bsdacct: account dying tasks in all relevant namespaces

[linux-2.6] / kernel / exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index f7fa21dbced4b17d86347582a410e97c2f5c105c..8a4d4d12e29456701990729d6c7dc7859767b929 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -664,26 +664,40 @@ assign_new_owner:
 static void exit_mm(struct task_struct * tsk)
 {
        struct mm_struct *mm = tsk->mm;
+       struct core_state *core_state;
 
        mm_release(tsk, mm);
        if (!mm)
                return;
        /*
         * Serialize with any possible pending coredump.
-        * We must hold mmap_sem around checking core_waiters
+        * We must hold mmap_sem around checking core_state
         * and clearing tsk->mm.  The core-inducing thread
-        * will increment core_waiters for each thread in the
+        * will increment ->nr_threads for each thread in the
         * group with ->mm != NULL.
         */
        down_read(&mm->mmap_sem);
-       if (mm->core_waiters) {
+       core_state = mm->core_state;
+       if (core_state) {
+               struct core_thread self;
                up_read(&mm->mmap_sem);
-               down_write(&mm->mmap_sem);
-               if (!--mm->core_waiters)
-                       complete(&mm->core_state->startup);
-               up_write(&mm->mmap_sem);
 
-               wait_for_completion(&mm->core_done);
+               self.task = tsk;
+               self.next = xchg(&core_state->dumper.next, &self);
+               /*
+                * Implies mb(), the result of xchg() must be visible
+                * to core_state->dumper.
+                */
+               if (atomic_dec_and_test(&core_state->nr_threads))
+                       complete(&core_state->startup);
+
+               for (;;) {
+                       set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+                       if (!self.task) /* see coredump_finish() */
+                               break;
+                       schedule();
+               }
+               __set_task_state(tsk, TASK_RUNNING);
                down_read(&mm->mmap_sem);
        }
        atomic_inc(&mm->mm_count);