[PATCH] ARM: module: fix modsign build error

[PATCH] ARM: module: fix modsign build error

[Arnd Bergmann]

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@arndb.de>
---
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

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@arndb.de>

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@armlinux.org.uk>

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

[Jessica Yu]

+++ Russell King - ARM Linux [06/07/18 14:00 +0100]:
>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@arndb.de>
>
>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?

Generally yes, it's just that in this case module_signing.c neither
needs nor includes linux/module.h. The needed load_info struct
definition just requires definitions for Elf_[SPE]hdr, Elf_Addr,
Elf_Sym, etc. and those are all defined in asm/module.h.

>That said, adding this is no bad thing.
>
>Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
>
>Thanks.

Thanks! Queued in modules-next.

Jessica