Re: [PATCH v2] tracing: devlink: Use static array for string in devlink_trap_report even

From: Jakub Kicinski
Date: Wed Jul 13 2022 - 15:51:36 EST


On Tue, 12 Jul 2022 18:58:20 -0400 Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
>
> The trace event devlink_trap_report uses the __dynamic_array() macro to
> determine the size of the input_dev_name field. This is because it needs
> to test the dev field for NULL, and will use "NULL" if it is. But it also
> has the size of the dynamic array as a fixed IFNAMSIZ bytes. This defeats
> the purpose of the dynamic array, as this will reserve that amount of
> bytes on the ring buffer, and to make matters worse, it will even save
> that size in the event as the event expects it to be dynamic (for which it
> is not).
>
> Since IFNAMSIZ is just 16 bytes, just make it a static array and this will
> remove the meta data from the event that records the size.
>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>

Acked-by: Jakub Kicinski <kuba@xxxxxxxxxx>