Re: [BUG] Error in copy_process, when enable CONFIG_PROVE_LOCKING.

[Stuart MENEFY <stuart.menefy@st.com>]

Paul Mundt wrote:
> On Tue, May 12, 2009 at 01:15:22PM +0100, Stuart MENEFY wrote:
>> Nobuhiro Iwamatsu wrote:
>>> Error in copy_process, when enable CONFIG_PROVE_LOCKING.
>>> This error has p->hardirqs_enabled in kernel.fork.c
>>>
>>>  987 #ifdef CONFIG_PROVE_LOCKING
>>>  988     DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
>>>  989     DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
>>>  990 #endif
>>>  991     retval = -EAGAIN;
>>>
>>> The error message is as follows.
>>> I am debuging this. Please teach if you know the revision method of
>>> this problem.
>> As it happens I was looking at this recently. I think there are some
>> missing calls to trace_hardirqs_on/off in the assembly
>> code. Unfortunately my kernel is quite different from the mainline in
>> this area, but you could try this patch which is an *untested* forward
>> port of the code I'm currently running successfully.
>>
> This deadlocks for me with PROVE_LOCKING enabled, though it is certainly
> an improvement over what we had before. I'll try and debug it a bit more
> over the next few days when I get some spare cycles. If you have your
> kernel source available somewhere it would certainly make comparing the
> differences easier.

There's a git tree at:
  git://git.stlinux.com/stm/linux-sh4-2.6.23.y.git
now.

Stuart