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Date:   Mon, 27 Mar 2023 20:24:38 +1000
Message-Id: <CRH3CENOOS9G.2EZ66CM1VSMUD@bobo>
Cc:     "Michael Ellerman" <mpe@ellerman.id.au>,
        "Christophe Leroy" <christophe.leroy@csgroup.eu>,
        "Fabiano Rosas" <farosas@linux.ibm.com>,
        "Sathvika Vasireddy" <sv@linux.ibm.com>,
        "Alexey Kardashevskiy" <aik@ozlabs.ru>,
        <linuxppc-dev@lists.ozlabs.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/2] arch/powerpc/kvm: kvmppc_hv_entry: remove
 .global scope
From:   "Nicholas Piggin" <npiggin@gmail.com>
To:     "Kautuk Consul" <kconsul@linux.vnet.ibm.com>
References: <20230316051025.1424093-1-kconsul@linux.vnet.ibm.com>
 <20230316051025.1424093-2-kconsul@linux.vnet.ibm.com>
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 <ZCFhnNPrMr3D5+rZ@li-a450e7cc-27df-11b2-a85c-b5a9ac31e8ef.ibm.com>
 <ZCFjJ1sMuLMUkBWc@li-a450e7cc-27df-11b2-a85c-b5a9ac31e8ef.ibm.com>
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In-Reply-To: <ZCFoBqReJekPd7GI@li-a450e7cc-27df-11b2-a85c-b5a9ac31e8ef.ibm.com>
Precedence: bulk

On Mon Mar 27, 2023 at 7:55 PM AEST, Kautuk Consul wrote:
> On 2023-03-27 19:51:34, Nicholas Piggin wrote:
> > On Mon Mar 27, 2023 at 7:34 PM AEST, Kautuk Consul wrote:
> > > On 2023-03-27 14:58:03, Kautuk Consul wrote:
> > > > On 2023-03-27 19:19:37, Nicholas Piggin wrote:
> > > > > On Thu Mar 16, 2023 at 3:10 PM AEST, Kautuk Consul wrote:
> > > > > > kvmppc_hv_entry isn't called from anywhere other than
> > > > > > book3s_hv_rmhandlers.S itself. Removing .global scope for
> > > > > > this function and annotating it with SYM_INNER_LABEL.
> > > > > >
> > > > > > Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com>
> > > > > > ---
> > > > > >  arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +--
> > > > > >  1 file changed, 1 insertion(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/pow=
erpc/kvm/book3s_hv_rmhandlers.S
> > > > > > index acf80915f406..b81ba4ee0521 100644
> > > > > > --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> > > > > > +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> > > > > > @@ -502,8 +502,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
> > > > > >   *                                                            =
                *
> > > > > >   *************************************************************=
****************/
> > > > > > =20
> > > > > > -.global kvmppc_hv_entry
> > > > >=20
> > > > > I think this is okay.
> > > > >=20
> > > > > > -kvmppc_hv_entry:
> > > > > > +SYM_INNER_LABEL(kvmppc_hv_entry, SYM_L_LOCAL)
> > > > >=20
> > > > > The documentation for SYM_INNER_LABEL says it for labels inside a=
 SYM
> > > > > function block, is that a problem? This is a function but doesn't=
 have
> > > > > C calling convention, so asm annotation docs say that it should u=
se
> > > > > SYM_CODE_START_LOCAL?
> > > > That is correct. Will create a v4 patch for this and send it.
> > > But using SYM_CODE_START_LOCAL again causes a warning in the build
> > > (which we were trying to avoid):
> > > arch/powerpc/kvm/book3s_hv_rmhandlers.o: warning: objtool: .text+0x48=
: unannotated intra-function call
> >=20
> > Are you using SYM_FUNC_END as well? Looks like you need that to
> > annotate the type properly. It should be the same as SYM_INNER_LABEL
> > in the end AFAIKS.
>
> What about SYM_CODE_START_LOCAL and SYM_CODE_END ?
> This seems to work fine for me without any build warnings from objtool.

That's what I meant. So you were just missing SYM_CODE_END?

Thanks,
Nick