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Re: [RFC v5 02/21] sysdeps/nanosleep: Use clock_nanosleep_time64 if avaliable


Hi Alistair,

> The nanosleep syscall is not supported on newer 32-bit platforms (such
> as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
> avaliable.
> 
> Let's use CLOCK_REALTIME when calling clock_nanosleep_time64 as the
> Linux specification says:
>   "POSIX.1 specifies that nanosleep() should measure time against the
>    CLOCK_REALTIME clock. However, Linux measures the time using the
>    CLOCK_MONOTONIC clock. This probably does not matter, since the
> POSIX.1 specification for clock_settime(2) says that discontinuous
> changes in CLOCK_REALTIME should not affect nanosleep()"
> 
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> 
> 	* nptl/thrd_sleep.c: Use clock_nanosleep_time64 instead of
> nanosleep.
> 	* sysdeps/unix/sysv/linux/nanosleep.c: Likewise.
> 	* sysdeps/unix/sysv/linux/clock_nanosleep.c: Likewise.
> 	* sysdeps/unix/sysv/linux/nanosleep_nocancel.c: Likewise.
> ---
>  include/time.h                               |  6 ++
>  nptl/thrd_sleep.c                            | 69 ++++++++++++++++--
>  sysdeps/unix/sysv/linux/clock_nanosleep.c    | 74
> ++++++++++++++++++-- sysdeps/unix/sysv/linux/nanosleep.c          |
> 65 ++++++++++++++++- sysdeps/unix/sysv/linux/nanosleep_nocancel.c |
> 64 ++++++++++++++++- 5 files changed, 264 insertions(+), 14
> deletions(-)
> 
> diff --git a/include/time.h b/include/time.h
> index 95b31429212..6d81f91384b 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -172,6 +172,12 @@ libc_hidden_proto (__difftime64)
>  
>  extern double __difftime (time_t time1, time_t time0);
>  
> +#if __TIMESIZE == 64
> +#define __thrd_sleep_time64 thrd_sleep
> +#define __clock_nanosleep_time64 __clock_nanosleep
> +#define __nanosleep_time64 __nanosleep
> +#define __nanosleep_nocancel_time64 __nanosleep_nocancel
> +#endif
>  
>  /* Use in the clock_* functions.  Size of the field representing the
>     actual clock ID.  */
> diff --git a/nptl/thrd_sleep.c b/nptl/thrd_sleep.c
> index 07a51808df2..e85da561c68 100644
> --- a/nptl/thrd_sleep.c
> +++ b/nptl/thrd_sleep.c
> @@ -22,18 +22,79 @@
>  #include "thrd_priv.h"
>  
>  int
> -thrd_sleep (const struct timespec* time_point, struct timespec*
> remaining) +__thrd_sleep_time64 (const struct timespec* time_point,
> struct timespec* remaining) {
>    INTERNAL_SYSCALL_DECL (err);
> -  int ret = INTERNAL_SYSCALL_CANCEL (nanosleep, err, time_point,
> remaining);
> +  int ret = -1;
> +
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_clock_nanosleep_time64
> +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> +# endif
> +  ret = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err,
> CLOCK_REALTIME,
> +                                 0, time_point, remaining);
> +#else
> +# ifdef __NR_clock_nanosleep_time64
> +  long int ret_64;
> +
> +  ret_64 = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err,
> CLOCK_REALTIME,
> +                                    0, time_point, remaining);
> +
> +  if (ret_64 == 0 || errno != ENOSYS)
> +    ret = ret_64;
> +# endif /* __NR_clock_nanosleep_time64 */
> +  if (ret < 0)
> +    {
> +      struct timespec tp32, tr32;
> +
> +      if (! in_time_t_range (time_point->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      valid_timespec64_to_timespec (time_point, &tp32);
> +      ret =  INTERNAL_SYSCALL_CANCEL (nanosleep, err, &tp32, &tr32);
> +
> +      if ((ret == 0 || errno != ENOSYS) && remaining)
> +        valid_timespec_to_timespec64(&tr32, remaining);
> +    }
> +#endif /* __ASSUME_TIME64_SYSCALLS */
> +
>    if (INTERNAL_SYSCALL_ERROR_P (ret, err))
>      {
>        /* C11 states thrd_sleep function returns -1 if it has been
> interrupted
> -	 by a signal, or a negative value if it fails.  */
> +         by a signal, or a negative value if it fails.  */
>        ret = INTERNAL_SYSCALL_ERRNO (ret, err);
>        if (ret == EINTR)
> -	return -1;
> +        return -1;
>        return -2;
>      }
>    return 0;
>  }
> +
> +#if __TIMESIZE != 64
> +int
> +thrd_sleep (const struct timespec* time_point, struct timespec*
> remaining) +{
> +  int ret;
> +  timespec64 tp64, tr64;
> +
> +  valid_timespec_to_timespec64(time_point, &tp64);
> +  ret = __thrd_sleep_time64 (&tp64, &tr64);
> +
> +  if (ret == 0 || errno != ENOSYS)
> +    {
> +      if (! in_time_t_range (tr64->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      if (remaining)
> +        valid_timespec64_to_timespec(&tr32, remaining);
> +    }
> +
> +  return ret;
> +}
> +#endif

This code seems to follow the pattern introduced in clock_settime()
conversion (already in the -master branch).

Do you plan to send this and the following patches:

https://patchwork.ozlabs.org/patch/1155396/    --> clock_gettime
https://patchwork.ozlabs.org/patch/1155398/    --> timespec_get

As a separate patch series so we can all benefit from having them in
the -master glibc branch?
Those patches seems to be orthogonal to ones adding support for RISC-V.


The gettimeofday() syscall handling code seems to being now converted to
clock_gettime() in the glibc (or at least there is some ongoing effort):

https://sourceware.org/git/?p=glibc.git;a=commit;h=b30d257ea8f557bdadca09f5b112538e7b807eb9

Similar situation is with stat and statfs (which are now under the
discussion/review):

https://patchwork.ozlabs.org/patch/1155399/    --> stat
https://patchwork.ozlabs.org/patch/1155401/    --> statfs

> diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> b/sysdeps/unix/sysv/linux/clock_nanosleep.c index
> 0cb6614dc92..64302fbcc69 100644 ---
> a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++
> b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -21,13 +21,14 @@
>  #include <sysdep-cancel.h>
>  #include "kernel-posix-cpu-timers.h"
>  
> -
>  /* We can simply use the syscall.  The CPU clocks are not supported
>     with this function.  */
>  int
> -__clock_nanosleep (clockid_t clock_id, int flags, const struct
> timespec *req,
> -		   struct timespec *rem)
> +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const
> struct timespec *req,
> +                          struct timespec *rem)
>  {
> +  int r = -1;
> +
>    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
>      return EINVAL;
>    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
> @@ -36,9 +37,70 @@ __clock_nanosleep (clockid_t clock_id, int flags,
> const struct timespec *req, /* If the call is interrupted by a signal
> handler or encounters an error, it returns a positive value similar
> to errno.  */ INTERNAL_SYSCALL_DECL (err);
> -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> flags,
> -				   req, rem);
> +
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_clock_nanosleep_time64
> +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> +# endif
> +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> +                               flags, req, rem);
> +#else
> +# ifdef __NR_clock_nanosleep_time64
> +  long int ret_64;
> +
> +  ret_64 = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err,
> clock_id,
> +                                    flags, req, rem);
> +
> +  if (ret_64 == 0 || errno != ENOSYS)
> +    r = ret_64;
> +# endif /* __NR_clock_nanosleep_time64 */
> +  if (r < 0)
> +    {
> +      struct timespec ts32, tr32;
> +
> +      if (! in_time_t_range (req->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      valid_timespec64_to_timespec (req, &ts32);
> +      r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, &ts32,
> &tr32); +
> +      if ((r == 0 || errno != ENOSYS) && rem)
> +        valid_timespec_to_timespec64(&tr32, rem);
> +    }
> +#endif /* __ASSUME_TIME64_SYSCALLS */
> +
>    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> -	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
>  }
> +
> +#if __TIMESIZE != 64
> +int
> +__clock_nanosleep (clockid_t clock_id, int flags, const struct
> timespec *req,
> +                   struct timespec *rem)
> +{
> +  int r;
> +  timespec64 treq64, trem64;
> +
> +  valid_timespec_to_timespec64(req, &treq64)
> +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> +
> +  if (r == 0 || errno != ENOSYS)
> +    {
> +      if (! in_time_t_range (trem64->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      if (remaining)
> +        valid_timespec64_to_timespec(&tr32, remaining);
> +    }
> +
> +  return r;
> +}
> +#endif
> +
>  weak_alias (__clock_nanosleep, clock_nanosleep)
> diff --git a/sysdeps/unix/sysv/linux/nanosleep.c
> b/sysdeps/unix/sysv/linux/nanosleep.c index f14ae565af5..9a8dd5a4b82
> 100644 --- a/sysdeps/unix/sysv/linux/nanosleep.c
> +++ b/sysdeps/unix/sysv/linux/nanosleep.c
> @@ -22,10 +22,71 @@
>  
>  /* Pause execution for a number of nanoseconds.  */
>  int
> +__nanosleep_time64 (const struct timespec *requested_time,
> +                    struct timespec *remaining)
> +{
> +#if defined(__ASSUME_TIME64_SYSCALLS)
> +# ifndef __NR_clock_nanosleep_time64
> +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> +# endif
> +  return SYSCALL_CANCEL (clock_nanosleep_time64, CLOCK_REALTIME, 0,
> +                         requested_time, remaining);
> +#else
> +# ifdef __NR_clock_nanosleep_time64
> +  long int ret_64;
> +
> +  ret_64 = SYSCALL_CANCEL (clock_nanosleep_time64, CLOCK_REALTIME, 0,
> +                           requested_time, remaining);
> +
> +  if (ret_64 == 0 || errno != ENOSYS)
> +    return ret_64;
> +# endif /* __NR_clock_nanosleep_time64 */
> +  int ret;
> +  struct timespec ts32, tr32;
> +
> +  if (! in_time_t_range (requested_time->tv_sec))
> +    {
> +      __set_errno (EOVERFLOW);
> +      return -1;
> +    }
> +
> +  valid_timespec64_to_timespec (requested_time, &ts32);
> +  ret = SYSCALL_CANCEL (nanosleep, &ts32, &tr32);
> +
> +  if ((ret == 0 || errno != ENOSYS) && remaining)
> +    valid_timespec_to_timespec64(&tr32, remaining);
> +
> +  return ret;
> +#endif /* __ASSUME_TIME64_SYSCALLS */
> +}
> +
> +#if __TIMESIZE != 64
> +int
>  __nanosleep (const struct timespec *requested_time,
> -	     struct timespec *remaining)
> +             struct timespec *remaining)
>  {
> -  return SYSCALL_CANCEL (nanosleep, requested_time, remaining);
> +  int r;
> +  timespec64 treq64, trem64;
> +
> +
> +  valid_timespec_to_timespec64(req, &treq64);
> +  r = __nanosleep_time64 (&treq64, &trem64);
> +
> +  if (r == 0 || errno != ENOSYS)
> +    {
> +      if (! in_time_t_range (trem64->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      if (remaining)
> +        valid_timespec64_to_timespec(&tr32, remaining);
> +    }
> +
> +  return r;
>  }
> +#endif
> +
>  hidden_def (__nanosleep)
>  weak_alias (__nanosleep, nanosleep)
> diff --git a/sysdeps/unix/sysv/linux/nanosleep_nocancel.c
> b/sysdeps/unix/sysv/linux/nanosleep_nocancel.c index
> 122ba627ff3..03f5be2ff9e 100644 ---
> a/sysdeps/unix/sysv/linux/nanosleep_nocancel.c +++
> b/sysdeps/unix/sysv/linux/nanosleep_nocancel.c @@ -20,10 +20,70 @@
>  #include <sysdep-cancel.h>
>  #include <not-cancel.h>
>  
> +int
> +__nanosleep_nocancel_time64 (const struct timespec *requested_time,
> +                             struct timespec *remaining)
> +{
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_clock_nanosleep_time64
> +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> +# endif
> +  return INLINE_SYSCALL_CALL (clock_nanosleep_time64,
> CLOCK_REALTIME, 0,
> +                              requested_time, remaining);
> +#else
> +# ifdef __NR_clock_nanosleep_time64
> +  long int ret_64;
> +
> +  ret_64 = INLINE_SYSCALL_CALL (clock_nanosleep_time64,
> CLOCK_REALTIME, 0,
> +                                requested_time, remaining);
> +
> +  if (ret_64 == 0 || errno != ENOSYS)
> +    return ret_64;
> +# endif /* __NR_clock_nanosleep_time64 */
> +  int ret;
> +  struct timespec ts32, tr32;
> +
> +  if (! in_time_t_range (requested_time->tv_sec))
> +    {
> +      __set_errno (EOVERFLOW);
> +      return -1;
> +    }
> +
> +  valid_timespec64_to_timespec (requested_time, &ts32);
> +  ret = INLINE_SYSCALL_CALL (nanosleep, &ts32, &tr32);
> +
> +  if (ret == 0 || errno != ENOSYS)
> +    valid_timespec_to_timespec64(&tr32, remaining);
> +
> +  return ret;
> +#endif /* __ASSUME_TIME64_SYSCALLS */
> +}
> +
> +#if __TIMESIZE != 64
>  int
>  __nanosleep_nocancel (const struct timespec *requested_time,
> -		      struct timespec *remaining)
> +                      struct timespec *remaining)
>  {
> -  return INLINE_SYSCALL_CALL (nanosleep, requested_time, remaining);
> +  int ret;
> +  timespec64 treq64, trem64;
> +
> +  valid_timespec_to_timespec64(req, &treq64)
> +  ret = __nanosleep_nocancel_time64 (&treq64, &trem64);
> +
> +  if (ret == 0 || errno != ENOSYS)
> +    {
> +      if (! in_time_t_range (trem64->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      if (remaining)
> +        valid_timespec64_to_timespec(&tr32, remaining);
> +    }
> +
> +  return ret;
>  }
> +#endif
> +
>  hidden_def (__nanosleep_nocancel)




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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