1 files changed, 113 insertions, 0 deletions

diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c
new file mode 100644
index 000000000000..b2163bfb6eb2
--- /dev/null
+++ b/lib/test_sysctl.c
@@ -0,0 +1,113 @@
+/*
+ * proc sysctl test driver
+ *
+ * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or at your option any
+ * later version; or, when distributed separately from the Linux kernel or
+ * when incorporated into other software packages, subject to the following
+ * license:
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of copyleft-next (version 0.3.1 or later) as published
+ * at http://copyleft-next.org/.
+ */
+
+/*
+ * This module provides an interface to the the proc sysctl interfaces.  This
+ * driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the
+ * system unless explicitly requested by name. You can also build this driver
+ * into your kernel.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/async.h>
+#include <linux/delay.h>
+#include <linux/vmalloc.h>
+
+static int i_zero;
+static int i_one_hundred = 100;
+
+struct test_sysctl_data {
+        int int_0001;
+        char string_0001[65];
+};
+
+static struct test_sysctl_data test_data = {
+        .int_0001 = 60,
+        .string_0001 = "(none)",
+};
+
+/* These are all under /proc/sys/debug/test_sysctl/ */
+static struct ctl_table test_table[] = {
+        {
+                .procname       = "int_0001",
+                .data           = &test_data.int_0001,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = proc_dointvec_minmax,
+                .extra1         = &i_zero,
+                .extra2         = &i_one_hundred,
+        },
+        {
+                .procname       = "string_0001",
+                .data           = &test_data.string_0001,
+                .maxlen         = sizeof(test_data.string_0001),
+                .mode           = 0644,
+                .proc_handler   = proc_dostring,
+        },
+        { }
+};
+
+static struct ctl_table test_sysctl_table[] = {
+        {
+                .procname       = "test_sysctl",
+                .maxlen         = 0,
+                .mode           = 0555,
+                .child          = test_table,
+        },
+        { }
+};
+
+static struct ctl_table test_sysctl_root_table[] = {
+        {
+                .procname       = "debug",
+                .maxlen         = 0,
+                .mode           = 0555,
+                .child          = test_sysctl_table,
+        },
+        { }
+};
+
+static struct ctl_table_header *test_sysctl_header;
+
+static int __init test_sysctl_init(void)
+{
+        test_sysctl_header = register_sysctl_table(test_sysctl_root_table);
+        if (!test_sysctl_header)
+                return -ENOMEM;
+        return 0;
+}
+late_initcall(test_sysctl_init);
+
+static void __exit test_sysctl_exit(void)
+{
+        if (test_sysctl_header)
+                unregister_sysctl_table(test_sysctl_header);
+}
+
+module_exit(test_sysctl_exit);
+
+MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>");
+MODULE_LICENSE("GPL");