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=-6.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 3A429C2D0A3 for ; Thu, 12 Nov 2020 06:35:00 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3BE88208FE for ; Thu, 12 Nov 2020 06:34:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pBTIiPmU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3BE88208FE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34716 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kd6CA-0002r9-7x for qemu-devel@archiver.kernel.org; Thu, 12 Nov 2020 01:34:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42904) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kd6Aj-0002Nn-VI for qemu-devel@nongnu.org; Thu, 12 Nov 2020 01:33:29 -0500 Received: from mail-yb1-xb42.google.com ([2607:f8b0:4864:20::b42]:36618) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kd6Ai-0007pQ-4d for qemu-devel@nongnu.org; Thu, 12 Nov 2020 01:33:29 -0500 Received: by mail-yb1-xb42.google.com with SMTP id l14so192120ybq.3 for ; Wed, 11 Nov 2020 22:33:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=CwTad+ug/WbwbBN9HdNnNqe5FWGBwV+ksp70aTHF578=; b=pBTIiPmULCASCSQCcUxCVEADChIaDuSSoopiwMmHiLF0mAJdYd3F6Ji72/uCn6xbxy 7RuLGbLqPs0kMOmQ7IygWxBEANV1Ui0uN0ITwkCAt/jz340XD9IfQnM3iqJaSs6IoyGe HmLazxGq1fe6PzO/zFAzsHeLJDgzE9h1RWebHCVd8QRerBZmXqaYDLNeGs2m4nTtmarE WWrXXfvmTZhBAdVyDgdzEfiYc3dLmuaGKOE8VzvRFL9l2t4XyHzhHDK2JOmUIQGWlZC2 16nTf+0agPOViPw1xpi3yHSGVPwJGz8yz/XCjFdWvVXgJDV23RRha8xLbcqqtNZXKi41 jhXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=CwTad+ug/WbwbBN9HdNnNqe5FWGBwV+ksp70aTHF578=; b=AfK5eNk5iZe54KBEyEIlrvsxDg4YtQB/t62imXw46uOPvBeWVgLDK5XN82ch0EuqJk 5rxfkwPdSu8P7OdDZRTpwEJniPi/Ib7qfW5GQCRWiCgmQW4dWH1PZGsXXZhrav3Yqi8v r/FUT47cZ7AS3bWXjmypXVxVKUCxCzhVfjCsm++f/xRjyYLIMZl9pC8vgGRvoGdRUEbH HtGBiECD0IccWVe36QzCf/7c8v5jLHQbCiEF1BnMwM/5qF4vmlCSL8ZMrNhTzIKYBEk/ DbAJWOMa1I3tSd/mAearF5Kn1Uf4WJo/3xv25gCh5+VHboEVKCyLz8hEVgfX0NQOoaCB CAyg== X-Gm-Message-State: AOAM531thd41Xvj5Uot6wdrLoJ6+SUm9j6GxJTkG8ZDGjTN+x542omMC Q/a1xjbqmmjX3ZM11uZAbT3QyGCnXlOCjaVnlxM= X-Google-Smtp-Source: ABdhPJyqG09uvOzm3fw4C2vOw+leyQkBFEMXlaAhQTX/67pjKAiiy3zMbXDoSTMQzJnOtukUpQVUVqUWClsFwDSasDw= X-Received: by 2002:a25:bacd:: with SMTP id a13mr41856877ybk.387.1605162807056; Wed, 11 Nov 2020 22:33:27 -0800 (PST) MIME-Version: 1.0 References: <1603361762-43062-1-git-send-email-bmeng.cn@gmail.com> In-Reply-To: From: Bin Meng Date: Thu, 12 Nov 2020 14:33:15 +0800 Message-ID: Subject: Re: [PATCH] target/i386: seg_helper: Correct segement selector nullification in the RET/IRET helper To: Eduardo Habkost , Paolo Bonzini , "qemu-devel@nongnu.org Developers" , Richard Henderson Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::b42; envelope-from=bmeng.cn@gmail.com; helo=mail-yb1-xb42.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bin Meng Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Nov 2, 2020 at 4:20 PM Bin Meng wrote: > > On Thu, Oct 22, 2020 at 6:16 PM Bin Meng wrote: > > > > From: Bin Meng > > > > Per the SDM, when returning to outer privilege level, for segment > > registers (ES, FS, GS, and DS) if the check fails, the segment > > selector becomes null, but QEMU clears the base/limit/flags as well > > as nullifying the segment selector, which should be a spec violation. > > > > Real hardware seems to be compliant with the spec, at least on one > > Coffee Lake board I tested. > > > > Signed-off-by: Bin Meng > > --- > > > > target/i386/seg_helper.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > Ping? Ping?