From: Kees Cook <[email protected]>
Date: Wed, 20 Sep 2023 13:25:13 -0700
> In the likely pathological case of building sky2 with 16k PAGE_SIZE,
> make sure there is at least 1 frag_addr in struct rx_ring_info:
>
> In file included from include/linux/skbuff.h:28,
> from include/net/net_namespace.h:43,
> from include/linux/netdevice.h:38,
> from drivers/net/ethernet/marvell/sky2.c:18:
> drivers/net/ethernet/marvell/sky2.c: In function 'sky2_rx_unmap_skb':
> include/linux/dma-mapping.h:416:36: warning: array subscript i is outside
> array bounds of 'dma_addr_t[0]' {aka 'long long unsigned int[]'}
> [-Warray-bounds=]
> 416 | #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s,
> r, 0)
> |
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/marvell/sky2.c:1257:17: note: in expansion of macro
> 'dma_unmap_page'
> 1257 | dma_unmap_page(&pdev->dev, re->frag_addr[i],
> | ^~~~~~~~~~~~~~
> In file included from drivers/net/ethernet/marvell/sky2.c:41:
> drivers/net/ethernet/marvell/sky2.h:2198:25: note: while referencing
> 'frag_addr'
> 2198 | dma_addr_t frag_addr[ETH_JUMBO_MTU >> PAGE_SHIFT];
> | ^~~~~~~~~
>
> With CONFIG_PAGE_SIZE_16KB=y, PAGE_SHIFT == 14, so:
>
> #define ETH_JUMBO_MTU 9000
>
> causes "ETH_JUMBO_MTU >> PAGE_SHIFT" to be 0. Use "?: 1" to solve this build
> warning.
>
> Cc: Mirko Lindner <[email protected]>
> Cc: Stephen Hemminger <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: [email protected]
> Reported-by: kernel test robot <[email protected]>
> Closes:
> https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Alexander Lobakin <[email protected]>
That "nobody uses this HW on non-x86 systems, why bother" is fun each time.
> ---
> drivers/net/ethernet/marvell/sky2.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/marvell/sky2.h
> b/drivers/net/ethernet/marvell/sky2.h
> index ddec1627f1a7..8d0bacf4e49c 100644
> --- a/drivers/net/ethernet/marvell/sky2.h
> +++ b/drivers/net/ethernet/marvell/sky2.h
> @@ -2195,7 +2195,7 @@ struct rx_ring_info {
> struct sk_buff *skb;
> dma_addr_t data_addr;
> DEFINE_DMA_UNMAP_LEN(data_size);
> - dma_addr_t frag_addr[ETH_JUMBO_MTU >> PAGE_SHIFT];
> + dma_addr_t frag_addr[ETH_JUMBO_MTU >> PAGE_SHIFT ?: 1];
> };
>
> enum flow_control {
Thanks,
Olek
