From owner-freebsd-arch@freebsd.org Sat Feb 25 17:25:53 2017 Return-Path: Delivered-To: freebsd-arch@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B1E1ACED1A0 for ; Sat, 25 Feb 2017 17:25:53 +0000 (UTC) (envelope-from eric@badgerio.us) Received: from sasl.smtp.pobox.com (pb-smtp2.pobox.com [64.147.108.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 86F15D26; Sat, 25 Feb 2017 17:25:53 +0000 (UTC) (envelope-from eric@badgerio.us) Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 3BF1A68DF9; Sat, 25 Feb 2017 12:25:51 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=subject:to :references:from:message-id:date:mime-version:in-reply-to :content-type:content-transfer-encoding; s=sasl; bh=xk7uHWjRrlLV Et6gnsz0DsffNbs=; b=x11f0EYbMJLYk0jPIe1Bf5M51nUAiwqF0nyRMpA8TicF gPct0kJlgH7MIXK2J5fNuc3Fr2lOY2qGKru4meOlTrE39Ledg8CvlgM0iYqkTPad eGxscDtYzZmZxO3gNd1oKEli2quCQvXIbZLWZK3Qpo6sKRBv3fu9jBoGpxy6Pg0= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 218E368DF7; Sat, 25 Feb 2017 12:25:51 -0500 (EST) Received: from [192.168.1.103] (unknown [24.7.205.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id 382B268DF6; Sat, 25 Feb 2017 12:25:50 -0500 (EST) Subject: Re: procfs ctl interface To: Eric van Gyzen , des@freebsd.org, freebsd-arch@freebsd.org References: <451312a7-9ae9-c5a1-4153-2268039c5942@badgerio.us> From: Eric Badger Message-ID: Date: Sat, 25 Feb 2017 11:25:48 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Pobox-Relay-ID: 73CD6D2A-FB7F-11E6-9557-A7617B1B28F4-46178211!pb-smtp2.pobox.com DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=badgerio.us; h=subject:to:references:from:message-id:date:mime-version:in-reply-to:content-type:content-transfer-encoding; s=2016-12.pbsmtp; bh=xk7uHWjRrlLVEt6gnsz0DsffNbs=; b=UFTacjfBL/pgTyHNJxnWJ+cfVYhVStQA2r0wf3e9kl+JEAMab/6p2ZsKgsOHOxHE7MlhTnRICi3woyFQBJ/WHv79eTDfCm0bqj1dlmFFsBd6zRAxKuvxRci/EEbkCk4WDYJyKWcnSUCKFhLFq0iliIzSCIO+ILf/PD1DYLzItPw= X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Feb 2017 17:25:53 -0000 On 02/25/2017 09:47 AM, Eric van Gyzen wrote: > On 02/24/2017 19:43, Eric Badger wrote: >> I started working on a change that will perturb procfs' ctl interface >> to some >> degree. In looking closer at procfs, it seems like it has been pretty >> well >> broken for use as a debugging interface since at least 9.3 (the oldest >> system I >> have handy). Is there any reason to maintain this interface at all? If >> anything, >> it should perhaps be made into an alternate front end for ptrace() >> rather than >> being entirely separate, but I'm not sure I see the value in that. > > As I recall, the last in-tree consumer was gcore, but attilio@ switched > it to ptrace in r199805. > > If nobody mentions a significant consumer, garbage-collecting it sounds > good to me. > > Eric To clarify, I'm only targeting (for now) the string interface "ctl" special file, not the ioctl interface on "mem" nor the other special files (e.g. "regs"). Items in that last category seem to still have legitimate (or at least convenient) uses, in that you can inspect a process without needing to attach to it. Here's what I plan to do: https://reviews.freebsd.org/D9802 CC des@, procfs maintainer. Eric