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    Subject[patch 10/14] x86, early_ioremap: fix fencepost error
    2.6.27-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
    @@ -595,7 +595,7 @@ 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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