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

["H. Peter Anvin" <hpa@zytor.com>]

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@gmail.com>
>> 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