From 5561bddd0599aa94a20036db7d7c495556771757 Mon Sep 17 00:00:00 2001 From: Ivan Malov Date: Tue, 28 Jun 2022 12:18:48 +0300 Subject: [PATCH] xsk: Clear page contiguity bit when unmapping pool [ Upstream commit 512d1999b8e94a5d43fba3afc73e774849674742 ] When a XSK pool gets mapped, xp_check_dma_contiguity() adds bit 0x1 to pages' DMA addresses that go in ascending order and at 4K stride. The problem is that the bit does not get cleared before doing unmap. As a result, a lot of warnings from iommu_dma_unmap_page() are seen in dmesg, which indicates that lookups by iommu_iova_to_phys() fail. Fixes: 2b43470add8c ("xsk: Introduce AF_XDP buffer allocation API") Signed-off-by: Ivan Malov Signed-off-by: Daniel Borkmann Acked-by: Magnus Karlsson Link: https://lore.kernel.org/bpf/20220628091848.534803-1-ivan.malov@oktetlabs.ru Signed-off-by: Sasha Levin --- net/xdp/xsk_buff_pool.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index 2ef6f926610e..e63a285a9856 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -318,6 +318,7 @@ static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) for (i = 0; i < dma_map->dma_pages_cnt; i++) { dma = &dma_map->dma_pages[i]; if (*dma) { + *dma &= ~XSK_NEXT_PG_CONTIG_MASK; dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, DMA_BIDIRECTIONAL, attrs); *dma = 0;