Bug 1977162 - [XDP] test program warning: libbpf: elf: skipping unrecognized data section(16) .eh_frame
Summary: [XDP] test program warning: libbpf: elf: skipping unrecognized data section(1...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: kernel
Version: 8.5
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: beta
: ---
Assignee: Yauheni Kaliuta
QA Contact: Zhiqian Guan
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2021-06-29 06:02 UTC by Zhiqian Guan
Modified: 2021-11-10 05:56 UTC (History)
8 users (show)

Fixed In Version: kernel-4.18.0-331.el8
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2021-11-09 19:22:59 UTC
Type: Bug
Target Upstream Version:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Gitlab redhat/rhel/src/kernel rhel-8 merge_requests 1084 0 None None None 2021-08-06 05:14:34 UTC
Red Hat Product Errata RHSA-2021:4356 0 None None None 2021-11-09 19:23:28 UTC

Description Zhiqian Guan 2021-06-29 06:02:55 UTC
Description of problem:
When use the test programs under ksamples/bpf, there's a warning, but seems no impact to the function.


libbpf: elf: skipping unrecognized data section(16) .eh_frame
libbpf: elf: skipping relo section(17) .rel.eh_frame for section(16) .eh_frame

Version-Release number of selected component (if applicable):
[root@netqe2 bpf]# uname -r
4.18.0-315.el8.x86_64

How reproducible:
100%

Steps to Reproduce:
1. try any of the test xdp program like  "./xdp_rxq_info --dev ens5f0 --action XDP_DROP"

Actual results:
a warning poped up

Expected results:
no warning

Additional info:

Comment 1 Toke Høiland-Jørgensen 2021-06-29 11:11:23 UTC
This is a known issue upstream because of the way the samples are compiled. The error itself is completely harmless, but I agree it's confusing. To fix this, either the samples Makefile needs to be changed, or libbpf needs to be taught to ignore those sections.

I sent a patch with the latter change, lets see what upstream thinks:
https://lore.kernel.org/bpf/20210629110923.580029-1-toke@redhat.com/T/

Comment 2 Zhiqian Guan 2021-06-30 11:01:55 UTC
(In reply to Toke Høiland-Jørgensen from comment #1)
> This is a known issue upstream because of the way the samples are compiled.
> The error itself is completely harmless, but I agree it's confusing. To fix
> this, either the samples Makefile needs to be changed, or libbpf needs to be
> taught to ignore those sections.
> 
> I sent a patch with the latter change, lets see what upstream thinks:
> https://lore.kernel.org/bpf/20210629110923.580029-1-toke@redhat.com/T/

Thanks, Toke! Glad to know we've already have a patch for this:)

Comment 3 Toke Høiland-Jørgensen 2021-07-05 21:04:22 UTC
Samples are now fixed upstream by this commit: https://git.kernel.org/bpf/bpf/c/5a0ae9872d5c

Jiri, do you think you could pull this out-of-order into one of the BPF backports? It's a pretty trivial fix, so would be good to not have to wait for the 5.14 backports to get it fixed up in RHEL...

Comment 4 Jiri Olsa 2021-07-07 12:36:13 UTC
as discussed on the mtg, let's ask jbenc in MR

Comment 5 Jiri Benc 2021-07-12 08:51:01 UTC
Please include it as a separate fix. We can use this bz to submit it against.

Comment 6 Yauheni Kaliuta 2021-08-04 14:07:52 UTC
Submitting as MR https://gitlab.com/redhat/rhel/src/kernel/rhel-8/-/merge_requests/108
Zhiqian, can it have qa_ack?

Comment 7 Zhiqian Guan 2021-08-05 06:10:08 UTC
(In reply to Yauheni Kaliuta from comment #6)
> Submitting as MR
> https://gitlab.com/redhat/rhel/src/kernel/rhel-8/-/merge_requests/108
> Zhiqian, can it have qa_ack?

Sure, set qa_ack

Comment 9 Zhiqian Guan 2021-08-11 11:56:02 UTC
https://beaker.engineering.redhat.com/jobs/5694267
:: [ 07:22:29 ] :: [  BEGIN   ] :: Running 'ebpf_xdp_test_XDP_DROP'
ebpf_xdp_test_XDP_DROP()...
/usr/libexec/ksamples/bpf /mnt/tests/kernel/networking/ebpf_xdp/sanity
./xdp_rxq_info --dev ens1f0 --action XDP_DROP 
root       40603   14847  0 07:22 ?        00:00:00 ./xdp_rxq_info --dev ens1f0 --action XDP_DROP
root       40605   14847  0 07:22 ?        00:00:00 grep xdp_rxq_info
/mnt/tests/kernel/networking/ebpf_xdp/sanity
3: ens1f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc mq state UP mode DEFAULT group default qlen 1000
3: ens1f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc mq state UP mode DEFAULT group default qlen 1000
wait for ens1f0 sec 0
3: ens1f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:de:ad:de:ad:01 brd ff:ff:ff:ff:ff:ff permaddr 40:a6:b7:2f:b9:20
    prog/xdp id 105 tag 943df0a1ce7ea5c2 jited 
Wait 0 secs until port becomes UP
3: ens1f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:de:ad:de:ad:01 brd ff:ff:ff:ff:ff:ff permaddr 40:a6:b7:2f:b9:20
    prog/xdp id 105 tag 943df0a1ce7ea5c2 jited 
SYNC_NC: sync_set client test_XDP_DROP
SYNC_NC: sent "test_XDP_DROP" to netqe2.knqe.lab.eng.bos.redhat.com
SYNC_NC: sync_wait client test_XDP_DROP
SYNC_NC: waiting "netqe2.knqe.lab.eng.bos.redhat.com"
SYNC_NC: got "test_XDP_DROP" from netqe2.knqe.lab.eng.bos.redhat.com


No libbpf: elf: skipping unrecognized data section(16) .eh_frame anymore, set this to verified:tested

Comment 14 Zhiqian Guan 2021-08-23 10:00:49 UTC
https://beaker.engineering.redhat.com/jobs/5729147

no more warnings, set this to VERIFIED

Comment 16 errata-xmlrpc 2021-11-09 19:22:59 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: kernel security, bug fix, and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2021:4356


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