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authorLi, Fei <fei.li@intel.com>2017-04-27 01:47:25 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-05-01 23:17:20 +0200
commit41dc750ea67f317c0deedde713d1728425524ef2 (patch)
tree747f8f64d194474672579a393ec4890ea9b9d8f1 /drivers/cpuidle
parent0baa91cb73e296242edad89cfe3f60c59ab8a95a (diff)
downloadlinux-41dc750ea67f317c0deedde713d1728425524ef2.tar.bz2
cpuidle: check dev before usage in cpuidle_use_deepest_state()
In case of there is no cpuidle devices registered, dev will be null, and panic will be triggered like below; In this patch, add checking of dev before usage, like that done in cpuidle_idle_call. Panic without fix: [ 184.961328] BUG: unable to handle kernel NULL pointer dereference at (null) [ 184.961328] IP: cpuidle_use_deepest_state+0x30/0x60 ... [ 184.961328] play_idle+0x8d/0x210 [ 184.961328] ? __schedule+0x359/0x8e0 [ 184.961328] ? _raw_spin_unlock_irqrestore+0x28/0x50 [ 184.961328] ? kthread_queue_delayed_work+0x41/0x80 [ 184.961328] clamp_idle_injection_func+0x64/0x1e0 Fixes: bb8313b603eb8 (cpuidle: Allow enforcing deepest idle state selection) Signed-off-by: Li, Fei <fei.li@intel.com> Tested-by: Shi, Feng <fengx.shi@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: 4.10+ <stable@vger.kernel.org> # 4.10+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 548b90be7685..2706be7ed334 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -111,7 +111,8 @@ void cpuidle_use_deepest_state(bool enable)
preempt_disable();
dev = cpuidle_get_device();
- dev->use_deepest_state = enable;
+ if (dev)
+ dev->use_deepest_state = enable;
preempt_enable();
}