Re: [PATCH] wusb: use correct format characters

From: Greg KH
Date: Thu Feb 28 2019 - 06:59:22 EST


On Thu, Feb 28, 2019 at 11:52:56AM +0000, Louis Taylor wrote:
> When compiling with -Wformat, clang warns:
>
> ./include/linux/usb/wusb.h:245:5: warning: format specifies type
> 'unsigned short' but the argument has type 'u8' (aka 'unsigned char')
> [-Wformat]
> ckhdid->data[0], ckhdid->data[1],
> ^~~~~~~~~~~~~~~
>
> ckhdid->data is unconditionally defined as `u8 data[16]`, so this patch
> updates the format characters to the correct one for unsigned char types.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Signed-off-by: Louis Taylor <louis@xxxxxxxxxx>
> ---
> include/linux/usb/wusb.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/usb/wusb.h b/include/linux/usb/wusb.h
> index 9e4a3213f2c2..0a3cdf10972d 100644
> --- a/include/linux/usb/wusb.h
> +++ b/include/linux/usb/wusb.h
> @@ -240,8 +240,8 @@ static inline size_t ckhdid_printf(char *pr_ckhdid, size_t size,
> const struct wusb_ckhdid *ckhdid)
> {
> return scnprintf(pr_ckhdid, size,
> - "%02hx %02hx %02hx %02hx %02hx %02hx %02hx %02hx "
> - "%02hx %02hx %02hx %02hx %02hx %02hx %02hx %02hx",
> + "%02hhu %02hhu %02hhu %02hhu %02hhu %02hhu %02hhu %02hhu "
> + "%02hhu %02hhu %02hhu %02hhu %02hhu %02hhu %02hhu %02hhu",

Why did you switch from hex to decimal in the output format? That feels
very wrong to me.

greg k-h