Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755393AbeAOOLs (ORCPT + 1 other); Mon, 15 Jan 2018 09:11:48 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46768 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754794AbeAOMkw (ORCPT ); Mon, 15 Jan 2018 07:40:52 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Guenter Roeck , Lepton Wu Subject: [PATCH 4.4 62/87] kaiser: Set _PAGE_NX only if supported Date: Mon, 15 Jan 2018 13:35:01 +0100 Message-Id: <20180115123355.962115950@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180115123349.252309699@linuxfoundation.org> References: <20180115123349.252309699@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lepton Wu 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(+) --- 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);