kernel/lockdep: move lockdep sysctls to its own file

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

All filesystem syctls now get reviewed by fs folks. This commit
follows the commit of fs, move the prove_locking and lock_stat sysctls
to its own file, kernel/lockdep.c.

Signed-off-by: tangmeng <tangmeng@uniontech.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

Author: imtangmeng

include/linux/lockdep.h

@@ -16,10 +16,6 @@
 
 struct task_struct;
 
-/* for sysctl */
-extern int prove_locking;
-extern int lock_stat;
-
 #ifdef CONFIG_LOCKDEP
 
 #include <linux/linkage.h>

kernel/locking/lockdep.c

@@ -64,19 +64,50 @@
 #include <trace/events/lock.h>
 
 #ifdef CONFIG_PROVE_LOCKING
-int prove_locking = 1;
+static int prove_locking = 1;
 module_param(prove_locking, int, 0644);
 #else
 #define prove_locking 0
 #endif
 
 #ifdef CONFIG_LOCK_STAT
-int lock_stat = 1;
+static int lock_stat = 1;
 module_param(lock_stat, int, 0644);
 #else
 #define lock_stat 0
 #endif
 
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_lockdep_table[] = {
+#ifdef CONFIG_PROVE_LOCKING
+	{
+		.procname       = "prove_locking",
+		.data           = &prove_locking,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec,
+	},
+#endif /* CONFIG_PROVE_LOCKING */
+#ifdef CONFIG_LOCK_STAT
+	{
+		.procname       = "lock_stat",
+		.data           = &lock_stat,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec,
+	},
+#endif /* CONFIG_LOCK_STAT */
+	{ }
+};
+
+static __init int kernel_lockdep_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_lockdep_table);
+	return 0;
+}
+late_initcall(kernel_lockdep_sysctls_init);
+#endif /* CONFIG_SYSCTL */
+
 DEFINE_PER_CPU(unsigned int, lockdep_recursion);
 EXPORT_PER_CPU_SYMBOL_GPL(lockdep_recursion);
 

kernel/sysctl.c

@@ -88,9 +88,6 @@
 #ifdef CONFIG_RT_MUTEXES
 #include <linux/rtmutex.h>
 #endif
-#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
-#include <linux/lockdep.h>
-#endif
 
 #if defined(CONFIG_SYSCTL)
 
@@ -1679,24 +1676,6 @@ static struct ctl_table kern_table[] = {
 		.extra2		= SYSCTL_FOUR,
 	},
 #endif /* CONFIG_NUMA_BALANCING */
-#ifdef CONFIG_PROVE_LOCKING
-	{
-		.procname	= "prove_locking",
-		.data		= &prove_locking,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
-#ifdef CONFIG_LOCK_STAT
-	{
-		.procname	= "lock_stat",
-		.data		= &lock_stat,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
 	{
 		.procname	= "panic",
 		.data		= &panic_timeout,