xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

NLS: improve UTF8 -> UTF16 string conversion routine

Browse Source 
The utf8s_to_utf16s conversion routine needs to be improved.  Unlike
its utf16s_to_utf8s sibling, it doesn't accept arguments specifying
the maximum length of the output buffer or the endianness of its
16-bit output.

This patch (as1501) adds the two missing arguments, and adjusts the
only two places in the kernel where the function is called.  A
follow-on patch will add a third caller that does utilize the new
capabilities.

The two conversion routines are still annoyingly inconsistent in the
way they handle invalid byte combinations.  But that's a subject for a
different patch.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
2011-11-17 16:42:19 -05:00
committed by Greg Kroah-Hartman
parent b7463c71fb
commit 0720a06a75
4 changed files with 48 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
fs/nls/nls_base.c
View File

@@ -114,34 +114,57 @@ int utf32_to_utf8(unicode_t u, u8 *s, int maxlen)
}
EXPORT_SYMBOL(utf32_to_utf8);
int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs)
static inline void put_utf16(wchar_t *s, unsigned c, enum utf16_endian endian)
{
switch (endian) {
default:
*s = (wchar_t) c;
break;
case UTF16_LITTLE_ENDIAN:
*s = __cpu_to_le16(c);
break;
case UTF16_BIG_ENDIAN:
*s = __cpu_to_be16(c);
break;
}
}
int utf8s_to_utf16s(const u8 *s, int len, enum utf16_endian endian,
wchar_t *pwcs, int maxlen)
{
u16 *op;
int size;
unicode_t u;
op = pwcs;
while (*s && len > 0) {
while (len > 0 && maxlen > 0 && *s) {
if (*s & 0x80) {
size = utf8_to_utf32(s, len, &u);
if (size < 0)
return -EINVAL;
if (u >= PLANE_SIZE) {
u -= PLANE_SIZE;
*op++ = (wchar_t) (SURROGATE_PAIR |
((u >> 10) & SURROGATE_BITS));
*op++ = (wchar_t) (SURROGATE_PAIR |
SURROGATE_LOW |
(u & SURROGATE_BITS));
} else {
*op++ = (wchar_t) u;
}
s += size;
len -= size;
if (u >= PLANE_SIZE) {
if (maxlen < 2)
break;
u -= PLANE_SIZE;
put_utf16(op++, SURROGATE_PAIR |
((u >> 10) & SURROGATE_BITS),
endian);
put_utf16(op++, SURROGATE_PAIR |
SURROGATE_LOW |
(u & SURROGATE_BITS),
endian);
maxlen -= 2;
} else {
put_utf16(op++, u, endian);
maxlen--;
}
} else {
*op++ = *s++;
put_utf16(op++, *s++, endian);
len--;
maxlen--;
}
}
return op - pwcs;