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/umtxvar.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> 97 dtrace_execexit_func_t dtrace_fasttrap_exit; 98 #endif 99 100 SDT_PROVIDER_DECLARE(proc); 101 SDT_PROBE_DEFINE1(proc, , , exit, "int"); 102 103 static int kern_kill_on_dbg_exit = 1; 104 SYSCTL_INT(_kern, OID_AUTO, kill_on_debugger_exit, CTLFLAG_RWTUN, 105 &kern_kill_on_dbg_exit, 0, 106 "Kill ptraced processes when debugger exits"); 107 108 static bool kern_wait_dequeue_sigchld = 1; 109 SYSCTL_BOOL(_kern, OID_AUTO, wait_dequeue_sigchld, CTLFLAG_RWTUN, 110 &kern_wait_dequeue_sigchld, 0, 111 "Dequeue SIGCHLD on wait(2) for live process"); 112 113 struct proc * 114 proc_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 } 133 134 void 135 reaper_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 } 158 159 static void 160 reaper_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 } 179 180 void 181 proc_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 void 199 exit_onexit(struct proc *p) 200 { 201 MPASS(p->p_numthreads == 1); 202 umtx_thread_exit(FIRST_THREAD_IN_PROC(p)); 203 } 204 205 /* 206 * exit -- death of process. 207 */ 208 void 209 sys_sys_exit(struct thread *td, struct sys_exit_args *uap) 210 { 211 212 exit1(td, uap->rval, 0); 213 /* NOTREACHED */ 214 } 215 216 /* 217 * Exit: deallocate address space and other resources, change proc state to 218 * zombie, and unlink proc from allproc and parent's lists. Save exit status 219 * and rusage for wait(). Check for child processes and orphan them. 220 */ 221 void 222 exit1(struct thread *td, int rval, int signo) 223 { 224 struct proc *p, *nq, *q, *t; 225 struct thread *tdt; 226 ksiginfo_t *ksi, *ksi1; 227 int signal_parent; 228 229 mtx_assert(&Giant, MA_NOTOWNED); 230 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo)); 231 232 p = td->td_proc; 233 /* 234 * XXX in case we're rebooting we just let init die in order to 235 * work around an unsolved stack overflow seen very late during 236 * shutdown on sparc64 when the gmirror worker process exists. 237 * XXX what to do now that sparc64 is gone... remove if? 238 */ 239 if (p == initproc && rebooting == 0) { 240 printf("init died (signal %d, exit %d)\n", signo, rval); 241 panic("Going nowhere without my init!"); 242 } 243 244 /* 245 * Deref SU mp, since the thread does not return to userspace. 246 */ 247 td_softdep_cleanup(td); 248 249 /* 250 * MUST abort all other threads before proceeding past here. 251 */ 252 PROC_LOCK(p); 253 /* 254 * First check if some other thread or external request got 255 * here before us. If so, act appropriately: exit or suspend. 256 * We must ensure that stop requests are handled before we set 257 * P_WEXIT. 258 */ 259 thread_suspend_check(0); 260 while (p->p_flag & P_HADTHREADS) { 261 /* 262 * Kill off the other threads. This requires 263 * some co-operation from other parts of the kernel 264 * so it may not be instantaneous. With this state set 265 * any thread entering the kernel from userspace will 266 * thread_exit() in trap(). Any thread attempting to 267 * sleep will return immediately with EINTR or EWOULDBLOCK 268 * which will hopefully force them to back out to userland 269 * freeing resources as they go. Any thread attempting 270 * to return to userland will thread_exit() from userret(). 271 * thread_exit() will unsuspend us when the last of the 272 * other threads exits. 273 * If there is already a thread singler after resumption, 274 * calling thread_single will fail; in that case, we just 275 * re-check all suspension request, the thread should 276 * either be suspended there or exit. 277 */ 278 if (!thread_single(p, SINGLE_EXIT)) 279 /* 280 * All other activity in this process is now 281 * stopped. Threading support has been turned 282 * off. 283 */ 284 break; 285 /* 286 * Recheck for new stop or suspend requests which 287 * might appear while process lock was dropped in 288 * thread_single(). 289 */ 290 thread_suspend_check(0); 291 } 292 KASSERT(p->p_numthreads == 1, 293 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 294 racct_sub(p, RACCT_NTHR, 1); 295 296 /* Let event handler change exit status */ 297 p->p_xexit = rval; 298 p->p_xsig = signo; 299 300 /* 301 * Ignore any pending request to stop due to a stop signal. 302 * Once P_WEXIT is set, future requests will be ignored as 303 * well. 304 */ 305 p->p_flag &= ~P_STOPPED_SIG; 306 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 307 308 /* Note that we are exiting. */ 309 p->p_flag |= P_WEXIT; 310 311 /* 312 * Wait for any processes that have a hold on our vmspace to 313 * release their reference. 314 */ 315 while (p->p_lock > 0) 316 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 317 318 PROC_UNLOCK(p); 319 /* Drain the limit callout while we don't have the proc locked */ 320 callout_drain(&p->p_limco); 321 322 #ifdef AUDIT 323 /* 324 * The Sun BSM exit token contains two components: an exit status as 325 * passed to exit(), and a return value to indicate what sort of exit 326 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 327 * what the return value is. 328 */ 329 AUDIT_ARG_EXIT(rval, 0); 330 AUDIT_SYSCALL_EXIT(0, td); 331 #endif 332 333 /* Are we a task leader with peers? */ 334 if (p->p_peers != NULL && p == p->p_leader) { 335 mtx_lock(&ppeers_lock); 336 q = p->p_peers; 337 while (q != NULL) { 338 PROC_LOCK(q); 339 kern_psignal(q, SIGKILL); 340 PROC_UNLOCK(q); 341 q = q->p_peers; 342 } 343 while (p->p_peers != NULL) 344 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 345 mtx_unlock(&ppeers_lock); 346 } 347 348 itimers_exit(p); 349 350 /* 351 * Check if any loadable modules need anything done at process exit. 352 * E.g. SYSV IPC stuff. 353 * Event handler could change exit status. 354 * XXX what if one of these generates an error? 355 */ 356 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 357 358 /* 359 * If parent is waiting for us to exit or exec, 360 * P_PPWAIT is set; we will wakeup the parent below. 361 */ 362 PROC_LOCK(p); 363 stopprofclock(p); 364 p->p_ptevents = 0; 365 366 /* 367 * Stop the real interval timer. If the handler is currently 368 * executing, prevent it from rearming itself and let it finish. 369 */ 370 if (timevalisset(&p->p_realtimer.it_value) && 371 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 372 timevalclear(&p->p_realtimer.it_interval); 373 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 374 KASSERT(!timevalisset(&p->p_realtimer.it_value), 375 ("realtime timer is still armed")); 376 } 377 378 PROC_UNLOCK(p); 379 380 if (p->p_sysent->sv_onexit != NULL) 381 p->p_sysent->sv_onexit(p); 382 seltdfini(td); 383 384 /* 385 * Reset any sigio structures pointing to us as a result of 386 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown(). 387 */ 388 funsetownlst(&p->p_sigiolst); 389 390 /* 391 * Close open files and release open-file table. 392 * This may block! 393 */ 394 pdescfree(td); 395 fdescfree(td); 396 397 /* 398 * If this thread tickled GEOM, we need to wait for the giggling to 399 * stop before we return to userland 400 */ 401 if (td->td_pflags & TDP_GEOM) 402 g_waitidle(); 403 404 /* 405 * Remove ourself from our leader's peer list and wake our leader. 406 */ 407 if (p->p_leader->p_peers != NULL) { 408 mtx_lock(&ppeers_lock); 409 if (p->p_leader->p_peers != NULL) { 410 q = p->p_leader; 411 while (q->p_peers != p) 412 q = q->p_peers; 413 q->p_peers = p->p_peers; 414 wakeup(p->p_leader); 415 } 416 mtx_unlock(&ppeers_lock); 417 } 418 419 vmspace_exit(td); 420 (void)acct_process(td); 421 422 #ifdef KTRACE 423 ktrprocexit(td); 424 #endif 425 /* 426 * Release reference to text vnode 427 */ 428 if (p->p_textvp != NULL) { 429 vrele(p->p_textvp); 430 p->p_textvp = NULL; 431 } 432 433 /* 434 * Release our limits structure. 435 */ 436 lim_free(p->p_limit); 437 p->p_limit = NULL; 438 439 tidhash_remove(td); 440 441 /* 442 * Call machine-dependent code to release any 443 * machine-dependent resources other than the address space. 444 * The address space is released by "vmspace_exitfree(p)" in 445 * vm_waitproc(). 446 */ 447 cpu_exit(td); 448 449 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 450 451 /* 452 * Remove from allproc. It still sits in the hash. 453 */ 454 sx_xlock(&allproc_lock); 455 LIST_REMOVE(p, p_list); 456 457 #ifdef DDB 458 /* 459 * Used by ddb's 'ps' command to find this process via the 460 * pidhash. 461 */ 462 p->p_list.le_prev = NULL; 463 #endif 464 sx_xunlock(&allproc_lock); 465 466 sx_xlock(&proctree_lock); 467 PROC_LOCK(p); 468 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 469 PROC_UNLOCK(p); 470 471 /* 472 * killjobc() might drop and re-acquire proctree_lock to 473 * revoke control tty if exiting process was a session leader. 474 */ 475 killjobc(); 476 477 /* 478 * Reparent all children processes: 479 * - traced ones to the original parent (or init if we are that parent) 480 * - the rest to init 481 */ 482 q = LIST_FIRST(&p->p_children); 483 if (q != NULL) /* only need this if any child is S_ZOMB */ 484 wakeup(q->p_reaper); 485 for (; q != NULL; q = nq) { 486 nq = LIST_NEXT(q, p_sibling); 487 ksi = ksiginfo_alloc(TRUE); 488 PROC_LOCK(q); 489 q->p_sigparent = SIGCHLD; 490 491 if ((q->p_flag & P_TRACED) == 0) { 492 proc_reparent(q, q->p_reaper, true); 493 if (q->p_state == PRS_ZOMBIE) { 494 /* 495 * Inform reaper about the reparented 496 * zombie, since wait(2) has something 497 * new to report. Guarantee queueing 498 * of the SIGCHLD signal, similar to 499 * the _exit() behaviour, by providing 500 * our ksiginfo. Ksi is freed by the 501 * signal delivery. 502 */ 503 if (q->p_ksi == NULL) { 504 ksi1 = NULL; 505 } else { 506 ksiginfo_copy(q->p_ksi, ksi); 507 ksi->ksi_flags |= KSI_INS; 508 ksi1 = ksi; 509 ksi = NULL; 510 } 511 PROC_LOCK(q->p_reaper); 512 pksignal(q->p_reaper, SIGCHLD, ksi1); 513 PROC_UNLOCK(q->p_reaper); 514 } else if (q->p_pdeathsig > 0) { 515 /* 516 * The child asked to received a signal 517 * when we exit. 518 */ 519 kern_psignal(q, q->p_pdeathsig); 520 } 521 } else { 522 /* 523 * Traced processes are killed by default 524 * since their existence means someone is 525 * screwing up. 526 */ 527 t = proc_realparent(q); 528 if (t == p) { 529 proc_reparent(q, q->p_reaper, true); 530 } else { 531 PROC_LOCK(t); 532 proc_reparent(q, t, true); 533 PROC_UNLOCK(t); 534 } 535 /* 536 * Since q was found on our children list, the 537 * proc_reparent() call moved q to the orphan 538 * list due to present P_TRACED flag. Clear 539 * orphan link for q now while q is locked. 540 */ 541 proc_clear_orphan(q); 542 q->p_flag &= ~P_TRACED; 543 q->p_flag2 &= ~P2_PTRACE_FSTP; 544 q->p_ptevents = 0; 545 p->p_xthread = NULL; 546 FOREACH_THREAD_IN_PROC(q, tdt) { 547 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 548 TDB_FSTP); 549 tdt->td_xsig = 0; 550 } 551 if (kern_kill_on_dbg_exit) { 552 q->p_flag &= ~P_STOPPED_TRACE; 553 kern_psignal(q, SIGKILL); 554 } else if ((q->p_flag & (P_STOPPED_TRACE | 555 P_STOPPED_SIG)) != 0) { 556 sigqueue_delete_proc(q, SIGTRAP); 557 ptrace_unsuspend(q); 558 } 559 } 560 PROC_UNLOCK(q); 561 if (ksi != NULL) 562 ksiginfo_free(ksi); 563 } 564 565 /* 566 * Also get rid of our orphans. 567 */ 568 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 569 PROC_LOCK(q); 570 KASSERT(q->p_oppid == p->p_pid, 571 ("orphan %p of %p has unexpected oppid %d", q, p, 572 q->p_oppid)); 573 q->p_oppid = q->p_reaper->p_pid; 574 575 /* 576 * If we are the real parent of this process 577 * but it has been reparented to a debugger, then 578 * check if it asked for a signal when we exit. 579 */ 580 if (q->p_pdeathsig > 0) 581 kern_psignal(q, q->p_pdeathsig); 582 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 583 q->p_pid); 584 proc_clear_orphan(q); 585 PROC_UNLOCK(q); 586 } 587 588 #ifdef KDTRACE_HOOKS 589 if (SDT_PROBES_ENABLED()) { 590 int reason = CLD_EXITED; 591 if (WCOREDUMP(signo)) 592 reason = CLD_DUMPED; 593 else if (WIFSIGNALED(signo)) 594 reason = CLD_KILLED; 595 SDT_PROBE1(proc, , , exit, reason); 596 } 597 #endif 598 599 /* Save exit status. */ 600 PROC_LOCK(p); 601 p->p_xthread = td; 602 603 if (p->p_sysent->sv_ontdexit != NULL) 604 p->p_sysent->sv_ontdexit(td); 605 606 #ifdef KDTRACE_HOOKS 607 /* 608 * Tell the DTrace fasttrap provider about the exit if it 609 * has declared an interest. 610 */ 611 if (dtrace_fasttrap_exit) 612 dtrace_fasttrap_exit(p); 613 #endif 614 615 /* 616 * Notify interested parties of our demise. 617 */ 618 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 619 620 /* 621 * If this is a process with a descriptor, we may not need to deliver 622 * a signal to the parent. proctree_lock is held over 623 * procdesc_exit() to serialize concurrent calls to close() and 624 * exit(). 625 */ 626 signal_parent = 0; 627 if (p->p_procdesc == NULL || procdesc_exit(p)) { 628 /* 629 * Notify parent that we're gone. If parent has the 630 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 631 * notify process 1 instead (and hope it will handle this 632 * situation). 633 */ 634 PROC_LOCK(p->p_pptr); 635 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 636 if (p->p_pptr->p_sigacts->ps_flag & 637 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 638 struct proc *pp; 639 640 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 641 pp = p->p_pptr; 642 PROC_UNLOCK(pp); 643 proc_reparent(p, p->p_reaper, true); 644 p->p_sigparent = SIGCHLD; 645 PROC_LOCK(p->p_pptr); 646 647 /* 648 * Notify parent, so in case he was wait(2)ing or 649 * executing waitpid(2) with our pid, he will 650 * continue. 651 */ 652 wakeup(pp); 653 } else 654 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 655 656 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 657 signal_parent = 1; 658 } else if (p->p_sigparent != 0) { 659 if (p->p_sigparent == SIGCHLD) { 660 signal_parent = 1; 661 } else { /* LINUX thread */ 662 signal_parent = 2; 663 } 664 } 665 } else 666 PROC_LOCK(p->p_pptr); 667 sx_xunlock(&proctree_lock); 668 669 if (signal_parent == 1) { 670 childproc_exited(p); 671 } else if (signal_parent == 2) { 672 kern_psignal(p->p_pptr, p->p_sigparent); 673 } 674 675 /* Tell the prison that we are gone. */ 676 prison_proc_free(p->p_ucred->cr_prison); 677 678 /* 679 * The state PRS_ZOMBIE prevents other proesses from sending 680 * signal to the process, to avoid memory leak, we free memory 681 * for signal queue at the time when the state is set. 682 */ 683 sigqueue_flush(&p->p_sigqueue); 684 sigqueue_flush(&td->td_sigqueue); 685 686 /* 687 * We have to wait until after acquiring all locks before 688 * changing p_state. We need to avoid all possible context 689 * switches (including ones from blocking on a mutex) while 690 * marked as a zombie. We also have to set the zombie state 691 * before we release the parent process' proc lock to avoid 692 * a lost wakeup. So, we first call wakeup, then we grab the 693 * sched lock, update the state, and release the parent process' 694 * proc lock. 695 */ 696 wakeup(p->p_pptr); 697 cv_broadcast(&p->p_pwait); 698 sched_exit(p->p_pptr, td); 699 PROC_SLOCK(p); 700 p->p_state = PRS_ZOMBIE; 701 PROC_UNLOCK(p->p_pptr); 702 703 /* 704 * Save our children's rusage information in our exit rusage. 705 */ 706 PROC_STATLOCK(p); 707 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 708 PROC_STATUNLOCK(p); 709 710 /* 711 * Make sure the scheduler takes this thread out of its tables etc. 712 * This will also release this thread's reference to the ucred. 713 * Other thread parts to release include pcb bits and such. 714 */ 715 thread_exit(); 716 } 717 718 #ifndef _SYS_SYSPROTO_H_ 719 struct abort2_args { 720 char *why; 721 int nargs; 722 void **args; 723 }; 724 #endif 725 726 int 727 sys_abort2(struct thread *td, struct abort2_args *uap) 728 { 729 struct proc *p = td->td_proc; 730 struct sbuf *sb; 731 void *uargs[16]; 732 int error, i, sig; 733 734 /* 735 * Do it right now so we can log either proper call of abort2(), or 736 * note, that invalid argument was passed. 512 is big enough to 737 * handle 16 arguments' descriptions with additional comments. 738 */ 739 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 740 sbuf_clear(sb); 741 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 742 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 743 /* 744 * Since we can't return from abort2(), send SIGKILL in cases, where 745 * abort2() was called improperly 746 */ 747 sig = SIGKILL; 748 /* Prevent from DoSes from user-space. */ 749 if (uap->nargs < 0 || uap->nargs > 16) 750 goto out; 751 if (uap->nargs > 0) { 752 if (uap->args == NULL) 753 goto out; 754 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 755 if (error != 0) 756 goto out; 757 } 758 /* 759 * Limit size of 'reason' string to 128. Will fit even when 760 * maximal number of arguments was chosen to be logged. 761 */ 762 if (uap->why != NULL) { 763 error = sbuf_copyin(sb, uap->why, 128); 764 if (error < 0) 765 goto out; 766 } else { 767 sbuf_printf(sb, "(null)"); 768 } 769 if (uap->nargs > 0) { 770 sbuf_printf(sb, "("); 771 for (i = 0;i < uap->nargs; i++) 772 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 773 sbuf_printf(sb, ")"); 774 } 775 /* 776 * Final stage: arguments were proper, string has been 777 * successfully copied from userspace, and copying pointers 778 * from user-space succeed. 779 */ 780 sig = SIGABRT; 781 out: 782 if (sig == SIGKILL) { 783 sbuf_trim(sb); 784 sbuf_printf(sb, " (Reason text inaccessible)"); 785 } 786 sbuf_cat(sb, "\n"); 787 sbuf_finish(sb); 788 log(LOG_INFO, "%s", sbuf_data(sb)); 789 sbuf_delete(sb); 790 exit1(td, 0, sig); 791 return (0); 792 } 793 794 #ifdef COMPAT_43 795 /* 796 * The dirty work is handled by kern_wait(). 797 */ 798 int 799 owait(struct thread *td, struct owait_args *uap __unused) 800 { 801 int error, status; 802 803 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 804 if (error == 0) 805 td->td_retval[1] = status; 806 return (error); 807 } 808 #endif /* COMPAT_43 */ 809 810 /* 811 * The dirty work is handled by kern_wait(). 812 */ 813 int 814 sys_wait4(struct thread *td, struct wait4_args *uap) 815 { 816 struct rusage ru, *rup; 817 int error, status; 818 819 if (uap->rusage != NULL) 820 rup = &ru; 821 else 822 rup = NULL; 823 error = kern_wait(td, uap->pid, &status, uap->options, rup); 824 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 825 error = copyout(&status, uap->status, sizeof(status)); 826 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 827 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 828 return (error); 829 } 830 831 int 832 sys_wait6(struct thread *td, struct wait6_args *uap) 833 { 834 struct __wrusage wru, *wrup; 835 siginfo_t si, *sip; 836 idtype_t idtype; 837 id_t id; 838 int error, status; 839 840 idtype = uap->idtype; 841 id = uap->id; 842 843 if (uap->wrusage != NULL) 844 wrup = &wru; 845 else 846 wrup = NULL; 847 848 if (uap->info != NULL) { 849 sip = &si; 850 bzero(sip, sizeof(*sip)); 851 } else 852 sip = NULL; 853 854 /* 855 * We expect all callers of wait6() to know about WEXITED and 856 * WTRAPPED. 857 */ 858 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 859 860 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 861 error = copyout(&status, uap->status, sizeof(status)); 862 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 863 error = copyout(&wru, uap->wrusage, sizeof(wru)); 864 if (uap->info != NULL && error == 0) 865 error = copyout(&si, uap->info, sizeof(si)); 866 return (error); 867 } 868 869 /* 870 * Reap the remains of a zombie process and optionally return status and 871 * rusage. Asserts and will release both the proctree_lock and the process 872 * lock as part of its work. 873 */ 874 void 875 proc_reap(struct thread *td, struct proc *p, int *status, int options) 876 { 877 struct proc *q, *t; 878 879 sx_assert(&proctree_lock, SA_XLOCKED); 880 PROC_LOCK_ASSERT(p, MA_OWNED); 881 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 882 883 mtx_spin_wait_unlocked(&p->p_slock); 884 885 q = td->td_proc; 886 887 if (status) 888 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 889 if (options & WNOWAIT) { 890 /* 891 * Only poll, returning the status. Caller does not wish to 892 * release the proc struct just yet. 893 */ 894 PROC_UNLOCK(p); 895 sx_xunlock(&proctree_lock); 896 return; 897 } 898 899 PROC_LOCK(q); 900 sigqueue_take(p->p_ksi); 901 PROC_UNLOCK(q); 902 903 /* 904 * If we got the child via a ptrace 'attach', we need to give it back 905 * to the old parent. 906 */ 907 if (p->p_oppid != p->p_pptr->p_pid) { 908 PROC_UNLOCK(p); 909 t = proc_realparent(p); 910 PROC_LOCK(t); 911 PROC_LOCK(p); 912 CTR2(KTR_PTRACE, 913 "wait: traced child %d moved back to parent %d", p->p_pid, 914 t->p_pid); 915 proc_reparent(p, t, false); 916 PROC_UNLOCK(p); 917 pksignal(t, SIGCHLD, p->p_ksi); 918 wakeup(t); 919 cv_broadcast(&p->p_pwait); 920 PROC_UNLOCK(t); 921 sx_xunlock(&proctree_lock); 922 return; 923 } 924 PROC_UNLOCK(p); 925 926 /* 927 * Remove other references to this process to ensure we have an 928 * exclusive reference. 929 */ 930 sx_xlock(PIDHASHLOCK(p->p_pid)); 931 LIST_REMOVE(p, p_hash); 932 sx_xunlock(PIDHASHLOCK(p->p_pid)); 933 LIST_REMOVE(p, p_sibling); 934 reaper_abandon_children(p, true); 935 reaper_clear(p); 936 PROC_LOCK(p); 937 proc_clear_orphan(p); 938 PROC_UNLOCK(p); 939 leavepgrp(p); 940 if (p->p_procdesc != NULL) 941 procdesc_reap(p); 942 sx_xunlock(&proctree_lock); 943 944 proc_id_clear(PROC_ID_PID, p->p_pid); 945 946 PROC_LOCK(p); 947 knlist_detach(p->p_klist); 948 p->p_klist = NULL; 949 PROC_UNLOCK(p); 950 951 /* 952 * Removal from allproc list and process group list paired with 953 * PROC_LOCK which was executed during that time should guarantee 954 * nothing can reach this process anymore. As such further locking 955 * is unnecessary. 956 */ 957 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 958 959 PROC_LOCK(q); 960 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 961 PROC_UNLOCK(q); 962 963 /* 964 * Decrement the count of procs running with this uid. 965 */ 966 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 967 968 /* 969 * Destroy resource accounting information associated with the process. 970 */ 971 #ifdef RACCT 972 if (racct_enable) { 973 PROC_LOCK(p); 974 racct_sub(p, RACCT_NPROC, 1); 975 PROC_UNLOCK(p); 976 } 977 #endif 978 racct_proc_exit(p); 979 980 /* 981 * Free credentials, arguments, and sigacts. 982 */ 983 proc_unset_cred(p); 984 pargs_drop(p->p_args); 985 p->p_args = NULL; 986 sigacts_free(p->p_sigacts); 987 p->p_sigacts = NULL; 988 989 /* 990 * Do any thread-system specific cleanups. 991 */ 992 thread_wait(p); 993 994 /* 995 * Give vm and machine-dependent layer a chance to free anything that 996 * cpu_exit couldn't release while still running in process context. 997 */ 998 vm_waitproc(p); 999 #ifdef MAC 1000 mac_proc_destroy(p); 1001 #endif 1002 1003 KASSERT(FIRST_THREAD_IN_PROC(p), 1004 ("proc_reap: no residual thread!")); 1005 uma_zfree(proc_zone, p); 1006 atomic_add_int(&nprocs, -1); 1007 } 1008 1009 static int 1010 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 1011 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 1012 int check_only) 1013 { 1014 struct rusage *rup; 1015 1016 sx_assert(&proctree_lock, SA_XLOCKED); 1017 1018 PROC_LOCK(p); 1019 1020 switch (idtype) { 1021 case P_ALL: 1022 if (p->p_procdesc == NULL || 1023 (p->p_pptr == td->td_proc && 1024 (p->p_flag & P_TRACED) != 0)) { 1025 break; 1026 } 1027 1028 PROC_UNLOCK(p); 1029 return (0); 1030 case P_PID: 1031 if (p->p_pid != (pid_t)id) { 1032 PROC_UNLOCK(p); 1033 return (0); 1034 } 1035 break; 1036 case P_PGID: 1037 if (p->p_pgid != (pid_t)id) { 1038 PROC_UNLOCK(p); 1039 return (0); 1040 } 1041 break; 1042 case P_SID: 1043 if (p->p_session->s_sid != (pid_t)id) { 1044 PROC_UNLOCK(p); 1045 return (0); 1046 } 1047 break; 1048 case P_UID: 1049 if (p->p_ucred->cr_uid != (uid_t)id) { 1050 PROC_UNLOCK(p); 1051 return (0); 1052 } 1053 break; 1054 case P_GID: 1055 if (p->p_ucred->cr_gid != (gid_t)id) { 1056 PROC_UNLOCK(p); 1057 return (0); 1058 } 1059 break; 1060 case P_JAILID: 1061 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1062 PROC_UNLOCK(p); 1063 return (0); 1064 } 1065 break; 1066 /* 1067 * It seems that the thread structures get zeroed out 1068 * at process exit. This makes it impossible to 1069 * support P_SETID, P_CID or P_CPUID. 1070 */ 1071 default: 1072 PROC_UNLOCK(p); 1073 return (0); 1074 } 1075 1076 if (p_canwait(td, p)) { 1077 PROC_UNLOCK(p); 1078 return (0); 1079 } 1080 1081 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1082 PROC_UNLOCK(p); 1083 return (0); 1084 } 1085 1086 /* 1087 * This special case handles a kthread spawned by linux_clone 1088 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1089 * functions need to be able to distinguish between waiting 1090 * on a process and waiting on a thread. It is a thread if 1091 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1092 * signifies we want to wait for threads and not processes. 1093 */ 1094 if ((p->p_sigparent != SIGCHLD) ^ 1095 ((options & WLINUXCLONE) != 0)) { 1096 PROC_UNLOCK(p); 1097 return (0); 1098 } 1099 1100 if (siginfo != NULL) { 1101 bzero(siginfo, sizeof(*siginfo)); 1102 siginfo->si_errno = 0; 1103 1104 /* 1105 * SUSv4 requires that the si_signo value is always 1106 * SIGCHLD. Obey it despite the rfork(2) interface 1107 * allows to request other signal for child exit 1108 * notification. 1109 */ 1110 siginfo->si_signo = SIGCHLD; 1111 1112 /* 1113 * This is still a rough estimate. We will fix the 1114 * cases TRAPPED, STOPPED, and CONTINUED later. 1115 */ 1116 if (WCOREDUMP(p->p_xsig)) { 1117 siginfo->si_code = CLD_DUMPED; 1118 siginfo->si_status = WTERMSIG(p->p_xsig); 1119 } else if (WIFSIGNALED(p->p_xsig)) { 1120 siginfo->si_code = CLD_KILLED; 1121 siginfo->si_status = WTERMSIG(p->p_xsig); 1122 } else { 1123 siginfo->si_code = CLD_EXITED; 1124 siginfo->si_status = p->p_xexit; 1125 } 1126 1127 siginfo->si_pid = p->p_pid; 1128 siginfo->si_uid = p->p_ucred->cr_uid; 1129 1130 /* 1131 * The si_addr field would be useful additional 1132 * detail, but apparently the PC value may be lost 1133 * when we reach this point. bzero() above sets 1134 * siginfo->si_addr to NULL. 1135 */ 1136 } 1137 1138 /* 1139 * There should be no reason to limit resources usage info to 1140 * exited processes only. A snapshot about any resources used 1141 * by a stopped process may be exactly what is needed. 1142 */ 1143 if (wrusage != NULL) { 1144 rup = &wrusage->wru_self; 1145 *rup = p->p_ru; 1146 PROC_STATLOCK(p); 1147 calcru(p, &rup->ru_utime, &rup->ru_stime); 1148 PROC_STATUNLOCK(p); 1149 1150 rup = &wrusage->wru_children; 1151 *rup = p->p_stats->p_cru; 1152 calccru(p, &rup->ru_utime, &rup->ru_stime); 1153 } 1154 1155 if (p->p_state == PRS_ZOMBIE && !check_only) { 1156 proc_reap(td, p, status, options); 1157 return (-1); 1158 } 1159 return (1); 1160 } 1161 1162 int 1163 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1164 struct rusage *rusage) 1165 { 1166 struct __wrusage wru, *wrup; 1167 idtype_t idtype; 1168 id_t id; 1169 int ret; 1170 1171 /* 1172 * Translate the special pid values into the (idtype, pid) 1173 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1174 * kern_wait6() on its own. 1175 */ 1176 if (pid == WAIT_ANY) { 1177 idtype = P_ALL; 1178 id = 0; 1179 } else if (pid < 0) { 1180 idtype = P_PGID; 1181 id = (id_t)-pid; 1182 } else { 1183 idtype = P_PID; 1184 id = (id_t)pid; 1185 } 1186 1187 if (rusage != NULL) 1188 wrup = &wru; 1189 else 1190 wrup = NULL; 1191 1192 /* 1193 * For backward compatibility we implicitly add flags WEXITED 1194 * and WTRAPPED here. 1195 */ 1196 options |= WEXITED | WTRAPPED; 1197 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1198 if (rusage != NULL) 1199 *rusage = wru.wru_self; 1200 return (ret); 1201 } 1202 1203 static void 1204 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1205 int *status, int options, int si_code) 1206 { 1207 bool cont; 1208 1209 PROC_LOCK_ASSERT(p, MA_OWNED); 1210 sx_assert(&proctree_lock, SA_XLOCKED); 1211 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1212 si_code == CLD_CONTINUED); 1213 1214 cont = si_code == CLD_CONTINUED; 1215 if ((options & WNOWAIT) == 0) { 1216 if (cont) 1217 p->p_flag &= ~P_CONTINUED; 1218 else 1219 p->p_flag |= P_WAITED; 1220 if (kern_wait_dequeue_sigchld && 1221 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) { 1222 PROC_LOCK(td->td_proc); 1223 sigqueue_take(p->p_ksi); 1224 PROC_UNLOCK(td->td_proc); 1225 } 1226 } 1227 sx_xunlock(&proctree_lock); 1228 if (siginfo != NULL) { 1229 siginfo->si_code = si_code; 1230 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1231 } 1232 if (status != NULL) 1233 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1234 PROC_UNLOCK(p); 1235 td->td_retval[0] = p->p_pid; 1236 } 1237 1238 int 1239 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1240 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1241 { 1242 struct proc *p, *q; 1243 pid_t pid; 1244 int error, nfound, ret; 1245 bool report; 1246 1247 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1248 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1249 AUDIT_ARG_VALUE(options); 1250 1251 q = td->td_proc; 1252 1253 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1254 PROC_LOCK(q); 1255 id = (id_t)q->p_pgid; 1256 PROC_UNLOCK(q); 1257 idtype = P_PGID; 1258 } 1259 1260 /* If we don't know the option, just return. */ 1261 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1262 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1263 return (EINVAL); 1264 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1265 /* 1266 * We will be unable to find any matching processes, 1267 * because there are no known events to look for. 1268 * Prefer to return error instead of blocking 1269 * indefinitely. 1270 */ 1271 return (EINVAL); 1272 } 1273 1274 loop: 1275 if (q->p_flag & P_STATCHILD) { 1276 PROC_LOCK(q); 1277 q->p_flag &= ~P_STATCHILD; 1278 PROC_UNLOCK(q); 1279 } 1280 sx_xlock(&proctree_lock); 1281 loop_locked: 1282 nfound = 0; 1283 LIST_FOREACH(p, &q->p_children, p_sibling) { 1284 pid = p->p_pid; 1285 ret = proc_to_reap(td, p, idtype, id, status, options, 1286 wrusage, siginfo, 0); 1287 if (ret == 0) 1288 continue; 1289 else if (ret != 1) { 1290 td->td_retval[0] = pid; 1291 return (0); 1292 } 1293 1294 nfound++; 1295 PROC_LOCK_ASSERT(p, MA_OWNED); 1296 1297 if ((options & WTRAPPED) != 0 && 1298 (p->p_flag & P_TRACED) != 0) { 1299 PROC_SLOCK(p); 1300 report = 1301 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1302 p->p_suspcount == p->p_numthreads && 1303 (p->p_flag & P_WAITED) == 0); 1304 PROC_SUNLOCK(p); 1305 if (report) { 1306 CTR4(KTR_PTRACE, 1307 "wait: returning trapped pid %d status %#x " 1308 "(xstat %d) xthread %d", 1309 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1310 p->p_xthread != NULL ? 1311 p->p_xthread->td_tid : -1); 1312 report_alive_proc(td, p, siginfo, status, 1313 options, CLD_TRAPPED); 1314 return (0); 1315 } 1316 } 1317 if ((options & WUNTRACED) != 0 && 1318 (p->p_flag & P_STOPPED_SIG) != 0) { 1319 PROC_SLOCK(p); 1320 report = (p->p_suspcount == p->p_numthreads && 1321 ((p->p_flag & P_WAITED) == 0)); 1322 PROC_SUNLOCK(p); 1323 if (report) { 1324 report_alive_proc(td, p, siginfo, status, 1325 options, CLD_STOPPED); 1326 return (0); 1327 } 1328 } 1329 if ((options & WCONTINUED) != 0 && 1330 (p->p_flag & P_CONTINUED) != 0) { 1331 report_alive_proc(td, p, siginfo, status, options, 1332 CLD_CONTINUED); 1333 return (0); 1334 } 1335 PROC_UNLOCK(p); 1336 } 1337 1338 /* 1339 * Look in the orphans list too, to allow the parent to 1340 * collect it's child exit status even if child is being 1341 * debugged. 1342 * 1343 * Debugger detaches from the parent upon successful 1344 * switch-over from parent to child. At this point due to 1345 * re-parenting the parent loses the child to debugger and a 1346 * wait4(2) call would report that it has no children to wait 1347 * for. By maintaining a list of orphans we allow the parent 1348 * to successfully wait until the child becomes a zombie. 1349 */ 1350 if (nfound == 0) { 1351 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1352 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1353 NULL, NULL, 1); 1354 if (ret != 0) { 1355 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1356 (int)td->td_retval[0])); 1357 PROC_UNLOCK(p); 1358 nfound++; 1359 break; 1360 } 1361 } 1362 } 1363 if (nfound == 0) { 1364 sx_xunlock(&proctree_lock); 1365 return (ECHILD); 1366 } 1367 if (options & WNOHANG) { 1368 sx_xunlock(&proctree_lock); 1369 td->td_retval[0] = 0; 1370 return (0); 1371 } 1372 PROC_LOCK(q); 1373 if (q->p_flag & P_STATCHILD) { 1374 q->p_flag &= ~P_STATCHILD; 1375 PROC_UNLOCK(q); 1376 goto loop_locked; 1377 } 1378 sx_xunlock(&proctree_lock); 1379 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1380 if (error) 1381 return (error); 1382 goto loop; 1383 } 1384 1385 void 1386 proc_add_orphan(struct proc *child, struct proc *parent) 1387 { 1388 1389 sx_assert(&proctree_lock, SX_XLOCKED); 1390 KASSERT((child->p_flag & P_TRACED) != 0, 1391 ("proc_add_orphan: not traced")); 1392 1393 if (LIST_EMPTY(&parent->p_orphans)) { 1394 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1395 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1396 } else { 1397 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1398 child, p_orphan); 1399 } 1400 child->p_treeflag |= P_TREE_ORPHANED; 1401 } 1402 1403 /* 1404 * Make process 'parent' the new parent of process 'child'. 1405 * Must be called with an exclusive hold of proctree lock. 1406 */ 1407 void 1408 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1409 { 1410 1411 sx_assert(&proctree_lock, SX_XLOCKED); 1412 PROC_LOCK_ASSERT(child, MA_OWNED); 1413 if (child->p_pptr == parent) 1414 return; 1415 1416 PROC_LOCK(child->p_pptr); 1417 sigqueue_take(child->p_ksi); 1418 PROC_UNLOCK(child->p_pptr); 1419 LIST_REMOVE(child, p_sibling); 1420 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1421 1422 proc_clear_orphan(child); 1423 if ((child->p_flag & P_TRACED) != 0) { 1424 proc_add_orphan(child, child->p_pptr); 1425 } 1426 1427 child->p_pptr = parent; 1428 if (set_oppid) 1429 child->p_oppid = parent->p_pid; 1430 } 1431