From: Insu Yun <wuninsu@gmail.com>
Date: Mon, 19 Oct 2015 16:42:21 +0000 (-0700)
Subject: Input: xen - check return value of xenbus_printf
X-Git-Tag: firefly_0821_release~176^2~541^2~15^2~8
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ec7aa963bf81803b70b7da71bf79943ae5b9c531;p=firefly-linux-kernel-4.4.55.git

Input: xen - check return value of xenbus_printf

Internally, xenbus_printf uses memory allocation, so it can fail under
memory pressure, leaving the input device configured as absolute with the
backend supplying relative coordinates.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Reviewed-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 23d0549539d4..0a9ad2cfb55c 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
 
 	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
 		abs = 0;
-	if (abs)
-		xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
+	if (abs) {
+		ret = xenbus_printf(XBT_NIL, dev->nodename,
+				    "request-abs-pointer", "1");
+		if (ret) {
+			pr_warning("xenkbd: can't request abs-pointer");
+			abs = 0;
+		}
+	}
 
 	/* keyboard */
 	kbd = input_allocate_device();