This is a note to let you know that I've just added the patch titled
net/mlx5e: Set page to null in case dma mapping fails
to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: net-mlx5e-set-page-to-null-in-case-dma-mapping-fails.patch and it can be found in the queue-4.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Tue Nov 21 13:07:20 CET 2017
From: Inbar Karmy inbark@mellanox.com Date: Sun, 15 Oct 2017 17:30:59 +0300 Subject: net/mlx5e: Set page to null in case dma mapping fails
From: Inbar Karmy inbark@mellanox.com
[ Upstream commit 2e50b2619538ea0224c037f6fa746023089e0654 ]
Currently, when dma mapping fails, put_page is called, but the page is not set to null. Later, in the page_reuse treatment in mlx5e_free_rx_descs(), mlx5e_page_release() is called for the second time, improperly doing dma_unmap (for a non-mapped address) and an extra put_page. Prevent this by nullifying the page pointer when dma_map fails.
Fixes: accd58833237 ("net/mlx5e: Introduce RX Page-Reuse") Signed-off-by: Inbar Karmy inbark@mellanox.com Reviewed-by: Tariq Toukan tariqt@mellanox.com Cc: kernel-team@fb.com Signed-off-by: Saeed Mahameed saeedm@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -213,22 +213,20 @@ static inline bool mlx5e_rx_cache_get(st static inline int mlx5e_page_alloc_mapped(struct mlx5e_rq *rq, struct mlx5e_dma_info *dma_info) { - struct page *page; - if (mlx5e_rx_cache_get(rq, dma_info)) return 0;
- page = dev_alloc_pages(rq->buff.page_order); - if (unlikely(!page)) + dma_info->page = dev_alloc_pages(rq->buff.page_order); + if (unlikely(!dma_info->page)) return -ENOMEM;
- dma_info->addr = dma_map_page(rq->pdev, page, 0, + dma_info->addr = dma_map_page(rq->pdev, dma_info->page, 0, RQ_PAGE_SIZE(rq), rq->buff.map_dir); if (unlikely(dma_mapping_error(rq->pdev, dma_info->addr))) { - put_page(page); + put_page(dma_info->page); + dma_info->page = NULL; return -ENOMEM; } - dma_info->page = page;
return 0; }
Patches currently in stable-queue which might be from inbark@mellanox.com are
queue-4.13/net-mlx5e-set-page-to-null-in-case-dma-mapping-fails.patch