net/mlx5e: Do not modify the TX SKB

If the SKB is cloned, or has an elevated users count, someone else
can be looking at it at the same time.

Signed-off-by: Achiad Shochat <achiad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index f689ce580b4467a4233efff4de41ba221dcacc6f..ae3f0e326c798088f7fa772796ecc409766a5bce 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -328,14 +328,12 @@ struct mlx5e_rq {
        struct mlx5e_priv     *priv;
 } ____cacheline_aligned_in_smp;
 
-struct mlx5e_tx_skb_cb {
+struct mlx5e_tx_wqe_info {
        u32 num_bytes;
        u8  num_wqebbs;
        u8  num_dma;
 };
 
-#define MLX5E_TX_SKB_CB(__skb) ((struct mlx5e_tx_skb_cb *)__skb->cb)
-
 enum mlx5e_dma_map_type {
        MLX5E_DMA_MAP_SINGLE,
        MLX5E_DMA_MAP_PAGE
@@ -371,6 +369,7 @@ struct mlx5e_sq {
        /* pointers to per packet info: write@xmit, read@completion */
        struct sk_buff           **skb;
        struct mlx5e_sq_dma       *dma_fifo;
+       struct mlx5e_tx_wqe_info  *wqe_info;
 
        /* read only */
        struct mlx5_wq_cyc         wq;

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index d4601a5646997d07704379d6359e389f1040dc8c..96775a29a4404e72dd413d8fcd488d04c1da32a0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -507,6 +507,7 @@ static void mlx5e_close_rq(struct mlx5e_rq *rq)
 
 static void mlx5e_free_sq_db(struct mlx5e_sq *sq)
 {
+       kfree(sq->wqe_info);
        kfree(sq->dma_fifo);
        kfree(sq->skb);
 }
@@ -519,8 +520,10 @@ static int mlx5e_alloc_sq_db(struct mlx5e_sq *sq, int numa)
        sq->skb = kzalloc_node(wq_sz * sizeof(*sq->skb), GFP_KERNEL, numa);
        sq->dma_fifo = kzalloc_node(df_sz * sizeof(*sq->dma_fifo), GFP_KERNEL,
                                    numa);
+       sq->wqe_info = kzalloc_node(wq_sz * sizeof(*sq->wqe_info), GFP_KERNEL,
+                                   numa);
 
-       if (!sq->skb || !sq->dma_fifo) {
+       if (!sq->skb || !sq->dma_fifo || !sq->wqe_info) {
                mlx5e_free_sq_db(sq);
                return -ENOMEM;
        }

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
index 1341b1d3c421d2a0f2050b7c0103853cbecf1cd6..aa037eb1a0b2e4628c7c20b82feddf607d8d7354 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -92,11 +92,11 @@ static inline struct mlx5e_sq_dma *mlx5e_dma_get(struct mlx5e_sq *sq, u32 i)
        return &sq->dma_fifo[i & sq->dma_fifo_mask];
 }
 
-static void mlx5e_dma_unmap_wqe_err(struct mlx5e_sq *sq, struct sk_buff *skb)
+static void mlx5e_dma_unmap_wqe_err(struct mlx5e_sq *sq, u8 num_dma)
 {
        int i;
 
-       for (i = 0; i < MLX5E_TX_SKB_CB(skb)->num_dma; i++) {
+       for (i = 0; i < num_dma; i++) {
                struct mlx5e_sq_dma *last_pushed_dma =
                        mlx5e_dma_get(sq, --sq->dma_fifo_pc);
 
@@ -139,19 +139,28 @@ static inline u16 mlx5e_get_inline_hdr_size(struct mlx5e_sq *sq,
        return MLX5E_MIN_INLINE;
 }
 
-static inline void mlx5e_insert_vlan(void *start, struct sk_buff *skb, u16 ihs)
+static inline void mlx5e_tx_skb_pull_inline(unsigned char **skb_data,
+                                           unsigned int *skb_len,
+                                           unsigned int len)
+{
+       *skb_len -= len;
+       *skb_data += len;
+}
+
+static inline void mlx5e_insert_vlan(void *start, struct sk_buff *skb, u16 ihs,
+                                    unsigned char **skb_data,
+                                    unsigned int *skb_len)
 {
        struct vlan_ethhdr *vhdr = (struct vlan_ethhdr *)start;
        int cpy1_sz = 2 * ETH_ALEN;
        int cpy2_sz = ihs - cpy1_sz;
 
-       skb_copy_from_linear_data(skb, vhdr, cpy1_sz);
-       skb_pull_inline(skb, cpy1_sz);
+       memcpy(vhdr, *skb_data, cpy1_sz);
+       mlx5e_tx_skb_pull_inline(skb_data, skb_len, cpy1_sz);
        vhdr->h_vlan_proto = skb->vlan_proto;
        vhdr->h_vlan_TCI = cpu_to_be16(skb_vlan_tag_get(skb));
-       skb_copy_from_linear_data(skb, &vhdr->h_vlan_encapsulated_proto,
-                                 cpy2_sz);
-       skb_pull_inline(skb, cpy2_sz);
+       memcpy(&vhdr->h_vlan_encapsulated_proto, *skb_data, cpy2_sz);
+       mlx5e_tx_skb_pull_inline(skb_data, skb_len, cpy2_sz);
 }
 
 static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
@@ -160,11 +169,14 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
 
        u16 pi = sq->pc & wq->sz_m1;
        struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(wq, pi);
+       struct mlx5e_tx_wqe_info *wi   = &sq->wqe_info[pi];
 
        struct mlx5_wqe_ctrl_seg *cseg = &wqe->ctrl;
        struct mlx5_wqe_eth_seg  *eseg = &wqe->eth;
        struct mlx5_wqe_data_seg *dseg;
 
+       unsigned char *skb_data = skb->data;
+       unsigned int skb_len = skb->len;
        u8  opcode = MLX5_OPCODE_SEND;
        dma_addr_t dma_addr = 0;
        bool bf = false;
@@ -192,8 +204,8 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
                opcode       = MLX5_OPCODE_LSO;
                ihs          = skb_transport_offset(skb) + tcp_hdrlen(skb);
                payload_len  = skb->len - ihs;
-               MLX5E_TX_SKB_CB(skb)->num_bytes = skb->len +
-                                       (skb_shinfo(skb)->gso_segs - 1) * ihs;
+               wi->num_bytes = skb->len +
+                               (skb_shinfo(skb)->gso_segs - 1) * ihs;
                sq->stats.tso_packets++;
                sq->stats.tso_bytes += payload_len;
        } else {
@@ -201,16 +213,16 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
                     !skb->xmit_more &&
                     !skb_shinfo(skb)->nr_frags;
                ihs = mlx5e_get_inline_hdr_size(sq, skb, bf);
-               MLX5E_TX_SKB_CB(skb)->num_bytes = max_t(unsigned int, skb->len,
-                                                       ETH_ZLEN);
+               wi->num_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
        }
 
        if (skb_vlan_tag_present(skb)) {
-               mlx5e_insert_vlan(eseg->inline_hdr_start, skb, ihs);
+               mlx5e_insert_vlan(eseg->inline_hdr_start, skb, ihs, &skb_data,
+                                 &skb_len);
                ihs += VLAN_HLEN;
        } else {
-               skb_copy_from_linear_data(skb, eseg->inline_hdr_start, ihs);
-               skb_pull_inline(skb, ihs);
+               memcpy(eseg->inline_hdr_start, skb_data, ihs);
+               mlx5e_tx_skb_pull_inline(&skb_data, &skb_len, ihs);
        }
 
        eseg->inline_hdr_sz = cpu_to_be16(ihs);
@@ -220,11 +232,11 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
                               MLX5_SEND_WQE_DS);
        dseg    = (struct mlx5_wqe_data_seg *)cseg + ds_cnt;
 
-       MLX5E_TX_SKB_CB(skb)->num_dma = 0;
+       wi->num_dma = 0;
 
-       headlen = skb_headlen(skb);
+       headlen = skb_len - skb->data_len;
        if (headlen) {
-               dma_addr = dma_map_single(sq->pdev, skb->data, headlen,
+               dma_addr = dma_map_single(sq->pdev, skb_data, headlen,
                                          DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
                        goto dma_unmap_wqe_err;
@@ -234,7 +246,7 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
                dseg->byte_count = cpu_to_be32(headlen);
 
                mlx5e_dma_push(sq, dma_addr, headlen, MLX5E_DMA_MAP_SINGLE);
-               MLX5E_TX_SKB_CB(skb)->num_dma++;
+               wi->num_dma++;
 
                dseg++;
        }
@@ -253,23 +265,22 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
                dseg->byte_count = cpu_to_be32(fsz);
 
                mlx5e_dma_push(sq, dma_addr, fsz, MLX5E_DMA_MAP_PAGE);
-               MLX5E_TX_SKB_CB(skb)->num_dma++;
+               wi->num_dma++;
 
                dseg++;
        }
 
-       ds_cnt += MLX5E_TX_SKB_CB(skb)->num_dma;
+       ds_cnt += wi->num_dma;
 
        cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | opcode);
        cseg->qpn_ds           = cpu_to_be32((sq->sqn << 8) | ds_cnt);
 
        sq->skb[pi] = skb;
 
-       MLX5E_TX_SKB_CB(skb)->num_wqebbs = DIV_ROUND_UP(ds_cnt,
-                                                       MLX5_SEND_WQEBB_NUM_DS);
-       sq->pc += MLX5E_TX_SKB_CB(skb)->num_wqebbs;
+       wi->num_wqebbs = DIV_ROUND_UP(ds_cnt, MLX5_SEND_WQEBB_NUM_DS);
+       sq->pc += wi->num_wqebbs;
 
-       netdev_tx_sent_queue(sq->txq, MLX5E_TX_SKB_CB(skb)->num_bytes);
+       netdev_tx_sent_queue(sq->txq, wi->num_bytes);
 
        if (unlikely(!mlx5e_sq_has_room_for(sq, MLX5E_SQ_STOP_ROOM))) {
                netif_tx_stop_queue(sq->txq);
@@ -280,7 +291,7 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
                int bf_sz = 0;
 
                if (bf && sq->uar_bf_map)
-                       bf_sz = MLX5E_TX_SKB_CB(skb)->num_wqebbs << 3;
+                       bf_sz = wi->num_wqebbs << 3;
 
                cseg->fm_ce_se = MLX5_WQE_CTRL_CQ_UPDATE;
                mlx5e_tx_notify_hw(sq, wqe, bf_sz);
@@ -297,7 +308,7 @@ static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
 
 dma_unmap_wqe_err:
        sq->stats.dropped++;
-       mlx5e_dma_unmap_wqe_err(sq, skb);
+       mlx5e_dma_unmap_wqe_err(sq, wi->num_dma);
 
        dev_kfree_skb_any(skb);
 
@@ -352,6 +363,7 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq)
                wqe_counter = be16_to_cpu(cqe->wqe_counter);
 
                do {
+                       struct mlx5e_tx_wqe_info *wi;
                        struct sk_buff *skb;
                        u16 ci;
                        int j;
@@ -360,6 +372,7 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq)
 
                        ci = sqcc & sq->wq.sz_m1;
                        skb = sq->skb[ci];
+                       wi = &sq->wqe_info[ci];
 
                        if (unlikely(!skb)) { /* nop */
                                sq->stats.nop++;
@@ -367,7 +380,7 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq)
                                continue;
                        }
 
-                       for (j = 0; j < MLX5E_TX_SKB_CB(skb)->num_dma; j++) {
+                       for (j = 0; j < wi->num_dma; j++) {
                                struct mlx5e_sq_dma *dma =
                                        mlx5e_dma_get(sq, dma_fifo_cc++);
 
@@ -375,8 +388,8 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq)
                        }
 
                        npkts++;
-                       nbytes += MLX5E_TX_SKB_CB(skb)->num_bytes;
-                       sqcc += MLX5E_TX_SKB_CB(skb)->num_wqebbs;
+                       nbytes += wi->num_bytes;
+                       sqcc += wi->num_wqebbs;
                        dev_kfree_skb(skb);
                } while (!last_wqe);
        }