1 files changed, 103 insertions, 0 deletions
diff --git a/compat/backport-4.6.c b/compat/backport-4.6.c
new file mode 100644
index 0000000..8d0ecf5
--- /dev/null
+++ b/compat/backport-4.6.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright(c) 2016 Hauke Mehrtens <hauke@hauke-m.de>
+ *
+ * Backport functionality introduced in Linux 4.6.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+
+/**
+ * kstrtobool - convert common user inputs into boolean values
+ * @s: input string
+ * @res: result
+ *
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
+ * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
+ * pointed to by res is updated upon finding a match.
+ */
+int kstrtobool(const char *s, bool *res)
+{
+	if (!s)
+		return -EINVAL;
+
+	switch (s[0]) {
+	case 'y':
+	case 'Y':
+	case '1':
+		*res = true;
+		return 0;
+	case 'n':
+	case 'N':
+	case '0':
+		*res = false;
+		return 0;
+	case 'o':
+	case 'O':
+		switch (s[1]) {
+		case 'n':
+		case 'N':
+			*res = true;
+			return 0;
+		case 'f':
+		case 'F':
+			*res = false;
+			return 0;
+		default:
+			break;
+		}
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(kstrtobool);
+
+/*
+ * Since "base" would be a nonsense argument, this open-codes the
+ * _from_user helper instead of using the helper macro below.
+ */
+int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
+{
+	/* Longest string needed to differentiate, newline, terminator */
+	char buf[4];
+
+	count = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, s, count))
+		return -EFAULT;
+	buf[count] = '\0';
+	return kstrtobool(buf, res);
+}
+EXPORT_SYMBOL_GPL(kstrtobool_from_user);
+
+/**
+ * match_string - matches given string in an array
+ * @array:	array of strings
+ * @n:		number of strings in the array or -1 for NULL terminated arrays
+ * @string:	string to match with
+ *
+ * Return:
+ * index of a @string in the @array if matches, or %-EINVAL otherwise.
+ */
+int match_string(const char * const *array, size_t n, const char *string)
+{
+	int index;
+	const char *item;
+
+	for (index = 0; index < n; index++) {
+		item = array[index];
+		if (!item)
+			break;
+		if (!strcmp(item, string))
+			return index;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(match_string);