swiotlb: avoid potential left shift overflow

The second operand passed to slot_addr() is declared as int or unsigned int in all call sites. The left-shift to get the offset of a slot can overflow if swiotlb size is larger than 4G. Convert the macro to an inline function and declare the second argument as phys_addr_t to avoid the potential overflow. Fixes: 26a7e09 ("swiotlb: refactor swiotlb_tbl_map_single") Signed-off-by: Chao Gao <[email protected]> Reviewed-by: Dongli Zhang <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]>
majek · Sep 7, 2022 · 3f04616 · 3f04616
1 parent 2995b80
commit 3f04616
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
@@ -575,7 +575,10 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
 	}
 }
 
-#define slot_addr(start, idx)	((start) + ((idx) << IO_TLB_SHIFT))
+static inline phys_addr_t slot_addr(phys_addr_t start, phys_addr_t idx)
+{
+	return start + (idx << IO_TLB_SHIFT);
+}
 
 /*
  * Carefully handle integer overflow which can occur when boundary_mask == ~0UL.