userns: Wrap call with a macro fore readability

Pass function name into a helper instead of pointer
wich doesn't provide much useful info.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/namespaces.h

 #ifndef __CR_NS_H__
 #define __CR_NS_H__
 
+#include "compiler.h"
 #include "files.h"
 
 struct ns_desc {
@@ -114,7 +115,11 @@ typedef int (*uns_call_t)(void *arg, int fd, pid_t pid);
  * In case we're not in userns, just call the callback immediatelly
  * in the context of calling task.
  */
-int userns_call(uns_call_t call, int flags,
-		void *arg, size_t arg_size, int fd);
+extern int __userns_call(const char *func_name, uns_call_t call, int flags,
+			 void *arg, size_t arg_size, int fd);
+
+#define userns_call(__call, __flags, __arg, __arg_size, __fd)	\
+	__userns_call(__stringify(__call), __call, __flags,	\
+		      __arg, __arg_size, __fd)
 
 #endif /* __CR_NS_H__ */

namespaces.c

@@ -1015,8 +1015,8 @@ static int usernsd(int sk)
 	}
 }
 
-int userns_call(uns_call_t call, int flags,
-		void *arg, size_t arg_size, int fd)
+int __userns_call(const char *func_name, uns_call_t call, int flags,
+		  void *arg, size_t arg_size, int fd)
 {
 	int ret, res, sk;
 	bool async = flags & UNS_ASYNC;
@@ -1031,7 +1031,7 @@ int userns_call(uns_call_t call, int flags,
 		return call(arg, fd, getpid());
 
 	sk = get_service_fd(USERNSD_SK);
-	pr_debug("UNS: calling %p (%d, %x)\n", call, fd, flags);
+	pr_debug("UNS: calling %s (%d, %x)\n", func_name, fd, flags);
 
 	if (!async)
 		/*