On 2/13/2025 4:04 PM, Jason Gunthorpe wrote:
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On Thu, Feb 13, 2025 at 02:51:26PM +0200, Leon Romanovsky wrote:
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index e7e428369159..63a92d6cfbc2 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -112,8 +112,7 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
/* If the current entry is physically contiguous with the previous
* one, no need to take its start addresses into consideration.
*/
- if (curr_base + curr_len != sg_dma_address(sg)) {
-
+ if (curr_base != sg_dma_address(sg) - curr_len) {
curr_base = sg_dma_address(sg);
curr_len = 0;
I'm not sure about this, what ensures sg_dma_address() > curr_len?
curr_base + curr_len could also overflow, we've seen that AMD IOMMU
sometimes uses the very high addresess already
I think the only case we care about where curr_base + curr_len can
overflow is when next sg_dma_address() == 0.
But maybe we should just add an explicit check:
- if (curr_base + curr_len != sg_dma_address(sg)) {
+ if (curr_base + curr_len < curr_base ||
+ curr_base + curr_len != sg_dma_address(sg)) {
curr_base = sg_dma_address(sg);
curr_len = 0;
Michael
