From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754214Ab3KPAZ3 (ORCPT ); Fri, 15 Nov 2013 19:25:29 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36915 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753559Ab3KPAYy (ORCPT ); Fri, 15 Nov 2013 19:24:54 -0500 Date: Fri, 15 Nov 2013 16:25:01 -0800 From: Greg KH To: Shuah Khan Cc: "Rafael J. Wysocki" , len.brown@intel.com, pavel@ucw.cz, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, shuahkhan@gmail.com, anton@enomsg.org, dwmw2@infradead.org, stable@vger.kernel.org Subject: Re: [PATCH] power: Change device_wakeup_enable() to check for null dev_name(dev) Message-ID: <20131116002501.GA20625@kroah.com> References: <1384560238-10708-1-git-send-email-shuah.kh@samsung.com> <4035469.UfR6Rto3I2@vostro.rjw.lan> <5286B95F.4040306@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5286B95F.4040306@samsung.com> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 15, 2013 at 05:16:31PM -0700, Shuah Khan wrote: > On 11/15/2013 05:21 PM, Rafael J. Wysocki wrote: > > On Friday, November 15, 2013 05:03:57 PM Shuah Khan wrote: > >> device_wakeup_enable() uses dev_name(dev) as the wakeup source name. > >> When it gets called with a device with its name not yet set, ws structure > >> with ws->name = NULL gets created. > >> > >> When kernel is booted with wakeup_source_activate enabled, it will panic > >> when the trace point code tries to derefernces ws->name. > >> > >> Change device_wakeup_enable() to check for dev_name(dev) null condition > >> and return -EINVAL to avoid panics when device_wakeup_enable() gets called > >> before device is fully initialized with its name. > return -EINVAL; > > > > Can you please use WARN_ON(!dev_name(dev)) here? While I agree that it is a > > bad idea to crash the kernel because dev has no name, that indicates a driver > > bug that shouldn't be too easy to ignore. > > > > Thanks! > > > > Right. ok I will re-cut the patch with WARN_ON and send it. fyi I did > send fix for the driver (power_supply) as well. > > http://www.kernelhub.org/?msg=362354&p=2 Why is a driver calling kobject_set_name() instead of device_set_name()? Yes, it's really the same thing deep down, but drivers should never care about a kobject, just 'struct device'. Well, even then it usually should care about it's type of 'struct device' but that's a different issue... Anyway, not saying your patch is wrong at all, just for the future if people are looking for code cleanups... thanks, greg k-h