Some different PMU types may have the same substring. For example, on
Icelake server we have PMU types "uncore_imc" and
"uncore_imc_free_running". Both PMU types have the substring
"uncore_imc".  But the parser wrongly thinks they are the same PMU type.

We enable an imc event,
perf stat -e uncore_imc/event=0xe3/ -a -- sleep 1

Perf actually expands the event to:

  uncore_imc_0/event=0xe3/
  uncore_imc_1/event=0xe3/
  uncore_imc_2/event=0xe3/
  uncore_imc_3/event=0xe3/
  uncore_imc_4/event=0xe3/
  uncore_imc_5/event=0xe3/
  uncore_imc_6/event=0xe3/
  uncore_imc_7/event=0xe3/
  uncore_imc_free_running_0/event=0xe3/
  uncore_imc_free_running_1/event=0xe3/
  uncore_imc_free_running_3/event=0xe3/
  uncore_imc_free_running_4/event=0xe3/

That's because the "uncore_imc_free_running" matches the
pattern "uncore_imc*".

Now we check that the last characters of PMU name is '_<digit>'.

For example, for pattern "uncore_imc*", "uncore_imc_0" is parsed ok, but
"uncore_imc_free_running_0" fails.

Fixes: b2b9d3a3 ("perf pmu: Support wildcards on pmu name in dynamic pmu events")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Agustin Vega-Frias <agustinv@codeaurora.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210701064253.1175-1-yao.jin@linux.intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>