linux-kernel - Re: [PATCH 4/4] modpost: do not set ->preloaded for symbols from Module.symvers

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Date:   Fri, 1 Nov 2019 10:13:10 +0900
From:   Masahiro Yamada <yamada.masahiro@...ionext.com>
To:     Jeff Moyer <jmoyer@...hat.com>
Cc:     Linux Kbuild mailing list <linux-kbuild@...r.kernel.org>,
        Sam Ravnborg <sam@...nborg.org>,
        Michal Marek <michal.lkml@...kovi.net>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        linux-nvdimm <linux-nvdimm@...ts.01.org>
Subject: Re: [PATCH 4/4] modpost: do not set ->preloaded for symbols from Module.symvers

On Fri, Nov 1, 2019 at 1:51 AM Jeff Moyer <jmoyer@...hat.com> wrote:
>
> Masahiro Yamada <yamada.masahiro@...ionext.com> writes:
>
> > Now that there is no overwrap between symbols from ELF files and
> > ones from Module.symvers.
> >
> > So, the 'exported twice' warning should be reported irrespective
> > of where the symbol in question came from. Only the exceptional case
> > is when __crc_<sym> symbol appears before __ksymtab_<sym>. This
> > typically occurs for EXPORT_SYMBOL in .S files.
>
> Hi, Masahiro,
>
> After apply this patch, I get the following modpost warnings when doing:
>
> $ make M=tools/tesing/nvdimm
> ...
>   Building modules, stage 2.
>   MODPOST 12 modules
> WARNING: tools/testing/nvdimm/libnvdimm: 'nvdimm_bus_lock' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> WARNING: tools/testing/nvdimm/libnvdimm: 'nvdimm_bus_unlock' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> WARNING: tools/testing/nvdimm/libnvdimm: 'is_nvdimm_bus_locked' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> WARNING: tools/testing/nvdimm/libnvdimm: 'devm_nvdimm_memremap' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> WARNING: tools/testing/nvdimm/libnvdimm: 'nd_fletcher64' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> WARNING: tools/testing/nvdimm/libnvdimm: 'to_nd_desc' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> WARNING: tools/testing/nvdimm/libnvdimm: 'to_nvdimm_bus_dev' exported twice. Previous export was in drivers/nvdimm/libnvdimm.ko
> ...
>
> There are a lot of these warnings.  :)

These warnings are correct since
drivers/nvdimm/Makefile and
tools/testing/nvdimm/Kbuild
compile the same files.




>  If I revert this patch, no
> complaints.
>
> Cheers,
> Jeff
>
>
> >
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@...ionext.com>
> > ---
> >
> >  scripts/mod/modpost.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> > index 5234555cf550..6ca38d10efc5 100644
> > --- a/scripts/mod/modpost.c
> > +++ b/scripts/mod/modpost.c
> > @@ -2457,7 +2457,6 @@ static void read_dump(const char *fname, unsigned int kernel)
> >               s = sym_add_exported(symname, namespace, mod,
> >                                    export_no(export));
> >               s->kernel    = kernel;
> > -             s->preloaded = 1;
> >               s->is_static = 0;
> >               sym_update_crc(symname, mod, crc, export_no(export));
> >       }
>


-- 
Best Regards
Masahiro Yamada