boost::lambda::bind temporary function objects.. and raw C
Hello everyone! I have a rather challenging question, that perhaps can be resolved without too much dark magic. A little background: I'm patching an executable (x86 platform, but could be easily extended to other architectures). players: void TargetFunc(some parameters); void Hook(some parameters); method: Grab first 5 bytes of TargetFunc. Back them up. Replace them with a jmp Hook. Make Hook finish as follows: Restore the backup of 5 bytes. Call TargetFunc again, this time the real one, not the jmp. Replace the 5 bytes with jmp Hook, getting ready for the next invocation. In a nutshell - typical trampoline. Now, I want to write a framework for this. I would prefer to be able to have some code reuse. Can either mem_fn or bind be helpful here? I'm trying to understand how they work. I feel like they are creating extra 'functions' with some game about parameters. Ideas? cheers, Tomasz
AMDG Tomasz Mloduchowski wrote:
Hello everyone!
I have a rather challenging question, that perhaps can be resolved without too much dark magic.
A little background: I'm patching an executable (x86 platform, but could be easily extended to other architectures).
players: void TargetFunc(some parameters); void Hook(some parameters);
method: Grab first 5 bytes of TargetFunc. Back them up. Replace them with a jmp Hook.
Make Hook finish as follows: Restore the backup of 5 bytes. Call TargetFunc again, this time the real one, not the jmp. Replace the 5 bytes with jmp Hook, getting ready for the next invocation.
In a nutshell - typical trampoline.
Now, I want to write a framework for this. I would prefer to be able to have some code reuse. Can either mem_fn or bind be helpful here?
No.
I'm trying to understand how they work. I feel like they are creating extra 'functions' with some game about parameters. Ideas?
In Christ, Steven Watanabe
On Fri, Jul 31, 2009 at 9:20 AM, Steven Watanabe<watanabesj@gmail.com> wrote:
AMDG
Tomasz Mloduchowski wrote:
Hello everyone!
I have a rather challenging question, that perhaps can be resolved without too much dark magic.
A little background: I'm patching an executable (x86 platform, but could be easily extended to other architectures).
players: void TargetFunc(some parameters); void Hook(some parameters);
method: Grab first 5 bytes of TargetFunc. Back them up. Replace them with a jmp Hook.
Make Hook finish as follows: Restore the backup of 5 bytes. Call TargetFunc again, this time the real one, not the jmp. Replace the 5 bytes with jmp Hook, getting ready for the next invocation.
In a nutshell - typical trampoline.
Now, I want to write a framework for this. I would prefer to be able to have some code reuse. Can either mem_fn or bind be helpful here?
No.
I'm trying to understand how they work. I feel like they are creating extra 'functions' with some game about parameters. Ideas?
This of them more like structs that hold the data they need and call it with operator (), not something you can pass. However, you can build your own functions in memory, then cast a function pointer to it. That is difficult to do correctly though, especially if you use multiple platforms, however, if you do not mind the heavy weight of it, you can use something like the rather awesome LLVM to build the functions for you.
participants (3)
-
OvermindDL1 -
Steven Watanabe -
Tomasz Mloduchowski