If epoll_ctl fails, the descr->ev array isinconsistent

Let's take an example: fd = open(..) /* fd = 3 for example */ lxc_mainloop_add_handler(descr, fd, cb1, data1) fails. the program take care of the error, it closes the fd Later, reopen a fd (get 3 for again) lxc_mainloop_add_handler(desc, fd, cb2, data2) is ok. When something happen on fd, cb1 with data1 will be called instead of cb2 with data2, because descr->ev contains 2 entries for fd == 3. Signed-off-by: Clement Calmels <clement.calmels@fr.ibm.com> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

If epoll_ctl fails, the descr->ev array isinconsistent
3ce45e64 · Clement Calmels · Daniel Lezcano · 312b3ca2 · 3ce45e64
Commit 3ce45e64 authored Jan 13, 2010 by Clement Calmels Committed by Daniel Lezcano Jan 13, 2010
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Showing with 11 additions and 13 deletions

mainloop.c src/lxc/mainloop.c +11 -13

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--- a/src/lxc/mainloop.c
+++ b/src/lxc/mainloop.c
@@ -81,7 +81,6 @@ int lxc_mainloop_add_handler(struct lxc_epoll_descr *descr, int fd,
 {
 	struct epoll_event *ev;
 	struct mainloop_handler *handler;
-	int ret = -1;
 	handler = malloc(sizeof(*handler));
 	if (!handler)
@@ -95,25 +94,24 @@ int lxc_mainloop_add_handler(struct lxc_epoll_descr *descr, int fd,
 	if (!ev)
 		goto out_free;
-	if (descr->nfds) {
+	memcpy(ev, descr->ev, sizeof(*descr->ev) * (descr->nfds));
-		memcpy(ev, descr->ev, sizeof(*descr->ev) * (descr->nfds));
-		free(descr->ev);
-	}
-	descr->ev = ev;
+	ev[descr->nfds].events = EPOLLIN;
-	descr->ev[descr->nfds].events = EPOLLIN;
+	ev[descr->nfds].data.ptr = handler;
-	descr->ev[descr->nfds].data.ptr = handler;
-	ret = epoll_ctl(descr->epfd, EPOLL_CTL_ADD, fd, 
+	if (epoll_ctl(descr->epfd, EPOLL_CTL_ADD, fd, &ev[descr->nfds]) < 0) {
-			&descr->ev[descr->nfds]);
+		free(ev);
+		goto out_free;
+	}
+	free(descr->ev);
+	descr->ev = ev;
 	descr->nfds++;
-out:
+	return 0;
-	return ret;
 out_free:
 	free(handler);
-	goto out;
+	return -1;
 }
 int lxc_mainloop_del_handler(struct lxc_epoll_descr *descr, int fd)