Re: [Xen-devel] [PATCH] x86/gnttab: fix asm() operand in gnttab_clear_flag()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 22.03.12 at 18:14, Keir Fraser <keir.xen@xxxxxxxxx> wrote:
> On 22/03/2012 15:55, "Jan Beulich" <JBeulich@xxxxxxxx> wrote:
> 
>> The operand needs to use the 'w' modifier in case the compiler happens
>> to pick a register (which apparently it does for no-one but the
>> reporter of this problem).
>> 
>> Reported-by: Lin Ming <mlin@xxxxxxxxxxxxx>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> Acked-by: Keir Fraser <keir@xxxxxxx>

Committed. Can you please also pull this over into both 4.x-testing
trees (as the now adjusted original c/s is in there too)?

Thanks, Jan

>> --- a/xen/include/asm-x86/grant_table.h
>> +++ b/xen/include/asm-x86/grant_table.h
>> @@ -54,7 +54,7 @@ static inline void gnttab_clear_flag(uns
>>       * Note that this cannot be clear_bit(), as the access must be
>>       * confined to the specified 2 bytes.
>>       */
>> -    asm volatile ("lock btrw %1,%0" : "=m" (*st) : "Ir" (nr), "m" (*st));
>> +    asm volatile ("lock btrw %w1,%0" : "=m" (*st) : "Ir" (nr), "m" (*st));
>>  }
>>  
>>  /* Foreign mappings of HHVM-guest pages do not modify the type count. */
>> 
>> 
>> 
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxx 
>> http://lists.xen.org/xen-devel 




_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel