Re: [PATCHv10 05/18] x86/kexec: Keep CR4.MCE set during kexec for TDX guest

[Kirill A. Shutemov]

On Tue, Apr 30, 2024 at 03:03:23PM +0200, Borislav Petkov wrote:
> On Tue, Apr 09, 2024 at 02:29:57PM +0300, Kirill A. Shutemov wrote:
> > +1:
> > +	testq	$X86_CR4_MCE, %r13
> > +	jz	1f
> > +	ALTERNATIVE "", __stringify(orl $X86_CR4_MCE, %eax), X86_FEATURE_TDX_GUEST
> >  1:
> 
> Please add the below patch to your set. Those same-number labels are
> just abominable.
> 
> Thx.
> 
> ---
> From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>
> Date: Tue, 30 Apr 2024 15:00:16 +0200
> Subject: [PATCH] x86/relocate_kernel: Use named labels for less confusion
> 
> That identity_mapped() function was loving that "1" label to the point
> of completely confusing its readers.
> 
> Use named labels in each place for clarity.
> 
> No functional changes.
> 
> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
> ---
>  arch/x86/kernel/relocate_kernel_64.S | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
> index 8e2037d78a1f..0077c9e562a7 100644
> --- a/arch/x86/kernel/relocate_kernel_64.S
> +++ b/arch/x86/kernel/relocate_kernel_64.S
> @@ -152,13 +152,15 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
>  	 */
>  	movl	$X86_CR4_PAE, %eax
>  	testq	$X86_CR4_LA57, %r13
> -	jz	1f
> +	jz	no_la57
>  	orl	$X86_CR4_LA57, %eax
> -1:
> +no_la57:

I assume all of these new labels have to be prefixed with ".L", right?

-- 
  Kiryl Shutsemau / Kirill A. Shutemov