netdev - [patch V2 25/26] timekeeping: Provide update for auxiliary timekeepers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250519083027.146958941@linutronix.de>
Date: Mon, 19 May 2025 10:33:44 +0200 (CEST)
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: netdev@...r.kernel.org,
 Richard Cochran <richardcochran@...il.com>,
 Christopher Hall <christopher.s.hall@...el.com>,
 John Stultz <jstultz@...gle.com>,
 Frederic Weisbecker <frederic@...nel.org>,
 Anna-Maria Behnsen <anna-maria@...utronix.de>,
 Miroslav Lichvar <mlichvar@...hat.com>,
 Werner Abt <werner.abt@...nberg-usa.com>,
 David Woodhouse <dwmw2@...radead.org>,
 Stephen Boyd <sboyd@...nel.org>,
 Thomas Weißschuh <thomas.weissschuh@...utronix.de>,
 Kurt Kanzenbach <kurt@...utronix.de>,
 Nam Cao <namcao@...utronix.de>,
 Antoine Tenart <atenart@...nel.org>
Subject: [patch V2 25/26] timekeeping: Provide update for auxiliary
 timekeepers

Update the auxiliary timekeepers periodically. For now this is tied to the system
timekeeper update from the tick. This might be revisited and moved out of the tick.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 kernel/time/timekeeping.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
---
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -131,9 +131,11 @@ static struct tk_fast tk_fast_raw  ____c
 #ifdef CONFIG_POSIX_AUX_CLOCKS
 static __init void tk_aux_setup(void);
 static void tk_aux_update_clocksource(void);
+static void tk_aux_advance(void);
 #else
 static inline void tk_aux_setup(void) { }
 static inline void tk_aux_update_clocksource(void) { }
+static inline void tk_aux_advance(void) { }
 #endif
 
 unsigned long timekeeper_lock_irqsave(void)
@@ -2312,11 +2314,13 @@ static bool timekeeping_advance(enum tim
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
+ * It also updates the enabled auxiliary clock timekeepers
  */
 void update_wall_time(void)
 {
 	if (timekeeping_advance(TK_ADV_TICK))
 		clock_was_set_delayed();
+	tk_aux_advance();
 }
 
 /**
@@ -2762,6 +2766,20 @@ static void tk_aux_update_clocksource(vo
 	}
 }
 
+static void tk_aux_advance(void)
+{
+	unsigned long active = READ_ONCE(aux_timekeepers);
+	unsigned int id;
+
+	for_each_set_bit(id, &active, BITS_PER_LONG) {
+		struct tk_data *tkd = &timekeeper_data[id + TIMEKEEPER_AUX];
+
+		guard(raw_spinlock)(&tkd->lock);
+		if (tkd->shadow_timekeeper.clock_valid)
+			__timekeeping_advance(tkd, TK_ADV_TICK);
+	}
+}
+
 /**
  * ktime_get_aux - Get TAI time for a AUX clock
  * @id:	ID of the clock to read (CLOCK_AUX...)