From 2627b29df65208ad9615fb761e37df13e3328e8c Mon Sep 17 00:00:00 2001 From: Lepton Wu Date: Fri, 12 Jan 2018 13:42:56 -0800 Subject: [PATCH 041/103] kaiser: Set _PAGE_NX only if supported 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 Signed-off-by: Lepton Wu Signed-off-by: Greg Kroah-Hartman --- 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 d8376b4..42a5307 100644 --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -184,6 +184,8 @@ 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); -- 2.7.4