From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mundt Date: Mon, 18 May 2009 04:11:56 +0000 Subject: Re: [BUG] Error in copy_process, when enable CONFIG_PROVE_LOCKING. Message-Id: <20090518041155.GA18919@linux-sh.org> List-Id: 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 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.