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authorVincent Donnefort <vincent.donnefort@arm.com>2018-09-03 09:02:07 +0900
committerMyungJoo Ham <myungjoo.ham@samsung.com>2018-10-02 10:16:41 +0900
commit2f061fd0c2d852e32e03a903fccd810663c5c31e (patch)
tree9cd1724ec2a4cf6aeb03d1e56c65d6fa371588d3 /drivers/devfreq/devfreq.c
parentf037eb8c1f476bc903d99695c1eb9f99ccb46b27 (diff)
downloadblackbird-op-linux-2f061fd0c2d852e32e03a903fccd810663c5c31e.tar.gz
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PM / devfreq: stopping the governor before device_unregister()
device_release() is freeing the resources before calling the device specific release callback which is, in the case of devfreq, stopping the governor. It is a problem as some governors are using the device resources. e.g. simpleondemand which is using the devfreq deferrable monitoring work. If it is not stopped before the resources are freed, it might lead to a use after free. Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com> Reviewed-by: John Einar Reitan <john.reitan@arm.com> [cw00.choi: Fix merge conflict] Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index b5e7af60723c..1868423355d9 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -575,10 +575,6 @@ static void devfreq_dev_release(struct device *dev)
list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
- if (devfreq->governor)
- devfreq->governor->event_handler(devfreq,
- DEVFREQ_GOV_STOP, NULL);
-
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
@@ -714,7 +710,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
err_init:
mutex_unlock(&devfreq_list_lock);
- device_unregister(&devfreq->dev);
+ devfreq_remove_device(devfreq);
devfreq = NULL;
err_dev:
if (devfreq)
@@ -735,6 +731,9 @@ int devfreq_remove_device(struct devfreq *devfreq)
if (!devfreq)
return -EINVAL;
+ if (devfreq->governor)
+ devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
device_unregister(&devfreq->dev);
return 0;
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