Commit 8f434708 authored by Hans de Goede's avatar Hans de Goede Committed by Greg Kroah-Hartman
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staging: rtl8723bs: Fix access-point mode deadlock 



Commit 54659ca0 ("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 a7ac783c ("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: 54659ca0 ("staging: rtl8723bs: remove possible deadlock when disconnect (v2)")
Cc: stable <stable@vger.kernel.org>
Cc: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: default avatarHans 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: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fc7f750d

drivers/staging/rtl8723bs/core/rtw_mlme_ext.c

+5 −2
Original line number Diff line number Diff line
@@ -5907,6 +5907,7 @@ u8 chk_bmc_sleepq_hdl(struct adapter *padapter, unsigned char *pbuf) 
	struct sta_info *psta_bmc;

	struct list_head *xmitframe_plist, *xmitframe_phead, *tmp;

	struct xmit_frame *pxmitframe = NULL;

	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;

	struct sta_priv  *pstapriv = &padapter->stapriv;



	/* for BC/MC Frames */
@@ -5917,7 +5918,8 @@ u8 chk_bmc_sleepq_hdl(struct adapter *padapter, unsigned char *pbuf) 
	if ((pstapriv->tim_bitmap&BIT(0)) && (psta_bmc->sleepq_len > 0)) {

		msleep(10);/*  10ms, ATIM(HIQ) Windows */



		spin_lock_bh(&psta_bmc->sleep_q.lock);

		/* spin_lock_bh(&psta_bmc->sleep_q.lock); */

		spin_lock_bh(&pxmitpriv->lock);



		xmitframe_phead = get_list_head(&psta_bmc->sleep_q);

		list_for_each_safe(xmitframe_plist, tmp, xmitframe_phead) {
@@ -5940,7 +5942,8 @@ u8 chk_bmc_sleepq_hdl(struct adapter *padapter, unsigned char *pbuf) 
			rtw_hal_xmitframe_enqueue(padapter, pxmitframe);

		}



		spin_unlock_bh(&psta_bmc->sleep_q.lock);

		/* spin_unlock_bh(&psta_bmc->sleep_q.lock); */

		spin_unlock_bh(&pxmitpriv->lock);



		/* check hi queue and bmc_sleepq */

		rtw_chk_hi_queue_cmd(padapter);

drivers/staging/rtl8723bs/core/rtw_recv.c

+7 −3
Original line number Diff line number Diff line
@@ -957,8 +957,10 @@ static signed int validate_recv_ctrl_frame(struct adapter *padapter, union recv_ 
		if ((psta->state&WIFI_SLEEP_STATE) && (pstapriv->sta_dz_bitmap&BIT(psta->aid))) {

			struct list_head	*xmitframe_plist, *xmitframe_phead;

			struct xmit_frame *pxmitframe = NULL;

			struct xmit_priv *pxmitpriv = &padapter->xmitpriv;



			spin_lock_bh(&psta->sleep_q.lock);

			/* spin_lock_bh(&psta->sleep_q.lock); */

			spin_lock_bh(&pxmitpriv->lock);



			xmitframe_phead = get_list_head(&psta->sleep_q);

			xmitframe_plist = get_next(xmitframe_phead);
@@ -989,10 +991,12 @@ static signed int validate_recv_ctrl_frame(struct adapter *padapter, union recv_ 
					update_beacon(padapter, WLAN_EID_TIM, NULL, true);

				}



				spin_unlock_bh(&psta->sleep_q.lock);

				/* spin_unlock_bh(&psta->sleep_q.lock); */

				spin_unlock_bh(&pxmitpriv->lock);



			} else {

				spin_unlock_bh(&psta->sleep_q.lock);

				/* spin_unlock_bh(&psta->sleep_q.lock); */

				spin_unlock_bh(&pxmitpriv->lock);



				if (pstapriv->tim_bitmap&BIT(psta->aid)) {

					if (psta->sleepq_len == 0) {

drivers/staging/rtl8723bs/core/rtw_sta_mgt.c

+10 −12
Original line number Diff line number Diff line
@@ -293,48 +293,46 @@ u32 rtw_free_stainfo(struct adapter *padapter, struct sta_info *psta) 


	/* list_del_init(&psta->wakeup_list); */



	spin_lock_bh(&psta->sleep_q.lock);

	spin_lock_bh(&pxmitpriv->lock);



	rtw_free_xmitframe_queue(pxmitpriv, &psta->sleep_q);

	psta->sleepq_len = 0;

	spin_unlock_bh(&psta->sleep_q.lock);



	spin_lock_bh(&pxmitpriv->lock);



	/* vo */

	spin_lock_bh(&pstaxmitpriv->vo_q.sta_pending.lock);

	/* spin_lock_bh(&(pxmitpriv->vo_pending.lock)); */

	rtw_free_xmitframe_queue(pxmitpriv, &pstaxmitpriv->vo_q.sta_pending);

	list_del_init(&(pstaxmitpriv->vo_q.tx_pending));

	phwxmit = pxmitpriv->hwxmits;

	phwxmit->accnt -= pstaxmitpriv->vo_q.qcnt;

	pstaxmitpriv->vo_q.qcnt = 0;

	spin_unlock_bh(&pstaxmitpriv->vo_q.sta_pending.lock);

	/* spin_unlock_bh(&(pxmitpriv->vo_pending.lock)); */



	/* vi */

	spin_lock_bh(&pstaxmitpriv->vi_q.sta_pending.lock);

	/* spin_lock_bh(&(pxmitpriv->vi_pending.lock)); */

	rtw_free_xmitframe_queue(pxmitpriv, &pstaxmitpriv->vi_q.sta_pending);

	list_del_init(&(pstaxmitpriv->vi_q.tx_pending));

	phwxmit = pxmitpriv->hwxmits+1;

	phwxmit->accnt -= pstaxmitpriv->vi_q.qcnt;

	pstaxmitpriv->vi_q.qcnt = 0;

	spin_unlock_bh(&pstaxmitpriv->vi_q.sta_pending.lock);

	/* spin_unlock_bh(&(pxmitpriv->vi_pending.lock)); */



	/* be */

	spin_lock_bh(&pstaxmitpriv->be_q.sta_pending.lock);

	/* spin_lock_bh(&(pxmitpriv->be_pending.lock)); */

	rtw_free_xmitframe_queue(pxmitpriv, &pstaxmitpriv->be_q.sta_pending);

	list_del_init(&(pstaxmitpriv->be_q.tx_pending));

	phwxmit = pxmitpriv->hwxmits+2;

	phwxmit->accnt -= pstaxmitpriv->be_q.qcnt;

	pstaxmitpriv->be_q.qcnt = 0;

	spin_unlock_bh(&pstaxmitpriv->be_q.sta_pending.lock);

	/* spin_unlock_bh(&(pxmitpriv->be_pending.lock)); */



	/* bk */

	spin_lock_bh(&pstaxmitpriv->bk_q.sta_pending.lock);

	/* spin_lock_bh(&(pxmitpriv->bk_pending.lock)); */

	rtw_free_xmitframe_queue(pxmitpriv, &pstaxmitpriv->bk_q.sta_pending);

	list_del_init(&(pstaxmitpriv->bk_q.tx_pending));

	phwxmit = pxmitpriv->hwxmits+3;

	phwxmit->accnt -= pstaxmitpriv->bk_q.qcnt;

	pstaxmitpriv->bk_q.qcnt = 0;

	spin_unlock_bh(&pstaxmitpriv->bk_q.sta_pending.lock);

	/* spin_unlock_bh(&(pxmitpriv->bk_pending.lock)); */



	spin_unlock_bh(&pxmitpriv->lock);

drivers/staging/rtl8723bs/core/rtw_xmit.c

+9 −7
Original line number Diff line number Diff line
@@ -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)

drivers/staging/rtl8723bs/hal/rtl8723bs_xmit.c

+2 −0
Original line number Diff line number Diff line
@@ -502,7 +502,9 @@ s32 rtl8723bs_hal_xmit( 
			rtw_issue_addbareq_cmd(padapter, pxmitframe);

	}



	spin_lock_bh(&pxmitpriv->lock);

	err = rtw_xmitframe_enqueue(padapter, pxmitframe);

	spin_unlock_bh(&pxmitpriv->lock);

	if (err != _SUCCESS) {

		rtw_free_xmitframe(pxmitpriv, pxmitframe);