From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: [PATCH v3 3/3] IB/ipoib: Log sysfs 'dev_id' accesses from userspace Date: Thu, 6 Sep 2018 16:03:58 +0300 Message-ID: <20180906130358.GJ3142@mtr-leonro.mtl.com> References: <20180903161316.25121-1-ar@cs.msu.ru> <20180903161316.25121-4-ar@cs.msu.ru> <20180905135035.GT2977@mtr-leonro.mtl.com> <20180906070433.GA13034@cello> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ytoMbUMiTKPMT3hY" Return-path: Content-Disposition: inline In-Reply-To: <20180906070433.GA13034@cello> Sender: netdev-owner@vger.kernel.org To: Arseny Maslennikov Cc: linux-rdma@vger.kernel.org, Doug Ledford , Jason Gunthorpe , netdev@vger.kernel.org List-Id: linux-rdma@vger.kernel.org --ytoMbUMiTKPMT3hY Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 06, 2018 at 10:04:33AM +0300, Arseny Maslennikov wrote: > On Wed, Sep 05, 2018 at 04:50:35PM +0300, Leon Romanovsky wrote: > > On Mon, Sep 03, 2018 at 07:13:16PM +0300, Arseny Maslennikov wrote: > > > Signed-off-by: Arseny Maslennikov > > > --- > > > drivers/infiniband/ulp/ipoib/ipoib_main.c | 38 +++++++++++++++++++++= ++ > > > 1 file changed, 38 insertions(+) > > > > > > diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infi= niband/ulp/ipoib/ipoib_main.c > > > index 30f840f874b3..7386e5bde3d3 100644 > > > --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c > > > +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c > > > @@ -2386,6 +2386,42 @@ int ipoib_add_pkey_attr(struct net_device *dev) > > > return device_create_file(&dev->dev, &dev_attr_pkey); > > > } > > > > > > +/* > > > + * We erroneously exposed the iface's port number in the dev_id > > > + * sysfs field long after dev_port was introduced for that purpose[1= ], > > > + * and we need to stop everyone from relying on that. > > > + * Let's overload the shower routine for the dev_id file here > > > + * to gently bring the issue up. > > > + * > > > + * [1] https://www.spinics.net/lists/netdev/msg272123.html > > > + */ > > > +static ssize_t dev_id_show(struct device *dev, > > > + struct device_attribute *attr, char *buf) > > > +{ > > > + struct net_device *ndev =3D to_net_dev(dev); > > > + ssize_t ret =3D -EINVAL; > > > + > > > + if (ndev->dev_id =3D=3D ndev->dev_port) { > > > + netdev_info_once(ndev, > > > + "\"%s\" wants to know my dev_id. " > > > + "Should it look at dev_port instead?\n", > > > + current->comm); > > > + netdev_info_once(ndev, > > > + "See Documentation/ABI/testing/sysfs-class-net for more info.\n"); > > > + } > > > + > > > + ret =3D sprintf(buf, "%#x\n", ndev->dev_id); > > > + > > > + return ret; > > > +} > > > +static DEVICE_ATTR_RO(dev_id); > > > + > > > > I don't see this field among exposed by IPoIB, why should we expose it = now? > > > > To deviate from standard netdev behaviour, which only prints the > field out. Doug wanted this to also print a deprecation message, and > netdev (obviously) does not do that. See below. > > > > +int ipoib_intercept_dev_id_attr(struct net_device *dev) > > > +{ > > > + device_remove_file(&dev->dev, &dev_attr_dev_id); > > > + return device_create_file(&dev->dev, &dev_attr_dev_id); > > > > Why isn't enough to rely on netdev code? > > > > Netdev code relies on macros around a *static* function 'netdev_show', > which is defined in net/core/net-sysfs.c; it is not listed in any header > files, and the macros aren't as well. This all leads me to believe it > was not really meant to be used from outside net/core/net-sysfs. > > The only way we could use any netdev code here is to set up our own > handler (again), printk() a message, then call netdev_show =E2=80=94 but = we have > no access to it. > > Of course, it also may be that I'm terribly missing a clue. Thanks, IMHO, the end result of adequate Doug's request is a little bit too much. I don't think that it justifies such remove->create construction. Personal opinion. > > > > +} > > > + > > > static struct net_device *ipoib_add_port(const char *format, > > > struct ib_device *hca, u8 port) > > > { > > > @@ -2427,6 +2463,8 @@ static struct net_device *ipoib_add_port(const = char *format, > > > */ > > > ndev->priv_destructor =3D ipoib_intf_free; > > > > > > + if (ipoib_intercept_dev_id_attr(ndev)) > > > + goto sysfs_failed; > > > if (ipoib_cm_add_mode_attr(ndev)) > > > goto sysfs_failed; > > > if (ipoib_add_pkey_attr(ndev)) > > > -- > > > 2.19.0.rc1 > > > > > --ytoMbUMiTKPMT3hY Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBAgAGBQJbkSW+AAoJEORje4g2clinOM0P/jW2EUmWZmH5AOJhZDUJ2LNg MYE7BXv5DluFMLnW4j5g4ehkc89pVOsW8LiX8HQ6Idg/u1BZ1ritc1pc8kAsQ3ua HKcv/6Da74hP9vgwEVtKE5DRff2vUEGS3eSOfKvQjBIlBuJNiASUt9RvKy9pke/N me4OjJo135uV2sQ2YZyZD8OKKyemhnP3aiLMJ19w20xabmT1T2Zp2LqQm+u5/xKV zb9RRV3SzX1Yqpcu47mnNlKAxSl/TUzdnzfyXoxJp0PBncf/LULoGbae6tUDkaeG BVkqa5Rje5P76XgMdhT4G+DAfxnKYP5ZujXD9dtFEZe6665R850WUZLDktLJUrL7 VSfARpo9LPOVpAun9vzjR/sO5F34TfiQSvLq0NtiwrRFa69SXEb3R0ZAxwzcCkTZ N9zghEiCNWGupogFj2U1NkAWon7NmoUeC/SjqqeBP9fvLYBoPY/a5Vfin8+AwNSd hEZo00LifPQm28UIyRzapl+c3MrMLX+atX6Jp0lz9FD8ih7HPpApJpjToOuru13o INwmB8LUTx62GEhRDtcU7q4m+GPQvVoihpWgph52RCZP1D+jhe2BbCS9BfYq9Up+ jbUVQHxBDksY3T1Jy5N0sUAseWRFwOEPYzVPG7fgB/QDleuiyFH8rEneXmVEIsWW T0rRUHh65Uk4zt1lNA+E =HYCE -----END PGP SIGNATURE----- --ytoMbUMiTKPMT3hY--