On Wed, Jan 19, 2011 at 9:58 AM, Shirish Pargaonkar
<shirishpargaonkar@xxxxxxxxx> wrote:
> On Tue, Jan 18, 2011 at 2:33 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>> Make sure we use get/put_unaligned routines when accessing wide
>> character strings.
>>
>> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
>> ---
>> fs/cifs/cifs_unicode.c | 49 ++++++++++++++++++++++++++---------------------
>> 1 files changed, 27 insertions(+), 22 deletions(-)
>>
>> diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
>> index 430f510..8134443 100644
>> --- a/fs/cifs/cifs_unicode.c
>> +++ b/fs/cifs/cifs_unicode.c
>> @@ -44,10 +44,14 @@ cifs_ucs2_bytes(const __le16 *from, int maxbytes,
>> int charlen, outlen = 0;
>> int maxwords = maxbytes / 2;
>> char tmp[NLS_MAX_CHARSET_SIZE];
>> + __u16 ftmp;
>>
>> - for (i = 0; i < maxwords && from[i]; i++) {
>> - charlen = codepage->uni2char(le16_to_cpu(from[i]), tmp,
>> - NLS_MAX_CHARSET_SIZE);
>> + for (i = 0; i < maxwords; i++) {
>> + ftmp = get_unaligned_le16(&from[i]);
>> + if (ftmp == 0)
>> + break;
>> +
>> + charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE);
>> if (charlen > 0)
>> outlen += charlen;
>> else
>> @@ -60,7 +64,7 @@ cifs_ucs2_bytes(const __le16 *from, int maxbytes,
>> /*
>> * cifs_mapchar - convert a little-endian char to proper char in codepage
>
> I think this wording is now incorrect since src_char is not le anymore.
>
>> * @target - where converted character should be copied
>> - * @src_char - 2 byte little-endian source character
>> + * @src_char - 2 byte host-endian source character
>> * @cp - codepage to which character should be converted
>> * @mapchar - should character be mapped according to mapchars mount option?
>> *
>> @@ -69,7 +73,7 @@ cifs_ucs2_bytes(const __le16 *from, int maxbytes,
>> * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
>> */
>> static int
>> -cifs_mapchar(char *target, const __le16 src_char, const struct nls_table *cp,
>> +cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp,
>> bool mapchar)
>> {
>> int len = 1;
>> @@ -82,7 +86,7 @@ cifs_mapchar(char *target, const __le16 src_char, const struct nls_table *cp,
>> * build_path_from_dentry are modified, as they use slash as
>> * separator.
>> */
>> - switch (le16_to_cpu(src_char)) {
>> + switch (src_char) {
>> case UNI_COLON:
>> *target = ':';
>> break;
>> @@ -109,8 +113,7 @@ out:
>> return len;
>>
>> cp_convert:
>> - len = cp->uni2char(le16_to_cpu(src_char), target,
>> - NLS_MAX_CHARSET_SIZE);
>> + len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
>> if (len <= 0) {
>> *target = '?';
>> len = 1;
>> @@ -149,6 +152,7 @@ cifs_from_ucs2(char *to, const __le16 *from, int tolen, int fromlen,
>> int nullsize = nls_nullsize(codepage);
>> int fromwords = fromlen / 2;
>> char tmp[NLS_MAX_CHARSET_SIZE];
>> + __u16 ftmp;
>>
>> /*
>> * because the chars can be of varying widths, we need to take care
>> @@ -158,19 +162,23 @@ cifs_from_ucs2(char *to, const __le16 *from, int tolen, int fromlen,
>> */
>> safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
>>
>> - for (i = 0; i < fromwords && from[i]; i++) {
>> + for (i = 0; i < fromwords; i++) {
>> + ftmp = get_unaligned_le16(&from[i]);
>> + if (ftmp == 0)
>> + break;
>> +
>
> Can the contents of from[i] be 0 so ftmp is 0 but we did
> not want to break out until fromwords?
>
Basically, why_does/what_it_means get_unaligned_le16()
returning 0 warrants breaking out of the loop!
>> /*
>> * check to see if converting this character might make the
>> * conversion bleed into the null terminator
>> */
>> if (outlen >= safelen) {
>> - charlen = cifs_mapchar(tmp, from[i], codepage, mapchar);
>> + charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar);
>> if ((outlen + charlen) > (tolen - nullsize))
>> break;
>> }
>>
>> /* put converted char into 'to' buffer */
>> - charlen = cifs_mapchar(&to[outlen], from[i], codepage, mapchar);
>> + charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar);
>> outlen += charlen;
>> }
>>
>> @@ -193,24 +201,21 @@ cifs_strtoUCS(__le16 *to, const char *from, int len,
>> {
>> int charlen;
>> int i;
>> - wchar_t *wchar_to = (wchar_t *)to; /* needed to quiet sparse */
>> + wchar_t wchar_to; /* needed to quiet sparse */
>>
>> for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
>> -
>> - /* works for 2.4.0 kernel or later */
>> - charlen = codepage->char2uni(from, len, &wchar_to[i]);
>> + charlen = codepage->char2uni(from, len, &wchar_to);
>> if (charlen < 1) {
>> - cERROR(1, "strtoUCS: char2uni of %d returned %d",
>> - (int)*from, charlen);
>> + cERROR(1, "strtoUCS: char2uni of 0x%x returned %d",
>> + *from, charlen);
>> /* A question mark */
>> - to[i] = cpu_to_le16(0x003f);
>> + wchar_to = 0x003f;
>> charlen = 1;
>> - } else
>> - to[i] = cpu_to_le16(wchar_to[i]);
>> -
>> + }
>> + put_unaligned_le16(wchar_to, &to[i]);
>> }
>>
>> - to[i] = 0;
>> + put_unaligned_le16(0, &to[i]);
>> return i;
>> }
>>
>> --
>> 1.7.3.4
>>
>> --
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>
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