[PATCH 4/5] drm/mediatek: Add casting before assign

Jason-JH.Lin jason-jh.lin at mediatek.com
Thu Apr 6 23:46:56 PDT 2023


Add casting before assign to avoid the unintentional integer overflow
or unintended sign extension.

Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
Fixes: 1a64a7aff8da ("drm/mediatek: Fix cursor plane no update")
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c   |  2 +-
 drivers/gpu/drm/mediatek/mtk_drm_plane.c | 20 +++++++++++---------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 9b8f72ed12e4..537e83b95001 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -121,7 +121,7 @@ int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
 	int ret;
 
 	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
-	args->size = args->pitch * args->height;
+	args->size = (unsigned long)args->pitch * args->height;
 
 	mtk_gem = mtk_drm_gem_create(dev, args->size, false);
 	if (IS_ERR(mtk_gem))
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index 31f9420aff6f..a1337f386bbf 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -140,7 +140,7 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
 	struct drm_framebuffer *fb = new_state->fb;
 	struct drm_gem_object *gem;
 	struct mtk_drm_gem_obj *mtk_gem;
-	unsigned int pitch, format;
+	unsigned int pitch, format, cpp;
 	u64 modifier;
 	dma_addr_t addr;
 	dma_addr_t hdr_addr = 0;
@@ -151,11 +151,12 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
 	addr = mtk_gem->dma_addr;
 	pitch = fb->pitches[0];
 	format = fb->format->format;
+	cpp = (unsigned int)fb->format->cpp[0];
 	modifier = fb->modifier;
 
 	if (modifier == DRM_FORMAT_MOD_LINEAR) {
-		addr += (new_state->src.x1 >> 16) * fb->format->cpp[0];
-		addr += (new_state->src.y1 >> 16) * pitch;
+		addr += (dma_addr_t)(new_state->src.x1 >> 16) * cpp;
+		addr += (dma_addr_t)(new_state->src.y1 >> 16) * pitch;
 	} else {
 		int width_in_blocks = ALIGN(fb->width, AFBC_DATA_BLOCK_WIDTH)
 				      / AFBC_DATA_BLOCK_WIDTH;
@@ -167,17 +168,18 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
 
 		hdr_pitch = width_in_blocks * AFBC_HEADER_BLOCK_SIZE;
 		pitch = width_in_blocks * AFBC_DATA_BLOCK_WIDTH *
-			AFBC_DATA_BLOCK_HEIGHT * fb->format->cpp[0];
+			AFBC_DATA_BLOCK_HEIGHT * cpp;
 
 		hdr_size = ALIGN(hdr_pitch * height_in_blocks, AFBC_HEADER_ALIGNMENT);
 
-		hdr_addr = addr + hdr_pitch * y_offset_in_blocks +
-			   AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
+		hdr_addr = addr +
+			   (dma_addr_t)hdr_pitch * y_offset_in_blocks +
+			   (dma_addr_t)AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
 		/* The data plane is offset by 1 additional block. */
 		addr = addr + hdr_size +
-		       pitch * y_offset_in_blocks +
-		       AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
-		       fb->format->cpp[0] * (x_offset_in_blocks + 1);
+		       (dma_addr_t)pitch * y_offset_in_blocks +
+		       (dma_addr_t)AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
+		       (dma_addr_t)cpp * (x_offset_in_blocks + 1);
 	}
 
 	mtk_plane_state->pending.enable = true;
-- 
2.18.0




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