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authorJon Medhurst (Tixy) <tixy@linaro.org>2012-08-16 00:11:00 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2012-08-17 21:37:08 +0400
commit5fbbb90dfdedb9a258550e4e5debd3013266372e (patch)
tree86f4ad339e193301a8ac2626cc28e664978089b7
parent63c6ba4352009a5f85b32307c001abeb5baebd28 (diff)
downloadlinux-5fbbb90dfdedb9a258550e4e5debd3013266372e.tar.xz
cpuidle: Prevent null pointer dereference in cpuidle_coupled_cpu_notify
When a kernel is built to support multiple hardware types it's possible that CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED is set but the hardware the kernel is run on doesn't support cpuidle and therefore doesn't load a driver for it. In this case, when the system is shut down, cpuidle_coupled_cpu_notify() gets called with cpuidle_devices set to NULL. There are quite possibly other circumstances where this situation can also occur and we should check for it. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
-rw-r--r--drivers/cpuidle/coupled.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index c24dda03c143..3265844839bf 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -693,7 +693,7 @@ static int cpuidle_coupled_cpu_notify(struct notifier_block *nb,
mutex_lock(&cpuidle_lock);
dev = per_cpu(cpuidle_devices, cpu);
- if (!dev->coupled)
+ if (!dev || !dev->coupled)
goto out;
switch (action & ~CPU_TASKS_FROZEN) {