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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 0FF9BC43461 for ; Fri, 11 Sep 2020 11:51:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B539F22204 for ; Fri, 11 Sep 2020 11:51:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725788AbgIKLvP (ORCPT ); Fri, 11 Sep 2020 07:51:15 -0400 Received: from mga04.intel.com ([192.55.52.120]:58812 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725838AbgIKLvE (ORCPT ); Fri, 11 Sep 2020 07:51:04 -0400 IronPort-SDR: j41a3vyCMSm65K5/Xo7R4A+zZ/sAYrpvA0ayEPCxhbecDsLk4RaQ/susFbwYzPAWku8r6j2ndF FqePnVZQN0Gg== X-IronPort-AV: E=McAfee;i="6000,8403,9740"; a="156139001" X-IronPort-AV: E=Sophos;i="5.76,415,1592895600"; d="scan'208";a="156139001" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2020 04:50:35 -0700 IronPort-SDR: sCXj8DwhkG+ftXl2ZCw3+NB1UoQfDr6Fyj1BEnNUFbpE3DRNLXbpF37A+5lhJESmq5OIbMHDtI cBgq5hwnyp8g== X-IronPort-AV: E=Sophos;i="5.76,415,1592895600"; d="scan'208";a="378541862" Received: from amaksymi-mobl.ger.corp.intel.com (HELO localhost) ([10.252.60.247]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2020 04:50:32 -0700 Date: Fri, 11 Sep 2020 14:50:30 +0300 From: Jarkko Sakkinen To: Darren Kenny Cc: linux-sgx@vger.kernel.org, Sean Christopherson , Borislav Petkov Subject: Re: [PATCH] x86/sgx: Roof the number of pages process in SGX_IOC_ENCLAVE_ADD_PAGES Message-ID: <20200911115030.GB5718@linux.intel.com> References: <20200908190042.24895-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Wed, Sep 09, 2020 at 10:55:58AM +0100, Darren Kenny wrote: > On Tuesday, 2020-09-08 at 22:00:42 +03, Jarkko Sakkinen wrote: > > Remove 'count' from struct sgx_enclave_add_pages and return number of > > pages processed as a positive return as there is no reasonable use for > > -EINTR for the caller. Then, roof the processing with a fixed constant > > and break out the loop also when this value is surpassed. > > > > Link: https://lore.kernel.org/linux-sgx/20200626153400.GE27151@zn.tnic/ > > Cc: Sean Christopherson > > Cc: Borislav Petkov > > Signed-off-by: Jarkko Sakkinen > > --- > > arch/x86/include/uapi/asm/sgx.h | 2 -- > > arch/x86/kernel/cpu/sgx/ioctl.c | 10 ++++------ > > arch/x86/kernel/cpu/sgx/sgx.h | 1 + > > 3 files changed, 5 insertions(+), 8 deletions(-) > > > > diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h > > index b3d5ccf5b976..1564d7f88597 100644 > > --- a/arch/x86/include/uapi/asm/sgx.h > > +++ b/arch/x86/include/uapi/asm/sgx.h > > @@ -45,7 +45,6 @@ struct sgx_enclave_create { > > * @length: length of the data (multiple of the page size) > > * @secinfo: address for the SECINFO data > > * @flags: page control flags > > - * @count: number of bytes added (multiple of the page size) > > */ > > struct sgx_enclave_add_pages { > > __u64 src; > > @@ -53,7 +52,6 @@ struct sgx_enclave_add_pages { > > __u64 length; > > __u64 secinfo; > > __u64 flags; > > - __u64 count; > > }; > > > > /** > > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c > > index 6c3c6177b690..0ae00fa9b589 100644 > > --- a/arch/x86/kernel/cpu/sgx/ioctl.c > > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > > @@ -490,7 +490,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, > > * caller. > > * > > * Return: > > - * 0 on success, > > + * length of the data processed on success, > > * -EACCES if an executable source page is located in a noexec partition, > > * -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails > > * -errno otherwise > > @@ -530,8 +530,8 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) > > return -EINVAL; > > > > for (c = 0 ; c < addp.length; c += PAGE_SIZE) { > > - if (signal_pending(current)) { > > - ret = -EINTR; > > + if (c == SGX_MAX_ADD_PAGES_LENGTH || signal_pending(current)) { > > I know that SGX_MAX_ADD_PAGES_LENGTH may be a multiple of PAGE_SIZE, but > to be sure that nothing breaks here in the future, I think it would be > better to use '>=' as the comparison rather than just '=='. I'm not forseeing this. We will change the comparison or remove it if the constant is no longer required. > > Also, the indentation seems off here w.r.t. using TABs when the break > below is using spaces - would be good to have them the same at least. Ugh, that must be my mistake. I'll check these before squashing this. Thank you. /Jarkko