perf test: AMD IBS swfilt skip kernel tests if paranoia is >1

If not root and the perf_event_paranoid is set >1 swfilt will fail to
open the event failing the test. Add check to skip the test in that
case.

Fixes: 0e71bcdcf1f0b10b ("perf test: Add AMD IBS sw filter test")
Reviewed-by: Namhyung Kim <[e-mail]>
Signed-off-by: Ian Rogers <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Collin Funk <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/shell/amd-ibs-swfilt.sh

···
 #!/bin/bash
 # AMD IBS software filtering
 
+ParanoidAndNotRoot() {
+  [ "$(id -u)" != 0 ] && [ "$(cat /proc/sys/kernel/perf_event_paranoid)" -gt $1 ]
+}
+
 echo "check availability of IBS swfilt"
 
 # check if IBS PMU is available
···
 fi
 
 echo "run perf record with modifier and swfilt"
+err=0
 
 # setting any modifiers should fail
 perf record -B -e ibs_op//u -o /dev/null true 2> /dev/null
···
     exit 1
 fi
 
-# setting it with swfilt=1 should be fine
-perf record -B -e ibs_op/swfilt=1/k -o /dev/null true
-if [ $? -ne 0 ]; then
-    echo "[FAIL] IBS op PMU cannot handle swfilt for exclude_user"
-    exit 1
+if ! ParanoidAndNotRoot 1
+then
+    # setting it with swfilt=1 should be fine
+    perf record -B -e ibs_op/swfilt=1/k -o /dev/null true
+    if [ $? -ne 0 ]; then
+        echo "[FAIL] IBS op PMU cannot handle swfilt for exclude_user"
+        exit 1
+    fi
+else
+    echo "[SKIP] not root and perf_event_paranoid too high for exclude_user"
+    err=2
 fi
 
 # check ibs_fetch PMU as well
···
 fi
 
 # check system wide recording
-perf record -aB --synth=no -e ibs_op/swfilt/k -o /dev/null true
-if [ $? -ne 0 ]; then
-    echo "[FAIL] IBS op PMU cannot handle swfilt in system-wide mode"
-    exit 1
+if ! ParanoidAndNotRoot 0
+then
+    perf record -aB --synth=no -e ibs_op/swfilt/k -o /dev/null true
+    if [ $? -ne 0 ]; then
+        echo "[FAIL] IBS op PMU cannot handle swfilt in system-wide mode"
+        exit 1
+    fi
+else
+    echo "[SKIP] not root and perf_event_paranoid too high for system-wide/exclude_user"
+    err=2
 fi
 
 echo "check number of samples with swfilt"
···
     exit 1
 fi
 
-user_sample=$(perf record -e ibs_fetch/swfilt/k -o- true | perf script -i- -F misc | grep -c ^U)
-if [ ${user_sample} -ne 0 ]; then
-    echo "[FAIL] unexpected user samples: " ${user_sample}
-    exit 1
+if ! ParanoidAndNotRoot 1
+then
+    user_sample=$(perf record -e ibs_fetch/swfilt/k -o- true | perf script -i- -F misc | grep -c ^U)
+    if [ ${user_sample} -ne 0 ]; then
+        echo "[FAIL] unexpected user samples: " ${user_sample}
+        exit 1
+    fi
+else
+    echo "[SKIP] not root and perf_event_paranoid too high for exclude_user"
+    err=2
 fi
+
+exit $err