drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

[PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

Posted by Nathan Huckleberry 3 years, 6 months ago

The mode_valid field in drm_connector_helper_funcs is expected to be of
type:
enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
                                     struct drm_display_mode *mode);

The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition.

The return type of mdp4_lvds_connector_mode_valid should be changed from
int to enum drm_mode_status.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@lists.linux.dev
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
---
 drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
index 7288041dd86a..7444b75c4215 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
@@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
 	return ret;
 }
 
-static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
-				 struct drm_display_mode *mode)
+static enum drm_mode_status
+mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
+			       struct drm_display_mode *mode)
 {
 	struct mdp4_lvds_connector *mdp4_lvds_connector =
 			to_mdp4_lvds_connector(connector);
-- 
2.37.2.789.g6183377224-goog

Re: [PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

Posted by Nathan Chancellor 3 years, 5 months ago

Hi all,

On Tue, Sep 13, 2022 at 01:55:48PM -0700, Nathan Huckleberry wrote:
> The mode_valid field in drm_connector_helper_funcs is expected to be of
> type:
> enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
>                                      struct drm_display_mode *mode);
> 
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
> 
> The return type of mdp4_lvds_connector_mode_valid should be changed from
> int to enum drm_mode_status.
> 
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
> ---
>  drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> index 7288041dd86a..7444b75c4215 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
>  	return ret;
>  }
>  
> -static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> -				 struct drm_display_mode *mode)
> +static enum drm_mode_status
> +mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> +			       struct drm_display_mode *mode)
>  {
>  	struct mdp4_lvds_connector *mdp4_lvds_connector =
>  			to_mdp4_lvds_connector(connector);
> -- 
> 2.37.2.789.g6183377224-goog
> 
> 

Did this patch get lost somewhere? I do not see it picked up. It is
needed to avoid a new WIP warning from clang for catching these CFI
failures:

drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c:89:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
        .mode_valid = mdp4_lvds_connector_mode_valid,
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

Cheers,
Nathan

Re: [PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

Posted by Dmitry Baryshkov 3 years, 5 months ago

On 01/11/2022 01:10, Nathan Chancellor wrote:
> On Tue, Sep 13, 2022 at 01:55:48PM -0700, Nathan Huckleberry wrote:
>> The mode_valid field in drm_connector_helper_funcs is expected to be of
>> type:
>> enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
>>                                       struct drm_display_mode *mode);
>>
>> The mismatched return type breaks forward edge kCFI since the underlying
>> function definition does not match the function hook definition.
>>
>> The return type of mdp4_lvds_connector_mode_valid should be changed from
>> int to enum drm_mode_status.
>>
>> Reported-by: Dan Carpenter <error27@gmail.com>
>> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
>> Cc: llvm@lists.linux.dev
>> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
>> ---
>>   drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
>> index 7288041dd86a..7444b75c4215 100644
>> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
>> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
>> @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
>>   	return ret;
>>   }
>>   
>> -static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
>> -				 struct drm_display_mode *mode)
>> +static enum drm_mode_status
>> +mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
>> +			       struct drm_display_mode *mode)
>>   {
>>   	struct mdp4_lvds_connector *mdp4_lvds_connector =
>>   			to_mdp4_lvds_connector(connector);
>> -- 
>> 2.37.2.789.g6183377224-goog
>>
>>
> 
> Did this patch get lost somewhere? I do not see it picked up. It is
> needed to avoid a new WIP warning from clang for catching these CFI
> failures:
> 
> drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c:89:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
>          .mode_valid = mdp4_lvds_connector_mode_valid,
>                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1 error generated.

It will be picked into 6.1-rc and then propagate through the stable 
kernel updates.

Anyway:

Fixes: 3e87599b68e7 ("drm/msm/mdp4: add LVDS panel support")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>


-- 
With best wishes
Dmitry

Re: [PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

Posted by Abhinav Kumar 3 years, 5 months ago


On 10/31/2022 5:24 PM, Dmitry Baryshkov wrote:
> On 01/11/2022 01:10, Nathan Chancellor wrote:
>> On Tue, Sep 13, 2022 at 01:55:48PM -0700, Nathan Huckleberry wrote:
>>> The mode_valid field in drm_connector_helper_funcs is expected to be of
>>> type:
>>> enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
>>>                                       struct drm_display_mode *mode);
>>>
>>> The mismatched return type breaks forward edge kCFI since the underlying
>>> function definition does not match the function hook definition.
>>>
>>> The return type of mdp4_lvds_connector_mode_valid should be changed from
>>> int to enum drm_mode_status.
>>>
>>> Reported-by: Dan Carpenter <error27@gmail.com>
>>> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
>>> Cc: llvm@lists.linux.dev
>>> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
>>> ---
>>>   drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
>>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c 
>>> b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
>>> index 7288041dd86a..7444b75c4215 100644
>>> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
>>> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
>>> @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct 
>>> drm_connector *connector)
>>>       return ret;
>>>   }
>>> -static int mdp4_lvds_connector_mode_valid(struct drm_connector 
>>> *connector,
>>> -                 struct drm_display_mode *mode)
>>> +static enum drm_mode_status
>>> +mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
>>> +                   struct drm_display_mode *mode)
>>>   {
>>>       struct mdp4_lvds_connector *mdp4_lvds_connector =
>>>               to_mdp4_lvds_connector(connector);
>>> -- 
>>> 2.37.2.789.g6183377224-goog
>>>
>>>
>>
>> Did this patch get lost somewhere? I do not see it picked up. It is
>> needed to avoid a new WIP warning from clang for catching these CFI
>> failures:
>>
>> drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c:89:16: error: 
>> incompatible function pointer types initializing 'enum drm_mode_status 
>> (*)(struct drm_connector *, struct drm_display_mode *)' with an 
>> expression of type 'int (struct drm_connector *, struct 
>> drm_display_mode *)' 
>> [-Werror,-Wincompatible-function-pointer-types-strict]
>>          .mode_valid = mdp4_lvds_connector_mode_valid,
>>                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> 1 error generated.
> 
> It will be picked into 6.1-rc and then propagate through the stable 
> kernel updates.
> 
> Anyway:
> 
> Fixes: 3e87599b68e7 ("drm/msm/mdp4: add LVDS panel support")
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Yes, it was already merged to the -fixes tree and a PR with it was sent 
out for 6.1-rc

https://gitlab.freedesktop.org/drm/msm/-/commit/0b33a33bd15d5bab73b87152b220a8d0153a4587

> 
>

Re: [PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

Posted by Nathan Chancellor 3 years, 6 months ago

On Tue, Sep 13, 2022 at 01:55:48PM -0700, Nathan Huckleberry wrote:
> The mode_valid field in drm_connector_helper_funcs is expected to be of
> type:
> enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
>                                      struct drm_display_mode *mode);
> 
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
> 
> The return type of mdp4_lvds_connector_mode_valid should be changed from
> int to enum drm_mode_status.
> 
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> index 7288041dd86a..7444b75c4215 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
>  	return ret;
>  }
>  
> -static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> -				 struct drm_display_mode *mode)
> +static enum drm_mode_status
> +mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> +			       struct drm_display_mode *mode)
>  {
>  	struct mdp4_lvds_connector *mdp4_lvds_connector =
>  			to_mdp4_lvds_connector(connector);
> -- 
> 2.37.2.789.g6183377224-goog
>

Re: [Freedreno] [PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

Posted by Abhinav Kumar 3 years, 6 months ago

Hi Nathan

Thanks for the patch.

On 9/13/2022 1:55 PM, Nathan Huckleberry wrote:
> The mode_valid field in drm_connector_helper_funcs is expected to be of
> type:
> enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
>                                       struct drm_display_mode *mode);
> 
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
> 
> The return type of mdp4_lvds_connector_mode_valid should be changed from
> int to enum drm_mode_status.
> 
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>

 From what I can see this one has been this way since lvds support was 
added. Hence this should have

Fixes: 3e87599b68e7 ("drm/msm/mdp4: add LVDS panel support")

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> index 7288041dd86a..7444b75c4215 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
>   	return ret;
>   }
>   
> -static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> -				 struct drm_display_mode *mode)
> +static enum drm_mode_status
> +mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> +			       struct drm_display_mode *mode)
>   {
>   	struct mdp4_lvds_connector *mdp4_lvds_connector =
>   			to_mdp4_lvds_connector(connector);