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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 4A464C5DF60 for ; Tue, 5 Nov 2019 22:52:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7784206BA for ; Tue, 5 Nov 2019 22:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730184AbfKEWwY (ORCPT ); Tue, 5 Nov 2019 17:52:24 -0500 Received: from mga09.intel.com ([134.134.136.24]:21897 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730054AbfKEWwX (ORCPT ); Tue, 5 Nov 2019 17:52:23 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Nov 2019 14:52:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,271,1569308400"; d="scan'208";a="285471803" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga001.jf.intel.com with ESMTP; 05 Nov 2019 14:52:23 -0800 Date: Tue, 5 Nov 2019 14:52:23 -0800 From: Sean Christopherson To: Jarkko Sakkinen Cc: linux-sgx@vger.kernel.org Subject: Re: [PATCH for v24 v2 4/4] x86/sgx: add @count to &sgx_enclave_add_pages Message-ID: <20191105225223.GC23297@linux.intel.com> References: <20191105112056.21452-1-jarkko.sakkinen@linux.intel.com> <20191105112056.21452-4-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191105112056.21452-4-jarkko.sakkinen@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Tue, Nov 05, 2019 at 01:20:56PM +0200, Jarkko Sakkinen wrote: > Add @count write the number of bytes added as there is not any good reason > to overwrite input parameters. I disagree, overwriting the params means userspace doesn't need to adjust the values to restart the ioctl(). Ditto for printing out the failing address if the ioctl() fails. > Also, three parameters are unnecessarily > overwritten as the amount of change is the same for each of them. > > Signed-off-by: Jarkko Sakkinen > --- > arch/x86/include/uapi/asm/sgx.h | 2 ++ > arch/x86/kernel/cpu/sgx/ioctl.c | 17 ++++++----------- > 2 files changed, 8 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h > index 88644b6ad849..e196cfd44b70 100644 > --- a/arch/x86/include/uapi/asm/sgx.h > +++ b/arch/x86/include/uapi/asm/sgx.h > @@ -45,6 +45,7 @@ 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; > @@ -52,6 +53,7 @@ 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 deca49bd4f58..e8697d145dfb 100644 > --- a/arch/x86/kernel/cpu/sgx/ioctl.c > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > @@ -491,11 +491,6 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, > * permissions. In effect, this allows mmap() with PROT_NONE to be used to seek > * an address range for the enclave that can be then populated into SECS. > * > - * @arg->addr, @arg->src and @arg->length are adjusted to reflect the > - * remaining pages that need to be added to the enclave, e.g. userspace can > - * re-invoke SGX_IOC_ENCLAVE_ADD_PAGES using the same struct in response to an > - * ERESTARTSYS error. > - * > * Return: > * 0 on success, > * -EACCES if an executable source page is located in a noexec partition, > @@ -506,6 +501,7 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) > { > struct sgx_enclave_add_pages addp; > struct sgx_secinfo secinfo; > + unsigned long c; > int ret; > > if (!(atomic_read(&encl->flags) & SGX_ENCL_CREATED)) > @@ -534,7 +530,7 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) > if (sgx_validate_secinfo(&secinfo)) > return -EINVAL; > > - for ( ; addp.length > 0; addp.length -= PAGE_SIZE) { > + for (c = 0 ; c < addp.length; c += PAGE_SIZE) { > if (signal_pending(current)) { > ret = -ERESTARTSYS; > break; > @@ -543,15 +539,14 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) > if (need_resched()) > cond_resched(); > > - ret = sgx_encl_add_page(encl, addp.src, addp.offset, > - addp.length, &secinfo, addp.flags); > + ret = sgx_encl_add_page(encl, addp.src + c, addp.offset + c, > + addp.length - c, &secinfo, addp.flags); > if (ret) > break; > - > - addp.offset += PAGE_SIZE; > - addp.src += PAGE_SIZE; > } > > + addp.count = c; > + > if (copy_to_user(arg, &addp, sizeof(addp))) > return -EFAULT; > > -- > 2.20.1 >