NLS: update handling of Unicode

This patch (as1239) updates the kernel's treatment of Unicode.  The
character-set conversion routines are well behind the current state of
the Unicode specification: They don't recognize the existence of code
points beyond plane 0 or of surrogate pairs in the UTF-16 encoding.

The old wchar_t 16-bit type is retained because it's still used in
lots of places.  This shouldn't cause any new problems; if a
conversion now results in an invalid 16-bit code then before it must
have yielded an undefined code.

Difficult-to-read names like "utf_mbstowcs" are replaced with more
transparent names like "utf8s_to_utf16s" and the ordering of the
parameters is rationalized (buffer lengths come immediate after the
pointers they refer to, and the inputs precede the outputs).
Fortunately the low-level conversion routines are used in only a few
places; the interfaces to the higher-level uni2char and char2uni
methods have been left unchanged.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 7 deletions

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index e98f928c08ea..9bd26dec7599 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -780,14 +780,13 @@ int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
 {
         unsigned char *tbuf;
         int err;
-        unsigned int u;
 
         if (dev->state == USB_STATE_SUSPENDED)
                 return -EHOSTUNREACH;
         if (size <= 0 || !buf || !index)
                 return -EINVAL;
         buf[0] = 0;
-        tbuf = kmalloc(256 + 2, GFP_NOIO);
+        tbuf = kmalloc(256, GFP_NOIO);
         if (!tbuf)
                 return -ENOMEM;
 
@@ -814,12 +813,9 @@ int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
         if (err < 0)
                 goto errout;
 
-        for (u = 2; u < err; u += 2)
-                le16_to_cpus((u16 *)&tbuf[u]);
-        tbuf[u] = 0;
-        tbuf[u + 1] = 0;
         size--;         /* leave room for trailing NULL char in output buffer */
-        err = utf8_wcstombs(buf, (u16 *)&tbuf[2], size);
+        err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
+                        UTF16_LITTLE_ENDIAN, buf, size);
         buf[err] = 0;
 
         if (tbuf[1] != USB_DT_STRING)