From owner-freebsd-hackers Wed Sep 29 0:56:48 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from herring.nlsystems.com (nlsys.demon.co.uk [158.152.125.33]) by hub.freebsd.org (Postfix) with ESMTP id 8C53F15192 for ; Wed, 29 Sep 1999 00:56:16 -0700 (PDT) (envelope-from dfr@nlsystems.com) Received: from salmon.nlsystems.com (salmon.nlsystems.com [10.0.0.3]) by herring.nlsystems.com (8.9.3/8.8.8) with ESMTP id IAA23437; Wed, 29 Sep 1999 08:59:23 +0100 (BST) (envelope-from dfr@nlsystems.com) Date: Wed, 29 Sep 1999 08:59:23 +0100 (BST) From: Doug Rabson To: John Polstra Cc: drdavis@calderasystems.com, hackers@freebsd.org Subject: Re: Netscape Bus Error In-Reply-To: <199909281813.LAA12154@vashon.polstra.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 28 Sep 1999, John Polstra wrote: > In article <37F0DC3D.7F4A969D@calderasystems.com>, > Darren R. Davis wrote: > > > I believe that a Bus Error is specifically referencing miss aligned > > data vs segmentation violation (SIGSEGV) which is accessing data > > that is either free'd or not yours, etc. > > That was the traditional distinction, but it's different on > FreeBSD/i386. SIGSEGV means you accessed memory that is unmapped. > SIGBUS means you accessed memory that is mapped, but protected > (unwritable and/or unreadable). To further confuse matters, > FreeBSD/alpha generates SIGSEGV for both cases. And it generates SIGBUS for unaligned accesses (when traps for that are enabled). -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message