From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1KgwDT-00027X-SN
	for qemu-devel@nongnu.org; Sat, 20 Sep 2008 02:45:15 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1KgwDR-00027L-ED
	for qemu-devel@nongnu.org; Sat, 20 Sep 2008 02:45:14 -0400
Received: from [199.232.76.173] (port=59945 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1KgwDR-00027I-9j
	for qemu-devel@nongnu.org; Sat, 20 Sep 2008 02:45:13 -0400
Received: from mx20.gnu.org ([199.232.41.8]:10185)
	by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32)
	(Exim 4.60) (envelope-from <kirill@shutemov.name>)
	id 1KgwDQ-0004H1-Uo
	for qemu-devel@nongnu.org; Sat, 20 Sep 2008 02:45:13 -0400
Received: from ey-out-1920.google.com ([74.125.78.146])
	by mx20.gnu.org with esmtp (Exim 4.60)
	(envelope-from <kirill@shutemov.name>) id 1KgwDP-00040B-Ml
	for qemu-devel@nongnu.org; Sat, 20 Sep 2008 02:45:11 -0400
Received: by ey-out-1920.google.com with SMTP id 4so219567eyk.4
	for <qemu-devel@nongnu.org>; Fri, 19 Sep 2008 23:45:10 -0700 (PDT)
Date: Sat, 20 Sep 2008 09:45:57 +0300
From: "Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: [Qemu-devel] [PATCH] Fix vfork() syscall emulation
Message-ID: <20080920064556.GA24679@localhost.localdomain>
References: <1221750426-14863-1-git-send-email-kirill@shutemov.name>
	<fb249edb0809191956i7c4132fdo1338d04a6d9bc35d@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="HlL+5n6rz5pIUxbD"
Content-Disposition: inline
In-Reply-To: <fb249edb0809191956i7c4132fdo1338d04a6d9bc35d@mail.gmail.com>
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: andrzej zaborowski <balrogg@gmail.com>
Cc: qemu-devel@nongnu.org


--HlL+5n6rz5pIUxbD
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Sat, Sep 20, 2008 at 04:56:45AM +0200, andrzej zaborowski wrote:
> 2008/9/18 Kirill A. Shutemov <kirill@shutemov.name>:
> > vfork() is a kind of fork, not thread despite CLONE_VM
>=20
> According to clone(2) it can be either, the only difference is that
> vfork() suspends the parent process.  So if CLONE_VM is set, I think
> still the pthread / clone way should be used and the child thread
> should be waited on.

vfork() suspends the parent process until a call of execve(2) or _exit(2).
If child call execnv(2) it replaces whole process, not only the thread.
If child call _exit(2) it stops while process, not only the thread.

> On the other hand the patch makes fork() and vfork() be treated identical=
ly?

$ cat usr/klibc/vfork.c
/*
 * vfork.c
 *
 * Emulate vfork() with fork() if necessary
 */

#include <unistd.h>
#include <klibc/compiler.h>
#include <klibc/sysconfig.h>

#if !_KLIBC_NO_MMU && !_KLIBC_REAL_VFORK
int vfork(void)
{
        return fork();
}
#endif

--=20
Regards,  Kirill A. Shutemov
 + Belarus, Minsk
 + ALT Linux Team, http://www.altlinux.com/

--HlL+5n6rz5pIUxbD
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)

iEYEARECAAYFAkjUnCMACgkQbWYnhzC5v6oxBgCfVszZQlX63OaP0hxWqa+B2hCU
DtsAnRhKdmOyKQV21dKTiWeHy02qHPhf
=Waq6
-----END PGP SIGNATURE-----

--HlL+5n6rz5pIUxbD--