Fix a NULL pointer dereference panic in cpuidle_play_dead() during
CPU off-lining when no cpuidle driver is registered. A cpuidle
driver may be registered at boot-time based on CPU type. This patch
allows an off-lined CPU to enter HLT-based idle in this condition.
Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxx>
---
drivers/cpuidle/cpuidle.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 87411ce..2f0083a 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -74,7 +74,7 @@ static cpuidle_enter_t cpuidle_enter_ops;
/**
* cpuidle_play_dead - cpu off-lining
*
- * Only returns in case of an error
+ * Returns in case of an error or no driver
*/
int cpuidle_play_dead(void)
{
@@ -83,6 +83,9 @@ int cpuidle_play_dead(void)
int i, dead_state = -1;
int power_usage = -1;
+ if (!drv)
+ return -ENODEV;
+
/* Find lowest-power state that supports long-term idle */
for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
struct cpuidle_state *s = &drv->states[i];
--
1.7.7.6
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