Commit d95daf5a authored Jul 18, 2019 by Arnaldo Carvalho de Melo

perf probe: Avoid calling freeing routine multiple times for same pointer

When perf_add_probe_events() we call cleanup_perf_probe_events() for the
pev pointer it receives, then, as part of handling this failure the main
'perf probe' goes on and calls cleanup_params() and that will again call
cleanup_perf_probe_events()for the same pointer, so just set nevents to
zero when handling the failure of perf_add_probe_events() to avoid the
double free.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-x8qgma4g813z96dvtw9w219q@git.kernel.org

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

parent df8350ed

tools/perf/builtin-probe.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -698,6 +698,16 @@ __cmd_probe(int argc, const char **argv)

		ret = perf_add_probe_events(params.events, params.nevents);
		if (ret < 0) {

		/*
		* When perf_add_probe_events() fails it calls
		* cleanup_perf_probe_events(pevs, npevs), i.e.
		* cleanup_perf_probe_events(params.events, params.nevents), which
		* will call clear_perf_probe_event(), so set nevents to zero
		* to avoid cleanup_params() to call clear_perf_probe_event() again
		* on the same pevs.
		*/
		params.nevents = 0;
		pr_err_with_code(" Error: Failed to add events.", ret);
		return ret;
		}

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