Re: mmotm 2019-05-29-20-52 uploaded (mpls) +linux-next

From: Matteo Croce <mcroce@redhat.com>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	broonie@kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Linux Next Mailing List <linux-next@vger.kernel.org>,
	mhocko@suse.cz, mm-commits@vger.kernel.org,
	Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: mmotm 2019-05-29-20-52 uploaded (mpls) +linux-next
Date: Mon, 10 Jun 2019 13:21:56 +0200	[thread overview]
Message-ID: <CAGnkfhyGQXL+Bybjbe3omdXkZ8ivWgEOAB9za47yDGD_=Wu9AA@mail.gmail.com> (raw)
In-Reply-To: <CAGnkfhyO0gtg=RGUMGHYH43UhUV1htmqa-56nuK2tt_CACzOfg@mail.gmail.com>

On Fri, Jun 7, 2019 at 2:24 AM Matteo Croce <mcroce@redhat.com> wrote:
>
> On Wed, Jun 5, 2019 at 12:29 AM Randy Dunlap <rdunlap@infradead.org> wrote:
> >
> > On 5/30/19 3:28 PM, Randy Dunlap wrote:
> > > On 5/29/19 8:53 PM, akpm@linux-foundation.org wrote:
> > >> The mm-of-the-moment snapshot 2019-05-29-20-52 has been uploaded to
> > >>
> > >>    http://www.ozlabs.org/~akpm/mmotm/
> > >>
> > >> mmotm-readme.txt says
> > >>
> > >> README for mm-of-the-moment:
> > >>
> > >> http://www.ozlabs.org/~akpm/mmotm/
> > >>
> > >> This is a snapshot of my -mm patch queue.  Uploaded at random hopefully
> > >> more than once a week.
> > >>
> > >> You will need quilt to apply these patches to the latest Linus release (5.x
> > >> or 5.x-rcY).  The series file is in broken-out.tar.gz and is duplicated in
> > >> http://ozlabs.org/~akpm/mmotm/series
> > >>
> > >> The file broken-out.tar.gz contains two datestamp files: .DATE and
> > >> .DATE-yyyy-mm-dd-hh-mm-ss.  Both contain the string yyyy-mm-dd-hh-mm-ss,
> > >> followed by the base kernel version against which this patch series is to
> > >> be applied.
> > >>
> > >
> > > on i386 or x86_64:
> > >
> > > when CONFIG_PROC_SYSCTL is not set/enabled:
> > >
> > > ld: net/mpls/af_mpls.o: in function `mpls_platform_labels':
> > > af_mpls.c:(.text+0x162a): undefined reference to `sysctl_vals'
> > > ld: net/mpls/af_mpls.o:(.rodata+0x830): undefined reference to `sysctl_vals'
> > > ld: net/mpls/af_mpls.o:(.rodata+0x838): undefined reference to `sysctl_vals'
> > > ld: net/mpls/af_mpls.o:(.rodata+0x870): undefined reference to `sysctl_vals'
> > >
> >
> > Hi,
> > This now happens in linux-next 20190604.
> >
> >
> > --
> > ~Randy
>
> Hi,
> I've just sent a patch to fix it.
>
> It seems that there is a lot of sysctl related code is built
> regardless of the CONFIG_SYSCTL value, but produces a build error only
> with my patch because I add a reference to sysctl_vals which is in
> kernel/sysctl.c.
>
> And it seems also that the compiler is unable to optimize out the
> unused code, which gets somehow in the final binary:
>
> $ grep PROC_SYSCTL .config
> # CONFIG_PROC_SYSCTL is not set
> $ readelf vmlinux -x .rodata |grep -A 2 platform_lab
>   0xffffffff81b09180 2e630070 6c617466 6f726d5f 6c616265 .c.platform_labe
>   0xffffffff81b09190 6c730069 705f7474 6c5f7072 6f706167 ls.ip_ttl_propag
>   0xffffffff81b091a0 61746500 64656661 756c745f 74746c00 ate.default_ttl.
>
> If the purpose of disabling sysctl is to save space, probably this
> code and definitions should all go under an #ifdef
>
> Regards,
> --
> Matteo Croce
> per aspera ad upstream

A proper fix was just merged in davem/net.git

commit c1a9d65954c68e13a6adc0225b0d38188fff68ca
Author: Matteo Croce <mcroce@redhat.com>
Date:   Sat Jun 8 14:50:19 2019 +0200

    mpls: fix af_mpls dependencies

Regards,
-- 
Matteo Croce
per aspera ad upstream