From 380b84e168e57c54d0a9e053a5558fddc43f0c1a Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Wei=C3=9Fschuh?= Date: Tue, 1 Jul 2025 10:58:05 +0200 Subject: [PATCH] vdso/vsyscall: Update auxiliary clock data in the datapage MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Expose the auxiliary clock data so it can be read from the vDSO. Architectures not using the generic vDSO time framework, namely SPARC64, are not supported. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250701-vdso-auxclock-v1-11-df7d9f87b9b8@linutronix.de --- include/linux/timekeeper_internal.h | 6 +++++ include/vdso/datapage.h | 3 +++ kernel/time/namespace.c | 5 ++++ kernel/time/timekeeping.c | 12 +++++++++ kernel/time/vsyscall.c | 40 +++++++++++++++++++++++++++++ 5 files changed, 66 insertions(+) diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index ca79938b62f39..c27aac67cb3f1 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -190,4 +190,10 @@ static inline void update_vsyscall_tz(void) } #endif +#if defined(CONFIG_GENERIC_GETTIMEOFDAY) && defined(CONFIG_POSIX_AUX_CLOCKS) +extern void vdso_time_update_aux(struct timekeeper *tk); +#else +static inline void vdso_time_update_aux(struct timekeeper *tk) { } +#endif + #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */ diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h index 1864e76e8f691..f4c96d9ce674a 100644 --- a/include/vdso/datapage.h +++ b/include/vdso/datapage.h @@ -38,6 +38,7 @@ struct vdso_arch_data { #endif #define VDSO_BASES (CLOCK_TAI + 1) +#define VDSO_BASE_AUX 0 #define VDSO_HRES (BIT(CLOCK_REALTIME) | \ BIT(CLOCK_MONOTONIC) | \ BIT(CLOCK_BOOTTIME) | \ @@ -117,6 +118,7 @@ struct vdso_clock { * @arch_data: architecture specific data (optional, defaults * to an empty struct) * @clock_data: clocksource related data (array) + * @aux_clock_data: auxiliary clocksource related data (array) * @tz_minuteswest: minutes west of Greenwich * @tz_dsttime: type of DST correction * @hrtimer_res: hrtimer resolution @@ -133,6 +135,7 @@ struct vdso_time_data { struct arch_vdso_time_data arch_data; struct vdso_clock clock_data[CS_BASES]; + struct vdso_clock aux_clock_data[MAX_AUX_CLOCKS]; s32 tz_minuteswest; s32 tz_dsttime; diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index e3642278df433..667452768ed3b 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -242,6 +242,11 @@ static void timens_set_vvar_page(struct task_struct *task, for (i = 0; i < CS_BASES; i++) timens_setup_vdso_clock_data(&vc[i], ns); + if (IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS)) { + for (i = 0; i < ARRAY_SIZE(vdata->aux_clock_data); i++) + timens_setup_vdso_clock_data(&vdata->aux_clock_data[i], ns); + } + out: mutex_unlock(&offset_lock); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index cbcf090bb4bed..243fe25e680a4 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -66,11 +66,21 @@ static inline bool tk_get_aux_ts64(unsigned int tkid, struct timespec64 *ts) { return ktime_get_aux_ts64(CLOCK_AUX + tkid - TIMEKEEPER_AUX_FIRST, ts); } + +static inline bool tk_is_aux(const struct timekeeper *tk) +{ + return tk->id >= TIMEKEEPER_AUX_FIRST && tk->id <= TIMEKEEPER_AUX_LAST; +} #else static inline bool tk_get_aux_ts64(unsigned int tkid, struct timespec64 *ts) { return false; } + +static inline bool tk_is_aux(const struct timekeeper *tk) +{ + return false; +} #endif /* flag for if timekeeping is suspended */ @@ -719,6 +729,8 @@ static void timekeeping_update_from_shadow(struct tk_data *tkd, unsigned int act update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); + } else if (tk_is_aux(tk)) { + vdso_time_update_aux(tk); } if (action & TK_CLOCK_WAS_SET) diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c index df6bada2d58ed..8ba8b0d8a3873 100644 --- a/kernel/time/vsyscall.c +++ b/kernel/time/vsyscall.c @@ -136,6 +136,46 @@ void update_vsyscall_tz(void) __arch_sync_vdso_time_data(vdata); } +#ifdef CONFIG_POSIX_AUX_CLOCKS +void vdso_time_update_aux(struct timekeeper *tk) +{ + struct vdso_time_data *vdata = vdso_k_time_data; + struct vdso_timestamp *vdso_ts; + struct vdso_clock *vc; + s32 clock_mode; + u64 nsec; + + vc = &vdata->aux_clock_data[tk->id - TIMEKEEPER_AUX_FIRST]; + vdso_ts = &vc->basetime[VDSO_BASE_AUX]; + clock_mode = tk->tkr_mono.clock->vdso_clock_mode; + if (!tk->clock_valid) + clock_mode = VDSO_CLOCKMODE_NONE; + + /* copy vsyscall data */ + vdso_write_begin_clock(vc); + + vc->clock_mode = clock_mode; + + if (clock_mode != VDSO_CLOCKMODE_NONE) { + fill_clock_configuration(vc, &tk->tkr_mono); + + vdso_ts->sec = tk->xtime_sec; + + nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; + nsec += tk->offs_aux; + vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); + nsec = nsec << tk->tkr_mono.shift; + vdso_ts->nsec = nsec; + } + + __arch_update_vdso_clock(vc); + + vdso_write_end_clock(vc); + + __arch_sync_vdso_time_data(vdata); +} +#endif + /** * vdso_update_begin - Start of a VDSO update section * -- 2.47.2