From d72fdef21f07540c6cbb8043cc93decd2a5d35dd Mon Sep 17 00:00:00 2001 From: Amit Cohen Date: Fri, 12 Aug 2022 17:32:02 +0200 Subject: mlxsw: spectrum_ptp: Protect PTP configuration with a mutex Currently the functions mlxsw_sp2_ptp_{configure, deconfigure}_port() assume that they are called when RTNL is locked and they warn otherwise. The deconfigure function can be called when port is removed, for example as part of device reload, then there is no locked RTNL and the function warns [1]. To avoid such case, do not assume that RTNL protects this code, add a dedicated mutex instead. The mutex protects 'ptp_state->config' which stores the existing global configuration in hardware. Use this mutex also to protect the code which configures the hardware. Then, there will be only one configuration in any time, which will be updated in 'ptp_state' and a race will be avoided. [1]: RTNL: assertion failed at drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c (1600) WARNING: CPU: 1 PID: 1583493 at drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c:1600 mlxsw_sp2_ptp_hwtstamp_set+0x2d3/0x300 [mlxsw_spectrum] [...] CPU: 1 PID: 1583493 Comm: devlink Not tainted5.19.0-rc8-custom-127022-gb371dffda095 #789 Hardware name: Mellanox Technologies Ltd.MSN3420/VMOD0005, BIOS 5.11 01/06/2019 RIP: 0010:mlxsw_sp2_ptp_hwtstamp_set+0x2d3/0x300[mlxsw_spectrum] [...] Call Trace: mlxsw_sp_port_remove+0x7e/0x190 [mlxsw_spectrum] mlxsw_sp_fini+0xd1/0x270 [mlxsw_spectrum] mlxsw_core_bus_device_unregister+0x55/0x280 [mlxsw_core] mlxsw_devlink_core_bus_device_reload_down+0x1c/0x30[mlxsw_core] devlink_reload+0x1ee/0x230 devlink_nl_cmd_reload+0x4de/0x580 genl_family_rcv_msg_doit+0xdc/0x140 genl_rcv_msg+0xd7/0x1d0 netlink_rcv_skb+0x49/0xf0 genl_rcv+0x1f/0x30 netlink_unicast+0x22f/0x350 netlink_sendmsg+0x208/0x440 __sys_sendto+0xf0/0x140 __x64_sys_sendto+0x1b/0x20 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 08ef8bc825d96 ("mlxsw: spectrum_ptp: Support SIOCGHWTSTAMP, SIOCSHWTSTAMP ioctls") Reported-by: Ido Schimmel Signed-off-by: Amit Cohen Signed-off-by: Ido Schimmel Signed-off-by: Petr Machata Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c | 27 ++++++++++++++++------ 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c index 2e0b704b8a31..f32c83603b84 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c @@ -46,6 +46,7 @@ struct mlxsw_sp2_ptp_state { * enabled. */ struct hwtstamp_config config; + struct mutex lock; /* Protects 'config' and HW configuration. */ }; struct mlxsw_sp1_ptp_key { @@ -1374,6 +1375,7 @@ struct mlxsw_sp_ptp_state *mlxsw_sp2_ptp_init(struct mlxsw_sp *mlxsw_sp) goto err_ptp_traps_set; refcount_set(&ptp_state->ptp_port_enabled_ref, 0); + mutex_init(&ptp_state->lock); return &ptp_state->common; err_ptp_traps_set: @@ -1388,6 +1390,7 @@ void mlxsw_sp2_ptp_fini(struct mlxsw_sp_ptp_state *ptp_state_common) ptp_state = mlxsw_sp2_ptp_state(mlxsw_sp); + mutex_destroy(&ptp_state->lock); mlxsw_sp_ptp_traps_unset(mlxsw_sp); kfree(ptp_state); } @@ -1461,7 +1464,10 @@ int mlxsw_sp2_ptp_hwtstamp_get(struct mlxsw_sp_port *mlxsw_sp_port, ptp_state = mlxsw_sp2_ptp_state(mlxsw_sp_port->mlxsw_sp); + mutex_lock(&ptp_state->lock); *config = ptp_state->config; + mutex_unlock(&ptp_state->lock); + return 0; } @@ -1574,8 +1580,6 @@ static int mlxsw_sp2_ptp_configure_port(struct mlxsw_sp_port *mlxsw_sp_port, struct mlxsw_sp2_ptp_state *ptp_state; int err; - ASSERT_RTNL(); - ptp_state = mlxsw_sp2_ptp_state(mlxsw_sp_port->mlxsw_sp); if (refcount_inc_not_zero(&ptp_state->ptp_port_enabled_ref)) @@ -1597,8 +1601,6 @@ static int mlxsw_sp2_ptp_deconfigure_port(struct mlxsw_sp_port *mlxsw_sp_port, struct mlxsw_sp2_ptp_state *ptp_state; int err; - ASSERT_RTNL(); - ptp_state = mlxsw_sp2_ptp_state(mlxsw_sp_port->mlxsw_sp); if (!refcount_dec_and_test(&ptp_state->ptp_port_enabled_ref)) @@ -1618,16 +1620,20 @@ err_ptp_disable: int mlxsw_sp2_ptp_hwtstamp_set(struct mlxsw_sp_port *mlxsw_sp_port, struct hwtstamp_config *config) { + struct mlxsw_sp2_ptp_state *ptp_state; enum hwtstamp_rx_filters rx_filter; struct hwtstamp_config new_config; u16 new_ing_types, new_egr_types; bool ptp_enabled; int err; + ptp_state = mlxsw_sp2_ptp_state(mlxsw_sp_port->mlxsw_sp); + mutex_lock(&ptp_state->lock); + err = mlxsw_sp2_ptp_get_message_types(config, &new_ing_types, &new_egr_types, &rx_filter); if (err) - return err; + goto err_get_message_types; new_config.flags = config->flags; new_config.tx_type = config->tx_type; @@ -1640,11 +1646,11 @@ int mlxsw_sp2_ptp_hwtstamp_set(struct mlxsw_sp_port *mlxsw_sp_port, err = mlxsw_sp2_ptp_configure_port(mlxsw_sp_port, new_ing_types, new_egr_types, new_config); if (err) - return err; + goto err_configure_port; } else if (!new_ing_types && !new_egr_types && ptp_enabled) { err = mlxsw_sp2_ptp_deconfigure_port(mlxsw_sp_port, new_config); if (err) - return err; + goto err_deconfigure_port; } mlxsw_sp_port->ptp.ing_types = new_ing_types; @@ -1652,8 +1658,15 @@ int mlxsw_sp2_ptp_hwtstamp_set(struct mlxsw_sp_port *mlxsw_sp_port, /* Notify the ioctl caller what we are actually timestamping. */ config->rx_filter = rx_filter; + mutex_unlock(&ptp_state->lock); return 0; + +err_deconfigure_port: +err_configure_port: +err_get_message_types: + mutex_unlock(&ptp_state->lock); + return err; } int mlxsw_sp2_ptp_get_ts_info(struct mlxsw_sp *mlxsw_sp, -- cgit v1.2.3-58-ga151