problem : win16 stack selector freed twice

Christian Costa titan.costa at
Sun Jun 2 17:50:58 CDT 2002

Hi everybody,

I encountered the following problem that completely broke MapLS.
I investigated a little and here is what I've found :

1) a selector is allocated for the win16 stack in THREAD_InitStack
2) the selector is freed and the stack replaced by another (the DGROUP 
of the module) in NE_StartTask
3) MapLS is called, allocates the freed selector and keep it in a linked 
4) the selector is freed in SYSDEPS_ExitThread which believes it to be 
the selector of the initial task
5) the selector being freed is allocated (from where is not important) 
and the associated descriptor is modified
6) further call to MapLS (wich makes the function to use this selector) 
make wine to crash because the
descriptor has been overwritten

So 2) and 4) are conflicting but I think only 4) is wrong.

4) should free the selector of the new stack instead of the old one.
Or should do nothing if the stack has been changed.

Any idea?


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