/* We rely heavily on various flags the CLONE function understands:
CLONE_VM, CLONE_FS, CLONE_FILES
   These flags select semantics with shared address space and
   file descriptors according to what POSIX requires.
CLONE_SIGHAND, CLONE_THREAD
   This flag selects the POSIX signal semantics and various
   other kinds of sharing (itimers, POSIX timers, etc.).
CLONE_SETTLS
   The sixth parameter to CLONE determines the TLS area for the
   new thread.
CLONE_PARENT_SETTID
   The kernels writes the thread ID of the newly created thread
   into the location pointed to by the fifth parameters to CLONE.
   Note that it would be semantically equivalent to use
   CLONE_CHILD_SETTID but it is be more expensive in the kernel.
CLONE_CHILD_CLEARTID
   The kernels clears the thread ID of a thread that has called
   sys_exit() in the location pointed to by the seventh parameter
   to CLONE.
The termination signal is chosen to be zero which means no signal
is sent.  */
const int clone_flags = (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SYSVSEM
                      | CLONE_SIGHAND | CLONE_THREAD
                      | CLONE_SETTLS | CLONE_PARENT_SETTID
                      | CLONE_CHILD_CLEARTID
                      | 0);