From patchwork Mon Jun 17 08:39:42 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ambresh K X-Patchwork-Id: 2731991 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id DADDF9F472 for ; Mon, 17 Jun 2013 08:41:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EEC6920220 for ; Mon, 17 Jun 2013 08:41:45 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2870320246 for ; Mon, 17 Jun 2013 08:41:41 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoUzR-0006Eg-OU; Mon, 17 Jun 2013 08:40:42 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoUzF-0000NZ-C6; Mon, 17 Jun 2013 08:40:29 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoUz5-0000Ku-4I for linux-arm-kernel@lists.infradead.org; Mon, 17 Jun 2013 08:40:20 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id r5H8duPt025141; Mon, 17 Jun 2013 03:39:56 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id r5H8dusd003395; Mon, 17 Jun 2013 03:39:56 -0500 Received: from dlelxv24.itg.ti.com (172.17.1.199) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.2.342.3; Mon, 17 Jun 2013 03:39:55 -0500 Received: from legion.dal.design.ti.com (legion.dal.design.ti.com [128.247.22.53]) by dlelxv24.itg.ti.com (8.13.8/8.13.8) with ESMTP id r5H8dtRo014174; Mon, 17 Jun 2013 03:39:56 -0500 Received: from localhost (ula0393775-172024147073.apr.dhcp.ti.com [172.24.147.73]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id r5H8dqV15728; Mon, 17 Jun 2013 03:39:52 -0500 (CDT) From: Ambresh K To: Mike Turquette Subject: [PATCH V2 1/3] clk: fix clk_mux_get_parent return's signed value Date: Mon, 17 Jun 2013 14:09:42 +0530 Message-ID: <1371458384-23936-2-git-send-email-ambresh@ti.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1371458384-23936-1-git-send-email-ambresh@ti.com> References: <1371458384-23936-1-git-send-email-ambresh@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130617_044019_307343_FECE32E5 X-CRM114-Status: GOOD ( 14.98 ) X-Spam-Score: -8.0 (--------) Cc: Nishanth Menon , Paul Walmsley , Tony Lindgren , Rajendra , linux-kernel@vger.kernel.org, Tero Kristo , Ambresh K , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 From: Ambresh K clk_mux_get_parent should return an error if the value read from the register is erroneous. Currently if the value read is greater than the number of available parents clk_mux_get_parent return's signed error which will result in NULL pointer dereferencing in the calling functions. Signed-off-by: Ambresh K --- drivers/clk/clk-mux.c | 2 +- drivers/clk/clk.c | 12 +++++++++++- include/linux/clk-provider.h | 6 +++--- 3 files changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index 614444c..001b4df 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -29,7 +29,7 @@ #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw) -static u8 clk_mux_get_parent(struct clk_hw *hw) +static int clk_mux_get_parent(struct clk_hw *hw) { struct clk_mux *mux = to_clk_mux(hw); int num_parents = __clk_get_num_parents(hw->clk); diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index edf3fe1..2842450 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1281,7 +1281,7 @@ EXPORT_SYMBOL_GPL(clk_get_parent); static struct clk *__clk_init_parent(struct clk *clk) { struct clk *ret = NULL; - u8 index; + int index; /* handle the trivial cases */ @@ -1309,6 +1309,11 @@ static struct clk *__clk_init_parent(struct clk *clk) */ index = clk->ops->get_parent(clk->hw); + if (index < 0) { + pr_err("%s: clk(%s) invalid parent index(%d)\n", + __func__, clk->name, index); + goto out; + } if (!clk->parents) clk->parents = @@ -1630,6 +1635,11 @@ int __clk_init(struct device *dev, struct clk *clk) hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { if (orphan->ops->get_parent) { i = orphan->ops->get_parent(orphan->hw); + if (i < 0) { + pr_err_once("%s: clk(%s) has invalid parent\n", + __func__, orphan->name); + continue; + } if (!strcmp(clk->name, orphan->parent_names[i])) __clk_reparent(orphan, clk); continue; diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 1ec14a7..b01cbdb 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -79,8 +79,8 @@ struct clk_hw; * @round_rate: Given a target rate as input, returns the closest rate actually * supported by the clock. * - * @get_parent: Queries the hardware to determine the parent of a clock. The - * return value is a u8 which specifies the index corresponding to + * @get_parent: Queries the hardware to determine the parent of a clock. The + * return value which specifies the index corresponding to * the parent clock. This index can be applied to either the * .parent_names or .parents arrays. In short, this function * translates the parent value read from hardware into an array @@ -127,7 +127,7 @@ struct clk_ops { long (*round_rate)(struct clk_hw *hw, unsigned long, unsigned long *); int (*set_parent)(struct clk_hw *hw, u8 index); - u8 (*get_parent)(struct clk_hw *hw); + int (*get_parent)(struct clk_hw *hw); int (*set_rate)(struct clk_hw *hw, unsigned long, unsigned long); void (*init)(struct clk_hw *hw);