diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2013-03-26 20:30:17 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-04-10 03:20:03 +0100 |
| commit | c39ea1c36ac173cd07643f91e19671de3fe377e2 (patch) | |
| tree | c7f848e07a8c9ea224bab40aed98ab8870fc105f | |
| parent | a0a551fcc3199a6e9fb6c0236daff99bbe278905 (diff) | |
vt: synchronize_rcu() under spinlock is not nice...
commit e8cd81693bbbb15db57d3c9aa7dd90eda4842874 upstream.
vcs_poll_data_free() calls unregister_vt_notifier(), which calls
atomic_notifier_chain_unregister(), which calls synchronize_rcu().
Do it *after* we'd dropped ->f_lock.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/tty/vt/vc_screen.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c index 7a367ff5122b..fd89c421b71f 100644 --- a/drivers/tty/vt/vc_screen.c +++ b/drivers/tty/vt/vc_screen.c @@ -93,7 +93,7 @@ vcs_poll_data_free(struct vcs_poll_data *poll) static struct vcs_poll_data * vcs_poll_data_get(struct file *file) { - struct vcs_poll_data *poll = file->private_data; + struct vcs_poll_data *poll = file->private_data, *kill = NULL; if (poll) return poll; @@ -122,10 +122,12 @@ vcs_poll_data_get(struct file *file) file->private_data = poll; } else { /* someone else raced ahead of us */ - vcs_poll_data_free(poll); + kill = poll; poll = file->private_data; } spin_unlock(&file->f_lock); + if (kill) + vcs_poll_data_free(kill); return poll; } |