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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 71946C433DB for ; Tue, 19 Jan 2021 19:39:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27CE52311C for ; Tue, 19 Jan 2021 19:39:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728523AbhASTir (ORCPT ); Tue, 19 Jan 2021 14:38:47 -0500 Received: from mga06.intel.com ([134.134.136.31]:26308 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729697AbhASThP (ORCPT ); Tue, 19 Jan 2021 14:37:15 -0500 IronPort-SDR: 0+4H1OMbq+Z3k3dNpg8TMaQ1vi7Vf67YJi4WVAtnLlhUNA0oBllE1cqyLmxczgLDudxOuUD88t xPN7QhvFlcQA== X-IronPort-AV: E=McAfee;i="6000,8403,9869"; a="240525703" X-IronPort-AV: E=Sophos;i="5.79,359,1602572400"; d="scan'208";a="240525703" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2021 11:36:34 -0800 IronPort-SDR: fm0aLemlT7MG5HKCe9xsp1Ifq+9Zp6/U4cGc0toMhg5UJPQKq6ePMCdEJXKxy7GxDh5YS8dhzE eRpoNdU525fw== X-IronPort-AV: E=Sophos;i="5.79,359,1602572400"; d="scan'208";a="501042644" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.209.139.183]) ([10.209.139.183]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2021 11:36:32 -0800 Subject: Re: [PATCH v17 06/26] x86/cet: Add control-protection fault handler To: Borislav Petkov Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , "Michael Kerrisk (man-pages)" References: <20201229213053.16395-1-yu-cheng.yu@intel.com> <20201229213053.16395-7-yu-cheng.yu@intel.com> <20210119120425.GI27433@zn.tnic> From: "Yu, Yu-cheng" Message-ID: Date: Tue, 19 Jan 2021 11:36:31 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210119120425.GI27433@zn.tnic> 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 1/19/2021 4:04 AM, Borislav Petkov wrote: > On Tue, Dec 29, 2020 at 01:30:33PM -0800, Yu-cheng Yu wrote: [...] >> +DEFINE_IDTENTRY_ERRORCODE(exc_control_protection) >> +{ >> + struct task_struct *tsk; >> + >> + if (!user_mode(regs)) { >> + if (notify_die(DIE_TRAP, "control protection fault", regs, >> + error_code, X86_TRAP_CP, SIGSEGV) == NOTIFY_STOP) >> + return; >> + die("Upexpected/unsupported kernel control protection fault", regs, error_code); > > Isn't the machine supposed to panic() here and do no further progress? Ok, make it panic(). >> + } >> + >> + cond_local_irq_enable(regs); >> + >> + if (!boot_cpu_has(X86_FEATURE_CET)) >> + WARN_ONCE(1, "Control protection fault with CET support disabled\n"); >> + >> + tsk = current; >> + tsk->thread.error_code = error_code; >> + tsk->thread.trap_nr = X86_TRAP_CP; >> + >> + if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && >> + printk_ratelimit()) { > > WARNING: Prefer printk_ratelimited or pr__ratelimited to printk_ratelimit > #136: FILE: arch/x86/kernel/traps.c:645: > + printk_ratelimit()) { > > Still not using checkpatch? Most places in arch/x86 still use printk_ratelimit(). I should have trusted checkpatch. I will fix it. >> + unsigned int max_err; >> + unsigned long ssp; >> + >> + max_err = ARRAY_SIZE(control_protection_err) - 1; >> + if ((error_code < 0) || (error_code > max_err)) >> + error_code = 0; >> + >> + rdmsrl(MSR_IA32_PL3_SSP, ssp); >> + pr_info("%s[%d] control protection ip:%lx sp:%lx ssp:%lx error:%lx(%s)", > > If anything, all this stuff should be pr_emerg(). I will fix it. -- Yu-cheng