Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1755834AbcLNKN4 (ORCPT <rfc822;w@1wt.eu>);
        Wed, 14 Dec 2016 05:13:56 -0500
Received: from mx2.suse.de ([195.135.220.15]:50355 "EHLO mx2.suse.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1755812AbcLNKNx (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 14 Dec 2016 05:13:53 -0500
Date: Wed, 14 Dec 2016 10:37:12 +0100
From: Michal Marek <mmarek@suse.com>
To: Dodji Seketeli <dodji@seketeli.org>
Cc: Nicholas Piggin <npiggin@gmail.com>, Ian Campbell <ijc@hellion.org.uk>,
        Ben Hutchings <ben@decadent.org.uk>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Adam Borowski <kilobyte@angband.pl>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Debian kernel maintainers <debian-kernel@lists.debian.org>,
        "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Ingo Molnar <mingo@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/kbuild: enable modversions for symbols exported from
 asm
Message-ID: <20161214093712.GA13721@sepie.suse.cz>
References: <1480559754.16599.92.camel@decadent.org.uk>
 <20161201143928.07a08348@roar.ozlabs.ibm.com>
 <6e8cf20b-2d2f-ba1f-e02c-c757d5a25db7@suse.com>
 <20161209133308.0acbb57a@roar.ozlabs.ibm.com>
 <1481296893.4509.135.camel@hellion.org.uk>
 <20161210021529.4a6e684f@roar.ozlabs.ibm.com>
 <86vaus3eld.fsf@seketeli.org>
 <f7c5d50d-8930-7ab1-62bb-8a5d0aead988@suse.com>
 <867f72vqec.fsf@seketeli.org>
 <20161214091539.GA9000@sepie.suse.cz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20161214091539.GA9000@sepie.suse.cz>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1435
Lines: 82

On 2016-12-14 10:15, Michal Marek wrote:
> A minimal example would be
> 
> t1.c:
> struct s1;
> struct s2 {
> 	int i;
> }
> struct s3 {
> 	struct s1 *ptr1;
> 	struct s2 *ptr2;
> }
> void foo(struct s3*);
> EXPORT_SYMBOL(foo);
> 
> t2.c:
> struct s1 {
> 	int j;
> }
> struct s2;
> struct s3 {
> 	struct s1 *ptr1;
> 	struct s2 *ptr2;
> }
> void foo(struct s3*);
> EXPORT_SYMBOL(foo);

Note that the above, if passed to genksyms verbatim, would result in
genksyms treating all the types as internal. Here is a complete
example including linemarkers:

$ cat t1.i
# 1 "t1.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "t1.c"
# 1 "t1.h" 1
# 1 "t.h" 1
struct s1;
struct s2;
struct s3 {
 struct s1 *ptr1;
 struct s2 *ptr2;
};
# 2 "t1.h" 2
struct s2 {
 int i;
};
# 2 "t1.c" 2
void foo(struct s3 *s) { }
EXPORT_SYMBOL(foo);

$ cat t2.i
# 1 "t2.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "t2.c"
# 1 "t2.h" 1
# 1 "t.h" 1
struct s1;
struct s2;
struct s3 {
 struct s1 *ptr1;
 struct s2 *ptr2;
};
# 2 "t2.h" 2
struct s1 {
 int j;
};
# 2 "t2.c" 2
void foo(struct s3 *s) { }
EXPORT_SYMBOL(foo);

$ ./scripts/genksyms/genksyms -D <t1.i 
Export foo == <void foo ( struct s3 { struct s1 { UNKNOWN } * ptr1 ; struct s2 { int i ; } * ptr2 ; } * ) >
__crc_foo = 0xf731cef8 ;

$ ./scripts/genksyms/genksyms -D <t2.i 
Export foo == <void foo ( struct s3 { struct s1 { int j ; } * ptr1 ; struct s2 { UNKNOWN } * ptr2 ; } * ) >
__crc_foo = 0xc925dae5 ;

Michal