blob: 20e05936551fd593793c758589aeeabb0d303910 [file] [log] [blame]
/*
* Copyright (C) 2015 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/buffer_head.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/device-mapper.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/key.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/of.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <asm/setup.h>
#include <crypto/hash.h>
#include <crypto/hash_info.h>
#include <crypto/public_key.h>
#include <crypto/sha.h>
#include <keys/asymmetric-type.h>
#include <keys/system_keyring.h>
#include "dm-verity.h"
#include "dm-android-verity.h"
static char verifiedbootstate[VERITY_COMMANDLINE_PARAM_LENGTH];
static char veritymode[VERITY_COMMANDLINE_PARAM_LENGTH];
static char veritykeyid[VERITY_DEFAULT_KEY_ID_LENGTH];
static char buildvariant[BUILD_VARIANT];
static bool target_added;
static bool verity_enabled = true;
struct dentry *debug_dir;
static int android_verity_ctr(struct dm_target *ti, unsigned argc, char **argv);
static struct target_type android_verity_target = {
.name = "android-verity",
.version = {1, 0, 0},
.module = THIS_MODULE,
.ctr = android_verity_ctr,
.dtr = verity_dtr,
.map = verity_map,
.status = verity_status,
.prepare_ioctl = verity_prepare_ioctl,
.iterate_devices = verity_iterate_devices,
.io_hints = verity_io_hints,
};
static int __init verified_boot_state_param(char *line)
{
strlcpy(verifiedbootstate, line, sizeof(verifiedbootstate));
return 1;
}
__setup("androidboot.verifiedbootstate=", verified_boot_state_param);
static int __init verity_mode_param(char *line)
{
strlcpy(veritymode, line, sizeof(veritymode));
return 1;
}
__setup("androidboot.veritymode=", verity_mode_param);
static int __init verity_keyid_param(char *line)
{
strlcpy(veritykeyid, line, sizeof(veritykeyid));
return 1;
}
__setup("veritykeyid=", verity_keyid_param);
static int __init verity_buildvariant(char *line)
{
strlcpy(buildvariant, line, sizeof(buildvariant));
return 1;
}
__setup("buildvariant=", verity_buildvariant);
static inline bool default_verity_key_id(void)
{
return veritykeyid[0] != '\0';
}
static inline bool is_eng(void)
{
static const char typeeng[] = "eng";
return !strncmp(buildvariant, typeeng, sizeof(typeeng));
}
static inline bool is_userdebug(void)
{
static const char typeuserdebug[] = "userdebug";
return !strncmp(buildvariant, typeuserdebug, sizeof(typeuserdebug));
}
static inline bool is_unlocked(void)
{
static const char unlocked[] = "orange";
return !strncmp(verifiedbootstate, unlocked, sizeof(unlocked));
}
static int read_block_dev(struct bio_read *payload, struct block_device *bdev,
sector_t offset, int length)
{
struct bio *bio;
int err = 0, i;
payload->number_of_pages = DIV_ROUND_UP(length, PAGE_SIZE);
bio = bio_alloc(GFP_KERNEL, payload->number_of_pages);
if (!bio) {
DMERR("Error while allocating bio");
return -ENOMEM;
}
bio_set_dev(bio, bdev);
bio->bi_iter.bi_sector = offset;
bio_set_op_attrs(bio, REQ_OP_READ, 0);
payload->page_io = kzalloc(sizeof(struct page *) *
payload->number_of_pages, GFP_KERNEL);
if (!payload->page_io) {
DMERR("page_io array alloc failed");
err = -ENOMEM;
goto free_bio;
}
for (i = 0; i < payload->number_of_pages; i++) {
payload->page_io[i] = alloc_page(GFP_KERNEL);
if (!payload->page_io[i]) {
DMERR("alloc_page failed");
err = -ENOMEM;
goto free_pages;
}
if (!bio_add_page(bio, payload->page_io[i], PAGE_SIZE, 0)) {
DMERR("bio_add_page error");
err = -EIO;
goto free_pages;
}
}
if (!submit_bio_wait(bio))
/* success */
goto free_bio;
DMERR("bio read failed");
err = -EIO;
free_pages:
for (i = 0; i < payload->number_of_pages; i++)
if (payload->page_io[i])
__free_page(payload->page_io[i]);
kfree(payload->page_io);
free_bio:
bio_put(bio);
return err;
}
static inline u64 fec_div_round_up(u64 x, u64 y)
{
u64 remainder;
return div64_u64_rem(x, y, &remainder) +
(remainder > 0 ? 1 : 0);
}
static inline void populate_fec_metadata(struct fec_header *header,
struct fec_ecc_metadata *ecc)
{
ecc->blocks = fec_div_round_up(le64_to_cpu(header->inp_size),
FEC_BLOCK_SIZE);
ecc->roots = le32_to_cpu(header->roots);
ecc->start = le64_to_cpu(header->inp_size);
}
static inline int validate_fec_header(struct fec_header *header, u64 offset)
{
/* move offset to make the sanity check work for backup header
* as well. */
offset -= offset % FEC_BLOCK_SIZE;
if (le32_to_cpu(header->magic) != FEC_MAGIC ||
le32_to_cpu(header->version) != FEC_VERSION ||
le32_to_cpu(header->size) != sizeof(struct fec_header) ||
le32_to_cpu(header->roots) == 0 ||
le32_to_cpu(header->roots) >= FEC_RSM)
return -EINVAL;
return 0;
}
static int extract_fec_header(dev_t dev, struct fec_header *fec,
struct fec_ecc_metadata *ecc)
{
u64 device_size;
struct bio_read payload;
int i, err = 0;
struct block_device *bdev;
bdev = blkdev_get_by_dev(dev, FMODE_READ, NULL);
if (IS_ERR_OR_NULL(bdev)) {
DMERR("bdev get error");
return PTR_ERR(bdev);
}
device_size = i_size_read(bdev->bd_inode);
/* fec metadata size is a power of 2 and PAGE_SIZE
* is a power of 2 as well.
*/
BUG_ON(FEC_BLOCK_SIZE > PAGE_SIZE);
/* 512 byte sector alignment */
BUG_ON(((device_size - FEC_BLOCK_SIZE) % (1 << SECTOR_SHIFT)) != 0);
err = read_block_dev(&payload, bdev, (device_size -
FEC_BLOCK_SIZE) / (1 << SECTOR_SHIFT), FEC_BLOCK_SIZE);
if (err) {
DMERR("Error while reading verity metadata");
goto error;
}
BUG_ON(sizeof(struct fec_header) > PAGE_SIZE);
memcpy(fec, page_address(payload.page_io[0]),
sizeof(*fec));
ecc->valid = true;
if (validate_fec_header(fec, device_size - FEC_BLOCK_SIZE)) {
/* Try the backup header */
memcpy(fec, page_address(payload.page_io[0]) + FEC_BLOCK_SIZE
- sizeof(*fec) ,
sizeof(*fec));
if (validate_fec_header(fec, device_size -
sizeof(struct fec_header)))
ecc->valid = false;
}
if (ecc->valid)
populate_fec_metadata(fec, ecc);
for (i = 0; i < payload.number_of_pages; i++)
__free_page(payload.page_io[i]);
kfree(payload.page_io);
error:
blkdev_put(bdev, FMODE_READ);
return err;
}
static void find_metadata_offset(struct fec_header *fec,
struct block_device *bdev, u64 *metadata_offset)
{
u64 device_size;
device_size = i_size_read(bdev->bd_inode);
if (le32_to_cpu(fec->magic) == FEC_MAGIC)
*metadata_offset = le64_to_cpu(fec->inp_size) -
VERITY_METADATA_SIZE;
else
*metadata_offset = device_size - VERITY_METADATA_SIZE;
}
static int find_size(dev_t dev, u64 *device_size)
{
struct block_device *bdev;
bdev = blkdev_get_by_dev(dev, FMODE_READ, NULL);
if (IS_ERR_OR_NULL(bdev)) {
DMERR("blkdev_get_by_dev failed");
return PTR_ERR(bdev);
}
*device_size = i_size_read(bdev->bd_inode);
*device_size >>= SECTOR_SHIFT;
DMINFO("blkdev size in sectors: %llu", *device_size);
blkdev_put(bdev, FMODE_READ);
return 0;
}
static int verify_header(struct android_metadata_header *header)
{
int retval = -EINVAL;
if (is_userdebug() && le32_to_cpu(header->magic_number) ==
VERITY_METADATA_MAGIC_DISABLE)
return VERITY_STATE_DISABLE;
if (!(le32_to_cpu(header->magic_number) ==
VERITY_METADATA_MAGIC_NUMBER) ||
(le32_to_cpu(header->magic_number) ==
VERITY_METADATA_MAGIC_DISABLE)) {
DMERR("Incorrect magic number");
return retval;
}
if (le32_to_cpu(header->protocol_version) !=
VERITY_METADATA_VERSION) {
DMERR("Unsupported version %u",
le32_to_cpu(header->protocol_version));
return retval;
}
return 0;
}
static int extract_metadata(dev_t dev, struct fec_header *fec,
struct android_metadata **metadata,
bool *verity_enabled)
{
struct block_device *bdev;
struct android_metadata_header *header;
int i;
u32 table_length, copy_length, offset;
u64 metadata_offset;
struct bio_read payload;
int err = 0;
bdev = blkdev_get_by_dev(dev, FMODE_READ, NULL);
if (IS_ERR_OR_NULL(bdev)) {
DMERR("blkdev_get_by_dev failed");
return -ENODEV;
}
find_metadata_offset(fec, bdev, &metadata_offset);
/* Verity metadata size is a power of 2 and PAGE_SIZE
* is a power of 2 as well.
* PAGE_SIZE is also a multiple of 512 bytes.
*/
if (VERITY_METADATA_SIZE > PAGE_SIZE)
BUG_ON(VERITY_METADATA_SIZE % PAGE_SIZE != 0);
/* 512 byte sector alignment */
BUG_ON(metadata_offset % (1 << SECTOR_SHIFT) != 0);
err = read_block_dev(&payload, bdev, metadata_offset /
(1 << SECTOR_SHIFT), VERITY_METADATA_SIZE);
if (err) {
DMERR("Error while reading verity metadata");
goto blkdev_release;
}
header = kzalloc(sizeof(*header), GFP_KERNEL);
if (!header) {
DMERR("kzalloc failed for header");
err = -ENOMEM;
goto free_payload;
}
memcpy(header, page_address(payload.page_io[0]),
sizeof(*header));
DMINFO("bio magic_number:%u protocol_version:%d table_length:%u",
le32_to_cpu(header->magic_number),
le32_to_cpu(header->protocol_version),
le32_to_cpu(header->table_length));
err = verify_header(header);
if (err == VERITY_STATE_DISABLE) {
DMERR("Mounting root with verity disabled");
*verity_enabled = false;
/* we would still have to read the metadata to figure out
* the data blocks size. Or may be could map the entire
* partition similar to mounting the device.
*
* Reset error as well as the verity_enabled flag is changed.
*/
err = 0;
} else if (err)
goto free_header;
*metadata = kzalloc(sizeof(**metadata), GFP_KERNEL);
if (!*metadata) {
DMERR("kzalloc for metadata failed");
err = -ENOMEM;
goto free_header;
}
(*metadata)->header = header;
table_length = le32_to_cpu(header->table_length);
if (table_length == 0 ||
table_length > (VERITY_METADATA_SIZE -
sizeof(struct android_metadata_header))) {
DMERR("table_length too long");
err = -EINVAL;
goto free_metadata;
}
(*metadata)->verity_table = kzalloc(table_length + 1, GFP_KERNEL);
if (!(*metadata)->verity_table) {
DMERR("kzalloc verity_table failed");
err = -ENOMEM;
goto free_metadata;
}
if (sizeof(struct android_metadata_header) +
table_length <= PAGE_SIZE) {
memcpy((*metadata)->verity_table,
page_address(payload.page_io[0])
+ sizeof(struct android_metadata_header),
table_length);
} else {
copy_length = PAGE_SIZE -
sizeof(struct android_metadata_header);
memcpy((*metadata)->verity_table,
page_address(payload.page_io[0])
+ sizeof(struct android_metadata_header),
copy_length);
table_length -= copy_length;
offset = copy_length;
i = 1;
while (table_length != 0) {
if (table_length > PAGE_SIZE) {
memcpy((*metadata)->verity_table + offset,
page_address(payload.page_io[i]),
PAGE_SIZE);
offset += PAGE_SIZE;
table_length -= PAGE_SIZE;
} else {
memcpy((*metadata)->verity_table + offset,
page_address(payload.page_io[i]),
table_length);
table_length = 0;
}
i++;
}
}
(*metadata)->verity_table[table_length] = '\0';
DMINFO("verity_table: %s", (*metadata)->verity_table);
goto free_payload;
free_metadata:
kfree(*metadata);
free_header:
kfree(header);
free_payload:
for (i = 0; i < payload.number_of_pages; i++)
if (payload.page_io[i])
__free_page(payload.page_io[i]);
kfree(payload.page_io);
blkdev_release:
blkdev_put(bdev, FMODE_READ);
return err;
}
/* helper functions to extract properties from dts */
const char *find_dt_value(const char *name)
{
struct device_node *firmware;
const char *value;
firmware = of_find_node_by_path("/firmware/android");
if (!firmware)
return NULL;
value = of_get_property(firmware, name, NULL);
of_node_put(firmware);
return value;
}
static int verity_mode(void)
{
static const char enforcing[] = "enforcing";
static const char verified_mode_prop[] = "veritymode";
const char *value;
value = find_dt_value(verified_mode_prop);
if (!value)
value = veritymode;
if (!strncmp(value, enforcing, sizeof(enforcing) - 1))
return DM_VERITY_MODE_RESTART;
return DM_VERITY_MODE_EIO;
}
static void handle_error(void)
{
int mode = verity_mode();
if (mode == DM_VERITY_MODE_RESTART) {
DMERR("triggering restart");
kernel_restart("dm-verity device corrupted");
} else {
DMERR("Mounting verity root failed");
}
}
static struct public_key_signature *table_make_digest(
enum hash_algo hash,
const void *table,
unsigned long table_len)
{
struct public_key_signature *pks = NULL;
struct crypto_shash *tfm;
struct shash_desc *desc;
size_t digest_size, desc_size;
int ret;
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
*/
tfm = crypto_alloc_shash(hash_algo_name[hash], 0, 0);
if (IS_ERR(tfm))
return ERR_CAST(tfm);
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
digest_size = crypto_shash_digestsize(tfm);
/* We allocate the hash operational data storage on the end of out
* context data and the digest output buffer on the end of that.
*/
ret = -ENOMEM;
pks = kzalloc(digest_size + sizeof(*pks) + desc_size, GFP_KERNEL);
if (!pks)
goto error;
pks->pkey_algo = "rsa";
pks->hash_algo = hash_algo_name[hash];
pks->digest = (u8 *)pks + sizeof(*pks) + desc_size;
pks->digest_size = digest_size;
desc = (struct shash_desc *)(pks + 1);
desc->tfm = tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
ret = crypto_shash_init(desc);
if (ret < 0)
goto error;
ret = crypto_shash_finup(desc, table, table_len, pks->digest);
if (ret < 0)
goto error;
crypto_free_shash(tfm);
return pks;
error:
kfree(pks);
crypto_free_shash(tfm);
return ERR_PTR(ret);
}
static int verify_verity_signature(char *key_id,
struct android_metadata *metadata)
{
struct public_key_signature *pks = NULL;
int retval = -EINVAL;
if (!key_id)
goto error;
pks = table_make_digest(HASH_ALGO_SHA256,
(const void *)metadata->verity_table,
le32_to_cpu(metadata->header->table_length));
if (IS_ERR(pks)) {
DMERR("hashing failed");
retval = PTR_ERR(pks);
pks = NULL;
goto error;
}
pks->s = kmemdup(&metadata->header->signature[0], RSANUMBYTES, GFP_KERNEL);
if (!pks->s) {
DMERR("Error allocating memory for signature");
goto error;
}
pks->s_size = RSANUMBYTES;
retval = verify_signature_one(pks, NULL, key_id);
kfree(pks->s);
error:
kfree(pks);
return retval;
}
static inline bool test_mult_overflow(sector_t a, u32 b)
{
sector_t r = (sector_t)~0ULL;
sector_div(r, b);
return a > r;
}
static int add_as_linear_device(struct dm_target *ti, char *dev)
{
/*Move to linear mapping defines*/
char *linear_table_args[DM_LINEAR_ARGS] = {dev,
DM_LINEAR_TARGET_OFFSET};
int err = 0;
android_verity_target.dtr = dm_linear_dtr,
android_verity_target.map = dm_linear_map,
android_verity_target.status = dm_linear_status,
android_verity_target.end_io = dm_linear_end_io,
android_verity_target.prepare_ioctl = dm_linear_prepare_ioctl,
android_verity_target.iterate_devices = dm_linear_iterate_devices,
android_verity_target.direct_access = dm_linear_dax_direct_access,
android_verity_target.dax_copy_from_iter = dm_linear_dax_copy_from_iter,
android_verity_target.io_hints = NULL;
set_disk_ro(dm_disk(dm_table_get_md(ti->table)), 0);
err = dm_linear_ctr(ti, DM_LINEAR_ARGS, linear_table_args);
if (!err) {
DMINFO("Added android-verity as a linear target");
target_added = true;
} else
DMERR("Failed to add android-verity as linear target");
return err;
}
static int create_linear_device(struct dm_target *ti, dev_t dev,
char *target_device)
{
u64 device_size = 0;
int err = find_size(dev, &device_size);
if (err) {
DMERR("error finding bdev size");
handle_error();
return err;
}
ti->len = device_size;
err = add_as_linear_device(ti, target_device);
if (err) {
handle_error();
return err;
}
verity_enabled = false;
return 0;
}
/*
* Target parameters:
* <key id> Key id of the public key in the system keyring.
* Verity metadata's signature would be verified against
* this. If the key id contains spaces, replace them
* with '#'.
* <block device> The block device for which dm-verity is being setup.
*/
static int android_verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
{
dev_t uninitialized_var(dev);
struct android_metadata *metadata = NULL;
int err = 0, i, mode;
char *key_id = NULL, *table_ptr, dummy, *target_device;
char *verity_table_args[VERITY_TABLE_ARGS + 2 + VERITY_TABLE_OPT_FEC_ARGS];
/* One for specifying number of opt args and one for mode */
sector_t data_sectors;
u32 data_block_size;
unsigned int no_of_args = VERITY_TABLE_ARGS + 2 + VERITY_TABLE_OPT_FEC_ARGS;
struct fec_header uninitialized_var(fec);
struct fec_ecc_metadata uninitialized_var(ecc);
char buf[FEC_ARG_LENGTH], *buf_ptr;
unsigned long long tmpll;
if (argc == 1) {
/* Use the default keyid */
if (default_verity_key_id())
key_id = veritykeyid;
else if (!is_eng()) {
DMERR("veritykeyid= is not set");
handle_error();
return -EINVAL;
}
target_device = argv[0];
} else if (argc == 2) {
key_id = argv[0];
target_device = argv[1];
} else {
DMERR("Incorrect number of arguments");
handle_error();
return -EINVAL;
}
dev = name_to_dev_t(target_device);
if (!dev) {
DMERR("no dev found for %s", target_device);
handle_error();
return -EINVAL;
}
if (is_eng())
return create_linear_device(ti, dev, target_device);
strreplace(key_id, '#', ' ');
DMINFO("key:%s dev:%s", key_id, target_device);
if (extract_fec_header(dev, &fec, &ecc)) {
DMERR("Error while extracting fec header");
handle_error();
return -EINVAL;
}
err = extract_metadata(dev, &fec, &metadata, &verity_enabled);
if (err) {
/* Allow invalid metadata when the device is unlocked */
if (is_unlocked()) {
DMWARN("Allow invalid metadata when unlocked");
return create_linear_device(ti, dev, target_device);
}
DMERR("Error while extracting metadata");
handle_error();
goto free_metadata;
}
if (verity_enabled) {
err = verify_verity_signature(key_id, metadata);
if (err) {
DMERR("Signature verification failed");
handle_error();
goto free_metadata;
} else
DMINFO("Signature verification success");
}
table_ptr = metadata->verity_table;
for (i = 0; i < VERITY_TABLE_ARGS; i++) {
verity_table_args[i] = strsep(&table_ptr, " ");
if (verity_table_args[i] == NULL)
break;
}
if (i != VERITY_TABLE_ARGS) {
DMERR("Verity table not in the expected format");
err = -EINVAL;
handle_error();
goto free_metadata;
}
if (sscanf(verity_table_args[5], "%llu%c", &tmpll, &dummy)
!= 1) {
DMERR("Verity table not in the expected format");
handle_error();
err = -EINVAL;
goto free_metadata;
}
if (tmpll > ULONG_MAX) {
DMERR("<num_data_blocks> too large. Forgot to turn on CONFIG_LBDAF?");
handle_error();
err = -EINVAL;
goto free_metadata;
}
data_sectors = tmpll;
if (sscanf(verity_table_args[3], "%u%c", &data_block_size, &dummy)
!= 1) {
DMERR("Verity table not in the expected format");
handle_error();
err = -EINVAL;
goto free_metadata;
}
if (test_mult_overflow(data_sectors, data_block_size >>
SECTOR_SHIFT)) {
DMERR("data_sectors too large");
handle_error();
err = -EOVERFLOW;
goto free_metadata;
}
data_sectors *= data_block_size >> SECTOR_SHIFT;
DMINFO("Data sectors %llu", (unsigned long long)data_sectors);
/* update target length */
ti->len = data_sectors;
/* Setup linear target and free */
if (!verity_enabled) {
err = add_as_linear_device(ti, target_device);
goto free_metadata;
}
/*substitute data_dev and hash_dev*/
verity_table_args[1] = target_device;
verity_table_args[2] = target_device;
mode = verity_mode();
if (ecc.valid && IS_BUILTIN(CONFIG_DM_VERITY_FEC)) {
if (mode) {
err = snprintf(buf, FEC_ARG_LENGTH,
"%u %s " VERITY_TABLE_OPT_FEC_FORMAT,
1 + VERITY_TABLE_OPT_FEC_ARGS,
mode == DM_VERITY_MODE_RESTART ?
VERITY_TABLE_OPT_RESTART :
VERITY_TABLE_OPT_LOGGING,
target_device,
ecc.start / FEC_BLOCK_SIZE, ecc.blocks,
ecc.roots);
} else {
err = snprintf(buf, FEC_ARG_LENGTH,
"%u " VERITY_TABLE_OPT_FEC_FORMAT,
VERITY_TABLE_OPT_FEC_ARGS, target_device,
ecc.start / FEC_BLOCK_SIZE, ecc.blocks,
ecc.roots);
}
} else if (mode) {
err = snprintf(buf, FEC_ARG_LENGTH,
"2 " VERITY_TABLE_OPT_IGNZERO " %s",
mode == DM_VERITY_MODE_RESTART ?
VERITY_TABLE_OPT_RESTART : VERITY_TABLE_OPT_LOGGING);
} else {
err = snprintf(buf, FEC_ARG_LENGTH, "1 %s",
"ignore_zero_blocks");
}
if (err < 0 || err >= FEC_ARG_LENGTH)
goto free_metadata;
buf_ptr = buf;
for (i = VERITY_TABLE_ARGS; i < (VERITY_TABLE_ARGS +
VERITY_TABLE_OPT_FEC_ARGS + 2); i++) {
verity_table_args[i] = strsep(&buf_ptr, " ");
if (verity_table_args[i] == NULL) {
no_of_args = i;
break;
}
}
err = verity_ctr(ti, no_of_args, verity_table_args);
if (err) {
DMERR("android-verity failed to create a verity target");
} else {
target_added = true;
DMINFO("android-verity created as verity target");
}
free_metadata:
if (metadata) {
kfree(metadata->header);
kfree(metadata->verity_table);
}
kfree(metadata);
return err;
}
static int __init dm_android_verity_init(void)
{
int r;
struct dentry *file;
r = dm_register_target(&android_verity_target);
if (r < 0)
DMERR("register failed %d", r);
/* Tracks the status of the last added target */
debug_dir = debugfs_create_dir("android_verity", NULL);
if (IS_ERR_OR_NULL(debug_dir)) {
DMERR("Cannot create android_verity debugfs directory: %ld",
PTR_ERR(debug_dir));
goto end;
}
file = debugfs_create_bool("target_added", S_IRUGO, debug_dir,
&target_added);
if (IS_ERR_OR_NULL(file)) {
DMERR("Cannot create android_verity debugfs directory: %ld",
PTR_ERR(debug_dir));
debugfs_remove_recursive(debug_dir);
goto end;
}
file = debugfs_create_bool("verity_enabled", S_IRUGO, debug_dir,
&verity_enabled);
if (IS_ERR_OR_NULL(file)) {
DMERR("Cannot create android_verity debugfs directory: %ld",
PTR_ERR(debug_dir));
debugfs_remove_recursive(debug_dir);
}
end:
return r;
}
static void __exit dm_android_verity_exit(void)
{
if (!IS_ERR_OR_NULL(debug_dir))
debugfs_remove_recursive(debug_dir);
dm_unregister_target(&android_verity_target);
}
module_init(dm_android_verity_init);
module_exit(dm_android_verity_exit);