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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 46BE4C43460 for ; Wed, 12 May 2021 20:12:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AA2361422 for ; Wed, 12 May 2021 20:12:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344066AbhELUAR (ORCPT ); Wed, 12 May 2021 16:00:17 -0400 Received: from terminus.zytor.com ([198.137.202.136]:38525 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244510AbhELSXB (ORCPT ); Wed, 12 May 2021 14:23:01 -0400 Received: from tazenda.hos.anvin.org ([IPv6:2601:646:8602:8be0:7285:c2ff:fefb:fd4]) (authenticated bits=0) by mail.zytor.com (8.16.1/8.15.2) with ESMTPSA id 14CILhci2815104 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Wed, 12 May 2021 11:21:43 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 14CILhci2815104 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2021042801; t=1620843704; bh=ekZSPls2yDO4DPwHF1C5XdT0UihMAICV+Xpliib4mw4=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=Fe+dexuQJoM//2USjEyZGbce02RNdj1qDpLvqifCgq7mPxxFmPFO2qO+menyZhpC0 TFsieAyRGL6B94SF6jSaSRoO24M0smeAlnd+eveVlDNsxQ4YnT+e8BlQvQIYJUCz6g hivhTQjIWZgexjxihVkEgZ9QnFO1oWlY3cNnml7J4Rj/rzn2MvIwMbxNTsoeYlUOJY 3tFtlkSo9acqCmtoOlVC70YHSEYmKCfW5C/DKX7T3nWUfZOMIjWCwaHOH15YjHVrdv xZ1OkjbrIs4TFmxdhlpxBrnj6NU8frBiIn8oaWGPZOkgidt/FM6+zpReg/WodfRNfn Cpc5KtdKYelXw== Subject: Re: [RFC v2 PATCH 7/7] x86/entry: use int for syscall number; handle all invalid syscall nrs To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski Cc: Linux Kernel Mailing List References: <871racf928.ffs@nanos.tec.linutronix.de> From: "H. Peter Anvin" Message-ID: <60495dd3-ea68-4db3-47ad-b7b45796bf76@zytor.com> Date: Wed, 12 May 2021 11:21:38 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <871racf928.ffs@nanos.tec.linutronix.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/12/21 5:09 AM, Thomas Gleixner wrote: > >> index 1d9db15fdc69..85f04ea0e368 100644 >> --- a/arch/x86/entry/entry_64.S >> +++ b/arch/x86/entry/entry_64.S >> @@ -108,7 +108,7 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL) >> >> /* IRQs are off. */ >> movq %rsp, %rdi >> - movq %rax, %rsi >> + movslq %eax, %rsi > > This is wrong. > > syscall(long number,...); > > So the above turns syscall(UINT_MAX + N, ...) into syscall(N, ...). > That is intentional, as (again) system calls are int. As stated in my reply to Ingo, I'll clean the various descriptions and try to capture the discussion better. -hpa