netdev - Re: [PATCH] ibmveth: Fix more little endian issues

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <71EC0FB0-80C9-4133-A384-35D212ACE968@suse.de>
Date:	Mon, 23 Dec 2013 11:17:47 +0100
From:	Alexander Graf <agraf@...e.de>
To:	Anton Blanchard <anton@...ba.org>
Cc:	linuxppc-dev@...ts.ozlabs.org,
	Ben Herrenschmidt <benh@...nel.crashing.org>,
	Dinar Valeev <dvaleev@...e.com>,
	Santiago Leon <santil@...ux.vnet.ibm.com>,
	netdev@...r.kernel.org
Subject: Re: [PATCH] ibmveth: Fix more little endian issues


On 23.12.2013, at 07:38, Anton Blanchard <anton@...ba.org> wrote:

> 
> Hi Alex,
> 
>> The ibmveth driver is memcpy()'ing the mac address between a variable
>> (register) and memory. This assumes a certain endianness of the
>> system, so let's make that implicit assumption work again.
> 
> Nice catch! I don't like how the driver has two different methods
> for creating these MAC addresses, both without comments. How does
> this look?

Heh - I didn't even realize those two places were doing the same thing.

Obviously your patch is by far nicer.

Reviewed-by: Alexander Graf <agraf@...e.de>


Alex

> 
> Anton
> --
> 
> The hypervisor expects MAC addresses passed in registers to be big
> endian u64. Create a helper function called ibmveth_encode_mac_addr
> which does the right thing in both big and little endian.
> 
> We were storing the MAC address in a long in struct ibmveth_adapter.
> It's never used so remove it - we don't need another place in the
> driver where we create endian issues with MAC addresses.
> 
> Reported-by: Alexander Graf <agraf@...e.de>
> Signed-off-by: Anton Blanchard <anton@...ba.org>
> ---
> 
> diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
> index 952d795..044178b 100644
> --- a/drivers/net/ethernet/ibm/ibmveth.c
> +++ b/drivers/net/ethernet/ibm/ibmveth.c
> @@ -523,6 +523,17 @@ retry:
> 	return rc;
> }
> 
> +/*
> + * The hypervisor expects MAC addresses passed in registers to be
> + * big endian u64.
> + */
> +static unsigned long ibmveth_encode_mac_addr(char *mac)
> +{
> +	unsigned long encoded = 0;
> +	memcpy(((char *)&encoded) + 2, mac, ETH_ALEN);
> +	return cpu_to_be64(encoded);
> +}
> +
> static int ibmveth_open(struct net_device *netdev)
> {
> 	struct ibmveth_adapter *adapter = netdev_priv(netdev);
> @@ -580,8 +591,7 @@ static int ibmveth_open(struct net_device *netdev)
> 	adapter->rx_queue.num_slots = rxq_entries;
> 	adapter->rx_queue.toggle = 1;
> 
> -	memcpy(&mac_address, netdev->dev_addr, netdev->addr_len);
> -	mac_address = mac_address >> 16;
> +	mac_address = ibmveth_encode_mac_addr(netdev->dev_addr);
> 
> 	rxq_desc.fields.flags_len = IBMVETH_BUF_VALID |
> 					adapter->rx_queue.queue_len;
> @@ -1184,8 +1194,8 @@ static void ibmveth_set_multicast_list(struct net_device *netdev)
> 		/* add the addresses to the filter table */
> 		netdev_for_each_mc_addr(ha, netdev) {
> 			/* add the multicast address to the filter table */
> -			unsigned long mcast_addr = 0;
> -			memcpy(((char *)&mcast_addr)+2, ha->addr, ETH_ALEN);
> +			unsigned long mcast_addr;
> +			mcast_addr = ibmveth_encode_mac_addr(ha->addr);
> 			lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
> 						   IbmVethMcastAddFilter,
> 						   mcast_addr);
> @@ -1369,9 +1379,6 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
> 
> 	netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);
> 
> -	adapter->mac_addr = 0;
> -	memcpy(&adapter->mac_addr, mac_addr_p, ETH_ALEN);
> -
> 	netdev->irq = dev->irq;
> 	netdev->netdev_ops = &ibmveth_netdev_ops;
> 	netdev->ethtool_ops = &netdev_ethtool_ops;
> @@ -1380,7 +1387,7 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
> 		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
> 	netdev->features |= netdev->hw_features;
> 
> -	memcpy(netdev->dev_addr, &adapter->mac_addr, netdev->addr_len);
> +	memcpy(netdev->dev_addr, mac_addr_p, ETH_ALEN);
> 
> 	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
> 		struct kobject *kobj = &adapter->rx_buff_pool[i].kobj;
> diff --git a/drivers/net/ethernet/ibm/ibmveth.h b/drivers/net/ethernet/ibm/ibmveth.h
> index 84066ba..2c636cb 100644
> --- a/drivers/net/ethernet/ibm/ibmveth.h
> +++ b/drivers/net/ethernet/ibm/ibmveth.h
> @@ -139,7 +139,6 @@ struct ibmveth_adapter {
>     struct napi_struct napi;
>     struct net_device_stats stats;
>     unsigned int mcastFilterSize;
> -    unsigned long mac_addr;
>     void * buffer_list_addr;
>     void * filter_list_addr;
>     dma_addr_t buffer_list_dma;

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html