From patchwork Tue Sep 30 21:16:11 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suman Anna X-Patchwork-Id: 5007191 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id ECD73BEEA7 for ; Tue, 30 Sep 2014 21:16:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2E72C201C7 for ; Tue, 30 Sep 2014 21:16:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 356852020E for ; Tue, 30 Sep 2014 21:16:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751488AbaI3VQd (ORCPT ); Tue, 30 Sep 2014 17:16:33 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:44915 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105AbaI3VQ3 (ORCPT ); Tue, 30 Sep 2014 17:16:29 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id s8ULGJNl031732; Tue, 30 Sep 2014 16:16:19 -0500 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id s8ULGJVs023992; Tue, 30 Sep 2014 16:16:19 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.174.1; Tue, 30 Sep 2014 16:16:19 -0500 Received: from legion.dal.design.ti.com (legion.dal.design.ti.com [128.247.22.53]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id s8ULGJRk022450; Tue, 30 Sep 2014 16:16:19 -0500 Received: from localhost (irmo.am.dhcp.ti.com [128.247.71.175]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id s8ULGJt15682; Tue, 30 Sep 2014 16:16:19 -0500 (CDT) From: Suman Anna To: Joerg Roedel CC: Laurent Pinchart , , , Suman Anna Subject: [PATCH 16/17] iommu/omap: Fix bus error on debugfs access of unattached IOMMU Date: Tue, 30 Sep 2014 16:16:11 -0500 Message-ID: <1412111772-38006-17-git-send-email-s-anna@ti.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1412111772-38006-1-git-send-email-s-anna@ti.com> References: <1412111772-38006-1-git-send-email-s-anna@ti.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Any debugfs access on an OMAP IOMMU that is not enabled (done during attach) results in a bus error due to access of registers without the clock or the reset enabled for the respective IOMMU. So, add a check to make sure the IOMMU is enabled/attached by a client device. This gracefully prints a "Operation not permitted" trace when the corresponding IOMMU is not enabled. Signed-off-by: Suman Anna --- drivers/iommu/omap-iommu-debug.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c index 54a0dc6..e7b8aca 100644 --- a/drivers/iommu/omap-iommu-debug.c +++ b/drivers/iommu/omap-iommu-debug.c @@ -24,6 +24,11 @@ static DEFINE_MUTEX(iommu_debug_lock); static struct dentry *iommu_debug_root; +static inline bool is_omap_iommu_detached(struct omap_iommu *obj) +{ + return !obj->domain; +} + static ssize_t debug_read_regs(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { @@ -31,6 +36,9 @@ static ssize_t debug_read_regs(struct file *file, char __user *userbuf, char *p, *buf; ssize_t bytes; + if (is_omap_iommu_detached(obj)) + return -EPERM; + buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -54,6 +62,9 @@ static ssize_t debug_read_tlb(struct file *file, char __user *userbuf, char *p, *buf; ssize_t bytes, rest; + if (is_omap_iommu_detached(obj)) + return -EPERM; + buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -139,6 +150,9 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf, char *p, *buf; size_t bytes; + if (is_omap_iommu_detached(obj)) + return -EPERM; + buf = (char *)__get_free_page(GFP_KERNEL); if (!buf) return -ENOMEM;