Re: [PATCH v2 1/3] bcm-vk: add bcm_vk UAPI

[Scott Branden]

On 2020-08-20 1:57 p.m., Florian Fainelli wrote:
> On 8/20/20 1:55 PM, Kees Cook wrote:
>> On Thu, Aug 20, 2020 at 09:37:46AM -0700, Scott Branden wrote:
>>> On 2020-08-19 12:00 a.m., Greg Kroah-Hartman wrote:
>>>> On Tue, Aug 18, 2020 at 05:35:04PM -0700, Scott Branden wrote:
>>>>> On 2020-08-18 10:44 a.m., Greg Kroah-Hartman wrote:
>>>>>> On Tue, Aug 18, 2020 at 10:23:42AM -0700, Scott Branden wrote:
>>>>>>>>> +#define VK_FWSTS_RELOCATION_ENTRY	BIT(0)
>>>>>>>> <snip>
>>>>>>>>
>>>>>>>> I thought BIT() was not allowed in uapi .h files, this really works
>>>>>>>> properly???
>>>>>>> I did some investigation and it looks like a few other header files in include/uapi also use the BIT() macro:
>>>>>>> include/uapi/misc/uacce/uacce.h
>>>>>>> include/uapi/linux/psci.h
>>>>>>> include/uapi/linux/v4l2-subdev.h
>>>>>> Does the header install test target now fail for these?
>>>>> I do not understand the question above.  make headers_install works.
>>>>> But I guess the above headers would have similar issue with the BIT macro.
>>>> Try enabling CONFIG_UAPI_HEADER_TEST and see what happens :)
>>> I enabled CONFIG_UAPI_HEADER_TEST and then
>>> built using "make" and "make headers_install".
>>>
>>> There didn't appear to be any issue with the BIT macro in the headers.
>> FWIW, other subsystems have not been so lucky:
>>
>> https://git.kernel.org/linus/23b2c96fad21886c53f5e1a4ffedd45ddd2e85ba
>>
>> It may just be better to avoid BIT(), even if it works "by accident"(?)
>> for some header combinations...
> Since we ship a copy of unifdef.c in tree, we could certainly teach it
> to undo the BIT() definition and replace it with an appropriate constant
> definition.
That sounds appealing given the rest of the code wants us to use the BIT macro.