LinuxLists.cc - Revert "leds: avoid races with workqueue"?

2019-05-24 23:10:43

Subject: Revert "leds: avoid races with workqueue"?

Hi Pavel,

I'm having to revert 0db37915d912 ("leds: avoid races with workqueue")
from my 5.2-rc testing tree, because lockdep and other debug options
don't like it: net/mac80211/led.c arranges for led_blink_setup() to be
called at softirq time, and flush_work() is not good for calling then.

Hugh

================================
WARNING: inconsistent lock state
5.2.0-rc1 #1 Tainted: G W
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
000000006e30541b ((work_completion)(&led_cdev->set_brightness_work)){+.?.}, at: __flush_work+0x3b/0x38a
{SOFTIRQ-ON-W} state was registered at:
lock_acquire+0x146/0x1a1
__flush_work+0x5b/0x38a
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
ieee80211_mod_tpt_led_trig+0xed/0x112
__ieee80211_recalc_idle+0xd9/0x11f
ieee80211_idle_off+0xe/0x10
ieee80211_add_chanctx+0x6c/0x2df
ieee80211_new_chanctx+0x7d/0xe8
ieee80211_vif_use_channel+0x163/0x1fe
ieee80211_prep_connection+0x9db/0xbac
ieee80211_mgd_auth+0x274/0x328
ieee80211_auth+0x13/0x15
cfg80211_mlme_auth+0x1e1/0x341
nl80211_authenticate+0x25c/0x29e
genl_family_rcv_msg+0x2b7/0x31a
genl_rcv_msg+0x4a/0x6c
netlink_rcv_skb+0x55/0xaa
genl_rcv+0x23/0x32
netlink_unicast+0xfc/0x1bb
netlink_sendmsg+0x2c6/0x335
sock_sendmsg+0x12/0x1d
___sys_sendmsg+0x1c5/0x23d
__sys_sendmsg+0x4b/0x75
__x64_sys_sendmsg+0x1a/0x1c
do_syscall_64+0x51/0x182
entry_SYSCALL_64_after_hwframe+0x49/0xbe
irq event stamp: 44098
hardirqs last enabled at (44098): [<ffffffff818a2375>] _raw_spin_unlock_irqrestore+0x3a/0x5b
hardirqs last disabled at (44097): [<ffffffff818a21fd>] _raw_spin_lock_irqsave+0x13/0x4c
softirqs last enabled at (44088): [<ffffffff810fbb8e>] _local_bh_enable+0x1e/0x20
softirqs last disabled at (44089): [<ffffffff810fbecf>] irq_exit+0x69/0xb9

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock((work_completion)(&led_cdev->set_brightness_work));
<Interrupt>
lock((work_completion)(&led_cdev->set_brightness_work));

*** DEADLOCK ***

2 locks held by swapper/1/0:
#0: 0000000002d634a0 ((&tpt_trig->timer)){+.-.}, at: call_timer_fn+0x0/0x2ce
#1: 000000007ed2567d (&trig->leddev_list_lock){.+.?}, at: tpt_trig_timer+0xbe/0x106

stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
print_usage_bug+0x292/0x2a5
? print_irq_inversion_bug+0x1cb/0x1cb
mark_lock+0x307/0x51e
__lock_acquire+0x2c0/0x762
lock_acquire+0x146/0x1a1
? __flush_work+0x3b/0x38a
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__flush_work+0x5b/0x38a
? __flush_work+0x3b/0x38a
? mark_held_locks+0x47/0x63
? _raw_spin_unlock_irqrestore+0x3a/0x5b
? _raw_spin_unlock_irqrestore+0x3a/0x5b
? lockdep_hardirqs_on+0x196/0x1a5
? try_to_del_timer_sync+0x44/0x4f
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: ffff888234d84300 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888234d84300
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 0000000000000ed5 R11: 0000000000000086 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0
BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8108e14f>] start_secondary+0x48/0x11b
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
? start_secondary+0x48/0x11b
___might_sleep+0x229/0x240
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__might_sleep+0x63/0x77
? __flush_work+0x3b/0x38a
__flush_work+0x84/0x38a
? mark_held_locks+0x47/0x63
? _raw_spin_unlock_irqrestore+0x3a/0x5b
? _raw_spin_unlock_irqrestore+0x3a/0x5b
? lockdep_hardirqs_on+0x196/0x1a5
? try_to_del_timer_sync+0x44/0x4f
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: ffff888234d84300 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888234d84300
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 0000000000000ed5 R11: 0000000000000086 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0
ing mDNS multicast group on interface wlp3s0.IPv6 with address fe80::2677:3ff:fe6f:637c.
ing mDNS multicast group on interface wlp3s0.IPv6 with address 2600:1700:3ec0:f40:2677:3ff:fe6f:637c.
stering new address record for 2600:1700:3ec0:f40:2677:3ff:fe6f:637c on wlp3s0.*.
drawing address record for fe80::2677:3ff:fe6f:637c on wlp3s0.
BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8108e14f>] start_secondary+0x48/0x11b
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
? start_secondary+0x48/0x11b
___might_sleep+0x229/0x240
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__might_sleep+0x63/0x77
? __flush_work+0x3b/0x38a
__flush_work+0x84/0x38a
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
? ktime_get+0x8e/0xe4
? trace_hardirqs_on+0xc7/0xf7
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 0000001c6cff9837 RDI: ffffffff81664055
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 000000000000e848 R11: 0000000000016727 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0
BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8108e14f>] start_secondary+0x48/0x11b
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
? start_secondary+0x48/0x11b
___might_sleep+0x229/0x240
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__might_sleep+0x63/0x77
? __flush_work+0x3b/0x38a
__flush_work+0x84/0x38a
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
? ktime_get+0x8e/0xe4
? trace_hardirqs_on+0xc7/0xf7
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 0000001d051767b2 RDI: ffffffff81664055
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 0000000000031f74 R11: 0000000000034923 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0
BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8108e14f>] start_secondary+0x48/0x11b
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
? start_secondary+0x48/0x11b
___might_sleep+0x229/0x240
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__might_sleep+0x63/0x77
? __flush_work+0x3b/0x38a
__flush_work+0x84/0x38a
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
? ktime_get+0x8e/0xe4
? trace_hardirqs_on+0xc7/0xf7
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 0000001e2bc5a50d RDI: ffffffff81664055
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 0000000000007d25 R11: 00000000000300c8 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0
BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8108e14f>] start_secondary+0x48/0x11b
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
? start_secondary+0x48/0x11b
___might_sleep+0x229/0x240
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__might_sleep+0x63/0x77
? __flush_work+0x3b/0x38a
__flush_work+0x84/0x38a
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
? ktime_get+0x8e/0xe4
? trace_hardirqs_on+0xc7/0xf7
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 0000001f57348651 RDI: ffffffff81664055
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 0000000000006ac4 R11: 0000000000007e37 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0
BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8108e14f>] start_secondary+0x48/0x11b
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
Call Trace:
<IRQ>
dump_stack+0x67/0x93
? start_secondary+0x48/0x11b
___might_sleep+0x229/0x240
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
__might_sleep+0x63/0x77
? __flush_work+0x3b/0x38a
__flush_work+0x84/0x38a
? trace_hardirqs_on+0xc7/0xf7
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
? _raw_spin_unlock_irqrestore+0x46/0x5b
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
? add_timer_on+0xce/0xce
call_timer_fn+0x11e/0x2ce
? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
expire_timers+0x141/0x197
run_timer_softirq+0x65/0x10e
? ktime_get+0x8e/0xe4
? trace_hardirqs_on+0xc7/0xf7
__do_softirq+0x1bf/0x430
irq_exit+0x69/0xb9
smp_apic_timer_interrupt+0x1ee/0x269
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
RDX: 0000000000000000 RSI: 000000207de2bdf6 RDI: ffffffff81664055
RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
R10: 000000000000afc8 R11: 00000000000185c2 R12: ffffffff8229e320
R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
? cpuidle_enter_state+0x1f0/0x34d
? cpuidle_enter_state+0x1f0/0x34d
cpuidle_enter+0x28/0x36
call_cpuidle+0x3b/0x3d
do_idle+0x189/0x1eb
cpu_startup_entry+0x1a/0x1e
start_secondary+0xfe/0x11b
secondary_startup_64+0xa4/0xb0

2019-05-25 09:09:42

by Pavel Machek

[permalink] [raw]

Subject: Re: Revert "leds: avoid races with workqueue"?

Hi!

> I'm having to revert 0db37915d912 ("leds: avoid races with workqueue")
> from my 5.2-rc testing tree, because lockdep and other debug options
> don't like it: net/mac80211/led.c arranges for led_blink_setup() to be
> called at softirq time, and flush_work() is not good for calling
> then.

Yep, I noticed something is fishy during code review, and asked Sasha
not to queue it for stable yesterday.

Thanks for confirmation.

Standby.

LED code is "interesting" but I should be able to keep the X60 working
as it is. Unbreaking code will mean more changes.

Best regards,
Pavel

> ================================
> WARNING: inconsistent lock state
> 5.2.0-rc1 #1 Tainted: G W
> --------------------------------
> inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
> swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
> 000000006e30541b ((work_completion)(&led_cdev->set_brightness_work)){+.?.}, at: __flush_work+0x3b/0x38a
> {SOFTIRQ-ON-W} state was registered at:
> lock_acquire+0x146/0x1a1
> __flush_work+0x5b/0x38a
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ieee80211_mod_tpt_led_trig+0xed/0x112
> __ieee80211_recalc_idle+0xd9/0x11f
> ieee80211_idle_off+0xe/0x10
> ieee80211_add_chanctx+0x6c/0x2df
> ieee80211_new_chanctx+0x7d/0xe8
> ieee80211_vif_use_channel+0x163/0x1fe
> ieee80211_prep_connection+0x9db/0xbac
> ieee80211_mgd_auth+0x274/0x328
> ieee80211_auth+0x13/0x15
> cfg80211_mlme_auth+0x1e1/0x341
> nl80211_authenticate+0x25c/0x29e
> genl_family_rcv_msg+0x2b7/0x31a
> genl_rcv_msg+0x4a/0x6c
> netlink_rcv_skb+0x55/0xaa
> genl_rcv+0x23/0x32
> netlink_unicast+0xfc/0x1bb
> netlink_sendmsg+0x2c6/0x335
> sock_sendmsg+0x12/0x1d
> ___sys_sendmsg+0x1c5/0x23d
> __sys_sendmsg+0x4b/0x75
> __x64_sys_sendmsg+0x1a/0x1c
> do_syscall_64+0x51/0x182
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> irq event stamp: 44098
> hardirqs last enabled at (44098): [<ffffffff818a2375>] _raw_spin_unlock_irqrestore+0x3a/0x5b
> hardirqs last disabled at (44097): [<ffffffff818a21fd>] _raw_spin_lock_irqsave+0x13/0x4c
> softirqs last enabled at (44088): [<ffffffff810fbb8e>] _local_bh_enable+0x1e/0x20
> softirqs last disabled at (44089): [<ffffffff810fbecf>] irq_exit+0x69/0xb9
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock((work_completion)(&led_cdev->set_brightness_work));
> <Interrupt>
> lock((work_completion)(&led_cdev->set_brightness_work));
>
> *** DEADLOCK ***
>
> 2 locks held by swapper/1/0:
> #0: 0000000002d634a0 ((&tpt_trig->timer)){+.-.}, at: call_timer_fn+0x0/0x2ce
> #1: 000000007ed2567d (&trig->leddev_list_lock){.+.?}, at: tpt_trig_timer+0xbe/0x106
>
> stack backtrace:
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> print_usage_bug+0x292/0x2a5
> ? print_irq_inversion_bug+0x1cb/0x1cb
> mark_lock+0x307/0x51e
> __lock_acquire+0x2c0/0x762
> lock_acquire+0x146/0x1a1
> ? __flush_work+0x3b/0x38a
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __flush_work+0x5b/0x38a
> ? __flush_work+0x3b/0x38a
> ? mark_held_locks+0x47/0x63
> ? _raw_spin_unlock_irqrestore+0x3a/0x5b
> ? _raw_spin_unlock_irqrestore+0x3a/0x5b
> ? lockdep_hardirqs_on+0x196/0x1a5
> ? try_to_del_timer_sync+0x44/0x4f
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: ffff888234d84300 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888234d84300
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 0000000000000ed5 R11: 0000000000000086 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0
> BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
> in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
> INFO: lockdep is turned off.
> Preemption disabled at:
> [<ffffffff8108e14f>] start_secondary+0x48/0x11b
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> ? start_secondary+0x48/0x11b
> ___might_sleep+0x229/0x240
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __might_sleep+0x63/0x77
> ? __flush_work+0x3b/0x38a
> __flush_work+0x84/0x38a
> ? mark_held_locks+0x47/0x63
> ? _raw_spin_unlock_irqrestore+0x3a/0x5b
> ? _raw_spin_unlock_irqrestore+0x3a/0x5b
> ? lockdep_hardirqs_on+0x196/0x1a5
> ? try_to_del_timer_sync+0x44/0x4f
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: ffff888234d84300 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888234d84300
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 0000000000000ed5 R11: 0000000000000086 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0
> ing mDNS multicast group on interface wlp3s0.IPv6 with address fe80::2677:3ff:fe6f:637c.
> ing mDNS multicast group on interface wlp3s0.IPv6 with address 2600:1700:3ec0:f40:2677:3ff:fe6f:637c.
> stering new address record for 2600:1700:3ec0:f40:2677:3ff:fe6f:637c on wlp3s0.*.
> drawing address record for fe80::2677:3ff:fe6f:637c on wlp3s0.
> BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
> in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
> INFO: lockdep is turned off.
> Preemption disabled at:
> [<ffffffff8108e14f>] start_secondary+0x48/0x11b
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> ? start_secondary+0x48/0x11b
> ___might_sleep+0x229/0x240
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __might_sleep+0x63/0x77
> ? __flush_work+0x3b/0x38a
> __flush_work+0x84/0x38a
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> ? ktime_get+0x8e/0xe4
> ? trace_hardirqs_on+0xc7/0xf7
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 0000001c6cff9837 RDI: ffffffff81664055
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 000000000000e848 R11: 0000000000016727 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0
> BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
> in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
> INFO: lockdep is turned off.
> Preemption disabled at:
> [<ffffffff8108e14f>] start_secondary+0x48/0x11b
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> ? start_secondary+0x48/0x11b
> ___might_sleep+0x229/0x240
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __might_sleep+0x63/0x77
> ? __flush_work+0x3b/0x38a
> __flush_work+0x84/0x38a
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> ? ktime_get+0x8e/0xe4
> ? trace_hardirqs_on+0xc7/0xf7
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 0000001d051767b2 RDI: ffffffff81664055
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 0000000000031f74 R11: 0000000000034923 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0
> BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
> in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
> INFO: lockdep is turned off.
> Preemption disabled at:
> [<ffffffff8108e14f>] start_secondary+0x48/0x11b
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> ? start_secondary+0x48/0x11b
> ___might_sleep+0x229/0x240
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __might_sleep+0x63/0x77
> ? __flush_work+0x3b/0x38a
> __flush_work+0x84/0x38a
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> ? ktime_get+0x8e/0xe4
> ? trace_hardirqs_on+0xc7/0xf7
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 0000001e2bc5a50d RDI: ffffffff81664055
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 0000000000007d25 R11: 00000000000300c8 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0
> BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
> in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
> INFO: lockdep is turned off.
> Preemption disabled at:
> [<ffffffff8108e14f>] start_secondary+0x48/0x11b
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> ? start_secondary+0x48/0x11b
> ___might_sleep+0x229/0x240
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __might_sleep+0x63/0x77
> ? __flush_work+0x3b/0x38a
> __flush_work+0x84/0x38a
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> ? ktime_get+0x8e/0xe4
> ? trace_hardirqs_on+0xc7/0xf7
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 0000001f57348651 RDI: ffffffff81664055
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 0000000000006ac4 R11: 0000000000007e37 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0
> BUG: sleeping function called from invalid context at kernel/workqueue.c:2974
> in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
> INFO: lockdep is turned off.
> Preemption disabled at:
> [<ffffffff8108e14f>] start_secondary+0x48/0x11b
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 5.2.0-rc1 #1
> Hardware name: LENOVO 4174EH1/4174EH1, BIOS 8CET51WW (1.31 ) 11/29/2011
> Call Trace:
> <IRQ>
> dump_stack+0x67/0x93
> ? start_secondary+0x48/0x11b
> ___might_sleep+0x229/0x240
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> __might_sleep+0x63/0x77
> ? __flush_work+0x3b/0x38a
> __flush_work+0x84/0x38a
> ? trace_hardirqs_on+0xc7/0xf7
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> ? _raw_spin_unlock_irqrestore+0x46/0x5b
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> flush_work+0xb/0xd
> led_blink_setup+0x1e/0xd3
> led_blink_set+0x3f/0x44
> tpt_trig_timer+0xdb/0x106
> ? add_timer_on+0xce/0xce
> call_timer_fn+0x11e/0x2ce
> ? __ieee80211_create_tpt_led_trigger+0xcb/0xcb
> expire_timers+0x141/0x197
> run_timer_softirq+0x65/0x10e
> ? ktime_get+0x8e/0xe4
> ? trace_hardirqs_on+0xc7/0xf7
> __do_softirq+0x1bf/0x430
> irq_exit+0x69/0xb9
> smp_apic_timer_interrupt+0x1ee/0x269
> apic_timer_interrupt+0xf/0x20
> </IRQ>
> RIP: 0010:cpuidle_enter_state+0x1f4/0x34d
> Code: ff e8 36 0c ac ff 45 84 ff 74 16 9c 58 f6 c4 02 74 08 0f 0b fa e8 e5 da b4 ff 31 ff e8 23 c9 b1 ff e8 f0 d8 b4 ff fb 45 85 ed <0f> 88 e2 00 00 00 49 63 f5 b9 e8 03 00 00 48 6b c6 60 49 8d 7c 04
> RSP: 0018:ffff888234d8be58 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
> RAX: 0000000000000000 RBX: ffffe8ffffc864c0 RCX: 000000000000001f
> RDX: 0000000000000000 RSI: 000000207de2bdf6 RDI: ffffffff81664055
> RBP: ffff888234d8be98 R08: 0000000000000002 R09: fffffffa2dd3f8df
> R10: 000000000000afc8 R11: 00000000000185c2 R12: ffffffff8229e320
> R13: 0000000000000005 R14: ffffffff8229e518 R15: 0000000000000000
> ? cpuidle_enter_state+0x1f0/0x34d
> ? cpuidle_enter_state+0x1f0/0x34d
> cpuidle_enter+0x28/0x36
> call_cpuidle+0x3b/0x3d
> do_idle+0x189/0x1eb
> cpu_startup_entry+0x1a/0x1e
> start_secondary+0xfe/0x11b
> secondary_startup_64+0xa4/0xb0

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Attachments:

(No filename) (18.63 kB)
signature.asc (188.00 B)
Digital signature Download all attachments

2019-05-25 09:39:35

by Pavel Machek

[permalink] [raw]

Subject: Re: Revert "leds: avoid races with workqueue"?

Attachments:

(No filename) (2.15 kB)
signature.asc (188.00 B)
Digital signature Download all attachments

2019-05-25 17:35:04

by Hugh Dickins

[permalink] [raw]

Subject: Re: Revert "leds: avoid races with workqueue"?

On Sat, 25 May 2019, Pavel Machek wrote:

> Hi!
>
> > I'm having to revert 0db37915d912 ("leds: avoid races with workqueue")
> > from my 5.2-rc testing tree, because lockdep and other debug options
> > don't like it: net/mac80211/led.c arranges for led_blink_setup() to be
> > called at softirq time, and flush_work() is not good for calling
> > then.
>
> This should keep X60 working (as well as it is now; X60 will still
> have problems with lost events in setup like yours).
>
> Can you test this instead of the revert?

Thanks, Pavel: yes, that works fine for me on the T420s, no debug
complaints, good and silent; and the wifi LED is blinking as before.

Hugh

>
> Thanks,
> Pavel
>
> diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
> index aefac4d..ebaac4d 100644
> --- a/drivers/leds/led-core.c
> +++ b/drivers/leds/led-core.c
> @@ -158,19 +159,14 @@ static void led_set_software_blink(struct led_classdev *led_cdev,
> }
>
> set_bit(LED_BLINK_SW, &led_cdev->work_flags);
> - mod_timer(&led_cdev->blink_timer, jiffies + 1);
> + mod_timer(&led_cdev->blink_timer, jiffies + 1); /* Why oh why? Just call it directly? */
> }
>
> -
> +/* May not block */
> static void led_blink_setup(struct led_classdev *led_cdev,
> unsigned long *delay_on,
> unsigned long *delay_off)
> {
> - /*
> - * If "set brightness to 0" is pending in workqueue, we don't
> - * want that to be reordered after blink_set()
> - */
> - flush_work(&led_cdev->set_brightness_work);
> if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
> led_cdev->blink_set &&
> !led_cdev->blink_set(led_cdev, delay_on, delay_off))
> diff --git a/drivers/leds/trigger/ledtrig-timer.c b/drivers/leds/trigger/ledtrig-timer.c
> index ca898c1..427fc3c 100644
> --- a/drivers/leds/trigger/ledtrig-timer.c
> +++ b/drivers/leds/trigger/ledtrig-timer.c
> @@ -113,6 +113,11 @@ static int timer_trig_activate(struct led_classdev *led_cdev)
> led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
> }
>
> + /*
> + * If "set brightness to 0" is pending in workqueue, we don't
> + * want that to be reordered after blink_set()
> + */
> + flush_work(&led_cdev->set_brightness_work);
> led_blink_set(led_cdev, &led_cdev->blink_delay_on,
> &led_cdev->blink_delay_off);
>
>
>
>
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

2019-05-26 17:23:19

by Pavel Machek

[permalink] [raw]

Subject: Re: Revert "leds: avoid races with workqueue"?

On Sat 2019-05-25 10:32:31, Hugh Dickins wrote:
> On Sat, 25 May 2019, Pavel Machek wrote:
>
> > Hi!
> >
> > > I'm having to revert 0db37915d912 ("leds: avoid races with workqueue")
> > > from my 5.2-rc testing tree, because lockdep and other debug options
> > > don't like it: net/mac80211/led.c arranges for led_blink_setup() to be
> > > called at softirq time, and flush_work() is not good for calling
> > > then.
> >
> > This should keep X60 working (as well as it is now; X60 will still
> > have problems with lost events in setup like yours).
> >
> > Can you test this instead of the revert?
>
> Thanks, Pavel: yes, that works fine for me on the T420s, no debug
> complaints, good and silent; and the wifi LED is blinking as before.

I'd like to prevent recurrence of similar problem, and I wonder if you
can give me a hint.

I can annotate code that can sleep with might_sleep().

How can I annotate code that can not sleep? I might do

spin_lock(&dummy);
this_should_not_sleep();
spin_unlock(&dummy);

But I don't really need extra serialization. I just want annotations for
lockdep. Any ideas?

Pavel

2019-05-26 20:38:41

by Hugh Dickins

[permalink] [raw]

Subject: Re: Revert "leds: avoid races with workqueue"?

On Sun, 26 May 2019, Pavel Machek wrote:
> On Sat 2019-05-25 10:32:31, Hugh Dickins wrote:
> >
> > Thanks, Pavel: yes, that works fine for me on the T420s, no debug
> > complaints, good and silent; and the wifi LED is blinking as before.
>
> I'd like to prevent recurrence of similar problem, and I wonder if you
> can give me a hint.
>
> I can annotate code that can sleep with might_sleep().
>
> How can I annotate code that can not sleep? I might do
>
> spin_lock(&dummy);
> this_should_not_sleep();
> spin_unlock(&dummy);
>
> But I don't really need extra serialization. I just want annotations for
> lockdep. Any ideas?

I haven't tried to do that directly, so I'm likely to give bad advice:
in particular, I forget the limitations of checking in_atomic().

But very useful (and much cheaper than lockdep) debug options in
this area are CONFIG_DEBUG_PREEMPT and CONFIG_DEBUG_ATOMIC_SLEEP.

Hugh