lkml.org 
[lkml]   [2008]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 03/14] x86, early_ioremap: fix fencepost error
2.6.25-stable review patch.  If anyone has any objections, please let us
know.

------------------
From: Alan Cox <alan@redhat.com>

commit c613ec1a7ff3714da11c7c48a13bab03beb5c376 upstream

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>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/mm/ioremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -438,7 +438,7 @@ void __init *early_ioremap(unsigned long
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
- size = PAGE_ALIGN(last_addr) - phys_addr;
+ size = PAGE_ALIGN(last_addr + 1) - phys_addr;

/*
* Mappings have to fit in the FIX_BTMAP area.
--


\
 
 \ /
  Last update: 2008-10-18 21:23    [W:0.268 / U:0.764 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site