[RFC v3 04/23] sysdeps/clock_gettime: Use clock_gettime64 if avaliable
Lukasz Majewski
lukma@denx.de
Wed Jul 17 12:37:00 GMT 2019
Hi Alistair,
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
> nptl/pthread_mutex_timedlock.c | 7 ++++++
> sysdeps/unix/sysv/linux/clock_gettime.c | 30
> +++++++++++++++++++++++++ 2 files changed, 37 insertions(+)
>
> diff --git a/nptl/pthread_mutex_timedlock.c
> b/nptl/pthread_mutex_timedlock.c index 52c258e33d..8d9cae7d87 100644
> --- a/nptl/pthread_mutex_timedlock.c
> +++ b/nptl/pthread_mutex_timedlock.c
> @@ -402,10 +402,17 @@ __pthread_mutex_clocklock_common
> (pthread_mutex_t *mutex, /* Delay the thread until the timeout is
> reached. Then return ETIMEDOUT. */
> struct timespec reltime;
> +#ifdef __NR_clock_gettime64
> + struct __timespec64 now;
> +
> + INTERNAL_SYSCALL (clock_gettime64, __err, 2,
> CLOCK_REALTIME,
> + &now);
> +#else
> struct timespec now;
>
> INTERNAL_SYSCALL (clock_gettime, __err, 2,
> clockid, &now);
> +#endif
> reltime.tv_sec = abstime->tv_sec - now.tv_sec;
> reltime.tv_nsec = abstime->tv_nsec - now.tv_nsec;
> if (reltime.tv_nsec < 0)
> diff --git a/sysdeps/unix/sysv/linux/clock_gettime.c
> b/sysdeps/unix/sysv/linux/clock_gettime.c index
> 5fc47fb7dc..4832069c34 100644 ---
> a/sysdeps/unix/sysv/linux/clock_gettime.c +++
> b/sysdeps/unix/sysv/linux/clock_gettime.c @@ -27,10 +27,40 @@
> #include <sysdep-vdso.h>
>
> /* Get current value of CLOCK and store it in TP. */
> +
> +#if __WORDSIZE == 32
> +int
> +__clock_gettime (clockid_t clock_id, struct timespec *tp)
> +{
> + int ret;
> +
> +#ifdef __NR_clock_gettime64
> + struct __timespec64 tp64;
> + ret = INLINE_VSYSCALL (clock_gettime64, 2, clock_id, &tp64);
> +
> + tp->tv_sec = tp64.tv_sec;
> + tp->tv_nsec = tp64.tv_nsec;
> +
> + if (! in_time_t_range (tp->tv_sec))
> + {
> + __set_errno (EOVERFLOW);
> + return -1;
> + }
> +#endif
> +
> +#ifndef __ASSUME_TIME64_SYSCALLS
I think that the context of using the __ASSUME_TIME64_SYSCALLS doesn't
comply with the semantics which was proposed in its introduction patch
[1].
In short:
This define means that the system is supporting 64 bit time, not that
it has (can use) introduced in Linux 5.1 64 bit time related syscalls
(i.e. clock_gettime64, clock_settime64, clock_nanosleep64).
Maybe you could consider using the "conversion" approach as proposed
for __clock_settime64 conversion [2]?
The version in [2] is more "developer/validator" friendly (as suggested
by Arnd) as it uses for __TIMESIZE != 64 archs the 32 bit clock_settime.
The version from [3] is the one recommended by Joseph (which does the
32 to 64 bit conversion and calls clock_settime64).
The full code for a reference with clock_settime conversion and Y2038
support [4].
> + ret = INLINE_VSYSCALL (clock_gettime, 2, clock_id, tp);
> +#endif
> +
> + return ret;
> +}
> +#else
> int
> __clock_gettime (clockid_t clock_id, struct timespec *tp)
> {
> return INLINE_VSYSCALL (clock_gettime, 2, clock_id, tp);
> }
> +#endif
> +
> weak_alias (__clock_gettime, clock_gettime)
> libc_hidden_def (__clock_gettime)
Note:
[1] -
https://github.com/lmajewski/y2038_glibc/commit/1fdbc6002101a78a8a6a076bbb642b3082c2225d
[2] -
https://github.com/lmajewski/y2038_glibc/commit/69f842a8519ca13ed11fab0ff1bcc6fa1a524192
[3] -
https://github.com/lmajewski/y2038_glibc/commit/fa0f5ff6c942beca383daeff3d48829829ace5b1
[4] -
https://github.com/lmajewski/y2038_glibc/commits/Y2038-2.29-glibc-__clock-internal-struct-timespec-v6
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
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