From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: Re: [PATCH 1/1] Drivers: input: serio: New driver to support Hyper-V synthetic keyboard Date: Tue, 17 Sep 2013 01:13:37 +0300 Message-ID: <20130916221337.GS25896@mwanda> References: <20130916082110.GN25896@mwanda> <3b5096d0190b4440a8e25afbd22ab72d@SN2PR03MB061.namprd03.prod.outlook.com> <20130916150548.GO25896@mwanda> <20130916170951.GB20734@core.coreip.homeip.net> <3e45f054c6e243eabf2896ab1dcf38d4@SN2PR03MB061.namprd03.prod.outlook.com> <20130916183319.GM19256@mwanda> <117fbf407a554684b4d72ab06b033eeb@SN2PR03MB061.namprd03.prod.outlook.com> <20130916201328.GN19256@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: driverdev-devel-bounces@linuxdriverproject.org To: KY Srinivasan Cc: "olaf@aepfle.de" , "gregkh@linuxfoundation.org" , "jasowang@redhat.com" , Dmitry Torokhov , "linux-kernel@vger.kernel.org" , "vojtech@suse.cz" , "linux-input@vger.kernel.org" , "apw@canonical.com" , "devel@linuxdriverproject.org" List-Id: linux-input@vger.kernel.org On Mon, Sep 16, 2013 at 09:55:44PM +0000, KY Srinivasan wrote: > > > > -----Original Message----- > > From: Dan Carpenter [mailto:dan.carpenter@oracle.com] > > Sent: Monday, September 16, 2013 1:13 PM > > To: KY Srinivasan > > Cc: olaf@aepfle.de; gregkh@linuxfoundation.org; jasowang@redhat.com; Dmitry > > Torokhov; linux-kernel@vger.kernel.org; vojtech@suse.cz; linux- > > input@vger.kernel.org; apw@canonical.com; devel@linuxdriverproject.org > > Subject: Re: [PATCH 1/1] Drivers: input: serio: New driver to support Hyper-V > > synthetic keyboard > > > > On Mon, Sep 16, 2013 at 06:42:25PM +0000, KY Srinivasan wrote: > > > Dan, > > > > > > Rolling the changes you have indicated is not the issue; this can trivially be > > done. > > > My contention is that it is not needed given that the underlying function is > > already > > > doing that. Look at the function vmbus_recvpacket_raw() in > > drivers/hv/channel.c. > > > > > > > I'm confused. > > > > There is no mention of ->offset8 in vmbus_recvpacket_raw(). > > As you can see the vmbus_recvpacket_raw() ensures that the complete > packet is read and if the buffer specified is not large enough nothing is > read. The packet header has information about the length of the packet > and the offset where the payload is. > > No one is talking about the ->len8. I'm saying that we should check ->offset8. > > It's a good idea to add a check there but the lower levels don't know > > about the sizeof(synth_kbd_protocol_response) so we would still need > > something like my check. > > Why would the lower level code need to know anything about the layout of a > particular message type. The lower level code is guaranteeing that a complete > packet has been read in and that should be sufficient - assuming we trust the host. > Of course, we don't need to check anything if we trust the host. I said that already. Just add the check for robustness. > We have already spent more time on this than we should; I will make the necessary > changes. Thank you. regards, dan carpenter