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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 26928C433DF for ; Thu, 11 Jun 2020 07:36:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03D922074B for ; Thu, 11 Jun 2020 07:36:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726876AbgFKHgY (ORCPT ); Thu, 11 Jun 2020 03:36:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726375AbgFKHgX (ORCPT ); Thu, 11 Jun 2020 03:36:23 -0400 Received: from mail.kapsi.fi (mail.kapsi.fi [IPv6:2001:67c:1be8::25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4103FC08C5C1 for ; Thu, 11 Jun 2020 00:36:23 -0700 (PDT) Received: from kapsi.fi ([2001:67c:1be8::11] helo=lakka.kapsi.fi) by mail.kapsi.fi with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jjHku-0004TY-5Y; Thu, 11 Jun 2020 10:36:08 +0300 Received: from jpa by lakka.kapsi.fi with local (Exim 4.92) (envelope-from ) id 1jjHku-0000c4-2E; Thu, 11 Jun 2020 10:36:08 +0300 Date: Thu, 11 Jun 2020 10:36:08 +0300 From: Petteri Aimonen To: Andy Lutomirski Cc: Borislav Petkov , Shuah Khan , Dave Hansen , "H. Peter Anvin" , x86-ml , lkml Subject: Re: [PATCH] arch/x86: reset MXCSR to default in kernel_fpu_begin() Message-ID: <20200611073607.GH17423@lakka.kapsi.fi> References: <20200602101119.GA11634@zn.tnic> <20200602102951.GE17423@lakka.kapsi.fi> <20200602105649.GB11634@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspam-Score: 1.2 (+) X-Rspam-Report: Action: no action Symbol: RCVD_TLS_LAST(0.00) Symbol: ARC_NA(0.00) Symbol: FROM_HAS_DN(0.00) Symbol: TO_MATCH_ENVRCPT_ALL(0.00) Symbol: MIME_GOOD(-0.10) Symbol: DMARC_NA(0.00) Symbol: AUTH_NA(1.00) Symbol: NEURAL_SPAM(0.00) Symbol: TO_DN_ALL(0.00) Symbol: RCPT_COUNT_SEVEN(0.00) Symbol: R_SPF_NA(0.00) Symbol: FORGED_SENDER(0.30) Symbol: R_DKIM_NA(0.00) Symbol: MIME_TRACE(0.00) Symbol: ASN(0.00) Symbol: FROM_NEQ_ENVFROM(0.00) Symbol: RCVD_COUNT_TWO(0.00) Message-ID: 20200611073607.GH17423@lakka.kapsi.fi X-Rspam-Bar: + X-SA-Exim-Connect-IP: 2001:67c:1be8::11 X-SA-Exim-Mail-From: jpa@lakka.kapsi.fi X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > How about putting the file you frob in > /sys/kernel/debug/selftest_helpers/something_or_other. The idea would > be that /sys/kernel/debug/selftest_helpers would be a general place > for kernel helpers needed to make selftests work. Seems like this is the consensus for now. Any opinions on whether the module should remove "selftest_helpers" directory on unloading, or not? 1) Removing would break if other test modules will use the same dir. 2) Not removing will leave the directory dangling. 3) Remove only if empty is one option, though I'm unsure how to cleanly check if debugfs directory is empty. 4) E.g. /sys/kernel/debug/x86/ is created centrally and a symbol is exported for its dentry. But I'm not sure if it really makes sense to add another exported symbol just for selftest_helpers. -- Petteri