Eric Lee / smarc-fsl-linux-kernel

11 Jan, 2012

1 commit

  • c0a32fc5a   mm: more intensive memory corruption debugging ... Browse Code »

    With CONFIG_DEBUG_PAGEALLOC configured, the CPU will generate an exception
    on access (read,write) to an unallocated page, which permits us to catch
    code which corrupts memory. However the kernel is trying to maximise
    memory usage, hence there are usually few free pages in the system and
    buggy code usually corrupts some crucial data.

    This patch changes the buddy allocator to keep more free/protected pages
    and to interlace free/protected and allocated pages to increase the
    probability of catching corruption.

    When the kernel is compiled with CONFIG_DEBUG_PAGEALLOC,
    debug_guardpage_minorder defines the minimum order used by the page
    allocator to grant a request. The requested size will be returned with
    the remaining pages used as guard pages.

    The default value of debug_guardpage_minorder is zero: no change from
    current behaviour.

    [akpm@linux-foundation.org: tweak documentation, s/flg/flag/]
    Signed-off-by: Stanislaw Gruszka
    Cc: Mel Gorman
    Cc: Andrea Arcangeli
    Cc: "Rafael J. Wysocki"
    Cc: Christoph Lameter
    Cc: Pekka Enberg
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Stanislaw Gruszka
     

23 Mar, 2011

1 commit

  • 7bc32f6f9   mm: debug-pagealloc: fix kconfig dependency warning ... Browse Code »

    Fix kconfig dependency warning to satisfy dependencies:

    warning: (PAGE_POISONING) selects DEBUG_PAGEALLOC which has unmet
    direct dependencies (DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC &&
    (!HIBERNATION || !PPC && !SPARC) && !KMEMCHECK)

    Signed-off-by: Akinobu Mita
    Cc: Randy Dunlap
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     

21 Sep, 2009

1 commit

15 Jun, 2009

1 commit

03 Apr, 2009

1 commit

  • ee3b4290a   generic debug pagealloc: build fix ... Browse Code »

    This fixes a build failure with generic debug pagealloc:

    mm/debug-pagealloc.c: In function 'set_page_poison':
    mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
    mm/debug-pagealloc.c: In function 'clear_page_poison':
    mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
    mm/debug-pagealloc.c: In function 'page_poison':
    mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
    mm/debug-pagealloc.c: At top level:
    mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
    include/linux/mm.h:1278: error: previous definition of 'kernel_map_pages' was here
    mm/debug-pagealloc.c: In function 'kernel_map_pages':
    mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared (first use in this function)

    by fixing

    - debug_flags should be in struct page
    - define DEBUG_PAGEALLOC config option for all architectures

    Signed-off-by: Akinobu Mita
    Reported-by: Alexander Beregalov
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     

01 Apr, 2009

1 commit

  • 6a11f75b6   generic debug pagealloc ... Browse Code »

    CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
    s390. This patch implements it for the rest of the architectures by
    filling the pages with poison byte patterns after free_pages() and
    verifying the poison patterns before alloc_pages().

    This generic one cannot detect invalid page accesses immediately but
    invalid read access may cause invalid dereference by poisoned memory and
    invalid write access can be detected after a long delay.

    Signed-off-by: Akinobu Mita
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita