perf session: Fail on processing event with unknown size

Currently if we cannot decide the size of the event, we guess next
event possition by:
  "... check alignment, and increment a single u64 in the hope
  to catch on again 'soon'"

This usually ends up with segfault or endless loop. It's better
to admit the failure right away, then pretend nothing happened.
It makes the life easier ;)

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120416184251.GA11503@m.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -1100,16 +1100,10 @@ more:
 	}
 
 	if ((skip = perf_session__process_event(self, &event, tool, head)) < 0) {
-		dump_printf("%#" PRIx64 " [%#x]: skipping unknown header type: %d\n",
+		pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
-			    head, event.header.size, event.header.type);
+		       head, event.header.size, event.header.type);
-		/*
+		err = -EINVAL;
-		 * assume we lost track of the stream, check alignment, and
+		goto out_err;
-		 * increment a single u64 in the hope to catch on again 'soon'.
-		 */
-		if (unlikely(head & 7))
-			head &= ~7ULL;
-
-		size = 8;
 	}
 
 	head += size;
@@ -1218,17 +1212,11 @@ more:
 
 	if (size == 0 ||
 	    perf_session__process_event(session, event, tool, file_pos) < 0) {
-		dump_printf("%#" PRIx64 " [%#x]: skipping unknown header type: %d\n",
+		pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
-			    file_offset + head, event->header.size,
+		       file_offset + head, event->header.size,
-			    event->header.type);
+		       event->header.type);
-		/*
+		err = -EINVAL;
-		 * assume we lost track of the stream, check alignment, and
+		goto out_err;
-		 * increment a single u64 in the hope to catch on again 'soon'.
-		 */
-		if (unlikely(head & 7))
-			head &= ~7ULL;
-
-		size = 8;
 	}
 
 	head += size;