Re: 2.6.23-rc2-mm1: sleeping function called from invalid context at kernel/mutex.c:86

Mariusz Kozlowski
2007-08-10T07:27:22Z

> >> This probably doesn't have great impact ;) but ...
> >> To reproduce: run torture tests for RCU and then sysrq+q.
> >>
> >> SysRq : Show Pending Timers
> >> Timer List Version: v0.3
> >> HRTIMER_MAX_CLOCK_BASES: 2
> >> now at 1764338760370 nsecs
> >>
> >> cpu: 0
> >> clock 0:
> >> .index: 0
> >> .resolution: 1 nsecs
> >> .get_time: ktime_get_real
> >> .offset: 1186699025823815427 nsecs
> >> active timers:
> >> clock 1:
> >> .index: 1
> >> .resolution: 1 nsecs
> >> .get_time: ktime_get
> >> .offset: 0 nsecs
> >> active timers:
> >> #0: <3>BUG: sleeping function called from invalid context at kernel/mutex.c:86
> >> in_atomic():1, irqs_disabled():1
> >> INFO: lockdep is turned off.
> >> irq event stamp: 0
> >> hardirqs last enabled at (0): [<00000000>] 0x0
> >> hardirqs last disabled at (0): [<c0117def>] copy_process+0x4a8/0x144c
> >> softirqs last enabled at (0): [<c0117e0d>] copy_process+0x4c6/0x144c
> >> softirqs last disabled at (0): [<00000000>] 0x0
> >> [<c0104869>] show_trace_log_lvl+0x1a/0x30
> >> [<c01053ad>] show_trace+0x12/0x14
> >> [<c0105515>] dump_stack+0x15/0x17
> >> [<c0114da7>] __might_sleep+0xb7/0xc9
> >> [<c0451771>] mutex_lock+0x15/0x1f
> >> [<c0141b75>] lookup_module_symbol_name+0x17/0xc0
> >> [<c014272a>] lookup_symbol_name+0x3f/0x43
> >> [<c013287e>] print_name_offset+0x1f/0x96
> >> [<c01330f7>] timer_list_show+0x802/0xcbd
> >> [<c01335be>] sysrq_timer_list_show+0xc/0xe
> >> [<c02cc4a1>] sysrq_handle_show_timers+0x8/0xa
> >> [<c02cc3ac>] __handle_sysrq+0x7b/0x115
> >> [<c02cc466>] handle_sysrq+0x20/0x24
> >> [<c02c69c1>] kbd_event+0x3a8/0x5c7
> >> [<c0362f8f>] input_pass_event+0x8f/0x91
> >> [<c0363e77>] input_handle_event+0x98/0x38d
> >> [<c0364e6d>] input_event+0x54/0x67
> >> [<c03682c2>] atkbd_interrupt+0x200/0x59e
> >> [<c0360cd0>] serio_interrupt+0x7c/0x80
> >> [<c0361965>] i8042_interrupt+0x17a/0x289
> >> [<c0147a5d>] handle_IRQ_event+0x28/0x59
> >> [<c01493ca>] handle_level_irq+0xad/0x10b
> >> [<c0105a13>] do_IRQ+0x93/0xd0
> >> [<c010441e>] common_interrupt+0x2e/0x34
> >> [<df39d7e3>] rcu_read_delay+0x8/0x36 [rcutorture]
> >> [<df39d99a>] rcu_torture_reader+0x6e/0x169 [rcutorture]
> >> [<c012c11e>] kthread+0x36/0x58
> >> [<c010451b>] kernel_thread_helper+0x7/0x1c
> >> =======================
> >
> > We seem to have made a mess in there. timer_list_show() ends up calling
> > lookup_module_symbol_name(), which takes a mutex. However print_symbol()
> > (which is called at oops time, interrupt time, etc) calls
> > module_address_lookup(), which is basically the same, only it doesn't take
> > the mutex.
> >
> > I guess a quicky fix would be to switch
> > kernel/time/timer_list.c:print_name_offset() from
> > lookup_module_symbol_name() to module_address_lookup(). But we'd still
> > have a mess in there.
> >
> > (adds ccs, runs away)
>
> I don't think rcutorture matters for this bug.

Maybe not but that's the only way I could trigger it (insmod rcutorture and sysrq+q).

Thanks,

Mariusz