qed: fix LL2 RX buffer allocation

Driver allocates the LL2 rx buffers from kmalloc()
area to construct the skb using slab_build_skb()

The required size allocation seems to have overlooked
for accounting both skb_shared_info size and device
placement padding bytes which results into the below
panic when doing skb_put() for a standard MTU sized frame.

skbuff: skb_over_panic: text:ffffffffc0b0225f len:1514 put:1514
head:ff3dabceaf39c000 data:ff3dabceaf39c042 tail:0x62c end:0x566
dev:<NULL>
…
skb_panic+0x48/0x4a
skb_put.cold+0x10/0x10
qed_ll2b_complete_rx_packet+0x14f/0x260 [qed]
qed_ll2_rxq_handle_completion.constprop.0+0x169/0x200 [qed]
qed_ll2_rxq_completion+0xba/0x320 [qed]
qed_int_sp_dpc+0x1a7/0x1e0 [qed]

This patch fixes this by accouting skb_shared_info and device
placement padding size bytes when allocating the buffers.

Cc: David S. Miller <davem@davemloft.net>
Fixes: 0a7fb11c23c0 ("qed: Add Light L2 support")
Signed-off-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qlogic/qed/qed_ll2.c b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
index 717a0b3..ab5ef25 100644 (file)
--- a/drivers/net/ethernet/qlogic/qed/qed_ll2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
@@ -113,7 +113,10 @@ static void qed_ll2b_complete_tx_packet(void *cxt,
 static int qed_ll2_alloc_buffer(struct qed_dev *cdev,
                                u8 **data, dma_addr_t *phys_addr)
 {
-       *data = kmalloc(cdev->ll2->rx_size, GFP_ATOMIC);
+       size_t size = cdev->ll2->rx_size + NET_SKB_PAD +
+                     SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+       *data = kmalloc(size, GFP_ATOMIC);
        if (!(*data)) {
                DP_INFO(cdev, "Failed to allocate LL2 buffer data\n");
                return -ENOMEM;
@@ -2589,7 +2592,7 @@ static int qed_ll2_start(struct qed_dev *cdev, struct qed_ll2_params *params)
        INIT_LIST_HEAD(&cdev->ll2->list);
        spin_lock_init(&cdev->ll2->lock);
 
-       cdev->ll2->rx_size = NET_SKB_PAD + ETH_HLEN +
+       cdev->ll2->rx_size = PRM_DMA_PAD_BYTES_NUM + ETH_HLEN +
                             L1_CACHE_BYTES + params->mtu;
 
        /* Allocate memory for LL2.