libretro rewind feature randomly crashes and sometimes causes graphical glitches about sameboy

[LIJI32]

Found the bug, it's actually in RetroArch itself:

https://github.com/libretro/RetroArch/blob/9c305f7e95c1392aab25c9830957f7d1a979b3ad/audio/audio_driver.c#L765

audio_driver_rewind_ptr can underflow and randomly overwrite memory.

[andres-asm]

Can you get a stacktrace?

[prataczak]

Is stacktrace the same thing as log? (pardon my ignorance :) )

[prataczak]

I'll assume the answer to my question is yes, please give me instructions on how to proceed otherwise.

Log 1 - RetroArch crashes when 'escape' is pressed to exit emulator, after rewinding for a couple of seconds, and waiting a couple more. https://pastebin.com/x1D2Xw9j

Log 2 - RetroArch crashes as soon as the rewind hotkey is released. https://pastebin.com/XRR5mS3Q

Log 3 - RetroArch displays glitched graphics after release of rewind key, then crashes when 'escape' key is pressed. https://pastebin.com/E2HDqPpA

Again, I do have 'Auto Save State' turned on. I suspect that has something to do with the crash on exit.
Edit: I turned off auto save, and the issue still occurs, so scratch this.

It is worth noting that exiting the emulator without attempting a rewind does not seem to trigger a crash. I do have a core override for SameBoy, it only one line - aspect_ratio_index = "21".

[prataczak]

More details that may be helpful - the ROM's crc is 6C41D3CD, and is called Batman - The Video Game (World).gb. It is loaded from a zipped archive.

I am using Windows 10 with the latest updates.

[LIJI32]

I'll try to reproduce it on my Mac, probably some silly memory management issue.

[LIJI32]

...But rewinding doesn't seem to work for me at all with RetroArch, holding the rewind key seems to do nothing :S

[LIJI32]

Managed to reproduce a memory corruption on the macOS build after using rewind, should be easy now.

[LIJI32]

Opened a relevant RetroArch issue (libretro/RetroArch#6382)

[andres-asm]

Thanks for looking into it!