[PATCH] rcu: Convert timers to use timer_setup()

From: Kees Cook
Date: Tue Oct 24 2017 - 05:32:18 EST


In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
kernel/rcu/rcutorture.c | 4 ++--
kernel/rcu/tree_plugin.h | 9 +++++----
2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index e1d3fa534ac0..b6fbbeb5a7da 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1078,7 +1078,7 @@ static void rcu_torture_timer_cb(struct rcu_head *rhp)
* counter in the element should never be greater than 1, otherwise, the
* RCU implementation is broken.
*/
-static void rcu_torture_timer(unsigned long unused)
+static void rcu_torture_timer(struct timer_list *unused)
{
int idx;
unsigned long started;
@@ -1165,7 +1165,7 @@ rcu_torture_reader(void *arg)
VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
set_user_nice(current, MAX_NICE);
if (irqreader && cur_ops->irq_capable)
- setup_timer_on_stack(&t, rcu_torture_timer, 0);
+ timer_setup_on_stack(&t, rcu_torture_timer, 0);

do {
if (irqreader && cur_ops->irq_capable) {
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 8a5a3f9b1250..5fb7beee76aa 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2265,9 +2265,11 @@ static void do_nocb_deferred_wakeup_common(struct rcu_data *rdp)
}

/* Do a deferred wakeup of rcu_nocb_kthread() from a timer handler. */
-static void do_nocb_deferred_wakeup_timer(unsigned long x)
+static void do_nocb_deferred_wakeup_timer(struct timer_list *t)
{
- do_nocb_deferred_wakeup_common((struct rcu_data *)x);
+ struct rcu_data *x = from_timer(x, t, nocb_timer);
+
+ do_nocb_deferred_wakeup_common(x);
}

/*
@@ -2331,8 +2333,7 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
init_swait_queue_head(&rdp->nocb_wq);
rdp->nocb_follower_tail = &rdp->nocb_follower_head;
raw_spin_lock_init(&rdp->nocb_lock);
- setup_timer(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer,
- (unsigned long)rdp);
+ timer_setup(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer, 0);
}

/*
--
2.7.4


--
Kees Cook
Pixel Security