Date: Fri, 5 Jun 2009 15:13:46 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: lkml@morethan.org, linux-kernel@vger.kernel.org
Subject: Re: [Compile Warning] 2.6.30-rc8 build
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On Fri, 5 Jun 2009 23:06:41 +0100
Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

> > I don't think there's any way in which gcc can deduce that h->first is
> > non-zero on entry to that loop.  Even if it inlines
> > serial_unlink_irq_chain() into serial8250_shutdown().
> 
> Why does it care ?
> 
> Suppose the list is empty, n is loaded with NULL
> 
> That follows the BUG_ON path which expands to include a function marked
> as not returning

Ah, OK.

btw, I think there are still several architectures whose BUG() isn't
correctly set up to tell gcc that it doesn't return.  Not that this is
a reason to change the serial code.
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