From owner-svn-src-all@freebsd.org Fri Nov 1 19:42:57 2019 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 2907117FF75; Fri, 1 Nov 2019 19:42:57 +0000 (UTC) (envelope-from luporl@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 474XfT0HVRz4g2C; Fri, 1 Nov 2019 19:42:57 +0000 (UTC) (envelope-from luporl@freebsd.org) Received: from mail-io1-f45.google.com (mail-io1-f45.google.com [209.85.166.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) (Authenticated sender: luporl/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id D28007DF; Fri, 1 Nov 2019 19:42:56 +0000 (UTC) (envelope-from luporl@freebsd.org) Received: by mail-io1-f45.google.com with SMTP id c6so12054874ioo.13; Fri, 01 Nov 2019 12:42:56 -0700 (PDT) X-Gm-Message-State: APjAAAW8ICd+6FKth9LYyuosQuGpySElDr5lLFgy6KWxucZ73TDpPDL+ agry5L/OC6hwXVGpvWTu3OJWCguGvGW4sZ8ISgg= X-Google-Smtp-Source: APXvYqxNiTm3fHKd1OEJ9jjxPSC7ap8y4zuytAag/uA1WBoUADlCxqw6iWgn+yVvcX6uuyVltne8hF/YZCu1j2Km02I= X-Received: by 2002:a02:1c41:: with SMTP id c62mr9208188jac.132.1572637376229; Fri, 01 Nov 2019 12:42:56 -0700 (PDT) MIME-Version: 1.0 References: <201911011128.xA1BShOC057227@repo.freebsd.org> In-Reply-To: From: luporl Date: Fri, 1 Nov 2019 16:42:45 -0300 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: svn commit: r354239 - head/contrib/gdb/gdb To: John Baldwin Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Nov 2019 19:42:57 -0000 The kernel parts were fixed by r354213 and r354214. I've used old kgdb to test remote debugging through serial only, not for inspecting crash dumps. On Fri, Nov 1, 2019 at 4:34 PM John Baldwin wrote: > On 11/1/19 12:26 PM, luporl wrote: > > Well, after evaluating remote kernel debugging through serial port, on > > amd64, I've run into several issues while using latest ports gdb/kgdb. > > I don't remember all of them, but were things like step/next not always > > working, connection being lost, and similar things. > > OTOH, /usr/libexec/kgdb worked fine and reliably, although older and more > > limited. > > This is probably due to some incompatibility in GDB Remote Serial > Protocol, > > between the kernel backend and newer GDB from ports. > > > > So, that's why I chose to use /usr/libexec/kgdb while fixing/enabling > > remote debugging on PPC64, because it works reasonably well, and I could > > focus on testing/fixing other parts first. > > With only this change on gdb, it is now possible to use it to test some > > basic functionality, like remote debugger attach, backtrace and data > > inspection. > > > > My goal is not to fix every issue in /usr/libexec/kgdb, but just to get > the > > basics working, to then move on and switch to ports' GDB. > > What's odd about this commit is it only affects userland binaries, not the > kernel, so a bit odd for kgdb, especially since the old kgdb in the tree > doesn't include user support IIRC, only kernel bits (in modern gdb, kgdb > is just a wrapper, and you can use 'target vmcore' from within gdb itself > against a crash dump, etc.) > > -- > John Baldwin >