On 6/1/20 7:42 AM, Lorenz Bauer wrote:
For some reason the initial e-mail wasn't plain text, apologies.
---------- Forwarded message ---------
From: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
Date: Mon, 1 Jun 2020 at 15:32
Subject: Trouble running bpf_iter tests
To: Yonghong Song <yhs@xxxxxx>, bpf <bpf@xxxxxxxxxxxxxxx>
Cc: kernel-team <kernel-team@xxxxxxxxxxxxxx>
Hi Yonghong,
I'm having trouble running the bpf_iter tests on bpf-next at 551f08b1d8eadbc.
On a freshly built kernel running in a VM I get the following:
root@vm:/home/lorenz/dev/bpf-next/tools/testing/selftests/bpf#
./test_progs -t bpf_iter
510 bits_offset=640
#3/1 btf_id_or_null:OK
libbpf: failed to open system Kconfig
libbpf: failed to load object 'bpf_iter_ipv6_route'
libbpf: failed to load BPF skeleton 'bpf_iter_ipv6_route': -22
test_ipv6_route:FAIL:bpf_iter_ipv6_route__open_and_load skeleton
open_and_load failed1510 bits_offset=1024
#3/2 ipv6_route:FAIL
libbpf: netlink is not found in vmlinux BTF
libbpf: failed to load object 'bpf_iter_netlink'
libbpf: failed to load BPF skeleton 'bpf_iter_netlink': -2
test_netlink:FAIL:bpf_iter_netlink__open_and_load skeleton
open_and_load failed1510 bits_offset=1408
#3/3 netlink:FAIL
libbpf: bpf_map is not found in vmlinux BTF
libbpf: failed to load object 'bpf_iter_bpf_map'
libbpf: failed to load BPF skeleton 'bpf_iter_bpf_map': -2
test_bpf_map:FAIL:bpf_iter_bpf_map__open_and_load skeleton
open_and_load failed
#3/4 bpf_map:FAIL
....
#3 bpf_iter:FAIL
Summary: 0/1 PASSED, 0 SKIPPED, 12 FAILED
If I understand correctly, this is because there is no function
information for bpf_iter_bpf_map
present in my /sys/kernel/btf/vmlinux:
# ./bpftool btf dump file /sys/kernel/btf/vmlinux format raw |
grep bpf_iter_bpf_map
#
Yes, this is the reason.
There is an entry in /proc/kallsyms however:
# grep bpf_iter_bpf_map /proc/kallsyms
ffffffff826b2f13 T bpf_iter_bpf_map
That means the kernel actually haves the right information.
And other bpf_iter related symbols are available in BTF:
# ./bpftool btf dump file /sys/kernel/btf/vmlinux format raw |
grep bpf_iter_
[12602] TYPEDEF 'bpf_iter_init_seq_priv_t' type_id=9310
[12603] TYPEDEF 'bpf_iter_fini_seq_priv_t' type_id=352
[12604] STRUCT 'bpf_iter_reg' size=56 vlen=7
[12608] STRUCT 'bpf_iter_meta' size=24 vlen=3
[12609] STRUCT 'bpf_iter_target_info' size=32 vlen=3
[12611] STRUCT 'bpf_iter_link' size=72 vlen=2
[12613] STRUCT 'bpf_iter_priv_data' size=40 vlen=6
[12617] STRUCT 'bpf_iter_seq_map_info' size=4 vlen=1
[12620] STRUCT 'bpf_iter__bpf_map' size=16 vlen=2
[12622] STRUCT 'bpf_iter_seq_task_common' size=8 vlen=1
[12623] STRUCT 'bpf_iter_seq_task_info' size=16 vlen=2
[12625] STRUCT 'bpf_iter__task' size=16 vlen=2
[12626] STRUCT 'bpf_iter_seq_task_file_info' size=32 vlen=5
[12628] STRUCT 'bpf_iter__task_file' size=32 vlen=4
[25591] STRUCT 'bpf_iter__netlink' size=16 vlen=2
[27509] STRUCT 'bpf_iter__ipv6_route' size=16 vlen=2
Can you help me make this work?
Looks like you have old pahole in your system. You need pahole 1.16 or later
to enable global functions emitted to vmlinux BTF. Could you give a try?
Thanks
Lorenz
