kprobe: move sysctl_kprobes_optimization to kprobes.c20211118-sysctl-cleanups-set-04-v4

The 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.

Move sysctl_kprobes_optimization from kernel/sysctl.c to kernel/kprobes.c.
Use register_sysctl() to register the sysctl interface.

Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

3 files changed, 25 insertions, 22 deletions

diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index e974caf39d3e3..e9c3687c84d56 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -346,12 +346,6 @@ extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
 
 DEFINE_INSN_CACHE_OPS(optinsn);
 
-#ifdef CONFIG_SYSCTL
-extern int sysctl_kprobes_optimization;
-extern int proc_kprobes_optimization_handler(struct ctl_table *table,
-					     int write, void *buffer,
-					     size_t *length, loff_t *ppos);
-#endif /* CONFIG_SYSCTL */
 extern void wait_for_kprobe_optimizer(void);
 #else /* !CONFIG_OPTPROBES */
 static inline void wait_for_kprobe_optimizer(void) { }
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index e9db0c810554e..71a005609fd3e 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -938,10 +938,10 @@ static void unoptimize_all_kprobes(void)
 }
 
 static DEFINE_MUTEX(kprobe_sysctl_mutex);
-int sysctl_kprobes_optimization;
-int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
-				      void *buffer, size_t *length,
-				      loff_t *ppos)
+static int sysctl_kprobes_optimization;
+static int proc_kprobes_optimization_handler(struct ctl_table *table,
+					     int write, void *buffer,
+					     size_t *length, loff_t *ppos)
 {
 	int ret;
 
@@ -957,6 +957,26 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
 
 	return ret;
 }
+
+static struct ctl_table kprobe_sysctls[] = {
+	{
+		.procname	= "kprobes-optimization",
+		.data		= &sysctl_kprobes_optimization,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_kprobes_optimization_handler,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{}
+};
+
+static void __init kprobe_sysctls_init(void)
+{
+	register_sysctl_init("debug", kprobe_sysctls);
+}
+#else
+#define kprobe_sysctls_init() do { } while (0)
 #endif /* CONFIG_SYSCTL */
 
 /* Put a breakpoint for a probe. */
@@ -2581,6 +2601,7 @@ static int __init init_kprobes(void)
 		err = register_module_notifier(&kprobe_module_nb);
 
 	kprobes_initialized = (err == 0);
+	kprobe_sysctls_init();
 	return err;
 }
 early_initcall(init_kprobes);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 6059dc5a08383..e316df722560e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -55,7 +55,6 @@
 #include <linux/reboot.h>
 #include <linux/ftrace.h>
 #include <linux/perf_event.h>
-#include <linux/kprobes.h>
 #include <linux/oom.h>
 #include <linux/kmod.h>
 #include <linux/capability.h>
@@ -2818,17 +2817,6 @@ static struct ctl_table debug_table[] = {
 		.proc_handler	= proc_dointvec
 	},
 #endif
-#if defined(CONFIG_OPTPROBES)
-	{
-		.procname	= "kprobes-optimization",
-		.data		= &sysctl_kprobes_optimization,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_kprobes_optimization_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-#endif
 	{ }
 };