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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 CA215C433EF for ; Wed, 15 Sep 2021 14:46:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEECA60E90 for ; Wed, 15 Sep 2021 14:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237966AbhIOOrx (ORCPT ); Wed, 15 Sep 2021 10:47:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230499AbhIOOrw (ORCPT ); Wed, 15 Sep 2021 10:47:52 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2A26C061574 for ; Wed, 15 Sep 2021 07:46:33 -0700 (PDT) Received: from zn.tnic (p200300ec2f0d070065ba1755d00b04e0.dip0.t-ipconnect.de [IPv6:2003:ec:2f0d:700:65ba:1755:d00b:4e0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 08B7E1EC050D; Wed, 15 Sep 2021 16:46:28 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1631717188; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0+YZv5+sPbIpazwClKymdP6vtvru7X2E3N05hF9hXgA=; b=nPpVSMpH1mSTuYuE4guYP9ZpD1R3CL5aCMeHTtc0SoIt13prq087JMt99HzeOFCzlRHmUI Ovarp6WBYyyrkHiMunoddrA/i/ndIKF6cO0L29Q4ny6Y1++47x5glvIDvJ3a9XPdQKzx7x jN7E1sU/B9dlo33e8sa6ZzxhGaQlhS8= Date: Wed, 15 Sep 2021 16:46:20 +0200 From: Borislav Petkov To: Ricardo Neri Cc: X86 ML , LKML , Marcus =?utf-8?Q?R=C3=BCckert?= Subject: [PATCH] x86/umip: Downgrade warning messages to debug loglevel Message-ID: References: <20210907200454.30458-1-bp@alien8.de> <20210911011459.GA11980@ranerica-svr.sc.intel.com> <20210913213836.GA10627@ranerica-svr.sc.intel.com> <20210915113410.GA7130@ranerica-svr.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210915113410.GA7130@ranerica-svr.sc.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 15, 2021 at 04:34:10AM -0700, Ricardo Neri wrote: > The goal at the time was encourage users to report bugs on the > applications and eventually have them fixed. It also meant to warn users > about degraded performance due to emulation. To my knowledge, no one has > reported the latter thus far. Probably because people do not even get to need UMIP a whole lot, apparently. > Since after almost 4 years, performance degradation does not seem to be a > concern, I think it is sensible to remove the warnings. Yap. > They could also be salvaged by converting them to umiip_pr_debug(), just > to err on the cautious side without having to add a new command line > argument. Yap, that's a good idea too: --- From: Borislav Petkov Date: Wed, 15 Sep 2021 16:39:18 +0200 Subject: [PATCH] x86/umip: Downgrade warning messages to debug loglevel MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After four years in the wild, those have not fullfilled their initial purpose of pushing people to fix their software to not use UMIP-emulated instructions, and to warn users about the degraded emulation performance. Yet, the only thing that "degrades" performance is overflowing dmesg with those: [Di Sep 7 00:24:05 2021] umip_printk: 1345 callbacks suppressed [Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: SIDT instruction cannot be used by applications. [Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: For now, expensive software emulation returns the result. ... [Di Sep 7 00:26:06 2021] umip_printk: 2227 callbacks suppressed [Di Sep 7 00:26:06 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b940: SIDT instruction cannot be used by applications. and users don't really care about that - they just want to play their games in wine. So convert those to debug loglevel - in case someone is still interested in them, someone can boot with "debug" on the kernel cmdline. Reported-by: Marcus Rückert Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210907200454.30458-1-bp@alien8.de --- arch/x86/kernel/umip.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c index 576b47e7523d..5a4b21389b1d 100644 --- a/arch/x86/kernel/umip.c +++ b/arch/x86/kernel/umip.c @@ -92,8 +92,8 @@ static const char * const umip_insns[5] = { #define umip_pr_err(regs, fmt, ...) \ umip_printk(regs, KERN_ERR, fmt, ##__VA_ARGS__) -#define umip_pr_warn(regs, fmt, ...) \ - umip_printk(regs, KERN_WARNING, fmt, ##__VA_ARGS__) +#define umip_pr_debug(regs, fmt, ...) \ + umip_printk(regs, KERN_DEBUG, fmt, ##__VA_ARGS__) /** * umip_printk() - Print a rate-limited message @@ -361,10 +361,10 @@ bool fixup_umip_exception(struct pt_regs *regs) if (umip_inst < 0) return false; - umip_pr_warn(regs, "%s instruction cannot be used by applications.\n", + umip_pr_debug(regs, "%s instruction cannot be used by applications.\n", umip_insns[umip_inst]); - umip_pr_warn(regs, "For now, expensive software emulation returns the result.\n"); + umip_pr_debug(regs, "For now, expensive software emulation returns the result.\n"); if (emulate_umip_insn(&insn, umip_inst, dummy_data, &dummy_data_size, user_64bit_mode(regs))) -- 2.29.2 -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette