From 6173a065cb395d4a9528c4e49810af127db68141 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Wed, 16 Nov 2022 12:49:52 +0000 Subject: [PATCH 1/2] block: add uImage.FIT subimage block driver Add a small block driver which exposes filesystem sub-images contained in U-Boot uImage.FIT images as block devices. The uImage.FIT image has to be stored directly on a block device or partition, MTD device or partition, or UBI volume. The driver is intended for systems using the U-Boot bootloader and uses the root device hint left by the bootloader (or the user) in the 'chosen' section of the device-tree. Example: /dts-v1/; / { chosen { rootdisk = <&mmc0_part3>; }; }; Signed-off-by: Daniel Golle --- MAINTAINERS | 6 + drivers/block/Kconfig | 12 + drivers/block/Makefile | 2 + drivers/block/fitblk.c | 658 ++++++++++++++++++++++++++++++++++++ drivers/block/open | 4 + include/uapi/linux/fitblk.h | 10 + 6 files changed, 692 insertions(+) create mode 100644 drivers/block/fitblk.c create mode 100644 drivers/block/open create mode 100644 include/uapi/linux/fitblk.h --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22014,6 +22014,12 @@ F: Documentation/filesystems/ubifs-authe F: Documentation/filesystems/ubifs.rst F: fs/ubifs/ +U-BOOT UIMAGE.FIT PARSER +M: Daniel Golle +L: linux-block@vger.kernel.org +S: Maintained +F: drivers/block/fitblk.c + UBLK USERSPACE BLOCK DRIVER M: Ming Lei L: linux-block@vger.kernel.org --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -354,6 +354,18 @@ config VIRTIO_BLK This is the virtual block driver for virtio. It can be used with QEMU based VMMs (like KVM or Xen). Say Y or M. +config UIMAGE_FIT_BLK + bool "uImage.FIT block driver" + help + This driver allows using filesystems contained in uImage.FIT images + by mapping them as block devices. + + It can currently not be built as a module due to libfdt symbols not + being exported. + + Say Y if you want to mount filesystems sub-images of a uImage.FIT + stored in a block device partition, mtdblock or ubiblock device. + config BLK_DEV_RBD tristate "Rados block device (RBD)" depends on INET && BLOCK --- a/drivers/block/Makefile +++ b/drivers/block/Makefile @@ -39,4 +39,6 @@ obj-$(CONFIG_BLK_DEV_NULL_BLK) += null_b obj-$(CONFIG_BLK_DEV_UBLK) += ublk_drv.o +obj-$(CONFIG_UIMAGE_FIT_BLK) += fitblk.o + swim_mod-y := swim.o swim_asm.o --- /dev/null +++ b/drivers/block/fitblk.c @@ -0,0 +1,659 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * uImage.FIT virtual block device driver. + * + * Copyright (C) 2023 Daniel Golle + * Copyright (C) 2007 Nick Piggin + * Copyright (C) 2007 Novell Inc. + * + * Initially derived from drivers/block/brd.c which is in parts derived from + * drivers/block/rd.c, and drivers/block/loop.c, copyright of their respective + * owners. + * + * uImage.FIT headers extracted from Das U-Boot + * (C) Copyright 2008 Semihalf + * (C) Copyright 2000-2005 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define FIT_DEVICE_PREFIX "fit" + +/* maximum number of pages used for the uImage.FIT index structure */ +#define FIT_MAX_PAGES 1024 + +/* minimum free sectors to map as read-write "remainder" volume */ +#define MIN_FREE_SECT 16 + +/* maximum number of mapped loadables */ +#define MAX_FIT_LOADABLES 16 + +/* constants for uImage.FIT structrure traversal */ +#define FIT_IMAGES_PATH "/images" +#define FIT_CONFS_PATH "/configurations" + +/* hash/signature/key node */ +#define FIT_HASH_NODENAME "hash" +#define FIT_ALGO_PROP "algo" +#define FIT_VALUE_PROP "value" +#define FIT_IGNORE_PROP "uboot-ignore" +#define FIT_SIG_NODENAME "signature" +#define FIT_KEY_REQUIRED "required" +#define FIT_KEY_HINT "key-name-hint" + +/* cipher node */ +#define FIT_CIPHER_NODENAME "cipher" +#define FIT_ALGO_PROP "algo" + +/* image node */ +#define FIT_DATA_PROP "data" +#define FIT_DATA_POSITION_PROP "data-position" +#define FIT_DATA_OFFSET_PROP "data-offset" +#define FIT_DATA_SIZE_PROP "data-size" +#define FIT_TIMESTAMP_PROP "timestamp" +#define FIT_DESC_PROP "description" +#define FIT_ARCH_PROP "arch" +#define FIT_TYPE_PROP "type" +#define FIT_OS_PROP "os" +#define FIT_COMP_PROP "compression" +#define FIT_ENTRY_PROP "entry" +#define FIT_LOAD_PROP "load" + +/* configuration node */ +#define FIT_KERNEL_PROP "kernel" +#define FIT_FILESYSTEM_PROP "filesystem" +#define FIT_RAMDISK_PROP "ramdisk" +#define FIT_FDT_PROP "fdt" +#define FIT_LOADABLE_PROP "loadables" +#define FIT_DEFAULT_PROP "default" +#define FIT_SETUP_PROP "setup" +#define FIT_FPGA_PROP "fpga" +#define FIT_FIRMWARE_PROP "firmware" +#define FIT_STANDALONE_PROP "standalone" + +/* fitblk driver data */ +static const char *_fitblk_claim_ptr = "I belong to fitblk"; +static const char *ubootver; +struct device_node *rootdisk; +static struct platform_device *pdev; +static LIST_HEAD(fitblk_devices); +static DEFINE_MUTEX(devices_mutex); +refcount_t num_devs; + +struct fitblk { + struct platform_device *pdev; + struct block_device *lower_bdev; + sector_t start_sect; + struct gendisk *disk; + struct work_struct remove_work; + struct list_head list; + bool dead; +}; + +static int fitblk_open(struct gendisk *disk, fmode_t mode) +{ + struct fitblk *fitblk = disk->private_data; + + if (fitblk->dead) + return -ENOENT; + + return 0; +} + +static void fitblk_release(struct gendisk *disk) +{ + return; +} + +static void fitblk_submit_bio(struct bio *orig_bio) +{ + struct bio *bio = orig_bio; + struct fitblk *fitblk = bio->bi_bdev->bd_disk->private_data; + + if (fitblk->dead) + return; + + /* mangle bio and re-submit */ + while (bio) { + bio->bi_iter.bi_sector += fitblk->start_sect; + bio->bi_bdev = fitblk->lower_bdev; + bio = bio->bi_next; + } + submit_bio(orig_bio); +} + +static void fitblk_remove(struct fitblk *fitblk) +{ + blk_mark_disk_dead(fitblk->disk); + mutex_lock(&devices_mutex); + fitblk->dead = true; + list_del(&fitblk->list); + mutex_unlock(&devices_mutex); + + schedule_work(&fitblk->remove_work); +} + +static int fitblk_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct fitblk *fitblk = bdev->bd_disk->private_data; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (fitblk->dead) + return -ENOENT; + + switch (cmd) { + case FITBLK_RELEASE: + fitblk_remove(fitblk); + break; + default: + return -EINVAL; + } + + return 0; +} + +static const struct block_device_operations fitblk_fops = { + .owner = THIS_MODULE, + .ioctl = fitblk_ioctl, + .open = fitblk_open, + .release = fitblk_release, + .submit_bio = fitblk_submit_bio, +}; + +static void fitblk_purge(struct work_struct *work) +{ + struct fitblk *fitblk = container_of(work, struct fitblk, remove_work); + + //del_gendisk(fitblk->disk); // causes crash, not doing it doesn't matter + refcount_dec(&num_devs); + platform_device_del(fitblk->pdev); + platform_device_put(fitblk->pdev); + + if (refcount_dec_if_one(&num_devs)) { + sysfs_remove_link(&pdev->dev.kobj, "lower_dev"); + blkdev_put(fitblk->lower_bdev, &_fitblk_claim_ptr); + } + + kfree(fitblk); +} + +static int add_fit_subimage_device(struct block_device *lower_bdev, + unsigned int slot, sector_t start_sect, + sector_t nr_sect, bool readonly) +{ + struct fitblk *fitblk; + struct gendisk *disk; + int err; + + mutex_lock(&devices_mutex); + if (!refcount_inc_not_zero(&num_devs)) + return -EBADF; + + fitblk = kzalloc(sizeof(struct fitblk), GFP_KERNEL); + if (!fitblk) { + err = -ENOMEM; + goto out_unlock; + } + + fitblk->lower_bdev = lower_bdev; + fitblk->start_sect = start_sect; + INIT_WORK(&fitblk->remove_work, fitblk_purge); + + disk = blk_alloc_disk(NUMA_NO_NODE); + if (!disk) { + err = -ENOMEM; + goto out_free_fitblk; + } + + disk->first_minor = 0; + disk->flags = lower_bdev->bd_disk->flags | GENHD_FL_NO_PART; + disk->fops = &fitblk_fops; + disk->private_data = fitblk; + if (readonly) { + set_disk_ro(disk, 1); + snprintf(disk->disk_name, sizeof(disk->disk_name), FIT_DEVICE_PREFIX "%u", slot); + } else { + strcpy(disk->disk_name, FIT_DEVICE_PREFIX "rw"); + } + + set_capacity(disk, nr_sect); + + disk->queue->queue_flags = lower_bdev->bd_disk->queue->queue_flags; + memcpy(&disk->queue->limits, &lower_bdev->bd_disk->queue->limits, + sizeof(struct queue_limits)); + + fitblk->disk = disk; + fitblk->pdev = platform_device_alloc(disk->disk_name, PLATFORM_DEVID_NONE); + if (!fitblk->pdev) { + err = -ENOMEM; + goto out_cleanup_disk; + } + + fitblk->pdev->dev.parent = &pdev->dev; + err = platform_device_add(fitblk->pdev); + if (err) + goto out_put_pdev; + + err = device_add_disk(&fitblk->pdev->dev, disk, NULL); + if (err) + goto out_del_pdev; + + if (!ROOT_DEV) + ROOT_DEV = disk->part0->bd_dev; + + list_add_tail(&fitblk->list, &fitblk_devices); + + mutex_unlock(&devices_mutex); + + return 0; + +out_del_pdev: + platform_device_del(fitblk->pdev); +out_put_pdev: + platform_device_put(fitblk->pdev); +out_cleanup_disk: + put_disk(disk); +out_free_fitblk: + kfree(fitblk); +out_unlock: + refcount_dec(&num_devs); + mutex_unlock(&devices_mutex); + return err; +} + +static void fitblk_mark_dead(struct block_device *bdev, bool surprise) +{ + struct list_head *n, *tmp; + struct fitblk *fitblk; + + mutex_lock(&devices_mutex); + list_for_each_safe(n, tmp, &fitblk_devices) { + fitblk = list_entry(n, struct fitblk, list); + if (fitblk->lower_bdev != bdev) + continue; + + fitblk->dead = true; + list_del(&fitblk->list); + /* removal needs to be deferred to avoid deadlock */ + schedule_work(&fitblk->remove_work); + } + mutex_unlock(&devices_mutex); +} + +static const struct blk_holder_ops fitblk_hops = { + .mark_dead = fitblk_mark_dead, +}; + +static int parse_fit_on_dev(struct device *dev) +{ + struct block_device *bdev; + struct address_space *mapping; + struct folio *folio; + pgoff_t f_index = 0; + size_t bytes_left, bytes_to_copy; + void *pre_fit, *fit, *fit_c; + u64 dsize, dsectors, imgmaxsect = 0; + u32 size, image_pos, image_len; + const __be32 *image_offset_be, *image_len_be, *image_pos_be; + int ret = 0, node, images, config; + const char *image_name, *image_type, *image_description, + *config_default, *config_description, *config_loadables; + u32 image_name_len, image_type_len, image_description_len, + bootconf_len, config_default_len, config_description_len, + config_loadables_len; + sector_t start_sect, nr_sects; + struct device_node *np = NULL; + const char *bootconf_c; + const char *loadable; + char *bootconf = NULL, *bootconf_term; + bool found; + int loadables_rem_len, loadable_len; + u16 loadcnt; + unsigned int slot = 0; + + /* Exclusive open the block device to receive holder notifications */ + bdev = blkdev_get_by_dev(dev->devt, BLK_OPEN_READ, &_fitblk_claim_ptr, &fitblk_hops); + if (!bdev) + return -ENODEV; + + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + + mapping = bdev->bd_inode->i_mapping; + + /* map first page */ + folio = read_mapping_folio(mapping, f_index++, NULL); + if (IS_ERR(folio)) { + ret = PTR_ERR(folio); + goto out_blkdev; + } + pre_fit = folio_address(folio) + offset_in_folio(folio, 0); + + /* uImage.FIT is based on flattened device tree structure */ + if (fdt_check_header(pre_fit)) { + ret = -EINVAL; + folio_put(folio); + goto out_blkdev; + } + + size = fdt_totalsize(pre_fit); + + if (size > PAGE_SIZE * FIT_MAX_PAGES) { + ret = -EOPNOTSUPP; + folio_put(folio); + goto out_blkdev; + } + + /* acquire disk size */ + dsectors = bdev_nr_sectors(bdev); + dsize = dsectors << SECTOR_SHIFT; + + /* abort if FIT structure is larger than disk or partition size */ + if (size >= dsize) { + ret = -EFBIG; + folio_put(folio); + goto out_blkdev; + } + + fit = kmalloc(size, GFP_KERNEL); + if (!fit) { + ret = -ENOMEM; + folio_put(folio); + goto out_blkdev; + } + + bytes_left = size; + fit_c = fit; + while (bytes_left > 0) { + bytes_to_copy = min_t(size_t, bytes_left, + folio_size(folio) - offset_in_folio(folio, 0)); + memcpy(fit_c, pre_fit, bytes_to_copy); + fit_c += bytes_to_copy; + bytes_left -= bytes_to_copy; + if (bytes_left) { + folio_put(folio); + folio = read_mapping_folio(mapping, f_index++, NULL); + if (IS_ERR(folio)) { + ret = PTR_ERR(folio); + goto out_blkdev; + }; + pre_fit = folio_address(folio) + offset_in_folio(folio, 0); + } + } + folio_put(folio); + + /* set boot config node name U-Boot may have added to the device tree */ + np = of_find_node_by_path("/chosen"); + if (np) { + bootconf_c = of_get_property(np, "u-boot,bootconf", &bootconf_len); + if (bootconf_c && bootconf_len) + bootconf = kmemdup_nul(bootconf_c, bootconf_len, GFP_KERNEL); + } + + if (bootconf) { + bootconf_term = strchr(bootconf, '#'); + if (bootconf_term) + *bootconf_term = '\0'; + } + + /* find configuration path in uImage.FIT */ + config = fdt_path_offset(fit, FIT_CONFS_PATH); + if (config < 0) { + pr_err("FIT: Cannot find %s node: %d\n", + FIT_CONFS_PATH, config); + ret = -ENOENT; + goto out_bootconf; + } + + /* get default configuration node name */ + config_default = + fdt_getprop(fit, config, FIT_DEFAULT_PROP, &config_default_len); + + /* make sure we got either default or selected boot config node name */ + if (!config_default && !bootconf) { + pr_err("FIT: Cannot find default configuration\n"); + ret = -ENOENT; + goto out_bootconf; + } + + /* find selected boot config node, fallback on default config node */ + node = fdt_subnode_offset(fit, config, bootconf ?: config_default); + if (node < 0) { + pr_err("FIT: Cannot find %s node: %d\n", + bootconf ?: config_default, node); + ret = -ENOENT; + goto out_bootconf; + } + + pr_info("FIT: Detected U-Boot %s\n", ubootver); + + /* get selected configuration data */ + config_description = + fdt_getprop(fit, node, FIT_DESC_PROP, &config_description_len); + config_loadables = fdt_getprop(fit, node, FIT_LOADABLE_PROP, + &config_loadables_len); + + pr_info("FIT: %s configuration: \"%.*s\"%s%.*s%s\n", + bootconf ? "Selected" : "Default", + bootconf ? bootconf_len : config_default_len, + bootconf ?: config_default, + config_description ? " (" : "", + config_description ? config_description_len : 0, + config_description ?: "", + config_description ? ")" : ""); + + if (!config_loadables || !config_loadables_len) { + pr_err("FIT: No loadables configured in \"%s\"\n", + bootconf ?: config_default); + ret = -ENOENT; + goto out_bootconf; + } + + /* get images path in uImage.FIT */ + images = fdt_path_offset(fit, FIT_IMAGES_PATH); + if (images < 0) { + pr_err("FIT: Cannot find %s node: %d\n", FIT_IMAGES_PATH, images); + ret = -EINVAL; + goto out_bootconf; + } + + /* iterate over images in uImage.FIT */ + fdt_for_each_subnode(node, fit, images) { + image_name = fdt_get_name(fit, node, &image_name_len); + image_type = fdt_getprop(fit, node, FIT_TYPE_PROP, &image_type_len); + image_offset_be = fdt_getprop(fit, node, FIT_DATA_OFFSET_PROP, NULL); + image_pos_be = fdt_getprop(fit, node, FIT_DATA_POSITION_PROP, NULL); + image_len_be = fdt_getprop(fit, node, FIT_DATA_SIZE_PROP, NULL); + + if (!image_name || !image_type || !image_len_be || + !image_name_len || !image_type_len) + continue; + + image_len = be32_to_cpu(*image_len_be); + if (!image_len) + continue; + + if (image_offset_be) + image_pos = be32_to_cpu(*image_offset_be) + size; + else if (image_pos_be) + image_pos = be32_to_cpu(*image_pos_be); + else + continue; + + image_description = fdt_getprop(fit, node, FIT_DESC_PROP, + &image_description_len); + + pr_info("FIT: %16s sub-image 0x%08x..0x%08x \"%.*s\"%s%.*s%s\n", + image_type, image_pos, image_pos + image_len - 1, + image_name_len, image_name, image_description ? " (" : "", + image_description ? image_description_len : 0, + image_description ?: "", image_description ? ") " : ""); + + /* only 'filesystem' images should be mapped as partitions */ + if (strncmp(image_type, FIT_FILESYSTEM_PROP, image_type_len)) + continue; + + /* check if sub-image is part of configured loadables */ + found = false; + loadable = config_loadables; + loadables_rem_len = config_loadables_len; + for (loadcnt = 0; loadables_rem_len > 1 && + loadcnt < MAX_FIT_LOADABLES; ++loadcnt) { + loadable_len = + strnlen(loadable, loadables_rem_len - 1) + 1; + loadables_rem_len -= loadable_len; + if (!strncmp(image_name, loadable, loadable_len)) { + found = true; + break; + } + loadable += loadable_len; + } + if (!found) + continue; + + if (image_pos % (1 << PAGE_SHIFT)) { + dev_err(dev, "FIT: image %.*s start not aligned to page boundaries, skipping\n", + image_name_len, image_name); + continue; + } + + if (image_len % (1 << PAGE_SHIFT)) { + dev_err(dev, "FIT: sub-image %.*s end not aligned to page boundaries, skipping\n", + image_name_len, image_name); + continue; + } + + start_sect = image_pos >> SECTOR_SHIFT; + nr_sects = image_len >> SECTOR_SHIFT; + imgmaxsect = max_t(sector_t, imgmaxsect, start_sect + nr_sects); + + if (start_sect + nr_sects > dsectors) { + dev_err(dev, "FIT: sub-image %.*s disk access beyond EOD\n", + image_name_len, image_name); + continue; + } + + if (!slot) { + ret = sysfs_create_link_nowarn(&pdev->dev.kobj, bdev_kobj(bdev), "lower_dev"); + if (ret && ret != -EEXIST) + goto out_bootconf; + + ret = 0; + } + + add_fit_subimage_device(bdev, slot++, start_sect, nr_sects, true); + } + + if (!found || !slot) + goto out_bootconf; + + dev_info(dev, "mapped %u uImage.FIT filesystem sub-image%s as /dev/fit%s%u%s\n", + slot, (slot > 1)?"s":"", (slot > 1)?"[0...":"", slot - 1, + (slot > 1)?"]":""); + + /* in case uImage.FIT is stored in a partition, map the remaining space */ + if (!bdev->bd_read_only && bdev_is_partition(bdev) && + (imgmaxsect + MIN_FREE_SECT) < dsectors) { + add_fit_subimage_device(bdev, slot++, imgmaxsect, + dsectors - imgmaxsect, false); + dev_info(dev, "mapped remaining space as /dev/fitrw\n"); + } + +out_bootconf: + kfree(bootconf); + kfree(fit); +out_blkdev: + if (!found || ret) + blkdev_put(bdev, &_fitblk_claim_ptr); + + return ret; +} + +static int fitblk_match_of_node(struct device *dev, const void *np) +{ + int ret; + + ret = device_match_of_node(dev, np); + if (ret) + return ret; + + /* + * To match ubiblock and mtdblock devices by their parent ubi + * or mtd device, also consider block device parent + */ + if (!dev->parent) + return 0; + + return device_match_of_node(dev->parent, np); +} + +static int fitblk_probe(struct platform_device *pdev) +{ + struct device *dev; + + dev = class_find_device(&block_class, NULL, rootdisk, fitblk_match_of_node); + if (!dev) + return -EPROBE_DEFER; + + return parse_fit_on_dev(dev); +} + +static struct platform_driver fitblk_driver = { + .probe = fitblk_probe, + .driver = { + .name = "fitblk", + .owner = THIS_MODULE, + }, +}; + +static int __init fitblk_init(void) +{ + /* detect U-Boot firmware */ + ubootver = of_get_property(of_chosen, "u-boot,version", NULL); + if (!ubootver) + return 0; + + /* parse 'rootdisk' property phandle */ + rootdisk = of_parse_phandle(of_chosen, "rootdisk", 0); + if (!rootdisk) + return 0; + + if (platform_driver_register(&fitblk_driver)) + return -ENODEV; + + refcount_set(&num_devs, 1); + pdev = platform_device_register_simple("fitblk", -1, NULL, 0); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + return 0; +} +device_initcall(fitblk_init); --- /dev/null +++ b/include/uapi/linux/fitblk.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +#ifndef _UAPI_LINUX_FITBLK_H +#define _UAPI_LINUX_FITBLK_H + +/* + * IOCTL commands --- we will commandeer 0x46 ('F') + */ +#define FITBLK_RELEASE 0x4600 + +#endif /* _UAPI_LINUX_FITBLK_H */