Re: [PATCH] net/mlx5e: reduce stack usage in mlx5_eswitch_termtbl_create

From: David Miller
Date: Mon Jun 17 2019 - 17:07:31 EST


From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Mon, 17 Jun 2019 13:08:22 +0200

> Putting an empty 'mlx5_flow_spec' structure on the stack is a bit
> wasteful and causes a warning on 32-bit architectures when building
> with clang -fsanitize-coverage:
>
> drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads_termtbl.c: In function 'mlx5_eswitch_termtbl_create':
> drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads_termtbl.c:90:1: error: the frame size of 1032 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
>
> Since the structure is never written to, we can statically allocate
> it to avoid the stack usage. To be on the safe side, mark all
> subsequent function arguments that we pass it into as 'const'
> as well.
>
> Fixes: 10caabdaad5a ("net/mlx5e: Use termination table for VLAN push actions")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Saeed, once Arnd fixes the reverse christmas tree issue, I assume you will take
this in via your tree?

Thanks.