Line data    Source code

       1             : /* SPDX-License-Identifier: GPL-2.0 */
       2             : #ifndef _LINUX_TIME64_H
       3             : #define _LINUX_TIME64_H
       4             : 
       5             : #include <linux/math64.h>
       6             : #include <vdso/time64.h>
       7             : 
       8             : typedef __s64 time64_t;
       9             : typedef __u64 timeu64_t;
      10             : 
      11             : #include <uapi/linux/time.h>
      12             : 
      13             : struct timespec64 {
      14             :         time64_t        tv_sec;                 /* seconds */
      15             :         long            tv_nsec;                /* nanoseconds */
      16             : };
      17             : 
      18             : struct itimerspec64 {
      19             :         struct timespec64 it_interval;
      20             :         struct timespec64 it_value;
      21             : };
      22             : 
      23             : /* Located here for timespec[64]_valid_strict */
      24             : #define TIME64_MAX                      ((s64)~((u64)1 << 63))
      25             : #define TIME64_MIN                      (-TIME64_MAX - 1)
      26             : 
      27             : #define KTIME_MAX                       ((s64)~((u64)1 << 63))
      28             : #define KTIME_MIN                       (-KTIME_MAX - 1)
      29             : #define KTIME_SEC_MAX                   (KTIME_MAX / NSEC_PER_SEC)
      30             : #define KTIME_SEC_MIN                   (KTIME_MIN / NSEC_PER_SEC)
      31             : 
      32             : /*
      33             :  * Limits for settimeofday():
      34             :  *
      35             :  * To prevent setting the time close to the wraparound point time setting
      36             :  * is limited so a reasonable uptime can be accomodated. Uptime of 30 years
      37             :  * should be really sufficient, which means the cutoff is 2232. At that
      38             :  * point the cutoff is just a small part of the larger problem.
      39             :  */
      40             : #define TIME_UPTIME_SEC_MAX             (30LL * 365 * 24 *3600)
      41             : #define TIME_SETTOD_SEC_MAX             (KTIME_SEC_MAX - TIME_UPTIME_SEC_MAX)
      42             : 
      43             : static inline int timespec64_equal(const struct timespec64 *a,
      44             :                                    const struct timespec64 *b)
      45             : {
      46           0 :         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
      47             : }
      48             : 
      49             : /*
      50             :  * lhs < rhs:  return <0
      51             :  * lhs == rhs: return 0
      52             :  * lhs > rhs:  return >0
      53             :  */
      54             : static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
      55             : {
      56           1 :         if (lhs->tv_sec < rhs->tv_sec)
      57             :                 return -1;
      58           1 :         if (lhs->tv_sec > rhs->tv_sec)
      59             :                 return 1;
      60           0 :         return lhs->tv_nsec - rhs->tv_nsec;
      61             : }
      62             : 
      63             : extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
      64             : 
      65             : static inline struct timespec64 timespec64_add(struct timespec64 lhs,
      66             :                                                 struct timespec64 rhs)
      67             : {
      68             :         struct timespec64 ts_delta;
      69           0 :         set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
      70           0 :                                 lhs.tv_nsec + rhs.tv_nsec);
      71           0 :         return ts_delta;
      72             : }
      73             : 
      74             : /*
      75             :  * sub = lhs - rhs, in normalized form
      76             :  */
      77             : static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
      78             :                                                 struct timespec64 rhs)
      79             : {
      80             :         struct timespec64 ts_delta;
      81           1 :         set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
      82           1 :                                 lhs.tv_nsec - rhs.tv_nsec);
      83           1 :         return ts_delta;
      84             : }
      85             : 
      86             : /*
      87             :  * Returns true if the timespec64 is norm, false if denorm:
      88             :  */
      89             : static inline bool timespec64_valid(const struct timespec64 *ts)
      90             : {
      91             :         /* Dates before 1970 are bogus */
      92           1 :         if (ts->tv_sec < 0)
      93             :                 return false;
      94             :         /* Can't have more nanoseconds then a second */
      95           1 :         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
      96             :                 return false;
      97             :         return true;
      98             : }
      99             : 
     100             : static inline bool timespec64_valid_strict(const struct timespec64 *ts)
     101             : {
     102           0 :         if (!timespec64_valid(ts))
     103             :                 return false;
     104             :         /* Disallow values that could overflow ktime_t */
     105           0 :         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
     106             :                 return false;
     107             :         return true;
     108             : }
     109             : 
     110             : static inline bool timespec64_valid_settod(const struct timespec64 *ts)
     111             : {
     112           1 :         if (!timespec64_valid(ts))
     113             :                 return false;
     114             :         /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */
     115           1 :         if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX)
     116             :                 return false;
     117             :         return true;
     118             : }
     119             : 
     120             : /**
     121             :  * timespec64_to_ns - Convert timespec64 to nanoseconds
     122             :  * @ts:         pointer to the timespec64 variable to be converted
     123             :  *
     124             :  * Returns the scalar nanosecond representation of the timespec64
     125             :  * parameter.
     126             :  */
     127             : static inline s64 timespec64_to_ns(const struct timespec64 *ts)
     128             : {
     129             :         /* Prevent multiplication overflow / underflow */
     130           1 :         if (ts->tv_sec >= KTIME_SEC_MAX)
     131             :                 return KTIME_MAX;
     132             : 
     133           1 :         if (ts->tv_sec <= KTIME_SEC_MIN)
     134             :                 return KTIME_MIN;
     135             : 
     136           1 :         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
     137             : }
     138             : 
     139             : /**
     140             :  * ns_to_timespec64 - Convert nanoseconds to timespec64
     141             :  * @nsec:       the nanoseconds value to be converted
     142             :  *
     143             :  * Returns the timespec64 representation of the nsec parameter.
     144             :  */
     145             : extern struct timespec64 ns_to_timespec64(const s64 nsec);
     146             : 
     147             : /**
     148             :  * timespec64_add_ns - Adds nanoseconds to a timespec64
     149             :  * @a:          pointer to timespec64 to be incremented
     150             :  * @ns:         unsigned nanoseconds value to be added
     151             :  *
     152             :  * This must always be inlined because its used from the x86-64 vdso,
     153             :  * which cannot call other kernel functions.
     154             :  */
     155             : static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
     156             : {
     157           0 :         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
     158           0 :         a->tv_nsec = ns;
     159             : }
     160             : 
     161             : /*
     162             :  * timespec64_add_safe assumes both values are positive and checks for
     163             :  * overflow. It will return TIME64_MAX in case of overflow.
     164             :  */
     165             : extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
     166             :                                          const struct timespec64 rhs);
     167             : 
     168             : #endif /* _LINUX_TIME64_H */