[PATCH 01/26] drm/amd/display: fix bug of accessing invalid memory
Bhawanpreet Lakha
Bhawanpreet.Lakha at amd.com
Wed Oct 10 22:08:56 UTC 2018
From: Su Sung Chung <Su.Chung at amd.com>
[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 <Su.Chung at amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr at amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
---
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 15427f4fc990..cdcefd087487 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);
--
2.14.1
More information about the amd-gfx
mailing list