Commit e8cd8169 authored by Al Viro's avatar Al Viro
Browse files

vt: synchronize_rcu() under spinlock is not nice...



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.

Cc: stable@vger.kernel.org (all kernels since 2.6.37)
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7ea600b5
......@@ -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;
}
......
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