1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_TIME64_H
3 #define _LINUX_TIME64_H
4
5 #include <linux/math64.h>
6
7 typedef __s64 time64_t;
8 typedef __u64 timeu64_t;
9
10 /* CONFIG_64BIT_TIME enables new 64 bit time_t syscalls in the compat path
11 * and 32-bit emulation.
12 */
13 #ifndef CONFIG_64BIT_TIME
14 #define __kernel_timespec timespec
15 #define __kernel_itimerspec itimerspec
16 #endif
17
18 #include <uapi/linux/time.h>
19
20 struct timespec64 {
21 time64_t tv_sec; /* seconds */
22 long tv_nsec; /* nanoseconds */
23 };
24
25 struct itimerspec64 {
26 struct timespec64 it_interval;
27 struct timespec64 it_value;
28 };
29
30 /* Parameters used to convert the timespec values: */
31 #define MSEC_PER_SEC 1000L
32 #define USEC_PER_MSEC 1000L
33 #define NSEC_PER_USEC 1000L
34 #define NSEC_PER_MSEC 1000000L
35 #define USEC_PER_SEC 1000000L
36 #define NSEC_PER_SEC 1000000000L
37 #define FSEC_PER_SEC 1000000000000000LL
38
39 /* Located here for timespec[64]_valid_strict */
40 #define TIME64_MAX ((s64)~((u64)1 << 63))
41 #define KTIME_MAX ((s64)~((u64)1 << 63))
42 #define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
43
44 /*
45 * Limits for settimeofday():
46 *
47 * To prevent setting the time close to the wraparound point time setting
48 * is limited so a reasonable uptime can be accomodated. Uptime of 30 years
49 * should be really sufficient, which means the cutoff is 2232. At that
50 * point the cutoff is just a small part of the larger problem.
51 */
52 #define TIME_UPTIME_SEC_MAX (30LL * 365 * 24 *3600)
53 #define TIME_SETTOD_SEC_MAX (KTIME_SEC_MAX - TIME_UPTIME_SEC_MAX)
54
timespec64_equal(const struct timespec64 * a,const struct timespec64 * b)55 static inline int timespec64_equal(const struct timespec64 *a,
56 const struct timespec64 *b)
57 {
58 return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
59 }
60
61 /*
62 * lhs < rhs: return <0
63 * lhs == rhs: return 0
64 * lhs > rhs: return >0
65 */
timespec64_compare(const struct timespec64 * lhs,const struct timespec64 * rhs)66 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
67 {
68 if (lhs->tv_sec < rhs->tv_sec)
69 return -1;
70 if (lhs->tv_sec > rhs->tv_sec)
71 return 1;
72 return lhs->tv_nsec - rhs->tv_nsec;
73 }
74
75 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
76
timespec64_add(struct timespec64 lhs,struct timespec64 rhs)77 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
78 struct timespec64 rhs)
79 {
80 struct timespec64 ts_delta;
81 set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
82 lhs.tv_nsec + rhs.tv_nsec);
83 return ts_delta;
84 }
85
86 /*
87 * sub = lhs - rhs, in normalized form
88 */
timespec64_sub(struct timespec64 lhs,struct timespec64 rhs)89 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
90 struct timespec64 rhs)
91 {
92 struct timespec64 ts_delta;
93 set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
94 lhs.tv_nsec - rhs.tv_nsec);
95 return ts_delta;
96 }
97
98 /*
99 * Returns true if the timespec64 is norm, false if denorm:
100 */
timespec64_valid(const struct timespec64 * ts)101 static inline bool timespec64_valid(const struct timespec64 *ts)
102 {
103 /* Dates before 1970 are bogus */
104 if (ts->tv_sec < 0)
105 return false;
106 /* Can't have more nanoseconds then a second */
107 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
108 return false;
109 return true;
110 }
111
timespec64_valid_strict(const struct timespec64 * ts)112 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
113 {
114 if (!timespec64_valid(ts))
115 return false;
116 /* Disallow values that could overflow ktime_t */
117 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
118 return false;
119 return true;
120 }
121
timespec64_valid_settod(const struct timespec64 * ts)122 static inline bool timespec64_valid_settod(const struct timespec64 *ts)
123 {
124 if (!timespec64_valid(ts))
125 return false;
126 /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */
127 if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX)
128 return false;
129 return true;
130 }
131
132 /**
133 * timespec64_to_ns - Convert timespec64 to nanoseconds
134 * @ts: pointer to the timespec64 variable to be converted
135 *
136 * Returns the scalar nanosecond representation of the timespec64
137 * parameter.
138 */
timespec64_to_ns(const struct timespec64 * ts)139 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
140 {
141 /* Prevent multiplication overflow */
142 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
143 return KTIME_MAX;
144
145 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
146 }
147
148 /**
149 * ns_to_timespec64 - Convert nanoseconds to timespec64
150 * @nsec: the nanoseconds value to be converted
151 *
152 * Returns the timespec64 representation of the nsec parameter.
153 */
154 extern struct timespec64 ns_to_timespec64(const s64 nsec);
155
156 /**
157 * timespec64_add_ns - Adds nanoseconds to a timespec64
158 * @a: pointer to timespec64 to be incremented
159 * @ns: unsigned nanoseconds value to be added
160 *
161 * This must always be inlined because its used from the x86-64 vdso,
162 * which cannot call other kernel functions.
163 */
timespec64_add_ns(struct timespec64 * a,u64 ns)164 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
165 {
166 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
167 a->tv_nsec = ns;
168 }
169
170 /*
171 * timespec64_add_safe assumes both values are positive and checks for
172 * overflow. It will return TIME64_MAX in case of overflow.
173 */
174 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
175 const struct timespec64 rhs);
176
177 #endif /* _LINUX_TIME64_H */
178