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From: "Dave Korn" <dave DOT korn AT artimi DOT com>
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Subject: RE: cygwin bash crashes on Win Serv 2008
Date: Thu, 23 Oct 2008 16:40:26 +0100
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Corinna Vinschen wrote on 23 October 2008 15:09:

>> The crashes don't occur in Cygwin, but in the application code.  As I
>> said, one of the crashing apps is bash.  I created a full debug bash
>> version and a special debug version of GDB which, for some reason, runs
>> fine, in contrast to the net release version of GDB.  What happens is
>> that some arbitrary application function is called from main() and the
>> first instruction in this function is the opcode for storing the frame
>> pointer on the stack, `push %ebp'.
> 
> I seem to have missed the point here.  The point is, this `push %ebp'
> instruction is the one crashing, producing a segmentation violation.

  What's the underlying windows exception (i.e. before cygwin translates that
into SEGV)?  

> 
>>   This is, in theory, an entirely
>> harmless operation.  The stack and register content before and after the
>> crash are looking absolutely normal.  The push does neither operate on
>> an invalid address nor on a page boundary, nor is it misaligned.  It's
>> just a push to some arbitrary address within an existing stack page.

  Only thing I can think of is "Not if %ss has been mucked around with it
isn't".

  I'd use windbg on this, take a look at the exception record and selectors
and stuff.


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....


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