[bug report] wifi: ath11k: fix peer addition/deletion error on sta band migration

[Christian Marangi]

On Thu, Feb 09, 2023 at 12:35:20PM +0300, Dan Carpenter wrote:
> Hello Christian Marangi,
> 
> The patch d673cb6fe6c0: "wifi: ath11k: fix peer addition/deletion
> error on sta band migration" from Sep 22, 2022, leads to the
> following Smatch static checker warning:
> 
> 	drivers/net/wireless/ath/ath11k/peer.c:396 ath11k_peer_create()
> 	warn: sleeping in atomic context
> 
> drivers/net/wireless/ath/ath11k/peer.c
>     370 int ath11k_peer_create(struct ath11k *ar, struct ath11k_vif *arvif,
>     371                        struct ieee80211_sta *sta, struct peer_create_params *param)
>     372 {
>     373         struct ath11k_peer *peer;
>     374         struct ath11k_sta *arsta;
>     375         int ret, fbret;
>     376 
>     377         lockdep_assert_held(&ar->conf_mutex);
>     378 
>     379         if (ar->num_peers > (ar->max_num_peers - 1)) {
>     380                 ath11k_warn(ar->ab,
>     381                             "failed to create peer due to insufficient peer entry resource in firmware\n");
>     382                 return -ENOBUFS;
>     383         }
>     384 
>     385         spin_lock_bh(&ar->ab->base_lock);
>                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Holding a spin lock.
> 
>     386         peer = ath11k_peer_find_by_addr(ar->ab, param->peer_addr);
>     387         if (peer) {
>     388                 if (peer->vdev_id == param->vdev_id) {
>     389                         spin_unlock_bh(&ar->ab->base_lock);
>     390                         return -EINVAL;
>     391                 }
>     392 
>     393                 /* Assume sta is transitioning to another band.
>     394                  * Remove here the peer from rhash.
>     395                  */
> --> 396                 mutex_lock(&ar->ab->tbl_mtx_lock);
>                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> So we can't take a mutex.
> 
>     397                 ath11k_peer_rhash_delete(ar->ab, peer);
>     398                 mutex_unlock(&ar->ab->tbl_mtx_lock);
>     399         }
>     400         spin_unlock_bh(&ar->ab->base_lock);
>     401 
>     402         ret = ath11k_wmi_send_peer_create_cmd(ar, param);

Hi,
thanks for the report. I send a patch to ath mailing list that should
fix this bug!

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