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Message-ID: <dd2dfeb0-aa7b-43e4-ae9f-e2a22b3dac30@redhat.com>
Date:   Tue, 28 Nov 2023 18:05:41 +0100
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Subject: Re: [PATCH RFC v2 14/27] arm64: mte: Disable dynamic tag storage
 management if HW KASAN is enabled
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To:     Alexandru Elisei <alexandru.elisei@arm.com>
Cc:     catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev,
        maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com,
        yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org,
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References: <20231119165721.9849-1-alexandru.elisei@arm.com>
 <20231119165721.9849-15-alexandru.elisei@arm.com>
 <e8f7d855-e5e7-48dd-adce-7c641a561e2b@redhat.com> <ZWSwrKS6EtJMEu1p@raptor>
From:   David Hildenbrand <david@redhat.com>
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In-Reply-To: <ZWSwrKS6EtJMEu1p@raptor>
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On 27.11.23 16:07, Alexandru Elisei wrote:
> Hi,
> 
> On Fri, Nov 24, 2023 at 08:54:12PM +0100, David Hildenbrand wrote:
>> On 19.11.23 17:57, Alexandru Elisei wrote:
>>> To be able to reserve the tag storage associated with a page requires that
>>> the tag storage page can be migrated.
>>>
>>> When HW KASAN is enabled, the kernel allocates pages, which are now tagged,
>>> in non-preemptible contexts, which can make reserving the associate tag
>>> storage impossible.
>>
>> I assume that it's the only in-kernel user that actually requires tagged
>> memory (besides for user space), correct?
> 
> Indeed, this is the case. I'll expand the commit message to be more clear about
> it.
> 

Great, thanks!

-- 
Cheers,

David / dhildenb