Nowdays they don't use INT 0x80 for syscalls anymore. It's faster to use something called "virtual system calls" from what I understand (I am not a kernel dev, so don't quote me). It's just what it sounds like. If you ldd a linux binary, you'll see a shared object called `linux-gate.so` or `linux-vdso.so` (it's been renamed a few times). This file doesn't actually exist. It's an imaginary library that exists as the doorway into the kernel for making these calls.
Nowdays they don't use INT 0x80 for syscalls anymore. It's faster to use something called "virtual system calls" from what I understand (I am not a kernel dev, so don't quote me). It's just what it sounds like. If you ldd a linux binary, you'll see a shared object called `linux-gate.so` or `linux-vdso.so` (it's been renamed a few times). This file doesn't actually exist. It's an imaginary library that exists as the doorway into the kernel for making these calls.
I tried to dig up something I read on this. This is what I found if anyone is interested: http://www.trilithium.com/johan/2005/08/linux-gate/