From 5727faafa56eeacb1f409969b373d912ef259ca5 Mon Sep 17 00:00:00 2001 From: Brian King Date: Fri, 17 Nov 2017 11:05:44 -0600 Subject: [PATCH] i40e: Use smp_rmb rather than read_barrier_depends commit 52c6912fde0133981ee50ba08808f257829c4c93 upstream. The original issue being fixed in this patch was seen with the ixgbe driver, but the same issue exists with i40e 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. Signed-off-by: Brian King Acked-by: Jesse Brandeburg Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/intel/i40e/i40e_main.c | 2 +- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 6498da8..ea20aac 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -3760,7 +3760,7 @@ static bool i40e_clean_fdir_tx_irq(struct i40e_ring *tx_ring, int budget) break; /* prevent any other reads prior to eop_desc */ - read_barrier_depends(); + smp_rmb(); /* if the descriptor isn't done, no work yet to do */ if (!(eop_desc->cmd_type_offset_bsz & diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 120c68f..3c07ff1 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -759,7 +759,7 @@ 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); /* we have caught up to head, no work left to do */ -- 2.7.4