From: Leon Romanovsky leonro@nvidia.com
[ Upstream commit 64ea2d0e7263b67d8efc93fa1baace041ed36d1e ]
The change of devlink_alloc() to accept device makes sure that device is fully initialized and device_register() does nothing except allowing users to use that devlink instance.
Such change ensures that no user input will be usable till that point and it eliminates the need to worry about internal locking as long as devlink_register is called last since all accesses to the devlink are during initialization.
This change fixes the following lockdep warning.
====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #27 Not tainted ------------------------------------------------------ devlink/265 is trying to acquire lock: ffff8880133c2bc0 (&dev->intf_state_mutex){+.+.}-{3:3}, at: mlx5_unload_one+0x1e/0xa0 [mlx5_core] but task is already holding lock: ffffffff8362b468 (devlink_mutex){+.+.}-{3:3}, at: devlink_nl_pre_doit+0x2b/0x8d0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is:
-> #1 (devlink_mutex){+.+.}-{3:3}: __mutex_lock+0x149/0x1310 devlink_register+0xe7/0x280 mlx5_devlink_register+0x118/0x480 [mlx5_core] mlx5_init_one+0x34b/0x440 [mlx5_core] probe_one+0x480/0x6e0 [mlx5_core] pci_device_probe+0x2a0/0x4a0 really_probe+0x1cb/0xba0 __driver_probe_device+0x18f/0x470 driver_probe_device+0x49/0x120 __driver_attach+0x1ce/0x400 bus_for_each_dev+0x11e/0x1a0 bus_add_driver+0x309/0x570 driver_register+0x20f/0x390 0xffffffffa04a0062 do_one_initcall+0xd5/0x400 do_init_module+0x1c8/0x760 load_module+0x7d9d/0xa4b0 __do_sys_finit_module+0x118/0x1a0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (&dev->intf_state_mutex){+.+.}-{3:3}: __lock_acquire+0x2999/0x5a40 lock_acquire+0x1a9/0x4a0 __mutex_lock+0x149/0x1310 mlx5_unload_one+0x1e/0xa0 [mlx5_core] mlx5_devlink_reload_down+0x185/0x2b0 [mlx5_core] devlink_reload+0x1f2/0x640 devlink_nl_cmd_reload+0x6c3/0x10d0 genl_family_rcv_msg_doit+0x1e9/0x2f0 genl_rcv_msg+0x27f/0x4a0 netlink_rcv_skb+0x11e/0x340 genl_rcv+0x24/0x40 netlink_unicast+0x433/0x700 netlink_sendmsg+0x6fb/0xbe0 sock_sendmsg+0xb0/0xe0 __sys_sendto+0x192/0x240 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(devlink_mutex); lock(&dev->intf_state_mutex); lock(devlink_mutex); lock(&dev->intf_state_mutex);
*** DEADLOCK ***
3 locks held by devlink/265: #0: ffffffff836371d0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 #1: ffffffff83637288 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x31a/0x4a0 #2: ffffffff8362b468 (devlink_mutex){+.+.}-{3:3}, at: devlink_nl_pre_doit+0x2b/0x8d0
stack backtrace: CPU: 0 PID: 265 Comm: devlink Not tainted 5.14.0-rc2+ #27 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x45/0x59 check_noncircular+0x268/0x310 ? print_circular_bug+0x460/0x460 ? __kernel_text_address+0xe/0x30 ? alloc_chain_hlocks+0x1e6/0x5a0 __lock_acquire+0x2999/0x5a40 ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0 ? add_lock_to_list.constprop.0+0x6c/0x530 lock_acquire+0x1a9/0x4a0 ? mlx5_unload_one+0x1e/0xa0 [mlx5_core] ? lock_release+0x6c0/0x6c0 ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0 ? lock_is_held_type+0x98/0x110 __mutex_lock+0x149/0x1310 ? mlx5_unload_one+0x1e/0xa0 [mlx5_core] ? lock_is_held_type+0x98/0x110 ? mlx5_unload_one+0x1e/0xa0 [mlx5_core] ? find_held_lock+0x2d/0x110 ? mutex_lock_io_nested+0x1160/0x1160 ? mlx5_lag_is_active+0x72/0x90 [mlx5_core] ? lock_downgrade+0x6d0/0x6d0 ? do_raw_spin_lock+0x12e/0x270 ? rwlock_bug.part.0+0x90/0x90 ? mlx5_unload_one+0x1e/0xa0 [mlx5_core] mlx5_unload_one+0x1e/0xa0 [mlx5_core] mlx5_devlink_reload_down+0x185/0x2b0 [mlx5_core] ? netlink_broadcast_filtered+0x308/0xac0 ? mlx5_devlink_info_get+0x1f0/0x1f0 [mlx5_core] ? __build_skb_around+0x110/0x2b0 ? __alloc_skb+0x113/0x2b0 devlink_reload+0x1f2/0x640 ? devlink_unregister+0x1e0/0x1e0 ? security_capable+0x51/0x90 devlink_nl_cmd_reload+0x6c3/0x10d0 ? devlink_nl_cmd_get_doit+0x1e0/0x1e0 ? devlink_nl_pre_doit+0x72/0x8d0 genl_family_rcv_msg_doit+0x1e9/0x2f0 ? __lock_acquire+0x15e2/0x5a40 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240 ? mutex_lock_io_nested+0x1160/0x1160 ? security_capable+0x51/0x90 genl_rcv_msg+0x27f/0x4a0 ? genl_get_cmd+0x3c0/0x3c0 ? lock_acquire+0x1a9/0x4a0 ? devlink_nl_cmd_get_doit+0x1e0/0x1e0 ? lock_release+0x6c0/0x6c0 netlink_rcv_skb+0x11e/0x340 ? genl_get_cmd+0x3c0/0x3c0 ? netlink_ack+0x930/0x930 genl_rcv+0x24/0x40 netlink_unicast+0x433/0x700 ? netlink_attachskb+0x750/0x750 ? __alloc_skb+0x113/0x2b0 netlink_sendmsg+0x6fb/0xbe0 ? netlink_unicast+0x700/0x700 ? netlink_unicast+0x700/0x700 sock_sendmsg+0xb0/0xe0 __sys_sendto+0x192/0x240 ? __x64_sys_getpeername+0xb0/0xb0 ? do_sys_openat2+0x10a/0x370 ? down_write_nested+0x150/0x150 ? do_user_addr_fault+0x215/0xd50 ? __x64_sys_openat+0x11f/0x1d0 ? __x64_sys_open+0x1a0/0x1a0 __x64_sys_sendto+0xdc/0x1b0 ? syscall_enter_from_user_mode+0x1d/0x50 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f50b50b6b3a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 c3 0f 1f 44 00 00 55 48 83 ec 30 44 89 4c RSP: 002b:00007fff6c0d3f38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f50b50b6b3a RDX: 0000000000000038 RSI: 000055763ac08440 RDI: 0000000000000003 RBP: 000055763ac08410 R08: 00007f50b5192200 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055763ac08410 R15: 000055763ac08440 mlx5_core 0000:00:09.0: firmware version: 4.8.9999 mlx5_core 0000:00:09.0: 0.000 Gb/s available PCIe bandwidth (8.0 GT/s PCIe x255 link) mlx5_core 0000:00:09.0 eth1: Link up
Fixes: a6f3b62386a0 ("net/mlx5: Move devlink registration before interfaces load") Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/devlink.c | 12 ++---------- drivers/net/ethernet/mellanox/mlx5/core/main.c | 2 ++ .../net/ethernet/mellanox/mlx5/core/sf/dev/driver.c | 2 ++ 3 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c index 7d56a927081d0..d7576b6fa43b7 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c @@ -793,14 +793,11 @@ int mlx5_devlink_register(struct devlink *devlink) { int err;
- err = devlink_register(devlink); - if (err) - return err; - err = devlink_params_register(devlink, mlx5_devlink_params, ARRAY_SIZE(mlx5_devlink_params)); if (err) - goto params_reg_err; + return err; + mlx5_devlink_set_params_init_values(devlink);
err = mlx5_devlink_auxdev_params_register(devlink); @@ -811,7 +808,6 @@ int mlx5_devlink_register(struct devlink *devlink) if (err) goto traps_reg_err;
- devlink_params_publish(devlink); return 0;
traps_reg_err: @@ -819,17 +815,13 @@ traps_reg_err: auxdev_reg_err: devlink_params_unregister(devlink, mlx5_devlink_params, ARRAY_SIZE(mlx5_devlink_params)); -params_reg_err: - devlink_unregister(devlink); return err; }
void mlx5_devlink_unregister(struct devlink *devlink) { - devlink_params_unpublish(devlink); mlx5_devlink_traps_unregister(devlink); mlx5_devlink_auxdev_params_unregister(devlink); devlink_params_unregister(devlink, mlx5_devlink_params, ARRAY_SIZE(mlx5_devlink_params)); - devlink_unregister(devlink); } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c index 79482824c64ff..92b08fa07efae 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c @@ -1537,6 +1537,7 @@ static int probe_one(struct pci_dev *pdev, const struct pci_device_id *id) dev_err(&pdev->dev, "mlx5_crdump_enable failed with error code %d\n", err);
pci_save_state(pdev); + devlink_register(devlink); if (!mlx5_core_is_mp_slave(dev)) devlink_reload_enable(devlink); return 0; @@ -1559,6 +1560,7 @@ static void remove_one(struct pci_dev *pdev) struct devlink *devlink = priv_to_devlink(dev);
devlink_reload_disable(devlink); + devlink_unregister(devlink); mlx5_crdump_disable(dev); mlx5_drain_health_wq(dev); mlx5_uninit_one(dev); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/driver.c b/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/driver.c index 052f48068dc16..3cf272fa21646 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/driver.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/driver.c @@ -46,6 +46,7 @@ static int mlx5_sf_dev_probe(struct auxiliary_device *adev, const struct auxilia mlx5_core_warn(mdev, "mlx5_init_one err=%d\n", err); goto init_one_err; } + devlink_register(devlink); devlink_reload_enable(devlink); return 0;
@@ -65,6 +66,7 @@ static void mlx5_sf_dev_remove(struct auxiliary_device *adev)
devlink = priv_to_devlink(sf_dev->mdev); devlink_reload_disable(devlink); + devlink_unregister(devlink); mlx5_uninit_one(sf_dev->mdev); iounmap(sf_dev->mdev->iseg); mlx5_mdev_uninit(sf_dev->mdev);