This is a note to let you know that I've just added the patch titled
cpuidle: check dev before usage in cpuidle_use_deepest_state()
to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cpuidle-check-dev-before-usage-in-cpuidle_use_deepest_state.patch
and it can be found in the queue-4.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 41dc750ea67f317c0deedde713d1728425524ef2 Mon Sep 17 00:00:00 2001
From: "Li, Fei" <fei.li@xxxxxxxxx>
Date: Thu, 27 Apr 2017 01:47:25 +0000
Subject: cpuidle: check dev before usage in cpuidle_use_deepest_state()
From: Li, Fei <fei.li@xxxxxxxxx>
commit 41dc750ea67f317c0deedde713d1728425524ef2 upstream.
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@xxxxxxxxx>
Tested-by: Shi, Feng <fengx.shi@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cpuidle/cpuidle.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -111,7 +111,8 @@ void cpuidle_use_deepest_state(bool enab
preempt_disable();
dev = cpuidle_get_device();
- dev->use_deepest_state = enable;
+ if (dev)
+ dev->use_deepest_state = enable;
preempt_enable();
}
Patches currently in stable-queue which might be from fei.li@xxxxxxxxx are
queue-4.11/cpuidle-check-dev-before-usage-in-cpuidle_use_deepest_state.patch