From nobody Mon Nov 22 17:04:40 2021 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id BD74C189B012 for ; Mon, 22 Nov 2021 17:04:45 +0000 (UTC) (envelope-from mgorny@moritz.systems) Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) (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 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4HyYXs4RcCz4SRH for ; Mon, 22 Nov 2021 17:04:45 +0000 (UTC) (envelope-from mgorny@moritz.systems) Received: by mail-lf1-x130.google.com with SMTP id n12so83916994lfe.1 for ; Mon, 22 Nov 2021 09:04:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=moritz-systems.20210112.gappssmtp.com; s=20210112; h=message-id:subject:from:to:cc:date:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=4raGIPJi99jL7v7LGb37pxgYK7vXlGBCH19HUoESHzM=; b=YrM6dthwFitIMPZhc5UZAFuWdEu9Wld0u0WyTMcj8l+LUJ5SHhdAaCHHmd0XwQmQ2n OFhQhhmUY8I3LjAQ/FT1UE35oYWfrODfWrWo5qxwxsu0SagZcRvQiWnXH7+8+QRkMxHo jTGuR9ySVmHRXKRWpeZJuPuezL63sJeM0tSLoD6b3wy+rLz0l8GKcNp59mlMPM3B22tP a0LuzwbAnYlAxPkAp6maxbxMHJ9ecdOm9U7vdd9MnfUl6Spq2XyyUKc0YfzcTN085X4A nV5Q2QwgbqOLFaFr++FBYK3QbTqCdYjbm3PiAXdAD4A33mSjZ7G7mPT1WWQTqsiGHXZ7 rdBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=4raGIPJi99jL7v7LGb37pxgYK7vXlGBCH19HUoESHzM=; b=1lmeLeF3W5aW6XvHm1yUeu3+K8xBb25oEBhAFMSRtGUFt5sFg10ayjKIpz2IEU/x3P 6DsPjxDIxumBiqrcyoEpB59YlOdLqvPOjZS1L8A6x23re3W2REPlhmbW34I7WNyQyA0a uckk/WqD96Ak+nXhHnnORHs0wUvk84QRkdkW4EcY1xoT2gY4gcXPGQ+486qtwtZqTN0L 6bj1vqZeKVH3cGRmJSdYGMOObyFct1NOIJtirWz/c1g0tTOOyC3dsCQa0EyjV03P13TD yw0bfSy5E/sQ+NVkgSGkrG7o147+xRBJaCZetaCK4okkA94w/DsyaN3Lq+ODEvIyq0/Q tslA== X-Gm-Message-State: AOAM5307PbN96vbWOBZ9qn4A5SqRjIcxA593QwOCt94zNSYspe+xtnlD R7Iqz/EZqJA79UbiMLiFiLRvvA== X-Google-Smtp-Source: ABdhPJw3CULPUH7OMl5Ua8EkMhtuNCMI857+1u/Lv9UVmX4HGBAhHh1hqVdaPlun/VhX927uIroIzA== X-Received: by 2002:a05:6512:39ca:: with SMTP id k10mr60538968lfu.426.1637600682565; Mon, 22 Nov 2021 09:04:42 -0800 (PST) Received: from [192.168.1.12] (c139-65.icpnet.pl. [85.221.139.65]) by smtp.gmail.com with ESMTPSA id k15sm968103ljh.102.2021.11.22.09.04.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Nov 2021 09:04:42 -0800 (PST) Message-ID: <1b140e6f5e3a44fe875820fd0a5a2d621ae23ae5.camel@moritz.systems> Subject: Re: Looking for rationale for the minidump format From: =?UTF-8?Q?Micha=C5=82_G=C3=B3rny?= To: Ed Maste Cc: FreeBSD Hackers , John Baldwin , Peter Wemm Date: Mon, 22 Nov 2021 18:04:40 +0100 In-Reply-To: References: <305082d9f216bb8382773c074eaf7a5c3101cc13.camel@moritz.systems> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.1 List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4HyYXs4RcCz4SRH X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-ThisMailContainsUnwantedMimeParts: N On Mon, 2021-11-22 at 10:26 -0500, Ed Maste wrote: > On Sun, 21 Nov 2021 at 09:42, Michał Górny wrote: > > > > Hi, everyone. > > > > As part of the work contracted by the FreeBSD Foundation, I'm working > > on adding explicit minidump support to LLDB. When discussing > > the options with upstream, I've been asked why FreeBSD created their own > > minidump format. > > > > I did a bit of digging but TBH all the rationale I could get was to > > create partial memory dumps. However, unless I'm mistaken the ELF > > format is perfectly capable of that -- e.g. via creating an explicit > > segment for every continuous active region. > > ELF can, indeed. One of my previous co-op students wrote a little tool > to convert a minidump to ELF, see https://reviews.freebsd.org/D19253. > That's what it does - creates a segment for each contiguous region. If > we ended up going this way we could integrate D19253 into savecore. Thank you for your reply. I think this approach makes sense. Do you want us to pursue updating D19253 to build again (it's failing due to libkvm API changes and -Werror) and moving it into savecore instead of adding FreeBSD minidump support in LLDB? -- Best regards, Michał Górny