diff mbox series

[v4,05/17] perf: cs-etm: Only save valid trace IDs into files

Message ID 20240625133105.671245-6-james.clark@arm.com (mailing list archive)
State New, archived
Headers show
Series coresight: Use per-sink trace ID maps for Perf sessions | expand

Commit Message

James Clark June 25, 2024, 1:30 p.m. UTC 
This isn't a bug because Perf always masks with
CORESIGHT_TRACE_ID_VAL_MASK before using these values, but to avoid it
looking like it could be, make an effort to not save bad values.

Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/arch/arm/util/cs-etm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index b0118546cd4d..14b8afabce3a 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -643,7 +643,8 @@  static bool cs_etm_is_ete(struct perf_pmu *cs_etm_pmu, struct perf_cpu cpu)
 
 static __u64 cs_etm_get_legacy_trace_id(struct perf_cpu cpu)
 {
-	return CORESIGHT_LEGACY_CPU_TRACE_ID(cpu.cpu);
+	/* Wrap at 48 so that invalid trace IDs aren't saved into files. */
+	return CORESIGHT_LEGACY_CPU_TRACE_ID(cpu.cpu % 48);
 }
 
 static void cs_etm_save_etmv4_header(__u64 data[], struct auxtrace_record *itr, struct perf_cpu cpu)