From 2ae416b142b625c58c9ccb039aa3ef48ad0e9bae Mon Sep 17 00:00:00 2001 From: Laurent Dufour Date: Wed, 24 Jun 2015 16:56:16 -0700 Subject: mm: new mm hook framework 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: Laurent Dufour Suggested-by: Andrew Morton Cc: "Kirill A. Shutemov" Cc: Hugh Dickins Cc: Rik van Riel Cc: Mel Gorman Cc: Pavel Emelyanov Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm-arch-hooks.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 include/linux/mm-arch-hooks.h (limited to 'include/linux/mm-arch-hooks.h') diff --git a/include/linux/mm-arch-hooks.h b/include/linux/mm-arch-hooks.h new file mode 100644 index 000000000000..63005e367abd --- /dev/null +++ b/include/linux/mm-arch-hooks.h @@ -0,0 +1,16 @@ +/* + * Generic mm no-op hooks. + * + * Copyright (C) 2015, IBM Corporation + * Author: Laurent Dufour + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef _LINUX_MM_ARCH_HOOKS_H +#define _LINUX_MM_ARCH_HOOKS_H + +#include + +#endif /* _LINUX_MM_ARCH_HOOKS_H */ -- cgit v1.2.3