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 * $FreeBSD$ 40 */ 41 42 #include "opt_compat.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/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/sx.h> 61 #include <sys/ptrace.h> 62 #include <sys/acct.h> /* for acct_process() function prototype */ 63 #include <sys/filedesc.h> 64 #include <sys/shm.h> 65 #include <sys/sem.h> 66 #include <sys/jail.h> 67 #ifdef KTRACE 68 #include <sys/ktrace.h> 69 #endif 70 71 #include <vm/vm.h> 72 #include <vm/vm_extern.h> 73 #include <vm/vm_param.h> 74 #include <vm/pmap.h> 75 #include <vm/vm_map.h> 76 #include <vm/uma.h> 77 #include <sys/user.h> 78 79 /* Required to be non-static for SysVR4 emulator */ 80 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 81 82 static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback"); 83 84 static int wait1(struct thread *, struct wait_args *, int); 85 86 /* 87 * callout list for things to do at exit time 88 */ 89 struct exitlist { 90 exitlist_fn function; 91 TAILQ_ENTRY(exitlist) next; 92 }; 93 94 TAILQ_HEAD(exit_list_head, exitlist); 95 static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list); 96 97 /* 98 * exit -- 99 * Death of process. 100 * 101 * MPSAFE 102 */ 103 void 104 sys_exit(td, uap) 105 struct thread *td; 106 struct sys_exit_args /* { 107 int rval; 108 } */ *uap; 109 { 110 111 mtx_lock(&Giant); 112 exit1(td, W_EXITCODE(uap->rval, 0)); 113 /* NOTREACHED */ 114 } 115 116 /* 117 * Exit: deallocate address space and other resources, change proc state 118 * to zombie, and unlink proc from allproc and parent's lists. Save exit 119 * status and rusage for wait(). Check for child processes and orphan them. 120 */ 121 void 122 exit1(td, rv) 123 register struct thread *td; 124 int rv; 125 { 126 struct exitlist *ep; 127 struct proc *p, *nq, *q; 128 struct tty *tp; 129 struct vnode *ttyvp; 130 register struct vmspace *vm; 131 struct vnode *vtmp; 132 #ifdef KTRACE 133 struct vnode *tracevp; 134 #endif 135 136 GIANT_REQUIRED; 137 138 p = td->td_proc; 139 if (p == initproc) { 140 printf("init died (signal %d, exit %d)\n", 141 WTERMSIG(rv), WEXITSTATUS(rv)); 142 panic("Going nowhere without my init!"); 143 } 144 145 /* 146 * XXXXKSE: MUST abort all other threads before proceeding past here. 147 */ 148 PROC_LOCK(p); 149 if (p->p_flag & P_KSES) { 150 /* 151 * First check if some other thread got here before us.. 152 * if so, act apropriatly, (exit or suspend); 153 */ 154 thread_suspend_check(0); 155 /* 156 * Here is a trick.. 157 * We need to free up our KSE to process other threads 158 * so that we can safely set the UNBOUND flag 159 * (whether or not we have a mailbox) as we are NEVER 160 * going to return to the user. 161 * The flag will not be set yet if we are exiting 162 * because of a signal, pagefault, or similar 163 * (or even an exit(2) from the UTS). 164 */ 165 td->td_flags |= TDF_UNBOUND; 166 167 /* 168 * Kill off the other threads. This requires 169 * Some co-operation from other parts of the kernel 170 * so it may not be instant. 171 * With this state set: 172 * Any thread entering the kernel from userspace will 173 * thread_exit() in trap(). Any thread attempting to 174 * sleep will return immediatly 175 * with EINTR or EWOULDBLOCK, which will hopefully force them 176 * to back out to userland, freeing resources as they go, and 177 * anything attempting to return to userland will thread_exit() 178 * from userret(). thread_exit() will unsuspend us 179 * when the last other thread exits. 180 */ 181 if (thread_single(SNGLE_EXIT)) { 182 panic ("Exit: Single threading fouled up"); 183 } 184 /* 185 * All other activity in this process is now stopped. 186 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them) 187 * ... 188 * Turn off threading support. 189 */ 190 p->p_flag &= ~P_KSES; 191 td->td_flags &= ~TDF_UNBOUND; 192 thread_single_end(); /* Don't need this any more. */ 193 } 194 /* 195 * With this state set: 196 * Any thread entering the kernel from userspace will thread_exit() 197 * in trap(). Any thread attempting to sleep will return immediatly 198 * with EINTR or EWOULDBLOCK, which will hopefully force them 199 * to back out to userland, freeing resources as they go, and 200 * anything attempting to return to userland will thread_exit() 201 * from userret(). thread_exit() will do a wakeup on p->p_numthreads 202 * if it transitions to 1. 203 */ 204 205 p->p_flag |= P_WEXIT; 206 PROC_UNLOCK(p); 207 if (td->td_kse->ke_mdstorage) 208 cpu_free_kse_mdstorage(td->td_kse); 209 210 /* Are we a task leader? */ 211 PROC_LOCK(p); 212 if (p == p->p_leader) { 213 q = p->p_peers; 214 while (q != NULL) { 215 PROC_LOCK(q); 216 psignal(q, SIGKILL); 217 PROC_UNLOCK(q); 218 q = q->p_peers; 219 } 220 while (p->p_peers) 221 msleep(p, &p->p_mtx, PWAIT, "exit1", 0); 222 } 223 PROC_UNLOCK(p); 224 225 #ifdef PGINPROF 226 vmsizmon(); 227 #endif 228 STOPEVENT(p, S_EXIT, rv); 229 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 230 231 /* 232 * Check if any loadable modules need anything done at process exit. 233 * e.g. SYSV IPC stuff 234 * XXX what if one of these generates an error? 235 */ 236 TAILQ_FOREACH(ep, &exit_list, next) 237 (*ep->function)(p); 238 239 stopprofclock(p); 240 241 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 242 M_ZOMBIE, M_WAITOK); 243 /* 244 * If parent is waiting for us to exit or exec, 245 * P_PPWAIT is set; we will wakeup the parent below. 246 */ 247 PROC_LOCK(p); 248 p->p_flag &= ~(P_TRACED | P_PPWAIT); 249 SIGEMPTYSET(p->p_siglist); 250 PROC_UNLOCK(p); 251 if (timevalisset(&p->p_realtimer.it_value)) 252 callout_stop(&p->p_itcallout); 253 254 /* 255 * Reset any sigio structures pointing to us as a result of 256 * F_SETOWN with our pid. 257 */ 258 funsetownlst(&p->p_sigiolst); 259 260 /* 261 * Close open files and release open-file table. 262 * This may block! 263 */ 264 fdfree(td); /* XXXKSE *//* may not be the one in proc */ 265 266 /* 267 * Remove ourself from our leader's peer list and wake our leader. 268 */ 269 PROC_LOCK(p->p_leader); 270 if (p->p_leader->p_peers) { 271 q = p->p_leader; 272 while (q->p_peers != p) 273 q = q->p_peers; 274 q->p_peers = p->p_peers; 275 wakeup(p->p_leader); 276 } 277 PROC_UNLOCK(p->p_leader); 278 279 /* The next two chunks should probably be moved to vmspace_exit. */ 280 vm = p->p_vmspace; 281 /* 282 * Release user portion of address space. 283 * This releases references to vnodes, 284 * which could cause I/O if the file has been unlinked. 285 * Need to do this early enough that we can still sleep. 286 * Can't free the entire vmspace as the kernel stack 287 * may be mapped within that space also. 288 */ 289 if (--vm->vm_refcnt == 0) { 290 if (vm->vm_shm) 291 shmexit(p); 292 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_ADDRESS, 293 VM_MAXUSER_ADDRESS); 294 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 295 VM_MAXUSER_ADDRESS); 296 vm->vm_freer = p; 297 } 298 299 sx_xlock(&proctree_lock); 300 if (SESS_LEADER(p)) { 301 register struct session *sp; 302 303 sp = p->p_session; 304 if (sp->s_ttyvp) { 305 /* 306 * Controlling process. 307 * Signal foreground pgrp, 308 * drain controlling terminal 309 * and revoke access to controlling terminal. 310 */ 311 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 312 tp = sp->s_ttyp; 313 if (sp->s_ttyp->t_pgrp) { 314 PGRP_LOCK(sp->s_ttyp->t_pgrp); 315 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 316 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 317 } 318 /* XXX tp should be locked. */ 319 sx_xunlock(&proctree_lock); 320 (void) ttywait(tp); 321 sx_xlock(&proctree_lock); 322 /* 323 * The tty could have been revoked 324 * if we blocked. 325 */ 326 if (sp->s_ttyvp) { 327 ttyvp = sp->s_ttyvp; 328 SESS_LOCK(p->p_session); 329 sp->s_ttyvp = NULL; 330 SESS_UNLOCK(p->p_session); 331 sx_xunlock(&proctree_lock); 332 VOP_REVOKE(ttyvp, REVOKEALL); 333 vrele(ttyvp); 334 sx_xlock(&proctree_lock); 335 } 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 vrele(ttyvp); 343 } 344 /* 345 * s_ttyp is not zero'd; we use this to indicate 346 * that the session once had a controlling terminal. 347 * (for logging and informational purposes) 348 */ 349 } 350 SESS_LOCK(p->p_session); 351 sp->s_leader = NULL; 352 SESS_UNLOCK(p->p_session); 353 } 354 fixjobc(p, p->p_pgrp, 0); 355 sx_xunlock(&proctree_lock); 356 (void)acct_process(td); 357 #ifdef KTRACE 358 /* 359 * release trace file 360 */ 361 PROC_LOCK(p); 362 mtx_lock(&ktrace_mtx); 363 p->p_traceflag = 0; /* don't trace the vrele() */ 364 tracevp = p->p_tracep; 365 p->p_tracep = NULL; 366 mtx_unlock(&ktrace_mtx); 367 PROC_UNLOCK(p); 368 if (tracevp != NULL) 369 vrele(tracevp); 370 #endif 371 /* 372 * Release reference to text vnode 373 */ 374 if ((vtmp = p->p_textvp) != NULL) { 375 p->p_textvp = NULL; 376 vrele(vtmp); 377 } 378 379 /* 380 * Release our limits structure. 381 */ 382 mtx_assert(&Giant, MA_OWNED); 383 if (--p->p_limit->p_refcnt == 0) { 384 FREE(p->p_limit, M_SUBPROC); 385 p->p_limit = NULL; 386 } 387 388 /* 389 * Release this thread's reference to the ucred. The actual proc 390 * reference will stay around until the proc is harvested by 391 * wait(). At this point the ucred is immutable (no other threads 392 * from this proc are around that can change it) so we leave the 393 * per-thread ucred pointer intact in case it is needed although 394 * in theory nothing should be using it at this point. 395 */ 396 crfree(td->td_ucred); 397 398 /* 399 * Remove proc from allproc queue and pidhash chain. 400 * Place onto zombproc. Unlink from parent's child list. 401 */ 402 sx_xlock(&allproc_lock); 403 LIST_REMOVE(p, p_list); 404 LIST_INSERT_HEAD(&zombproc, p, p_list); 405 LIST_REMOVE(p, p_hash); 406 sx_xunlock(&allproc_lock); 407 408 sx_xlock(&proctree_lock); 409 q = LIST_FIRST(&p->p_children); 410 if (q != NULL) /* only need this if any child is S_ZOMB */ 411 wakeup(initproc); 412 for (; q != NULL; q = nq) { 413 nq = LIST_NEXT(q, p_sibling); 414 PROC_LOCK(q); 415 proc_reparent(q, initproc); 416 q->p_sigparent = SIGCHLD; 417 /* 418 * Traced processes are killed 419 * since their existence means someone is screwing up. 420 */ 421 if (q->p_flag & P_TRACED) { 422 q->p_flag &= ~P_TRACED; 423 psignal(q, SIGKILL); 424 } 425 PROC_UNLOCK(q); 426 } 427 428 /* 429 * Save exit status and final rusage info, adding in child rusage 430 * info and self times. 431 */ 432 PROC_LOCK(p); 433 p->p_xstat = rv; 434 *p->p_ru = p->p_stats->p_ru; 435 mtx_lock_spin(&sched_lock); 436 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 437 mtx_unlock_spin(&sched_lock); 438 ruadd(p->p_ru, &p->p_stats->p_cru); 439 440 /* 441 * Notify interested parties of our demise. 442 */ 443 KNOTE(&p->p_klist, NOTE_EXIT); 444 445 /* 446 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 447 * flag set, or if the handler is set to SIG_IGN, notify process 448 * 1 instead (and hope it will handle this situation). 449 */ 450 PROC_LOCK(p->p_pptr); 451 if (p->p_pptr->p_procsig->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 452 struct proc *pp; 453 454 pp = p->p_pptr; 455 PROC_UNLOCK(pp); 456 proc_reparent(p, initproc); 457 PROC_LOCK(p->p_pptr); 458 /* 459 * If this was the last child of our parent, notify 460 * parent, so in case he was wait(2)ing, he will 461 * continue. 462 */ 463 if (LIST_EMPTY(&pp->p_children)) 464 wakeup(pp); 465 } 466 467 if (p->p_sigparent && p->p_pptr != initproc) 468 psignal(p->p_pptr, p->p_sigparent); 469 else 470 psignal(p->p_pptr, SIGCHLD); 471 PROC_UNLOCK(p->p_pptr); 472 473 /* 474 * If this is a kthread, then wakeup anyone waiting for it to exit. 475 */ 476 if (p->p_flag & P_KTHREAD) 477 wakeup(p); 478 PROC_UNLOCK(p); 479 480 /* 481 * Finally, call machine-dependent code to release the remaining 482 * resources including address space, the kernel stack and pcb. 483 * The address space is released by "vmspace_exitfree(p)" in 484 * vm_waitproc(). 485 */ 486 cpu_exit(td); 487 488 PROC_LOCK(p); 489 PROC_LOCK(p->p_pptr); 490 sx_xunlock(&proctree_lock); 491 mtx_lock_spin(&sched_lock); 492 while (mtx_owned(&Giant)) 493 mtx_unlock(&Giant); 494 495 /* 496 * We have to wait until after releasing all locks before 497 * changing p_state. If we block on a mutex then we will be 498 * back at SRUN when we resume and our parent will never 499 * harvest us. 500 */ 501 p->p_state = PRS_ZOMBIE; 502 503 wakeup(p->p_pptr); 504 PROC_UNLOCK(p->p_pptr); 505 cnt.v_swtch++; 506 binuptime(PCPU_PTR(switchtime)); 507 PCPU_SET(switchticks, ticks); 508 509 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */ 510 /* 511 * Make sure this thread is discarded from the zombie. 512 * This will also release this thread's reference to the ucred. 513 */ 514 thread_exit(); 515 panic("exit1"); 516 } 517 518 #ifdef COMPAT_43 519 /* 520 * MPSAFE. The dirty work is handled by wait1(). 521 */ 522 int 523 owait(td, uap) 524 struct thread *td; 525 register struct owait_args /* { 526 int dummy; 527 } */ *uap; 528 { 529 struct wait_args w; 530 531 w.options = 0; 532 w.rusage = NULL; 533 w.pid = WAIT_ANY; 534 w.status = NULL; 535 return (wait1(td, &w, 1)); 536 } 537 #endif /* COMPAT_43 */ 538 539 /* 540 * MPSAFE. The dirty work is handled by wait1(). 541 */ 542 int 543 wait4(td, uap) 544 struct thread *td; 545 struct wait_args *uap; 546 { 547 548 return (wait1(td, uap, 0)); 549 } 550 551 /* 552 * MPSAFE 553 */ 554 static int 555 wait1(td, uap, compat) 556 register struct thread *td; 557 register struct wait_args /* { 558 int pid; 559 int *status; 560 int options; 561 struct rusage *rusage; 562 } */ *uap; 563 int compat; 564 { 565 struct rusage ru; 566 register int nfound; 567 register struct proc *p, *q, *t; 568 int status, error; 569 struct kse *ke; 570 struct ksegrp *kg; 571 572 q = td->td_proc; 573 if (uap->pid == 0) { 574 PROC_LOCK(q); 575 uap->pid = -q->p_pgid; 576 PROC_UNLOCK(q); 577 } 578 if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 579 return (EINVAL); 580 mtx_lock(&Giant); 581 loop: 582 nfound = 0; 583 sx_xlock(&proctree_lock); 584 LIST_FOREACH(p, &q->p_children, p_sibling) { 585 PROC_LOCK(p); 586 if (uap->pid != WAIT_ANY && 587 p->p_pid != uap->pid && p->p_pgid != -uap->pid) { 588 PROC_UNLOCK(p); 589 continue; 590 } 591 592 /* 593 * This special case handles a kthread spawned by linux_clone 594 * (see linux_misc.c). The linux_wait4 and linux_waitpid 595 * functions need to be able to distinguish between waiting 596 * on a process and waiting on a thread. It is a thread if 597 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 598 * signifies we want to wait for threads and not processes. 599 */ 600 if ((p->p_sigparent != SIGCHLD) ^ 601 ((uap->options & WLINUXCLONE) != 0)) { 602 PROC_UNLOCK(p); 603 continue; 604 } 605 606 nfound++; 607 if (p->p_state == PRS_ZOMBIE) { 608 /* 609 * charge childs scheduling cpu usage to parent 610 * XXXKSE assume only one thread & kse & ksegrp 611 * keep estcpu in each ksegrp 612 * so charge it to the ksegrp that did the wait 613 * since process estcpu is sum of all ksegrps, 614 * this is strictly as expected. 615 * Assume that the child process aggregated all 616 * tke estcpu into the 'build-in' ksegrp. 617 * XXXKSE 618 */ 619 if (curthread->td_proc->p_pid != 1) { 620 mtx_lock_spin(&sched_lock); 621 curthread->td_ksegrp->kg_estcpu = 622 ESTCPULIM(curthread->td_ksegrp->kg_estcpu + 623 p->p_ksegrp.kg_estcpu); 624 mtx_unlock_spin(&sched_lock); 625 } 626 627 td->td_retval[0] = p->p_pid; 628 #ifdef COMPAT_43 629 if (compat) 630 td->td_retval[1] = p->p_xstat; 631 else 632 #endif 633 if (uap->status) { 634 status = p->p_xstat; /* convert to int */ 635 PROC_UNLOCK(p); 636 if ((error = copyout(&status, 637 uap->status, sizeof(status)))) { 638 sx_xunlock(&proctree_lock); 639 mtx_unlock(&Giant); 640 return (error); 641 } 642 PROC_LOCK(p); 643 } 644 if (uap->rusage) { 645 bcopy(p->p_ru, &ru, sizeof(ru)); 646 PROC_UNLOCK(p); 647 if ((error = copyout(&ru, 648 uap->rusage, sizeof (struct rusage)))) { 649 sx_xunlock(&proctree_lock); 650 mtx_unlock(&Giant); 651 return (error); 652 } 653 } else 654 PROC_UNLOCK(p); 655 /* 656 * If we got the child via a ptrace 'attach', 657 * we need to give it back to the old parent. 658 */ 659 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 660 PROC_LOCK(p); 661 p->p_oppid = 0; 662 proc_reparent(p, t); 663 PROC_UNLOCK(p); 664 psignal(t, SIGCHLD); 665 wakeup(t); 666 PROC_UNLOCK(t); 667 sx_xunlock(&proctree_lock); 668 mtx_unlock(&Giant); 669 return (0); 670 } 671 /* 672 * Remove other references to this process to ensure 673 * we have an exclusive reference. 674 */ 675 leavepgrp(p); 676 677 sx_xlock(&allproc_lock); 678 LIST_REMOVE(p, p_list); /* off zombproc */ 679 sx_xunlock(&allproc_lock); 680 681 LIST_REMOVE(p, p_sibling); 682 sx_xunlock(&proctree_lock); 683 684 /* 685 * As a side effect of this lock, we know that 686 * all other writes to this proc are visible now, so 687 * no more locking is needed for p. 688 */ 689 PROC_LOCK(p); 690 p->p_xstat = 0; /* XXX: why? */ 691 PROC_UNLOCK(p); 692 PROC_LOCK(q); 693 ruadd(&q->p_stats->p_cru, p->p_ru); 694 PROC_UNLOCK(q); 695 FREE(p->p_ru, M_ZOMBIE); 696 p->p_ru = NULL; 697 698 /* 699 * Decrement the count of procs running with this uid. 700 */ 701 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 702 703 /* 704 * Free up credentials. 705 */ 706 crfree(p->p_ucred); 707 p->p_ucred = NULL; /* XXX: why? */ 708 709 /* 710 * Remove unused arguments 711 */ 712 pargs_drop(p->p_args); 713 p->p_args = NULL; 714 715 if (--p->p_procsig->ps_refcnt == 0) { 716 if (p->p_sigacts != &p->p_uarea->u_sigacts) 717 FREE(p->p_sigacts, M_SUBPROC); 718 FREE(p->p_procsig, M_SUBPROC); 719 p->p_procsig = NULL; 720 } 721 722 /* 723 * There should only be one KSE/KSEGRP but 724 * do it right anyhow. 725 */ 726 FOREACH_KSEGRP_IN_PROC(p, kg) { 727 FOREACH_KSE_IN_GROUP(kg, ke) { 728 /* Free the KSE spare thread. */ 729 if (ke->ke_tdspare != NULL) { 730 thread_free(ke->ke_tdspare); 731 p->p_kse.ke_tdspare = NULL; 732 } 733 } 734 } 735 thread_reap(); /* check for zombie threads */ 736 737 /* 738 * Give vm and machine-dependent layer a chance 739 * to free anything that cpu_exit couldn't 740 * release while still running in process context. 741 */ 742 vm_waitproc(p); 743 mtx_destroy(&p->p_mtx); 744 uma_zfree(proc_zone, p); 745 sx_xlock(&allproc_lock); 746 nprocs--; 747 sx_xunlock(&allproc_lock); 748 mtx_unlock(&Giant); 749 return (0); 750 } 751 if (P_SHOULDSTOP(p) && ((p->p_flag & P_WAITED) == 0) && 752 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 753 p->p_flag |= P_WAITED; 754 sx_xunlock(&proctree_lock); 755 td->td_retval[0] = p->p_pid; 756 #ifdef COMPAT_43 757 if (compat) { 758 td->td_retval[1] = W_STOPCODE(p->p_xstat); 759 PROC_UNLOCK(p); 760 error = 0; 761 } else 762 #endif 763 if (uap->status) { 764 status = W_STOPCODE(p->p_xstat); 765 PROC_UNLOCK(p); 766 error = copyout(&status, 767 uap->status, sizeof(status)); 768 } else { 769 PROC_UNLOCK(p); 770 error = 0; 771 } 772 mtx_unlock(&Giant); 773 return (error); 774 } 775 if (uap->options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 776 sx_xunlock(&proctree_lock); 777 td->td_retval[0] = p->p_pid; 778 p->p_flag &= ~P_CONTINUED; 779 PROC_UNLOCK(p); 780 781 if (uap->status) { 782 status = SIGCONT; 783 error = copyout(&status, 784 uap->status, sizeof(status)); 785 } else 786 error = 0; 787 788 mtx_unlock(&Giant); 789 return (error); 790 } 791 PROC_UNLOCK(p); 792 } 793 if (nfound == 0) { 794 sx_xunlock(&proctree_lock); 795 mtx_unlock(&Giant); 796 return (ECHILD); 797 } 798 if (uap->options & WNOHANG) { 799 sx_xunlock(&proctree_lock); 800 td->td_retval[0] = 0; 801 mtx_unlock(&Giant); 802 return (0); 803 } 804 PROC_LOCK(q); 805 sx_xunlock(&proctree_lock); 806 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 807 PROC_UNLOCK(q); 808 if (error) { 809 mtx_unlock(&Giant); 810 return (error); 811 } 812 goto loop; 813 } 814 815 /* 816 * Make process 'parent' the new parent of process 'child'. 817 * Must be called with an exclusive hold of proctree lock. 818 */ 819 void 820 proc_reparent(child, parent) 821 register struct proc *child; 822 register struct proc *parent; 823 { 824 825 sx_assert(&proctree_lock, SX_XLOCKED); 826 PROC_LOCK_ASSERT(child, MA_OWNED); 827 if (child->p_pptr == parent) 828 return; 829 830 LIST_REMOVE(child, p_sibling); 831 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 832 child->p_pptr = parent; 833 } 834 835 /* 836 * The next two functions are to handle adding/deleting items on the 837 * exit callout list 838 * 839 * at_exit(): 840 * Take the arguments given and put them onto the exit callout list, 841 * However first make sure that it's not already there. 842 * returns 0 on success. 843 */ 844 845 int 846 at_exit(function) 847 exitlist_fn function; 848 { 849 struct exitlist *ep; 850 851 #ifdef INVARIANTS 852 /* Be noisy if the programmer has lost track of things */ 853 if (rm_at_exit(function)) 854 printf("WARNING: exit callout entry (%p) already present\n", 855 function); 856 #endif 857 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT); 858 if (ep == NULL) 859 return (ENOMEM); 860 ep->function = function; 861 TAILQ_INSERT_TAIL(&exit_list, ep, next); 862 return (0); 863 } 864 865 /* 866 * Scan the exit callout list for the given item and remove it. 867 * Returns the number of items removed (0 or 1) 868 */ 869 int 870 rm_at_exit(function) 871 exitlist_fn function; 872 { 873 struct exitlist *ep; 874 875 TAILQ_FOREACH(ep, &exit_list, next) { 876 if (ep->function == function) { 877 TAILQ_REMOVE(&exit_list, ep, next); 878 free(ep, M_ATEXIT); 879 return (1); 880 } 881 } 882 return (0); 883 } 884