Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timekeeping fix from Thomas Gleixner:
 "A single fix for a regression caused by the generic VDSO
  implementation where a math overflow causes CLOCK_BOOTTIME to become a
  random number generator"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping/vsyscall: Prevent math overflow in BOOTTIME update

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index 7acb953298a7..84ff2844df2a 100644
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -57,6 +57,7 @@ struct tk_read_base {
  * @cs_was_changed_seq:	The sequence number of clocksource change events
  * @next_leap_ktime:	CLOCK_MONOTONIC time value of a pending leap-second
  * @raw_sec:		CLOCK_MONOTONIC_RAW  time in seconds
+ * @monotonic_to_boot:	CLOCK_MONOTONIC to CLOCK_BOOTTIME offset
  * @cycle_interval:	Number of clock cycles in one NTP interval
  * @xtime_interval:	Number of clock shifted nano seconds in one NTP
  *			interval.
@@ -84,6 +85,9 @@ struct tk_read_base {
  *
  * wall_to_monotonic is no longer the boot time, getboottime must be
  * used instead.
+ *
+ * @monotonic_to_boottime is a timespec64 representation of @offs_boot to
+ * accelerate the VDSO update for CLOCK_BOOTTIME.
  */
 struct timekeeper {
 	struct tk_read_base	tkr_mono;
@@ -99,6 +103,7 @@ struct timekeeper {
 	u8			cs_was_changed_seq;
 	ktime_t			next_leap_ktime;
 	u64			raw_sec;
+	struct timespec64	monotonic_to_boot;
 
 	/* The following members are for timekeeping internal use */
 	u64			cycle_interval;