Re: [PATCH] staging: rtl8192e: use explicitly signed char

[Dan Carpenter <dan.carpenter@oracle.com>]

On Mon, Oct 24, 2022 at 06:30:05PM +0200, Jason A. Donenfeld wrote:
> With char becoming unsigned by default, and with `char` alone being
> ambiguous and based on architecture, signed chars need to be marked
> explicitly as such. In this case, passing `char *extra` is part of the
> iw API, and that extra is mostly intended to be somewhat opaque. So just
> cast to `s8 *` for the sign test. This fixes warnings like:
> 
> drivers/staging/rtl8192e/rtllib_softmac_wx.c:459 rtllib_wx_set_essid() warn: impossible condition '(extra[i] < 0) => (0-255 < 0)'
> 
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-staging@lists.linux.dev
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>  drivers/staging/rtl8192e/rtllib_softmac_wx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8192e/rtllib_softmac_wx.c b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> index f9589c5b62ba..4563e3b5bd47 100644
> --- a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> +++ b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> @@ -456,7 +456,7 @@ int rtllib_wx_set_essid(struct rtllib_device *ieee,
>  	}
>  
>  	for (i = 0; i < len; i++) {
> -		if (extra[i] < 0) {
> +		if (((s8 *)extra)[i] < 0) {

I agree with Linus that this if statement is nonsense and should just be
deleted.

regards,
dan carpenter

>  			ret = -1;
>  			goto out;
>  		}