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=-9.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 2AE90C43387 for ; Fri, 21 Dec 2018 23:14:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F38582190A for ; Fri, 21 Dec 2018 23:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403906AbeLUXOZ (ORCPT ); Fri, 21 Dec 2018 18:14:25 -0500 Received: from mga14.intel.com ([192.55.52.115]:13668 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730803AbeLUXOZ (ORCPT ); Fri, 21 Dec 2018 18:14:25 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Dec 2018 15:14:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,383,1539673200"; d="scan'208";a="120338514" Received: from ncanderx-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.238]) by FMSMGA003.fm.intel.com with ESMTP; 21 Dec 2018 15:14:18 -0800 From: Jarkko Sakkinen To: 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, Jarkko Sakkinen Subject: [PATCH v18 15/25] x86/sgx: Add functions to allocate and free EPC pages Date: Sat, 22 Dec 2018 01:11:44 +0200 Message-Id: <20181221231154.6120-16-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181221231154.6120-1-jarkko.sakkinen@linux.intel.com> References: <20181221231154.6120-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org At this time there is no support for reclaiming pages prior to the owner explicitly freeing the page. As for freeing pages, because freeing a page is expected to succeed in the vast majority of cases and because most call sites will not be equipped to handle failure, provide a variant for freeing a page that warns on failure, e.g. due to ENCLS[EREMOVE] failing. Signed-off-by: Jarkko Sakkinen Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson --- arch/x86/include/asm/sgx.h | 4 ++ arch/x86/kernel/cpu/sgx/main.c | 88 ++++++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index a37bc3650253..40caaac58747 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -303,4 +303,8 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void *addr) return __encls_ret_2(SGX_EMODT, secinfo, addr); } +struct sgx_epc_page *sgx_alloc_page(void); +int __sgx_free_page(struct sgx_epc_page *page); +void sgx_free_page(struct sgx_epc_page *page); + #endif /* _ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index cd5090ca00e5..0c74dcace908 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -22,6 +22,94 @@ static void sgx_section_put_page(struct sgx_epc_section *section, section->free_cnt++; } +static struct sgx_epc_page *sgx_section_get_page( + struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + + if (!section->free_cnt) + return NULL; + + page = list_first_entry(§ion->page_list, + struct sgx_epc_page, list); + list_del_init(&page->list); + section->free_cnt--; + return page; +} + +/** + * sgx_alloc_page - Allocate an EPC page + * + * Try to grab a page from the free EPC page list. + * + * Return: + * a pointer to a &struct sgx_epc_page instance, + * -errno on error + */ +struct sgx_epc_page *sgx_alloc_page(void) +{ + struct sgx_epc_section *section; + struct sgx_epc_page *page; + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) { + section = &sgx_epc_sections[i]; + spin_lock(§ion->lock); + page = sgx_section_get_page(section); + spin_unlock(§ion->lock); + + if (page) + return page; + } + + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(sgx_alloc_page); + +/** + * __sgx_free_page - Free an EPC page + * @page: pointer a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages. + * + * Return: + * 0 on success + * SGX error code if EREMOVE fails + */ +int __sgx_free_page(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_epc_section(page); + int ret; + + ret = __eremove(sgx_epc_addr(page)); + if (ret) + return ret; + + spin_lock(§ion->lock); + sgx_section_put_page(section, page); + spin_unlock(§ion->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(__sgx_free_page); + +/** + * sgx_free_page - Free an EPC page and WARN on failure + * @page: pointer to a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages, and WARN + * if EREMOVE fails. For use when the call site cannot (or chooses not to) + * handle failure, i.e. the page is leaked on failure. + */ +void sgx_free_page(struct sgx_epc_page *page) +{ + int ret; + + ret = __sgx_free_page(page); + WARN(ret > 0, "sgx: EREMOVE returned %d (0x%x)", ret, ret); +} +EXPORT_SYMBOL_GPL(sgx_free_page); + static __init void sgx_free_epc_section(struct sgx_epc_section *section) { struct sgx_epc_page *page; -- 2.19.1