4.4-stable review patch. If anyone has any objections, please let me know.
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From: Brian King brking@linux.vnet.ibm.com
commit 7b8edcc685b5e2c3c37aa13dc50a88e84a5bfef8 upstream.
The original issue being fixed in this patch was seen with the ixgbe driver, but the same issue exists with fm10k 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 Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/ethernet/intel/fm10k/fm10k_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c @@ -1226,7 +1226,7 @@ static bool fm10k_clean_tx_irq(struct fm break;
/* prevent any other reads prior to eop_desc */ - read_barrier_depends(); + smp_rmb();
/* if DD is not set pending work has not been completed */ if (!(eop_desc->flags & FM10K_TXD_FLAG_DONE))