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From:   James Clark <james.clark@arm.com>
To:     mathieu.poirier@linaro.org, leo.yan@linaro.org,
        coresight@lists.linaro.org, linux-perf-users@vger.kernel.org,
        mike.leach@linaro.org
Cc:     acme@kernel.org, suzuki.poulose@arm.com,
        James Clark <james.clark@arm.com>,
        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 v2 9/9] perf cs-etm: Show a warning for an unknown magic number
Date:   Fri,  6 Aug 2021 14:41:09 +0100
Message-Id: <20210806134109.1182235-10-james.clark@arm.com>
In-Reply-To: <20210806134109.1182235-1-james.clark@arm.com>
References: <20210806134109.1182235-1-james.clark@arm.com>
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Currently perf reports "Cannot allocate memory" which isn't very helpful
for a potentially user facing issue. If we add a new magic number in
the future, perf will be able to report unrecognised magic numbers.

Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/util/cs-etm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 788ad5a099f6..5b276bdb96a6 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -2973,6 +2973,11 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
 
 			/* ETE shares first part of metadata with ETMv4 */
 			trcidr_idx = CS_ETMV4_TRCTRACEIDR;
+		} else {
+			ui__error("CS ETM Trace: Unrecognised magic number %#"PRIx64". File could be from a newer version of perf.\n",
+				  ptr[i]);
+			err = -EINVAL;
+			goto err_free_metadata;
 		}
 
 		if (!metadata[j]) {
-- 
2.28.0