linux.git/drivers/staging/rtl8723bs/hal, branch v5.17 Linux kernel source tree staging: rtl8723bs: Fix access-point mode deadlock 2022-03-02T15:38:19+00:00 Hans de Goede hdegoede@redhat.com 2022-03-02T10:16:36+00:00 8f4347081be32e67b0873827e0138ab0fdaaf450 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> 
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>
staging: rtl8723bs: removed unused if blocks 2021-12-28T16:08:07+00:00 Ismayil Mirzali ismayilmirzeli@gmail.com 2021-12-22T18:51:15+00:00 b846c0bd43f29225d385972b5ee2b47c74b75d64 Deleted the commented if blocks that weren't being used as suggested by the maintainers. Signed-off-by: Ismayil Mirzali <ismayilmirzeli@gmail.com> Link: https://lore.kernel.org/r/b4652b7490f3574445d567ef662270605533bfa4.1640197297.git.ismayilmirzeli@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Deleted the commented if blocks that weren't being used as suggested by
the maintainers.

Signed-off-by: Ismayil Mirzali <ismayilmirzeli@gmail.com>
Link: https://lore.kernel.org/r/b4652b7490f3574445d567ef662270605533bfa4.1640197297.git.ismayilmirzeli@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-11T00:15:54+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-11-11T00:15:54+00:00 5147da902e0dd162c6254a61e4c57f21b60a9b1c Pull exit cleanups from Eric Biederman: "While looking at some issues related to the exit path in the kernel I found several instances where the code is not using the existing abstractions properly. This set of changes introduces force_fatal_sig a way of sending a signal and not allowing it to be caught, and corrects the misuse of the existing abstractions that I found. A lot of the misuse of the existing abstractions are silly things such as doing something after calling a no return function, rolling BUG by hand, doing more work than necessary to terminate a kernel thread, or calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL). In the review a deficiency in force_fatal_sig and force_sig_seccomp where ptrace or sigaction could prevent the delivery of the signal was found. I have added a change that adds SA_IMMUTABLE to change that makes it impossible to interrupt the delivery of those signals, and allows backporting to fix force_sig_seccomp And Arnd found an issue where a function passed to kthread_run had the wrong prototype, and after my cleanup was failing to build." * 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits) soc: ti: fix wkup_m3_rproc_boot_thread return type signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV) exit/r8188eu: Replace the macro thread_exit with a simple return 0 exit/rtl8712: Replace the macro thread_exit with a simple return 0 exit/rtl8723bs: Replace the macro thread_exit with a simple return 0 signal/x86: In emulate_vsyscall force a signal instead of calling do_exit signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails exit/syscall_user_dispatch: Send ordinary signals on failure signal: Implement force_fatal_sig exit/kthread: Have kernel threads return instead of calling do_exit signal/s390: Use force_sigsegv in default_trap_handler signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved. signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON signal/sparc: In setup_tsb_params convert open coded BUG into BUG signal/powerpc: On swapcontext failure force SIGSEGV signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT signal/sparc32: Remove unreachable do_exit in do_sparc_fault ... 
Pull exit cleanups from Eric Biederman:
 "While looking at some issues related to the exit path in the kernel I
  found several instances where the code is not using the existing
  abstractions properly.

  This set of changes introduces force_fatal_sig a way of sending a
  signal and not allowing it to be caught, and corrects the misuse of
  the existing abstractions that I found.

  A lot of the misuse of the existing abstractions are silly things such
  as doing something after calling a no return function, rolling BUG by
  hand, doing more work than necessary to terminate a kernel thread, or
  calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL).

  In the review a deficiency in force_fatal_sig and force_sig_seccomp
  where ptrace or sigaction could prevent the delivery of the signal was
  found. I have added a change that adds SA_IMMUTABLE to change that
  makes it impossible to interrupt the delivery of those signals, and
  allows backporting to fix force_sig_seccomp

  And Arnd found an issue where a function passed to kthread_run had the
  wrong prototype, and after my cleanup was failing to build."

* 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits)
  soc: ti: fix wkup_m3_rproc_boot_thread return type
  signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed
  signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV)
  exit/r8188eu: Replace the macro thread_exit with a simple return 0
  exit/rtl8712: Replace the macro thread_exit with a simple return 0
  exit/rtl8723bs: Replace the macro thread_exit with a simple return 0
  signal/x86: In emulate_vsyscall force a signal instead of calling do_exit
  signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig
  signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails
  exit/syscall_user_dispatch: Send ordinary signals on failure
  signal: Implement force_fatal_sig
  exit/kthread: Have kernel threads return instead of calling do_exit
  signal/s390: Use force_sigsegv in default_trap_handler
  signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.
  signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON
  signal/sparc: In setup_tsb_params convert open coded BUG into BUG
  signal/powerpc: On swapcontext failure force SIGSEGV
  signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL)
  signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT
  signal/sparc32: Remove unreachable do_exit in do_sparc_fault
  ...
staging: rtl8723bs: hal remove the assignment to itself 2021-10-30T09:14:53+00:00 Saurav Girepunje saurav.girepunje@gmail.com 2021-10-28T04:45:13+00:00 cacd73e55e77f6d290d827eaf23e9bf28ed20836 Remove the assignment of variable to itself. Assigning the variable to itself not make any difference on value. Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com> Link: https://lore.kernel.org/r/YXoq2ViLxPVwAgLq@Sauravs-MacBook-Air.local Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Remove the assignment of variable to itself.
Assigning the variable to itself not make any difference on value.

Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Link: https://lore.kernel.org/r/YXoq2ViLxPVwAgLq@Sauravs-MacBook-Air.local
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
exit/rtl8723bs: Replace the macro thread_exit with a simple return 0 2021-10-29T19:31:34+00:00 Eric W. Biederman ebiederm@xmission.com 2021-10-20T17:44:04+00:00 501c88722797a1923145658cce85fb3661121832 Every place thread_exit is called is at the end of a function started with kthread_run. The code in kthread_run has arranged things so a kernel thread can just return and do_exit will be called. So just have the threads return instead of calling complete_and_exit. Link: https://lkml.kernel.org/r/20211020174406.17889-18-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> 
Every place thread_exit is called is at the end of a function started
with kthread_run.  The code in kthread_run has arranged things so a
kernel thread can just return and do_exit will be called.

So just have the threads return instead of calling complete_and_exit.

Link: https://lkml.kernel.org/r/20211020174406.17889-18-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
staging: rtl8723bs: hal: remove duplicate check 2021-10-10T13:00:05+00:00 Saurav Girepunje saurav.girepunje@gmail.com 2021-10-10T07:08:45+00:00 98f668b30e8e65324b06332e9a3e2ea340bfd7f1 Remove 'bPerformance' from if condition check. As on previous if condition it is already check for same variable. Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com> Link: https://lore.kernel.org/r/YWKRfYpTioAmTWa0@user Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Remove 'bPerformance' from if condition check. As on previous
if condition it is already check for same variable.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Link: https://lore.kernel.org/r/YWKRfYpTioAmTWa0@user
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: rtl8723bs: remove possible deadlock when disconnect (v2) 2021-09-21T15:30:55+00:00 Fabio Aiuto fabioaiuto83@gmail.com 2021-09-20T14:55:00+00:00 54659ca026e586bbb33a7e60daa6443a3ac6b5df when turning off a connection, lockdep complains with the following warning (a modprobe has been done but the same happens with a disconnection from NetworkManager, it's enough to trigger a cfg80211_disconnect call): [ 682.855867] ====================================================== [ 682.855877] WARNING: possible circular locking dependency detected [ 682.855887] 5.14.0-rc6+ #16 Tainted: G C OE [ 682.855898] ------------------------------------------------------ [ 682.855906] modprobe/1770 is trying to acquire lock: [ 682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2}, at: rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.856073] but task is already holding lock: [ 682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 682.856207] which lock already depends on the new lock. [ 682.856215] the existing dependency chain (in reverse order) is: [ 682.856223] -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}: [ 682.856247] _raw_spin_lock_bh+0x34/0x40 [ 682.856265] rtw_get_stainfo+0x9a/0x110 [r8723bs] [ 682.856389] rtw_xmit_classifier+0x27/0x130 [r8723bs] [ 682.856515] rtw_xmitframe_enqueue+0xa/0x20 [r8723bs] [ 682.856642] rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs] [ 682.856752] rtw_xmit+0x4ef/0x890 [r8723bs] [ 682.856879] _rtw_xmit_entry+0xba/0x350 [r8723bs] [ 682.856981] dev_hard_start_xmit+0xee/0x320 [ 682.856999] sch_direct_xmit+0x8c/0x330 [ 682.857014] __dev_queue_xmit+0xba5/0xf00 [ 682.857030] packet_sendmsg+0x981/0x1b80 [ 682.857047] sock_sendmsg+0x5b/0x60 [ 682.857060] __sys_sendto+0xf1/0x160 [ 682.857073] __x64_sys_sendto+0x24/0x30 [ 682.857087] do_syscall_64+0x3a/0x80 [ 682.857102] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.857117] -> #0 (&pxmitpriv->lock){+.-.}-{2:2}: [ 682.857142] __lock_acquire+0xfd9/0x1b50 [ 682.857158] lock_acquire+0xb4/0x2c0 [ 682.857172] _raw_spin_lock_bh+0x34/0x40 [ 682.857185] rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.857308] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 682.857415] cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs] [ 682.857522] cfg80211_disconnect+0x12e/0x2f0 [cfg80211] [ 682.857759] cfg80211_leave+0x2b/0x40 [cfg80211] [ 682.857961] cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211] [ 682.858163] raw_notifier_call_chain+0x41/0x50 [ 682.858180] __dev_close_many+0x62/0x100 [ 682.858195] dev_close_many+0x7d/0x120 [ 682.858209] unregister_netdevice_many+0x416/0x680 [ 682.858225] unregister_netdevice_queue+0xab/0xf0 [ 682.858240] unregister_netdev+0x18/0x20 [ 682.858255] rtw_unregister_netdevs+0x28/0x40 [r8723bs] [ 682.858360] rtw_dev_remove+0x24/0xd0 [r8723bs] [ 682.858463] sdio_bus_remove+0x31/0xd0 [mmc_core] [ 682.858532] device_release_driver_internal+0xf7/0x1d0 [ 682.858550] driver_detach+0x47/0x90 [ 682.858564] bus_remove_driver+0x77/0xd0 [ 682.858579] rtw_drv_halt+0xc/0x678 [r8723bs] [ 682.858685] __x64_sys_delete_module+0x13f/0x250 [ 682.858699] do_syscall_64+0x3a/0x80 [ 682.858715] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.858729] other info that might help us debug this: [ 682.858737] Possible unsafe locking scenario: [ 682.858744] CPU0 CPU1 [ 682.858751] ---- ---- [ 682.858758] lock(&pstapriv->sta_hash_lock); [ 682.858772] lock(&pxmitpriv->lock); [ 682.858786] lock(&pstapriv->sta_hash_lock); [ 682.858799] lock(&pxmitpriv->lock); [ 682.858812] *** DEADLOCK *** [ 682.858820] 5 locks held by modprobe/1770: [ 682.858831] #0: ffff8d870697d980 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x1a/0x1d0 [ 682.858869] #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 [ 682.858906] #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211] [ 682.859131] #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3}, at: cfg80211_leave+0x20/0x40 [cfg80211] [ 682.859354] #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 682.859482] stack backtrace: [ 682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G C OE 5.14.0-rc6+ #16 [ 682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015 [ 682.859517] Call Trace: [ 682.859531] dump_stack_lvl+0x56/0x6f [ 682.859551] check_noncircular+0xdb/0xf0 [ 682.859579] __lock_acquire+0xfd9/0x1b50 [ 682.859606] lock_acquire+0xb4/0x2c0 [ 682.859623] ? rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.859752] ? mark_held_locks+0x48/0x70 [ 682.859769] ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs] [ 682.859898] _raw_spin_lock_bh+0x34/0x40 [ 682.859914] ? rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.860039] rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.860171] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 682.860286] cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs] [ 682.860397] cfg80211_disconnect+0x12e/0x2f0 [cfg80211] [ 682.860629] cfg80211_leave+0x2b/0x40 [cfg80211] [ 682.860836] cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211] [ 682.861048] ? __lock_acquire+0x4dc/0x1b50 [ 682.861070] ? lock_is_held_type+0xa8/0x110 [ 682.861089] ? lock_is_held_type+0xa8/0x110 [ 682.861104] ? find_held_lock+0x2d/0x90 [ 682.861120] ? packet_notifier+0x173/0x300 [ 682.861141] ? lock_release+0xb3/0x250 [ 682.861160] ? packet_notifier+0x192/0x300 [ 682.861184] raw_notifier_call_chain+0x41/0x50 [ 682.861205] __dev_close_many+0x62/0x100 [ 682.861224] dev_close_many+0x7d/0x120 [ 682.861245] unregister_netdevice_many+0x416/0x680 [ 682.861264] ? find_held_lock+0x2d/0x90 [ 682.861284] unregister_netdevice_queue+0xab/0xf0 [ 682.861306] unregister_netdev+0x18/0x20 [ 682.861325] rtw_unregister_netdevs+0x28/0x40 [r8723bs] [ 682.861434] rtw_dev_remove+0x24/0xd0 [r8723bs] [ 682.861542] sdio_bus_remove+0x31/0xd0 [mmc_core] [ 682.861615] device_release_driver_internal+0xf7/0x1d0 [ 682.861637] driver_detach+0x47/0x90 [ 682.861656] bus_remove_driver+0x77/0xd0 [ 682.861674] rtw_drv_halt+0xc/0x678 [r8723bs] [ 682.861782] __x64_sys_delete_module+0x13f/0x250 [ 682.861801] ? lockdep_hardirqs_on_prepare+0xf3/0x170 [ 682.861817] ? syscall_enter_from_user_mode+0x20/0x70 [ 682.861836] do_syscall_64+0x3a/0x80 [ 682.861855] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.861873] RIP: 0033:0x7f6dbe85400b [ 682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 1e 0c 00 f7 d8 64 89 01 48 [ 682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b [ 682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88 [ 682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000 [ 682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88 [ 682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848 This happens because when we enqueue a frame for transmission we do it under xmit_priv lock, then calling rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock and this leads to the following lock dependency: xmit_priv->lock -> sta_hash_lock Turning off a connection will bring to call rtw_free_assoc_resources which will set up the inverse dependency: sta_hash_lock -> xmit_priv_lock This could lead to a deadlock as lockdep complains. Fix it by removing the xmit_priv->lock around rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit and put it in a smaller critical section inside rtw_xmit_classifier, the only place where xmit_priv data are actually accessed. Replace spin_{lock,unlock}_bh(pxmitpriv->lock) in other tx paths leading to rtw_xmitframe_enqueue call with spin_{lock,unlock}_bh(psta->sleep_q.lock) - it's not clear why accessing a sleep_q was protected by a spinlock on xmitpriv->lock. This way is avoided the same faulty lock nesting order. Extra changes in v2 by Hans de Goede: -Lift the taking of the struct __queue.lock spinlock out of rtw_free_xmitframe_queue() into the callers this allows also protecting a bunch of related state in rtw_free_stainfo(): -Protect psta->sleepq_len on rtw_free_xmitframe_queue(&psta->sleep_q); -Protect struct tx_servq.tx_pending and tx_servq.qcnt when calling rtw_free_xmitframe_queue(&tx_servq.sta_pending) -This also allows moving the spin_lock_bh(&pxmitpriv->lock); to below the sleep_q free-ing code, avoiding another ABBA locking issue CC: Larry Finger <Larry.Finger@lwfinger.net> Co-developed-by: Hans de Goede <hdegoede@redhat.com> Tested-on: Lenovo Ideapad MiiX 300-10IBY Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20210920145502.155454-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
when turning off a connection, lockdep complains with the
following warning (a modprobe has been done but the same
happens with a disconnection from NetworkManager,
it's enough to trigger a cfg80211_disconnect call):

[  682.855867] ======================================================
[  682.855877] WARNING: possible circular locking dependency detected
[  682.855887] 5.14.0-rc6+ #16 Tainted: G         C OE
[  682.855898] ------------------------------------------------------
[  682.855906] modprobe/1770 is trying to acquire lock:
[  682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2},
		at: rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.856073]
               but task is already holding lock:
[  682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.856207]
               which lock already depends on the new lock.

[  682.856215]
               the existing dependency chain (in reverse order) is:
[  682.856223]
               -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}:
[  682.856247]        _raw_spin_lock_bh+0x34/0x40
[  682.856265]        rtw_get_stainfo+0x9a/0x110 [r8723bs]
[  682.856389]        rtw_xmit_classifier+0x27/0x130 [r8723bs]
[  682.856515]        rtw_xmitframe_enqueue+0xa/0x20 [r8723bs]
[  682.856642]        rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs]
[  682.856752]        rtw_xmit+0x4ef/0x890 [r8723bs]
[  682.856879]        _rtw_xmit_entry+0xba/0x350 [r8723bs]
[  682.856981]        dev_hard_start_xmit+0xee/0x320
[  682.856999]        sch_direct_xmit+0x8c/0x330
[  682.857014]        __dev_queue_xmit+0xba5/0xf00
[  682.857030]        packet_sendmsg+0x981/0x1b80
[  682.857047]        sock_sendmsg+0x5b/0x60
[  682.857060]        __sys_sendto+0xf1/0x160
[  682.857073]        __x64_sys_sendto+0x24/0x30
[  682.857087]        do_syscall_64+0x3a/0x80
[  682.857102]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.857117]
               -> #0 (&pxmitpriv->lock){+.-.}-{2:2}:
[  682.857142]        __lock_acquire+0xfd9/0x1b50
[  682.857158]        lock_acquire+0xb4/0x2c0
[  682.857172]        _raw_spin_lock_bh+0x34/0x40
[  682.857185]        rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.857308]        rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.857415]        cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.857522]        cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.857759]        cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.857961]        cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.858163]        raw_notifier_call_chain+0x41/0x50
[  682.858180]        __dev_close_many+0x62/0x100
[  682.858195]        dev_close_many+0x7d/0x120
[  682.858209]        unregister_netdevice_many+0x416/0x680
[  682.858225]        unregister_netdevice_queue+0xab/0xf0
[  682.858240]        unregister_netdev+0x18/0x20
[  682.858255]        rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.858360]        rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.858463]        sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.858532]        device_release_driver_internal+0xf7/0x1d0
[  682.858550]        driver_detach+0x47/0x90
[  682.858564]        bus_remove_driver+0x77/0xd0
[  682.858579]        rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.858685]        __x64_sys_delete_module+0x13f/0x250
[  682.858699]        do_syscall_64+0x3a/0x80
[  682.858715]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.858729]
               other info that might help us debug this:

[  682.858737]  Possible unsafe locking scenario:

[  682.858744]        CPU0                    CPU1
[  682.858751]        ----                    ----
[  682.858758]   lock(&pstapriv->sta_hash_lock);
[  682.858772]                                lock(&pxmitpriv->lock);
[  682.858786]                                lock(&pstapriv->sta_hash_lock);
[  682.858799]   lock(&pxmitpriv->lock);
[  682.858812]
                *** DEADLOCK ***

[  682.858820] 5 locks held by modprobe/1770:
[  682.858831]  #0: ffff8d870697d980 (&dev->mutex){....}-{3:3},
		at: device_release_driver_internal+0x1a/0x1d0
[  682.858869]  #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3},
		at: unregister_netdev+0xe/0x20
[  682.858906]  #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3},
		at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211]
[  682.859131]  #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3},
		at: cfg80211_leave+0x20/0x40 [cfg80211]
[  682.859354]  #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.859482]
               stack backtrace:
[  682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G
		C OE     5.14.0-rc6+ #16
[  682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015
[  682.859517] Call Trace:
[  682.859531]  dump_stack_lvl+0x56/0x6f
[  682.859551]  check_noncircular+0xdb/0xf0
[  682.859579]  __lock_acquire+0xfd9/0x1b50
[  682.859606]  lock_acquire+0xb4/0x2c0
[  682.859623]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.859752]  ? mark_held_locks+0x48/0x70
[  682.859769]  ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs]
[  682.859898]  _raw_spin_lock_bh+0x34/0x40
[  682.859914]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860039]  rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860171]  rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.860286]  cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.860397]  cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.860629]  cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.860836]  cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.861048]  ? __lock_acquire+0x4dc/0x1b50
[  682.861070]  ? lock_is_held_type+0xa8/0x110
[  682.861089]  ? lock_is_held_type+0xa8/0x110
[  682.861104]  ? find_held_lock+0x2d/0x90
[  682.861120]  ? packet_notifier+0x173/0x300
[  682.861141]  ? lock_release+0xb3/0x250
[  682.861160]  ? packet_notifier+0x192/0x300
[  682.861184]  raw_notifier_call_chain+0x41/0x50
[  682.861205]  __dev_close_many+0x62/0x100
[  682.861224]  dev_close_many+0x7d/0x120
[  682.861245]  unregister_netdevice_many+0x416/0x680
[  682.861264]  ? find_held_lock+0x2d/0x90
[  682.861284]  unregister_netdevice_queue+0xab/0xf0
[  682.861306]  unregister_netdev+0x18/0x20
[  682.861325]  rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.861434]  rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.861542]  sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.861615]  device_release_driver_internal+0xf7/0x1d0
[  682.861637]  driver_detach+0x47/0x90
[  682.861656]  bus_remove_driver+0x77/0xd0
[  682.861674]  rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.861782]  __x64_sys_delete_module+0x13f/0x250
[  682.861801]  ? lockdep_hardirqs_on_prepare+0xf3/0x170
[  682.861817]  ? syscall_enter_from_user_mode+0x20/0x70
[  682.861836]  do_syscall_64+0x3a/0x80
[  682.861855]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.861873] RIP: 0033:0x7f6dbe85400b
[  682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa
b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d
1e 0c 00 f7 d8 64 89 01 48
[  682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[  682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b
[  682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88
[  682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000
[  682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88
[  682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848

This happens because when we enqueue a frame for
transmission we do it under xmit_priv lock, then calling
rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock
and this leads to the following lock dependency:

xmit_priv->lock -> sta_hash_lock

Turning off a connection will bring to call
rtw_free_assoc_resources which will set up
the inverse dependency:

sta_hash_lock -> xmit_priv_lock

This could lead to a deadlock as lockdep complains.

Fix it by removing the xmit_priv->lock around
rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit
and put it in a smaller critical section inside
rtw_xmit_classifier, the only place where
xmit_priv data are actually accessed.

Replace spin_{lock,unlock}_bh(pxmitpriv->lock)
in other tx paths leading to rtw_xmitframe_enqueue
call with spin_{lock,unlock}_bh(psta->sleep_q.lock)
- it's not clear why accessing a sleep_q was protected
by a spinlock on xmitpriv->lock.

This way is avoided the same faulty lock nesting
order.

Extra changes in v2 by Hans de Goede:
-Lift the taking of the struct __queue.lock spinlock out of
 rtw_free_xmitframe_queue() into the callers this allows also
 protecting a bunch of related state in rtw_free_stainfo():
-Protect psta->sleepq_len on rtw_free_xmitframe_queue(&psta->sleep_q);
-Protect struct tx_servq.tx_pending and tx_servq.qcnt when
 calling rtw_free_xmitframe_queue(&tx_servq.sta_pending)
-This also allows moving the spin_lock_bh(&pxmitpriv->lock); to below
 the sleep_q free-ing code, avoiding another ABBA locking issue

CC: Larry Finger <Larry.Finger@lwfinger.net>
Co-developed-by: Hans de Goede <hdegoede@redhat.com>
Tested-on: Lenovo Ideapad MiiX 300-10IBY
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210920145502.155454-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "staging: rtl8723bs: remove possible deadlock when disconnect" 2021-09-17T14:26:09+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-09-17T14:25:33+00:00 ea2054baaddccfb04ba216a4f48889f334804483 This reverts commit 78a1614a81f06032055a25b7acd9965a81196433. There's been attempts to fix this, but it's not quite right yet, so just remove the original commit. Link: https://lore.kernel.org/r/20210913130346.2390-1-fabioaiuto83@gmail.com Cc: Larry Finger <Larry.Finger@lwfinger.net> Cc: Fabio Aiuto <fabioaiuto83@gmail.com> Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This reverts commit 78a1614a81f06032055a25b7acd9965a81196433.

There's been attempts to fix this, but it's not quite right yet, so just
remove the original commit.

Link: https://lore.kernel.org/r/20210913130346.2390-1-fabioaiuto83@gmail.com
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Fabio Aiuto <fabioaiuto83@gmail.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: rtl8723bs: remove possible deadlock when disconnect 2021-09-13T06:49:46+00:00 Fabio Aiuto fabioaiuto83@gmail.com 2021-09-02T09:35:59+00:00 78a1614a81f06032055a25b7acd9965a81196433 when turning off a connection, lockdep complains with the following warning (a modprobe has been done but the same happens with a disconnection from NetworkManager, it's enough to trigger a cfg80211_disconnect call): [ 682.855867] ====================================================== [ 682.855877] WARNING: possible circular locking dependency detected [ 682.855887] 5.14.0-rc6+ #16 Tainted: G C OE [ 682.855898] ------------------------------------------------------ [ 682.855906] modprobe/1770 is trying to acquire lock: [ 682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2}, at: rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.856073] but task is already holding lock: [ 682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 682.856207] which lock already depends on the new lock. [ 682.856215] the existing dependency chain (in reverse order) is: [ 682.856223] -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}: [ 682.856247] _raw_spin_lock_bh+0x34/0x40 [ 682.856265] rtw_get_stainfo+0x9a/0x110 [r8723bs] [ 682.856389] rtw_xmit_classifier+0x27/0x130 [r8723bs] [ 682.856515] rtw_xmitframe_enqueue+0xa/0x20 [r8723bs] [ 682.856642] rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs] [ 682.856752] rtw_xmit+0x4ef/0x890 [r8723bs] [ 682.856879] _rtw_xmit_entry+0xba/0x350 [r8723bs] [ 682.856981] dev_hard_start_xmit+0xee/0x320 [ 682.856999] sch_direct_xmit+0x8c/0x330 [ 682.857014] __dev_queue_xmit+0xba5/0xf00 [ 682.857030] packet_sendmsg+0x981/0x1b80 [ 682.857047] sock_sendmsg+0x5b/0x60 [ 682.857060] __sys_sendto+0xf1/0x160 [ 682.857073] __x64_sys_sendto+0x24/0x30 [ 682.857087] do_syscall_64+0x3a/0x80 [ 682.857102] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.857117] -> #0 (&pxmitpriv->lock){+.-.}-{2:2}: [ 682.857142] __lock_acquire+0xfd9/0x1b50 [ 682.857158] lock_acquire+0xb4/0x2c0 [ 682.857172] _raw_spin_lock_bh+0x34/0x40 [ 682.857185] rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.857308] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 682.857415] cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs] [ 682.857522] cfg80211_disconnect+0x12e/0x2f0 [cfg80211] [ 682.857759] cfg80211_leave+0x2b/0x40 [cfg80211] [ 682.857961] cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211] [ 682.858163] raw_notifier_call_chain+0x41/0x50 [ 682.858180] __dev_close_many+0x62/0x100 [ 682.858195] dev_close_many+0x7d/0x120 [ 682.858209] unregister_netdevice_many+0x416/0x680 [ 682.858225] unregister_netdevice_queue+0xab/0xf0 [ 682.858240] unregister_netdev+0x18/0x20 [ 682.858255] rtw_unregister_netdevs+0x28/0x40 [r8723bs] [ 682.858360] rtw_dev_remove+0x24/0xd0 [r8723bs] [ 682.858463] sdio_bus_remove+0x31/0xd0 [mmc_core] [ 682.858532] device_release_driver_internal+0xf7/0x1d0 [ 682.858550] driver_detach+0x47/0x90 [ 682.858564] bus_remove_driver+0x77/0xd0 [ 682.858579] rtw_drv_halt+0xc/0x678 [r8723bs] [ 682.858685] __x64_sys_delete_module+0x13f/0x250 [ 682.858699] do_syscall_64+0x3a/0x80 [ 682.858715] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.858729] other info that might help us debug this: [ 682.858737] Possible unsafe locking scenario: [ 682.858744] CPU0 CPU1 [ 682.858751] ---- ---- [ 682.858758] lock(&pstapriv->sta_hash_lock); [ 682.858772] lock(&pxmitpriv->lock); [ 682.858786] lock(&pstapriv->sta_hash_lock); [ 682.858799] lock(&pxmitpriv->lock); [ 682.858812] *** DEADLOCK *** [ 682.858820] 5 locks held by modprobe/1770: [ 682.858831] #0: ffff8d870697d980 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x1a/0x1d0 [ 682.858869] #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 [ 682.858906] #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211] [ 682.859131] #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3}, at: cfg80211_leave+0x20/0x40 [cfg80211] [ 682.859354] #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 682.859482] stack backtrace: [ 682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G C OE 5.14.0-rc6+ #16 [ 682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015 [ 682.859517] Call Trace: [ 682.859531] dump_stack_lvl+0x56/0x6f [ 682.859551] check_noncircular+0xdb/0xf0 [ 682.859579] __lock_acquire+0xfd9/0x1b50 [ 682.859606] lock_acquire+0xb4/0x2c0 [ 682.859623] ? rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.859752] ? mark_held_locks+0x48/0x70 [ 682.859769] ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs] [ 682.859898] _raw_spin_lock_bh+0x34/0x40 [ 682.859914] ? rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.860039] rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.860171] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 682.860286] cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs] [ 682.860397] cfg80211_disconnect+0x12e/0x2f0 [cfg80211] [ 682.860629] cfg80211_leave+0x2b/0x40 [cfg80211] [ 682.860836] cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211] [ 682.861048] ? __lock_acquire+0x4dc/0x1b50 [ 682.861070] ? lock_is_held_type+0xa8/0x110 [ 682.861089] ? lock_is_held_type+0xa8/0x110 [ 682.861104] ? find_held_lock+0x2d/0x90 [ 682.861120] ? packet_notifier+0x173/0x300 [ 682.861141] ? lock_release+0xb3/0x250 [ 682.861160] ? packet_notifier+0x192/0x300 [ 682.861184] raw_notifier_call_chain+0x41/0x50 [ 682.861205] __dev_close_many+0x62/0x100 [ 682.861224] dev_close_many+0x7d/0x120 [ 682.861245] unregister_netdevice_many+0x416/0x680 [ 682.861264] ? find_held_lock+0x2d/0x90 [ 682.861284] unregister_netdevice_queue+0xab/0xf0 [ 682.861306] unregister_netdev+0x18/0x20 [ 682.861325] rtw_unregister_netdevs+0x28/0x40 [r8723bs] [ 682.861434] rtw_dev_remove+0x24/0xd0 [r8723bs] [ 682.861542] sdio_bus_remove+0x31/0xd0 [mmc_core] [ 682.861615] device_release_driver_internal+0xf7/0x1d0 [ 682.861637] driver_detach+0x47/0x90 [ 682.861656] bus_remove_driver+0x77/0xd0 [ 682.861674] rtw_drv_halt+0xc/0x678 [r8723bs] [ 682.861782] __x64_sys_delete_module+0x13f/0x250 [ 682.861801] ? lockdep_hardirqs_on_prepare+0xf3/0x170 [ 682.861817] ? syscall_enter_from_user_mode+0x20/0x70 [ 682.861836] do_syscall_64+0x3a/0x80 [ 682.861855] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.861873] RIP: 0033:0x7f6dbe85400b [ 682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 1e 0c 00 f7 d8 64 89 01 48 [ 682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b [ 682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88 [ 682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000 [ 682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88 [ 682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848 This happens because when we enqueue a frame for transmission we do it under xmit_priv lock, then calling rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock and this leads to the following lock dependency: xmit_priv->lock -> sta_hash_lock Turning off a connection will bring to call rtw_free_assoc_resources which will set up the inverse dependency: sta_hash_lock -> xmit_priv_lock This could lead to a deadlock as lockdep complains. Fix it by removing the xmit_priv->lock around rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit and put it in a smaller critical section inside rtw_xmit_classifier, the only place where xmit_priv data are actually accessed. Replace spin_{lock,unlock}_bh(pxmitpriv->lock) in other tx paths leading to rtw_xmitframe_enqueue call with spin_{lock,unlock}_bh(psta->sleep_q.lock) - it's not clear why accessing a sleep_q was protected by a spinlock on xmitpriv->lock. This way is avoided the same faulty lock nesting order. CC: Larry Finger <Larry.Finger@lwfinger.net> Tested-on: Lenovo Ideapad MiiX 300-10IBY Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com> Link: https://lore.kernel.org/r/20210902093559.9779-1-fabioaiuto83@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
when turning off a connection, lockdep complains with the
following warning (a modprobe has been done but the same
happens with a disconnection from NetworkManager,
it's enough to trigger a cfg80211_disconnect call):

[  682.855867] ======================================================
[  682.855877] WARNING: possible circular locking dependency detected
[  682.855887] 5.14.0-rc6+ #16 Tainted: G         C OE
[  682.855898] ------------------------------------------------------
[  682.855906] modprobe/1770 is trying to acquire lock:
[  682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2},
		at: rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.856073]
               but task is already holding lock:
[  682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.856207]
               which lock already depends on the new lock.

[  682.856215]
               the existing dependency chain (in reverse order) is:
[  682.856223]
               -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}:
[  682.856247]        _raw_spin_lock_bh+0x34/0x40
[  682.856265]        rtw_get_stainfo+0x9a/0x110 [r8723bs]
[  682.856389]        rtw_xmit_classifier+0x27/0x130 [r8723bs]
[  682.856515]        rtw_xmitframe_enqueue+0xa/0x20 [r8723bs]
[  682.856642]        rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs]
[  682.856752]        rtw_xmit+0x4ef/0x890 [r8723bs]
[  682.856879]        _rtw_xmit_entry+0xba/0x350 [r8723bs]
[  682.856981]        dev_hard_start_xmit+0xee/0x320
[  682.856999]        sch_direct_xmit+0x8c/0x330
[  682.857014]        __dev_queue_xmit+0xba5/0xf00
[  682.857030]        packet_sendmsg+0x981/0x1b80
[  682.857047]        sock_sendmsg+0x5b/0x60
[  682.857060]        __sys_sendto+0xf1/0x160
[  682.857073]        __x64_sys_sendto+0x24/0x30
[  682.857087]        do_syscall_64+0x3a/0x80
[  682.857102]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.857117]
               -> #0 (&pxmitpriv->lock){+.-.}-{2:2}:
[  682.857142]        __lock_acquire+0xfd9/0x1b50
[  682.857158]        lock_acquire+0xb4/0x2c0
[  682.857172]        _raw_spin_lock_bh+0x34/0x40
[  682.857185]        rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.857308]        rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.857415]        cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.857522]        cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.857759]        cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.857961]        cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.858163]        raw_notifier_call_chain+0x41/0x50
[  682.858180]        __dev_close_many+0x62/0x100
[  682.858195]        dev_close_many+0x7d/0x120
[  682.858209]        unregister_netdevice_many+0x416/0x680
[  682.858225]        unregister_netdevice_queue+0xab/0xf0
[  682.858240]        unregister_netdev+0x18/0x20
[  682.858255]        rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.858360]        rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.858463]        sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.858532]        device_release_driver_internal+0xf7/0x1d0
[  682.858550]        driver_detach+0x47/0x90
[  682.858564]        bus_remove_driver+0x77/0xd0
[  682.858579]        rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.858685]        __x64_sys_delete_module+0x13f/0x250
[  682.858699]        do_syscall_64+0x3a/0x80
[  682.858715]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.858729]
               other info that might help us debug this:

[  682.858737]  Possible unsafe locking scenario:

[  682.858744]        CPU0                    CPU1
[  682.858751]        ----                    ----
[  682.858758]   lock(&pstapriv->sta_hash_lock);
[  682.858772]                                lock(&pxmitpriv->lock);
[  682.858786]                                lock(&pstapriv->sta_hash_lock);
[  682.858799]   lock(&pxmitpriv->lock);
[  682.858812]
                *** DEADLOCK ***

[  682.858820] 5 locks held by modprobe/1770:
[  682.858831]  #0: ffff8d870697d980 (&dev->mutex){....}-{3:3},
		at: device_release_driver_internal+0x1a/0x1d0
[  682.858869]  #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3},
		at: unregister_netdev+0xe/0x20
[  682.858906]  #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3},
		at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211]
[  682.859131]  #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3},
		at: cfg80211_leave+0x20/0x40 [cfg80211]
[  682.859354]  #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2},
		at: rtw_free_assoc_resources+0x48/0x110 [r8723bs]
[  682.859482]
               stack backtrace:
[  682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G
		C OE     5.14.0-rc6+ #16
[  682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015
[  682.859517] Call Trace:
[  682.859531]  dump_stack_lvl+0x56/0x6f
[  682.859551]  check_noncircular+0xdb/0xf0
[  682.859579]  __lock_acquire+0xfd9/0x1b50
[  682.859606]  lock_acquire+0xb4/0x2c0
[  682.859623]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.859752]  ? mark_held_locks+0x48/0x70
[  682.859769]  ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs]
[  682.859898]  _raw_spin_lock_bh+0x34/0x40
[  682.859914]  ? rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860039]  rtw_free_stainfo+0x52/0x4a0 [r8723bs]
[  682.860171]  rtw_free_assoc_resources+0x53/0x110 [r8723bs]
[  682.860286]  cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs]
[  682.860397]  cfg80211_disconnect+0x12e/0x2f0 [cfg80211]
[  682.860629]  cfg80211_leave+0x2b/0x40 [cfg80211]
[  682.860836]  cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211]
[  682.861048]  ? __lock_acquire+0x4dc/0x1b50
[  682.861070]  ? lock_is_held_type+0xa8/0x110
[  682.861089]  ? lock_is_held_type+0xa8/0x110
[  682.861104]  ? find_held_lock+0x2d/0x90
[  682.861120]  ? packet_notifier+0x173/0x300
[  682.861141]  ? lock_release+0xb3/0x250
[  682.861160]  ? packet_notifier+0x192/0x300
[  682.861184]  raw_notifier_call_chain+0x41/0x50
[  682.861205]  __dev_close_many+0x62/0x100
[  682.861224]  dev_close_many+0x7d/0x120
[  682.861245]  unregister_netdevice_many+0x416/0x680
[  682.861264]  ? find_held_lock+0x2d/0x90
[  682.861284]  unregister_netdevice_queue+0xab/0xf0
[  682.861306]  unregister_netdev+0x18/0x20
[  682.861325]  rtw_unregister_netdevs+0x28/0x40 [r8723bs]
[  682.861434]  rtw_dev_remove+0x24/0xd0 [r8723bs]
[  682.861542]  sdio_bus_remove+0x31/0xd0 [mmc_core]
[  682.861615]  device_release_driver_internal+0xf7/0x1d0
[  682.861637]  driver_detach+0x47/0x90
[  682.861656]  bus_remove_driver+0x77/0xd0
[  682.861674]  rtw_drv_halt+0xc/0x678 [r8723bs]
[  682.861782]  __x64_sys_delete_module+0x13f/0x250
[  682.861801]  ? lockdep_hardirqs_on_prepare+0xf3/0x170
[  682.861817]  ? syscall_enter_from_user_mode+0x20/0x70
[  682.861836]  do_syscall_64+0x3a/0x80
[  682.861855]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  682.861873] RIP: 0033:0x7f6dbe85400b
[  682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa
b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d
1e 0c 00 f7 d8 64 89 01 48
[  682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[  682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b
[  682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88
[  682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000
[  682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88
[  682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848

This happens because when we enqueue a frame for
transmission we do it under xmit_priv lock, then calling
rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock
and this leads to the following lock dependency:

xmit_priv->lock -> sta_hash_lock

Turning off a connection will bring to call
rtw_free_assoc_resources which will set up
the inverse dependency:

sta_hash_lock -> xmit_priv_lock

This could lead to a deadlock as lockdep complains.

Fix it by removing the xmit_priv->lock around
rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit
and put it in a smaller critical section inside
rtw_xmit_classifier, the only place where
xmit_priv data are actually accessed.

Replace spin_{lock,unlock}_bh(pxmitpriv->lock)
in other tx paths leading to rtw_xmitframe_enqueue
call with spin_{lock,unlock}_bh(psta->sleep_q.lock)
- it's not clear why accessing a sleep_q was protected
by a spinlock on xmitpriv->lock.

This way is avoided the same faulty lock nesting
order.

CC: Larry Finger <Larry.Finger@lwfinger.net>
Tested-on: Lenovo Ideapad MiiX 300-10IBY
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/20210902093559.9779-1-fabioaiuto83@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: rtl8723bs: unwrap initialization of queues 2021-09-13T06:49:43+00:00 Fabio Aiuto fabioaiuto83@gmail.com 2021-08-30T07:09:23+00:00 d1cfdcad99f0e79b46fd0e81bc1a940adbc2069d unwrap initialization of queues to avoid false positive lockdep warning: [ 27.350258] ============================================ [ 27.350267] WARNING: possible recursive locking detected [ 27.350276] 5.14.0-rc6+ #16 Tainted: G C OE [ 27.350288] -------------------------------------------- [ 27.350295] RTW_CMD_THREAD/679 is trying to acquire lock: [ 27.350306] ffffa846c03290c8 (&(pqueue->lock)){+.-.}-{2:2}, at: rtw_alloc_network+0x1b/0xa0 [r8723bs] [ 27.350441] but task is already holding lock: [ 27.350448] ffffa846c0329118 (&(pqueue->lock)){+.-.}-{2:2}, at: rtw_update_scanned_network+0x33/0x1d0 [r8723bs] [ 27.350573] other info that might help us debug this: [ 27.350581] Possible unsafe locking scenario: [ 27.350588] CPU0 [ 27.350594] ---- [ 27.350600] lock(&(pqueue->lock)); [ 27.350614] lock(&(pqueue->lock)); [ 27.350627] *** DEADLOCK *** [ 27.350634] May be due to missing lock nesting notation [ 27.350641] 2 locks held by RTW_CMD_THREAD/679: [ 27.350652] #0: ffffa846c0329038 (&pmlmepriv->lock){+...}-{2:2}, at: rtw_survey_event_callback+0x2d/0xe0 [r8723bs] [ 27.350780] #1: ffffa846c0329118 (&(pqueue->lock)){+.-.}-{2:2}, at: rtw_update_scanned_network+0x33/0x1d0 [r8723bs] [ 27.350907] stack backtrace: [ 27.350916] CPU: 3 PID: 679 Comm: RTW_CMD_THREAD Tainted: G C OE 5.14.0-rc6+ #16 [ 27.350933] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015 [ 27.350943] Call Trace: [ 27.350959] dump_stack_lvl+0x56/0x6f [ 27.350982] __lock_acquire.cold.79+0x137/0x298 [ 27.351012] lock_acquire+0xb4/0x2c0 [ 27.351031] ? rtw_alloc_network+0x1b/0xa0 [r8723bs] [ 27.351140] ? rtw_update_scanned_network+0x33/0x1d0 [r8723bs] [ 27.351254] _raw_spin_lock_bh+0x34/0x40 [ 27.351271] ? rtw_alloc_network+0x1b/0xa0 [r8723bs] [ 27.351378] rtw_alloc_network+0x1b/0xa0 [r8723bs] [ 27.351488] rtw_update_scanned_network+0xa5/0x1d0 [r8723bs] [ 27.351605] rtw_survey_event_callback+0x54/0xe0 [r8723bs] [ 27.351719] mlme_evt_hdl+0x4e/0x70 [r8723bs] [ 27.351839] rtw_cmd_thread+0x16c/0x3d0 [r8723bs] [ 27.351945] ? rtw_stop_cmd_thread+0x50/0x50 [r8723bs] [ 27.352045] kthread+0x136/0x160 [ 27.352064] ? set_kthread_struct+0x40/0x40 [ 27.352083] ret_from_fork+0x22/0x30 This happens because the wrapping function _rtw_init_queues() bring lockdep considering all queues as a single one. But all queues are different with their own lock. Applied the following semantic patch: @@ expression a; @@ - _rtw_init_queue(&a); + INIT_LIST_HEAD(&a.queue); + spin_lock_init(&a.lock); Reported-by: Hans De Goede <hdegoede@redhat.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com> Link: https://lore.kernel.org/r/c2c3a18cc2b883feab74f150ccbaa4f2cc11995c.1630307025.git.fabioaiuto83@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
unwrap initialization of queues to avoid false positive
lockdep warning:

[   27.350258] ============================================
[   27.350267] WARNING: possible recursive locking detected
[   27.350276] 5.14.0-rc6+ #16 Tainted: G         C OE
[   27.350288] --------------------------------------------
[   27.350295] RTW_CMD_THREAD/679 is trying to acquire lock:
[   27.350306] ffffa846c03290c8 (&(pqueue->lock)){+.-.}-{2:2},
		at: rtw_alloc_network+0x1b/0xa0 [r8723bs]
[   27.350441]
               but task is already holding lock:
[   27.350448] ffffa846c0329118 (&(pqueue->lock)){+.-.}-{2:2},
		at: rtw_update_scanned_network+0x33/0x1d0 [r8723bs]
[   27.350573]
               other info that might help us debug this:
[   27.350581]  Possible unsafe locking scenario:

[   27.350588]        CPU0
[   27.350594]        ----
[   27.350600]   lock(&(pqueue->lock));
[   27.350614]   lock(&(pqueue->lock));
[   27.350627]
                *** DEADLOCK ***

[   27.350634]  May be due to missing lock nesting notation

[   27.350641] 2 locks held by RTW_CMD_THREAD/679:
[   27.350652]  #0: ffffa846c0329038 (&pmlmepriv->lock){+...}-{2:2},
	at: rtw_survey_event_callback+0x2d/0xe0 [r8723bs]
[   27.350780]  #1: ffffa846c0329118 (&(pqueue->lock)){+.-.}-{2:2},
	at: rtw_update_scanned_network+0x33/0x1d0 [r8723bs]
[   27.350907]
               stack backtrace:
[   27.350916] CPU: 3 PID: 679 Comm: RTW_CMD_THREAD Tainted: G
		C OE     5.14.0-rc6+ #16
[   27.350933] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW
		08/20/2015
[   27.350943] Call Trace:
[   27.350959]  dump_stack_lvl+0x56/0x6f
[   27.350982]  __lock_acquire.cold.79+0x137/0x298
[   27.351012]  lock_acquire+0xb4/0x2c0
[   27.351031]  ? rtw_alloc_network+0x1b/0xa0 [r8723bs]
[   27.351140]  ? rtw_update_scanned_network+0x33/0x1d0 [r8723bs]
[   27.351254]  _raw_spin_lock_bh+0x34/0x40
[   27.351271]  ? rtw_alloc_network+0x1b/0xa0 [r8723bs]
[   27.351378]  rtw_alloc_network+0x1b/0xa0 [r8723bs]
[   27.351488]  rtw_update_scanned_network+0xa5/0x1d0 [r8723bs]
[   27.351605]  rtw_survey_event_callback+0x54/0xe0 [r8723bs]
[   27.351719]  mlme_evt_hdl+0x4e/0x70 [r8723bs]
[   27.351839]  rtw_cmd_thread+0x16c/0x3d0 [r8723bs]
[   27.351945]  ? rtw_stop_cmd_thread+0x50/0x50 [r8723bs]
[   27.352045]  kthread+0x136/0x160
[   27.352064]  ? set_kthread_struct+0x40/0x40
[   27.352083]  ret_from_fork+0x22/0x30

This happens because the wrapping function _rtw_init_queues()
bring lockdep considering all queues as a single one. But
all queues are different with their own lock.

Applied the following semantic patch:

@@
expression a;
@@

-       _rtw_init_queue(&a);
+       INIT_LIST_HEAD(&a.queue);
+       spin_lock_init(&a.lock);

Reported-by: Hans De Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/c2c3a18cc2b883feab74f150ccbaa4f2cc11995c.1630307025.git.fabioaiuto83@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>