general protection fault on boot.

[Vincent Hoffman]

John Baldwin wrote:
> On Wednesday 09 September 2009 1:38:59 pm John Baldwin wrote:
>   
>> On Wednesday 09 September 2009 12:32:51 pm Vincent Hoffman wrote:
>>     
>>> Hi all,
>>>           I've been running the 8.0-BETAs in a xen virtual machine
>>> (hvm/fully virtualised) for testing and something between r196730 and
>>> r196746 causes a general protection fault on boot. I'll try and narrow
>>> it down if i get a chance but I'm a a bit busy at the moment.
>>>  
>>> backtrace is available at
>>> http://unsane.co.uk/~jhary/freebsd/GPF-09-09-09.gif 
>>> Xen dom0 is a centos5.3 box using the xen-3.3.1 rpms from
>>> http://www.gitco.de/linux/i386/centos/5/rpms/  if thats of any use.
>>>
>>> Let me know if I need to provide any more info.
>>>       
>> Hmm, can you try reverting 196737?  Or actually, can you print out the value 
>> of %ebx ('p $ebx' in ddb will work I think)?  I wonder if this patch would 
>> fix it:
>>
>> Index: pmap.c
>> ===================================================================
>> --- pmap.c	(revision 196974)
>> +++ pmap.c	(working copy)
>> @@ -999,7 +999,7 @@
>>  		 * coherence domain.
>>  		 */
>>  		mfence();
>> -		for (; sva < eva; sva += cpu_clflush_line_size)
>> +		for (; sva <= eva; sva += cpu_clflush_line_size)
>>  			clflush(sva);
>>  		mfence();
>>  	} else {
>>     
>
> This patch is probably bogus.  I am curious what %ebx is however.
>
>   
p $ebx
gives
c25a7000

Vince