From: Malcolm Crossley <malcolm.crossley@citrix.com>
Date: Mon, 28 Sep 2015 10:36:52 +0000 (+0100)
Subject: x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing map
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=64c98e7f49100b637cd20a6c63508caed6bbba7a;p=linux-beck.git

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.

Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 4ebfcecc2a8b..1c30e4ab1022 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -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();