[PATCH v2 1/7] y2038: Introduce internal for glibc struct __timespec64

[Lukasz Majewski <lukma at denx dot de>]

This type is a glibc's type similar to struct timespec
but whose tv_sec field is a __time64_t rather than a time_t,
which makes it Y2038-proof and usable to pass between user
code and Y2038-proof kernel syscalls (e.g. clock_gettime()).

To support passing this structure to the kernel - the tv_pad,
32 bit padding field has been introduced. The placement of it
depends on endiannes of the SoC.

Tested on x86_64 and ARM.

* include/time.h: Add struct __timespec64 definition

---
Changes for v2:
- None
---
 include/time.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/include/time.h b/include/time.h
index 61dd9e180b..7540ac0f8b 100644
--- a/include/time.h
+++ b/include/time.h
@@ -3,6 +3,7 @@
 
 #ifndef _ISOMAC
 # include <bits/types/locale_t.h>
+# include <endian.h>
 
 extern __typeof (strftime_l) __strftime_l;
 libc_hidden_proto (__strftime_l)
@@ -58,6 +59,27 @@ extern time_t __mktime_internal (struct tm *__tp,
 				 long int *__offset) attribute_hidden;
 
 #if __TIMESIZE == 64
+# define __timespec64 timespec
+#else
+/* The glibc Y2038-proof struct __timespec64 structure for a time value.
+   To keep things Posix-ish, we keep the nanoseconds field a 32-bit
+   signed long, but since the Linux field is a 64-bit signed int, we
+   pad our tv_nsec with a 32-bit bitfield, which should always be 0. */
+
+struct __timespec64
+{
+  __time64_t tv_sec;         /* Seconds */
+# if BYTE_ORDER == BIG_ENDIAN
+  int tv_pad: 32;            /* Padding named for checking/setting */
+  __int32_t tv_nsec;         /* Nanoseconds */
+# else
+  __int32_t tv_nsec;         /* Nanoseconds */
+  int tv_pad: 32;            /* Padding named for checking/setting */
+# endif
+};
+#endif
+
+#if __TIMESIZE == 64
 # define __ctime64 ctime
 #else
 extern char *__ctime64 (const __time64_t *__timer) __THROW;
-- 
2.11.0