[PATCH] drm/vkms: fix gamma LUT size check

[Renjun Wang <renjunw0@foxmail.com>]

vkms_atomic_check() computed the gamma LUT entry count using
sizeof(struct drm_color_lut *), which uses pointer size and
can incorrectly reject or accept LUT sizes. Use
drm_color_lut_size() instead to validate against VKMS_LUT_SIZE.

Signed-off-by: Renjun Wang <renjunw0@foxmail.com>
---
 drivers/gpu/drm/vkms/vkms_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index dd1402f43773..a09589949f48 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -17,6 +17,7 @@
 #include <drm/drm_gem.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_color_mgmt.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fbdev_shmem.h>
 #include <drm/drm_file.h>
@@ -111,8 +112,7 @@ static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *st
 		if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed)
 			continue;
 
-		if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *)
-		    > VKMS_LUT_SIZE)
+		if (drm_color_lut_size(new_crtc_state->gamma_lut) > VKMS_LUT_SIZE)
 			return -EINVAL;
 	}
 
-- 
2.47.3