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Date: Sun, 10 Jun 2001 18:56:33 +0400
From: egor duda <deo AT logos-m DOT ru>
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To: Christopher Faylor <cygwin-developers AT cygwin DOT com>
Subject: Re: dll base address
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 <20010610004015 DOT D29231 AT redhat DOT com>
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Hi!

Sunday, 10 June, 2001 Christopher Faylor cgf AT redhat DOT com wrote:

>>As you can see, cygwin1.dll has been loaded at 02561000. It seems to me
>>that if __cygwin_user_data is a non-relocatble variable, that we should
>>mark cygwin1.dll as non-relocatable.
>>
>>Thoughts?

CF> It's possible that this is just an artifact of faulty handling by gdb.
CF> I'm not aware of any reason for cygwin1.dll to be unrelocatable.

i believe it isn't. when fhandlers are passed between processes,
they're just copied as array of bytes. this includes their vtables. as
long as cygwin1.dll is loaded at equal base addresses, everything's
fine -- all vtables remain valid after copying. but if cygwin1.dll is
relocated in exec()ed process, first call to virtual method in
fhandler cause referencing invalid memory.

i hadn't found a way to access vtable in gcc, so i don't know an
elegant way to fix this.

Egor.            mailto:deo AT logos-m DOT ru ICQ 5165414 FidoNet 2:5020/496.19