perf session: Fail on processing event with unknown size (9389a460) · Commits · 戴 / test

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

+9 −21

Original line number	Diff line number	Diff line
		@@ -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);
		/*
		* assume we lost track of the stream, check alignment, and
		* increment a single u64 in the hope to catch on again 'soon'.
		*/
		if (unlikely(head & 7))
		head &= ~7ULL;

		size = 8;
		err = -EINVAL;
		goto out_err;
		}

		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,
		event->header.type);
		/*
		* assume we lost track of the stream, check alignment, and
		* increment a single u64 in the hope to catch on again 'soon'.
		*/
		if (unlikely(head & 7))
		head &= ~7ULL;

		size = 8;
		err = -EINVAL;
		goto out_err;
		}

		head += size;

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