linux/net/devlink/core.c

545 lines
13 KiB

devlink: don't take instance lock for nested handle put Lockdep reports following issue: WARNING: possible circular locking dependency detected ------------------------------------------------------ devlink/8191 is trying to acquire lock: ffff88813f32c250 (&devlink->lock_key#14){+.+.}-{3:3}, at: devlink_rel_devlink_handle_put+0x11e/0x2d0 but task is already holding lock: ffffffff8511eca8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (rtnl_mutex){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 register_netdevice_notifier_net+0x13/0x30 mlx5_lag_add_mdev+0x51c/0xa00 [mlx5_core] mlx5_load+0x222/0xc70 [mlx5_core] mlx5_init_one_devl_locked+0x4a0/0x1310 [mlx5_core] mlx5_init_one+0x3b/0x60 [mlx5_core] probe_one+0x786/0xd00 [mlx5_core] local_pci_probe+0xd7/0x180 pci_device_probe+0x231/0x720 really_probe+0x1e4/0xb60 __driver_probe_device+0x261/0x470 driver_probe_device+0x49/0x130 __driver_attach+0x215/0x4c0 bus_for_each_dev+0xf0/0x170 bus_add_driver+0x21d/0x590 driver_register+0x133/0x460 vdpa_match_remove+0x89/0xc0 [vdpa] do_one_initcall+0xc4/0x360 do_init_module+0x22d/0x760 load_module+0x51d7/0x6750 init_module_from_file+0xd2/0x130 idempotent_init_module+0x326/0x5a0 __x64_sys_finit_module+0xc1/0x130 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #2 (mlx5_intf_mutex){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 mlx5_register_device+0x3e/0xd0 [mlx5_core] mlx5_init_one_devl_locked+0x8fa/0x1310 [mlx5_core] mlx5_devlink_reload_up+0x147/0x170 [mlx5_core] devlink_reload+0x203/0x380 devlink_nl_cmd_reload+0xb84/0x10e0 genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #1 (&dev->lock_key#8){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 mlx5_init_one_devl_locked+0x45/0x1310 [mlx5_core] mlx5_devlink_reload_up+0x147/0x170 [mlx5_core] devlink_reload+0x203/0x380 devlink_nl_cmd_reload+0xb84/0x10e0 genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #0 (&devlink->lock_key#14){+.+.}-{3:3}: check_prev_add+0x1af/0x2300 __lock_acquire+0x31d7/0x4eb0 lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 devlink_rel_devlink_handle_put+0x11e/0x2d0 devlink_nl_port_fill+0xddf/0x1b00 devlink_port_notify+0xb5/0x220 __devlink_port_type_set+0x151/0x510 devlink_port_netdevice_event+0x17c/0x220 notifier_call_chain+0x97/0x240 unregister_netdevice_many_notify+0x876/0x1790 unregister_netdevice_queue+0x274/0x350 unregister_netdev+0x18/0x20 mlx5e_vport_rep_unload+0xc5/0x1c0 [mlx5_core] __esw_offloads_unload_rep+0xd8/0x130 [mlx5_core] mlx5_esw_offloads_rep_unload+0x52/0x70 [mlx5_core] mlx5_esw_offloads_unload_rep+0x85/0xc0 [mlx5_core] mlx5_eswitch_unload_sf_vport+0x41/0x90 [mlx5_core] mlx5_devlink_sf_port_del+0x120/0x280 [mlx5_core] genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 other info that might help us debug this: Chain exists of: &devlink->lock_key#14 --> mlx5_intf_mutex --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(mlx5_intf_mutex); lock(rtnl_mutex); lock(&devlink->lock_key#14); Problem is taking the devlink instance lock of nested instance when RTNL is already held. To fix this, don't take the devlink instance lock when putting nested handle. Instead, rely on the preparations done by previous two patches to be able to access device pointer and obtain netns id without devlink instance lock held. Fixes: c137743bce02 ("devlink: introduce object and nested devlink relationship infra") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-13 14:10:26 +02:00
devlink: don't take instance lock for nested handle put Lockdep reports following issue: WARNING: possible circular locking dependency detected ------------------------------------------------------ devlink/8191 is trying to acquire lock: ffff88813f32c250 (&devlink->lock_key#14){+.+.}-{3:3}, at: devlink_rel_devlink_handle_put+0x11e/0x2d0 but task is already holding lock: ffffffff8511eca8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (rtnl_mutex){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 register_netdevice_notifier_net+0x13/0x30 mlx5_lag_add_mdev+0x51c/0xa00 [mlx5_core] mlx5_load+0x222/0xc70 [mlx5_core] mlx5_init_one_devl_locked+0x4a0/0x1310 [mlx5_core] mlx5_init_one+0x3b/0x60 [mlx5_core] probe_one+0x786/0xd00 [mlx5_core] local_pci_probe+0xd7/0x180 pci_device_probe+0x231/0x720 really_probe+0x1e4/0xb60 __driver_probe_device+0x261/0x470 driver_probe_device+0x49/0x130 __driver_attach+0x215/0x4c0 bus_for_each_dev+0xf0/0x170 bus_add_driver+0x21d/0x590 driver_register+0x133/0x460 vdpa_match_remove+0x89/0xc0 [vdpa] do_one_initcall+0xc4/0x360 do_init_module+0x22d/0x760 load_module+0x51d7/0x6750 init_module_from_file+0xd2/0x130 idempotent_init_module+0x326/0x5a0 __x64_sys_finit_module+0xc1/0x130 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #2 (mlx5_intf_mutex){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 mlx5_register_device+0x3e/0xd0 [mlx5_core] mlx5_init_one_devl_locked+0x8fa/0x1310 [mlx5_core] mlx5_devlink_reload_up+0x147/0x170 [mlx5_core] devlink_reload+0x203/0x380 devlink_nl_cmd_reload+0xb84/0x10e0 genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #1 (&dev->lock_key#8){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 mlx5_init_one_devl_locked+0x45/0x1310 [mlx5_core] mlx5_devlink_reload_up+0x147/0x170 [mlx5_core] devlink_reload+0x203/0x380 devlink_nl_cmd_reload+0xb84/0x10e0 genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #0 (&devlink->lock_key#14){+.+.}-{3:3}: check_prev_add+0x1af/0x2300 __lock_acquire+0x31d7/0x4eb0 lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 devlink_rel_devlink_handle_put+0x11e/0x2d0 devlink_nl_port_fill+0xddf/0x1b00 devlink_port_notify+0xb5/0x220 __devlink_port_type_set+0x151/0x510 devlink_port_netdevice_event+0x17c/0x220 notifier_call_chain+0x97/0x240 unregister_netdevice_many_notify+0x876/0x1790 unregister_netdevice_queue+0x274/0x350 unregister_netdev+0x18/0x20 mlx5e_vport_rep_unload+0xc5/0x1c0 [mlx5_core] __esw_offloads_unload_rep+0xd8/0x130 [mlx5_core] mlx5_esw_offloads_rep_unload+0x52/0x70 [mlx5_core] mlx5_esw_offloads_unload_rep+0x85/0xc0 [mlx5_core] mlx5_eswitch_unload_sf_vport+0x41/0x90 [mlx5_core] mlx5_devlink_sf_port_del+0x120/0x280 [mlx5_core] genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 other info that might help us debug this: Chain exists of: &devlink->lock_key#14 --> mlx5_intf_mutex --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(mlx5_intf_mutex); lock(rtnl_mutex); lock(&devlink->lock_key#14); Problem is taking the devlink instance lock of nested instance when RTNL is already held. To fix this, don't take the devlink instance lock when putting nested handle. Instead, rely on the preparations done by previous two patches to be able to access device pointer and obtain netns id without devlink instance lock held. Fixes: c137743bce02 ("devlink: introduce object and nested devlink relationship infra") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-13 14:10:26 +02:00
devlink: don't take instance lock for nested handle put Lockdep reports following issue: WARNING: possible circular locking dependency detected ------------------------------------------------------ devlink/8191 is trying to acquire lock: ffff88813f32c250 (&devlink->lock_key#14){+.+.}-{3:3}, at: devlink_rel_devlink_handle_put+0x11e/0x2d0 but task is already holding lock: ffffffff8511eca8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (rtnl_mutex){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 register_netdevice_notifier_net+0x13/0x30 mlx5_lag_add_mdev+0x51c/0xa00 [mlx5_core] mlx5_load+0x222/0xc70 [mlx5_core] mlx5_init_one_devl_locked+0x4a0/0x1310 [mlx5_core] mlx5_init_one+0x3b/0x60 [mlx5_core] probe_one+0x786/0xd00 [mlx5_core] local_pci_probe+0xd7/0x180 pci_device_probe+0x231/0x720 really_probe+0x1e4/0xb60 __driver_probe_device+0x261/0x470 driver_probe_device+0x49/0x130 __driver_attach+0x215/0x4c0 bus_for_each_dev+0xf0/0x170 bus_add_driver+0x21d/0x590 driver_register+0x133/0x460 vdpa_match_remove+0x89/0xc0 [vdpa] do_one_initcall+0xc4/0x360 do_init_module+0x22d/0x760 load_module+0x51d7/0x6750 init_module_from_file+0xd2/0x130 idempotent_init_module+0x326/0x5a0 __x64_sys_finit_module+0xc1/0x130 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #2 (mlx5_intf_mutex){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 mlx5_register_device+0x3e/0xd0 [mlx5_core] mlx5_init_one_devl_locked+0x8fa/0x1310 [mlx5_core] mlx5_devlink_reload_up+0x147/0x170 [mlx5_core] devlink_reload+0x203/0x380 devlink_nl_cmd_reload+0xb84/0x10e0 genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #1 (&dev->lock_key#8){+.+.}-{3:3}: lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 mlx5_init_one_devl_locked+0x45/0x1310 [mlx5_core] mlx5_devlink_reload_up+0x147/0x170 [mlx5_core] devlink_reload+0x203/0x380 devlink_nl_cmd_reload+0xb84/0x10e0 genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #0 (&devlink->lock_key#14){+.+.}-{3:3}: check_prev_add+0x1af/0x2300 __lock_acquire+0x31d7/0x4eb0 lock_acquire+0x1c3/0x500 __mutex_lock+0x14c/0x1b20 devlink_rel_devlink_handle_put+0x11e/0x2d0 devlink_nl_port_fill+0xddf/0x1b00 devlink_port_notify+0xb5/0x220 __devlink_port_type_set+0x151/0x510 devlink_port_netdevice_event+0x17c/0x220 notifier_call_chain+0x97/0x240 unregister_netdevice_many_notify+0x876/0x1790 unregister_netdevice_queue+0x274/0x350 unregister_netdev+0x18/0x20 mlx5e_vport_rep_unload+0xc5/0x1c0 [mlx5_core] __esw_offloads_unload_rep+0xd8/0x130 [mlx5_core] mlx5_esw_offloads_rep_unload+0x52/0x70 [mlx5_core] mlx5_esw_offloads_unload_rep+0x85/0xc0 [mlx5_core] mlx5_eswitch_unload_sf_vport+0x41/0x90 [mlx5_core] mlx5_devlink_sf_port_del+0x120/0x280 [mlx5_core] genl_family_rcv_msg_doit+0x1cc/0x2a0 genl_rcv_msg+0x3c9/0x670 netlink_rcv_skb+0x12c/0x360 genl_rcv+0x24/0x40 netlink_unicast+0x435/0x6f0 netlink_sendmsg+0x7a0/0xc70 sock_sendmsg+0xc5/0x190 __sys_sendto+0x1c8/0x290 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 other info that might help us debug this: Chain exists of: &devlink->lock_key#14 --> mlx5_intf_mutex --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(mlx5_intf_mutex); lock(rtnl_mutex); lock(&devlink->lock_key#14); Problem is taking the devlink instance lock of nested instance when RTNL is already held. To fix this, don't take the devlink instance lock when putting nested handle. Instead, rely on the preparations done by previous two patches to be able to access device pointer and obtain netns id without devlink instance lock held. Fixes: c137743bce02 ("devlink: introduce object and nested devlink relationship infra") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-13 14:10:26 +02:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-05 22:33:58 -08:00
devlink: Fix crash with CONFIG_NET_NS=n '__net_initdata' becomes a no-op with CONFIG_NET_NS=y, but when this option is disabled it becomes '__initdata', which means the data can be freed after the initialization phase. This annotation is obviously incorrect for the devlink net device notifier block which is still registered after the initialization phase [1]. Fix this crash by removing the '__net_initdata' annotation. [1] general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] PREEMPT SMP CPU: 3 PID: 117 Comm: (udev-worker) Not tainted 6.4.0-rc1-custom-gdf0acdc59b09 #64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:notifier_call_chain+0x58/0xc0 [...] Call Trace: <TASK> dev_set_mac_address+0x85/0x120 dev_set_mac_address_user+0x30/0x50 do_setlink+0x219/0x1270 rtnl_setlink+0xf7/0x1a0 rtnetlink_rcv_msg+0x142/0x390 netlink_rcv_skb+0x58/0x100 netlink_unicast+0x188/0x270 netlink_sendmsg+0x214/0x470 __sys_sendto+0x12f/0x1a0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: e93c9378e33f ("devlink: change per-devlink netdev notifier to static one") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Closes: https://lore.kernel.org/netdev/600ddf9e-589a-2aa0-7b69-a438f833ca10@samsung.com/ Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230515162925.1144416-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-15 19:29:25 +03:00
devlink: change per-devlink netdev notifier to static one The commit 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") changed original per-net notifier to be per-devlink instance. That fixed the issue of non-receiving events of netdev uninit if that moved to a different namespace. That worked fine in -net tree. However, later on when commit ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") and commit 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") were merged, a deadlock was introduced when removing a namespace with devlink instance with another nested instance. Here there is the bad flow example resulting in deadlock with mlx5: net_cleanup_work -> cleanup_net (takes down_read(&pernet_ops_rwsem) -> devlink_pernet_pre_exit() -> devlink_reload() -> mlx5_devlink_reload_down() -> mlx5_unload_one_devl_locked() -> mlx5_detach_device() -> del_adev() -> mlx5e_remove() -> mlx5e_destroy_devlink() -> devlink_free() -> unregister_netdevice_notifier() (takes down_write(&pernet_ops_rwsem) Steps to reproduce: $ modprobe mlx5_core $ ip netns add ns1 $ devlink dev reload pci/0000:08:00.0 netns ns1 $ ip netns del ns1 Resolve this by converting the notifier from per-devlink instance to a static one registered during init phase and leaving it registered forever. Use this notifier for all devlink port instances created later on. Note what a tree needs this fix only in case all of the cited fixes commits are present. Reported-by: Moshe Shemesh <moshe@nvidia.com> Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Fixes: ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") Fixes: 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230510144621.932017-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10 16:46:21 +02:00
devlink: change per-devlink netdev notifier to static one The commit 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") changed original per-net notifier to be per-devlink instance. That fixed the issue of non-receiving events of netdev uninit if that moved to a different namespace. That worked fine in -net tree. However, later on when commit ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") and commit 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") were merged, a deadlock was introduced when removing a namespace with devlink instance with another nested instance. Here there is the bad flow example resulting in deadlock with mlx5: net_cleanup_work -> cleanup_net (takes down_read(&pernet_ops_rwsem) -> devlink_pernet_pre_exit() -> devlink_reload() -> mlx5_devlink_reload_down() -> mlx5_unload_one_devl_locked() -> mlx5_detach_device() -> del_adev() -> mlx5e_remove() -> mlx5e_destroy_devlink() -> devlink_free() -> unregister_netdevice_notifier() (takes down_write(&pernet_ops_rwsem) Steps to reproduce: $ modprobe mlx5_core $ ip netns add ns1 $ devlink dev reload pci/0000:08:00.0 netns ns1 $ ip netns del ns1 Resolve this by converting the notifier from per-devlink instance to a static one registered during init phase and leaving it registered forever. Use this notifier for all devlink port instances created later on. Note what a tree needs this fix only in case all of the cited fixes commits are present. Reported-by: Moshe Shemesh <moshe@nvidia.com> Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Fixes: ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") Fixes: 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230510144621.932017-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10 16:46:21 +02:00