lockdep warning while booting POWER9 PowerNV

[Qian Cai]

https://raw.githubusercontent.com/cailca/linux-mm/master/powerpc.config

Once in a while, booting an IBM POWER9 PowerNV system (8335-GTH) would generate
a warning in lockdep_register_key() at,

if (WARN_ON_ONCE(static_obj(key)))

because

key = 0xc0000000019ad118
&_stext = 0xc000000000000000
&_end = 0xc0000000049d0000

i.e., it will cause static_obj() returns 1.


[   23.738200][   T13] ahci 0004:03:00.0: enabling device (0541 -> 0543)
[   23.748692][    T5] tg3.c:v3.137 (May 11, 2014)
[   23.748731][    T5] tg3 0005:01:00.0: enabling device (0140 -> 0142)
[   23.751478][   T13] ahci 0004:03:00.0: AHCI 0001.0000 32 slots 4 ports 6 Gbps
0xf impl SATA mode
[   23.751517][   T13] ahci 0004:03:00.0: flags: 64bit ncq sntf led only pmp fbs
pio slum part sxs 
[   23.791077][   T13] scsi host0: ahci
[   23.802752][   T13] ------------[ cut here ]------------
[   23.802786][   T13] WARNING: CPU: 0 PID: 13 at kernel/locking/lockdep.c:1120
lockdep_register_key+0x68/0x200
[   23.802814][   T13] Modules linked in: mdio tg3(+) ahci(+) libahci libphy
firmware_class libata dm_mirror dm_region_hash dm_log dm_mod
[   23.802884][   T13] CPU: 0 PID: 13 Comm: kworker/0:1 Not tainted 5.3.0-rc6-
next-20190830 #4
[   23.802930][   T13] Workqueue: events work_for_cpu_fn
[   23.802962][   T13] NIP:  c00000000019eed8 LR: c000000000129400 CTR:
c0000000008a46dc
[   23.802988][   T13] REGS: c00000002db2f130 TRAP: 0700   Not tainted  (5.3.0-
rc6-next-20190830)
[   23.803032][   T13] MSR:  900000000282b033
<SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 48800a89  XER: 20040000
[   23.803096][   T13] CFAR: c00000000019eeac IRQMASK: 0 
[   23.803096][   T13] GPR00: c000000000129400 c00000002db2f3c0 c000000002bb9400
c0000000049d0000 
[   23.803096][   T13] GPR04: 0000000000000000 c000000002d84718 0000000000000000
ffff0a01ffffff10 
[   23.803096][   T13] GPR08: c000000000b8a16b c000000000a515cc c000000000b8a16a
0000000000000044 
[   23.803096][   T13] GPR12: 0000000088800a89 c0000000049d0000 c00800000eea3290
0000000000000001 
[   23.803096][   T13] GPR16: c000001bca584500 c000000007244954 c000001bca584508
0000000000000020 
[   23.803096][   T13] GPR20: c000000001aea180 0000000000000001 c00800000eee7560
c000001bca584500 
[   23.803096][   T13] GPR24: c000001bca584448 000000000002000a c000000001aea148
c000000000b8a161 
[   23.803096][   T13] GPR28: c000000001aea020 c000000001aea118 c000000001aea000
c00000002db2f440 
[   23.803407][   T13] NIP [c00000000019eed8] lockdep_register_key+0x68/0x200
[   23.803432][   T13] LR [c000000000129400] wq_init_lockdep+0x40/0xc0
[   23.803461][   T13] Call Trace:
[   23.803491][   T13] [c00000002db2f3c0] [c000000000b8a16a]
trunc_msg+0x385f9/0x4c30f (unreliable)
[   23.803531][   T13] [c00000002db2f440] [c000000000129400]
wq_init_lockdep+0x40/0xc0
[   23.803577][   T13] [c00000002db2f4c0] [c000000000128d90]
alloc_workqueue+0x1e0/0x620
[   23.803623][   T13] [c00000002db2f5c0] [c0000000006ca048]
scsi_host_alloc+0x3d8/0x490
[   23.803701][   T13] [c00000002db2f660] [c00800000ee73198]
ata_scsi_add_hosts+0xd0/0x220 [libata]
[   23.803771][   T13] [c00000002db2f6f0] [c00800000ee6d440]
ata_host_register+0x178/0x400 [libata]
[   23.803840][   T13] [c00000002db2f7d0] [c00800000ee6d8f4]
ata_host_activate+0x17c/0x210 [libata]
[   23.803883][   T13] [c00000002db2f880] [c00800000edf4c3c]
ahci_host_activate+0x84/0x250 [libahci]
[   23.803944][   T13] [c00000002db2f940] [c00800000f050c7c]
ahci_init_one+0xc74/0xdc0 [ahci]
[   23.803992][   T13] [c00000002db2faa0] [c00000000062b188]
local_pci_probe+0x78/0x100
[   23.804048][   T13] [c00000002db2fb30] [c00000000012c0b0]
work_for_cpu_fn+0x40/0x70
[   23.804087][   T13] [c00000002db2fb60] [c000000000130328]
process_one_work+0x388/0x750
[   23.804135][   T13] [c00000002db2fc60] [c00000000012fe30]
process_scheduled_works+0x50/0x90
[   23.804180][   T13] [c00000002db2fca0] [c000000000130c50]
worker_thread+0x3d0/0x570
[   23.804216][   T13] [c00000002db2fda0] [c000000000139a08] kthread+0x1b8/0x1e0
[   23.804253][   T13] [c00000002db2fe20] [c00000000000b660]
ret_from_kernel_thread+0x5c/0x7c
[   23.804298][   T13] Instruction dump:
[   23.804326][   T13] fbc10070 4194002c 7fa3eb78 481864a5 60000000 70630001
41810018 7fa3eb78 
[   23.804373][   T13] 48075121 60000000 70630001 40810020 <0fe00000> ebc10070
eba10068 38210080 
[   23.804419][   T13] ---[ end trace 9ceca43eedad2a2b ]---
[   23.810924][    T5] tg3 0005:01:00.0 eth0: Tigon3 [partno(BCM95719) rev
5719001] (PCI Express) MAC address 08:94:ef:80:81:c0
[   23.810967][    T5] tg3 0005:01:00.0 eth0: attached PHY is 5719C
(10/100/1000Base-T Ethernet) (WireSpeed[1], EEE[1])
[   23.811027][    T5] tg3 0005:01:00.0 eth0: RXcsums[1] LinkChgREG[0] MIirq[0]
ASF[1] TSOcap[1]
[   23.811074][    T5] tg3 0005:01:00.0 eth0: dma_rwctrl[00000000] dma_mask[64-
bit]
[   23.811284][   T13] scsi host1: ahci