Commit ccf53eac authored Sep 06, 2013 by Arnaldo Carvalho de Melo

perf trace: Handle perf.data files with no tracepoints

Before:

  perf trace -i perf.data
  Segmentation fault (core dumped)
  #

After:

 # perf trace -i perf.data
 Data file does not have raw_syscalls:sys_enter events
 #

When there are no tracepoints in a perf.data file the struct pevent
that contains the list of tracepoints that will be used to lookup the
tracepoint id by name will not be populated, causing a NULL deref.

And we don't need to do all that dance to look at pevents for an entry
with a slighly different name to then lookup the tracepoint by its id on
the evlist, just use the perf_evlist__find_tracepoint_by_name() routine,
that will find the tracepoint, if present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-egcm21k1e6gcyxpcgjxtmsq3@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 72f4a11d

tools/perf/util/session.c

+7 −33

Original line number	Diff line number	Diff line
		@@ -1620,52 +1620,26 @@ int __perf_session__set_tracepoints_handlers(struct perf_session *session,
		const struct perf_evsel_str_handler *assocs,
		size_t nr_assocs)
		{
		struct perf_evlist *evlist = session->evlist;
		struct event_format *format;
		struct perf_evsel *evsel;
		char tracepoint, name;
		size_t i;
		int err;

		for (i = 0; i < nr_assocs; i++) {
		err = -ENOMEM;
		tracepoint = strdup(assocs[i].name);
		if (tracepoint == NULL)
		goto out;

		err = -ENOENT;
		name = strchr(tracepoint, ':');
		if (name == NULL)
		goto out_free;

		*name++ = '\0';
		format = pevent_find_event_by_name(session->pevent,
		tracepoint, name);
		if (format == NULL) {
		/*
		* Adding a handler for an event not in the session,
		* just ignore it.
		*/
		goto next;
		}

		evsel = perf_evlist__find_tracepoint_by_id(evlist, format->id);
		evsel = perf_evlist__find_tracepoint_by_name(session->evlist, assocs[i].name);
		if (evsel == NULL)
		goto next;
		continue;

		err = -EEXIST;
		if (evsel->handler.func != NULL)
		goto out_free;
		goto out;
		evsel->handler.func = assocs[i].handler;
		next:
		free(tracepoint);
		}

		err = 0;
		out:
		return err;

		out_free:
		free(tracepoint);
		goto out;
		}