From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E607C433FE for ; Tue, 4 Oct 2022 17:36:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D7F5D6B0071; Tue, 4 Oct 2022 13:36:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D2F4F6B0073; Tue, 4 Oct 2022 13:36:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BCFD88E0001; Tue, 4 Oct 2022 13:36:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A90076B0071 for ; Tue, 4 Oct 2022 13:36:04 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 7665F80CAF for ; Tue, 4 Oct 2022 17:36:04 +0000 (UTC) X-FDA: 79983970248.04.A0E5EE7 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf19.hostedemail.com (Postfix) with ESMTP id CEC761A0011 for ; Tue, 4 Oct 2022 17:36:03 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F38D360F1E; Tue, 4 Oct 2022 17:36:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F49DC433D7; Tue, 4 Oct 2022 17:36:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664904962; bh=kayiSIodoZR3mJ1pBQAy28WrEVULtTONXZgr/Z9D3es=; h=In-Reply-To:References:Date:From:To:Cc:Subject:From; b=PUIU4GUyuHhT3A9BskdSWSh7FAcmtx2E8PXZrViNak6i8qa++6QJi1Ci0qtDR1rdz L5sZVo/A9qAg6VjphwERSIrk/LYnSins7Dxk8hc7gg1ZcnXZRbgOn9cL4/ePXvpyM0 uG8R4Cr/dxrIicuBvK9dtRtRUBf7XcCuKFnjI1k+7zODgusivc2SVpQ3ACWWp3T5hQ QFZKroS87GdIyzrJqiaFs+9JNJm2FMspNauX29//NDF/s7yQjoFQIwtAUgcDwSex3+ yt0SMr10IVG39obPfi+kuvGaFXURicLZK6Qn9Nm2nKH+F+1mmKAH/g4pZziS2/LbRO 539Eil4yaf/0A== Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailauth.nyi.internal (Postfix) with ESMTP id 2BF7427C0054; Tue, 4 Oct 2022 13:36:00 -0400 (EDT) Received: from imap48 ([10.202.2.98]) by compute2.internal (MEProxy); Tue, 04 Oct 2022 13:36:00 -0400 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrfeeiuddguddugecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefofgggkfgjfhffhffvvefutgesthdtredtreertdenucfhrhhomhepfdet nhguhicunfhuthhomhhirhhskhhifdcuoehluhhtoheskhgvrhhnvghlrdhorhhgqeenuc ggtffrrghtthgvrhhnpedvhfeuvddthfdufffhkeekffetgffhledtleegffetheeugeej ffduhefgteeihfenucevlhhushhtvghrufhiiigvpedunecurfgrrhgrmhepmhgrihhlfh hrohhmpegrnhguhidomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqudduiedu keehieefvddqvdeifeduieeitdekqdhluhhtoheppehkvghrnhgvlhdrohhrgheslhhinh hugidrlhhuthhordhush X-ME-Proxy: Feedback-ID: ieff94742:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 80CC631A0062; Tue, 4 Oct 2022 13:35:59 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.7.0-alpha0-1015-gaf7d526680-fm-20220929.001-gaf7d5266 Mime-Version: 1.0 Message-Id: <20d483b6-da24-4ddc-b6d4-c0c23b8e5ea2@app.fastmail.com> In-Reply-To: <20221003222133.20948-10-aliraza@bu.edu> References: <20221003222133.20948-1-aliraza@bu.edu> <20221003222133.20948-10-aliraza@bu.edu> Date: Tue, 04 Oct 2022 10:35:38 -0700 From: "Andy Lutomirski" To: "Ali Raza" , "Linux Kernel Mailing List" Cc: "Jonathan Corbet" , masahiroy@kernel.org, michal.lkml@markovi.net, "Nick Desaulniers" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , "H. Peter Anvin" , "Eric W. Biederman" , "Kees Cook" , "Peter Zijlstra (Intel)" , "Al Viro" , "Arnd Bergmann" , juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, "Steven Rostedt" , "Ben Segall" , mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, "Paolo Bonzini" , jpoimboe@kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, "the arch/x86 maintainers" , rjones@redhat.com, munsoner@bu.edu, tommyu@bu.edu, drepper@redhat.com, lwoodman@redhat.com, mboydmcse@gmail.com, okrieg@bu.edu, rmancuso@bu.edu Subject: Re: [RFC UKL 09/10] exec: Give userspace a method for starting UKL process Content-Type: text/plain ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664904963; a=rsa-sha256; cv=none; b=fLoHh59Znt8qY7HzScmqDzeq2AVyyOtb4XojOjKkVDVSR/kzrbI5kemK3oiR1ee4iynPjY u1uCeJS+NlxMDy9PxHxBSCQuXVqwNWKW2ZQki7sqOyCFqxKrmfjs74mvq8pHDSTswGDYW2 sn/Ld/CKuXk4SK5UGF/mWQForl/Vsok= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=PUIU4GUy; spf=pass (imf19.hostedemail.com: domain of luto@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=luto@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664904963; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=SHyJZXYPN1QI62fyrGI9Gbn+rnXSTErV7Nor5YLLsHE=; b=WT4rVq9weqOky/vGliYWaV6/jFrerJwsag5oK+YNGZ+1HTuEPaE+j4eyUm+Vblrm3CTNpF daPXlK98JNvc+/lqDyZvsELYKBcNhtbUZOUDqnId6bS8HF+JqQkcg5QXCoGpTV0HWY0eZ9 X54N5u+mJqywkYXtqovuKq8pXu4KTCo= X-Rspamd-Server: rspam08 X-Rspam-User: X-Rspamd-Queue-Id: CEC761A0011 Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=PUIU4GUy; spf=pass (imf19.hostedemail.com: domain of luto@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=luto@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Stat-Signature: h9grdkjdiwor53hpbs4mcokin4ummid7 X-HE-Tag: 1664904963-13194 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Oct 3, 2022, at 3:21 PM, Ali Raza wrote: > From: Eric B Munson > > From: Eric B Munson > > The UKL process might depend on setup that is to be done by user space > prior to its initialization. We need a way to let userspace signal that it > is ready for the UKL process to run. We will have setup a special name for > this process in the kernel config and if this name is passed to exec that > will start the UKL process. This way, if user space setup is required we > can be sure that the process doesn't run until explicitly started. This is just bizarre IMO. Why is there one single UKL process? How about having a way to start a UKL process and then, if desired, start *another* UKL process? (And obviously there would be a security mode in which only a UKL process that is actually part of the kernel image can run or that only a UKL process with a hash that's part of the kernel image can run.) --Andy