tweaks

man7/signal.7

@@ -575,7 +575,10 @@ and
 The following interfaces are never restarted after
 being interrupted by a signal handler,
 regardless of the use of
-.BR SA_RESTART :
+.BR SA_RESTART ;
+they always fail with the error
+.B EINTR
+when interrupted by a signal handler:
 .\" These are the system calls that give EINTR or ERESTARTNOHAND
 .\" on interruption by a signal handler.
 .RS 4
@@ -607,7 +610,6 @@ and
 Sleep interfaces:
 .BR clock_nanosleep (2),
 .BR nanosleep (2),
-.BR sleep (3),
 and
 .BR usleep (3).
 .IP *
@@ -618,6 +620,11 @@ file descriptor.
 .IP *
 .BR io_getevents (2).
 .RE
+.PP
+The
+.BR sleep (3)
+function is also never restarted if interrupted by a handler,
+but gives a success return: the number of seconds remaining to sleep.
 .SS Interruption of System Calls and Library Functions by Stop Signals
 On Linux, even in the absence of signal handlers,
 certain blocking interfaces can fail with the error
@@ -659,7 +666,7 @@ Linux 2.4 and earlier:
 .BR nanosleep (2).
 .RE
 .SH "CONFORMING TO"
-POSIX.1
+POSIX.1, except as noted.
 .SH BUGS
 .B SIGIO
 and