Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1527 insertions, 0 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
new file mode 100644
index 000000000000..6dd4ebe1dd90
--- /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