From owner-freebsd-hackers@FreeBSD.ORG  Tue Jul 30 07:56:06 2013
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTP id 67EA5A74
 for <freebsd-hackers@freebsd.org>; Tue, 30 Jul 2013 07:56:06 +0000 (UTC)
 (envelope-from shrikanth07@gmail.com)
Received: from mail-vb0-x22d.google.com (mail-vb0-x22d.google.com
 [IPv6:2607:f8b0:400c:c02::22d])
 (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id 2C4E72AA5
 for <freebsd-hackers@freebsd.org>; Tue, 30 Jul 2013 07:56:06 +0000 (UTC)
Received: by mail-vb0-f45.google.com with SMTP id p14so3539401vbm.32
 for <freebsd-hackers@freebsd.org>; Tue, 30 Jul 2013 00:56:04 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=mime-version:date:message-id:subject:from:to:content-type;
 bh=IgW2y3ZuK7H2Gr26taRMXZoSyR3ItGldSdV20X0YWa0=;
 b=i2LGaNmwC9TuVrM9j4s5VdvWIH9SxBD9pK6lPFuSKEXKbiSnUZkoLxY7UONZeDidyi
 IIBNwWtS2ltPv1yzZBKwdrQpiVR52GRPfOc61FjWg1aI6Mpu2jzQH6vWn+D2rYNW6aq5
 iEN+EwdL5N/tjke1CrhSMmv7PAD7OF5cWYeXIcburC/ThI8S2XEn6e5aSHAtCI1KWV9D
 mQQcrQv0+MIGUCrolN7LINchYIrfxdiAVj6abPmBnuL4fVDdt1bB/Dg8rh/1p6wZ1W2C
 jaSK8UV5EUKShKZqF5H+E1hxswTVJCt4DTsEg6wXC4PNJWwYHBQcOodqtaorvPNIb+qF
 gZyw==
MIME-Version: 1.0
X-Received: by 10.220.173.195 with SMTP id q3mr9455404vcz.86.1375170964719;
 Tue, 30 Jul 2013 00:56:04 -0700 (PDT)
Received: by 10.58.232.41 with HTTP; Tue, 30 Jul 2013 00:56:04 -0700 (PDT)
Date: Tue, 30 Jul 2013 00:56:04 -0700
Message-ID: <CAEOAkMUbRW_1SHZ4L66+Rec++Rx=Eq+Z27_=ZANO7q_LcXXXOg@mail.gmail.com>
Subject: Symbols in symtab reordered between module.kld and module.ko?
From: Shrikanth Kamath <shrikanth07@gmail.com>
To: freebsd-hackers@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 30 Jul 2013 07:56:06 -0000

I am comparing the readelf -s snapshot from module.kld and module.ko
for a module build  in a cross compiler FreeBSD 10 environment,

Do the symbols in symtab get reordered between module.kld and
module.ko, as an example

readelf -s module.kld we pick 2 symbols
  2651: 000b8230    74 FUNC    GLOBAL DEFAULT    1 prison_equal_ip6
  2652: 00030140  3318 FUNC    GLOBAL DEFAULT    1 ip_output

Compare them with readelf -s from module.ko
  2558: 0007a6d0  3318 FUNC    GLOBAL DEFAULT    5 ip_output
  2559: 001027c0    74 FUNC    GLOBAL DEFAULT    5 prison_equal_ip6

So the symbol ip_output appears after prison_equal_ip6 in module.kld
but appears before it in module.ko. The problem is this is affecting
the DTrace FBT probing, running FBT probe of ip_output shows as having
arguments of prison_equal_ip6.

The way module.ko is being derived from module.kld is
ld -m elf_i386 -Bshareable --verbose  -o module.ko.debug module.kld

How can I suppress this re-ordering?