FYI, this patch also clean applied to 4.9.y tree. I guess I don't need to send another one to 4.9 tree. Just applied it to 4.9 should be fine. On Fri, Jan 12, 2018 at 1:48 PM, lepton <ytht.net@xxxxxxxxx> wrote: > The last version is "V4" and I added it in subject. > > On Fri, Jan 12, 2018 at 1:46 PM, Guenter Roeck <groeck@xxxxxxxxxx> wrote: >> On Fri, Jan 12, 2018 at 1:41 PM, Lepton Wu <ytht.net@xxxxxxxxx> wrote: >>> 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 >>> >>> Signed-off-by: Lepton Wu <ytht.net@xxxxxxxxx> >> >> Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx> >> >> Hint: You might want to version your patches; otherwise it is >> difficult for the maintainer(s) to find the latest version. >> >> Note that the fix probably also applies to v4.9 as well as to older >> stable kernels. >> >> Guenter >> >>> --- >>> 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 6a7a77929a8c..8af98513d36c 100644 >>> --- a/arch/x86/mm/kaiser.c >>> +++ b/arch/x86/mm/kaiser.c >>> @@ -198,6 +198,8 @@ 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); >>> -- >>> 2.16.0.rc1.238.g530d649a79-goog >>>