adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2024-12-28 03:36:19 +00:00
Code Issues Projects Releases Packages Wiki Activity

net: fix packet socket delivery in rx irq handler

Browse source 
The changes to deliver hardware accelerated VLAN packets to packet
sockets (commit bc1d0411) caused a warning for non-NAPI drivers.
The __vlan_hwaccel_rx() function is called directly from the drivers
RX function, for non-NAPI drivers that means its still in RX IRQ
context:

[   27.779463] ------------[ cut here ]------------
[   27.779509] WARNING: at kernel/softirq.c:136 local_bh_enable+0x37/0x81()
...
[   27.782520]  [<c0264755>] netif_nit_deliver+0x5b/0x75
[   27.782590]  [<c02bba83>] __vlan_hwaccel_rx+0x79/0x162
[   27.782664]  [<f8851c1d>] atl1_intr+0x9a9/0xa7c [atl1]
[   27.782738]  [<c0155b17>] handle_IRQ_event+0x23/0x51
[   27.782808]  [<c015692e>] handle_edge_irq+0xc2/0x102
[   27.782878]  [<c0105fd5>] do_IRQ+0x4d/0x64

Split hardware accelerated VLAN reception into two parts to fix this:

- __vlan_hwaccel_rx just stores the VLAN TCI and performs the VLAN
  device lookup, then calls netif_receive_skb()/netif_rx()

- vlan_hwaccel_do_receive(), which is invoked by netif_receive_skb()
  in softirq context, performs the real reception and delivery to
  packet sockets.

Reported-and-tested-by: Ramon Casellas <ramon.casellas@cttc.es>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2008-11-04 14:49:57 -08:00 committed by David S. Miller
parent 79654a7698
commit 9b22ea5609
3 changed files with 43 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
include/linux/if_vlan.h
View file

@ -114,6 +114,8 @@ extern u16 vlan_dev_vlan_id(const struct net_device *dev);
extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
u16 vlan_tci, int polling);
extern int vlan_hwaccel_do_receive(struct sk_buff *skb);
#else
static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{
@ -133,6 +135,11 @@ static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
BUG();
return NET_XMIT_SUCCESS;
}
static inline int vlan_hwaccel_do_receive(struct sk_buff *skb)
{
return 0;
}
#endif
/**

46
net/8021q/vlan_core.c
View file

@ -3,11 +3,20 @@
#include <linux/if_vlan.h>
#include "vlan.h"
struct vlan_hwaccel_cb {
struct net_device *dev;
};
static inline struct vlan_hwaccel_cb *vlan_hwaccel_cb(struct sk_buff *skb)
{
return (struct vlan_hwaccel_cb *)skb->cb;
}
/* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
u16 vlan_tci, int polling)
{
struct net_device_stats *stats;
struct vlan_hwaccel_cb *cb = vlan_hwaccel_cb(skb);
if (skb_bond_should_drop(skb)) {
dev_kfree_skb_any(skb);
@ -15,23 +24,35 @@ int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
}
skb->vlan_tci = vlan_tci;
cb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
return (polling ? netif_receive_skb(skb) : netif_rx(skb));
}
EXPORT_SYMBOL(__vlan_hwaccel_rx);
int vlan_hwaccel_do_receive(struct sk_buff *skb)
{
struct vlan_hwaccel_cb *cb = vlan_hwaccel_cb(skb);
struct net_device *dev = cb->dev;
struct net_device_stats *stats;
netif_nit_deliver(skb);
skb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
if (skb->dev == NULL) {
dev_kfree_skb_any(skb);
/* Not NET_RX_DROP, this is not being dropped
* due to congestion. */
return NET_RX_SUCCESS;
if (dev == NULL) {
kfree_skb(skb);
return -1;
}
skb->dev->last_rx = jiffies;
skb->dev = dev;
skb->priority = vlan_get_ingress_priority(dev, skb->vlan_tci);
skb->vlan_tci = 0;
stats = &skb->dev->stats;
dev->last_rx = jiffies;
stats = &dev->stats;
stats->rx_packets++;
stats->rx_bytes += skb->len;
skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tci);
switch (skb->pkt_type) {
case PACKET_BROADCAST:
break;
@ -43,13 +64,12 @@ int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
* This allows the VLAN to have a different MAC than the
* underlying device, and still route correctly. */
if (!compare_ether_addr(eth_hdr(skb)->h_dest,
skb->dev->dev_addr))
dev->dev_addr))
skb->pkt_type = PACKET_HOST;
break;
};
return (polling ? netif_receive_skb(skb) : netif_rx(skb));
return 0;
}
EXPORT_SYMBOL(__vlan_hwaccel_rx);
struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{

3
net/core/dev.c
View file

@ -2218,6 +2218,9 @@ int netif_receive_skb(struct sk_buff *skb)
int ret = NET_RX_DROP;
__be16 type;
if (skb->vlan_tci && vlan_hwaccel_do_receive(skb))
return NET_RX_SUCCESS;
/* if we've gotten here through NAPI, check netpoll */
if (netpoll_receive_skb(skb))
return NET_RX_DROP;