Subject: Re: [next-20220225] powerpc boot broken with maple tree code ?

From: Abdul Haleem <[email-masked]>
Date: Thu, 3 Mar 2022 17:11:15 +0530

On 3/2/22 8:22 PM, Liam Howlett wrote:

> * Abdul Haleem <[email-masked]> [220302 01:22]:
>> Greeting's
>>
>> linux-next kernel 5.17.0-rc5-next-20220225 boot is broken on powerpc
>>
>> Is this due to Introduction of maple patch series ?
> It could be - those are certainly maple tree functions.  I do have a
> ppc64le VM booting here with a bunch of debug turned on.
>
> Could you test the maple tree branch itself?
> https://github.com/oracle/linux-uek/tree/howlett/maple/20220301

Kernel crash is not seen with howlett/maple/20220301 branch, boots fine on my powerpc box.

Thanks

>> Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
>>   BUG: Kernel NULL pointer dereference on read at 0x00000000
>>   Faulting instruction address: 0xc0000000006f1560
>>   Oops: Kernel access of bad area, sig: 11 [#1]
>>   LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
>>   Modules linked in: nfnetlink tcp_diag udp_diag inet_diag unix_diag af_packet_diag ibmvnic netlink_diag bonding rfkill sunrpc pseries_rng xts vmx_crypto gf128mul sch_fq_codel binfmt_misc ip_tables ext4 mbcache jbd2 dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse [last unloaded: ibmvnic]
>>   CPU: 31 PID: 7527 Comm: pmpost Not tainted 5.17.0-rc5-next-20220225-autotest #1
>>   NIP:  c0000000006f1560 LR: c0000000006f6f48 CTR: 0000000000000000
>>   REGS: c0000000251732f0 TRAP: 0300   Not tainted  (5.17.0-rc5-next-20220225-autotest)
>>   MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24422888  XER: 20040000
>>   CFAR: c0000000006f17a4 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0
>>   GPR00: c0000000006feb04 c000000025173590 c0000000028d1400 c0000000251735b8
>>   GPR04: 0000000000000001 c000000028364200 c0000000251735b8 0000000000000000
>>   GPR08: 0000000000000004 0000000000000002 0000000000000000 c000000028364200
>>   GPR12: 0000000044422888 c0000013ffaa4e80 0000000000000003 c0000000355eef48
>>   GPR16: 00007ffff23ee710 00000000003a164c 0000000000000002 0000000000000001
>>   GPR20: 0000000000000000 0000000000000073 000000007fff8a79 0000000000000000
>>   GPR24: c000000018aade00 00007fff8a79ffff c000000025173680 0000000000000002
>>   GPR28: c000000000d448e8 0000000000000002 0000000000000001 c0000000251736c0
>>   NIP [c0000000006f1560] mas_ascend+0x60/0x2e0
>>   LR [c0000000006f6f48] mas_next_sibling+0xd8/0x290
>>   Call Trace:
>>   [c000000025173590] [c000000025173b18] 0xc000000025173b18 (unreliable)
>>   [c000000025173620] [c0000000006feb04] mas_wr_modify+0x6c4/0x910
>>   [c0000000251739a0] [c0000000006ff0b8] mas_wr_store_entry+0x198/0x3f0
>>   [c0000000251739d0] [c00000000070167c] mas_store_gfp+0x6c/0x190
>>   [c000000025173a80] [c0000000003b1164] mmap_region+0x304/0xda0
>>   [c000000025173bf0] [c0000000003b1fcc] do_mmap+0x3cc/0x5e0
>>   [c000000025173c90] [c000000000372ea0] vm_mmap_pgoff+0x130/0x1f0
>>   [c000000025173d20] [c0000000003adc8c] ksys_mmap_pgoff+0x6c/0x2c0
>>   [c000000025173d90] [c000000000013780] sys_mmap+0x40/0xb0
>>   [c000000025173db0] [c00000000002f7e8] system_call_exception+0x178/0x380
>>   [c000000025173e10] [c00000000000c64c] system_call_common+0xec/0x250
>>   --- interrupt: c00 at 0x7fff8a7678b8
>>   NIP:  00007fff8a7678b8 LR: 00007fff8a749e84 CTR: 0000000000000000
>>   REGS: c000000025173e80 TRAP: 0c00   Not tainted  (5.17.0-rc5-next-20220225-autotest)
>>   MSR:  800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 24422284  XER: 00000000
>>   IRQMASK: 0
>>   GPR00: 000000000000005a 00007ffff23ee680 00007fff8a797e00 00007fff8a790000
>>   GPR04: 0000000000000008 0000000000000003 0000000000000032 ffffffffffffffff
>>   GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>>   GPR12: 0000000000000000 0000000000000000 0000000000000003 00007ffff23ee740
>>   GPR16: 00007ffff23ee710 00000000003a164c 0000000000000002 0000000000000006
>>   GPR20: 0000000000000000 00007fff8a790000 00007fff8a5fa1eb 00007fff8a793d70
>>   GPR24: 00007fff8a791178 0000000000000000 0000000000000003 00007ffff23eea40
>>   GPR28: 0000000000000000 000000000000fd04 00007fff8a793d90 00007ffff23ee7d0
>>   NIP [00007fff8a7678b8] 0x7fff8a7678b8
>>   LR [00007fff8a749e84] 0x7fff8a749e84
>>   --- interrupt: c00
>>   Instruction dump:
>>   712a0002 e8a30000 552a067a 41820264 71290086 2ba90006 419e01a8 39200003
>>   7d4a4c36 61080004 99460039 f9060018 <e9270000> 792a07e0 2eaa0000 7d4c5378
>>   ---[ end trace 0000000000000000 ]---
>>   Kernel panic - not syncing: Fatal exception
>>
>> kernel config attached
>>
>> -- 
>> Regard's
>>
>> Abdul Haleem
>> IBM Linux Technology Center

-- 
Regard's

Abdul Haleem
IBM Linux Technology Center