perf test: Update sample filtering test

Now it can run the BPF filtering test with normal user if the BPF
objects are pinned by 'sudo perf record --setup-filter pin'.  Let's
update the test case to verify the behavior.  It'll skip the test if the
filter check is failed from a normal user, but it shows a message how to
set up the filters.

First, run the test as a normal user and it fails.

  $ perf test -vv filtering
   95: perf record sample filtering (by BPF) tests:
  --- start ---
  test child forked, pid 425677
  Checking BPF-filter privilege
  try 'sudo perf record --setup-filter pin' first.       <<<--- here
  bpf-filter test [Skipped permission]
  ---- end(-2) ----
   95: perf record sample filtering (by BPF) tests                     : Skip

According to the message, run the perf record command to pin the BPF
objects.

  $ sudo perf record --setup-filter pin

And re-run the test as a normal user.

  $ perf test -vv filtering
   95: perf record sample filtering (by BPF) tests:
  --- start ---
  test child forked, pid 424486
  Checking BPF-filter privilege
  Basic bpf-filter test
  Basic bpf-filter test [Success]
  Failing bpf-filter test
  Error: task-clock event does not have PERF_SAMPLE_CPU
  Failing bpf-filter test [Success]
  Group bpf-filter test
  Error: task-clock event does not have PERF_SAMPLE_CPU
  Error: task-clock event does not have PERF_SAMPLE_CODE_PAGE_SIZE
  Group bpf-filter test [Success]
  ---- end(0) ----
   95: perf record sample filtering (by BPF) tests                     : Ok
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20240703223035.2024586-9-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/record_bpf_filter.sh

@@ -22,15 +22,16 @@ trap trap_cleanup EXIT TERM INT
 test_bpf_filter_priv() {
   echo "Checking BPF-filter privilege"
 
-  if [ "$(id -u)" != 0 ]
-  then
-    echo "bpf-filter test [Skipped permission]"
-    err=2
-    return
-  fi
   if ! perf record -e task-clock --filter 'period > 1' \
 	  -o /dev/null --quiet true 2>&1
   then
+    if [ "$(id -u)" != 0 ]
+    then
+      echo "try 'sudo perf record --setup-filter pin' first."
+      echo "bpf-filter test [Skipped permission]"
+      err=2
+      return
+    fi
     echo "bpf-filter test [Skipped missing BPF support]"
     err=2
     return