[PATCH 5.15 077/171] perf intel-pt: Fix sync state when a PSB (synchronization) packet is found

Greg Kroah-Hartman
2021-12-13T10:01:44Z

From: Adrian Hunter <adrian.hunter@intel.com>

commit ad106a26aef3a95ac7ca88d033b431661ba346ce upstream.

When syncing, it may be that branch packet generation is not enabled at
that point, in which case there will not immediately be a control-flow
packet, so some packets before a control flow packet turns up, get
ignored. However, the decoder is in sync as soon as a PSB is found, so
the state should be set accordingly.

Fixes: f4aa081949e7b6 ("perf tools: Add Intel PT decoder")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v5.15+
Link: https://lore.kernel.org/r/20211210162303.2288710-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -3607,7 +3607,7 @@ static int intel_pt_sync(struct intel_pt
}

decoder->have_last_ip = true;
- decoder->pkt_state = INTEL_PT_STATE_NO_IP;
+ decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;

err = intel_pt_walk_psb(decoder);
if (err)