Re: [PATCHv11 05/19] x86/relocate_kernel: Use named labels for less confusion

[H. Peter Anvin]

On 5/29/24 03:47, Nikolay Borisov wrote:
> > diff --git a/arch/x86/kernel/relocate_kernel_64.S 
> > b/arch/x86/kernel/relocate_kernel_64.S
> > index 56cab1bb25f5..085eef5c3904 100644
> > --- a/arch/x86/kernel/relocate_kernel_64.S
> > +++ b/arch/x86/kernel/relocate_kernel_64.S
> > @@ -148,9 +148,10 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
> >        */
> >       movl    $X86_CR4_PAE, %eax
> >       testq    $X86_CR4_LA57, %r13
> > -    jz    1f
> > +    jz    .Lno_la57
> >       orl    $X86_CR4_LA57, %eax
> > -1:
> > +.Lno_la57:
> > +
> >       movq    %rax, %cr4
> >       jmp 1f

Sorry if this is a duplicate; something strange happened with my email.

If you are cleaning up this code anyway...

this whole piece of code can be simplified to:

	and $(X86_CR4_PAE | X86_CR4_LA57), %r13d
	mov %r13, %cr4

The PAE bit in %r13 is guaranteed to be set, and %r13 is dead after this.

	-hpa