Description of problem:
the clone syscall can return with some error codes that are not documented in the man page. In particular:

  ERESTARTSYS = 512 (To be restarted if SA_RESTART is set)
    Most common type of signal-interrupted syscall exit code.  The
    system call will be restarted with the same arguments if
    SA_RESTART is set; otherwise, it will fail with EINTR.

  ERESTARTNOINTR = 513 (To be restarted)
    Rare. For example, fork() returns this if interrupted.
    SA_RESTART is ignored (assumed set): the restart is
    unconditional.

  ERESTARTNOHAND = 514  (To be restarted if no handler)
    pause(), rt_sigsuspend() etc use this code.  SA_RESTART is
    ignored (assumed not set): syscall won't restart (will return
    EINTR instead) even after signal with SA_RESTART set. However,
    after SIG_IGN or SIG_DFL signal it will restart (thus the name
    "restart only if has no handler").

  ERESTART_RESTARTBLOCK = 516 (Interrupted by signal)
    Syscalls like nanosleep(), poll() which can't be restarted with
    their original arguments use this code. Kernel will execute
    restart_syscall() instead, which changes arguments before
    restarting syscall.  SA_RESTART is ignored (assumed not set)
    similarly to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
    since restart data is saved in "restart block" in task struct,
    and if signal handler uses a syscall which in turn saves
    another such restart block, old data is lost and restart
    becomes impossible)


Version-Release number of selected component (if applicable):
This is true for all man pages right up until the latest version in Fedora.