Re: [PATCH for-4.5] xen/arm: Correct the opcode for BUG_INSTR on arm32

[Julien Grall <julien.grall@linaro.org>]

Hi Konrad,

On 04/12/2014 19:34, Konrad Rzeszutek Wilk wrote:
> On Thu, Dec 04, 2014 at 07:26:55PM +0000, Julien Grall wrote:
>> A 0 was forgotten when the arm32 BUG instruction opcode has been added in commit
>> 3e802c6ca1fb9a9549258c2855a57cad483f3cbd "xen/arm: Correctly support WARN_ON".
>>
>> This will result to use a valid instruction (mcreq 0, 3, r0, cr15, cr0, {7}),
>> and inhibit usage of BUG/WARN_ON and co.
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>>
>> ---
>>
>> Not sure, why I dropped the 0 when I implemented the patch...
>> This is a bug fixed for Xen 4.5. This is only affected ARM32 where the
>> BUG opcode was malformed.
>>
>> With the malformed opcode, the ASSERT/BUG_ON is skipped and the
>> processor may execute another patch (because the compiler has optimized
>
> s/patch/path/ ?

Yes.

>> due the unreachable in both macro).
>>
>> The code modified is only executed when Xen is in bad state.
>
> Release-Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Thanks!

Regards,



-- 
Julien Grall