[6/6] y2038: linux: Provide __settimeofday64 implementation

  This patch provides new __settimeofday64 explicit 64 bit function for setting
64 bit time in the kernel (by internally calling __clock_settime64).
Moreover, a 32 bit version - __settimeofday has been refactored to internally
use __settimeofday64.

The __settimeofday is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion of struct
timeval to 64 bit struct __timespec64.

Internally the settimeofday uses __settimeofday64. This patch is necessary
for having architectures with __WORDSIZE == 32 Y2038 safe.

Build tests:
./src/scripts/build-many-glibcs.py glibcs

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

Above tests were performed with Y2038 redirection applied as well as without
to test proper usage of both __settimeofday64 and __settimeofday.
---
 include/time.h      |  9 +++++++++
 time/settimeofday.c | 19 +++++++++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)
  

On Sat, Jan 18, 2020 at 5:21 PM Lukasz Majewski <lukma@denx.de> wrote:
>
> This patch provides new __settimeofday64 explicit 64 bit function for setting
> 64 bit time in the kernel (by internally calling __clock_settime64).
> Moreover, a 32 bit version - __settimeofday has been refactored to internally
> use __settimeofday64.
>
> The __settimeofday is now supposed to be used on systems still supporting 32
> bit time (__TIMESIZE != 64) - hence the necessary conversion of struct
> timeval to 64 bit struct __timespec64.
>
> Internally the settimeofday uses __settimeofday64. This patch is necessary
> for having architectures with __WORDSIZE == 32 Y2038 safe.
>
> Build tests:
> ./src/scripts/build-many-glibcs.py glibcs
>
> 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
>
> Above tests were performed with Y2038 redirection applied as well as without
> to test proper usage of both __settimeofday64 and __settimeofday.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  include/time.h      |  9 +++++++++
>  time/settimeofday.c | 19 +++++++++++++++----
>  2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/include/time.h b/include/time.h
> index b40214c006..b76ffea225 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -8,6 +8,7 @@
>  # include <time/mktime-internal.h>
>  # include <endian.h>
>  # include <time-clockid.h>
> +# include <sys/time.h>
>
>  extern __typeof (strftime_l) __strftime_l;
>  libc_hidden_proto (__strftime_l)
> @@ -224,6 +225,14 @@ extern int __sched_rr_get_interval64 (pid_t pid, struct __timespec64 *tp);
>  libc_hidden_proto (__sched_rr_get_interval64);
>  #endif
>
> +#if __TIMESIZE == 64
> +# define __settimeofday64 __settimeofday
> +#else
> +extern int __settimeofday64 (const struct __timeval64 *tv,
> +                             const struct timezone *tz);
> +libc_hidden_proto (__settimeofday64)
> +#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.
> diff --git a/time/settimeofday.c b/time/settimeofday.c
> index bc43e70f61..dbf6cf501f 100644
> --- a/time/settimeofday.c
> +++ b/time/settimeofday.c
> @@ -22,7 +22,7 @@
>  /* Set the current time of day and timezone information.
>     This call is restricted to the super-user.  */
>  int
> -__settimeofday (const struct timeval *tv, const struct timezone *tz)
> +__settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)
>  {
>    if (__glibc_unlikely (tz != 0))
>      {
> @@ -34,11 +34,22 @@ __settimeofday (const struct timeval *tv, const struct timezone *tz)
>        return __settimezone (tz);
>      }
>
> -  struct timespec ts;
> -  TIMEVAL_TO_TIMESPEC (tv, &ts);
> -  return __clock_settime (CLOCK_REALTIME, &ts);
> +  struct __timespec64 ts = timeval64_to_timespec64 (*tv);
> +  return __clock_settime64 (CLOCK_REALTIME, &ts);
>  }
>
> +#if __TIMESIZE != 64
> +libc_hidden_def (__settimeofday64)
> +
> +int
> +__settimeofday (const struct timeval *tv, const struct timezone *tz)
> +{
> +  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);
> +
> +  return __settimeofday64 (&tv64, tz);
> +}
> +#endif
> +
>  #ifdef VERSION_settimeofday
>  weak_alias (__settimeofday, __settimeofday_w);
>  default_symbol_version (__settimeofday_w, settimeofday, VERSION_settimeofday);
> --
> 2.20.1
>