Commit e616cb8d authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner
Browse files

lockdep: Always inline lockdep_{off,on}() 



These functions are called {early,late} in nmi_{enter,exit} and should
not be traced or probed. They are also puny, so 'inline' them.

Reported-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarAlexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200505134101.048523500@linutronix.de
parent 69ea03b5

include/linux/lockdep.h

+21 −2
Original line number Diff line number Diff line
@@ -308,8 +308,27 @@ extern void lockdep_set_selftest_task(struct task_struct *task); 


extern void lockdep_init_task(struct task_struct *task);



extern void lockdep_off(void);

extern void lockdep_on(void);

/*

 * Split the recrursion counter in two to readily detect 'off' vs recursion.

 */

#define LOCKDEP_RECURSION_BITS	16

#define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)

#define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)



/*

 * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due

 * to header dependencies.

 */



#define lockdep_off()					\

do {							\

	current->lockdep_recursion += LOCKDEP_OFF;	\

} while (0)



#define lockdep_on()					\

do {							\

	current->lockdep_recursion -= LOCKDEP_OFF;	\

} while (0)



extern void lockdep_register_key(struct lock_class_key *key);

extern void lockdep_unregister_key(struct lock_class_key *key);

kernel/locking/lockdep.c

+0 −19
Original line number Diff line number Diff line
@@ -393,25 +393,6 @@ void lockdep_init_task(struct task_struct *task) 
	task->lockdep_recursion = 0;

}



/*

 * Split the recrursion counter in two to readily detect 'off' vs recursion.

 */

#define LOCKDEP_RECURSION_BITS	16

#define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)

#define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)



void lockdep_off(void)

{

	current->lockdep_recursion += LOCKDEP_OFF;

}

EXPORT_SYMBOL(lockdep_off);



void lockdep_on(void)

{

	current->lockdep_recursion -= LOCKDEP_OFF;

}

EXPORT_SYMBOL(lockdep_on);



static inline void lockdep_recursion_finish(void)

{

	if (WARN_ON_ONCE(--current->lockdep_recursion))

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