FAILED: patch "[PATCH] x86/xen: Do not clip xen_e820_map to xen_e820_map_entries" failed to apply to 4.2-stable tree

The patch below does not apply to the 4.2-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Malcolm Crossley <[email protected]>
Date: Mon, 28 Sep 2015 11:36:52 +0100
Subject: [PATCH] x86/xen: Do not clip xen_e820_map to xen_e820_map_entries
when sanitizing map

Sanitizing the e820 map may produce extra E820 entries which would result in the topmost E820 entries being removed. The removed entries would typically include the top E820 usable RAM region and thus result in the domain having signicantly less RAM available to it.

Fix by allowing sanitize_e820_map to use the full size of the allocated E820 array.

index 4ebfcecc2a8b..1c30e4ab1022 100644
@@ -798,7 +798,7 @@ char * __init xen_memory_setup(void)
 		xen_ignore_unusable();
 
 	/* Make sure the Xen-supplied memory map is well-ordered. */
-	sanitize_e820_map(xen_e820_map, xen_e820_map_entries,
+	sanitize_e820_map(xen_e820_map, ARRAY_SIZE(xen_e820_map),
 			  &xen_e820_map_entries);
 
 	max_pages = xen_get_max_pages();