[rtems commit] Check that the file offset is valid after a seek

[Joel Sherrill]

This looks like something that should also be on the 4.10 branch
with a PR.

What do you think?

--joel

On 02/09/2012 04:08 AM, Sebastian Huber wrote:
> Module:    rtems
> Branch:    master
> Commit:    e303adf4445919d4d87e8467854c404f9bd0d076
> Changeset: http://git.rtems.org/rtems/commit/?id=e303adf4445919d4d87e8467854c404f9bd0d076
>
> Author:    Sebastian Huber<sebastian.huber at embedded-brains.de>
> Date:      Thu Feb  9 10:53:16 2012 +0100
>
> Check that the file offset is valid after a seek
>
> ---
>
>   cpukit/libfs/src/dosfs/msdos_dir.c  |   18 ++++--------------
>   cpukit/libfs/src/dosfs/msdos_file.c |    4 ++++
>   2 files changed, 8 insertions(+), 14 deletions(-)
>
> diff --git a/cpukit/libfs/src/dosfs/msdos_dir.c b/cpukit/libfs/src/dosfs/msdos_dir.c
> index 9a8ed1e..a0ef507 100644
> --- a/cpukit/libfs/src/dosfs/msdos_dir.c
> +++ b/cpukit/libfs/src/dosfs/msdos_dir.c
> @@ -500,21 +500,11 @@ msdos_dir_read(rtems_libio_t *iop, void *buffer, size_t count)
>   off_t
>   msdos_dir_lseek(rtems_libio_t *iop, off_t offset, int whence)
>   {
> -    switch (whence)
> -    {
> -        case SEEK_SET:
> -        case SEEK_CUR:
> -            break;
> -        /*
> -         * Movement past the end of the directory via lseek is not a
> -         * permitted operation
> -         */
> -        case SEEK_END:
> -        default:
> -            rtems_set_errno_and_return_minus_one( EINVAL );
> -            break;
> +    if (iop->offset>= 0&&  iop->offset<= iop->size) {
> +        return 0;
> +    } else {
> +        rtems_set_errno_and_return_minus_one(EINVAL);
>       }
> -    return RC_OK;
>   }
>
>   /* msdos_dir_stat --
> diff --git a/cpukit/libfs/src/dosfs/msdos_file.c b/cpukit/libfs/src/dosfs/msdos_file.c
> index b0eeba9..5378a25 100644
> --- a/cpukit/libfs/src/dosfs/msdos_file.c
> +++ b/cpukit/libfs/src/dosfs/msdos_file.c
> @@ -231,6 +231,10 @@ msdos_file_lseek(rtems_libio_t *iop, off_t offset, int whence)
>       fat_file_fd_t     *fat_fd = iop->pathinfo.node_access;
>       uint32_t           real_size = 0;
>
> +    if (iop->offset<  0 || iop->offset>  UINT32_MAX) {
> +        rtems_set_errno_and_return_minus_one(EINVAL);
> +    }
> +
>       sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
>                                   MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
>       if (sc != RTEMS_SUCCESSFUL)
>
> _______________________________________________
> rtems-vc mailing list
> rtems-vc at rtems.org
> http://www.rtems.org/mailman/listinfo/rtems-vc


-- 
Joel Sherrill, Ph.D.             Director of Research&   Development
joel.sherrill at OARcorp.com        On-Line Applications Research
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