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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CA74C00140 for ; Fri, 5 Aug 2022 12:12:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240694AbiHEMMl (ORCPT ); Fri, 5 Aug 2022 08:12:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231192AbiHEMMj (ORCPT ); Fri, 5 Aug 2022 08:12:39 -0400 Received: from mail-ot1-x32c.google.com (mail-ot1-x32c.google.com [IPv6:2607:f8b0:4864:20::32c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD12D1D0DE for ; Fri, 5 Aug 2022 05:12:37 -0700 (PDT) Received: by mail-ot1-x32c.google.com with SMTP id x1-20020a056830278100b00636774b0e54so1796000otu.4 for ; Fri, 05 Aug 2022 05:12:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=VrVuJuhrSZE+9DmS5M6DpJAhDp1BcvxZgTQm+rO0ARg=; b=YbZ2Y78Rhf7+LSn7fDJEM5mcxwVzCDJb5lhY5JWU+HbqP1AhzX5aeRcrr4zPyLXAkU Fk850q3fMMmUXfGJJlFA6UTuSZUE9AVMUtS49UVeFoiaq5F4Igzc16xEW8INwClzyYw3 3gLytTV6qvmLqc9NQPUy7qQ74lhFQDPca+KcTERr+mQuYw6YivHuEjTbqoG7t2a/WTHu 0f4GAlhYMIwErVQvW0TITlsKiAO80f1V5KIl8SRzJPUNM06pO+19iOsfALk4Uc68sHom yLc7l3+vHv+CSehz7VjZxMUxYuxyBfJAr9O1s0TpfgYo8xcj3GJCACAAJvyslHdDKdTl uKQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=VrVuJuhrSZE+9DmS5M6DpJAhDp1BcvxZgTQm+rO0ARg=; b=nR9ZMNJA4j1QAMXOtdpyNj+JthsOqybz7xOey9wvuVSz/aEuqso+oCANsX0Zvy6LDM oPwkC4dCvQc0t35jKCC90hw4ogCTpDCPQBFx+qEZ6SVGJX5tXFkR9PmSOosfyABIdILM jr5T8W4dms3hi1p4LdTFWDMachHFzPvAzwNQ/1ZZ49pbyRQiIaeMusF+Kv7jGYSU8KVf ChxxbMKo/DkGUwD++hVRCQYUGldp0YnFs4pEz6DmhrwGygKBfZ5zAIEn8RBWWZ4yNTlu DgLjziWtNMtVJUrZ3FyvXD2Ow4LXo5QQ9llJWnPaNOPr1qDtiQYTw2ekNYZFB2moqNdo ZvKw== X-Gm-Message-State: ACgBeo28tUEcIIN6poeHdx+JnMvU7AqDDA4/i4LkTC9K33hkXDd9qJ5y L9NeHlVzbehc1QImnPrwYsbcnbGm2tDmhMyA1kE= X-Google-Smtp-Source: AA6agR7kklYXTJ+Ss410QTU7DK05grNnqNjwUjZLQ89wKHHhQYawiYoF1jCuNesJJpuLN/K8T/i+oYo2xa6l1brViCw= X-Received: by 2002:a9d:ef3:0:b0:636:bc6d:4916 with SMTP id 106-20020a9d0ef3000000b00636bc6d4916mr191665otj.341.1659701556849; Fri, 05 Aug 2022 05:12:36 -0700 (PDT) MIME-Version: 1.0 References: <20210623120127.327154589@linutronix.de> <20210623121452.214903673@linutronix.de> <4812abd6-626c-67e4-7314-be282cd25a4a@intel.com> <291808ee-d5ab-a7b2-33e2-62a449e90cbf@intel.com> <37ba2de3-26b3-12eb-6a9d-c0f0572b832c@intel.com> In-Reply-To: <37ba2de3-26b3-12eb-6a9d-c0f0572b832c@intel.com> From: Andrei Vagin Date: Fri, 5 Aug 2022 05:12:23 -0700 Message-ID: Subject: Re: [patch V4 09/65] x86/fpu: Sanitize xstateregs_set() To: "Chang S. Bae" Cc: Dave Hansen , Thomas Gleixner , LKML , Andy Lutomirski , Dave Hansen , Fenghua Yu , Tony Luck , Yu-cheng Yu , Sebastian Andrzej Siewior , Borislav Petkov , Peter Zijlstra , Kan Liang , Megha Dey , Oliver Sang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 28, 2022 at 4:32 PM Chang S. Bae wrote: > > On 7/25/2022 2:26 PM, Dave Hansen wrote: > > > > Do you happen to have a quick reproducer for this, or at least the > > contents of the buffer that you are trying to restore? > > While not following this report, I think there is a regression along > with the changes: > > As looking into the spec, this state load does not depend on XSTATE_BV: > > RFBM := XCR0 AND EDX:EAX; > COMPMASK := XCOMP_BV field from XSAVE header; > > IF COMPMASK[63] = 0 > THEN > ... > IF RFBM[1] = 1 OR RFBM[2] = 1 > THEN load MXCSR from legacy region of XSAVE area; > FI; > ... > ELSE > ... > > But our upstream code does reference XSTATE_BV instead of RFBM [1,2]. > > My test case [3] fails with the upstream but works with 5.13, which is > before the series. Then, this change looks to make it work at least for it: gVisor test passes with this change too. Chang, are you going to send a patch? Thanks, Andrei