Re: [PATCH] ARM: module: fix modsign build error

[Russell King - ARM Linux]

On Fri, Jul 06, 2018 at 02:48:47PM +0200, Arnd Bergmann wrote:
> The asm/module.h header file can not be included standalone, which
> breaks the module signing code after a recent change:
> 
> In file included from kernel/module-internal.h:13,
>                  from kernel/module_signing.c:17:
> arch/arm/include/asm/module.h:37:27: error: 'struct module' declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
>  u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val);
> 
> This adds a forward declaration of struct module to make it all work.
> 
> Fixes: f314dfea16a0 ("modsign: log module name in the event of an error")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

We used to have a general rule that where an asm/foo.h header and
linux/foo.h header exists, and the linux/foo.h includes the asm/foo.h,
then the linux/foo.h header will be used for including in .c files
rather than the asm/ version of the same.  Is there a reason why
that can't be done here?

That said, adding this is no bad thing.

Acked-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>

Thanks.

> ---
> I guess it would be useful if Jessica can pick this change up
> in her tree that introduced the warning.
> ---
>  arch/arm/include/asm/module.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h
> index 89ad0596033a..9e81b7c498d8 100644
> --- a/arch/arm/include/asm/module.h
> +++ b/arch/arm/include/asm/module.h
> @@ -34,6 +34,7 @@ struct mod_arch_specific {
>  #endif
>  };
>  
> +struct module;
>  u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val);
>  
>  /*
> -- 
> 2.9.0
> 

-- 
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