On 2017-03-13 11:23 +0100, Pedro Lopes wrote:
> I'm trying to detect the addresses of the instructions which performs
> a memory access to a specific global variable.
I think we can just
$ cat test.c
int x, y;
int foo()
{
int t = x;
x = y;
y = t;
return 0;
}
int main() {}
$ cc test.c
$ objdump -d | grep "\<[xy]\>"
40047a: 8b 05 2c 04 20 00 mov 0x20042c(%rip),%eax # 6008ac <x>
400483: 8b 05 27 04 20 00 mov 0x200427(%rip),%eax # 6008b0 <y>
400489: 89 05 1d 04 20 00 mov %eax,0x20041d(%rip) # 6008ac <x>
400492: 89 05 18 04 20 00 mov %eax,0x200418(%rip) # 6008b0 <y>
Inserting instructions seems overkill. It's even enough to implement hooks.
--
Xi Ruoyao <ryxi@xxxxxxxxxxxxxxxxx>
School of Aerospace Science and Technology, Xidian University
