From d248953a3ccd218893b5119a0e63058f0dabca67 Mon Sep 17 00:00:00 2001 From: Martin Habets Date: Wed, 15 Jun 2016 17:48:49 +0100 Subject: [PATCH] sfc: Take mac_lock before calling efx_ef10_filter_table_probe 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 Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ef10.c | 4 ++++ drivers/net/ethernet/sfc/ef10_sriov.c | 7 +++++-- drivers/net/ethernet/sfc/efx.c | 2 ++ 3 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c index a3c00ffae8a0..add9f46542fc 100644 --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -4666,6 +4666,8 @@ static int efx_ef10_set_mac_address(struct efx_nic *efx) efx_device_detach_sync(efx); efx_net_stop(efx->net_dev); + + mutex_lock(&efx->mac_lock); down_write(&efx->filter_sem); efx_ef10_filter_table_remove(efx); @@ -4678,6 +4680,8 @@ static int efx_ef10_set_mac_address(struct efx_nic *efx) efx_ef10_filter_table_probe(efx); up_write(&efx->filter_sem); + mutex_unlock(&efx->mac_lock); + if (was_enabled) efx_net_open(efx->net_dev); netif_device_attach(efx->net_dev); diff --git a/drivers/net/ethernet/sfc/ef10_sriov.c b/drivers/net/ethernet/sfc/ef10_sriov.c index 3c17f274e802..a76610ae9fb4 100644 --- a/drivers/net/ethernet/sfc/ef10_sriov.c +++ b/drivers/net/ethernet/sfc/ef10_sriov.c @@ -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, diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index 902bcf292b09..130ee176cd4f 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -1729,6 +1729,7 @@ static int efx_probe_filters(struct efx_nic *efx) spin_lock_init(&efx->filter_lock); init_rwsem(&efx->filter_sem); + mutex_lock(&efx->mac_lock); down_write(&efx->filter_sem); rc = efx->type->filter_table_probe(efx); if (rc) @@ -1767,6 +1768,7 @@ static int efx_probe_filters(struct efx_nic *efx) #endif out_unlock: up_write(&efx->filter_sem); + mutex_unlock(&efx->mac_lock); return rc; } -- 2.20.1