From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [regression] F_DUPFD_CLOEXEC breakage fix Date: Mon, 8 Oct 2012 23:21:58 +0100 Message-ID: <20121008222158.GQ2616@ZenIV.linux.org.uk> References: <20121008171517.GA15039@rhmail.home.annexia.org> <20121008172103.GB15039@rhmail.home.annexia.org> <87a9vwrgtl.fsf@rho.meyering.net> <20121008215030.GI24071@rhmail.home.annexia.org> <20121008215325.GC15039@rhmail.home.annexia.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jim Meyering , bug-gnulib@gnu.org, "Richard W.M. Jones" , linux-fsdevel@vger.kernel.org To: Linus Torvalds Return-path: Received: from zeniv.linux.org.uk ([195.92.253.2]:59049 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751089Ab2JHWWG (ORCPT ); Mon, 8 Oct 2012 18:22:06 -0400 Content-Disposition: inline In-Reply-To: <20121008215325.GC15039@rhmail.home.annexia.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, Oct 08, 2012 at 10:53:25PM +0100, Richard W.M. Jones wrote: > On Mon, Oct 08, 2012 at 10:50:30PM +0100, Richard W.M. Jones wrote: > [.. discussion on gnulib test-cloexec test snipped ..] > > I'm suspicious this is a kernel bug: > > > > creat("test-cloexec.tmp", 0600) = 3 > > fcntl(3, F_GETFD) = 0 > > fcntl(3, F_GETFD) = 0 > > fcntl(3, F_SETFD, FD_CLOEXEC) = 0 > > fcntl(3, F_GETFD) = 0x1 (flags FD_CLOEXEC) > > fcntl(3, F_GETFD) = 0x1 (flags FD_CLOEXEC) > > fcntl(3, F_SETFD, 0) = 0 > > fcntl(3, F_GETFD) = 0 > > fcntl(3, F_DUPFD_CLOEXEC, 0) = 4 > > fcntl(4, F_GETFD) = 0 > > write(2, "test-cloexec.c:97: assertion failed\n", 36) = 36 > > > > It seems to me from the description in the man page that > > F_DUPFD_CLOEXEC ought to be setting the FD_CLOEXEC flag on file > > descriptor 4, so either it's not or else F_GETFD isn't reading the > > flag for some reason. Interesting... Oh, crap. OK, that's easily fixed: in fs/fcntl.c err = f_dupfd(arg, filp, FD_CLOEXEC); should get s/FD_/O_/. Linus, could you apply the following? Fix a braino in F_DUPFD_CLOEXEC; f_dupfd() expects flags for alloc_fd()/get_unused_fd()/etc. and there clone-on-exec if O_CLOEXEC, not FD_CLOEXEC. Signed-off-by: Al Viro --- diff --git a/fs/fcntl.c b/fs/fcntl.c index 8f70429..71a600a 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -258,7 +258,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, err = f_dupfd(arg, filp, 0); break; case F_DUPFD_CLOEXEC: - err = f_dupfd(arg, filp, FD_CLOEXEC); + err = f_dupfd(arg, filp, O_CLOEXEC); break; case F_GETFD: err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;