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| author | Al Viro <viro@zeniv.linux.org.uk> | 2013-03-26 20:30:17 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-03-26 20:30:17 -0400 |
| commit | e8cd81693bbbb15db57d3c9aa7dd90eda4842874 (patch) | |
| tree | f8ba631b03652f9e570fa1e8bd0395af63cf2bb3 | |
| parent | 7ea600b5314529f9d1b9d6d3c41cb26fce6a7a4a (diff) | |
| download | linux-e8cd81693bbbb15db57d3c9aa7dd90eda4842874.tar.bz2 | |
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: Al Viro <viro@zeniv.linux.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 e4ca345873c3..d7799deacb21 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; } |