#250 ESP stack corruption(?) on Linux 2.6.34 x86_64 SMP

[Moira Lachesis]

Note: this is probably a kernel bug, not a dosemu bug. But I do not have sufficient knwoledge to file a kernel bug. As dosemu seems to know the problem, I hope you can aid in either filing a kernel bug, or helping me find an already filed one.

$ dosemu
ERROR: MFS: couldn't find root path /media/CDROM
ERROR: Stack Fault, ESP corrupted due to a CPU bug.
For more details on that problem and possible work-arounds,
please read EMUfailure.txt, section 1.6.2.
ERROR: DPMI: Warning: trying to leave DPMI when in_dpmi_pm_stack=2

$ uname -a
Linux cami 2.6.34-gentoo-r12 #1 SMP Sun Oct 31 10:18:50 CET 2010 x86_64 Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz GenuineIntel GNU/Linux

reproducible e.g. with Quest for Glory IV (freely available at abandonia)

[Stas Sergeev]

Beleive it or not, but this, as said in the error message, indeed, is the CPU bug,
so there is nowhere to report or complain.
You should really read the mentioned doc if you want to know the details, it is here:
http://www.dosemu.org/docs/EMUfailure/t1.html#AEN54
Unfortunately, that doc boldly claims that the problem has a work-around since linux-2.6.12.
That's where I implemented it for x86_32, but the work-around code was never ported
to x86_64 because I stopped developing dosemu shortly thereafter.
If your program uses dos4gw (watcom), then just use dos32a instead, and you are fine.
Otherwise, you can boot the 32bit kernel, or enable the CPU emulation in dosemu even
for DPMI, or try to port the workaround code to x86_64 kernel (I promise you it won't be easy! :))