4.17-stable review patch. If anyone has any objections, please let me know.
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From: Bert Kenward bkenward@solarflare.com
[ Upstream commit 1c56c0994a533ce564843a0d17af7a3e6e68f269 ]
In some situations we may end up calling down_read while already holding the semaphore for write, thus hanging. This has been seen when setting the MAC address for the interface. The hung task log in this situation includes this stack: down_read efx_ef10_filter_insert efx_ef10_filter_insert_addr_list efx_ef10_filter_vlan_sync_rx_mode efx_ef10_filter_add_vlan efx_ef10_filter_table_probe efx_ef10_set_mac_address efx_set_mac_address dev_set_mac_address
In addition, lockdep rightly points out that nested calling of down_read is incorrect.
Fixes: c2bebe37c6b6 ("sfc: give ef10 its own rwsem in the filter table instead of filter_lock") Tested-by: Jarod Wilson jarod@redhat.com Signed-off-by: Bert Kenward bkenward@solarflare.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/sfc/ef10.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-)
--- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -4288,9 +4288,9 @@ static int efx_ef10_filter_pri(struct ef return -EPROTONOSUPPORT; }
-static s32 efx_ef10_filter_insert(struct efx_nic *efx, - struct efx_filter_spec *spec, - bool replace_equal) +static s32 efx_ef10_filter_insert_locked(struct efx_nic *efx, + struct efx_filter_spec *spec, + bool replace_equal) { DECLARE_BITMAP(mc_rem_map, EFX_EF10_FILTER_SEARCH_LIMIT); struct efx_ef10_nic_data *nic_data = efx->nic_data; @@ -4307,7 +4307,7 @@ static s32 efx_ef10_filter_insert(struct bool is_mc_recip; s32 rc;
- down_read(&efx->filter_sem); + WARN_ON(!rwsem_is_locked(&efx->filter_sem)); table = efx->filter_state; down_write(&table->lock);
@@ -4498,10 +4498,22 @@ out_unlock: if (rss_locked) mutex_unlock(&efx->rss_lock); up_write(&table->lock); - up_read(&efx->filter_sem); return rc; }
+static s32 efx_ef10_filter_insert(struct efx_nic *efx, + struct efx_filter_spec *spec, + bool replace_equal) +{ + s32 ret; + + down_read(&efx->filter_sem); + ret = efx_ef10_filter_insert_locked(efx, spec, replace_equal); + up_read(&efx->filter_sem); + + return ret; +} + static void efx_ef10_filter_update_rx_scatter(struct efx_nic *efx) { /* no need to do anything here on EF10 */ @@ -5284,7 +5296,7 @@ static int efx_ef10_filter_insert_addr_l EFX_WARN_ON_PARANOID(ids[i] != EFX_EF10_FILTER_ID_INVALID); efx_filter_init_rx(&spec, EFX_FILTER_PRI_AUTO, filter_flags, 0); efx_filter_set_eth_local(&spec, vlan->vid, addr_list[i].addr); - rc = efx_ef10_filter_insert(efx, &spec, true); + rc = efx_ef10_filter_insert_locked(efx, &spec, true); if (rc < 0) { if (rollback) { netif_info(efx, drv, efx->net_dev, @@ -5313,7 +5325,7 @@ static int efx_ef10_filter_insert_addr_l efx_filter_init_rx(&spec, EFX_FILTER_PRI_AUTO, filter_flags, 0); eth_broadcast_addr(baddr); efx_filter_set_eth_local(&spec, vlan->vid, baddr); - rc = efx_ef10_filter_insert(efx, &spec, true); + rc = efx_ef10_filter_insert_locked(efx, &spec, true); if (rc < 0) { netif_warn(efx, drv, efx->net_dev, "Broadcast filter insert failed rc=%d\n", rc); @@ -5369,7 +5381,7 @@ static int efx_ef10_filter_insert_def(st if (vlan->vid != EFX_FILTER_VID_UNSPEC) efx_filter_set_eth_local(&spec, vlan->vid, NULL);
- rc = efx_ef10_filter_insert(efx, &spec, true); + rc = efx_ef10_filter_insert_locked(efx, &spec, true); if (rc < 0) { const char *um = multicast ? "Multicast" : "Unicast"; const char *encap_name = ""; @@ -5429,7 +5441,7 @@ static int efx_ef10_filter_insert_def(st filter_flags, 0); eth_broadcast_addr(baddr); efx_filter_set_eth_local(&spec, vlan->vid, baddr); - rc = efx_ef10_filter_insert(efx, &spec, true); + rc = efx_ef10_filter_insert_locked(efx, &spec, true); if (rc < 0) { netif_warn(efx, drv, efx->net_dev, "Broadcast filter insert failed rc=%d\n",