When checking for the presence of ETE, a register is read that may not be present on older kernels or if ETE isn't available. cs_etm_get_ro() will print a warning if it doesn't exist, so check for the existence first before accessing it.
Signed-off-by: James Clark james.clark@arm.com --- tools/perf/arch/arm/util/cs-etm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 59b50dd70330..86b61ad74f90 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -659,8 +659,12 @@ static bool cs_etm_is_ete(struct auxtrace_record *itr, int cpu) { struct cs_etm_recording *ptr = container_of(itr, struct cs_etm_recording, itr); struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu; - int trcdevarch = cs_etm_get_ro(cs_etm_pmu, cpu, metadata_ete_ro[CS_ETE_TRCDEVARCH]); + int trcdevarch;
+ if (!cs_etm_pmu_path_exists(cs_etm_pmu, cpu, metadata_ete_ro[CS_ETE_TRCDEVARCH])) + return false; + + trcdevarch = cs_etm_get_ro(cs_etm_pmu, cpu, metadata_ete_ro[CS_ETE_TRCDEVARCH]); /* * ETE if ARCHVER is 5 (ARCHVER is 4 for ETM) and ARCHPART is 0xA13. * See ETM_DEVARCH_ETE_ARCH in coresight-etm4x.h