perf test shell tpebs: Avoid failures with perf event paranoia

When not running as root and with higher perf event paranoia values
the perf record forked by TPEBS can fail to attach to the process. Skip
the test in these scenarios.

Signed-off-by: Ian Rogers <[email protected]>

tools/perf/tests/shell/test_stat_intel_tpebs.sh

@@ -3,7 +3,22 @@
 # SPDX-License-Identifier: GPL-2.0
 
 set -e
-grep -q GenuineIntel /proc/cpuinfo || { echo Skipping non-Intel; exit 2; }
+
+ParanoidAndNotRoot() {
+  [ "$(id -u)" != 0 ] && [ "$(cat /proc/sys/kernel/perf_event_paranoid)" -gt $1 ]
+}
+
+if ! grep -q GenuineIntel /proc/cpuinfo
+then
+  echo "Skipping non-Intel"
+  exit 2
+fi
+
+if ParanoidAndNotRoot 0
+then
+  echo "Skipping paranoid >0 and not root"
+  exit 2
+fi
 
 # Use this event for testing because it should exist in all platforms
 event=cache-misses:R
@@ -20,3 +35,4 @@ alt_name=/cache-misses/R
 echo "Testing with --record-tpebs"
 result=$(perf stat -e "$event" --record-tpebs -a sleep 0.01 2>&1)
 [[ "$result" =~ "perf record" && "$result" =~ $event || "$result" =~ $alt_name ]] || exit 1
+echo "Success!"