Messages in this thread Patch in this message | | | From | Chao Gao <> | Subject | [PATCH v2] swiotlb: avoid potential left shift overflow | Date | Fri, 19 Aug 2022 16:45:37 +0800 |
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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 <chao.gao@intel.com> --- 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 c5a9190b218f..41ea9fb3efe1 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -579,7 +579,10 @@ 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. base-commit: 5c850d31880e00f063fa2a3746ba212c4bcc510f -- 2.25.1
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