BUG/MINOR: listener: enforce all_threads_mask on bind_thread on init

When intializing a listener, let's make sure the bind_thread mask is
always limited to all_threads_mask when inserting the FD. This will
avoid seeing listening FDs with bits corresponding to threads that are
not active (e.g. when using "bind ... process 1/even"). The side effect
is very limited, all that was identified is that atomic operations are
used in fd_update_events() when not necessary. It's more a matter of
long-term correctness in practice.

This fix might be backported as far as 1.8 (then proto_sockpair must
be dropped).

src/proto_sockpair.c

@@ -158,7 +158,7 @@ static int sockpair_bind_listener(struct listener *listener, char *errmsg, int e
 	listener->state = LI_LISTEN;
 
 	fd_insert(fd, listener, listener->proto->accept,
-	          thread_mask(listener->bind_conf->bind_thread));
+	          thread_mask(listener->bind_conf->bind_thread) & all_threads_mask);
 
 	return err;
 

src/proto_tcp.c

@@ -999,7 +999,7 @@ int tcp_bind_listener(struct listener *listener, char *errmsg, int errlen)
 	listener->state = LI_LISTEN;
 
 	fd_insert(fd, listener, listener->proto->accept,
-	          thread_mask(listener->bind_conf->bind_thread));
+	          thread_mask(listener->bind_conf->bind_thread) & all_threads_mask);
 
  tcp_return:
 	if (msg && errlen) {

src/proto_uxst.c

@@ -343,7 +343,7 @@ static int uxst_bind_listener(struct listener *listener, char *errmsg, int errle
 	listener->state = LI_LISTEN;
 
 	fd_insert(fd, listener, listener->proto->accept,
-	          thread_mask(listener->bind_conf->bind_thread));
+	          thread_mask(listener->bind_conf->bind_thread) & all_threads_mask);
 
 	return err;