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 /* 53 * lhs < rhs: return <0 54 * lhs == rhs: return 0 55 * lhs > rhs: return >0 56 */ 57 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs) 58 { 59 if (lhs->tv_sec < rhs->tv_sec) 60 return -1; 61 if (lhs->tv_sec > rhs->tv_sec) 62 return 1; 63 return lhs->tv_nsec - rhs->tv_nsec; 64 } 65 66 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec); 67 68 static inline struct timespec64 timespec64_add(struct timespec64 lhs, 69 struct timespec64 rhs) 70 { 71 struct timespec64 ts_delta; 72 set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec, 73 lhs.tv_nsec + rhs.tv_nsec); 74 return ts_delta; 75 } 76 77 /* 78 * sub = lhs - rhs, in normalized form 79 */ 80 static inline struct timespec64 timespec64_sub(struct timespec64 lhs, 81 struct timespec64 rhs) 82 { 83 struct timespec64 ts_delta; 84 set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec, 85 lhs.tv_nsec - rhs.tv_nsec); 86 return ts_delta; 87 } 88 89 /* 90 * Returns true if the timespec64 is norm, false if denorm: 91 */ 92 static inline bool timespec64_valid(const struct timespec64 *ts) 93 { 94 /* Dates before 1970 are bogus */ 95 if (ts->tv_sec < 0) 96 return false; 97 /* Can't have more nanoseconds then a second */ 98 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) 99 return false; 100 return true; 101 } 102 103 static inline bool timespec64_valid_strict(const struct timespec64 *ts) 104 { 105 if (!timespec64_valid(ts)) 106 return false; 107 /* Disallow values that could overflow ktime_t */ 108 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX) 109 return false; 110 return true; 111 } 112 113 static inline bool timespec64_valid_settod(const struct timespec64 *ts) 114 { 115 if (!timespec64_valid(ts)) 116 return false; 117 /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */ 118 if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX) 119 return false; 120 return true; 121 } 122 123 /** 124 * timespec64_to_ns - Convert timespec64 to nanoseconds 125 * @ts: pointer to the timespec64 variable to be converted 126 * 127 * Returns the scalar nanosecond representation of the timespec64 128 * parameter. 129 */ 130 static inline s64 timespec64_to_ns(const struct timespec64 *ts) 131 { 132 /* Prevent multiplication overflow / underflow */ 133 if (ts->tv_sec >= KTIME_SEC_MAX) 134 return KTIME_MAX; 135 136 if (ts->tv_sec <= KTIME_SEC_MIN) 137 return KTIME_MIN; 138 139 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec; 140 } 141 142 /** 143 * ns_to_timespec64 - Convert nanoseconds to timespec64 144 * @nsec: the nanoseconds value to be converted 145 * 146 * Returns the timespec64 representation of the nsec parameter. 147 */ 148 extern struct timespec64 ns_to_timespec64(s64 nsec); 149 150 /** 151 * timespec64_add_ns - Adds nanoseconds to a timespec64 152 * @a: pointer to timespec64 to be incremented 153 * @ns: unsigned nanoseconds value to be added 154 * 155 * This must always be inlined because its used from the x86-64 vdso, 156 * which cannot call other kernel functions. 157 */ 158 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns) 159 { 160 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns); 161 a->tv_nsec = ns; 162 } 163 164 /* 165 * timespec64_add_safe assumes both values are positive and checks for 166 * overflow. It will return TIME64_MAX in case of overflow. 167 */ 168 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 169 const struct timespec64 rhs); 170 171 #endif /* _LINUX_TIME64_H */ 172