From: Mike McCormack <mikem@ring3k•org>
To: Stephen Hemminger <shemminger@linux-foundation•org>
Cc: netdev@vger•kernel.org
Subject: [PATCH resend] sky2: Account for VLAN tag in tx_le_req
Date: Mon, 14 Sep 2009 08:07:41 +0900 [thread overview]
Message-ID: <4AAD7B3D.7010403@ring3k.org> (raw)
With VLAN enabled, tx_le_req could return fewer list elements than required,
leading to a potential wrap around of the transmit ring buffer.
Signed-off-by: Mike McCormack <mikem@ring3k•org>
---
drivers/net/sky2.c | 14 +++++++++++---
1 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 00bc65a..c8ebc03 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1563,7 +1563,7 @@ static inline int tx_avail(const struct sky2_port *sky2)
}
/* Estimate of number of transmit list elements required */
-static unsigned tx_le_req(const struct sk_buff *skb)
+static unsigned tx_le_req(const struct sk_buff *skb, int vlan_tag)
{
unsigned count;
@@ -1573,6 +1573,9 @@ static unsigned tx_le_req(const struct sk_buff *skb)
if (skb_is_gso(skb))
++count;
+ else if (sizeof(dma_addr_t) == sizeof(u32) && vlan_tag)
+ ++count;
+
if (skb->ip_summed == CHECKSUM_PARTIAL)
++count;
@@ -1611,8 +1614,13 @@ static netdev_tx_t sky2_xmit_frame(struct sk_buff *skb,
u16 slot;
u16 mss;
u8 ctrl;
+ unsigned vlan_tag = 0;
+
+#ifdef SKY2_VLAN_TAG_USED
+ vlan_tag = sky2->vlgrp && vlan_tx_tag_present(skb);
+#endif
- if (unlikely(tx_avail(sky2) < tx_le_req(skb)))
+ if (unlikely(tx_avail(sky2) < tx_le_req(skb, vlan_tag)))
return NETDEV_TX_BUSY;
len = skb_headlen(skb);
@@ -1657,7 +1665,7 @@ static netdev_tx_t sky2_xmit_frame(struct sk_buff *skb,
ctrl = 0;
#ifdef SKY2_VLAN_TAG_USED
/* Add VLAN tag, can piggyback on LRGLEN or ADDR64 */
- if (sky2->vlgrp && vlan_tx_tag_present(skb)) {
+ if (vlan_tag) {
if (!le) {
le = get_tx_le(sky2, &slot);
le->addr = 0;
--
1.5.6.5
next reply other threads:[~2009-09-13 23:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-13 23:07 Mike McCormack [this message]
2009-09-14 16:12 ` [PATCH alt] sky2: transmit ring accounting Stephen Hemminger
2009-09-15 9:50 ` David Miller
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