From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51948 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932179AbdK0RJp (ORCPT ); Mon, 27 Nov 2017 12:09:45 -0500 Subject: Patch "i40e: Use smp_rmb rather than read_barrier_depends" has been added to the 4.4-stable tree To: brking@linux.vnet.ibm.com, andrewx.bowers@intel.com, gregkh@linuxfoundation.org, jeffrey.t.kirsher@intel.com, jesse.brandeburg@intel.com Cc: , From: Date: Mon, 27 Nov 2017 18:08:33 +0100 Message-ID: <15118025132184@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 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 4.4-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-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 52c6912fde0133981ee50ba08808f257829c4c93 Mon Sep 17 00:00:00 2001 From: Brian King Date: Fri, 17 Nov 2017 11:05:44 -0600 Subject: i40e: Use smp_rmb rather than read_barrier_depends From: Brian King 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(-) --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -3595,7 +3595,7 @@ 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 @@ -663,7 +663,7 @@ 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@linux.vnet.ibm.com are queue-4.4/i40evf-use-smp_rmb-rather-than-read_barrier_depends.patch queue-4.4/igb-use-smp_rmb-rather-than-read_barrier_depends.patch queue-4.4/ixgbevf-use-smp_rmb-rather-than-read_barrier_depends.patch queue-4.4/igbvf-use-smp_rmb-rather-than-read_barrier_depends.patch queue-4.4/fm10k-use-smp_rmb-rather-than-read_barrier_depends.patch queue-4.4/ixgbe-fix-skb-list-corruption-on-power-systems.patch queue-4.4/i40e-use-smp_rmb-rather-than-read_barrier_depends.patch