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
timespec64_equal(const struct timespec64 * a,const struct timespec64 * b)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 */
timespec64_compare(const struct timespec64 * lhs,const struct timespec64 * rhs)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
timespec64_add(struct timespec64 lhs,struct timespec64 rhs)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 */
timespec64_sub(struct timespec64 lhs,struct timespec64 rhs)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 */
timespec64_valid(const struct timespec64 * ts)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
timespec64_valid_strict(const struct timespec64 * ts)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
timespec64_valid_settod(const struct timespec64 * ts)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 */
timespec64_to_ns(const struct timespec64 * ts)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 */
timespec64_add_ns(struct timespec64 * a,u64 ns)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
