Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932506Ab3FQIkY (ORCPT ); Mon, 17 Jun 2013 04:40:24 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:35275 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932350Ab3FQIkV (ORCPT ); Mon, 17 Jun 2013 04:40:21 -0400 From: Ambresh K To: Mike Turquette CC: , , , Tero Kristo , Rajendra , Ambresh K , Nishanth Menon , Tony Lindgren , Paul Walmsley 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 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3476 Lines: 99 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); -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/