From 180235600934bef6add3be637c296d6cf3272e67 Mon Sep 17 00:00:00 2001 From: Til Kaiser Date: Sun, 7 Jun 2026 15:49:40 +0200 Subject: [PATCH 1/4] net: mvpp2: sync RX data at the hardware packet offset mvpp2 programs the RX queue packet offset, so hardware writes received data at dma_addr + MVPP2_SKB_HEADROOM. The current CPU sync starts at dma_addr and only covers rx_bytes + MVPP2_MH_SIZE bytes, which syncs the unused headroom and misses the same number of bytes at the packet tail. On non-coherent DMA systems this can leave the CPU reading stale cache contents for the end of the received frame. Use dma_sync_single_range_for_cpu() with MVPP2_SKB_HEADROOM as the range offset so the sync covers the Marvell header and packet data actually written by hardware. Fixes: e1921168bbd4 ("mvpp2: sync only the received frame") Signed-off-by: Til Kaiser Link: https://patch.msgid.link/20260607134943.21996-2-mail@tk154.de Signed-off-by: Paolo Abeni --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index f442b874bb59..92a701f4fe3f 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3946,9 +3946,10 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, dma_dir = DMA_FROM_DEVICE; } - dma_sync_single_for_cpu(dev->dev.parent, dma_addr, - rx_bytes + MVPP2_MH_SIZE, - dma_dir); + dma_sync_single_range_for_cpu(dev->dev.parent, dma_addr, + MVPP2_SKB_HEADROOM, + rx_bytes + MVPP2_MH_SIZE, + dma_dir); /* Buffer header not supported */ if (rx_status & MVPP2_RXD_BUF_HDR) From f3c6aa078927e6fe8121c9c591ddee8716c5305a Mon Sep 17 00:00:00 2001 From: Til Kaiser Date: Sun, 7 Jun 2026 15:49:41 +0200 Subject: [PATCH 2/4] net: mvpp2: limit XDP frame size to the RX buffer mvpp2 has short and long BM pools, and short pool buffers can be smaller than PAGE_SIZE. The XDP path nevertheless initializes every xdp_buff with PAGE_SIZE as frame size. XDP helpers use frame_sz to validate tail growth and to derive the hard end of the data area. Advertising PAGE_SIZE for short buffers can let bpf_xdp_adjust_tail() grow a packet past the real allocation, corrupting memory or later tripping skb tailroom checks. Initialize the XDP buffer with bm_pool->frag_size so XDP tailroom matches the actual buffer backing the packet. Fixes: 07dd0a7aae7f ("mvpp2: add basic XDP support") Signed-off-by: Til Kaiser Link: https://patch.msgid.link/20260607134943.21996-3-mail@tk154.de Signed-off-by: Paolo Abeni --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 92a701f4fe3f..3372ed27cc8d 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3979,7 +3979,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, else xdp_rxq = &rxq->xdp_rxq_long; - xdp_init_buff(&xdp, PAGE_SIZE, xdp_rxq); + xdp_init_buff(&xdp, bm_pool->frag_size, xdp_rxq); xdp_prepare_buff(&xdp, data, MVPP2_MH_SIZE + MVPP2_SKB_HEADROOM, rx_bytes, true); From 5e8e2a9624df72fca7c736b2966b2cbf6c9c3ff6 Mon Sep 17 00:00:00 2001 From: Til Kaiser Date: Sun, 7 Jun 2026 15:49:42 +0200 Subject: [PATCH 3/4] net: mvpp2: refill RX buffers before XDP or skb use The RX error path returns the current descriptor buffer to the hardware BM pool. That is only valid while the driver still owns the buffer. mvpp2_rx_refill() can fail after the current buffer has been handed to XDP or attached to an skb. In those cases mvpp2_run_xdp() may have recycled, redirected, or queued the page for XDP_TX, and an skb free also retires the data buffer. Returning such a buffer to BM lets hardware DMA into memory that is no longer owned by the RX ring. Refill the BM pool before handing the current buffer to XDP or to the skb. If the allocation fails there, drop the packet and return the still-owned current buffer to BM, preserving the pool depth. Once the refill succeeds, later local drops retire/free the current buffer instead of returning it to BM. Fixes: 07dd0a7aae7f ("mvpp2: add basic XDP support") Fixes: d6526926de73 ("net: mvpp2: fix memory leak in mvpp2_rx") Signed-off-by: Til Kaiser Link: https://patch.msgid.link/20260607134943.21996-4-mail@tk154.de Signed-off-by: Paolo Abeni --- .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 43 +++++++++++-------- 1 file changed, 24 insertions(+), 19 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 3372ed27cc8d..481daafdc1cb 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3971,6 +3971,12 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, else frag_size = bm_pool->frag_size; + err = mvpp2_rx_refill(port, bm_pool, pp, pool); + if (err) { + netdev_err(port->dev, "failed to refill BM pools\n"); + goto err_drop_frame; + } + if (xdp_prog) { struct xdp_rxq_info *xdp_rxq; @@ -3988,12 +3994,6 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, if (ret) { xdp_ret |= ret; - err = mvpp2_rx_refill(port, bm_pool, pp, pool); - if (err) { - netdev_err(port->dev, "failed to refill BM pools\n"); - goto err_drop_frame; - } - ps.rx_packets++; ps.rx_bytes += rx_bytes; continue; @@ -4008,8 +4008,21 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, skb = slab_build_skb(data); if (!skb) { netdev_warn(port->dev, "skb build failed\n"); - goto err_drop_frame; + if (pp) { + page_pool_put_page(pp, virt_to_head_page(data), + rx_bytes + MVPP2_MH_SIZE, + true); + } else { + dma_unmap_single_attrs(dev->dev.parent, dma_addr, + bm_pool->buf_size, + DMA_FROM_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); + mvpp2_frag_free(bm_pool, pp, data); + } + goto err_drop_frame_retired; } + if (pp) + skb_mark_for_recycle(skb); /* If we have RX hardware timestamping enabled, grab the * timestamp from the queue and convert. @@ -4020,16 +4033,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, skb_hwtstamps(skb)); } - err = mvpp2_rx_refill(port, bm_pool, pp, pool); - if (err) { - netdev_err(port->dev, "failed to refill BM pools\n"); - dev_kfree_skb_any(skb); - goto err_drop_frame; - } - - if (pp) - skb_mark_for_recycle(skb); - else + if (!pp) dma_unmap_single_attrs(dev->dev.parent, dma_addr, bm_pool->buf_size, DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC); @@ -4048,13 +4052,14 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, continue; err_drop_frame: - dev->stats.rx_errors++; - mvpp2_rx_error(port, rx_desc); /* Return the buffer to the pool */ if (rx_status & MVPP2_RXD_BUF_HDR) mvpp2_buff_hdr_pool_put(port, rx_desc, pool, rx_status); else mvpp2_bm_pool_put(port, pool, dma_addr, phys_addr); +err_drop_frame_retired: + dev->stats.rx_errors++; + mvpp2_rx_error(port, rx_desc); } if (xdp_ret & MVPP2_XDP_REDIR) From 77a6b90ce56bc982dcfa94229b8e28e6abb16e95 Mon Sep 17 00:00:00 2001 From: Til Kaiser Date: Sun, 7 Jun 2026 15:49:43 +0200 Subject: [PATCH 4/4] net: mvpp2: build skb from XDP-adjusted data on XDP_PASS When an XDP program uses bpf_xdp_adjust_head() or bpf_xdp_adjust_tail() and then returns XDP_PASS, mvpp2 still builds the skb from fixed offsets derived from the original RX descriptor. Packet geometry changes made by the XDP program are therefore discarded before the skb reaches the stack. Update rx_offset and rx_bytes from xdp.data and xdp.data_end for XDP_PASS. This makes skb_reserve() and skb_put() reflect the packet seen by XDP, and makes RX byte accounting for XDP_PASS follow the length of the skb passed to the network stack. Keep a separate rx_sync_size for page-pool recycling on skb allocation failure, which must stay tied to the received buffer range. Non-PASS verdicts continue to account the descriptor length because no skb is passed up in those cases. Fixes: 07dd0a7aae7f ("mvpp2: add basic XDP support") Signed-off-by: Til Kaiser Link: https://patch.msgid.link/20260607134943.21996-5-mail@tk154.de Signed-off-by: Paolo Abeni --- .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 21 +++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 481daafdc1cb..ccc24a1301f2 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3917,10 +3917,10 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, struct mvpp2_bm_pool *bm_pool; struct page_pool *pp = NULL; struct sk_buff *skb; - unsigned int frag_size; + unsigned int frag_size, rx_sync_size; dma_addr_t dma_addr; phys_addr_t phys_addr; - int pool, rx_bytes, err, ret; + int pool, rx_bytes, rx_offset, err, ret; struct page *page; void *data; @@ -3933,6 +3933,8 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, rx_status = mvpp2_rxdesc_status_get(port, rx_desc); rx_bytes = mvpp2_rxdesc_size_get(port, rx_desc); rx_bytes -= MVPP2_MH_SIZE; + rx_sync_size = rx_bytes + MVPP2_MH_SIZE; + rx_offset = MVPP2_MH_SIZE + MVPP2_SKB_HEADROOM; dma_addr = mvpp2_rxdesc_dma_addr_get(port, rx_desc); pool = (rx_status & MVPP2_RXD_BM_POOL_ID_MASK) >> @@ -3948,7 +3950,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, dma_sync_single_range_for_cpu(dev->dev.parent, dma_addr, MVPP2_SKB_HEADROOM, - rx_bytes + MVPP2_MH_SIZE, + rx_sync_size, dma_dir); /* Buffer header not supported */ @@ -3999,6 +4001,14 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, continue; } + rx_sync_size = max_t(unsigned int, rx_sync_size, + xdp.data_end - xdp.data_hard_start - + MVPP2_SKB_HEADROOM); + + /* Update offset and length to reflect any XDP adjustments. */ + rx_offset = xdp.data - data; + rx_bytes = xdp.data_end - xdp.data; + metasize = xdp.data - xdp.data_meta; } @@ -4010,8 +4020,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, netdev_warn(port->dev, "skb build failed\n"); if (pp) { page_pool_put_page(pp, virt_to_head_page(data), - rx_bytes + MVPP2_MH_SIZE, - true); + rx_sync_size, true); } else { dma_unmap_single_attrs(dev->dev.parent, dma_addr, bm_pool->buf_size, @@ -4041,7 +4050,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, ps.rx_packets++; ps.rx_bytes += rx_bytes; - skb_reserve(skb, MVPP2_MH_SIZE + MVPP2_SKB_HEADROOM); + skb_reserve(skb, rx_offset); skb_put(skb, rx_bytes); if (metasize) skb_metadata_set(skb, metasize);