# Commit 017e667c433a1040306db6265b05e104568c70c8
# Date 2015-05-05 18:00:03 +0200
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
domctl: don't truncate XEN_DOMCTL_max_mem requests

Instead saturate the value if the input can't be represented in the
respective struct domain field.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>

--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -943,7 +943,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xe
 
     case XEN_DOMCTL_max_mem:
     {
-        unsigned long new_max;
+        uint64_t new_max;
 
         ret = -EINVAL;
         new_max = op->u.max_mem.max_memkb >> (PAGE_SHIFT-10);
@@ -954,7 +954,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xe
          * that the domain will now be allowed to "ratchet" down to new_max. In
          * the meantime, while tot > max, all new allocations are disallowed.
          */
-        d->max_pages = new_max;
+        d->max_pages = min(new_max, (uint64_t)(typeof(d->max_pages))-1);
         ret = 0;
         spin_unlock(&d->page_alloc_lock);
     }