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[209.132.180.67]) by mx.google.com with ESMTP id w17si10389280edc.152.2019.10.29.03.38.11; Tue, 29 Oct 2019 03:38:35 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732756AbfJ2J33 (ORCPT + 99 others); Tue, 29 Oct 2019 05:29:29 -0400 Received: from mga17.intel.com ([192.55.52.151]:29616 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726025AbfJ2J33 (ORCPT ); Tue, 29 Oct 2019 05:29:29 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Oct 2019 02:29:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,243,1569308400"; d="scan'208";a="211694582" Received: from jsakkine-mobl1.tm.intel.com (HELO localhost) ([10.237.50.122]) by orsmga002.jf.intel.com with ESMTP; 29 Oct 2019 02:29:20 -0700 Date: Tue, 29 Oct 2019 11:29:20 +0200 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, linux-security-module@vger.kernel.org, Suresh Siddha Subject: Re: [PATCH v23 12/24] x86/sgx: Linux Enclave Driver Message-ID: <20191029092920.GA14494@linux.intel.com> References: <20191028210324.12475-1-jarkko.sakkinen@linux.intel.com> <20191028210324.12475-13-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191028210324.12475-13-jarkko.sakkinen@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 28, 2019 at 11:03:12PM +0200, Jarkko Sakkinen wrote: > +/** > + * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES > + * @encl: pointer to an enclave instance (via ioctl() file pointer) > + * @arg: a user pointer to a struct sgx_enclave_add_pages instance > + * > + * Add (EADD) one or more pages to an uninitialized enclave, and optionally > + * extend (EEXTEND) the measurement with the contents of the page. The range of > + * pages must be virtually contiguous. The SECINFO and measurement mask are > + * applied to all pages, i.e. pages with different properties must be added in > + * separate calls. > + * > + * A SECINFO for a TCS is required to always contain zero permissions because > + * CPU silently zeros them. Allowing anything else would cause a mismatch in > + * the measurement. > + * > + * mmap()'s protection bits are capped by the page permissions. For each page > + * address, the maximum protection bits are computed with the following > + * heuristics: > + * > + * 1. A regular page: PROT_R, PROT_W and PROT_X match the SECINFO permissions. > + * 2. A TCS page: PROT_R | PROT_W. > + * 3. No page: PROT_NONE. > + * > + * mmap() is not allowed to surpass the minimum of the maximum protection bits > + * within the given address range. > + * > + * As stated above, a non-existent page is interpreted as a page with no > + * 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, > + * -EINVAL if any input param or the SECINFO contains invalid data, > + * -EACCES if an executable source page is located in a noexec partition, > + * -ENOMEM if any memory allocation, including EPC, fails, > + * -ERESTARTSYS if a pending signal is recognized > + */ > +static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) This should return the number of pages processed instead of zero on success. Kernel needs to be able to cap the amount it will process. /Jarkko