Re: [PATCH] drm/amd/display: Verify Gamma & Degamma LUT sizes in amdgpu_dm_atomic_check

On 2021-06-04 1:01 p.m., Mark Yacoub wrote:

From: Mark Yacoub markyacoub@google.com

For each CRTC state, check the size of Gamma and Degamma LUTs so unexpected and larger sizes wouldn't slip through.

TEST: IGT:kms_color::pipe-invalid-gamma-lut-sizes

Signed-off-by: Mark Yacoub markyacoub@chromium.org Change-Id: I9d513a38e8ac2af1b4bf802e1feb1a4d726fba4c

---

.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++ .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 1 + .../amd/display/amdgpu_dm/amdgpu_dm_color.c | 40 ++++++++++++++++--- 3 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 38d497d30dba8..f6cd522b42a80 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -9402,6 +9402,9 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev, dm_old_crtc_state->dsc_force_changed == false) continue;

• if ((ret = amdgpu_dm_verify_lut_sizes(new_crtc_state)))
  

• 	goto fail;
  

• if (!new_crtc_state->enable) continue;

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h index 8bfe901cf2374..1b77cd2612691 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h @@ -541,6 +541,7 @@ void amdgpu_dm_trigger_timing_sync(struct drm_device *dev); #define MAX_COLOR_LEGACY_LUT_ENTRIES 256

void amdgpu_dm_init_color_mod(void); +int amdgpu_dm_verify_lut_sizes(const struct drm_crtc_state *crtc_state); int amdgpu_dm_update_crtc_color_mgmt(struct dm_crtc_state *crtc); int amdgpu_dm_update_plane_color_mgmt(struct dm_crtc_state *crtc, struct dc_plane_state *dc_plane_state); diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c index 157fe4efbb599..da6f9fcc0b415 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c @@ -284,6 +284,37 @@ static int __set_input_tf(struct dc_transfer_func *func, return res ? 0 : -ENOMEM; }

+/**

• • Verifies that the Degamma and Gamma LUTs attached to the |crtc_state| are of
• • the expected size.
• • Returns 0 on success.
• */

+int amdgpu_dm_verify_lut_sizes(const struct drm_crtc_state *crtc_state) +{

• const struct drm_color_lut *lut = NULL;
• uint32_t size = 0;
• lut = __extract_blob_lut(crtc_state->degamma_lut, &size);
• if (lut && size != MAX_COLOR_LUT_ENTRIES) {

Isn't the point of the LUT size that it can be variable? Did you observe any problems with LUTs that are not of size 4096?

Legacy X-based userspace will give us 256 size LUTs. We can't break support for that. See MAX_COLOR_LEGACY_LUT_ENTRIES.

Harry

• DRM_DEBUG_DRIVER(
  

• 	"Invalid Degamma LUT size. Should be %u but got %u.\n",
  

• 	MAX_COLOR_LUT_ENTRIES, size);
  

• return -EINVAL;
  

• }
• lut = __extract_blob_lut(crtc_state->gamma_lut, &size);
• if (lut && size != MAX_COLOR_LUT_ENTRIES &&

•    size != MAX_COLOR_LEGACY_LUT_ENTRIES) {
  

• DRM_DEBUG_DRIVER(
  

• 	"Invalid Gamma LUT size. Should be %u (or %u for legacy) but got %u.\n",
  

• 	MAX_COLOR_LUT_ENTRIES, MAX_COLOR_LEGACY_LUT_ENTRIES,
  

• 	size);
  

• return -EINVAL;
  

• }
• return 0;

+}

/**

• amdgpu_dm_update_crtc_color_mgmt: Maps DRM color management to DC stream.
• @crtc: amdgpu_dm crtc state

@@ -317,14 +348,11 @@ int amdgpu_dm_update_crtc_color_mgmt(struct dm_crtc_state *crtc) bool is_legacy; int r;

• degamma_lut = __extract_blob_lut(crtc->base.degamma_lut, &degamma_size);
• if (degamma_lut && degamma_size != MAX_COLOR_LUT_ENTRIES)

• return -EINVAL;
  

• if ((r = amdgpu_dm_verify_lut_sizes(&crtc->base)))

• return r;
  
  

• degamma_lut = __extract_blob_lut(crtc->base.degamma_lut, &degamma_size); regamma_lut = __extract_blob_lut(crtc->base.gamma_lut, &regamma_size);

• if (regamma_lut && regamma_size != MAX_COLOR_LUT_ENTRIES &&

•    regamma_size != MAX_COLOR_LEGACY_LUT_ENTRIES)
  

• return -EINVAL;
  
  

  has_degamma = degamma_lut && !__is_lut_linear(degamma_lut, degamma_size);