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 igb 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: Aaron Brown aaron.f.brown@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com --- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index e94d3c256667..c208753ff5b7 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -7317,7 +7317,7 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector, int napi_budget) 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(E1000_TXD_STAT_DD)))