From: Alan Cox <alan@redhat.com>
Date: Fri, 10 Oct 2008 09:46:45 +0000 (+0100)
Subject: x86, early_ioremap: fix fencepost error
X-Git-Tag: v2.6.28-rc1~703^2~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c613ec1a7ff3714da11c7c48a13bab03beb5c376;p=pandora-kernel.git

x86, early_ioremap: fix fencepost error

The x86 implementation of early_ioremap has an off by one error. If we get
an object which ends on the first byte of a page we undermap by one page and
this causes a crash on boot with the ASUS P5QL whose DMI table happens to fit
this alignment.

The size computation is currently

	last_addr = phys_addr + size - 1;
	npages = (PAGE_ALIGN(last_addr) - phys_addr)

(Consider a request for 1 byte at alignment 0...)

Closes #11693

Debugging work by Ian Campbell/Felix Geyer

Signed-off-by: Alan Cox <alan@rehat.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

Reading git-diff-tree failed