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sfc: Take mac_lock before calling efx_ef10_filter_table_probe

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When trying to enslave an SFC interface to a bond the following BUG_ON was
hit:

 kernel BUG [in ef10.c]!
 CPU: 0 PID: 4383 Comm: ifenslave Tainted: G
...
 Call Trace:
  efx_ef10_filter_add_vlan+0x121/0x180 [sfc]
  efx_ef10_filter_table_probe+0x2a2/0x4f0 [sfc]
  efx_ef10_set_mac_address+0x370/0x6d0 [sfc]
  efx_set_mac_address+0x7d/0x120 [sfc]
  dev_set_mac_address+0x43/0xa0
  bond_enslave+0x337/0xea0 [bonding]
This comes from function efx_ef10_filter_vlan_sync_rx_mode.

To solve the bug we ensure the mac_lock is taken before calling
efx_ef10_filter_add_vlan. But to avoid a priority inversion mac_lock must
be taken before filter_sem.
To satisfy these requirements we end up taking mac_lock in
efx_ef10_vport_set_mac_address, efx_ef10_set_mac_address,
efx_ef10_sriov_set_vf_vlan and efx_probe_filters.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Martin Habets
2016-06-15 17:48:49 +01:00
committed by David S. Miller
parent 4a53ea8a74
commit d248953a3c
3 changed files with 11 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/net/ethernet/sfc/ef10_sriov.c
View File

@@ -554,6 +554,7 @@ int efx_ef10_sriov_set_vf_vlan(struct efx_nic *efx, int vf_i, u16 vlan,
efx_device_detach_sync(vf->efx);
efx_net_stop(vf->efx->net_dev);
mutex_lock(&vf->efx->mac_lock);
down_write(&vf->efx->filter_sem);
vf->efx->type->filter_table_remove(vf->efx);
@@ -630,6 +631,7 @@ restore_filters:
goto reset_nic_up_write;
up_write(&vf->efx->filter_sem);
mutex_unlock(&vf->efx->mac_lock);
up_write(&vf->efx->filter_sem);
@@ -642,9 +644,10 @@ restore_filters:
return rc;
reset_nic_up_write:
if (vf->efx)
if (vf->efx) {
up_write(&vf->efx->filter_sem);
mutex_unlock(&vf->efx->mac_lock);
}
reset_nic:
if (vf->efx) {
netif_err(efx, drv, efx->net_dev,