Re: [PATCH AUTOSEL 5.11 31/52] x86, build: use objtool mcount

[Kees Cook]

On Tue, Mar 02, 2021 at 06:55:12AM -0500, Sasha Levin wrote:
> From: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
> 
> [ Upstream commit 6dafca97803309c3cb5148d449bfa711e41ddef2 ]
> 
> Select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION is selected to use
> objtool to generate __mcount_loc sections for dynamic ftrace with
> Clang and gcc <5 (later versions of gcc use -mrecord-mcount).
> 
> Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

This one doesn't make sense without all the other objtool changes for
it. Please drop this from autosel.

-Kees

> ---
>  arch/x86/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 21f851179ff0..300a9b5296fe 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -168,6 +168,7 @@ config X86
>  	select HAVE_CONTEXT_TRACKING		if X86_64
>  	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
>  	select HAVE_C_RECORDMCOUNT
> +	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
>  	select HAVE_DEBUG_KMEMLEAK
>  	select HAVE_DMA_CONTIGUOUS
>  	select HAVE_DYNAMIC_FTRACE
> -- 
> 2.30.1
> 

-- 
Kees Cook