Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Message-ID: <fdcb510863c801f1f64448e558ee0f8ed20db418.camel@codethink.co.uk>
Subject: Re: [Y2038] [PATCH 3/8] powerpc: fix vdso32 for ppc64le
From:   Ben Hutchings <ben.hutchings@codethink.co.uk>
To:     Arnd Bergmann <arnd@arndb.de>, y2038@lists.linaro.org,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Date:   Wed, 20 Nov 2019 19:13:12 +0000
In-Reply-To: <20191108203435.112759-4-arnd@arndb.de>
References: <20191108203435.112759-1-arnd@arndb.de>
         <20191108203435.112759-4-arnd@arndb.de>
Organization: Codethink Ltd.
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.30.5-1.1 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, 2019-11-08 at 21:34 +0100, Arnd Bergmann wrote:
> On little-endian 32-bit application running on 64-bit kernels,
> the current vdso would read the wrong half of the xtime seconds
> field. Change it to return the lower half like it does on
> big-endian.

ppc64le doesn't have 32-bit compat so this is only theoretical.

Ben.

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  arch/powerpc/kernel/vdso32/gettimeofday.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
> index becd9f8767ed..4327665ad86f 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -13,7 +13,7 @@
>  #include <asm/unistd.h>
>  
>  /* Offset for the low 32-bit part of a field of long type */
> -#ifdef CONFIG_PPC64
> +#if defined(CONFIG_PPC64) && defined(CONFIG_CPU_BIG_ENDIAN)
>  #define LOPART	4
>  #define TSPEC_TV_SEC	TSPC64_TV_SEC+LOPART
>  #else
-- 
Ben Hutchings, Software Developer                         Codethink Ltd
https://www.codethink.co.uk/                 Dale House, 35 Dale Street
                                     Manchester, M1 2HF, United Kingdom