From 3f0461613ebcdc8c4073e235053d06d5aa58750f Mon Sep 17 00:00:00 2001 From: Chao Gao Date: Fri, 19 Aug 2022 16:45:37 +0800 Subject: [PATCH] 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: 26a7e094783d ("swiotlb: refactor swiotlb_tbl_map_single") Signed-off-by: Chao Gao Reviewed-by: Dongli Zhang Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index dd8863987e0c..1ce8977d911c 100644 --- 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.