• M
    net/mlx5: Avoid false positive lockdep warning by adding lock_class_key · d59b73a6
    Moshe Shemesh 提交于
    Add a lock_class_key per mlx5 device to avoid a false positive
    "possible circular locking dependency" warning by lockdep, on flows
    which lock more than one mlx5 device, such as adding SF.
    
    kernel log:
     ======================================================
     WARNING: possible circular locking dependency detected
     5.19.0-rc8+ #2 Not tainted
     ------------------------------------------------------
     kworker/u20:0/8 is trying to acquire lock:
     ffff88812dfe0d98 (&dev->intf_state_mutex){+.+.}-{3:3}, at: mlx5_init_one+0x2e/0x490 [mlx5_core]
    
     but task is already holding lock:
     ffff888101aa7898 (&(&notifier->n_head)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5a/0x130
    
     which lock already depends on the new lock.
    
     the existing dependency chain (in reverse order) is:
    
     -> #1 (&(&notifier->n_head)->rwsem){++++}-{3:3}:
            down_write+0x90/0x150
            blocking_notifier_chain_register+0x53/0xa0
            mlx5_sf_table_init+0x369/0x4a0 [mlx5_core]
            mlx5_init_one+0x261/0x490 [mlx5_core]
            probe_one+0x430/0x680 [mlx5_core]
            local_pci_probe+0xd6/0x170
            work_for_cpu_fn+0x4e/0xa0
            process_one_work+0x7c2/0x1340
            worker_thread+0x6f6/0xec0
            kthread+0x28f/0x330
            ret_from_fork+0x1f/0x30
    
     -> #0 (&dev->intf_state_mutex){+.+.}-{3:3}:
            __lock_acquire+0x2fc7/0x6720
            lock_acquire+0x1c1/0x550
            __mutex_lock+0x12c/0x14b0
            mlx5_init_one+0x2e/0x490 [mlx5_core]
            mlx5_sf_dev_probe+0x29c/0x370 [mlx5_core]
            auxiliary_bus_probe+0x9d/0xe0
            really_probe+0x1e0/0xaa0
            __driver_probe_device+0x219/0x480
            driver_probe_device+0x49/0x130
            __device_attach_driver+0x1b8/0x280
            bus_for_each_drv+0x123/0x1a0
            __device_attach+0x1a3/0x460
            bus_probe_device+0x1a2/0x260
            device_add+0x9b1/0x1b40
            __auxiliary_device_add+0x88/0xc0
            mlx5_sf_dev_state_change_handler+0x67e/0x9d0 [mlx5_core]
            blocking_notifier_call_chain+0xd5/0x130
            mlx5_vhca_state_work_handler+0x2b0/0x3f0 [mlx5_core]
            process_one_work+0x7c2/0x1340
            worker_thread+0x59d/0xec0
            kthread+0x28f/0x330
            ret_from_fork+0x1f/0x30
    
      other info that might help us debug this:
    
      Possible unsafe locking scenario:
    
            CPU0                    CPU1
            ----                    ----
       lock(&(&notifier->n_head)->rwsem);
                                    lock(&dev->intf_state_mutex);
                                    lock(&(&notifier->n_head)->rwsem);
       lock(&dev->intf_state_mutex);
    
      *** DEADLOCK ***
    
     4 locks held by kworker/u20:0/8:
      #0: ffff888150612938 ((wq_completion)mlx5_events){+.+.}-{0:0}, at: process_one_work+0x6e2/0x1340
      #1: ffff888100cafdb8 ((work_completion)(&work->work)#3){+.+.}-{0:0}, at: process_one_work+0x70f/0x1340
      #2: ffff888101aa7898 (&(&notifier->n_head)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5a/0x130
      #3: ffff88813682d0e8 (&dev->mutex){....}-{3:3}, at:__device_attach+0x76/0x460
    
     stack backtrace:
     CPU: 6 PID: 8 Comm: kworker/u20:0 Not tainted 5.19.0-rc8+
     Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
     Workqueue: mlx5_events mlx5_vhca_state_work_handler [mlx5_core]
     Call Trace:
      <TASK>
      dump_stack_lvl+0x57/0x7d
      check_noncircular+0x278/0x300
      ? print_circular_bug+0x460/0x460
      ? lock_chain_count+0x20/0x20
      ? register_lock_class+0x1880/0x1880
      __lock_acquire+0x2fc7/0x6720
      ? register_lock_class+0x1880/0x1880
      ? register_lock_class+0x1880/0x1880
      lock_acquire+0x1c1/0x550
      ? mlx5_init_one+0x2e/0x490 [mlx5_core]
      ? lockdep_hardirqs_on_prepare+0x400/0x400
      __mutex_lock+0x12c/0x14b0
      ? mlx5_init_one+0x2e/0x490 [mlx5_core]
      ? mlx5_init_one+0x2e/0x490 [mlx5_core]
      ? _raw_read_unlock+0x1f/0x30
      ? mutex_lock_io_nested+0x1320/0x1320
      ? __ioremap_caller.constprop.0+0x306/0x490
      ? mlx5_sf_dev_probe+0x269/0x370 [mlx5_core]
      ? iounmap+0x160/0x160
      mlx5_init_one+0x2e/0x490 [mlx5_core]
      mlx5_sf_dev_probe+0x29c/0x370 [mlx5_core]
      ? mlx5_sf_dev_remove+0x130/0x130 [mlx5_core]
      auxiliary_bus_probe+0x9d/0xe0
      really_probe+0x1e0/0xaa0
      __driver_probe_device+0x219/0x480
      ? auxiliary_match_id+0xe9/0x140
      driver_probe_device+0x49/0x130
      __device_attach_driver+0x1b8/0x280
      ? driver_allows_async_probing+0x140/0x140
      bus_for_each_drv+0x123/0x1a0
      ? bus_for_each_dev+0x1a0/0x1a0
      ? lockdep_hardirqs_on_prepare+0x286/0x400
      ? trace_hardirqs_on+0x2d/0x100
      __device_attach+0x1a3/0x460
      ? device_driver_attach+0x1e0/0x1e0
      ? kobject_uevent_env+0x22d/0xf10
      bus_probe_device+0x1a2/0x260
      device_add+0x9b1/0x1b40
      ? dev_set_name+0xab/0xe0
      ? __fw_devlink_link_to_suppliers+0x260/0x260
      ? memset+0x20/0x40
      ? lockdep_init_map_type+0x21a/0x7d0
      __auxiliary_device_add+0x88/0xc0
      ? auxiliary_device_init+0x86/0xa0
      mlx5_sf_dev_state_change_handler+0x67e/0x9d0 [mlx5_core]
      blocking_notifier_call_chain+0xd5/0x130
      mlx5_vhca_state_work_handler+0x2b0/0x3f0 [mlx5_core]
      ? mlx5_vhca_event_arm+0x100/0x100 [mlx5_core]
      ? lock_downgrade+0x6e0/0x6e0
      ? lockdep_hardirqs_on_prepare+0x286/0x400
      process_one_work+0x7c2/0x1340
      ? lockdep_hardirqs_on_prepare+0x400/0x400
      ? pwq_dec_nr_in_flight+0x230/0x230
      ? rwlock_bug.part.0+0x90/0x90
      worker_thread+0x59d/0xec0
      ? process_one_work+0x1340/0x1340
      kthread+0x28f/0x330
      ? kthread_complete_and_exit+0x20/0x20
      ret_from_fork+0x1f/0x30
      </TASK>
    
    Fixes: 6a327321 ("net/mlx5: SF, Port function state change support")
    Signed-off-by: NMoshe Shemesh <moshe@nvidia.com>
    Reviewed-by: NShay Drory <shayd@nvidia.com>
    Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>
    d59b73a6
driver.h 33.9 KB