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 /* Parameters used to convert the timespec values: */ 24 #define PSEC_PER_NSEC 1000L 25 26 /* Located here for timespec[64]_valid_strict */ 27 #define TIME64_MAX ((s64)~((u64)1 << 63)) 28 #define TIME64_MIN (-TIME64_MAX - 1) 29 30 #define KTIME_MAX ((s64)~((u64)1 << 63)) 31 #define KTIME_MIN (-KTIME_MAX - 1) 32 #define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC) 33 #define KTIME_SEC_MIN (KTIME_MIN / NSEC_PER_SEC) 34 35 /* 36 * Limits for settimeofday(): 37 * 38 * To prevent setting the time close to the wraparound point time setting 39 * is limited so a reasonable uptime can be accomodated. Uptime of 30 years 40 * should be really sufficient, which means the cutoff is 2232. At that 41 * point the cutoff is just a small part of the larger problem. 42 */ 43 #define TIME_UPTIME_SEC_MAX (30LL * 365 * 24 *3600) 44 #define TIME_SETTOD_SEC_MAX (KTIME_SEC_MAX - TIME_UPTIME_SEC_MAX) 45 46 static inline int timespec64_equal(const struct timespec64 *a, 47 const struct timespec64 *b) 48 { 49 return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec); 50 } 51 52 static inline bool timespec64_is_epoch(const struct timespec64 *ts) 53 { 54 return ts->tv_sec == 0 && ts->tv_nsec == 0; 55 } 56 57 /* 58 * lhs < rhs: return <0 59 * lhs == rhs: return 0 60 * lhs > rhs: return >0 61 */ 62 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs) 63 { 64 if (lhs->tv_sec < rhs->tv_sec) 65 return -1; 66 if (lhs->tv_sec > rhs->tv_sec) 67 return 1; 68 return lhs->tv_nsec - rhs->tv_nsec; 69 } 70 71 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec); 72 73 static inline struct timespec64 timespec64_add(struct timespec64 lhs, 74 struct timespec64 rhs) 75 { 76 struct timespec64 ts_delta; 77 set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec, 78 lhs.tv_nsec + rhs.tv_nsec); 79 return ts_delta; 80 } 81 82 /* 83 * sub = lhs - rhs, in normalized form 84 */ 85 static inline struct timespec64 timespec64_sub(struct timespec64 lhs, 86 struct timespec64 rhs) 87 { 88 struct timespec64 ts_delta; 89 set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec, 90 lhs.tv_nsec - rhs.tv_nsec); 91 return ts_delta; 92 } 93 94 /* 95 * Returns true if the timespec64 is norm, false if denorm: 96 */ 97 static inline bool timespec64_valid(const struct timespec64 *ts) 98 { 99 /* Dates before 1970 are bogus */ 100 if (ts->tv_sec < 0) 101 return false; 102 /* Can't have more nanoseconds then a second */ 103 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) 104 return false; 105 return true; 106 } 107 108 static inline bool timespec64_valid_strict(const struct timespec64 *ts) 109 { 110 if (!timespec64_valid(ts)) 111 return false; 112 /* Disallow values that could overflow ktime_t */ 113 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX) 114 return false; 115 return true; 116 } 117 118 static inline bool timespec64_valid_settod(const struct timespec64 *ts) 119 { 120 if (!timespec64_valid(ts)) 121 return false; 122 /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */ 123 if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX) 124 return false; 125 return true; 126 } 127 128 /** 129 * timespec64_to_ns - Convert timespec64 to nanoseconds 130 * @ts: pointer to the timespec64 variable to be converted 131 * 132 * Returns the scalar nanosecond representation of the timespec64 133 * parameter. 134 */ 135 static inline s64 timespec64_to_ns(const struct timespec64 *ts) 136 { 137 /* Prevent multiplication overflow / underflow */ 138 if (ts->tv_sec >= KTIME_SEC_MAX) 139 return KTIME_MAX; 140 141 if (ts->tv_sec <= KTIME_SEC_MIN) 142 return KTIME_MIN; 143 144 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec; 145 } 146 147 /** 148 * ns_to_timespec64 - Convert nanoseconds to timespec64 149 * @nsec: the nanoseconds value to be converted 150 * 151 * Returns the timespec64 representation of the nsec parameter. 152 */ 153 extern struct timespec64 ns_to_timespec64(s64 nsec); 154 155 /** 156 * timespec64_add_ns - Adds nanoseconds to a timespec64 157 * @a: pointer to timespec64 to be incremented 158 * @ns: unsigned nanoseconds value to be added 159 * 160 * This must always be inlined because its used from the x86-64 vdso, 161 * which cannot call other kernel functions. 162 */ 163 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns) 164 { 165 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns); 166 a->tv_nsec = ns; 167 } 168 169 /* 170 * timespec64_add_safe assumes both values are positive and checks for 171 * overflow. It will return TIME64_MAX in case of overflow. 172 */ 173 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 174 const struct timespec64 rhs); 175 176 #endif /* _LINUX_TIME64_H */ 177