[bug report] wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices

[Dan Carpenter <error27@gmail.com>]

Hello Kalle Valo,

The patch d889913205cf: "wifi: ath12k: driver for Qualcomm Wi-Fi 7
devices" from Nov 28, 2022, leads to the following Smatch static
checker warning:

drivers/net/wireless/ath/ath12k/dp_rx.c:3254 ath12k_dp_rx_frag_h_mpdu() warn: missing error code here? 'ath12k_peer_find_by_id()' failed. 'ret' = '0'
drivers/net/wireless/ath/ath12k/dp_rx.c:3260 ath12k_dp_rx_frag_h_mpdu() warn: missing error code here? 'ath12k_dp_rx_h_defrag()' failed. 'ret' = '0'
drivers/net/wireless/ath/ath12k/dp_rx.c:3266 ath12k_dp_rx_frag_h_mpdu() warn: missing error code here? 'ath12k_dp_rx_h_defrag_reo_reinject()' failed. 'ret' = '0'

drivers/net/wireless/ath/ath12k/dp_rx.c
    3161 static int ath12k_dp_rx_frag_h_mpdu(struct ath12k *ar,
    3162                                     struct sk_buff *msdu,
    3163                                     struct hal_reo_dest_ring *ring_desc)
    3164 {
    3165         struct ath12k_base *ab = ar->ab;
    3166         struct hal_rx_desc *rx_desc;
    3167         struct ath12k_peer *peer;
    3168         struct ath12k_dp_rx_tid *rx_tid;
    3169         struct sk_buff *defrag_skb = NULL;
    3170         u32 peer_id;
    3171         u16 seqno, frag_no;
    3172         u8 tid;
    3173         int ret = 0;
    3174         bool more_frags;
    3175 
    3176         rx_desc = (struct hal_rx_desc *)msdu->data;
    3177         peer_id = ath12k_dp_rx_h_peer_id(ab, rx_desc);
    3178         tid = ath12k_dp_rx_h_tid(ab, rx_desc);
    3179         seqno = ath12k_dp_rx_h_seq_no(ab, rx_desc);
    3180         frag_no = ath12k_dp_rx_h_frag_no(ab, msdu);
    3181         more_frags = ath12k_dp_rx_h_more_frags(ab, msdu);
    3182 
    3183         if (!ath12k_dp_rx_h_seq_ctrl_valid(ab, rx_desc) ||
    3184             !ath12k_dp_rx_h_fc_valid(ab, rx_desc) ||
    3185             tid > IEEE80211_NUM_TIDS)
    3186                 return -EINVAL;
    3187 
    3188         /* received unfragmented packet in reo
    3189          * exception ring, this shouldn't happen
    3190          * as these packets typically come from
    3191          * reo2sw srngs.
    3192          */
    3193         if (WARN_ON_ONCE(!frag_no && !more_frags))
    3194                 return -EINVAL;
    3195 
    3196         spin_lock_bh(&ab->base_lock);
    3197         peer = ath12k_peer_find_by_id(ab, peer_id);
    3198         if (!peer) {
    3199                 ath12k_warn(ab, "failed to find the peer to de-fragment received fragment peer_id %d\n",
    3200                             peer_id);
    3201                 ret = -ENOENT;
    3202                 goto out_unlock;
    3203         }
    3204         rx_tid = &peer->rx_tid[tid];
    3205 
    3206         if ((!skb_queue_empty(&rx_tid->rx_frags) && seqno != rx_tid->cur_sn) ||
    3207             skb_queue_empty(&rx_tid->rx_frags)) {
    3208                 /* Flush stored fragments and start a new sequence */
    3209                 ath12k_dp_rx_frags_cleanup(rx_tid, true);
    3210                 rx_tid->cur_sn = seqno;
    3211         }
    3212 
    3213         if (rx_tid->rx_frag_bitmap & BIT(frag_no)) {
    3214                 /* Fragment already present */
    3215                 ret = -EINVAL;
    3216                 goto out_unlock;
    3217         }
    3218 
    3219         if (frag_no > __fls(rx_tid->rx_frag_bitmap))
    3220                 __skb_queue_tail(&rx_tid->rx_frags, msdu);
    3221         else
    3222                 ath12k_dp_rx_h_sort_frags(ab, &rx_tid->rx_frags, msdu);
    3223 
    3224         rx_tid->rx_frag_bitmap |= BIT(frag_no);
    3225         if (!more_frags)
    3226                 rx_tid->last_frag_no = frag_no;
    3227 
    3228         if (frag_no == 0) {
    3229                 rx_tid->dst_ring_desc = kmemdup(ring_desc,
    3230                                                 sizeof(*rx_tid->dst_ring_desc),
    3231                                                 GFP_ATOMIC);
    3232                 if (!rx_tid->dst_ring_desc) {
    3233                         ret = -ENOMEM;
    3234                         goto out_unlock;
    3235                 }
    3236         } else {
    3237                 ath12k_dp_rx_link_desc_return(ab, ring_desc,
    3238                                               HAL_WBM_REL_BM_ACT_PUT_IN_IDLE);
    3239         }
    3240 
    3241         if (!rx_tid->last_frag_no ||
    3242             rx_tid->rx_frag_bitmap != GENMASK(rx_tid->last_frag_no, 0)) {
    3243                 mod_timer(&rx_tid->frag_timer, jiffies +
    3244                                                ATH12K_DP_RX_FRAGMENT_TIMEOUT_MS);

error code?

    3245                 goto out_unlock;
    3246         }
    3247 
    3248         spin_unlock_bh(&ab->base_lock);
    3249         del_timer_sync(&rx_tid->frag_timer);
    3250         spin_lock_bh(&ab->base_lock);
    3251 
    3252         peer = ath12k_peer_find_by_id(ab, peer_id);
    3253         if (!peer)
--> 3254                 goto err_frags_cleanup;

here?

    3255 
    3256         if (!ath12k_dp_rx_h_defrag_validate_incr_pn(ar, rx_tid))
    3257                 goto err_frags_cleanup;

This definitely looks like an error path.  Similar warning
in ath12k_reg_chan_list_event().

drivers/net/wireless/ath/ath12k/wmi.c:5195 ath12k_reg_chan_list_event() warn: missing error code here? 'ath12k_reg_build_regd()' failed. 'ret' = '0'

    3258 
    3259         if (ath12k_dp_rx_h_defrag(ar, peer, rx_tid, &defrag_skb))
    3260                 goto err_frags_cleanup;
    3261 
    3262         if (!defrag_skb)
    3263                 goto err_frags_cleanup;
    3264 
    3265         if (ath12k_dp_rx_h_defrag_reo_reinject(ar, rx_tid, defrag_skb))
    3266                 goto err_frags_cleanup;
    3267 
    3268         ath12k_dp_rx_frags_cleanup(rx_tid, false);
    3269         goto out_unlock;
    3270 
    3271 err_frags_cleanup:
    3272         dev_kfree_skb_any(defrag_skb);
    3273         ath12k_dp_rx_frags_cleanup(rx_tid, true);
    3274 out_unlock:
    3275         spin_unlock_bh(&ab->base_lock);
    3276         return ret;
    3277 }

regards,
dan carpenter

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