Excerpts from Christophe Leroy's message of October 17, 2021 10:38 pm:
> We have three architectures using function descriptors, each with its
> own type and name.
>
> Add a common typedef that can be used in generic code.
>
> Also add a stub typedef for architecture without function descriptors,
> to avoid a forest of #ifdefs.
>
> It replaces the similar 'func_desc_t' previously defined in
> arch/powerpc/kernel/module_64.c
>
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> ---
[...]
> diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
> index a918388d9bf6..33b51efe3a24 100644
> --- a/include/asm-generic/sections.h
> +++ b/include/asm-generic/sections.h
> @@ -63,6 +63,9 @@ extern __visible const void __nosave_begin, __nosave_end;
> #else
> #define dereference_function_descriptor(p) ((void *)(p))
> #define dereference_kernel_function_descriptor(p) ((void *)(p))
> +typedef struct {
> + unsigned long addr;
> +} func_desc_t;
> #endif
>
I think that deserves a comment. If it's just to allow ifdef to be
avoided, I guess that's okay with a comment. Would be nice if you could
cause it to generate a link time error if it was ever used like
undefined functions, but I guess you can't. It's not a necessity though.
Thanks,
Nick
