From: Greg KH on
2.6.31-stable review patch. If anyone has any objections, please let us know.

From: Oliver Hartkopp <oliver(a)>

commit 481a8199142c050b72bff8a1956a49fd0a75bbe0 upstream.

When using nanosleep() in an userspace application we get a ratelimit warning

NOHZ: local_softirq_pending 08

for 10 times.

The echo of CAN frames is done from process context and softirq context only.
Therefore the usage of netif_rx() was wrong (for years).

This patch replaces netif_rx() with netif_rx_ni() which has to be used from
process/softirq context. It also adds a missing comment that can_send() must
no be used from hardirq context.

Signed-off-by: Oliver Hartkopp <oliver(a)>
Signed-off-by: Urs Thuermann <urs(a)>
Signed-off-by: David S. Miller <davem(a)>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)>

drivers/net/can/vcan.c | 2 +-
net/can/af_can.c | 4 +++-
2 files changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/can/vcan.c
+++ b/drivers/net/can/vcan.c
@@ -80,7 +80,7 @@ static void vcan_rx(struct sk_buff *skb,
skb->dev = dev;
skb->ip_summed = CHECKSUM_UNNECESSARY;

- netif_rx(skb);
+ netif_rx_ni(skb);

static int vcan_tx(struct sk_buff *skb, struct net_device *dev)
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -199,6 +199,8 @@ static int can_create(struct net *net, s
* @skb: pointer to socket buffer with CAN frame in data section
* @loop: loopback for listeners on local CAN sockets (recommended default!)
+ * Due to the loopback this routine must not be called from hardirq context.
+ *
* Return:
* 0 on success
* -ENETDOWN when the selected interface is down
@@ -278,7 +280,7 @@ int can_send(struct sk_buff *skb, int lo

if (newskb)
- netif_rx(newskb);
+ netif_rx_ni(newskb);

/* update statistics */

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