[PATCH] de_thread: fix lockless do_each_thread

[pandora-kernel.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index 0b88bf6..fffea1e 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -666,8 +666,6 @@ static int de_thread(struct task_struct *tsk)
         * and to assume its PID:
         */
        if (!thread_group_leader(current)) {
-               struct dentry *proc_dentry1, *proc_dentry2;
-
                /*
                 * Wait for the thread group leader to be a zombie.
                 * It should already be zombie at this point, most
@@ -689,10 +687,6 @@ static int de_thread(struct task_struct *tsk)
                 */
                current->start_time = leader->start_time;
 
-               spin_lock(&leader->proc_lock);
-               spin_lock(&current->proc_lock);
-               proc_dentry1 = proc_pid_unhash(current);
-               proc_dentry2 = proc_pid_unhash(leader);
                write_lock_irq(&tasklist_lock);
 
                BUG_ON(leader->tgid != current->tgid);
@@ -713,7 +707,7 @@ static int de_thread(struct task_struct *tsk)
                attach_pid(current, PIDTYPE_PID,  current->pid);
                attach_pid(current, PIDTYPE_PGID, current->signal->pgrp);
                attach_pid(current, PIDTYPE_SID,  current->signal->session);
-               list_add_tail_rcu(&current->tasks, &init_task.tasks);
+               list_replace_rcu(&leader->tasks, &current->tasks);
 
                current->group_leader = current;
                leader->group_leader = current;
@@ -721,7 +715,6 @@ static int de_thread(struct task_struct *tsk)
                /* Reduce leader to a thread */
                detach_pid(leader, PIDTYPE_PGID);
                detach_pid(leader, PIDTYPE_SID);
-               list_del_init(&leader->tasks);
 
                current->exit_signal = SIGCHLD;
 
@@ -729,10 +722,6 @@ static int de_thread(struct task_struct *tsk)
                leader->exit_state = EXIT_DEAD;
 
                write_unlock_irq(&tasklist_lock);
-               spin_unlock(&leader->proc_lock);
-               spin_unlock(&current->proc_lock);
-               proc_pid_flush(proc_dentry1);
-               proc_pid_flush(proc_dentry2);
         }
 
        /*