Re: [PATCH v2 6/6] x86/stacktrace: orc, mark it as reliable

[Josh Poimboeuf]

On Mon, May 14, 2018 at 04:06:53PM +0200, Jiri Slaby wrote:
> In SUSE, we need a reliable stack unwinder for kernel live patching, but
> we do not want to enable frame pointers for performance reasons. So
> after the previous patches to make the ORC reliable, mark ORC as a
> reliable stack unwinder on x86.
> 
> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> ---
>  arch/x86/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 47e7f582f86a..e4199fbcc7f2 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -181,7 +181,7 @@ config X86
>  	select HAVE_PERF_USER_STACK_DUMP
>  	select HAVE_RCU_TABLE_FREE
>  	select HAVE_REGS_AND_STACK_ACCESS_API
> -	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
> +	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
>  	select HAVE_STACK_VALIDATION		if X86_64
>  	select HAVE_SYSCALL_TRACEPOINTS
>  	select HAVE_UNSTABLE_SCHED_CLOCK

Maybe clarify the subject here as well:

  x86/stacktrace: Enable HAVE_RELIABLE_STACKTRACE for the ORC unwinder

-- 
Josh