linux-kernel - Re: [PATCH RFC v2 14/27] arm64: mte: Disable dynamic tag storage management if HW KASAN is enabled

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: <ZWSwrKS6EtJMEu1p@raptor>
Date:   Mon, 27 Nov 2023 15:07:24 +0000
From:   Alexandru Elisei <alexandru.elisei@....com>
To:     David Hildenbrand <david@...hat.com>
Cc:     catalin.marinas@....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,
        hyesoo.yu@...sung.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 v2 14/27] arm64: mte: Disable dynamic tag storage
 management if HW KASAN is enabled

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.

Thanks,
Alex

> 
> -- 
> Cheers,
> 
> David / dhildenb
>