[PW_SID:1080410] Bluetooth: SCO: fix sleeping under spinlock in sco_conn_ready

[BluezTestBot]

sco_conn_ready calls sleeping functions under conn->lock spinlock.

The critical section can be reduced: conn->hcon is modified only with
hdev->lock held. It is guaranteed to be held in sco_conn_ready, so
conn->lock is not needed to guard it.

Move taking conn->lock after lock_sock(parent). This also follows the
lock ordering lock_sock() > conn->lock elsewhere in the file.

Fixes: 27c24fd ("Bluetooth: switch to lock_sock in SCO")
Signed-off-by: Pauli Virtanen pav@iki.fi

net/bluetooth/sco.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)

[github-actions]

CheckPatch
Desc: Run checkpatch.pl script
Duration: 0.50 seconds
Result: PENDING

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GitLint
Desc: Run gitlint
Duration: 0.30 seconds
Result: PENDING

[github-actions]

SubjectPrefix
Desc: Check subject contains "Bluetooth" prefix
Duration: 0.08 seconds
Result: PASS

[github-actions]

BuildKernel
Desc: Build Kernel for Bluetooth
Duration: 23.67 seconds
Result: PASS

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CheckAllWarning
Desc: Run linux kernel with all warning enabled
Duration: 26.30 seconds
Result: PASS

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CheckSparse
Desc: Run sparse tool with linux kernel
Duration: 24.97 seconds
Result: PASS

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BuildKernel32
Desc: Build 32bit Kernel for Bluetooth
Duration: 23.06 seconds
Result: PASS

[github-actions]

TestRunnerSetup
Desc: Setup kernel and bluez for test-runner
Duration: 517.43 seconds
Result: PASS

[github-actions]

TestRunner_l2cap-tester
Desc: Run l2cap-tester with test-runner
Duration: 27.72 seconds
Result: FAIL
Output:

Total: 96, Passed: 95 (99.0%), Failed: 1, Not Run: 0

Failed Test Cases
L2CAP BR/EDR Server - Set PHY 2M                     Failed       0.114 seconds

[github-actions]

TestRunner_iso-tester
Desc: Run iso-tester with test-runner
Duration: 32.92 seconds
Result: PASS

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TestRunner_bnep-tester
Desc: Run bnep-tester with test-runner
Duration: 6.26 seconds
Result: PASS

[github-actions]

TestRunner_mgmt-tester
Desc: Run mgmt-tester with test-runner
Duration: 110.65 seconds
Result: FAIL
Output:

Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.102 seconds

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TestRunner_rfcomm-tester
Desc: Run rfcomm-tester with test-runner
Duration: 9.28 seconds
Result: PASS

[github-actions]

TestRunner_sco-tester
Desc: Run sco-tester with test-runner
Duration: 14.05 seconds
Result: PASS

[github-actions]

TestRunner_ioctl-tester
Desc: Run ioctl-tester with test-runner
Duration: 9.98 seconds
Result: PASS

[github-actions]

TestRunner_mesh-tester
Desc: Run mesh-tester with test-runner
Duration: 11.46 seconds
Result: FAIL
Output:

Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    1.829 seconds
Mesh - Send cancel - 2                               Timed out    2.004 seconds

[github-actions]

TestRunner_smp-tester
Desc: Run smp-tester with test-runner
Duration: 8.44 seconds
Result: PASS

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TestRunner_userchan-tester
Desc: Run userchan-tester with test-runner
Duration: 6.50 seconds
Result: PASS

[github-actions]

TestRunner_6lowpan-tester
Desc: Run 6lowpan-tester with test-runner
Duration: 8.83 seconds
Result: FAIL
Output:

WARNING: possible circular locking dependency detected
7.0.0-rc2-g48abf361eec2 #1 Not tainted
------------------------------------------------------
kworker/0:1/11 is trying to acquire lock:
ffff888002767140 ((wq_completion)hci0#2){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x75/0x180

but task is already holding lock:
ffffffff8844d720 (rtnl_mutex){+.+.}-{4:4}, at: lowpan_unregister_netdev+0xd/0x30

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (rtnl_mutex){+.+.}-{4:4}:
       lock_acquire+0xf7/0x2c0
       __mutex_lock+0x16b/0x1fc0
       lowpan_register_netdev+0x11/0x30
       chan_ready_cb+0x836/0xd00
       l2cap_recv_frame+0x6a06/0x8920
       l2cap_recv_acldata+0x790/0xdf0
       hci_rx_work+0x500/0xd00
       process_scheduled_works+0xb16/0x1ac0
       worker_thread+0x4ff/0xba0
       kthread+0x368/0x490
       ret_from_fork+0x498/0x7e0
       ret_from_fork_asm+0x19/0x30

-> #3 (&chan->lock#3/1){+.+.}-{4:4}:
       lock_acquire+0xf7/0x2c0
       __mutex_lock+0x16b/0x1fc0
       l2cap_chan_connect+0x74e/0x1980
       lowpan_control_write+0x523/0x660
       full_proxy_write+0x10b/0x190
       vfs_write+0x1c0/0xf60
       ksys_write+0xf1/0x1d0
       do_syscall_64+0xa0/0x570
       entry_SYSCALL_64_after_hwframe+0x74/0x7c

-> #2 (&conn->lock){+.+.}-{4:4}:
...
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0

[github-actions]

IncrementalBuild
Desc: Incremental build with the patches in the series
Duration: 0.30 seconds
Result: PENDING