[PATCH 2/2] perf test bpf: Skip test if kernel-debuginfo is not present

[Arnaldo Carvalho de Melo]

Em Mon, Feb 06, 2023 at 07:28:49PM +0530, Athira Rajeev escreveu:
> 
> 
> > On 05-Jan-2023, at 6:24 PM, Arnaldo Carvalho de Melo <acme at kernel.org> wrote:
> > 
> > Em Thu, Jan 05, 2023 at 05:47:42PM +0530, Athira Rajeev escreveu:
> >> Perf BPF filter test fails in environment where "kernel-debuginfo"
> >> is not installed.
> > 
> > I'll apply this to perf/core, for the next merge window, as its more an
> > improvement than a fix, i.e. we know why it fails, we're just improving
> > the user reporting to make that clear at first sight.
> > 
> > - Arnaldo
> > 
> 
> Hi Arnaldo,
> 
> Just wanted to check when we can have these two patches in perf/core.
> I didn't find these in https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/?h=tmp.perf/core
> Not sure if I missed.

Thanks for the reminder, applied those now.

- Arnaldo
 
> Thanks
> Athira
> 
> >> 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 subtest, "BPF prologue generation" failed and
> >> logs shows debuginfo is needed. After installing
> >> kernel-debuginfo package, testcase passes.
> >> 
> >> Subtest "BPF prologue generation" failed because, the "do_test"
> >> function returns "TEST_FAIL" without checking the error type
> >> returned by "parse_events_load_bpf_obj" function.
> >> Function 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: ba1fae431e74 ("perf test: Add 'perf test BPF'")
> >> Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
> >> ---
> >> Note: This is dependent on patch 1:
> >> tools/perf: Update the exit error codes in function
> >> try_to_find_probe_trace_event
> >> 
> >> tools/perf/tests/bpf.c | 6 +++++-
> >> 1 file changed, 5 insertions(+), 1 deletion(-)
> >> 
> >> diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
> >> index 17c023823713..6a4235a9cf57 100644
> >> --- a/tools/perf/tests/bpf.c
> >> +++ b/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
> >> -- 
> >> 2.31.1
> > 
> > -- 
> > 
> > - Arnaldo
> 

-- 

- Arnaldo