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 875A9C25B4E for ; Sun, 22 Jan 2023 04:34:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229788AbjAVEeN (ORCPT ); Sat, 21 Jan 2023 23:34:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229775AbjAVEeM (ORCPT ); Sat, 21 Jan 2023 23:34:12 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5261B15CAA for ; Sat, 21 Jan 2023 20:34:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1674362051; x=1705898051; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=q21kRTwJw+Eq+WoprO8u9oA8bN3/e1g2CKnGz/MGKNE=; b=d1BPzvtCJMJ7zqVfMKKjJYohsRVj8y1dlzsDz76XjYkOqyfDf4JaUvrD wc5R7l4NNgF7neuOgtd0dXiBAnu9+taI0uUaUrC3TtyFVUbrKMPkEZ0KB f/vPEY2O86Bl+X7egXKPJhJsYUSTMb3QLzs4FTHnTsD6gaITC8fjJtuqk foTM5ZPsQtAEBwyFIRTowGXxXDdoaf2NKYYCTB9199yQDR7IKJd7kMLpa 5DU5glGxIGSaBbN2bvjvhB2fP8cax+UmW21Nl2rKyJ8P4mRxxSPeO4++T DUK3OuWYVjljlcma04B6+SZp6kaoRo1uM0y1/Abb4Tow3EEGpo1GV58bD w==; X-IronPort-AV: E=McAfee;i="6500,9779,10597"; a="309440563" X-IronPort-AV: E=Sophos;i="5.97,235,1669104000"; d="scan'208";a="309440563" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jan 2023 20:34:10 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10597"; a="724420916" X-IronPort-AV: E=Sophos;i="5.97,235,1669104000"; d="scan'208";a="724420916" Received: from aureliaw-mobl.amr.corp.intel.com (HELO [10.255.230.48]) ([10.255.230.48]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jan 2023 20:34:10 -0800 Message-ID: Date: Sat, 21 Jan 2023 20:34:09 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: the x86 sysret_rip test fails on the Intel FRED architecture Content-Language: en-US To: "Li, Xin3" , "H. Peter Anvin" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "peterz@infradead.org" , "dave.hansen@linux.intel.com" Cc: "x86@kernel.org" , "linux-kernel@vger.kernel.org" References: <5d4ad3e3-034f-c7da-d141-9c001c2343af@intel.com> <18B5DB6D-AEBD-4A67-A7B3-CE64940819B7@zytor.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/21/23 19:38, Li, Xin3 wrote: >> However, it doesn't seem to make sense to do so to me. The current behavior is >> much more of an artifact than desired behavior. > We kind of have an agreement that %r11 = %flags after returning from the kernel. > > And the question is, is it what we want? Can the selftest just set r11=rflags before the syscall? The old syscall entry path will set r11=rflags. The FRED path won't touch it. Either case will pass an r11==rflags check.