Re: linux-next: Tree for Jul 6 (arch/riscv/)

[Palmer Dabbelt]

On Thu, 06 Jul 2023 16:40:27 PDT (-0700), rdunlap@xxxxxxxxxxxxx wrote:
> Hi Palmer,
>
> On 7/6/23 14:46, Palmer Dabbelt wrote:
> > On Thu, 06 Jul 2023 14:36:05 PDT (-0700), rdunlap@xxxxxxxxxxxxx wrote:
> > > On 7/6/23 14:32, Palmer Dabbelt wrote:
> > > > On Thu, 06 Jul 2023 14:27:53 PDT (-0700), rdunlap@xxxxxxxxxxxxx wrote:
> > > > > On 7/5/23 18:57, Stephen Rothwell wrote:
> > > > > > Hi all,
> > > > > >
> > > > > > Please do *not* add any v6.6 related stuff to your linux-next included
> > > > > > branches until after v6.5-rc1 has been released.
> > > > > >
> > > > > > Changes since 20230705:
> > > > >
> > > > > on riscv64:
> > > > >
> > > > > WARNING: modpost: vmlinux: section mismatch in reference: $xrv64i2p1_m2p0_a2p1_zicsr2p0_zifencei2p0_zihintpause2p0_zmmul1p0+0x14 (section: .text.unlikely.set_bit.constprop.0) -> numa_nodes_parsed (section: .init.data)
> > > > >
> > > > >
> > > > > Full randconfig file is attached.
> > > >
> > > > Thanks, I'm giving it a look.  Do you happen to also have your toolchain version easily availiable?  The mapping symbols are new and we've seen some odd stuff happen, something is likely broken somewhere...
> > >
> > > I'm using gcc-13.1.0 from  https://mirrors.edge.kernel.org/pub/tools/crosstool/
> >
> > Cool, those are pretty easy to run.  I've yet to actually reproduce the
> > failures, but I'd guess we just want to ignore the mapping symbols with
> > something like
> >
> > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> > index b29b29707f10..2f801469301d 100644
> > --- a/scripts/mod/modpost.c
> > +++ b/scripts/mod/modpost.c
> > @@ -614,6 +614,18 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
> >         /* Expoline thunks are linked on all kernel modules during final link of .ko */
> >         if (strstarts(symname, "__s390_indirect_jump_r"))
> >             return 1;
> > +
> > +    /*
> > +     * RISC-V defines various special symbols that start with "$".  The
> > +     * mapping symbols, which exist to differentiate between incompatible
> > +     * instruction encodings when disassembling, show up all over the place
> > +     * and are generally not meant to be treated like other symbols.  So
> > +     * just ignore any of the special symbols.
> > +     */
> > +    if (info->hdr->e_machine == EM_RISCV)
> > +        if (symname[0] == '$')
> > +            return 1;
> > +
> >     /* Do not ignore this symbol */
> >     return 0;
> > }
> >
> > I haven't even built that, though...
>
> That builds without any errors or warnings, but it doesn't fix the section mismatch
> warning.

Turns out there's a hook for mapping symbols, this fixes it for me:

https://lore.kernel.org/r/20230707054007.32591-1-palmer@xxxxxxxxxxxx/

> > These also trip up backtraces, so we probably need something over there as
> > well.

I think that might fix the backtraces as well.