[v2,03/14] linux: Add time64 semtimedop support

  Either the __NR_semtimedop_time64 (for 32-bit) or the __NR_semtimedop
(for 64-bit) syscall is used as default.  The 32-bit fallback is used
iff __ASSUME_TIME64_SYSCALLS is not defined, which assumes the kernel
ABI provides either __NR_ipc or __NR_semtimeop (for 32-bit time_t).

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).
---
 sysdeps/unix/sysv/linux/include/sys/sem.h |  6 +++
 sysdeps/unix/sysv/linux/semtimedop.c      | 57 +++++++++++++++++++----
 2 files changed, 55 insertions(+), 8 deletions(-)
  

On Tue, Sep 8, 2020 at 7:58 AM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> Either the __NR_semtimedop_time64 (for 32-bit) or the __NR_semtimedop
> (for 64-bit) syscall is used as default.  The 32-bit fallback is used
> iff __ASSUME_TIME64_SYSCALLS is not defined, which assumes the kernel
> ABI provides either __NR_ipc or __NR_semtimeop (for 32-bit time_t).
>
> Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
> kernel).

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

Alistair

> ---
>  sysdeps/unix/sysv/linux/include/sys/sem.h |  6 +++
>  sysdeps/unix/sysv/linux/semtimedop.c      | 57 +++++++++++++++++++----
>  2 files changed, 55 insertions(+), 8 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/include/sys/sem.h b/sysdeps/unix/sysv/linux/include/sys/sem.h
> index a9151e057d..f369c6b6d3 100644
> --- a/sysdeps/unix/sysv/linux/include/sys/sem.h
> +++ b/sysdeps/unix/sysv/linux/include/sys/sem.h
> @@ -7,9 +7,15 @@ __typeof__ (semtimedop) __semtimedop attribute_hidden;
>
>  #if __TIMESIZE == 64
>  # define __semctl64 __semctl
> +# define __semtimedop64 __semtimedop
>  #else
> +# include <struct___timespec64.h>
> +
>  extern int __semctl64 (int semid, int semnum, int cmd, ...);
>  libc_hidden_proto (__semctl64);
> +extern int __semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
> +                          const struct __timespec64 *tmo);
> +libc_hidden_proto (__semtimedop64);
>  #endif
>
>  # endif
> diff --git a/sysdeps/unix/sysv/linux/semtimedop.c b/sysdeps/unix/sysv/linux/semtimedop.c
> index 6fdde09bad..56121fb0bf 100644
> --- a/sysdeps/unix/sysv/linux/semtimedop.c
> +++ b/sysdeps/unix/sysv/linux/semtimedop.c
> @@ -22,18 +22,59 @@
>  #include <errno.h>
>
>  /* Perform user-defined atomical operation of array of semaphores.  */
> +int
> +__semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
> +               const struct __timespec64 *timeout)
> +{
> +#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> +# ifndef __NR_semtimedop_time64
> +#  define __NR_semtimedop_time64 __NR_semtimedop
> +# endif
> +  int r = INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops,
> +                              timeout);
> +#else
> +  int r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> +                              SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
> +#endif
> +
> +#ifndef __ASSUME_TIME64_SYSCALLS
> +  if (r == 0 || errno != ENOSYS)
> +    return r;
> +
> +  struct timespec ts32, *pts32 = NULL;
> +  if (timeout != NULL)
> +    {
> +      if (! in_time_t_range (timeout->tv_sec))
> +       {
> +         __set_errno (EINVAL);
> +         return -1;
> +       }
> +      ts32 = valid_timespec64_to_timespec (*timeout);
> +      pts32 = &ts32;
> +    }
> +# if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> +  r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
> +# else
> +  r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> +                          SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
> +# endif
> +#endif /* __ASSUME_TIME64_SYSCALLS  */
> +  return r;
> +}
> +#if __TIMESIZE != 64
> +libc_hidden_def (__semtimedop64)
>
>  int
>  __semtimedop (int semid, struct sembuf *sops, size_t nsops,
>               const struct timespec *timeout)
>  {
> -  /* semtimedop wire-up syscall is not exported for 32-bit ABIs (they have
> -     semtimedop_time64 instead with uses a 64-bit time_t).  */
> -#if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
> -  return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
> -#else
> -  return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> -                             SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
> -#endif
> +  struct __timespec64 ts64, *pts64 = NULL;
> +  if (timeout != NULL)
> +    {
> +      ts64 = valid_timespec_to_timespec64 (*timeout);
> +      pts64 = &ts64;
> +    }
> +  return __semtimedop64 (semid, sops, nsops, pts64);
>  }
> +#endif
>  weak_alias (__semtimedop, semtimedop)
> --
> 2.25.1
>