[PATCH 4.14 17/49] perf intel-pt: Fix error recovery from missing TIP packet

From: Greg Kroah-Hartman
Date: Tue Apr 17 2018 - 12:06:14 EST

4.14-stable review patch. If anyone has any objections, please let me know.


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

commit 1c196a6c771c47a2faa63d38d913e03284f73a16 upstream.

When a TIP packet is expected but there is a different packet, it is an
error. However the unexpected packet might be something important like a
TSC packet, so after the error, it is necessary to continue from there,
rather than the next packet. That is achieved by setting pkt_step to

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1520431349-30689-4-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 1 +
1 file changed, 1 insertion(+)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1616,6 +1616,7 @@ static int intel_pt_walk_fup_tip(struct
intel_pt_log("ERROR: Missing TIP after FUP\n");
decoder->pkt_state = INTEL_PT_STATE_ERR3;
+ decoder->pkt_step = 0;
return -ENOENT;