Commits
Subash Abhinov Kasiviswanathan committed b37f78f234b
net: qualcomm: rmnet: Fix crash on real dev unregistration With CONFIG_DEBUG_PREEMPT enabled, a crash with the following call stack was observed when removing a real dev which had rmnet devices attached to it. To fix this, remove the netdev_upper link APIs and instead use the existing information in rmnet_port and rmnet_priv to get the association between real and rmnet devs. BUG: sleeping function called from invalid context in_atomic(): 0, irqs_disabled(): 0, pid: 5762, name: ip Preemption disabled at: [<ffffff9d49043564>] debug_object_active_state+0xa4/0x16c Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: PC is at ___might_sleep+0x13c/0x180 LR is at ___might_sleep+0x17c/0x180 [<ffffff9d48ce0924>] ___might_sleep+0x13c/0x180 [<ffffff9d48ce09c0>] __might_sleep+0x58/0x8c [<ffffff9d49d6253c>] mutex_lock+0x2c/0x48 [<ffffff9d48ed4840>] kernfs_remove_by_name_ns+0x48/0xa8 [<ffffff9d48ed6ec8>] sysfs_remove_link+0x30/0x58 [<ffffff9d49b05840>] __netdev_adjacent_dev_remove+0x14c/0x1e0 [<ffffff9d49b05914>] __netdev_adjacent_dev_unlink_lists+0x40/0x68 [<ffffff9d49b08820>] netdev_upper_dev_unlink+0xb4/0x1fc [<ffffff9d494a29f0>] rmnet_dev_walk_unreg+0x6c/0xc8 [<ffffff9d49b00b40>] netdev_walk_all_lower_dev_rcu+0x58/0xb4 [<ffffff9d494a30fc>] rmnet_config_notify_cb+0xf4/0x134 [<ffffff9d48cd21b4>] raw_notifier_call_chain+0x58/0x78 [<ffffff9d49b028a4>] call_netdevice_notifiers_info+0x48/0x78 [<ffffff9d49b0b568>] rollback_registered_many+0x230/0x3c8 [<ffffff9d49b0b738>] unregister_netdevice_many+0x38/0x94 [<ffffff9d49b1e110>] rtnl_delete_link+0x58/0x88 [<ffffff9d49b201dc>] rtnl_dellink+0xbc/0x1cc [<ffffff9d49b2355c>] rtnetlink_rcv_msg+0xb0/0x244 [<ffffff9d49b5230c>] netlink_rcv_skb+0xb4/0xdc [<ffffff9d49b204f4>] rtnetlink_rcv+0x34/0x44 [<ffffff9d49b51af0>] netlink_unicast+0x1ec/0x294 [<ffffff9d49b51fdc>] netlink_sendmsg+0x320/0x390 [<ffffff9d49ae6858>] sock_sendmsg+0x54/0x60 [<ffffff9d49ae6f94>] ___sys_sendmsg+0x298/0x2b0 [<ffffff9d49ae98f8>] SyS_sendmsg+0xb4/0xf0 [<ffffff9d48c83770>] el0_svc_naked+0x24/0x28 Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Fixes: 60d58f971c10 ("net: qualcomm: rmnet: Implement bridge mode") Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Signed-off-by: David S. Miller <davem@davemloft.net>