perf report: Add stub processing of compressed events for -D

Committer note:

Split from a larger patch, this only dumps PERF_RECORD_COMPRESSED as
unhandled, so that when we introduce the record part in the next patch,
we don't see unhandled events when using 'perf record -D'.

Changed it so that we dump the event if the handler is just a stub, i.e.
for the case where we don't have ZSTD linked but we're processing a
perf.data file generated by a tool with that linked.

Also when failing to decompress we can't just dump the uncompressed
event and return 0, we have to propagate the error.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/304b0a59-942c-3fe1-da02-aa749f87108b@linux.intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -358,6 +358,14 @@ static int process_stat_round_stub(struct perf_session *perf_session __maybe_unu
 	return 0;
 }
 
+static int perf_session__process_compressed_event_stub(struct perf_session *session __maybe_unused,
+						       union perf_event *event __maybe_unused,
+						       u64 file_offset __maybe_unused)
+{
+       dump_printf(": unhandled!\n");
+       return 0;
+}
+
 void perf_tool__fill_defaults(struct perf_tool *tool)
 {
 	if (tool->sample == NULL)
@@ -430,6 +438,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->time_conv = process_event_op2_stub;
 	if (tool->feature == NULL)
 		tool->feature = process_event_op2_stub;
+	if (tool->compressed == NULL)
+		tool->compressed = perf_session__process_compressed_event_stub;
 }
 
 static void swap_sample_id_all(union perf_event *event, void *data)
@@ -1373,7 +1383,9 @@ static s64 perf_session__process_user_event(struct perf_session *session,
 	int fd = perf_data__fd(session->data);
 	int err;
 
-	dump_event(session->evlist, event, file_offset, &sample);
+	if (event->header.type != PERF_RECORD_COMPRESSED ||
+	    tool->compressed == perf_session__process_compressed_event_stub)
+		dump_event(session->evlist, event, file_offset, &sample);
 
 	/* These events are processed right away */
 	switch (event->header.type) {
@@ -1426,6 +1438,11 @@ static s64 perf_session__process_user_event(struct perf_session *session,
 		return tool->time_conv(session, event);
 	case PERF_RECORD_HEADER_FEATURE:
 		return tool->feature(session, event);
+	case PERF_RECORD_COMPRESSED:
+		err = tool->compressed(session, event, file_offset);
+		if (err)
+			dump_event(session->evlist, event, file_offset, &sample);
+		return err;
 	default:
 		return -EINVAL;
 	}

tools/perf/util/tool.h

@@ -28,6 +28,7 @@ typedef int (*event_attr_op)(struct perf_tool *tool,
 
 typedef int (*event_op2)(struct perf_session *session, union perf_event *event);
 typedef s64 (*event_op3)(struct perf_session *session, union perf_event *event);
+typedef int (*event_op4)(struct perf_session *session, union perf_event *event, u64 data);
 
 typedef int (*event_oe)(struct perf_tool *tool, union perf_event *event,
 			struct ordered_events *oe);
@@ -72,6 +73,7 @@ struct perf_tool {
 			stat,
 			stat_round,
 			feature;
+	event_op4	compressed;
 	event_op3	auxtrace;
 	bool		ordered_events;
 	bool		ordering_requires_timestamps;