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authorPeter Zijlstra <peterz@infradead.org>2020-02-24 22:14:51 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-05-19 15:51:18 +0200
commite616cb8daadf637175af4fe53138a94c190c4816 (patch)
tree60c33e92ebdb9d023fe37e3be98d4978e145dfc4 /include/linux/lockdep.h
parent69ea03b56ed2c7189ccd0b5910ad39f3cad1df21 (diff)
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
Diffstat (limited to 'include/linux/lockdep.h')
-rw-r--r--include/linux/lockdep.h23
1 files changed, 21 insertions, 2 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 206774ac6946..8fce5c98a4b0 100644
--- 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);