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timekeeping: Prepare do_adtimex() for auxiliary clocks

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Exclude ADJ_TAI, leap seconds and PPS functionality as they make no sense
in the context of auxiliary clocks and provide a time stamp based on the
actual clock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250625183758.253203783@linutronix.de
This commit is contained in:
Thomas Gleixner 2025-06-25 20:38:45 +02:00
parent 775f71ebed
commit 4eca49d0b6
1 changed files with 33 additions and 3 deletions
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36
kernel/time/timekeeping.c
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@ -58,6 +58,17 @@ static struct tk_data timekeeper_data[TIMEKEEPERS_MAX];
/* The core timekeeper */
#define tk_core (timekeeper_data[TIMEKEEPER_CORE])
#ifdef CONFIG_POSIX_AUX_CLOCKS
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);
}
#else
static inline bool tk_get_aux_ts64(unsigned int tkid, struct timespec64 *ts)
{
return false;
}
#endif
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;
@ -2508,7 +2519,7 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
/*
* timekeeping_validate_timex - Ensures the timex is ok for use in do_adjtimex
*/
static int timekeeping_validate_timex(const struct __kernel_timex *txc)
static int timekeeping_validate_timex(const struct __kernel_timex *txc, bool aux_clock)
{
if (txc->modes & ADJ_ADJTIME) {
/* singleshot must not be used with any other mode bits */
@ -2567,6 +2578,20 @@ static int timekeeping_validate_timex(const struct __kernel_timex *txc)
return -EINVAL;
}
if (aux_clock) {
/* Auxiliary clocks are similar to TAI and do not have leap seconds */
if (txc->status & (STA_INS | STA_DEL))
return -EINVAL;
/* No TAI offset setting */
if (txc->modes & ADJ_TAI)
return -EINVAL;
/* No PPS support either */
if (txc->status & (STA_PPSFREQ | STA_PPSTIME))
return -EINVAL;
}
return 0;
}
@ -2595,17 +2620,22 @@ static int __do_adjtimex(struct tk_data *tkd, struct __kernel_timex *txc,
struct adjtimex_result *result)
{
struct timekeeper *tks = &tkd->shadow_timekeeper;
bool aux_clock = !timekeeper_is_core_tk(tks);
struct timespec64 ts;
s32 orig_tai, tai;
int ret;
/* Validate the data before disabling interrupts */
ret = timekeeping_validate_timex(txc);
ret = timekeeping_validate_timex(txc, aux_clock);
if (ret)
return ret;
add_device_randomness(txc, sizeof(*txc));
ktime_get_real_ts64(&ts);
if (!aux_clock)
ktime_get_real_ts64(&ts);
else
tk_get_aux_ts64(tkd->timekeeper.id, &ts);
add_device_randomness(&ts, sizeof(ts));
guard(raw_spinlock_irqsave)(&tkd->lock);