linux-kernel - Re: [PATCH] arm64: define __alloc_zeroed_user

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Message-ID: <20200317183723.GH632169@arrakis.emea.arm.com>
Date:   Tue, 17 Mar 2020 18:37:23 +0000
From:   Catalin Marinas <catalin.marinas@....com>
To:     glider@...gle.com
Cc:     will.deacon@....com, mark.rutland@....com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        keescook@...omium.org, akpm@...ux-foundation.org
Subject: Re: [PATCH] arm64: define __alloc_zeroed_user_highpage

On Thu, Mar 12, 2020 at 04:59:20PM +0100, glider@...gle.com wrote:
> When running the kernel with init_on_alloc=1, calling the default
> implementation of __alloc_zeroed_user_highpage() from include/linux/highmem.h
> leads to double-initialization of the allocated page (first by the page
> allocator, then by clear_user_page().
> Calling alloc_page_vma() with __GFP_ZERO, similarly to e.g. x86, seems
> to be enough to ensure the user page is zeroed only once.
> 
> Signed-off-by: Alexander Potapenko <glider@...gle.com>

I queued this for 5.7. Thanks.

-- 
Catalin