19 Jul, 2010

1 commit


25 Jul, 2008

1 commit

  • On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
    boundary. For example:

    u64 val = PAGE_ALIGN(size);

    always returns a value < 4GB even if size is greater than 4GB.

    The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
    example):

    #define PAGE_SHIFT 12
    #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
    #define PAGE_MASK (~(PAGE_SIZE-1))
    ...
    #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)

    The "~" is performed on a 32-bit value, so everything in "and" with
    PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
    Using the ALIGN() macro seems to be the right way, because it uses
    typeof(addr) for the mask.

    Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
    include/linux/mm.h.

    See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

    [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
    [akpm@linux-foundation.org: fix v850]
    [akpm@linux-foundation.org: fix powerpc]
    [akpm@linux-foundation.org: fix arm]
    [akpm@linux-foundation.org: fix mips]
    [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
    [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
    [akpm@linux-foundation.org: fix powerpc]
    Signed-off-by: Andrea Righi
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     

03 May, 2007

1 commit

  • o __pa() should be used only on kernel linearly mapped virtual addresses
    and not on kernel text and data addresses.

    o Hibernation code needs to determine the physical address associated
    with kernel symbol to mark a section boundary which contains pages which
    don't have to be saved and restored during hibernate/resume operation.

    o Move this piece of code in arch dependent section. So that architectures
    which don't have kernel text/data mapped into kernel linearly mapped
    region can come up with their own ways of determining physical addresses
    associated with a kernel text.

    Signed-off-by: Vivek Goyal
    Signed-off-by: Andi Kleen

    Vivek Goyal