linux-kernel - Re: [PATCH RFC 00/37] Add support for arm64 MTE dynamic tag storage reuse

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: <ZTuZQYjcYFILtGYI@arm.com>
Date:   Fri, 27 Oct 2023 12:04:33 +0100
From:   Catalin Marinas <catalin.marinas@....com>
To:     Hyesoo Yu <hyesoo.yu@...sung.com>
Cc:     Alexandru Elisei <alexandru.elisei@....com>,
        David Hildenbrand <david@...hat.com>, will@...nel.org,
        oliver.upton@...ux.dev, maz@...nel.org, james.morse@....com,
        suzuki.poulose@....com, yuzenghui@...wei.com, arnd@...db.de,
        akpm@...ux-foundation.org, mingo@...hat.com, peterz@...radead.org,
        juri.lelli@...hat.com, vincent.guittot@...aro.org,
        dietmar.eggemann@....com, rostedt@...dmis.org, bsegall@...gle.com,
        mgorman@...e.de, bristot@...hat.com, vschneid@...hat.com,
        mhiramat@...nel.org, rppt@...nel.org, hughd@...gle.com,
        pcc@...gle.com, steven.price@....com, anshuman.khandual@....com,
        vincenzo.frascino@....com, eugenis@...gle.com, kcc@...gle.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kvmarm@...ts.linux.dev, linux-fsdevel@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-mm@...ck.org,
        linux-trace-kernel@...r.kernel.org
Subject: Re: [PATCH RFC 00/37] Add support for arm64 MTE dynamic tag storage
 reuse

On Wed, Oct 25, 2023 at 05:52:58PM +0900, Hyesoo Yu wrote:
> If we only avoid using ALLOC_CMA for __GFP_TAGGED, would we still be able to use
> the next iteration even if the hardware does not support "tag of tag" ? 

It depends on how the next iteration looks like. The plan was not to
support this so that we avoid another complication where a non-tagged
page is mprotect'ed to become tagged and it would need to be migrated
out of the CMA range. Not sure how much code it would save.

> I am not sure every vendor will support tag of tag, since there is no information
> related to that feature, like in the Google spec document.

If you are aware of any vendors not supporting this, please direct them
to the Arm support team, it would be very useful information for us.

Thanks.

-- 
Catalin