perf evsel: Fix ftrace:function event recording

Following patch fails (-EINVAL) ftrace:function with enabled user
space callchains:
  cfa77bc4 perf: Disallow user-space callchains for function trace events

We need to follow in perf tool itself and explicitly set the
perf_event_attr::exclude_callchain_user flag for ftrace:function
event.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1415899263-24820-1-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.c

@@ -658,6 +658,14 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
 		attr->mmap_data = track;
 	}
 
+	/*
+	 * We don't allow user space callchains for  function trace
+	 * event, due to issues with page faults while tracing page
+	 * fault handler and its overall trickiness nature.
+	 */
+	if (perf_evsel__is_function_event(evsel))
+		evsel->attr.exclude_callchain_user = 1;
+
 	if (callchain_param.enabled && !evsel->no_aux_samples)
 		perf_evsel__config_callgraph(evsel);