[PATCH] drm/xe/display: fix potential overflow when multiplying 2 u32

Arun R Murthy arun.r.murthy at intel.com
Mon Mar 18 11:01:03 UTC 2024


Multiplying XE_PAGE_SIZE with another u32 and the product stored in
u64 can potentially lead to overflow, use mul_u32_u32 instead.

Signed-off-by: Arun R Murthy <arun.r.murthy at intel.com>
---
 drivers/gpu/drm/xe/display/xe_fb_pin.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.c b/drivers/gpu/drm/xe/display/xe_fb_pin.c
index 722c84a56607..e0b511ff7eab 100644
--- a/drivers/gpu/drm/xe/display/xe_fb_pin.c
+++ b/drivers/gpu/drm/xe/display/xe_fb_pin.c
@@ -29,7 +29,7 @@ write_dpt_rotated(struct xe_bo *bo, struct iosys_map *map, u32 *dpt_ofs, u32 bo_
 		u32 src_idx = src_stride * (height - 1) + column + bo_ofs;
 
 		for (row = 0; row < height; row++) {
-			u64 pte = ggtt->pt_ops->pte_encode_bo(bo, src_idx * XE_PAGE_SIZE,
+			u64 pte = ggtt->pt_ops->pte_encode_bo(bo, mul_u32_u32(src_idx, XE_PAGE_SIZE),
 							      xe->pat.idx[XE_CACHE_WB]);
 
 			iosys_map_wr(map, *dpt_ofs, u64, pte);
@@ -61,7 +61,7 @@ write_dpt_remapped(struct xe_bo *bo, struct iosys_map *map, u32 *dpt_ofs,
 
 		for (column = 0; column < width; column++) {
 			iosys_map_wr(map, *dpt_ofs, u64,
-				     pte_encode_bo(bo, src_idx * XE_PAGE_SIZE,
+				     pte_encode_bo(bo, mul_u32_u32(src_idx, XE_PAGE_SIZE),
 				     xe->pat.idx[XE_CACHE_WB]));
 
 			*dpt_ofs += 8;
@@ -118,7 +118,7 @@ static int __xe_pin_fb_vma_dpt(struct intel_framebuffer *fb,
 		u32 x;
 
 		for (x = 0; x < size / XE_PAGE_SIZE; x++) {
-			u64 pte = ggtt->pt_ops->pte_encode_bo(bo, x * XE_PAGE_SIZE,
+			u64 pte = ggtt->pt_ops->pte_encode_bo(bo, mul_u32_u32(x, XE_PAGE_SIZE),
 							      xe->pat.idx[XE_CACHE_WB]);
 
 			iosys_map_wr(&dpt->vmap, x * 8, u64, pte);
@@ -164,7 +164,7 @@ write_ggtt_rotated(struct xe_bo *bo, struct xe_ggtt *ggtt, u32 *ggtt_ofs, u32 bo
 		u32 src_idx = src_stride * (height - 1) + column + bo_ofs;
 
 		for (row = 0; row < height; row++) {
-			u64 pte = ggtt->pt_ops->pte_encode_bo(bo, src_idx * XE_PAGE_SIZE,
+			u64 pte = ggtt->pt_ops->pte_encode_bo(bo, mul_u32_u32(src_idx, XE_PAGE_SIZE),
 							      xe->pat.idx[XE_CACHE_WB]);
 
 			xe_ggtt_set_pte(ggtt, *ggtt_ofs, pte);
@@ -381,4 +381,4 @@ struct i915_address_space *intel_dpt_create(struct intel_framebuffer *fb)
 void intel_dpt_destroy(struct i915_address_space *vm)
 {
 	return;
-}
\ No newline at end of file
+}
-- 
2.25.1



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