From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: May close() return any error code? Date: Wed, 29 Jul 2015 07:45:11 -0700 Message-ID: <20150729144511.GA11233@dtor-ws> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Takashi Iwai , Al Viro Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, "Dr. Werner Fink" List-Id: linux-input@vger.kernel.org HI Takashi, On Wed, Jul 29, 2015 at 12:46:59PM +0200, Takashi Iwai wrote: > Hi, > > while debugging a problem of X and gdm with the old systemd-210, we > encountered a sudden death of systemd-logind, and this turned out to > be an unexpected errno from close(). The close() call for input > devices returns ENODEV error. The logind in systemd-210 treats this > error code as fatal, triggers assert() and eventually kills itself. > The details are found in an openSUSE bugzilla thread: > https://bugzilla.opensuse.org/show_bug.cgi?id=939571 > > This seems coming from evdev_flush(). As there is no fd leak, it's no > big problem per se. But, now the question is whether returning such > an error code is correct behavior at all. At least, it doesn't seem > defined in POSIX: > http://pubs.opengroup.org/onlinepubs/009695399/functions/close.html Hmm, if I checked the right version of the code close_nointr_nofail() expects only 0 as the return code so even if we change the kernel to use more conforming -EIO instead of -ENODEV systemd will still die... The question is whether we really need to propagate return value from f_op->flush() up to userspace in filp_close(). Why don't we ask Al? Thanks. -- Dmitry