linux-kernel - Re: [PATCH v2] arch/powerpc/include/asm/barrier.h: redefine rmb and wmb to lwsync

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Y/XkjobvDPFErM7J@li-a450e7cc-27df-11b2-a85c-b5a9ac31e8ef.ibm.com>
Date:   Wed, 22 Feb 2023 15:16:54 +0530
From:   Kautuk Consul <kconsul@...ux.vnet.ibm.com>
To:     Christophe Leroy <christophe.leroy@...roup.eu>
Cc:     Michael Ellerman <mpe@...erman.id.au>,
        Nicholas Piggin <npiggin@...il.com>,
        Rohan McLure <rmclure@...ux.ibm.com>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] arch/powerpc/include/asm/barrier.h: redefine rmb and
 wmb to lwsync

> 
> Reviewed-by: Christophe Leroy <christophe.leroy@...roup.eu>
Thanks!
> 
> > ---
> >   arch/powerpc/include/asm/barrier.h | 7 +++++++
> >   1 file changed, 7 insertions(+)
> > 
> > diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
> > index b95b666f0374..e088dacc0ee8 100644
> > --- a/arch/powerpc/include/asm/barrier.h
> > +++ b/arch/powerpc/include/asm/barrier.h
> > @@ -36,8 +36,15 @@
> >    * heavy-weight sync, so smp_wmb() can be a lighter-weight eieio.
> >    */
> >   #define __mb()   __asm__ __volatile__ ("sync" : : : "memory")
> > +
> > +/* The sub-arch has lwsync. */
> > +#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_E500MC)
> > +#define __rmb() __asm__ __volatile__ ("lwsync" : : : "memory")
> > +#define __wmb() __asm__ __volatile__ ("lwsync" : : : "memory")
> 
> I'd have preferred with 'asm volatile' though.
Sorry about that! That wasn't the intent of this patch.
Probably another patch series should change this manner of #defining
assembly.