Messages in this thread | | | Date | Tue, 16 Nov 2004 22:33:18 +0100 (MET) | From | Jan Engelhardt <> | Subject | Re: Accessing program counter registers from within C or Aseembler. |
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>Hello, > >Does anybody know how to access the address of the >current executing instruction in C while the program >is executing?
With the aid of a second program, yes. For one program: not directly. It's because the EIP changes while you are calclating it. You could f.e.:
int main(void) {
printf("owned\n"); mark: printf("pwned\n"); printf("%p\n", &&mark); }
GCC specific. Or you could also poke around with __builtin_return_address, or even peek at the stack yourself.
>Also, is there a method to load a program image from >memory not a file (an exec that works with a memory >address)? Mainly I am looking for a method that brings >a program image into memory modify parts of it and >start the in-memory modified version.
No, because that opens a wide door for trojans and stack smashers.
>Can anybody think of a method to replace a thread >image without replacing the whole process image?
It would not be a thread then.
Jan Engelhardt -- Gesellschaft für Wissenschaftliche Datenverarbeitung Am Fassberg, 37077 Göttingen, www.gwdg.de - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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