From: Brian King <brking@linux.vnet.ibm.com>
Date: Fri, 17 Nov 2017 11:05:48 -0600
Subject: fm10k: Use smp_rmb rather than read_barrier_depends
Patch-mainline: v4.15-rc1
Git-commit: 7b8edcc685b5e2c3c37aa13dc50a88e84a5bfef8
References: bsc#1056660 FATE#322187

The original issue being fixed in this patch was seen with the ixgbe
driver, but the same issue exists with fm10k 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>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David Chang <dchang@suse.com>
---
 drivers/net/ethernet/intel/fm10k/fm10k_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
index 9dffaba85ae6..103c0a742d03 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -1229,7 +1229,7 @@ static bool fm10k_clean_tx_irq(struct fm10k_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->flags & FM10K_TXD_FLAG_DONE))
-- 
2.13.6