From owner-freebsd-stable Mon Feb 24 13:41:56 2003 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E766537B405 for ; Mon, 24 Feb 2003 13:41:54 -0800 (PST) Received: from bricore.com (adsl-64-168-71-68.dsl.snfc21.pacbell.net [64.168.71.68]) by mx1.FreeBSD.org (Postfix) with ESMTP id 28CCB43FBF for ; Mon, 24 Feb 2003 13:41:53 -0800 (PST) (envelope-from lchen@briontech.com) Received: from luoqi (luoqi.bricore.com [192.168.1.63]) by bricore.com (8.12.6/8.12.6) with SMTP id h1OLfoFA038456; Mon, 24 Feb 2003 13:41:50 -0800 (PST) (envelope-from lchen@briontech.com) From: "Luoqi Chen" To: "Luoqi Chen" , "Ulrich Spoerlein" , Subject: RE: How to debug mmap(2) with pcm(3)? Date: Mon, 24 Feb 2003 13:45:09 -0800 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 In-Reply-To: X-Virus-Scanned: by amavisd-milter (http://amavis.org/) Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > Hello, > > > > I'm looking into the issue with mmap()ing the pcm-driver as shown in > > this PR http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/41747 . You can > > quickly verify if this bug is present on your system when you compile > > the test program Maxim Sobolev posted here > > http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=utf-8&frame= > > right&th=848249298f77552a&seekm=7e40su4hduj42eufbh2e8vfahgutah94ch > > _4ax.com%40ns.sol.net#link1 > > > > Now what I want to do is, kill the bug with pcm & mmap _before_ 4.8 and > > I would need some pointers where I can start debugging this. > > > This is a "feature" of ia32 architecture, there isn't a notion of > write-only memory access, write access implies read access. If you > want to "fix" the problem with pcm device, very simple, go to file > sys/i386/trap.c and replace all occurrences of PROT_READ|PROT_WRITE > with PROT_WRITE. > > -lq > After checking with the cvs log, I realized I had checked this into -current over two years ago, and I have completely forgotten about it. I could do a MFC. Has the -stable branch been frozen yet? -lq To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message