This is the mail archive of the
mailing list for the binutils project.
moving instructions to another address
- From: Sebastian Wick <sebastian at sebastianwick dot net>
- To: <binutils at sourceware dot org>
- Date: Sat, 18 May 2013 16:17:57 +0200
- Subject: moving instructions to another address
I'm not sure if this is the right place to ask but I'll do it
Currently I try to write a library which can hook into any function you
know the address of. That means that the lib overwrites to first few
instructions of the function with a jmp (or something similar) to
another function. If you want to call the original function you need to
execute the instructions which are overwritten by the jmp instruction.
The lib currently mmaps memory and writes them there (trampoline). This
somehow worked well but I'm sure that moving instruction to another
address may cause undefined behavior. Is there something in binutils I
can use to make it safe? And is it even possible?
I'd love to hear your thoughts about it.