arm64: mm: __ptep_set_access_flags must hint correct TTL

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It has been reported that since commit 752a0d1d48 ("arm64: mm:
Provide level hint for flush_tlb_page()"), the arm64
check_hugetlb_options selftest has been locking up while running "Check
child hugetlb memory with private mapping, sync error mode and mmap
memory".

This is due to hugetlb (and THP) helpers casting their PMD/PUD entries
to PTE and calling __ptep_set_access_flags(), which issues a
__flush_tlb_page(). Now that this is hinted for level 3, in this case,
the TLB entry does not get evicted and we end up in a spurious fault
loop.

Fix this by creating a __ptep_set_access_flags_anysz() function which
takes the pgsize of the entry. It can then add the appropriate hint. The
"_anysz" approach is the established pattern for problems of this class.

Reported-by: Aishwarya TCV <Aishwarya.TCV@arm.com>
Fixes: 752a0d1d48 ("arm64: mm: Provide level hint for flush_tlb_page()")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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This commit is contained in:

Ryan Roberts 2026-03-23 16:39:16 +00:00 • committed by Catalin Marinas

parent 752a0d1d48

commit b7d9d2e3a8

3 changed files with 42 additions and 13 deletions

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19

arch/arm64/include/asm/pgtable.h

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30

arch/arm64/mm/fault.c

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6

arch/arm64/mm/hugetlbpage.c

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