From: Hans de Goede hdegoede@redhat.com
[ Upstream commit a7ac783c338bafc04d3259600646350dba989043 ]
Lockdep complains about rtw_free_assoc_resources() taking the sta_hash_lock followed by it calling rtw_free_stainfo() which takes xmitpriv->lock. While the rtl8723bs_xmit_thread takes the sta_hash_lock while already holding the xmitpriv->lock:
[ 103.849756] ====================================================== [ 103.849761] WARNING: possible circular locking dependency detected [ 103.849767] 5.15.0-rc1+ #470 Tainted: G C E [ 103.849773] ------------------------------------------------------ [ 103.849776] wpa_supplicant/695 is trying to acquire lock: [ 103.849781] ffffa5d0c0562b00 (&pxmitpriv->lock){+.-.}-{2:2}, at: rtw_free_stainfo+0x8a/0x510 [r8723bs] [ 103.849840] but task is already holding lock: [ 103.849843] ffffa5d0c05636a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 103.849881] which lock already depends on the new lock.
[ 103.849884] the existing dependency chain (in reverse order) is: [ 103.849887] -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}: [ 103.849898] _raw_spin_lock_bh+0x34/0x40 [ 103.849913] rtw_get_stainfo+0x93/0x110 [r8723bs] [ 103.849948] rtw_make_wlanhdr+0x14a/0x270 [r8723bs] [ 103.849983] rtw_xmitframe_coalesce+0x5c/0x6c0 [r8723bs] [ 103.850019] rtl8723bs_xmit_thread+0x4ac/0x620 [r8723bs] [ 103.850050] kthread+0x143/0x160 [ 103.850058] ret_from_fork+0x22/0x30 [ 103.850067] -> #0 (&pxmitpriv->lock){+.-.}-{2:2}: [ 103.850077] __lock_acquire+0x1158/0x1de0 [ 103.850084] lock_acquire+0xb5/0x2b0 [ 103.850090] _raw_spin_lock_bh+0x34/0x40 [ 103.850095] rtw_free_stainfo+0x8a/0x510 [r8723bs] [ 103.850130] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 103.850159] PHY_IQCalibrate_8723B+0x122b/0x36a0 [r8723bs] [ 103.850189] cfg80211_disconnect+0x173/0x320 [cfg80211] [ 103.850331] nl80211_disconnect+0x6e/0xb0 [cfg80211] [ 103.850422] genl_family_rcv_msg_doit+0xcd/0x110 [ 103.850430] genl_rcv_msg+0xce/0x1c0 [ 103.850435] netlink_rcv_skb+0x50/0xf0 [ 103.850441] genl_rcv+0x24/0x40 [ 103.850446] netlink_unicast+0x16d/0x230 [ 103.850452] netlink_sendmsg+0x22b/0x450 [ 103.850457] sock_sendmsg+0x5e/0x60 [ 103.850465] ____sys_sendmsg+0x22f/0x270 [ 103.850472] ___sys_sendmsg+0x81/0xc0 [ 103.850479] __sys_sendmsg+0x49/0x80 [ 103.850485] do_syscall_64+0x3b/0x90 [ 103.850493] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 103.850500] other info that might help us debug this:
[ 103.850504] Possible unsafe locking scenario:
[ 103.850507] CPU0 CPU1 [ 103.850510] ---- ---- [ 103.850512] lock(&pstapriv->sta_hash_lock); [ 103.850518] lock(&pxmitpriv->lock); [ 103.850524] lock(&pstapriv->sta_hash_lock); [ 103.850530] lock(&pxmitpriv->lock); [ 103.850535] *** DEADLOCK ***
Push the taking of sta_hash_lock down into rtw_free_stainfo(), where the critical section is, this allows taking the lock after rtw_free_stainfo() has released pxmitpriv->lock.
This requires changing rtw_free_all_stainfo() so that it does its freeing in 2 steps, first moving all stainfo-s to free to a local list while holding the sta_hash_lock and then walking that list to call rtw_free_stainfo() on them without holding the sta_hash_lock.
Pushing the taking of sta_hash_lock down into rtw_free_stainfo(), also fixes a whole bunch of callers of rtw_free_stainfo() which were not holding that lock even though they should.
Note that this also fixes the deadlock from the "remove possible deadlock when disconnect" patch in a different way. But the changes from that patch offer a nice locking cleanup regardless.
Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20210920145502.155454-2-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/staging/rtl8723bs/core/rtw_mlme.c | 5 ----- drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 4 ---- drivers/staging/rtl8723bs/core/rtw_sta_mgt.c | 11 +++++++++-- drivers/staging/rtl8723bs/os_dep/ioctl_linux.c | 2 -- 4 files changed, 9 insertions(+), 13 deletions(-)
diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme.c b/drivers/staging/rtl8723bs/core/rtw_mlme.c index ab6a24d70cc96..1f49c49e10b45 100644 --- a/drivers/staging/rtl8723bs/core/rtw_mlme.c +++ b/drivers/staging/rtl8723bs/core/rtw_mlme.c @@ -897,7 +897,6 @@ void rtw_free_assoc_resources(struct adapter *adapter, int lock_scanned_queue) { struct mlme_priv *pmlmepriv = &adapter->mlmepriv; struct wlan_network *tgt_network = &pmlmepriv->cur_network; - struct sta_priv *pstapriv = &adapter->stapriv; struct dvobj_priv *psdpriv = adapter->dvobj; struct debug_priv *pdbgpriv = &psdpriv->drv_dbg;
@@ -905,11 +904,7 @@ void rtw_free_assoc_resources(struct adapter *adapter, int lock_scanned_queue) struct sta_info *psta;
psta = rtw_get_stainfo(&adapter->stapriv, tgt_network->network.mac_address); - spin_lock_bh(&(pstapriv->sta_hash_lock)); rtw_free_stainfo(adapter, psta); - - spin_unlock_bh(&(pstapriv->sta_hash_lock)); - }
if (check_fwstate(pmlmepriv, WIFI_ADHOC_STATE|WIFI_ADHOC_MASTER_STATE|WIFI_AP_STATE)) { diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c index a1ae16ec69eb6..ad9c237054c4b 100644 --- a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c +++ b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c @@ -1489,9 +1489,7 @@ unsigned int OnDeAuth(struct adapter *padapter, union recv_frame *precv_frame) struct sta_info *psta; struct sta_priv *pstapriv = &padapter->stapriv;
- /* spin_lock_bh(&(pstapriv->sta_hash_lock)); */ /* rtw_free_stainfo(padapter, psta); */ - /* spin_unlock_bh(&(pstapriv->sta_hash_lock)); */
netdev_dbg(padapter->pnetdev, "ap recv deauth reason code(%d) sta:%pM\n", reason, @@ -1565,9 +1563,7 @@ unsigned int OnDisassoc(struct adapter *padapter, union recv_frame *precv_frame) struct sta_info *psta; struct sta_priv *pstapriv = &padapter->stapriv;
- /* spin_lock_bh(&(pstapriv->sta_hash_lock)); */ /* rtw_free_stainfo(padapter, psta); */ - /* spin_unlock_bh(&(pstapriv->sta_hash_lock)); */
netdev_dbg(padapter->pnetdev, "ap recv disassoc reason code(%d) sta:%pM\n", diff --git a/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c b/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c index c23d0c833ecf8..3d269842677dd 100644 --- a/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c +++ b/drivers/staging/rtl8723bs/core/rtw_sta_mgt.c @@ -263,7 +263,6 @@ exit: return psta; }
-/* using pstapriv->sta_hash_lock to protect */ u32 rtw_free_stainfo(struct adapter *padapter, struct sta_info *psta) { int i; @@ -334,8 +333,10 @@ u32 rtw_free_stainfo(struct adapter *padapter, struct sta_info *psta)
spin_unlock_bh(&pxmitpriv->lock);
+ spin_lock_bh(&pstapriv->sta_hash_lock); list_del_init(&psta->hash_list); pstapriv->asoc_sta_count--; + spin_unlock_bh(&pstapriv->sta_hash_lock);
/* re-init sta_info; 20061114 will be init in alloc_stainfo */ /* _rtw_init_sta_xmit_priv(&psta->sta_xmitpriv); */ @@ -430,6 +431,7 @@ void rtw_free_all_stainfo(struct adapter *padapter) struct sta_info *psta = NULL; struct sta_priv *pstapriv = &padapter->stapriv; struct sta_info *pbcmc_stainfo = rtw_get_bcmc_stainfo(padapter); + LIST_HEAD(stainfo_free_list);
if (pstapriv->asoc_sta_count == 1) return; @@ -442,11 +444,16 @@ void rtw_free_all_stainfo(struct adapter *padapter) psta = list_entry(plist, struct sta_info, hash_list);
if (pbcmc_stainfo != psta) - rtw_free_stainfo(padapter, psta); + list_move(&psta->hash_list, &stainfo_free_list); } }
spin_unlock_bh(&pstapriv->sta_hash_lock); + + list_for_each_safe(plist, tmp, &stainfo_free_list) { + psta = list_entry(plist, struct sta_info, hash_list); + rtw_free_stainfo(padapter, psta); + } }
/* any station allocated can be searched by hash list */ diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c index 9d4a233a861e3..295121c268bd4 100644 --- a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c @@ -835,9 +835,7 @@ static int rtw_add_sta(struct net_device *dev, struct ieee_param *param) psta = rtw_get_stainfo(pstapriv, param->sta_addr); if (psta) { - spin_lock_bh(&(pstapriv->sta_hash_lock)); rtw_free_stainfo(padapter, psta); - spin_unlock_bh(&(pstapriv->sta_hash_lock));
psta = NULL; }