kern_exit.c revision 112389
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: head/sys/kern/kern_exit.c 112389 2003-03-19 00:33:38Z des $ 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 */ 84MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 85 86static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback"); 87 88static int wait1(struct thread *, struct wait_args *, int); 89 90/* 91 * callout list for things to do at exit time 92 */ 93struct exitlist { 94 exitlist_fn function; 95 TAILQ_ENTRY(exitlist) next; 96}; 97 98TAILQ_HEAD(exit_list_head, exitlist); 99static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list); 100 101/* 102 * exit -- 103 * Death of process. 104 * 105 * MPSAFE 106 */ 107void 108sys_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 */ 125void 126exit1(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 struct ucred *tracecred; 139#endif 140 141 GIANT_REQUIRED; 142 143 p = td->td_proc; 144 if (p == initproc) { 145 printf("init died (signal %d, exit %d)\n", 146 WTERMSIG(rv), WEXITSTATUS(rv)); 147 panic("Going nowhere without my init!"); 148 } 149 150 /* 151 * XXXKSE: MUST abort all other threads before proceeding past here. 152 */ 153 PROC_LOCK(p); 154 if (p->p_flag & P_THREADED) { 155 /* 156 * First check if some other thread got here before us.. 157 * if so, act apropriatly, (exit or suspend); 158 */ 159 thread_suspend_check(0); 160 161 /* 162 * Kill off the other threads. This requires 163 * Some co-operation from other parts of the kernel 164 * so it may not be instant. 165 * With this state set: 166 * Any thread entering the kernel from userspace will 167 * thread_exit() in trap(). Any thread attempting to 168 * sleep will return immediatly 169 * with EINTR or EWOULDBLOCK, which will hopefully force them 170 * to back out to userland, freeing resources as they go, and 171 * anything attempting to return to userland will thread_exit() 172 * from userret(). thread_exit() will unsuspend us 173 * when the last other thread exits. 174 */ 175 if (thread_single(SINGLE_EXIT)) { 176 panic ("Exit: Single threading fouled up"); 177 } 178 /* 179 * All other activity in this process is now stopped. 180 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them) 181 * ... 182 * Turn off threading support. 183 */ 184 p->p_flag &= ~P_THREADED; 185 thread_single_end(); /* Don't need this any more. */ 186 } 187 /* 188 * With this state set: 189 * Any thread entering the kernel from userspace will thread_exit() 190 * in trap(). Any thread attempting to sleep will return immediatly 191 * with EINTR or EWOULDBLOCK, which will hopefully force them 192 * to back out to userland, freeing resources as they go, and 193 * anything attempting to return to userland will thread_exit() 194 * from userret(). thread_exit() will do a wakeup on p->p_numthreads 195 * if it transitions to 1. 196 */ 197 198 p->p_flag |= P_WEXIT; 199 PROC_UNLOCK(p); 200 201 /* Are we a task leader? */ 202 if (p == p->p_leader) { 203 mtx_lock(&ppeers_lock); 204 q = p->p_peers; 205 while (q != NULL) { 206 PROC_LOCK(q); 207 psignal(q, SIGKILL); 208 PROC_UNLOCK(q); 209 q = q->p_peers; 210 } 211 while (p->p_peers != NULL) 212 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 213 mtx_unlock(&ppeers_lock); 214 } 215 216#ifdef PGINPROF 217 vmsizmon(); 218#endif 219 STOPEVENT(p, S_EXIT, rv); 220 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 221 222 /* 223 * Check if any loadable modules need anything done at process exit. 224 * e.g. SYSV IPC stuff 225 * XXX what if one of these generates an error? 226 */ 227 TAILQ_FOREACH(ep, &exit_list, next) 228 (*ep->function)(p); 229 230 231 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 232 M_ZOMBIE, M_WAITOK); 233 /* 234 * If parent is waiting for us to exit or exec, 235 * P_PPWAIT is set; we will wakeup the parent below. 236 */ 237 PROC_LOCK(p); 238 stopprofclock(p); 239 p->p_flag &= ~(P_TRACED | P_PPWAIT); 240 SIGEMPTYSET(p->p_siglist); 241 if (timevalisset(&p->p_realtimer.it_value)) 242 callout_stop(&p->p_itcallout); 243 PROC_UNLOCK(p); 244 245 /* 246 * Reset any sigio structures pointing to us as a result of 247 * F_SETOWN with our pid. 248 */ 249 funsetownlst(&p->p_sigiolst); 250 251 /* 252 * Close open files and release open-file table. 253 * This may block! 254 */ 255 fdfree(td); 256 257 /* 258 * Remove ourself from our leader's peer list and wake our leader. 259 */ 260 mtx_lock(&ppeers_lock); 261 if (p->p_leader->p_peers) { 262 q = p->p_leader; 263 while (q->p_peers != p) 264 q = q->p_peers; 265 q->p_peers = p->p_peers; 266 wakeup(p->p_leader); 267 } 268 mtx_unlock(&ppeers_lock); 269 270 /* The next two chunks should probably be moved to vmspace_exit. */ 271 vm = p->p_vmspace; 272 /* 273 * Release user portion of address space. 274 * This releases references to vnodes, 275 * which could cause I/O if the file has been unlinked. 276 * Need to do this early enough that we can still sleep. 277 * Can't free the entire vmspace as the kernel stack 278 * may be mapped within that space also. 279 * 280 * Processes sharing the same vmspace may exit in one order, and 281 * get cleaned up by vmspace_exit() in a different order. The 282 * last exiting process to reach this point releases as much of 283 * the environment as it can, and the last process cleaned up 284 * by vmspace_exit() (which decrements exitingcnt) cleans up the 285 * remainder. 286 */ 287 ++vm->vm_exitingcnt; 288 if (--vm->vm_refcnt == 0) { 289 shmexit(vm); 290 vm_page_lock_queues(); 291 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 292 vm_map_max(&vm->vm_map)); 293 vm_page_unlock_queues(); 294 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 295 vm_map_max(&vm->vm_map)); 296 } 297 298 sx_xlock(&proctree_lock); 299 if (SESS_LEADER(p)) { 300 register struct session *sp; 301 302 sp = p->p_session; 303 if (sp->s_ttyvp) { 304 /* 305 * Controlling process. 306 * Signal foreground pgrp, 307 * drain controlling terminal 308 * and revoke access to controlling terminal. 309 */ 310 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 311 tp = sp->s_ttyp; 312 if (sp->s_ttyp->t_pgrp) { 313 PGRP_LOCK(sp->s_ttyp->t_pgrp); 314 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 315 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 316 } 317 /* XXX tp should be locked. */ 318 sx_xunlock(&proctree_lock); 319 (void) ttywait(tp); 320 sx_xlock(&proctree_lock); 321 /* 322 * The tty could have been revoked 323 * if we blocked. 324 */ 325 if (sp->s_ttyvp) { 326 ttyvp = sp->s_ttyvp; 327 SESS_LOCK(p->p_session); 328 sp->s_ttyvp = NULL; 329 SESS_UNLOCK(p->p_session); 330 sx_xunlock(&proctree_lock); 331 VOP_REVOKE(ttyvp, REVOKEALL); 332 vrele(ttyvp); 333 sx_xlock(&proctree_lock); 334 } 335 } 336 if (sp->s_ttyvp) { 337 ttyvp = sp->s_ttyvp; 338 SESS_LOCK(p->p_session); 339 sp->s_ttyvp = NULL; 340 SESS_UNLOCK(p->p_session); 341 vrele(ttyvp); 342 } 343 /* 344 * s_ttyp is not zero'd; we use this to indicate 345 * that the session once had a controlling terminal. 346 * (for logging and informational purposes) 347 */ 348 } 349 SESS_LOCK(p->p_session); 350 sp->s_leader = NULL; 351 SESS_UNLOCK(p->p_session); 352 } 353 fixjobc(p, p->p_pgrp, 0); 354 sx_xunlock(&proctree_lock); 355 (void)acct_process(td); 356#ifdef KTRACE 357 /* 358 * release trace file 359 */ 360 PROC_LOCK(p); 361 mtx_lock(&ktrace_mtx); 362 p->p_traceflag = 0; /* don't trace the vrele() */ 363 tracevp = p->p_tracevp; 364 p->p_tracevp = NULL; 365 tracecred = p->p_tracecred; 366 p->p_tracecred = NULL; 367 mtx_unlock(&ktrace_mtx); 368 PROC_UNLOCK(p); 369 if (tracevp != NULL) 370 vrele(tracevp); 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 vrele(vtmp); 380 } 381 382 /* 383 * Release our limits structure. 384 */ 385 mtx_assert(&Giant, MA_OWNED); 386 if (--p->p_limit->p_refcnt == 0) { 387 FREE(p->p_limit, M_SUBPROC); 388 p->p_limit = NULL; 389 } 390 391 /* 392 * Release this thread's reference to the ucred. The actual proc 393 * reference will stay around until the proc is harvested by 394 * wait(). At this point the ucred is immutable (no other threads 395 * from this proc are around that can change it) so we leave the 396 * per-thread ucred pointer intact in case it is needed although 397 * in theory nothing should be using it at this point. 398 */ 399 crfree(td->td_ucred); 400 401 /* 402 * Remove proc from allproc queue and pidhash chain. 403 * Place onto zombproc. Unlink from parent's child list. 404 */ 405 sx_xlock(&allproc_lock); 406 LIST_REMOVE(p, p_list); 407 LIST_INSERT_HEAD(&zombproc, p, p_list); 408 LIST_REMOVE(p, p_hash); 409 sx_xunlock(&allproc_lock); 410 411 sx_xlock(&proctree_lock); 412 q = LIST_FIRST(&p->p_children); 413 if (q != NULL) /* only need this if any child is S_ZOMB */ 414 wakeup(initproc); 415 for (; q != NULL; q = nq) { 416 nq = LIST_NEXT(q, p_sibling); 417 PROC_LOCK(q); 418 proc_reparent(q, initproc); 419 q->p_sigparent = SIGCHLD; 420 /* 421 * Traced processes are killed 422 * since their existence means someone is screwing up. 423 */ 424 if (q->p_flag & P_TRACED) { 425 q->p_flag &= ~P_TRACED; 426 psignal(q, SIGKILL); 427 } 428 PROC_UNLOCK(q); 429 } 430 431 /* 432 * Save exit status and final rusage info, adding in child rusage 433 * info and self times. 434 */ 435 PROC_LOCK(p); 436 p->p_xstat = rv; 437 *p->p_ru = p->p_stats->p_ru; 438 mtx_lock_spin(&sched_lock); 439 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 440 mtx_unlock_spin(&sched_lock); 441 ruadd(p->p_ru, &p->p_stats->p_cru); 442 443 /* 444 * Notify interested parties of our demise. 445 */ 446 KNOTE(&p->p_klist, NOTE_EXIT); 447 448 /* 449 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 450 * flag set, or if the handler is set to SIG_IGN, notify process 451 * 1 instead (and hope it will handle this situation). 452 */ 453 PROC_LOCK(p->p_pptr); 454 if (p->p_pptr->p_procsig->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 455 struct proc *pp; 456 457 pp = p->p_pptr; 458 PROC_UNLOCK(pp); 459 proc_reparent(p, initproc); 460 PROC_LOCK(p->p_pptr); 461 /* 462 * If this was the last child of our parent, notify 463 * parent, so in case he was wait(2)ing, he will 464 * continue. 465 */ 466 if (LIST_EMPTY(&pp->p_children)) 467 wakeup(pp); 468 } 469 470 if (p->p_sigparent && p->p_pptr != initproc) 471 psignal(p->p_pptr, p->p_sigparent); 472 else 473 psignal(p->p_pptr, SIGCHLD); 474 PROC_UNLOCK(p->p_pptr); 475 476 /* 477 * If this is a kthread, then wakeup anyone waiting for it to exit. 478 */ 479 if (p->p_flag & P_KTHREAD) 480 wakeup(p); 481 PROC_UNLOCK(p); 482 483 /* 484 * Finally, call machine-dependent code to release the remaining 485 * resources including address space. 486 * The address space is released by "vmspace_exitfree(p)" in 487 * vm_waitproc(). 488 */ 489 cpu_exit(td); 490 491 PROC_LOCK(p); 492 PROC_LOCK(p->p_pptr); 493 sx_xunlock(&proctree_lock); 494 mtx_lock_spin(&sched_lock); 495 496 while (mtx_owned(&Giant)) 497 mtx_unlock(&Giant); 498 499 /* 500 * We have to wait until after releasing all locks before 501 * changing p_state. If we block on a mutex then we will be 502 * back at SRUN when we resume and our parent will never 503 * harvest us. 504 */ 505 p->p_state = PRS_ZOMBIE; 506 507 wakeup(p->p_pptr); 508 PROC_UNLOCK(p->p_pptr); 509 cnt.v_swtch++; 510 binuptime(PCPU_PTR(switchtime)); 511 PCPU_SET(switchticks, ticks); 512 513 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */ 514 /* 515 * Make sure the scheduler takes this thread out of its tables etc. 516 * This will also release this thread's reference to the ucred. 517 * Other thread parts to release include pcb bits and such. 518 */ 519 thread_exit(); 520} 521 522#ifdef COMPAT_43 523/* 524 * MPSAFE. The dirty work is handled by wait1(). 525 */ 526int 527owait(td, uap) 528 struct thread *td; 529 register struct owait_args /* { 530 int dummy; 531 } */ *uap; 532{ 533 struct wait_args w; 534 535 w.options = 0; 536 w.rusage = NULL; 537 w.pid = WAIT_ANY; 538 w.status = NULL; 539 return (wait1(td, &w, 1)); 540} 541#endif /* COMPAT_43 */ 542 543/* 544 * MPSAFE. The dirty work is handled by wait1(). 545 */ 546int 547wait4(td, uap) 548 struct thread *td; 549 struct wait_args *uap; 550{ 551 552 return (wait1(td, uap, 0)); 553} 554 555/* 556 * MPSAFE 557 */ 558static int 559wait1(td, uap, compat) 560 register struct thread *td; 561 register struct wait_args /* { 562 int pid; 563 int *status; 564 int options; 565 struct rusage *rusage; 566 } */ *uap; 567 int compat; 568{ 569 struct rusage ru; 570 int nfound; 571 struct proc *p, *q, *t; 572 int status, error; 573 574 q = td->td_proc; 575 if (uap->pid == 0) { 576 PROC_LOCK(q); 577 uap->pid = -q->p_pgid; 578 PROC_UNLOCK(q); 579 } 580 if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 581 return (EINVAL); 582 mtx_lock(&Giant); 583loop: 584 nfound = 0; 585 sx_xlock(&proctree_lock); 586 LIST_FOREACH(p, &q->p_children, p_sibling) { 587 PROC_LOCK(p); 588 if (uap->pid != WAIT_ANY && 589 p->p_pid != uap->pid && p->p_pgid != -uap->pid) { 590 PROC_UNLOCK(p); 591 continue; 592 } 593 594 /* 595 * This special case handles a kthread spawned by linux_clone 596 * (see linux_misc.c). The linux_wait4 and linux_waitpid 597 * functions need to be able to distinguish between waiting 598 * on a process and waiting on a thread. It is a thread if 599 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 600 * signifies we want to wait for threads and not processes. 601 */ 602 if ((p->p_sigparent != SIGCHLD) ^ 603 ((uap->options & WLINUXCLONE) != 0)) { 604 PROC_UNLOCK(p); 605 continue; 606 } 607 608 nfound++; 609 if (p->p_state == PRS_ZOMBIE) { 610 /* 611 * Allow the scheduler to adjust the priority of the 612 * parent when a kseg is exiting. 613 */ 614 if (curthread->td_proc->p_pid != 1) { 615 mtx_lock_spin(&sched_lock); 616 sched_exit(curthread->td_ksegrp, 617 FIRST_KSEGRP_IN_PROC(p)); 618 mtx_unlock_spin(&sched_lock); 619 } 620 621 td->td_retval[0] = p->p_pid; 622#ifdef COMPAT_43 623 if (compat) 624 td->td_retval[1] = p->p_xstat; 625 else 626#endif 627 if (uap->status) { 628 status = p->p_xstat; /* convert to int */ 629 PROC_UNLOCK(p); 630 if ((error = copyout(&status, 631 uap->status, sizeof(status)))) { 632 sx_xunlock(&proctree_lock); 633 mtx_unlock(&Giant); 634 return (error); 635 } 636 PROC_LOCK(p); 637 } 638 if (uap->rusage) { 639 bcopy(p->p_ru, &ru, sizeof(ru)); 640 PROC_UNLOCK(p); 641 if ((error = copyout(&ru, 642 uap->rusage, sizeof (struct rusage)))) { 643 sx_xunlock(&proctree_lock); 644 mtx_unlock(&Giant); 645 return (error); 646 } 647 } else 648 PROC_UNLOCK(p); 649 /* 650 * If we got the child via a ptrace 'attach', 651 * we need to give it back to the old parent. 652 */ 653 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 654 PROC_LOCK(p); 655 p->p_oppid = 0; 656 proc_reparent(p, t); 657 PROC_UNLOCK(p); 658 psignal(t, SIGCHLD); 659 wakeup(t); 660 PROC_UNLOCK(t); 661 sx_xunlock(&proctree_lock); 662 mtx_unlock(&Giant); 663 return (0); 664 } 665 666 /* 667 * Remove other references to this process to ensure 668 * we have an exclusive reference. 669 */ 670 sx_xlock(&allproc_lock); 671 LIST_REMOVE(p, p_list); /* off zombproc */ 672 sx_xunlock(&allproc_lock); 673 LIST_REMOVE(p, p_sibling); 674 leavepgrp(p); 675 sx_xunlock(&proctree_lock); 676 677 /* 678 * As a side effect of this lock, we know that 679 * all other writes to this proc are visible now, so 680 * no more locking is needed for p. 681 */ 682 PROC_LOCK(p); 683 p->p_xstat = 0; /* XXX: why? */ 684 PROC_UNLOCK(p); 685 PROC_LOCK(q); 686 ruadd(&q->p_stats->p_cru, p->p_ru); 687 PROC_UNLOCK(q); 688 FREE(p->p_ru, M_ZOMBIE); 689 p->p_ru = NULL; 690 691 /* 692 * Decrement the count of procs running with this uid. 693 */ 694 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 695 696 /* 697 * Free up credentials. 698 */ 699 crfree(p->p_ucred); 700 p->p_ucred = NULL; /* XXX: why? */ 701 702 /* 703 * Remove unused arguments 704 */ 705 pargs_drop(p->p_args); 706 p->p_args = NULL; 707 708 if (--p->p_procsig->ps_refcnt == 0) { 709 if (p->p_sigacts != &p->p_uarea->u_sigacts) 710 FREE(p->p_sigacts, M_SUBPROC); 711 FREE(p->p_procsig, M_SUBPROC); 712 p->p_procsig = NULL; 713 } 714 715 /* 716 * do any thread-system specific cleanups 717 */ 718 thread_wait(p); 719 720 /* 721 * Give vm and machine-dependent layer a chance 722 * to free anything that cpu_exit couldn't 723 * release while still running in process context. 724 */ 725 vm_waitproc(p); 726 mtx_destroy(&p->p_mtx); 727#ifdef MAC 728 mac_destroy_proc(p); 729#endif 730 KASSERT(FIRST_THREAD_IN_PROC(p), 731 ("wait1: no residual thread!")); 732 uma_zfree(proc_zone, p); 733 sx_xlock(&allproc_lock); 734 nprocs--; 735 sx_xunlock(&allproc_lock); 736 mtx_unlock(&Giant); 737 return (0); 738 } 739 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) && 740 ((p->p_flag & P_WAITED) == 0) && 741 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 742 p->p_flag |= P_WAITED; 743 sx_xunlock(&proctree_lock); 744 td->td_retval[0] = p->p_pid; 745#ifdef COMPAT_43 746 if (compat) { 747 td->td_retval[1] = W_STOPCODE(p->p_xstat); 748 PROC_UNLOCK(p); 749 error = 0; 750 } else 751#endif 752 if (uap->status) { 753 status = W_STOPCODE(p->p_xstat); 754 PROC_UNLOCK(p); 755 error = copyout(&status, 756 uap->status, sizeof(status)); 757 } else { 758 PROC_UNLOCK(p); 759 error = 0; 760 } 761 mtx_unlock(&Giant); 762 return (error); 763 } 764 if (uap->options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 765 sx_xunlock(&proctree_lock); 766 td->td_retval[0] = p->p_pid; 767 p->p_flag &= ~P_CONTINUED; 768 PROC_UNLOCK(p); 769 770 if (uap->status) { 771 status = SIGCONT; 772 error = copyout(&status, 773 uap->status, sizeof(status)); 774 } else 775 error = 0; 776 777 mtx_unlock(&Giant); 778 return (error); 779 } 780 PROC_UNLOCK(p); 781 } 782 if (nfound == 0) { 783 sx_xunlock(&proctree_lock); 784 mtx_unlock(&Giant); 785 return (ECHILD); 786 } 787 if (uap->options & WNOHANG) { 788 sx_xunlock(&proctree_lock); 789 td->td_retval[0] = 0; 790 mtx_unlock(&Giant); 791 return (0); 792 } 793 PROC_LOCK(q); 794 sx_xunlock(&proctree_lock); 795 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 796 PROC_UNLOCK(q); 797 if (error) { 798 mtx_unlock(&Giant); 799 return (error); 800 } 801 goto loop; 802} 803 804/* 805 * Make process 'parent' the new parent of process 'child'. 806 * Must be called with an exclusive hold of proctree lock. 807 */ 808void 809proc_reparent(child, parent) 810 register struct proc *child; 811 register struct proc *parent; 812{ 813 814 sx_assert(&proctree_lock, SX_XLOCKED); 815 PROC_LOCK_ASSERT(child, MA_OWNED); 816 if (child->p_pptr == parent) 817 return; 818 819 LIST_REMOVE(child, p_sibling); 820 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 821 child->p_pptr = parent; 822} 823 824/* 825 * The next two functions are to handle adding/deleting items on the 826 * exit callout list 827 * 828 * at_exit(): 829 * Take the arguments given and put them onto the exit callout list, 830 * However first make sure that it's not already there. 831 * returns 0 on success. 832 */ 833 834int 835at_exit(function) 836 exitlist_fn function; 837{ 838 struct exitlist *ep; 839 840#ifdef INVARIANTS 841 /* Be noisy if the programmer has lost track of things */ 842 if (rm_at_exit(function)) 843 printf("WARNING: exit callout entry (%p) already present\n", 844 function); 845#endif 846 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT); 847 if (ep == NULL) 848 return (ENOMEM); 849 ep->function = function; 850 TAILQ_INSERT_TAIL(&exit_list, ep, next); 851 return (0); 852} 853 854/* 855 * Scan the exit callout list for the given item and remove it. 856 * Returns the number of items removed (0 or 1) 857 */ 858int 859rm_at_exit(function) 860 exitlist_fn function; 861{ 862 struct exitlist *ep; 863 864 TAILQ_FOREACH(ep, &exit_list, next) { 865 if (ep->function == function) { 866 TAILQ_REMOVE(&exit_list, ep, next); 867 free(ep, M_ATEXIT); 868 return (1); 869 } 870 } 871 return (0); 872} 873