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

Christophe Leroy (CS GROUP)
2026-01-22T09:53:37Z

Hi Alexandre,

Le 22/01/2026 à 10:39, Sverdlin, Alexander a écrit :
> 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
>
> Does it ring any bells? What could I try/test?
>
> I'm using gcc-15.2.0 and binutils 2.45.1.

Can you share your defconfig ?

I don't have such a problem with mpc885_ads_defconfig using same
gcc/binutils as you.

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(+)
>>
>> diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h b/arch/powerpc/include/asm/vdso/gettimeofday.h
>> index ab3df12c8d94..8ea397e26ad0 100644
>> --- a/arch/powerpc/include/asm/vdso/gettimeofday.h
>> +++ b/arch/powerpc/include/asm/vdso/gettimeofday.h
>> @@ -135,6 +135,8 @@ int __c_kernel_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts,
>> const struct vdso_time_data *vd);
>> int __c_kernel_clock_getres(clockid_t clock_id, struct old_timespec32 *res,
>> const struct vdso_time_data *vd);
>> +int __c_kernel_clock_getres_time64(clockid_t clock_id, struct __kernel_timespec *res,
>> + const struct vdso_time_data *vd);
>> #endif
>> int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
>> const struct vdso_time_data *vd);
>> diff --git a/arch/powerpc/kernel/vdso/gettimeofday.S b/arch/powerpc/kernel/vdso/gettimeofday.S
>> index 79c967212444..1c8e51691bf8 100644
>> --- a/arch/powerpc/kernel/vdso/gettimeofday.S
>> +++ b/arch/powerpc/kernel/vdso/gettimeofday.S
>> @@ -103,6 +103,18 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>> cvdso_call __c_kernel_clock_getres
>> V_FUNCTION_END(__kernel_clock_getres)
>>
>> +/*
>> + * Exact prototype of clock_getres_time64()
>> + *
>> + * int __kernel_clock_getres(clockid_t clock_id, struct __timespec64 *res);
>> + *
>> + */
>> +#ifndef __powerpc64__
>> +V_FUNCTION_BEGIN(__kernel_clock_getres_time64)
>> + cvdso_call __c_kernel_clock_getres_time64
>> +V_FUNCTION_END(__kernel_clock_getres_time64)
>> +#endif
>> +
>>
>> /*
>> * Exact prototype of time()
>> diff --git a/arch/powerpc/kernel/vdso/vdso32.lds.S b/arch/powerpc/kernel/vdso/vdso32.lds.S
>> index 72a1012b8a20..3f384a2526ae 100644
>> --- a/arch/powerpc/kernel/vdso/vdso32.lds.S
>> +++ b/arch/powerpc/kernel/vdso/vdso32.lds.S
>> @@ -124,6 +124,7 @@ VERSION
>> __kernel_clock_gettime;
>> __kernel_clock_gettime64;
>> __kernel_clock_getres;
>> + __kernel_clock_getres_time64;
>> __kernel_time;
>> __kernel_get_tbfreq;
>> __kernel_sync_dicache;
>> diff --git a/arch/powerpc/kernel/vdso/vgettimeofday.c b/arch/powerpc/kernel/vdso/vgettimeofday.c
>> index 6f5167d81af5..3c194e1ab562 100644
>> --- a/arch/powerpc/kernel/vdso/vgettimeofday.c
>> +++ b/arch/powerpc/kernel/vdso/vgettimeofday.c
>> @@ -35,6 +35,12 @@ int __c_kernel_clock_getres(clockid_t clock_id, struct old_timespec32 *res,
>> {
>> return __cvdso_clock_getres_time32_data(vd, clock_id, res);
>> }
>> +
>> +int __c_kernel_clock_getres_time64(clockid_t clock_id, struct __kernel_timespec *res,
>> + const struct vdso_time_data *vd)
>> +{
>> + return __cvdso_clock_getres_data(vd, clock_id, res);
>> +}
>> #endif
>>
>> int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
>>
>> ---
>> base-commit: 0e55e7636697077abceb2301d7d2718d75c34389
>> change-id: 20260113-vdso-powerpc-align-e8e93664da2b
>>
>> Best regards,
>