X-Spam-Check-By: sourceware.org Date: Tue, 9 Jan 2007 04:04:45 -0800 From: Christopher Layne To: cygwin@cygwin.com Subject: Re: 1.7.0 CVS mmap failure Message-ID: <20070109120445.GC19638@ns1.anodized.com> References: <20070105182234.GC12776@calimero.vinschen.de> <20070105192302.GD12776@calimero.vinschen.de> <20070106154519.GA19640@ns1.anodized.com> <20070107105844.GB10586@calimero.vinschen.de> <20070109090415.GA19638@ns1.anodized.com> <20070109115643.GD23638@calimero.vinschen.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070109115643.GD23638@calimero.vinschen.de> User-Agent: Mutt/1.5.11 X-Assp-Spam-Prob: 0.00000 X-Assp-Whitelisted: Yes X-Assp-Envelope-From: clayne@ns1.anodized.com X-Assp-Intended-For: cygwin@cygwin.com X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Real quick here and I'll follow up tomorrow. I don't get SIGSEGV in my application ever. I get an error back from mmap saying it cannot allocate memory when i'm simply trying to open a small file! The original events ere posted up in that first part of the strace - which is unmodified original behavior. Things did not start happening UNTIL the MEM_TOP_DOWN change. My code does not do ANYTHING out of the ordinary that it wasn't doing before and working completely fine with. On Tue, Jan 09, 2007 at 12:56:43PM +0100, Corinna Vinschen wrote: > > Yet the latter works for me, whereas the former results in mmap() > > failures for files smaller than the page size. > > The latter works for you because it's wrong. Since it uses 64K, mmap > thinks it doesn't have to add filler pages. So adding the filler pages > can't go wrong. So you can access your file, but you get the SEGV > exaclty after the last 4K page of the file, not at the end of the > expected 64K page. > > > Corinna -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/