From: Barry Song <v-songbaohua@xxxxxxxx> Hi Ryan, David, it seems contpte_ptep_set_access_flags() has never advanced pte pfn, and it is setting all entries' pfn to the first subpage. But I feel quite strange we never have a bug reported. Am I missing something? Fixes: 4602e5757bcc ("arm64/mm: wire up PTE_CONT for user mappings") Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx> --- arch/arm64/mm/contpte.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c index a3edced29ac1..10dcd2641184 100644 --- a/arch/arm64/mm/contpte.c +++ b/arch/arm64/mm/contpte.c @@ -421,8 +421,10 @@ int contpte_ptep_set_access_flags(struct vm_area_struct *vma, ptep = contpte_align_down(ptep); start_addr = addr = ALIGN_DOWN(addr, CONT_PTE_SIZE); - for (i = 0; i < CONT_PTES; i++, ptep++, addr += PAGE_SIZE) + for (i = 0; i < CONT_PTES; i++, ptep++, addr += PAGE_SIZE) { __ptep_set_access_flags(vma, addr, ptep, entry, 0); + entry = pte_advance_pfn(entry, 1); + } if (dirty) __flush_tlb_range(vma, start_addr, addr, -- 2.39.3 (Apple Git-146)