perf test: Be more tolerant of metricgroup failures

Previously "set -e" meant any non-zero exit code from perf stat would
cause a test failure. As a non-zero exit happens when there aren't
sufficient permissions, check for this case and make the exit code
2/skip for it.

Signed-off-by: Ian Rogers <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Acked-by: Veronika Molnarova <[e-mail]>
Cc: Athira Rajeev <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/tests/shell/stat_all_metricgroups.sh

···
-#!/bin/sh
+#!/bin/bash
 # perf all metricgroups test
 # SPDX-License-Identifier: GPL-2.0
-
-set -e
 
 ParanoidAndNotRoot()
 {
···
 then
   system_wide_flag=""
 fi
-
+err=0
 for m in $(perf list --raw-dump metricgroups)
 do
   echo "Testing $m"
-  perf stat -M "$m" $system_wide_flag sleep 0.01
+  result=$(perf stat -M "$m" $system_wide_flag sleep 0.01 2>&1)
+  result_err=$?
+  if [[ $result_err -gt 0 ]]
+  then
+    if [[ "$result" =~ \
+          "Access to performance monitoring and observability operations is limited" ]]
+    then
+      echo "Permission failure"
+      echo $result
+      if [[ $err -eq 0 ]]
+      then
+        err=2 # Skip
+      fi
+    elif [[ "$result" =~ "in per-thread mode, enable system wide" ]]
+    then
+      echo "Permissions - need system wide mode"
+      echo $result
+      if [[ $err -eq 0 ]]
+      then
+        err=2 # Skip
+      fi
+    else
+      echo "Metric group $m failed"
+      echo $result
+      err=1 # Fail
+    fi
+  fi
 done
 
-exit 0
+exit $err