Re: [PATCH v7 06/12] x86: pm-trace - Adapt assembly for PIE support

[Kees Cook]

On Mon, May 20, 2019 at 04:19:31PM -0700, Thomas Garnier wrote:
> From: Thomas Garnier <thgarnie@xxxxxxxxxx>
> 
> Change assembly to use the new _ASM_MOVABS macro instead of _ASM_MOV for
> the assembly to be PIE compatible.
> 
> Position Independent Executable (PIE) support will allow to extend the
> KASLR randomization range below 0xffffffff80000000.
> 
> Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
>  arch/x86/include/asm/pm-trace.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/pm-trace.h b/arch/x86/include/asm/pm-trace.h
> index bfa32aa428e5..972070806ce9 100644
> --- a/arch/x86/include/asm/pm-trace.h
> +++ b/arch/x86/include/asm/pm-trace.h
> @@ -8,7 +8,7 @@
>  do {								\
>  	if (pm_trace_enabled) {					\
>  		const void *tracedata;				\
> -		asm volatile(_ASM_MOV " $1f,%0\n"		\
> +		asm volatile(_ASM_MOVABS " $1f,%0\n"		\
>  			     ".section .tracedata,\"a\"\n"	\
>  			     "1:\t.word %c1\n\t"		\
>  			     _ASM_PTR " %c2\n"			\
> -- 
> 2.21.0.1020.gf2820cf01a-goog
> 

-- 
Kees Cook