From: Martin Kelly <martin@martingkelly.com>
Date: Fri, 17 Oct 2014 03:48:11 +0000 (-0700)
Subject: x86/xen: panic on bad Xen-provided memory map
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1ea644c8f93f3435760d8b88c25d56475d8b7778;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

x86/xen: panic on bad Xen-provided memory map

Panic if Xen provides a memory map with 0 entries. Although this is
unlikely, it is better to catch the error at the point of seeing the map
than later on as a symptom of some other crash.

Signed-off-by: Martin Kelly <martkell@amazon.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index af7216128d93..29834b3fd87f 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -595,6 +595,7 @@ char * __init xen_memory_setup(void)
 		rc = 0;
 	}
 	BUG_ON(rc);
+	BUG_ON(memmap.nr_entries == 0);
 
 	/*
 	 * Xen won't allow a 1:1 mapping to be created to UNUSABLE