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authorBrian King <brking@linux.vnet.ibm.com>2017-11-17 11:05:44 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-11-30 08:39:08 +0000
commite45d7db989db5722fa31541fa8b008ca00385f06 (patch)
tree23bf5c2ec3075850a007e9052481711db16e4205
parent12d7b5042e3b5d33074e3e6d59f4a21676555270 (diff)
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i40e: Use smp_rmb rather than read_barrier_depends
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>
-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 31c97e3937a4..2caafebb0295 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3604,7 +3604,7 @@ 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 6287bf63c43c..c5430394fac9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -679,7 +679,7 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
break;
/* prevent any other reads prior to eop_desc */
- read_barrier_depends();
+ smp_rmb();
/* we have caught up to head, no work left to do */
if (tx_head == tx_desc)