Re: WARNING: at net/ipv4/tcp.c:1610 tcp_recvmsg+0xb1b/0xc70()

Jack Stone
2012-05-28T08:34:10Z

On 05/28/2012 01:25 AM, Eric Dumazet wrote:
> On Sun, 2012-05-27 at 20:13 +0100, Jack Stone wrote:
>
>> Could it be something to do with my staging network driver?
>
> drivers/staging/rtl8712/rtl8712_recv.c
>
> line 1096
>
> precvframe->u.hdr.pkt = skb_clone(pskb, GFP_ATOMIC);
>
> This looks very wrong.
> Make sure you never _never_ hit this path.
>

I've applied the following debugging patch. Thanks for the suggestion.

diff --git a/drivers/staging/rtl8712/rtl8712_recv.c b/drivers/staging/rtl8712/rtl8712_recv.c
index 8e82ce2..fed62f8 100644
--- a/drivers/staging/rtl8712/rtl8712_recv.c
+++ b/drivers/staging/rtl8712/rtl8712_recv.c
@@ -1082,23 +1082,16 @@ static int recvbuf2recvframe(struct _adapter *padapter, struct sk_buff *pskb)
* 4 is for skb->data 4 bytes alignment. */
alloc_sz += 6;
pkt_copy = netdev_alloc_skb(padapter->pnetdev, alloc_sz);
- if (pkt_copy) {
- pkt_copy->dev = padapter->pnetdev;
- precvframe->u.hdr.pkt = pkt_copy;
- skb_reserve(pkt_copy, 4 - ((addr_t)(pkt_copy->data)
- % 4));
- skb_reserve(pkt_copy, shift_sz);
- memcpy(pkt_copy->data, pbuf, tmp_len);
- precvframe->u.hdr.rx_head = precvframe->u.hdr.rx_data =
- precvframe->u.hdr.rx_tail = pkt_copy->data;
- precvframe->u.hdr.rx_end = pkt_copy->data + alloc_sz;
- } else {
- precvframe->u.hdr.pkt = skb_clone(pskb, GFP_ATOMIC);
- precvframe->u.hdr.rx_head = pbuf;
- precvframe->u.hdr.rx_data = pbuf;
- precvframe->u.hdr.rx_tail = pbuf;
- precvframe->u.hdr.rx_end = pbuf + alloc_sz;
- }
+ WARN_ON(!pkt_copy)
+ pkt_copy->dev = padapter->pnetdev;
+ precvframe->u.hdr.pkt = pkt_copy;
+ skb_reserve(pkt_copy, 4 - ((addr_t)(pkt_copy->data)
+ % 4));
+ skb_reserve(pkt_copy, shift_sz);
+ memcpy(pkt_copy->data, pbuf, tmp_len);
+ precvframe->u.hdr.rx_head = precvframe->u.hdr.rx_data =
+ precvframe->u.hdr.rx_tail = pkt_copy->data;
+ precvframe->u.hdr.rx_end = pkt_copy->data + alloc_sz;
recvframe_put(precvframe, tmp_len);
recvframe_pull(precvframe, drvinfo_sz + RXDESC_SIZE);
/* because the endian issue, driver avoid reference to the