Received: by 2002:a25:e74b:0:0:0:0:0 with SMTP id e72csp448585ybh; Wed, 15 Jul 2020 06:23:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxvyKE2qjMC8EMnl2oYYl4ei2verwmmSmx+gNcxnCCJKanHA1eyMCw/vWxtVUppU7YM5g0S X-Received: by 2002:a17:906:57c5:: with SMTP id u5mr8841961ejr.311.1594819422352; Wed, 15 Jul 2020 06:23:42 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1594819422; cv=none; d=google.com; s=arc-20160816; b=ojczyEifYEAvefDcyQUb9698v2s3co9oJ9IU6CrydO4MRVjnMSyifbrs4iGWkaDi6H hv73CC59aAA/z6Vzb2Lx2DHhs7jly1uViqGy2cSOgJvQ1cBujfUb60MZrXPEBgtp5zc/ ju5LaUR7r3UvYTjxWbmeZ3/P44oOTnz9/kwKCtxbr1WfHDPC7I/OWOP37LNQ+fwwIrQJ EsZpiaQPndWdtpf1vcBNSuNkqp6z1wvuTITxADjPG7mOdBrXCS80qQQF7JPXaFdtkVIQ sT41VcERlp+GXzr2A3iUQu8xBBr80WbbVbKsf4JzZHY+1P6tHsc9Yk8aCRpgTYK6n2uR 0zxw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:user-agent:message-id:date :references:subject:cc:to:from:dkim-signature; bh=eujgVDOYWc3cCN8+v848SftAP3mzH/rlkfn6GJO88Cw=; b=l3qwHnysx86I0jtkZ+NVwBzzbrN/rh8duVeBK918GuoNos2Rlf3iEzitd3CtdkVOA0 DHGRVIddpkU2WzZOT+86insqFhc9a+Wkwu7J1IsmlGa1DnxO54qVT23XvuAFTnZKM399 HcAW1qW7/D3NJ7ulEKzIyC7D4tUZiB5h5QYyPE2s3I7gugNCc8VkXEwvwGbtRtpJbgBy 5Bq2RSBkXp1Eb3xOVe2/WWHPOl/NcDdBs1Fe4glZvReCOv4YsSz/Z0N6eBkgkjVcgOOw ISHVy+1//QN7S8VuZ6JjyBE8sph7txuktLo7g7NmKw4xLb2coP2MLOqIG6q7oSzn1468 KnIw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=heDS1LEu; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id ss22si1242512ejb.530.2020.07.15.06.23.18; Wed, 15 Jul 2020 06:23:42 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=heDS1LEu; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731852AbgGONWc (ORCPT + 99 others); Wed, 15 Jul 2020 09:22:32 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:25280 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731632AbgGONWc (ORCPT ); Wed, 15 Jul 2020 09:22:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594819351; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=eujgVDOYWc3cCN8+v848SftAP3mzH/rlkfn6GJO88Cw=; b=heDS1LEucImnJ7KivaLfq8WDf0HMOx5mfb0oQ1Pc7wuiWBSxssI7rwP6jKhrUQspXxvTeX l+CxPKj6fKu02rFsa2bpCOelxFyKg8wmJuNpTaMGyRRR1f1tlHtgbo2KE1PCrvYdxV3p3K B/CtpOueYP2IkHNV4r10xfHd7A4kzDw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-420-yLJrAiKwNNq5CnTy7sBerw-1; Wed, 15 Jul 2020 09:22:27 -0400 X-MC-Unique: yLJrAiKwNNq5CnTy7sBerw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 98F2718A1DE2; Wed, 15 Jul 2020 13:22:25 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-112-228.ams2.redhat.com [10.36.112.228]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8102E5D9CA; Wed, 15 Jul 2020 13:22:20 +0000 (UTC) From: Florian Weimer To: Mathieu Desnoyers Cc: carlos , Peter Zijlstra , linux-kernel , Thomas Gleixner , paulmck , Boqun Feng , "H. Peter Anvin" , Paul Turner , linux-api , Christian Brauner Subject: Re: [RFC PATCH 2/4] rseq: Allow extending struct rseq References: <20200714030348.6214-1-mathieu.desnoyers@efficios.com> <20200714030348.6214-3-mathieu.desnoyers@efficios.com> <87mu42bepq.fsf@oldenburg2.str.redhat.com> <131549905.11442.1594731035989.JavaMail.zimbra@efficios.com> <87a7028d5u.fsf@oldenburg2.str.redhat.com> <2452161.11491.1594732791558.JavaMail.zimbra@efficios.com> <71f08b3a-56f5-0e0f-53b0-cc680f7e8181@redhat.com> <2053637148.14136.1594818777608.JavaMail.zimbra@efficios.com> Date: Wed, 15 Jul 2020 15:22:18 +0200 Message-ID: <87y2nk29rp.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mathieu Desnoyers: > Practically speaking, I suspect this would mean postponing availability of > rseq for widely deployed applications for a few more years ? There is no rseq support in GCC today, so you have to write assembler code anyway. Thanks, Florian