Comment 24 for bug 54020

Revision history for this message
Rodney Gordon II (meff) wrote :

FIXED via 2.6.27.2
http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.27.2

commit d344a53f2e264ea07c950691c1451a4ff355694b
Author: Alan Cox <email address hidden>
Date: Sun Oct 12 19:40:08 2008 +0000

    x86, early_ioremap: fix fencepost error

    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 <email address hidden>
    Signed-off-by: Ingo Molnar <email address hidden>
    Signed-off-by: Greg Kroah-Hartman <email address hidden>