Ignoring a system call

Question

I know that you can capture a system call using ptrace . But I want to ignore the system call. Perhaps it is possible for ptrace to pick up a system call, see its number, and if the number has a system call to be ignored, ptrace stops the system call from continuing or immediately returning the system call.

The fact is that we must have the effect that the application ignores specific system calls using ptrace .

Answer 1

You can try PTRACE_GETREGS and PTRACE_SETREGS .
If you change the eip after the system call and eax to make the return value valid, the call may be skipped.
But I did not try, and would not be surprised if this did not work.