Function addfd_at 

pub fn addfd_at(
    listener: i32,
    id: u64,
    fd: i32,
    newfd: i32,
    cloexec: bool,
) -> Result<(), i32>

Installs fd into the tracee at descriptor number newfd, closing what was there, without answering the notification.

Used before a CONTINUE so the continued syscall finds a different object behind one of its descriptor arguments. Closes the supervisor’s copy of fd afterwards.

Arguments

• listener - Listener descriptor.
• id - Notification id.
• fd - Supervisor-side descriptor to hand over.
• newfd - Descriptor number in the tracee to install it at.
• cloexec - Set O_CLOEXEC on the tracee’s copy.

Errors

Errno from the ioctl.