Re: BUG #18503: Reproducible 'Segmentation fault' in 16.3 on ARM64

On 2024-06-12 23:41, Thomas Munro wrote:
> On Thu, Jun 13, 2024 at 1:47 AM Stefan Heine<github(dot)stheine(at)heine7(dot)de> wrote:
>> do you have instructions for the gdb backtrace?
> gdb /path/to/executable -c /path/to/core
> ... loads stuff ...
> (gdb) bt
> ... prints out function call stack ...
>
> It will probably just show some library names and addresses, but so
> far we don't even know if this is crashing in LLVM or in PostgreSQL
> code so that'd be a clue. Maybe function names would appear if you
> set up DEBUGINFOD_URLS, depending on where you got your packages from:
>
> https://wiki.debian.org/HowToGetABacktrace

# gdb /usr/lib/postgresql/16/bin/postgres -c core.19
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Reading symbols from /usr/lib/postgresql/16/bin/postgres...
(No debugging symbols found in /usr/lib/postgresql/16/bin/postgres)
warning: Can't open file /dev/shm/PostgreSQL.384567174 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.2343312096 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.1247406204 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.50860586 during file-backed
mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.4136010652 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.2304500154 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.817475720 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.526004662 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.1223723046 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.4190931822 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.3836724180 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.1707942452 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.4107375064 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.2885303254 during
file-backed mapping note processing
warning: Can't open file /dev/shm/PostgreSQL.4136268764 during
file-backed mapping note processing
warning: Can't open file /dev/zero (deleted) during file-backed mapping
note processing
warning: Can't open file /dev/shm/PostgreSQL.3153232120 during
file-backed mapping note processing
warning: Can't open file /SYSV03e40001 (deleted) during file-backed
mapping note processing
[New LWP 19]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".
Core was generated by `postgres: sa postgres 164.99.242.100(57456)
EXPLAIN                           '.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x0000fffe0fb635b8in ??()
(gdb) bt
#0 0x0000fffe0fb635b8in ??()
#1 0x0000aaaaefd84330in ??()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) quit

> Hoping to find time to repro this later on a cloud host. If this is a
> cloud host, can you tell me which cloud, instance type, memory size
> etc? I had already been trying on some local ARM hardware with no
> luck (same versions but diferrent OS, so going to try making more
> things match you case)...
> (I realise that the email from the other thread gives an AWS instance
> type that I can try, but that report is about memory usage and yours
> has a segfault so I'm curious to know what conditions are different
> for you..)

it's running on AWS, t4g.large, 8GB RAM. this server is running Ubuntu
22.04.3 LTS and hosting docker.
inside docker, there is a container running postgres, based on the
official postgres:16.3 (Based on Debian Bookwork) from
https://hub.docker.com/_/postgres .