tracing/probe: Check the size of argument name and body

Check the size of argument name and expression is not 0
and smaller than maximum length.

Link: http://lkml.kernel.org/r/155253783029.14922.12650939303827581096.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 8a63f8b..2177c20 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -32,6 +32,7 @@
 #define MAX_TRACE_ARGS		128
 #define MAX_ARGSTR_LEN		63
 #define MAX_ARRAY_LEN		64
+#define MAX_ARG_NAME_LEN	32
 #define MAX_STRING_SIZE		PATH_MAX
 
 /* Reserved field names */