[PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

[PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

[Anshuman Khandual]

Platform override for INIT_MM_CONTEXT() is redundant because swapper_pg_dir
always gets assigned as the pgd during init_mm initialization. So just drop
this override on arm64.

Originally this override was added via the 'commit 2b5548b68199 ("arm64/mm:
Separate boot-time page tables from swapper_pg_dir")' because non standard
init_pg_dir was assigned as the pgd. Subsequently it was changed as default
swapper_pg_dir by the 'commit ba5b0333a847 ("arm64: mm: omit redundant
remap of kernel image")', which might have also just dropped this override.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This patch applies on v6.13-rc1

 arch/arm64/include/asm/mmu.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 2ec96d91acc6..662471cfc536 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -109,8 +109,5 @@ static inline bool kaslr_requires_kpti(void)
 	return true;
 }
 
-#define INIT_MM_CONTEXT(name)	\
-	.pgd = swapper_pg_dir,
-
 #endif	/* !__ASSEMBLY__ */
 #endif
-- 
2.30.2

Re: [PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

[Ard Biesheuvel]

On Mon, 2 Dec 2024 at 05:36, Anshuman Khandual
<anshuman.khandual@arm.com> wrote:
>
> Platform override for INIT_MM_CONTEXT() is redundant because swapper_pg_dir
> always gets assigned as the pgd during init_mm initialization. So just drop
> this override on arm64.
>
> Originally this override was added via the 'commit 2b5548b68199 ("arm64/mm:
> Separate boot-time page tables from swapper_pg_dir")' because non standard
> init_pg_dir was assigned as the pgd. Subsequently it was changed as default
> swapper_pg_dir by the 'commit ba5b0333a847 ("arm64: mm: omit redundant
> remap of kernel image")', which might have also just dropped this override.
>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Ryan Roberts <ryan.roberts@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
> This patch applies on v6.13-rc1
>
>  arch/arm64/include/asm/mmu.h | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
> index 2ec96d91acc6..662471cfc536 100644
> --- a/arch/arm64/include/asm/mmu.h
> +++ b/arch/arm64/include/asm/mmu.h
> @@ -109,8 +109,5 @@ static inline bool kaslr_requires_kpti(void)
>         return true;
>  }
>
> -#define INIT_MM_CONTEXT(name)  \
> -       .pgd = swapper_pg_dir,
> -
>  #endif /* !__ASSEMBLY__ */
>  #endif
> --
> 2.30.2
>

Re: [PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

[Ryan Roberts]

On 02/12/2024 04:35, Anshuman Khandual wrote:
> Platform override for INIT_MM_CONTEXT() is redundant because swapper_pg_dir
> always gets assigned as the pgd during init_mm initialization. So just drop
> this override on arm64.
> 
> Originally this override was added via the 'commit 2b5548b68199 ("arm64/mm:
> Separate boot-time page tables from swapper_pg_dir")' because non standard
> init_pg_dir was assigned as the pgd. Subsequently it was changed as default
> swapper_pg_dir by the 'commit ba5b0333a847 ("arm64: mm: omit redundant
> remap of kernel image")', which might have also just dropped this override.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Ryan Roberts <ryan.roberts@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>

> ---
> This patch applies on v6.13-rc1
> 
>  arch/arm64/include/asm/mmu.h | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
> index 2ec96d91acc6..662471cfc536 100644
> --- a/arch/arm64/include/asm/mmu.h
> +++ b/arch/arm64/include/asm/mmu.h
> @@ -109,8 +109,5 @@ static inline bool kaslr_requires_kpti(void)
>  	return true;
>  }
>  
> -#define INIT_MM_CONTEXT(name)	\
> -	.pgd = swapper_pg_dir,
> -
>  #endif	/* !__ASSEMBLY__ */
>  #endif

Re: [PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

[Gavin Shan]

On 12/2/24 2:35 PM, Anshuman Khandual wrote:
> Platform override for INIT_MM_CONTEXT() is redundant because swapper_pg_dir
> always gets assigned as the pgd during init_mm initialization. So just drop
> this override on arm64.
> 
> Originally this override was added via the 'commit 2b5548b68199 ("arm64/mm:
> Separate boot-time page tables from swapper_pg_dir")' because non standard
> init_pg_dir was assigned as the pgd. Subsequently it was changed as default
> swapper_pg_dir by the 'commit ba5b0333a847 ("arm64: mm: omit redundant
> remap of kernel image")', which might have also just dropped this override.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Ryan Roberts <ryan.roberts@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> This patch applies on v6.13-rc1
> 
>   arch/arm64/include/asm/mmu.h | 3 ---
>   1 file changed, 3 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>

Re: [PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

[Will Deacon]

On Mon, 02 Dec 2024 10:05:53 +0530, Anshuman Khandual wrote:
> Platform override for INIT_MM_CONTEXT() is redundant because swapper_pg_dir
> always gets assigned as the pgd during init_mm initialization. So just drop
> this override on arm64.
> 
> Originally this override was added via the 'commit 2b5548b68199 ("arm64/mm:
> Separate boot-time page tables from swapper_pg_dir")' because non standard
> init_pg_dir was assigned as the pgd. Subsequently it was changed as default
> swapper_pg_dir by the 'commit ba5b0333a847 ("arm64: mm: omit redundant
> remap of kernel image")', which might have also just dropped this override.
> 
> [...]

Applied to arm64 (for-next/misc), thanks!

[1/1] arm64/mm: Drop INIT_MM_CONTEXT()
      https://git.kernel.org/arm64/c/5f882f4aa8aa

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev