From 292a089d78d3e2f7944e60bb897c977785a321e3 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 20 Dec 2022 13:45:19 -0500 Subject: 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) Acked-by: Pavel Machek [ LED ] Acked-by: Kalle Valo [ wireless ] Acked-by: Paolo Abeni [ networking ] Signed-off-by: Linus Torvalds --- block/blk-iolatency.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/blk-iolatency.c') diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 778a0057193e..ecdc10741836 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -644,7 +644,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos) { struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos); - del_timer_sync(&blkiolat->timer); + timer_shutdown_sync(&blkiolat->timer); flush_work(&blkiolat->enable_work); blkcg_deactivate_policy(rqos->q, &blkcg_policy_iolatency); kfree(blkiolat); -- cgit