On Tue, Aug 18, 2020 at 06:44:47PM +0100, Matthew Wilcox wrote:

On Tue, Aug 18, 2020 at 07:34:00PM +0200, Christian Brauner wrote:

quoted

The only remaining function callable outside of kernel/fork.c is
_do_fork(). It doesn't really follow the naming of kernel-internal
syscall helpers as Christoph righly pointed out. Switch all callers and
references to kernel_clone() and remove _do_fork() once and for all.

My only concern is around return type.  long, int, pid_t ... can we
choose one and stick to it?  pid_t is probably the right return type
within the kernel, despite the return type of clone3().  It'll save us
some work if we ever go through the hassle of growing pid_t beyond 31-bit.

We have at least the futex ABI restricting PID space to 30 bits.