]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
ixgbe: Fix skb list corruption on Power systems
authorBrian King <brking@linux.vnet.ibm.com>
Fri, 17 Nov 2017 17:05:43 +0000 (11:05 -0600)
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>
Wed, 22 Nov 2017 07:42:03 +0000 (23:42 -0800)
commit0a9a17e3bb4564caf4bfe2a6783ae1287667d188
tree4b79d519ea128fda29a3ca3f36b3e8941305a8a2
parentbd5608b3223bc711a5b365f80d4e67866ac7cc44
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>
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c