From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754294Ab3AHBjo (ORCPT ); Mon, 7 Jan 2013 20:39:44 -0500 Received: from mailout1.samsung.com ([203.254.224.24]:25683 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753277Ab3AHBjm (ORCPT ); Mon, 7 Jan 2013 20:39:42 -0500 X-AuditID: cbfee61b-b7f616d00000319b-52-50eb78ddfb0a 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> <003c01cded3f$0f25a3e0$2d70eba0$%han@samsung.com> <20130107173557.dadc0a7a.akpm@linux-foundation.org> In-reply-to: <20130107173557.dadc0a7a.akpm@linux-foundation.org> Subject: Re: [PATCH] backlight: check null deference of name when device is registered Date: Tue, 08 Jan 2013 10:39:40 +0900 Message-id: <004301cded41$06e0b7e0$14a227a0$%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: Ac3tQEhIXwseABj3STijvV2zeul/gQAAGG5g Content-language: ko DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrNIsWRmVeSWpSXmKPExsVy+t8zY927Fa8DDG4uYbY40feB1eLyrjls DkwenzfJBTBGcdmkpOZklqUW6dslcGVM2HWMpeAeX8W3O1OZGhiXcncxcnJICJhILLw7nx3C FpO4cG89WxcjF4eQwDJGiatfNrPAFD1duwesSEhgEaPEqhNBEEW/GCXWN70EK2ITUJP48uUw UBEHh4iAvkRbiwZImFlgP6PE431OEPV3GSV+Hp7HBJLgFHCQuDfrJhuILSwQIXFhz1xGEJtF QFXi25w9zCA2r4CtxLmzd5kgbEGJH5PvsUAM1ZJYv/M4E4QtL7F5zVtmkL0SAuoSj/7qgoRF BIwkOmftZYUoEZHY9+Id1HgBiW+TD7FAlMtKbDrADHKahMA6dol1h54xQ/wrKXFwxQ2WCYwS s5BsnoVk8ywkm2chWbGAkWUVo2hqQXJBcVJ6rpFecWJucWleul5yfu4mRkiMSe9gXNVgcYhR gINRiYf3UszrACHWxLLiytxDjBIczEoivLdSgEK8KYmVValF+fFFpTmpxYcYfYAun8gsJZqc D4z/vJJ4Q2NjEzMTUxNzS1NzUxzCSuK8jKeeBAgJpCeWpGanphakFsGMY+LglGpgDJZ36v/2 w8q0rPuQ15Ko+V8f9LrNLDXkP1vCG/+Z8ZN8dd0Nk5NOrIJ3YibO2Ozu8evhsVnck7YtENzp s3fOoavbk4vimX4+ZzgX8/nfDOGHKnMK7E70hYe83jD36q5NFUGrtriusj3F8sN/czr78wUl 03LF0m/VrrErzGw6F9l4zef2r6C2RCWW4oxEQy3mouJEABdwjs3eAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrFIsWRmVeSWpSXmKPExsVy+t9jAd07Fa8DDB7ftrI40feB1eLyrjls DkwenzfJBTBGNTDaZKQmpqQWKaTmJeenZOal2yp5B8c7x5uaGRjqGlpamCsp5CXmptoqufgE 6Lpl5gCNVlIoS8wpBQoFJBYXK+nbYZoQGuKmawHTGKHrGxIE12NkgAYS1jFmTNh1jKXgHl/F tztTmRoYl3J3MXJySAiYSDxdu4cdwhaTuHBvPRuILSSwiFFi1YmgLkYuIPsXo8T6ppcsIAk2 ATWJL18OAzVwcIgI6Eu0tWiAhJkF9jNKPN7nBFF/l1Hi5+F5TCAJTgEHiXuzboINFRaIkLiw Zy4jiM0ioCrxbc4eZhCbV8BW4tzZu0wQtqDEj8n3WCCGakms33mcCcKWl9i85i0zyF4JAXWJ R391QcIiAkYSnbP2skKUiEjse/GOcQKj0Cwkk2YhmTQLyaRZSFoWMLKsYhRNLUguKE5KzzXS K07MLS7NS9dLzs/dxAiO4GfSOxhXNVgcYhTgYFTi4b0U8zpAiDWxrLgy9xCjBAezkgjvrRSg EG9KYmVValF+fFFpTmrxIUYfoEcnMkuJJucDk0teSbyhsYmZkaWRmYWRibk5DmElcV7GU08C hATSE0tSs1NTC1KLYMYxcXBKNTBuy1142dPo3pcYlUZj/0frVb4zC2bfnDrllbf1ibrH3mwP Sp6Z7rB7N1FlTsS+pBUXg279CQiLWKCz+aecNn+WotpvpsIJKmckutyVanZ7Tng6c6/Igvzj f3OmfPGdNHVS2I4wvpfP125uatXZIfIx83iz/bOULZ8ir22QnVH4xmqlvHymnbS4EktxRqKh FnNRcSIA6SEI6A0DAAA= 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 10:36 AM, Andrew Morton wrote > On Tue, 08 Jan 2013 10:25:35 +0900 Jingoo Han wrote: > > > 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); > > Nope; I'm suggesting we leave the code alone. If someone passes in > NULL they will get a nice oops and their bug will then get fixed. I see. I agree with you. Please, abandon this patch. Best regards, Jingoo Han > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html