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Date:   Mon, 07 Nov 2022 22:14:16 +1000
Message-Id: <CO6202HG8VAN.1ROEE25G4KDK2@bobo>
Subject: Re: [PATCH v5 2/2] powerpc/64: Add module check for ELF ABI version
From:   "Nicholas Piggin" <npiggin@gmail.com>
To:     "Christophe Leroy" <christophe.leroy@csgroup.eu>,
        "linux-modules@vger.kernel.org" <linux-modules@vger.kernel.org>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Michael Ellerman" <mpe@ellerman.id.au>,
        "Jessica Yu" <jeyu@kernel.org>,
        "Luis Chamberlain" <mcgrof@kernel.org>
References: <20221031120733.3956781-1-npiggin@gmail.com>
 <20221031120733.3956781-3-npiggin@gmail.com>
 <513e1973-a1d4-c698-1441-9c7d0f5205ed@csgroup.eu>
In-Reply-To: <513e1973-a1d4-c698-1441-9c7d0f5205ed@csgroup.eu>
Precedence: bulk

On Thu Nov 3, 2022 at 6:35 PM AEST, Christophe Leroy wrote:
>
>
> Le 31/10/2022 =C3=A0 13:07, Nicholas Piggin a =C3=A9crit=C2=A0:
> > Override the generic module ELF check to provide a check for the ELF AB=
I
> > version. This becomes important if we allow big-endian ELF ABI V2 build=
s
> > but it doesn't hurt to check now.
> >=20
> > Cc: Jessica Yu <jeyu@kernel.org>
> > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> > [np: split patch, added changelog, adjust to Jessica's proposal]
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >   arch/powerpc/kernel/module.c | 17 +++++++++++++++++
> >   1 file changed, 17 insertions(+)
> >=20
> > diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.=
c
> > index f6d6ae0a1692..d46bf9bfda26 100644
> > --- a/arch/powerpc/kernel/module.c
> > +++ b/arch/powerpc/kernel/module.c
> > @@ -19,6 +19,23 @@
> >  =20
> >   static LIST_HEAD(module_bug_list);
> >  =20
> > +#ifdef CONFIG_PPC64
>
> Can it go in arch/powerpc/kernel/module_64.c instead ?
>
> > +bool module_elf_check_arch(Elf_Ehdr *hdr)
> > +{
> > +	unsigned long abi_level =3D hdr->e_flags & 0x3;
> > +
> > +	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) {
> > +		if (abi_level !=3D 2)
> > +			return false;
> > +	} else {
> > +		if (abi_level >=3D 2)
> > +			return false;
> > +	}
> > +
> > +	return true;
>
> Can be simpler:
>
> 	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
> 		return abi_level =3D=3D 2;
> 	else
> 		return abi_level < 2;

Yes I think both of those can be done. Good suggestions.

Thanks,
Nick