OS/2 guest crashes on floating point exception

[rudi]

The following code snippet (which is supposed to die by SIGFPE) causes an OS/2 guest to trap. Kernel is 14.104_W4.

#include <stdio.h>
#include <float.h>

int main(void)
{
  double d1 = 1.0;
  double d2 = 0.0;

  _control87(0, 0x1f);

  printf("%lf\n", d1 / d2);

  return 0;
}

[Frank Mehnert]

A VBox.log file is missing. It will show us which configuration your VM has and which processor features of your host are used.

[rudi]

Log file

[Brian Smith]

This appears to be the bug I have been experiencing on my Macs. They have Intel CPUs, my AMD based Windows 7 64bit systems don't experience this problem and it results in SIGFPE.

[bird]

I have not been able to reproduce this with the current trunk version of VirtualBox, testing on both intel i7 core and amd phenom 2.

[Brian Smith]

It happens on both my Macs... MacBook Pro with an Intel Core 2 Duo and MacPro with an Intel Quad Core Xeon.

It does not happen on my PCs with AMD Phenom 2 and X2.

[rudi]

With 4.1.4r74291 it happens here. See attached screenshot...

[rudi]

Trap screen after executing the program snippet.

[Brian Smith]

Trap screen with eCS 2.0 on MacBook Pro w/ Intel Core 2 Duo

[Lars Erdmann]

I can add that this very same trap also happens with more complex OS/2 applications, namely Firefox 8.x and Seamonkey 2.3. But I guess that can be expected as the error is so fundamental.

[Lars Erdmann]

Replying to Erdmann:

I can add that this very same trap also happens with more complex OS/2 applications, namely Firefox 8.x and Seamonkey 2.3. But I guess that can be expected as the error is so fundamental.

Forgot to add: I am using VirtualBox Version 4.1.6.

[Lars Erdmann]

Yet another log: Windows 7 host, Intel Core2 Duo CPU, 2 GB RAM

[Lars Erdmann]

The error still exists in VBox 4.1.8

[michaln]

Reproducible here on an Intel Core 2 Quad host. No problem on an AMD system. I wonder if this is specific to the crummy old VT-x implementation.

[Lars Erdmann]

I still experience this crash, funny enough it now occurs less often since I upgraded to Seamonkey 2.5 from Seamonkey 2.3.3. Maybe Seamonkey 2.5 uses less floating point. Unfortunately I don't know the technical details behind VT-x (I could have a look into the Intel manual but I am sure I am lacking years behind ...). I am using Intel Core2 Duo with Windows 7 as host. I had another trap on bootup just now, unfortunately I forgot to take a photo. The only thing I can say is that it happens pretty randomly. If you want me to test anything ...

[Lars Erdmann]

Sudden trap on using Seamonkey 2.5

[Lars Erdmann]

I got a trap using Seamonkey. I attached trap screen. With the very same kernel the trap address has now changed.

[michaln]

There's one crucial piece of information missing here. This problem does not occur with the SMP OS/2 kernel. The reason being that the SMP kernel runs with the CR0.NE bit set. The actual number of processors in the guest does not matter.