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Subject: Re: [FTRACE] Enabling function_graph causes OOPS
From: Steven Rostedt <rostedt@goodmis.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Date: Mon, 05 Oct 2009 16:37:53 -0400
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On Tue, 2009-10-06 at 07:20 +1100, Benjamin Herrenschmidt wrote:
> On Mon, 2009-10-05 at 09:25 -0400, Steven Rostedt wrote:
> > > > Sachin, can you give me more details on how you built that kernel ? (or
> > > > give them again in case I missed them the first time around :-), ie,
> > > > what toolchain, options, etc... or even better, give me remote access to
> > > > the build host ?
> > > 
> > > Ok, got access and had a quick look... seems to be a toolchain problem
> > > to me. I'll investigate more tomorrow.
> > 
> > Hi Ben,
> > 
> > Any more word on this issue? 
> 
> Didn't you fix it using a TOC access ?
> 
> Unless I'm confusing things, I think the problem is the usage
> of LOAD_REG_IMMEDIATE which generates relocs that we don't support
> when CONFIG_RELOCATABLE is set.
> 
> I've merged a patch that post-processes the kernel now, to check
> for such relocs so at least you should be warned at build time.

I thought we had two issues. One was the use of the relocs that did
cause issues. But then there was still crashes reported after that.
IIRC. I'm still suffering jetlag, so my memory is not that fresh about
this.

-- Steve