Part Number:AM3352
Tool/software: Linux
Hi All,
We would debug a kernel lockup issue in AM335x Kernel 4.4.113, so we selected some Lockups&Hangs Detect options in Kernel menuconfig.
But now the kernel throw out " [ INFO: suspicious RCU usage. ] " when startup.
Will it also affect the stability of the kernel?
How can i fix this firstly.
Below is part of the log, see the appendix in detail.
[ 21.517337] ===============================
[ 21.521759] [ INFO: suspicious RCU usage. ]
[ 21.526095] 4.4.113 #4 Not tainted
[ 21.529546] -------------------------------
[ 21.533874] net/ipv4/cipso_ipv4.c:1940 suspicious rcu_dereference_protected() usage!
[ 21.541766]
[ 21.541766] other info that might help us debug this:
[ 21.541766]
[ 21.549940]
[ 21.549940] rcu_scheduler_active = 1, debug_locks = 0
[ 21.556621] 3 locks held by swapper/0/1:
[ 21.560676] #0: (net_mutex){+.+.+.}, at: [<c0964a14>] register_pernet_subsys+0x30/0x50
[ 21.569181] #1: (slock-AF_INET/1){+.....}, at: [<c0608f1c>] smack_netlabel+0x3c/0xa0
[ 21.577515] #2: (rcu_read_lock){......}, at: [<c0b0ecd4>] netlbl_sock_setattr+0x0/0x17c
[ 21.586187]
[ 21.586187] stack backtrace:
[ 21.590701] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.113 #4
[ 21.596769] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 21.602988] [<c001c5bc>] (unwind_backtrace) from [<c00163e8>] (show_stack+0x20/0x24)
[ 21.610833] [<c00163e8>] (show_stack) from [<c0692008>] (dump_stack+0xa0/0xcc)
[ 21.618148] [<c0692008>] (dump_stack) from [<c00a4360>] (lockdep_rcu_suspicious+0xe8/0x11c)
[ 21.626605] [<c00a4360>] (lockdep_rcu_suspicious) from [<c0a5d9c8>] (cipso_v4_sock_setattr+0x188/0x18c)
[ 21.636100] [<c0a5d9c8>] (cipso_v4_sock_setattr) from [<c0b0edd8>] (netlbl_sock_setattr+0x104/0x17c)
[ 21.645327] [<c0b0edd8>] (netlbl_sock_setattr) from [<c0608f70>] (smack_netlabel+0x90/0xa0)
[ 21.653777] [<c0608f70>] (smack_netlabel) from [<c060dfc8>] (smack_socket_post_create+0x68/0x6c)
[ 21.662673] [<c060dfc8>] (smack_socket_post_create) from [<c05e45cc>] (security_socket_post_create+0x70/0x90)
[ 21.672709] [<c05e45cc>] (security_socket_post_create) from [<c094f29c>] (__sock_create+0x320/0x390)
[ 21.681938] [<c094f29c>] (__sock_create) from [<c094f38c>] (sock_create_kern+0x28/0x30)
[ 21.690046] [<c094f38c>] (sock_create_kern) from [<c0a31c6c>] (inet_ctl_sock_create+0x40/0x90)
[ 21.698762] [<c0a31c6c>] (inet_ctl_sock_create) from [<c0aee568>] (sctp_ctrlsock_init+0x7c/0xb0)
[ 21.707636] [<c0aee568>] (sctp_ctrlsock_init) from [<c0963f50>] (ops_init+0xc0/0x174)
[ 21.715551] [<c0963f50>] (ops_init) from [<c0964960>] (register_pernet_operations+0x124/0x1a8)
[ 21.724251] [<c0964960>] (register_pernet_operations) from [<c0964a20>] (register_pernet_subsys+0x3c/0x50)
[ 21.734016] [<c0964a20>] (register_pernet_subsys) from [<c0fcc348>] (sctp_init+0x458/0x500)
[ 21.742465] [<c0fcc348>] (sctp_init) from [<c00098fc>] (do_one_initcall+0xd8/0x22c)
[ 21.750218] [<c00098fc>] (do_one_initcall) from [<c0f76078>] (kernel_init_freeable+0x250/0x2ec)
[ 21.759019] [<c0f76078>] (kernel_init_freeable) from [<c0b18f08>] (kernel_init+0x1c/0xf8)
[ 21.767295] [<c0b18f08>] (kernel_init) from [<c0011024>] (ret_from_fork+0x14/0x30)
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