FYI: RIP: 0010:[<ffffffff8122f04f>] [<ffffffff8122f04f>] cfq_free_io_context+0x18/0x34

[Michał Piotrowski]

Yet another "invoked rcu_dereference_check"


===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
kernel/exit.c:1387 invoked rcu_dereference_check() without protection!

other info that might help us debug this:


rcu_scheduler_active = 1, debug_locks = 0
2 locks held by mc/1364:
 #0:  (tasklist_lock){.+.+..}, at: [<ffffffff81054a76>] do_wait+0xde/0x233
 #1:  (&(&sighand->siglock)->rlock){-.....}, at: [<ffffffff810545a7>]
wait_consider_task+0x705/0xaf6

stack backtrace:
Pid: 1364, comm: mc Not tainted 2.6.35.5-29.fc13.x86_64 #1
Call Trace:
 [<ffffffff8107bda6>] lockdep_rcu_dereference+0xaa/0xb2
 [<ffffffff81054636>] wait_consider_task+0x794/0xaf6
 [<ffffffff81054aa0>] do_wait+0x108/0x233
 [<ffffffff81054c69>] sys_wait4+0x9e/0xc1
 [<ffffffff814a12f5>] ? retint_swapgs+0x13/0x1b
 [<ffffffff81052f11>] ? child_wait_callback+0x0/0x58
 [<ffffffff81009c32>] system_call_fastpath+0x16/0x1b