PAGE_NX and PAGE_GLOBAL might be not supported or disabled on the command line, but KAISER sets them unconditionally. Add proper protection against that. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/pgtable_64.h | 3 ++- arch/x86/mm/kaiser.c | 12 +++++++++++- 2 files changed, 13 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -222,7 +222,8 @@ static inline pgd_t kaiser_set_shadow_pg * wrong CR3 value, userspace will crash * instead of running. */ - pgd.pgd |= _PAGE_NX; + if (__supported_pte_mask & _PAGE_NX) + pgd.pgd |= _PAGE_NX; } } else if (pgd_userspace_access(*pgdp)) { /* --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -42,6 +42,8 @@ #define KAISER_WALK_ATOMIC 0x1 +static pteval_t kaiser_pte_mask __ro_after_init = ~(_PAGE_NX | _PAGE_GLOBAL); + /* * At runtime, the only things we map are some things for CPU * hotplug, and stacks for new processes. No two CPUs will ever @@ -244,11 +246,14 @@ static pte_t *kaiser_shadow_pagetable_wa int kaiser_add_user_map(const void *__start_addr, unsigned long size, unsigned long flags) { - pte_t *pte; unsigned long start_addr = (unsigned long)__start_addr; unsigned long address = start_addr & PAGE_MASK; unsigned long end_addr = PAGE_ALIGN(start_addr + size); unsigned long target_address; + pte_t *pte; + + /* Clear not supported bits */ + flags &= kaiser_pte_mask; for (; address < end_addr; address += PAGE_SIZE) { target_address = get_pa_from_kernel_map(address); @@ -308,6 +313,11 @@ static void __init kaiser_init_all_pgds( pgd_t *pgd; int i; + if (__supported_pte_mask & _PAGE_NX) + kaiser_pte_mask |= _PAGE_NX; + if (boot_cpu_has(X86_FEATURE_PGE)) + kaiser_pte_mask |= _PAGE_GLOBAL; + pgd = kernel_to_shadow_pgdp(pgd_offset_k(0UL)); for (i = PTRS_PER_PGD / 2; i < PTRS_PER_PGD; i++) { /*