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

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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: bf0bf77f65 ('mlx5: Support communicating arbitrary host page size to firmware')
Signed-off-by: Honggang Li <honli@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Honggang LI 2015-04-15 16:36:15 +08:00 committed by Doug Ledford
parent cc47d369b5
commit 59d2d18cc4
1 changed files with 6 additions and 4 deletions
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10
drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c
View file

@ -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) {