Segfault when playing intro on Linux

[Orzipan]

On Arch Linux I get a segfault when trying to play the intro. No error.log gets created.

Stack trace:

libSDL2-2.0.so.0![Unknown/Just-In-Time compiled code] (Unknown Source:0)
LbWindowsControl() (/home/user/work/syndwarsfx/bflibrary/src/x86-win-sdl2/swindows.c:179)
MSSSMACKTIMERSETUP() (/home/user/work/syndwarsfx/bfsmacklib/src/smack2ail.c:165)
ac_MSSSMACKTIMERSETUP() (/home/user/work/syndwarsfx/build/src/wrappers_game.sx:3878)
SMACKOPEN() (/home/user/work/syndwarsfx/bfsmacklib/src/bfsmacklib_s.sx:8536)
SMACKSOUNDUSEMSS(uint32_t speed, void * digdrv) (/home/user/work/syndwarsfx/bfsmacklib/src/smack2ail.c:242)

If I comment out the assembly call to ASM_play_smk_direct in play_smk_direct the game starts without the intro.

[mefistotelis]

No error.log gets created.

If no write access is given to the CWD, log file is not created, but a message should be printed to stdout.

If I comment out the assembly call to ASM_play_smk_direct in play_smk_direct the game starts without the intro.

Try commenting out play_intro() instead. Then if you wait 65 seconds in the main menu, the intro should start playing from there. Check if that will crash too.

if it plays the intro - this is some kind of initialization order / initialization race problem
if it doesn't - it's an issue with the SMK playback assembly, or connection between the assembly and C

[Orzipan]

I commented out play_intro() and it segfaulted the at the same SDL_PollEvent after waiting 65 seconds.

Console output:

Syndicate Wars Fan Expansion ver 0.3.8.3653 (debug release)
The original by Bullfrog
Ported by Unavowed and Gynvael Coldwind.
Expanded by other fans, signed in commits.
Web site: https://github.com/swfans/syndwarsfx/
setup_simple_screen_mode 13
libEGL warning: pci id for fd 12: 10de:2208, driver (null)

pci id for fd 13: 10de:2208, driver (null)
pci id for fd 14: 10de:2208, driver (null)
libEGL warning: egl: failed to create dri2 screen
pci id for fd 13: 10de:2208, driver (null)
pci id for fd 14: 10de:2208, driver (null)
libEGL warning: egl: failed to create dri2 screen
setup_simple_screen_mode 1

[mefistotelis]

Try the latest version from "Actions". If the issue still exist, it should be easier to trace.

EDIT: I meant the latest source; forgot you're building it yourself.

[Orzipan]

error.log

I still get a segfault, but at a different place.

I tried to access lbDisplay.GraphicsScreenWidth before the call to SMACKOPEN(0xFFFFFFFF, soflags, fname);and it returns 320, but if I try to access lbDisplay.GraphicsScreenWidth or even lbDisplay directly after the call it segfaults.

Call stack:

play_smk_direct(const char * fname, ulong smkflags, ushort plyflags, ushort mode) (/home/user/work/syndwarsfx/bfsmacklib/src/bfsmack.c:165)
play_smk(const char * fname, ulong smkflags, ushort plyflags) (/home/user/work/syndwarsfx/bfsmacklib/src/bfsmack.c:243)
play_smacker(ushort vid_type) (/home/user/work/syndwarsfx/src/game.c:886)
play_smacker_then_back_to_menu(ushort vid_type) (/home/user/work/syndwarsfx/src/game.c:928)
play_intro() (/home/user/work/syndwarsfx/src/game.c:944)
setup_host() (/home/user/work/syndwarsfx/src/game.c:2315)
game_setup() (/home/user/work/syndwarsfx/src/game.c:3526)
main(int argc, char ** argv) (/home/user/work/syndwarsfx/src/main.c:565)

[mefistotelis]

The version from "Actions" - looks like it requires you to put the game files into /share/syndwarsfx. So currently it bails out earlier because it cannot find any game files.

For your findings on lbDisplay - that is surprising as what you're accessing is a global variable.
I'm not even sure what mechanism could damage a global variable to the point where it's inaccessible.
The memory tables for that are static for the lifetime of the app, so I guess the symbol must have been damaged?
Not sure.

It's good we know the issue is within SMACKOPEN(), maybe that will lead to some clues.

[mefistotelis]

If you disable SMK playback completely, ie. return just at start of play_smk(), is the game working fine? I mean can you play missions, everything is working?

If the issue is limited to SMK playback only, then we can assume the cause is with something we use only for SMK playback - the stdcall calling convention in assembly-to-c glue code generated by util/mkwrappers.

[Orzipan]

I changed play_smk() to just return and I was able to play and complete the first mission.

[mefistotelis]

ok, everything points towards the stdcall, then. I'm not sure what exactly could be wrong, though.

[Orzipan]

Is there a reason (other than time I guess) the project is decoding SMK video in assembly and not using libsmacker?

[mefistotelis]

The video playback API is slightly different, but that should be easy to adjust.

Not that sure about integration with my AIL implementation.