From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guillaume Nault Date: Thu, 30 Aug 2018 13:09:57 +0000 Subject: Re: [PATCH net-next 1/5] pppoe: fix PPPOEIOCSFWD compat handling Message-Id: <20180830130957.GD1473@alphalink.fr> List-Id: References: <20180829140409.833488-1-arnd@arndb.de> <20180830110453.GC1473@alphalink.fr> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Arnd Bergmann Cc: Paul Mackerras , linux-ppp@vger.kernel.org, Networking , mitch@sfgoth.com, mostrows@earthlink.net, jchapman@katalix.com, xeb@mail.ru, David Miller , Al Viro , y2038 Mailman List , Linux Kernel Mailing List On Thu, Aug 30, 2018 at 01:54:48PM +0200, Arnd Bergmann wrote: > On Thu, Aug 30, 2018 at 1:04 PM Guillaume Nault wrote: > > > > On Wed, Aug 29, 2018 at 04:03:26PM +0200, Arnd Bergmann wrote: > > > Support for handling the PPPOEIOCSFWD ioctl in compat mode was added in > > > linux-2.5.69 along with hundreds of other commands, but was always broken > > > sincen only the structure is compatible, but the command number is not, > > > due to the size being sizeof(size_t), or at first sizeof(sizeof((struct > > > sockaddr_pppox)), which is different on 64-bit architectures. > > > > > And the implementation was broken until 2016 (see 29e73269aa4d ("pppoe: > > fix reference counting in PPPoE proxy")), and nobody ever noticed. I > > should probably have removed this ioctl entirely instead of fixing it. > > Clearly, it has never been used. > > > > If you think it's worth fixing (as opposed to dropping this ioctl or > > its compat mode), then, > > Acked-by: Guillaume Nault > > I don't care much, but fixing it seems seems easier than coming > up with a convincing rationale for dropping. > > I'll update the changelog text to include your additional background > information though, unless someone else prefers to have it dropped. > Sounds good. Thanks.