path: root/drivers
diff options
authorBrian King <brking@linux.vnet.ibm.com>2017-11-17 11:05:43 -0600
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2017-11-21 23:42:03 -0800
commit0a9a17e3bb4564caf4bfe2a6783ae1287667d188 (patch)
tree4b79d519ea128fda29a3ca3f36b3e8941305a8a2 /drivers
parentbd5608b3223bc711a5b365f80d4e67866ac7cc44 (diff)
ixgbe: Fix skb list corruption on Power systems
This patch fixes an issue seen on Power systems with ixgbe which results in skb list corruption and an eventual kernel oops. The following is what was observed: CPU 1 CPU2 ============================ ============================ 1: ixgbe_xmit_frame_ring ixgbe_clean_tx_irq 2: first->skb = skb eop_desc = tx_buffer->next_to_watch 3: ixgbe_tx_map read_barrier_depends() 4: wmb check adapter written status bit 5: first->next_to_watch = tx_desc napi_consume_skb(tx_buffer->skb ..); 6: writel(i, tx_ring->tail); The read_barrier_depends is insufficient to ensure that tx_buffer->skb does not get loaded prior to tx_buffer->next_to_watch, which then results in loading a stale skb pointer. This patch replaces the read_barrier_depends with smp_rmb to ensure loads are ordered with respect to the load of tx_buffer->next_to_watch. 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>
Diffstat (limited to 'drivers')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index ca06c3cc2ca8..62a18914f00f 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1192,7 +1192,7 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector,
/* 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->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))

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