1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 #include "opt_mac.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/eventhandler.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <sys/lock.h> 51 #include <sys/mutex.h> 52 #include <sys/proc.h> 53 #include <sys/pioctl.h> 54 #include <sys/tty.h> 55 #include <sys/wait.h> 56 #include <sys/vmmeter.h> 57 #include <sys/vnode.h> 58 #include <sys/resourcevar.h> 59 #include <sys/signalvar.h> 60 #include <sys/sched.h> 61 #include <sys/sx.h> 62 #include <sys/ptrace.h> 63 #include <sys/acct.h> /* for acct_process() function prototype */ 64 #include <sys/filedesc.h> 65 #include <sys/mac.h> 66 #include <sys/shm.h> 67 #include <sys/sem.h> 68 #ifdef KTRACE 69 #include <sys/ktrace.h> 70 #endif 71 72 #include <vm/vm.h> 73 #include <vm/vm_extern.h> 74 #include <vm/vm_param.h> 75 #include <vm/pmap.h> 76 #include <vm/vm_map.h> 77 #include <vm/vm_page.h> 78 #include <vm/uma.h> 79 #include <sys/user.h> 80 81 /* Required to be non-static for SysVR4 emulator */ 82 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 83 84 /* 85 * exit -- 86 * Death of process. 87 * 88 * MPSAFE 89 */ 90 void 91 sys_exit(struct thread *td, struct sys_exit_args *uap) 92 { 93 94 exit1(td, W_EXITCODE(uap->rval, 0)); 95 /* NOTREACHED */ 96 } 97 98 /* 99 * Exit: deallocate address space and other resources, change proc state 100 * to zombie, and unlink proc from allproc and parent's lists. Save exit 101 * status and rusage for wait(). Check for child processes and orphan them. 102 */ 103 void 104 exit1(struct thread *td, int rv) 105 { 106 struct proc *p, *nq, *q; 107 struct tty *tp; 108 struct vnode *ttyvp; 109 struct vmspace *vm; 110 struct vnode *vtmp; 111 #ifdef KTRACE 112 struct vnode *tracevp; 113 struct ucred *tracecred; 114 #endif 115 struct plimit *plim; 116 117 /* 118 * Drop Giant if caller has it. Eventually we should warn about 119 * being called with Giant held. 120 */ 121 while (mtx_owned(&Giant)) 122 mtx_unlock(&Giant); 123 124 p = td->td_proc; 125 if (p == initproc) { 126 printf("init died (signal %d, exit %d)\n", 127 WTERMSIG(rv), WEXITSTATUS(rv)); 128 panic("Going nowhere without my init!"); 129 } 130 131 /* 132 * MUST abort all other threads before proceeding past here. 133 */ 134 PROC_LOCK(p); 135 if (p->p_flag & P_SA || p->p_numthreads > 1) { 136 /* 137 * First check if some other thread got here before us.. 138 * if so, act apropriatly, (exit or suspend); 139 */ 140 thread_suspend_check(0); 141 142 /* 143 * Kill off the other threads. This requires 144 * Some co-operation from other parts of the kernel 145 * so it may not be instant. 146 * With this state set: 147 * Any thread entering the kernel from userspace will 148 * thread_exit() in trap(). Any thread attempting to 149 * sleep will return immediatly 150 * with EINTR or EWOULDBLOCK, which will hopefully force them 151 * to back out to userland, freeing resources as they go, and 152 * anything attempting to return to userland will thread_exit() 153 * from userret(). thread_exit() will unsuspend us 154 * when the last other thread exits. 155 */ 156 if (thread_single(SINGLE_EXIT)) 157 panic ("Exit: Single threading fouled up"); 158 /* 159 * All other activity in this process is now stopped. 160 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them) 161 * ... 162 * Turn off threading support. 163 */ 164 p->p_flag &= ~P_SA; 165 thread_single_end(); /* Don't need this any more. */ 166 } 167 /* 168 * With this state set: 169 * Any thread entering the kernel from userspace will thread_exit() 170 * in trap(). Any thread attempting to sleep will return immediatly 171 * with EINTR or EWOULDBLOCK, which will hopefully force them 172 * to back out to userland, freeing resources as they go, and 173 * anything attempting to return to userland will thread_exit() 174 * from userret(). thread_exit() will do a wakeup on p->p_numthreads 175 * if it transitions to 1. 176 */ 177 178 p->p_flag |= P_WEXIT; 179 PROC_UNLOCK(p); 180 181 /* Are we a task leader? */ 182 if (p == p->p_leader) { 183 mtx_lock(&ppeers_lock); 184 q = p->p_peers; 185 while (q != NULL) { 186 PROC_LOCK(q); 187 psignal(q, SIGKILL); 188 PROC_UNLOCK(q); 189 q = q->p_peers; 190 } 191 while (p->p_peers != NULL) 192 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 193 mtx_unlock(&ppeers_lock); 194 } 195 196 #ifdef PGINPROF 197 mtx_lock(&Giant); 198 vmsizmon(); 199 mtx_unlock(&Giant); 200 #endif 201 PROC_LOCK(p); 202 _STOPEVENT(p, S_EXIT, rv); 203 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 204 PROC_UNLOCK(p); 205 206 /* 207 * Check if any loadable modules need anything done at process exit. 208 * e.g. SYSV IPC stuff 209 * XXX what if one of these generates an error? 210 */ 211 EVENTHANDLER_INVOKE(process_exit, p); 212 213 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 214 M_ZOMBIE, M_WAITOK); 215 /* 216 * If parent is waiting for us to exit or exec, 217 * P_PPWAIT is set; we will wakeup the parent below. 218 */ 219 PROC_LOCK(p); 220 stopprofclock(p); 221 p->p_flag &= ~(P_TRACED | P_PPWAIT); 222 SIGEMPTYSET(p->p_siglist); 223 SIGEMPTYSET(td->td_siglist); 224 225 /* 226 * Stop the real interval timer. If the handler is currently 227 * executing, prevent it from rearming itself and let it finish. 228 */ 229 if (timevalisset(&p->p_realtimer.it_value) && 230 callout_stop(&p->p_itcallout) == 0) { 231 timevalclear(&p->p_realtimer.it_interval); 232 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 233 KASSERT(!timevalisset(&p->p_realtimer.it_value), 234 ("realtime timer is still armed")); 235 } 236 PROC_UNLOCK(p); 237 238 /* 239 * Reset any sigio structures pointing to us as a result of 240 * F_SETOWN with our pid. 241 */ 242 mtx_lock(&Giant); /* XXX: not sure if needed */ 243 funsetownlst(&p->p_sigiolst); 244 245 /* 246 * Close open files and release open-file table. 247 * This may block! 248 */ 249 fdfree(td); 250 mtx_unlock(&Giant); 251 252 /* 253 * Remove ourself from our leader's peer list and wake our leader. 254 */ 255 mtx_lock(&ppeers_lock); 256 if (p->p_leader->p_peers) { 257 q = p->p_leader; 258 while (q->p_peers != p) 259 q = q->p_peers; 260 q->p_peers = p->p_peers; 261 wakeup(p->p_leader); 262 } 263 mtx_unlock(&ppeers_lock); 264 265 mtx_lock(&Giant); 266 /* The next two chunks should probably be moved to vmspace_exit. */ 267 vm = p->p_vmspace; 268 /* 269 * Release user portion of address space. 270 * This releases references to vnodes, 271 * which could cause I/O if the file has been unlinked. 272 * Need to do this early enough that we can still sleep. 273 * Can't free the entire vmspace as the kernel stack 274 * may be mapped within that space also. 275 * 276 * Processes sharing the same vmspace may exit in one order, and 277 * get cleaned up by vmspace_exit() in a different order. The 278 * last exiting process to reach this point releases as much of 279 * the environment as it can, and the last process cleaned up 280 * by vmspace_exit() (which decrements exitingcnt) cleans up the 281 * remainder. 282 */ 283 ++vm->vm_exitingcnt; 284 if (--vm->vm_refcnt == 0) { 285 shmexit(vm); 286 vm_page_lock_queues(); 287 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 288 vm_map_max(&vm->vm_map)); 289 vm_page_unlock_queues(); 290 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 291 vm_map_max(&vm->vm_map)); 292 } 293 294 sx_xlock(&proctree_lock); 295 if (SESS_LEADER(p)) { 296 struct session *sp; 297 298 sp = p->p_session; 299 if (sp->s_ttyvp) { 300 /* 301 * Controlling process. 302 * Signal foreground pgrp, 303 * drain controlling terminal 304 * and revoke access to controlling terminal. 305 */ 306 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 307 tp = sp->s_ttyp; 308 if (sp->s_ttyp->t_pgrp) { 309 PGRP_LOCK(sp->s_ttyp->t_pgrp); 310 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 311 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 312 } 313 /* XXX tp should be locked. */ 314 sx_xunlock(&proctree_lock); 315 (void) ttywait(tp); 316 sx_xlock(&proctree_lock); 317 /* 318 * The tty could have been revoked 319 * if we blocked. 320 */ 321 if (sp->s_ttyvp) { 322 ttyvp = sp->s_ttyvp; 323 SESS_LOCK(p->p_session); 324 sp->s_ttyvp = NULL; 325 SESS_UNLOCK(p->p_session); 326 sx_xunlock(&proctree_lock); 327 VOP_REVOKE(ttyvp, REVOKEALL); 328 vrele(ttyvp); 329 sx_xlock(&proctree_lock); 330 } 331 } 332 if (sp->s_ttyvp) { 333 ttyvp = sp->s_ttyvp; 334 SESS_LOCK(p->p_session); 335 sp->s_ttyvp = NULL; 336 SESS_UNLOCK(p->p_session); 337 vrele(ttyvp); 338 } 339 /* 340 * s_ttyp is not zero'd; we use this to indicate 341 * that the session once had a controlling terminal. 342 * (for logging and informational purposes) 343 */ 344 } 345 SESS_LOCK(p->p_session); 346 sp->s_leader = NULL; 347 SESS_UNLOCK(p->p_session); 348 } 349 fixjobc(p, p->p_pgrp, 0); 350 sx_xunlock(&proctree_lock); 351 (void)acct_process(td); 352 mtx_unlock(&Giant); 353 #ifdef KTRACE 354 /* 355 * release trace file 356 */ 357 PROC_LOCK(p); 358 mtx_lock(&ktrace_mtx); 359 p->p_traceflag = 0; /* don't trace the vrele() */ 360 tracevp = p->p_tracevp; 361 p->p_tracevp = NULL; 362 tracecred = p->p_tracecred; 363 p->p_tracecred = NULL; 364 mtx_unlock(&ktrace_mtx); 365 PROC_UNLOCK(p); 366 if (tracevp != NULL) { 367 mtx_lock(&Giant); 368 vrele(tracevp); 369 mtx_unlock(&Giant); 370 } 371 if (tracecred != NULL) 372 crfree(tracecred); 373 #endif 374 /* 375 * Release reference to text vnode 376 */ 377 if ((vtmp = p->p_textvp) != NULL) { 378 p->p_textvp = NULL; 379 mtx_lock(&Giant); 380 vrele(vtmp); 381 mtx_unlock(&Giant); 382 } 383 384 /* 385 * Release our limits structure. 386 */ 387 PROC_LOCK(p); 388 plim = p->p_limit; 389 p->p_limit = NULL; 390 PROC_UNLOCK(p); 391 lim_free(plim); 392 393 /* 394 * Release this thread's reference to the ucred. The actual proc 395 * reference will stay around until the proc is harvested by 396 * wait(). At this point the ucred is immutable (no other threads 397 * from this proc are around that can change it) so we leave the 398 * per-thread ucred pointer intact in case it is needed although 399 * in theory nothing should be using it at this point. 400 */ 401 crfree(td->td_ucred); 402 403 /* 404 * Remove proc from allproc queue and pidhash chain. 405 * Place onto zombproc. Unlink from parent's child list. 406 */ 407 sx_xlock(&allproc_lock); 408 LIST_REMOVE(p, p_list); 409 LIST_INSERT_HEAD(&zombproc, p, p_list); 410 LIST_REMOVE(p, p_hash); 411 sx_xunlock(&allproc_lock); 412 413 sx_xlock(&proctree_lock); 414 q = LIST_FIRST(&p->p_children); 415 if (q != NULL) /* only need this if any child is S_ZOMB */ 416 wakeup(initproc); 417 for (; q != NULL; q = nq) { 418 nq = LIST_NEXT(q, p_sibling); 419 PROC_LOCK(q); 420 proc_reparent(q, initproc); 421 q->p_sigparent = SIGCHLD; 422 /* 423 * Traced processes are killed 424 * since their existence means someone is screwing up. 425 */ 426 if (q->p_flag & P_TRACED) { 427 q->p_flag &= ~P_TRACED; 428 psignal(q, SIGKILL); 429 } 430 PROC_UNLOCK(q); 431 } 432 433 /* 434 * Save exit status and final rusage info, adding in child rusage 435 * info and self times. 436 */ 437 mtx_lock(&Giant); 438 PROC_LOCK(p); 439 p->p_xstat = rv; 440 *p->p_ru = p->p_stats->p_ru; 441 mtx_lock_spin(&sched_lock); 442 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 443 mtx_unlock_spin(&sched_lock); 444 ruadd(p->p_ru, &p->p_stats->p_cru); 445 446 /* 447 * Notify interested parties of our demise. 448 */ 449 KNOTE(&p->p_klist, NOTE_EXIT); 450 mtx_unlock(&Giant); 451 /* 452 * Just delete all entries in the p_klist. At this point we won't 453 * report any more events, and there are nasty race conditions that 454 * can beat us if we don't. 455 */ 456 while (SLIST_FIRST(&p->p_klist)) 457 SLIST_REMOVE_HEAD(&p->p_klist, kn_selnext); 458 459 /* 460 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 461 * flag set, or if the handler is set to SIG_IGN, notify process 462 * 1 instead (and hope it will handle this situation). 463 */ 464 PROC_LOCK(p->p_pptr); 465 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 466 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 467 struct proc *pp; 468 469 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 470 pp = p->p_pptr; 471 PROC_UNLOCK(pp); 472 proc_reparent(p, initproc); 473 p->p_sigparent = SIGCHLD; 474 PROC_LOCK(p->p_pptr); 475 /* 476 * If this was the last child of our parent, notify 477 * parent, so in case he was wait(2)ing, he will 478 * continue. 479 */ 480 if (LIST_EMPTY(&pp->p_children)) 481 wakeup(pp); 482 } else 483 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 484 485 if (p->p_pptr == initproc) 486 psignal(p->p_pptr, SIGCHLD); 487 else if (p->p_sigparent != 0) 488 psignal(p->p_pptr, p->p_sigparent); 489 PROC_UNLOCK(p->p_pptr); 490 491 /* 492 * If this is a kthread, then wakeup anyone waiting for it to exit. 493 */ 494 if (p->p_flag & P_KTHREAD) 495 wakeup(p); 496 PROC_UNLOCK(p); 497 498 /* 499 * Finally, call machine-dependent code to release the remaining 500 * resources including address space. 501 * The address space is released by "vmspace_exitfree(p)" in 502 * vm_waitproc(). 503 */ 504 cpu_exit(td); 505 506 PROC_LOCK(p); 507 PROC_LOCK(p->p_pptr); 508 sx_xunlock(&proctree_lock); 509 510 while (mtx_owned(&Giant)) 511 mtx_unlock(&Giant); 512 513 /* 514 * We have to wait until after acquiring all locks before 515 * changing p_state. We need to avoid any possibly context 516 * switches while marked as a zombie including blocking on 517 * a mutex. 518 */ 519 mtx_lock_spin(&sched_lock); 520 p->p_state = PRS_ZOMBIE; 521 critical_enter(); 522 mtx_unlock_spin(&sched_lock); 523 524 wakeup(p->p_pptr); 525 PROC_UNLOCK(p->p_pptr); 526 527 mtx_lock_spin(&sched_lock); 528 critical_exit(); 529 cnt.v_swtch++; 530 binuptime(PCPU_PTR(switchtime)); 531 PCPU_SET(switchticks, ticks); 532 533 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */ 534 /* 535 * Allow the scheduler to adjust the priority of the 536 * parent when a kseg is exiting. 537 */ 538 if (p->p_pid != 1) 539 sched_exit(p->p_pptr, p); 540 541 /* 542 * Make sure the scheduler takes this thread out of its tables etc. 543 * This will also release this thread's reference to the ucred. 544 * Other thread parts to release include pcb bits and such. 545 */ 546 thread_exit(); 547 } 548 549 #ifdef COMPAT_43 550 /* 551 * MPSAFE. The dirty work is handled by kern_wait(). 552 */ 553 int 554 owait(struct thread *td, struct owait_args *uap __unused) 555 { 556 int error, status; 557 558 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 559 if (error == 0) 560 td->td_retval[1] = status; 561 return (error); 562 } 563 #endif /* COMPAT_43 */ 564 565 /* 566 * MPSAFE. The dirty work is handled by kern_wait(). 567 */ 568 int 569 wait4(struct thread *td, struct wait_args *uap) 570 { 571 struct rusage ru; 572 int error, status; 573 574 error = kern_wait(td, uap->pid, &status, uap->options, &ru); 575 if (uap->status != NULL && error == 0) 576 error = copyout(&status, uap->status, sizeof(status)); 577 if (uap->rusage != NULL && error == 0) 578 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 579 return (error); 580 } 581 582 int 583 kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage) 584 { 585 int nfound; 586 struct proc *p, *q, *t; 587 int error; 588 589 q = td->td_proc; 590 if (pid == 0) { 591 PROC_LOCK(q); 592 pid = -q->p_pgid; 593 PROC_UNLOCK(q); 594 } 595 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 596 return (EINVAL); 597 loop: 598 nfound = 0; 599 sx_xlock(&proctree_lock); 600 LIST_FOREACH(p, &q->p_children, p_sibling) { 601 PROC_LOCK(p); 602 if (pid != WAIT_ANY && 603 p->p_pid != pid && p->p_pgid != -pid) { 604 PROC_UNLOCK(p); 605 continue; 606 } 607 608 /* 609 * This special case handles a kthread spawned by linux_clone 610 * (see linux_misc.c). The linux_wait4 and linux_waitpid 611 * functions need to be able to distinguish between waiting 612 * on a process and waiting on a thread. It is a thread if 613 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 614 * signifies we want to wait for threads and not processes. 615 */ 616 if ((p->p_sigparent != SIGCHLD) ^ 617 ((options & WLINUXCLONE) != 0)) { 618 PROC_UNLOCK(p); 619 continue; 620 } 621 622 nfound++; 623 if (p->p_state == PRS_ZOMBIE) { 624 td->td_retval[0] = p->p_pid; 625 if (status) 626 *status = p->p_xstat; /* convert to int */ 627 if (rusage) 628 bcopy(p->p_ru, rusage, sizeof(struct rusage)); 629 630 /* 631 * If we got the child via a ptrace 'attach', 632 * we need to give it back to the old parent. 633 */ 634 PROC_UNLOCK(p); 635 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 636 PROC_LOCK(p); 637 p->p_oppid = 0; 638 proc_reparent(p, t); 639 PROC_UNLOCK(p); 640 psignal(t, SIGCHLD); 641 wakeup(t); 642 PROC_UNLOCK(t); 643 sx_xunlock(&proctree_lock); 644 return (0); 645 } 646 647 /* 648 * Remove other references to this process to ensure 649 * we have an exclusive reference. 650 */ 651 sx_xlock(&allproc_lock); 652 LIST_REMOVE(p, p_list); /* off zombproc */ 653 sx_xunlock(&allproc_lock); 654 LIST_REMOVE(p, p_sibling); 655 leavepgrp(p); 656 sx_xunlock(&proctree_lock); 657 658 /* 659 * As a side effect of this lock, we know that 660 * all other writes to this proc are visible now, so 661 * no more locking is needed for p. 662 */ 663 mtx_lock(&Giant); 664 PROC_LOCK(p); 665 p->p_xstat = 0; /* XXX: why? */ 666 PROC_UNLOCK(p); 667 PROC_LOCK(q); 668 ruadd(&q->p_stats->p_cru, p->p_ru); 669 PROC_UNLOCK(q); 670 FREE(p->p_ru, M_ZOMBIE); 671 p->p_ru = NULL; 672 mtx_unlock(&Giant); 673 674 /* 675 * Decrement the count of procs running with this uid. 676 */ 677 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 678 679 /* 680 * Free credentials, arguments, and sigacts 681 */ 682 crfree(p->p_ucred); 683 p->p_ucred = NULL; 684 pargs_drop(p->p_args); 685 p->p_args = NULL; 686 sigacts_free(p->p_sigacts); 687 p->p_sigacts = NULL; 688 689 /* 690 * do any thread-system specific cleanups 691 */ 692 thread_wait(p); 693 694 /* 695 * Give vm and machine-dependent layer a chance 696 * to free anything that cpu_exit couldn't 697 * release while still running in process context. 698 */ 699 mtx_lock(&Giant); 700 vm_waitproc(p); 701 mtx_unlock(&Giant); 702 #ifdef MAC 703 mac_destroy_proc(p); 704 #endif 705 KASSERT(FIRST_THREAD_IN_PROC(p), 706 ("kern_wait: no residual thread!")); 707 uma_zfree(proc_zone, p); 708 sx_xlock(&allproc_lock); 709 nprocs--; 710 sx_xunlock(&allproc_lock); 711 return (0); 712 } 713 mtx_lock_spin(&sched_lock); 714 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) && 715 ((p->p_flag & P_WAITED) == 0) && 716 (p->p_flag & P_TRACED || options & WUNTRACED)) { 717 mtx_unlock_spin(&sched_lock); 718 p->p_flag |= P_WAITED; 719 sx_xunlock(&proctree_lock); 720 td->td_retval[0] = p->p_pid; 721 if (status) 722 *status = W_STOPCODE(p->p_xstat); 723 PROC_UNLOCK(p); 724 return (0); 725 } 726 mtx_unlock_spin(&sched_lock); 727 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 728 sx_xunlock(&proctree_lock); 729 td->td_retval[0] = p->p_pid; 730 p->p_flag &= ~P_CONTINUED; 731 PROC_UNLOCK(p); 732 733 if (status) 734 *status = SIGCONT; 735 return (0); 736 } 737 PROC_UNLOCK(p); 738 } 739 if (nfound == 0) { 740 sx_xunlock(&proctree_lock); 741 return (ECHILD); 742 } 743 if (options & WNOHANG) { 744 sx_xunlock(&proctree_lock); 745 td->td_retval[0] = 0; 746 return (0); 747 } 748 PROC_LOCK(q); 749 sx_xunlock(&proctree_lock); 750 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 751 PROC_UNLOCK(q); 752 if (error) 753 return (error); 754 goto loop; 755 } 756 757 /* 758 * Make process 'parent' the new parent of process 'child'. 759 * Must be called with an exclusive hold of proctree lock. 760 */ 761 void 762 proc_reparent(struct proc *child, struct proc *parent) 763 { 764 765 sx_assert(&proctree_lock, SX_XLOCKED); 766 PROC_LOCK_ASSERT(child, MA_OWNED); 767 if (child->p_pptr == parent) 768 return; 769 770 LIST_REMOVE(child, p_sibling); 771 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 772 child->p_pptr = parent; 773 } 774