Re: [PATCH] powerpc/vdso: Provide clock_getres_time64()

Christophe Leroy (CS GROUP)
2026-01-22T10:27:53Z

Hi Thomas,

Le 22/01/2026 à 10:50, Thomas Weißschuh a écrit :
> Hi Alexander,
>
> On Thu, Jan 22, 2026 at 09:39:09AM +0000, Sverdlin, Alexander wrote:
>> Hi Thomas, Christophe,
>>
>> On Wed, 2026-01-14 at 08:26 +0100, Thomas Weißschuh wrote:
>>> For consistency with __vdso_clock_gettime64() there should also be a
>>> 64-bit variant of clock_getres(). This will allow the extension of
>>> CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
>>> time types from the kernel and UAPI.
>>>
>>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>>
>> I've bisected this patch to cause the following build failure on my side:
>>
>> LDS arch/powerpc/kernel/vdso/vdso32.lds
>> VDSO32A arch/powerpc/kernel/vdso/sigtramp32-32.o
>> VDSO32A arch/powerpc/kernel/vdso/gettimeofday-32.o
>> VDSO32A arch/powerpc/kernel/vdso/datapage-32.o
>> VDSO32A arch/powerpc/kernel/vdso/cacheflush-32.o
>> VDSO32A arch/powerpc/kernel/vdso/note-32.o
>> VDSO32A arch/powerpc/kernel/vdso/getcpu-32.o
>> VDSO32A arch/powerpc/kernel/vdso/getrandom-32.o
>> VDSO32A arch/powerpc/kernel/vdso/vgetrandom-chacha-32.o
>> VDSO32C arch/powerpc/kernel/vdso/vgettimeofday-32.o
>> VDSO32C arch/powerpc/kernel/vdso/vgetrandom-32.o
>> VDSO32A arch/powerpc/kernel/vdso/crtsavres-32.o
>> VDSO32L arch/powerpc/kernel/vdso/vdso32.so.dbg
>> arch/powerpc/kernel/vdso/vdso32.so.dbg: dynamic relocations are not supported
>> make[2]: *** [arch/powerpc/kernel/vdso/Makefile:79: arch/powerpc/kernel/vdso/vdso32.so.dbg] Error 1
>> make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2
>
> Thanks for the report!
>
>> Does it ring any bells? What could I try/test?
>
> Not immediately, but I'll look into it.
>
>> I'm using gcc-15.2.0 and binutils 2.45.1.
>
> Is this a toolchain from https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcdn.kernel.org%2Fpub%2Ftools%2Fcrosstool%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C03b93d2aa659407b3e5a08de599bb85e%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639046722536758587%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=b9WoZvMR2V3RUpOwrJtm6kmXrpnLti%2BeMJ6zpyB%2Fv4k%3D&reserved=0 ?
> Could you also share your configuration?

I've just been able to reproduce it with ppc64_defconfig +
CONFIG_CC_OPTIMIZE_FOR_SIZE

VDSO32L arch/powerpc/kernel/vdso/vdso32.so.dbg
arch/powerpc/kernel/vdso/vdso32.so.dbg: dynamic relocations are not
supported
make[2]: *** [arch/powerpc/kernel/vdso/Makefile:79:
arch/powerpc/kernel/vdso/vdso32.so.dbg] Error 1
make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2
make: *** [Makefile:248: __sub-make] Error 2

I'll investigate

Christophe

>
>>> ---
>>> Based on tip/timers/vdso.
>>>
>>> This was missed in the original vdso_getres_time64() series as powerpc
>>> does not use include/vdso/gettime.h.
>>> ---
>>> arch/powerpc/include/asm/vdso/gettimeofday.h | 2 ++
>>> arch/powerpc/kernel/vdso/gettimeofday.S | 12 ++++++++++++
>>> arch/powerpc/kernel/vdso/vdso32.lds.S | 1 +
>>> arch/powerpc/kernel/vdso/vgettimeofday.c | 6 ++++++
>>> 4 files changed, 21 insertions(+)
>
> (...)