From owner-freebsd-current Tue Oct 15 12:36:58 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7B65E37B401 for ; Tue, 15 Oct 2002 12:36:57 -0700 (PDT) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6A9C843EA9 for ; Tue, 15 Oct 2002 12:36:56 -0700 (PDT) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.6/8.12.6) with ESMTP id g9FJagIw031481; Tue, 15 Oct 2002 21:36:52 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: Nate Lawson Cc: current@freebsd.org Subject: Re: GEOM/fdisk/USB drive problem In-Reply-To: Your message of "Tue, 15 Oct 2002 12:29:26 PDT." Date: Tue, 15 Oct 2002 21:36:42 +0200 Message-ID: <31480.1034710602@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message , Nate Lawson wri tes: >fdisk against my USB flash drive crashes with divide by zero. It turns >out that get_params() starts with some default values (since there is >no disklabel) and then runs some ioctls: DIOCGFWSECTORS and DIOCGFWHEADS. > >The problem is that fdisk checks the error from that ioctl and then >happily uses whatever parameters it returned. My question is, should I >add the error checking in userland (error == 0 && sector != 0) or in >g_dev_ioctl? IMO, it should be in g_dev_ioctl so that we only have to >validate the data in one place instead of multiple utilities (fdisk, >disklabel, ...?) I really think it belongs in userland and not in the kernel. The "FW" values are advisory, and if they are not there or not sensible, userland should cope. I could agree to make g_dev_ioctl fail the ioctl with some errno if they came back as zero, but not substituting another value. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message