From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758977Ab0BYKMu (ORCPT ); Thu, 25 Feb 2010 05:12:50 -0500 Received: from hera.kernel.org ([140.211.167.34]:40864 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758944Ab0BYKMm (ORCPT ); Thu, 25 Feb 2010 05:12:42 -0500 Date: Thu, 25 Feb 2010 10:11:40 GMT From: "tip-bot for Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, viro@zeniv.linux.org.uk, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, viro@zeniv.linux.org.uk, mingo@elte.hu In-Reply-To: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> References: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/rcu] vfs: Apply lockdep-based checking to rcu_dereference() uses Message-ID: Git-Commit-ID: 7dc52157982ab771f40e3c0b7dc55b954c3c2d19 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 25 Feb 2010 10:11:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7dc52157982ab771f40e3c0b7dc55b954c3c2d19 Gitweb: http://git.kernel.org/tip/7dc52157982ab771f40e3c0b7dc55b954c3c2d19 Author: Paul E. McKenney AuthorDate: Mon, 22 Feb 2010 17:04:52 -0800 Committer: Ingo Molnar CommitDate: Thu, 25 Feb 2010 10:34:48 +0100 vfs: Apply lockdep-based checking to rcu_dereference() uses Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and fcheck_files(). Cc: Alexander Viro Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: Alexander Viro LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- fs/file.c | 2 +- fs/proc/array.c | 2 ++ fs/proc/base.c | 6 +++++- include/linux/fdtable.h | 8 ++++++-- 4 files changed, 14 insertions(+), 4 deletions(-) diff --git a/fs/file.c b/fs/file.c index 87e1290..38039af 100644 --- a/fs/file.c +++ b/fs/file.c @@ -478,7 +478,7 @@ repeat: error = fd; #if 1 /* Sanity check */ - if (rcu_dereference(fdt->fd[fd]) != NULL) { + if (rcu_dereference_raw(fdt->fd[fd]) != NULL) { printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd); rcu_assign_pointer(fdt->fd[fd], NULL); } diff --git a/fs/proc/array.c b/fs/proc/array.c index 13b5d07..18e20fe 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -270,7 +270,9 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p) blocked = p->blocked; collect_sigign_sigcatch(p, &ignored, &caught); num_threads = atomic_read(&p->signal->count); + rcu_read_lock(); /* FIXME: is this correct? */ qsize = atomic_read(&__task_cred(p)->user->sigpending); + rcu_read_unlock(); qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur; unlock_task_sighand(p, &flags); } diff --git a/fs/proc/base.c b/fs/proc/base.c index 58324c2..623e2ff 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1095,8 +1095,12 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, if (!capable(CAP_AUDIT_CONTROL)) return -EPERM; - if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) + rcu_read_lock(); + if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { + rcu_read_unlock(); return -EPERM; + } + rcu_read_unlock(); if (count >= PAGE_SIZE) count = PAGE_SIZE - 1; diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index a2ec74b..144412f 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -57,7 +57,11 @@ struct files_struct { struct file * fd_array[NR_OPEN_DEFAULT]; }; -#define files_fdtable(files) (rcu_dereference((files)->fdt)) +#define files_fdtable(files) \ + (rcu_dereference_check((files)->fdt, \ + rcu_read_lock_held() || \ + lockdep_is_held(&(files)->file_lock) || \ + atomic_read(&files->count) == 1)) struct file_operations; struct vfsmount; @@ -78,7 +82,7 @@ static inline struct file * fcheck_files(struct files_struct *files, unsigned in struct fdtable *fdt = files_fdtable(files); if (fd < fdt->max_fds) - file = rcu_dereference(fdt->fd[fd]); + file = rcu_dereference_check(fdt->fd[fd], rcu_read_lock_held() || lockdep_is_held(&files->file_lock) || atomic_read(&files->count) == 1); return file; }