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authorBrian King <brking@linux.vnet.ibm.com>2017-11-17 11:05:44 -0600
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2017-11-21 23:43:21 -0800
commit52c6912fde0133981ee50ba08808f257829c4c93 (patch)
tree0b2a74cdf9f7e46035a6a6b712e59788f80cb8a9
parent0a9a17e3bb4564caf4bfe2a6783ae1287667d188 (diff)
i40e: Use smp_rmb rather than read_barrier_depends
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. Cc: stable <stable@vger.kernel.org> 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>
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_main.c2
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.c2
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 775d5a125887..4c08cc86463e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3966,7 +3966,7 @@ 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 d6d352a6e6ea..4566d66ffc7c 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 */