Commit 58b2e382 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915/bios: Trust the LFP data pointers 



Now that we've sufficiently validated the LFP data pointers we
can trust them.

Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405173410.11436-6-ville.syrjala@linux.intel.com


Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
parent 514003e1

drivers/gpu/drm/i915/display/intel_bios.c

+16 −44
Original line number Diff line number Diff line
@@ -397,44 +397,19 @@ fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode, 
}



static const struct lvds_dvo_timing *

get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,

		    const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,

get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *data,

		    const struct bdb_lvds_lfp_data_ptrs *ptrs,

		    int index)

{

	/*

	 * the size of fp_timing varies on the different platform.

	 * So calculate the DVO timing relative offset in LVDS data

	 * entry to get the DVO timing entry

	 */



	int lfp_data_size =

		lvds_lfp_data_ptrs->ptr[1].dvo_timing.offset -

		lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset;

	int dvo_timing_offset =

		lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset -

		lvds_lfp_data_ptrs->ptr[0].fp_timing.offset;

	char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;



	return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);

	return (const void *)data + ptrs->ptr[index].dvo_timing.offset;

}



/* get lvds_fp_timing entry

 * this function may return NULL if the corresponding entry is invalid

 */

static const struct lvds_fp_timing *

get_lvds_fp_timing(const struct bdb_lvds_lfp_data *data,

		   const struct bdb_lvds_lfp_data_ptrs *ptrs,

		   int index)

{

	u16 data_size = ((const u16 *)data)[-1]; /* stored in header */

	size_t ofs;



	if (index >= ARRAY_SIZE(ptrs->ptr))

		return NULL;

	ofs = ptrs->ptr[index].fp_timing.offset;

	if (ofs + sizeof(struct lvds_fp_timing) > data_size)

		return NULL;

	return (const struct lvds_fp_timing *)((const u8 *)data + ofs);

	return (const void *)data + ptrs->ptr[index].fp_timing.offset;

}



/* Parse general panel options */
@@ -499,8 +474,7 @@ parse_panel_options(struct drm_i915_private *i915) 


/* Try to find integrated panel timing data */

static void

parse_lfp_panel_dtd(struct drm_i915_private *i915,

		    const struct bdb_header *bdb)

parse_lfp_panel_dtd(struct drm_i915_private *i915)

{

	const struct bdb_lvds_lfp_data *lvds_lfp_data;

	const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
@@ -536,7 +510,7 @@ parse_lfp_panel_dtd(struct drm_i915_private *i915, 
	fp_timing = get_lvds_fp_timing(lvds_lfp_data,

				       lvds_lfp_data_ptrs,

				       panel_type);

	if (fp_timing) {



	/* check the resolution, just to be sure */

	if (fp_timing->x_res == panel_fixed_mode->hdisplay &&

	    fp_timing->y_res == panel_fixed_mode->vdisplay) {
@@ -546,7 +520,6 @@ parse_lfp_panel_dtd(struct drm_i915_private *i915, 
			    i915->vbt.bios_lvds_val);

	}

}

}



static void

parse_generic_dtd(struct drm_i915_private *i915)
@@ -627,8 +600,7 @@ parse_generic_dtd(struct drm_i915_private *i915) 
}



static void

parse_panel_dtd(struct drm_i915_private *i915,

		const struct bdb_header *bdb)

parse_panel_dtd(struct drm_i915_private *i915)

{

	/*

	 * Older VBTs provided provided DTD information for internal displays
@@ -641,7 +613,7 @@ parse_panel_dtd(struct drm_i915_private *i915, 
	if (i915->vbt.version >= 229)

		parse_generic_dtd(i915);

	if (!i915->vbt.lfp_lvds_vbt_mode)

		parse_lfp_panel_dtd(i915, bdb);

		parse_lfp_panel_dtd(i915);

}



static void
@@ -2720,7 +2692,7 @@ void intel_bios_init(struct drm_i915_private *i915) 
	parse_general_features(i915);

	parse_general_definitions(i915);

	parse_panel_options(i915);

	parse_panel_dtd(i915, bdb);

	parse_panel_dtd(i915);

	parse_lfp_backlight(i915);

	parse_sdvo_panel_data(i915);

	parse_driver_features(i915);