bpf: test_btf run failed on debian9

[Ma Xinjian <max.xinjian@xxxxxxxxx>]

Hi Andrii.

I noticed you add tools/testing/selftests/bpf/progs/test_btf_*, so drop 
this problem to you.


I failed to run bpf: test_btf on debian9(stretch), hope you can give me 
some suggestion.



Testing env: "Debian GNU/Linux 9 (stretch)"

kernel: 5.7.0-rc2 5.6 both failed


Description: run bpf: test_btf failed with ""Arg#0 type PTR in 
test_long_fname_2() is not supported yet.""

Whole run log  and kconfig please see the attatchment.


Error info

```

 root@vm-snb-42 
/usr/src/perf_selftests-x86_64-rhel-7.6-kselftests-ae83d0b416db002fe95601e7f97f64b59514d936/tools/testing/selftests/bpf# 
./test_btf
BTF raw test[1] (struct test #1): OK
BTF raw test[2] (struct test #2): OK
BTF raw test[3] (struct test #3 Invalid member offset): OK


[snip]

BTF libbpf test[1] (test_btf_haskv.o): libbpf: load bpf program failed: 
Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
Validating test_long_fname_2() func#1...
Arg#0 type PTR in test_long_fname_2() is not supported yet.
processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 
peak_states 0 mark_read 0

libbpf: -- END LOG --
libbpf: failed to load program 'dummy_tracepoint'
libbpf: failed to load object 'test_btf_haskv.o'
do_test_file:4201:FAIL bpf_object__load: -4007
BTF libbpf test[2] (test_btf_newkv.o): libbpf: load bpf program failed: 
Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
Validating test_long_fname_2() func#1...
Arg#0 type PTR in test_long_fname_2() is not supported yet.
processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 
peak_states 0 mark_read 0

libbpf: -- END LOG --
libbpf: failed to load program 'dummy_tracepoint'
libbpf: failed to load object 'test_btf_newkv.o'
do_test_file:4201:FAIL bpf_object__load: -4007
BTF libbpf test[3] (test_btf_nokv.o): libbpf: load bpf program failed: 
Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
Validating test_long_fname_2() func#1...
Arg#0 type PTR in test_long_fname_2() is not supported yet.
processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 
peak_states 0 mark_read 0

libbpf: -- END LOG --
libbpf: failed to load program 'dummy_tracepoint'
libbpf: failed to load object 'test_btf_nokv.o'
do_test_file:4201:FAIL bpf_object__load: -4007

[snip]

```

--
Best Regards.
Ma Xinjian

Attachment: bpf_test_btf_log.gz
Description: application/gzip

Attachment: kconfig.gz
Description: application/gzip