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Re: [PATCH v2] sysdeps/nanosleep: Use clock_nanosleep_time64 if avaliable



On 24/10/2019 20:41, Alistair Francis wrote:
> 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()"
> ---
> This was patch was runtime tested with RV32 and RV64
> It was build tested using the ./scripts/build-many-glibcs.py script.
> 
> I am currently running:
> $ make ; make install ; make check
> tests on native ARM (32-bit) with the following three confiugrations:
>  - 4.19 Kernel and 4.19 Headers
>  - 5.2 Kernel and 4.19 Headers
>  - 5.2 Kernel and 5.2 Headers
> I should have the results tomorrow.
> 
> v2:
>  - Explicitly include `#include <kernel-features.h>`
> 
>  include/time.h                               | 20 ++++++
>  nptl/thrd_sleep.c                            | 70 +++++++++++++++++--
>  sysdeps/unix/sysv/linux/clock_nanosleep.c    | 73 ++++++++++++++++++--
>  sysdeps/unix/sysv/linux/nanosleep.c          | 65 ++++++++++++++++-
>  sysdeps/unix/sysv/linux/nanosleep_nocancel.c | 65 ++++++++++++++++-
>  5 files changed, 280 insertions(+), 13 deletions(-)
> 
> diff --git a/include/time.h b/include/time.h
> index d93b16a7810..0e703f87cef 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -174,6 +174,26 @@ 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
> +#else
> +extern int __thrd_sleep_time64 (const struct __timespec64* time_point,
> +                                struct __timespec64* remaining);
> +libc_hidden_proto (__thrd_sleep_time64)
> +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> +                                     int flags, const struct __timespec64 *req,
> +                                     struct __timespec64 *rem);
> +libc_hidden_proto (__clock_nanosleep_time64)
> +extern  int __nanosleep_time64 (const struct __timespec64 *requested_time,
> +                                struct __timespec64 *remaining);
> +libc_hidden_proto (__nanosleep_time64)
> +extern int __nanosleep_nocancel_time64 (const struct __timespec64 *requested_time,
> +                                        struct __timespec64 *remaining);
> +libc_hidden_proto (__nanosleep_nocancel_time64)
> +#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 2e185dd748e..2a6bb1f9e3f 100644
> --- a/nptl/thrd_sleep.c
> +++ b/nptl/thrd_sleep.c
> @@ -17,23 +17,85 @@
>     <https://www.gnu.org/licenses/>.  */
>  
>  #include <time.h>
> +#include <kernel-features.h>
>  #include <sysdep-cancel.h>
>  
>  #include "thrd_priv.h"
>  
>  int
> -thrd_sleep (const struct timespec* time_point, struct timespec* remaining)
> +__thrd_sleep_time64 (const struct __timespec64* time_point, struct __timespec64* 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;
> +        }
> +
> +      tp32 = valid_timespec64_to_timespec (*time_point);
> +      ret =  INTERNAL_SYSCALL_CANCEL (nanosleep, err, &tp32, &tr32);
> +
> +      if ((ret == 0 || errno != ENOSYS) && remaining)
> +        *remaining = valid_timespec_to_timespec64 (tr32);
> +    }
> +#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;
>  }

Wouldn't be simple to just call __clock_nanosleep_time64 instead of duplicate
the syscall handling and the required error code for c11 thread?  Something
like:

int
__thrd_sleep_time64 (const struct __timespec64* time_point,
		     struct __timespec64* remaining)
{
  int ret = __clock_nanosleep (CLOCK_REALTIME, 0, time_point, remaining);
  /* C11 states thrd_sleep function returns -1 if it has been interrupted
     by a signal, or a negative value if it fails.  */
  switch (ret)
  {
     case 0:      return 0;
     case EINTR:  return -1;
     default:     return -2;
  }
}

> +
> +#if __TIMESIZE != 64
> +int
> +thrd_sleep (const struct timespec* time_point, struct timespec* remaining)
> +{
> +  int ret;
> +  struct __timespec64 tp64, tr64;
> +
> +  tp64 = valid_timespec_to_timespec64 (*time_point);
> +  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)
> +        *remaining = valid_timespec64_to_timespec (tr64);
> +    }
> +
> +  return ret;
> +}
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> index 1f240b8720a..d257ea57fb0 100644
> --- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> +++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> @@ -16,6 +16,7 @@
>     <https://www.gnu.org/licenses/>.  */
>  
>  #include <time.h>
> +#include <kernel-features.h>
>  #include <errno.h>
>  
>  #include <sysdep-cancel.h>
> @@ -26,9 +27,11 @@
>  /* 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 __timespec64 *req,
> +                          struct __timespec64 *rem)
>  {
> +  int r = -1;
> +
>    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
>      return EINVAL;
>    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
> @@ -37,12 +40,72 @@ __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;
> +        }
> +
> +      ts32 = valid_timespec64_to_timespec (*req);
> +      r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, &ts32, &tr32);
> +
> +      if ((r == 0 || errno != ENOSYS) && rem)
> +        *rem = valid_timespec_to_timespec64 (tr32);
> +    }
> +#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;
> +  struct __timespec64 treq64, trem64;
> +
> +  treq64 = valid_timespec_to_timespec64 (*req);
> +  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 (rem)
> +        *rem = valid_timespec64_to_timespec (trem64);
> +    }
> +
> +  return r;
> +}
> +#endif
> +
>  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
>  /* clock_nanosleep moved to libc in version 2.17;
>     old binaries may expect the symbol version it had in librt.  */
> diff --git a/sysdeps/unix/sysv/linux/nanosleep.c b/sysdeps/unix/sysv/linux/nanosleep.c
> index 6787909248f..10a6d57a1de 100644
> --- a/sysdeps/unix/sysv/linux/nanosleep.c
> +++ b/sysdeps/unix/sysv/linux/nanosleep.c
> @@ -17,15 +17,76 @@
>     <https://www.gnu.org/licenses/>.  */
>  
>  #include <time.h>
> +#include <kernel-features.h>
>  #include <sysdep-cancel.h>
>  #include <not-cancel.h>
>  
>  /* Pause execution for a number of nanoseconds.  */
>  int
> +__nanosleep_time64 (const struct __timespec64 *requested_time,
> +                    struct __timespec64 *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;
> +    }
> +
> +  ts32 = valid_timespec64_to_timespec (*requested_time);
> +  ret = SYSCALL_CANCEL (nanosleep, &ts32, &tr32);
> +
> +  if ((ret == 0 || errno != ENOSYS) && remaining)
> +    *remaining = valid_timespec_to_timespec64 (tr32);
> +
> +  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;
> +  struct __timespec64 treq64, trem64;
> +
> +  treq64 = valid_timespec_to_timespec64 (*requested_time);
> +  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)
> +        *remaining = valid_timespec64_to_timespec (trem64);
> +    }
> +
> +  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 d6442bf4f7f..1a6c6c0a48a 100644
> --- a/sysdeps/unix/sysv/linux/nanosleep_nocancel.c
> +++ b/sysdeps/unix/sysv/linux/nanosleep_nocancel.c
> @@ -17,13 +17,74 @@
>     <https://www.gnu.org/licenses/>.  */
>  
>  #include <time.h>
> +#include <kernel-features.h>
>  #include <sysdep-cancel.h>
>  #include <not-cancel.h>
>  
> +int
> +__nanosleep_nocancel_time64 (const struct __timespec64 *requested_time,
> +                             struct __timespec64 *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;
> +    }
> +
> +  ts32 = valid_timespec64_to_timespec (*requested_time);
> +  ret = INLINE_SYSCALL_CALL (nanosleep, &ts32, &tr32);
> +
> +  if (ret == 0 || errno != ENOSYS)
> +    *remaining = valid_timespec_to_timespec64 (tr32);
> +
> +  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;
> +  struct __timespec64 treq64, trem64;
> +
> +  treq64 = valid_timespec_to_timespec64 (*requested_time);
> +  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)
> +        *remaining = valid_timespec64_to_timespec (trem64);
> +    }
> +
> +  return ret;
>  }
> +#endif
> +
>  hidden_def (__nanosleep_nocancel)
> 


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