perf test trace_btf_enum: Add regression test for the BTF augmentation of enums in 'perf trace'

Trace landlock_add_rule syscall to see if the output is desirable.

Trace the non-syscall tracepoint 'timer:hrtimer_init' and
'timer:hrtimer_start', see if the 'mode' argument is augmented,
the 'mode' enum argument has the prefix of 'HRTIMER_MODE_'
in its name.

Committer testing:

  root@x1:~# perf test enum
  124: perf trace enum augmentation tests                              : Ok
  root@x1:~# perf test -v enum
  124: perf trace enum augmentation tests                              : Ok
  root@x1:~# perf trace -e landlock_add_rule perf test -v enum
       0.000 ( 0.010 ms): perf/749827 landlock_add_rule(ruleset_fd: 11, rule_type: LANDLOCK_RULE_PATH_BENEATH, rule_attr: 0x7ffd324171d4, flags: 45) = -1 EINVAL (Invalid argument)
       0.012 ( 0.002 ms): perf/749827 landlock_add_rule(ruleset_fd: 11, rule_type: LANDLOCK_RULE_NET_PORT, rule_attr: 0x7ffd324171e0, flags: 45) = -1 EINVAL (Invalid argument)
     457.821 ( 0.007 ms): perf/749830 landlock_add_rule(ruleset_fd: 11, rule_type: LANDLOCK_RULE_PATH_BENEATH, rule_attr: 0x7ffd4acd31e4, flags: 45) = -1 EINVAL (Invalid argument)
     457.832 ( 0.003 ms): perf/749830 landlock_add_rule(ruleset_fd: 11, rule_type: LANDLOCK_RULE_NET_PORT, rule_attr: 0x7ffd4acd31f0, flags: 45) = -1 EINVAL (Invalid argument)
  124: perf trace enum augmentation tests                              : Ok
  root@x1:~#
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20240619082042.4173621-6-howardchu95@gmail.com
Link: https://lore.kernel.org/r/20240624181345.124764-7-howardchu95@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/trace_btf_enum.sh

+#!/bin/sh
+# perf trace enum augmentation tests
+# SPDX-License-Identifier: GPL-2.0
+
+err=0
+set -e
+
+syscall="landlock_add_rule"
+non_syscall="timer:hrtimer_init,timer:hrtimer_start"
+
+TESTPROG="perf test -w landlock"
+
+. "$(dirname $0)"/lib/probe.sh
+skip_if_no_perf_trace || exit 2
+
+check_vmlinux() {
+  echo "Checking if vmlinux exists"
+  if ! ls /sys/kernel/btf/vmlinux 1>/dev/null 2>&1
+  then
+    echo "trace+enum test [Skipped missing vmlinux BTF support]"
+    err=2
+  fi
+}
+
+trace_landlock() {
+  echo "Tracing syscall ${syscall}"
+
+  # test flight just to see if landlock_add_rule and libbpf are available
+  $TESTPROG
+
+  if perf trace -e $syscall $TESTPROG 2>&1 | \
+     grep -q -E ".*landlock_add_rule\(ruleset_fd: 11, rule_type: (LANDLOCK_RULE_PATH_BENEATH|LANDLOCK_RULE_NET_PORT), rule_attr: 0x[a-f0-9]+, flags: 45\) = -1.*"
+  then
+    err=0
+  else
+    err=1
+  fi
+}
+
+trace_non_syscall() {
+  echo "Tracing non-syscall tracepoint ${non-syscall}"
+  if perf trace -e $non_syscall --max-events=1 2>&1 | \
+     grep -q -E '.*timer:hrtimer_.*\(.*mode: HRTIMER_MODE_.*\)$'
+  then
+    err=0
+  else
+    err=1
+  fi
+}
+
+check_vmlinux
+
+if [ $err = 0 ]; then
+  trace_landlock
+fi
+
+if [ $err = 0 ]; then
+  trace_non_syscall
+fi
+
+exit $err