Test that PERF_EVENT_IOC_MODIFY_ATTRIBUTES correctly modifies
perf_event_attr::sig_data as well.
Signed-off-by: NMarco Elver <elver@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/r/20220131103407.1971678-2-elver@google.com