From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH 03/17] Drivers: hv: kvp: Cleanup error handling in KVP Date: Wed, 25 Jul 2012 15:47:25 +0100 Message-ID: <20120725144724.GD1894@decadent.org.uk> References: <1343145672-3641-1-git-send-email-kys@microsoft.com> <1343145701-3691-1-git-send-email-kys@microsoft.com> <1343145701-3691-3-git-send-email-kys@microsoft.com> <1343178644.5132.103.camel@deadeye.wl.decadent.org.uk> <426367E2313C2449837CD2DE46E7EAF9236A8B61@SN2PRD0310MB382.namprd03.prod.outlook.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <426367E2313C2449837CD2DE46E7EAF9236A8B61@SN2PRD0310MB382.namprd03.prod.outlook.com> Sender: linux-kernel-owner@vger.kernel.org To: KY Srinivasan Cc: "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , "virtualization@lists.osdl.org" , "olaf@aepfle.de" , "apw@canonical.com" , "netdev@vger.kernel.org" List-Id: virtualization@lists.linuxfoundation.org On Wed, Jul 25, 2012 at 02:10:05PM +0000, KY Srinivasan wrote: > > > > -----Original Message----- > > From: Ben Hutchings [mailto:ben@decadent.org.uk] > > Sent: Tuesday, July 24, 2012 9:11 PM > > To: KY Srinivasan > > Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; > > devel@linuxdriverproject.org; virtualization@lists.osdl.org; olaf@aepfle.de; > > apw@canonical.com; netdev@vger.kernel.org > > Subject: Re: [PATCH 03/17] Drivers: hv: kvp: Cleanup error handling in KVP > > > > On Tue, 2012-07-24 at 09:01 -0700, K. Y. Srinivasan wrote: > > > In preparation to implementing IP injection, cleanup the way we propagate > > > and handle errors both in the driver as well as in the user level daemon. > > > > > > Signed-off-by: K. Y. Srinivasan > > > Reviewed-by: Haiyang Zhang > > > --- > > > drivers/hv/hv_kvp.c | 112 +++++++++++++++++++++++++++++++++++++- > > -------- > > > include/linux/hyperv.h | 17 +++++--- > > > tools/hv/hv_kvp_daemon.c | 70 +++++++++++++++------------- > > > 3 files changed, 138 insertions(+), 61 deletions(-) > > > > > > diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c > > > index 0012eed..9b7fc4a 100644 > > > --- a/drivers/hv/hv_kvp.c > > > +++ b/drivers/hv/hv_kvp.c > > [...] > > > @@ -109,27 +154,52 @@ kvp_cn_callback(struct cn_msg *msg, struct > > netlink_skb_parms *nsp) > > > { > > > struct hv_kvp_msg *message; > > > struct hv_kvp_msg_enumerate *data; > > > + int error = 0; > > > > > > message = (struct hv_kvp_msg *)msg->data; > > > - switch (message->kvp_hdr.operation) { > > > + > > > + /* > > > + * If we are negotiating the version information > > > + * with the daemon; handle that first. > > > + */ > > > + > > > + if (in_hand_shake) { > > > + if (kvp_handle_handshake(message)) > > > + in_hand_shake = false; > > > + return; > > > + } > > > + > > > + /* > > > + * Based on the version of the daemon, we propagate errors from the > > > + * daemon differently. > > > + */ > > > + > > > + data = &message->body.kvp_enum_data; > > > + > > > + switch (dm_reg_value) { > > > case KVP_OP_REGISTER: > > > - pr_info("KVP: user-mode registering done.\n"); > > > - kvp_register(); > > > - kvp_transaction.active = false; > > > - hv_kvp_onchannelcallback(kvp_transaction.kvp_context); > > > + /* > > > + * Null string is used to pass back error condition. > > > + */ > > > + if (!strlen(data->data.key)) > > > > Do we know that the key is null-terminated here? Shouldn't we just > > check whether data->data.key[0] == 0? > > Yes, currently we do return null string to indicate error. [...] So the kernel should assume userland input is always valid? Ben. -- Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camus