From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 1/2] kernfs_path_from_node_locked: don't overwrite nlen Date: Mon, 2 May 2016 12:32:56 -0400 Message-ID: <20160502163256.GT7822@mtj.duckdns.org> References: <1460923472-29370-1-git-send-email-serge.hallyn@ubuntu.com> <1460923472-29370-2-git-send-email-serge.hallyn@ubuntu.com> <20160420194313.GA4775@htj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20160420194313.GA4775-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, adityakali-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org List-Id: linux-api@vger.kernel.org On Wed, Apr 20, 2016 at 03:43:13PM -0400, Tejun Heo wrote: > On Sun, Apr 17, 2016 at 03:04:31PM -0500, serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org wrote: > > From: Serge Hallyn > > > > We've calculated @len to be the bytes we need for '/..' entries from > > @kn_from to the common ancestor, and calculated @nlen to be the extra > > bytes we need to get from the common ancestor to @kn_to. We use them > > as such at the end. But in the loop copying the actual entries, we > > overwrite @nlen. Use a temporary variable for that instead. > > > > Without this, the return length, when the buffer is large enough, is > > wrong. (When the buffer is NULL or too small, the returned value is > > correct. The buffer contents are also correct.) > > > > Interestingly, no callers of this function are affected by this as of > > yet. However the upcoming cgroup_show_path() will be. > > > > Signed-off-by: Serge Hallyn > > Acked-by: Tejun Heo > > Greg, can you please pick this one up for v4.6? Looks like Greg missed this one. Greg, I'll route this through cgroup/for-4.6-fixes. Thanks. -- tejun