* miscfuncs.cc (check_iovec_for_read): Don't check buffer when zero length

iov_len.
(check_iovec_for_write): Ditto.
* fhandler.h (fhandler_base::readv): New method.
(fhandler_base::writev): Ditto.
* fhandler.cc (fhandler_base::readv): New method.
(fhandler_base::writev): Ditto.
* syscalls.cc (_read): Delegate to readv(2).
(_write): Ditto, mutatis mutandi.
(readv): Rewrite, based on the old _read code, to use the new
fhandler_base::readv method.  Improve access mode handling and ensure all calls
reach the final strace statement.
(writev): Ditto, mutatis mutandi.
* include/sys/uio.h (struct iovec): Change field types to match SUSv3.
* winsup.h (check_iovec_for_read): New function.
(check_iovec_for_write): Ditto.
* miscfuncs.cc (check_iovec_for_read): Ditto.
(check_iovec_for_write): Ditto.

1 files changed, 3 insertions, 1 deletions

diff --git a/winsup/cygwin/fhandler_socket.cc b/winsup/cygwin/fhandler_socket.cc
index 85b210752..94866e3fe 100644
--- a/winsup/cygwin/fhandler_socket.cc
+++ b/winsup/cygwin/fhandler_socket.cc
@@ -736,7 +736,9 @@ fhandler_socket::recvmsg (struct msghdr *msg, int flags)
   p = buf;
   while (nb > 0)
     {
-      ssize_t cnt = min(nb, iov->iov_len);
+      ssize_t cnt = iov->iov_len;
+      if (nb < cnt)
+	cnt = nb;
       memcpy (iov->iov_base, p, cnt);
       p += cnt;
       nb -= cnt;