dd45d8ad18
1/ session leader 2/ Have a console device vnode (/dev/console) 3/ have NULL pointer for a consoel tty struct. fix the only case where the tty struct is referenced without a prior check for existance.
557 lines
14 KiB
C
557 lines
14 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1989, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
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* $Id: kern_exit.c,v 1.39 1996/09/13 09:17:03 bde Exp $
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*/
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#include "opt_ktrace.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/sysent.h>
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#include <sys/ioctl.h>
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#include <sys/proc.h>
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#include <sys/tty.h>
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#include <sys/time.h>
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#include <sys/resource.h>
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#include <sys/kernel.h>
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#include <sys/buf.h>
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#include <sys/wait.h>
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#include <sys/file.h>
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#include <sys/vnode.h>
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#include <sys/syslog.h>
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#include <sys/malloc.h>
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#include <sys/resourcevar.h>
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#include <sys/signalvar.h>
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#include <sys/ptrace.h>
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#include <sys/acct.h> /* for acct_process() function prototype */
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#include <sys/filedesc.h>
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#include <sys/shm.h>
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#include <sys/sem.h>
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#ifdef COMPAT_43
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#include <machine/reg.h>
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#include <machine/psl.h>
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#endif
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_prot.h>
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#include <vm/lock.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_kern.h>
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static int wait1 __P((struct proc *, struct wait_args *, int [], int));
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/*
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* callout list for things to do at exit time
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*/
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typedef struct exit_list_element {
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struct exit_list_element *next;
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exitlist_fn function;
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} *ele_p;
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static ele_p exit_list;
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/*
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* exit --
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* Death of process.
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*/
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void
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exit(p, uap, retval)
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struct proc *p;
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struct rexit_args /* {
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int rval;
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} */ *uap;
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int *retval;
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{
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exit1(p, W_EXITCODE(uap->rval, 0));
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/* NOTREACHED */
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}
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/*
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* Exit: deallocate address space and other resources, change proc state
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* to zombie, and unlink proc from allproc and parent's lists. Save exit
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* status and rusage for wait(). Check for child processes and orphan them.
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*/
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void
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exit1(p, rv)
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register struct proc *p;
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int rv;
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{
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register struct proc *q, *nq;
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register struct vmspace *vm;
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ele_p ep = exit_list;
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if (p->p_pid == 1) {
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printf("init died (signal %d, exit %d)\n",
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WTERMSIG(rv), WEXITSTATUS(rv));
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panic("Going nowhere without my init!");
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}
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#ifdef PGINPROF
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vmsizmon();
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#endif
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/*
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* Check if any LKMs need anything done at process exit.
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* e.g. SYSV IPC stuff
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* XXX what if one of these generates an error?
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*/
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while (ep) {
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(*ep->function)(p);
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ep = ep->next;
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}
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if (p->p_flag & P_PROFIL)
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stopprofclock(p);
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MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
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M_ZOMBIE, M_WAITOK);
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/*
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* If parent is waiting for us to exit or exec,
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* P_PPWAIT is set; we will wakeup the parent below.
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*/
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p->p_flag &= ~(P_TRACED | P_PPWAIT);
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p->p_flag |= P_WEXIT;
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p->p_sigignore = ~0;
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p->p_siglist = 0;
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untimeout(realitexpire, (caddr_t)p);
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/*
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* Close open files and release open-file table.
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* This may block!
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*/
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fdfree(p);
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/*
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* Delete select() buffers
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*/
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if (p->p_selbits)
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free (p->p_selbits, M_SELECT);
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/*
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* XXX Shutdown SYSV semaphores
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*/
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semexit(p);
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/* The next two chunks should probably be moved to vmspace_exit. */
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vm = p->p_vmspace;
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if (vm->vm_shm)
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shmexit(p);
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/*
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* Release user portion of address space.
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* This releases references to vnodes,
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* which could cause I/O if the file has been unlinked.
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* Need to do this early enough that we can still sleep.
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* Can't free the entire vmspace as the kernel stack
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* may be mapped within that space also.
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*/
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if (vm->vm_refcnt == 1)
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(void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
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VM_MAXUSER_ADDRESS);
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if (SESS_LEADER(p)) {
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register struct session *sp = p->p_session;
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if (sp->s_ttyvp) {
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/*
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* Controlling process.
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* Signal foreground pgrp,
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* drain controlling terminal
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* and revoke access to controlling terminal.
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*/
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if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
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if (sp->s_ttyp->t_pgrp)
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pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
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(void) ttywait(sp->s_ttyp);
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/*
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* The tty could have been revoked
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* if we blocked.
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*/
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if (sp->s_ttyvp)
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vgoneall(sp->s_ttyvp);
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}
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if (sp->s_ttyvp)
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vrele(sp->s_ttyvp);
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sp->s_ttyvp = NULL;
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/*
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* s_ttyp is not zero'd; we use this to indicate
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* that the session once had a controlling terminal.
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* (for logging and informational purposes)
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*/
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}
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sp->s_leader = NULL;
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}
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fixjobc(p, p->p_pgrp, 0);
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p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
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(void)acct_process(p);
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#ifdef KTRACE
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/*
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* release trace file
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*/
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p->p_traceflag = 0; /* don't trace the vrele() */
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if (p->p_tracep)
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vrele(p->p_tracep);
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#endif
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/*
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* Remove proc from allproc queue and pidhash chain.
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* Place onto zombproc. Unlink from parent's child list.
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*/
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LIST_REMOVE(p, p_list);
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LIST_INSERT_HEAD(&zombproc, p, p_list);
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p->p_stat = SZOMB;
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LIST_REMOVE(p, p_hash);
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q = p->p_children.lh_first;
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if (q) /* only need this if any child is S_ZOMB */
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wakeup((caddr_t) initproc);
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for (; q != 0; q = nq) {
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nq = q->p_sibling.le_next;
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LIST_REMOVE(q, p_sibling);
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LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling);
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q->p_pptr = initproc;
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/*
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* Traced processes are killed
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* since their existence means someone is screwing up.
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*/
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if (q->p_flag & P_TRACED) {
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q->p_flag &= ~P_TRACED;
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psignal(q, SIGKILL);
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}
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}
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/*
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* Save exit status and final rusage info, adding in child rusage
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* info and self times.
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*/
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p->p_xstat = rv;
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*p->p_ru = p->p_stats->p_ru;
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calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
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ruadd(p->p_ru, &p->p_stats->p_cru);
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/*
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* Notify parent that we're gone.
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*/
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psignal(p->p_pptr, SIGCHLD);
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wakeup((caddr_t)p->p_pptr);
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#if defined(tahoe)
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/* move this to cpu_exit */
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p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
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#endif
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/*
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* Clear curproc after we've done all operations
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* that could block, and before tearing down the rest
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* of the process state that might be used from clock, etc.
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* Also, can't clear curproc while we're still runnable,
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* as we're not on a run queue (we are current, just not
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* a proper proc any longer!).
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*
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* Other substructures are freed from wait().
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*/
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curproc = NULL;
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if (--p->p_limit->p_refcnt == 0) {
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FREE(p->p_limit, M_SUBPROC);
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p->p_limit = NULL;
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}
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/*
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* Finally, call machine-dependent code to release the remaining
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* resources including address space, the kernel stack and pcb.
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* The address space is released by "vmspace_free(p->p_vmspace)";
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* This is machine-dependent, as we may have to change stacks
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* or ensure that the current one isn't reallocated before we
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* finish. cpu_exit will end with a call to cpu_switch(), finishing
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* our execution (pun intended).
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*/
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cpu_exit(p);
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}
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#ifdef COMPAT_43
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#if defined(hp300) || defined(luna68k)
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#include <machine/frame.h>
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#define GETPS(rp) ((struct frame *)(rp))->f_sr
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#else
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#define GETPS(rp) (rp)[PS]
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#endif
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int
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owait(p, uap, retval)
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struct proc *p;
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register struct owait_args /* {
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int dummy;
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} */ *uap;
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int *retval;
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{
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struct wait_args w;
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#ifdef PSL_ALLCC
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if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) {
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w.options = 0;
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w.rusage = NULL;
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} else {
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w.options = p->p_md.md_regs[R0];
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w.rusage = (struct rusage *)p->p_md.md_regs[R1];
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}
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#else
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w.options = 0;
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w.rusage = NULL;
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#endif
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w.pid = WAIT_ANY;
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w.status = NULL;
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return (wait1(p, &w, retval, 1));
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}
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#endif /* COMPAT_43 */
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int
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wait4(p, uap, retval)
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struct proc *p;
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struct wait_args *uap;
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int *retval;
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{
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return (wait1(p, uap, retval, 0));
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}
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static int
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wait1(q, uap, retval, compat)
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register struct proc *q;
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register struct wait_args /* {
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int pid;
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int *status;
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int options;
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struct rusage *rusage;
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} */ *uap;
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int retval[];
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int compat;
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{
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register int nfound;
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register struct proc *p, *t;
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int status, error;
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if (uap->pid == 0)
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uap->pid = -q->p_pgid;
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#ifdef notyet
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if (uap->options &~ (WUNTRACED|WNOHANG))
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return (EINVAL);
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#endif
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loop:
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nfound = 0;
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for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) {
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if (uap->pid != WAIT_ANY &&
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p->p_pid != uap->pid && p->p_pgid != -uap->pid)
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continue;
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nfound++;
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if (p->p_stat == SZOMB) {
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/* charge childs scheduling cpu usage to parent */
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if (curproc->p_pid != 1) {
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curproc->p_estcpu = min(curproc->p_estcpu +
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p->p_estcpu, UCHAR_MAX);
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}
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retval[0] = p->p_pid;
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#ifdef COMPAT_43
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if (compat)
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retval[1] = p->p_xstat;
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else
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#endif
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if (uap->status) {
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status = p->p_xstat; /* convert to int */
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if ((error = copyout((caddr_t)&status,
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(caddr_t)uap->status, sizeof(status))))
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return (error);
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}
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if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
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(caddr_t)uap->rusage, sizeof (struct rusage))))
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return (error);
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/*
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* If we got the child via a ptrace 'attach',
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* we need to give it back to the old parent.
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*/
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if (p->p_oppid && (t = pfind(p->p_oppid))) {
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p->p_oppid = 0;
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proc_reparent(p, t);
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psignal(t, SIGCHLD);
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wakeup((caddr_t)t);
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return (0);
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}
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p->p_xstat = 0;
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ruadd(&q->p_stats->p_cru, p->p_ru);
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FREE(p->p_ru, M_ZOMBIE);
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p->p_ru = NULL;
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/*
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* Decrement the count of procs running with this uid.
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*/
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(void)chgproccnt(p->p_cred->p_ruid, -1);
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/*
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* Release reference to text vnode
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*/
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if (p->p_textvp)
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vrele(p->p_textvp);
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/*
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* Free up credentials.
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*/
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if (--p->p_cred->p_refcnt == 0) {
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crfree(p->p_cred->pc_ucred);
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FREE(p->p_cred, M_SUBPROC);
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p->p_cred = NULL;
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}
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/*
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* Finally finished with old proc entry.
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* Unlink it from its process group and free it.
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*/
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leavepgrp(p);
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LIST_REMOVE(p, p_list); /* off zombproc */
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LIST_REMOVE(p, p_sibling);
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/*
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* Give machine-dependent layer a chance
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* to free anything that cpu_exit couldn't
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* release while still running in process context.
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*/
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cpu_wait(p);
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FREE(p, M_PROC);
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nprocs--;
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return (0);
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}
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if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
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(p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
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p->p_flag |= P_WAITED;
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retval[0] = p->p_pid;
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#ifdef COMPAT_43
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if (compat) {
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retval[1] = W_STOPCODE(p->p_xstat);
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error = 0;
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} else
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#endif
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if (uap->status) {
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status = W_STOPCODE(p->p_xstat);
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error = copyout((caddr_t)&status,
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(caddr_t)uap->status, sizeof(status));
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} else
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error = 0;
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return (error);
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}
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}
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if (nfound == 0)
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return (ECHILD);
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if (uap->options & WNOHANG) {
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retval[0] = 0;
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return (0);
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}
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if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)))
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return (error);
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goto loop;
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}
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/*
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* make process 'parent' the new parent of process 'child'.
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*/
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void
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proc_reparent(child, parent)
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register struct proc *child;
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register struct proc *parent;
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{
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if (child->p_pptr == parent)
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return;
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LIST_REMOVE(child, p_sibling);
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LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
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child->p_pptr = parent;
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}
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/*
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* The next two functions are to handle adding/deleting items on the
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* exit callout list
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|
*
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* at_exit():
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* Take the arguments given and put them onto the exit callout list,
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* However first make sure that it's not already there.
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* returns 0 on success.
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*/
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int
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at_exit(exitlist_fn function)
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{
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|
ele_p ep;
|
|
|
|
/* Be noisy if the programmer has lost track of things */
|
|
if (rm_at_exit(function))
|
|
printf("exit callout entry already present\n");
|
|
ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT);
|
|
if (ep == NULL)
|
|
return (ENOMEM);
|
|
ep->next = exit_list;
|
|
ep->function = function;
|
|
exit_list = ep;
|
|
return (0);
|
|
}
|
|
/*
|
|
* Scan the exit callout list for the given items and remove them.
|
|
* Returns the number of items removed.
|
|
* Logically this can only be 0 or 1.
|
|
*/
|
|
int
|
|
rm_at_exit(exitlist_fn function)
|
|
{
|
|
ele_p *epp, ep;
|
|
int count;
|
|
|
|
count = 0;
|
|
epp = &exit_list;
|
|
ep = *epp;
|
|
while (ep) {
|
|
if (ep->function == function) {
|
|
*epp = ep->next;
|
|
free(ep, M_TEMP);
|
|
count++;
|
|
} else {
|
|
epp = &ep->next;
|
|
}
|
|
ep = *epp;
|
|
}
|
|
return (count);
|
|
}
|
|
|
|
|