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From:   James Clark <james.clark@arm.com>
To:     acme@kernel.org, linux-perf-users@vger.kernel.org,
        mathieu.poirier@linaro.org, coresight@lists.linaro.org
Cc:     James Clark <james.clark@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        John Garry <john.garry@huawei.com>,
        Will Deacon <will@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] perf: cs-etm: Fix corrupt inject files when only last branch option is enabled
Date:   Thu, 10 Feb 2022 20:06:20 +0000
Message-Id: <20220210200620.1227232-2-james.clark@arm.com>
In-Reply-To: <20220210200620.1227232-1-james.clark@arm.com>
References: <20220210200620.1227232-1-james.clark@arm.com>
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Perf inject with Coresight data generates files that cannot be opened
when only the last branch option is specified:

  perf inject -i perf.data --itrace=l -o inject.data
  perf script -i inject.data
  0x33faa8 [0x8]: failed to process type: 9 [Bad address]

This is because cs_etm__synth_instruction_sample() is called even when
the sample type for instructions hasn't been setup. Last branch records
are attached to instruction samples so it doesn't make sense to generate
them when --itrace=i isn't specified anyway.

This change disables all calls of cs_etm__synth_instruction_sample()
unless --itrace=i is specified, resulting in a file with no samples if
only --itrace=l is provided, rather than a bad file.

Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/util/cs-etm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 796a065a500e..8b95fb3c4d7b 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -1553,6 +1553,7 @@ static int cs_etm__flush(struct cs_etm_queue *etmq,
 		goto swap_packet;
 
 	if (etmq->etm->synth_opts.last_branch &&
+	    etmq->etm->synth_opts.instructions &&
 	    tidq->prev_packet->sample_type == CS_ETM_RANGE) {
 		u64 addr;
 
@@ -1610,6 +1611,7 @@ static int cs_etm__end_block(struct cs_etm_queue *etmq,
 	 * the trace.
 	 */
 	if (etmq->etm->synth_opts.last_branch &&
+	    etmq->etm->synth_opts.instructions &&
 	    tidq->prev_packet->sample_type == CS_ETM_RANGE) {
 		u64 addr;
 
-- 
2.28.0