[v7,2/3] y2038: Provide conversion helpers for struct __timespec64
Commit Message
Those functions allow easy conversion between Y2038 safe struct
__timespec64 and other time related data structures (like struct timeval).
* include/time.h (valid_timeval_to_timespec64): Add.
* include/time.h (valid_timespec_to_timespec64): Likewise.
* include/time.h (valid_timespec64_to_timespec): Likewise.
* include/time.h (valid_timespec64_to_timeval): Likewise.
* include/time.h (IS_VALID_NANOSECONDS): Likewise.
* include/time.h (timespec_to_timespec64): Likewise.
* include/time.h (timespec64_to_timespec): Likewise.
* include/time.h (timespec64_to_timeval): Likewise.
---
Changes for v7:
- None
Changes for v6:
- Remove the #ifdef guard on __ASSUME_TIME64_SYSCALLS as those functions
may be needed for fallback execution paths (on e.g. __clock_settime64).
Changes for v5:
- This code is now only compiled in when __ASSUME_TIME64_SYSCALLS is NOT
defined. Previously it was depending on #if __TIMESIZE != 64.
Changes for v4:
- None
Changes for v3:
- Remove misleading comments regarding clearing tv_pad values during
conversion (as Linux kernel on its own ignores upper 32 bits of tv_nsec).
Changes for v3:
- Remove timespec64_clear_padding function - as kernel ignores upper 32
bits of tv_nsec when passed via syscall to the Linux kernel
Changes for v2:
- Add timespec64_clear_padding function
---
include/time.h | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 83 insertions(+)
@@ -179,5 +179,88 @@ in_time_t_range (__time64_t t)
return s == t;
}
+/* Convert a known valid struct timeval into a struct __timespec64. */
+static inline void
+valid_timeval_to_timespec64 (const struct timeval *tv32,
+ struct __timespec64 *ts64)
+{
+ ts64->tv_sec = tv32->tv_sec;
+ ts64->tv_nsec = tv32->tv_usec * 1000;
+}
+
+/* Convert a known valid struct timespec into a struct __timespec64. */
+static inline void
+valid_timespec_to_timespec64 (const struct timespec *ts32,
+ struct __timespec64 *ts64)
+{
+ ts64->tv_sec = ts32->tv_sec;
+ ts64->tv_nsec = ts32->tv_nsec;
+}
+
+/* Convert a known valid struct __timespec64 into a struct timespec. */
+static inline void
+valid_timespec64_to_timespec (const struct __timespec64 *ts64,
+ struct timespec *ts32)
+{
+ ts32->tv_sec = (time_t) ts64->tv_sec;
+ ts32->tv_nsec = ts64->tv_nsec;
+}
+
+/* Convert a known valid struct __timespec64 into a struct timeval. */
+static inline void
+valid_timespec64_to_timeval (const struct __timespec64 *ts64,
+ struct timeval *tv32)
+{
+ tv32->tv_sec = (time_t) ts64->tv_sec;
+ tv32->tv_usec = ts64->tv_nsec / 1000;
+}
+
+/* Check if a value lies with the valid nanoseconds range. */
+#define IS_VALID_NANOSECONDS(ns) ((ns) >= 0 && (ns) <= 999999999)
+
+/* Check and convert a struct timespec into a struct __timespec64. */
+static inline bool
+timespec_to_timespec64 (const struct timespec *ts32,
+ struct __timespec64 *ts64)
+{
+ /* Check that ts32 holds a valid count of nanoseconds. */
+ if (! IS_VALID_NANOSECONDS (ts32->tv_nsec))
+ return false;
+ /* All ts32 fields can fit in ts64, so copy them. */
+ valid_timespec_to_timespec64 (ts32, ts64);
+ return true;
+}
+
+/* Check and convert a struct __timespec64 into a struct timespec. */
+static inline bool
+timespec64_to_timespec (const struct __timespec64 *ts64,
+ struct timespec *ts32)
+{
+ /* Check that tv_nsec holds a valid count of nanoseconds. */
+ if (! IS_VALID_NANOSECONDS (ts64->tv_nsec))
+ return false;
+ /* Check that tv_sec can fit in a __time_t. */
+ if (! in_time_t_range (ts64->tv_sec))
+ return false;
+ /* All ts64 fields can fit in ts32, so copy them. */
+ valid_timespec64_to_timespec (ts64, ts32);
+ return true;
+}
+
+/* Check and convert a struct __timespec64 into a struct timeval. */
+static inline bool
+timespec64_to_timeval (const struct __timespec64 *ts64,
+ struct timeval *tv32)
+{
+ /* Check that tv_nsec holds a valid count of nanoseconds. */
+ if (! IS_VALID_NANOSECONDS (ts64->tv_nsec))
+ return false;
+ /* Check that tv_sec can fit in a __time_t. */
+ if (! in_time_t_range (ts64->tv_sec))
+ return false;
+ /* All ts64 fields can fit in tv32, so copy them. */
+ valid_timespec64_to_timeval (ts64, tv32);
+ return true;
+}
#endif
#endif