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Date: Wed, 11 Feb 2009 10:53:25 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
       Steven Rostedt <rostedt@goodmis.org>,
       LKML <linux-kernel@vger.kernel.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: git pull request for tip/tracing/urgent
Message-ID: <20090211095325.GD20518@elte.hu>
References: <alpine.DEB.1.10.0902101314440.23505@gandalf.stny.rr.com> <20090210183046.GA1342@nowhere> <alpine.DEB.1.10.0902101724190.23505@gandalf.stny.rr.com> <20090211012856.GA4921@nowhere> <20090211090229.GG21105@elte.hu> <49929763.3080608@kernel.org>
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* Tejun Heo <tj@kernel.org> wrote:

> Hello,
> 
> Ingo Molnar wrote:
> > This bit:
> > 
> >   	".section .fixup, \"ax\"\n"
> >  	"4: movl $1, %[faulted]\n"
> >  	"   jmp 3b\n"
> >  	".previous\n"
> > 
> > Can be thought of as an 'embedded' or 'nested' section - the '.previous'
> > directive jumps back to whatever section we were in before. This can be
> > nested multiple times too:
> > 
> >    .section A
> >    [...]
> >      .section B
> >      [...]
> >         .section C
> >         [...]
> >         .previous
> >      [...]
> >      .previous
> >    [...]
> >    .previous
> 
> That will result in...
> 
>  A->B->C->B->C->B
> 
> .pushsection and .popsection should be used for nesting, right?
> 
> Thanks.

hm ... doh, yes. I think we even had a bug in this area.

Why is it implemented like this? These semantics seem to make no sense.

	Ingo