linux-next (4.12-rc1): DEADLOCK: WARNING: possible circular locking dependency detected

From: Naresh Kamboju
Date: Thu May 18 2017 - 06:35:41 EST

Hi Team,

DEADLOCK detected on HiKey (arm64) development board running
linux-next-4.12.0-rc1.
This DEADLOCK occurred two times while booting the device and other
one is while running libhugetlbfs test suite.

Please find error log in pastebin
https://pastebin.com/LWWHPJ87

LAVA job id:
https://validation.linaro.org/scheduler/job/1498548/log_file#L_195_866

Linux kernel version:
Linux version 4.12.0-rc1-next-20170515 (buildslave@x86-64-07) (gcc
version 6.2.1 20161016 (Linaro GCC 6.2-2016.11) ) #1 SMP PREEMPT Mon
May 15 03:12:43 UTC 2017

Build location:
-------------------
https://snapshots.linaro.org/openembedded/lkft/morty/hikey/rpb/linux-next/10

Boot image:
- boot-0.0+AUTOINC+06e4def583-4adfdd06f1-r0-hikey-20170515030615-10.uefi.img
Rootfs:
- rpb-console-image-hikey-20170515030615-10.rootfs.img.gz

steps to reproduce:
--------------------------
- sudo fastboot flash boot
boot-0.0+AUTOINC+06e4def583-4adfdd06f1-r0-hikey-20170515030615-10.uefi.img
- sudo fastboot flash system
rpb-console-image-hikey-20170515030615-10.rootfs.img

Boot HiKey board.

[ 76.039134] ======================================================
[ 76.045319] WARNING: possible circular locking dependency detected
[ 76.051507] 4.12.0-rc1-next-20170515 #1 Not tainted
[ 76.056387] ------------------------------------------------------
[ 76.062572] irq/56-wl18xx/2354 is trying to acquire lock:
[ 76.067974] (rtnl_mutex){+.+.+.}, at: [<ffff0000089b92f8>]
rtnl_lock+0x18/0x20
[ 76.075309]
[ 76.075309] but task is already holding lock:
[ 76.081145] (&wl->mutex){+.+.+.}, at: [<ffff000000f24054>]
wlcore_irq+0xdc/0x1a0 [wlcore]
[ 76.089510]
[ 76.089510] which lock already depends on the new lock.
[ 76.089510]
[ 76.097697]
[ 76.097697] the existing dependency chain (in reverse order) is:
[ 76.105187]
[ 76.105187] -> #1 (&wl->mutex){+.+.+.}:
[ 76.110519] __lock_acquire+0x17b4/0x1928
[ 76.115053] lock_acquire+0xc8/0x290
[ 76.119155] __mutex_lock+0x78/0x8a8
[ 76.123261] mutex_lock_nested+0x1c/0x28
[ 76.127775] wlcore_regdomain_config.part.25+0x20/0x78 [wlcore]
[ 76.134292] wl1271_reg_notify+0x30/0x40 [wlcore]
[ 76.139727] wiphy_update_regulatory+0x294/0x420 [cfg80211]
[ 76.145975] wiphy_regulatory_register+0x34/0x48 [cfg80211]
[ 76.152218] wiphy_register+0x5fc/0x7d8 [cfg80211]
[ 76.157812] ieee80211_register_hw+0x3d4/0xa48 [mac80211]
[ 76.163811] wlcore_nvs_cb+0x758/0x9a8 [wlcore]
[ 76.168936] wlcore_probe+0x98/0xf0 [wlcore]
[ 76.173779] wl18xx_probe+0x4c/0xa8 [wl18xx]
[ 76.178586] platform_drv_probe+0x58/0xc0
[ 76.183127] driver_probe_device+0x214/0x2d0
[ 76.187926] __driver_attach+0xb4/0xb8
[ 76.192204] bus_for_each_dev+0x64/0xa0
[ 76.196568] driver_attach+0x20/0x28
[ 76.200672] bus_add_driver+0x110/0x230
[ 76.205037] driver_register+0x60/0xf8
[ 76.209315] __platform_driver_register+0x40/0x48
[ 76.214551] 0xffff000000f90018
[ 76.218222] do_one_initcall+0x38/0x120
[ 76.222589] do_init_module+0x5c/0x1c0
[ 76.226868] load_module+0x1cac/0x2428
[ 76.231145] SyS_finit_module+0xc0/0xd0
[ 76.235510] __sys_trace_return+0x0/0x4
[ 76.239872]
[ 76.239872] -> #0 (rtnl_mutex){+.+.+.}:
[ 76.245215] print_circular_bug+0x80/0x2e0
[ 76.249840] __lock_acquire+0x17dc/0x1928
[ 76.254379] lock_acquire+0xc8/0x290
[ 76.258485] __mutex_lock+0x78/0x8a8
[ 76.262589] mutex_lock_nested+0x1c/0x28
[ 76.267042] rtnl_lock+0x18/0x20
[ 76.270956] cfg80211_sched_scan_results+0x60/0x230 [cfg80211]
[ 76.277587] ieee80211_sched_scan_results+0x5c/0x1e0 [mac80211]
[ 76.284117] wlcore_scan_sched_scan_results+0x24/0x60 [wlcore]
[ 76.290523] wl18xx_process_mailbox_events+0x60/0x468 [wl18xx]
[ 76.296955] wl1271_event_handle+0xc4/0x160 [wlcore]
[ 76.302514] wlcore_irq_locked+0x4e0/0x660 [wlcore]
[ 76.307986] wlcore_irq+0xe4/0x1a0 [wlcore]
[ 76.312703] irq_thread_fn+0x28/0x68
[ 76.316809] irq_thread+0x158/0x1f8
[ 76.320827] kthread+0x108/0x138
[ 76.324584] ret_from_fork+0x10/0x40
[ 76.328686]
[ 76.328686] other info that might help us debug this:
[ 76.328686]
[ 76.336715] Possible unsafe locking scenario:
[ 76.336715]
[ 76.342650] CPU0 CPU1
[ 76.347186] ---- ----
[ 76.351722] lock(&wl->mutex);
[ 76.354872] lock(rtnl_mutex);
[ 76.360543] lock(&wl->mutex);
[ 76.366213] lock(rtnl_mutex);
[ 76.369361]
[ 76.369361] *** DEADLOCK ***
[ 76.369361]
[ 76.375304] 1 lock held by irq/56-wl18xx/2354:
[ 76.379753] #0: (&wl->mutex){+.+.+.}, at: [<ffff000000f24054>]
wlcore_irq+0xdc/0x1a0 [wlcore]
[ 76.388547]
[ 76.388547] stack backtrace:
[ 76.392922] CPU: 4 PID: 2354 Comm: irq/56-wl18xx Not tainted
4.12.0-rc1-next-20170515 #1
[ 76.401032] Hardware name: HiKey Development Board (DT)
[ 76.406267] Call trace:
[ 76.408720] [<ffff00000808a028>] dump_backtrace+0x0/0x240
[ 76.414131] [<ffff00000808a32c>] show_stack+0x14/0x20
[ 76.419195] [<ffff0000084984f4>] dump_stack+0xbc/0xf8
[ 76.424258] [<ffff000008124504>] print_circular_bug+0x1f4/0x2e0
[ 76.430190] [<ffff00000812757c>] __lock_acquire+0x17dc/0x1928
[ 76.435947] [<ffff000008127f38>] lock_acquire+0xc8/0x290
[ 76.441272] [<ffff000008af5888>] __mutex_lock+0x78/0x8a8
[ 76.446595] [<ffff000008af60d4>] mutex_lock_nested+0x1c/0x28
[ 76.452267] [<ffff0000089b92f8>] rtnl_lock+0x18/0x20
[ 76.457402] [<ffff000000cf4518>]
cfg80211_sched_scan_results+0x60/0x230 [cfg80211]
[ 76.465253] [<ffff000000dfb0cc>]
ieee80211_sched_scan_results+0x5c/0x1e0 [mac80211]
[ 76.472994] [<ffff000000f3887c>]
wlcore_scan_sched_scan_results+0x24/0x60 [wlcore]
[ 76.480624] [<ffff000000f77640>]
wl18xx_process_mailbox_events+0x60/0x468 [wl18xx]
[ 76.488278] [<ffff000000f2c874>] wl1271_event_handle+0xc4/0x160 [wlcore]
[ 76.495056] [<ffff000000f22c28>] wlcore_irq_locked+0x4e0/0x660 [wlcore]
[ 76.501747] [<ffff000000f2405c>] wlcore_irq+0xe4/0x1a0 [wlcore]
[ 76.507682] [<ffff00000813dab8>] irq_thread_fn+0x28/0x68
[ 76.513005] [<ffff00000813dda0>] irq_thread+0x158/0x1f8
[ 76.518242] [<ffff0000080f4b38>] kthread+0x108/0x138
[ 76.523217] [<ffff000008083710>] ret_from_fork+0x10/0x40


Best regards
Naresh Kamboju