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-rw-r--r--fs/proc/proc_sysctl.c63
1 files changed, 61 insertions, 2 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 389e1e42e7d9..7d9cfc730bd4 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -16,6 +16,7 @@
#include <linux/module.h>
#include <linux/bpf-cgroup.h>
#include <linux/mount.h>
+#include <linux/kmemleak.h>
#include "internal.h"
static const struct dentry_operations proc_sys_dentry_operations;
@@ -25,15 +26,32 @@ static const struct file_operations proc_sys_dir_file_operations;
static const struct inode_operations proc_sys_dir_operations;
/* shared constants to be used in various sysctls */
-const int sysctl_vals[] = { 0, 1, INT_MAX };
+const int sysctl_vals[] = { -1, 0, 1, 2, 4, 100, 200, 1000, 3000, INT_MAX, 65535 };
EXPORT_SYMBOL(sysctl_vals);
+const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
+EXPORT_SYMBOL_GPL(sysctl_long_vals);
+
/* Support for permanently empty directories */
struct ctl_table sysctl_mount_point[] = {
{ }
};
+/**
+ * register_sysctl_mount_point() - registers a sysctl mount point
+ * @path: path for the mount point
+ *
+ * Used to create a permanently empty directory to serve as mount point.
+ * There are some subtle but important permission checks this allows in the
+ * case of unprivileged mounts.
+ */
+struct ctl_table_header *register_sysctl_mount_point(const char *path)
+{
+ return register_sysctl(path, sysctl_mount_point);
+}
+EXPORT_SYMBOL(register_sysctl_mount_point);
+
static bool is_empty_dir(struct ctl_table_header *head)
{
return head->ctl_table[0].child == sysctl_mount_point;
@@ -1383,6 +1401,38 @@ struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *tab
}
EXPORT_SYMBOL(register_sysctl);
+/**
+ * __register_sysctl_init() - register sysctl table to path
+ * @path: path name for sysctl base
+ * @table: This is the sysctl table that needs to be registered to the path
+ * @table_name: The name of sysctl table, only used for log printing when
+ * registration fails
+ *
+ * The sysctl interface is used by userspace to query or modify at runtime
+ * a predefined value set on a variable. These variables however have default
+ * values pre-set. Code which depends on these variables will always work even
+ * if register_sysctl() fails. If register_sysctl() fails you'd just loose the
+ * ability to query or modify the sysctls dynamically at run time. Chances of
+ * register_sysctl() failing on init are extremely low, and so for both reasons
+ * this function does not return any error as it is used by initialization code.
+ *
+ * Context: Can only be called after your respective sysctl base path has been
+ * registered. So for instance, most base directories are registered early on
+ * init before init levels are processed through proc_sys_init() and
+ * sysctl_init_bases().
+ */
+void __init __register_sysctl_init(const char *path, struct ctl_table *table,
+ const char *table_name)
+{
+ struct ctl_table_header *hdr = register_sysctl(path, table);
+
+ if (unlikely(!hdr)) {
+ pr_err("failed when register_sysctl %s to %s\n", table_name, path);
+ return;
+ }
+ kmemleak_not_leak(hdr);
+}
+
static char *append_path(const char *path, char *pos, const char *name)
{
int namelen;
@@ -1596,6 +1646,15 @@ struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
}
EXPORT_SYMBOL(register_sysctl_table);
+int __register_sysctl_base(struct ctl_table *base_table)
+{
+ struct ctl_table_header *hdr;
+
+ hdr = register_sysctl_table(base_table);
+ kmemleak_not_leak(hdr);
+ return 0;
+}
+
static void put_links(struct ctl_table_header *header)
{
struct ctl_table_set *root_set = &sysctl_table_root.default_set;
@@ -1709,7 +1768,7 @@ int __init proc_sys_init(void)
proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations;
proc_sys_root->nlink = 0;
- return sysctl_init();
+ return sysctl_init_bases();
}
struct sysctl_alias {