v3 of a patch to correct a data corruption issue caused by improper handling of shared huge PMDs during page migration. This issue was observed in a customer environment and can be recreated fairly easily with a test program. Patch 0001 addresses this issue only and is copied to stable with the intention that this will go to stable releases. It has existed since the addition of shared huge PMD support. While considering the issue above, Kirill Shutemov noticed that other callers of huge_pmd_unshare have potential issues with cache and TLB flushing. A separate patch (0002) takes advantage of the new routine huge_pmd_sharing_possible() to adjust flushing ranges in the cases where huge PMD sharing is possible. There is no copy to stable for this patch as it has not been reported as an issue and discovered only via code inspection. Mike Kravetz (2): mm: migration: fix migration of huge PMD shared pages hugetlb: take PMD sharing into account when flushing tlb/caches include/linux/hugetlb.h | 14 +++++++ mm/hugetlb.c | 93 +++++++++++++++++++++++++++++++++++++---- mm/rmap.c | 42 +++++++++++++++++-- 3 files changed, 137 insertions(+), 12 deletions(-) -- 2.17.1
