Re: [PATCH RESEND] arm64: entry: drop the unused tmp2 argument of mte_set_kernel_gcr()

[Bradley Morgan]

On 9 October 2026 11:37:45 BST, Vladimir Murzin <vladimir.murzin at arm.com>
wrote:
>On 10/7/26 18:45, Bradley Morgan wrote:
>> mte_set_kernel_gcr() takes a tmp2 argument the macro never uses. It
>> used to, the body passed \tmp and \tmp2 to mte_set_gcr, then
>> commit 82868247897b ("arm64: kasan: mte: use a constant kernel
>> GCR_EL1 value") swapped that for
>> 
>>     mov     \tmp, KERNEL_GCR_EL1
>> 
>> and tmp2 stayed in the declaration and in the one caller, which
>> passes x23 for it.
>> 
>> Drop it, both places.
>> 
>> Signed-off-by: Bradley Morgan <brads at mainlining.org>
>> ---
>> Resending, the first send's body got mangled.
>> 
>>  arch/arm64/kernel/entry.S | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
>> index f63049ac32dc..c3106dee61e1 100644
>> --- a/arch/arm64/kernel/entry.S
>> +++ b/arch/arm64/kernel/entry.S
>> @@ -171,7 +171,7 @@ alternative_else_nop_endif
>>  #endif
>>  	.endm
>>  
>> -	.macro mte_set_kernel_gcr, tmp, tmp2
>> +	.macro mte_set_kernel_gcr, tmp
>>  #ifdef CONFIG_KASAN_HW_TAGS
>>  alternative_cb	ARM64_ALWAYS_SYSTEM, kasan_hw_tags_enable
>>  	b	1f
>> @@ -258,7 +258,7 @@ alternative_else_nop_endif
>>  
>>  	apply_ssbd 1, x22, x23
>>  
>> -	mte_set_kernel_gcr x22, x23
>> +	mte_set_kernel_gcr x22
>>  
>>  	/*
>>  	 * Any non-self-synchronizing system register updates required for
>> -- 2.53.0
>> 
>
>Reviewed-by: Vladimir Murzin <vladimir.murzin at arm.com>


cheers, sorry for the oopsie on 1/1

--- Thanks!
"I'm not a very positive person" - Linus torvalds