From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 20 Apr 2018 06:46:24 +0000 (+0200)
Subject: 4.9-stable patches
X-Git-Tag: v3.18.106~69
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eac4c3ce76a1e8aed8ba5f8d5c7e49f0d7442106;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	xen-netfront-fix-hang-on-device-removal.patch
---

diff --git a/queue-4.9/series b/queue-4.9/series
index 8833927ce32..6a6b86465ac 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -13,3 +13,4 @@ arm-dts-at91-at91sam9g25-fix-mux-mask-pinctrl-property.patch
 arm-dts-exynos-fix-iommu-support-for-gscaler-devices-on-exynos5250.patch
 arm-dts-at91-sama5d4-fix-pinctrl-compatible-string.patch
 spi-fix-scatterlist-elements-size-in-spi_map_buf.patch
+xen-netfront-fix-hang-on-device-removal.patch
diff --git a/queue-4.9/xen-netfront-fix-hang-on-device-removal.patch b/queue-4.9/xen-netfront-fix-hang-on-device-removal.patch
new file mode 100644
index 00000000000..63c24e19ba7
--- /dev/null
+++ b/queue-4.9/xen-netfront-fix-hang-on-device-removal.patch
@@ -0,0 +1,54 @@
+From c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 Mon Sep 17 00:00:00 2001
+From: Jason Andryuk <jandryuk@gmail.com>
+Date: Wed, 28 Feb 2018 07:23:23 -0500
+Subject: xen-netfront: Fix hang on device removal
+
+From: Jason Andryuk <jandryuk@gmail.com>
+
+commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 upstream.
+
+A toolstack may delete the vif frontend and backend xenstore entries
+while xen-netfront is in the removal code path.  In that case, the
+checks for xenbus_read_driver_state would return XenbusStateUnknown, and
+xennet_remove would hang indefinitely.  This hang prevents system
+shutdown.
+
+xennet_remove must be able to handle XenbusStateUnknown, and
+netback_changed must also wake up the wake_queue for that state as well.
+
+Fixes: 5b5971df3bc2 ("xen-netfront: remove warning when unloading module")
+
+Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
+Cc: Eduardo Otubo <otubo@redhat.com>
+Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/net/xen-netfront.c |    7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+--- a/drivers/net/xen-netfront.c
++++ b/drivers/net/xen-netfront.c
+@@ -2038,7 +2038,10 @@ static void netback_changed(struct xenbu
+ 	case XenbusStateInitialised:
+ 	case XenbusStateReconfiguring:
+ 	case XenbusStateReconfigured:
++		break;
++
+ 	case XenbusStateUnknown:
++		wake_up_all(&module_unload_q);
+ 		break;
+ 
+ 	case XenbusStateInitWait:
+@@ -2169,7 +2172,9 @@ static int xennet_remove(struct xenbus_d
+ 		xenbus_switch_state(dev, XenbusStateClosing);
+ 		wait_event(module_unload_q,
+ 			   xenbus_read_driver_state(dev->otherend) ==
+-			   XenbusStateClosing);
++			   XenbusStateClosing ||
++			   xenbus_read_driver_state(dev->otherend) ==
++			   XenbusStateUnknown);
+ 
+ 		xenbus_switch_state(dev, XenbusStateClosed);
+ 		wait_event(module_unload_q,