Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 59d2d18c authored by Honggang LI's avatar Honggang LI Committed by Doug Ledford
Browse files

mlx5: wrong page mask if CONFIG_ARCH_DMA_ADDR_T_64BIT enabled for 32Bit architectures 



If CONFIG_ARCH_DMA_ADDR_T_64BIT enabled for x86 systems and physical
memory is more than 4GB, dma_map_page may return a valid memory
address which greater than 0xffffffff. As a result, the mlx5 device page
allocator RB tree will be initialized with valid addresses greater than
0xfffffff.

However, (addr & PAGE_MASK) set the high four bytes to zeros. So, it's
impossible for the function, free_4k, to release the pages whose
addresses greater than 4GB. Memory leaks. And mlx5_ib module can't
release the pages when user try to remove the module, as a result,
system hang.

[root@rdma05 root]# dmesg  | grep addr | head
addr             = 3fe384000
addr & PAGE_MASK =  fe384000
[root@rdma05 root]# rmmod mlx5_ib   <---- hang on

---------------------- cosnole log -----------------
mlx5_ib 0000:04:00.0: irq 138 for MSI/MSI-X
  alloc irq_desc for 139 on node -1
  alloc kstat_irqs on node -1
mlx5_ib 0000:04:00.0: irq 139 for MSI/MSI-X
0000:04:00.0:free_4k:221:(pid 1519): page not found
0000:04:00.0:free_4k:221:(pid 1519): page not found
0000:04:00.0:free_4k:221:(pid 1519): page not found
0000:04:00.0:free_4k:221:(pid 1519): page not found
---------------------- cosnole log -----------------

Fixes: bf0bf77f ('mlx5: Support communicating arbitrary host page size to firmware')
Signed-off-by: default avatarHonggang Li <honli@redhat.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent cc47d369

drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c

+6 −4
Original line number Diff line number Diff line
@@ -211,26 +211,28 @@ static int alloc_4k(struct mlx5_core_dev *dev, u64 *addr) 
	return 0;

}



#define MLX5_U64_4K_PAGE_MASK ((~(u64)0U) << PAGE_SHIFT)



static void free_4k(struct mlx5_core_dev *dev, u64 addr)

{

	struct fw_page *fwp;

	int n;



	fwp = find_fw_page(dev, addr & PAGE_MASK);

	fwp = find_fw_page(dev, addr & MLX5_U64_4K_PAGE_MASK);

	if (!fwp) {

		mlx5_core_warn(dev, "page not found\n");

		return;

	}



	n = (addr & ~PAGE_MASK) >> MLX5_ADAPTER_PAGE_SHIFT;

	n = (addr & ~MLX5_U64_4K_PAGE_MASK) >> MLX5_ADAPTER_PAGE_SHIFT;

	fwp->free_count++;

	set_bit(n, &fwp->bitmask);

	if (fwp->free_count == MLX5_NUM_4K_IN_PAGE) {

		rb_erase(&fwp->rb_node, &dev->priv.page_root);

		if (fwp->free_count != 1)

			list_del(&fwp->list);

		dma_unmap_page(&dev->pdev->dev, addr & PAGE_MASK, PAGE_SIZE,

			       DMA_BIDIRECTIONAL);

		dma_unmap_page(&dev->pdev->dev, addr & MLX5_U64_4K_PAGE_MASK,

			       PAGE_SIZE, DMA_BIDIRECTIONAL);

		__free_page(fwp->page);

		kfree(fwp);

	} else if (fwp->free_count == 1) {