Re: [PATCH] x86: relocate_kernel - use predefined PAGE_SIZE insteadof own alias

[H. Peter Anvin]

Cyrill Gorcunov wrote:
> [H. Peter Anvin - Fri, Mar 21, 2008 at 01:18:13PM -0700]
> > Cyrill Gorcunov wrote:
> > > This patch does clean up relocate_kernel_(32|64).S a bit by getting rid
> > > of local PAGE_ALIGNED macro. We should use well-known PAGE_SIZE instead
> > > Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
> > Looks good!
> >
> > 	-hpa
>
> Thanks Peter for review, btw we have in relocate_kernel_32.S
>
> 188:	movl	%cr4, %eax
> 189:	andl	$0, %eax
> 190:	movl	%eax, %cr4
>
> but maybe would be better just replace it with
>
> 	xorl	%eax, %eax
> 	movl	%eax, %cr4
>
> or there is some nonobvious reason not to do so?

The only case I can think of would be if the code expects to patch the 
zero, but even then it'd be cantankerous, because gas will optimize that 
zero down to a single byte.

So, no :)

	-hpa


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