From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Networking <netdev@vger.kernel.org>,
Linux Next Mailing List <linux-next@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>
Subject: Re: linux-next: build failure after merge of the bpf-next tree
Date: Mon, 24 Aug 2020 20:27:28 -0700 [thread overview]
Message-ID: <CAADnVQKGf7o8gJ60m_zjh+QcmRTNH+y1ha_B2q-1ixcCSAoHaw@mail.gmail.com> (raw)
In-Reply-To: <20200825130445.655885f8@canb.auug.org.au>
On Mon, Aug 24, 2020 at 8:04 PM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi Alexei,
>
> On Mon, 24 Aug 2020 18:25:44 -0700 Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> >
> > On Mon, Aug 24, 2020 at 6:20 PM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> > >
> > > On Fri, 21 Aug 2020 11:11:11 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> > > >
> > > > After merging the bpf-next tree, today's linux-next build (x86_64
> > > > allmodconfig) failed like this:
> > > >
> > > > Auto-detecting system features:
> > > > ... libelf: [ [31mOFF [m ]
> > > > ... zlib: [ [31mOFF [m ]
> > > > ... bpf: [ [32mon [m ]
> > > >
> > > > No libelf found
> > > > make[5]: *** [Makefile:284: elfdep] Error 1
> > > >
> > > > Caused by commit
> > > >
> > > > d71fa5c9763c ("bpf: Add kernel module with user mode driver that populates bpffs.")
> > > >
> > > > [For a start, can we please *not* add this verbose feature detection
> > > > output to the nrormal build?]
> > > >
> > > > This is a PowerPC hosted cross build.
> > > >
> > > > I have marked BPF_PRELOAD as BROKEN for now.
> > >
> > > Still getting this failure ...
> >
> > I don't have powerpc with crosscompiler to x86 to reproduce.
> > What exactly the error?
>
> Just as above.
I didn't receive the first email you've replied to.
The build error is:
"
No libelf found
make[5]: *** [Makefile:284: elfdep] Error 1
"
and build process stops because libelf is not found, right?
That is expected and necessary.
bpf_preload needs libbpf that depends on libelf.
The only 'fix' is to turn off bpf_preload.
It's off by default.
allmodconfig cannot build bpf_preload umd if there is no libelf.
There is CC_CAN_LINK that does feature detection.
We can extend scripts/cc-can-link.sh or add another script that
will do CC_CAN_LINK_LIBELF, but such approach doesn't scale.
imo it's cleaner to rely on feature detection by libbpf Makefile with
an error above instead of adding such knobs to top Kconfig.
Does it make sense?
next prev parent reply other threads:[~2020-08-25 3:27 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-21 1:11 linux-next: build failure after merge of the bpf-next tree Stephen Rothwell
2020-08-25 1:20 ` Stephen Rothwell
2020-08-25 1:25 ` Alexei Starovoitov
2020-08-25 3:04 ` Stephen Rothwell
2020-08-25 3:27 ` Alexei Starovoitov [this message]
2020-08-25 6:50 ` Stephen Rothwell
2020-08-25 14:33 ` Alexei Starovoitov
2020-08-25 21:10 ` Stephen Rothwell
2020-08-25 22:34 ` Alexei Starovoitov
2020-08-25 23:09 ` Stephen Rothwell
-- strict thread matches above, loose matches on Subject: below --
2023-03-19 23:26 Stephen Rothwell
2023-03-20 12:07 ` Alexander Lobakin
2023-03-21 22:35 ` Stephen Rothwell
2022-07-20 1:59 Stephen Rothwell
2022-07-20 3:42 ` Alexei Starovoitov
2022-07-20 3:44 ` Stanislav Fomichev
2022-04-19 1:56 Stephen Rothwell
2022-04-21 0:32 ` Stephen Rothwell
2022-04-21 9:45 ` Daniel Borkmann
2022-04-21 10:40 ` Maciej Fijalkowski
2022-02-09 0:21 Stephen Rothwell
2021-12-03 0:15 Stephen Rothwell
2021-09-14 1:37 Stephen Rothwell
2021-09-14 23:25 ` Andrii Nakryiko
2021-09-14 23:38 ` Stephen Rothwell
2021-09-14 23:40 ` Andrii Nakryiko
2021-09-14 23:59 ` Stephen Rothwell
2021-09-15 1:27 ` Alexei Starovoitov
2021-08-26 1:50 Stephen Rothwell
2021-08-26 2:01 ` Daniel Xu
2021-03-11 0:47 Stephen Rothwell
2021-03-11 6:47 ` Björn Töpel
2021-03-12 1:00 ` Stephen Rothwell
2021-03-26 1:18 ` Stephen Rothwell
2020-12-01 8:07 Stephen Rothwell
2020-12-01 14:55 ` Daniel Borkmann
2020-09-08 3:08 Stephen Rothwell
2020-09-08 17:54 ` Andrii Nakryiko
2020-07-14 2:22 Stephen Rothwell
2020-07-14 6:16 ` Jiri Olsa
2020-07-14 8:31 ` Jiri Olsa
2020-07-14 9:19 ` Geert Uytterhoeven
2019-07-01 4:57 Stephen Rothwell
2019-07-01 5:01 ` Stephen Rothwell
2019-04-18 1:57 Stephen Rothwell
2019-02-28 1:31 Stephen Rothwell
2019-02-28 2:18 ` Alexei Starovoitov
2018-10-03 3:18 Stephen Rothwell
2018-10-03 5:29 ` Joe Stringer
2018-09-07 0:19 Stephen Rothwell
2018-09-07 0:22 ` Alexei Starovoitov
2018-09-07 5:21 ` Björn Töpel
2018-09-07 5:45 ` Alexei Starovoitov
2017-12-13 1:32 Stephen Rothwell
2017-12-13 1:47 ` Alexei Starovoitov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAADnVQKGf7o8gJ60m_zjh+QcmRTNH+y1ha_B2q-1ixcCSAoHaw@mail.gmail.com \
--to=alexei.starovoitov@gmail.com \
--cc=ast@kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=sfr@canb.auug.org.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).