On Tue, May 09, 2023 at 08:06:32AM +0200, Louis Peens wrote:
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(-)
Thanks, Reviewed-by: Leon Romanovsky leonro@nvidia.com