* [PATCH RESEND] arm64: entry: drop the unused tmp2 argument of mte_set_kernel_gcr()
@ 2026-10-07 17:45 Bradley Morgan
2026-10-09 10:37 ` Vladimir Murzin
0 siblings, 1 reply; 3+ messages in thread
From: Bradley Morgan @ 2026-10-07 17:45 UTC (permalink / raw)
To: catalin.marinas, will; +Cc: mark.rutland, linux-arm-kernel, linux-kernel, brads
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@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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH RESEND] arm64: entry: drop the unused tmp2 argument of mte_set_kernel_gcr()
2026-10-07 17:45 [PATCH RESEND] arm64: entry: drop the unused tmp2 argument of mte_set_kernel_gcr() Bradley Morgan
@ 2026-10-09 10:37 ` Vladimir Murzin
2026-10-09 15:01 ` Bradley Morgan
0 siblings, 1 reply; 3+ messages in thread
From: Vladimir Murzin @ 2026-10-09 10:37 UTC (permalink / raw)
To: Bradley Morgan, catalin.marinas, will
Cc: mark.rutland, linux-arm-kernel, linux-kernel
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@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@arm.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH RESEND] arm64: entry: drop the unused tmp2 argument of mte_set_kernel_gcr()
2026-10-09 10:37 ` Vladimir Murzin
@ 2026-10-09 15:01 ` Bradley Morgan
0 siblings, 0 replies; 3+ messages in thread
From: Bradley Morgan @ 2026-10-09 15:01 UTC (permalink / raw)
To: Vladimir Murzin, catalin.marinas, will
Cc: mark.rutland, linux-arm-kernel, linux-kernel
On 9 October 2026 11:37:45 BST, Vladimir Murzin <vladimir.murzin@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@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@arm.com>
cheers, sorry for the oopsie on 1/1
--- Thanks!
"I'm not a very positive person" - Linus torvalds
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-10-07 17:45 [PATCH RESEND] arm64: entry: drop the unused tmp2 argument of mte_set_kernel_gcr() Bradley Morgan
2026-10-09 10:37 ` Vladimir Murzin
2026-10-09 15:01 ` Bradley Morgan
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