x86/mm/shadow: fix unlocking on error path in p2m allocator

One unlock path wasn't gated to match the lock.

Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 65a2b03e4f6294cfa315fa54d972b8a8d962255a..dd9a1555ae51b5fe7b01fe5ee5d86dd5fd7dda1e 100644 (file)
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -1634,7 +1634,8 @@ shadow_alloc_p2m_page(struct domain *d)
     if ( d->arch.paging.shadow.total_pages 
          < shadow_min_acceptable_pages(d) + 1 )
     {
-        shadow_unlock(d);
+        if ( do_locking )
+            shadow_unlock(d);
         return NULL;
     }