[PATCH 3/5] coredump: use a freezable_schedule for the coredump_finish wait

[Mandeep Singh Baines <msb@chromium.org>]

Prevents hung_task detector from panicing the machine. This is also
needed to prevent this wait from blocking suspend.

(It doesnt' currently block suspend but it would once the next
patch in this series is applied.)

Changes since v1:
* <20130215145323.GA30829@redhat.com> Oleg Nesterov
 * Rebased after dropping earlier cleanup patch.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Tejun Heo <tj@kernel.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Rafael J. Wysocki <rjw@sisk.pl>
CC: Ingo Molnar <mingo@redhat.com>
---
 kernel/exit.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index 88a706c..89532e8 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -20,6 +20,7 @@
 #include <linux/tsacct_kern.h>
 #include <linux/file.h>
 #include <linux/fdtable.h>
+#include <linux/freezer.h>
 #include <linux/binfmts.h>
 #include <linux/nsproxy.h>
 #include <linux/pid_namespace.h>
@@ -483,7 +484,7 @@ static void exit_mm(struct task_struct * tsk)
 			set_task_state(tsk, TASK_UNINTERRUPTIBLE);
 			if (!self.task) /* see coredump_finish() */
 				break;
-			schedule();
+			freezable_schedule();
 		}
 		__set_task_state(tsk, TASK_RUNNING);
 		down_read(&mm->mmap_sem);
-- 
1.7.12.4