From owner-freebsd-bugs Mon Nov 18 3:10:15 2002 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B03D137B404 for ; Mon, 18 Nov 2002 03:10:13 -0800 (PST) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2EF6943E77 for ; Mon, 18 Nov 2002 03:10:13 -0800 (PST) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.12.6/8.12.6) with ESMTP id gAIBACx3054955 for ; Mon, 18 Nov 2002 03:10:12 -0800 (PST) (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.6/8.12.6/Submit) id gAIBACHW054954; Mon, 18 Nov 2002 03:10:12 -0800 (PST) Date: Mon, 18 Nov 2002 03:10:12 -0800 (PST) Message-Id: <200211181110.gAIBACHW054954@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: Bruce Evans Subject: Re: i386/45391: /usr/bin/cmp coredumps while reading a faulty CD-R Reply-To: Bruce Evans Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org The following reply was made to PR i386/45391; it has been noted by GNATS. From: Bruce Evans To: Cinek Cc: FreeBSD-gnats-submit@FreeBSD.ORG Subject: Re: i386/45391: /usr/bin/cmp coredumps while reading a faulty CD-R Date: Mon, 18 Nov 2002 22:21:06 +1100 (EST) > >Description: > When using the command /usr/bin/cmp from the default > FreeBSD-4.7 package, it is possible to produce a coredump. > It seems, there is a problem in handling errors while > reading faulty files. It happened to me while I was comparing > two files which I suspected to be dupes on my CD-Rs. I think there is a problem with mmap() on files with i/o errors in them. Pages should not be mapped if some part of them is unreadable, and this should result in the application getting signals. cmp makes no attempt to handle signals. > I guess it will not help much when I post the output > from gdb without symbol tables, but let's try at least: Not much, but you might be able to see that the fauilting instruction is an ordinary memory access, which would indicate that the problem is just unmapped memory. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message