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, 27 insertions, 13 deletions

diff --git a/kernel/drivers/xen/balloon.c b/kernel/drivers/xen/balloon.c
index 12eab503e..cfab1d24e 100644
--- a/kernel/drivers/xen/balloon.c
+++ b/kernel/drivers/xen/balloon.c
@@ -247,6 +247,19 @@ static enum bp_state update_schedule(enum bp_state state)
 }
 
 #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
+static void release_memory_resource(struct resource *resource)
+{
+	if (!resource)
+		return;
+
+	/*
+	 * No need to reset region to identity mapped since we now
+	 * know that no I/O can be in this region
+	 */
+	release_resource(resource);
+	kfree(resource);
+}
+
 static struct resource *additional_memory_resource(phys_addr_t size)
 {
 	struct resource *res;
@@ -268,20 +281,21 @@ static struct resource *additional_memory_resource(phys_addr_t size)
 		return NULL;
 	}
 
-	return res;
-}
-
-static void release_memory_resource(struct resource *resource)
-{
-	if (!resource)
-		return;
+#ifdef CONFIG_SPARSEMEM
+	{
+		unsigned long limit = 1UL << (MAX_PHYSMEM_BITS - PAGE_SHIFT);
+		unsigned long pfn = res->start >> PAGE_SHIFT;
+
+		if (pfn > limit) {
+			pr_err("New System RAM resource outside addressable RAM (%lu > %lu)\n",
+			       pfn, limit);
+			release_memory_resource(res);
+			return NULL;
+		}
+	}
+#endif
 
-	/*
-	 * No need to reset region to identity mapped since we now
-	 * know that no I/O can be in this region
-	 */
-	release_resource(resource);
-	kfree(resource);
+	return res;
 }
 
 static enum bp_state reserve_additional_memory(void)