From 4645bf306746106f805d2afa5330bf31df381626 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Thu, 29 Sep 2011 13:12:43 -0400
Subject: [PATCH] xen/pciback: Check if the device is found instead of blindly
 assuming so.

Just in case it is not found, don't try to dereference it.

[v1: Added WARN_ON, suggested by Jan Beulich <JBeulich@suse.com>]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/xen/xen-pciback/pci_stub.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 3cc3fbe5bf8d..8f06e1ed028c 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -220,6 +220,8 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
 	}
 
 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
+	if (WARN_ON(!found_psdev))
+		return;
 
 	/*hold this lock for avoiding breaking link between
 	* pcistub and xen_pcibk when AER is in processing