Re: BUG #18503: Reproducible 'Segmentation fault' in 16.3 on ARM64 - Mailing list pgsql-bugs

On 2024-06-12 23:41, Thomas Munro wrote:

On Thu, Jun 13, 2024 at 1:47 AM Stefan Heine <github.stheine@heine7.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  0x0000fffe0fb635b8 in ?? ()
(gdb) bt
#0  0x0000fffe0fb635b8 in ?? ()
#1  0x0000aaaaefd84330 in ?? ()
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 .