From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bird.elm.relay.mailchannels.net (bird.elm.relay.mailchannels.net [23.83.212.17]) by sourceware.org (Postfix) with ESMTPS id 331823857C66 for ; Thu, 26 Nov 2020 17:13:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 331823857C66 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=gotplt.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=siddhesh@gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 583461814D3; Thu, 26 Nov 2020 17:13:56 +0000 (UTC) Received: from pdx1-sub0-mail-a90.g.dreamhost.com (100-100-138-54.trex.outbound.svc.cluster.local [100.100.138.54]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id C6CC91819B4; Thu, 26 Nov 2020 17:13:55 +0000 (UTC) X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from pdx1-sub0-mail-a90.g.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384) by 0.0.0.0:2500 (trex/5.18.10); Thu, 26 Nov 2020 17:13:56 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Decisive-Suffer: 71d04f0a55e1b81c_1606410836071_3718618408 X-MC-Loop-Signature: 1606410836071:747684873 X-MC-Ingress-Time: 1606410836071 Received: from pdx1-sub0-mail-a90.g.dreamhost.com (localhost [127.0.0.1]) by pdx1-sub0-mail-a90.g.dreamhost.com (Postfix) with ESMTP id 6F1D67F5E1; Thu, 26 Nov 2020 09:13:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gotplt.org; h=subject:to :cc:references:from:message-id:date:mime-version:in-reply-to :content-type:content-transfer-encoding; s=gotplt.org; bh=bj74c9 zVmC9TvimDm7gcNzJX3w8=; b=pr+jKcSunAGd59GTEuib3tReBHaD1xzdzpUp2M PLXwhhW8sUzAAyAb5361id5XOsEMNmh6uF1kdORpXgOKf4LBrCqTds2taVZ8lGgj 04DqMGmgXCV+DmYauvDsrpBNIpNQz1NYE3lIEzIMeaqNCKHcttYk1KaviDv0FFDd /Snd0= Received: from [192.168.1.111] (unknown [1.186.101.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a90.g.dreamhost.com (Postfix) with ESMTPSA id 008577F13F; Thu, 26 Nov 2020 09:13:52 -0800 (PST) Subject: Re: [PATCH v3 2/8] elf: Add a tunable to control use of tagged memory To: "H.J. Lu" Cc: Richard Earnshaw , GNU C Library , Richard Earnshaw References: <20201123154236.25809-1-rearnsha@arm.com> <20201123154236.25809-3-rearnsha@arm.com> <378cba09-12c1-59de-578a-1ca3a84015c5@foss.arm.com> <2a2cbd34-8dbc-34af-c5ee-b7d0ef5b48a7@gotplt.org> <26b8b11e-919a-b6e0-ff5f-51e724faffb2@foss.arm.com> <8ddb9604-5a6d-a656-0585-57a1b26c39f6@gotplt.org> <87e8b15f-8c86-4b2c-a5e4-3e70631ea505@gotplt.org> <23a8ad00-a376-48ae-cc6a-2684261146a1@foss.arm.com> <6173c59d-ee67-9499-ac61-c2dd37b56c67@foss.arm.com> <1938dee9-f8e5-ca9a-8f28-efb3ac91bf61@gotplt.org> X-DH-BACKEND: pdx1-sub0-mail-a90 From: Siddhesh Poyarekar Message-ID: <23462613-48c0-9fdf-aa89-18c98d9c6656@gotplt.org> Date: Thu, 26 Nov 2020 22:43:47 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-0.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Nov 2020 17:14:01 -0000 On 11/26/20 9:49 PM, H.J. Lu wrote: > The ultimate goal is to have a single glibc binary which runs everywhere. > Glibc needs to handle static executables, dynamic executables as well as > dlopened shared objects. Initially, no binaries are marked and memory > tag should be disabled by default. Tunable can be used to enable memory The patchset seems to tick all those boxes. > tag manually at run-time. We don't know if there are any issues in the current > patches without considering the memory tag marker support. Sure, which is why I asked the question so that we can discuss how memory tag marker support in the binary would impact this feature. Could you please elaborate on that because I still don't see it. I can see how having binaries marked to always run with tagging enabled could be a good way to ensure that they're always executed that way, but it's something that could get added on top of the current patchset and perhaps even backported since it doesn't affect ABI. Siddhesh