Re: [PATCH RESEND v1 2/4] lib/vdso: Add vdso_data pointer as input to __arch_get_timens_vdso_data()

Vincenzo Frascino
2021-04-12T12:56:30Z

On 3/31/21 5:48 PM, Christophe Leroy wrote:
> For the same reason as commit e876f0b69dc9 ("lib/vdso: Allow
> architectures to provide the vdso data pointer"), powerpc wants to
> avoid calculation of relative position to code.
>
> As the timens_vdso_data is next page to vdso_data, provide
> vdso_data pointer to __arch_get_timens_vdso_data() in order
> to ease the calculation on powerpc in following patches.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
> arch/arm64/include/asm/vdso/compat_gettimeofday.h | 3 ++-
> arch/arm64/include/asm/vdso/gettimeofday.h | 2 +-
> arch/s390/include/asm/vdso/gettimeofday.h | 3 ++-
> arch/x86/include/asm/vdso/gettimeofday.h | 3 ++-
> lib/vdso/gettimeofday.c | 15 +++++++++------
> 5 files changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
> index 7508b0ac1d21..ecb6fd4c3c64 100644
> --- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h
> +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
> @@ -155,7 +155,8 @@ static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
> }
>
> #ifdef CONFIG_TIME_NS
> -static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
> +static __always_inline
> +const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
> {
> const struct vdso_data *ret;
>
> diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h
> index 631ab1281633..de86230a9436 100644
> --- a/arch/arm64/include/asm/vdso/gettimeofday.h
> +++ b/arch/arm64/include/asm/vdso/gettimeofday.h
> @@ -100,7 +100,7 @@ const struct vdso_data *__arch_get_vdso_data(void)
>
> #ifdef CONFIG_TIME_NS
> static __always_inline
> -const struct vdso_data *__arch_get_timens_vdso_data(void)
> +const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
> {
> return _timens_data;
> }
> diff --git a/arch/s390/include/asm/vdso/gettimeofday.h b/arch/s390/include/asm/vdso/gettimeofday.h
> index ed89ef742530..383c53c3dddd 100644
> --- a/arch/s390/include/asm/vdso/gettimeofday.h
> +++ b/arch/s390/include/asm/vdso/gettimeofday.h
> @@ -68,7 +68,8 @@ long clock_getres_fallback(clockid_t clkid, struct __kernel_timespec *ts)
> }
>
> #ifdef CONFIG_TIME_NS
> -static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
> +static __always_inline
> +const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
> {
> return _timens_data;
> }
> diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
> index df01d7349d79..1936f21ed8cd 100644
> --- a/arch/x86/include/asm/vdso/gettimeofday.h
> +++ b/arch/x86/include/asm/vdso/gettimeofday.h
> @@ -58,7 +58,8 @@ extern struct ms_hyperv_tsc_page hvclock_page
> #endif
>
> #ifdef CONFIG_TIME_NS
> -static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
> +static __always_inline
> +const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
> {
> return __timens_vdso_data;
> }
> diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
> index c6f6dee08746..ce2f69552003 100644
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -49,13 +49,15 @@ static inline bool vdso_cycles_ok(u64 cycles)
> static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
> struct __kernel_timespec *ts)
> {
> - const struct vdso_data *vd = __arch_get_timens_vdso_data();
> + const struct vdso_data *vd;
> const struct timens_offset *offs = &vdns->offset[clk];
> const struct vdso_timestamp *vdso_ts;
> u64 cycles, last, ns;
> u32 seq;
> s64 sec;
>
> + vd = vdns - (clk == CLOCK_MONOTONIC_RAW ? CS_RAW : CS_HRES_COARSE);
> + vd = __arch_get_timens_vdso_data(vd);
> if (clk != CLOCK_MONOTONIC_RAW)
> vd = &vd[CS_HRES_COARSE];
> else
> @@ -92,7 +94,8 @@ static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_
> return 0;
> }
> #else
> -static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
> +static __always_inline
> +const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
> {
> return NULL;
> }
> @@ -162,7 +165,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
> static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
> struct __kernel_timespec *ts)
> {
> - const struct vdso_data *vd = __arch_get_timens_vdso_data();
> + const struct vdso_data *vd = __arch_get_timens_vdso_data(vdns);
> const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
> const struct timens_offset *offs = &vdns->offset[clk];
> u64 nsec;
> @@ -310,7 +313,7 @@ __cvdso_gettimeofday_data(const struct vdso_data *vd,
> if (unlikely(tz != NULL)) {
> if (IS_ENABLED(CONFIG_TIME_NS) &&
> vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
> - vd = __arch_get_timens_vdso_data();
> + vd = __arch_get_timens_vdso_data(vd);
>
> tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
> tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime;
> @@ -333,7 +336,7 @@ __cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
>
> if (IS_ENABLED(CONFIG_TIME_NS) &&
> vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
> - vd = __arch_get_timens_vdso_data();
> + vd = __arch_get_timens_vdso_data(vd);
>
> t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
>
> @@ -363,7 +366,7 @@ int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
>
> if (IS_ENABLED(CONFIG_TIME_NS) &&
> vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
> - vd = __arch_get_timens_vdso_data();
> + vd = __arch_get_timens_vdso_data(vd);
>
> /*
> * Convert the clockid to a bitmask and use it to check which
>

--
Regards,
Vincenzo