Re: [PATCH v2 06/14] linux: Add time64 sigtimedwait support

[Alistair Francis <alistair23@gmail.com>]

On Tue, Sep 8, 2020 at 8:00 AM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> The syscall __NR_sigtimedwait_time64 (for 32-bit) or __NR_sigtimedwait
> (for 64-bit) 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_rt_sigtimedwait (32-bit time_t).
>
> Checked on x86_64-linux-gnu and i686-linux-gnu.

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

Alistair

> ---
>  include/signal.h                       |  8 +++++
>  sysdeps/unix/sysv/linux/sigtimedwait.c | 50 +++++++++++++++++++++-----
>  2 files changed, 50 insertions(+), 8 deletions(-)
>
> diff --git a/include/signal.h b/include/signal.h
> index b4ee02d153..544d701bce 100644
> --- a/include/signal.h
> +++ b/include/signal.h
> @@ -38,6 +38,14 @@ extern int __sigwait (const sigset_t *__set, int *__sig);
>  libc_hidden_proto (__sigwait)
>  extern int __sigwaitinfo (const sigset_t *__set, siginfo_t *__info);
>  libc_hidden_proto (__sigwaitinfo)
> +#if __TIMESIZE == 64
> +# define __sigtimedwait64 __sigtimedwait
> +#else
> +# include <struct___timespec64.h>
> +extern int __sigtimedwait64 (const sigset_t *__set, siginfo_t *__info,
> +                            const struct __timespec64 *__timeout);
> +libc_hidden_proto (__sigtimedwait64)
> +#endif
>  extern int __sigtimedwait (const sigset_t *__set, siginfo_t *__info,
>                            const struct timespec *__timeout);
>  libc_hidden_proto (__sigtimedwait)
> diff --git a/sysdeps/unix/sysv/linux/sigtimedwait.c b/sysdeps/unix/sysv/linux/sigtimedwait.c
> index f2ef3aad45..4405606571 100644
> --- a/sysdeps/unix/sysv/linux/sigtimedwait.c
> +++ b/sysdeps/unix/sysv/linux/sigtimedwait.c
> @@ -15,20 +15,38 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>
> -#include <errno.h>
>  #include <signal.h>
> -#include <string.h>
> -#include <sysdep-cancel.h>
> +#include <sysdep.h>
>
>  int
> -__sigtimedwait (const sigset_t *set, siginfo_t *info,
> -               const struct timespec *timeout)
> +__sigtimedwait64 (const sigset_t *set, siginfo_t *info,
> +                 const struct __timespec64 *timeout)
>  {
> -  /* XXX The size argument hopefully will have to be changed to the
> -     real size of the user-level sigset_t.  */
> -  int result = SYSCALL_CANCEL (rt_sigtimedwait, set, info, timeout,
> +#ifndef __NR_rt_sigtimedwait_time64
> +# define __NR_rt_sigtimedwait_time64 __NR_rt_sigtimedwait
> +#endif
> +  int result = SYSCALL_CANCEL (rt_sigtimedwait_time64, set, info, timeout,
>                                __NSIG_BYTES);
>
> +#ifndef __ASSUME_TIME64_SYSCALLS
> +  if (result != 0 && errno == ENOSYS)
> +    {
> +      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;
> +       }
> +      result = SYSCALL_CANCEL (rt_sigtimedwait, set, info, pts32,
> +                              __NSIG_BYTES);
> +    }
> +#endif
> +
>    /* The kernel generates a SI_TKILL code in si_code in case tkill is
>       used.  tkill is transparently used in raise().  Since having
>       SI_TKILL as a code is useful in general we fold the results
> @@ -38,5 +56,21 @@ __sigtimedwait (const sigset_t *set, siginfo_t *info,
>
>    return result;
>  }
> +#if __TIMESIZE != 64
> +libc_hidden_def (__sigtimedwait64)
> +
> +int
> +__sigtimedwait (const sigset_t *set, siginfo_t *info,
> +               const struct timespec *timeout)
> +{
> +  struct __timespec64 ts64, *pts64 = NULL;
> +  if (timeout != NULL)
> +    {
> +      ts64 = valid_timespec_to_timespec64 (*timeout);
> +      pts64 = &ts64;
> +    }
> +  return __sigtimedwait64 (set, info, pts64);
> +}
> +#endif
>  libc_hidden_def (__sigtimedwait)
>  weak_alias (__sigtimedwait, sigtimedwait)
> --
> 2.25.1
>