Jan Kiszka authored Jun 19, 2015 and Philippe Gerum committed Jul 17, 2015

The oneway mode meant norestart, thus return -EINTR instead of retrying
the syscall after signal processing. But this caused damaged to the
register state of the mayday-interrupted thread, most visible on x86-64
where RAX is holding the RIP.

Fix this by restarting the syscall on signals. The syscall is supposed
to deliver the same result then, including a correct register state.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>