From: Vlad Buslov vladbu@nvidia.com
[ Upstream commit 5aa56105930374928d567744595fd7ac525d0688 ]
The cited commit changed class of tc_ht internal mutex in order to avoid false lock dependency with fs_core node and flow_table hash table structures. However, hash table implementation internally also includes a workqueue task with its own lockdep map which causes similar bogus lockdep splat[0]. Fix it by also adding dedicated class for hash table workqueue work structure of tc_ht.
[0]:
[ 1139.672465] ====================================================== [ 1139.673552] WARNING: possible circular locking dependency detected [ 1139.674635] 6.1.0_for_upstream_debug_2022_12_12_17_02 #1 Not tainted [ 1139.675734] ------------------------------------------------------ [ 1139.676801] modprobe/5998 is trying to acquire lock: [ 1139.677726] ffff88811e7b93b8 (&node->lock){++++}-{3:3}, at: down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.679662] but task is already holding lock: [ 1139.680703] ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0 [ 1139.682223] which lock already depends on the new lock.
[ 1139.683640] the existing dependency chain (in reverse order) is: [ 1139.684887] -> #2 (&tc_ht_lock_key){+.+.}-{3:3}: [ 1139.685975] __mutex_lock+0x12c/0x14b0 [ 1139.686659] rht_deferred_worker+0x35/0x1540 [ 1139.687405] process_one_work+0x7c2/0x1310 [ 1139.688134] worker_thread+0x59d/0xec0 [ 1139.688820] kthread+0x28f/0x330 [ 1139.689444] ret_from_fork+0x1f/0x30 [ 1139.690106] -> #1 ((work_completion)(&ht->run_work)){+.+.}-{0:0}: [ 1139.691250] __flush_work+0xe8/0x900 [ 1139.691915] __cancel_work_timer+0x2ca/0x3f0 [ 1139.692655] rhashtable_free_and_destroy+0x22/0x6f0 [ 1139.693472] del_sw_flow_table+0x22/0xb0 [mlx5_core] [ 1139.694592] tree_put_node+0x24c/0x450 [mlx5_core] [ 1139.695686] tree_remove_node+0x6e/0x100 [mlx5_core] [ 1139.696803] mlx5_destroy_flow_table+0x187/0x690 [mlx5_core] [ 1139.698017] mlx5e_tc_nic_cleanup+0x2f8/0x400 [mlx5_core] [ 1139.699217] mlx5e_cleanup_nic_rx+0x2b/0x210 [mlx5_core] [ 1139.700397] mlx5e_detach_netdev+0x19d/0x2b0 [mlx5_core] [ 1139.701571] mlx5e_suspend+0xdb/0x140 [mlx5_core] [ 1139.702665] mlx5e_remove+0x89/0x190 [mlx5_core] [ 1139.703756] auxiliary_bus_remove+0x52/0x70 [ 1139.704492] device_release_driver_internal+0x3c1/0x600 [ 1139.705360] bus_remove_device+0x2a5/0x560 [ 1139.706080] device_del+0x492/0xb80 [ 1139.706724] mlx5_rescan_drivers_locked+0x194/0x6a0 [mlx5_core] [ 1139.707961] mlx5_unregister_device+0x7a/0xa0 [mlx5_core] [ 1139.709138] mlx5_uninit_one+0x5f/0x160 [mlx5_core] [ 1139.710252] remove_one+0xd1/0x160 [mlx5_core] [ 1139.711297] pci_device_remove+0x96/0x1c0 [ 1139.722721] device_release_driver_internal+0x3c1/0x600 [ 1139.723590] unbind_store+0x1b1/0x200 [ 1139.724259] kernfs_fop_write_iter+0x348/0x520 [ 1139.725019] vfs_write+0x7b2/0xbf0 [ 1139.725658] ksys_write+0xf3/0x1d0 [ 1139.726292] do_syscall_64+0x3d/0x90 [ 1139.726942] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 1139.727769] -> #0 (&node->lock){++++}-{3:3}: [ 1139.728698] __lock_acquire+0x2cf5/0x62f0 [ 1139.729415] lock_acquire+0x1c1/0x540 [ 1139.730076] down_write+0x8e/0x1f0 [ 1139.730709] down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.731841] mlx5_del_flow_rules+0x6f/0x610 [mlx5_core] [ 1139.732982] __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core] [ 1139.734207] mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core] [ 1139.735491] mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core] [ 1139.736716] mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core] [ 1139.738007] mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core] [ 1139.739213] mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core] [ 1139.740377] _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core] [ 1139.741534] rhashtable_free_and_destroy+0x3be/0x6f0 [ 1139.742351] mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core] [ 1139.743512] mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core] [ 1139.744683] mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core] [ 1139.745860] mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core] [ 1139.747098] mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core] [ 1139.748372] mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core] [ 1139.749590] __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core] [ 1139.750813] mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core] [ 1139.752147] mlx5e_rep_remove+0x62/0x80 [mlx5_core] [ 1139.753293] auxiliary_bus_remove+0x52/0x70 [ 1139.754028] device_release_driver_internal+0x3c1/0x600 [ 1139.754885] driver_detach+0xc1/0x180 [ 1139.755553] bus_remove_driver+0xef/0x2e0 [ 1139.756260] auxiliary_driver_unregister+0x16/0x50 [ 1139.757059] mlx5e_rep_cleanup+0x19/0x30 [mlx5_core] [ 1139.758207] mlx5e_cleanup+0x12/0x30 [mlx5_core] [ 1139.759295] mlx5_cleanup+0xc/0x49 [mlx5_core] [ 1139.760384] __x64_sys_delete_module+0x2b5/0x450 [ 1139.761166] do_syscall_64+0x3d/0x90 [ 1139.761827] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 1139.762663] other info that might help us debug this:
[ 1139.763925] Chain exists of: &node->lock --> (work_completion)(&ht->run_work) --> &tc_ht_lock_key
[ 1139.765743] Possible unsafe locking scenario:
[ 1139.766688] CPU0 CPU1 [ 1139.767399] ---- ---- [ 1139.768111] lock(&tc_ht_lock_key); [ 1139.768704] lock((work_completion)(&ht->run_work)); [ 1139.769869] lock(&tc_ht_lock_key); [ 1139.770770] lock(&node->lock); [ 1139.771326] *** DEADLOCK ***
[ 1139.772345] 2 locks held by modprobe/5998: [ 1139.772994] #0: ffff88813c1ff0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x8d/0x600 [ 1139.774399] #1: ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0 [ 1139.775822] stack backtrace: [ 1139.776579] CPU: 3 PID: 5998 Comm: modprobe Not tainted 6.1.0_for_upstream_debug_2022_12_12_17_02 #1 [ 1139.777935] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 1139.779529] Call Trace: [ 1139.779992] <TASK> [ 1139.780409] dump_stack_lvl+0x57/0x7d [ 1139.781015] check_noncircular+0x278/0x300 [ 1139.781687] ? print_circular_bug+0x460/0x460 [ 1139.782381] ? rcu_read_lock_sched_held+0x3f/0x70 [ 1139.783121] ? lock_release+0x487/0x7c0 [ 1139.783759] ? orc_find.part.0+0x1f1/0x330 [ 1139.784423] ? mark_lock.part.0+0xef/0x2fc0 [ 1139.785091] __lock_acquire+0x2cf5/0x62f0 [ 1139.785754] ? register_lock_class+0x18e0/0x18e0 [ 1139.786483] lock_acquire+0x1c1/0x540 [ 1139.787093] ? down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.788195] ? lockdep_hardirqs_on_prepare+0x3f0/0x3f0 [ 1139.788978] ? register_lock_class+0x18e0/0x18e0 [ 1139.789715] down_write+0x8e/0x1f0 [ 1139.790292] ? down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.791380] ? down_write_killable+0x220/0x220 [ 1139.792080] ? find_held_lock+0x2d/0x110 [ 1139.792713] down_write_ref_node+0x7c/0xe0 [mlx5_core] [ 1139.793795] mlx5_del_flow_rules+0x6f/0x610 [mlx5_core] [ 1139.794879] __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core] [ 1139.796032] ? __esw_offloads_unload_rep+0xd0/0xd0 [mlx5_core] [ 1139.797227] ? xa_load+0x11a/0x200 [ 1139.797800] ? __xa_clear_mark+0xf0/0xf0 [ 1139.798438] mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core] [ 1139.799660] mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core] [ 1139.800821] mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core] [ 1139.802049] ? mlx5_eswitch_get_uplink_priv+0x25/0x80 [mlx5_core] [ 1139.803260] mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core] [ 1139.804398] ? __cancel_work_timer+0x1c2/0x3f0 [ 1139.805099] ? mlx5e_tc_unoffload_from_slow_path+0x460/0x460 [mlx5_core] [ 1139.806387] mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core] [ 1139.807481] _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core] [ 1139.808564] rhashtable_free_and_destroy+0x3be/0x6f0 [ 1139.809336] ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core] [ 1139.809336] ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core] [ 1139.810455] mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core] [ 1139.811552] mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core] [ 1139.812655] mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core] [ 1139.813768] mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core] [ 1139.814952] mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core] [ 1139.816166] mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core] [ 1139.817336] __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core] [ 1139.818507] mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core] [ 1139.819788] ? mlx5_eswitch_uplink_get_proto_dev+0x30/0x30 [mlx5_core] [ 1139.821051] ? kernfs_find_ns+0x137/0x310 [ 1139.821705] mlx5e_rep_remove+0x62/0x80 [mlx5_core] [ 1139.822778] auxiliary_bus_remove+0x52/0x70 [ 1139.823449] device_release_driver_internal+0x3c1/0x600 [ 1139.824240] driver_detach+0xc1/0x180 [ 1139.824842] bus_remove_driver+0xef/0x2e0 [ 1139.825504] auxiliary_driver_unregister+0x16/0x50 [ 1139.826245] mlx5e_rep_cleanup+0x19/0x30 [mlx5_core] [ 1139.827322] mlx5e_cleanup+0x12/0x30 [mlx5_core] [ 1139.828345] mlx5_cleanup+0xc/0x49 [mlx5_core] [ 1139.829382] __x64_sys_delete_module+0x2b5/0x450 [ 1139.830119] ? module_flags+0x300/0x300 [ 1139.830750] ? task_work_func_match+0x50/0x50 [ 1139.831440] ? task_work_cancel+0x20/0x20 [ 1139.832088] ? lockdep_hardirqs_on_prepare+0x273/0x3f0 [ 1139.832873] ? syscall_enter_from_user_mode+0x1d/0x50 [ 1139.833661] ? trace_hardirqs_on+0x2d/0x100 [ 1139.834328] do_syscall_64+0x3d/0x90 [ 1139.834922] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 1139.835700] RIP: 0033:0x7f153e71288b [ 1139.836302] Code: 73 01 c3 48 8b 0d 9d 75 0e 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 6d 75 0e 00 f7 d8 64 89 01 48 [ 1139.838866] RSP: 002b:00007ffe0a3ed938 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 1139.840020] RAX: ffffffffffffffda RBX: 0000564c2cbf8220 RCX: 00007f153e71288b [ 1139.841043] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000564c2cbf8288 [ 1139.842072] RBP: 0000564c2cbf8220 R08: 0000000000000000 R09: 0000000000000000 [ 1139.843094] R10: 00007f153e7a3ac0 R11: 0000000000000206 R12: 0000564c2cbf8288 [ 1139.844118] R13: 0000000000000000 R14: 0000564c2cbf7ae8 R15: 00007ffe0a3efcb8
Fixes: 9ba33339c043 ("net/mlx5e: Avoid false lock depenency warning on tc_ht") Signed-off-by: Vlad Buslov vladbu@nvidia.com Reviewed-by: Eli Cohen elic@nvidia.com Reviewed-by: Roi Dayan roid@nvidia.com Signed-off-by: Saeed Mahameed saeedm@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c index 4c313b7424bf..c1cf3917baa4 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -157,6 +157,7 @@ struct mlx5_fs_chains *mlx5e_nic_chains(struct mlx5e_tc_table *tc) * it's different than the ht->mutex here. */ static struct lock_class_key tc_ht_lock_key; +static struct lock_class_key tc_ht_wq_key;
static void mlx5e_put_flow_tunnel_id(struct mlx5e_tc_flow *flow); static void free_flow_post_acts(struct mlx5e_tc_flow *flow); @@ -4971,6 +4972,7 @@ int mlx5e_tc_nic_init(struct mlx5e_priv *priv) return err;
lockdep_set_class(&tc->ht.mutex, &tc_ht_lock_key); + lockdep_init_map(&tc->ht.run_work.lockdep_map, "tc_ht_wq_key", &tc_ht_wq_key, 0);
mapping_id = mlx5_query_nic_system_image_guid(dev);
@@ -5077,6 +5079,7 @@ int mlx5e_tc_ht_init(struct rhashtable *tc_ht) return err;
lockdep_set_class(&tc_ht->mutex, &tc_ht_lock_key); + lockdep_init_map(&tc_ht->run_work.lockdep_map, "tc_ht_wq_key", &tc_ht_wq_key, 0);
return 0; }