From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757094Ab0AOBDa (ORCPT ); Thu, 14 Jan 2010 20:03:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756818Ab0AOBDU (ORCPT ); Thu, 14 Jan 2010 20:03:20 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:38650 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755725Ab0AOBDL (ORCPT ); Thu, 14 Jan 2010 20:03:11 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, "Paul E. McKenney" , Alexander Viro Subject: [PATCH tip/core/rcu 6/9] vfs: apply lockdep-based checking to rcu_dereference() uses Date: Thu, 14 Jan 2010 17:02:43 -0800 Message-Id: <12635173662545-git-send-email-> X-Mailer: git-send-email 1.5.2.5 In-Reply-To: <20100115010157.GA28221@linux.vnet.ibm.com> References: <20100115010157.GA28221@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul E. McKenney Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and fcheck_files(). Cc: Alexander Viro Signed-off-by: Paul E. McKenney --- 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 18d5cc6..db19ca8 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; } -- 1.5.2.5