linux-kernel - Re: [PATCH] x86/fault: ignore RSVD flag in error code if P flag is 0

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: <3e39adad-3b1d-18c0-29d5-e0268c0fa083@intel.com>
Date:   Thu, 30 Jun 2022 07:22:08 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Vasily Averin <vvs@...nvz.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>
Cc:     kernel@...nvz.org, linux-kernel@...r.kernel.org,
        Konstantin Khorenko <khorenko@...tuozzo.com>,
        steve.sipes@...andsolutions.com
Subject: Re: [PATCH] x86/fault: ignore RSVD flag in error code if P flag is 0

On 6/29/22 22:58, Vasily Averin wrote:
> Some older Intel CPUs have errata:
> "Not-Present Page Faults May Set the RSVD Flag in the Error Code

Please include a link to the documentation when you cite things like
this.  For example, this is very helpful:

	Several older Intel CPUs have this or a similar erratum.  For
	instance, the "Intel Xeon Processor 5400 Series Specification
	Update" has "AX74 ... Not-Present Page Faults May Set the RSVD
	Flag in the Error Code".

	https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-5400-spec-update.pdf

That makes it a *LOT* easier to find the actual erratum and its text.  I
honestly also woudln't mind if you just copy a chunk of the problem text
verbatim into the changelog.  Intel does have a habit of updating text
in documents like that and it's quite handy to have a snapshot of what
you were reading when you wrote the patch.