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: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200505134101.048523500@linutronix.de

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 206774ac69460af889af852598a5f14fad651a21..8fce5c98a4b0ecadee49f08a1d3addae1254a08c 100644 (file)
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -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);

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index ac10db66cc63f4b8f96ad59e89ac3caee18a2b6d..6f1c8cba09c6d9f0b2e0a0acda545ac0867317e2 100644 (file)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -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))