Return correct number of total bits set in all fd_set's.

Change case of POLLNVAL as an error.
Remove POLLHUP and POLLERR from one case, their place is most likely
amongst read events.

PR:		33723
Submitted by:	Alexander Litvin <archer@whichever.org>
Reviewed by:	deischen [Provided a small change to the PR patch as well]
MFC after:	4 weeks

1 files changed, 18 insertions, 9 deletions

diff --git a/lib/libpthread/thread/thr_select.c b/lib/libpthread/thread/thr_select.c
index 5860efe..8d03bbd 100644
--- a/lib/libpthread/thread/thr_select.c
+++ b/lib/libpthread/thread/thr_select.c
@@ -52,7 +52,7 @@ _select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds,
 	struct pthread	*curthread = _get_curthread();
 	struct timespec ts;
 	int             i, ret = 0, f_wait = 1;
-	int		pfd_index, got_one = 0, fd_count = 0;
+	int		pfd_index, got_events = 0, fd_count = 0;
 	struct pthread_poll_data data;
 
 	if (numfds > _thread_dtablesize) {
@@ -166,12 +166,22 @@ _select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds,
 			 * this file descriptor from the fdset if
 			 * the requested event wasn't ready.
 			 */
-			got_one = 0;
+
+			/*
+			 * First check for invalid descriptor.
+			 * If found, set errno and return -1.
+			 */
+			if (data.fds[i].revents & POLLNVAL) {
+				errno = EBADF;
+				return -1;
+			}
+
+			got_events = 0;
 			if (readfds != NULL) {
 				if (FD_ISSET(data.fds[i].fd, readfds)) {
 					if (data.fds[i].revents & (POLLIN |
 					    POLLRDNORM))
-						got_one = 1;
+						got_events++;
 					else
 						FD_CLR(data.fds[i].fd, readfds);
 				}
@@ -180,7 +190,7 @@ _select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds,
 				if (FD_ISSET(data.fds[i].fd, writefds)) {
 					if (data.fds[i].revents & (POLLOUT |
 					    POLLWRNORM | POLLWRBAND))
-						got_one = 1;
+						got_events++;
 					else
 						FD_CLR(data.fds[i].fd,
 						    writefds);
@@ -189,16 +199,15 @@ _select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds,
 			if (exceptfds != NULL) {
 				if (FD_ISSET(data.fds[i].fd, exceptfds)) {
 					if (data.fds[i].revents & (POLLRDBAND |
-					    POLLPRI | POLLHUP | POLLERR |
-					    POLLNVAL))
-						got_one = 1;
+					    POLLPRI))
+						got_events++;
 					else
 						FD_CLR(data.fds[i].fd,
 						    exceptfds);
 				}
 			}
-			if (got_one)
-				numfds++;
+			if (got_events != 0)
+				numfds+=got_events;
 		}
 		ret = numfds;
 	}