969 * Do any thread-system specific cleanups. 970 */ 971 thread_wait(p); 972 973 /* 974 * Give vm and machine-dependent layer a chance to free anything that 975 * cpu_exit couldn't release while still running in process context. 976 */ 977 vm_waitproc(p); 978 #ifdef MAC 979 mac_proc_destroy(p); 980 #endif 981 982 KASSERT(FIRST_THREAD_IN_PROC(p), 983 ("proc_reap: no residual thread!")); 984 uma_zfree(proc_zone, p); 985 atomic_add_int(&nprocs, -1); 986 } 987 988 static int 989 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 990 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 991 int check_only) 992 { 993 struct rusage *rup; 994 995 sx_assert(&proctree_lock, SA_XLOCKED); 996 997 PROC_LOCK(p); 998 999 switch (idtype) { 1000 case P_ALL: 1001 if (p->p_procdesc != NULL) { 1002 PROC_UNLOCK(p); 1003 return (0); 1004 } 1005 break; 1006 case P_PID: 1007 if (p->p_pid != (pid_t)id) { 1008 PROC_UNLOCK(p); 1009 return (0); 1010 } 1011 break; 1012 case P_PGID: 1013 if (p->p_pgid != (pid_t)id) { 1014 PROC_UNLOCK(p); 1015 return (0); 1016 } 1017 break; 1018 case P_SID: 1019 if (p->p_session->s_sid != (pid_t)id) { 1020 PROC_UNLOCK(p); 1021 return (0); 1022 } 1023 break; 1024 case P_UID: 1025 if (p->p_ucred->cr_uid != (uid_t)id) { 1026 PROC_UNLOCK(p); 1027 return (0); 1028 } 1029 break; 1030 case P_GID: 1031 if (p->p_ucred->cr_gid != (gid_t)id) { 1032 PROC_UNLOCK(p); 1033 return (0); 1034 } 1035 break; 1036 case P_JAILID: 1037 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1038 PROC_UNLOCK(p); 1039 return (0); 1040 } 1041 break; 1042 /* 1043 * It seems that the thread structures get zeroed out 1044 * at process exit. This makes it impossible to 1045 * support P_SETID, P_CID or P_CPUID. 1046 */ 1047 default: 1048 PROC_UNLOCK(p); 1049 return (0); 1050 } 1051 1052 if (p_canwait(td, p)) { 1053 PROC_UNLOCK(p); 1054 return (0); 1055 } 1056 1057 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1058 PROC_UNLOCK(p); 1059 return (0); 1060 } 1061 1062 /* 1063 * This special case handles a kthread spawned by linux_clone 1064 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1065 * functions need to be able to distinguish between waiting 1066 * on a process and waiting on a thread. It is a thread if 1067 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1068 * signifies we want to wait for threads and not processes. 1069 */ 1070 if ((p->p_sigparent != SIGCHLD) ^ 1071 ((options & WLINUXCLONE) != 0)) { 1072 PROC_UNLOCK(p); 1073 return (0); 1074 } 1075 1076 if (siginfo != NULL) { 1077 bzero(siginfo, sizeof(*siginfo)); 1078 siginfo->si_errno = 0; 1079 1080 /* 1081 * SUSv4 requires that the si_signo value is always 1082 * SIGCHLD. Obey it despite the rfork(2) interface 1083 * allows to request other signal for child exit 1084 * notification. 1085 */ 1086 siginfo->si_signo = SIGCHLD; 1087 1088 /* 1089 * This is still a rough estimate. We will fix the 1090 * cases TRAPPED, STOPPED, and CONTINUED later. 1091 */ 1092 if (WCOREDUMP(p->p_xsig)) { 1093 siginfo->si_code = CLD_DUMPED; 1094 siginfo->si_status = WTERMSIG(p->p_xsig); 1095 } else if (WIFSIGNALED(p->p_xsig)) { 1096 siginfo->si_code = CLD_KILLED; 1097 siginfo->si_status = WTERMSIG(p->p_xsig); 1098 } else { 1099 siginfo->si_code = CLD_EXITED; 1100 siginfo->si_status = p->p_xexit; 1101 } 1102 1103 siginfo->si_pid = p->p_pid; 1104 siginfo->si_uid = p->p_ucred->cr_uid; 1105 1106 /* 1107 * The si_addr field would be useful additional 1108 * detail, but apparently the PC value may be lost 1109 * when we reach this point. bzero() above sets 1110 * siginfo->si_addr to NULL. 1111 */ 1112 } 1113 1114 /* 1115 * There should be no reason to limit resources usage info to 1116 * exited processes only. A snapshot about any resources used 1117 * by a stopped process may be exactly what is needed. 1118 */ 1119 if (wrusage != NULL) { 1120 rup = &wrusage->wru_self; 1121 *rup = p->p_ru; 1122 PROC_STATLOCK(p); 1123 calcru(p, &rup->ru_utime, &rup->ru_stime); 1124 PROC_STATUNLOCK(p); 1125 1126 rup = &wrusage->wru_children; 1127 *rup = p->p_stats->p_cru; 1128 calccru(p, &rup->ru_utime, &rup->ru_stime); 1129 } 1130 1131 if (p->p_state == PRS_ZOMBIE && !check_only) { 1132 proc_reap(td, p, status, options); 1133 return (-1); 1134 } 1135 return (1); 1136 } 1137 1138 int 1139 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1140 struct rusage *rusage) 1141 { 1142 struct __wrusage wru, *wrup; 1143 idtype_t idtype; 1144 id_t id; 1145 int ret; 1146 1147 /* 1148 * Translate the special pid values into the (idtype, pid) 1149 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1150 * kern_wait6() on its own. 1151 */ 1152 if (pid == WAIT_ANY) { 1153 idtype = P_ALL; 1154 id = 0; 1155 } else if (pid < 0) { 1156 idtype = P_PGID; 1157 id = (id_t)-pid; 1158 } else { 1159 idtype = P_PID; 1160 id = (id_t)pid; 1161 } 1162 1163 if (rusage != NULL) 1164 wrup = &wru; 1165 else 1166 wrup = NULL; 1167 1168 /* 1169 * For backward compatibility we implicitly add flags WEXITED 1170 * and WTRAPPED here. 1171 */ 1172 options |= WEXITED | WTRAPPED; 1173 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1174 if (rusage != NULL) 1175 *rusage = wru.wru_self; 1176 return (ret); 1177 } 1178 1179 static void 1180 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1181 int *status, int options, int si_code) 1182 { 1183 bool cont; 1184 1185 PROC_LOCK_ASSERT(p, MA_OWNED); 1186 sx_assert(&proctree_lock, SA_XLOCKED); 1187 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1188 si_code == CLD_CONTINUED); 1189 1190 cont = si_code == CLD_CONTINUED; 1191 if ((options & WNOWAIT) == 0) { 1192 if (cont) 1193 p->p_flag &= ~P_CONTINUED; 1194 else 1195 p->p_flag |= P_WAITED; 1196 PROC_LOCK(td->td_proc); 1197 sigqueue_take(p->p_ksi); 1198 PROC_UNLOCK(td->td_proc); 1199 } 1200 sx_xunlock(&proctree_lock); 1201 if (siginfo != NULL) { 1202 siginfo->si_code = si_code; 1203 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1204 } 1205 if (status != NULL) 1206 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1207 PROC_UNLOCK(p); 1208 td->td_retval[0] = p->p_pid; 1209 } 1210 1211 int 1212 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1213 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1214 { 1215 struct proc *p, *q; 1216 pid_t pid; 1217 int error, nfound, ret; 1218 bool report; 1219 1220 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1221 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1222 AUDIT_ARG_VALUE(options); 1223 1224 q = td->td_proc; 1225 1226 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1227 PROC_LOCK(q); 1228 id = (id_t)q->p_pgid; 1229 PROC_UNLOCK(q); 1230 idtype = P_PGID; 1231 } 1232 1233 /* If we don't know the option, just return. */ 1234 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1235 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1236 return (EINVAL); 1237 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1238 /* 1239 * We will be unable to find any matching processes, 1240 * because there are no known events to look for. 1241 * Prefer to return error instead of blocking 1242 * indefinitely. 1243 */ 1244 return (EINVAL); 1245 } 1246 1247 loop: 1248 if (q->p_flag & P_STATCHILD) { 1249 PROC_LOCK(q); 1250 q->p_flag &= ~P_STATCHILD; 1251 PROC_UNLOCK(q); 1252 } 1253 sx_xlock(&proctree_lock); 1254 loop_locked: 1255 nfound = 0; 1256 LIST_FOREACH(p, &q->p_children, p_sibling) { 1257 pid = p->p_pid; 1258 ret = proc_to_reap(td, p, idtype, id, status, options, 1259 wrusage, siginfo, 0); 1260 if (ret == 0) 1261 continue; 1262 else if (ret != 1) { 1263 td->td_retval[0] = pid; 1264 return (0); 1265 } 1266 1267 nfound++; 1268 PROC_LOCK_ASSERT(p, MA_OWNED); 1269 1270 if ((options & WTRAPPED) != 0 && 1271 (p->p_flag & P_TRACED) != 0) { 1272 PROC_SLOCK(p); 1273 report = 1274 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1275 p->p_suspcount == p->p_numthreads && 1276 (p->p_flag & P_WAITED) == 0); 1277 PROC_SUNLOCK(p); 1278 if (report) { 1279 CTR4(KTR_PTRACE, 1280 "wait: returning trapped pid %d status %#x " 1281 "(xstat %d) xthread %d", 1282 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1283 p->p_xthread != NULL ? 1284 p->p_xthread->td_tid : -1); 1285 report_alive_proc(td, p, siginfo, status, 1286 options, CLD_TRAPPED); 1287 return (0); 1288 } 1289 } 1290 if ((options & WUNTRACED) != 0 && 1291 (p->p_flag & P_STOPPED_SIG) != 0) { 1292 PROC_SLOCK(p); 1293 report = (p->p_suspcount == p->p_numthreads && 1294 ((p->p_flag & P_WAITED) == 0)); 1295 PROC_SUNLOCK(p); 1296 if (report) { 1297 report_alive_proc(td, p, siginfo, status, 1298 options, CLD_STOPPED); 1299 return (0); 1300 } 1301 } 1302 if ((options & WCONTINUED) != 0 && 1303 (p->p_flag & P_CONTINUED) != 0) { 1304 report_alive_proc(td, p, siginfo, status, options, 1305 CLD_CONTINUED); 1306 return (0); 1307 } 1308 PROC_UNLOCK(p); 1309 } 1310 1311 /* 1312 * Look in the orphans list too, to allow the parent to 1313 * collect it's child exit status even if child is being 1314 * debugged. 1315 * 1316 * Debugger detaches from the parent upon successful 1317 * switch-over from parent to child. At this point due to 1318 * re-parenting the parent loses the child to debugger and a 1319 * wait4(2) call would report that it has no children to wait 1320 * for. By maintaining a list of orphans we allow the parent 1321 * to successfully wait until the child becomes a zombie. 1322 */ 1323 if (nfound == 0) { 1324 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1325 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1326 NULL, NULL, 1); 1327 if (ret != 0) { 1328 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1329 (int)td->td_retval[0])); 1330 PROC_UNLOCK(p); 1331 nfound++; 1332 break; 1333 } 1334 } 1335 } 1336 if (nfound == 0) { 1337 sx_xunlock(&proctree_lock); 1338 return (ECHILD); 1339 } 1340 if (options & WNOHANG) { 1341 sx_xunlock(&proctree_lock); 1342 td->td_retval[0] = 0; 1343 return (0); 1344 } 1345 PROC_LOCK(q); 1346 if (q->p_flag & P_STATCHILD) { 1347 q->p_flag &= ~P_STATCHILD; 1348 PROC_UNLOCK(q); 1349 goto loop_locked; 1350 } 1351 sx_xunlock(&proctree_lock); 1352 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1353 if (error) 1354 return (error); 1355 goto loop; 1356 } 1357 1358 void 1359 proc_add_orphan(struct proc *child, struct proc *parent) 1360 { 1361 1362 sx_assert(&proctree_lock, SX_XLOCKED); 1363 KASSERT((child->p_flag & P_TRACED) != 0, 1364 ("proc_add_orphan: not traced")); 1365 1366 if (LIST_EMPTY(&parent->p_orphans)) { 1367 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1368 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1369 } else { 1370 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1371 child, p_orphan); 1372 } 1373 child->p_treeflag |= P_TREE_ORPHANED; 1374 } 1375 1376 /* 1377 * Make process 'parent' the new parent of process 'child'. 1378 * Must be called with an exclusive hold of proctree lock. 1379 */ 1380 void 1381 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1382 { 1383 1384 sx_assert(&proctree_lock, SX_XLOCKED); 1385 PROC_LOCK_ASSERT(child, MA_OWNED); 1386 if (child->p_pptr == parent) 1387 return; 1388 1389 PROC_LOCK(child->p_pptr); 1390 sigqueue_take(child->p_ksi); 1391 PROC_UNLOCK(child->p_pptr); 1392 LIST_REMOVE(child, p_sibling); 1393 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1394 1395 proc_clear_orphan(child); 1396 if ((child->p_flag & P_TRACED) != 0) { 1397 proc_add_orphan(child, child->p_pptr); 1398 } 1399 1400 child->p_pptr = parent; 1401 if (set_oppid) 1402 child->p_oppid = parent->p_pid; 1403 } 1404