From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932598AbaFXQpn (ORCPT ); Tue, 24 Jun 2014 12:45:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60929 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755396AbaFXPwb (ORCPT ); Tue, 24 Jun 2014 11:52:31 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Hogan , Paolo Bonzini , Gleb Natapov , kvm@vger.kernel.org, Ralf Baechle , linux-mips@linux-mips.org, Sanjay Lal Subject: [PATCH 3.10 29/52] MIPS: KVM: Allocate at least 16KB for exception handlers Date: Tue, 24 Jun 2014 11:50:44 -0400 Message-Id: <20140624154715.254248878@linuxfoundation.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <20140624154713.428945460@linuxfoundation.org> References: <20140624154713.428945460@linuxfoundation.org> User-Agent: quilt/0.63-1 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 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Hogan commit 7006e2dfda9adfa40251093604db76d7e44263b3 upstream. Each MIPS KVM guest has its own copy of the KVM exception vector. This contains the TLB refill exception handler at offset 0x000, the general exception handler at offset 0x180, and interrupt exception handlers at offset 0x200 in case Cause_IV=1. A common handler is copied to offset 0x2000 and offset 0x3000 is used for temporarily storing k1 during entry from guest. However the amount of memory allocated for this purpose is calculated as 0x200 rounded up to the next page boundary, which is insufficient if 4KB pages are in use. This can lead to the common handler at offset 0x2000 being overwritten and infinitely recursive exceptions on the next exit from the guest. Increase the minimum size from 0x200 to 0x4000 to cover the full use of the page. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Gleb Natapov Cc: kvm@vger.kernel.org Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: Sanjay Lal Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/mips/kvm/kvm_mips.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/kvm/kvm_mips.c +++ b/arch/mips/kvm/kvm_mips.c @@ -299,7 +299,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(st if (cpu_has_veic || cpu_has_vint) { size = 0x200 + VECTORSPACING * 64; } else { - size = 0x200; + size = 0x4000; } /* Save Linux EBASE */