rcu: Make rcu_read_lock_bh_held() allow for disabled BH (e3818b8d) · Commits · 戴 / test

include/linux/rcupdate.h

+4 −15

Original line number	Diff line number	Diff line
		@@ -123,22 +123,11 @@ static inline int rcu_read_lock_held(void)
		return lock_is_held(&rcu_lock_map);
		}

		/**
		* rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section?
		*
		* If CONFIG_PROVE_LOCKING is selected and enabled, returns nonzero iff in
		* an RCU-bh read-side critical section. In absence of CONFIG_PROVE_LOCKING,
		* this assumes we are in an RCU-bh read-side critical section unless it can
		* prove otherwise.
		*
		* Check rcu_scheduler_active to prevent false positives during boot.
		/*
		* rcu_read_lock_bh_held() is defined out of line to avoid #include-file
		* hell.
		*/
		static inline int rcu_read_lock_bh_held(void)
		{
		if (!debug_lockdep_rcu_enabled())
		return 1;
		return lock_is_held(&rcu_bh_lock_map);
		}
		extern int rcu_read_lock_bh_held(void);

		/**
		* rcu_read_lock_sched_held - might we be in RCU-sched read-side critical section?

+23 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,7 @@
		#include <linux/mutex.h>
		#include <linux/module.h>
		#include <linux/kernel_stat.h>
		#include <linux/hardirq.h>

		#ifdef CONFIG_DEBUG_LOCK_ALLOC
		static struct lock_class_key rcu_lock_key;
		@@ -66,6 +67,28 @@ EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
		int rcu_scheduler_active __read_mostly;
		EXPORT_SYMBOL_GPL(rcu_scheduler_active);

		#ifdef CONFIG_DEBUG_LOCK_ALLOC

		/**
		* rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section?
		*
		* Check for bottom half being disabled, which covers both the
		* CONFIG_PROVE_RCU and not cases. Note that if someone uses
		* rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
		* will show the situation.
		*
		* Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
		*/
		int rcu_read_lock_bh_held(void)
		{
		if (!debug_lockdep_rcu_enabled())
		return 1;
		return in_softirq();
		}
		EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);

		#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */

		/*
		* This function is invoked towards the end of the scheduler's initialization
		* process. Before this is called, the idle task might contain