Make ERESTARTxyz messages more descriptive

There is widespread confusion about exact meaning
of ERESTARTxyz codes. Before this change, we were showing
all four of them the same: as "(To be restarted)".

This change prints better explanations for these codes,
and contains verbose comments which explain *why* we display
codes that way - or else someone confused
is bound to come later and mangle them again.
New messages are:

ERESTARTSYS (To be restarted if SA_RESTART is set)
ERESTARTNOINTR (To be restarted)
ERESTARTNOHAND (Interrupted by signal)
ERESTART_RESTARTBLOCK (Interrupted by signal)

* syscall.c (trace_syscall_exiting): Make ERESTARTxyz messages
more descriptive.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
1 file changed