stop_machine: fix race with return value (fixes Bug #11989)
Bug #11989: Suspend failure on NForce4-based boards due to chanes in
stop_machine
We should not access active.fnret outside the lock; in theory the next
stop_machine could overwrite it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 9bc4c00..24e8cea 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -112,7 +112,7 @@
int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
{
struct work_struct *sm_work;
- int i;
+ int i, ret;
/* Set up initial state. */
mutex_lock(&lock);
@@ -137,8 +137,9 @@
/* This will release the thread on our CPU. */
put_cpu();
flush_workqueue(stop_machine_wq);
+ ret = active.fnret;
mutex_unlock(&lock);
- return active.fnret;
+ return ret;
}
int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
