linux-kernel - Re: [PATCH] arm64/mm: Drop INIT_MM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAMj1kXGPcMYsJV9w_fBXEyxUJFGZhSpn2etWie9wKA_HS3kF_g@mail.gmail.com>
Date: Mon, 2 Dec 2024 11:01:18 +0100
From: Ard Biesheuvel <ardb@...nel.org>
To: Anshuman Khandual <anshuman.khandual@....com>
Cc: linux-arm-kernel@...ts.infradead.org, 
	Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>, 
	Ryan Roberts <ryan.roberts@....com>, Mark Rutland <mark.rutland@....com>, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] arm64/mm: Drop INIT_MM_CONTEXT()

On Mon, 2 Dec 2024 at 05:36, Anshuman Khandual
<anshuman.khandual@....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@....com>
> Cc: Will Deacon <will@...nel.org>
> Cc: Ard Biesheuvel <ardb@...nel.org>
> Cc: Ryan Roberts <ryan.roberts@....com>
> Cc: Mark Rutland <mark.rutland@....com>
> Cc: linux-arm-kernel@...ts.infradead.org
> Cc: linux-kernel@...r.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>

Acked-by: Ard Biesheuvel <ardb@...nel.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
>