3.16.54-rc1 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> (backported from Greg K-H's 4.4 stable-queue) Signed-off-by: Juerg Haefliger <juerg.haefliger@xxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- arch/x86/mm/kaiser.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c index 2d5ac54dbcee..7cb57d14ddc0 100644 --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -195,6 +195,8 @@ static int kaiser_add_user_map(const void *__start_addr, unsigned long size, * 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);