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Date: Fri, 16 Apr 1999 22:53:20 -0400
From: Chris Faylor <cgf AT cygnus DOT com>
To: cygwin-developers AT sourceware DOT cygnus DOT com
Subject: [fortinj AT ibm DOT net: GDB and newest snapshots]
Message-ID: <19990416225320.A1704@cygnus.com>
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----- Forwarded message from fortinj AT ibm DOT net -----

From: fortinj AT ibm DOT net
Date: Fri, 16 Apr 1999 22:31:40 -0400
Reply-To: fortinj AT ibm DOT net
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To: Chris Faylor <cgf AT cygnus DOT com>
Subject: GDB and newest snapshots

Chris,
	It seems I am banned again from the mail-list.  Same problem as
before.  Could you forward the to the developers list.

Thanks,
John Fortin...


> 
> all,
> Looking at this a bir more closely, it seems that GDB itself is OK.  The
> failure is in loading the program to be debugged when it is a 'cygwin'
> linked program. Probably in the initialization before main() is
> executed.  The program being debugged fails in
> _size_of_stack_reserve().  The memory location of the executed statement
> is 0xbffa0eb2 which is in the system dll area for win98
> (0x80000000-0xBFFFFFFF)
> 
> It says it cannot access memory at 0x2000000 ( and hence the SIGSEGV).
> This is in the program's private  address space (0x00400000 -
> 0x7FFFFFFF) So it should be able to read this unless it has been locked
> or set unreadable somehow.
> 
> Unfortunately, I haven't a clue where to begin debugging this.  It looks
> like the function  may be in kernel32.dll or advapi32.dll, but I can't
> get a trace as to how it was called.  I don't pretend to understand how
> gdb starts a program executing ( some type of fork() ? )
> 
> When I looked in the Changelog, I did see that there were changes in
> varios type of shared memory on Mar. 31 and it is after this that the
> cygwin1.dll and gdb don't work well together.
> 
> As I mentioned before, programs compiled with -mno-cygwin work fine.
> 
> If any other info is needed, please let me know.
> 
> John Fortin,
> fortinj AT ibm DOT net
> 
> fortinj AT ibm DOT net wrote:
> > 4
> > All,
> >
> > I compiled GDB 4.17.87 with the April 8th cygwin-src snapshot.  Compiled
> > fine.
> >
> > However, whenever i try to run a program, it gets a SIGSEGV in
> > _size_of_stack_reserve().
> >
> > When I used a cygwin1.dll from march 30 and earlier ( from the snapshot
> > site ) it works fine.
> >
> > The latest 2 snapshot dlls will not even run bash.exe.
> >
> > Thanks,
> > John Fortin

----- End forwarded message -----

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