Re: [PATCH] treewide: Convert del_timer*() to timer_shutdown*()

Paolo Abeni
2022-12-22T10:03:06Z

On Tue, 2022-12-20 at 13:45 -0500, Steven Rostedt wrote:
> [
> Linus,
>
> I ran the script against your latest master branch:
> commit b6bb9676f2165d518b35ba3bea5f1fcfc0d969bf
>
> As the timer_shutdown*() code is now in your tree, I figured
> we can start doing the conversions. At least add the trivial ones
> now as Thomas suggested that this gets applied at the end of the
> merge window, to avoid conflicts with linux-next during the
> development cycle. I can wait to Friday to run it again, and
> resubmit.
>
> What is the best way to handle this?
> ]
>
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
>
> 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>

For the networking bits:

> drivers/net/ethernet/intel/i40e/i40e_main.c | 6 +++---
> drivers/net/ethernet/marvell/sky2.c | 2 +-
> drivers/net/ethernet/sun/sunvnet.c | 2 +-
> drivers/net/usb/sierra_net.c | 2 +-
> net/802/garp.c | 2 +-
> net/802/mrp.c | 4 ++--
> net/bridge/br_multicast.c | 8 ++++----
> net/bridge/br_multicast_eht.c | 4 ++--
> net/core/gen_estimator.c | 2 +-
> net/ipv4/ipmr.c | 2 +-
> net/ipv6/ip6mr.c | 2 +-
> net/mac80211/mesh_pathtbl.c | 2 +-
> net/netfilter/ipset/ip_set_list_set.c | 2 +-
> net/netfilter/ipvs/ip_vs_lblc.c | 2 +-
> net/netfilter/ipvs/ip_vs_lblcr.c | 2 +-
> net/netfilter/xt_IDLETIMER.c | 4 ++--
> net/netfilter/xt_LED.c | 2 +-
> net/sched/cls_flow.c | 2 +-
> net/sunrpc/svc.c | 2 +-
> net/tipc/discover.c | 2 +-
> net/tipc/monitor.c | 2 +-

Acked-by: Paolo Abeni <pabeni@redhat.com>