On Fri, Aug 12, 2022 at 01:32:59PM +0200, Magnus Karlsson wrote:
> From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
>
> Fix an issue in XDP_SHARED_UMEM mode together with aligned mode were
s/were/where
> packets are corrupted for the second and any further sockets bound to
> the same umem. In other words, this does not affect the first socket
> bound to the umem. The culprit for this bug is that the initialization
> of the DMA addresses for the pre-populated xsk buffer pool entries was
> not performed for any socket but the first one bound to the umem. Only
> the linear array of DMA addresses was populated. Fix this by
> populating the DMA addresses in the xsk buffer pool for every socket
> bound to the same umem.
>
> Fixes: 94033cd8e73b8 ("xsk: Optimize for aligned case")
> Reported-by: Alasdair McWilliam <alasdair.mcwilliam@xxxxxxxxxxx>
> Reported-by: Intrusion Shield Team <dnevil@xxxxxxxxxxxxx>
> Tested-by: Alasdair McWilliam <alasdair.mcwilliam@xxxxxxxxxxx>
> Link: https://lore.kernel.org/xdp-newbies/6205E10C-292E-4995-9D10-409649354226@xxxxxxxxxxx/
> Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> ---
> net/xdp/xsk_buff_pool.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> index f70112176b7c..a71a8c6edf55 100644
> --- a/net/xdp/xsk_buff_pool.c
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -379,6 +379,16 @@ static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
>
> static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
> {
> + if (!pool->unaligned) {
> + u32 i;
> +
> + for (i = 0; i < pool->heads_cnt; i++) {
> + struct xdp_buff_xsk *xskb = &pool->heads[i];
> +
> + xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
I wondered if it would be better to move it to the end of func and use
pool->dma_pages, but it probably doesn't matter in the end.
Great catch!
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> + }
> + }
> +
> pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
> if (!pool->dma_pages)
> return -ENOMEM;
> @@ -428,12 +438,6 @@ int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
>
> if (pool->unaligned)
> xp_check_dma_contiguity(dma_map);
> - else
> - for (i = 0; i < pool->heads_cnt; i++) {
> - struct xdp_buff_xsk *xskb = &pool->heads[i];
> -
> - xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
> - }
>
> err = xp_init_dma_info(pool, dma_map);
> if (err) {
>
> base-commit: 4e4588f1c4d2e67c993208f0550ef3fae33abce4
> --
> 2.34.1
>
