From owner-freebsd-bugs  Fri Jan  7  4:27:24 2000
Delivered-To: freebsd-bugs@freebsd.org
Received: from freebsd.dk (freebsd.dk [212.242.42.178])
	by hub.freebsd.org (Postfix) with ESMTP id 5A9021565C
	for <freebsd-bugs@FreeBSD.ORG>; Fri,  7 Jan 2000 04:27:19 -0800 (PST)
	(envelope-from sos@freebsd.dk)
Received: (from sos@localhost)
	by freebsd.dk (8.9.3/8.9.1) id NAA83738;
	Fri, 7 Jan 2000 13:17:51 +0100 (CET)
	(envelope-from sos)
From: Soren Schmidt <sos@freebsd.dk>
Message-Id: <200001071217.NAA83738@freebsd.dk>
Subject: Re: kern/15956: Off-by-1 error in diskstrategy() triggers bug in ATA
In-Reply-To: <200001071210.EAA13523@freefall.freebsd.org> from Poul-Henning Kamp at "Jan 7, 2000 04:10:02 am"
To: phk@critter.freebsd.dk (Poul-Henning Kamp)
Date: Fri, 7 Jan 2000 13:17:51 +0100 (CET)
Cc: freebsd-bugs@FreeBSD.ORG
X-Mailer: ELM [version 2.4ME+ PL54 (25)]
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
Sender: owner-freebsd-bugs@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

It seems Poul-Henning Kamp wrote:
>  >Index: subr_disk.c
>  >===================================================================
>  >RCS file: /home/CVSROOT/src/sys/kern/subr_disk.c,v
>  >retrieving revision 1.16
>  >diff -u -r1.16 subr_disk.c
>  >--- subr_disk.c	1999/12/19 12:36:41	1.16
>  >+++ subr_disk.c	2000/01/06 21:39:34
>  >@@ -193,7 +193,7 @@
>  > 		return;
>  > 	}
>  > 
>  >-	if (dscheck(bp, dp->d_slice) < 0) {
>  >+	if (dscheck(bp, dp->d_slice) <= 0) {
>  > 		biodone(bp);
>  > 		return;
>  > 	}
>  >
>  >	2) Add belt-and-braces checks to ATA device (this code compiles
>  >	   and links, but I haven't booted from the resultant kernel):
>  
>  This was actually done that way deliberately, but not for any
>  specific reason.
>  
>  Input welcome...

I've put this in the ata drivers:

    /* if it's a null transfer, return immediatly. */
    if (bp->b_bcount == 0) {
        bp->b_resid = 0;
        biodone(bp);
        return;
    }

-Søren


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message