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