linux-kernel - Re: [PATCH 3/6] MIPS: Octeon: qspinlock: Flush write buffer

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: <f8344f35-cdf1-ec3d-dcd0-7bfc392ef6e0@nokia.com>
Date:   Thu, 28 Jan 2021 13:13:03 +0100
From:   Alexander Sverdlin <alexander.sverdlin@...ia.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Paul Burton <paul.burton@...tec.com>, linux-mips@...r.kernel.org,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Will Deacon <will@...nel.org>,
        Boqun Feng <boqun.feng@...il.com>,
        Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/6] MIPS: Octeon: qspinlock: Flush write buffer

Hi!

On 28/01/2021 12:35, Peter Zijlstra wrote:
>> My point was that original MIPS spinlocks had this write-buffer-flush and
>> it got lost on the conversion to qspinlocks. The referenced commit just
>> allows to see the last MIPS-specific implementation before deletion.
> Hardware that needs a store-buffer flush after release is highly suspect
> and needs big and explicit comments. Not vague hints.

I have a feeling that you are not going to suggest the comments for the code
and one has to guess what is it you have in mind?

Do you think the proper approach would be to undelete MIPS spinlocks and
make these broken qspinlocks a configurable option for MIPS? I don't even
mind if they will be default option for those not interested in performance
or latency.

-- 
Best regards,
Alexander Sverdlin.