[ofa-general] [PATCH] ipoib: null tx/rx_ring skb pointers on free

[Jack Morgenstein]

On Thursday 06 November 2008 03:23, akepner at sgi.com wrote:
> I described an IPoIB-related panic we were seeing on large 
> clusters. The signature was a backtrace like this:
> 
>         skb_over_panic
>         :ib_ipoib:ipoib_ib_handle_rx_wc
>         :ib_ipoib:ipoib_poll
>         net_rx_action
>         .....
> 
> The bug is difficult to reproduce, but we finally got a crashdump, 
> and the problem appears to be that stale skb pointers on the tx_ring 
> were left pointing to skbs that had been since reused, so that the 
> skb's data region was now unexpectedly short, etc. 
> 
How does ipoib_ib_handle_rx_wc() involve the tx_ring? This is receive processing.

- Jack