perf script: Fix --per-event-dump for auxtrace synth evsels

When processing PERF_RECORD_AUXTRACE_INFO several perf_evsel entries
will be synthesized and inserted into session->evlist, eventually ending
in perf_script.tool.sample(), which ends up calling builtin-script.c's
process_event(), that expects evsel->priv to be a perf_evsel_script
object with a valid FILE pointer in fp.

So we need to intercept the processing of PERF_RECORD_AUXTRACE_INFO and
then setup evsel->priv for these newly created perf_evsel instances, do
it to fix the segfault in process_event() trying to use a NULL for that
FILE pointer.

Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: yuzhoujian <yuzhoujian@didichuxing.com>
Fixes: a14390fde64e ("perf script: Allow creating per-event dump files")
Link: http://lkml.kernel.org/n/tip-bthnur8r8de01gxvn2qayx6e@git.kernel.org
[ Merge fix by Ravi Bangoria before pushing upstream to preserv bisectability ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 68f36dc..9b43bda 100644 (file)
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1955,6 +1955,16 @@ static int perf_script__fopen_per_event_dump(struct perf_script *script)
        struct perf_evsel *evsel;
 
        evlist__for_each_entry(script->session->evlist, evsel) {
+               /*
+                * Already setup? I.e. we may be called twice in cases like
+                * Intel PT, one for the intel_pt// and dummy events, then
+                * for the evsels syntheized from the auxtrace info.
+                *
+                * Ses perf_script__process_auxtrace_info.
+                */
+               if (evsel->priv != NULL)
+                       continue;
+
                evsel->priv = perf_evsel_script__new(evsel, script->session->data);
                if (evsel->priv == NULL)
                        goto out_err_fclose;
@@ -2838,6 +2848,25 @@ int process_cpu_map_event(struct perf_tool *tool __maybe_unused,
        return set_maps(script);
 }
 
+#ifdef HAVE_AUXTRACE_SUPPORT
+static int perf_script__process_auxtrace_info(struct perf_tool *tool,
+                                             union perf_event *event,
+                                             struct perf_session *session)
+{
+       int ret = perf_event__process_auxtrace_info(tool, event, session);
+
+       if (ret == 0) {
+               struct perf_script *script = container_of(tool, struct perf_script, tool);
+
+               ret = perf_script__setup_per_event_dump(script);
+       }
+
+       return ret;
+}
+#else
+#define perf_script__process_auxtrace_info 0
+#endif
+
 int cmd_script(int argc, const char **argv)
 {
        bool show_full_info = false;
@@ -2866,7 +2895,7 @@ int cmd_script(int argc, const char **argv)
                        .feature         = perf_event__process_feature,
                        .build_id        = perf_event__process_build_id,
                        .id_index        = perf_event__process_id_index,
-                       .auxtrace_info   = perf_event__process_auxtrace_info,
+                       .auxtrace_info   = perf_script__process_auxtrace_info,
                        .auxtrace        = perf_event__process_auxtrace,
                        .auxtrace_error  = perf_event__process_auxtrace_error,
                        .stat            = perf_event__process_stat_event,