From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754056Ab3AHBZj (ORCPT ); Mon, 7 Jan 2013 20:25:39 -0500 Received: from mailout2.samsung.com ([203.254.224.25]:43154 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751980Ab3AHBZh (ORCPT ); Mon, 7 Jan 2013 20:25:37 -0500 X-AuditID: cbfee61b-b7f616d00000319b-29-50eb758ffd71 From: Jingoo Han To: "'Andrew Morton'" Cc: "'LKML'" , linux-fbdev@vger.kernel.org, "'Richard Purdie'" , "'Devendra Naga'" , "'Jingoo Han'" References: <000b01cdea55$92725aa0$b7570fe0$%han@samsung.com> <20130107160137.dec5098a.akpm@linux-foundation.org> In-reply-to: <20130107160137.dec5098a.akpm@linux-foundation.org> Subject: Re: [PATCH] backlight: check null deference of name when device is registered Date: Tue, 08 Jan 2013 10:25:35 +0900 Message-id: <003c01cded3f$0f25a3e0$2d70eba0$%han@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-index: Ac3tM1ZDNAznOdAjTA2zBfNY2HYi5QACx3vA Content-language: ko DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrJIsWRmVeSWpSXmKPExsVy+t8zI93+0tcBBmtW61uc6PvAanF51xw2 ByaPz5vkAhijuGxSUnMyy1KL9O0SuDKmf3rIVrCEs2LWrCOMDYxz2LsYOTgkBEwkLi0p7mLk BDLFJC7cW8/WxcjFISSwjFHicONidoiEicTsb/egEosYJRafWsEI4fxilFj6DaSFk4NNQE3i y5fDYFNFBPQl2lo0QMLMAvsZJR7vcwKxhQSKJVZs2sEIYnMKOEgcmPeFBcQWFoiQuLBnLlic RUBV4uflx2A2r4CtxK8JC1ghbEGJH5PvsUDM1JJYv/M4E4QtL7F5zVtmiGfUJR791YW4wEji xVI/iAoRiX0v3kFNF5D4NvkQC0S1rMSmA8wgj0gILGOXmD2xnRHiXUmJgytusExglJiFZPEs JItnIVk8C8mKBYwsqxhFUwuSC4qT0nON9IoTc4tL89L1kvNzNzFC4kt6B+OqBotDjAIcjEo8 vJdiXgcIsSaWFVfmHmKU4GBWEuG9lQIU4k1JrKxKLcqPLyrNSS0+xOgDdPlEZinR5Hxg7OeV xBsaG5uYmZiamFuampviEFYS52U89SRASCA9sSQ1OzW1ILUIZhwTB6dUA+Oa3dkZt8InF8ic /NHTpqzeK5fIY/5kI3uCuM2aPz33084x796lZPJCln+Kb0DDv09516cXH1nJvq0s4bDzvD+f njB+EVht0l706SZLP+/hG3OZuf+eKAuMmDrxmIK8k9hDf28NSYaDvR7sz8UDjrhJ7WFht+z+ fy3rVK5d3I0jKk2PkyefsVdiKc5INNRiLipOBABbhhEI3AIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrJIsWRmVeSWpSXmKPExsVy+t9jAd3+0tcBBkvnalmc6PvAanF51xw2 ByaPz5vkAhijGhhtMlITU1KLFFLzkvNTMvPSbZW8g+Od403NDAx1DS0tzJUU8hJzU22VXHwC dN0yc4BGKymUJeaUAoUCEouLlfTtME0IDXHTtYBpjND1DQmC6zEyQAMJ6xgzpn96yFawhLNi 1qwjjA2Mc9i7GDk5JARMJGZ/u8cGYYtJXLi3Hsjm4hASWMQosfjUCkYI5xejxNJv68Gq2ATU JL58OQzUzcEhIqAv0daiARJmFtjPKPF4nxOILSRQLLFi0w5GEJtTwEHiwLwvLCC2sECExIU9 c8HiLAKqEj8vPwazeQVsJX5NWMAKYQtK/Jh8jwVippbE+p3HmSBseYnNa94yg6yVEFCXePRX F+ICI4kXS/0gKkQk9r14xziBUWgWkkGzkAyahWTQLCQtCxhZVjGKphYkFxQnpeca6RUn5haX 5qXrJefnbmIEx+8z6R2MqxosDjEKcDAq8fBeinkdIMSaWFZcmXuIUYKDWUmE91YKUIg3JbGy KrUoP76oNCe1+BCjD9CfE5mlRJPzgaklryTe0NjEzMjSyMzCyMTcHIewkjgv46knAUIC6Ykl qdmpqQWpRTDjmDg4pRoY527M2ux4wkn/jteHtyzpfBYTI+VeB84uWiimffdMTkPk8fvChWlG goHmPiZHOc+JKQTJGGcWB+VdOeabZWVsxSP6yvrqyjsy3mXGIZu8Fq2sebtK3yTefPtjwc1/ J569+qMsuL3gb4+a8q4Kdt2q5u+Ws0tevVy4UJfR/d91LdkvCgV1MlpKLMUZiYZazEXFiQCb wEKdDAMAAA== X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, January 08, 2013 9:02 AM, Andrew Morton wrote > On Fri, 04 Jan 2013 17:29:11 +0900 > Jingoo Han wrote: > > > NULL deference of name is checked when device is registered. > > If the name is null, it will cause a kernel oops in dev_set_name(). > > > > ... > > > > --- a/drivers/video/backlight/backlight.c > > +++ b/drivers/video/backlight/backlight.c > > @@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name, > > struct backlight_device *new_bd; > > int rc; > > > > + if (name == NULL) { > > + pr_err("backlight name is null\n"); > > + return ERR_PTR(-EINVAL); > > + } > > + > > pr_debug("backlight_device_register: name=%s\n", name); > > I don't understand this. > > Is there some driver which is calling these functions with name=NULL? > If so, which one(s)? No, there is no one. > > If "no" then why don't we declare that "passing name=NULL is a bug" and > leave the code as-is? Do you mean following? + if (name == NULL) + pr_err("passing name=NULL is a bug"); + pr_debug("backlight_device_register: name=%s\n", name); Best regards, Jingoo Han