Commit ce679dea authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915/dp: Sanitize link common rate array lookups 



Add an assert that lookups from the intel_dp->common_rates[] array
are always valid.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211018094154.1407705-7-imre.deak@intel.com
parent caae4fb5

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

+16 −17
Original line number Diff line number Diff line
@@ -267,10 +267,19 @@ static int intel_dp_common_len_rate_limit(const struct intel_dp *intel_dp, 
				       intel_dp->num_common_rates, max_rate);

}



static int intel_dp_common_rate(struct intel_dp *intel_dp, int index)

{

	if (drm_WARN_ON(&dp_to_i915(intel_dp)->drm,

			index < 0 || index >= intel_dp->num_common_rates))

		return 162000;



	return intel_dp->common_rates[index];

}



/* Theoretical max between source and sink */

static int intel_dp_max_common_rate(struct intel_dp *intel_dp)

{

	return intel_dp->common_rates[intel_dp->num_common_rates - 1];

	return intel_dp_common_rate(intel_dp, intel_dp->num_common_rates - 1);

}



/* Theoretical max between source and sink */
@@ -610,13 +619,13 @@ int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, 
	if (index > 0) {

		if (intel_dp_is_edp(intel_dp) &&

		    !intel_dp_can_link_train_fallback_for_edp(intel_dp,

							      intel_dp->common_rates[index - 1],

							      intel_dp_common_rate(intel_dp, index - 1),

							      lane_count)) {

			drm_dbg_kms(&i915->drm,

				    "Retrying Link training for eDP with same parameters\n");

			return 0;

		}

		intel_dp->max_link_rate = intel_dp->common_rates[index - 1];

		intel_dp->max_link_rate = intel_dp_common_rate(intel_dp, index - 1);

		intel_dp->max_link_lane_count = lane_count;

	} else if (lane_count > 1) {

		if (intel_dp_is_edp(intel_dp) &&
@@ -1056,14 +1065,11 @@ static void intel_dp_print_rates(struct intel_dp *intel_dp) 
int

intel_dp_max_link_rate(struct intel_dp *intel_dp)

{

	struct drm_i915_private *i915 = dp_to_i915(intel_dp);

	int len;



	len = intel_dp_common_len_rate_limit(intel_dp, intel_dp->max_link_rate);

	if (drm_WARN_ON(&i915->drm, len <= 0))

		return 162000;



	return intel_dp->common_rates[len - 1];

	return intel_dp_common_rate(intel_dp, len - 1);

}



int intel_dp_rate_select(struct intel_dp *intel_dp, int rate)
@@ -1260,7 +1266,7 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp, 
						   output_bpp);



		for (i = 0; i < intel_dp->num_common_rates; i++) {

			link_rate = intel_dp->common_rates[i];

			link_rate = intel_dp_common_rate(intel_dp, i);

			if (link_rate < limits->min_rate ||

			    link_rate > limits->max_rate)

				continue;
@@ -1508,17 +1514,10 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, 
		&pipe_config->hw.adjusted_mode;

	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

	struct link_config_limits limits;

	int common_len;

	int ret;



	common_len = intel_dp_common_len_rate_limit(intel_dp,

						    intel_dp->max_link_rate);



	/* No common link rates between source and sink */

	drm_WARN_ON(encoder->base.dev, common_len <= 0);



	limits.min_rate = intel_dp->common_rates[0];

	limits.max_rate = intel_dp->common_rates[common_len - 1];

	limits.min_rate = intel_dp_common_rate(intel_dp, 0);

	limits.max_rate = intel_dp_max_link_rate(intel_dp);



	limits.min_lane_count = 1;

	limits.max_lane_count = intel_dp_max_lane_count(intel_dp);