Re: [Y2038] [PATCH 07/23] y2038: vdso: powerpc: avoid timespec references

From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>,
	y2038 Mailman List <y2038@lists.linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com>,
	Paul Mackerras <paulus@samba.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Allison Randal <allison@lohutok.net>
Subject: Re: [Y2038] [PATCH 07/23] y2038: vdso: powerpc: avoid timespec references
Date: Thu, 21 Nov 2019 17:25:29 +0100	[thread overview]
Message-ID: <20191121172529.Horde.0uDMS4xQ-xexjp4a2mIoXQ5@messagerie.si.c-s.fr> (raw)
In-Reply-To: <CAK8P3a1nRq98ngfKnR2Du+7_vOxSRFD9AyjHyUCsAtk_gLR_Uw@mail.gmail.com>

Arnd Bergmann <arnd@arndb.de> a écrit :

> On Wed, Nov 20, 2019 at 11:43 PM Ben Hutchings
> <ben.hutchings@codethink.co.uk> wrote:
>>
>> On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
>> [...]
>> > --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
>> > +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
>> > @@ -15,10 +15,8 @@
>> >  /* Offset for the low 32-bit part of a field of long type */
>> >  #if defined(CONFIG_PPC64) && defined(CONFIG_CPU_BIG_ENDIAN)
>> >  #define LOPART       4
>> > -#define TSPEC_TV_SEC TSPC64_TV_SEC+LOPART
>> >  #else
>> >  #define LOPART       0
>> > -#define TSPEC_TV_SEC TSPC32_TV_SEC
>> >  #endif
>> >
>> >       .text
>> > @@ -192,7 +190,7 @@ V_FUNCTION_BEGIN(__kernel_time)
>> >       bl      __get_datapage@local
>> >       mr      r9, r3                  /* datapage ptr in r9 */
>> >
>> > -     lwz     r3,STAMP_XTIME+TSPEC_TV_SEC(r9)
>> > +     lwz     r3,STAMP_XTIME_SEC+LOWPART(r9)
>>
>> "LOWPART" should be "LOPART".
>>
>
> Thanks, fixed both instances in a patch on top now. I considered folding
> it into the original patch, but as it's close to the merge window I'd
> rather not rebase it, and this way I also give you credit for  
> finding the bug.

Take care, might conflict with  
https://github.com/linuxppc/linux/commit/5e381d727fe8834ca5a126f510194a7a4ac6dd3a

Christophe

>
> I'm surprised that the 0-day bot did not report this already.
>
> Thanks fro the careful review!
>
>         Arnd
>
> commit 1c11ca7a0584ddede5b8c93057b40d31e8a96d3d (HEAD)
> Author: Arnd Bergmann <arnd@arndb.de>
> Date:   Thu Nov 21 15:19:49 2019 +0100
>
>     y2038: fix typo in powerpc vdso "LOPART"
>
>     The earlier patch introduced a typo, change LOWPART back to
>     LOPART.
>
>     Fixes: 176ed98c8a76 ("y2038: vdso: powerpc: avoid timespec references")
>     Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
>     Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S
> b/arch/powerpc/kernel/vdso32/gettimeofday.S
> index a7180b0f4aa1..c8e6902cb01b 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -190,7 +190,7 @@ V_FUNCTION_BEGIN(__kernel_time)
>         bl      __get_datapage@local
>         mr      r9, r3                  /* datapage ptr in r9 */
>
> -       lwz     r3,STAMP_XTIME_SEC+LOWPART(r9)
> +       lwz     r3,STAMP_XTIME_SEC+LOPART(r9)
>
>         cmplwi  r11,0                   /* check if t is NULL */
>         beq     2f
> @@ -266,7 +266,7 @@ __do_get_tspec:
>          * as a 32.32 fixed-point number in r3 and r4.
>          * Load & add the xtime stamp.
>          */
> -       lwz     r5,STAMP_XTIME_SEC+LOWPART(r9)
> +       lwz     r5,STAMP_XTIME_SEC+LOPART(r9)
>
>         lwz     r6,STAMP_SEC_FRAC(r9)
>         addc    r4,r4,r6
>         adde    r3,r3,r5