arm64: mm: implement arch_faults_on_old_pte() on arm64

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On arm64 without hardware Access Flag, copying from user will fail because
the pte is old and cannot be marked young. So we always end up with zeroed
page after fork() + CoW for pfn mappings. We don't always have a
hardware-managed Access Flag on arm64.

Hence implement arch_faults_on_old_pte on arm64 to indicate that it might
cause page fault when accessing old pte.

Signed-off-by: Jia He <justin.he@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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Jia He 2019-10-11 22:09:37 +08:00 • committed by Catalin Marinas

parent 47d7b15b88

commit 6af31226d0

1 changed files with 14 additions and 0 deletions

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arch/arm64/include/asm/pgtable.h

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