From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752747AbdKMOQR (ORCPT ); Mon, 13 Nov 2017 09:16:17 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:55802 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752263AbdKMOQO (ORCPT ); Mon, 13 Nov 2017 09:16:14 -0500 X-Google-Smtp-Source: AGs4zMbKeTQXMQR7omlFHkb31OEnsCFI4G8mZEMOBaDg1ppkEdL1TaX7VRB4zXJwH1PaBjIyUWHX6A== Subject: Re: [PATCH 1/3] backlight: as3711_bl: fix device-tree node lookup To: Johan Hovold , Lee Jones Cc: Jingoo Han , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable , Guennadi Liakhovetski References: <20171113102049.9342-1-johan@kernel.org> From: Daniel Thompson Message-ID: <94c3debe-17f6-9151-eefe-129f2bd1cfd4@linaro.org> Date: Mon, 13 Nov 2017 14:16:09 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171113102049.9342-1-johan@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/11/17 10:20, Johan Hovold wrote: > Fix child-node lookup during probe, which ended up searching the whole > device tree depth-first starting at the parent rather than just matching > on its children. > > To make things worse, the parent mfd node was also prematurely freed. > > Note that the nodes returned from the two calls to of_parse_phandle() > are also leaking, but fixing that is a bit more involved as pointers to > node fields are being stored for later use. Is using a devm_kstrdup() to remember the full_name sufficient so get each of the FIXMEs cleaned up as well? Daniel. > Fixes: 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support") > Cc: stable # 3.10 > Cc: Guennadi Liakhovetski > Signed-off-by: Johan Hovold > --- > drivers/video/backlight/as3711_bl.c | 35 +++++++++++++++++++++++++---------- > 1 file changed, 25 insertions(+), 10 deletions(-) > > diff --git a/drivers/video/backlight/as3711_bl.c b/drivers/video/backlight/as3711_bl.c > index 734a9158946b..21ce56053c88 100644 > --- a/drivers/video/backlight/as3711_bl.c > +++ b/drivers/video/backlight/as3711_bl.c > @@ -262,15 +262,16 @@ static int as3711_bl_register(struct platform_device *pdev, > static int as3711_backlight_parse_dt(struct device *dev) > { > struct as3711_bl_pdata *pdata = dev_get_platdata(dev); > - struct device_node *bl = > - of_find_node_by_name(dev->parent->of_node, "backlight"), *fb; > + struct device_node *bl, *fb; > int ret; > > + bl = of_get_child_by_name(dev->parent->of_node, "backlight"); > if (!bl) { > dev_dbg(dev, "backlight node not found\n"); > return -ENODEV; > } > > + /* FIXME: need to drop reference to returned node */ > fb = of_parse_phandle(bl, "su1-dev", 0); > if (fb) { > pdata->su1_fb = fb->full_name; > @@ -279,9 +280,10 @@ static int as3711_backlight_parse_dt(struct device *dev) > if (pdata->su1_max_uA <= 0) > ret = -EINVAL; > if (ret < 0) > - return ret; > + goto err_put_bl; > } > > + /* FIXME: need to drop reference to returned node */ > fb = of_parse_phandle(bl, "su2-dev", 0); > if (fb) { > int count = 0; > @@ -292,7 +294,7 @@ static int as3711_backlight_parse_dt(struct device *dev) > if (pdata->su2_max_uA <= 0) > ret = -EINVAL; > if (ret < 0) > - return ret; > + goto err_put_bl; > > if (of_find_property(bl, "su2-feedback-voltage", NULL)) { > pdata->su2_feedback = AS3711_SU2_VOLTAGE; > @@ -314,8 +316,10 @@ static int as3711_backlight_parse_dt(struct device *dev) > pdata->su2_feedback = AS3711_SU2_CURR_AUTO; > count++; > } > - if (count != 1) > - return -EINVAL; > + if (count != 1) { > + ret = -EINVAL; > + goto err_put_bl; > + } > > count = 0; > if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) { > @@ -334,8 +338,10 @@ static int as3711_backlight_parse_dt(struct device *dev) > pdata->su2_fbprot = AS3711_SU2_GPIO4; > count++; > } > - if (count != 1) > - return -EINVAL; > + if (count != 1) { > + ret = -EINVAL; > + goto err_put_bl; > + } > > count = 0; > if (of_find_property(bl, "su2-auto-curr1", NULL)) { > @@ -355,11 +361,20 @@ static int as3711_backlight_parse_dt(struct device *dev) > * At least one su2-auto-curr* must be specified iff > * AS3711_SU2_CURR_AUTO is used > */ > - if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) > - return -EINVAL; > + if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) { > + ret = -EINVAL; > + goto err_put_bl; > + } > } > > + of_node_put(bl); > + > return 0; > + > +err_put_bl: > + of_node_put(bl); > + > + return ret; > } > > static int as3711_backlight_probe(struct platform_device *pdev) >