linux-kernel - Re: PAT support for i386 and x86

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]

Date:	Wed, 8 Aug 2007 12:14:41 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Loic Prylli <loic@...i.com>
Cc:	Andi Kleen <andi@...stfloor.org>,
	Cédric Augonnet <cedric.augonnet@...il.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...l.org>, brice@...i.com,
	cedric.augonnet@...-lyon.org
Subject: Re: PAT support for i386 and x86_64

> I don't see why we have to worry about cache corruption in the case at
> hand. Write-combining is needed to map io (typically pci-mem regions)
> which are never mapped cachable anywhere, including in the linear map.

If we WC them using PAT then there would be a UC<->WC conflict with
the direct mapping and possibly others. That's already undefined
and not allowed.

After some very bad experiences in the past I'm not going to take
chances on this.

We really need to keep all possible mappings synchronized.

-Andi

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/