From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 23 Apr 2018 14:12:01 +0000 (+0200)
Subject: x86: correct assertion in destroy_perdomain_mapping()
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~159
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=f26441439e5bacff948b172cb4d2da3ad8ec7ebd;p=xen.git

x86: correct assertion in destroy_perdomain_mapping()

hvm_domain_initialise() may call this with nr being zero, which triggers
the "does not cross L3 boundary" check.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
---

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 9fe5583fc3..53b36d8889 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5475,7 +5475,7 @@ void destroy_perdomain_mapping(struct domain *d, unsigned long va,
 
     ASSERT(va >= PERDOMAIN_VIRT_START &&
            va < PERDOMAIN_VIRT_SLOT(PERDOMAIN_SLOTS));
-    ASSERT(!l3_table_offset(va ^ (va + nr * PAGE_SIZE - 1)));
+    ASSERT(!nr || !l3_table_offset(va ^ (va + nr * PAGE_SIZE - 1)));
 
     if ( !d->arch.perdomain_l3_pg )
         return;