From owner-freebsd-current@FreeBSD.ORG Sun Mar 21 17:09:04 2004 Return-Path: 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 D820A16A4CE for ; Sun, 21 Mar 2004 17:09:04 -0800 (PST) Received: from mailout1.pacific.net.au (mailout1.pacific.net.au [61.8.0.84]) by mx1.FreeBSD.org (Postfix) with ESMTP id 106EB43D2F for ; Sun, 21 Mar 2004 17:09:02 -0800 (PST) (envelope-from bde@zeta.org.au) Received: from mailproxy2.pacific.net.au (mailproxy2.pacific.net.au [61.8.0.87])i2M1904u021833 for ; Mon, 22 Mar 2004 12:09:00 +1100 Received: from gamplex.bde.org (katana.zip.com.au [61.8.7.246]) i2M18w67019449 for ; Mon, 22 Mar 2004 12:08:59 +1100 Date: Mon, 22 Mar 2004 12:08:58 +1100 (EST) From: Bruce Evans X-X-Sender: bde@gamplex.bde.org To: current@freebsd.org Message-ID: <20040322115952.O11632@gamplex.bde.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Subject: gdb remote kernel debugging on i386's broken? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Mar 2004 01:09:05 -0000 Has anyone found gdb remote kernel debugging on i386's to _not_ be broken lately? There have been rumours of its brokenness for several months. I rarely use it, but tried it yesterday and found that breakpoints just don't work. gdb apparently doesn't understand its own breakpoints. It stops on them, and IIRC it removes the breakpoint instruction that it has put in the instruction stream, but doesn't fix up %eip to where the original instruction was, so it normally wants to resume execution in the middle of a multi-byte instruction. This tends to crash. Fixing up %eip manually works. Single stepping works. Bruce