diff options
Diffstat (limited to 'arch/arm64/mm/mmu.c')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ec23aec6433f..382ebd6ef46f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -103,7 +103,15 @@ static bool pgattr_change_is_safe(u64 old, u64 new) */ static const pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE; - return old == 0 || new == 0 || ((old ^ new) & ~mask) == 0; + /* creating or taking down mappings is always safe */ + if (old == 0 || new == 0) + return true; + + /* live contiguous mappings may not be manipulated at all */ + if ((old | new) & PTE_CONT) + return false; + + return ((old ^ new) & ~mask) == 0; } static void alloc_init_pte(pmd_t *pmd, unsigned long addr, |