Linux死锁检测-Lockdep( 二 )


but task is already holding lock:(hack_spinB){+.+...}, at: [<bf000038>] hack_spinAB+0x38/0x3c [lock]--------------------------------hack_spinB已经在hack_spinAB函数中被持有
other info that might help us debug this:-----------------------------------------------------------------------锁的其它补充信息Possible unsafe locking scenario:
CPU0
----
lock(hack_spinB);
lock(hack_spinB);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by insmod/658:----------------------------------------------------------------------------------------进程共持有两个锁
#0: (hack_spinA){+.+...}, at: [<bf000030>] hack_spinAB+0x30/0x3c [lock]
#1: (hack_spinB){+.+...}, at: [<bf000038>] hack_spinAB+0x38/0x3c [lock]
stack backtrace:--------------------------------------------------------------------------------------------------------栈回溯信息:可以看出从lockdep_test_init->_raw_spin_lock->lock_acquire的调用路径 。
CPU: 0 PID: 658 Comm: insmod Tainted: G O 4.0.0+ #87
Hardware name: ARM-Versatile Express
[<c00171b4>] (unwind_backtrace) from [<c0012e7c>] (show_stack+0x20/0x24)
[<c0012e7c>] (show_stack) from [<c05ade10>] (dump_stack+0x8c/0xb4)
[<c05ade10>] (dump_stack) from [<c006b988>] (__lock_acquire+0x1aa4/0x1f64)
[<c006b988>] (__lock_acquire) from [<c006c55c>] (lock_acquire+0xf4/0x190)
[<c006c55c>] (lock_acquire) from [<c05b4ec8>] (_raw_spin_lock+0x60/0x98)
[<c05b4ec8>] (_raw_spin_lock) from [<bf002030>] (lockdep_test_init+0x30/0x3c [lock])
[<bf002030>] (lockdep_test_init [lock]) from [<c0008a28>] (do_one_initcall+0x9c/0x1e8)
[<c0008a28>] (do_one_initcall) from [<c05abf30>] (do_init_module+0x70/0x1c0)
[<c05abf30>] (do_init_module) from [<c00a4ddc>] (load_module+0x18b0/0x1f90)
[<c00a4ddc>] (load_module) from [<c00a55fc>] (SyS_init_module+0x140/0x150)
[<c00a55fc>] (SyS_init_module) from [<c000ec80>] (ret_fast_syscall+0x0/0x4c)
INFO: rcu_sched self-detected stall on CPU
0: (2099 ticks this GP) idle=5ed/140000000000001/0 softirq=13024/13024 fqs=1783
(t=2100 jiffies g=-51 c=-52 q=22)
Task dump for CPU 0:
insmod R running 0 658 657 0x00000002
[<c00171b4>] (unwind_backtrace) from [<c0012e7c>] (show_stack+0x20/0x24)
[<c0012e7c>] (show_stack) from [<c0052874>] (sched_show_task+0x128/0x184)
[<c0052874>] (sched_show_task) from [<c0055dd0>] (dump_cpu_task+0x48/0x4c)
[<c0055dd0>] (dump_cpu_task) from [<c0082878>] (rcu_dump_cpu_stacks+0x9c/0xd4)
[<c0082878>] (rcu_dump_cpu_stacks) from [<c008665c>] (rcu_check_callbacks+0x640/0x968)
[<c008665c>] (rcu_check_callbacks) from [<c008b628>] (update_process_times+0x4c/0x74)
[<c008b628>] (update_process_times) from [<c009a1d4>] (tick_periodic+0x54/0xf8)
[<c009a1d4>] (tick_periodic) from [<c009a3d8>] (tick_handle_periodic+0x38/0x98)
[<c009a3d8>] (tick_handle_periodic) from [<c00164a4>] (twd_handler+0x40/0x50)
[<c00164a4>] (twd_handler) from [<c007dfc4>] (handle_percpu_devid_irq+0xd8/0x1dc)
[<c007dfc4>] (handle_percpu_devid_irq) from [<c0079a7c>] (generic_handle_irq+0x3c/0x4c)
[<c0079a7c>] (generic_handle_irq) from [<c0079dc4>] (__handle_domain_irq+0x6c/0xc4)
[<c0079dc4>] (__handle_domain_irq) from [<c0008740>] (gic_handle_irq+0x34/0x6c)
[<c0008740>] (gic_handle_irq) from [<c0013a44>] (__irq_svc+0x44/0x5c)
Exception stack(0xed5c9d18 to 0xed5c9d60)
9d00: 00000000 00010000
9d20: 0000ffff c02f3898 bf0001b0 c0b1d248 123cc000 00000000 0c99b2c5 00000000
9d40: 00000000 ed5c9d84 ed5c9d60 ed5c9d60 c0070cb4 c0070cb4 60000013 ffffffff
[<c0013a44>] (__irq_svc) from [<c0070cb4>] (do_raw_spin_lock+0xf0/0x1e0)
[<c0070cb4>] (do_raw_spin_lock) from [<c05b4eec>] (_raw_spin_lock+0x84/0x98)
[<c05b4eec>] (_raw_spin_lock) from [<bf002030>] (lockdep_test_init+0x30/0x3c [lock])
[<bf002030>] (lockdep_test_init [lock]) from [<c0008a28>] (do_one_initcall+0x9c/0x1e8)
[<c0008a28>] (do_one_initcall) from [<c05abf30>] (do_init_module+0x70/0x1c0)
[<c05abf30>] (do_init_module) from [<c00a4ddc>] (load_module+0x18b0/0x1f90)
[<c00a4ddc>] (load_module) from [<c00a55fc>] (SyS_init_module+0x140/0x150)
[<c00a55fc>] (SyS_init_module) from [<c000ec80>] (ret_fast_syscall+0x0/0x4c)


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