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
This commit is contained in:
commit
5a13fc3d8b
|
@ -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;
|
||||
|
|
|
@ -146,6 +146,11 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
|
|||
static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
|
||||
{
|
||||
tk->offs_boot = ktime_add(tk->offs_boot, delta);
|
||||
/*
|
||||
* Timespec representation for VDSO update to avoid 64bit division
|
||||
* on every update.
|
||||
*/
|
||||
tk->monotonic_to_boot = ktime_to_timespec64(tk->offs_boot);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
|
@ -17,7 +17,7 @@ static inline void update_vdso_data(struct vdso_data *vdata,
|
|||
struct timekeeper *tk)
|
||||
{
|
||||
struct vdso_timestamp *vdso_ts;
|
||||
u64 nsec;
|
||||
u64 nsec, sec;
|
||||
|
||||
vdata[CS_HRES_COARSE].cycle_last = tk->tkr_mono.cycle_last;
|
||||
vdata[CS_HRES_COARSE].mask = tk->tkr_mono.mask;
|
||||
|
@ -45,23 +45,27 @@ static inline void update_vdso_data(struct vdso_data *vdata,
|
|||
}
|
||||
vdso_ts->nsec = nsec;
|
||||
|
||||
/* CLOCK_MONOTONIC_RAW */
|
||||
vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
|
||||
vdso_ts->sec = tk->raw_sec;
|
||||
vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
|
||||
/* Copy MONOTONIC time for BOOTTIME */
|
||||
sec = vdso_ts->sec;
|
||||
/* Add the boot offset */
|
||||
sec += tk->monotonic_to_boot.tv_sec;
|
||||
nsec += (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift;
|
||||
|
||||
/* CLOCK_BOOTTIME */
|
||||
vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
|
||||
vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
|
||||
nsec = tk->tkr_mono.xtime_nsec;
|
||||
nsec += ((u64)(tk->wall_to_monotonic.tv_nsec +
|
||||
ktime_to_ns(tk->offs_boot)) << tk->tkr_mono.shift);
|
||||
vdso_ts->sec = sec;
|
||||
|
||||
while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
|
||||
nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
|
||||
vdso_ts->sec++;
|
||||
}
|
||||
vdso_ts->nsec = nsec;
|
||||
|
||||
/* CLOCK_MONOTONIC_RAW */
|
||||
vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
|
||||
vdso_ts->sec = tk->raw_sec;
|
||||
vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
|
||||
|
||||
/* CLOCK_TAI */
|
||||
vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
|
||||
vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
|
||||
|
|
Loading…
Reference in a new issue