From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755682Ab0ITH5K (ORCPT ); Mon, 20 Sep 2010 03:57:10 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:59402 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755567Ab0ITH5I (ORCPT ); Mon, 20 Sep 2010 03:57:08 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Greg Kroah-Hartman Cc: , Tejun Heo , Hugh Dickins References: Date: Mon, 20 Sep 2010 00:57:03 -0700 In-Reply-To: (Eric W. Biederman's message of "Mon, 20 Sep 2010 00:55:33 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=98.207.157.188;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 98.207.157.188 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa03 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa03 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Greg Kroah-Hartman X-Spam-Relay-Country: Subject: [PATCH 2/2] sysfs: only access bin file vm_ops with the active lock X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org bb->vm_ops is a cached copy of the vm_ops of the underlying sysfs bin file, which means that after sysfs_bin_remove_file completes it is only longer valid to deference bb->vm_ops. So move all of the tests of bb->vm_ops inside of where we hold the sysfs active lock. Signed-off-by: Eric W. Biederman --- fs/sysfs/bin.c | 42 ++++++++++++++++++++++++++---------------- 1 files changed, 26 insertions(+), 16 deletions(-) diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index d31d7b7..a475983 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -179,13 +179,14 @@ static void bin_vma_open(struct vm_area_struct *vma) struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - if (!bb->vm_ops || !bb->vm_ops->open) + if (!bb->vm_ops) return; if (!sysfs_get_active(attr_sd)) return; - bb->vm_ops->open(vma); + if (bb->vm_ops->open) + bb->vm_ops->open(vma); sysfs_put_active(attr_sd); } @@ -197,13 +198,15 @@ static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; - if (!bb->vm_ops || !bb->vm_ops->fault) + if (!bb->vm_ops) return VM_FAULT_SIGBUS; if (!sysfs_get_active(attr_sd)) return VM_FAULT_SIGBUS; - ret = bb->vm_ops->fault(vma, vmf); + ret = VM_FAULT_SIGBUS; + if (bb->vm_ops->fault) + ret = bb->vm_ops->fault(vma, vmf); sysfs_put_active(attr_sd); return ret; @@ -219,13 +222,12 @@ static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) if (!bb->vm_ops) return VM_FAULT_SIGBUS; - if (!bb->vm_ops->page_mkwrite) - return 0; - if (!sysfs_get_active(attr_sd)) return VM_FAULT_SIGBUS; - ret = bb->vm_ops->page_mkwrite(vma, vmf); + ret = 0; + if (bb->vm_ops->page_mkwrite) + ret = bb->vm_ops->page_mkwrite(vma, vmf); sysfs_put_active(attr_sd); return ret; @@ -239,13 +241,15 @@ static int bin_access(struct vm_area_struct *vma, unsigned long addr, struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; - if (!bb->vm_ops || !bb->vm_ops->access) + if (!bb->vm_ops) return -EINVAL; if (!sysfs_get_active(attr_sd)) return -EINVAL; - ret = bb->vm_ops->access(vma, addr, buf, len, write); + ret = -EINVAL; + if (bb->vm_ops->access) + ret = bb->vm_ops->access(vma, addr, buf, len, write); sysfs_put_active(attr_sd); return ret; @@ -259,13 +263,15 @@ static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new) struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; - if (!bb->vm_ops || !bb->vm_ops->set_policy) + if (!bb->vm_ops) return 0; if (!sysfs_get_active(attr_sd)) return -EINVAL; - ret = bb->vm_ops->set_policy(vma, new); + ret = 0; + if (bb->vm_ops->set_policy) + ret = bb->vm_ops->set_policy(vma, new); sysfs_put_active(attr_sd); return ret; @@ -279,13 +285,15 @@ static struct mempolicy *bin_get_policy(struct vm_area_struct *vma, struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct mempolicy *pol; - if (!bb->vm_ops || !bb->vm_ops->get_policy) + if (!bb->vm_ops) return vma->vm_policy; if (!sysfs_get_active(attr_sd)) return vma->vm_policy; - pol = bb->vm_ops->get_policy(vma, addr); + pol = vma->vm_policy; + if (bb->vm_ops->get_policy) + pol = bb->vm_ops->get_policy(vma, addr); sysfs_put_active(attr_sd); return pol; @@ -299,13 +307,15 @@ static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; - if (!bb->vm_ops || !bb->vm_ops->migrate) + if (!bb->vm_ops) return 0; if (!sysfs_get_active(attr_sd)) return 0; - ret = bb->vm_ops->migrate(vma, from, to, flags); + ret = 0; + if (bb->vm_ops->migrate) + ret = bb->vm_ops->migrate(vma, from, to, flags); sysfs_put_active(attr_sd); return ret; -- 1.7.2.2