From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 63BB21D68F for ; Fri, 10 May 2024 00:25:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715300727; cv=none; b=flLGWEh2x60OXFbv/m0rYxqZI+N7Fp5bxRWhO7Bi2Q9PGluGF9ZG6LHcq3fxrm2DpPPplpRzYp2VbjsZCD0aQV3QzC1bE+thwMTlUiQn1Jh15+zDbpQPx3Qa8JRGuWScgjl/e/Gz1HEjEwfmAErl163gyqrYhASmYHOPzq3nKts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715300727; c=relaxed/simple; bh=nzhgzXBLVmxRg+MI59G3H3An2IVTrWtLtRJv538SxT4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CbPn9RxlkFwm7eVFf+ZeqoA+1Ltwsrc6mP1w4OVUreperWBPI2s4jFPUNry+5Of6CLKfqJTJLtaI/DnJlUc9GjHM0CFY8Vw5rw0C8d2CiDw3Ln9JSBVHl/8k/L4eRMAu3Zs0q9f3Q9CGMmRIROX6UUGHCf2h16ukqKlpvZEuF0c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=aftEdi20; arc=none smtp.client-ip=198.175.65.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="aftEdi20" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715300726; x=1746836726; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=nzhgzXBLVmxRg+MI59G3H3An2IVTrWtLtRJv538SxT4=; b=aftEdi20DR+XHd4W/SvAarFHS6hoTeFOpMNuco4cQbbkXJkHZw0URFtH TZjTcN8VQdb7cn6R935cERaB/uqUUKXhYsoPOizS8kWdTd25lvrCX3nXm XtNVWxI4ZK8CeqjfkgSum0PsD011SnIqjiS+w12wLClp/3BlOV6grmwsB Z7GiCsDVHEvB3G5DusstkbncaiR8ZU7RCtcb/oFVy7MQZsjCPVK3/yYj3 XFG/j+c/FKjRxDYuXYqYzVS0nZDwvgo+PzQTzG/e+VRofiPy3CT0ikCmB QyhL5DpAxtunnHXYk4KfA+ao8ZiUZP5GENFNStH6WvX1TC/q/pflJGWBZ A==; X-CSE-ConnectionGUID: afsq/Wv3S0WKZ7NgsZMvrg== X-CSE-MsgGUID: POCDxGRdQRatXvPz4KDQLA== X-IronPort-AV: E=McAfee;i="6600,9927,11068"; a="22409601" X-IronPort-AV: E=Sophos;i="6.08,149,1712646000"; d="scan'208";a="22409601" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 17:24:42 -0700 X-CSE-ConnectionGUID: HYoMje3ASTmMq3J1efmzxA== X-CSE-MsgGUID: rXLoGBOgS6KbqEAn/FoqZA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,149,1712646000"; d="scan'208";a="29492622" Received: from vuongchr-mobl.amr.corp.intel.com (HELO desk) ([10.209.114.189]) by fmviesa010-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 17:24:42 -0700 Date: Thu, 9 May 2024 17:24:34 -0700 From: Pawan Gupta To: Dave Hansen Cc: Borislav Petkov , Dave Hansen , linux-kernel@vger.kernel.org, x86@kernel.org, Robert Gill , "Linux regression tracking (Thorsten Leemhuis)" , antonio.gomez.iglesias@linux.intel.com, daniel.sneddon@linux.intel.com Subject: Re: [PATCH] x86/entry_32: Move CLEAR_CPU_BUFFERS before CR3 switch Message-ID: <20240510002434.gevlrqdiuhtosafa@desk> References: <20240426-fix-dosemu-vm86-v1-1-88c826a3f378@linux.intel.com> <5b5e597d-7620-4a5a-9bfa-bae26f0b0fa3@intel.com> <20240509221425.zcl6c45thb7wxyza@desk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, May 09, 2024 at 05:04:36PM -0700, Dave Hansen wrote: > On 5/9/24 15:17, Pawan Gupta wrote: > > It probably can go right before the SWITCH_TO_USER_CR3. I didn't have > > 32-bit setup with dosemu to experiment with. I will attach a debug patch to > > the bugzilla and request the reporter to test it. > > There's an enter_from_vm86.c in the kernel selftests. That will at > least exercise this path. Yes, entry_from_vm86.c should be a good test case for this, thanks.