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 <viro@zeniv.linux.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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 <viro@zeniv.linux.org.uk>
LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 13b5d0708175..18e20feee251 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);
         }