actually, Linux uses at least two of these: for security reasons (ASLR), the vsyscall page is implemented on modern kernels by unmapping the page, trapping the

actually, Linux uses at least two of these: for security reasons (ASLR), the vsyscall page is implemented on modern kernels by unmapping the page, trapping the page fault, and emulating the system call. the recently introduced io_uring interface provides an interface to set up a buffer ring which is asynchronously polled by the kernel for system calls to execute.