Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 26 insertions, 5 deletions

diff --git a/kernel/net/sched/cls_flower.c b/kernel/net/sched/cls_flower.c
index 95b021243..e5a58c827 100644
--- a/kernel/net/sched/cls_flower.c
+++ b/kernel/net/sched/cls_flower.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/rhashtable.h>
+#include <linux/workqueue.h>
 
 #include <linux/if_ether.h>
 #include <linux/in6.h>
@@ -55,7 +56,10 @@ struct cls_fl_head {
 	bool mask_assigned;
 	struct list_head filters;
 	struct rhashtable_params ht_params;
-	struct rcu_head rcu;
+	union {
+		struct work_struct work;
+		struct rcu_head	rcu;
+	};
 };
 
 struct cls_fl_filter {
@@ -165,6 +169,24 @@ static void fl_destroy_filter(struct rcu_head *head)
 	kfree(f);
 }
 
+static void fl_destroy_sleepable(struct work_struct *work)
+{
+	struct cls_fl_head *head = container_of(work, struct cls_fl_head,
+						work);
+	if (head->mask_assigned)
+		rhashtable_destroy(&head->ht);
+	kfree(head);
+	module_put(THIS_MODULE);
+}
+
+static void fl_destroy_rcu(struct rcu_head *rcu)
+{
+	struct cls_fl_head *head = container_of(rcu, struct cls_fl_head, rcu);
+
+	INIT_WORK(&head->work, fl_destroy_sleepable);
+	schedule_work(&head->work);
+}
+
 static bool fl_destroy(struct tcf_proto *tp, bool force)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
@@ -177,10 +199,9 @@ static bool fl_destroy(struct tcf_proto *tp, bool force)
 		list_del_rcu(&f->list);
 		call_rcu(&f->rcu, fl_destroy_filter);
 	}
-	RCU_INIT_POINTER(tp->root, NULL);
-	if (head->mask_assigned)
-		rhashtable_destroy(&head->ht);
-	kfree_rcu(head, rcu);
+
+	__module_get(THIS_MODULE);
+	call_rcu(&head->rcu, fl_destroy_rcu);
 	return true;
 }