Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 21 May 2009 16:26:41 +0300
From:      Kostik Belousov <kostikbel@gmail.com>
To:        Attilio Rao <attilio@freebsd.org>
Cc:        svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org
Subject:   Re: svn commit: r192535 - head/sys/kern
Message-ID:  <20090521132641.GJ1927@deviant.kiev.zoral.com.ua>
In-Reply-To: <200905211322.n4LDM73t067924@svn.freebsd.org>
References:  <200905211322.n4LDM73t067924@svn.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help

--KiOS11rrlPLUJaFM
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Thu, May 21, 2009 at 01:22:07PM +0000, Attilio Rao wrote:
> Author: attilio
> Date: Thu May 21 13:22:07 2009
> New Revision: 192535
> URL: http://svn.freebsd.org/changeset/base/192535
>=20
> Log:
>   Move the M_WAITOK flag in notify() into an M_NOWAIT one in order to mat=
ch
>   the behaviour alredy present with the further malloc() call in
>   devctl_notify().
>   This fixes a bug in the CAM layer where the camisr handler finished to
>   call camperiphfree() (and subsequently destroy_dev() resulting in a new
>   dev notify) while the xpt lock is held.
This is wrong. You cannot call destroy_dev() while holding any mutex.
Taking this into account, it makes no sense to use M_NOWAIT in notify().

>  =20
>   PR:		kern/130330
>   Tested by:	Riccardo Torrini <riccardo dot torrini at esaote dot com>
>=20
> Modified:
>   head/sys/kern/kern_conf.c
>=20
> Modified: head/sys/kern/kern_conf.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
> --- head/sys/kern/kern_conf.c	Thu May 21 12:36:40 2009	(r192534)
> +++ head/sys/kern/kern_conf.c	Thu May 21 13:22:07 2009	(r192535)
> @@ -491,7 +491,9 @@ notify(struct cdev *dev, const char *ev)
>  	if (cold)
>  		return;
>  	namelen =3D strlen(dev->si_name);
> -	data =3D malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK);
> +	data =3D malloc(namelen + sizeof(prefix), M_TEMP, M_NOWAIT);
> +	if (data =3D=3D NULL)
> +		return;
>  	memcpy(data, prefix, sizeof(prefix) - 1);
>  	memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
>  	devctl_notify("DEVFS", "CDEV", ev, data);

--KiOS11rrlPLUJaFM
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (FreeBSD)

iEYEARECAAYFAkoVVpEACgkQC3+MBN1Mb4glQQCdEM0ah4yu8InyG1m5bUD95rXO
97UAmwe15Zq8oxgGyo8a190TS0MprCeh
=S2ta
-----END PGP SIGNATURE-----

--KiOS11rrlPLUJaFM--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090521132641.GJ1927>