This is a note to let you know that I've just added the patch titled
i40e: Use smp_rmb rather than read_barrier_depends
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i40e-use-smp_rmb-rather-than-read_barrier_depends.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 52c6912fde0133981ee50ba08808f257829c4c93 Mon Sep 17 00:00:00 2001
From: Brian King <brking@xxxxxxxxxxxxxxxxxx>
Date: Fri, 17 Nov 2017 11:05:44 -0600
Subject: i40e: Use smp_rmb rather than read_barrier_depends
From: Brian King <brking@xxxxxxxxxxxxxxxxxx>
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 <brking@xxxxxxxxxxxxxxxxxx>
Acked-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3214,7 +3214,7 @@ static bool i40e_clean_fdir_tx_irq(struc
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 &
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -688,7 +688,7 @@ static bool i40e_clean_tx_irq(struct i40
break;
/* prevent any other reads prior to eop_desc */
- read_barrier_depends();
+ smp_rmb();
/* we have caught up to head, no work left to do */
if (tx_head == tx_desc)
Patches currently in stable-queue which might be from brking@xxxxxxxxxxxxxxxxxx are
queue-3.18/i40evf-use-smp_rmb-rather-than-read_barrier_depends.patch
queue-3.18/igb-use-smp_rmb-rather-than-read_barrier_depends.patch
queue-3.18/ixgbevf-use-smp_rmb-rather-than-read_barrier_depends.patch
queue-3.18/igbvf-use-smp_rmb-rather-than-read_barrier_depends.patch
queue-3.18/fm10k-use-smp_rmb-rather-than-read_barrier_depends.patch
queue-3.18/ixgbe-fix-skb-list-corruption-on-power-systems.patch
queue-3.18/i40e-use-smp_rmb-rather-than-read_barrier_depends.patch