+2015-02-20 Paul Eggert <eggert@cs.ucla.edu>
+
+ poll: fixes for large fds
+ * lib/poll.c (poll): Don't check directly for NFD too large.
+ Don't rely on undefined behavior in FD_SET when an arg exceeds
+ FD_SETSIZE. Always set revents afterwards, even if to zero.
+ * tests/test-poll.c (poll1): Set revents to -1 instead of 0,
+ as that makes the test a bit stricter.
+
2015-02-19 Kevin Cernekee <cernekee@google.com>
fcntl: Fix cross compiling
int maxfd, rc;
nfds_t i;
-# ifdef _SC_OPEN_MAX
- static int sc_open_max = -1;
-
- if (nfd < 0
- || (nfd > sc_open_max
- && (sc_open_max != -1
- || nfd > (sc_open_max = sysconf (_SC_OPEN_MAX)))))
- {
- errno = EINVAL;
- return -1;
- }
-# else /* !_SC_OPEN_MAX */
-# ifdef OPEN_MAX
- if (nfd < 0 || nfd > OPEN_MAX)
+ if (nfd < 0)
{
errno = EINVAL;
return -1;
}
-# endif /* OPEN_MAX -- else, no check is needed */
-# endif /* !_SC_OPEN_MAX */
+ /* Don't check directly for NFD too large. Any practical use of a
+ too-large NFD is caught by one of the other checks below, and
+ checking directly for getdtablesize is too much of a portability
+ and/or performance and/or correctness hassle. */
/* EFAULT is not necessary to implement, but let's do it in the
simplest case. */
{
if (pfd[i].fd < 0)
continue;
-
+ if (maxfd < pfd[i].fd)
+ {
+ maxfd = pfd[i].fd;
+ if (FD_SETSIZE <= maxfd)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+ }
if (pfd[i].events & (POLLIN | POLLRDNORM))
FD_SET (pfd[i].fd, &rfds);
-
/* see select(2): "the only exceptional condition detectable
is out-of-band data received on a socket", hence we push
POLLWRBAND events onto wfds instead of efds. */
FD_SET (pfd[i].fd, &wfds);
if (pfd[i].events & (POLLPRI | POLLRDBAND))
FD_SET (pfd[i].fd, &efds);
- if (pfd[i].fd >= maxfd
- && (pfd[i].events & (POLLIN | POLLOUT | POLLPRI
- | POLLRDNORM | POLLRDBAND
- | POLLWRNORM | POLLWRBAND)))
- {
- maxfd = pfd[i].fd;
- if (maxfd > FD_SETSIZE)
- {
- errno = EOVERFLOW;
- return -1;
- }
- }
}
/* examine fd sets */
/* establish results */
rc = 0;
for (i = 0; i < nfd; i++)
- if (pfd[i].fd < 0)
- pfd[i].revents = 0;
- else
- {
- int happened = compute_revents (pfd[i].fd, pfd[i].events,
- &rfds, &wfds, &efds);
- if (happened)
- {
- pfd[i].revents = happened;
- rc++;
- }
- }
+ {
+ pfd[i].revents = (pfd[i].fd < 0
+ ? 0
+ : compute_revents (pfd[i].fd, pfd[i].events,
+ &rfds, &wfds, &efds));
+ rc += pfd[i].revents != 0;
+ }
return rc;
#else