From mboxrd@z Thu Jan 1 00:00:00 1970 From: Taesoo Kim Subject: Re: [PATCH 1/1] ext4: better error handling of kstrdup() Date: Fri, 3 Apr 2015 13:44:20 -0400 Message-ID: <20150403174420.GY28537@taesoo.org> References: <1426886514-23522-1-git-send-email-tsgatesv@gmail.com> <20150403050943.GB9988@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Theodore Ts'o , Taesoo Kim , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, changwoo@gatech.edu, sanidhya@gatech.edu, blee@gatech.edu, csong84@gatech.edu Return-path: Content-Disposition: inline In-Reply-To: <20150403050943.GB9988@thunk.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hi Ted, It's my fault. I didn't properly check the case of having data = NULL to kstrdup() as my system has long mounting options.. Sorry for the trouble. I think there is no clean way to handle this error (better), other than implicitly letting kstrdup() fail (and ignore). Taesoo On 04/03/15 at 01:09am, Theodore Ts'o wrote: > On Fri, Mar 20, 2015 at 05:21:54PM -0400, Taesoo Kim wrote: > > Upon memory pressure, kstrdup() might fail and correctly > > handle memory error, although current implementation do not > > refer orig_data. > > > > NOTE. fortunately the correct impl works, other than a > > corner case where kstrdup() fails and kzalloc() succeeds; > > it might record 'NULL' in the log. > > > > Signed-off-by: Taesoo Kim > > Did you test this patch? If there are no mount options (such as when > mounting the root file system, data is NULL, so orig_data is NULL), > and the mount fails. So a kernel won't boot with this patch applied. > > - Ted