File 5b76b780-rangeset-inquiry-functions-tolerate-NULL.patch of Package xen.10697

# Commit ad0a9f273d6d6f0545cd9b708b2d4be581a6cadd
# Date 2018-08-17 13:54:40 +0200
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
rangeset: make inquiry functions tolerate NULL inputs

Rather than special casing the ->iomem_caps check in x86's
get_page_from_l1e() for the dom_xen case, let's be more tolerant in
general, along the lines of rangeset_is_empty(): A never allocated
rangeset can't possibly contain or overlap any range.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>

--- a/xen/common/rangeset.c
+++ b/xen/common/rangeset.c
@@ -235,6 +235,9 @@ int rangeset_contains_range(
 
     ASSERT(s <= e);
 
+    if ( !r )
+        return 0;
+
     spin_lock(&r->lock);
     x = find_range(r, s);
     contains = (x && (x->e >= e));
@@ -251,6 +254,9 @@ int rangeset_overlaps_range(
 
     ASSERT(s <= e);
 
+    if ( !r )
+        return 0;
+
     spin_lock(&r->lock);
     x = find_range(r, e);
     overlaps = (x && (s <= x->e));