[powerpc] Use new method to detect NULL xencomm handle

old method wasted cycles and could give false positive.

Signed-off-by: Jimi Xenidis <jimix@watson.ibm.com>

diff --git a/xen/arch/powerpc/usercopy.c b/xen/arch/powerpc/usercopy.c
index 77ec80c66c14ef224e504c1275b8c49f3fde9547..b5555860079b173ddd5650e808747e9ff52c3900 100644 (file)
--- a/xen/arch/powerpc/usercopy.c
+++ b/xen/arch/powerpc/usercopy.c
@@ -238,5 +238,5 @@ int xencomm_handle_is_null(void *ptr)
 
     desc = (struct xencomm_desc *)paddr_to_maddr((unsigned long)ptr);
 
-    return (desc->address[0] == XENCOMM_INVALID);
+    return (desc->nr_addrs == 0);
 }