X-Recipient: archive-cygwin AT delorie DOT com X-SWARE-Spam-Status: No, hits=-1.6 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,UNPARSEABLE_RELAY X-Spam-Check-By: sourceware.org X-Yahoo-SMTP: jenXL62swBAWhMTL3wnej93oaS0ClBQOAKs8jbEbx_o- Date: Thu, 21 Jul 2011 13:05:03 -0400 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: ioctl: FIONREAD and ENOTTY Message-ID: <20110721170502.GA11218@ednor.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com References: <1311149476 DOT 7796 DOT 50 DOT camel AT YAAKOV04> <20110720154647 DOT GA15150 AT calimero DOT vinschen DOT de> <1311201422 DOT 6248 DOT 10 DOT camel AT YAAKOV04> <20110721143930 DOT GP15150 AT calimero DOT vinschen DOT de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110721143930.GP15150@calimero.vinschen.de> User-Agent: Mutt/1.5.20 (2009-06-14) Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com On Thu, Jul 21, 2011 at 04:39:31PM +0200, Corinna Vinschen wrote: >On Jul 20 17:37, Yaakov (Cygwin/X) wrote: >> On Wed, 2011-07-20 at 17:46 +0200, Corinna Vinschen wrote: >> > On Jul 20 03:11, Yaakov (Cygwin/X) wrote: >> > > On Linux, ioctl(2) returns several different errors[1]: >> > > >> > > EBADF d is not a valid descriptor. >> > > EFAULT argp references an inaccessible memory area. >> > > EINVAL Request or argp is not valid. >> > > ENOTTY d is not associated with a character special device. >> > > ENOTTY The specified request does not apply to the kind of object that >> > > the descriptor d references. >> > > >> > > In the case of FIONREAD, Cygwin doesn't seem to distinguish between >> > > EINVAL and ENOTTY, and this causes at least one major bug: >> > > >> > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35536 >> > > >> > > I have patched GCJ and GNU classpath to work around it, but this really >> > > needs to be fixed in Cygwin itself. >> > >> > Would this patch be sufficient? >> > >> > Index: fhandler.cc >> > =================================================================== >> > RCS file: /cvs/src/src/winsup/cygwin/fhandler.cc,v >> > retrieving revision 1.397 >> > diff -u -p -r1.397 fhandler.cc >> > --- fhandler.cc 5 Jul 2011 12:02:10 -0000 1.397 >> > +++ fhandler.cc 20 Jul 2011 15:46:40 -0000 >> > @@ -1151,6 +1151,10 @@ fhandler_base::ioctl (unsigned int cmd, >> > set_nonblocking (*(int *) buf); >> > res = 0; >> > break; >> > + case FIONREAD: >> > + set_errno (ENOTTY); >> > + res = -1; >> > + break; >> > default: >> > set_errno (EINVAL); >> > res = -1; >> >> Given my testcases, give me a few days to check this out. > >Ok, but the patch doesn't build as is. You have to add > > #include > >to get the FIONREAD definition. Sorry about that. Btw, I don't think the above is sufficient. I think you'll have to add a similar test to other fhandlers (like fhandler_windows) which completely implement ioctl without reverting to fhandler_base. cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple