From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934247AbYETWgb (ORCPT ); Tue, 20 May 2008 18:36:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934420AbYETWfo (ORCPT ); Tue, 20 May 2008 18:35:44 -0400 Received: from ns2.suse.de ([195.135.220.15]:39660 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934411AbYETWfm (ORCPT ); Tue, 20 May 2008 18:35:42 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Kay Sievers , Arthur Jones , Peter Zijlstra , Miklos Szeredi Subject: [PATCH 02/13] mm: bdi: fix race in bdi_class device creation Date: Tue, 20 May 2008 15:34:49 -0700 Message-Id: <1211322900-12705-2-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.5.5.1 In-Reply-To: <20080520223237.GA12383@suse.de> References: <20080520223237.GA12383@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a race from when a device is created with device_create() and then the drvdata is set with a call to dev_set_drvdata() in which a sysfs file could be open, yet the drvdata will be NULL, causing all sorts of bad things to happen. This patch fixes the problem by using the new function, device_create_vargs(). Many thanks to Arthur Jones for reporting the bug, and testing patches out. Cc: Kay Sievers Cc: Arthur Jones Cc: Peter Zijlstra Cc: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- mm/backing-dev.c | 12 ++---------- 1 files changed, 2 insertions(+), 10 deletions(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 7c4f9e0..f2e574d 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -172,30 +172,22 @@ postcore_initcall(bdi_class_init); int bdi_register(struct backing_dev_info *bdi, struct device *parent, const char *fmt, ...) { - char *name; va_list args; int ret = 0; struct device *dev; va_start(args, fmt); - name = kvasprintf(GFP_KERNEL, fmt, args); + dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args); va_end(args); - - if (!name) - return -ENOMEM; - - dev = device_create(bdi_class, parent, MKDEV(0, 0), name); if (IS_ERR(dev)) { ret = PTR_ERR(dev); goto exit; } bdi->dev = dev; - dev_set_drvdata(bdi->dev, bdi); - bdi_debug_register(bdi, name); + bdi_debug_register(bdi, dev_name(dev)); exit: - kfree(name); return ret; } EXPORT_SYMBOL(bdi_register); -- 1.5.5.1