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Subject: Re: [PATCH v9 30/44] arm64: kasan: Allow enabling in-kernel MTE
To:     Catalin Marinas <catalin.marinas@arm.com>,
        Andrey Konovalov <andreyknvl@google.com>
Cc:     Will Deacon <will.deacon@arm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Branislav Rankov <Branislav.Rankov@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <cover.1605046192.git.andreyknvl@google.com>
 <5ce2fc45920e59623a4a9d8d39b6c96792f1e055.1605046192.git.andreyknvl@google.com>
 <20201112094354.GF29613@gaia>
From:   Vincenzo Frascino <vincenzo.frascino@arm.com>
Message-ID: <66ef4957-f399-4af1-eec5-d5782551e995@arm.com>
Date:   Fri, 13 Nov 2020 11:17:15 +0000
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Hi Catalin,

On 11/12/20 9:43 AM, Catalin Marinas wrote:
> On Tue, Nov 10, 2020 at 11:10:27PM +0100, Andrey Konovalov wrote:
>> From: Vincenzo Frascino <vincenzo.frascino@arm.com>
>>
>> Hardware tag-based KASAN relies on Memory Tagging Extension (MTE)
>> feature and requires it to be enabled. MTE supports
>>
>> This patch adds a new mte_init_tags() helper, that enables MTE in
>> Synchronous mode in EL1 and is intended to be called from KASAN runtime
>> during initialization.
> 
> There's no mte_init_tags() in this function.
> 

During the rework, I realized that the description of mte_init_tags() in this
patch refers to mte_enable_kernel(). In fact the only thing that mte_init_tags()
does is to configure the GCR_EL1 register, hence my preference would be to keep
all the code that deals with such a register in one patch.

What is your preference?

-- 
Regards,
Vincenzo