linux-kernel - Re: [patch] Make MMCONFIG space (extended PCI config space) a driver opt-in issue

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: <1198444387.6686.20.camel@pasglop>
Date:	Mon, 24 Dec 2007 08:13:07 +1100
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	Jeff Garzik <jeff@...zik.org>
Cc:	Loic Prylli <loic@...i.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Arjan van de Ven <arjan@...radead.org>,
	linux-kernel@...r.kernel.org, gregkh@...e.de,
	linux-pci@...ey.karlin.mff.cuni.cz
Subject: Re: [patch] Make MMCONFIG space (extended PCI config space) a
	driver opt-in issue


> Are you prepared to guarantee that freely mixing mmconfig and type1 
> config accesses at runtime will always work, on all chipsets?  I'm 
> talking about silicon here, not kernel software.

We spinlock config space accesses. So the silicon will never see
simultaneous accesses, which is what I strongly suspect would be broken
in chipsets (asking for livelocks here).

Now there is the question of whether the silicon implements MMCONFIG
writes in some asynchronous way, in which case, there might be an issue
if you go bang the port right away but I very much doubt it.

Ben.


--
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/