From owner-freebsd-current@freebsd.org Wed Dec 2 17:52:38 2020 Return-Path: Delivered-To: freebsd-current@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 0AA6E4A21DA for ; Wed, 2 Dec 2020 17:52:38 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CmRPw6Hp6z3MgT for ; Wed, 2 Dec 2020 17:52:36 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-qk1-x72c.google.com with SMTP id z188so2048256qke.9 for ; Wed, 02 Dec 2020 09:52:36 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xkk1aiACUvH1iIODleAdkFkCa06qlsfrcjDbIJM9MZ4=; b=VRNxoH1cmg628ilG606BehqY5nDo5diNxgttJz+fsMJFQGDPJOYJYkDgxBvTTzteMs 6i1TWsuZppDJPqXf9UHHSRjZU4RbGblwaNhgHj0YeALQCpjeb4nmJuz6Y8p/NMaRvuyd ca9RwWamAeLjMNfO248wYw+l7rhsZA/6F3QjrM4ThdC1UKRoqBQP0WaRfqbcwQMergf8 dL2aSqazTb6M92/IHkE/DIeGTri7NDRzoAbicBoWSXxYY9BIEwb4AMt6u2RVyLEtcm3f jsscMQHX/KekAsMxvQXuE4dSRxmmwlM5UG8W9fxhjqGwdJIKkqxS9oc4gEt7+TBLYP5p 4p1g== X-Gm-Message-State: AOAM532rgdGqFST8pYy6MG7ghpTnt/SZTdL2VGenF/n6Lr5Q4KERK1p6 aMUZxeR83xGYOOc8F9zm+KpSDfhIc1zS6hCbNHeJeOB3G0S2LQ== X-Google-Smtp-Source: ABdhPJz1HUE3277Va907b9YGzqDFJ6kecBmNhBS1GhsapAbFnOeRTfgTUJx3zE5oi5aLw+jWrYOmjDP+cWQcsBiTlMQ= X-Received: by 2002:a05:620a:88e:: with SMTP id b14mr3734794qka.195.1606931555539; Wed, 02 Dec 2020 09:52:35 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Warner Losh Date: Wed, 2 Dec 2020 10:52:24 -0700 Message-ID: Subject: Re: Removing obsolete GDB 6.1.1 for FreeBSD 13 To: Ed Maste Cc: FreeBSD Current , "freebsd-toolchain@FreeBSD.org" X-Rspamd-Queue-Id: 4CmRPw6Hp6z3MgT X-Spamd-Bar: -- X-Spamd-Result: default: False [-2.82 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; ARC_NA(0.00)[]; R_DKIM_ALLOW(-0.20)[bsdimp-com.20150623.gappssmtp.com:s=20150623]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-current@freebsd.org]; DMARC_NA(0.00)[bsdimp.com]; SPAMHAUS_ZRD(0.00)[2607:f8b0:4864:20::72c:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; DKIM_TRACE(0.00)[bsdimp-com.20150623.gappssmtp.com:+]; NEURAL_HAM_SHORT(-0.82)[-0.820]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::72c:from]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_SPF_NA(0.00)[no SPF record]; FORGED_SENDER(0.30)[imp@bsdimp.com,wlosh@bsdimp.com]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RBL_DBL_DONT_QUERY_IPS(0.00)[2607:f8b0:4864:20::72c:from]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; FROM_NEQ_ENVFROM(0.00)[imp@bsdimp.com,wlosh@bsdimp.com]; MAILMAN_DEST(0.00)[freebsd-current]; RCVD_COUNT_TWO(0.00)[2] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.34 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: Wed, 02 Dec 2020 17:52:38 -0000 On Wed, Dec 2, 2020 at 10:44 AM Ed Maste wrote: > We currently have an obsolete version of GDB 6.1 installed as > /usr/libexec/gdb, kept only for use by crashinfo(8), which extracts > some basic information from a kernel core dump after a crash. If the > gdb port is installed crashinfo will use that in preference to > /usr/libexec/gdb. If neither exists it will not perform any analysis, > reporting "Unable to find a kernel debugger." > > GDB 6.1.1 was released in June 2004 and is long obsolete. It does not > support all of the architectures that FreeBSD does, and imposes > limitations on the FreeBSD kernel build - the continued use of DWARF2. > > I would like to remove GDB 6.1.1 before FreeBSD 13, and propose to > switch the GDB knob to default to NO in the near future. If the > crashinfo utility and related man pages do not already include > references to installing the gdb port/package I will add those before > making the change. > > In the fullness of time we may use LLDB to extract the same > information, or provide other tooling to do so, but I do not want to > block GDB 6.1.1's removal on this. > > Please let me know of any objections or comments. > I fully support this action. We kept gdb on board for 12 (and 11?) for crashinfo as a transition to the new gdb port and to help smooth over bumps from moving kgdb support into that port. jhb@ has done a great job in getting kgdb moved into the port. I use the port exclusively these days for all the kernel debugging I have to do from panics in our fleet (although I have some minorly special needs so I use a special script to fit into our buildenv vs deployed env). The current gdb in the base can't cope with anything more complicated than 'hello world'. It's broken for threads. It's broken for much of the code clang generates. It's useless for kernel dumps (even tracebacks are unreliable in my experience). There's little to no value that having gdb in the tree at this point. I also agree that none of this should be gated on lldb. gdb in tree is so out of date that we are much better off removing it, even if lldb isn't a complete drop in replacement (I've not used it at all, so I can't say one way or another). Warner