[ARM] 3500/1: fix PXA27x DMA allocation priority

[linux-2.6-omap-h63xx.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index 0291a68a36261ada2dca60e411af634b1373bc1c..3a79d97ac234422c353ad6c37ab973d3363471bd 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -665,9 +665,7 @@ static int de_thread(struct task_struct *tsk)
         * and to assume its PID:
         */
        if (!thread_group_leader(current)) {
-               struct task_struct *parent;
                struct dentry *proc_dentry1, *proc_dentry2;
-               unsigned long ptrace;
 
                /*
                 * Wait for the thread group leader to be a zombie.
@@ -678,6 +676,18 @@ static int de_thread(struct task_struct *tsk)
                while (leader->exit_state != EXIT_ZOMBIE)
                        yield();
 
+               /*
+                * The only record we have of the real-time age of a
+                * process, regardless of execs it's done, is start_time.
+                * All the past CPU time is accumulated in signal_struct
+                * from sister threads now dead.  But in this non-leader
+                * exec, nothing survives from the original leader thread,
+                * whose birth marks the true age of this process now.
+                * When we take on its identity by switching to its PID, we
+                * also take its birthdate (always earlier than our own).
+                */
+               current->start_time = leader->start_time;
+
                spin_lock(&leader->proc_lock);
                spin_lock(&current->proc_lock);
                proc_dentry1 = proc_pid_unhash(current);
@@ -692,22 +702,6 @@ static int de_thread(struct task_struct *tsk)
                 * two threads with a switched PID, and release
                 * the former thread group leader:
                 */
-               ptrace = leader->ptrace;
-               parent = leader->parent;
-               if (unlikely(ptrace) && unlikely(parent == current)) {
-                       /*
-                        * Joker was ptracing his own group leader,
-                        * and now he wants to be his own parent!
-                        * We can't have that.
-                        */
-                       ptrace = 0;
-               }
-
-               ptrace_unlink(current);
-               ptrace_unlink(leader);
-               remove_parent(current);
-               remove_parent(leader);
-
 
                /* Become a process group leader with the old leader's pid.
                 * Note: The old leader also uses thispid until release_task
@@ -718,19 +712,15 @@ 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(&current->tasks, &init_task.tasks);
+               list_add_tail_rcu(&current->tasks, &init_task.tasks);
 
-               current->parent = current->real_parent = leader->real_parent;
-               leader->parent = leader->real_parent = child_reaper;
                current->group_leader = current;
-               leader->group_leader = leader;
+               leader->group_leader = current;
 
-               add_parent(current);
-               add_parent(leader);
-               if (ptrace) {
-                       current->ptrace = ptrace;
-                       __ptrace_link(current, parent);
-               }
+               /* Reduce leader to a thread */
+               detach_pid(leader, PIDTYPE_PGID);
+               detach_pid(leader, PIDTYPE_SID);
+               list_del_init(&leader->tasks);
 
                current->exit_signal = SIGCHLD;