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 TSPROCEXIT(td->td_proc->p_pid); 232 233 p = td->td_proc; 234 /* 235 * XXX in case we're rebooting we just let init die in order to 236 * work around an unsolved stack overflow seen very late during 237 * shutdown on sparc64 when the gmirror worker process exists. 238 * XXX what to do now that sparc64 is gone... remove if? 239 */ 240 if (p == initproc && rebooting == 0) { 241 printf("init died (signal %d, exit %d)\n", signo, rval); 242 panic("Going nowhere without my init!"); 243 } 244 245 /* 246 * Deref SU mp, since the thread does not return to userspace. 247 */ 248 td_softdep_cleanup(td); 249 250 /* 251 * MUST abort all other threads before proceeding past here. 252 */ 253 PROC_LOCK(p); 254 /* 255 * First check if some other thread or external request got 256 * here before us. If so, act appropriately: exit or suspend. 257 * We must ensure that stop requests are handled before we set 258 * P_WEXIT. 259 */ 260 thread_suspend_check(0); 261 while (p->p_flag & P_HADTHREADS) { 262 /* 263 * Kill off the other threads. This requires 264 * some co-operation from other parts of the kernel 265 * so it may not be instantaneous. With this state set 266 * any thread entering the kernel from userspace will 267 * thread_exit() in trap(). Any thread attempting to 268 * sleep will return immediately with EINTR or EWOULDBLOCK 269 * which will hopefully force them to back out to userland 270 * freeing resources as they go. Any thread attempting 271 * to return to userland will thread_exit() from userret(). 272 * thread_exit() will unsuspend us when the last of the 273 * other threads exits. 274 * If there is already a thread singler after resumption, 275 * calling thread_single will fail; in that case, we just 276 * re-check all suspension request, the thread should 277 * either be suspended there or exit. 278 */ 279 if (!thread_single(p, SINGLE_EXIT)) 280 /* 281 * All other activity in this process is now 282 * stopped. Threading support has been turned 283 * off. 284 */ 285 break; 286 /* 287 * Recheck for new stop or suspend requests which 288 * might appear while process lock was dropped in 289 * thread_single(). 290 */ 291 thread_suspend_check(0); 292 } 293 KASSERT(p->p_numthreads == 1, 294 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 295 racct_sub(p, RACCT_NTHR, 1); 296 297 /* Let event handler change exit status */ 298 p->p_xexit = rval; 299 p->p_xsig = signo; 300 301 /* 302 * Ignore any pending request to stop due to a stop signal. 303 * Once P_WEXIT is set, future requests will be ignored as 304 * well. 305 */ 306 p->p_flag &= ~P_STOPPED_SIG; 307 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 308 309 /* Note that we are exiting. */ 310 p->p_flag |= P_WEXIT; 311 312 /* 313 * Wait for any processes that have a hold on our vmspace to 314 * release their reference. 315 */ 316 while (p->p_lock > 0) 317 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 318 319 PROC_UNLOCK(p); 320 /* Drain the limit callout while we don't have the proc locked */ 321 callout_drain(&p->p_limco); 322 323 #ifdef AUDIT 324 /* 325 * The Sun BSM exit token contains two components: an exit status as 326 * passed to exit(), and a return value to indicate what sort of exit 327 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 328 * what the return value is. 329 */ 330 AUDIT_ARG_EXIT(rval, 0); 331 AUDIT_SYSCALL_EXIT(0, td); 332 #endif 333 334 /* Are we a task leader with peers? */ 335 if (p->p_peers != NULL && p == p->p_leader) { 336 mtx_lock(&ppeers_lock); 337 q = p->p_peers; 338 while (q != NULL) { 339 PROC_LOCK(q); 340 kern_psignal(q, SIGKILL); 341 PROC_UNLOCK(q); 342 q = q->p_peers; 343 } 344 while (p->p_peers != NULL) 345 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 346 mtx_unlock(&ppeers_lock); 347 } 348 349 itimers_exit(p); 350 351 /* 352 * Check if any loadable modules need anything done at process exit. 353 * E.g. SYSV IPC stuff. 354 * Event handler could change exit status. 355 * XXX what if one of these generates an error? 356 */ 357 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 358 359 /* 360 * If parent is waiting for us to exit or exec, 361 * P_PPWAIT is set; we will wakeup the parent below. 362 */ 363 PROC_LOCK(p); 364 stopprofclock(p); 365 p->p_ptevents = 0; 366 367 /* 368 * Stop the real interval timer. If the handler is currently 369 * executing, prevent it from rearming itself and let it finish. 370 */ 371 if (timevalisset(&p->p_realtimer.it_value) && 372 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 373 timevalclear(&p->p_realtimer.it_interval); 374 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 375 KASSERT(!timevalisset(&p->p_realtimer.it_value), 376 ("realtime timer is still armed")); 377 } 378 379 PROC_UNLOCK(p); 380 381 if (p->p_sysent->sv_onexit != NULL) 382 p->p_sysent->sv_onexit(p); 383 seltdfini(td); 384 385 /* 386 * Reset any sigio structures pointing to us as a result of 387 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown(). 388 */ 389 funsetownlst(&p->p_sigiolst); 390 391 /* 392 * Close open files and release open-file table. 393 * This may block! 394 */ 395 pdescfree(td); 396 fdescfree(td); 397 398 /* 399 * If this thread tickled GEOM, we need to wait for the giggling to 400 * stop before we return to userland 401 */ 402 if (td->td_pflags & TDP_GEOM) 403 g_waitidle(); 404 405 /* 406 * Remove ourself from our leader's peer list and wake our leader. 407 */ 408 if (p->p_leader->p_peers != NULL) { 409 mtx_lock(&ppeers_lock); 410 if (p->p_leader->p_peers != NULL) { 411 q = p->p_leader; 412 while (q->p_peers != p) 413 q = q->p_peers; 414 q->p_peers = p->p_peers; 415 wakeup(p->p_leader); 416 } 417 mtx_unlock(&ppeers_lock); 418 } 419 420 vmspace_exit(td); 421 (void)acct_process(td); 422 423 #ifdef KTRACE 424 ktrprocexit(td); 425 #endif 426 /* 427 * Release reference to text vnode 428 */ 429 if (p->p_textvp != NULL) { 430 vrele(p->p_textvp); 431 p->p_textvp = NULL; 432 } 433 434 /* 435 * Release our limits structure. 436 */ 437 lim_free(p->p_limit); 438 p->p_limit = NULL; 439 440 tidhash_remove(td); 441 442 /* 443 * Call machine-dependent code to release any 444 * machine-dependent resources other than the address space. 445 * The address space is released by "vmspace_exitfree(p)" in 446 * vm_waitproc(). 447 */ 448 cpu_exit(td); 449 450 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 451 452 /* 453 * Remove from allproc. It still sits in the hash. 454 */ 455 sx_xlock(&allproc_lock); 456 LIST_REMOVE(p, p_list); 457 458 #ifdef DDB 459 /* 460 * Used by ddb's 'ps' command to find this process via the 461 * pidhash. 462 */ 463 p->p_list.le_prev = NULL; 464 #endif 465 sx_xunlock(&allproc_lock); 466 467 sx_xlock(&proctree_lock); 468 PROC_LOCK(p); 469 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 470 PROC_UNLOCK(p); 471 472 /* 473 * killjobc() might drop and re-acquire proctree_lock to 474 * revoke control tty if exiting process was a session leader. 475 */ 476 killjobc(); 477 478 /* 479 * Reparent all children processes: 480 * - traced ones to the original parent (or init if we are that parent) 481 * - the rest to init 482 */ 483 q = LIST_FIRST(&p->p_children); 484 if (q != NULL) /* only need this if any child is S_ZOMB */ 485 wakeup(q->p_reaper); 486 for (; q != NULL; q = nq) { 487 nq = LIST_NEXT(q, p_sibling); 488 ksi = ksiginfo_alloc(TRUE); 489 PROC_LOCK(q); 490 q->p_sigparent = SIGCHLD; 491 492 if ((q->p_flag & P_TRACED) == 0) { 493 proc_reparent(q, q->p_reaper, true); 494 if (q->p_state == PRS_ZOMBIE) { 495 /* 496 * Inform reaper about the reparented 497 * zombie, since wait(2) has something 498 * new to report. Guarantee queueing 499 * of the SIGCHLD signal, similar to 500 * the _exit() behaviour, by providing 501 * our ksiginfo. Ksi is freed by the 502 * signal delivery. 503 */ 504 if (q->p_ksi == NULL) { 505 ksi1 = NULL; 506 } else { 507 ksiginfo_copy(q->p_ksi, ksi); 508 ksi->ksi_flags |= KSI_INS; 509 ksi1 = ksi; 510 ksi = NULL; 511 } 512 PROC_LOCK(q->p_reaper); 513 pksignal(q->p_reaper, SIGCHLD, ksi1); 514 PROC_UNLOCK(q->p_reaper); 515 } else if (q->p_pdeathsig > 0) { 516 /* 517 * The child asked to received a signal 518 * when we exit. 519 */ 520 kern_psignal(q, q->p_pdeathsig); 521 } 522 } else { 523 /* 524 * Traced processes are killed by default 525 * since their existence means someone is 526 * screwing up. 527 */ 528 t = proc_realparent(q); 529 if (t == p) { 530 proc_reparent(q, q->p_reaper, true); 531 } else { 532 PROC_LOCK(t); 533 proc_reparent(q, t, true); 534 PROC_UNLOCK(t); 535 } 536 /* 537 * Since q was found on our children list, the 538 * proc_reparent() call moved q to the orphan 539 * list due to present P_TRACED flag. Clear 540 * orphan link for q now while q is locked. 541 */ 542 proc_clear_orphan(q); 543 q->p_flag &= ~P_TRACED; 544 q->p_flag2 &= ~P2_PTRACE_FSTP; 545 q->p_ptevents = 0; 546 p->p_xthread = NULL; 547 FOREACH_THREAD_IN_PROC(q, tdt) { 548 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 549 TDB_FSTP); 550 tdt->td_xsig = 0; 551 } 552 if (kern_kill_on_dbg_exit) { 553 q->p_flag &= ~P_STOPPED_TRACE; 554 kern_psignal(q, SIGKILL); 555 } else if ((q->p_flag & (P_STOPPED_TRACE | 556 P_STOPPED_SIG)) != 0) { 557 sigqueue_delete_proc(q, SIGTRAP); 558 ptrace_unsuspend(q); 559 } 560 } 561 PROC_UNLOCK(q); 562 if (ksi != NULL) 563 ksiginfo_free(ksi); 564 } 565 566 /* 567 * Also get rid of our orphans. 568 */ 569 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 570 PROC_LOCK(q); 571 KASSERT(q->p_oppid == p->p_pid, 572 ("orphan %p of %p has unexpected oppid %d", q, p, 573 q->p_oppid)); 574 q->p_oppid = q->p_reaper->p_pid; 575 576 /* 577 * If we are the real parent of this process 578 * but it has been reparented to a debugger, then 579 * check if it asked for a signal when we exit. 580 */ 581 if (q->p_pdeathsig > 0) 582 kern_psignal(q, q->p_pdeathsig); 583 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 584 q->p_pid); 585 proc_clear_orphan(q); 586 PROC_UNLOCK(q); 587 } 588 589 #ifdef KDTRACE_HOOKS 590 if (SDT_PROBES_ENABLED()) { 591 int reason = CLD_EXITED; 592 if (WCOREDUMP(signo)) 593 reason = CLD_DUMPED; 594 else if (WIFSIGNALED(signo)) 595 reason = CLD_KILLED; 596 SDT_PROBE1(proc, , , exit, reason); 597 } 598 #endif 599 600 /* Save exit status. */ 601 PROC_LOCK(p); 602 p->p_xthread = td; 603 604 if (p->p_sysent->sv_ontdexit != NULL) 605 p->p_sysent->sv_ontdexit(td); 606 607 #ifdef KDTRACE_HOOKS 608 /* 609 * Tell the DTrace fasttrap provider about the exit if it 610 * has declared an interest. 611 */ 612 if (dtrace_fasttrap_exit) 613 dtrace_fasttrap_exit(p); 614 #endif 615 616 /* 617 * Notify interested parties of our demise. 618 */ 619 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 620 621 /* 622 * If this is a process with a descriptor, we may not need to deliver 623 * a signal to the parent. proctree_lock is held over 624 * procdesc_exit() to serialize concurrent calls to close() and 625 * exit(). 626 */ 627 signal_parent = 0; 628 if (p->p_procdesc == NULL || procdesc_exit(p)) { 629 /* 630 * Notify parent that we're gone. If parent has the 631 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 632 * notify process 1 instead (and hope it will handle this 633 * situation). 634 */ 635 PROC_LOCK(p->p_pptr); 636 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 637 if (p->p_pptr->p_sigacts->ps_flag & 638 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 639 struct proc *pp; 640 641 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 642 pp = p->p_pptr; 643 PROC_UNLOCK(pp); 644 proc_reparent(p, p->p_reaper, true); 645 p->p_sigparent = SIGCHLD; 646 PROC_LOCK(p->p_pptr); 647 648 /* 649 * Notify parent, so in case he was wait(2)ing or 650 * executing waitpid(2) with our pid, he will 651 * continue. 652 */ 653 wakeup(pp); 654 } else 655 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 656 657 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 658 signal_parent = 1; 659 } else if (p->p_sigparent != 0) { 660 if (p->p_sigparent == SIGCHLD) { 661 signal_parent = 1; 662 } else { /* LINUX thread */ 663 signal_parent = 2; 664 } 665 } 666 } else 667 PROC_LOCK(p->p_pptr); 668 sx_xunlock(&proctree_lock); 669 670 if (signal_parent == 1) { 671 childproc_exited(p); 672 } else if (signal_parent == 2) { 673 kern_psignal(p->p_pptr, p->p_sigparent); 674 } 675 676 /* Tell the prison that we are gone. */ 677 prison_proc_free(p->p_ucred->cr_prison); 678 679 /* 680 * The state PRS_ZOMBIE prevents other proesses from sending 681 * signal to the process, to avoid memory leak, we free memory 682 * for signal queue at the time when the state is set. 683 */ 684 sigqueue_flush(&p->p_sigqueue); 685 sigqueue_flush(&td->td_sigqueue); 686 687 /* 688 * We have to wait until after acquiring all locks before 689 * changing p_state. We need to avoid all possible context 690 * switches (including ones from blocking on a mutex) while 691 * marked as a zombie. We also have to set the zombie state 692 * before we release the parent process' proc lock to avoid 693 * a lost wakeup. So, we first call wakeup, then we grab the 694 * sched lock, update the state, and release the parent process' 695 * proc lock. 696 */ 697 wakeup(p->p_pptr); 698 cv_broadcast(&p->p_pwait); 699 sched_exit(p->p_pptr, td); 700 PROC_SLOCK(p); 701 p->p_state = PRS_ZOMBIE; 702 PROC_UNLOCK(p->p_pptr); 703 704 /* 705 * Save our children's rusage information in our exit rusage. 706 */ 707 PROC_STATLOCK(p); 708 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 709 PROC_STATUNLOCK(p); 710 711 /* 712 * Make sure the scheduler takes this thread out of its tables etc. 713 * This will also release this thread's reference to the ucred. 714 * Other thread parts to release include pcb bits and such. 715 */ 716 thread_exit(); 717 } 718 719 #ifndef _SYS_SYSPROTO_H_ 720 struct abort2_args { 721 char *why; 722 int nargs; 723 void **args; 724 }; 725 #endif 726 727 int 728 sys_abort2(struct thread *td, struct abort2_args *uap) 729 { 730 struct proc *p = td->td_proc; 731 struct sbuf *sb; 732 void *uargs[16]; 733 int error, i, sig; 734 735 /* 736 * Do it right now so we can log either proper call of abort2(), or 737 * note, that invalid argument was passed. 512 is big enough to 738 * handle 16 arguments' descriptions with additional comments. 739 */ 740 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 741 sbuf_clear(sb); 742 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 743 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 744 /* 745 * Since we can't return from abort2(), send SIGKILL in cases, where 746 * abort2() was called improperly 747 */ 748 sig = SIGKILL; 749 /* Prevent from DoSes from user-space. */ 750 if (uap->nargs < 0 || uap->nargs > 16) 751 goto out; 752 if (uap->nargs > 0) { 753 if (uap->args == NULL) 754 goto out; 755 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 756 if (error != 0) 757 goto out; 758 } 759 /* 760 * Limit size of 'reason' string to 128. Will fit even when 761 * maximal number of arguments was chosen to be logged. 762 */ 763 if (uap->why != NULL) { 764 error = sbuf_copyin(sb, uap->why, 128); 765 if (error < 0) 766 goto out; 767 } else { 768 sbuf_printf(sb, "(null)"); 769 } 770 if (uap->nargs > 0) { 771 sbuf_printf(sb, "("); 772 for (i = 0;i < uap->nargs; i++) 773 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 774 sbuf_printf(sb, ")"); 775 } 776 /* 777 * Final stage: arguments were proper, string has been 778 * successfully copied from userspace, and copying pointers 779 * from user-space succeed. 780 */ 781 sig = SIGABRT; 782 out: 783 if (sig == SIGKILL) { 784 sbuf_trim(sb); 785 sbuf_printf(sb, " (Reason text inaccessible)"); 786 } 787 sbuf_cat(sb, "\n"); 788 sbuf_finish(sb); 789 log(LOG_INFO, "%s", sbuf_data(sb)); 790 sbuf_delete(sb); 791 exit1(td, 0, sig); 792 return (0); 793 } 794 795 #ifdef COMPAT_43 796 /* 797 * The dirty work is handled by kern_wait(). 798 */ 799 int 800 owait(struct thread *td, struct owait_args *uap __unused) 801 { 802 int error, status; 803 804 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 805 if (error == 0) 806 td->td_retval[1] = status; 807 return (error); 808 } 809 #endif /* COMPAT_43 */ 810 811 /* 812 * The dirty work is handled by kern_wait(). 813 */ 814 int 815 sys_wait4(struct thread *td, struct wait4_args *uap) 816 { 817 struct rusage ru, *rup; 818 int error, status; 819 820 if (uap->rusage != NULL) 821 rup = &ru; 822 else 823 rup = NULL; 824 error = kern_wait(td, uap->pid, &status, uap->options, rup); 825 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 826 error = copyout(&status, uap->status, sizeof(status)); 827 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 828 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 829 return (error); 830 } 831 832 int 833 sys_wait6(struct thread *td, struct wait6_args *uap) 834 { 835 struct __wrusage wru, *wrup; 836 siginfo_t si, *sip; 837 idtype_t idtype; 838 id_t id; 839 int error, status; 840 841 idtype = uap->idtype; 842 id = uap->id; 843 844 if (uap->wrusage != NULL) 845 wrup = &wru; 846 else 847 wrup = NULL; 848 849 if (uap->info != NULL) { 850 sip = &si; 851 bzero(sip, sizeof(*sip)); 852 } else 853 sip = NULL; 854 855 /* 856 * We expect all callers of wait6() to know about WEXITED and 857 * WTRAPPED. 858 */ 859 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 860 861 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 862 error = copyout(&status, uap->status, sizeof(status)); 863 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 864 error = copyout(&wru, uap->wrusage, sizeof(wru)); 865 if (uap->info != NULL && error == 0) 866 error = copyout(&si, uap->info, sizeof(si)); 867 return (error); 868 } 869 870 /* 871 * Reap the remains of a zombie process and optionally return status and 872 * rusage. Asserts and will release both the proctree_lock and the process 873 * lock as part of its work. 874 */ 875 void 876 proc_reap(struct thread *td, struct proc *p, int *status, int options) 877 { 878 struct proc *q, *t; 879 880 sx_assert(&proctree_lock, SA_XLOCKED); 881 PROC_LOCK_ASSERT(p, MA_OWNED); 882 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 883 884 mtx_spin_wait_unlocked(&p->p_slock); 885 886 q = td->td_proc; 887 888 if (status) 889 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 890 if (options & WNOWAIT) { 891 /* 892 * Only poll, returning the status. Caller does not wish to 893 * release the proc struct just yet. 894 */ 895 PROC_UNLOCK(p); 896 sx_xunlock(&proctree_lock); 897 return; 898 } 899 900 PROC_LOCK(q); 901 sigqueue_take(p->p_ksi); 902 PROC_UNLOCK(q); 903 904 /* 905 * If we got the child via a ptrace 'attach', we need to give it back 906 * to the old parent. 907 */ 908 if (p->p_oppid != p->p_pptr->p_pid) { 909 PROC_UNLOCK(p); 910 t = proc_realparent(p); 911 PROC_LOCK(t); 912 PROC_LOCK(p); 913 CTR2(KTR_PTRACE, 914 "wait: traced child %d moved back to parent %d", p->p_pid, 915 t->p_pid); 916 proc_reparent(p, t, false); 917 PROC_UNLOCK(p); 918 pksignal(t, SIGCHLD, p->p_ksi); 919 wakeup(t); 920 cv_broadcast(&p->p_pwait); 921 PROC_UNLOCK(t); 922 sx_xunlock(&proctree_lock); 923 return; 924 } 925 PROC_UNLOCK(p); 926 927 /* 928 * Remove other references to this process to ensure we have an 929 * exclusive reference. 930 */ 931 sx_xlock(PIDHASHLOCK(p->p_pid)); 932 LIST_REMOVE(p, p_hash); 933 sx_xunlock(PIDHASHLOCK(p->p_pid)); 934 LIST_REMOVE(p, p_sibling); 935 reaper_abandon_children(p, true); 936 reaper_clear(p); 937 PROC_LOCK(p); 938 proc_clear_orphan(p); 939 PROC_UNLOCK(p); 940 leavepgrp(p); 941 if (p->p_procdesc != NULL) 942 procdesc_reap(p); 943 sx_xunlock(&proctree_lock); 944 945 proc_id_clear(PROC_ID_PID, p->p_pid); 946 947 PROC_LOCK(p); 948 knlist_detach(p->p_klist); 949 p->p_klist = NULL; 950 PROC_UNLOCK(p); 951 952 /* 953 * Removal from allproc list and process group list paired with 954 * PROC_LOCK which was executed during that time should guarantee 955 * nothing can reach this process anymore. As such further locking 956 * is unnecessary. 957 */ 958 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 959 960 PROC_LOCK(q); 961 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 962 PROC_UNLOCK(q); 963 964 /* 965 * Decrement the count of procs running with this uid. 966 */ 967 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 968 969 /* 970 * Destroy resource accounting information associated with the process. 971 */ 972 #ifdef RACCT 973 if (racct_enable) { 974 PROC_LOCK(p); 975 racct_sub(p, RACCT_NPROC, 1); 976 PROC_UNLOCK(p); 977 } 978 #endif 979 racct_proc_exit(p); 980 981 /* 982 * Free credentials, arguments, and sigacts. 983 */ 984 proc_unset_cred(p); 985 pargs_drop(p->p_args); 986 p->p_args = NULL; 987 sigacts_free(p->p_sigacts); 988 p->p_sigacts = NULL; 989 990 /* 991 * Do any thread-system specific cleanups. 992 */ 993 thread_wait(p); 994 995 /* 996 * Give vm and machine-dependent layer a chance to free anything that 997 * cpu_exit couldn't release while still running in process context. 998 */ 999 vm_waitproc(p); 1000 #ifdef MAC 1001 mac_proc_destroy(p); 1002 #endif 1003 1004 KASSERT(FIRST_THREAD_IN_PROC(p), 1005 ("proc_reap: no residual thread!")); 1006 uma_zfree(proc_zone, p); 1007 atomic_add_int(&nprocs, -1); 1008 } 1009 1010 static int 1011 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 1012 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 1013 int check_only) 1014 { 1015 struct rusage *rup; 1016 1017 sx_assert(&proctree_lock, SA_XLOCKED); 1018 1019 PROC_LOCK(p); 1020 1021 switch (idtype) { 1022 case P_ALL: 1023 if (p->p_procdesc == NULL || 1024 (p->p_pptr == td->td_proc && 1025 (p->p_flag & P_TRACED) != 0)) { 1026 break; 1027 } 1028 1029 PROC_UNLOCK(p); 1030 return (0); 1031 case P_PID: 1032 if (p->p_pid != (pid_t)id) { 1033 PROC_UNLOCK(p); 1034 return (0); 1035 } 1036 break; 1037 case P_PGID: 1038 if (p->p_pgid != (pid_t)id) { 1039 PROC_UNLOCK(p); 1040 return (0); 1041 } 1042 break; 1043 case P_SID: 1044 if (p->p_session->s_sid != (pid_t)id) { 1045 PROC_UNLOCK(p); 1046 return (0); 1047 } 1048 break; 1049 case P_UID: 1050 if (p->p_ucred->cr_uid != (uid_t)id) { 1051 PROC_UNLOCK(p); 1052 return (0); 1053 } 1054 break; 1055 case P_GID: 1056 if (p->p_ucred->cr_gid != (gid_t)id) { 1057 PROC_UNLOCK(p); 1058 return (0); 1059 } 1060 break; 1061 case P_JAILID: 1062 if (p->p_ucred->cr_prison->pr_id != (int)id) { 1063 PROC_UNLOCK(p); 1064 return (0); 1065 } 1066 break; 1067 /* 1068 * It seems that the thread structures get zeroed out 1069 * at process exit. This makes it impossible to 1070 * support P_SETID, P_CID or P_CPUID. 1071 */ 1072 default: 1073 PROC_UNLOCK(p); 1074 return (0); 1075 } 1076 1077 if (p_canwait(td, p)) { 1078 PROC_UNLOCK(p); 1079 return (0); 1080 } 1081 1082 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1083 PROC_UNLOCK(p); 1084 return (0); 1085 } 1086 1087 /* 1088 * This special case handles a kthread spawned by linux_clone 1089 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1090 * functions need to be able to distinguish between waiting 1091 * on a process and waiting on a thread. It is a thread if 1092 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1093 * signifies we want to wait for threads and not processes. 1094 */ 1095 if ((p->p_sigparent != SIGCHLD) ^ 1096 ((options & WLINUXCLONE) != 0)) { 1097 PROC_UNLOCK(p); 1098 return (0); 1099 } 1100 1101 if (siginfo != NULL) { 1102 bzero(siginfo, sizeof(*siginfo)); 1103 siginfo->si_errno = 0; 1104 1105 /* 1106 * SUSv4 requires that the si_signo value is always 1107 * SIGCHLD. Obey it despite the rfork(2) interface 1108 * allows to request other signal for child exit 1109 * notification. 1110 */ 1111 siginfo->si_signo = SIGCHLD; 1112 1113 /* 1114 * This is still a rough estimate. We will fix the 1115 * cases TRAPPED, STOPPED, and CONTINUED later. 1116 */ 1117 if (WCOREDUMP(p->p_xsig)) { 1118 siginfo->si_code = CLD_DUMPED; 1119 siginfo->si_status = WTERMSIG(p->p_xsig); 1120 } else if (WIFSIGNALED(p->p_xsig)) { 1121 siginfo->si_code = CLD_KILLED; 1122 siginfo->si_status = WTERMSIG(p->p_xsig); 1123 } else { 1124 siginfo->si_code = CLD_EXITED; 1125 siginfo->si_status = p->p_xexit; 1126 } 1127 1128 siginfo->si_pid = p->p_pid; 1129 siginfo->si_uid = p->p_ucred->cr_uid; 1130 1131 /* 1132 * The si_addr field would be useful additional 1133 * detail, but apparently the PC value may be lost 1134 * when we reach this point. bzero() above sets 1135 * siginfo->si_addr to NULL. 1136 */ 1137 } 1138 1139 /* 1140 * There should be no reason to limit resources usage info to 1141 * exited processes only. A snapshot about any resources used 1142 * by a stopped process may be exactly what is needed. 1143 */ 1144 if (wrusage != NULL) { 1145 rup = &wrusage->wru_self; 1146 *rup = p->p_ru; 1147 PROC_STATLOCK(p); 1148 calcru(p, &rup->ru_utime, &rup->ru_stime); 1149 PROC_STATUNLOCK(p); 1150 1151 rup = &wrusage->wru_children; 1152 *rup = p->p_stats->p_cru; 1153 calccru(p, &rup->ru_utime, &rup->ru_stime); 1154 } 1155 1156 if (p->p_state == PRS_ZOMBIE && !check_only) { 1157 proc_reap(td, p, status, options); 1158 return (-1); 1159 } 1160 return (1); 1161 } 1162 1163 int 1164 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1165 struct rusage *rusage) 1166 { 1167 struct __wrusage wru, *wrup; 1168 idtype_t idtype; 1169 id_t id; 1170 int ret; 1171 1172 /* 1173 * Translate the special pid values into the (idtype, pid) 1174 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1175 * kern_wait6() on its own. 1176 */ 1177 if (pid == WAIT_ANY) { 1178 idtype = P_ALL; 1179 id = 0; 1180 } else if (pid < 0) { 1181 idtype = P_PGID; 1182 id = (id_t)-pid; 1183 } else { 1184 idtype = P_PID; 1185 id = (id_t)pid; 1186 } 1187 1188 if (rusage != NULL) 1189 wrup = &wru; 1190 else 1191 wrup = NULL; 1192 1193 /* 1194 * For backward compatibility we implicitly add flags WEXITED 1195 * and WTRAPPED here. 1196 */ 1197 options |= WEXITED | WTRAPPED; 1198 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1199 if (rusage != NULL) 1200 *rusage = wru.wru_self; 1201 return (ret); 1202 } 1203 1204 static void 1205 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1206 int *status, int options, int si_code) 1207 { 1208 bool cont; 1209 1210 PROC_LOCK_ASSERT(p, MA_OWNED); 1211 sx_assert(&proctree_lock, SA_XLOCKED); 1212 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1213 si_code == CLD_CONTINUED); 1214 1215 cont = si_code == CLD_CONTINUED; 1216 if ((options & WNOWAIT) == 0) { 1217 if (cont) 1218 p->p_flag &= ~P_CONTINUED; 1219 else 1220 p->p_flag |= P_WAITED; 1221 if (kern_wait_dequeue_sigchld && 1222 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) { 1223 PROC_LOCK(td->td_proc); 1224 sigqueue_take(p->p_ksi); 1225 PROC_UNLOCK(td->td_proc); 1226 } 1227 } 1228 sx_xunlock(&proctree_lock); 1229 if (siginfo != NULL) { 1230 siginfo->si_code = si_code; 1231 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1232 } 1233 if (status != NULL) 1234 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1235 PROC_UNLOCK(p); 1236 td->td_retval[0] = p->p_pid; 1237 } 1238 1239 int 1240 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1241 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1242 { 1243 struct proc *p, *q; 1244 pid_t pid; 1245 int error, nfound, ret; 1246 bool report; 1247 1248 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1249 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1250 AUDIT_ARG_VALUE(options); 1251 1252 q = td->td_proc; 1253 1254 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1255 PROC_LOCK(q); 1256 id = (id_t)q->p_pgid; 1257 PROC_UNLOCK(q); 1258 idtype = P_PGID; 1259 } 1260 1261 /* If we don't know the option, just return. */ 1262 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1263 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1264 return (EINVAL); 1265 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1266 /* 1267 * We will be unable to find any matching processes, 1268 * because there are no known events to look for. 1269 * Prefer to return error instead of blocking 1270 * indefinitely. 1271 */ 1272 return (EINVAL); 1273 } 1274 1275 loop: 1276 if (q->p_flag & P_STATCHILD) { 1277 PROC_LOCK(q); 1278 q->p_flag &= ~P_STATCHILD; 1279 PROC_UNLOCK(q); 1280 } 1281 sx_xlock(&proctree_lock); 1282 loop_locked: 1283 nfound = 0; 1284 LIST_FOREACH(p, &q->p_children, p_sibling) { 1285 pid = p->p_pid; 1286 ret = proc_to_reap(td, p, idtype, id, status, options, 1287 wrusage, siginfo, 0); 1288 if (ret == 0) 1289 continue; 1290 else if (ret != 1) { 1291 td->td_retval[0] = pid; 1292 return (0); 1293 } 1294 1295 nfound++; 1296 PROC_LOCK_ASSERT(p, MA_OWNED); 1297 1298 if ((options & WTRAPPED) != 0 && 1299 (p->p_flag & P_TRACED) != 0) { 1300 PROC_SLOCK(p); 1301 report = 1302 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1303 p->p_suspcount == p->p_numthreads && 1304 (p->p_flag & P_WAITED) == 0); 1305 PROC_SUNLOCK(p); 1306 if (report) { 1307 CTR4(KTR_PTRACE, 1308 "wait: returning trapped pid %d status %#x " 1309 "(xstat %d) xthread %d", 1310 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1311 p->p_xthread != NULL ? 1312 p->p_xthread->td_tid : -1); 1313 report_alive_proc(td, p, siginfo, status, 1314 options, CLD_TRAPPED); 1315 return (0); 1316 } 1317 } 1318 if ((options & WUNTRACED) != 0 && 1319 (p->p_flag & P_STOPPED_SIG) != 0) { 1320 PROC_SLOCK(p); 1321 report = (p->p_suspcount == p->p_numthreads && 1322 ((p->p_flag & P_WAITED) == 0)); 1323 PROC_SUNLOCK(p); 1324 if (report) { 1325 report_alive_proc(td, p, siginfo, status, 1326 options, CLD_STOPPED); 1327 return (0); 1328 } 1329 } 1330 if ((options & WCONTINUED) != 0 && 1331 (p->p_flag & P_CONTINUED) != 0) { 1332 report_alive_proc(td, p, siginfo, status, options, 1333 CLD_CONTINUED); 1334 return (0); 1335 } 1336 PROC_UNLOCK(p); 1337 } 1338 1339 /* 1340 * Look in the orphans list too, to allow the parent to 1341 * collect it's child exit status even if child is being 1342 * debugged. 1343 * 1344 * Debugger detaches from the parent upon successful 1345 * switch-over from parent to child. At this point due to 1346 * re-parenting the parent loses the child to debugger and a 1347 * wait4(2) call would report that it has no children to wait 1348 * for. By maintaining a list of orphans we allow the parent 1349 * to successfully wait until the child becomes a zombie. 1350 */ 1351 if (nfound == 0) { 1352 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1353 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1354 NULL, NULL, 1); 1355 if (ret != 0) { 1356 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1357 (int)td->td_retval[0])); 1358 PROC_UNLOCK(p); 1359 nfound++; 1360 break; 1361 } 1362 } 1363 } 1364 if (nfound == 0) { 1365 sx_xunlock(&proctree_lock); 1366 return (ECHILD); 1367 } 1368 if (options & WNOHANG) { 1369 sx_xunlock(&proctree_lock); 1370 td->td_retval[0] = 0; 1371 return (0); 1372 } 1373 PROC_LOCK(q); 1374 if (q->p_flag & P_STATCHILD) { 1375 q->p_flag &= ~P_STATCHILD; 1376 PROC_UNLOCK(q); 1377 goto loop_locked; 1378 } 1379 sx_xunlock(&proctree_lock); 1380 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1381 if (error) 1382 return (error); 1383 goto loop; 1384 } 1385 1386 void 1387 proc_add_orphan(struct proc *child, struct proc *parent) 1388 { 1389 1390 sx_assert(&proctree_lock, SX_XLOCKED); 1391 KASSERT((child->p_flag & P_TRACED) != 0, 1392 ("proc_add_orphan: not traced")); 1393 1394 if (LIST_EMPTY(&parent->p_orphans)) { 1395 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1396 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); 1397 } else { 1398 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), 1399 child, p_orphan); 1400 } 1401 child->p_treeflag |= P_TREE_ORPHANED; 1402 } 1403 1404 /* 1405 * Make process 'parent' the new parent of process 'child'. 1406 * Must be called with an exclusive hold of proctree lock. 1407 */ 1408 void 1409 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) 1410 { 1411 1412 sx_assert(&proctree_lock, SX_XLOCKED); 1413 PROC_LOCK_ASSERT(child, MA_OWNED); 1414 if (child->p_pptr == parent) 1415 return; 1416 1417 PROC_LOCK(child->p_pptr); 1418 sigqueue_take(child->p_ksi); 1419 PROC_UNLOCK(child->p_pptr); 1420 LIST_REMOVE(child, p_sibling); 1421 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1422 1423 proc_clear_orphan(child); 1424 if ((child->p_flag & P_TRACED) != 0) { 1425 proc_add_orphan(child, child->p_pptr); 1426 } 1427 1428 child->p_pptr = parent; 1429 if (set_oppid) 1430 child->p_oppid = parent->p_pid; 1431 } 1432