diff options
author | Hans de Goede <hdegoede@redhat.com> | 2022-03-02 11:16:36 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-02 16:38:19 +0100 |
commit | 8f4347081be32e67b0873827e0138ab0fdaaf450 (patch) | |
tree | 1eaaed82bee3946266fc029a2104576b57e0703c /drivers/staging/rtl8723bs/core/rtw_xmit.c | |
parent | fc7f750dc9d102c1ed7bbe4591f991e770c99033 (diff) | |
download | linux-8f4347081be32e67b0873827e0138ab0fdaaf450.tar.bz2 |
staging: rtl8723bs: Fix access-point mode deadlock
Commit 54659ca026e5 ("staging: rtl8723bs: remove possible deadlock when
disconnect (v2)") split the locking of pxmitpriv->lock vs sleep_q/lock
into 2 locks in attempt to fix a lockdep reported issue with the locking
order of the sta_hash_lock vs pxmitpriv->lock.
But in the end this turned out to not fully solve the sta_hash_lock issue
so commit a7ac783c338b ("staging: rtl8723bs: remove a second possible
deadlock") was added to fix this in another way.
The original fix was kept as it was still seen as a good thing to have,
but now it turns out that it creates a deadlock in access-point mode:
[Feb20 23:47] ======================================================
[ +0.074085] WARNING: possible circular locking dependency detected
[ +0.074077] 5.16.0-1-amd64 #1 Tainted: G C E
[ +0.064710] ------------------------------------------------------
[ +0.074075] ksoftirqd/3/29 is trying to acquire lock:
[ +0.060542] ffffb8b30062ab00 (&pxmitpriv->lock){+.-.}-{2:2}, at: rtw_xmit_classifier+0x8a/0x140 [r8723bs]
[ +0.114921]
but task is already holding lock:
[ +0.069908] ffffb8b3007ab704 (&psta->sleep_q.lock){+.-.}-{2:2}, at: wakeup_sta_to_xmit+0x3b/0x300 [r8723bs]
[ +0.116976]
which lock already depends on the new lock.
[ +0.098037]
the existing dependency chain (in reverse order) is:
[ +0.089704]
-> #1 (&psta->sleep_q.lock){+.-.}-{2:2}:
[ +0.077232] _raw_spin_lock_bh+0x34/0x40
[ +0.053261] xmitframe_enqueue_for_sleeping_sta+0xc1/0x2f0 [r8723bs]
[ +0.082572] rtw_xmit+0x58b/0x940 [r8723bs]
[ +0.056528] _rtw_xmit_entry+0xba/0x350 [r8723bs]
[ +0.062755] dev_hard_start_xmit+0xf1/0x320
[ +0.056381] sch_direct_xmit+0x9e/0x360
[ +0.052212] __dev_queue_xmit+0xce4/0x1080
[ +0.055334] ip6_finish_output2+0x18f/0x6e0
[ +0.056378] ndisc_send_skb+0x2c8/0x870
[ +0.052209] ndisc_send_ns+0xd3/0x210
[ +0.050130] addrconf_dad_work+0x3df/0x5a0
[ +0.055338] process_one_work+0x274/0x5a0
[ +0.054296] worker_thread+0x52/0x3b0
[ +0.050124] kthread+0x16c/0x1a0
[ +0.044925] ret_from_fork+0x1f/0x30
[ +0.049092]
-> #0 (&pxmitpriv->lock){+.-.}-{2:2}:
[ +0.074101] __lock_acquire+0x10f5/0x1d80
[ +0.054298] lock_acquire+0xd7/0x300
[ +0.049088] _raw_spin_lock_bh+0x34/0x40
[ +0.053248] rtw_xmit_classifier+0x8a/0x140 [r8723bs]
[ +0.066949] rtw_xmitframe_enqueue+0xa/0x20 [r8723bs]
[ +0.066946] rtl8723bs_hal_xmitframe_enqueue+0x14/0x50 [r8723bs]
[ +0.078386] wakeup_sta_to_xmit+0xa6/0x300 [r8723bs]
[ +0.065903] rtw_recv_entry+0xe36/0x1160 [r8723bs]
[ +0.063809] rtl8723bs_recv_tasklet+0x349/0x6c0 [r8723bs]
[ +0.071093] tasklet_action_common.constprop.0+0xe5/0x110
[ +0.070966] __do_softirq+0x16f/0x50a
[ +0.050134] __irq_exit_rcu+0xeb/0x140
[ +0.051172] irq_exit_rcu+0xa/0x20
[ +0.047006] common_interrupt+0xb8/0xd0
[ +0.052214] asm_common_interrupt+0x1e/0x40
[ +0.056381] finish_task_switch.isra.0+0x100/0x3a0
[ +0.063670] __schedule+0x3ad/0xd20
[ +0.048047] schedule+0x4e/0xc0
[ +0.043880] smpboot_thread_fn+0xc4/0x220
[ +0.054298] kthread+0x16c/0x1a0
[ +0.044922] ret_from_fork+0x1f/0x30
[ +0.049088]
other info that might help us debug this:
[ +0.095950] Possible unsafe locking scenario:
[ +0.070952] CPU0 CPU1
[ +0.054282] ---- ----
[ +0.054285] lock(&psta->sleep_q.lock);
[ +0.047004] lock(&pxmitpriv->lock);
[ +0.074082] lock(&psta->sleep_q.lock);
[ +0.077209] lock(&pxmitpriv->lock);
[ +0.043873]
*** DEADLOCK ***
[ +0.070950] 1 lock held by ksoftirqd/3/29:
[ +0.049082] #0: ffffb8b3007ab704 (&psta->sleep_q.lock){+.-.}-{2:2}, at: wakeup_sta_to_xmit+0x3b/0x300 [r8723bs]
Analysis shows that in hindsight the splitting of the lock was not
a good idea, so revert this to fix the access-point mode deadlock.
Note this is a straight-forward revert done with git revert, the commented
out "/* spin_lock_bh(&psta_bmc->sleep_q.lock); */" lines were part of the
code before the reverted changes.
Fixes: 54659ca026e5 ("staging: rtl8723bs: remove possible deadlock when disconnect (v2)")
Cc: stable <stable@vger.kernel.org>
Cc: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215542
Link: https://lore.kernel.org/r/20220302101637.26542-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/rtl8723bs/core/rtw_xmit.c')
-rw-r--r-- | drivers/staging/rtl8723bs/core/rtw_xmit.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/staging/rtl8723bs/core/rtw_xmit.c b/drivers/staging/rtl8723bs/core/rtw_xmit.c index 13b8bd5ffabc..f466bfd248fb 100644 --- a/drivers/staging/rtl8723bs/core/rtw_xmit.c +++ b/drivers/staging/rtl8723bs/core/rtw_xmit.c @@ -1734,12 +1734,15 @@ void rtw_free_xmitframe_queue(struct xmit_priv *pxmitpriv, struct __queue *pfram struct list_head *plist, *phead, *tmp; struct xmit_frame *pxmitframe; + spin_lock_bh(&pframequeue->lock); + phead = get_list_head(pframequeue); list_for_each_safe(plist, tmp, phead) { pxmitframe = list_entry(plist, struct xmit_frame, list); rtw_free_xmitframe(pxmitpriv, pxmitframe); } + spin_unlock_bh(&pframequeue->lock); } s32 rtw_xmitframe_enqueue(struct adapter *padapter, struct xmit_frame *pxmitframe) @@ -1794,7 +1797,6 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe) struct sta_info *psta; struct tx_servq *ptxservq; struct pkt_attrib *pattrib = &pxmitframe->attrib; - struct xmit_priv *xmit_priv = &padapter->xmitpriv; struct hw_xmit *phwxmits = padapter->xmitpriv.hwxmits; signed int res = _SUCCESS; @@ -1812,14 +1814,12 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe) ptxservq = rtw_get_sta_pending(padapter, psta, pattrib->priority, (u8 *)(&ac_index)); - spin_lock_bh(&xmit_priv->lock); if (list_empty(&ptxservq->tx_pending)) list_add_tail(&ptxservq->tx_pending, get_list_head(phwxmits[ac_index].sta_queue)); list_add_tail(&pxmitframe->list, get_list_head(&ptxservq->sta_pending)); ptxservq->qcnt++; phwxmits[ac_index].accnt++; - spin_unlock_bh(&xmit_priv->lock); exit: @@ -2202,10 +2202,11 @@ void wakeup_sta_to_xmit(struct adapter *padapter, struct sta_info *psta) struct list_head *xmitframe_plist, *xmitframe_phead, *tmp; struct xmit_frame *pxmitframe = NULL; struct sta_priv *pstapriv = &padapter->stapriv; + struct xmit_priv *pxmitpriv = &padapter->xmitpriv; psta_bmc = rtw_get_bcmc_stainfo(padapter); - spin_lock_bh(&psta->sleep_q.lock); + spin_lock_bh(&pxmitpriv->lock); xmitframe_phead = get_list_head(&psta->sleep_q); list_for_each_safe(xmitframe_plist, tmp, xmitframe_phead) { @@ -2306,7 +2307,7 @@ void wakeup_sta_to_xmit(struct adapter *padapter, struct sta_info *psta) _exit: - spin_unlock_bh(&psta->sleep_q.lock); + spin_unlock_bh(&pxmitpriv->lock); if (update_mask) update_beacon(padapter, WLAN_EID_TIM, NULL, true); @@ -2318,8 +2319,9 @@ void xmit_delivery_enabled_frames(struct adapter *padapter, struct sta_info *pst struct list_head *xmitframe_plist, *xmitframe_phead, *tmp; struct xmit_frame *pxmitframe = NULL; struct sta_priv *pstapriv = &padapter->stapriv; + struct xmit_priv *pxmitpriv = &padapter->xmitpriv; - spin_lock_bh(&psta->sleep_q.lock); + spin_lock_bh(&pxmitpriv->lock); xmitframe_phead = get_list_head(&psta->sleep_q); list_for_each_safe(xmitframe_plist, tmp, xmitframe_phead) { @@ -2372,7 +2374,7 @@ void xmit_delivery_enabled_frames(struct adapter *padapter, struct sta_info *pst } } - spin_unlock_bh(&psta->sleep_q.lock); + spin_unlock_bh(&pxmitpriv->lock); } void enqueue_pending_xmitbuf(struct xmit_priv *pxmitpriv, struct xmit_buf *pxmitbuf) |