From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754311AbbCMAUc (ORCPT ); Thu, 12 Mar 2015 20:20:32 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:59493 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751006AbbCMAUa (ORCPT ); Thu, 12 Mar 2015 20:20:30 -0400 From: "Rafael J. Wysocki" To: Linux Kernel Mailing List Cc: Bjorn Helgaas , ACPI Devel Maling List Subject: [RFC v2][PATCH 2/2] PNP: Avoid leaving unregistered device objects in lists Date: Fri, 13 Mar 2015 01:44 +0100 Message-ID: <3432638.ctp6G8xFFl@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.19.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <10735840.fKeKX5WA1g@vostro.rjw.lan> References: <2163789.xYALhKGkH0@vostro.rjw.lan> <10735840.fKeKX5WA1g@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki pnp_register_protocol() and __pnp_add_device() both have a problem that if device_register() fails, the objects they create will be left in the lists they have been put one beforehand. Unfortunately, that is not handled by the callers of those routines either, so in case of a device registration errors the PNP bus type's data structures will end up in an inconsistent state. Make pnp_register_protocol() and __pnp_add_device() remove the objects from the lists if device registration fails. Signed-off-by: Rafael J. Wysocki --- drivers/pnp/core.c | 53 ++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 13 deletions(-) Index: linux-pm/drivers/pnp/core.c =================================================================== --- linux-pm.orig/drivers/pnp/core.c +++ linux-pm/drivers/pnp/core.c @@ -42,6 +42,13 @@ void *pnp_alloc(long size) return result; } +static void pnp_remove_protocol(struct pnp_protocol *protocol) +{ + mutex_lock(&pnp_lock); + list_del(&protocol->protocol_list); + mutex_unlock(&pnp_lock); +} + /** * pnp_protocol_register - adds a pnp protocol to the pnp layer * @protocol: pointer to the corresponding pnp_protocol structure @@ -50,12 +57,13 @@ void *pnp_alloc(long size) */ int pnp_register_protocol(struct pnp_protocol *protocol) { - int nodenum; struct list_head *pos; + int nodenum, ret; INIT_LIST_HEAD(&protocol->devices); INIT_LIST_HEAD(&protocol->cards); nodenum = 0; + mutex_lock(&pnp_lock); /* assign the lowest unused number */ @@ -67,12 +75,18 @@ int pnp_register_protocol(struct pnp_pro } } + protocol->number = nodenum; + dev_set_name(&protocol->dev, "pnp%d", nodenum); + list_add_tail(&protocol->protocol_list, &pnp_protocols); + mutex_unlock(&pnp_lock); - protocol->number = nodenum; - dev_set_name(&protocol->dev, "pnp%d", nodenum); - return device_register(&protocol->dev); + ret = device_register(&protocol->dev); + if (ret) + pnp_remove_protocol(protocol); + + return ret; } /** @@ -81,9 +95,7 @@ int pnp_register_protocol(struct pnp_pro */ void pnp_unregister_protocol(struct pnp_protocol *protocol) { - mutex_lock(&pnp_lock); - list_del(&protocol->protocol_list); - mutex_unlock(&pnp_lock); + pnp_remove_protocol(protocol); device_unregister(&protocol->dev); } @@ -158,18 +170,36 @@ struct pnp_dev *pnp_alloc_dev(struct pnp return dev; } +static void pnp_delist_device(struct pnp_dev *dev) +{ + mutex_lock(&pnp_lock); + list_del(&dev->global_list); + list_del(&dev->protocol_list); + mutex_unlock(&pnp_lock); +} + int __pnp_add_device(struct pnp_dev *dev) { + int ret; + pnp_fixup_device(dev); dev->status = PNP_READY; + mutex_lock(&pnp_lock); + list_add_tail(&dev->global_list, &pnp_global); list_add_tail(&dev->protocol_list, &dev->protocol->devices); + mutex_unlock(&pnp_lock); - if (dev->protocol->can_wakeup) + + ret = device_register(&dev->dev); + if (ret) + pnp_delist_device(dev); + else if (dev->protocol->can_wakeup) device_set_wakeup_capable(&dev->dev, dev->protocol->can_wakeup(dev)); - return device_register(&dev->dev); + + return ret; } /* @@ -204,10 +234,7 @@ int pnp_add_device(struct pnp_dev *dev) void __pnp_remove_device(struct pnp_dev *dev) { - mutex_lock(&pnp_lock); - list_del(&dev->global_list); - list_del(&dev->protocol_list); - mutex_unlock(&pnp_lock); + pnp_delist_device(dev); device_unregister(&dev->dev); }