From: Al Grant al.grant@arm.com
[ Upstream commit f5f8e7e55fbdb4fdddec73518e23c48083108fbb ]
Commit 42bbabed09ce6208 ("perf tools: Add hw_idx in struct branch_stack") changed the format of branch stacks in perf samples. When samples use this new format, a flag must be set in the corresponding event.
Synthesized branch stacks generated from CoreSight ETM trace were using the new format, but not setting the event attribute, leading to consumers seeing corrupt data. This patch fixes the issue by setting the event attribute to indicate use of the new format.
Fixes: 42bbabed09ce6208 ("perf tools: Add hw_idx in struct branch_stack") Signed-off-by: Al Grant al.grant@arm.com Reviewed-by: Andrea Brunato andrea.brunato@arm.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Kan Liang kan.liang@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Suzuki Poulouse suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Leo Yan leo.yan@linaro.org Link: http://lore.kernel.org/lkml/20200819084751.17686-1-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/cs-etm.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index c283223fb31f2..a2a369e2fbb67 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1344,8 +1344,15 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm, attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR; }
- if (etm->synth_opts.last_branch) + if (etm->synth_opts.last_branch) { attr.sample_type |= PERF_SAMPLE_BRANCH_STACK; + /* + * We don't use the hardware index, but the sample generation + * code uses the new format branch_stack with this field, + * so the event attributes must indicate that it's present. + */ + attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX; + }
if (etm->synth_opts.instructions) { attr.config = PERF_COUNT_HW_INSTRUCTIONS;