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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Pavel Machek <pavel@suse.cz>
Cc: mathias.schnarrenberger@gmx.de,
	Olaf van der Spek <olafvdspek@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: Re: security: delete BIOS password in keyboard buffer during kernel bootup
Date: Tue, 11 Nov 2008 16:54:21 +0000	[thread overview]
Message-ID: <20081111165421.4f1e836d@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <20081111161808.GA4473@ucw.cz>

> OTOH we don't call BIOS from linux, so we assume that low 64K is
> usable memory (unless marked otherwise in memmap, I guess).

We use the BIOS in some cases for PCI routing, PCI services, APM, and
indirectly for SMM traps, ACPI and via user space for other stuff. So we
preserve the bottom 4K for the BIOS 0x40:xx page
> 
> Anyway, proper place to do clearing is bootloader; it interacts with
> bios already, anyway...

Agreed entirely.

  reply	other threads:[~2008-11-11 16:54 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-08 10:00 security: delete BIOS password in keyboard buffer during kernel bootup Mathias Schnarrenberger
2008-11-08 14:27 ` Alan Cox
2008-11-08 14:36   ` Mathias Schnarrenberger
2008-11-08 16:39 ` Olaf van der Spek
2008-11-09  8:41   ` Mathias Schnarrenberger
2008-11-09 11:08     ` Alan Cox
2008-11-11 16:18       ` Pavel Machek
2008-11-11 16:54         ` Alan Cox [this message]
2008-11-12  8:51           ` Gerhard Mack
2008-11-09 15:36     ` Arjan van de Ven

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