Re: [PATCH] objtool: move libelf detection to Kconfig from Makefile

[Josh Poimboeuf]

On Sun, Jul 08, 2018 at 06:59:42PM +0900, Masahiro Yamada wrote:
> Currently, users are allowed to enable STACK_VALIDATION regardless
> of the compiler capability.  The top-level Makefile warns or breaks
> the build if it turns out that the host compiler cannot link libelf.
> 
> Move the libelf test to Kconfig so that users can enable the feature
> only when the host compiler can build the objtool.  The ugly check
> in the Makefile will go away.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

Thanks for cleaning this up!

> I am sure about this patch only from the build system point of view.
> 
> Please review this from x86 and objtool point of view.
> 
> In my understanding:
> 
>  - UNWINDER_ORC _requires_ objtool,
>    so I added 'depends on STACK_VALIDATION'.
>    ('select' would end up with unmet depenency)

Correct.

>  - RETPOLINE _wants_ objtool, so I added 'imply'

Yeah, I think this is fine.

Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

-- 
Josh