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