From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stuart MENEFY <stuart.menefy@st.com>
Date: Mon, 18 May 2009 17:18:02 +0000
Subject: Re: [BUG] Error in copy_process, when enable CONFIG_PROVE_LOCKING.
Message-Id: <4A11984A.3000809@st.com>
List-Id: <linux-sh.vger.kernel.org>
References: <29ab51dc0905112140v3187b462qcc8a9e5385de8ef6@mail.gmail.com>
In-Reply-To: <29ab51dc0905112140v3187b462qcc8a9e5385de8ef6@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: linux-sh@vger.kernel.org

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