[PATCH] drm/amdkfd: Replace one-element array with flexible-array member

[PATCH] drm/amdkfd: Replace one-element array with flexible-array member

[cgel.zte]

From: Changcheng Deng <deng.changcheng@zte.com.cn>

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use "flexible array members" for these cases. The older
style of one-element or zero-length arrays should no longer be used.
Reference:
https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
---
 drivers/gpu/drm/amd/amdkfd/kfd_crat.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
index 482ba84a728d..d7c38fbc533e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
@@ -310,7 +310,7 @@ struct cdit_header {
 	uint32_t	creator_revision;
 	uint32_t	total_entries;
 	uint16_t	num_domains;
-	uint8_t		entry[1];
+	uint8_t		entry[];
 };
 
 #pragma pack()
-- 
2.25.1

Re: [PATCH] drm/amdkfd: Replace one-element array with flexible-array member

[Christian König]

Felix need to comment as well, but I don't think that this will work 
that easily.

By changing the entry from 1 to 0 your are also changing the size of the 
structure.

Regards,
Christian.

Am 18.02.22 um 04:09 schrieb cgel.zte@gmail.com:
> From: Changcheng Deng <deng.changcheng@zte.com.cn>
>
> There is a regular need in the kernel to provide a way to declare having
> a dynamically sized set of trailing elements in a structure. Kernel code
> should always use "flexible array members" for these cases. The older
> style of one-element or zero-length arrays should no longer be used.
> Reference:
> https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_crat.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
> index 482ba84a728d..d7c38fbc533e 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
> @@ -310,7 +310,7 @@ struct cdit_header {
>   	uint32_t	creator_revision;
>   	uint32_t	total_entries;
>   	uint16_t	num_domains;
> -	uint8_t		entry[1];
> +	uint8_t		entry[];
>   };
>   
>   #pragma pack()

Re: [PATCH] drm/amdkfd: Replace one-element array with flexible-array member

[Felix Kuehling]

It looks like this structure isn't being used at all. So I'm OK with 
this change, in case we ever use it in the future.

Regards,
   Felix


Am 2022-02-18 um 02:47 schrieb Christian König:
> Felix need to comment as well, but I don't think that this will work 
> that easily.
>
> By changing the entry from 1 to 0 your are also changing the size of 
> the structure.
>
> Regards,
> Christian.
>
> Am 18.02.22 um 04:09 schrieb cgel.zte@gmail.com:
>> From: Changcheng Deng <deng.changcheng@zte.com.cn>
>>
>> There is a regular need in the kernel to provide a way to declare having
>> a dynamically sized set of trailing elements in a structure. Kernel code
>> should always use "flexible array members" for these cases. The older
>> style of one-element or zero-length arrays should no longer be used.
>> Reference:
>> https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays 
>>
>>
>> Reported-by: Zeal Robot <zealci@zte.com.cn>
>> Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
>> ---
>>   drivers/gpu/drm/amd/amdkfd/kfd_crat.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
>> index 482ba84a728d..d7c38fbc533e 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
>> @@ -310,7 +310,7 @@ struct cdit_header {
>>       uint32_t    creator_revision;
>>       uint32_t    total_entries;
>>       uint16_t    num_domains;
>> -    uint8_t        entry[1];
>> +    uint8_t        entry[];
>>   };
>>     #pragma pack()
>

Re: [PATCH] drm/amdkfd: Replace one-element array with flexible-array member

[Christian König]

Well in that case somebody could argue that we should probably remove 
the structure altogether.

Regards,
Christian.

Am 18.02.22 um 17:15 schrieb Felix Kuehling:
> It looks like this structure isn't being used at all. So I'm OK with 
> this change, in case we ever use it in the future.
>
> Regards,
>   Felix
>
>
> Am 2022-02-18 um 02:47 schrieb Christian König:
>> Felix need to comment as well, but I don't think that this will work 
>> that easily.
>>
>> By changing the entry from 1 to 0 your are also changing the size of 
>> the structure.
>>
>> Regards,
>> Christian.
>>
>> Am 18.02.22 um 04:09 schrieb cgel.zte@gmail.com:
>>> From: Changcheng Deng <deng.changcheng@zte.com.cn>
>>>
>>> There is a regular need in the kernel to provide a way to declare 
>>> having
>>> a dynamically sized set of trailing elements in a structure. Kernel 
>>> code
>>> should always use "flexible array members" for these cases. The older
>>> style of one-element or zero-length arrays should no longer be used.
>>> Reference:
>>> https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays 
>>>
>>>
>>> Reported-by: Zeal Robot <zealci@zte.com.cn>
>>> Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
>>> ---
>>>   drivers/gpu/drm/amd/amdkfd/kfd_crat.h | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h 
>>> b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
>>> index 482ba84a728d..d7c38fbc533e 100644
>>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
>>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
>>> @@ -310,7 +310,7 @@ struct cdit_header {
>>>       uint32_t    creator_revision;
>>>       uint32_t    total_entries;
>>>       uint16_t    num_domains;
>>> -    uint8_t        entry[1];
>>> +    uint8_t        entry[];
>>>   };
>>>     #pragma pack()
>>