Re: [PATCH bpf-next] bpf: add config to allow loading modules with BTF mismatches

[Shung-Hsi Yu]

On Wed, Feb 23, 2022 at 01:28:14AM +0000, Connor O'Brien wrote:
> BTF mismatch can occur for a separately-built module even when the ABI
> is otherwise compatible and nothing else would prevent successfully
> loading. Add a new config to control how mismatches are handled. By
> default, preserve the current behavior of refusing to load the
> module. If MODULE_ALLOW_BTF_MISMATCH is enabled, load the module but
> ignore its BTF information.
> 
> Suggested-by: Yonghong Song <yhs@xxxxxx>
> Suggested-by: Michal Suchánek <msuchanek@xxxxxxx>
> Signed-off-by: Connor O'Brien <connoro@xxxxxxxxxx>

Maybe reference the discussion thread as well?

Link: https://lore.kernel.org/bpf/CAADnVQJ+OVPnBz8z3vNu8gKXX42jCUqfuvhWAyCQDu8N_yqqwQ@xxxxxxxxxxxxxx/

Otherwise

Acked-by: Shung-Hsi Yu <shung-hsi.yu@xxxxxxxx>

> ---
> Hello,
> 
> In the discussion regarding BTF compatibility & modules, there seemed
> to be broad agreement that an option to ignore mismatches would be
> reasonable. Currently the only option for handling this problem seems
> to be to disable BTF entirely, so this would at least be an
> incremental improvement.
> 
> Thanks,
> Connor