[PATCH] perf tools: Fix ftrace:function event recording

[Jiri Olsa]

Following patch fails (-EINVAL) ftrace:function with enabled user
space callchains:
  cfa77bc4af2c 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.

Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 tools/perf/util/evsel.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ec5eb8033296..a3baaa31231e 100644
--- a/tools/perf/util/evsel.c
+++ b/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);
 
-- 
1.9.3

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