From patchwork Fri Dec 4 19:51:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11952237 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=-26.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 9B3E9C2BB3F for ; Fri, 4 Dec 2020 19:53:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DF2122CA0 for ; Fri, 4 Dec 2020 19:53:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726021AbgLDTwo (ORCPT ); Fri, 4 Dec 2020 14:52:44 -0500 Received: from linux.microsoft.com ([13.77.154.182]:52672 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730647AbgLDTwi (ORCPT ); Fri, 4 Dec 2020 14:52:38 -0500 Received: from localhost.localdomain (c-73-42-176-67.hsd1.wa.comcast.net [73.42.176.67]) by linux.microsoft.com (Postfix) with ESMTPSA id 26F0820B7187; Fri, 4 Dec 2020 11:51:57 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 26F0820B7187 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607111517; bh=QjzwkKap5j6BGZIXUMFZtVLppXuA87W5hY580CxO5Fg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JsemOQH9A0VzQkpzu03at+NXfh706D2DoAoDdrG1/MmUhSONyN2/YTRZXVoXyQ5qW QirUmFfkFCoE9TbQUEtDcbIJysS5MV1n6YhCF9SgBjjaQSgTaEjPSgSu/8KLYVc6yr E/V1PcoQJRM/YLEXSx3DOw9eUrApETd35T5b+7Z4= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, bauerman@linux.ibm.com, robh@kernel.org, gregkh@linuxfoundation.org, james.morse@arm.com, catalin.marinas@arm.com, sashal@kernel.org, will@kernel.org, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, robh+dt@kernel.org, frowand.list@gmail.com, vincenzo.frascino@arm.com, mark.rutland@arm.com, dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com, pasha.tatashin@soleen.com, allison@lohutok.net, kstewart@linuxfoundation.org, takahiro.akashi@linaro.org, tglx@linutronix.de, masahiroy@kernel.org, bhsharma@redhat.com, mbrugger@suse.com, hsinyi@chromium.org, tao.li@vivo.com, christophe.leroy@c-s.fr Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, prsriva@linux.microsoft.com, balajib@linux.microsoft.com Subject: [PATCH v10 3/8] powerpc: Move ima buffer functions to drivers/of/kexec.c Date: Fri, 4 Dec 2020 11:51:44 -0800 Message-Id: <20201204195149.611-4-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201204195149.611-1-nramas@linux.microsoft.com> References: <20201204195149.611-1-nramas@linux.microsoft.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The functions do_get_kexec_buffer() and get_addr_size_cells(), defined in arch/powerpc/kexec/ima.c, retrieve the address and size of the given property from the device tree blob. These functions do not have architecture specific code, but are currently limited to powerpc. do_get_kexec_buffer() correctly handles a device tree property that is a child node of the root node, but not anything other than the immediate root child nodes. Move architecture independent functions get_ima_kexec_buffer() and get_root_addr_size_cells() to "drivers/of/kexec.c". These functions retrieve the chosen node "linux,ima-kexec-buffer" from the device tree, and return the address and size of the buffer used for carrying forward the IMA measurement log across kexec system call. Co-developed-by: Prakhar Srivastava Signed-off-by: Prakhar Srivastava Signed-off-by: Lakshmi Ramasubramanian Reviewed-by: Thiago Jung Bauermann --- drivers/of/kexec.c | 70 +++++++++++++++++++++++++++++++++++++++++++ include/linux/kexec.h | 3 ++ 2 files changed, 73 insertions(+) diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c index b7d59105fcb8..516b86f7113a 100644 --- a/drivers/of/kexec.c +++ b/drivers/of/kexec.c @@ -59,3 +59,73 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) return -ENOENT; } + +/** + * get_root_addr_size_cells - Get address and size of root node + * + * @addr_cells: Return address of the root node + * @size_cells: Return size of the root node + * + * Return: 0 on success, or negative errno on error. + */ +int get_root_addr_size_cells(int *addr_cells, int *size_cells) +{ + struct device_node *root; + + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) + return -EOPNOTSUPP; + + root = of_find_node_by_path("/"); + if (!root) + return -EINVAL; + + *addr_cells = of_n_addr_cells(root); + *size_cells = of_n_size_cells(root); + + of_node_put(root); + + return 0; +} + +/** + * get_ima_kexec_buffer - Get address and size of IMA kexec buffer + * + * @fdt: Flattened Device Tree + * @chosen_node: Offset of chosen node in the FDT + * @addr: Return address of the node + * @size: Return size of the node + * + * Return: 0 on success, or negative errno on error. + */ +int get_ima_kexec_buffer(void *fdt, int chosen_node, + unsigned long *addr, size_t *size) +{ + const void *prop; + int addr_cells, size_cells, prop_len; + int rc; + + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) + return -EOPNOTSUPP; + + rc = get_root_addr_size_cells(&addr_cells, &size_cells); + if (rc) + return rc; + + if (fdt) + prop = fdt_getprop(fdt, chosen_node, + "linux,ima-kexec-buffer", &prop_len); + else + prop = of_get_property(of_chosen, + "linux,ima-kexec-buffer", &prop_len); + + if (!prop) + return -ENOENT; + + if (prop_len < 4 * (addr_cells + size_cells)) + return -EINVAL; + + *addr = of_read_number(prop, addr_cells); + *size = of_read_number(prop + 4 * addr_cells, size_cells); + + return 0; +} diff --git a/include/linux/kexec.h b/include/linux/kexec.h index d0234c4815da..10ff704ab670 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -408,6 +408,9 @@ static inline int kexec_crash_loaded(void) { return 0; } #endif /* CONFIG_KEXEC_CORE */ #if defined(CONFIG_OF_FLATTREE) +extern int get_root_addr_size_cells(int *addr_cells, int *size_cells); +extern int get_ima_kexec_buffer(void *fdt, int chosen_node, + unsigned long *addr, size_t *size); extern int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size); #endif /* CONFIG_OF_FLATTREE */