[uecker]

A ptrace_syscall would be interesting and would seem to be a full replacement for having the pid argument everywhere.

But frankly, I am not really seeing the value.

[trumpdong]

The value is not needing to change every other syscall and not needing to write new ones with a pid argument (besides which, what when you want to change it to a pidfd argument? then you add pidfd_syscall instead of duplicating every syscall again)

[uecker]

I meant the value of running syscalls in another process from the parent process in contrast to (v)forking and running them in the child directly.

[trumpdong]

The value is starting the child with a clean slate instead of a copy of its parent.