Preempt-safe RCU file usage

Fix up fs/compat.c fixes.

diff --git a/fs/compat.c b/fs/compat.c
index c2e0813..ac3fb9e 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1645,8 +1645,10 @@ compat_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp
                goto out_nofds;
 
        /* max_fdset can increase, so grab it once to avoid race */
+       rcu_read_lock();
        fdt = files_fdtable(current->files);
        max_fdset = fdt->max_fdset;
+       rcu_read_unlock();
        if (n > max_fdset)
                n = max_fdset;