Nouveau - Jun 2025 - [PATCH] drm/nouveau/bl: Use kasprintf for interface name

On Wed, 2025-06-04 at 14:03 -0700, Jacob Keller wrote:
> This could also be fixed by simply increasing BL_NAME_SIZE to 24, making it
> large enough to fit any size integer into its format string, or by checking
> the return value of snprintf.
I think this would be a better approach.  backlist_name[24] is still small
enough to fit on the
stack with ease, and it would eliminate the alloc/free churn.  kasprintf()
should be reserved for
long-term or larger allocations, IMHO.

On 6/4/2025 3:01 PM, Timur Tabi wrote:
> On Wed, 2025-06-04 at 14:03 -0700, Jacob Keller wrote:
>> This could also be fixed by simply increasing BL_NAME_SIZE to 24,
making it
>> large enough to fit any size integer into its format string, or by
checking
>> the return value of snprintf.
> 
> I think this would be a better approach.  backlist_name[24] is still small
enough to fit on the
> stack with ease, and it would eliminate the alloc/free churn.  kasprintf()
should be reserved for
> long-term or larger allocations, IMHO.
Fair enough. Another alternative which saves the stack and macro would
be to add a new version of backlight_register_device which can pass the
integer number itself into dev_set_name, but thats probably not worth
the churn either. (Currently we snprintf into a buffer and then again
copy that again into the device name...)

Thanks,
Jake