Re: [OLPC-devel] Re: [PATCH 0/4] Compile kernel with -fwhole-program --combine

From: David Woodhouse <dwmw2@infradead.org>
To: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Cc: devel@laptop.org, Jan Engelhardt <jengelh@linux01.gwdg.de>,
	linux-tiny@selenic.com, linux-kernel@vger.kernel.org
Subject: Re: [OLPC-devel] Re: [PATCH 0/4] Compile kernel with -fwhole-program --combine
Date: Thu, 24 Aug 2006 18:25:07 +0100	[thread overview]
Message-ID: <1156440307.3012.165.camel@pmac.infradead.org> (raw)
In-Reply-To: <200608241915.47451.arnd.bergmann@de.ibm.com>

On Thu, 2006-08-24 at 19:15 +0200, Arnd Bergmann wrote:
> It's probably true, but the way it's done today gave us CONFIG_MODVERSIONS
> and EXPORT_SYMBOL_GPL, which would break when turning EXPORT_SYMBOL into a
> simple __attribute__(). 

ELF can do symbol versioning too. But I don't really see a simple way to
make normal ELF linking work with a kernel like that. The vmlinux ELF
file is long gone by the time the kernel boots -- it needs its own
mechanism for managing its symbols anyway; its own internal dynamic
linker. I suppose you _could_ make it work from the standard ELF linkage
but I don't think it'd be fun.

ObMODVERSIONS: Forgot to mention that my makefile hacks for --combine
break that completely. It tries to preprocess all the files together
with 'gcc -E -D__GENKSYMS__ *.c' -- and you can't do that. 

-- 
dwmw2