Re: [PATCH v2] Support regular file type in _swistat for ARM

[Corinna Vinschen <vinschen@redhat.com>]

CC'ing Richard.

On Jun 23 10:30, Joe Ramsay 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        | 44 +++++++++++++++++++-----------
> newlib/libc/sys/arm/syscalls.c | 61 ++++++++++++++++++++++++++++++++++++------
> 2 files changed, 82 insertions(+), 23 deletions(-)
> 
> diff --git a/libgloss/arm/syscalls.c b/libgloss/arm/syscalls.c
> index fc394f9..652301c 100644
> --- a/libgloss/arm/syscalls.c
> +++ b/libgloss/arm/syscalls.c
> @@ -59,6 +59,7 @@ struct fdent
> };
>  #define MAX_OPEN_FILES 20
> +#define DEFAULT_BLOCK_SIZE 1024
>  /* User file descriptors (fd) are integer indexes into
>     the openfiles[] array. Error checking is done by using
> @@ -728,33 +729,46 @@ _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;
> #ifdef ARM_RDI_MONITOR
> -  res = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
> +  isCharDevice = checkerror (do_AngelSWI (AngelSWI_Reason_IsTTY, &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);
> +#endif
> +
> +  int flen;
> +#ifdef ARM_RDI_MONITOR
> +  flen = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
> +#else
> +  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)
> -    return -1;
> -  /* Return the file size. */
> -  st->st_size = res;
> +
> +  st->st_size = flen;
> +  st->st_blksize = DEFAULT_BLOCK_SIZE;
> +
> +  if (isCharDevice)
> +    st->st_mode |= S_IFCHR;
> +  else
> +    {
> +      st->st_mode |= S_IFREG;
> +      st->st_blocks = (flen + DEFAULT_BLOCK_SIZE - 1) / DEFAULT_BLOCK_SIZE;
> +    }
> +
>   return 0;
> }
> diff --git a/newlib/libc/sys/arm/syscalls.c b/newlib/libc/sys/arm/syscalls.c
> index 1f72229..5156f1a 100644
> --- a/newlib/libc/sys/arm/syscalls.c
> +++ b/newlib/libc/sys/arm/syscalls.c
> @@ -28,6 +28,7 @@ int               _unlink                 (const char *);
> int          _link                      (const char *, const char *);
> int          _stat                      (const char *, struct stat *);
> int          _fstat                     (int, struct stat *);
> +int     _swistat        (int fd, struct stat * st);
> void *   _sbrk                     (ptrdiff_t);
> pid_t     _getpid                 (void);
> int          _kill                        (int, int);
> @@ -84,6 +85,8 @@ poslog;
> #define MAX_OPEN_FILES 20
> static poslog openfiles [MAX_OPEN_FILES];
> +#define DEFAULT_BLOCK_SIZE 1024
> +
> static int
> findslot (int fh)
> {
> @@ -543,33 +546,75 @@ _sbrk (ptrdiff_t incr)
>    return (void *) prev_heap_end;
> }
> +int
> +_swistat (int fd, struct stat * st)
> +{
> +  struct fdent *pfd = findslot (fd);
> +  if (pfd == NULL)
> +    {
> +      errno = EBADF;
> +      return -1;
> +    }
> +
> +  int isCharDevice;
> +#ifdef ARM_RDI_MONITOR
> +  isCharDevice = checkerror (do_AngelSWI (AngelSWI_Reason_IsTTY, &pfd->handle));
> +#else
> +  asm ("mov r0, %2; swi %a1; mov %0, r0"
> +       : "=r" (isCharDevice)
> +       : "i" (SWI_IsTTY), "r" (pfd->handle)
> +       : "r0");
> +  checkerror(isCharDevice);
> +#endif
> +
> +  int flen;
> +#ifdef ARM_RDI_MONITOR
> +  flen = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
> +#else
> +  asm ("mov r0, %2; swi %a1; mov %0, r0"
> +       : "=r" (flen)
> +       : "i" (SWI_Flen), "r" (pfd->handle)
> +       : "r0");
> +  checkerror(flen);
> +#endif
> +
> +  st->st_size = flen;
> +  st->st_blksize = DEFAULT_BLOCK_SIZE;
> +
> +  if (isCharDevice)
> +    st->st_mode |= S_IFCHR;
> +  else
> +    {
> +      st->st_mode |= S_IFREG;
> +      st->st_blocks = (flen + DEFAULT_BLOCK_SIZE - 1) / DEFAULT_BLOCK_SIZE;
> +    }
> +
> +  return 0;
> +}
> +
> extern void memset (struct stat *, int, unsigned int);
>  int __attribute__((weak))
> _fstat (int file, struct stat * st)
> {
>    memset (st, 0, sizeof (* st));
> -  st->st_mode = S_IFCHR;
> -  st->st_blksize = 1024;
> -  return 0;
> -  file = file;
> +  return _swistat (file, st);
> }
>  int __attribute__((weak))
> _stat (const char *fname, struct stat *st)
> {
>    int file;
> -
> +  memset (st, 0, sizeof (* st));
>    /* The best we can do is try to open the file readonly.  If it exists,
>       then we can guess a few things about it.  */
>    if ((file = _open (fname, O_RDONLY)) < 0)
>      return -1;
> -  memset (st, 0, sizeof (* st));
>    st->st_mode = S_IFREG | S_IREAD;
> -  st->st_blksize = 1024;
> +  res = _swistat (file, st);
>    _swiclose (file); /* Not interested in the error.  */
> -  return 0;
> +  return res;
> }
>  int __attribute__((weak))
> --
> 2.7.4
> 

-- 
Corinna Vinschen
Cygwin Maintainer
Red Hat