4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lepton Wu <ytht.net@xxxxxxxxx> This finally resolve crash if loaded under qemu + haxm. Haitao Shan pointed out that the reason of that crash is that NX bit get set for page tables. It seems we missed checking if _PAGE_NX is supported in kaiser_add_user_map Link: https://www.spinics.net/lists/kernel/msg2689835.html Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx> Signed-off-by: Lepton Wu <ytht.net@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/kaiser.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -198,6 +198,8 @@ static int kaiser_add_user_map(const voi * requires that not to be #defined to 0): so mask it off here. */ flags &= ~_PAGE_GLOBAL; + if (!(__supported_pte_mask & _PAGE_NX)) + flags &= ~_PAGE_NX; for (; address < end_addr; address += PAGE_SIZE) { target_address = get_pa_from_mapping(address);