[PATCH 1/2] selftests/arm64: Implement cmpbr_sigill() to hwcap test

[wuyifan]

Hi Mark,

On 2/28/2026 9:23 PM, Mark Brown wrote:
> On Fri, Feb 27, 2026 at 11:19:32AM +0800, Yifan Wu wrote:
>
>>   static void cmpbr_sigill(void)
>>   {
>> -	/* Not implemented, too complicated and unreliable anyway */
>> +	/* CBEQ x0, x0, +8 */
>> +	asm volatile(".inst 0x74C00040" : : : "x0");
>> +	/* UDF #0 */
>> +	asm volatile("udf #0" : : : );
>>   }
> I don't expect it to make a difference but it'd be nice if these were a
> single asm volatile statement, just to make it absolutely clear that no
> instrumentation or anything is supposed to go between the two.
Thanks for the review. That's a good point, I'll combine them in v2.

Regards,
Yifan Wu