tracing/probe: Check event/group naming rule at parsing

Check event and group naming rule at parsing it instead
of allocating probes.

Link: http://lkml.kernel.org/r/155253784064.14922.2336893061156236237.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace_kprobe.c

@@ -221,7 +221,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 
 	tk->rp.maxactive = maxactive;
 
-	if (!event || !is_good_name(event)) {
+	if (!event || !group) {
 		ret = -EINVAL;
 		goto error;
 	}
@@ -231,11 +231,6 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 	if (!tk->tp.call.name)
 		goto error;
 
-	if (!group || !is_good_name(group)) {
-		ret = -EINVAL;
-		goto error;
-	}
-
 	tk->tp.class.system = kstrdup(group, GFP_KERNEL);
 	if (!tk->tp.class.system)
 		goto error;

kernel/trace/trace_probe.c

@@ -172,6 +172,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 			return -E2BIG;
 		}
 		strlcpy(buf, event, slash - event + 1);
+		if (!is_good_name(buf)) {
+			pr_info("Group name must follow the same rules as C identifiers\n");
+			return -EINVAL;
+		}
 		*pgroup = buf;
 		*pevent = slash + 1;
 		event = *pevent;
@@ -184,6 +188,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 		pr_info("Event name is too long\n");
 		return -E2BIG;
 	}
+	if (!is_good_name(event)) {
+		pr_info("Event name must follow the same rules as C identifiers\n");
+		return -EINVAL;
+	}
 	return 0;
 }
 

kernel/trace/trace_uprobe.c

@@ -266,10 +266,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 {
 	struct trace_uprobe *tu;
 
-	if (!event || !is_good_name(event))
-		return ERR_PTR(-EINVAL);
-
-	if (!group || !is_good_name(group))
+	if (!event || !group)
 		return ERR_PTR(-EINVAL);
 
 	tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);