The original issue being fixed in this patch was seen with the ixgbe driver, but the same issue exists with i40evf as well, as the code is very similar. read_barrier_depends is not sufficient to ensure loads following it are not speculatively loaded out of order by the CPU, which can result in stale data being loaded, causing potential system crashes.
Cc: stablestable@vger.kernel.org Signed-off-by: Brian King brking@linux.vnet.ibm.com --- drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index c32c624..07a4e6e 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -179,7 +179,7 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi, break;
/* prevent any other reads prior to eop_desc */ - read_barrier_depends(); + smp_rmb();
i40e_trace(clean_tx_irq, tx_ring, tx_desc, tx_buf); /* if the descriptor isn't done, no work yet to do */