perf test bpf: Skip test if kernel-debuginfo is not present

Perf BPF filter test fails in environment where "kernel-debuginfo"
is not installed.

Test failure logs:

  <<>>
  42: BPF filter                            :
  42.1: Basic BPF filtering                 : Ok
  42.2: BPF pinning                         : Ok
  42.3: BPF prologue generation             : FAILED!
  <<>>

Enabling verbose option provided debug logs, which says debuginfo
needs to be installed. Snippet of verbose logs:

  <<>>
  42.3: BPF prologue generation                                       :
  --- start ---
  test child forked, pid 28218
  <<>>
  Rebuild with CONFIG_DEBUG_INFO=y, or install an appropriate debuginfo
  package.
  bpf_probe: failed to convert perf probe events
  Failed to add events selected by BPF
  test child finished with -1
  ---- end ----
  BPF filter subtest 3: FAILED!
  <<>>

Here the subtest "BPF prologue generation" failed and logs shows
debuginfo is needed. After installing kernel-debuginfo package, testcase
passes.

The "BPF prologue generation" subtest failed because, the do_test()
returns TEST_FAIL without checking the error type returned by
parse_events_load_bpf_obj().

parse_events_load_bpf_obj() can also return error of type -ENODATA
incase kernel-debuginfo package is not installed. Fix this by adding
check for -ENODATA error.

Test result after the patch changes:

Test failure logs:

  <<>>
  42: BPF filter                 :
  42.1: Basic BPF filtering      : Ok
  42.2: BPF pinning              : Ok
  42.3: BPF prologue generation  : Skip (clang/debuginfo isn't installed or environment missing BPF support)
  <<>>

Fixes: ba1fae4 ("perf test: Add 'perf test BPF'")
Signed-off-by: Athira Rajeev <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Disha Goel <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nageswara R Sastry <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Cc: [email protected]
Link: http://lore.kernel.org/linux-perf-users/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: athira-rajeev

tools/perf/tests/bpf.c

@@ -126,6 +126,10 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 
 	err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
 	parse_events_error__exit(&parse_error);
+	if (err == -ENODATA) {
+		pr_debug("Failed to add events selected by BPF, debuginfo package not installed\n");
+		return TEST_SKIP;
+	}
 	if (err || list_empty(&parse_state.list)) {
 		pr_debug("Failed to add events selected by BPF\n");
 		return TEST_FAIL;
@@ -368,7 +372,7 @@ static struct test_case bpf_tests[] = {
 			"clang isn't installed or environment missing BPF support"),
 #ifdef HAVE_BPF_PROLOGUE
 	TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test,
-			"clang isn't installed or environment missing BPF support"),
+			"clang/debuginfo isn't installed or environment missing BPF support"),
 #else
 	TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
 #endif