Variables being modified but not used in net/wireless/lib80211_crypt_tkip.c

[Colin King (gmail)]

Hi,

I was reviewing some clang scan build static analysis results and found 
an interesting warning:

Source: net/wireless/lib80211_crypt_tkip.c

net/wireless/lib80211_crypt_tkip.c:667:7: warning: variable 'iv32' set 
but not used [-Wunused-but-set-variable]
                u32 iv32 = tkey->tx_iv32;

The variables iv32 and iv16 are being decremented, but are not 
referenced after that. The seq[] array is being updated with the 
pre-decremented values. Is that correct?

        if (seq) {
                /* Return the sequence number of the last transmitted 
frame. */
                u16 iv16 = tkey->tx_iv16;
                u32 iv32 = tkey->tx_iv32;
                if (iv16 == 0)
                        iv32--;
                iv16--;
                seq[0] = tkey->tx_iv16;
                seq[1] = tkey->tx_iv16 >> 8;
                seq[2] = tkey->tx_iv32;
                seq[3] = tkey->tx_iv32 >> 8;
                seq[4] = tkey->tx_iv32 >> 16;
                seq[5] = tkey->tx_iv32 >> 24;
        }

        return TKIP_KEY_LEN;

Colin