Subject: [PATCH v5 0/3] Tracking user space vDSO remaping

From: Laurent Dufour <[email-masked]>
Date: Wed, 15 Apr 2015 16:16:55 +0200

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.

Changes in v5:
- Jumping over v4 which was too complex (PowerPC part) for the need.
- Introducing new mm hook framework as suggested by Andrew Morton.

Changes in v4:
- Reviewing the PowerPC part of the patch to handle partial unmap and remap
  of the vDSO.

Changes in v3:
- Fixed grammatical error in a comment of the second patch. 
  Thanks again, Ingo.

Changes in v2:
--------------
- Following the Ingo Molnar's advice, enabling the call to arch_remap through
  the __HAVE_ARCH_REMAP macro. This reduces considerably the first patch.

Laurent Dufour (3):
  mm: New mm hook framework
  mm: New arch_remap hook
  powerpc/mm: Tracking vDSO remap

 arch/alpha/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/arc/include/asm/mm-arch-hooks.h        | 15 +++++++++++++++
 arch/arm/include/asm/mm-arch-hooks.h        | 15 +++++++++++++++
 arch/arm64/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/avr32/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/blackfin/include/asm/mm-arch-hooks.h   | 15 +++++++++++++++
 arch/c6x/include/asm/mm-arch-hooks.h        | 15 +++++++++++++++
 arch/cris/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/frv/include/asm/mm-arch-hooks.h        | 15 +++++++++++++++
 arch/hexagon/include/asm/mm-arch-hooks.h    | 15 +++++++++++++++
 arch/ia64/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/m32r/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/m68k/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/metag/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/microblaze/include/asm/mm-arch-hooks.h | 15 +++++++++++++++
 arch/mips/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/mn10300/include/asm/mm-arch-hooks.h    | 15 +++++++++++++++
 arch/nios2/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/openrisc/include/asm/mm-arch-hooks.h   | 15 +++++++++++++++
 arch/parisc/include/asm/mm-arch-hooks.h     | 15 +++++++++++++++
 arch/powerpc/include/asm/mm-arch-hooks.h    | 28 ++++++++++++++++++++++++++++
 arch/powerpc/include/asm/mmu_context.h      | 23 ++++++++++++++++++++++-
 arch/s390/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/score/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/sh/include/asm/mm-arch-hooks.h         | 15 +++++++++++++++
 arch/sparc/include/asm/mm-arch-hooks.h      | 15 +++++++++++++++
 arch/tile/include/asm/mm-arch-hooks.h       | 15 +++++++++++++++
 arch/um/include/asm/mm-arch-hooks.h         | 15 +++++++++++++++
 arch/unicore32/include/asm/mm-arch-hooks.h  | 15 +++++++++++++++
 arch/x86/include/asm/mm-arch-hooks.h        | 15 +++++++++++++++
 arch/xtensa/include/asm/mm-arch-hooks.h     | 15 +++++++++++++++
 include/linux/mm-arch-hooks.h               | 25 +++++++++++++++++++++++++
 mm/mremap.c                                 | 17 +++++++++++------
 33 files changed, 521 insertions(+), 7 deletions(-)
 create mode 100644 arch/alpha/include/asm/mm-arch-hooks.h
 create mode 100644 arch/arc/include/asm/mm-arch-hooks.h
 create mode 100644 arch/arm/include/asm/mm-arch-hooks.h
 create mode 100644 arch/arm64/include/asm/mm-arch-hooks.h
 create mode 100644 arch/avr32/include/asm/mm-arch-hooks.h
 create mode 100644 arch/blackfin/include/asm/mm-arch-hooks.h
 create mode 100644 arch/c6x/include/asm/mm-arch-hooks.h
 create mode 100644 arch/cris/include/asm/mm-arch-hooks.h
 create mode 100644 arch/frv/include/asm/mm-arch-hooks.h
 create mode 100644 arch/hexagon/include/asm/mm-arch-hooks.h
 create mode 100644 arch/ia64/include/asm/mm-arch-hooks.h
 create mode 100644 arch/m32r/include/asm/mm-arch-hooks.h
 create mode 100644 arch/m68k/include/asm/mm-arch-hooks.h
 create mode 100644 arch/metag/include/asm/mm-arch-hooks.h
 create mode 100644 arch/microblaze/include/asm/mm-arch-hooks.h
 create mode 100644 arch/mips/include/asm/mm-arch-hooks.h
 create mode 100644 arch/mn10300/include/asm/mm-arch-hooks.h
 create mode 100644 arch/nios2/include/asm/mm-arch-hooks.h
 create mode 100644 arch/openrisc/include/asm/mm-arch-hooks.h
 create mode 100644 arch/parisc/include/asm/mm-arch-hooks.h
 create mode 100644 arch/powerpc/include/asm/mm-arch-hooks.h
 create mode 100644 arch/s390/include/asm/mm-arch-hooks.h
 create mode 100644 arch/score/include/asm/mm-arch-hooks.h
 create mode 100644 arch/sh/include/asm/mm-arch-hooks.h
 create mode 100644 arch/sparc/include/asm/mm-arch-hooks.h
 create mode 100644 arch/tile/include/asm/mm-arch-hooks.h
 create mode 100644 arch/um/include/asm/mm-arch-hooks.h
 create mode 100644 arch/unicore32/include/asm/mm-arch-hooks.h
 create mode 100644 arch/x86/include/asm/mm-arch-hooks.h
 create mode 100644 arch/xtensa/include/asm/mm-arch-hooks.h
 create mode 100644 include/linux/mm-arch-hooks.h

-- 
1.9.1