diff --git a/kernel/exit.c b/kernel/exit.c
new file mode 100644
index 0000000..6dd4ebe
--- /dev/null
+++ b/kernel/exit.c
@@ -0,0 +1,1527 @@
+/*
+ *  linux/kernel/exit.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/config.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/smp_lock.h>
+#include <linux/module.h>
+#include <linux/completion.h>
+#include <linux/personality.h>
+#include <linux/tty.h>
+#include <linux/namespace.h>
+#include <linux/key.h>
+#include <linux/security.h>
+#include <linux/cpu.h>
+#include <linux/acct.h>
+#include <linux/file.h>
+#include <linux/binfmts.h>
+#include <linux/ptrace.h>
+#include <linux/profile.h>
+#include <linux/mount.h>
+#include <linux/proc_fs.h>
+#include <linux/mempolicy.h>
+#include <linux/cpuset.h>
+#include <linux/syscalls.h>
+
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+#include <asm/pgtable.h>
+#include <asm/mmu_context.h>
+
+extern void sem_exit (void);
+extern struct task_struct *child_reaper;
+
+int getrusage(struct task_struct *, int, struct rusage __user *);
+
+static void __unhash_process(struct task_struct *p)
+{
+	nr_threads--;
+	detach_pid(p, PIDTYPE_PID);
+	detach_pid(p, PIDTYPE_TGID);
+	if (thread_group_leader(p)) {
+		detach_pid(p, PIDTYPE_PGID);
+		detach_pid(p, PIDTYPE_SID);
+		if (p->pid)
+			__get_cpu_var(process_counts)--;
+	}
+
+	REMOVE_LINKS(p);
+}
+
+void release_task(struct task_struct * p)
+{
+	int zap_leader;
+	task_t *leader;
+	struct dentry *proc_dentry;
+
+repeat: 
+	atomic_dec(&p->user->processes);
+	spin_lock(&p->proc_lock);
+	proc_dentry = proc_pid_unhash(p);
+	write_lock_irq(&tasklist_lock);
+	if (unlikely(p->ptrace))
+		__ptrace_unlink(p);
+	BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
+	__exit_signal(p);
+	__exit_sighand(p);
+	__unhash_process(p);
+
+	/*
+	 * If we are the last non-leader member of the thread
+	 * group, and the leader is zombie, then notify the
+	 * group leader's parent process. (if it wants notification.)
+	 */
+	zap_leader = 0;
+	leader = p->group_leader;
+	if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
+		BUG_ON(leader->exit_signal == -1);
+		do_notify_parent(leader, leader->exit_signal);
+		/*
+		 * If we were the last child thread and the leader has
+		 * exited already, and the leader's parent ignores SIGCHLD,
+		 * then we are the one who should release the leader.
+		 *
+		 * do_notify_parent() will have marked it self-reaping in
+		 * that case.
+		 */
+		zap_leader = (leader->exit_signal == -1);
+	}
+
+	sched_exit(p);
+	write_unlock_irq(&tasklist_lock);
+	spin_unlock(&p->proc_lock);
+	proc_pid_flush(proc_dentry);
+	release_thread(p);
+	put_task_struct(p);
+
+	p = leader;
+	if (unlikely(zap_leader))
+		goto repeat;
+}
+
+/* we are using it only for SMP init */
+
+void unhash_process(struct task_struct *p)
+{
+	struct dentry *proc_dentry;
+
+	spin_lock(&p->proc_lock);
+	proc_dentry = proc_pid_unhash(p);
+	write_lock_irq(&tasklist_lock);
+	__unhash_process(p);
+	write_unlock_irq(&tasklist_lock);
+	spin_unlock(&p->proc_lock);
+	proc_pid_flush(proc_dentry);
+}
+
+/*
+ * This checks not only the pgrp, but falls back on the pid if no
+ * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
+ * without this...
+ */
+int session_of_pgrp(int pgrp)
+{
+	struct task_struct *p;
+	int sid = -1;
+
+	read_lock(&tasklist_lock);
+	do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
+		if (p->signal->session > 0) {
+			sid = p->signal->session;
+			goto out;
+		}
+	} while_each_task_pid(pgrp, PIDTYPE_PGID, p);
+	p = find_task_by_pid(pgrp);
+	if (p)
+		sid = p->signal->session;
+out:
+	read_unlock(&tasklist_lock);
+	
+	return sid;
+}
+
+/*
+ * Determine if a process group is "orphaned", according to the POSIX
+ * definition in 2.2.2.52.  Orphaned process groups are not to be affected
+ * by terminal-generated stop signals.  Newly orphaned process groups are
+ * to receive a SIGHUP and a SIGCONT.
+ *
+ * "I ask you, have you ever known what it is to be an orphan?"
+ */
+static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task)
+{
+	struct task_struct *p;
+	int ret = 1;
+
+	do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
+		if (p == ignored_task
+				|| p->exit_state
+				|| p->real_parent->pid == 1)
+			continue;
+		if (process_group(p->real_parent) != pgrp
+			    && p->real_parent->signal->session == p->signal->session) {
+			ret = 0;
+			break;
+		}
+	} while_each_task_pid(pgrp, PIDTYPE_PGID, p);
+	return ret;	/* (sighing) "Often!" */
+}
+
+int is_orphaned_pgrp(int pgrp)
+{
+	int retval;
+
+	read_lock(&tasklist_lock);
+	retval = will_become_orphaned_pgrp(pgrp, NULL);
+	read_unlock(&tasklist_lock);
+
+	return retval;
+}
+
+static inline int has_stopped_jobs(int pgrp)
+{
+	int retval = 0;
+	struct task_struct *p;
+
+	do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
+		if (p->state != TASK_STOPPED)
+			continue;
+
+		/* If p is stopped by a debugger on a signal that won't
+		   stop it, then don't count p as stopped.  This isn't
+		   perfect but it's a good approximation.  */
+		if (unlikely (p->ptrace)
+		    && p->exit_code != SIGSTOP
+		    && p->exit_code != SIGTSTP
+		    && p->exit_code != SIGTTOU
+		    && p->exit_code != SIGTTIN)
+			continue;
+
+		retval = 1;
+		break;
+	} while_each_task_pid(pgrp, PIDTYPE_PGID, p);
+	return retval;
+}
+
+/**
+ * reparent_to_init() - Reparent the calling kernel thread to the init task.
+ *
+ * If a kernel thread is launched as a result of a system call, or if
+ * it ever exits, it should generally reparent itself to init so that
+ * it is correctly cleaned up on exit.
+ *
+ * The various task state such as scheduling policy and priority may have
+ * been inherited from a user process, so we reset them to sane values here.
+ *
+ * NOTE that reparent_to_init() gives the caller full capabilities.
+ */
+void reparent_to_init(void)
+{
+	write_lock_irq(&tasklist_lock);
+
+	ptrace_unlink(current);
+	/* Reparent to init */
+	REMOVE_LINKS(current);
+	current->parent = child_reaper;
+	current->real_parent = child_reaper;
+	SET_LINKS(current);
+
+	/* Set the exit signal to SIGCHLD so we signal init on exit */
+	current->exit_signal = SIGCHLD;
+
+	if ((current->policy == SCHED_NORMAL) && (task_nice(current) < 0))
+		set_user_nice(current, 0);
+	/* cpus_allowed? */
+	/* rt_priority? */
+	/* signals? */
+	security_task_reparent_to_init(current);
+	memcpy(current->signal->rlim, init_task.signal->rlim,
+	       sizeof(current->signal->rlim));
+	atomic_inc(&(INIT_USER->__count));
+	write_unlock_irq(&tasklist_lock);
+	switch_uid(INIT_USER);
+}
+
+void __set_special_pids(pid_t session, pid_t pgrp)
+{
+	struct task_struct *curr = current;
+
+	if (curr->signal->session != session) {
+		detach_pid(curr, PIDTYPE_SID);
+		curr->signal->session = session;
+		attach_pid(curr, PIDTYPE_SID, session);
+	}
+	if (process_group(curr) != pgrp) {
+		detach_pid(curr, PIDTYPE_PGID);
+		curr->signal->pgrp = pgrp;
+		attach_pid(curr, PIDTYPE_PGID, pgrp);
+	}
+}
+
+void set_special_pids(pid_t session, pid_t pgrp)
+{
+	write_lock_irq(&tasklist_lock);
+	__set_special_pids(session, pgrp);
+	write_unlock_irq(&tasklist_lock);
+}
+
+/*
+ * Let kernel threads use this to say that they
+ * allow a certain signal (since daemonize() will
+ * have disabled all of them by default).
+ */
+int allow_signal(int sig)
+{
+	if (sig < 1 || sig > _NSIG)
+		return -EINVAL;
+
+	spin_lock_irq(&current->sighand->siglock);
+	sigdelset(&current->blocked, sig);
+	if (!current->mm) {
+		/* Kernel threads handle their own signals.
+		   Let the signal code know it'll be handled, so
+		   that they don't get converted to SIGKILL or
+		   just silently dropped */
+		current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
+	}
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+	return 0;
+}
+
+EXPORT_SYMBOL(allow_signal);
+
+int disallow_signal(int sig)
+{
+	if (sig < 1 || sig > _NSIG)
+		return -EINVAL;
+
+	spin_lock_irq(&current->sighand->siglock);
+	sigaddset(&current->blocked, sig);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+	return 0;
+}
+
+EXPORT_SYMBOL(disallow_signal);
+
+/*
+ *	Put all the gunge required to become a kernel thread without
+ *	attached user resources in one place where it belongs.
+ */
+
+void daemonize(const char *name, ...)
+{
+	va_list args;
+	struct fs_struct *fs;
+	sigset_t blocked;
+
+	va_start(args, name);
+	vsnprintf(current->comm, sizeof(current->comm), name, args);
+	va_end(args);
+
+	/*
+	 * If we were started as result of loading a module, close all of the
+	 * user space pages.  We don't need them, and if we didn't close them
+	 * they would be locked into memory.
+	 */
+	exit_mm(current);
+
+	set_special_pids(1, 1);
+	down(&tty_sem);
+	current->signal->tty = NULL;
+	up(&tty_sem);
+
+	/* Block and flush all signals */
+	sigfillset(&blocked);
+	sigprocmask(SIG_BLOCK, &blocked, NULL);
+	flush_signals(current);
+
+	/* Become as one with the init task */
+
+	exit_fs(current);	/* current->fs->count--; */
+	fs = init_task.fs;
+	current->fs = fs;
+	atomic_inc(&fs->count);
+ 	exit_files(current);
+	current->files = init_task.files;
+	atomic_inc(&current->files->count);
+
+	reparent_to_init();
+}
+
+EXPORT_SYMBOL(daemonize);
+
+static inline void close_files(struct files_struct * files)
+{
+	int i, j;
+
+	j = 0;
+	for (;;) {
+		unsigned long set;
+		i = j * __NFDBITS;
+		if (i >= files->max_fdset || i >= files->max_fds)
+			break;
+		set = files->open_fds->fds_bits[j++];
+		while (set) {
+			if (set & 1) {
+				struct file * file = xchg(&files->fd[i], NULL);
+				if (file)
+					filp_close(file, files);
+			}
+			i++;
+			set >>= 1;
+		}
+	}
+}
+
+struct files_struct *get_files_struct(struct task_struct *task)
+{
+	struct files_struct *files;
+
+	task_lock(task);
+	files = task->files;
+	if (files)
+		atomic_inc(&files->count);
+	task_unlock(task);
+
+	return files;
+}
+
+void fastcall put_files_struct(struct files_struct *files)
+{
+	if (atomic_dec_and_test(&files->count)) {
+		close_files(files);
+		/*
+		 * Free the fd and fdset arrays if we expanded them.
+		 */
+		if (files->fd != &files->fd_array[0])
+			free_fd_array(files->fd, files->max_fds);
+		if (files->max_fdset > __FD_SETSIZE) {
+			free_fdset(files->open_fds, files->max_fdset);
+			free_fdset(files->close_on_exec, files->max_fdset);
+		}
+		kmem_cache_free(files_cachep, files);
+	}
+}
+
+EXPORT_SYMBOL(put_files_struct);
+
+static inline void __exit_files(struct task_struct *tsk)
+{
+	struct files_struct * files = tsk->files;
+
+	if (files) {
+		task_lock(tsk);
+		tsk->files = NULL;
+		task_unlock(tsk);
+		put_files_struct(files);
+	}
+}
+
+void exit_files(struct task_struct *tsk)
+{
+	__exit_files(tsk);
+}
+
+static inline void __put_fs_struct(struct fs_struct *fs)
+{
+	/* No need to hold fs->lock if we are killing it */
+	if (atomic_dec_and_test(&fs->count)) {
+		dput(fs->root);
+		mntput(fs->rootmnt);
+		dput(fs->pwd);
+		mntput(fs->pwdmnt);
+		if (fs->altroot) {
+			dput(fs->altroot);
+			mntput(fs->altrootmnt);
+		}
+		kmem_cache_free(fs_cachep, fs);
+	}
+}
+
+void put_fs_struct(struct fs_struct *fs)
+{
+	__put_fs_struct(fs);
+}
+
+static inline void __exit_fs(struct task_struct *tsk)
+{
+	struct fs_struct * fs = tsk->fs;
+
+	if (fs) {
+		task_lock(tsk);
+		tsk->fs = NULL;
+		task_unlock(tsk);
+		__put_fs_struct(fs);
+	}
+}
+
+void exit_fs(struct task_struct *tsk)
+{
+	__exit_fs(tsk);
+}
+
+EXPORT_SYMBOL_GPL(exit_fs);
+
+/*
+ * Turn us into a lazy TLB process if we
+ * aren't already..
+ */
+void exit_mm(struct task_struct * tsk)
+{
+	struct mm_struct *mm = tsk->mm;
+
+	mm_release(tsk, mm);
+	if (!mm)
+		return;
+	/*
+	 * Serialize with any possible pending coredump.
+	 * We must hold mmap_sem around checking core_waiters
+	 * and clearing tsk->mm.  The core-inducing thread
+	 * will increment core_waiters for each thread in the
+	 * group with ->mm != NULL.
+	 */
+	down_read(&mm->mmap_sem);
+	if (mm->core_waiters) {
+		up_read(&mm->mmap_sem);
+		down_write(&mm->mmap_sem);
+		if (!--mm->core_waiters)
+			complete(mm->core_startup_done);
+		up_write(&mm->mmap_sem);
+
+		wait_for_completion(&mm->core_done);
+		down_read(&mm->mmap_sem);
+	}
+	atomic_inc(&mm->mm_count);
+	if (mm != tsk->active_mm) BUG();
+	/* more a memory barrier than a real lock */
+	task_lock(tsk);
+	tsk->mm = NULL;
+	up_read(&mm->mmap_sem);
+	enter_lazy_tlb(mm, current);
+	task_unlock(tsk);
+	mmput(mm);
+}
+
+static inline void choose_new_parent(task_t *p, task_t *reaper, task_t *child_reaper)
+{
+	/*
+	 * Make sure we're not reparenting to ourselves and that
+	 * the parent is not a zombie.
+	 */
+	BUG_ON(p == reaper || reaper->exit_state >= EXIT_ZOMBIE);
+	p->real_parent = reaper;
+	if (p->parent == p->real_parent)
+		BUG();
+}
+
+static inline void reparent_thread(task_t *p, task_t *father, int traced)
+{
+	/* We don't want people slaying init.  */
+	if (p->exit_signal != -1)
+		p->exit_signal = SIGCHLD;
+
+	if (p->pdeath_signal)
+		/* We already hold the tasklist_lock here.  */
+		group_send_sig_info(p->pdeath_signal, (void *) 0, p);
+
+	/* Move the child from its dying parent to the new one.  */
+	if (unlikely(traced)) {
+		/* Preserve ptrace links if someone else is tracing this child.  */
+		list_del_init(&p->ptrace_list);
+		if (p->parent != p->real_parent)
+			list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
+	} else {
+		/* If this child is being traced, then we're the one tracing it
+		 * anyway, so let go of it.
+		 */
+		p->ptrace = 0;
+		list_del_init(&p->sibling);
+		p->parent = p->real_parent;
+		list_add_tail(&p->sibling, &p->parent->children);
+
+		/* If we'd notified the old parent about this child's death,
+		 * also notify the new parent.
+		 */
+		if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
+		    thread_group_empty(p))
+			do_notify_parent(p, p->exit_signal);
+		else if (p->state == TASK_TRACED) {
+			/*
+			 * If it was at a trace stop, turn it into
+			 * a normal stop since it's no longer being
+			 * traced.
+			 */
+			ptrace_untrace(p);
+		}
+	}
+
+	/*
+	 * process group orphan check
+	 * Case ii: Our child is in a different pgrp
+	 * than we are, and it was the only connection
+	 * outside, so the child pgrp is now orphaned.
+	 */
+	if ((process_group(p) != process_group(father)) &&
+	    (p->signal->session == father->signal->session)) {
+		int pgrp = process_group(p);
+
+		if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
+			__kill_pg_info(SIGHUP, (void *)1, pgrp);
+			__kill_pg_info(SIGCONT, (void *)1, pgrp);
+		}
+	}
+}
+
+/*
+ * When we die, we re-parent all our children.
+ * Try to give them to another thread in our thread
+ * group, and if no such member exists, give it to
+ * the global child reaper process (ie "init")
+ */
+static inline void forget_original_parent(struct task_struct * father,
+					  struct list_head *to_release)
+{
+	struct task_struct *p, *reaper = father;
+	struct list_head *_p, *_n;
+
+	do {
+		reaper = next_thread(reaper);
+		if (reaper == father) {
+			reaper = child_reaper;
+			break;
+		}
+	} while (reaper->exit_state);
+
+	/*
+	 * There are only two places where our children can be:
+	 *
+	 * - in our child list
+	 * - in our ptraced child list
+	 *
+	 * Search them and reparent children.
+	 */
+	list_for_each_safe(_p, _n, &father->children) {
+		int ptrace;
+		p = list_entry(_p,struct task_struct,sibling);
+
+		ptrace = p->ptrace;
+
+		/* if father isn't the real parent, then ptrace must be enabled */
+		BUG_ON(father != p->real_parent && !ptrace);
+
+		if (father == p->real_parent) {
+			/* reparent with a reaper, real father it's us */
+			choose_new_parent(p, reaper, child_reaper);
+			reparent_thread(p, father, 0);
+		} else {
+			/* reparent ptraced task to its real parent */
+			__ptrace_unlink (p);
+			if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
+			    thread_group_empty(p))
+				do_notify_parent(p, p->exit_signal);
+		}
+
+		/*
+		 * if the ptraced child is a zombie with exit_signal == -1
+		 * we must collect it before we exit, or it will remain
+		 * zombie forever since we prevented it from self-reap itself
+		 * while it was being traced by us, to be able to see it in wait4.
+		 */
+		if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1))
+			list_add(&p->ptrace_list, to_release);
+	}
+	list_for_each_safe(_p, _n, &father->ptrace_children) {
+		p = list_entry(_p,struct task_struct,ptrace_list);
+		choose_new_parent(p, reaper, child_reaper);
+		reparent_thread(p, father, 1);
+	}
+}
+
+/*
+ * Send signals to all our closest relatives so that they know
+ * to properly mourn us..
+ */
+static void exit_notify(struct task_struct *tsk)
+{
+	int state;
+	struct task_struct *t;
+	struct list_head ptrace_dead, *_p, *_n;
+
+	if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT)
+	    && !thread_group_empty(tsk)) {
+		/*
+		 * This occurs when there was a race between our exit
+		 * syscall and a group signal choosing us as the one to
+		 * wake up.  It could be that we are the only thread
+		 * alerted to check for pending signals, but another thread
+		 * should be woken now to take the signal since we will not.
+		 * Now we'll wake all the threads in the group just to make
+		 * sure someone gets all the pending signals.
+		 */
+		read_lock(&tasklist_lock);
+		spin_lock_irq(&tsk->sighand->siglock);
+		for (t = next_thread(tsk); t != tsk; t = next_thread(t))
+			if (!signal_pending(t) && !(t->flags & PF_EXITING)) {
+				recalc_sigpending_tsk(t);
+				if (signal_pending(t))
+					signal_wake_up(t, 0);
+			}
+		spin_unlock_irq(&tsk->sighand->siglock);
+		read_unlock(&tasklist_lock);
+	}
+
+	write_lock_irq(&tasklist_lock);
+
+	/*
+	 * This does two things:
+	 *
+  	 * A.  Make init inherit all the child processes
+	 * B.  Check to see if any process groups have become orphaned
+	 *	as a result of our exiting, and if they have any stopped
+	 *	jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
+	 */
+
+	INIT_LIST_HEAD(&ptrace_dead);
+	forget_original_parent(tsk, &ptrace_dead);
+	BUG_ON(!list_empty(&tsk->children));
+	BUG_ON(!list_empty(&tsk->ptrace_children));
+
+	/*
+	 * Check to see if any process groups have become orphaned
+	 * as a result of our exiting, and if they have any stopped
+	 * jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
+	 *
+	 * Case i: Our father is in a different pgrp than we are
+	 * and we were the only connection outside, so our pgrp
+	 * is about to become orphaned.
+	 */
+	 
+	t = tsk->real_parent;
+	
+	if ((process_group(t) != process_group(tsk)) &&
+	    (t->signal->session == tsk->signal->session) &&
+	    will_become_orphaned_pgrp(process_group(tsk), tsk) &&
+	    has_stopped_jobs(process_group(tsk))) {
+		__kill_pg_info(SIGHUP, (void *)1, process_group(tsk));
+		__kill_pg_info(SIGCONT, (void *)1, process_group(tsk));
+	}
+
+	/* Let father know we died 
+	 *
+	 * Thread signals are configurable, but you aren't going to use
+	 * that to send signals to arbitary processes. 
+	 * That stops right now.
+	 *
+	 * If the parent exec id doesn't match the exec id we saved
+	 * when we started then we know the parent has changed security
+	 * domain.
+	 *
+	 * If our self_exec id doesn't match our parent_exec_id then
+	 * we have changed execution domain as these two values started
+	 * the same after a fork.
+	 *	
+	 */
+	
+	if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
+	    ( tsk->parent_exec_id != t->self_exec_id  ||
+	      tsk->self_exec_id != tsk->parent_exec_id)
+	    && !capable(CAP_KILL))
+		tsk->exit_signal = SIGCHLD;
+
+
+	/* If something other than our normal parent is ptracing us, then
+	 * send it a SIGCHLD instead of honoring exit_signal.  exit_signal
+	 * only has special meaning to our real parent.
+	 */
+	if (tsk->exit_signal != -1 && thread_group_empty(tsk)) {
+		int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD;
+		do_notify_parent(tsk, signal);
+	} else if (tsk->ptrace) {
+		do_notify_parent(tsk, SIGCHLD);
+	}
+
+	state = EXIT_ZOMBIE;
+	if (tsk->exit_signal == -1 &&
+	    (likely(tsk->ptrace == 0) ||
+	     unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT)))
+		state = EXIT_DEAD;
+	tsk->exit_state = state;
+
+	write_unlock_irq(&tasklist_lock);
+
+	list_for_each_safe(_p, _n, &ptrace_dead) {
+		list_del_init(_p);
+		t = list_entry(_p,struct task_struct,ptrace_list);
+		release_task(t);
+	}
+
+	/* If the process is dead, release it - nobody will wait for it */
+	if (state == EXIT_DEAD)
+		release_task(tsk);
+
+	/* PF_DEAD causes final put_task_struct after we schedule. */
+	preempt_disable();
+	tsk->flags |= PF_DEAD;
+}
+
+fastcall NORET_TYPE void do_exit(long code)
+{
+	struct task_struct *tsk = current;
+	int group_dead;
+
+	profile_task_exit(tsk);
+
+	if (unlikely(in_interrupt()))
+		panic("Aiee, killing interrupt handler!");
+	if (unlikely(!tsk->pid))
+		panic("Attempted to kill the idle task!");
+	if (unlikely(tsk->pid == 1))
+		panic("Attempted to kill init!");
+	if (tsk->io_context)
+		exit_io_context();
+
+	if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
+		current->ptrace_message = code;
+		ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
+	}
+
+	tsk->flags |= PF_EXITING;
+
+	/*
+	 * Make sure we don't try to process any timer firings
+	 * while we are already exiting.
+	 */
+ 	tsk->it_virt_expires = cputime_zero;
+ 	tsk->it_prof_expires = cputime_zero;
+	tsk->it_sched_expires = 0;
+
+	if (unlikely(in_atomic()))
+		printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
+				current->comm, current->pid,
+				preempt_count());
+
+	acct_update_integrals(tsk);
+	update_mem_hiwater(tsk);
+	group_dead = atomic_dec_and_test(&tsk->signal->live);
+	if (group_dead) {
+ 		del_timer_sync(&tsk->signal->real_timer);
+		acct_process(code);
+	}
+	exit_mm(tsk);
+
+	exit_sem(tsk);
+	__exit_files(tsk);
+	__exit_fs(tsk);
+	exit_namespace(tsk);
+	exit_thread();
+	cpuset_exit(tsk);
+	exit_keys(tsk);
+
+	if (group_dead && tsk->signal->leader)
+		disassociate_ctty(1);
+
+	module_put(tsk->thread_info->exec_domain->module);
+	if (tsk->binfmt)
+		module_put(tsk->binfmt->module);
+
+	tsk->exit_code = code;
+	exit_notify(tsk);
+#ifdef CONFIG_NUMA
+	mpol_free(tsk->mempolicy);
+	tsk->mempolicy = NULL;
+#endif
+
+	BUG_ON(!(current->flags & PF_DEAD));
+	schedule();
+	BUG();
+	/* Avoid "noreturn function does return".  */
+	for (;;) ;
+}
+
+NORET_TYPE void complete_and_exit(struct completion *comp, long code)
+{
+	if (comp)
+		complete(comp);
+	
+	do_exit(code);
+}
+
+EXPORT_SYMBOL(complete_and_exit);
+
+asmlinkage long sys_exit(int error_code)
+{
+	do_exit((error_code&0xff)<<8);
+}
+
+task_t fastcall *next_thread(const task_t *p)
+{
+	return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID);
+}
+
+EXPORT_SYMBOL(next_thread);
+
+/*
+ * Take down every thread in the group.  This is called by fatal signals
+ * as well as by sys_exit_group (below).
+ */
+NORET_TYPE void
+do_group_exit(int exit_code)
+{
+	BUG_ON(exit_code & 0x80); /* core dumps don't get here */
+
+	if (current->signal->flags & SIGNAL_GROUP_EXIT)
+		exit_code = current->signal->group_exit_code;
+	else if (!thread_group_empty(current)) {
+		struct signal_struct *const sig = current->signal;
+		struct sighand_struct *const sighand = current->sighand;
+		read_lock(&tasklist_lock);
+		spin_lock_irq(&sighand->siglock);
+		if (sig->flags & SIGNAL_GROUP_EXIT)
+			/* Another thread got here before we took the lock.  */
+			exit_code = sig->group_exit_code;
+		else {
+			sig->flags = SIGNAL_GROUP_EXIT;
+			sig->group_exit_code = exit_code;
+			zap_other_threads(current);
+		}
+		spin_unlock_irq(&sighand->siglock);
+		read_unlock(&tasklist_lock);
+	}
+
+	do_exit(exit_code);
+	/* NOTREACHED */
+}
+
+/*
+ * this kills every thread in the thread group. Note that any externally
+ * wait4()-ing process will get the correct exit code - even if this
+ * thread is not the thread group leader.
+ */
+asmlinkage void sys_exit_group(int error_code)
+{
+	do_group_exit((error_code & 0xff) << 8);
+}
+
+static int eligible_child(pid_t pid, int options, task_t *p)
+{
+	if (pid > 0) {
+		if (p->pid != pid)
+			return 0;
+	} else if (!pid) {
+		if (process_group(p) != process_group(current))
+			return 0;
+	} else if (pid != -1) {
+		if (process_group(p) != -pid)
+			return 0;
+	}
+
+	/*
+	 * Do not consider detached threads that are
+	 * not ptraced:
+	 */
+	if (p->exit_signal == -1 && !p->ptrace)
+		return 0;
+
+	/* Wait for all children (clone and not) if __WALL is set;
+	 * otherwise, wait for clone children *only* if __WCLONE is
+	 * set; otherwise, wait for non-clone children *only*.  (Note:
+	 * A "clone" child here is one that reports to its parent
+	 * using a signal other than SIGCHLD.) */
+	if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
+	    && !(options & __WALL))
+		return 0;
+	/*
+	 * Do not consider thread group leaders that are
+	 * in a non-empty thread group:
+	 */
+	if (current->tgid != p->tgid && delay_group_leader(p))
+		return 2;
+
+	if (security_task_wait(p))
+		return 0;
+
+	return 1;
+}
+
+static int wait_noreap_copyout(task_t *p, pid_t pid, uid_t uid,
+			       int why, int status,
+			       struct siginfo __user *infop,
+			       struct rusage __user *rusagep)
+{
+	int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0;
+	put_task_struct(p);
+	if (!retval)
+		retval = put_user(SIGCHLD, &infop->si_signo);
+	if (!retval)
+		retval = put_user(0, &infop->si_errno);
+	if (!retval)
+		retval = put_user((short)why, &infop->si_code);
+	if (!retval)
+		retval = put_user(pid, &infop->si_pid);
+	if (!retval)
+		retval = put_user(uid, &infop->si_uid);
+	if (!retval)
+		retval = put_user(status, &infop->si_status);
+	if (!retval)
+		retval = pid;
+	return retval;
+}
+
+/*
+ * Handle sys_wait4 work for one task in state EXIT_ZOMBIE.  We hold
+ * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
+ * the lock and this task is uninteresting.  If we return nonzero, we have
+ * released the lock and the system call should return.
+ */
+static int wait_task_zombie(task_t *p, int noreap,
+			    struct siginfo __user *infop,
+			    int __user *stat_addr, struct rusage __user *ru)
+{
+	unsigned long state;
+	int retval;
+	int status;
+
+	if (unlikely(noreap)) {
+		pid_t pid = p->pid;
+		uid_t uid = p->uid;
+		int exit_code = p->exit_code;
+		int why, status;
+
+		if (unlikely(p->exit_state != EXIT_ZOMBIE))
+			return 0;
+		if (unlikely(p->exit_signal == -1 && p->ptrace == 0))
+			return 0;
+		get_task_struct(p);
+		read_unlock(&tasklist_lock);
+		if ((exit_code & 0x7f) == 0) {
+			why = CLD_EXITED;
+			status = exit_code >> 8;
+		} else {
+			why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
+			status = exit_code & 0x7f;
+		}
+		return wait_noreap_copyout(p, pid, uid, why,
+					   status, infop, ru);
+	}
+
+	/*
+	 * Try to move the task's state to DEAD
+	 * only one thread is allowed to do this:
+	 */
+	state = xchg(&p->exit_state, EXIT_DEAD);
+	if (state != EXIT_ZOMBIE) {
+		BUG_ON(state != EXIT_DEAD);
+		return 0;
+	}
+	if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) {
+		/*
+		 * This can only happen in a race with a ptraced thread
+		 * dying on another processor.
+		 */
+		return 0;
+	}
+
+	if (likely(p->real_parent == p->parent) && likely(p->signal)) {
+		/*
+		 * The resource counters for the group leader are in its
+		 * own task_struct.  Those for dead threads in the group
+		 * are in its signal_struct, as are those for the child
+		 * processes it has previously reaped.  All these
+		 * accumulate in the parent's signal_struct c* fields.
+		 *
+		 * We don't bother to take a lock here to protect these
+		 * p->signal fields, because they are only touched by
+		 * __exit_signal, which runs with tasklist_lock
+		 * write-locked anyway, and so is excluded here.  We do
+		 * need to protect the access to p->parent->signal fields,
+		 * as other threads in the parent group can be right
+		 * here reaping other children at the same time.
+		 */
+		spin_lock_irq(&p->parent->sighand->siglock);
+		p->parent->signal->cutime =
+			cputime_add(p->parent->signal->cutime,
+			cputime_add(p->utime,
+			cputime_add(p->signal->utime,
+				    p->signal->cutime)));
+		p->parent->signal->cstime =
+			cputime_add(p->parent->signal->cstime,
+			cputime_add(p->stime,
+			cputime_add(p->signal->stime,
+				    p->signal->cstime)));
+		p->parent->signal->cmin_flt +=
+			p->min_flt + p->signal->min_flt + p->signal->cmin_flt;
+		p->parent->signal->cmaj_flt +=
+			p->maj_flt + p->signal->maj_flt + p->signal->cmaj_flt;
+		p->parent->signal->cnvcsw +=
+			p->nvcsw + p->signal->nvcsw + p->signal->cnvcsw;
+		p->parent->signal->cnivcsw +=
+			p->nivcsw + p->signal->nivcsw + p->signal->cnivcsw;
+		spin_unlock_irq(&p->parent->sighand->siglock);
+	}
+
+	/*
+	 * Now we are sure this task is interesting, and no other
+	 * thread can reap it because we set its state to EXIT_DEAD.
+	 */
+	read_unlock(&tasklist_lock);
+
+	retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
+	status = (p->signal->flags & SIGNAL_GROUP_EXIT)
+		? p->signal->group_exit_code : p->exit_code;
+	if (!retval && stat_addr)
+		retval = put_user(status, stat_addr);
+	if (!retval && infop)
+		retval = put_user(SIGCHLD, &infop->si_signo);
+	if (!retval && infop)
+		retval = put_user(0, &infop->si_errno);
+	if (!retval && infop) {
+		int why;
+
+		if ((status & 0x7f) == 0) {
+			why = CLD_EXITED;
+			status >>= 8;
+		} else {
+			why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
+			status &= 0x7f;
+		}
+		retval = put_user((short)why, &infop->si_code);
+		if (!retval)
+			retval = put_user(status, &infop->si_status);
+	}
+	if (!retval && infop)
+		retval = put_user(p->pid, &infop->si_pid);
+	if (!retval && infop)
+		retval = put_user(p->uid, &infop->si_uid);
+	if (retval) {
+		// TODO: is this safe?
+		p->exit_state = EXIT_ZOMBIE;
+		return retval;
+	}
+	retval = p->pid;
+	if (p->real_parent != p->parent) {
+		write_lock_irq(&tasklist_lock);
+		/* Double-check with lock held.  */
+		if (p->real_parent != p->parent) {
+			__ptrace_unlink(p);
+			// TODO: is this safe?
+			p->exit_state = EXIT_ZOMBIE;
+			/*
+			 * If this is not a detached task, notify the parent.
+			 * If it's still not detached after that, don't release
+			 * it now.
+			 */
+			if (p->exit_signal != -1) {
+				do_notify_parent(p, p->exit_signal);
+				if (p->exit_signal != -1)
+					p = NULL;
+			}
+		}
+		write_unlock_irq(&tasklist_lock);
+	}
+	if (p != NULL)
+		release_task(p);
+	BUG_ON(!retval);
+	return retval;
+}
+
+/*
+ * Handle sys_wait4 work for one task in state TASK_STOPPED.  We hold
+ * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
+ * the lock and this task is uninteresting.  If we return nonzero, we have
+ * released the lock and the system call should return.
+ */
+static int wait_task_stopped(task_t *p, int delayed_group_leader, int noreap,
+			     struct siginfo __user *infop,
+			     int __user *stat_addr, struct rusage __user *ru)
+{
+	int retval, exit_code;
+
+	if (!p->exit_code)
+		return 0;
+	if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
+	    p->signal && p->signal->group_stop_count > 0)
+		/*
+		 * A group stop is in progress and this is the group leader.
+		 * We won't report until all threads have stopped.
+		 */
+		return 0;
+
+	/*
+	 * Now we are pretty sure this task is interesting.
+	 * Make sure it doesn't get reaped out from under us while we
+	 * give up the lock and then examine it below.  We don't want to
+	 * keep holding onto the tasklist_lock while we call getrusage and
+	 * possibly take page faults for user memory.
+	 */
+	get_task_struct(p);
+	read_unlock(&tasklist_lock);
+
+	if (unlikely(noreap)) {
+		pid_t pid = p->pid;
+		uid_t uid = p->uid;
+		int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
+
+		exit_code = p->exit_code;
+		if (unlikely(!exit_code) ||
+		    unlikely(p->state > TASK_STOPPED))
+			goto bail_ref;
+		return wait_noreap_copyout(p, pid, uid,
+					   why, (exit_code << 8) | 0x7f,
+					   infop, ru);
+	}
+
+	write_lock_irq(&tasklist_lock);
+
+	/*
+	 * This uses xchg to be atomic with the thread resuming and setting
+	 * it.  It must also be done with the write lock held to prevent a
+	 * race with the EXIT_ZOMBIE case.
+	 */
+	exit_code = xchg(&p->exit_code, 0);
+	if (unlikely(p->exit_state)) {
+		/*
+		 * The task resumed and then died.  Let the next iteration
+		 * catch it in EXIT_ZOMBIE.  Note that exit_code might
+		 * already be zero here if it resumed and did _exit(0).
+		 * The task itself is dead and won't touch exit_code again;
+		 * other processors in this function are locked out.
+		 */
+		p->exit_code = exit_code;
+		exit_code = 0;
+	}
+	if (unlikely(exit_code == 0)) {
+		/*
+		 * Another thread in this function got to it first, or it
+		 * resumed, or it resumed and then died.
+		 */
+		write_unlock_irq(&tasklist_lock);
+bail_ref:
+		put_task_struct(p);
+		/*
+		 * We are returning to the wait loop without having successfully
+		 * removed the process and having released the lock. We cannot
+		 * continue, since the "p" task pointer is potentially stale.
+		 *
+		 * Return -EAGAIN, and do_wait() will restart the loop from the
+		 * beginning. Do _not_ re-acquire the lock.
+		 */
+		return -EAGAIN;
+	}
+
+	/* move to end of parent's list to avoid starvation */
+	remove_parent(p);
+	add_parent(p, p->parent);
+
+	write_unlock_irq(&tasklist_lock);
+
+	retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
+	if (!retval && stat_addr)
+		retval = put_user((exit_code << 8) | 0x7f, stat_addr);
+	if (!retval && infop)
+		retval = put_user(SIGCHLD, &infop->si_signo);
+	if (!retval && infop)
+		retval = put_user(0, &infop->si_errno);
+	if (!retval && infop)
+		retval = put_user((short)((p->ptrace & PT_PTRACED)
+					  ? CLD_TRAPPED : CLD_STOPPED),
+				  &infop->si_code);
+	if (!retval && infop)
+		retval = put_user(exit_code, &infop->si_status);
+	if (!retval && infop)
+		retval = put_user(p->pid, &infop->si_pid);
+	if (!retval && infop)
+		retval = put_user(p->uid, &infop->si_uid);
+	if (!retval)
+		retval = p->pid;
+	put_task_struct(p);
+
+	BUG_ON(!retval);
+	return retval;
+}
+
+/*
+ * Handle do_wait work for one task in a live, non-stopped state.
+ * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
+ * the lock and this task is uninteresting.  If we return nonzero, we have
+ * released the lock and the system call should return.
+ */
+static int wait_task_continued(task_t *p, int noreap,
+			       struct siginfo __user *infop,
+			       int __user *stat_addr, struct rusage __user *ru)
+{
+	int retval;
+	pid_t pid;
+	uid_t uid;
+
+	if (unlikely(!p->signal))
+		return 0;
+
+	if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
+		return 0;
+
+	spin_lock_irq(&p->sighand->siglock);
+	/* Re-check with the lock held.  */
+	if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
+		spin_unlock_irq(&p->sighand->siglock);
+		return 0;
+	}
+	if (!noreap)
+		p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
+	spin_unlock_irq(&p->sighand->siglock);
+
+	pid = p->pid;
+	uid = p->uid;
+	get_task_struct(p);
+	read_unlock(&tasklist_lock);
+
+	if (!infop) {
+		retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
+		put_task_struct(p);
+		if (!retval && stat_addr)
+			retval = put_user(0xffff, stat_addr);
+		if (!retval)
+			retval = p->pid;
+	} else {
+		retval = wait_noreap_copyout(p, pid, uid,
+					     CLD_CONTINUED, SIGCONT,
+					     infop, ru);
+		BUG_ON(retval == 0);
+	}
+
+	return retval;
+}
+
+
+static inline int my_ptrace_child(struct task_struct *p)
+{
+	if (!(p->ptrace & PT_PTRACED))
+		return 0;
+	if (!(p->ptrace & PT_ATTACHED))
+		return 1;
+	/*
+	 * This child was PTRACE_ATTACH'd.  We should be seeing it only if
+	 * we are the attacher.  If we are the real parent, this is a race
+	 * inside ptrace_attach.  It is waiting for the tasklist_lock,
+	 * which we have to switch the parent links, but has already set
+	 * the flags in p->ptrace.
+	 */
+	return (p->parent != p->real_parent);
+}
+
+static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
+		    int __user *stat_addr, struct rusage __user *ru)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	struct task_struct *tsk;
+	int flag, retval;
+
+	add_wait_queue(&current->signal->wait_chldexit,&wait);
+repeat:
+	/*
+	 * We will set this flag if we see any child that might later
+	 * match our criteria, even if we are not able to reap it yet.
+	 */
+	flag = 0;
+	current->state = TASK_INTERRUPTIBLE;
+	read_lock(&tasklist_lock);
+	tsk = current;
+	do {
+		struct task_struct *p;
+		struct list_head *_p;
+		int ret;
+
+		list_for_each(_p,&tsk->children) {
+			p = list_entry(_p,struct task_struct,sibling);
+
+			ret = eligible_child(pid, options, p);
+			if (!ret)
+				continue;
+
+			switch (p->state) {
+			case TASK_TRACED:
+				if (!my_ptrace_child(p))
+					continue;
+				/*FALLTHROUGH*/
+			case TASK_STOPPED:
+				/*
+				 * It's stopped now, so it might later
+				 * continue, exit, or stop again.
+				 */
+				flag = 1;
+				if (!(options & WUNTRACED) &&
+				    !my_ptrace_child(p))
+					continue;
+				retval = wait_task_stopped(p, ret == 2,
+							   (options & WNOWAIT),
+							   infop,
+							   stat_addr, ru);
+				if (retval == -EAGAIN)
+					goto repeat;
+				if (retval != 0) /* He released the lock.  */
+					goto end;
+				break;
+			default:
+			// case EXIT_DEAD:
+				if (p->exit_state == EXIT_DEAD)
+					continue;
+			// case EXIT_ZOMBIE:
+				if (p->exit_state == EXIT_ZOMBIE) {
+					/*
+					 * Eligible but we cannot release
+					 * it yet:
+					 */
+					if (ret == 2)
+						goto check_continued;
+					if (!likely(options & WEXITED))
+						continue;
+					retval = wait_task_zombie(
+						p, (options & WNOWAIT),
+						infop, stat_addr, ru);
+					/* He released the lock.  */
+					if (retval != 0)
+						goto end;
+					break;
+				}
+check_continued:
+				/*
+				 * It's running now, so it might later
+				 * exit, stop, or stop and then continue.
+				 */
+				flag = 1;
+				if (!unlikely(options & WCONTINUED))
+					continue;
+				retval = wait_task_continued(
+					p, (options & WNOWAIT),
+					infop, stat_addr, ru);
+				if (retval != 0) /* He released the lock.  */
+					goto end;
+				break;
+			}
+		}
+		if (!flag) {
+			list_for_each(_p, &tsk->ptrace_children) {
+				p = list_entry(_p, struct task_struct,
+						ptrace_list);
+				if (!eligible_child(pid, options, p))
+					continue;
+				flag = 1;
+				break;
+			}
+		}
+		if (options & __WNOTHREAD)
+			break;
+		tsk = next_thread(tsk);
+		if (tsk->signal != current->signal)
+			BUG();
+	} while (tsk != current);
+
+	read_unlock(&tasklist_lock);
+	if (flag) {
+		retval = 0;
+		if (options & WNOHANG)
+			goto end;
+		retval = -ERESTARTSYS;
+		if (signal_pending(current))
+			goto end;
+		schedule();
+		goto repeat;
+	}
+	retval = -ECHILD;
+end:
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&current->signal->wait_chldexit,&wait);
+	if (infop) {
+		if (retval > 0)
+		retval = 0;
+		else {
+			/*
+			 * For a WNOHANG return, clear out all the fields
+			 * we would set so the user can easily tell the
+			 * difference.
+			 */
+			if (!retval)
+				retval = put_user(0, &infop->si_signo);
+			if (!retval)
+				retval = put_user(0, &infop->si_errno);
+			if (!retval)
+				retval = put_user(0, &infop->si_code);
+			if (!retval)
+				retval = put_user(0, &infop->si_pid);
+			if (!retval)
+				retval = put_user(0, &infop->si_uid);
+			if (!retval)
+				retval = put_user(0, &infop->si_status);
+		}
+	}
+	return retval;
+}
+
+asmlinkage long sys_waitid(int which, pid_t pid,
+			   struct siginfo __user *infop, int options,
+			   struct rusage __user *ru)
+{
+	long ret;
+
+	if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
+		return -EINVAL;
+	if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
+		return -EINVAL;
+
+	switch (which) {
+	case P_ALL:
+		pid = -1;
+		break;
+	case P_PID:
+		if (pid <= 0)
+			return -EINVAL;
+		break;
+	case P_PGID:
+		if (pid <= 0)
+			return -EINVAL;
+		pid = -pid;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = do_wait(pid, options, infop, NULL, ru);
+
+	/* avoid REGPARM breakage on x86: */
+	prevent_tail_call(ret);
+	return ret;
+}
+
+asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr,
+			  int options, struct rusage __user *ru)
+{
+	long ret;
+
+	if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
+			__WNOTHREAD|__WCLONE|__WALL))
+		return -EINVAL;
+	ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru);
+
+	/* avoid REGPARM breakage on x86: */
+	prevent_tail_call(ret);
+	return ret;
+}
+
+#ifdef __ARCH_WANT_SYS_WAITPID
+
+/*
+ * sys_waitpid() remains for compatibility. waitpid() should be
+ * implemented by calling sys_wait4() from libc.a.
+ */
+asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options)
+{
+	return sys_wait4(pid, stat_addr, options, NULL);
+}
+
+#endif