MongoDB crashing on STM32MP157F-DK2 board

[KMOHA.1]

I followed the steps to install the mongodb from the openSTLinux distribution.

when I run the mongodb from the terminal, it is crashing with the bus error.

root@stm32mp1:/usr/bin# mongod

Bus error (core dumped)

Appreciate your help..

[Olivier GALLIEN]

Hi @KMOHA.1​ ,

By steps do you means installing with apt-get from package repository or else ?

Can you specify OpenSTLinux version you use ?

Thanks

Olivier

[Jean-Marc B]

Hi @KMOHA.1​ 

Here, the «bus error» probably means unaligned data access.

By compiling the mongodb package with the compiler option «-Wcast-align=strict», I see a lot of conversion problems (see the attachment file extracted from the bitbake log.do_compile log). ARM devices are less tolerant than other architectures hence the crash.

Do you see anything related to an unaligned access in the /var/log/mongodb or other log files?

Best regards,

--JM

[Jean-Marc B · Accepted solution]

@KMOHA.1​ 

I confirm my initial guess after installing the mongodb package from the ecosystem-3.1:

root@stm32mp1:~# apt-cache policy mongodb
mongodb:
  Installed: 4.2.2-r0
  Candidate: 4.2.2-r0
  Version table:
 *** 4.2.2-r0 500
        500 http://packages.openstlinux.st.com/3.1 dunfell/untested armhf Packages
        100 /var/lib/dpkg/status

Before launching mongod:

root@stm32mp1:~# cat /proc/cpu/alignment
User:           0
System:         0 (0x0)
Skipped:        0
Half:           0
Word:           0
DWord:          0
Multi:          0
User faults:    2 (fixup)

Then after launching mongod:

root@stm32mp1:~# cat /proc/cpu/alignment
User:           1
System:         0 (0x0)
Skipped:        1
Half:           0
Word:           0
DWord:          0
Multi:          0
User faults:    2 (fixup)

The output of dmesg shows:

[  211.231332] Alignment trap: not handling instruction f9660aef at [<016d8dca>]
[  211.237169] 8<--- cut here ---
[  211.240230] Unhandled fault: alignment exception (0x001) at 0xbeeb6aa8
[  211.248709] pgd = f2925d3c
[  211.249969] [beeb6aa8] *pgd=c58cc835, *pte=d9e1875f, *ppte=d9e18c7f

I think you should report a bug to the Mongod team.

Best regards,

--JM

[KMOHA.1]

thanks Jean. I will check how we can report this to mongodb team.

[Jean-Marc B]

For the record, same behavior with ecosystem-4.0.0:

mongodb:
  Installed: 4.4.13-r0
  Candidate: 4.4.13-r0
  Version table:
 *** 4.4.13-r0 500
        500 http://packages.openstlinux.st.com/4.0 kirkstone/untested armhf Packages
        100 /var/lib/dpkg/status