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 'arch_remap' 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 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 (2): mm: Introducing arch_remap hook powerpc/mm: Tracking vDSO remap arch/powerpc/include/asm/mmu_context.h | 32 +++++++++++++++++++++++++++- arch/powerpc/kernel/vdso.c | 39 ++++++++++++++++++++++++++++++++++ mm/mremap.c | 11 ++++++++-- 3 files changed, 79 insertions(+), 3 deletions(-) -- 1.9.1 ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
