Hi Marek,
On 3/8/25 9:12 PM, Marek Vasut wrote:
Fix the following conversion overflow errors. The input field is already
limited to 3/2/1 bits using the bitwise and, move the parenthesis around
to avoid the bogus warning:
"
fs/exfat/utf.c: In function ‘utf8_to_wchar’:
fs/exfat/utf.c:165:23: warning: overflow in conversion from ‘int’ to ‘wchar_t’ {aka
‘short unsigned int’} changes value from ‘(int)(short unsigned int)*input << 18
& 1835008’ to ‘0’ [-Woverflow]
165 | *wc = ((wchar_t) input[0] & 0x07) << 18;
| ^
fs/exfat/utf.c:170:23: warning: overflow in conversion from ‘int’ to ‘wchar_t’ {aka
‘short unsigned int’} changes value from ‘(int)(short unsigned int)*input << 24
& 50331648’ to ‘0’ [-Woverflow]
170 | *wc = ((wchar_t) input[0] & 0x03) << 24;
| ^
fs/exfat/utf.c:175:23: warning: overflow in conversion from ‘int’ to ‘wchar_t’ {aka
‘short unsigned int’} changes value from ‘(int)(short unsigned int)*input << 30
& 1073741824’ to ‘0’ [-Woverflow]
175 | *wc = ((wchar_t) input[0] & 0x01) << 30;
| ^
"
Since this doesn't seem to be U-Boot-specific, any chance to open a Pull
Request on the project so we may be able to not carry this patch when
upgrading (yes, the last commit in the branch was two years ago, but it
seems the maintainer is still active on issues).
Considering that wchar_t is an unsigned short int and that USHRT_MAX is
0xffff (so 2B or 16b)...
Signed-off-by: Marek Vasut <ma...@denx.de>
---
Cc: Baruch Siach <bar...@tkos.co.il>
Cc: Francesco Dolcini <francesco.dolc...@toradex.com>
Cc: Heinrich Schuchardt <xypron.g...@gmx.de>
Cc: Hiago De Franco <hiago.fra...@toradex.com>
Cc: Ilias Apalodimas <ilias.apalodi...@linaro.org>
Cc: Nam Cao <nam...@linutronix.de>
Cc: Simon Glass <s...@chromium.org>
Cc: Sughosh Ganu <sughosh.g...@linaro.org>
Cc: Tom Rini <tr...@konsulko.com>
Cc: u-boot@lists.denx.de
---
fs/exfat/utf.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/exfat/utf.c b/fs/exfat/utf.c
index b1d09e76478..5be8dcc2170 100644
--- a/fs/exfat/utf.c
+++ b/fs/exfat/utf.c
@@ -162,17 +162,17 @@ static const char* utf8_to_wchar(const char* input,
wchar_t* wc,
}
else if ((input[0] & 0xf8) == 0xf0)
{
- *wc = ((wchar_t) input[0] & 0x07) << 18;
+ *wc = (wchar_t)((input[0] & 0x07) << 18);
size = 4;
}
else if ((input[0] & 0xfc) == 0xf8)
{
- *wc = ((wchar_t) input[0] & 0x03) << 24;
+ *wc = (wchar_t)((input[0] & 0x03) << 24);
size = 5;
}
else if ((input[0] & 0xfe) == 0xfc)
{
- *wc = ((wchar_t) input[0] & 0x01) << 30;
+ *wc = (wchar_t)((input[0] & 0x01) << 30);
... wouldn't those still overflow? I assume unsigned short int like int
may have an architecture-dependent size, but seems to be at least 2B,
which wouldn't be enough to store all that?
Cheers,
Quentin
