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authorDavid Woodhouse <dwmw2@infradead.org>2015-09-24 13:38:22 +0300
committerDavid S. Miller <davem@davemloft.net>2015-09-27 08:38:34 +0300
commit8b7a7048220f86547db31de0abe1ea6dd2cfa892 (patch)
treed2fc6cc721822b02e326569b2d011bd906a6842b /drivers/net/ethernet/realtek
parent5a58f227790faded5a3ef6075f3ddd65093e0f86 (diff)
downloadlinux-8b7a7048220f86547db31de0abe1ea6dd2cfa892.tar.xz
8139cp: Fix GSO MSS handling
When fixing the TSO support I noticed we just mask ->gso_size with the MSSMask value and don't care about the consequences. Provide a .ndo_features_check() method which drops the NETIF_F_TSO feature for any skb which would exceed the maximum, and thus forces it to be segmented by software. Then we can stop the masking in cp_start_xmit(), and just WARN if the maximum is exceeded, which should now never happen. Finally, Francois Romieu noticed that we didn't even have the right value for MSSMask anyway; it should be 0x7ff (11 bits) not 0xfff. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/realtek')
-rw-r--r--drivers/net/ethernet/realtek/8139cp.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c
index e5173f33428b..deae10d7426d 100644
--- a/drivers/net/ethernet/realtek/8139cp.c
+++ b/drivers/net/ethernet/realtek/8139cp.c
@@ -175,7 +175,7 @@ enum {
LastFrag = (1 << 28), /* Final segment of a packet */
LargeSend = (1 << 27), /* TCP Large Send Offload (TSO) */
MSSShift = 16, /* MSS value position */
- MSSMask = 0xfff, /* MSS value: 11 bits */
+ MSSMask = 0x7ff, /* MSS value: 11 bits */
TxError = (1 << 23), /* Tx error summary */
RxError = (1 << 20), /* Rx error summary */
IPCS = (1 << 18), /* Calculate IP checksum */
@@ -754,10 +754,16 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb,
eor = (entry == (CP_TX_RING_SIZE - 1)) ? RingEnd : 0;
mss = skb_shinfo(skb)->gso_size;
+ if (mss > MSSMask) {
+ WARN_ONCE(1, "Net bug: GSO size %d too large for 8139CP\n",
+ mss);
+ goto out_dma_error;
+ }
+
opts2 = cpu_to_le32(cp_tx_vlan_tag(skb));
opts1 = DescOwn;
if (mss)
- opts1 |= LargeSend | ((mss & MSSMask) << MSSShift);
+ opts1 |= LargeSend | (mss << MSSShift);
else if (skb->ip_summed == CHECKSUM_PARTIAL) {
const struct iphdr *ip = ip_hdr(skb);
if (ip->protocol == IPPROTO_TCP)
@@ -1852,6 +1858,15 @@ static void cp_set_d3_state (struct cp_private *cp)
pci_set_power_state (cp->pdev, PCI_D3hot);
}
+static netdev_features_t cp_features_check(struct sk_buff *skb,
+ struct net_device *dev,
+ netdev_features_t features)
+{
+ if (skb_shinfo(skb)->gso_size > MSSMask)
+ features &= ~NETIF_F_TSO;
+
+ return vlan_features_check(skb, features);
+}
static const struct net_device_ops cp_netdev_ops = {
.ndo_open = cp_open,
.ndo_stop = cp_close,
@@ -1864,6 +1879,7 @@ static const struct net_device_ops cp_netdev_ops = {
.ndo_tx_timeout = cp_tx_timeout,
.ndo_set_features = cp_set_features,
.ndo_change_mtu = cp_change_mtu,
+ .ndo_features_check = cp_features_check,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = cp_poll_controller,