Re: LTP: fork13: kernel panic on rk3399-rock-pi-4 running mainline 6.10.rc3

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 2024/6/11 18:32, David Hildenbrand wrote:
> On 11.06.24 12:14, Naresh Kamboju wrote:
>> The kernel panic was noticed while running LTP syscalls fork13 (long 
>> running) on
>> the mainline master 6.10.rc3 kernel on arm64 rk3399-rock-pi-4 device.
>>
>> Please find detailed logs in the links,
>>
>> As you know fork13 is a stress test case trying to generate a maximum 
>> number
>> of PID's in a 100,000 loop.
>>
>> This device is running via NFS mounted filesystem.
>>
>> I have tried to reproduce this problem in a loop but failed to 
>> reproduce the
>> crash.
>>
>>
>> Crash flow:
>> ------
>> fork13 run started
>> BUG: Bad page map in process fork13
>> BUG: Bad rss-counter state mm:
>> Unable to handle kernel paging request at virtual address
>> Internal error: Oops: 0000000096000046
>> run for 800 secs ( 13 minutes) and more.
>> fork14 run started and completed
>>
>> fpathconf01 run started and completed
>> sugov:
>>
>> Unable to handle kernel NULL pointer dereference at virtual address
>>
>> Insufficient stack space to handle exception!
>> end Kernel panic - not syncing: kernel stack overflow
>>
>> I have tried to decode stack dump by not being useful [1].
>> [1] https://people.linaro.org/~naresh.kamboju/output-rk3399.txt
>>
>> Test log :
>> --------
>> tst_test.c:1733: TINFO: LTP version: 20240524
>> tst_test.c:1617: TINFO: Timeout per run is 0h 15m 00s
>> [  904.280569] BUG: Bad page map in process fork13  pte:2000000019ffc3
>> pmd:80000000df55003
>> [  904.281397] page: refcount:1 mapcount:-1 mapping:0000000000000000
>> index:0x0 pfn:0x19f
> 
> Mapcount underflow on a small folio (head: not printed).
> 
> [...]
> 
>> [  904.294564] BUG: Bad page map in process fork13  pte:200000002e4fc3
>> pmd:80000000df55003
>> [  904.295275] page: refcount:2 mapcount:-1 mapping:000000007885152f
>> index:0x6 pfn:0x2e4
> 
> Another mapcount underflow on a small folio (head: not printed).
> 
> 
>> [  904.309309] BUG: Bad page map in process fork13  pte:20000000cc6fc3
>> pmd:80000000df55003
>> [  904.310031] page: refcount:1 mapcount:-1 mapping:0000000000000000
>> index:0x6 pfn:0xcc6
>> [  904.310728] head: order:3 mapcount:-1 entire_mapcount:0
>> nr_pages_mapped:8388607 pincount:0
> 
> Mapcount underflow on a large folio.
> 
> ...
> 
>> [  904.326666] BUG: Bad page map in process fork13  pte:20000000268fc3
>> pmd:80000000df55003
>> [  904.327390] page: refcount:1 mapcount:-1 mapping:00000000f0624181
>> index:0x1b pfn:0x268
> 
> Another mapcount underflow on a small folio (head: not printed).
> 
>> [  904.328094] memcg:ffff0000016b4000
>> [  904.328401] aops:nfs_file_aops ino:8526e6 dentry
>> name:"libgpg-error.so.0.36.0"
>> [  904.329051] flags:
>> 0x3fffe000000002c(referenced|uptodate|lru|node=0|zone=0|lastcpupid=0x1ffff)
>> [  904.329878] raw: 03fffe000000002c fffffdffc0009a48 fffffdffc022f3c8
>> ffff00000688bd60
>> [  904.330561] raw: 000000000000001b 0000000000000000 00000001fffffffe
>> ffff0000016b4000
>> [  904.331240] page dumped because: bad pte
>> [  904.331590] addr:0000aaaad9afe000 vm_flags:00000075
>> anon_vma:0000000000000000 mapping:ffff0000300d4188 index:2e
>> [  904.332476] file:fork13 fault:filemap_fault mmap:nfs_file_mmap
>> read_folio:nfs_read_folio
>> [  904.333245] CPU: 5 PID: 22685 Comm: fork13 Tainted: G    B
> 
> 
> Are these maybe side-effects due to
> 
> https://lkml.kernel.org/r/20240607103241.1298388-1-wangkefeng.wang@huawei.com

IIUC, the rk3399-rock-pi-4b device has no NUMA nodes (6 arm64 cores), so 
I don't think the numa balancing will cause this issue.

Anyway, I will run fork13 test case on my arm64 server to try.