Do a strlcat() to go with the strlcpy().

include/linux/string.h

@@ -37,6 +37,9 @@ extern char * strcat(char *, const char *);
 #ifndef __HAVE_ARCH_STRNCAT
 extern char * strncat(char *, const char *, __kernel_size_t);
 #endif
+#ifndef __HAVE_ARCH_STRLCAT
+extern size_t strlcat(char *, const char *, __kernel_size_t);
+#endif
 #ifndef __HAVE_ARCH_STRCMP
 extern int strcmp(const char *,const char *);
 #endif

lib/string.c

@@ -169,6 +169,33 @@ char * strncat(char *dest, const char *src, size_t count)
 }
 #endif
 
+#ifndef __HAVE_ARCH_STRLCAT
+/**
+ * strlcat - Append a length-limited, %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ * @count: The size of the destination buffer.
+ */
+size_t strlcat(char *dest, const char *src, size_t count)
+{
+	size_t dsize = strlen(dest);
+	size_t len = strlen(src);
+	size_t res = dsize + len;
+
+	/* This would be a bug */
+	BUG_ON(dsize >= count);
+
+	dest += dsize;
+	count -= dsize;
+	if (len >= count)
+		len = count-1;
+	memcpy(dest, src, len);
+	dest[len] = 0;
+	return res;
+}
+EXPORT_SYMBOL(strlcat);
+#endif
+
 #ifndef __HAVE_ARCH_STRCMP
 /**
  * strcmp - Compare two strings