From a347306fbec5dcaf7c276777b11d530eab6a4526 Mon Sep 17 00:00:00 2001 From: Al Grant Date: Wed, 19 Aug 2020 16:47:51 +0800 Subject: perf intel-pt: Fix corrupt data after perf inject from 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 Intel PT 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 Acked-by: Adrian Hunter Reviewed-by: Mathieu Poirier Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: linux-arm-kernel@lists.infradead.org Link: http://lore.kernel.org/lkml/20200819084751.17686-2-leo.yan@linaro.org Signed-off-by: Leo Yan Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/intel-pt.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index 2a8d245351e7..0af4e81c46e2 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -3017,8 +3017,15 @@ static int intel_pt_synth_events(struct intel_pt *pt, if (pt->synth_opts.callchain) attr.sample_type |= PERF_SAMPLE_CALLCHAIN; - if (pt->synth_opts.last_branch) + if (pt->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 (pt->synth_opts.instructions) { attr.config = PERF_COUNT_HW_INSTRUCTIONS; -- cgit v1.2.3