diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index d9680b798b2113..cfeb43bfc719e3 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -53,7 +53,7 @@ void __rcu_read_unlock(void); * nesting depth, but makes sense only if CONFIG_PREEMPT_RCU -- in other * types of kernel builds, the rcu_read_lock() nesting depth is unknowable. */ -#define rcu_preempt_depth() (current->rcu_read_lock_nesting) +#define rcu_preempt_depth() READ_ONCE(current->rcu_read_lock_nesting) #else /* #ifdef CONFIG_PREEMPT_RCU */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index de1dc3bb7f7016..83a702a4e29632 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -405,17 +405,20 @@ static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp) static void rcu_preempt_read_enter(void) { - current->rcu_read_lock_nesting++; + WRITE_ONCE(current->rcu_read_lock_nesting, READ_ONCE(current->rcu_read_lock_nesting) + 1); } static int rcu_preempt_read_exit(void) { - return --current->rcu_read_lock_nesting; + int ret = READ_ONCE(current->rcu_read_lock_nesting) - 1; + + WRITE_ONCE(current->rcu_read_lock_nesting, ret); + return ret; } static void rcu_preempt_depth_set(int val) { - current->rcu_read_lock_nesting = val; + WRITE_ONCE(current->rcu_read_lock_nesting, val); } /*