[PATCH v4 1/4] lib/ucs2_string: Add UCS-2 strlcpy function

[Maximilian Luz <luzmaximilian@gmail.com>]

Add a ucs2_strlcpy() function for UCS-2 strings. The behavior is
equivalent to the standard strlcpy() function, just for 16-bit character
UCS-2 strings.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
---

Patch introduced in v4

---
 include/linux/ucs2_string.h |  1 +
 lib/ucs2_string.c           | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h
index cf3ada3e820e..ffd2a3ed84bb 100644
--- a/include/linux/ucs2_string.h
+++ b/include/linux/ucs2_string.h
@@ -10,6 +10,7 @@ typedef u16 ucs2_char_t;
 unsigned long ucs2_strnlen(const ucs2_char_t *s, size_t maxlength);
 unsigned long ucs2_strlen(const ucs2_char_t *s);
 unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength);
+unsigned long ucs2_strlcpy(ucs2_char_t *dst, const ucs2_char_t *src, unsigned long size);
 int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len);
 
 unsigned long ucs2_utf8size(const ucs2_char_t *src);
diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c
index 0a559a42359b..f474c6b2fe9e 100644
--- a/lib/ucs2_string.c
+++ b/lib/ucs2_string.c
@@ -32,6 +32,22 @@ ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength)
 }
 EXPORT_SYMBOL(ucs2_strsize);
 
+unsigned long
+ucs2_strlcpy(ucs2_char_t *dst, const ucs2_char_t *src, unsigned long size)
+{
+	unsigned long ret = ucs2_strlen(src);
+	unsigned long len;
+
+	if (size) {
+		len = (ret >= size) ? size - 1 : ret;
+		memcpy(dst, src, len * sizeof(*src));
+		dst[len] = 0;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(ucs2_strlcpy);
+
 int
 ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
 {
-- 
2.40.1