virtual_region: address Misra C:2012 rule 18.3

find_text_region() tests whether an arbitrary address lies inside
[text_start, text_end). The address and those bounds are not known to
point into one object, so relational operators on the pointers are
undefined behaviour and violate Misra C:2012 rule 18.3.

The bounds are cast to unsigned long because addr already has that
type. The type is wide enough to hold a pointer, so the comparison
result stays the same.

No functional changes.

Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@epam.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/common/virtual_region.c

@@ -83,8 +83,8 @@ const struct virtual_region *find_text_region(unsigned long addr)
     rcu_read_lock(&rcu_virtual_region_lock);
     list_for_each_entry_rcu ( iter, &virtual_region_list, list )
     {
-        if ( (void *)addr >= iter->text_start &&
-             (void *)addr <  iter->text_end )
+        if ( addr >= (unsigned long)iter->text_start &&
+             addr <  (unsigned long)iter->text_end )
         {
             region = iter;
             break;