Hi,
On Fri, Nov 22, 2019 at 11:29:41AM +0100, Greg Kroah-Hartman wrote:
From: Enric Balletbo i Serra enric.balletbo@collabora.com
[ Upstream commit b53b0128052ffd687797d5f4deeb76327e7b5711 ]
The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when drivers are built as modules." leads to the following static checker warning:
drivers/devfreq/devfreq.c:1043 governor_store() warn: 'governor' can also be NULLThe reason is that the try_then_request_governor() function returns both error pointers and NULL. It should just return error pointers, so fix this by returning a ERR_PTR to the error intead of returning NULL.
Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.") Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Reviewed-by: Chanwoo Choi cw00.choi@samsung.com Signed-off-by: MyungJoo Ham myungjoo.ham@samsung.com Signed-off-by: Sasha Levin sashal@kernel.org
The following commits are provided for this fix:
commit 7544fd7f384591038646d3cd9efb311ab4509e24 Author: Ezequiel Garcia ezequiel@collabora.com Date: Fri Jun 21 18:39:49 2019 -0300
PM / devfreq: Fix kernel oops on governor module load
A bit unexpectedly (but still documented), request_module may return a positive value, in case of a modprobe error. This is currently causing issues in the devfreq framework.
When a request_module exits with a positive value, we currently return that via ERR_PTR. However, because the value is positive, it's not a ERR_VALUE proper, and is therefore treated as a valid struct devfreq_governor pointer, leading to a kernel oops.
Fix this by returning -EINVAL if request_module returns a positive value.
Fixes: b53b0128052ff ("PM / devfreq: Fix static checker warning in try_then_request_governor") Signed-off-by: Ezequiel Garcia ezequiel@collabora.com Reviewed-by: Chanwoo Choi cw00.choi@samsung.com Signed-off-by: MyungJoo Ham myungjoo.ham@samsung.com
Please apply.
Best regards, Nobuhiro