From: Thomas Gleixner Date: Wed, 9 Oct 2024 08:29:08 +0000 (+0200) Subject: timekeeping: Provide timekeeping_restore_shadow() X-Git-Tag: v6.13-rc1~171^2~75 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=97e53792538dd8993172e231f09dadee57f66d69;p=thirdparty%2Flinux.git timekeeping: Provide timekeeping_restore_shadow() Functions which operate on the real timekeeper, e.g. do_settimeofday(), have error conditions. If they are hit a full timekeeping update is still required because the already committed operations modified the timekeeper. When switching these functions to operate on the shadow timekeeper then the full update can be avoided in the error case, but the modified shadow timekeeper has to be restored. Provide a helper function for that. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Acked-by: John Stultz Link: https://lore.kernel.org/all/20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-15-554456a44a15@linutronix.de --- diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index c30b1870fc58d..ed0e328fedd02 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -774,6 +774,15 @@ static inline void tk_update_ktime_data(struct timekeeper *tk) tk->tkr_raw.base = ns_to_ktime(tk->raw_sec * NSEC_PER_SEC); } +/* + * Restore the shadow timekeeper from the real timekeeper. + */ +static void timekeeping_restore_shadow(struct tk_data *tkd) +{ + lockdep_assert_held(&tkd->lock); + memcpy(&tkd->shadow_timekeeper, &tkd->timekeeper, sizeof(tkd->timekeeper)); +} + static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsigned int action) { lockdep_assert_held(&tkd->lock); @@ -801,7 +810,7 @@ static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsig * timekeeper structure on the next update with stale data */ if (action & TK_MIRROR) - memcpy(&tkd->shadow_timekeeper, tk, sizeof(*tk)); + timekeeping_restore_shadow(tkd); } static void timekeeping_update_from_shadow(struct tk_data *tkd, unsigned int action)