[PATCH 5.10 26/33] perf intel-pt: Fix next err value, walking trace

[Greg Kroah-Hartman]

From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

commit a32e6c5da599dbf49e60622a4dfb5b9b40ece029 upstream.

Code after label 'next:' in intel_pt_walk_trace() assumes 'err' is zero,
but it may not be, if arrived at via a 'goto'. Ensure it is zero.

Fixes: 7c1b16ba0e26e6 ("perf intel-pt: Add support for decoding FUP/TIP only")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.15+
Link: https://lore.kernel.org/r/20211210162303.2288710-6-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
[Adrian: Backport to v5.10]
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
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
@@ -2068,6 +2068,7 @@ static int intel_pt_walk_trace(struct in
 		if (err)
 			return err;
 next:
+		err = 0;
 		if (decoder->cyc_threshold) {
 			if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
 				decoder->sample_cyc = false;