On Mon, Dec 21, 2015 at 03:10:56PM +0200, Jani Nikula wrote:
> Make the whole thing easier to read.
>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/intel_bios.c | 76 +++++++++++++++++++++------------------
> 1 file changed, 42 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 7393596df37d..9511a5341562 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -697,7 +697,7 @@ parse_psr(struct drm_i915_private *dev_priv, const struct bdb_header *bdb)
> dev_priv->vbt.psr.tp2_tp3_wakeup_time = psr_table->tp2_tp3_wakeup_time;
> }
>
> -static u8 *goto_next_sequence(u8 *data, int *size)
> +static u8 *goto_next_sequence(u8 *data, u16 *size)
> {
> u16 len;
> int tmp = *size;
> @@ -818,15 +818,52 @@ parse_mipi_config(struct drm_i915_private *dev_priv,
> dev_priv->vbt.dsi.panel_id = MIPI_DSI_GENERIC_PANEL_ID;
> }
>
> +/* Find the sequence block and size for the given panel. */
> +static const u8 *
> +find_panel_sequence_block(const struct bdb_mipi_sequence *sequence,
> + u16 panel_id, u16 *seq_size)
> +{
> + u32 total = get_blocksize(sequence);
> + const u8 *data = &sequence->data[0];
> + u8 current_id;
> + u16 current_size;
> + int index = 0;
> + int i;
> +
> + for (i = 0; i < MAX_MIPI_CONFIGURATIONS && index + 3 < total; i++) {
Commit message should mention that you make the parsin more robust and
ensure we don't walk over the end of the allocated buffer.
> + current_id = *(data + index);
> + index++;
> +
> + current_size = *((const u16 *)(data + index));
> + index += 2;
> +
> + if (index + current_size > total) {
> + DRM_ERROR("Invalid sequence block\n");
> + return NULL;
> + }
> +
> + if (current_id == panel_id) {
> + *seq_size = current_size;
> + return data + index;
> + }
> +
> + index += current_size;
> + }
> +
> + DRM_ERROR("Sequence block detected but no valid configuration\n");
> +
> + return NULL;
> +}
> +
> static void
> parse_mipi_sequence(struct drm_i915_private *dev_priv,
> const struct bdb_header *bdb)
> {
> const struct bdb_mipi_sequence *sequence;
> const u8 *seq_data;
> + u16 seq_size;
> u8 *data;
> u16 block_size;
> - int i, panel_id, seq_size;
>
> /* Only our generic panel driver uses the sequence block. */
> if (dev_priv->vbt.dsi.panel_id != MIPI_DSI_GENERIC_PANEL_ID)
> @@ -853,40 +890,11 @@ parse_mipi_sequence(struct drm_i915_private *dev_priv,
> */
> dev_priv->vbt.dsi.seq_version = sequence->version;
>
> - seq_data = &sequence->data[0];
> -
> - /*
> - * sequence block is variable length and hence we need to parse and
> - * get the sequence data for specific panel id
> - */
> - for (i = 0; i < MAX_MIPI_CONFIGURATIONS; i++) {
> - panel_id = *seq_data;
> - seq_size = *((u16 *) (seq_data + 1));
> - if (panel_id == panel_type)
> - break;
> -
> - /* skip the sequence including seq header of 3 bytes */
> - seq_data = seq_data + 3 + seq_size;
> - if ((seq_data - &sequence->data[0]) > block_size) {
> - DRM_ERROR("Sequence start is beyond sequence block size, corrupted sequence block\n");
> - return;
> - }
> - }
> -
> - if (i == MAX_MIPI_CONFIGURATIONS) {
> - DRM_ERROR("Sequence block detected but no valid configuration\n");
> + seq_data = find_panel_sequence_block(sequence, panel_type, &seq_size);
> + if (!seq_data)
> return;
> - }
> -
> - /* check if found sequence is completely within the sequence block
> - * just being paranoid */
> - if (seq_size > block_size) {
> - DRM_ERROR("Corrupted sequence/size, bailing out\n");
> - return;
> - }
>
> - /* skip the panel id(1 byte) and seq size(2 bytes) */
> - dev_priv->vbt.dsi.data = kmemdup(seq_data + 3, seq_size, GFP_KERNEL);
> + dev_priv->vbt.dsi.data = kmemdup(seq_data, seq_size, GFP_KERNEL);
Should dropping the +3 be in a separate patch?
Otherwise looks good, with the above 2 addressed
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> if (!dev_priv->vbt.dsi.data)
> return;
>
> --
> 2.1.4
>
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> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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