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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A363EC433DB for ; Tue, 9 Feb 2021 19:01:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4076B64E56 for ; Tue, 9 Feb 2021 19:01:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233103AbhBIS6p (ORCPT ); Tue, 9 Feb 2021 13:58:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233444AbhBISv6 (ORCPT ); Tue, 9 Feb 2021 13:51:58 -0500 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FDFAC0617AA for ; Tue, 9 Feb 2021 10:26:40 -0800 (PST) Received: by mail-pl1-x636.google.com with SMTP id b8so10206305plh.12 for ; Tue, 09 Feb 2021 10:26:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amacapital-net.20150623.gappssmtp.com; s=20150623; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:cc:in-reply-to:to; bh=dgZXefq5Ur84gHyH0jeL4t8oBY1mdlQ4zBj7nzzrp20=; b=ZDvJHo02c2NueaZiHJVY9dsPPQfI5TZBk2lx6FMtMBs2S3DsUfh4MDB88Tam5Ne62M gqacRfYI29Z5OeW1IFK/YXCbId9cuotvC09kAO1Icl73SgryW35dzMCzpnaHdNveegdN ygZqRc9ymtDHpuIMFdGl6mXnJvEjLQKDz6b4CdrV+HgtiWjhus5dLYd4S1Til/XfGpe8 Pc5Gj/hca/fweWXv6Gkqyp2LdoiwNLgTIlkcmw1ZhjXXWOVW08jDrJL52xMNoK7+TQ71 Bx+b/3/or6mk3RacVA0J2+7DFASZkaTb7kQNFCaXAzfXP1TZfsX8od8/UJ6PFbZrM6If pqDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:cc:in-reply-to:to; bh=dgZXefq5Ur84gHyH0jeL4t8oBY1mdlQ4zBj7nzzrp20=; b=ekewM+0UP4/V46h4uoOLoWiq820xf6DMZqdE1jDza57k6Xsr7BTHwcXr0W436dMbFL k/oXWuAYC0jwpXAMZ2QixiM8gfz5Bl884lqCzLufTGHeilckILEohjuHWV/aQTg0Pzav DaXH+59Z+2be9hY+2nyE4qPGP5Yf/T1OXGndFd2tq1uyNaqjHoQvr350z2dpblYoPgQZ NvnlNafgFDF60jfFzM7zSKPShD/ouheIH+PwSD0fzE1IJs8NNTqo4qgjjl1deA62T3AA jLRQRSwr7TQLEca6SQ5a2TmnazKtprJu3HcHmd9e6qNKmWayBbZuqyU+7hgES+1UIzZD Nnbg== X-Gm-Message-State: AOAM5318hWZgw+J4DWnj4z2rIJsB4t9/nsk1uCvWsvkvaGD8pfDcMn5+ oCXOr574e4VNoVb2rsGIRJJHHmIpQONz7/1p X-Google-Smtp-Source: ABdhPJz3XrtIvAlXMoRc7qFrUi4rN8p+1C4uGXcWjLTUAKkrtA4IOwCvx+nbFwE9/Jwk7a9j3SHzSw== X-Received: by 2002:a17:902:d202:b029:e1:8936:cf31 with SMTP id t2-20020a170902d202b02900e18936cf31mr22413279ply.51.1612895199485; Tue, 09 Feb 2021 10:26:39 -0800 (PST) Received: from ?IPv6:2601:646:c200:1ef2:f811:395b:ab09:b007? ([2601:646:c200:1ef2:f811:395b:ab09:b007]) by smtp.gmail.com with ESMTPSA id i1sm24729351pfb.54.2021.02.09.10.26.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Feb 2021 10:26:38 -0800 (PST) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Andy Lutomirski Mime-Version: 1.0 (1.0) Subject: Re: [GIT PULL] x86/urgent for v5.11-rc7 Date: Tue, 9 Feb 2021 10:26:37 -0800 Message-Id: <3C17D187-8691-4521-9B64-F42A0B514F13@amacapital.net> References: Cc: Alexei Starovoitov , Steven Rostedt , Miroslav Benes , Peter Zijlstra , Josh Poimboeuf , Borislav Petkov , Dave Hansen , x86-ml , lkml , Alexei Starovoitov , live-patching@vger.kernel.org In-Reply-To: To: Linus Torvalds X-Mailer: iPhone Mail (18D52) Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org > On Feb 9, 2021, at 10:09 AM, Linus Torvalds wrote: >=20 > =EF=BB=BFOn Tue, Feb 9, 2021 at 8:55 AM Andy Lutomirski wrote: >>=20 >> Or we hack up #CP to handle this case. I don=E2=80=99t quite know how I f= eel about this. >=20 > I think that's the sane model - if we've replaced the instruction with > 'int3', and we end up getting #CP due to that, just do the #BP > handling. >=20 > Anything else would just be insanely complicated, I feel. The other model is =E2=80=9Cdon=E2=80=99t do that then.=E2=80=9D I suppose a nice property of patching ENDBR to INT3 is that, not only is it a= tomic, but ENDBR is sort of a NOP, so we don=E2=80=99t need to replace the E= NDBR with anything. >=20 > Linus