[powerpc] kernel BUG at mm/mmap.c:3233! with ltp/mmapstress03

[Sachin Sant]

While running LTP test mmapstress03 on a Power10 LPAR running
5.18.0-rc6-next-20220512 following kernel bug was seen

[  944.492475] mmap: mmapstress03 (1919217): VmData 18446744073706799104 exceed data ulimit 18446744073709551615. Update limits or use boot option ignore_rlimit_data.
[  944.492511] ------------[ cut here ]------------
[  944.492512] kernel BUG at mm/mmap.c:3233!
[  944.492514] Oops: Exception in kernel mode, sig: 5 [#1]
[  944.492529] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
[  944.492533] Modules linked in: dm_mod(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) rfkill(E) ip_set(E) bonding(E) nf_tables(E) tls(E) libcrc32c(E) nfnetlink(E) sunrpc(E) pseries_rng(E) vmx_crypto(E) ext4(E) mbcache(E) jbd2(E) sd_mod(E) t10_pi(E) crc64_rocksoft(E) crc64(E) sg(E) ibmvscsi(E) scsi_transport_srp(E) ibmveth(E) fuse(E)
[  944.492571] CPU: 5 PID: 1919217 Comm: mmapstress03 Tainted: G   M        E     5.18.0-rc6-next-20220512 #1
[  944.492576] NIP:  c00000000047e450 LR: c00000000047e434 CTR: c000000000478e60
[  944.492579] REGS: c000000086dcb880 TRAP: 0700   Tainted: G   M        E      (5.18.0-rc6-next-20220512)
[  944.492583] MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 22002484  XER: 00000000
[  944.492590] CFAR: c000000000837a2c IRQMASK: 0 
[  944.492590] GPR00: c00000000047e434 c000000086dcbb20 c000000002a7f100 0000000000000000 
[  944.492590] GPR04: 0000000000000000 ffffffffffffffff 000000000000000f 0000000000000000 
[  944.492590] GPR08: ffffffffffffffff 0000000000000001 000000000000000e 0000000000000008 
[  944.492590] GPR12: 0000000000000008 c000000effff7f00 0000000000000000 0000000000000000 
[  944.492590] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
[  944.492590] GPR20: 0000000000000000 00007fffb8a04ee0 0000000000000001 0000000000000001 
[  944.492590] GPR24: 0000000000000000 00007fffb8c32bd0 0000000000000000 c000000021003c60 
[  944.492590] GPR28: 000000000000000c c000000021003c00 0000000000000001 0000000000000000 
[  944.492629] NIP [c00000000047e450] exit_mmap+0x190/0x380
[  944.492635] LR [c00000000047e434] exit_mmap+0x174/0x380
[  944.492638] Call Trace:
[  944.492639] [c000000086dcbb20] [c00000000047e434] exit_mmap+0x174/0x380 (unreliable)
[  944.492644] [c000000086dcbc40] [c000000000152990] mmput+0xb0/0x240
[  944.492650] [c000000086dcbc80] [c000000000160390] do_exit+0x370/0xc30
[  944.492653] [c000000086dcbd50] [c000000000160dfc] do_group_exit+0x4c/0xe0
[  944.492658] [c000000086dcbd90] [c000000000160eb4] sys_exit_group+0x24/0x30
[  944.492661] [c000000086dcbdb0] [c0000000000336bc] system_call_exception+0x17c/0x350
[  944.492666] [c000000086dcbe10] [c00000000000c53c] system_call_common+0xec/0x270
[  944.492671] --- interrupt: c00 at 0x7fffb88f318c
[  944.492675] NIP:  00007fffb88f318c LR: 00007fffb884cf24 CTR: 0000000000000000
[  944.492678] REGS: c000000086dcbe80 TRAP: 0c00   Tainted: G   M        E      (5.18.0-rc6-next-20220512)
[  944.492681] MSR:  800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 22000202  XER: 00000000
[  944.492690] IRQMASK: 0 
[  944.492690] GPR00: 00000000000000ea 00007fffc61d2de0 00007fffb8a07300 0000000000000001 
[  944.492690] GPR04: 0000000000000000 000000002e5b02a0 0000000000000000 00007fffb8c32bd0 
[  944.492690] GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
[  944.492690] GPR12: 0000000000000000 00007fffb8c3a340 0000000000000000 0000000000000000 
[  944.492690] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
[  944.492690] GPR20: 0000000000000000 00007fffb8a04ee0 0000000000000001 0000000000000001 
[  944.492690] GPR24: 00007fffb8a008a0 0000000000000000 0000000000000001 0000000000000001 
[  944.492690] GPR28: 0000000000000000 0000000000000000 00007fffb8c33350 0000000000000001 
[  944.492725] NIP [00007fffb88f318c] 0x7fffb88f318c
[  944.492728] LR [00007fffb884cf24] 0x7fffb884cf24
[  944.492730] --- interrupt: c00
[  944.492732] Instruction dump:
[  944.492734] 48a29539 60000000 3880ffff 38610020 483c0bc9 60000000 7c7f1b79 4082ffb4 
[  944.492741] 815d0058 39200001 7f8af000 7fc04f9e <0b1e0000> 60000000 7fa3eb78 483b916d 
[  944.492748] ---[ end trace 0000000000000000 ]---
[  944.493479] 
[  945.493481] Kernel panic - not syncing: Fatal exception

The BUG_ON was introduced by following commit with next-20220511
commit 369a899d3aff (mm: remove the vma linked list)

- Sachin