int clone ( int (*fn) (void *), void *child_stack, int flags, void *arg, ...);
CLONE_SIGHAND - share signal handler table
CLONE_FILES - share file descriptor table
CLONE_FS - share filesystem context (root directory, current directory, file creation mask)
CLONE_IO - share device scheduler context
CLONE_VM - share address space
CLONE_NEWIPC - create new process communication namespace
CLONE_NEWPID - create new process identifier namespace
CLONE_NEWUTS - create new host platform namespace
CLONE_NEWNET - create new network namespace
CLONE_NEWNS - create new mount namespace