Re: [PATCH][next] drm/amd/display: Fix Wstringop-overflow warnings in dc_link_dp.c

[Kees Cook]

On Thu, Mar 03, 2022 at 11:25:03AM -0600, Gustavo A. R. Silva wrote:
> Fix the following Wstringop-overflow warnings when building with GCC-11:
> 
> drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:493:17: warning: 
> ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 
> [-Wstringop-overflow=]

Can you "show your work" a little more here? I don't actually see the
what is getting fixed:

enum dc_lane_count {
        ...
        LANE_COUNT_FOUR = 4,
        ...
        LANE_COUNT_DP_MAX = LANE_COUNT_FOUR
};

struct link_training_settings {
        ...
        union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX];
};

void dp_hw_to_dpcd_lane_settings(
                ...
                union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX])
{
        ...
}

static enum link_training_result dpia_training_cr_transparent(
                ...
                struct link_training_settings *lt_settings)
{
        ...
                dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
                                lt_settings->hw_lane_settings, 
lt_settings->dpcd_lane_settings);
        ...
}

Everything looks to be the correct size?

-- 
Kees Cook