treewide: Convert del_timer*() to timer_shutdown*()

Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following

    $ cat timer.cocci
    expression ptr, slab;
    identifier timer, rfield;
    -       del_timer(&ptr->timer);
    +       timer_shutdown(&ptr->timer);
    -       del_timer_sync(&ptr->timer);
    +       timer_shutdown_sync(&ptr->timer);
      ... when strict
          when != ptr->timer
            kfree_rcu(ptr, rfield);
            kmem_cache_free(slab, ptr);

    $ spatch timer.cocci . > /tmp/t.patch
    $ patch -p1 < /tmp/t.patch

Signed-off-by: Steven Rostedt (Google) <>
Acked-by: Pavel Machek <> [ LED ]
Acked-by: Kalle Valo <> [ wireless ]
Acked-by: Paolo Abeni <> [ networking ]
Signed-off-by: Linus Torvalds <>
69 files changed