From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 36/37] perf probe: Avoid calling freeing routine multiple times for same pointer Date: Mon, 22 Jul 2019 14:38:38 -0300 Message-ID: <20190722173839.22898-37-acme@kernel.org> References: <20190722173839.22898-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190722173839.22898-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Masami Hiramatsu List-Id: linux-perf-users.vger.kernel.org From: Arnaldo Carvalho de Melo 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 Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-x8qgma4g813z96dvtw9w219q@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-probe.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index 6418782951a4..3d0ffd41fb55 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -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; } -- 2.21.0