From: Brian King brking@linux.vnet.ibm.com
The original issue being fixed in this patch was seen with the ixgbe driver, but the same issue exists with ixgbevf 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: stable stable@vger.kernel.org Signed-off-by: Brian King brking@linux.vnet.ibm.com Acked-by: Jesse Brandeburg jesse.brandeburg@intel.com Tested-by: Andrew Bowers andrewx.bowers@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com --- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index feed11bc9ddf..1f4a69134ade 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -326,7 +326,7 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector, break;
/* prevent any other reads prior to eop_desc */ - read_barrier_depends(); + smp_rmb();
/* if DD is not set pending work has not been completed */ if (!(eop_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))