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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 AF72FC3A59B for ; Sat, 31 Aug 2019 00:11:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70B822342E for ; Sat, 31 Aug 2019 00:11:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728217AbfHaALp (ORCPT ); Fri, 30 Aug 2019 20:11:45 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50126 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727708AbfHaALp (ORCPT ); Fri, 30 Aug 2019 20:11:45 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7V06vfY189487; Fri, 30 Aug 2019 20:11:41 -0400 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0a-001b2d01.pphosted.com with ESMTP id 2uq0kth90e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 Aug 2019 20:11:40 -0400 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x7V09toO017188; Sat, 31 Aug 2019 00:11:40 GMT Received: from b01cxnp23032.gho.pok.ibm.com (b01cxnp23032.gho.pok.ibm.com [9.57.198.27]) by ppma02dal.us.ibm.com with ESMTP id 2un65kjujg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 31 Aug 2019 00:11:40 +0000 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7V0BdZC43516174 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 31 Aug 2019 00:11:39 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4D084112064; Sat, 31 Aug 2019 00:11:39 +0000 (GMT) Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A8FB0112063; Sat, 31 Aug 2019 00:11:37 +0000 (GMT) Received: from morokweng.localdomain (unknown [9.85.207.220]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTPS; Sat, 31 Aug 2019 00:11:37 +0000 (GMT) References: <20190829200532.13545-1-prsriva@linux.microsoft.com> <20190829200532.13545-2-prsriva@linux.microsoft.com> User-agent: mu4e 1.2.0; emacs 26.2 From: Thiago Jung Bauermann To: Prakhar Srivastava Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-integrity@vger.kernel.org, jmorris@namei.org, zohar@linux.ibm.com Subject: Re: [RFC][PATCH 1/1] Carry ima measurement log for arm64 via kexec_file_load In-reply-to: <20190829200532.13545-2-prsriva@linux.microsoft.com> Date: Fri, 30 Aug 2019 21:11:35 -0300 Message-ID: <87r252kxc8.fsf@morokweng.localdomain> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-30_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908310000 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Hello Prakhar, Answering this part from the cover letter: > The code is in most part same as powerpc, i want to get feedback as to > how/correct way to refactor the code so that cross architecture > partial helpers can be put in a common place. That's a great idea. If it could go to drivers/of/ as Stephen Boyd mentioned in the other email that would be great. More comments below. Prakhar Srivastava writes: > Carry ima measurement log for arm64 via kexec_file_load. > add support to kexec_file_load to pass the ima measurement log > > This patch adds entry for the ima measurement log in the > dtb which is then used in the kexec'ed session to fetch the > segment and then load the ima measurement log. > > Signed-off-by: Prakhar Srivastava > --- > arch/arm64/Kconfig | 7 + > arch/arm64/include/asm/ima.h | 31 ++++ > arch/arm64/include/asm/kexec.h | 4 + > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/ima_kexec.c | 219 +++++++++++++++++++++++++ > arch/arm64/kernel/machine_kexec_file.c | 39 +++++ > 6 files changed, 301 insertions(+) > create mode 100644 arch/arm64/include/asm/ima.h > create mode 100644 arch/arm64/kernel/ima_kexec.c > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 3adcec05b1f6..9e1b831e7baa 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -964,6 +964,13 @@ config KEXEC_FILE > for kernel and initramfs as opposed to list of segments as > accepted by previous system call. > > +config HAVE_IMA_KEXEC > + bool "enable arch specific ima buffer pass" > + depends on KEXEC_FILE > + help > + This adds support to carry ima log to the next kernel in case > + of kexec_file_load > + > config KEXEC_VERIFY_SIG > bool "Verify kernel signature during kexec_file_load() syscall" > depends on KEXEC_FILE This Kconfig should be defined in arch/Kconfig so that both arm64 and powerpc can select it. > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > index 478491f07b4f..9620f90bd0e1 100644 > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -63,6 +63,7 @@ obj-$(CONFIG_CRASH_CORE) += crash_core.o > obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o > obj-$(CONFIG_ARM64_SSBD) += ssbd.o > obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o > +obj-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o > > obj-y += vdso/ probes/ > obj-$(CONFIG_COMPAT_VDSO) += vdso32/ > diff --git a/arch/arm64/kernel/ima_kexec.c b/arch/arm64/kernel/ima_kexec.c > new file mode 100644 > index 000000000000..5ae0d776ec42 > --- /dev/null > +++ b/arch/arm64/kernel/ima_kexec.c > @@ -0,0 +1,219 @@ > +/* > + * Copyright (C) 2016 IBM Corporation > + * > + * Authors: > + * Thiago Jung Bauermann > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ The powerpc file was updated to use the SPDX tag and remove the paragraph above. Please update your file to match. > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +static int get_addr_size_cells(int *addr_cells, int *size_cells) > +{ > + struct device_node *root; > + > + 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; > +} > + > +static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr, > + size_t *size) > +{ > + This spurious blank line only exists in the arm64 version. Should be removed. > + int ret, addr_cells, size_cells; > + > + ret = get_addr_size_cells(&addr_cells, &size_cells); > + if (ret) > + return ret; > + > + if (len < 4 * (addr_cells + size_cells)) > + return -ENOENT; > + > + *addr = of_read_number(prop, addr_cells); > + *size = of_read_number(prop + 4 * addr_cells, size_cells); > + > + return 0; > +} > + > +/** > + * ima_get_kexec_buffer - get IMA buffer from the previous kernel > + * @addr: On successful return, set to point to the buffer contents. > + * @size: On successful return, set to the buffer size. > + * > + * Return: 0 on success, negative errno on error. > + */ > +int ima_get_kexec_buffer(void **addr, size_t *size) > +{ > + int ret, len; > + unsigned long tmp_addr; > + size_t tmp_size; > + const void *prop; > + > + prop = of_get_property(of_chosen, FDT_PROP_KEXEC_BUFFER, &len); > + if (!prop) > + return -ENOENT; > + > + ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size); > + if (ret) > + return ret; > + > + *addr = __va(tmp_addr); > + *size = tmp_size; > + return 0; > +} > + > +/** > + * ima_free_kexec_buffer - free memory used by the IMA buffer > + */ > +int ima_free_kexec_buffer(void) > +{ > + int ret; > + unsigned long addr; > + size_t size; > + struct property *prop; > + > + prop = of_find_property(of_chosen, FDT_PROP_KEXEC_BUFFER, NULL); > + if (!prop) > + return -ENOENT; > + > + ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size); > + if (ret) > + return ret; > + > + ret = of_remove_property(of_chosen, prop); > + if (ret) > + return ret; > + > + return memblock_free(addr, size); On the other hand you removed the spurious blank line that exists in powerpc. Thanks. :-) > +} > + > +#ifdef CONFIG_IMA remove_ima_buffer() should exist even if CONFIG_IMA isn't set. If I recall correctly, Mimi requested that kernels that are booted via kexec should remove the IMA buffer even if they won't use it. > +/** > + * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt > + * > + * The IMA measurement buffer is of no use to a subsequent kernel, so we always > + * remove it from the device tree. > + */ > +void remove_ima_buffer(void *fdt, int chosen_node) > +{ > + int ret, len; > + unsigned long addr; > + size_t size; > + const void *prop; > + > + prop = fdt_getprop(fdt, chosen_node, FDT_PROP_KEXEC_BUFFER, &len); > + if (!prop) > + return; > + > + ret = do_get_kexec_buffer(prop, len, &addr, &size); > + fdt_delprop(fdt, chosen_node, FDT_PROP_KEXEC_BUFFER); > + if (ret) > + return; > + > + ret = delete_fdt_mem_rsv(fdt, addr, size); > + if (!ret) > + pr_debug("Removed old IMA buffer reservation.\n"); > +} > +#endif /* CONFIG_IMA */ > + > +#ifdef CONFIG_IMA_KEXEC > +/** > + * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer > + * > + * Architectures should use this function to pass on the IMA buffer > + * information to the next kernel. > + * > + * Return: 0 on success, negative errno on error. > + */ > +int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr, > + size_t size) > +{ > + image->arch.ima_buffer_addr = load_addr; > + image->arch.ima_buffer_size = size; > + return 0; > +} > + > +static int write_number(void *p, u64 value, int cells) > +{ > + if (cells == 1) { > + u32 tmp; > + > + if (value > U32_MAX) > + return -EINVAL; > + > + tmp = cpu_to_be32(value); > + memcpy(p, &tmp, sizeof(tmp)); > + } else if (cells == 2) { > + u64 tmp; > + > + tmp = cpu_to_be64(value); > + memcpy(p, &tmp, sizeof(tmp)); > + } else > + return -EINVAL; > + return 0; > +} > + > +/** > + * setup_ima_buffer - add IMA buffer information to the fdt > + * @image: kexec image being loaded. > + * @dtb: Flattened device tree for the next kernel. > + * @chosen_node: Offset to the chosen node. > + * > + * Return: 0 on success, or negative errno on error. > + */ > +int setup_ima_buffer(const struct kimage *image, void *dtb, int chosen_node) > +{ Is there any particular reason to rename the fdt parameter to dtb? > + int ret, addr_cells, size_cells, entry_size; > + u8 value[16]; > + > + remove_ima_buffer(dtb, chosen_node); In the powerpc version, there's an if here to return early if image->arch.ima_buffer_size == 0. Is there a reason why you removed it? > + > + ret = get_addr_size_cells(&addr_cells, &size_cells); > + if (ret) > + return ret; > + > + entry_size = 4 * (addr_cells + size_cells); > + > + if (entry_size > sizeof(value)) > + return -EINVAL; > + > + ret = write_number(value, image->arch.ima_buffer_addr, addr_cells); > + if (ret) > + return ret; > + > + ret = write_number(value + 4 * addr_cells, image->arch.ima_buffer_size, > + size_cells); > + if (ret) > + return ret; > + > + ret = fdt_setprop(dtb, chosen_node, FDT_PROP_KEXEC_BUFFER, value, > + entry_size); > + if (ret < 0) > + return -EINVAL; > + > + ret = fdt_add_mem_rsv(dtb, image->segment[0].mem, > + image->segment[0].memsz); powerpc uses image->arch.ima_buffer_addr and image->arch.ima_buffer_size here. Why do you use segment[0] above? > + if (ret) > + return -EINVAL; > + > + return 0; > +} > +#endif /* CONFIG_IMA_KEXEC */ > diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c > index 58871333737a..c05ad6b74b62 100644 > --- a/arch/arm64/kernel/machine_kexec_file.c > +++ b/arch/arm64/kernel/machine_kexec_file.c > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > > /* relevant device tree properties */ > #define FDT_PROP_INITRD_START "linux,initrd-start" > @@ -85,6 +86,11 @@ static int setup_dtb(struct kimage *image, > goto out; > } > > + /* add ima_buffer */ > + ret = setup_ima_buffer(image, dtb, off); > + if (ret) > + goto out; > + > /* add kaslr-seed */ > ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED); > if (ret == -FDT_ERR_NOTFOUND) > @@ -114,6 +120,39 @@ static int setup_dtb(struct kimage *image, > */ > #define DTB_EXTRA_SPACE 0x1000 > > + > +/** > + * delete_fdt_mem_rsv - delete memory reservation with given address and size > + * > + * Return: 0 on success, or negative errno on error. > + */ > +int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) > +{ > + int i, ret, num_rsvs = fdt_num_mem_rsv(fdt); > + > + for (i = 0; i < num_rsvs; i++) { > + uint64_t rsv_start, rsv_size; > + > + ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size); > + if (ret) { > + pr_err("Malformed device tree.\n"); > + return -EINVAL; > + } > + > + if (rsv_start == start && rsv_size == size) { > + ret = fdt_del_mem_rsv(fdt, i); > + if (ret) { > + pr_err("Error deleting device tree reservation.\n"); > + return -EINVAL; > + } > + > + return 0; > + } > + } > + > + return -ENOENT; > +} This functions is the same as the one in powerpc, and should be shared too. -- Thiago Jung Bauermann IBM Linux Technology Center