Hello Toke,
On Sat, 2 Apr 2022 14:27:51 +0200, Toke Høiland-Jørgensen <toke@xxxxxxx> wrote:
> From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
>
> The ieee80211_tx_info_clear_status() helper also clears the rate counts, so
> we should restore them after clearing. However, we can get rid of the
> existing clearing of the counts of invalid rates. Rearrange the code a bit
> so the order fits the indexes, and so the setting of the count to
> hw->max_rate_tries on underrun is not immediately overridden.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Peter Seiderer <ps.report@xxxxxxx>
> Fixes: 037250f0a45c ("ath9k: Properly clear TX status area before reporting to mac80211")
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> ---
> drivers/net/wireless/ath/ath9k/xmit.c | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
> index cbcf96ac303e..ac7efecff29c 100644
> --- a/drivers/net/wireless/ath/ath9k/xmit.c
> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
> @@ -2551,16 +2551,19 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
> struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
> struct ieee80211_hw *hw = sc->hw;
> struct ath_hw *ah = sc->sc_ah;
> - u8 i, tx_rateindex;
> + u8 i, tx_rateindex, tries[IEEE80211_TX_MAX_RATES];
> +
> + tx_rateindex = ts->ts_rateindex;
> + WARN_ON(tx_rateindex >= hw->max_rates);
> +
> + for (i = 0; i < tx_rateindex; i++)
> + tries[i] = tx_info->status.rates[i].count;
>
> ieee80211_tx_info_clear_status(tx_info);
>
> if (txok)
> tx_info->status.ack_signal = ts->ts_rssi;
>
> - tx_rateindex = ts->ts_rateindex;
> - WARN_ON(tx_rateindex >= hw->max_rates);
> -
> if (tx_info->flags & IEEE80211_TX_CTL_AMPDU) {
> tx_info->flags |= IEEE80211_TX_STAT_AMPDU;
>
> @@ -2569,6 +2572,14 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
> tx_info->status.ampdu_len = nframes;
> tx_info->status.ampdu_ack_len = nframes - nbad;
>
> + for (i = 0; i < tx_rateindex; i++)
> + tx_info->status.rates[i].count = tries[i];
> +
> + tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
> +
> + for (i = tx_rateindex + 1; i < hw->max_rates; i++)
> + tx_info->status.rates[i].idx = -1;
> +
> if ((ts->ts_status & ATH9K_TXERR_FILT) == 0 &&
> (tx_info->flags & IEEE80211_TX_CTL_NO_ACK) == 0) {
> /*
> @@ -2591,12 +2602,6 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
> hw->max_rate_tries;
> }
The full lines above read:
2597 if (unlikely(ts->ts_flags & (ATH9K_TX_DATA_UNDERRUN |
2598 ATH9K_TX_DELIM_UNDERRUN)) &&
2599 ieee80211_is_data(hdr->frame_control) &&
2600 ah->tx_trig_level >= sc->sc_ah->config.max_txtrig_level )
2601 tx_info->status.rates[tx_rateindex].count =
2602 hw->max_rate_tries;
2603 }
So this patch fixes by drive-by a overwrite of tx_info->status.rates[tx_rateindex].count...
>
> - for (i = tx_rateindex + 1; i < hw->max_rates; i++) {
> - tx_info->status.rates[i].count = 0;
> - tx_info->status.rates[i].idx = -1;
> - }
> -
> - tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
> }
>
> static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
Otherwise looks good ;-), would like to give a Reviewed-by/Tested-by but still
affected by the underlying ieee80211_tx_info status vs. rate_driver_data overwrite
as mentioned in the other thread (see [1])...
Regards,
Peter
[1] https://lore.kernel.org/linux-wireless/20220404130453.5ec6e045@xxxxxxx/
