Re: [PATCH] fat: avoid stack overflow warning

[Christian Brauner]

On Fri, May 15, 2026 at 10:44:46PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> Building the fat kunit tests on with -fsanitize=alignment
> reveals some rather excessive stack usage:
> 
> fs/fat/fat_test.c: In function 'fat_clus_to_blknr_test':
> fs/fat/fat_test.c:33:1: error: the frame size of 4736 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
>    33 | }
>       | ^
> fs/fat/fat_test.c: In function 'fat_get_blknr_offset_test':
> fs/fat/fat_test.c:52:1: error: the frame size of 4800 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
> 
> The problem is clearly related to the on-stack copy of a local
> msdos_sb_info structure. Avoid this by making that copy
> 'static const' and changing the called functions to accept
> a constant input.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---

What is this based on, Arnd? I'm getting errors applying this.