From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60282 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932176AbdC1MlD (ORCPT ); Tue, 28 Mar 2017 08:41:03 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Feeney , Sudip Mukherjee Subject: [PATCH 4.10 066/111] ppdev: fix registering same device name Date: Tue, 28 Mar 2017 14:30:52 +0200 Message-Id: <20170328122918.452001179@linuxfoundation.org> In-Reply-To: <20170328122915.640228468@linuxfoundation.org> References: <20170328122915.640228468@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sudip Mukherjee commit 9a69645dde1188723d80745c1bc6ee9af2cbe2a7 upstream. Usually every parallel port will have a single pardev registered with it. But ppdev driver is an exception. This userspace parallel port driver allows to create multiple parrallel port devices for a single parallel port. And as a result we were having a big warning like: "sysfs: cannot create duplicate filename '/devices/parport0/ppdev0.0'". And with that many parallel port printers stopped working. We have been using the minor number as the id field while registering a parralel port device with a parralel port. But when there are multiple parrallel port device for one single parallel port, they all tried to register with the same name like 'pardev0.0' and everything started failing. Use an incremented index as the id instead of the minor number. Fixes: 8b7d3a9d903e ("ppdev: use new parport device model") Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1414656 Bugzilla: https://bugs.archlinux.org/task/52322 Tested-by: James Feeney Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- drivers/char/ppdev.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -84,11 +84,14 @@ struct pp_struct { struct ieee1284_info state; struct ieee1284_info saved_state; long default_inactivity; + int index; }; /* should we use PARDEVICE_MAX here? */ static struct device *devices[PARPORT_MAX]; +static DEFINE_IDA(ida_index); + /* pp_struct.flags bitfields */ #define PP_CLAIMED (1<<0) #define PP_EXCL (1<<1) @@ -290,7 +293,7 @@ static int register_device(int minor, st struct pardevice *pdev = NULL; char *name; struct pardev_cb ppdev_cb; - int rc = 0; + int rc = 0, index; name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor); if (name == NULL) @@ -303,20 +306,23 @@ static int register_device(int minor, st goto err; } + index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL); memset(&ppdev_cb, 0, sizeof(ppdev_cb)); ppdev_cb.irq_func = pp_irq; ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0; ppdev_cb.private = pp; - pdev = parport_register_dev_model(port, name, &ppdev_cb, minor); + pdev = parport_register_dev_model(port, name, &ppdev_cb, index); parport_put_port(port); if (!pdev) { pr_warn("%s: failed to register device!\n", name); rc = -ENXIO; + ida_simple_remove(&ida_index, index); goto err; } pp->pdev = pdev; + pp->index = index; dev_dbg(&pdev->dev, "registered pardevice\n"); err: kfree(name); @@ -755,6 +761,7 @@ static int pp_release(struct inode *inod if (pp->pdev) { parport_unregister_device(pp->pdev); + ida_simple_remove(&ida_index, pp->index); pp->pdev = NULL; pr_debug(CHRDEV "%x: unregistered pardevice\n", minor); }