From: Paolo Galtieri <[EMAIL PROTECTED]> Fix the dma_map/dma_unmap relationships and a NULL pointer dereference. If you do a dma_map_single you must do dma_unmap_single and if you do a dma_map_page you must do a dma_unmap_page. The NULL pointer dereference was caused because the buf_ptr and byte_cnt fields of the pkt_info structure were not filled in by eth_tx_return_desc().
Signed-off-by: Paolo Galtieri <[EMAIL PROTECTED]> Signed-off-by: Dale Farnsworth <[EMAIL PROTECTED]> Index: linux-2.6-mv643xx_enet/drivers/net/mv643xx_eth.c =================================================================== --- linux-2.6-mv643xx_enet.orig/drivers/net/mv643xx_eth.c +++ linux-2.6-mv643xx_enet/drivers/net/mv643xx_eth.c @@ -351,27 +351,19 @@ static int mv643xx_eth_free_tx_queue(str stats->tx_errors++; } - /* - * If return_info is different than 0, release the skb. - * The case where return_info is not 0 is only in case - * when transmitted a scatter/gather packet, where only - * last skb releases the whole chain. - */ - if (pkt_info.return_info) { - if (skb_shinfo(pkt_info.return_info)->nr_frags) - dma_unmap_page(NULL, pkt_info.buf_ptr, - pkt_info.byte_cnt, - DMA_TO_DEVICE); - else - dma_unmap_single(NULL, pkt_info.buf_ptr, - pkt_info.byte_cnt, - DMA_TO_DEVICE); + if (pkt_info.cmd_sts & ETH_TX_FIRST_DESC) + dma_unmap_single(NULL, pkt_info.buf_ptr, + pkt_info.byte_cnt, + DMA_TO_DEVICE); + else + dma_unmap_page(NULL, pkt_info.buf_ptr, + pkt_info.byte_cnt, + DMA_TO_DEVICE); + if (pkt_info.return_info) { dev_kfree_skb_irq(pkt_info.return_info); released = 0; - } else - dma_unmap_page(NULL, pkt_info.buf_ptr, - pkt_info.byte_cnt, DMA_TO_DEVICE); + } } spin_unlock(&mp->lock); @@ -1022,20 +1014,17 @@ static void mv643xx_tx(struct net_device struct pkt_info pkt_info; while (eth_tx_return_desc(mp, &pkt_info) == ETH_OK) { - if (pkt_info.return_info) { - if (skb_shinfo(pkt_info.return_info)->nr_frags) - dma_unmap_page(NULL, pkt_info.buf_ptr, - pkt_info.byte_cnt, - DMA_TO_DEVICE); - else - dma_unmap_single(NULL, pkt_info.buf_ptr, - pkt_info.byte_cnt, - DMA_TO_DEVICE); + if (pkt_info.cmd_sts & ETH_TX_FIRST_DESC) + dma_unmap_single(NULL, pkt_info.buf_ptr, + pkt_info.byte_cnt, + DMA_TO_DEVICE); + else + dma_unmap_page(NULL, pkt_info.buf_ptr, + pkt_info.byte_cnt, + DMA_TO_DEVICE); + if (pkt_info.return_info) dev_kfree_skb_irq(pkt_info.return_info); - } else - dma_unmap_page(NULL, pkt_info.buf_ptr, - pkt_info.byte_cnt, DMA_TO_DEVICE); } if (netif_queue_stopped(dev) && @@ -2669,6 +2658,8 @@ static ETH_FUNC_RET_STATUS eth_tx_return /* Pass the packet information to the caller */ p_pkt_info->cmd_sts = command_status; p_pkt_info->return_info = mp->tx_skb[tx_desc_used]; + p_pkt_info->buf_ptr = p_tx_desc_used->buf_ptr; + p_pkt_info->byte_cnt = p_tx_desc_used->byte_cnt; mp->tx_skb[tx_desc_used] = NULL; /* Update the next descriptor to release. */ - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html