I noticed a few collision usage on VM_FAULT_* definition in the page fault path on arm/arm64/s390 where the VM_FAULT_* can overlap with the generic definition of vm_fault_reason. The major overlapped part being VM_FAULT_HINDEX_MASK which is used only by the hugetlb hwpoisoning. I'm not sure whether any of them can have a real impact, but that does not look like to be expected. I didn't copy stable, if anyone thinks it should please shoot. Nor did I test them in any form - I just changed the allocations from top bits and added a comment for each of them. Please have a look, thanks. Peter Xu (3): mm/arm: Define private VM_FAULT_* reasons from top bits mm/arm64: Define private VM_FAULT_* reasons from top bits mm/s390: Define private VM_FAULT_* reasons from top bits arch/arm/mm/fault.c | 8 ++++++-- arch/arm64/mm/fault.c | 8 ++++++-- arch/s390/mm/fault.c | 14 +++++++++----- 3 files changed, 21 insertions(+), 9 deletions(-) -- 2.37.3