From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) by sourceware.org (Postfix) with ESMTPS id 14D043858D33 for ; Wed, 27 Sep 2023 12:41:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 14D043858D33 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=palves.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wr1-f46.google.com with SMTP id ffacd0b85a97d-3231df054c4so7003089f8f.0 for ; Wed, 27 Sep 2023 05:41:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695818516; x=1696423316; h=content-transfer-encoding:subject:to:from:content-language :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=ey5t9k4KoWEpeEnayHk2ra12rSEG843mdKsiDKDc4SA=; b=VRecEdrk6LKxyIWI3qETOD/oVi/kOfhotrE4ck29Rk4As3DyjiVtDLYsKGR4ZFM+Vj xFhSdOPmnYsqvQnM82TtCrPcBVRad1ys7dJVB4SxMM/CQQQhHeBCOOvxiy3gRKpk9n+1 n4y5tlwyaRU5+Hp6mHX26can4kBjyovGcaoig1SmSiftH8Sk9ccmILaDkZFhOBy4HcLz yzYQzm5NGwTNQaxGS4lcYPfO9wEFso0OWulj46QaeQ/BkLhtuCvoBytFf7wTBxyEBv6K yKURAu8Y/nAYM+YHK8flmW8ILGWpxjK2vM7CjGP/UBBtUNyyb0AChrRulCanIhf+KyvY 63MQ== X-Gm-Message-State: AOJu0Yzwu4WbF9L0gAT/LjjVKnZzg1hfkc9QgewNBNsTC2GcMPeEAq6O jjyNOUfnUVblZ9UoQGM3jJX8CqePMnTALQ== X-Google-Smtp-Source: AGHT+IHi2/DKyk8/gsQZsx0v1rYB5W0L+OEEN31RDhAGjAaojz9Su5bbF6eF+cBkt1/aJYiJRpVyHg== X-Received: by 2002:adf:f485:0:b0:321:cec8:e64d with SMTP id l5-20020adff485000000b00321cec8e64dmr1671137wro.62.1695818515887; Wed, 27 Sep 2023 05:41:55 -0700 (PDT) Received: from ?IPV6:2001:8a0:f939:d200:4dbf:db9a:66fe:534c? ([2001:8a0:f939:d200:4dbf:db9a:66fe:534c]) by smtp.gmail.com with ESMTPSA id v14-20020a05600c444e00b0040535648639sm17508547wmn.36.2023.09.27.05.41.54 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 Sep 2023 05:41:55 -0700 (PDT) Message-ID: <1e26c71e-e242-de11-a687-46e05586e608@palves.net> Date: Wed, 27 Sep 2023 13:41:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Content-Language: en-US From: Pedro Alves To: gdb@sourceware.org Subject: GDB BoF notes - GNU Cauldron 2023 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3.4 required=5.0 tests=BAYES_00,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi all, We had a GDB BoF at the GNU Cauldron this past weekend, like in previous years. I was positively surprised with the attendance and the engagement. Thanks all! I took notes live while we were discussing. Thanks to Mark Wielaard for letting me use this computer. :-) Below's an edited version of the notes, with some more details filled in. =========== GDB BoF / GNU Cauldron 2023 =============== - Testsuite and CI discussion With either Linaro's CI and the sourceware.org buildbot, pre-commit, post-commit, should breakages result in emails to mailing list? Are post-commit breakage emails sent to git author only? Should go to git committer as well, for e.g., the scenario of a maintainer applying a non-maintainer's patch. AI: Talk with Maxim Kuvyrkov about it. Be mindful of overwhelming gdb-testers traffic. Counter argument raised -- list is also used as results archive. - Can we require C++17? Lancelot has patches for this. Looked at / discussed policy established when we migrated to C++11: https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#When_is_GDB_going_to_start_requiring_C.2B-.2B-NN_.3F "Our general policy is to wait until the oldest compiler that supports C++NN is at least 3 years old." Discussion about whether the bump is problematic for current distros. Looked for first GCC version that claims supports C++17. In GCC 9 release notes: "The C++17 implementation is no longer experimental." GCC 9.1 was released on May 3, 2019. Do we need full C++17, though? We can use language features even if the standard library implementation doesn't support everything. Were there actual ABI breakages between compiler releases before it was made non-experimental, though? AI: ask Jonathan Wakely. On whether we have easy availability of a new enough compiler in distros, in practice: - Tom de Vries to double check for SuSE. - Carlos O'Donell confirms that for RHEL we're good, because of GCC Toolset. - Someone should check Debian/Ubuntu and others. - BSDs tend to have easy access to recent Clang. - MinGW toolchains tend to use newer GCCs. - Patch review/approval mechanisms How to tag approval for just parts you're responsible for? #1 Add subsystem in parens after approved-by? Approved-by: John Doe (docs) #2 Alternative discussed which had most consensus: Use "Approved-by" for whole patch approval. Use "Acked-by" for partial/subsystem approval. Discussion on acked-by (linux kernel: partial approval for subsystem). Alternative probably better for tooling, like b4. People nervous about extra tags breaking those. Gwen takes action item to bring this up on the list. - Security policy. Piggy back on binutils policy? GDB can do lots of potentially unsafe things, need to containerize. What about GDB remote protocol? Must be a considered a trusted connection, users are responsible for security/authentication/encryption. qemu policy: https://www.qemu.org/docs/master/system/gdb.html "Connecting to the GDB socket allows running arbitrary code inside the guest; in case of the TCG emulation, which is not considered a security boundary, this also means running arbitrary code on the host. Additionally, when debugging qemu-user, it allows directly downloading any file readable by QEMU from the host." AI: Sid and Andrew already working on policy. - Revisiting defaults - Can we turn history saving on by default? Maybe default to history on home dir by default, too (~/.gdb_history). That would align us with bash. Some in the room have had this enabled in their gdbinits for so long they no longer remembered this wasn't on by default. Others weren't even aware you can turn this on. - Can we disable pagination by default? Surprisingly, no one in the room expressed that they like pagination on. Sevearl people mentioned that they have it off by default, and then use either the terminal scroll function, or: "(gdb) pipe GDB_COMMAND | less" when necessary.