SIGSEGV in MixHrtf_SSE when exiting Lugaru (OpenAL 1.17.2 Debian)

[akien-mga]

• Lugaru bug report: https://gitlab.com/osslugaru/lugaru/issues/98
• Debian bug report: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=874086

Lugaru can apparently crash when exiting on Debian (as reported by @pabs3), and the issues seems to happen directly in OpenAL 1.17.2 SSE code:

#0  _mm_store_ps (__A=..., __P=0x7fb8d3019000) at /usr/lib/gcc/x86_64-linux-gnu/6/include/xmmintrin.h:973
#1  SetupCoeffs (Counter=0, IrSize=22022, hrtfparams=<optimized out>, OutCoeffs=0x7fb8d3017770) at ./Alc/mixer_sse.c:87
#2  MixHrtf_SSE (OutBuffer=0x56066a9a2ba0, data=0x56066a99aba0, Counter=0, Offset=752640, OutPos=0, IrSize=22022, hrtfparams=0x0, hrtfstate=0x0, BufferSize=0) at ./Alc/mixer_inc.c:34
#3  0x0000000000000000 in ?? ()

Since I don't see much in the crash log that ties the bug to Lugaru's specific usage of OpenAL, I thought I'd report it directly upstream to get more experienced eyes on the issue.

[akien-mga]

It looks like we were badly closing the application on Linux, which is now fixed by https://gitlab.com/osslugaru/lugaru/commit/8f8250f231122f66e75fc83506dd51dbce948dd0

Testing is still ongoing to check if it actually solves the SIGSEGV too; feel free to close this issue if you think this was indeed a downstream bug.

[kcat]

Ideally there shouldn't be anything an app can do to make OpenAL crash. However, leaving a device open and running when the process exits does put it into a precarious position since there are resources in use and threads running that the lib can't safely do anything about once its process-end callbacks are invoked (some say OpenAL Soft already does more than it should at process end, but I like to be as thorough as I safely can with cleaning up).

I can't say why closing OpenAL caused a problem in the first place, but leaving a device running does put it at the mercy of the system to clean things up correctly, especially if _exit is called rather than exit.

[kcat]

Given no further info, I'm assuming this has been dealt with. There's simply not much OpenAL Soft can do if a device is left open and running when the process terminates.