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

[Athira Rajeev]

> 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
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