| From 52c6912fde0133981ee50ba08808f257829c4c93 Mon Sep 17 00:00:00 2001 |
| From: Brian King <brking@linux.vnet.ibm.com> |
| Date: Fri, 17 Nov 2017 11:05:44 -0600 |
| Subject: i40e: Use smp_rmb rather than read_barrier_depends |
| |
| From: Brian King <brking@linux.vnet.ibm.com> |
| |
| 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@linux.vnet.ibm.com> |
| Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com> |
| Tested-by: Andrew Bowers <andrewx.bowers@intel.com> |
| Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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) |
