From patchwork Thu Nov 15 16:43:16 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 1750831 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 1EABADF2AB for ; Thu, 15 Nov 2012 16:45:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1768433Ab2KOQoh (ORCPT ); Thu, 15 Nov 2012 11:44:37 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:55490 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1768408Ab2KOQog (ORCPT ); Thu, 15 Nov 2012 11:44:36 -0500 Received: by mail-pa0-f46.google.com with SMTP id hz1so1190476pad.19 for ; Thu, 15 Nov 2012 08:44:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer; bh=gJZi3WXmWGs5Yp3db/WzcU/5m+j5SXWeu78cANq4IdE=; b=VoCsYmpHEipOtGY/KbV8hLg5Y/NoZhuuKEfdfkXIPAV6HPd0Zf9AdRvangU5Zhxqic ni430CDV+KXrgloHU3jwzjhBW1FwsMlE92mqA6fdk2bdWG3VytZAMzft1qnp4JTw3EoV u7AXG6CUjR8OtAqxv9eNG1wpiSaANYY3fZPO62g+NJmW8cOnjk1SlZzBGpBApLzfC5M1 ZSyyDxNOPjon65VDZHe7BkENMjdg/kytbtC7ZsUuh8mCH6tYGpVAETP+yuYm5wubr11h v1t6YzdIiXxe1CGeNyDS31Knmev3Bak8JObopbeJyA4oHhr3F+2SJyMdreuE1Xgy2CHU WlNw== Received: by 10.68.209.133 with SMTP id mm5mr598775pbc.42.1352997875365; Thu, 15 Nov 2012 08:44:35 -0800 (PST) Received: from localhost.localdomain ([120.193.5.254]) by mx.google.com with ESMTPS id bd2sm9962516pab.36.2012.11.15.08.44.32 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 15 Nov 2012 08:44:34 -0800 (PST) From: Jiang Liu To: Alex Williamson , Greg Kroah-Hartman Cc: Jiang Liu , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Hanjun Guo Subject: [PATCH v2 1/3] VFIO: unregister IOMMU notifier on error recovery path Date: Fri, 16 Nov 2012 00:43:16 +0800 Message-Id: <1352997798-18891-1-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.7.9.5 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On error recovery path in function vfio_create_group(), it should unregister the IOMMU notifier for the new VFIO group. Otherwise it may cause invalid memory access later when handling bus notifications. Signed-off-by: Jiang Liu --- drivers/vfio/vfio.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 17830c9..3359ec2 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -191,6 +191,17 @@ static void vfio_container_put(struct vfio_container *container) kref_put(&container->kref, vfio_container_release); } +static void vfio_group_unlock_and_free(struct vfio_group *group) +{ + mutex_unlock(&vfio.group_lock); + /* + * Unregister outside of lock. A spurious callback is harmless now + * that the group is no longer in vfio.group_list. + */ + iommu_group_unregister_notifier(group->iommu_group, &group->nb); + kfree(group); +} + /** * Group objects - create, release, get, put, search */ @@ -229,8 +240,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) minor = vfio_alloc_group_minor(group); if (minor < 0) { - mutex_unlock(&vfio.group_lock); - kfree(group); + vfio_group_unlock_and_free(group); return ERR_PTR(minor); } @@ -239,8 +249,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) if (tmp->iommu_group == iommu_group) { vfio_group_get(tmp); vfio_free_group_minor(minor); - mutex_unlock(&vfio.group_lock); - kfree(group); + vfio_group_unlock_and_free(group); return tmp; } } @@ -249,8 +258,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) group, "%d", iommu_group_id(iommu_group)); if (IS_ERR(dev)) { vfio_free_group_minor(minor); - mutex_unlock(&vfio.group_lock); - kfree(group); + vfio_group_unlock_and_free(group); return (struct vfio_group *)dev; /* ERR_PTR */ } @@ -274,16 +282,7 @@ static void vfio_group_release(struct kref *kref) device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor)); list_del(&group->vfio_next); vfio_free_group_minor(group->minor); - - mutex_unlock(&vfio.group_lock); - - /* - * Unregister outside of lock. A spurious callback is harmless now - * that the group is no longer in vfio.group_list. - */ - iommu_group_unregister_notifier(group->iommu_group, &group->nb); - - kfree(group); + vfio_group_unlock_and_free(group); } static void vfio_group_put(struct vfio_group *group)