From: David van Moolenbroek <david@minix3.org>
Date: Wed, 5 Oct 2016 17:37:56 +0000 (+0000)
Subject: libc: bugfixes for minix's poll(3) wrapper
X-Git-Url: http://zhaoyanbai.com/repos/?a=commitdiff_plain;h=6956dd2b516c6d226afb5b4ae854532a02fcbd3d;p=minix.git

libc: bugfixes for minix's poll(3) wrapper

- clear "revents" fields even when the call times out;
- do not call FD_ISSET with a negative file descriptor number.

Change-Id: I7aeaae79e73e39aed127a75495ea08256b18c182
---

diff --git a/minix/lib/libc/sys/poll.c b/minix/lib/libc/sys/poll.c
index 72fe6238e..8735833c2 100644
--- a/minix/lib/libc/sys/poll.c
+++ b/minix/lib/libc/sys/poll.c
@@ -57,6 +57,7 @@ poll(struct pollfd *p, nfds_t nfds, int timout)
 
 	highfd = -1;
 	for (i = 0; i < nfds; i++) {
+		p[i].revents = 0;
 		if (p[i].fd < 0)
 			continue;
 		if (p[i].fd >= FD_SETSIZE) {
@@ -83,7 +84,8 @@ poll(struct pollfd *p, nfds_t nfds, int timout)
 
 	rval = 0;
 	for (i = 0; i < nfds; i++) {
-		p[i].revents = 0;
+		if (p[i].fd < 0)
+			continue;
 		if (FD_ISSET(p[i].fd, &rd))
 			p[i].revents |= POLLIN|POLLRDNORM|POLLRDBAND|POLLPRI;
 		if (FD_ISSET(p[i].fd, &wr))