From: Tianyu Yuan tianyu.yuan@corigine.com

When CONFIG_PROVE_LOCKING and CONFIG_PROVE_RCU are enabled, using OVS with vf reprs on bridge will lead to following log in dmesg:

''' .../nfp/flower/main.c:269 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1 no locks held by swapper/15/0.

...... Call Trace: <IRQ> dump_stack_lvl+0x8c/0xa0 lockdep_rcu_suspicious+0x118/0x1a0 nfp_flower_dev_get+0xc1/0x240 [nfp] nfp_nfd3_rx+0x419/0xb90 [nfp] ? validate_chain+0x640/0x1880 nfp_nfd3_poll+0x3e/0x180 [nfp] __napi_poll+0x28/0x1d0 net_rx_action+0x2bd/0x3c0 ? _raw_spin_unlock_irqrestore+0x42/0x70 __do_softirq+0xc3/0x3c6 irq_exit_rcu+0xeb/0x130 common_interrupt+0xb9/0xd0 </IRQ> <TASK> ...... </TASK> '''

This debug log is caused by missing of rcu_read_lock()/unlock(). In previous patch rcu_read_lock/unlock are removed while they are still needed when calling rcu_dereference() in nfp_app_dev_get().

Fixes: d5789621b658 ("nfp: Remove rcu_read_lock() around XDP program invocation") CC: stable@vger.kernel.org Signed-off-by: Tianyu Yuan tianyu.yuan@corigine.com Acked-by: Simon Horman simon.horman@corigine.com Signed-off-by: Louis Peens louis.peens@corigine.com --- drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- drivers/net/ethernet/netronome/nfp/nfd3/xsk.c | 2 +- drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- drivers/net/ethernet/netronome/nfp/nfp_app.h | 16 ++++++++++++++++ 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c index 0cc026b0aefd..3e5a84370d8a 100644 --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c @@ -1058,8 +1058,8 @@ static int nfp_nfd3_rx(struct nfp_net_rx_ring *rx_ring, int budget) struct nfp_net *nn;

nn = netdev_priv(dp->netdev); - netdev = nfp_app_dev_get(nn->app, meta.portid, - &redir_egress); + netdev = nfp_app_dev_get_locked(nn->app, meta.portid, + &redir_egress); if (unlikely(!netdev)) { nfp_nfd3_rx_drop(dp, r_vec, rx_ring, rxbuf, NULL); diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/xsk.c b/drivers/net/ethernet/netronome/nfp/nfd3/xsk.c index 5d9db8c2a5b4..6ec5b0d430ea 100644 --- a/drivers/net/ethernet/netronome/nfp/nfd3/xsk.c +++ b/drivers/net/ethernet/netronome/nfp/nfd3/xsk.c @@ -71,7 +71,7 @@ static void nfp_nfd3_xsk_rx_skb(struct nfp_net_rx_ring *rx_ring, } else { struct nfp_net *nn = netdev_priv(dp->netdev);

- netdev = nfp_app_dev_get(nn->app, meta->portid, NULL); + netdev = nfp_app_dev_get_locked(nn->app, meta->portid, NULL); if (unlikely(!netdev)) { nfp_net_xsk_rx_drop(r_vec, xrxbuf); return; diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c index 33b6d74adb4b..0ac68985d289 100644 --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c @@ -1177,8 +1177,8 @@ static int nfp_nfdk_rx(struct nfp_net_rx_ring *rx_ring, int budget) struct nfp_net *nn;

nn = netdev_priv(dp->netdev); - netdev = nfp_app_dev_get(nn->app, meta.portid, - &redir_egress); + netdev = nfp_app_dev_get_locked(nn->app, meta.portid, + &redir_egress); if (unlikely(!netdev)) { nfp_nfdk_rx_drop(dp, r_vec, rx_ring, rxbuf, NULL); diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.h b/drivers/net/ethernet/netronome/nfp/nfp_app.h index 90707346a4ef..639bb1a6349b 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_app.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_app.h @@ -417,6 +417,22 @@ struct net_device *nfp_app_dev_get(struct nfp_app *app, u32 id, return app->type->dev_get(app, id, redir_egress); }

+static inline +struct net_device *nfp_app_dev_get_locked(struct nfp_app *app, u32 id, + bool *redir_egress) +{ + struct net_device *dev; + + if (unlikely(!app || !app->type->dev_get)) + return NULL; + + rcu_read_lock(); + dev = app->type->dev_get(app, id, redir_egress); + rcu_read_unlock(); + + return dev; +} + struct nfp_app *nfp_app_from_netdev(struct net_device *netdev);

u64 *nfp_app_port_get_stats(struct nfp_port *port, u64 *data);