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]

Date:	Sat, 22 Dec 2007 20:40:14 -0800 (PST)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Jeff Garzik <jeff@...zik.org>
cc:	Arjan van de Ven <arjan@...radead.org>,
	linux-kernel@...r.kernel.org, gregkh@...e.de,
	linux-pci@...ey.karlin.mff.cuni.cz,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Subject: Re: [patch] Make MMCONFIG space (extended PCI config space) a driver
 opt-in issue

On Sat, 22 Dec 2007, Jeff Garzik wrote:
> 
> It should be self-evident that mmconfig doesn't work on old hardware, is not
> needed on old hardware, should not be turned on for old hardware, and in
> general should never disturb old hardware.

.. but it does. How do you figure out when to turn it off?

By "old hardware" I don't mean stuff from the last century, that generally 
doesn't even *have* MMCONFIG. I mean the stuff you can buy *today*, which 
will be old by the time people really start _needing_ MMCONFIG.

The fact is, 99% of the hardware you buy *today* has absolutely zero need 
for extended PCI config access. In fact, I would not be surprised at all 
if most hardware sold today generally doesn't have *any* devices that even 
have config registers in the 0x100+ range.

So those are the kinds of machines we want to protect from blowing up. 
Stuff that isn't sold with Vista, and has never been tested (or where 
vista does some work-arounds we don't even know about - somebody was 
mentioning things like looking at the BIOS date etc).

			Linus
--
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/