[PATCH tip/core/rcu 37/41] livepatch: Replace synchronize_sched() with synchronize_rcu()

Paul E. McKenney
2018-11-11T19:46:21Z

Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu(). This commit therefore makes this change,
even though it is but a comment.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
kernel/livepatch/patch.c | 4 ++--
kernel/livepatch/transition.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index 82d584225dc6..7702cb4064fc 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -61,7 +61,7 @@ static void notrace klp_ftrace_handler(unsigned long ip,
ops = container_of(fops, struct klp_ops, fops);

/*
- * A variant of synchronize_sched() is used to allow patching functions
+ * A variant of synchronize_rcu() is used to allow patching functions
* where RCU is not watching, see klp_synchronize_transition().
*/
preempt_disable_notrace();
@@ -72,7 +72,7 @@ static void notrace klp_ftrace_handler(unsigned long ip,
/*
* func should never be NULL because preemption should be disabled here
* and unregister_ftrace_function() does the equivalent of a
- * synchronize_sched() before the func_stack removal.
+ * synchronize_rcu() before the func_stack removal.
*/
if (WARN_ON_ONCE(!func))
goto unlock;
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index 5bc349805e03..304d5eb8a98c 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -52,7 +52,7 @@ static DECLARE_DELAYED_WORK(klp_transition_work, klp_transition_work_fn);

/*
* This function is just a stub to implement a hard force
- * of synchronize_sched(). This requires synchronizing
+ * of synchronize_rcu(). This requires synchronizing
* tasks even in userspace and idle.
*/
static void klp_sync(struct work_struct *work)
@@ -175,7 +175,7 @@ void klp_cancel_transition(void)
void klp_update_patch_state(struct task_struct *task)
{
/*
- * A variant of synchronize_sched() is used to allow patching functions
+ * A variant of synchronize_rcu() is used to allow patching functions
* where RCU is not watching, see klp_synchronize_transition().
*/
preempt_disable_notrace();
--
2.17.1