Floating point exception

[vai-terokinnunen]

Describe the bug
Floating point exception core dump with nng_req0_open with main branch. This is also reproducible with demo/raw and demo/async apps.
Bisected the commit to 713b80f ("refactor initialization/finalization")

Expected behavior
Raw server started.

Actual Behavior

$ ./raw tcp://127.0.0.1:55995 -s
Floating point exception (core dumped)
$

To Reproduce

• Build demo/raw app.
• Start ./raw tcp://127.0.0.1:55995 -s

Environment Details

• NNG version: main branch c3620e6 ("sockfd: inline aio structs")
• Operating system and version: Fedora 40
• Compiler and language used: gcc 14.2.1
• Shared or static library

Additional context

Core dump details:

$ coredumpctl debug
           PID: 349527 (raw)
           UID: 1000 (tero)
           GID: 1000 (tero)
        Signal: 8 (FPE)
     Timestamp: Wed 2024-11-27 10:52:39 EET (13min ago)
  Command Line: ./raw tcp://127.0.0.1:55995 -s
    Executable: /home/tero/work/nng/build-raw/raw
 Control Group: /user.slice/user-1000.slice/[email protected]/app.slice/app-org.gnome.Terminal.slice/vte-spawn-90bf9612-9cd4-4b4f-895b-3c6db604d91a.scope
          Unit: [email protected]
     User Unit: vte-spawn-90bf9612-9cd4-4b4f-895b-3c6db604d91a.scope
         Slice: user-1000.slice
     Owner UID: 1000 (tero)
       Boot ID: 4e592ff17e094950a051295ba32ed48c
    Machine ID: 8b88de00be60453b9851b40e6cc52131
      Hostname: fedora
       Storage: /var/lib/systemd/coredump/core.raw.1000.4e592ff17e094950a051295ba32ed48c.349527.1732697559000000.zst (present)
  Size on Disk: 26.4K
       Message: Process 349527 (raw) of user 1000 dumped core.
                
                Stack trace of thread 349527:
                #0  0x0000000000414eb9 n/a (/home/tero/work/nng/build-raw/raw + 0x14eb9)
                #1  0x00000000004290d3 n/a (/home/tero/work/nng/build-raw/raw + 0x290d3)
                #2  0x000000000041e62c n/a (/home/tero/work/nng/build-raw/raw + 0x1e62c)
                #3  0x000000000041e73f n/a (/home/tero/work/nng/build-raw/raw + 0x1e73f)
                #4  0x0000000000429afb n/a (/home/tero/work/nng/build-raw/raw + 0x29afb)
                #5  0x0000000000429ad6 n/a (/home/tero/work/nng/build-raw/raw + 0x29ad6)
                #6  0x0000000000410b55 n/a (/home/tero/work/nng/build-raw/raw + 0x10b55)
                #7  0x0000000000410de4 n/a (/home/tero/work/nng/build-raw/raw + 0x10de4)
                #8  0x00007fde89e4e088 __libc_start_call_main (libc.so.6 + 0x2a088)
                #9  0x00007fde89e4e14b __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x2a14b)
                #10 0x00000000004107d5 n/a (/home/tero/work/nng/build-raw/raw + 0x107d5)
                ELF object binary architecture: AMD x86-64

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Reading symbols from /home/tero/work/nng/build-raw/raw...

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(No debugging symbols found in /home/tero/work/nng/build-raw/raw)
[New LWP 349527]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `./raw tcp://127.0.0.1:55995 -s'.
Program terminated with signal SIGFPE, Arithmetic exception.
#0  0x0000000000414eb9 in nni_aio_init ()
(gdb) bt
#0  0x0000000000414eb9 in nni_aio_init ()
#1  0x00000000004290d3 in xrep0_sock_init ()
#2  0x000000000041e62c in nni_sock_create ()
#3  0x000000000041e73f in nni_sock_open ()
#4  0x0000000000429afb in nni_proto_open ()
#5  0x0000000000429ad6 in nng_rep0_open_raw ()
#6  0x0000000000410b55 in server ()
#7  0x0000000000410de4 in main ()
(gdb)

nni_aio_expire_q_cnt in https://github.com/nanomsg/nng/blob/main/src/core/aio.c#L89 is zero.