Process of analyzing events caused by 2 functions: mmap_read() and
finished_round().
During mmap_read(), perf receives events from shared memory, queues
their pointers for further processing in finished_round() and notifies
the kernel that the events have been processed.
By the time when finished_round() is invoked, queued events can be
overwritten by the kernel, so the finished_round() occurs on potentially
corrupted memory.
Since there is no place where the event can be safely consumed,
let's copy events when queueing.
Signed-off-by: Alexander Yarygin <yary...@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Christian Borntraeger <borntrae...@de.ibm.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
---
tools/perf/builtin-kvm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index f5d3ae4..80efbfa 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1370,6 +1370,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
}
kvm->session->evlist = kvm->evlist;
perf_session__set_id_hdr_size(kvm->session);
+ ordered_events__set_copy_on_queue(&kvm->session->ordered_events, true);
machine__synthesize_threads(&kvm->session->machines.host,
&kvm->opts.target,
kvm->evlist->threads, false);
err = kvm_live_open_events(kvm);
--
1.9.1
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