diff options
Diffstat (limited to 'arch/arm64/mm/mmu.c')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index d77c9f56b7b4..6f9d8898a025 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; |