From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Fedin Subject: [PATCH 0/3] KVM: arm64: BUG FIX: Correctly handle zero register transfers Date: Thu, 03 Dec 2015 12:58:39 +0300 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 57B3B4999F for ; Thu, 3 Dec 2015 04:57:19 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zU1EOS6gbnvI for ; Thu, 3 Dec 2015 04:57:17 -0500 (EST) Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 73EC349973 for ; Thu, 3 Dec 2015 04:57:16 -0500 (EST) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NYS00BH811YMP00@mailout2.w1.samsung.com> for kvmarm@lists.cs.columbia.edu; Thu, 03 Dec 2015 09:58:46 +0000 (GMT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Marc Zyngier List-Id: kvmarm@lists.cs.columbia.edu ARM64 CPU has zero register which is read-only, with a value of 0. However, KVM currently incorrectly recognizes it being SP (because Rt == 31, and in struct user_pt_regs 'regs' array is followed by SP), resulting in invalid value being read, or even SP corruption on write. The problem has been discovered by performing an operation *((volatile int *)reg) = 0; which compiles as "str xzr, [xx]", and resulted in strange values being written. Pavel Fedin (3): KVM: arm64: Correctly handle zero register during MMIO KVM: arm64: Correctly handle zero register in system register accesses KVM: arm64: Get rid of old vcpu_reg() arch/arm/include/asm/kvm_emulate.h | 12 ++++++ arch/arm/kvm/mmio.c | 5 ++- arch/arm/kvm/psci.c | 20 ++++----- arch/arm64/include/asm/kvm_emulate.h | 18 +++++--- arch/arm64/kvm/handle_exit.c | 2 +- arch/arm64/kvm/sys_regs.c | 79 ++++++++++++++++++++---------------- arch/arm64/kvm/sys_regs.h | 4 +- arch/arm64/kvm/sys_regs_generic_v8.c | 2 +- 8 files changed, 85 insertions(+), 57 deletions(-) -- 2.4.4