On Thu, 2016-01-14 at 17:12 +0200, Jani Nikula wrote:
> Two errors in a single line. The size was read from the wrong offset,
> and the end index didn't take the five bytes for sequence byte and size
> of sequence into account. Fix it all, and break up the calculations a
> bit to make it clearer.
> 
Tested-by: Mika Kahola <mika.kah...@intel.com>
> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> Reported-by: Mika Kahola <mika.kah...@intel.com>
> Fixes: 2a33d93486f2 ("drm/i915/bios: add support for MIPI sequence block v3")
> Signed-off-by: Jani Nikula <jani.nik...@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_bios.c | 17 ++++++++++++++---
>  1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_bios.c 
> b/drivers/gpu/drm/i915/intel_bios.c
> index 12e2f8b8bf9c..bf62a19c8f69 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -842,6 +842,7 @@ static int goto_next_sequence_v3(const u8 *data, int 
> index, int total)
>  {
>       int seq_end;
>       u16 len;
> +     u32 size_of_sequence;
>  
>       /*
>        * Could skip sequence based on Size of Sequence alone, but also do some
> @@ -852,14 +853,24 @@ static int goto_next_sequence_v3(const u8 *data, int 
> index, int total)
>               return 0;
>       }
>  
> -     seq_end = index + *((const u32 *)(data + 1));
> +     /* Skip Sequence Byte. */
> +     index++;
> +
> +     /*
> +      * Size of Sequence. Excludes the Sequence Byte and the size itself,
> +      * includes MIPI_SEQ_ELEM_END byte, excludes the final MIPI_SEQ_END
> +      * byte.
> +      */
> +     size_of_sequence = *((const uint32_t *)(data + index));
> +     index += 4;
> +
> +     seq_end = index + size_of_sequence;
>       if (seq_end > total) {
>               DRM_ERROR("Invalid sequence size\n");
>               return 0;
>       }
>  
> -     /* Skip Sequence Byte and Size of Sequence. */
> -     for (index = index + 5; index < total; index += len) {
> +     for (; index < total; index += len) {
>               u8 operation_byte = *(data + index);
>               index++;
>  


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