xnu-792.6.22.tar.gz

[apple/xnu.git] / bsd / kern / kern_exit.c

/*
 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1982, 1986, 1989, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
 */
 
#include <machine/reg.h>
#include <machine/psl.h>

#include "compat_43.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/kernel.h>
#include <sys/wait.h>
#include <sys/file_internal.h>
#include <sys/vnode_internal.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/resourcevar.h>
#include <sys/ptrace.h>
#include <sys/user.h>
#include <sys/aio_kern.h>
#include <sys/sysproto.h>
#include <sys/signalvar.h>
#include <sys/filedesc.h>       /* fdfree */
#include <sys/shm_internal.h>   /* shmexit */
#include <sys/acct.h>           /* acct_process */
#include <machine/spl.h>

#include <bsm/audit_kernel.h>
#include <bsm/audit_kevents.h>

#include <mach/mach_types.h>

#include <kern/kern_types.h>
#include <kern/kalloc.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/sched_prim.h>
#include <kern/assert.h>
#if KTRACE   
#include <sys/ktrace.h>
#endif

#include <mach/mach_types.h>
#include <mach/task.h>
#include <mach/thread_act.h>
#include <mach/mach_traps.h>    /* init_process */

extern char init_task_failure_data[];
int exit1(struct proc *, int, int *);
void proc_prepareexit(struct proc *p);
void vfork_exit(struct proc *p, int rv);
void vproc_exit(struct proc *p);
__private_extern__ void munge_rusage(struct rusage *a_rusage_p, struct user_rusage *a_user_rusage_p);

/*
 * Things which should have prototypes in headers, but don't
 */
void    unix_syscall_return(int);
void    *get_bsduthreadarg(thread_t);
void    proc_exit(struct proc *p);
int     wait1continue(int result);
int     waitidcontinue(int result);
int     *get_bsduthreadrval(thread_t);
kern_return_t   sys_perf_notify(struct task *task, exception_data_t code,
                        mach_msg_type_number_t codeCnt);

/*
 * NOTE: Source and target may *NOT* overlap!
 * XXX Should share code with bsd/dev/ppc/unix_signal.c
 */
static void
siginfo_64to32(user_siginfo_t *in, siginfo_t *out)
{
        out->si_signo   = in->si_signo;
        out->si_errno   = in->si_errno;
        out->si_code    = in->si_code;
        out->si_pid     = in->si_pid;
        out->si_uid     = in->si_uid;
        out->si_status  = in->si_status;
        out->si_addr    = CAST_DOWN(void *,in->si_addr);
        /* following cast works for sival_int because of padding */
        out->si_value.sival_ptr = CAST_DOWN(void *,in->si_value.sival_ptr);
        out->si_band    = in->si_band;                  /* range reduction */
        out->pad[0]     = in->pad[0];                   /* mcontext.ss.r1 */
}

/*
 * exit --
 *      Death of process.
 */
void
exit(struct proc *p, struct exit_args *uap, int *retval)
{
        exit1(p, W_EXITCODE(uap->rval, 0), retval);

        /* drop funnel before we return */
        thread_funnel_set(kernel_flock, FALSE);
        thread_exception_return();
        /* NOTREACHED */
        while (TRUE)
                thread_block(THREAD_CONTINUE_NULL);
        /* NOTREACHED */
}

/*
 * Exit: deallocate address space and other resources, change proc state
 * to zombie, and unlink proc from allproc and parent's lists.  Save exit
 * status and rusage for wait().  Check for child processes and orphan them.
 */
int
exit1(struct proc *p, int rv, int *retval)
{
        thread_t self = current_thread();
        struct task *task = p->task;
        register int s;
        struct uthread *ut;

        /*
         * If a thread in this task has already
         * called exit(), then halt any others
         * right here.
         */

         ut = get_bsdthread_info(self);
         if (ut->uu_flag & UT_VFORK) {
                        vfork_exit(p, rv);
                        vfork_return(self, p->p_pptr, p , retval);
                        unix_syscall_return(0);
                        /* NOT REACHED */
         }
        AUDIT_SYSCALL_EXIT(0, p, ut); /* Exit is always successfull */
        signal_lock(p);
        while (p->exit_thread != self) {
                if (sig_try_locked(p) <= 0) {
                        if (get_threadtask(self) != task) {
                                signal_unlock(p);
                                return(0);
                        }
                        signal_unlock(p);
                        thread_terminate(self);
                        thread_funnel_set(kernel_flock, FALSE);
                        thread_exception_return();
                        /* NOTREACHED */
                }
                sig_lock_to_exit(p);
        }
        signal_unlock(p);
        if (p->p_pid == 1) {
                printf("pid 1 exited (signal %d, exit %d)",
                    WTERMSIG(rv), WEXITSTATUS(rv));
                panic("init died\nState at Last Exception:\n\n%s", 
                                                        init_task_failure_data);
        }

        s = splsched();
        p->p_flag |= P_WEXIT;
        splx(s);
        proc_prepareexit(p);
        p->p_xstat = rv;

        /* task terminate will call proc_terminate and that cleans it up */
        task_terminate_internal(task);

        return(0);
}

void
proc_prepareexit(struct proc *p) 
{
        struct uthread *ut;
        exception_data_t        code[EXCEPTION_CODE_MAX];
        thread_t self = current_thread();

        code[0] = (exception_data_t)0xFF000001;         /* Set terminate code */
        code[1] = (exception_data_t)p->p_pid;           /* Pass out the pid */
        /* Notify the perf server */
        (void)sys_perf_notify(p->task, (exception_data_t)&code, 2);

        /*
         * Remove proc from allproc queue and from pidhash chain.
         * Need to do this before we do anything that can block.
         * Not doing causes things like mount() find this on allproc
         * in partially cleaned state.
         */
        LIST_REMOVE(p, p_list);
        LIST_INSERT_HEAD(&zombproc, p, p_list); /* Place onto zombproc. */
        LIST_REMOVE(p, p_hash);

#ifdef PGINPROF
        vmsizmon();
#endif
        /*
         * If parent is waiting for us to exit or exec,
         * P_PPWAIT is set; we will wakeup the parent below.
         */
        p->p_flag &= ~(P_TRACED | P_PPWAIT);
        p->p_sigignore = ~(sigcantmask);
        p->p_siglist = 0;
        ut = get_bsdthread_info(self);
        ut->uu_siglist = 0;
        untimeout(realitexpire, (caddr_t)p->p_pid);
}

void 
proc_exit(struct proc *p)
{
        register struct proc *q, *nq, *pp;
        struct task *task = p->task;
        register int s;
        boolean_t funnel_state;

        /* This can happen if thread_terminate of the single thread
         * process 
         */

        funnel_state = thread_funnel_set(kernel_flock, TRUE);
        if( !(p->p_flag & P_WEXIT)) {
                s = splsched();
                p->p_flag |= P_WEXIT;
                splx(s);
                proc_prepareexit(p);    
        }

        p->p_lflag |= P_LPEXIT;
        /* XXX Zombie allocation may fail, in which case stats get lost */
        MALLOC_ZONE(p->p_ru, struct rusage *,
                        sizeof (*p->p_ru), M_ZOMBIE, M_WAITOK);

        /*
         * need to cancel async IO requests that can be cancelled and wait for those
         * already active.  MAY BLOCK!
         */
        _aio_exit( p );

        /*
         * Close open files and release open-file table.
         * This may block!
         */
        fdfree(p);

        /* Close ref SYSV Shared memory*/
        if (p->vm_shm)
                shmexit(p);
        /* Release SYSV semaphores */
        semexit(p);
        
        if (SESS_LEADER(p)) {
                register struct session *sp = p->p_session;

                if (sp->s_ttyvp) {
                        struct vnode *ttyvp;
                        struct vfs_context context;

                        /*
                         * Controlling process.
                         * Signal foreground pgrp,
                         * drain controlling terminal
                         * and revoke access to controlling terminal.
                         */
                        if (sp->s_ttyp->t_session == sp) {
                                if (sp->s_ttyp->t_pgrp)
                                        pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
                                (void) ttywait(sp->s_ttyp);
                                /*
                                 * The tty could have been revoked
                                 * if we blocked.
                                 */
                                context.vc_proc = p;
                                context.vc_ucred = p->p_ucred;
                                if (sp->s_ttyvp)
                                        VNOP_REVOKE(sp->s_ttyvp, REVOKEALL, &context);
                        }
                        ttyvp = sp->s_ttyvp;
                        sp->s_ttyvp = NULL;
                        if (ttyvp) {
                                vnode_rele(ttyvp);
                        }
                        /*
                         * s_ttyp is not zero'd; we use this to indicate
                         * that the session once had a controlling terminal.
                         * (for logging and informational purposes)
                         */
                }
                sp->s_leader = NULL;
        }

        fixjobc(p, p->p_pgrp, 0);
        p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
        (void)acct_process(p);

#if KTRACE
        /* 
         * release trace file
         */
        p->p_traceflag = 0;     /* don't trace the vnode_put() */
        if (p->p_tracep) {
                struct vnode *tvp = p->p_tracep;
                p->p_tracep = NULL;
                vnode_rele(tvp);
        }
#endif

        while (q = p->p_children.lh_first) {
                proc_reparent(q, initproc);
                /*
                 * Traced processes are killed
                 * since their existence means someone is messing up.
                 */
                if (q->p_flag & P_TRACED) {
                        q->p_flag &= ~P_TRACED;
                        if (q->sigwait_thread) {
                                /*
                                 * The sigwait_thread could be stopped at a
                                 * breakpoint. Wake it up to kill.
                                 * Need to do this as it could be a thread which is not
                                 * the first thread in the task. So any attempts to kill
                                 * the process would result into a deadlock on q->sigwait.
                                 */
                                thread_resume((thread_t)q->sigwait_thread);
                                clear_wait(q->sigwait_thread, THREAD_INTERRUPTED);
                                threadsignal((thread_t)q->sigwait_thread, SIGKILL, 0);
                        }
                        psignal(q, SIGKILL);
                }
        }

        /*
         * Save exit status and final rusage info, adding in child rusage
         * info and self times.  If we were unable to allocate a zombie
         * structure, this information is lost.
         */
        if (p->p_ru != NULL) {
            *p->p_ru = p->p_stats->p_ru;

            timerclear(&p->p_ru->ru_utime);
            timerclear(&p->p_ru->ru_stime);

            if (task) {
                task_basic_info_data_t tinfo;
                task_thread_times_info_data_t ttimesinfo;
                int task_info_stuff, task_ttimes_stuff;
                struct timeval ut,st;

                task_info_stuff = TASK_BASIC_INFO_COUNT;
                task_info(task, TASK_BASIC_INFO,
                          (task_info_t)&tinfo, &task_info_stuff);
                p->p_ru->ru_utime.tv_sec = tinfo.user_time.seconds;
                p->p_ru->ru_utime.tv_usec = tinfo.user_time.microseconds;
                p->p_ru->ru_stime.tv_sec = tinfo.system_time.seconds;
                p->p_ru->ru_stime.tv_usec = tinfo.system_time.microseconds;

                task_ttimes_stuff = TASK_THREAD_TIMES_INFO_COUNT;
                task_info(task, TASK_THREAD_TIMES_INFO,
                          (task_info_t)&ttimesinfo, &task_ttimes_stuff);

                ut.tv_sec = ttimesinfo.user_time.seconds;
                ut.tv_usec = ttimesinfo.user_time.microseconds;
                st.tv_sec = ttimesinfo.system_time.seconds;
                st.tv_usec = ttimesinfo.system_time.microseconds;
                timeradd(&ut,&p->p_ru->ru_utime,&p->p_ru->ru_utime);
                timeradd(&st,&p->p_ru->ru_stime,&p->p_ru->ru_stime);
            }

            ruadd(p->p_ru, &p->p_stats->p_cru);
        }

        /*
         * Free up profiling buffers.
         */
        {
                struct uprof *p0 = &p->p_stats->p_prof, *p1, *pn;

                p1 = p0->pr_next;
                p0->pr_next = NULL;
                p0->pr_scale = 0;

                for (; p1 != NULL; p1 = pn) {
                        pn = p1->pr_next;
                        kfree(p1, sizeof *p1);
                }
        }

        /*
         * Other substructures are freed from wait().
         */
        FREE_ZONE(p->p_stats, sizeof *p->p_stats, M_SUBPROC);
        p->p_stats = NULL;

        FREE_ZONE(p->p_sigacts, sizeof *p->p_sigacts, M_SUBPROC);
        p->p_sigacts = NULL;

        if (--p->p_limit->p_refcnt == 0)
                FREE_ZONE(p->p_limit, sizeof *p->p_limit, M_SUBPROC);
        p->p_limit = NULL;

        /*
         * Finish up by terminating the task
         * and halt this thread (only if a
         * member of the task exiting).
         */
        p->task = TASK_NULL;
        //task->proc = NULL;
        set_bsdtask_info(task, NULL);

        KNOTE(&p->p_klist, NOTE_EXIT);

        /*
         * Notify parent that we're gone.
         */
        if (p->p_pptr->p_flag & P_NOCLDWAIT) {
                struct proc *opp = p->p_pptr;

                /*
                 * Add child resource usage to parent before giving
                 * zombie to init.  If we were unable to allocate a
                 * zombie structure, this information is lost.
                 */
                if (p->p_ru != NULL)
                        ruadd(&p->p_pptr->p_stats->p_cru, p->p_ru);

                proc_reparent(p, initproc);
                /* If there are no more children wakeup parent */
                if (LIST_EMPTY(&opp->p_children))
                        wakeup((caddr_t)opp);
        }
        /* should be fine as parent proc would be initproc */
        pp = p->p_pptr;
        if (pp != initproc) {
                pp->si_pid = p->p_pid;
                pp->si_status = p->p_xstat;
                pp->si_code = CLD_EXITED;
                pp->si_uid = p->p_ucred->cr_ruid;
        }
        /* mark as a zombie */
        p->p_stat = SZOMB;

        psignal(pp, SIGCHLD);

        /* and now wakeup the parent */
        wakeup((caddr_t)p->p_pptr);

        (void) thread_funnel_set(kernel_flock, funnel_state);
}


/*
 * reap_child_process
 *
 * Description: Given a process from which all status information needed
 *              has already been extracted, if the process is a ptrace
 *              attach process, detach it and give it back to its real
 *              parent, else recover all resources remaining associated
 *              with it.
 *
 * Parameters:  struct proc *parent     Parent of process being reaped
 *              struct proc *child      Process to reap
 *
 * Returns:     0                       Process was not reaped because it
 *                                      came from an attach
 *              1                       Process was reaped
 */
static int
reap_child_process(struct proc *parent, struct proc *child)
{
        struct proc *trace_parent;      /* Traced parent process, if tracing */
        struct vnode *tvp;              /* Traced vnode pointer, if used */

        /*
         * If we got the child via a ptrace 'attach',
         * we need to give it back to the old parent.
         */
        if (child->p_oppid && (trace_parent = pfind(child->p_oppid))) {
                child->p_oppid = 0;
                proc_reparent(child, trace_parent);
                if (trace_parent != initproc) {
                        trace_parent->si_pid = child->p_pid;
                        trace_parent->si_status = child->p_xstat;
                        trace_parent->si_code = CLD_CONTINUED;
                        trace_parent->si_uid = child->p_ucred->cr_ruid;
                }
                psignal(trace_parent, SIGCHLD);
                wakeup((caddr_t)trace_parent);
                return (0);
        }
        child->p_xstat = 0;
        if (child->p_ru) {
                ruadd(&parent->p_stats->p_cru, child->p_ru);
                FREE_ZONE(child->p_ru, sizeof *child->p_ru, M_ZOMBIE);
                child->p_ru = NULL;
        } else {
                printf("Warning : lost p_ru for %s\n", child->p_comm);
        }

        /*
         * Decrement the count of procs running with this uid.
         */
        (void)chgproccnt(child->p_ucred->cr_ruid, -1);

        /*
         * Free up credentials.
         */
        if (child->p_ucred != NOCRED) {
                kauth_cred_t ucr = child->p_ucred;
                        child->p_ucred = NOCRED;
                        kauth_cred_rele(ucr);
                }

        /*
         * Release reference to text vnode
         */
        tvp = child->p_textvp;
        child->p_textvp = NULL;
        if (tvp) {
                vnode_rele(tvp);
        }
        /*
         * Finally finished with old proc entry.
         * Unlink it from its process group and free it.
         */
        leavepgrp(child);
        LIST_REMOVE(child, p_list);     /* off zombproc */
        LIST_REMOVE(child, p_sibling);
        child->p_lflag &= ~P_LWAITING;
        wakeup(&child->p_stat);

        lck_mtx_destroy(&child->p_mlock, proc_lck_grp);
        lck_mtx_destroy(&child->p_fdmlock, proc_lck_grp);
        FREE_ZONE(child, sizeof *child, M_PROC);
        nprocs--;
        return (1);
}


int
wait1continue(int result)
{
        void *vt;
        thread_t thread;
        int *retval;
        struct proc *p;

        if (result)
                return(result);

        p = current_proc();
        thread = current_thread();
        vt = get_bsduthreadarg(thread);
        retval = get_bsduthreadrval(thread);
        return(wait4((struct proc *)p, (struct wait4_args *)vt, retval));
}

int
wait4(struct proc *q, struct wait4_args *uap, register_t *retval)
{
        register int nfound;
        register struct proc *p;
        int status, error;

        if (uap->pid == 0)
                uap->pid = -q->p_pgid;

loop:
        nfound = 0;
        for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) {
                if (uap->pid != WAIT_ANY &&
                    p->p_pid != uap->pid &&
                    p->p_pgid != -(uap->pid))
                        continue;
                nfound++;

                /* XXX This is racy because we don't get the lock!!!! */

                if (p->p_lflag & P_LWAITING) {
                        (void)tsleep(&p->p_stat, PWAIT, "waitcoll", 0);
                        goto loop;
                }
                p->p_lflag |= P_LWAITING;   /* only allow single thread to wait() */

                if (p->p_stat == SZOMB) {
                        retval[0] = p->p_pid;
                        if (uap->status) {
                                status = p->p_xstat;    /* convert to int */
                                error = copyout((caddr_t)&status,
                                                        uap->status,
                                                    sizeof(status));
                                if (error) {
                                        p->p_lflag &= ~P_LWAITING;
                                        wakeup(&p->p_stat);
                                        return (error);
                                }
                        }
                        if (uap->rusage) {
                                if (p->p_ru == NULL) {
                                        error = ENOMEM;
                                } else {
                                        if (IS_64BIT_PROCESS(q)) {
                                                struct user_rusage      my_rusage;
                                                munge_rusage(p->p_ru, &my_rusage);
                                                error = copyout((caddr_t)&my_rusage,
                                                        uap->rusage,
                                                        sizeof (my_rusage));
                                        }
                                        else {
                                                error = copyout((caddr_t)p->p_ru,
                                                        uap->rusage,
                                                        sizeof (struct rusage));
                                        }
                                }
                                /* information unavailable? */
                                if (error) {
                                        p->p_lflag &= ~P_LWAITING;
                                        wakeup(&p->p_stat);
                                        return (error);
                                }
                        }

                        /* Clean up */
                        if (!reap_child_process(q, p)) {
                                p->p_lflag &= ~P_LWAITING;
                                wakeup(&p->p_stat);
                        }

                        return (0);
                }
                if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
                    (p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
                        p->p_flag |= P_WAITED;
                        retval[0] = p->p_pid;
                        if (uap->status) {
                                status = W_STOPCODE(p->p_xstat);
                                error = copyout((caddr_t)&status,
                                        uap->status,
                                    sizeof(status));
                        } else
                                error = 0;
                        p->p_lflag &= ~P_LWAITING;
                        wakeup(&p->p_stat);
                        return (error);
                }
                p->p_lflag &= ~P_LWAITING;
                wakeup(&p->p_stat);
        }
        if (nfound == 0)
                return (ECHILD);

        if (uap->options & WNOHANG) {
                retval[0] = 0;
                return (0);
        }

        if ((error = tsleep0((caddr_t)q, PWAIT | PCATCH, "wait", 0, wait1continue)))
                return (error);

        goto loop;
}


int
waitidcontinue(int result)
{
        void *vt;
        thread_t thread;
        int *retval;
        struct proc *p;

        if (result)
                return(result);

        p = current_proc();
        thread = current_thread();
        vt = get_bsduthreadarg(thread);
        retval = get_bsduthreadrval(thread);
        return(waitid((struct proc *)p, (struct waitid_args *)vt, retval));
}

/*
 * Description: Suspend the calling thread until one child of the process
 *              containing the calling thread changes state.
 *
 * Parameters:  uap->idtype             one of P_PID, P_PGID, P_ALL
 *              uap->id                 pid_t or gid_t or ignored
 *              uap->infop              Address of signinfo_t struct in
 *                                      user space into which to return status
 *              uap->options            flag values
 *
 * Returns:     0                       Success
 *              !0                      Error returning status to user space
 */
int
waitid(struct proc *q, struct waitid_args *uap, register_t *retval)
{
        user_siginfo_t  collect64;      /* siginfo data to return to caller */

        register int nfound;
        register struct proc *p;
        int error;

loop:
        nfound = 0;
        for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) {
                switch(uap->idtype) {
                case P_PID:     /* child with process ID equal to... */
                        if (p->p_pid != (pid_t)uap->id)
                                continue;
                        break;
                case P_PGID:    /* child with process group ID equal to... */
                        if (p->p_pgid != (pid_t)uap->id)
                                continue;
                        break;
                case P_ALL:     /* any child */
                        break;
                }

                /* XXX This is racy because we don't get the lock!!!! */

                /*
                 * Wait collision; go to sleep and restart; used to maintain
                 * the single return for waited process guarantee.
                 */
                if (p->p_lflag & P_LWAITING) {
                        (void)tsleep(&p->p_stat, PWAIT, "waitidcoll", 0);
                        goto loop;
                }
                p->p_lflag |= P_LWAITING;               /* mark busy */

                nfound++;

                /*
                 * Types of processes we are interested in
                 *
                 * XXX Don't know what to do for WCONTINUED?!?
                 */
                switch(p->p_stat) {
                case SZOMB:             /* Exited */
                        if (!(uap->options & WEXITED))
                                break;

                        /* Collect "siginfo" information for caller */
                        collect64.si_signo = 0;
                        collect64.si_code = 0;
                        collect64.si_errno = 0;
                        collect64.si_pid = 0;
                        collect64.si_uid = 0;
                        collect64.si_addr  = 0;
                        collect64.si_status = p->p_xstat;
                        collect64.si_band = 0;

                        if (IS_64BIT_PROCESS(p)) {
                                error = copyout((caddr_t)&collect64,
                                        uap->infop,
                                        sizeof(collect64));
                        } else {
                                siginfo_t collect;
                                siginfo_64to32(&collect64,&collect);
                                error = copyout((caddr_t)&collect,
                                        uap->infop,
                                        sizeof(collect));
                        }
                        /* information unavailable? */
                        if (error) {
                                p->p_lflag &= ~P_LWAITING;
                                wakeup(&p->p_stat);
                                return (error);
                        }

                        /* Prevent other process for waiting for this event? */
                        if (!(uap->options & WNOWAIT)) {
                                /* Clean up */
                                if (!reap_child_process(q, p)) {
                                        p->p_lflag &= ~P_LWAITING;
                                        wakeup(&p->p_stat);
                                }
                        }

                        return (0);

                case SSTOP:             /* Stopped */
                        /*
                         * If we are not interested in stopped processes, then
                         * ignore this one.
                         */
                        if (!(uap->options & WSTOPPED))
                                break;

                        /*
                         * If someone has already waited it, we lost a race
                         * to be the one to return status.
                         */
                        if ((p->p_flag & P_WAITED) != 0)
                                break;

                        /*
                         * If this is not a traced process, and they haven't
                         * indicated an interest in untraced processes, then
                         * ignore this one.
                         */
                        if (!(p->p_flag & P_TRACED) && !(uap->options & WUNTRACED))
                                break;

                        /* Collect "siginfo" information for caller */
                        collect64.si_signo = 0;
                        collect64.si_code = 0;
                        collect64.si_errno = 0;
                        collect64.si_pid = 0;
                        collect64.si_uid = 0;
                        collect64.si_addr  = 0;
                        collect64.si_status = p->p_xstat;
                        collect64.si_band = 0;

                        if (IS_64BIT_PROCESS(p)) {
                                error = copyout((caddr_t)&collect64,
                                        uap->infop,
                                        sizeof(collect64));
                        } else {
                                siginfo_t collect;
                                siginfo_64to32(&collect64,&collect);
                                error = copyout((caddr_t)&collect,
                                        uap->infop,
                                        sizeof(collect));
                        }
                        /* information unavailable? */
                        if (error) {
                                p->p_lflag &= ~P_LWAITING;
                                wakeup(&p->p_stat);
                                return (error);
                        }

                        /* Prevent other process for waiting for this event? */
                        if (!(uap->options & WNOWAIT)) {
                                p->p_flag |= P_WAITED;
                        }

                        p->p_lflag &= ~P_LWAITING;
                        wakeup(&p->p_stat);
                        return (0);

                default:                /* All others */
                                        /* ...meaning Continued */
                        if (!(uap->options & WCONTINUED))
                                break;

                        /*
                         * If the flag isn't set, then this process has not
                         * been stopped and continued, or the status has
                         * already been reaped by another caller of waitid().
                         */
                        if ((p->p_flag & P_CONTINUED) == 0)
                                break;

                        /* Collect "siginfo" information for caller */
                        collect64.si_signo = 0;
                        collect64.si_code = 0;
                        collect64.si_errno = 0;
                        collect64.si_pid = 0;
                        collect64.si_uid = 0;
                        collect64.si_addr  = 0;
                        collect64.si_status = p->p_xstat;
                        collect64.si_band = 0;

                        if (IS_64BIT_PROCESS(p)) {
                                error = copyout((caddr_t)&collect64,
                                        uap->infop,
                                        sizeof(collect64));
                        } else {
                                siginfo_t collect;
                                siginfo_64to32(&collect64,&collect);
                                error = copyout((caddr_t)&collect,
                                        uap->infop,
                                        sizeof(collect));
                        }
                        /* information unavailable? */
                        if (error) {
                                p->p_lflag &= ~P_LWAITING;
                                wakeup(&p->p_stat);
                                return (error);
                        }

                        /* Prevent other process for waiting for this event? */
                        if (!(uap->options & WNOWAIT)) {
                                p->p_flag &= ~P_CONTINUED;
                        }

                        p->p_lflag &= ~P_LWAITING;
                        wakeup(&p->p_stat);
                        return (0);

                        break;
                }


                /* Not a process we are interested in; go on to next child */
                p->p_lflag &= ~P_LWAITING;
                wakeup(&p->p_stat);
        }

        /* No child processes that could possibly satisfy the request? */
        if (nfound == 0)
                return (ECHILD);

        if (uap->options & WNOHANG) {
                retval[0] = 0;
                return (0);
        }

        if ((error = tsleep0((caddr_t)q, PWAIT | PCATCH, "waitid", 0, waitidcontinue)))
                return (error);

        goto loop;
}

/*
 * make process 'parent' the new parent of process 'child'.
 */
void
proc_reparent(struct proc *child, struct proc *parent)
{

        if (child->p_pptr == parent)
                return;

        LIST_REMOVE(child, p_sibling);
        LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
        child->p_pptr = parent;

        if (initproc == parent && child->p_stat == SZOMB)
                psignal(initproc, SIGCHLD);
}

/*
 *      Make the current process an "init" process, meaning
 *      that it doesn't have a parent, and that it won't be
 *      gunned down by kill(-1, 0).
 */
kern_return_t
init_process(__unused struct init_process_args *args)
{
        register struct proc *p = current_proc();

        AUDIT_MACH_SYSCALL_ENTER(AUE_INITPROCESS);
        if (suser(kauth_cred_get(), &p->p_acflag)) {
                AUDIT_MACH_SYSCALL_EXIT(KERN_NO_ACCESS);
                return(KERN_NO_ACCESS);
        }

        if (p->p_pid != 1 && p->p_pgid != p->p_pid)
                enterpgrp(p, p->p_pid, 0);
        p->p_flag |= P_SYSTEM;

        /*
         *      Take us out of the sibling chain, and
         *      out of our parent's child chain.
         */
        LIST_REMOVE(p, p_sibling);
        p->p_sibling.le_prev = NULL;
        p->p_sibling.le_next = NULL;
        p->p_pptr = kernproc;

        AUDIT_MACH_SYSCALL_EXIT(KERN_SUCCESS);
        return(KERN_SUCCESS);
}


/*
 * Exit: deallocate address space and other resources, change proc state
 * to zombie, and unlink proc from allproc and parent's lists.  Save exit
 * status and rusage for wait().  Check for child processes and orphan them.
 */

void
vfork_exit(struct proc *p, int rv)
{
        thread_t self = current_thread();
#ifdef FIXME
        struct task *task = p->task;
#endif
        register int s;
        struct uthread *ut;
        exception_data_t        code[EXCEPTION_CODE_MAX];

        /*
         * If a thread in this task has already
         * called exit(), then halt any others
         * right here.
         */

         ut = get_bsdthread_info(self);
#ifdef FIXME
        signal_lock(p);
        while (p->exit_thread != self) {
                if (sig_try_locked(p) <= 0) {
                        if (get_threadtask(self) != task) {
                                signal_unlock(p);
                                return;
                        }
                        signal_unlock(p);
                        thread_terminate(self);
                        thread_funnel_set(kernel_flock, FALSE);
                        thread_exception_return();
                        /* NOTREACHED */
                }
                sig_lock_to_exit(p);
        }
        signal_unlock(p);
        if (p->p_pid == 1) {
                printf("pid 1 exited (signal %d, exit %d)",
                    WTERMSIG(rv), WEXITSTATUS(rv));
panic("init died\nState at Last Exception:\n\n%s", init_task_failure_data);
        }
#endif /* FIXME */

        s = splsched();
        p->p_flag |= P_WEXIT;
        p->p_lflag |= P_LPEXIT;
        splx(s);

        code[0] = (exception_data_t)0xFF000001;         /* Set terminate code */
        code[1] = (exception_data_t)p->p_pid;           /* Pass out the pid */
        /* Notify the perf server */
        (void)sys_perf_notify(p->task, (exception_data_t)&code, 2);

        /*
         * Remove proc from allproc queue and from pidhash chain.
         * Need to do this before we do anything that can block.
         * Not doing causes things like mount() find this on allproc
         * in partially cleaned state.
         */
        LIST_REMOVE(p, p_list);
        LIST_INSERT_HEAD(&zombproc, p, p_list); /* Place onto zombproc. */
        LIST_REMOVE(p, p_hash);
        /*
         * If parent is waiting for us to exit or exec,
         * P_PPWAIT is set; we will wakeup the parent below.
         */
        p->p_flag &= ~(P_TRACED | P_PPWAIT);
        p->p_sigignore = ~0;
        p->p_siglist = 0;

        ut->uu_siglist = 0;
        untimeout(realitexpire, (caddr_t)p->p_pid);

        p->p_xstat = rv;

        vproc_exit(p);
}

void 
vproc_exit(struct proc *p)
{
        register struct proc *q, *nq, *pp;
#ifdef FIXME
        struct task *task = p->task;
#endif

        /* XXX Zombie allocation may fail, in which case stats get lost */
        MALLOC_ZONE(p->p_ru, struct rusage *,
                        sizeof (*p->p_ru), M_ZOMBIE, M_WAITOK);

        /*
         * Close open files and release open-file table.
         * This may block!
         */
        fdfree(p);

        if (SESS_LEADER(p)) {
                register struct session *sp = p->p_session;

                if (sp->s_ttyvp) {
                        struct vnode *ttyvp;
                        struct vfs_context context;

                        /*
                         * Controlling process.
                         * Signal foreground pgrp,
                         * drain controlling terminal
                         * and revoke access to controlling terminal.
                         */
                        if (sp->s_ttyp->t_session == sp) {
                                if (sp->s_ttyp->t_pgrp)
                                        pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
                                (void) ttywait(sp->s_ttyp);
                                /*
                                 * The tty could have been revoked
                                 * if we blocked.
                                 */
                                context.vc_proc = p;
                                context.vc_ucred = p->p_ucred;
                                if (sp->s_ttyvp)
                                        VNOP_REVOKE(sp->s_ttyvp, REVOKEALL, &context);
                        }
                        ttyvp = sp->s_ttyvp;
                        sp->s_ttyvp = NULL;
                        if (ttyvp) {
                                vnode_rele(ttyvp);
                        }
                        /*
                         * s_ttyp is not zero'd; we use this to indicate
                         * that the session once had a controlling terminal.
                         * (for logging and informational purposes)
                         */
                }
                sp->s_leader = NULL;
        }

        fixjobc(p, p->p_pgrp, 0);
        p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;

#if KTRACE
        /* 
         * release trace file
         */
        p->p_traceflag = 0;     /* don't trace the vnode_rele() */
        if (p->p_tracep) {
                struct vnode *tvp = p->p_tracep;
                p->p_tracep = NULL;
                vnode_rele(tvp);
        }
#endif

        while (q = p->p_children.lh_first) {
                proc_reparent(q, initproc);
                /*
                 * Traced processes are killed
                 * since their existence means someone is messing up.
                 */
                if (q->p_flag & P_TRACED) {
                        q->p_flag &= ~P_TRACED;
                        if (q->sigwait_thread) {
                                /*
                                 * The sigwait_thread could be stopped at a
                                 * breakpoint. Wake it up to kill.
                                 * Need to do this as it could be a thread which is not
                                 * the first thread in the task. So any attempts to kill
                                 * the process would result into a deadlock on q->sigwait.
                                 */
                                thread_resume((thread_t)q->sigwait_thread);
                                clear_wait(q->sigwait_thread, THREAD_INTERRUPTED);
                                threadsignal((thread_t)q->sigwait_thread, SIGKILL, 0);
                        }
                        psignal(q, SIGKILL);
                }
        }

        /*
         * Save exit status and final rusage info, adding in child rusage
         * info and self times.  If we were unable to allocate a zombie
         * structure, this information is lost.
         */
        if (p->p_ru != NULL) {
            *p->p_ru = p->p_stats->p_ru;
            timerclear(&p->p_ru->ru_utime);
            timerclear(&p->p_ru->ru_stime);

#ifdef  FIXME
            if (task) {
                task_basic_info_data_t tinfo;
                task_thread_times_info_data_t ttimesinfo;
                int task_info_stuff, task_ttimes_stuff;
                struct timeval ut,st;

                task_info_stuff = TASK_BASIC_INFO_COUNT;
                task_info(task, TASK_BASIC_INFO,
                          &tinfo, &task_info_stuff);
                p->p_ru->ru_utime.tv_sec = tinfo.user_time.seconds;
                p->p_ru->ru_utime.tv_usec = tinfo.user_time.microseconds;
                p->p_ru->ru_stime.tv_sec = tinfo.system_time.seconds;
                p->p_ru->ru_stime.tv_usec = tinfo.system_time.microseconds;

                task_ttimes_stuff = TASK_THREAD_TIMES_INFO_COUNT;
                task_info(task, TASK_THREAD_TIMES_INFO,
                          &ttimesinfo, &task_ttimes_stuff);

                ut.tv_sec = ttimesinfo.user_time.seconds;
                ut.tv_usec = ttimesinfo.user_time.microseconds;
                st.tv_sec = ttimesinfo.system_time.seconds;
                st.tv_usec = ttimesinfo.system_time.microseconds;
                timeradd(&ut,&p->p_ru->ru_utime,&p->p_ru->ru_utime);
                        timeradd(&st,&p->p_ru->ru_stime,&p->p_ru->ru_stime);
            }
#endif /* FIXME */

            ruadd(p->p_ru, &p->p_stats->p_cru);
        }

        /*
         * Free up profiling buffers.
         */
        {
                struct uprof *p0 = &p->p_stats->p_prof, *p1, *pn;

                p1 = p0->pr_next;
                p0->pr_next = NULL;
                p0->pr_scale = 0;

                for (; p1 != NULL; p1 = pn) {
                        pn = p1->pr_next;
                        kfree(p1, sizeof *p1);
                }
        }

        /*
         * Other substructures are freed from wait().
         */
        FREE_ZONE(p->p_stats, sizeof *p->p_stats, M_SUBPROC);
        p->p_stats = NULL;

        FREE_ZONE(p->p_sigacts, sizeof *p->p_sigacts, M_SUBPROC);
        p->p_sigacts = NULL;

        if (--p->p_limit->p_refcnt == 0)
                FREE_ZONE(p->p_limit, sizeof *p->p_limit, M_SUBPROC);
        p->p_limit = NULL;

        /*
         * Finish up by terminating the task
         * and halt this thread (only if a
         * member of the task exiting).
         */
        p->task = TASK_NULL;

        /*
         * Notify parent that we're gone.
         */
        pp = p->p_pptr;
        if (pp != initproc) {
                pp->si_pid = p->p_pid;
                pp->si_status = p->p_xstat;
                pp->si_code = CLD_EXITED;
                pp->si_uid = p->p_ucred->cr_ruid;
        }
        /* mark as a zombie */
        p->p_stat = SZOMB;

        psignal(p->p_pptr, SIGCHLD);

        /* and now wakeup the parent */
        wakeup((caddr_t)p->p_pptr);
}

                                                
/*
 * munge_rusage
 *      LP64 support - long is 64 bits if we are dealing with a 64 bit user
 *      process.  We munge the kernel (32 bit) version of rusage into the
 *      64 bit version.
 */
__private_extern__  void 
munge_rusage(struct rusage *a_rusage_p, struct user_rusage *a_user_rusage_p)
{
        /* timeval changes size, so utime and stime need special handling */
        a_user_rusage_p->ru_utime.tv_sec = a_rusage_p->ru_utime.tv_sec;
        a_user_rusage_p->ru_utime.tv_usec = a_rusage_p->ru_utime.tv_usec;
        a_user_rusage_p->ru_stime.tv_sec = a_rusage_p->ru_stime.tv_sec;
        a_user_rusage_p->ru_stime.tv_usec = a_rusage_p->ru_stime.tv_usec;
        /*
         * everything else can be a direct assign, since there is no loss
         * of precision implied boing 32->64.
         */
        a_user_rusage_p->ru_maxrss = a_rusage_p->ru_maxrss;
        a_user_rusage_p->ru_ixrss = a_rusage_p->ru_ixrss;
        a_user_rusage_p->ru_idrss = a_rusage_p->ru_idrss;
        a_user_rusage_p->ru_isrss = a_rusage_p->ru_isrss;
        a_user_rusage_p->ru_minflt = a_rusage_p->ru_minflt;
        a_user_rusage_p->ru_majflt = a_rusage_p->ru_majflt;
        a_user_rusage_p->ru_nswap = a_rusage_p->ru_nswap;
        a_user_rusage_p->ru_inblock = a_rusage_p->ru_inblock;
        a_user_rusage_p->ru_oublock = a_rusage_p->ru_oublock;
        a_user_rusage_p->ru_msgsnd = a_rusage_p->ru_msgsnd;
        a_user_rusage_p->ru_msgrcv = a_rusage_p->ru_msgrcv;
        a_user_rusage_p->ru_nsignals = a_rusage_p->ru_nsignals;
        a_user_rusage_p->ru_nvcsw = a_rusage_p->ru_nvcsw;
        a_user_rusage_p->ru_nivcsw = a_rusage_p->ru_nivcsw;
}