From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: [PATCH] xen-kbdfront: correct return value checks on xenbus_scanf() Date: Thu, 07 Jul 2016 01:53:40 -0600 Message-ID: <577E26A402000078000FBE93@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Return-path: Received: from prv-mh.provo.novell.com ([137.65.248.74]:33983 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbcGGHxl convert rfc822-to-8bit (ORCPT ); Thu, 7 Jul 2016 03:53:41 -0400 Content-Disposition: inline Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: dmitry.torokhov@gmail.com Cc: david.vrabel@citrix.com, xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com, Juergen Gross , linux-input@vger.kernel.org Only a positive return value indicates success. Signed-off-by: Jan Beulich --- drivers/input/misc/xen-kbdfront.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- 4.7-rc6-xenbus_scanf.orig/drivers/input/misc/xen-kbdfront.c +++ 4.7-rc6-xenbus_scanf/drivers/input/misc/xen-kbdfront.c @@ -127,7 +127,8 @@ static int xenkbd_probe(struct xenbus_de if (!info->page) goto error_nomem; - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0) + if (xenbus_scanf(XBT_NIL, dev->otherend, + "feature-abs-pointer", "%d", &abs) <= 0) abs = 0; if (abs) { ret = xenbus_printf(XBT_NIL, dev->nodename, @@ -324,7 +325,7 @@ static void xenkbd_backend_changed(struc InitWait: ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend, "feature-abs-pointer", "%d", &val); - if (ret < 0) + if (ret <= 0) val = 0; if (val) { ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,