Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exit.c
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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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 39 * $FreeBSD: releng/5.0/sys/kern/kern_exit.c 108169 2002-12-22 03:30:34Z dillon $ 40 */ 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 #include "opt_mac.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/sysproto.h> 49 #include <sys/kernel.h> 50 #include <sys/malloc.h> 51 #include <sys/lock.h> 52 #include <sys/mutex.h> 53 #include <sys/proc.h> 54 #include <sys/pioctl.h> 55 #include <sys/tty.h> 56 #include <sys/wait.h> 57 #include <sys/vmmeter.h> 58 #include <sys/vnode.h> 59 #include <sys/resourcevar.h> 60 #include <sys/signalvar.h> 61 #include <sys/sched.h> 62 #include <sys/sx.h> 63 #include <sys/ptrace.h> 64 #include <sys/acct.h> /* for acct_process() function prototype */ 65 #include <sys/filedesc.h> 66 #include <sys/mac.h> 67 #include <sys/shm.h> 68 #include <sys/sem.h> 69 #include <sys/jail.h> 70 #ifdef KTRACE 71 #include <sys/ktrace.h> 72 #endif 73 74 #include <vm/vm.h> 75 #include <vm/vm_extern.h> 76 #include <vm/vm_param.h> 77 #include <vm/pmap.h> 78 #include <vm/vm_map.h> 79 #include <vm/vm_page.h> 80 #include <vm/uma.h> 81 #include <sys/user.h> 82 83 /* Required to be non-static for SysVR4 emulator */ 84 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 85 86 static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback"); 87 88 static int wait1(struct thread *, struct wait_args *, int); 89 90 /* 91 * callout list for things to do at exit time 92 */ 93 struct exitlist { 94 exitlist_fn function; 95 TAILQ_ENTRY(exitlist) next; 96 }; 97 98 TAILQ_HEAD(exit_list_head, exitlist); 99 static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list); 100 101 /* 102 * exit -- 103 * Death of process. 104 * 105 * MPSAFE 106 */ 107 void 108 sys_exit(td, uap) 109 struct thread *td; 110 struct sys_exit_args /* { 111 int rval; 112 } */ *uap; 113 { 114 115 mtx_lock(&Giant); 116 exit1(td, W_EXITCODE(uap->rval, 0)); 117 /* NOTREACHED */ 118 } 119 120 /* 121 * Exit: deallocate address space and other resources, change proc state 122 * to zombie, and unlink proc from allproc and parent's lists. Save exit 123 * status and rusage for wait(). Check for child processes and orphan them. 124 */ 125 void 126 exit1(td, rv) 127 register struct thread *td; 128 int rv; 129 { 130 struct exitlist *ep; 131 struct proc *p, *nq, *q; 132 struct tty *tp; 133 struct vnode *ttyvp; 134 register struct vmspace *vm; 135 struct vnode *vtmp; 136 #ifdef KTRACE 137 struct vnode *tracevp; 138 #endif 139 140 GIANT_REQUIRED; 141 142 p = td->td_proc; 143 if (p == initproc) { 144 printf("init died (signal %d, exit %d)\n", 145 WTERMSIG(rv), WEXITSTATUS(rv)); 146 panic("Going nowhere without my init!"); 147 } 148 149 /* 150 * XXXXKSE: MUST abort all other threads before proceeding past here. 151 */ 152 PROC_LOCK(p); 153 if (p->p_flag & P_KSES) { 154 /* 155 * First check if some other thread got here before us.. 156 * if so, act apropriatly, (exit or suspend); 157 */ 158 thread_suspend_check(0); 159 /* 160 * Here is a trick.. 161 * We need to free up our KSE to process other threads 162 * so that we can safely set the UNBOUND flag 163 * (whether or not we have a mailbox) as we are NEVER 164 * going to return to the user. 165 * The flag will not be set yet if we are exiting 166 * because of a signal, pagefault, or similar 167 * (or even an exit(2) from the UTS). 168 */ 169 td->td_flags |= TDF_UNBOUND; 170 171 /* 172 * Kill off the other threads. This requires 173 * Some co-operation from other parts of the kernel 174 * so it may not be instant. 175 * With this state set: 176 * Any thread entering the kernel from userspace will 177 * thread_exit() in trap(). Any thread attempting to 178 * sleep will return immediatly 179 * with EINTR or EWOULDBLOCK, which will hopefully force them 180 * to back out to userland, freeing resources as they go, and 181 * anything attempting to return to userland will thread_exit() 182 * from userret(). thread_exit() will unsuspend us 183 * when the last other thread exits. 184 */ 185 if (thread_single(SINGLE_EXIT)) { 186 panic ("Exit: Single threading fouled up"); 187 } 188 /* 189 * All other activity in this process is now stopped. 190 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them) 191 * ... 192 * Turn off threading support. 193 */ 194 p->p_flag &= ~P_KSES; 195 td->td_flags &= ~TDF_UNBOUND; 196 thread_single_end(); /* Don't need this any more. */ 197 } 198 /* 199 * With this state set: 200 * Any thread entering the kernel from userspace will thread_exit() 201 * in trap(). Any thread attempting to sleep will return immediatly 202 * with EINTR or EWOULDBLOCK, which will hopefully force them 203 * to back out to userland, freeing resources as they go, and 204 * anything attempting to return to userland will thread_exit() 205 * from userret(). thread_exit() will do a wakeup on p->p_numthreads 206 * if it transitions to 1. 207 */ 208 209 p->p_flag |= P_WEXIT; 210 PROC_UNLOCK(p); 211 212 /* Are we a task leader? */ 213 if (p == p->p_leader) { 214 mtx_lock(&ppeers_lock); 215 q = p->p_peers; 216 while (q != NULL) { 217 PROC_LOCK(q); 218 psignal(q, SIGKILL); 219 PROC_UNLOCK(q); 220 q = q->p_peers; 221 } 222 while (p->p_peers != NULL) 223 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 224 mtx_unlock(&ppeers_lock); 225 } 226 227 #ifdef PGINPROF 228 vmsizmon(); 229 #endif 230 STOPEVENT(p, S_EXIT, rv); 231 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 232 233 /* 234 * Check if any loadable modules need anything done at process exit. 235 * e.g. SYSV IPC stuff 236 * XXX what if one of these generates an error? 237 */ 238 TAILQ_FOREACH(ep, &exit_list, next) 239 (*ep->function)(p); 240 241 stopprofclock(p); 242 243 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 244 M_ZOMBIE, M_WAITOK); 245 /* 246 * If parent is waiting for us to exit or exec, 247 * P_PPWAIT is set; we will wakeup the parent below. 248 */ 249 PROC_LOCK(p); 250 p->p_flag &= ~(P_TRACED | P_PPWAIT); 251 SIGEMPTYSET(p->p_siglist); 252 PROC_UNLOCK(p); 253 if (timevalisset(&p->p_realtimer.it_value)) 254 callout_stop(&p->p_itcallout); 255 256 /* 257 * Reset any sigio structures pointing to us as a result of 258 * F_SETOWN with our pid. 259 */ 260 funsetownlst(&p->p_sigiolst); 261 262 /* 263 * Close open files and release open-file table. 264 * This may block! 265 */ 266 fdfree(td); /* XXXKSE *//* may not be the one in proc */ 267 268 /* 269 * Remove ourself from our leader's peer list and wake our leader. 270 */ 271 mtx_lock(&ppeers_lock); 272 if (p->p_leader->p_peers) { 273 q = p->p_leader; 274 while (q->p_peers != p) 275 q = q->p_peers; 276 q->p_peers = p->p_peers; 277 wakeup(p->p_leader); 278 } 279 mtx_unlock(&ppeers_lock); 280 281 /* The next two chunks should probably be moved to vmspace_exit. */ 282 vm = p->p_vmspace; 283 /* 284 * Release user portion of address space. 285 * This releases references to vnodes, 286 * which could cause I/O if the file has been unlinked. 287 * Need to do this early enough that we can still sleep. 288 * Can't free the entire vmspace as the kernel stack 289 * may be mapped within that space also. 290 * 291 * Processes sharing the same vmspace may exit in one order, and 292 * get cleaned up by vmspace_exit() in a different order. The 293 * last exiting process to reach this point releases as much of 294 * the environment as it can, and the last process cleaned up 295 * by vmspace_exit() (which decrements exitingcnt) cleans up the 296 * remainder. 297 */ 298 ++vm->vm_exitingcnt; 299 if (--vm->vm_refcnt == 0) { 300 if (vm->vm_shm) 301 shmexit(p); 302 vm_page_lock_queues(); 303 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 304 vm_map_max(&vm->vm_map)); 305 vm_page_unlock_queues(); 306 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 307 vm_map_max(&vm->vm_map)); 308 } 309 310 sx_xlock(&proctree_lock); 311 if (SESS_LEADER(p)) { 312 register struct session *sp; 313 314 sp = p->p_session; 315 if (sp->s_ttyvp) { 316 /* 317 * Controlling process. 318 * Signal foreground pgrp, 319 * drain controlling terminal 320 * and revoke access to controlling terminal. 321 */ 322 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 323 tp = sp->s_ttyp; 324 if (sp->s_ttyp->t_pgrp) { 325 PGRP_LOCK(sp->s_ttyp->t_pgrp); 326 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 327 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 328 } 329 /* XXX tp should be locked. */ 330 sx_xunlock(&proctree_lock); 331 (void) ttywait(tp); 332 sx_xlock(&proctree_lock); 333 /* 334 * The tty could have been revoked 335 * if we blocked. 336 */ 337 if (sp->s_ttyvp) { 338 ttyvp = sp->s_ttyvp; 339 SESS_LOCK(p->p_session); 340 sp->s_ttyvp = NULL; 341 SESS_UNLOCK(p->p_session); 342 sx_xunlock(&proctree_lock); 343 VOP_REVOKE(ttyvp, REVOKEALL); 344 vrele(ttyvp); 345 sx_xlock(&proctree_lock); 346 } 347 } 348 if (sp->s_ttyvp) { 349 ttyvp = sp->s_ttyvp; 350 SESS_LOCK(p->p_session); 351 sp->s_ttyvp = NULL; 352 SESS_UNLOCK(p->p_session); 353 vrele(ttyvp); 354 } 355 /* 356 * s_ttyp is not zero'd; we use this to indicate 357 * that the session once had a controlling terminal. 358 * (for logging and informational purposes) 359 */ 360 } 361 SESS_LOCK(p->p_session); 362 sp->s_leader = NULL; 363 SESS_UNLOCK(p->p_session); 364 } 365 fixjobc(p, p->p_pgrp, 0); 366 sx_xunlock(&proctree_lock); 367 (void)acct_process(td); 368 #ifdef KTRACE 369 /* 370 * release trace file 371 */ 372 PROC_LOCK(p); 373 mtx_lock(&ktrace_mtx); 374 p->p_traceflag = 0; /* don't trace the vrele() */ 375 tracevp = p->p_tracep; 376 p->p_tracep = NULL; 377 mtx_unlock(&ktrace_mtx); 378 PROC_UNLOCK(p); 379 if (tracevp != NULL) 380 vrele(tracevp); 381 #endif 382 /* 383 * Release reference to text vnode 384 */ 385 if ((vtmp = p->p_textvp) != NULL) { 386 p->p_textvp = NULL; 387 vrele(vtmp); 388 } 389 390 /* 391 * Release our limits structure. 392 */ 393 mtx_assert(&Giant, MA_OWNED); 394 if (--p->p_limit->p_refcnt == 0) { 395 FREE(p->p_limit, M_SUBPROC); 396 p->p_limit = NULL; 397 } 398 399 /* 400 * Release this thread's reference to the ucred. The actual proc 401 * reference will stay around until the proc is harvested by 402 * wait(). At this point the ucred is immutable (no other threads 403 * from this proc are around that can change it) so we leave the 404 * per-thread ucred pointer intact in case it is needed although 405 * in theory nothing should be using it at this point. 406 */ 407 crfree(td->td_ucred); 408 409 /* 410 * Remove proc from allproc queue and pidhash chain. 411 * Place onto zombproc. Unlink from parent's child list. 412 */ 413 sx_xlock(&allproc_lock); 414 LIST_REMOVE(p, p_list); 415 LIST_INSERT_HEAD(&zombproc, p, p_list); 416 LIST_REMOVE(p, p_hash); 417 sx_xunlock(&allproc_lock); 418 419 sx_xlock(&proctree_lock); 420 q = LIST_FIRST(&p->p_children); 421 if (q != NULL) /* only need this if any child is S_ZOMB */ 422 wakeup(initproc); 423 for (; q != NULL; q = nq) { 424 nq = LIST_NEXT(q, p_sibling); 425 PROC_LOCK(q); 426 proc_reparent(q, initproc); 427 q->p_sigparent = SIGCHLD; 428 /* 429 * Traced processes are killed 430 * since their existence means someone is screwing up. 431 */ 432 if (q->p_flag & P_TRACED) { 433 q->p_flag &= ~P_TRACED; 434 psignal(q, SIGKILL); 435 } 436 PROC_UNLOCK(q); 437 } 438 439 /* 440 * Save exit status and final rusage info, adding in child rusage 441 * info and self times. 442 */ 443 PROC_LOCK(p); 444 p->p_xstat = rv; 445 *p->p_ru = p->p_stats->p_ru; 446 mtx_lock_spin(&sched_lock); 447 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 448 mtx_unlock_spin(&sched_lock); 449 ruadd(p->p_ru, &p->p_stats->p_cru); 450 451 /* 452 * Notify interested parties of our demise. 453 */ 454 KNOTE(&p->p_klist, NOTE_EXIT); 455 456 /* 457 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 458 * flag set, or if the handler is set to SIG_IGN, notify process 459 * 1 instead (and hope it will handle this situation). 460 */ 461 PROC_LOCK(p->p_pptr); 462 if (p->p_pptr->p_procsig->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 463 struct proc *pp; 464 465 pp = p->p_pptr; 466 PROC_UNLOCK(pp); 467 proc_reparent(p, initproc); 468 PROC_LOCK(p->p_pptr); 469 /* 470 * If this was the last child of our parent, notify 471 * parent, so in case he was wait(2)ing, he will 472 * continue. 473 */ 474 if (LIST_EMPTY(&pp->p_children)) 475 wakeup(pp); 476 } 477 478 if (p->p_sigparent && p->p_pptr != initproc) 479 psignal(p->p_pptr, p->p_sigparent); 480 else 481 psignal(p->p_pptr, SIGCHLD); 482 PROC_UNLOCK(p->p_pptr); 483 484 /* 485 * If this is a kthread, then wakeup anyone waiting for it to exit. 486 */ 487 if (p->p_flag & P_KTHREAD) 488 wakeup(p); 489 PROC_UNLOCK(p); 490 491 /* 492 * Finally, call machine-dependent code to release the remaining 493 * resources including address space. 494 * The address space is released by "vmspace_exitfree(p)" in 495 * vm_waitproc(). 496 */ 497 cpu_exit(td); 498 499 PROC_LOCK(p); 500 PROC_LOCK(p->p_pptr); 501 sx_xunlock(&proctree_lock); 502 mtx_lock_spin(&sched_lock); 503 504 while (mtx_owned(&Giant)) 505 mtx_unlock(&Giant); 506 507 /* 508 * We have to wait until after releasing all locks before 509 * changing p_state. If we block on a mutex then we will be 510 * back at SRUN when we resume and our parent will never 511 * harvest us. 512 */ 513 p->p_state = PRS_ZOMBIE; 514 515 wakeup(p->p_pptr); 516 PROC_UNLOCK(p->p_pptr); 517 cnt.v_swtch++; 518 binuptime(PCPU_PTR(switchtime)); 519 PCPU_SET(switchticks, ticks); 520 521 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */ 522 /* 523 * Make sure the scheduler takes this thread out of its tables etc. 524 * This will also release this thread's reference to the ucred. 525 * Other thread parts to release include pcb bits and such. 526 */ 527 thread_exit(); 528 } 529 530 #ifdef COMPAT_43 531 /* 532 * MPSAFE. The dirty work is handled by wait1(). 533 */ 534 int 535 owait(td, uap) 536 struct thread *td; 537 register struct owait_args /* { 538 int dummy; 539 } */ *uap; 540 { 541 struct wait_args w; 542 543 w.options = 0; 544 w.rusage = NULL; 545 w.pid = WAIT_ANY; 546 w.status = NULL; 547 return (wait1(td, &w, 1)); 548 } 549 #endif /* COMPAT_43 */ 550 551 /* 552 * MPSAFE. The dirty work is handled by wait1(). 553 */ 554 int 555 wait4(td, uap) 556 struct thread *td; 557 struct wait_args *uap; 558 { 559 560 return (wait1(td, uap, 0)); 561 } 562 563 /* 564 * MPSAFE 565 */ 566 static int 567 wait1(td, uap, compat) 568 register struct thread *td; 569 register struct wait_args /* { 570 int pid; 571 int *status; 572 int options; 573 struct rusage *rusage; 574 } */ *uap; 575 int compat; 576 { 577 struct rusage ru; 578 int nfound; 579 struct proc *p, *q, *t; 580 int status, error; 581 582 q = td->td_proc; 583 if (uap->pid == 0) { 584 PROC_LOCK(q); 585 uap->pid = -q->p_pgid; 586 PROC_UNLOCK(q); 587 } 588 if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 589 return (EINVAL); 590 mtx_lock(&Giant); 591 loop: 592 nfound = 0; 593 sx_xlock(&proctree_lock); 594 LIST_FOREACH(p, &q->p_children, p_sibling) { 595 PROC_LOCK(p); 596 if (uap->pid != WAIT_ANY && 597 p->p_pid != uap->pid && p->p_pgid != -uap->pid) { 598 PROC_UNLOCK(p); 599 continue; 600 } 601 602 /* 603 * This special case handles a kthread spawned by linux_clone 604 * (see linux_misc.c). The linux_wait4 and linux_waitpid 605 * functions need to be able to distinguish between waiting 606 * on a process and waiting on a thread. It is a thread if 607 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 608 * signifies we want to wait for threads and not processes. 609 */ 610 if ((p->p_sigparent != SIGCHLD) ^ 611 ((uap->options & WLINUXCLONE) != 0)) { 612 PROC_UNLOCK(p); 613 continue; 614 } 615 616 nfound++; 617 if (p->p_state == PRS_ZOMBIE) { 618 /* 619 * Allow the scheduler to adjust the priority of the 620 * parent when a kseg is exiting. 621 */ 622 if (curthread->td_proc->p_pid != 1) { 623 mtx_lock_spin(&sched_lock); 624 sched_exit(curthread->td_ksegrp, 625 FIRST_KSEGRP_IN_PROC(p)); 626 mtx_unlock_spin(&sched_lock); 627 } 628 629 td->td_retval[0] = p->p_pid; 630 #ifdef COMPAT_43 631 if (compat) 632 td->td_retval[1] = p->p_xstat; 633 else 634 #endif 635 if (uap->status) { 636 status = p->p_xstat; /* convert to int */ 637 PROC_UNLOCK(p); 638 if ((error = copyout(&status, 639 uap->status, sizeof(status)))) { 640 sx_xunlock(&proctree_lock); 641 mtx_unlock(&Giant); 642 return (error); 643 } 644 PROC_LOCK(p); 645 } 646 if (uap->rusage) { 647 bcopy(p->p_ru, &ru, sizeof(ru)); 648 PROC_UNLOCK(p); 649 if ((error = copyout(&ru, 650 uap->rusage, sizeof (struct rusage)))) { 651 sx_xunlock(&proctree_lock); 652 mtx_unlock(&Giant); 653 return (error); 654 } 655 } else 656 PROC_UNLOCK(p); 657 /* 658 * If we got the child via a ptrace 'attach', 659 * we need to give it back to the old parent. 660 */ 661 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 662 PROC_LOCK(p); 663 p->p_oppid = 0; 664 proc_reparent(p, t); 665 PROC_UNLOCK(p); 666 psignal(t, SIGCHLD); 667 wakeup(t); 668 PROC_UNLOCK(t); 669 sx_xunlock(&proctree_lock); 670 mtx_unlock(&Giant); 671 return (0); 672 } 673 /* 674 * Remove other references to this process to ensure 675 * we have an exclusive reference. 676 */ 677 leavepgrp(p); 678 679 sx_xlock(&allproc_lock); 680 LIST_REMOVE(p, p_list); /* off zombproc */ 681 sx_xunlock(&allproc_lock); 682 683 LIST_REMOVE(p, p_sibling); 684 sx_xunlock(&proctree_lock); 685 686 /* 687 * As a side effect of this lock, we know that 688 * all other writes to this proc are visible now, so 689 * no more locking is needed for p. 690 */ 691 PROC_LOCK(p); 692 p->p_xstat = 0; /* XXX: why? */ 693 PROC_UNLOCK(p); 694 PROC_LOCK(q); 695 ruadd(&q->p_stats->p_cru, p->p_ru); 696 PROC_UNLOCK(q); 697 FREE(p->p_ru, M_ZOMBIE); 698 p->p_ru = NULL; 699 700 /* 701 * Decrement the count of procs running with this uid. 702 */ 703 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 704 705 /* 706 * Free up credentials. 707 */ 708 crfree(p->p_ucred); 709 p->p_ucred = NULL; /* XXX: why? */ 710 711 /* 712 * Remove unused arguments 713 */ 714 pargs_drop(p->p_args); 715 p->p_args = NULL; 716 717 if (--p->p_procsig->ps_refcnt == 0) { 718 if (p->p_sigacts != &p->p_uarea->u_sigacts) 719 FREE(p->p_sigacts, M_SUBPROC); 720 FREE(p->p_procsig, M_SUBPROC); 721 p->p_procsig = NULL; 722 } 723 724 /* 725 * do any thread-system specific cleanups 726 */ 727 thread_wait(p); 728 729 /* 730 * Give vm and machine-dependent layer a chance 731 * to free anything that cpu_exit couldn't 732 * release while still running in process context. 733 */ 734 vm_waitproc(p); 735 mtx_destroy(&p->p_mtx); 736 #ifdef MAC 737 mac_destroy_proc(p); 738 #endif 739 KASSERT(FIRST_THREAD_IN_PROC(p), 740 ("wait1: no residual thread!")); 741 uma_zfree(proc_zone, p); 742 sx_xlock(&allproc_lock); 743 nprocs--; 744 sx_xunlock(&allproc_lock); 745 mtx_unlock(&Giant); 746 return (0); 747 } 748 if (P_SHOULDSTOP(p) && ((p->p_flag & P_WAITED) == 0) && 749 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 750 p->p_flag |= P_WAITED; 751 sx_xunlock(&proctree_lock); 752 td->td_retval[0] = p->p_pid; 753 #ifdef COMPAT_43 754 if (compat) { 755 td->td_retval[1] = W_STOPCODE(p->p_xstat); 756 PROC_UNLOCK(p); 757 error = 0; 758 } else 759 #endif 760 if (uap->status) { 761 status = W_STOPCODE(p->p_xstat); 762 PROC_UNLOCK(p); 763 error = copyout(&status, 764 uap->status, sizeof(status)); 765 } else { 766 PROC_UNLOCK(p); 767 error = 0; 768 } 769 mtx_unlock(&Giant); 770 return (error); 771 } 772 if (uap->options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 773 sx_xunlock(&proctree_lock); 774 td->td_retval[0] = p->p_pid; 775 p->p_flag &= ~P_CONTINUED; 776 PROC_UNLOCK(p); 777 778 if (uap->status) { 779 status = SIGCONT; 780 error = copyout(&status, 781 uap->status, sizeof(status)); 782 } else 783 error = 0; 784 785 mtx_unlock(&Giant); 786 return (error); 787 } 788 PROC_UNLOCK(p); 789 } 790 if (nfound == 0) { 791 sx_xunlock(&proctree_lock); 792 mtx_unlock(&Giant); 793 return (ECHILD); 794 } 795 if (uap->options & WNOHANG) { 796 sx_xunlock(&proctree_lock); 797 td->td_retval[0] = 0; 798 mtx_unlock(&Giant); 799 return (0); 800 } 801 PROC_LOCK(q); 802 sx_xunlock(&proctree_lock); 803 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 804 PROC_UNLOCK(q); 805 if (error) { 806 mtx_unlock(&Giant); 807 return (error); 808 } 809 goto loop; 810 } 811 812 /* 813 * Make process 'parent' the new parent of process 'child'. 814 * Must be called with an exclusive hold of proctree lock. 815 */ 816 void 817 proc_reparent(child, parent) 818 register struct proc *child; 819 register struct proc *parent; 820 { 821 822 sx_assert(&proctree_lock, SX_XLOCKED); 823 PROC_LOCK_ASSERT(child, MA_OWNED); 824 if (child->p_pptr == parent) 825 return; 826 827 LIST_REMOVE(child, p_sibling); 828 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 829 child->p_pptr = parent; 830 } 831 832 /* 833 * The next two functions are to handle adding/deleting items on the 834 * exit callout list 835 * 836 * at_exit(): 837 * Take the arguments given and put them onto the exit callout list, 838 * However first make sure that it's not already there. 839 * returns 0 on success. 840 */ 841 842 int 843 at_exit(function) 844 exitlist_fn function; 845 { 846 struct exitlist *ep; 847 848 #ifdef INVARIANTS 849 /* Be noisy if the programmer has lost track of things */ 850 if (rm_at_exit(function)) 851 printf("WARNING: exit callout entry (%p) already present\n", 852 function); 853 #endif 854 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT); 855 if (ep == NULL) 856 return (ENOMEM); 857 ep->function = function; 858 TAILQ_INSERT_TAIL(&exit_list, ep, next); 859 return (0); 860 } 861 862 /* 863 * Scan the exit callout list for the given item and remove it. 864 * Returns the number of items removed (0 or 1) 865 */ 866 int 867 rm_at_exit(function) 868 exitlist_fn function; 869 { 870 struct exitlist *ep; 871 872 TAILQ_FOREACH(ep, &exit_list, next) { 873 if (ep->function == function) { 874 TAILQ_REMOVE(&exit_list, ep, next); 875 free(ep, M_ATEXIT); 876 return (1); 877 } 878 } 879 return (0); 880 }
Cache object: b987350877673ee7b756f6a4724ec958
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