diff options
| -rw-r--r-- | arch/x86/include/asm/kfence.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/include/asm/kfence.h b/arch/x86/include/asm/kfence.h index acf9ffa1a171..dfd5c74ba41a 100644 --- a/arch/x86/include/asm/kfence.h +++ b/arch/x86/include/asm/kfence.h @@ -42,7 +42,7 @@ static inline bool kfence_protect_page(unsigned long addr, bool protect) { unsigned int level; pte_t *pte = lookup_address(addr, &level); - pteval_t val; + pteval_t val, new; if (WARN_ON(!pte || level != PG_LEVEL_4K)) return false; @@ -57,11 +57,12 @@ static inline bool kfence_protect_page(unsigned long addr, bool protect) return true; /* - * Otherwise, invert the entire PTE. This avoids writing out an + * Otherwise, flip the Present bit, taking care to avoid writing an * L1TF-vulnerable PTE (not present, without the high address bits * set). */ - set_pte(pte, __pte(~val)); + new = val ^ _PAGE_PRESENT; + set_pte(pte, __pte(flip_protnone_guard(val, new, PTE_PFN_MASK))); /* * If the page was protected (non-present) and we're making it |