Messages in this thread Patch in this message | | | Date | Sat, 18 Oct 2008 11:57:19 -0700 | From | Greg KH <> | Subject | [patch 03/14] x86, early_ioremap: fix fencepost error |
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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. --
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