• Robert Hentosh's avatar
    [PATCH] x86_64: Fix off by one in bad_addr checking in find_e820_area · 7ca97c61
    Robert Hentosh authored
    From: Robert Hentosh <robert_hentosh@dell.com>
    Actually, we just stumbled on a different bug found in find_e820_area() in
    e820.c.  The following code does not handle the edge condition correctly:
       while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
       last = addr + size;
       if ( last > ei->addr + ei->size )
    The second statement in the while loop needs to be a <= b so that it is the
    logical negavite of the if (a > b) outside it. It needs to read:
       while (bad_addr(&addr, size) && addr+size <= ei->addr + ei->size)
    In the case that failed bad_addr was returning an address that is exactly size
    bellow the end of the e820 range.
    AK: Again together with the earlier avoid edma fix this fixes
    boot on a Dell PE6850/16GB
    Signed-off-by: default avatarAndi Kleen <ak@suse.de>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
e820.c 18 KB