From owner-freebsd-current@FreeBSD.ORG  Fri Mar 11 11:33:54 2005
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 1D2EB16A4CE; Fri, 11 Mar 2005 11:33:54 +0000 (GMT)
Received: from darkness.comp.waw.pl (darkness.comp.waw.pl [195.117.238.136])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id B3AE943D2D; Fri, 11 Mar 2005 11:33:53 +0000 (GMT)
	(envelope-from pjd@darkness.comp.waw.pl)
Received: by darkness.comp.waw.pl (Postfix, from userid 1009)
	id 93059ACBCB; Fri, 11 Mar 2005 12:33:51 +0100 (CET)
Date: Fri, 11 Mar 2005 12:33:51 +0100
From: Pawel Jakub Dawidek <pjd@FreeBSD.org>
To: freebsd-current@freebsd.org
Message-ID: <20050311113351.GC9291@darkness.comp.waw.pl>
Mime-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="E+r5CZjTUHNgkElv"
Content-Disposition: inline
User-Agent: Mutt/1.4.2i
X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc
X-OS: FreeBSD 5.2.1-RC2 i386
Subject: crypto_q_mtx recursion.
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 11 Mar 2005 11:33:54 -0000


--E+r5CZjTUHNgkElv
Content-Type: text/plain; charset=iso-8859-2
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi.

I had a panic related to mutex recursion, the code path is as follows:

	crypto_dispatch()
	CRYPTO_Q_LOCK()
	crypto_invoke()
	crypto_done()
	cryptodev_cb() (via crp->crp_callback)
	crypto_dispatch()
	CRYPTO_Q_LOCK() <- recursion.

Not sure how to fix it. Calling 'locked' version of crypto_dispatch()
is not an option, as we can call cryptodev_cb() with or without
crypto_q_mtx held.
The only fix I can came up with right not is a "pseudo-recursion" in
crypto_dispatch():

	int unlock =3D 0;

	[...]

	if (!mtx_owned(&crypto_q_mtx)) {
		unlock =3D 1;
		CRYPTO_Q_LOCK();
	}

	[...]

	if (unlock)
		CRYPTO_Q_LOCK();

--=20
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd@FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!

--E+r5CZjTUHNgkElv
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (FreeBSD)

iD8DBQFCMYIfForvXbEpPzQRAsCtAJ9aaGcM8dzT/jnHGxAmrNyPhx98vACdGC99
7o/U8Lch2UJZ5ZWOe03U7qw=
=Iakb
-----END PGP SIGNATURE-----

--E+r5CZjTUHNgkElv--