Commit-ID: 3eb3e07bcfee0670d7142f839c76f33f3d265793 Gitweb: https://git.kernel.org/tip/3eb3e07bcfee0670d7142f839c76f33f3d265793 Author: Leo Yan <leo....@linaro.org> AuthorDate: Wed, 11 Jul 2018 15:45:42 +0800 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 31 Jul 2018 10:57:56 -0300
perf cs-etm: Fix start tracing packet handling Usually the start tracing packet is a CS_ETM_TRACE_ON packet, this packet is passed to cs_etm__flush(); cs_etm__flush() will check the condition 'prev_packet->sample_type == CS_ETM_RANGE' but 'prev_packet' is allocated by zalloc() so 'prev_packet->sample_type' is zero in initialization and this condition is false. So cs_etm__flush() will directly bail out without handling the start tracing packet. This patch is to introduce a new sample type CS_ETM_EMPTY, which is used to indicate the packet is an empty packet. cs_etm__flush() will swap packets when it finds the previous packet is empty, so this can record the start tracing packet into 'etmq->prev_packet'. Signed-off-by: Leo Yan <leo....@linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Jiri Olsa <jo...@redhat.com> Cc: Kim Phillips <kim.phill...@arm.com> Cc: Mike Leach <mike.le...@linaro.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Robert Walker <robert.wal...@arm.com> Cc: linux-arm-ker...@lists.infradead.org Link: http://lkml.kernel.org/r/1531295145-596-4-git-send-email-leo....@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/cs-etm-decoder/cs-etm-decoder.h | 1 + tools/perf/util/cs-etm.c | 19 ++++++++++++++++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h index 743f5f444304..612b5755f742 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h @@ -23,6 +23,7 @@ struct cs_etm_buffer { }; enum cs_etm_sample_type { + CS_ETM_EMPTY = 0, CS_ETM_RANGE = 1 << 0, CS_ETM_TRACE_ON = 1 << 1, }; diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 8b2c099e750a..ae7c9c880cb2 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -924,8 +924,14 @@ static int cs_etm__flush(struct cs_etm_queue *etmq) int err = 0; struct cs_etm_packet *tmp; + if (!etmq->prev_packet) + return 0; + + /* Handle start tracing packet */ + if (etmq->prev_packet->sample_type == CS_ETM_EMPTY) + goto swap_packet; + if (etmq->etm->synth_opts.last_branch && - etmq->prev_packet && etmq->prev_packet->sample_type == CS_ETM_RANGE) { /* * Generate a last branch event for the branches left in the @@ -944,6 +950,10 @@ static int cs_etm__flush(struct cs_etm_queue *etmq) etmq->period_instructions = 0; + } + +swap_packet: + if (etmq->etm->synth_opts.last_branch) { /* * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for * the next incoming packet. @@ -1023,6 +1033,13 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq) */ cs_etm__flush(etmq); break; + case CS_ETM_EMPTY: + /* + * Should not receive empty packet, + * report error. + */ + pr_err("CS ETM Trace: empty packet\n"); + return -EINVAL; default: break; }
