From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933784AbbJANGn (ORCPT ); Thu, 1 Oct 2015 09:06:43 -0400 Received: from mga11.intel.com ([192.55.52.93]:1376 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932966AbbJANGk (ORCPT ); Thu, 1 Oct 2015 09:06:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,617,1437462000"; d="scan'208";a="655852636" From: "Kweh, Hock Leong" To: Matt Fleming , Greg Kroah-Hartman Cc: Ong Boon Leong , LKML , linux-efi@vger.kernel.org, Sam Protsenko , Peter Jones , Andy Lutomirski , Roy Franz , Borislav Petkov , James Bottomley , Linux FS Devel , "Kweh, Hock Leong" , Fleming Matt Subject: [PATCH v6 2/2] efi: a misc char interface for user to update efi firmware Date: Fri, 2 Oct 2015 05:05:54 +0800 Message-Id: <1443733554-22743-3-git-send-email-hock.leong.kweh@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1443733554-22743-1-git-send-email-hock.leong.kweh@intel.com> References: <1443733554-22743-1-git-send-email-hock.leong.kweh@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Kweh, Hock Leong" Introducing a kernel module to expose capsule loader interface (misc char device file note) for user to upload capsule binaries. Example method to load the capsule binary: cat firmware.bin > /dev/efi_capsule_loader Cc: Matt Fleming Signed-off-by: Kweh, Hock Leong --- drivers/firmware/efi/Kconfig | 10 ++ drivers/firmware/efi/Makefile | 1 + drivers/firmware/efi/efi-capsule-loader.c | 246 +++++++++++++++++++++++++++++ 3 files changed, 257 insertions(+) create mode 100644 drivers/firmware/efi/efi-capsule-loader.c diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index f712d47..0be8ee3 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -60,6 +60,16 @@ config EFI_RUNTIME_WRAPPERS config EFI_ARMSTUB bool +config EFI_CAPSULE_LOADER + tristate "EFI capsule loader" + depends on EFI + help + This option exposes a loader interface "/dev/efi_capsule_loader" for + user to load EFI capsule binary and update the EFI firmware through + system reboot. + + If unsure, say N. + endmenu config UEFI_CPER diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 698846e..5ab031a 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_UEFI_CPER) += cper.o obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o obj-$(CONFIG_EFI_STUB) += libstub/ +obj-$(CONFIG_EFI_CAPSULE_LOADER) += efi-capsule-loader.o diff --git a/drivers/firmware/efi/efi-capsule-loader.c b/drivers/firmware/efi/efi-capsule-loader.c new file mode 100644 index 0000000..571e0c8 --- /dev/null +++ b/drivers/firmware/efi/efi-capsule-loader.c @@ -0,0 +1,246 @@ +/* + * EFI capsule loader driver. + * + * Copyright 2015 Intel Corporation + * + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include + +#define DEV_NAME "efi_capsule_loader" + +static struct capsule_info { + char header_obtained; + long index; + unsigned long count; + unsigned long total_size; + struct page **pages; + unsigned long page_count_remain; +} cap_info; + +static DEFINE_MUTEX(capsule_loader_lock); + +/* + * This function will free the current & all previous allocated buffer pages. + * The input parameter is the allocated buffer page for current execution which + * has not yet assigned to pages array. The input param can be NULL if the + * current execution has not allocated any buffer page. + */ +static void efi_free_all_buff_pages(struct page *kbuff_page) +{ + if (!kbuff_page) + __free_page(kbuff_page); + + if (cap_info.index > 0) + while (cap_info.index > 0) + __free_page(cap_info.pages[--cap_info.index]); + + if (cap_info.header_obtained) + kfree(cap_info.pages); + + /* indicate to the next that error had occurred */ + cap_info.index = -2; +} + +/* + * This function will store the capsule binary and pass it to + * efi_capsule_update() API in capsule.c. + * + * Expectation: + * - userspace tool should start at the beginning of capsule binary and pass + * data in sequential. + * - user should close and re-open this file note in order to upload more + * capsules. + * - any error occurred, user should close the file and restart the operation + * for the next try otherwise -EIO will be returned until the file is closed. + */ +static ssize_t efi_capsule_write(struct file *file, const char __user *buff, + size_t count, loff_t *offp) +{ + int ret = 0; + struct page *kbuff_page; + void *kbuff; + size_t write_byte; + + pr_debug("%s: Entering Write()\n", __func__); + if (count == 0) + return 0; + + /* return error while error had occurred or capsule uploading is done */ + if (cap_info.index < 0) + return -EIO; + + /* only alloc a new page when the current page is full */ + if (!cap_info.page_count_remain) { + kbuff_page = alloc_page(GFP_KERNEL); + if (!kbuff_page) { + pr_debug("%s: alloc_page() failed\n", __func__); + efi_free_all_buff_pages(NULL); + return -ENOMEM; + } + cap_info.page_count_remain = PAGE_SIZE; + } else { + kbuff_page = cap_info.pages[--cap_info.index]; + } + kbuff = kmap(kbuff_page); + if (!kbuff) { + pr_debug("%s: kmap() failed\n", __func__); + efi_free_all_buff_pages(kbuff_page); + return -EFAULT; + } + kbuff += PAGE_SIZE - cap_info.page_count_remain; + + /* copy capsule binary data from user space to kernel space buffer */ + write_byte = min_t(size_t, count, cap_info.page_count_remain); + if (copy_from_user(kbuff, buff, write_byte)) { + pr_debug("%s: copy_from_user() failed\n", __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return -EFAULT; + } + cap_info.page_count_remain -= write_byte; + + /* setup capsule binary info structure */ + if (cap_info.header_obtained == 0 && cap_info.index == 0) { + efi_capsule_header_t *cap_hdr = kbuff; + int reset_type; + size_t pages_needed = ALIGN(cap_hdr->imagesize, PAGE_SIZE) >> + PAGE_SHIFT; + + if (pages_needed == 0) { + pr_err("%s: pages count invalid\n", __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return -EINVAL; + } + + /* check if the capsule binary supported */ + ret = efi_capsule_supported(cap_hdr->guid, cap_hdr->flags, + cap_hdr->imagesize, &reset_type); + if (ret) { + pr_err("%s: efi_capsule_supported() failed\n", + __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return ret; + } + + cap_info.total_size = cap_hdr->imagesize; + cap_info.pages = kmalloc_array(pages_needed, sizeof(void *), + GFP_KERNEL); + if (!cap_info.pages) { + pr_debug("%s: kmalloc_array() failed\n", __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return -ENOMEM; + } + + cap_info.header_obtained = 1; + } + + cap_info.pages[cap_info.index++] = kbuff_page; + cap_info.count += write_byte; + kunmap(kbuff_page); + + /* submit the full binary to efi_capsule_update() API */ + if (cap_info.count >= cap_info.total_size) { + void *cap_hdr_temp; + + cap_hdr_temp = kmap(cap_info.pages[0]); + if (!cap_hdr_temp) { + pr_debug("%s: kmap() failed\n", __func__); + efi_free_all_buff_pages(NULL); + return -EFAULT; + } + ret = efi_capsule_update(cap_hdr_temp, cap_info.pages); + kunmap(cap_info.pages[0]); + if (ret) { + pr_err("%s: efi_capsule_update() failed\n", __func__); + efi_free_all_buff_pages(NULL); + return ret; + } + /* indicate capsule binary uploading is done */ + cap_info.index = -1; + } + + return write_byte; +} + +static int efi_capsule_release(struct inode *inode, struct file *file) +{ + int ret = 0; + + pr_debug("%s: Exit in Release()\n", __func__); + /* release uncompleted capsule upload */ + if (cap_info.index > 0) { + pr_err("%s: capsule upload not complete\n", __func__); + efi_free_all_buff_pages(NULL); + ret = -ECANCELED; + } + mutex_unlock(&capsule_loader_lock); + + /* + * we would not free the successful submitted buffer pages here due to + * efi update require system reboot with data maintained. + */ + return ret; +} + +static int efi_capsule_open(struct inode *inode, struct file *file) +{ + pr_debug("%s: Entering Open()\n", __func__); + if (!mutex_trylock(&capsule_loader_lock)) + return -EBUSY; + + memset(&cap_info, 0, sizeof(cap_info)); + return 0; +} + +static const struct file_operations efi_capsule_fops = { + .owner = THIS_MODULE, + .open = efi_capsule_open, + .write = efi_capsule_write, + .release = efi_capsule_release, + .llseek = no_llseek, +}; + +static struct miscdevice efi_capsule_misc = { + .minor = MISC_DYNAMIC_MINOR, + .name = DEV_NAME, + .fops = &efi_capsule_fops, +}; + +static int __init efi_capsule_loader_init(void) +{ + int ret; + + mutex_init(&capsule_loader_lock); + + ret = misc_register(&efi_capsule_misc); + if (ret) + pr_err("%s: Failed to register misc char file note\n", + __func__); + + return ret; +} +module_init(efi_capsule_loader_init); + +static void __exit efi_capsule_loader_exit(void) +{ + mutex_destroy(&capsule_loader_lock); + misc_deregister(&efi_capsule_misc); +} +module_exit(efi_capsule_loader_exit); + +MODULE_DESCRIPTION("EFI capsule firmware binary loader"); +MODULE_LICENSE("GPL v2"); -- 1.7.9.5