[PATCH v4 -next 05/15] mm: util: move sysctls to mm/util.c

This moves all util related sysctls to mm/util.c, as part of the
kernel/sysctl.c cleaning, also removes redundant external
variable declarations and function declarations.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
---
v4:
 - const qualify struct ctl_table util_sysctl_table
v3:
 - change the title
---
---
 include/linux/mm.h   | 11 --------
 include/linux/mman.h |  2 --
 kernel/sysctl.c      | 37 ------------------------
 mm/util.c            | 67 ++++++++++++++++++++++++++++++++++++++------
 4 files changed, 59 insertions(+), 58 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8941ba3d9a77..b3b87c1dc1e4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -205,17 +205,6 @@ extern int sysctl_max_map_count;
 extern unsigned long sysctl_user_reserve_kbytes;
 extern unsigned long sysctl_admin_reserve_kbytes;
 
-extern int sysctl_overcommit_memory;
-extern int sysctl_overcommit_ratio;
-extern unsigned long sysctl_overcommit_kbytes;
-
-int overcommit_ratio_handler(const struct ctl_table *, int, void *, size_t *,
-		loff_t *);
-int overcommit_kbytes_handler(const struct ctl_table *, int, void *, size_t *,
-		loff_t *);
-int overcommit_policy_handler(const struct ctl_table *, int, void *, size_t *,
-		loff_t *);
-
 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
 #define folio_page_idx(folio, p)	(page_to_pfn(p) - folio_pfn(folio))
diff --git a/include/linux/mman.h b/include/linux/mman.h
index a842783ffa62..bce214fece16 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -59,8 +59,6 @@
 		| MAP_HUGE_1GB)
 
 extern int sysctl_overcommit_memory;
-extern int sysctl_overcommit_ratio;
-extern unsigned long sysctl_overcommit_kbytes;
 extern struct percpu_counter vm_committed_as;
 
 #ifdef CONFIG_SMP
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index cb6ca272fe9f..aea3482106e0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2020,29 +2020,6 @@ static struct ctl_table kern_table[] = {
 };
 
 static struct ctl_table vm_table[] = {
-	{
-		.procname	= "overcommit_memory",
-		.data		= &sysctl_overcommit_memory,
-		.maxlen		= sizeof(sysctl_overcommit_memory),
-		.mode		= 0644,
-		.proc_handler	= overcommit_policy_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_TWO,
-	},
-	{
-		.procname	= "overcommit_ratio",
-		.data		= &sysctl_overcommit_ratio,
-		.maxlen		= sizeof(sysctl_overcommit_ratio),
-		.mode		= 0644,
-		.proc_handler	= overcommit_ratio_handler,
-	},
-	{
-		.procname	= "overcommit_kbytes",
-		.data		= &sysctl_overcommit_kbytes,
-		.maxlen		= sizeof(sysctl_overcommit_kbytes),
-		.mode		= 0644,
-		.proc_handler	= overcommit_kbytes_handler,
-	},
 	{
 		.procname	= "dirtytime_expire_seconds",
 		.data		= &dirtytime_expire_interval,
@@ -2123,20 +2100,6 @@ static struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 	},
 #endif
-	{
-		.procname	= "user_reserve_kbytes",
-		.data		= &sysctl_user_reserve_kbytes,
-		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
-		.mode		= 0644,
-		.proc_handler	= proc_doulongvec_minmax,
-	},
-	{
-		.procname	= "admin_reserve_kbytes",
-		.data		= &sysctl_admin_reserve_kbytes,
-		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
-		.mode		= 0644,
-		.proc_handler	= proc_doulongvec_minmax,
-	},
 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
 	{
 		.procname	= "mmap_rnd_bits",
diff --git a/mm/util.c b/mm/util.c
index b7dc6fabaae5..6c64664937b3 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -12,6 +12,7 @@
 #include <linux/security.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
+#include <linux/sysctl.h>
 #include <linux/mman.h>
 #include <linux/hugetlb.h>
 #include <linux/vmalloc.h>
@@ -911,14 +912,16 @@ int folio_mc_copy(struct folio *dst, struct folio *src)
 EXPORT_SYMBOL(folio_mc_copy);
 
 int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS;
-int sysctl_overcommit_ratio __read_mostly = 50;
-unsigned long sysctl_overcommit_kbytes __read_mostly;
+static int sysctl_overcommit_ratio __read_mostly = 50;
+static unsigned long sysctl_overcommit_kbytes __read_mostly;
 int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
 unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */
 unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */
 
-int overcommit_ratio_handler(const struct ctl_table *table, int write, void *buffer,
-		size_t *lenp, loff_t *ppos)
+#ifdef CONFIG_SYSCTL
+
+static int overcommit_ratio_handler(const struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -933,8 +936,8 @@ static void sync_overcommit_as(struct work_struct *dummy)
 	percpu_counter_sync(&vm_committed_as);
 }
 
-int overcommit_policy_handler(const struct ctl_table *table, int write, void *buffer,
-		size_t *lenp, loff_t *ppos)
+static int overcommit_policy_handler(const struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	int new_policy = -1;
@@ -969,8 +972,8 @@ int overcommit_policy_handler(const struct ctl_table *table, int write, void *bu
 	return ret;
 }
 
-int overcommit_kbytes_handler(const struct ctl_table *table, int write, void *buffer,
-		size_t *lenp, loff_t *ppos)
+static int overcommit_kbytes_handler(const struct ctl_table *table, int write,
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -980,6 +983,54 @@ int overcommit_kbytes_handler(const struct ctl_table *table, int write, void *bu
 	return ret;
 }
 
+static const struct ctl_table util_sysctl_table[] = {
+	{
+		.procname	= "overcommit_memory",
+		.data		= &sysctl_overcommit_memory,
+		.maxlen		= sizeof(sysctl_overcommit_memory),
+		.mode		= 0644,
+		.proc_handler	= overcommit_policy_handler,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_TWO,
+	},
+	{
+		.procname	= "overcommit_ratio",
+		.data		= &sysctl_overcommit_ratio,
+		.maxlen		= sizeof(sysctl_overcommit_ratio),
+		.mode		= 0644,
+		.proc_handler	= overcommit_ratio_handler,
+	},
+	{
+		.procname	= "overcommit_kbytes",
+		.data		= &sysctl_overcommit_kbytes,
+		.maxlen		= sizeof(sysctl_overcommit_kbytes),
+		.mode		= 0644,
+		.proc_handler	= overcommit_kbytes_handler,
+	},
+	{
+		.procname	= "user_reserve_kbytes",
+		.data		= &sysctl_user_reserve_kbytes,
+		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+	},
+	{
+		.procname	= "admin_reserve_kbytes",
+		.data		= &sysctl_admin_reserve_kbytes,
+		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+	},
+};
+
+static int __init init_vm_util_sysctls(void)
+{
+	register_sysctl_init("vm", util_sysctl_table);
+	return 0;
+}
+subsys_initcall(init_vm_util_sysctls);
+#endif /* CONFIG_SYSCTL */
+
 /*
  * Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
  */
-- 
2.34.1