perf probe: Fix memory leakage when the probe point is not found

[ Upstream commit 12d572e785b15bc764e956caaa8a4c846fd15694 ]

Fix the memory leakage in debuginfo__find_trace_events() when the probe
point is not found in the debuginfo. If there is no probe point found in
the debuginfo, debuginfo__find_probes() will NOT return -ENOENT, but 0.

Thus the caller of debuginfo__find_probes() must check the tf.ntevs and
release the allocated memory for the array of struct probe_trace_event.

The current code releases the memory only if the debuginfo__find_probes()
hits an error but not checks tf.ntevs. In the result, the memory allocated
on *tevs are not released if tf.ntevs == 0.

This fixes the memory leakage by checking tf.ntevs == 0 in addition to
ret < 0.

Fixes: ff741783506c ("perf probe: Introduce debuginfo to encapsulate dwarf information")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/159438668346.62703.10887420400718492503.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 7d0d44b4f3d5ca2bad8bafe0292414be93080a29..863f668a073558489ebe0caa8e8d9c85f435b6cc 100644 (file)
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1351,7 +1351,7 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
        tf.ntevs = 0;
 
        ret = debuginfo__find_probes(dbg, &tf.pf);
-       if (ret < 0) {
+       if (ret < 0 || tf.ntevs == 0) {
                for (i = 0; i < tf.ntevs; i++)
                        clear_probe_trace_event(&tf.tevs[i]);
                zfree(tevs);