From e876f0b69dc993e86ca7795e63e98385aa9a7ef3 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 7 Feb 2020 13:39:04 +0100 Subject: [PATCH] lib/vdso: Allow architectures to provide the vdso data pointer On powerpc, __arch_get_vdso_data() clobbers the link register, requiring the caller to save it. As the parent function already has to set a stack frame and saves the link register before calling the C vdso function, retrieving the vdso data pointer there is less overhead. Split out the functional code from the __cvdso.*() interfaces into new static functions which can either be called from the existing interfaces with the vdso data pointer supplied via __arch_get_vdso_data() or directly from ASM code. Signed-off-by: Christophe Leroy Signed-off-by: Thomas Gleixner Tested-by: Vincenzo Frascino Reviewed-by: Vincenzo Frascino Link: https://lore.kernel.org/r/abf97996602ef07223fec30c005df78e5ed41b2e.1580399657.git.christophe.leroy@c-s.fr Link: https://lkml.kernel.org/r/20200207124403.965789141@linutronix.de --- lib/vdso/gettimeofday.c | 74 +++++++++++++++++++++++++++++++---------- 1 file changed, 57 insertions(+), 17 deletions(-) diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index b95aef97501e..72d282ffd156 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -233,9 +233,9 @@ static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk, } static __maybe_unused int -__cvdso_clock_gettime_common(clockid_t clock, struct __kernel_timespec *ts) +__cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock, + struct __kernel_timespec *ts) { - const struct vdso_data *vd = __arch_get_vdso_data(); u32 msk; /* Check for negative values or invalid clocks */ @@ -260,23 +260,31 @@ __cvdso_clock_gettime_common(clockid_t clock, struct __kernel_timespec *ts) } static __maybe_unused int -__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +__cvdso_clock_gettime_data(const struct vdso_data *vd, clockid_t clock, + struct __kernel_timespec *ts) { - int ret = __cvdso_clock_gettime_common(clock, ts); + int ret = __cvdso_clock_gettime_common(vd, clock, ts); if (unlikely(ret)) return clock_gettime_fallback(clock, ts); return 0; } +static __maybe_unused int +__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime_data(__arch_get_vdso_data(), clock, ts); +} + #ifdef BUILD_VDSO32 static __maybe_unused int -__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res) +__cvdso_clock_gettime32_data(const struct vdso_data *vd, clockid_t clock, + struct old_timespec32 *res) { struct __kernel_timespec ts; int ret; - ret = __cvdso_clock_gettime_common(clock, &ts); + ret = __cvdso_clock_gettime_common(vd, clock, &ts); if (unlikely(ret)) return clock_gettime32_fallback(clock, res); @@ -287,12 +295,18 @@ __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res) return ret; } + +static __maybe_unused int +__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res) +{ + return __cvdso_clock_gettime32_data(__arch_get_vdso_data(), clock, res); +} #endif /* BUILD_VDSO32 */ static __maybe_unused int -__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) +__cvdso_gettimeofday_data(const struct vdso_data *vd, + struct __kernel_old_timeval *tv, struct timezone *tz) { - const struct vdso_data *vd = __arch_get_vdso_data(); if (likely(tv != NULL)) { struct __kernel_timespec ts; @@ -316,10 +330,16 @@ __cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) return 0; } -#ifdef VDSO_HAS_TIME -static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time) +static __maybe_unused int +__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) +{ + return __cvdso_gettimeofday_data(__arch_get_vdso_data(), tv, tz); +} + +#ifdef VDSO_HAS_TIME +static __maybe_unused __kernel_old_time_t +__cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time) { - const struct vdso_data *vd = __arch_get_vdso_data(); __kernel_old_time_t t; if (IS_ENABLED(CONFIG_TIME_NS) && @@ -333,13 +353,18 @@ static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time return t; } + +static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time) +{ + return __cvdso_time_data(__arch_get_vdso_data(), time); +} #endif /* VDSO_HAS_TIME */ #ifdef VDSO_HAS_CLOCK_GETRES static __maybe_unused -int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res) +int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock, + struct __kernel_timespec *res) { - const struct vdso_data *vd = __arch_get_vdso_data(); u32 msk; u64 ns; @@ -378,23 +403,31 @@ int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res) } static __maybe_unused -int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res) +int __cvdso_clock_getres_data(const struct vdso_data *vd, clockid_t clock, + struct __kernel_timespec *res) { - int ret = __cvdso_clock_getres_common(clock, res); + int ret = __cvdso_clock_getres_common(vd, clock, res); if (unlikely(ret)) return clock_getres_fallback(clock, res); return 0; } +static __maybe_unused +int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res) +{ + return __cvdso_clock_getres_data(__arch_get_vdso_data(), clock, res); +} + #ifdef BUILD_VDSO32 static __maybe_unused int -__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) +__cvdso_clock_getres_time32_data(const struct vdso_data *vd, clockid_t clock, + struct old_timespec32 *res) { struct __kernel_timespec ts; int ret; - ret = __cvdso_clock_getres_common(clock, &ts); + ret = __cvdso_clock_getres_common(vd, clock, &ts); if (unlikely(ret)) return clock_getres32_fallback(clock, res); @@ -405,5 +438,12 @@ __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) } return ret; } + +static __maybe_unused int +__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) +{ + return __cvdso_clock_getres_time32_data(__arch_get_vdso_data(), + clock, res); +} #endif /* BUILD_VDSO32 */ #endif /* VDSO_HAS_CLOCK_GETRES */