[RFC PATCH] freezer: allow killing of frozen tasks

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

Change __refrigerator() to allow SIGKILL signal handling during
the frozen state (by setting task to a TASK_KILLABLE state instead
of TASK_UNINTERRUPTIBLE one before entering sleep) and make tasks
leave __refrigerator() upon receiving such signal.

These changes allow frozen tasks to be killed immediately without
the need to thaw them first.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 kernel/freezer.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/freezer.c b/kernel/freezer.c
index b462fa1..0c05a7a 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -57,12 +57,13 @@ bool __refrigerator(bool check_kthr_stop)
 	pr_debug("%s entered refrigerator\n", current->comm);
 
 	for (;;) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
+		set_current_state(TASK_KILLABLE);
 
 		spin_lock_irq(&freezer_lock);
 		current->flags |= PF_FROZEN;
 		if (!freezing(current) ||
-		    (check_kthr_stop && kthread_should_stop()))
+		    (check_kthr_stop && kthread_should_stop()) ||
+		    fatal_signal_pending(current))
 			current->flags &= ~PF_FROZEN;
 		spin_unlock_irq(&freezer_lock);
 
-- 
1.8.2.3