From patchwork Tue Oct 16 03:06:30 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 1598461 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 58A50DFB34 for ; Tue, 16 Oct 2012 03:07:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755395Ab2JPDH3 (ORCPT ); Mon, 15 Oct 2012 23:07:29 -0400 Received: from ozlabs.org ([203.10.76.45]:35990 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752756Ab2JPDH1 (ORCPT ); Mon, 15 Oct 2012 23:07:27 -0400 Received: by ozlabs.org (Postfix, from userid 1003) id A7ED72C00A7; Tue, 16 Oct 2012 14:07:25 +1100 (EST) Date: Tue, 16 Oct 2012 14:06:30 +1100 From: Paul Mackerras To: Alexander Graf Cc: kvm@vger.kernel.org Subject: [PATCH 7/8] KVM: PPC: Book3S HV: Allow DTL to be set to address 0, length 0 Message-ID: <20121016030630.GH1218@drongo> References: <20121016030303.GA1218@drongo> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20121016030303.GA1218@drongo> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Commit 55b665b026 ("KVM: PPC: Book3S HV: Provide a way for userspace to get/set per-vCPU areas") includes a check on the length of the dispatch trace log (DTL) to make sure the buffer is at least one entry long. This is appropriate when registering a buffer, but the interface also allows for any existing buffer to be unregistered by specifying a zero address. In this case the length check is not appropriate. This makes the check conditional on the address being non-zero. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 8b3c470..812764c 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -811,9 +811,8 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val) addr = val->vpaval.addr; len = val->vpaval.length; r = -EINVAL; - if (len < sizeof(struct dtl_entry)) - break; - if (addr && !vcpu->arch.vpa.next_gpa) + if (addr && (len < sizeof(struct dtl_entry) || + !vcpu->arch.vpa.next_gpa)) break; len -= len % sizeof(struct dtl_entry); r = set_vpa(vcpu, &vcpu->arch.dtl, addr, len);