On Fri, 2016-04-01 at 02:21 +0200, Hannes Frederic Sowa wrote: > > [ 31.064029] =============================== > [ 31.064030] [ INFO: suspicious RCU usage. ] > [ 31.064032] 4.5.0+ #13 Not tainted > [ 31.064033] ------------------------------- > [ 31.064034] include/net/sock.h:1594 suspicious > rcu_dereference_check() usage! > [ 31.064035] > other info that might help us debug this: > > [ 31.064041] > rcu_scheduler_active = 1, debug_locks = 1 > [ 31.064042] no locks held by ssh/817. > [ 31.064043] > stack backtrace: > [ 31.064045] CPU: 0 PID: 817 Comm: ssh Not tainted 4.5.0+ #13 > [ 31.064046] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS 1.8.2-20150714_191134- 04/01/2014 > [ 31.064047] 0000000000000286 000000006730b46b ffff8800badf7bd0 > ffffffff81442b33 > [ 31.064050] ffff8800b8c78000 0000000000000001 ffff8800badf7c00 > ffffffff8110ae75 > [ 31.064052] ffff880035ea2f00 ffff8800b8e28000 0000000000000003 > 00000000000004c4 > [ 31.064054] Call Trace: > [ 31.064058] [<ffffffff81442b33>] dump_stack+0x85/0xc2 > [ 31.064062] [<ffffffff8110ae75>] lockdep_rcu_suspicious+0xc5/0x100 > [ 31.064064] [<ffffffff8173bf57>] __sk_dst_check+0x77/0xb0 > [ 31.064066] [<ffffffff8182e502>] inet6_sk_rebuild_header+0x52/0x300 > [ 31.064068] [<ffffffff813bb61e>] ? selinux_skb_peerlbl_sid+0x5e/0xa0 > [ 31.064070] [<ffffffff813bb69e>] ? > selinux_inet_conn_established+0x3e/0x40 > [ 31.064072] [<ffffffff817c2bad>] tcp_finish_connect+0x4d/0x270 > [ 31.064074] [<ffffffff817c33f7>] tcp_rcv_state_process+0x627/0xe40 > [ 31.064076] [<ffffffff81866584>] tcp_v6_do_rcv+0xd4/0x410 > [ 31.064078] [<ffffffff8173bc65>] release_sock+0x85/0x1c0 > [ 31.064079] [<ffffffff817e9983>] __inet_stream_connect+0x1c3/0x340 > [ 31.064081] [<ffffffff8173b089>] ? lock_sock_nested+0x49/0xb0 > [ 31.064083] [<ffffffff81100270>] ? abort_exclusive_wait+0xb0/0xb0 > [ 31.064084] [<ffffffff817e9b38>] inet_stream_connect+0x38/0x50 > [ 31.064086] [<ffffffff8173794f>] SYSC_connect+0xcf/0xf0 > [ 31.064088] [<ffffffff8110d069>] ? trace_hardirqs_on_caller+0x129/0x1b0 > [ 31.064090] [<ffffffff8100301b>] ? trace_hardirqs_on_thunk+0x1b/0x1d > [ 31.064091] [<ffffffff8173854e>] SyS_connect+0xe/0x10 > [ 31.064094] [<ffffffff818a0e7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd > > Bye, > Hannes
Thanks. As you can see, release_sock() messes badly lockdep (once your other patches are in ) Once we properly fix release_sock() and/or __release_sock(), all these false positives disappear.
