Re: [PATCH] rt-mutex: fixup rt-mutex debug code

[Ingo Molnar]

* Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:

> BUG: warning at kernel/rtmutex-debug.c:125/rt_mutex_debug_task_free() (Not tainted)
>  [<c04051e3>] show_trace_log_lvl+0x58/0x16a
>  [<c04057f0>] show_trace+0xd/0x10
>  [<c0405900>] dump_stack+0x19/0x1b
>  [<c043f03d>] rt_mutex_debug_task_free+0x35/0x6a
>  [<c04224c0>] free_task+0x15/0x24
>  [<c042378c>] copy_process+0x12bd/0x1324
>  [<c0423835>] do_fork+0x42/0x113
>  [<c04021dd>] sys_fork+0x19/0x1b
>  [<c0403fb7>] syscall_call+0x7/0xb
> 
> In copy_process(), dup_task_struct() also duplicates the ->pi_lock, 
> ->pi_waiters and ->pi_blocked_on members. rt_mutex_debug_task_free() 
> called from free_task() validates these members. However free_task() 
> can be invoked before these members are reset for the new task.
> 
> Move the initialization code before the first bail that can hit 
> free_task().
> 
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>

thanks for tracking this one down!

Acked-by: Ingo Molnar <mingo@xxxxxxx>

	Ingo
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