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authorThomas Gleixner <tglx@linutronix.de>2017-10-31 23:17:28 +0100
committerThomas Gleixner <tglx@linutronix.de>2017-10-31 23:17:28 +0100
commitfb56d689fb1c8f13d4d7168abf3838657b042885 (patch)
treea7e75f65e440d6c078c8e8eb25a2186c3c685261 /kernel/time/timekeeping.c
parent6c1e272f962da249f289846cec944bcd1c162a49 (diff)
parent6546911ed369af8d747215ff8b6144618e91c6ab (diff)
Merge branch 'fortglx/4.15/time' of https://git.linaro.org/people/john.stultz/linux into timers/core
Pull timekeeping updates from John Stultz: - More y2038 work from Arnd Bergmann - A new mechanism to allow RTC drivers to specify the resolution of the RTC so the suspend/resume code can make informed decisions whether to inject the suspended time or not in case of fast suspend/resume cycles.
Diffstat (limited to 'kernel/time/timekeeping.c')
-rw-r--r--kernel/time/timekeeping.c121
1 files changed, 109 insertions, 12 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 8af77006e937..353f7bd1eeb0 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1306,33 +1306,31 @@ EXPORT_SYMBOL(do_settimeofday64);
*
* Adds or subtracts an offset value from the current time.
*/
-int timekeeping_inject_offset(struct timespec *ts)
+static int timekeeping_inject_offset(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned long flags;
- struct timespec64 ts64, tmp;
+ struct timespec64 tmp;
int ret = 0;
- if (!timespec_inject_offset_valid(ts))
+ if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
- ts64 = timespec_to_timespec64(*ts);
-
raw_spin_lock_irqsave(&timekeeper_lock, flags);
write_seqcount_begin(&tk_core.seq);
timekeeping_forward_now(tk);
/* Make sure the proposed value is valid */
- tmp = timespec64_add(tk_xtime(tk), ts64);
- if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 ||
+ tmp = timespec64_add(tk_xtime(tk), *ts);
+ if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 ||
!timespec64_valid_strict(&tmp)) {
ret = -EINVAL;
goto error;
}
- tk_xtime_add(tk, &ts64);
- tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64));
+ tk_xtime_add(tk, ts);
+ tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *ts));
error: /* even if we error out, we forwarded the time, so call update */
timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
@@ -1345,7 +1343,40 @@ error: /* even if we error out, we forwarded the time, so call update */
return ret;
}
-EXPORT_SYMBOL(timekeeping_inject_offset);
+
+/*
+ * Indicates if there is an offset between the system clock and the hardware
+ * clock/persistent clock/rtc.
+ */
+int persistent_clock_is_local;
+
+/*
+ * Adjust the time obtained from the CMOS to be UTC time instead of
+ * local time.
+ *
+ * This is ugly, but preferable to the alternatives. Otherwise we
+ * would either need to write a program to do it in /etc/rc (and risk
+ * confusion if the program gets run more than once; it would also be
+ * hard to make the program warp the clock precisely n hours) or
+ * compile in the timezone information into the kernel. Bad, bad....
+ *
+ * - TYT, 1992-01-01
+ *
+ * The best thing to do is to keep the CMOS clock in universal time (UTC)
+ * as real UNIX machines always do it. This avoids all headaches about
+ * daylight saving times and warping kernel clocks.
+ */
+void timekeeping_warp_clock(void)
+{
+ if (sys_tz.tz_minuteswest != 0) {
+ struct timespec64 adjust;
+
+ persistent_clock_is_local = 1;
+ adjust.tv_sec = sys_tz.tz_minuteswest * 60;
+ adjust.tv_nsec = 0;
+ timekeeping_inject_offset(&adjust);
+ }
+}
/**
* __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic
@@ -2290,6 +2321,72 @@ 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(struct timex *txc)
+{
+ if (txc->modes & ADJ_ADJTIME) {
+ /* singleshot must not be used with any other mode bits */
+ if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
+ return -EINVAL;
+ if (!(txc->modes & ADJ_OFFSET_READONLY) &&
+ !capable(CAP_SYS_TIME))
+ return -EPERM;
+ } else {
+ /* In order to modify anything, you gotta be super-user! */
+ if (txc->modes && !capable(CAP_SYS_TIME))
+ return -EPERM;
+ /*
+ * if the quartz is off by more than 10% then
+ * something is VERY wrong!
+ */
+ if (txc->modes & ADJ_TICK &&
+ (txc->tick < 900000/USER_HZ ||
+ txc->tick > 1100000/USER_HZ))
+ return -EINVAL;
+ }
+
+ if (txc->modes & ADJ_SETOFFSET) {
+ /* In order to inject time, you gotta be super-user! */
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /*
+ * Validate if a timespec/timeval used to inject a time
+ * offset is valid. Offsets can be postive or negative, so
+ * we don't check tv_sec. The value of the timeval/timespec
+ * is the sum of its fields,but *NOTE*:
+ * The field tv_usec/tv_nsec must always be non-negative and
+ * we can't have more nanoseconds/microseconds than a second.
+ */
+ if (txc->time.tv_usec < 0)
+ return -EINVAL;
+
+ if (txc->modes & ADJ_NANO) {
+ if (txc->time.tv_usec >= NSEC_PER_SEC)
+ return -EINVAL;
+ } else {
+ if (txc->time.tv_usec >= USEC_PER_SEC)
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * Check for potential multiplication overflows that can
+ * only happen on 64-bit systems:
+ */
+ if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {
+ if (LLONG_MIN / PPM_SCALE > txc->freq)
+ return -EINVAL;
+ if (LLONG_MAX / PPM_SCALE < txc->freq)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+
+/**
* do_adjtimex() - Accessor function to NTP __do_adjtimex function
*/
int do_adjtimex(struct timex *txc)
@@ -2301,12 +2398,12 @@ int do_adjtimex(struct timex *txc)
int ret;
/* Validate the data before disabling interrupts */
- ret = ntp_validate_timex(txc);
+ ret = timekeeping_validate_timex(txc);
if (ret)
return ret;
if (txc->modes & ADJ_SETOFFSET) {
- struct timespec delta;
+ struct timespec64 delta;
delta.tv_sec = txc->time.tv_sec;
delta.tv_nsec = txc->time.tv_usec;
if (!(txc->modes & ADJ_NANO))