Re: [PATCH] Support regular file type in _swistat for ARM

[Jeff Johnston <jjohnstn@redhat.com>]

cc'ing Richard.

On Thu, Jun 4, 2020 at 5:53 AM Joe Ramsay <Joe.Ramsay@arm.com> wrote:

> Hi!
>
> Previously, the implementation of _swistat() for ARM assumed all files
> to be of type character device. This change adds support for stat-ing
> regular files. Tested with arm-none-eabi
> ---
> libgloss/arm/syscalls.c | 43 +++++++++++++++++++++++++++++--------------
> 1 file changed, 29 insertions(+), 14 deletions(-)
>
> diff --git a/libgloss/arm/syscalls.c b/libgloss/arm/syscalls.c
> index fc394f9..b4bd329 100644
> --- a/libgloss/arm/syscalls.c
> +++ b/libgloss/arm/syscalls.c
> @@ -728,33 +728,48 @@ _sbrk (ptrdiff_t incr)
> int
>  _swistat (int fd, struct stat * st)
> {
> -  struct fdent *pfd;
> -  int res;
> -
> -  pfd = findslot (fd);
> +  struct fdent *pfd = findslot (fd);
>    if (pfd == NULL)
>      {
>        errno = EBADF;
>        return -1;
>      }
>
> -  /* Always assume a character device,
> -     with 1024 byte blocks. */
> -  st->st_mode |= S_IFCHR;
> -  st->st_blksize = 1024;
> +  int isCharDevice, flen;
> #ifdef ARM_RDI_MONITOR
> -  res = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
> +  isCharDevice = checkerror (do_AngelSWI (AngelSWI_Reason_IsTTY,
> &pfd->handle));
> +  flen = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
> #else
>    asm ("mov r0, %2; swi %a1; mov %0, r0"
> -       : "=r" (res)
> +       : "=r" (isCharDevice)
> +       : "i" (SWI_IsTTY), "r" (pfd->handle)
> +       : "r0");
> +  checkerror(isCharDevice);
> +  asm ("mov r0, %2; swi %a1; mov %0, r0"
> +       : "=r" (flen)
>         : "i" (SWI_Flen), "r" (pfd->handle)
>         : "r0");
> -  checkerror (res);
> +  checkerror(flen);
> #endif
> -  if (res == -1)
> +
> +  if (isCharDevice != 0 && isCharDevice != 1)
> +    return error(-1);
> +
> +  if (flen == -1)
>      return -1;
> -  /* Return the file size. */
> -  st->st_size = res;
> +
> +  st->st_size = flen;
> +  /* Always assume 1024 byte blocks */
> +  st->st_blksize = 1024;
> +
> +  if (isCharDevice)
> +    st->st_mode |= S_IFCHR;
> +  else
> +    {
> +      st->st_mode |= S_IFREG;
> +      st->st_blocks = (flen + 1023) / 1024;
> +    }
> +
>    return 0;
> }
>
> --
> 2.7.4
>
>