From 43c3ff27a47d83d153c4adc088243ba594582bf5 Mon Sep 17 00:00:00 2001 From: Su Sung Chung Date: Thu, 20 Sep 2018 15:03:27 -0400 Subject: [PATCH] drm/amd/display: fix bug of accessing invalid memory [Why] A loop inside of build_evenly_distributed_points function that traverse through the array of points become an infinite loop when m_GammaUpdates does not get assigned to any value. [How] In DMColor, clear m_gammaIsValid bit just before writting all Zeromem for m_GammaUpdates, to prevent calling build_evenly_distributed_points before m_GammaUpdates gets assigned to some value. Signed-off-by: Su Sung Chung Reviewed-by: Aric Cyr Acked-by: Bhawanpreet Lakha Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c index 15427f4..cdcefd0 100644 --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c @@ -1069,10 +1069,14 @@ static void build_evenly_distributed_points( struct dividers dividers) { struct gamma_pixel *p = points; - struct gamma_pixel *p_last = p + numberof_points - 1; + struct gamma_pixel *p_last; uint32_t i = 0; + // This function should not gets called with 0 as a parameter + ASSERT(numberof_points > 0); + p_last = p + numberof_points - 1; + do { struct fixed31_32 value = dc_fixpt_from_fraction(i, numberof_points - 1); @@ -1083,7 +1087,7 @@ static void build_evenly_distributed_points( ++p; ++i; - } while (i != numberof_points); + } while (i < numberof_points); p->r = dc_fixpt_div(p_last->r, dividers.divider1); p->g = dc_fixpt_div(p_last->g, dividers.divider1); -- 2.7.4