[25/29,AARCH64] Add kernel_sigaction.h for AARCH64 ILP32

  In ILP32, the sigaction struct is the same as AARCH64 so we need
the header file kernel_sigaction.h.  To allow for this to work,
we use a long long fields and then add extra casts when converting
between the user exposed struct and the kernel exposed struct.

* sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h: New file.
* sysdeps/unix/sysv/linux/aarch64/sigaction.c (__libc_sigaction):
Add cast here it is necessary.
---
 sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h |   12 ++++++++++++
 sysdeps/unix/sysv/linux/aarch64/sigaction.c        |   10 ++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h
  

On 27 October 2014 07:59, Andrew Pinski <apinski@cavium.com> wrote:
> In ILP32, the sigaction struct is the same as AARCH64 so we need
> the header file kernel_sigaction.h.  To allow for this to work,
> we use a long long fields and then add extra casts when converting
> between the user exposed struct and the kernel exposed struct.
>
> * sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h: New file.
> * sysdeps/unix/sysv/linux/aarch64/sigaction.c (__libc_sigaction):
> Add cast here it is necessary.

Add casts where necessary.

> ---
>  sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h |   12 ++++++++++++
>  sysdeps/unix/sysv/linux/aarch64/sigaction.c        |   10 ++++++----
>  2 files changed, 18 insertions(+), 4 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h
>
> diff --git a/sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h b/sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h
> new file mode 100644
> index 0000000..7b3023b
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/kernel_sigaction.h
> @@ -0,0 +1,12 @@
> +
> +#define HAVE_SA_RESTORER
> +
> +/* This is the sigaction structure in aarch64 kernel.
> +   Note the ILP32 struct uses the same struct as LP64
> +   which is why the fields are 64bit in size. */

Two spaces before end of comment.

> +struct kernel_sigaction {
> +       unsigned long long k_sa_handler;
> +       unsigned long long sa_flags;
> +       unsigned long long sa_restorer;
> +       sigset_t sa_mask;
> +};
> diff --git a/sysdeps/unix/sysv/linux/aarch64/sigaction.c b/sysdeps/unix/sysv/linux/aarch64/sigaction.c
> index ae6c3fd..8adcbba 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/sigaction.c
> +++ b/sysdeps/unix/sysv/linux/aarch64/sigaction.c
> @@ -39,15 +39,17 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>
>    if (act)
>      {
> -      kact.k_sa_handler = act->sa_handler;
> +      kact.k_sa_handler = (unsigned long long)(uintptr_t)act->sa_handler;
>        memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
>        kact.sa_flags = act->sa_flags;
>  #ifdef HAVE_SA_RESTORER
>        if (kact.sa_flags & SA_RESTORER)
> -       kact.sa_restorer = act->sa_restorer;
> +       kact.sa_restorer = (unsigned long long)(uintptr_t)act->sa_restorer;
>  #endif
>      }
>
> +  /* This is needed for ILP32 as the structures are two different sizes due to
> +     using the LP64 structure.  */

It's not clear to me what this comment refers to.

>    result = INLINE_SYSCALL (rt_sigaction, 4, sig,
>                            act ? &kact : NULL,
>                            oact ? &koact : NULL, _NSIG / 8);
> @@ -55,11 +57,11 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
>      {
>        if (oact && result >= 0)
>         {
> -         oact->sa_handler = koact.k_sa_handler;
> +         oact->sa_handler = (void*)(uintptr_t)koact.k_sa_handler;
>           memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
>           oact->sa_flags = koact.sa_flags;
>  #ifdef HAVE_SA_RESTORER
> -         oact->sa_restorer = koact.sa_restorer;
> +         oact->sa_restorer = (void*)(uintptr_t)koact.sa_restorer;

Space before * and after casts.

>  #endif
>         }
>      }
> --
> 1.7.2.5
>

Otherwise looks ok.