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    SubjectRe: [PATCH -fixes 0/2] Fix set_huge_pte_at()
    From
    +cc Andrew: Would  you mind taking this patchset in your tree for the 
    next rc? This patchset depends on a previous fix for arm64 that you
    merged in rc4 which is not in the riscv -fixes branch yet.

    I saw with Palmer and he should ack this shortly.

    If I can do anything else to help, let me know.

    Thanks,

    Alex

    On 28/09/2023 17:18, Alexandre Ghiti wrote:
    > A recent report [1] from Ryan for arm64 revealed that we do not handle
    > swap entries when setting a hugepage backed by a NAPOT region (the
    > contpte riscv equivalent).
    >
    > As explained in [1], the issue was discovered by a new test in kselftest
    > which uses poison entries, but the symptoms are different from arm64 though:
    >
    > - the riscv kernel bugs because we do not handle VM_FAULT_HWPOISON*,
    > this is fixed by patch 1,
    > - after that, the test passes because the first pte_napot() fails (the
    > poison entry does not have the N bit set), and then we only set the
    > first page table entry covering the NAPOT hugepage, which is enough
    > for hugetlb_fault() to correctly raise a VM_FAULT_HWPOISON wherever we
    > write in this mapping since only this first page table entry is
    > checked
    > (see https://elixir.bootlin.com/linux/v6.6-rc3/source/mm/hugetlb.c#L6071).
    > But this seems fragile so patch 2 sets all page table entries of a
    > NAPOT mapping.
    >
    > [1]: https://lore.kernel.org/linux-arm-kernel/20230922115804.2043771-1-ryan.roberts@arm.com/
    >
    >
    > Alexandre Ghiti (2):
    > riscv: Handle VM_FAULT_[HWPOISON|HWPOISON_LARGE] faults instead of
    > panicking
    > riscv: Fix set_huge_pte_at() for NAPOT mappings when a swap entry is
    > set
    >
    > arch/riscv/mm/fault.c | 2 +-
    > arch/riscv/mm/hugetlbpage.c | 19 +++++++++++++------
    > 2 files changed, 14 insertions(+), 7 deletions(-)
    >

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