diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b4bbeed80fb6ed..832c9c8fb58f16 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -275,6 +275,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte) } extern void __sync_icache_dcache(pte_t pteval); +bool pgattr_change_is_safe(u64 old, u64 new); /* * PTE bits configuration in the presence of hardware Dirty Bit Management @@ -292,7 +293,7 @@ extern void __sync_icache_dcache(pte_t pteval); * PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY) */ -static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep, +static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, pte_t pte) { pte_t old_pte; @@ -318,6 +319,9 @@ static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep, VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte), "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx", __func__, pte_val(old_pte), pte_val(pte)); + VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)), + "%s: unsafe attribute change: 0x%016llx -> 0x%016llx", + __func__, pte_val(old_pte), pte_val(pte)); } static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, @@ -346,7 +350,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, mte_sync_tags(old_pte, pte); } - __check_racy_pte_update(mm, ptep, pte); + __check_safe_pte_update(mm, ptep, pte); set_pte(ptep, pte); } diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 14c87e8d69d839..34d5f7c4c64e2f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -133,7 +133,7 @@ static phys_addr_t __init early_pgtable_alloc(int shift) return phys; } -static bool pgattr_change_is_safe(u64 old, u64 new) +bool pgattr_change_is_safe(u64 old, u64 new) { /* * The following mapping attributes may be updated in live @@ -142,9 +142,13 @@ static bool pgattr_change_is_safe(u64 old, u64 new) pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG; /* creating or taking down mappings is always safe */ - if (old == 0 || new == 0) + if (!pte_valid(__pte(old)) || !pte_valid(__pte(new))) return true; + /* A live entry's pfn should not change */ + if (pte_pfn(__pte(old)) != pte_pfn(__pte(new))) + return false; + /* live contiguous mappings may not be manipulated at all */ if ((old | new) & PTE_CONT) return false;