tracing/uprobes: Support mix of ftrace and perf

It seems there's no reason to prevent mixed used of ftrace and perf
for a single uprobe event.  At least the kprobes already support it.

Link: http://lkml.kernel.org/r/[email protected]

Reviewed-by: Masami Hiramatsu <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
Cc: zhangwei(Jovi) <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

Author: namhyung

kernel/trace/trace_uprobe.c

@@ -882,9 +882,6 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
 	int ret;
 
 	if (file) {
-		if (tu->tp.flags & TP_FLAG_PROFILE)
-			return -EINTR;
-
 		link = kmalloc(sizeof(*link), GFP_KERNEL);
 		if (!link)
 			return -ENOMEM;
@@ -893,12 +890,8 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
 		list_add_tail_rcu(&link->list, &tu->tp.files);
 
 		tu->tp.flags |= TP_FLAG_TRACE;
-	} else {
-		if (tu->tp.flags & TP_FLAG_TRACE)
-			return -EINTR;
-
+	} else
 		tu->tp.flags |= TP_FLAG_PROFILE;
-	}
 
 	ret = uprobe_buffer_enable();
 	if (ret < 0)