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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 97A0AC55178 for ; Tue, 3 Nov 2020 18:14:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2559720757 for ; Tue, 3 Nov 2020 18:14:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="VimesJGl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2559720757 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 667096B0068; Tue, 3 Nov 2020 13:14:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5EF8F6B006C; Tue, 3 Nov 2020 13:14:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4C7D56B006E; Tue, 3 Nov 2020 13:14:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0065.hostedemail.com [216.40.44.65]) by kanga.kvack.org (Postfix) with ESMTP id 1564F6B0068 for ; Tue, 3 Nov 2020 13:14:15 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8F6BC362A for ; Tue, 3 Nov 2020 18:14:14 +0000 (UTC) X-FDA: 77443906428.04.back43_330aa2c272ba Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id 6A913800763C for ; Tue, 3 Nov 2020 18:14:14 +0000 (UTC) X-HE-Tag: back43_330aa2c272ba X-Filterd-Recvd-Size: 3590 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Nov 2020 18:14:13 +0000 (UTC) Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A35C720780; Tue, 3 Nov 2020 18:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604427252; bh=xcmtesgScEThQWVAlyFHd721UIZTZBM+vfZNEw5TWHw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VimesJGlvik33xmtNnlRSxLtCoeagRnzi3P48Mt4udCeWae8MrB7kbLbSumPf5F15 Ku982wT3xj9JAYwm4Ol3n+M9OgWO5KrFlHYhIod0StZ0pIG7z+e+jY0wUOJ/cHUyho JVeirJgujY0qEwRZE13TH1EGI5f/uLoc09DA1ca4= Date: Tue, 3 Nov 2020 19:14:07 +0100 From: Greg KH To: Ira Weiny Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra , Dave Hansen , Fenghua Yu , x86@kernel.org, Dan Williams , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH V2 05/10] x86/pks: Add PKS kernel API Message-ID: <20201103181407.GA83845@kroah.com> References: <20201102205320.1458656-1-ira.weiny@intel.com> <20201102205320.1458656-6-ira.weiny@intel.com> <20201103065024.GC75930@kroah.com> <20201103175335.GA1531489@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201103175335.GA1531489@iweiny-DESK2.sc.intel.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Nov 03, 2020 at 09:53:36AM -0800, Ira Weiny wrote: > On Tue, Nov 03, 2020 at 07:50:24AM +0100, Greg KH wrote: > > On Mon, Nov 02, 2020 at 12:53:15PM -0800, ira.weiny@intel.com wrote: > > > From: Fenghua Yu > > > > > [snip] > > > > diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h > > > index 2955ba976048..0959a4c0ca64 100644 > > > --- a/include/linux/pkeys.h > > > +++ b/include/linux/pkeys.h > > > @@ -50,4 +50,28 @@ static inline void copy_init_pkru_to_fpregs(void) > > > > > > #endif /* ! CONFIG_ARCH_HAS_PKEYS */ > > > > > > +#define PKS_FLAG_EXCLUSIVE 0x00 > > > + > > > +#ifndef CONFIG_ARCH_HAS_SUPERVISOR_PKEYS > > > +static inline int pks_key_alloc(const char * const pkey_user, int flags) > > > +{ > > > + return -EOPNOTSUPP; > > > +} > > > +static inline void pks_key_free(int pkey) > > > +{ > > > +} > > > +static inline void pks_mk_noaccess(int pkey) > > > +{ > > > + WARN_ON_ONCE(1); > > > > So for panic-on-warn systems, this is ok to reboot the box? > > I would not expect this to reboot the box no. But it is a violation of the API > contract. If pky_key_alloc() returns an error calling any of the other > functions is an error. > > > > > Are you sure, that feels odd... > > It does feel odd and downright wrong... But there are a lot of WARN_ON_ONCE's > out there to catch this type of internal programming error. Is panic-on-warn > commonly used? Yes it is, and we are trying to recover from that as it is something that you should recover from. Properly handle the error and move on. thanks, greg k-h