glibc/include/time.h
Lukasz Majewski 7ce198e123 y2038: linux: Provide __clock_settime64 implementation
This patch provides new __clock_settime64 explicit 64 bit function for
setting the time. Moreover, a 32 bit version - __clock_settime - has been
refactored to internally use __clock_settime64.

The __clock_settime is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit
struct timespec.

The new clock_settime64 syscall available from Linux 5.1+ has been used,
when applicable.

In this patch the internal padding (tv_pad) of struct __timespec64 is
left untouched (on systems with __WORDSIZE == 32) as Linux kernel ignores
upper 32 bits of tv_nsec.

Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"

- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

- Use of cross-test-ssh.sh for ARM (armv7):
  make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck

Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with clock_settime64) and glibc build with v5.1 as minimal
  kernel version (--enable-kernel="5.1.0")
  The __ASSUME_TIME64_SYSCALLS flag defined.

- Linux v5.1 and default minimal kernel version
  The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
  __clock_settime64 syscalls.

- Linux v4.19 (no clock_settime64 support) with default minimal kernel
  version for contemporary glibc

  This kernel doesn't support __clock_settime64 syscalls, so the fallback
  to clock_settime is tested.

The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).

No regressions were observed.

* include/time.h (__clock_settime64):
  Add __clock_settime alias according to __TIMESIZE define
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime):
  Refactor this function to be used only on 32 bit machines as a wrapper
  on __clock_settime64.
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Add
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64):
  Use clock_settime64 kernel syscall (available from 5.1+ Linux)
2019-10-10 00:17:46 +02:00

241 lines
6.5 KiB
C

#ifndef _TIME_H
#include <time/time.h>
#ifndef _ISOMAC
# include <bits/types/struct_timeval.h>
# include <bits/types/locale_t.h>
# include <stdbool.h>
# include <time/mktime-internal.h>
# include <endian.h>
extern __typeof (strftime_l) __strftime_l;
libc_hidden_proto (__strftime_l)
extern __typeof (strptime_l) __strptime_l;
libc_hidden_proto (time)
libc_hidden_proto (asctime)
libc_hidden_proto (mktime)
libc_hidden_proto (timelocal)
libc_hidden_proto (localtime)
libc_hidden_proto (strftime)
libc_hidden_proto (strptime)
extern __typeof (clock_gettime) __clock_gettime;
libc_hidden_proto (__clock_gettime)
extern __typeof (clock_settime) __clock_settime;
libc_hidden_proto (__clock_settime)
/* Now define the internal interfaces. */
struct tm;
/* Defined in mktime.c. */
extern const unsigned short int __mon_yday[2][13] attribute_hidden;
/* Defined in localtime.c. */
extern struct tm _tmbuf attribute_hidden;
/* Defined in tzset.c. */
extern char *__tzstring (const char *string) attribute_hidden;
extern int __use_tzfile attribute_hidden;
extern void __tzfile_read (const char *file, size_t extra,
char **extrap) attribute_hidden;
extern void __tzfile_compute (__time64_t timer, int use_localtime,
long int *leap_correct, int *leap_hit,
struct tm *tp) attribute_hidden;
extern void __tzfile_default (const char *std, const char *dst,
int stdoff, int dstoff)
attribute_hidden;
extern void __tzset_parse_tz (const char *tz) attribute_hidden;
extern void __tz_compute (__time64_t timer, struct tm *tm, int use_localtime)
__THROW 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 unnamed bit-field padding.
As a general rule the Linux kernel is ignoring upper 32 bits of
tv_nsec field. */
struct __timespec64
{
__time64_t tv_sec; /* Seconds */
# if BYTE_ORDER == BIG_ENDIAN
__int32_t :32; /* Padding */
__int32_t tv_nsec; /* Nanoseconds */
# else
__int32_t tv_nsec; /* Nanoseconds */
__int32_t :32; /* Padding */
# endif
};
#endif
#if __TIMESIZE == 64
# define __ctime64 ctime
#else
extern char *__ctime64 (const __time64_t *__timer) __THROW;
libc_hidden_proto (__ctime64)
#endif
#if __TIMESIZE == 64
# define __ctime64_r ctime_r
#else
extern char *__ctime64_r (const __time64_t *__restrict __timer,
char *__restrict __buf) __THROW;
libc_hidden_proto (__ctime64_r)
#endif
#if __TIMESIZE == 64
# define __localtime64 localtime
#else
extern struct tm *__localtime64 (const __time64_t *__timer);
libc_hidden_proto (__localtime64)
#endif
extern struct tm *__localtime_r (const time_t *__timer,
struct tm *__tp) attribute_hidden;
#if __TIMESIZE != 64
extern struct tm *__localtime64_r (const __time64_t *__timer,
struct tm *__tp);
libc_hidden_proto (__localtime64_r)
extern __time64_t __mktime64 (struct tm *__tp) __THROW;
libc_hidden_proto (__mktime64)
#endif
extern struct tm *__gmtime_r (const time_t *__restrict __timer,
struct tm *__restrict __tp);
libc_hidden_proto (__gmtime_r)
#if __TIMESIZE == 64
# define __gmtime64 gmtime
#else
extern struct tm *__gmtime64 (const __time64_t *__timer);
libc_hidden_proto (__gmtime64)
extern struct tm *__gmtime64_r (const __time64_t *__restrict __timer,
struct tm *__restrict __tp);
libc_hidden_proto (__gmtime64_r)
extern __time64_t __timegm64 (struct tm *__tp) __THROW;
libc_hidden_proto (__timegm64)
#endif
#if __TIMESIZE == 64
# define __clock_settime64 __clock_settime
#else
extern int __clock_settime64 (clockid_t clock_id,
const struct __timespec64 *tp);
libc_hidden_proto (__clock_settime64)
#endif
/* Compute the `struct tm' representation of T,
offset OFFSET seconds east of UTC,
and store year, yday, mon, mday, wday, hour, min, sec into *TP.
Return nonzero if successful. */
extern int __offtime (__time64_t __timer,
long int __offset,
struct tm *__tp) attribute_hidden;
extern char *__asctime_r (const struct tm *__tp, char *__buf)
attribute_hidden;
extern void __tzset (void) attribute_hidden;
/* Prototype for the internal function to get information based on TZ. */
extern struct tm *__tz_convert (__time64_t timer, int use_localtime,
struct tm *tp) attribute_hidden;
extern int __nanosleep (const struct timespec *__requested_time,
struct timespec *__remaining);
hidden_proto (__nanosleep)
extern int __getdate_r (const char *__string, struct tm *__resbufp)
attribute_hidden;
/* Determine CLK_TCK value. */
extern int __getclktck (void) attribute_hidden;
/* strptime support. */
extern char * __strptime_internal (const char *rp, const char *fmt,
struct tm *tm, void *statep,
locale_t locparam) attribute_hidden;
#if __TIMESIZE == 64
# define __difftime64 __difftime
#else
extern double __difftime64 (__time64_t time1, __time64_t time0);
libc_hidden_proto (__difftime64)
#endif
extern double __difftime (time_t time1, time_t time0);
/* Use in the clock_* functions. Size of the field representing the
actual clock ID. */
#define CLOCK_IDFIELD_SIZE 3
/* Check whether T fits in time_t. */
static inline bool
in_time_t_range (__time64_t t)
{
time_t s = t;
return s == t;
}
/* Convert a known valid struct timeval into a struct __timespec64. */
static inline struct __timespec64
valid_timeval_to_timespec64 (const struct timeval tv)
{
struct __timespec64 ts64;
ts64.tv_sec = tv.tv_sec;
ts64.tv_nsec = tv.tv_usec * 1000;
return ts64;
}
/* Convert a known valid struct timespec into a struct __timespec64. */
static inline struct __timespec64
valid_timespec_to_timespec64 (const struct timespec ts)
{
struct __timespec64 ts64;
ts64.tv_sec = ts.tv_sec;
ts64.tv_nsec = ts.tv_nsec;
return ts64;
}
/* Convert a valid and within range of struct timespec, struct
__timespec64 into a struct timespec. */
static inline struct timespec
valid_timespec64_to_timespec (const struct __timespec64 ts64)
{
struct timespec ts;
ts.tv_sec = (time_t) ts64.tv_sec;
ts.tv_nsec = ts64.tv_nsec;
return ts;
}
/* Convert a valid and within range of struct timeval struct
__timespec64 into a struct timeval. */
static inline struct timeval
valid_timespec64_to_timeval (const struct __timespec64 ts64)
{
struct timeval tv;
tv.tv_sec = (time_t) ts64.tv_sec;
tv.tv_usec = ts64.tv_nsec / 1000;
return tv;
}
#endif
#endif