On Tue, Oct 09, 2012 at 10:07:22PM +0800, Cong Wang wrote: > On Tue, Oct 9, 2012 at 6:05 AM, Richard W.M. Jones <[email protected]> wrote: > > Let's move this to LKML ... > > > > 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. > >> > >> Al Viro (CC'd) made some changes in this area recently .. > > > > Attached is a self-contained test program that demonstrates the bug. > > > > Seems we passed a wrong flag to f_dupfd()... > Does the following patch help? > > 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;
Yes .. the same patch has already been sent upstream. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones New in Fedora 11: Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 70 libraries supprt'd http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
