linux-kernel - Re: [PATCH] x86/mm: Simplify redundant overlap calculation

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: <c5c56248-4831-4a0c-91ee-c9041dd69a7e@intel.com>
Date: Tue, 23 Jan 2024 08:47:08 -0800
From: Dave Hansen <dave.hansen@...el.com>
To: Dave Hansen <dave.hansen@...ux.intel.com>, linux-kernel@...r.kernel.org
Cc: David Binderman <dcb314@...mail.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
Subject: Re: [PATCH] x86/mm: Simplify redundant overlap calculation

On 1/23/24 08:36, Dave Hansen wrote:
> There have been a couple of reports that the two sides of the
> overlaps() calculation are redundant.  I spent way too much time
> looking at this, but I became convinced that they are redundant
> when a little test program of mine produced identical disassembly
> for both versions of the check.
> 
> Remove the second condition.  It is exactly the same as the first.
> 
> Fixes: 91ee8f5c1f50 ("x86/mm/cpa: Allow range check for static protections")
> Reported-by: David Binderman <dcb314@...mail.com>

Gah, that one escaped a moment too soon:

Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>

.. obviously