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Index > Windows > fixups ?

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ouadji



Joined: 24 Dec 2008
Posts: 1081
Location: Belgium
ouadji 09 Nov 2009, 11:09
hello, Smile
when should we use the directive "fixups" and why ?
I do not understand this directive and I find no clear explanation to this forum topic.
(sorry for my bad english)
Thank you very much.
Post 09 Nov 2009, 11:09
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid 09 Nov 2009, 12:30
Simply speaking, you need to use it in DLL. You don't have to use it in EXE.
Post 09 Nov 2009, 12:30
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chaoscode



Joined: 21 Nov 2006
Posts: 64
chaoscode 09 Nov 2009, 13:46
When an File is loaded into Ram for execution it gets relocated (did i spell it right?)
and every address in the Programm is not right
and "fixups" tells fasm to create automatically a Section which is interpreted by windows.
in this section is where the adresses are and how they have to be manipulated before the Programm can be executed.
Usually exe files don't need to be relocated, but DLL-Files often need.
Post 09 Nov 2009, 13:46
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 20486
Location: In your JS exploiting you and your system
revolution 09 Nov 2009, 13:47
fixups are generally used for code relocation. And then usually only needed for relocating global variable pointers. And, as vid says, usually only needed when you are making a DLL.
Post 09 Nov 2009, 13:47
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ouadji



Joined: 24 Dec 2008
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ouadji 09 Nov 2009, 14:58
thank you all, I understand now.
Post 09 Nov 2009, 14:58
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comrade



Joined: 16 Jun 2003
Posts: 1150
Location: Russian Federation
comrade 10 Nov 2009, 06:38
If you want your app to enroll into ASLR (not sure if FASM can set the right PE flag), then you need fixups for executables as well.
Post 10 Nov 2009, 06:38
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sinsi



Joined: 10 Aug 2007
Posts: 794
Location: Adelaide
sinsi 10 Nov 2009, 06:46
Trivia: on win 3.1 using win32s, 32-bit exe's needed a reloc section.
Post 10 Nov 2009, 06:46
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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4624
Location: Argentina
LocoDelAssembly 16 Nov 2009, 22:30
The not easy to follow discussion that originated in this thread was moved here
Post 16 Nov 2009, 22:30
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