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
commands:

    $ 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);
    |
            kfree(ptr);
    )

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

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index f0cac1900552..b19c39dcfbd9 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -2792,7 +2792,7 @@ void pn53x_common_clean(struct pn533 *priv)
 	struct pn533_cmd *cmd, *n;
 
 	/* delete the timer before cleanup the worker */
-	del_timer_sync(&priv->listen_timer);
+	timer_shutdown_sync(&priv->listen_timer);
 
 	flush_delayed_work(&priv->poll_work);
 	destroy_workqueue(priv->wq);
diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c
index 07596bf5f7d6..a556acdb947b 100644
--- a/drivers/nfc/pn533/uart.c
+++ b/drivers/nfc/pn533/uart.c
@@ -310,7 +310,7 @@ static void pn532_uart_remove(struct serdev_device *serdev)
 	pn53x_unregister_nfc(pn532->priv);
 	serdev_device_close(serdev);
 	pn53x_common_clean(pn532->priv);
-	del_timer_sync(&pn532->cmd_timeout);
+	timer_shutdown_sync(&pn532->cmd_timeout);
 	kfree_skb(pn532->recv_skb);
 	kfree(pn532);
 }