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: Tue, 25 Aug 2020 07:33:51 -0700 [thread overview]
Message-ID: <CAADnVQ+SZj-Q=vijGkoUkmWeA=MM2S2oaVvJ7fj6=c4S4y-LMA@mail.gmail.com> (raw)
In-Reply-To: <20200825165029.795a8428@canb.auug.org.au>
On Mon, Aug 24, 2020 at 11:50 PM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi Alexei,
>
> On Mon, 24 Aug 2020 20:27:28 -0700 Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> >
> > 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?
>
> Sorry, but if this is not necessary to build the kernel, then an
> allmodconfig build needs to succeed so you need to do the detection and
> turn it off automatically. Or you could make it so that it has to be
> manually enabled in all circumstances.
what do you suggest to use to make it 'manually enabled' ?
All I could think of is to add:
depends on !COMPILE_TEST
so that allmodconfig doesn't pick it up.
next prev parent reply other threads:[~2020-08-25 14:34 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
2020-08-25 6:50 ` Stephen Rothwell
2020-08-25 14:33 ` Alexei Starovoitov [this message]
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
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