• Laurent Dufour's avatar
    mm: new mm hook framework · 2ae416b1
    Laurent Dufour authored
    CRIU is recreating the process memory layout by remapping the checkpointee
    memory area on top of the current process (criu).  This includes remapping
    the vDSO to the place it has at checkpoint time.
    
    However some architectures like powerpc are keeping a reference to the
    vDSO base address to build the signal return stack frame by calling the
    vDSO sigreturn service.  So once the vDSO has been moved, this reference
    is no more valid and the signal frame built later are not usable.
    
    This patch serie is introducing a new mm hook framework, and a new
    arch_remap hook which is called when mremap is done and the mm lock still
    hold.  The next patch is adding the vDSO remap and unmap tracking to the
    powerpc architecture.
    
    This patch (of 3):
    
    This patch introduces a new set of header file to manage mm hooks:
    - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
    - a generic header (include/linux/mm-arch-hooks.h)
    
    The architecture which need to overwrite a hook as to redefine it in its
    header file, while architecture which doesn't need have nothing to do.
    
    The default hooks are defined in the generic header and are used in the
    case the architecture is not defining it.
    
    In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
    be moved here.
    Signed-off-by: default avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
    Suggested-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
    Cc: Hugh Dickins <hughd@google.com>
    Cc: Rik van Riel <riel@redhat.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Pavel Emelyanov <xemul@parallels.com>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Michael Ellerman <mpe@ellerman.id.au>
    Cc: Ingo Molnar <mingo@kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    2ae416b1
mm-arch-hooks.h 446 Bytes