[PATCH] file descriptor array extension off by 1
Hello,
Running my program inside of valgrind I noticed two problems in version
1.4.9 (problems look to still be there in trunk). I've attached a Problem1
patch for version 1.4.9. Sorry I don't have time right now to solve
Problem2.
Problem1:
Line 268 in epoll.c looks to see if the file descriptor array needs to be
extended, but passes in the wrong argument. 'fd' is passed into
epoll_recalc as the size to expand to, but since the array is zero indexed
it needs to be expanded to 'fd+1' if you intend to access element 'fd'
(which line 273 does).
Solution:
pass 'fd+1' into epoll_recalc.
Problem2:
Resizing the fd array potentially moves the array, invalidating any
existing pointers into the array. Especially user data pointers set with
epoll_ctl at epoll.c:292. The reallocating functionality needs to update
all existing pointers if the array moved.
Thanks,
Kevin Springborn
--- a/epoll.c
+++ b/epoll.c
@@ -267,7 +267,7 @@
fd = ev->ev_fd;
if (fd >= epollop->nfds) {
/* Extent the file descriptor array as necessary */
- if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
+ if (epoll_recalc(ev->ev_base, epollop, fd+1) == -1)
return (-1);
}
evep = &epollop->fds[fd];_______________________________________________
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