From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761933AbZB0Kim (ORCPT ); Fri, 27 Feb 2009 05:38:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755553AbZB0K20 (ORCPT ); Fri, 27 Feb 2009 05:28:26 -0500 Received: from mx2.redhat.com ([66.187.237.31]:53576 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755358AbZB0K1K (ORCPT ); Fri, 27 Feb 2009 05:27:10 -0500 From: Avi Kivity To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 18/37] KVM: Properly lock PIT creation Date: Fri, 27 Feb 2009 12:26:41 +0200 Message-Id: <1235730420-7929-19-git-send-email-avi@redhat.com> In-Reply-To: <1235730420-7929-1-git-send-email-avi@redhat.com> References: <1235730420-7929-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Otherwise, two threads can create a PIT in parallel and cause a memory leak. Signed-off-by: Avi Kivity --- arch/x86/kvm/i8254.c | 2 -- arch/x86/kvm/x86.c | 6 ++++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 528daad..69d1bbf 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -548,9 +548,7 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm) if (!pit) return NULL; - mutex_lock(&kvm->lock); pit->irq_source_id = kvm_request_irq_source_id(kvm); - mutex_unlock(&kvm->lock); if (pit->irq_source_id < 0) { kfree(pit); return NULL; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a1f1461..6fbc346 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1837,10 +1837,16 @@ long kvm_arch_vm_ioctl(struct file *filp, goto out; break; case KVM_CREATE_PIT: + mutex_lock(&kvm->lock); + r = -EEXIST; + if (kvm->arch.vpit) + goto create_pit_unlock; r = -ENOMEM; kvm->arch.vpit = kvm_create_pit(kvm); if (kvm->arch.vpit) r = 0; + create_pit_unlock: + mutex_unlock(&kvm->lock); break; case KVM_IRQ_LINE: { struct kvm_irq_level irq_event; -- 1.6.0.6