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_ddb.h" 43#include "opt_ktrace.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/sysproto.h> 48#include <sys/capsicum.h> 49#include <sys/eventhandler.h> 50#include <sys/kernel.h> 51#include <sys/ktr.h> 52#include <sys/malloc.h> 53#include <sys/lock.h> 54#include <sys/mutex.h> 55#include <sys/proc.h> 56#include <sys/procdesc.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/sysctl.h> 70#include <sys/syslog.h> 71#include <sys/ptrace.h> 72#include <sys/acct.h> /* for acct_process() function prototype */ 73#include <sys/filedesc.h> 74#include <sys/sdt.h> 75#include <sys/shm.h> 76#include <sys/sem.h> 77#include <sys/sysent.h> 78#include <sys/timers.h> 79#include <sys/umtx.h> 80#ifdef KTRACE 81#include <sys/ktrace.h> 82#endif 83 84#include <security/audit/audit.h> 85#include <security/mac/mac_framework.h> 86 87#include <vm/vm.h> 88#include <vm/vm_extern.h> 89#include <vm/vm_param.h> 90#include <vm/pmap.h> 91#include <vm/vm_map.h> 92#include <vm/vm_page.h> 93#include <vm/uma.h> 94 95#ifdef KDTRACE_HOOKS 96#include <sys/dtrace_bsd.h> 97dtrace_execexit_func_t dtrace_fasttrap_exit; 98#endif 99 100SDT_PROVIDER_DECLARE(proc); 101SDT_PROBE_DEFINE1(proc, , , exit, "int"); 102 103static int kern_kill_on_dbg_exit = 1; 104SYSCTL_INT(_kern, OID_AUTO, kill_on_debugger_exit, CTLFLAG_RWTUN, 105 &kern_kill_on_dbg_exit, 0, 106 "Kill ptraced processes when debugger exits"); 107 108static bool kern_wait_dequeue_sigchld = 1; 109SYSCTL_BOOL(_kern, OID_AUTO, wait_dequeue_sigchld, CTLFLAG_RWTUN, 110 &kern_wait_dequeue_sigchld, 0, 111 "Dequeue SIGCHLD on wait(2) for live process"); 112 113struct proc * 114proc_realparent(struct proc *child) 115{ 116 struct proc *p, *parent; 117 118 sx_assert(&proctree_lock, SX_LOCKED); 119 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) 120 return (child->p_pptr->p_pid == child->p_oppid ? 121 child->p_pptr : child->p_reaper); 122 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) { 123 /* Cannot use LIST_PREV(), since the list head is not known. */ 124 p = __containerof(p->p_orphan.le_prev, struct proc, 125 p_orphan.le_next); 126 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0, 127 ("missing P_ORPHAN %p", p)); 128 } 129 parent = __containerof(p->p_orphan.le_prev, struct proc, 130 p_orphans.lh_first); 131 return (parent); 132} 133 134void 135reaper_abandon_children(struct proc *p, bool exiting) 136{ 137 struct proc *p1, *p2, *ptmp; 138 139 sx_assert(&proctree_lock, SX_LOCKED); 140 KASSERT(p != initproc, ("reaper_abandon_children for initproc")); 141 if ((p->p_treeflag & P_TREE_REAPER) == 0) 142 return; 143 p1 = p->p_reaper; 144 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) { 145 LIST_REMOVE(p2, p_reapsibling); 146 p2->p_reaper = p1; 147 p2->p_reapsubtree = p->p_reapsubtree; 148 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling); 149 if (exiting && p2->p_pptr == p) { 150 PROC_LOCK(p2); 151 proc_reparent(p2, p1, true); 152 PROC_UNLOCK(p2); 153 } 154 } 155 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty")); 156 p->p_treeflag &= ~P_TREE_REAPER; 157} 158 159static void 160reaper_clear(struct proc *p) 161{ 162 struct proc *p1; 163 bool clear; 164 165 sx_assert(&proctree_lock, SX_LOCKED); 166 LIST_REMOVE(p, p_reapsibling); 167 if (p->p_reapsubtree == 1) 168 return; 169 clear = true; 170 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) { 171 if (p1->p_reapsubtree == p->p_reapsubtree) { 172 clear = false; 173 break; 174 } 175 } 176 if (clear) 177 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree); 178} 179 180void 181proc_clear_orphan(struct proc *p) 182{ 183 struct proc *p1; 184 185 sx_assert(&proctree_lock, SA_XLOCKED); 186 if ((p->p_treeflag & P_TREE_ORPHANED) == 0) 187 return; 188 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) { 189 p1 = LIST_NEXT(p, p_orphan); 190 if (p1 != NULL) 191 p1->p_treeflag |= P_TREE_FIRST_ORPHAN; 192 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN; 193 } 194 LIST_REMOVE(p, p_orphan); 195 p->p_treeflag &= ~P_TREE_ORPHANED; 196} 197 198/* 199 * exit -- death of process. 200 */ 201void 202sys_sys_exit(struct thread *td, struct sys_exit_args *uap) 203{ 204 205 exit1(td, uap->rval, 0); 206 /* NOTREACHED */ 207} 208 209/* 210 * Exit: deallocate address space and other resources, change proc state to 211 * zombie, and unlink proc from allproc and parent's lists. Save exit status 212 * and rusage for wait(). Check for child processes and orphan them. 213 */ 214void 215exit1(struct thread *td, int rval, int signo) 216{ 217 struct proc *p, *nq, *q, *t; 218 struct thread *tdt; 219 ksiginfo_t *ksi, *ksi1; 220 int signal_parent; 221 222 mtx_assert(&Giant, MA_NOTOWNED); 223 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo)); 224 225 p = td->td_proc; 226 /* 227 * XXX in case we're rebooting we just let init die in order to 228 * work around an unsolved stack overflow seen very late during 229 * shutdown on sparc64 when the gmirror worker process exists. 230 * XXX what to do now that sparc64 is gone... remove if? 231 */ 232 if (p == initproc && rebooting == 0) { 233 printf("init died (signal %d, exit %d)\n", signo, rval); 234 panic("Going nowhere without my init!"); 235 } 236 237 /* 238 * Deref SU mp, since the thread does not return to userspace. 239 */ 240 td_softdep_cleanup(td); 241 242 /* 243 * MUST abort all other threads before proceeding past here. 244 */ 245 PROC_LOCK(p); 246 /* 247 * First check if some other thread or external request got 248 * here before us. If so, act appropriately: exit or suspend. 249 * We must ensure that stop requests are handled before we set 250 * P_WEXIT. 251 */ 252 thread_suspend_check(0); 253 while (p->p_flag & P_HADTHREADS) { 254 /* 255 * Kill off the other threads. This requires 256 * some co-operation from other parts of the kernel 257 * so it may not be instantaneous. With this state set 258 * any thread entering the kernel from userspace will 259 * thread_exit() in trap(). Any thread attempting to 260 * sleep will return immediately with EINTR or EWOULDBLOCK 261 * which will hopefully force them to back out to userland 262 * freeing resources as they go. Any thread attempting 263 * to return to userland will thread_exit() from userret(). 264 * thread_exit() will unsuspend us when the last of the 265 * other threads exits. 266 * If there is already a thread singler after resumption, 267 * calling thread_single will fail; in that case, we just 268 * re-check all suspension request, the thread should 269 * either be suspended there or exit. 270 */ 271 if (!thread_single(p, SINGLE_EXIT)) 272 /* 273 * All other activity in this process is now 274 * stopped. Threading support has been turned 275 * off. 276 */ 277 break; 278 /* 279 * Recheck for new stop or suspend requests which 280 * might appear while process lock was dropped in 281 * thread_single(). 282 */ 283 thread_suspend_check(0); 284 } 285 KASSERT(p->p_numthreads == 1, 286 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 287 racct_sub(p, RACCT_NTHR, 1); 288 289 /* Let event handler change exit status */ 290 p->p_xexit = rval; 291 p->p_xsig = signo; 292 293 /* 294 * Ignore any pending request to stop due to a stop signal. 295 * Once P_WEXIT is set, future requests will be ignored as 296 * well. 297 */ 298 p->p_flag &= ~P_STOPPED_SIG; 299 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 300 301 /* Note that we are exiting. */ 302 p->p_flag |= P_WEXIT; 303 304 /* 305 * Wait for any processes that have a hold on our vmspace to 306 * release their reference. 307 */ 308 while (p->p_lock > 0) 309 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 310 311 PROC_UNLOCK(p); 312 /* Drain the limit callout while we don't have the proc locked */ 313 callout_drain(&p->p_limco); 314 315#ifdef AUDIT 316 /* 317 * The Sun BSM exit token contains two components: an exit status as 318 * passed to exit(), and a return value to indicate what sort of exit 319 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 320 * what the return value is. 321 */ 322 AUDIT_ARG_EXIT(rval, 0); 323 AUDIT_SYSCALL_EXIT(0, td); 324#endif 325 326 /* Are we a task leader with peers? */ 327 if (p->p_peers != NULL && p == p->p_leader) { 328 mtx_lock(&ppeers_lock); 329 q = p->p_peers; 330 while (q != NULL) { 331 PROC_LOCK(q); 332 kern_psignal(q, SIGKILL); 333 PROC_UNLOCK(q); 334 q = q->p_peers; 335 } 336 while (p->p_peers != NULL) 337 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 338 mtx_unlock(&ppeers_lock); 339 } 340 341 itimers_exit(p); 342 343 if (p->p_sysent->sv_onexit != NULL) 344 p->p_sysent->sv_onexit(p); 345 346 /* 347 * Check if any loadable modules need anything done at process exit. 348 * E.g. SYSV IPC stuff. 349 * Event handler could change exit status. 350 * XXX what if one of these generates an error? 351 */ 352 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 353 354 /* 355 * If parent is waiting for us to exit or exec, 356 * P_PPWAIT is set; we will wakeup the parent below. 357 */ 358 PROC_LOCK(p); 359 stopprofclock(p); 360 p->p_ptevents = 0; 361 362 /* 363 * Stop the real interval timer. If the handler is currently 364 * executing, prevent it from rearming itself and let it finish. 365 */ 366 if (timevalisset(&p->p_realtimer.it_value) && 367 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 368 timevalclear(&p->p_realtimer.it_interval); 369 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 370 KASSERT(!timevalisset(&p->p_realtimer.it_value), 371 ("realtime timer is still armed")); 372 } 373 374 PROC_UNLOCK(p); 375 376 umtx_thread_exit(td); 377 seltdfini(td); 378 379 /* 380 * Reset any sigio structures pointing to us as a result of 381 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown(). 382 */ 383 funsetownlst(&p->p_sigiolst); 384 385 /* 386 * Close open files and release open-file table. 387 * This may block! 388 */ 389 pdescfree(td); 390 fdescfree(td); 391 392 /* 393 * If this thread tickled GEOM, we need to wait for the giggling to 394 * stop before we return to userland 395 */ 396 if (td->td_pflags & TDP_GEOM) 397 g_waitidle(); 398 399 /* 400 * Remove ourself from our leader's peer list and wake our leader. 401 */ 402 if (p->p_leader->p_peers != NULL) { 403 mtx_lock(&ppeers_lock); 404 if (p->p_leader->p_peers != NULL) { 405 q = p->p_leader; 406 while (q->p_peers != p) 407 q = q->p_peers; 408 q->p_peers = p->p_peers; 409 wakeup(p->p_leader); 410 } 411 mtx_unlock(&ppeers_lock); 412 } 413 414 vmspace_exit(td); 415 (void)acct_process(td); 416 417#ifdef KTRACE 418 ktrprocexit(td); 419#endif 420 /* 421 * Release reference to text vnode 422 */ 423 if (p->p_textvp != NULL) { 424 vrele(p->p_textvp); 425 p->p_textvp = NULL; 426 } 427 428 /* 429 * Release our limits structure. 430 */ 431 lim_free(p->p_limit); 432 p->p_limit = NULL; 433 434 tidhash_remove(td); 435 436 /* 437 * Call machine-dependent code to release any 438 * machine-dependent resources other than the address space. 439 * The address space is released by "vmspace_exitfree(p)" in 440 * vm_waitproc(). 441 */ 442 cpu_exit(td); 443 444 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 445 446 /* 447 * Remove from allproc. It still sits in the hash. 448 */ 449 sx_xlock(&allproc_lock); 450 LIST_REMOVE(p, p_list); 451 452#ifdef DDB 453 /* 454 * Used by ddb's 'ps' command to find this process via the 455 * pidhash. 456 */ 457 p->p_list.le_prev = NULL; 458#endif 459 sx_xunlock(&allproc_lock); 460 461 sx_xlock(&proctree_lock); 462 PROC_LOCK(p); 463 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 464 PROC_UNLOCK(p); 465 466 /* 467 * killjobc() might drop and re-acquire proctree_lock to 468 * revoke control tty if exiting process was a session leader. 469 */ 470 killjobc(); 471 472 /* 473 * Reparent all children processes: 474 * - traced ones to the original parent (or init if we are that parent) 475 * - the rest to init 476 */ 477 q = LIST_FIRST(&p->p_children); 478 if (q != NULL) /* only need this if any child is S_ZOMB */ 479 wakeup(q->p_reaper); 480 for (; q != NULL; q = nq) { 481 nq = LIST_NEXT(q, p_sibling); 482 ksi = ksiginfo_alloc(TRUE); 483 PROC_LOCK(q); 484 q->p_sigparent = SIGCHLD; 485 486 if ((q->p_flag & P_TRACED) == 0) { 487 proc_reparent(q, q->p_reaper, true); 488 if (q->p_state == PRS_ZOMBIE) { 489 /* 490 * Inform reaper about the reparented 491 * zombie, since wait(2) has something 492 * new to report. Guarantee queueing 493 * of the SIGCHLD signal, similar to 494 * the _exit() behaviour, by providing 495 * our ksiginfo. Ksi is freed by the 496 * signal delivery. 497 */ 498 if (q->p_ksi == NULL) { 499 ksi1 = NULL; 500 } else { 501 ksiginfo_copy(q->p_ksi, ksi); 502 ksi->ksi_flags |= KSI_INS; 503 ksi1 = ksi; 504 ksi = NULL; 505 } 506 PROC_LOCK(q->p_reaper); 507 pksignal(q->p_reaper, SIGCHLD, ksi1); 508 PROC_UNLOCK(q->p_reaper); 509 } else if (q->p_pdeathsig > 0) { 510 /* 511 * The child asked to received a signal 512 * when we exit. 513 */ 514 kern_psignal(q, q->p_pdeathsig); 515 } 516 } else { 517 /* 518 * Traced processes are killed by default 519 * since their existence means someone is 520 * screwing up. 521 */ 522 t = proc_realparent(q); 523 if (t == p) { 524 proc_reparent(q, q->p_reaper, true); 525 } else { 526 PROC_LOCK(t); 527 proc_reparent(q, t, true); 528 PROC_UNLOCK(t); 529 } 530 /* 531 * Since q was found on our children list, the 532 * proc_reparent() call moved q to the orphan 533 * list due to present P_TRACED flag. Clear 534 * orphan link for q now while q is locked. 535 */ 536 proc_clear_orphan(q); 537 q->p_flag &= ~P_TRACED; 538 q->p_flag2 &= ~P2_PTRACE_FSTP; 539 q->p_ptevents = 0; 540 p->p_xthread = NULL; 541 FOREACH_THREAD_IN_PROC(q, tdt) { 542 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 543 TDB_FSTP); 544 tdt->td_xsig = 0; 545 } 546 if (kern_kill_on_dbg_exit) { 547 q->p_flag &= ~P_STOPPED_TRACE; 548 kern_psignal(q, SIGKILL); 549 } else if ((q->p_flag & (P_STOPPED_TRACE | 550 P_STOPPED_SIG)) != 0) { 551 sigqueue_delete_proc(q, SIGTRAP); 552 ptrace_unsuspend(q); 553 } 554 } 555 PROC_UNLOCK(q); 556 if (ksi != NULL) 557 ksiginfo_free(ksi); 558 } 559 560 /* 561 * Also get rid of our orphans. 562 */ 563 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 564 PROC_LOCK(q); 565 KASSERT(q->p_oppid == p->p_pid, 566 ("orphan %p of %p has unexpected oppid %d", q, p, 567 q->p_oppid)); 568 q->p_oppid = q->p_reaper->p_pid; 569 570 /* 571 * If we are the real parent of this process 572 * but it has been reparented to a debugger, then 573 * check if it asked for a signal when we exit. 574 */ 575 if (q->p_pdeathsig > 0) 576 kern_psignal(q, q->p_pdeathsig); 577 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 578 q->p_pid); 579 proc_clear_orphan(q); 580 PROC_UNLOCK(q); 581 } 582 583#ifdef KDTRACE_HOOKS 584 if (SDT_PROBES_ENABLED()) { 585 int reason = CLD_EXITED; 586 if (WCOREDUMP(signo)) 587 reason = CLD_DUMPED; 588 else if (WIFSIGNALED(signo)) 589 reason = CLD_KILLED; 590 SDT_PROBE1(proc, , , exit, reason); 591 } 592#endif 593 594 /* Save exit status. */ 595 PROC_LOCK(p); 596 p->p_xthread = td; 597 598 if (p->p_sysent->sv_ontdexit != NULL) 599 p->p_sysent->sv_ontdexit(td); 600 601#ifdef KDTRACE_HOOKS 602 /* 603 * Tell the DTrace fasttrap provider about the exit if it 604 * has declared an interest. 605 */ 606 if (dtrace_fasttrap_exit) 607 dtrace_fasttrap_exit(p); 608#endif 609 610 /* 611 * Notify interested parties of our demise. 612 */ 613 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 614 615 /* 616 * If this is a process with a descriptor, we may not need to deliver 617 * a signal to the parent. proctree_lock is held over 618 * procdesc_exit() to serialize concurrent calls to close() and 619 * exit(). 620 */ 621 signal_parent = 0; 622 if (p->p_procdesc == NULL || procdesc_exit(p)) { 623 /* 624 * Notify parent that we're gone. If parent has the 625 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 626 * notify process 1 instead (and hope it will handle this 627 * situation). 628 */ 629 PROC_LOCK(p->p_pptr); 630 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 631 if (p->p_pptr->p_sigacts->ps_flag & 632 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 633 struct proc *pp; 634 635 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 636 pp = p->p_pptr; 637 PROC_UNLOCK(pp); 638 proc_reparent(p, p->p_reaper, true); 639 p->p_sigparent = SIGCHLD; 640 PROC_LOCK(p->p_pptr); 641 642 /* 643 * Notify parent, so in case he was wait(2)ing or 644 * executing waitpid(2) with our pid, he will 645 * continue. 646 */ 647 wakeup(pp); 648 } else 649 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 650 651 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 652 signal_parent = 1; 653 } else if (p->p_sigparent != 0) { 654 if (p->p_sigparent == SIGCHLD) { 655 signal_parent = 1; 656 } else { /* LINUX thread */ 657 signal_parent = 2; 658 } 659 } 660 } else 661 PROC_LOCK(p->p_pptr); 662 sx_xunlock(&proctree_lock); 663 664 if (signal_parent == 1) { 665 childproc_exited(p); 666 } else if (signal_parent == 2) { 667 kern_psignal(p->p_pptr, p->p_sigparent); 668 } 669 670 /* Tell the prison that we are gone. */ 671 prison_proc_free(p->p_ucred->cr_prison); 672 673 /* 674 * The state PRS_ZOMBIE prevents other proesses from sending 675 * signal to the process, to avoid memory leak, we free memory 676 * for signal queue at the time when the state is set. 677 */ 678 sigqueue_flush(&p->p_sigqueue); 679 sigqueue_flush(&td->td_sigqueue); 680 681 /* 682 * We have to wait until after acquiring all locks before 683 * changing p_state. We need to avoid all possible context 684 * switches (including ones from blocking on a mutex) while 685 * marked as a zombie. We also have to set the zombie state 686 * before we release the parent process' proc lock to avoid 687 * a lost wakeup. So, we first call wakeup, then we grab the 688 * sched lock, update the state, and release the parent process' 689 * proc lock. 690 */ 691 wakeup(p->p_pptr); 692 cv_broadcast(&p->p_pwait); 693 sched_exit(p->p_pptr, td); 694 PROC_SLOCK(p); 695 p->p_state = PRS_ZOMBIE; 696 PROC_UNLOCK(p->p_pptr); 697 698 /* 699 * Save our children's rusage information in our exit rusage. 700 */ 701 PROC_STATLOCK(p); 702 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 703 PROC_STATUNLOCK(p); 704 705 /* 706 * Make sure the scheduler takes this thread out of its tables etc. 707 * This will also release this thread's reference to the ucred. 708 * Other thread parts to release include pcb bits and such. 709 */ 710 thread_exit(); 711} 712 713#ifndef _SYS_SYSPROTO_H_ 714struct abort2_args { 715 char *why; 716 int nargs; 717 void **args; 718}; 719#endif 720 721int 722sys_abort2(struct thread *td, struct abort2_args *uap) 723{ 724 struct proc *p = td->td_proc; 725 struct sbuf *sb; 726 void *uargs[16]; 727 int error, i, sig; 728 729 /* 730 * Do it right now so we can log either proper call of abort2(), or 731 * note, that invalid argument was passed. 512 is big enough to 732 * handle 16 arguments' descriptions with additional comments. 733 */ 734 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 735 sbuf_clear(sb); 736 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 737 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 738 /* 739 * Since we can't return from abort2(), send SIGKILL in cases, where 740 * abort2() was called improperly 741 */ 742 sig = SIGKILL; 743 /* Prevent from DoSes from user-space. */ 744 if (uap->nargs < 0 || uap->nargs > 16) 745 goto out; 746 if (uap->nargs > 0) { 747 if (uap->args == NULL) 748 goto out; 749 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 750 if (error != 0) 751 goto out; 752 } 753 /* 754 * Limit size of 'reason' string to 128. Will fit even when 755 * maximal number of arguments was chosen to be logged. 756 */ 757 if (uap->why != NULL) { 758 error = sbuf_copyin(sb, uap->why, 128); 759 if (error < 0) 760 goto out; 761 } else { 762 sbuf_printf(sb, "(null)"); 763 } 764 if (uap->nargs > 0) { 765 sbuf_printf(sb, "("); 766 for (i = 0;i < uap->nargs; i++) 767 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 768 sbuf_printf(sb, ")"); 769 } 770 /* 771 * Final stage: arguments were proper, string has been 772 * successfully copied from userspace, and copying pointers 773 * from user-space succeed. 774 */ 775 sig = SIGABRT; 776out: 777 if (sig == SIGKILL) { 778 sbuf_trim(sb); 779 sbuf_printf(sb, " (Reason text inaccessible)"); 780 } 781 sbuf_cat(sb, "\n"); 782 sbuf_finish(sb); 783 log(LOG_INFO, "%s", sbuf_data(sb)); 784 sbuf_delete(sb); 785 exit1(td, 0, sig); 786 return (0); 787} 788 789#ifdef COMPAT_43 790/* 791 * The dirty work is handled by kern_wait(). 792 */ 793int 794owait(struct thread *td, struct owait_args *uap __unused) 795{ 796 int error, status; 797 798 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 799 if (error == 0) 800 td->td_retval[1] = status; 801 return (error); 802} 803#endif /* COMPAT_43 */ 804 805/* 806 * The dirty work is handled by kern_wait(). 807 */ 808int 809sys_wait4(struct thread *td, struct wait4_args *uap) 810{ 811 struct rusage ru, *rup; 812 int error, status; 813 814 if (uap->rusage != NULL) 815 rup = &ru; 816 else 817 rup = NULL; 818 error = kern_wait(td, uap->pid, &status, uap->options, rup); 819 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 820 error = copyout(&status, uap->status, sizeof(status)); 821 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 822 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 823 return (error); 824} 825 826int 827sys_wait6(struct thread *td, struct wait6_args *uap) 828{ 829 struct __wrusage wru, *wrup; 830 siginfo_t si, *sip; 831 idtype_t idtype; 832 id_t id; 833 int error, status; 834 835 idtype = uap->idtype; 836 id = uap->id; 837 838 if (uap->wrusage != NULL) 839 wrup = &wru; 840 else 841 wrup = NULL; 842 843 if (uap->info != NULL) { 844 sip = &si; 845 bzero(sip, sizeof(*sip)); 846 } else 847 sip = NULL; 848 849 /* 850 * We expect all callers of wait6() to know about WEXITED and 851 * WTRAPPED. 852 */ 853 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 854 855 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 856 error = copyout(&status, uap->status, sizeof(status)); 857 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 858 error = copyout(&wru, uap->wrusage, sizeof(wru)); 859 if (uap->info != NULL && error == 0) 860 error = copyout(&si, uap->info, sizeof(si)); 861 return (error); 862} 863 864/* 865 * Reap the remains of a zombie process and optionally return status and 866 * rusage. Asserts and will release both the proctree_lock and the process 867 * lock as part of its work. 868 */ 869void 870proc_reap(struct thread *td, struct proc *p, int *status, int options) 871{ 872 struct proc *q, *t; 873 874 sx_assert(&proctree_lock, SA_XLOCKED); 875 PROC_LOCK_ASSERT(p, MA_OWNED); 876 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 877 878 mtx_spin_wait_unlocked(&p->p_slock); 879 880 q = td->td_proc; 881 882 if (status) 883 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 884 if (options & WNOWAIT) { 885 /* 886 * Only poll, returning the status. Caller does not wish to 887 * release the proc struct just yet. 888 */ 889 PROC_UNLOCK(p); 890 sx_xunlock(&proctree_lock); 891 return; 892 } 893 894 PROC_LOCK(q); 895 sigqueue_take(p->p_ksi); 896 PROC_UNLOCK(q); 897 898 /* 899 * If we got the child via a ptrace 'attach', we need to give it back 900 * to the old parent. 901 */ 902 if (p->p_oppid != p->p_pptr->p_pid) { 903 PROC_UNLOCK(p); 904 t = proc_realparent(p); 905 PROC_LOCK(t); 906 PROC_LOCK(p); 907 CTR2(KTR_PTRACE, 908 "wait: traced child %d moved back to parent %d", p->p_pid, 909 t->p_pid); 910 proc_reparent(p, t, false); 911 PROC_UNLOCK(p); 912 pksignal(t, SIGCHLD, p->p_ksi); 913 wakeup(t); 914 cv_broadcast(&p->p_pwait); 915 PROC_UNLOCK(t); 916 sx_xunlock(&proctree_lock); 917 return; 918 } 919 PROC_UNLOCK(p); 920 921 /* 922 * Remove other references to this process to ensure we have an 923 * exclusive reference. 924 */ 925 sx_xlock(PIDHASHLOCK(p->p_pid)); 926 LIST_REMOVE(p, p_hash); 927 sx_xunlock(PIDHASHLOCK(p->p_pid)); 928 LIST_REMOVE(p, p_sibling); 929 reaper_abandon_children(p, true); 930 reaper_clear(p); 931 PROC_LOCK(p); 932 proc_clear_orphan(p); 933 PROC_UNLOCK(p); 934 leavepgrp(p); 935 if (p->p_procdesc != NULL) 936 procdesc_reap(p); 937 sx_xunlock(&proctree_lock); 938 939 proc_id_clear(PROC_ID_PID, p->p_pid); 940 941 PROC_LOCK(p); 942 knlist_detach(p->p_klist); 943 p->p_klist = NULL; 944 PROC_UNLOCK(p); 945 946 /* 947 * Removal from allproc list and process group list paired with 948 * PROC_LOCK which was executed during that time should guarantee 949 * nothing can reach this process anymore. As such further locking 950 * is unnecessary. 951 */ 952 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 953 954 PROC_LOCK(q); 955 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 956 PROC_UNLOCK(q); 957 958 /* 959 * Decrement the count of procs running with this uid. 960 */ 961 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 962 963 /* 964 * Destroy resource accounting information associated with the process. 965 */ 966#ifdef RACCT 967 if (racct_enable) { 968 PROC_LOCK(p); 969 racct_sub(p, RACCT_NPROC, 1); 970 PROC_UNLOCK(p); 971 } 972#endif 973 racct_proc_exit(p); 974 975 /* 976 * Free credentials, arguments, and sigacts. 977 */ 978 proc_unset_cred(p); 979 pargs_drop(p->p_args); 980 p->p_args = NULL; 981 sigacts_free(p->p_sigacts); 982 p->p_sigacts = NULL; 983 984 /* 985 * Do any thread-system specific cleanups. 986 */ 987 thread_wait(p); 988 989 /* 990 * Give vm and machine-dependent layer a chance to free anything that 991 * cpu_exit couldn't release while still running in process context. 992 */ 993 vm_waitproc(p); 994#ifdef MAC 995 mac_proc_destroy(p); 996#endif 997 998 KASSERT(FIRST_THREAD_IN_PROC(p), 999 ("proc_reap: no residual thread!")); 1000 uma_zfree(proc_zone, p); 1001 atomic_add_int(&nprocs, -1); 1002} 1003 1004static int 1005proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 1006 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 1007 int check_only) 1008{ 1009 struct rusage *rup; 1010 1011 sx_assert(&proctree_lock, SA_XLOCKED); 1012 1013 PROC_LOCK(p); 1014 1015 switch (idtype) { 1016 case P_ALL: 1017 if (p->p_procdesc == NULL || 1018 (p->p_pptr == td->td_proc && 1019 (p->p_flag & P_TRACED) != 0)) { 1020 break; 1021 } 1022 1023 PROC_UNLOCK(p); 1024 return (0); 1025 case P_PID: 1026 if (p->p_pid != (pid_t)id) { 1027 PROC_UNLOCK(p); 1028 return (0); 1029 } 1030 break; 1031 case P_PGID: 1032 if (p->p_pgid != (pid_t)id) { 1033 PROC_UNLOCK(p); 1034 return (0); 1035 } 1036 break; 1037 case P_SID: 1038 if (p->p_session->s_sid != (pid_t)id) { 1039 PROC_UNLOCK(p); 1040 return (0); 1041 } 1042 break; 1043 case P_UID: 1044 if (p->p_ucred->cr_uid != (uid_t)id) { 1045 PROC_UNLOCK(p); 1046 return (0); 1047 } 1048 break; 1049 case P_GID: 1050 if (p->p_ucred->cr_gid != (gid_t)id) { 1051 PROC_UNLOCK(p); 1052 return (0); 1053 } 1054 break; 1055 case P_JAILID: 1056 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1057 PROC_UNLOCK(p); 1058 return (0); 1059 } 1060 break; 1061 /* 1062 * It seems that the thread structures get zeroed out 1063 * at process exit. This makes it impossible to 1064 * support P_SETID, P_CID or P_CPUID. 1065 */ 1066 default: 1067 PROC_UNLOCK(p); 1068 return (0); 1069 } 1070 1071 if (p_canwait(td, p)) { 1072 PROC_UNLOCK(p); 1073 return (0); 1074 } 1075 1076 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1077 PROC_UNLOCK(p); 1078 return (0); 1079 } 1080 1081 /* 1082 * This special case handles a kthread spawned by linux_clone 1083 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1084 * functions need to be able to distinguish between waiting 1085 * on a process and waiting on a thread. It is a thread if 1086 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1087 * signifies we want to wait for threads and not processes. 1088 */ 1089 if ((p->p_sigparent != SIGCHLD) ^ 1090 ((options & WLINUXCLONE) != 0)) { 1091 PROC_UNLOCK(p); 1092 return (0); 1093 } 1094 1095 if (siginfo != NULL) { 1096 bzero(siginfo, sizeof(*siginfo)); 1097 siginfo->si_errno = 0; 1098 1099 /* 1100 * SUSv4 requires that the si_signo value is always 1101 * SIGCHLD. Obey it despite the rfork(2) interface 1102 * allows to request other signal for child exit 1103 * notification. 1104 */ 1105 siginfo->si_signo = SIGCHLD; 1106 1107 /* 1108 * This is still a rough estimate. We will fix the 1109 * cases TRAPPED, STOPPED, and CONTINUED later. 1110 */ 1111 if (WCOREDUMP(p->p_xsig)) { 1112 siginfo->si_code = CLD_DUMPED; 1113 siginfo->si_status = WTERMSIG(p->p_xsig); 1114 } else if (WIFSIGNALED(p->p_xsig)) { 1115 siginfo->si_code = CLD_KILLED; 1116 siginfo->si_status = WTERMSIG(p->p_xsig); 1117 } else { 1118 siginfo->si_code = CLD_EXITED; 1119 siginfo->si_status = p->p_xexit; 1120 } 1121 1122 siginfo->si_pid = p->p_pid; 1123 siginfo->si_uid = p->p_ucred->cr_uid; 1124 1125 /* 1126 * The si_addr field would be useful additional 1127 * detail, but apparently the PC value may be lost 1128 * when we reach this point. bzero() above sets 1129 * siginfo->si_addr to NULL. 1130 */ 1131 } 1132 1133 /* 1134 * There should be no reason to limit resources usage info to 1135 * exited processes only. A snapshot about any resources used 1136 * by a stopped process may be exactly what is needed. 1137 */ 1138 if (wrusage != NULL) { 1139 rup = &wrusage->wru_self; 1140 *rup = p->p_ru; 1141 PROC_STATLOCK(p); 1142 calcru(p, &rup->ru_utime, &rup->ru_stime); 1143 PROC_STATUNLOCK(p); 1144 1145 rup = &wrusage->wru_children; 1146 *rup = p->p_stats->p_cru; 1147 calccru(p, &rup->ru_utime, &rup->ru_stime); 1148 } 1149 1150 if (p->p_state == PRS_ZOMBIE && !check_only) { 1151 proc_reap(td, p, status, options); 1152 return (-1); 1153 } 1154 return (1); 1155} 1156 1157int 1158kern_wait(struct thread *td, pid_t pid, int *status, int options, 1159 struct rusage *rusage) 1160{ 1161 struct __wrusage wru, *wrup; 1162 idtype_t idtype; 1163 id_t id; 1164 int ret; 1165 1166 /* 1167 * Translate the special pid values into the (idtype, pid) 1168 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1169 * kern_wait6() on its own. 1170 */ 1171 if (pid == WAIT_ANY) { 1172 idtype = P_ALL; 1173 id = 0; 1174 } else if (pid < 0) { 1175 idtype = P_PGID; 1176 id = (id_t)-pid; 1177 } else { 1178 idtype = P_PID; 1179 id = (id_t)pid; 1180 } 1181 1182 if (rusage != NULL) 1183 wrup = &wru; 1184 else 1185 wrup = NULL; 1186 1187 /* 1188 * For backward compatibility we implicitly add flags WEXITED 1189 * and WTRAPPED here. 1190 */ 1191 options |= WEXITED | WTRAPPED; 1192 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1193 if (rusage != NULL) 1194 *rusage = wru.wru_self; 1195 return (ret); 1196} 1197 1198static void 1199report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1200 int *status, int options, int si_code) 1201{ 1202 bool cont; 1203 1204 PROC_LOCK_ASSERT(p, MA_OWNED); 1205 sx_assert(&proctree_lock, SA_XLOCKED); 1206 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1207 si_code == CLD_CONTINUED); 1208 1209 cont = si_code == CLD_CONTINUED; 1210 if ((options & WNOWAIT) == 0) { 1211 if (cont) 1212 p->p_flag &= ~P_CONTINUED; 1213 else 1214 p->p_flag |= P_WAITED; 1215 if (kern_wait_dequeue_sigchld && 1216 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) { 1217 PROC_LOCK(td->td_proc); 1218 sigqueue_take(p->p_ksi); 1219 PROC_UNLOCK(td->td_proc); 1220 } 1221 } 1222 sx_xunlock(&proctree_lock); 1223 if (siginfo != NULL) { 1224 siginfo->si_code = si_code; 1225 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1226 } 1227 if (status != NULL) 1228 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1229 PROC_UNLOCK(p); 1230 td->td_retval[0] = p->p_pid; 1231} 1232 1233int 1234kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1235 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1236{ 1237 struct proc *p, *q; 1238 pid_t pid; 1239 int error, nfound, ret; 1240 bool report; 1241 1242 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1243 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1244 AUDIT_ARG_VALUE(options); 1245 1246 q = td->td_proc; 1247 1248 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1249 PROC_LOCK(q); 1250 id = (id_t)q->p_pgid; 1251 PROC_UNLOCK(q); 1252 idtype = P_PGID; 1253 } 1254 1255 /* If we don't know the option, just return. */ 1256 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1257 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1258 return (EINVAL); 1259 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1260 /* 1261 * We will be unable to find any matching processes, 1262 * because there are no known events to look for. 1263 * Prefer to return error instead of blocking 1264 * indefinitely. 1265 */ 1266 return (EINVAL); 1267 } 1268 1269loop: 1270 if (q->p_flag & P_STATCHILD) { 1271 PROC_LOCK(q); 1272 q->p_flag &= ~P_STATCHILD; 1273 PROC_UNLOCK(q); 1274 } 1275 sx_xlock(&proctree_lock); 1276loop_locked: 1277 nfound = 0; 1278 LIST_FOREACH(p, &q->p_children, p_sibling) { 1279 pid = p->p_pid; 1280 ret = proc_to_reap(td, p, idtype, id, status, options, 1281 wrusage, siginfo, 0); 1282 if (ret == 0) 1283 continue; 1284 else if (ret != 1) { 1285 td->td_retval[0] = pid; 1286 return (0); 1287 } 1288 1289 nfound++; 1290 PROC_LOCK_ASSERT(p, MA_OWNED); 1291 1292 if ((options & WTRAPPED) != 0 && 1293 (p->p_flag & P_TRACED) != 0) { 1294 PROC_SLOCK(p); 1295 report = 1296 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1297 p->p_suspcount == p->p_numthreads && 1298 (p->p_flag & P_WAITED) == 0); 1299 PROC_SUNLOCK(p); 1300 if (report) { 1301 CTR4(KTR_PTRACE, 1302 "wait: returning trapped pid %d status %#x " 1303 "(xstat %d) xthread %d", 1304 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1305 p->p_xthread != NULL ? 1306 p->p_xthread->td_tid : -1); 1307 report_alive_proc(td, p, siginfo, status, 1308 options, CLD_TRAPPED); 1309 return (0); 1310 } 1311 } 1312 if ((options & WUNTRACED) != 0 && 1313 (p->p_flag & P_STOPPED_SIG) != 0) { 1314 PROC_SLOCK(p); 1315 report = (p->p_suspcount == p->p_numthreads && 1316 ((p->p_flag & P_WAITED) == 0)); 1317 PROC_SUNLOCK(p); 1318 if (report) { 1319 report_alive_proc(td, p, siginfo, status, 1320 options, CLD_STOPPED); 1321 return (0); 1322 } 1323 } 1324 if ((options & WCONTINUED) != 0 && 1325 (p->p_flag & P_CONTINUED) != 0) { 1326 report_alive_proc(td, p, siginfo, status, options, 1327 CLD_CONTINUED); 1328 return (0); 1329 } 1330 PROC_UNLOCK(p); 1331 } 1332 1333 /* 1334 * Look in the orphans list too, to allow the parent to 1335 * collect it's child exit status even if child is being 1336 * debugged. 1337 * 1338 * Debugger detaches from the parent upon successful 1339 * switch-over from parent to child. At this point due to 1340 * re-parenting the parent loses the child to debugger and a 1341 * wait4(2) call would report that it has no children to wait 1342 * for. By maintaining a list of orphans we allow the parent 1343 * to successfully wait until the child becomes a zombie. 1344 */ 1345 if (nfound == 0) { 1346 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1347 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1348 NULL, NULL, 1); 1349 if (ret != 0) { 1350 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1351 (int)td->td_retval[0])); 1352 PROC_UNLOCK(p); 1353 nfound++; 1354 break; 1355 } 1356 } 1357 } 1358 if (nfound == 0) { 1359 sx_xunlock(&proctree_lock); 1360 return (ECHILD); 1361 } 1362 if (options & WNOHANG) { 1363 sx_xunlock(&proctree_lock); 1364 td->td_retval[0] = 0; 1365 return (0); 1366 } 1367 PROC_LOCK(q); 1368 if (q->p_flag & P_STATCHILD) { 1369 q->p_flag &= ~P_STATCHILD; 1370 PROC_UNLOCK(q); 1371 goto loop_locked; 1372 } 1373 sx_xunlock(&proctree_lock); 1374 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1375 if (error) 1376 return (error); 1377 goto loop; 1378} 1379 1380void 1381proc_add_orphan(struct proc *child, struct proc *parent) 1382{ 1383 1384 sx_assert(&proctree_lock, SX_XLOCKED); 1385 KASSERT((child->p_flag & P_TRACED) != 0, 1386 ("proc_add_orphan: not traced")); 1387 1388 if (LIST_EMPTY(&parent->p_orphans)) { 1389 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1390 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1391 } else { 1392 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1393 child, p_orphan); 1394 } 1395 child->p_treeflag |= P_TREE_ORPHANED; 1396} 1397 1398/* 1399 * Make process 'parent' the new parent of process 'child'. 1400 * Must be called with an exclusive hold of proctree lock. 1401 */ 1402void 1403proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1404{ 1405 1406 sx_assert(&proctree_lock, SX_XLOCKED); 1407 PROC_LOCK_ASSERT(child, MA_OWNED); 1408 if (child->p_pptr == parent) 1409 return; 1410 1411 PROC_LOCK(child->p_pptr); 1412 sigqueue_take(child->p_ksi); 1413 PROC_UNLOCK(child->p_pptr); 1414 LIST_REMOVE(child, p_sibling); 1415 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1416 1417 proc_clear_orphan(child); 1418 if ((child->p_flag & P_TRACED) != 0) { 1419 proc_add_orphan(child, child->p_pptr); 1420 } 1421 1422 child->p_pptr = parent; 1423 if (set_oppid) 1424 child->p_oppid = parent->p_pid; 1425} 1426