Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 Red Hat, Inc. |
| 3 | * |
| 4 | * Author: Mikulas Patocka <mpatocka@redhat.com> |
| 5 | * |
| 6 | * Based on Chromium dm-verity driver (C) 2011 The Chromium OS Authors |
| 7 | * |
| 8 | * This file is released under the GPLv2. |
| 9 | * |
| 10 | * In the file "/sys/module/dm_verity/parameters/prefetch_cluster" you can set |
| 11 | * default prefetch value. Data are read in "prefetch_cluster" chunks from the |
| 12 | * hash device. Setting this greatly improves performance when data and hash |
| 13 | * are on the same disk on different partitions on devices with poor random |
| 14 | * access behavior. |
| 15 | */ |
| 16 | |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 17 | #include "dm-verity.h" |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 18 | #include "dm-verity-fec.h" |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 19 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 20 | #include <linux/delay.h> |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 21 | #include <linux/module.h> |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 22 | #include <linux/reboot.h> |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 23 | #include <linux/vmalloc.h> |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 24 | |
| 25 | #define DM_MSG_PREFIX "verity" |
| 26 | |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 27 | #define DM_VERITY_ENV_LENGTH 42 |
| 28 | #define DM_VERITY_ENV_VAR_NAME "DM_VERITY_ERR_BLOCK_NR" |
| 29 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 30 | #define DM_VERITY_DEFAULT_PREFETCH_SIZE 262144 |
| 31 | |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 32 | #define DM_VERITY_MAX_CORRUPTED_ERRS 100 |
| 33 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 34 | #define DM_VERITY_OPT_DEVICE_WAIT "device_wait" |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 35 | #define DM_VERITY_OPT_LOGGING "ignore_corruption" |
| 36 | #define DM_VERITY_OPT_RESTART "restart_on_corruption" |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 37 | #define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks" |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 38 | #define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once" |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 39 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 40 | #define DM_VERITY_OPTS_MAX (3 + DM_VERITY_OPTS_FEC) |
Sami Tolvanen | 753c1fd | 2015-11-05 02:02:32 +0000 | [diff] [blame] | 41 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 42 | static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE; |
| 43 | |
| 44 | module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR); |
| 45 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 46 | static int dm_device_wait; |
| 47 | |
Mikulas Patocka | 3b6b781 | 2013-03-20 17:21:25 +0000 | [diff] [blame] | 48 | struct dm_verity_prefetch_work { |
| 49 | struct work_struct work; |
| 50 | struct dm_verity *v; |
| 51 | sector_t block; |
| 52 | unsigned n_blocks; |
| 53 | }; |
| 54 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 55 | /* |
| 56 | * Auxiliary structure appended to each dm-bufio buffer. If the value |
| 57 | * hash_verified is nonzero, hash of the block has been verified. |
| 58 | * |
| 59 | * The variable hash_verified is set to 0 when allocating the buffer, then |
| 60 | * it can be changed to 1 and it is never reset to 0 again. |
| 61 | * |
| 62 | * There is no lock around this value, a race condition can at worst cause |
| 63 | * that multiple processes verify the hash of the same buffer simultaneously |
| 64 | * and write 1 to hash_verified simultaneously. |
| 65 | * This condition is harmless, so we don't need locking. |
| 66 | */ |
| 67 | struct buffer_aux { |
| 68 | int hash_verified; |
| 69 | }; |
| 70 | |
| 71 | /* |
| 72 | * Initialize struct buffer_aux for a freshly created buffer. |
| 73 | */ |
| 74 | static void dm_bufio_alloc_callback(struct dm_buffer *buf) |
| 75 | { |
| 76 | struct buffer_aux *aux = dm_bufio_get_aux_data(buf); |
| 77 | |
| 78 | aux->hash_verified = 0; |
| 79 | } |
| 80 | |
| 81 | /* |
| 82 | * Translate input sector number to the sector number on the target device. |
| 83 | */ |
| 84 | static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector) |
| 85 | { |
| 86 | return v->data_start + dm_target_offset(v->ti, bi_sector); |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * Return hash position of a specified block at a specified tree level |
| 91 | * (0 is the lowest level). |
| 92 | * The lowest "hash_per_block_bits"-bits of the result denote hash position |
| 93 | * inside a hash block. The remaining bits denote location of the hash block. |
| 94 | */ |
| 95 | static sector_t verity_position_at_level(struct dm_verity *v, sector_t block, |
| 96 | int level) |
| 97 | { |
| 98 | return block >> (level * v->hash_per_block_bits); |
| 99 | } |
| 100 | |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 101 | /* |
| 102 | * Wrapper for crypto_shash_init, which handles verity salting. |
| 103 | */ |
| 104 | static int verity_hash_init(struct dm_verity *v, struct shash_desc *desc) |
| 105 | { |
| 106 | int r; |
| 107 | |
| 108 | desc->tfm = v->tfm; |
| 109 | desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 110 | |
| 111 | r = crypto_shash_init(desc); |
| 112 | |
| 113 | if (unlikely(r < 0)) { |
| 114 | DMERR("crypto_shash_init failed: %d", r); |
| 115 | return r; |
| 116 | } |
| 117 | |
| 118 | if (likely(v->version >= 1)) { |
| 119 | r = crypto_shash_update(desc, v->salt, v->salt_size); |
| 120 | |
| 121 | if (unlikely(r < 0)) { |
| 122 | DMERR("crypto_shash_update failed: %d", r); |
| 123 | return r; |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | static int verity_hash_update(struct dm_verity *v, struct shash_desc *desc, |
| 131 | const u8 *data, size_t len) |
| 132 | { |
| 133 | int r = crypto_shash_update(desc, data, len); |
| 134 | |
| 135 | if (unlikely(r < 0)) |
| 136 | DMERR("crypto_shash_update failed: %d", r); |
| 137 | |
| 138 | return r; |
| 139 | } |
| 140 | |
| 141 | static int verity_hash_final(struct dm_verity *v, struct shash_desc *desc, |
| 142 | u8 *digest) |
| 143 | { |
| 144 | int r; |
| 145 | |
| 146 | if (unlikely(!v->version)) { |
| 147 | r = crypto_shash_update(desc, v->salt, v->salt_size); |
| 148 | |
| 149 | if (r < 0) { |
| 150 | DMERR("crypto_shash_update failed: %d", r); |
| 151 | return r; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | r = crypto_shash_final(desc, digest); |
| 156 | |
| 157 | if (unlikely(r < 0)) |
| 158 | DMERR("crypto_shash_final failed: %d", r); |
| 159 | |
| 160 | return r; |
| 161 | } |
| 162 | |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 163 | int verity_hash(struct dm_verity *v, struct shash_desc *desc, |
| 164 | const u8 *data, size_t len, u8 *digest) |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 165 | { |
| 166 | int r; |
| 167 | |
| 168 | r = verity_hash_init(v, desc); |
| 169 | if (unlikely(r < 0)) |
| 170 | return r; |
| 171 | |
| 172 | r = verity_hash_update(v, desc, data, len); |
| 173 | if (unlikely(r < 0)) |
| 174 | return r; |
| 175 | |
| 176 | return verity_hash_final(v, desc, digest); |
| 177 | } |
| 178 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 179 | static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, |
| 180 | sector_t *hash_block, unsigned *offset) |
| 181 | { |
| 182 | sector_t position = verity_position_at_level(v, block, level); |
| 183 | unsigned idx; |
| 184 | |
| 185 | *hash_block = v->hash_level_block[level] + (position >> v->hash_per_block_bits); |
| 186 | |
| 187 | if (!offset) |
| 188 | return; |
| 189 | |
| 190 | idx = position & ((1 << v->hash_per_block_bits) - 1); |
| 191 | if (!v->version) |
| 192 | *offset = idx * v->digest_size; |
| 193 | else |
| 194 | *offset = idx << (v->hash_dev_block_bits - v->hash_per_block_bits); |
| 195 | } |
| 196 | |
| 197 | /* |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 198 | * Handle verification errors. |
| 199 | */ |
| 200 | static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, |
| 201 | unsigned long long block) |
| 202 | { |
| 203 | char verity_env[DM_VERITY_ENV_LENGTH]; |
| 204 | char *envp[] = { verity_env, NULL }; |
| 205 | const char *type_str = ""; |
| 206 | struct mapped_device *md = dm_table_get_md(v->ti->table); |
| 207 | |
| 208 | /* Corruption should be visible in device status in all modes */ |
| 209 | v->hash_failed = 1; |
| 210 | |
| 211 | if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) |
| 212 | goto out; |
| 213 | |
| 214 | v->corrupted_errs++; |
| 215 | |
| 216 | switch (type) { |
| 217 | case DM_VERITY_BLOCK_TYPE_DATA: |
| 218 | type_str = "data"; |
| 219 | break; |
| 220 | case DM_VERITY_BLOCK_TYPE_METADATA: |
| 221 | type_str = "metadata"; |
| 222 | break; |
| 223 | default: |
| 224 | BUG(); |
| 225 | } |
| 226 | |
Milan Broz | 7357feb | 2019-06-20 13:00:19 +0200 | [diff] [blame] | 227 | DMERR_LIMIT("%s: %s block %llu is corrupted", v->data_dev->name, |
| 228 | type_str, block); |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 229 | |
| 230 | if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS) |
| 231 | DMERR("%s: reached maximum errors", v->data_dev->name); |
| 232 | |
| 233 | snprintf(verity_env, DM_VERITY_ENV_LENGTH, "%s=%d,%llu", |
| 234 | DM_VERITY_ENV_VAR_NAME, type, block); |
| 235 | |
| 236 | kobject_uevent_env(&disk_to_dev(dm_disk(md))->kobj, KOBJ_CHANGE, envp); |
| 237 | |
| 238 | out: |
| 239 | if (v->mode == DM_VERITY_MODE_LOGGING) |
| 240 | return 0; |
| 241 | |
David Zeuthen | 9dc978d | 2017-01-24 13:17:01 -0500 | [diff] [blame] | 242 | if (v->mode == DM_VERITY_MODE_RESTART) { |
| 243 | #ifdef CONFIG_DM_VERITY_AVB |
| 244 | dm_verity_avb_error_handler(); |
| 245 | #endif |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 246 | kernel_restart("dm-verity device corrupted"); |
David Zeuthen | 9dc978d | 2017-01-24 13:17:01 -0500 | [diff] [blame] | 247 | } |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 248 | |
| 249 | return 1; |
| 250 | } |
| 251 | |
| 252 | /* |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 253 | * Verify hash of a metadata block pertaining to the specified data block |
| 254 | * ("block" argument) at a specified level ("level" argument). |
| 255 | * |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 256 | * On successful return, verity_io_want_digest(v, io) contains the hash value |
| 257 | * for a lower tree level or for the data block (if we're at the lowest level). |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 258 | * |
| 259 | * If "skip_unverified" is true, unverified buffer is skipped and 1 is returned. |
| 260 | * If "skip_unverified" is false, unverified buffer is hashed and verified |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 261 | * against current value of verity_io_want_digest(v, io). |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 262 | */ |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 263 | static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io, |
| 264 | sector_t block, int level, bool skip_unverified, |
| 265 | u8 *want_digest) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 266 | { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 267 | struct dm_buffer *buf; |
| 268 | struct buffer_aux *aux; |
| 269 | u8 *data; |
| 270 | int r; |
| 271 | sector_t hash_block; |
| 272 | unsigned offset; |
| 273 | |
| 274 | verity_hash_at_level(v, block, level, &hash_block, &offset); |
| 275 | |
| 276 | data = dm_bufio_read(v->bufio, hash_block, &buf); |
viresh kumar | fc0a446 | 2015-08-10 11:42:26 +0530 | [diff] [blame] | 277 | if (IS_ERR(data)) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 278 | return PTR_ERR(data); |
| 279 | |
| 280 | aux = dm_bufio_get_aux_data(buf); |
| 281 | |
| 282 | if (!aux->hash_verified) { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 283 | if (skip_unverified) { |
| 284 | r = 1; |
| 285 | goto release_ret_r; |
| 286 | } |
| 287 | |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 288 | r = verity_hash(v, verity_io_hash_desc(v, io), |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 289 | data, 1 << v->hash_dev_block_bits, |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 290 | verity_io_real_digest(v, io)); |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 291 | if (unlikely(r < 0)) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 292 | goto release_ret_r; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 293 | |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 294 | if (likely(memcmp(verity_io_real_digest(v, io), want_digest, |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 295 | v->digest_size) == 0)) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 296 | aux->hash_verified = 1; |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 297 | else if (verity_fec_decode(v, io, |
| 298 | DM_VERITY_BLOCK_TYPE_METADATA, |
| 299 | hash_block, data, NULL) == 0) |
| 300 | aux->hash_verified = 1; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 301 | else if (verity_handle_err(v, |
| 302 | DM_VERITY_BLOCK_TYPE_METADATA, |
| 303 | hash_block)) { |
| 304 | r = -EIO; |
| 305 | goto release_ret_r; |
| 306 | } |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 307 | } |
| 308 | |
| 309 | data += offset; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 310 | memcpy(want_digest, data, v->digest_size); |
| 311 | r = 0; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 312 | |
| 313 | release_ret_r: |
| 314 | dm_bufio_release(buf); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 315 | return r; |
| 316 | } |
| 317 | |
| 318 | /* |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 319 | * Find a hash for a given block, write it to digest and verify the integrity |
| 320 | * of the hash tree if necessary. |
| 321 | */ |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 322 | int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 323 | sector_t block, u8 *digest, bool *is_zero) |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 324 | { |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 325 | int r = 0, i; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 326 | |
| 327 | if (likely(v->levels)) { |
| 328 | /* |
| 329 | * First, we try to get the requested hash for |
| 330 | * the current block. If the hash block itself is |
| 331 | * verified, zero is returned. If it isn't, this |
| 332 | * function returns 1 and we fall back to whole |
| 333 | * chain verification. |
| 334 | */ |
| 335 | r = verity_verify_level(v, io, block, 0, true, digest); |
| 336 | if (likely(r <= 0)) |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 337 | goto out; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 338 | } |
| 339 | |
| 340 | memcpy(digest, v->root_digest, v->digest_size); |
| 341 | |
| 342 | for (i = v->levels - 1; i >= 0; i--) { |
| 343 | r = verity_verify_level(v, io, block, i, false, digest); |
| 344 | if (unlikely(r)) |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 345 | goto out; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 346 | } |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 347 | out: |
| 348 | if (!r && v->zero_digest) |
| 349 | *is_zero = !memcmp(v->zero_digest, digest, v->digest_size); |
| 350 | else |
| 351 | *is_zero = false; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 352 | |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 353 | return r; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 354 | } |
| 355 | |
| 356 | /* |
Sami Tolvanen | bb4d73a | 2015-12-03 16:30:36 -0500 | [diff] [blame] | 357 | * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec |
| 358 | * starting from iter. |
| 359 | */ |
| 360 | int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, |
| 361 | struct bvec_iter *iter, |
| 362 | int (*process)(struct dm_verity *v, |
| 363 | struct dm_verity_io *io, u8 *data, |
| 364 | size_t len)) |
| 365 | { |
| 366 | unsigned todo = 1 << v->data_dev_block_bits; |
Mike Snitzer | 30187e1 | 2016-01-31 13:28:26 -0500 | [diff] [blame] | 367 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
Sami Tolvanen | bb4d73a | 2015-12-03 16:30:36 -0500 | [diff] [blame] | 368 | |
| 369 | do { |
| 370 | int r; |
| 371 | u8 *page; |
| 372 | unsigned len; |
| 373 | struct bio_vec bv = bio_iter_iovec(bio, *iter); |
| 374 | |
| 375 | page = kmap_atomic(bv.bv_page); |
| 376 | len = bv.bv_len; |
| 377 | |
| 378 | if (likely(len >= todo)) |
| 379 | len = todo; |
| 380 | |
| 381 | r = process(v, io, page + bv.bv_offset, len); |
| 382 | kunmap_atomic(page); |
| 383 | |
| 384 | if (r < 0) |
| 385 | return r; |
| 386 | |
| 387 | bio_advance_iter(bio, iter, len); |
| 388 | todo -= len; |
| 389 | } while (todo); |
| 390 | |
| 391 | return 0; |
| 392 | } |
| 393 | |
| 394 | static int verity_bv_hash_update(struct dm_verity *v, struct dm_verity_io *io, |
| 395 | u8 *data, size_t len) |
| 396 | { |
| 397 | return verity_hash_update(v, verity_io_hash_desc(v, io), data, len); |
| 398 | } |
| 399 | |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 400 | static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io, |
| 401 | u8 *data, size_t len) |
| 402 | { |
| 403 | memset(data, 0, len); |
| 404 | return 0; |
| 405 | } |
| 406 | |
Sami Tolvanen | bb4d73a | 2015-12-03 16:30:36 -0500 | [diff] [blame] | 407 | /* |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 408 | * Moves the bio iter one data block forward. |
| 409 | */ |
| 410 | static inline void verity_bv_skip_block(struct dm_verity *v, |
| 411 | struct dm_verity_io *io, |
| 412 | struct bvec_iter *iter) |
| 413 | { |
| 414 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
| 415 | |
| 416 | bio_advance_iter(bio, iter, 1 << v->data_dev_block_bits); |
| 417 | } |
| 418 | |
| 419 | /* |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 420 | * Verify one "dm_verity_io" structure. |
| 421 | */ |
| 422 | static int verity_verify_io(struct dm_verity_io *io) |
| 423 | { |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 424 | bool is_zero; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 425 | struct dm_verity *v = io->v; |
Sami Tolvanen | bb4d73a | 2015-12-03 16:30:36 -0500 | [diff] [blame] | 426 | struct bvec_iter start; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 427 | unsigned b; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 428 | |
| 429 | for (b = 0; b < io->n_blocks; b++) { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 430 | int r; |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 431 | sector_t cur_block = io->block + b; |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 432 | struct shash_desc *desc = verity_io_hash_desc(v, io); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 433 | |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 434 | if (v->validated_blocks && |
| 435 | likely(test_bit(cur_block, v->validated_blocks))) { |
| 436 | verity_bv_skip_block(v, io, &io->iter); |
| 437 | continue; |
| 438 | } |
| 439 | |
| 440 | r = verity_hash_for_block(v, io, cur_block, |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 441 | verity_io_want_digest(v, io), |
| 442 | &is_zero); |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 443 | if (unlikely(r < 0)) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 444 | return r; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 445 | |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 446 | if (is_zero) { |
| 447 | /* |
| 448 | * If we expect a zero block, don't validate, just |
| 449 | * return zeros. |
| 450 | */ |
| 451 | r = verity_for_bv_block(v, io, &io->iter, |
| 452 | verity_bv_zero); |
| 453 | if (unlikely(r < 0)) |
| 454 | return r; |
| 455 | |
| 456 | continue; |
| 457 | } |
| 458 | |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 459 | r = verity_hash_init(v, desc); |
| 460 | if (unlikely(r < 0)) |
| 461 | return r; |
| 462 | |
Sami Tolvanen | bb4d73a | 2015-12-03 16:30:36 -0500 | [diff] [blame] | 463 | start = io->iter; |
| 464 | r = verity_for_bv_block(v, io, &io->iter, verity_bv_hash_update); |
| 465 | if (unlikely(r < 0)) |
| 466 | return r; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 467 | |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 468 | r = verity_hash_final(v, desc, verity_io_real_digest(v, io)); |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 469 | if (unlikely(r < 0)) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 470 | return r; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 471 | |
Sami Tolvanen | ffa3938 | 2015-12-03 16:01:51 -0500 | [diff] [blame] | 472 | if (likely(memcmp(verity_io_real_digest(v, io), |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 473 | verity_io_want_digest(v, io), v->digest_size) == 0)) { |
| 474 | if (v->validated_blocks) |
| 475 | set_bit(cur_block, v->validated_blocks); |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 476 | continue; |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 477 | } |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 478 | else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA, |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 479 | cur_block, NULL, &start) == 0) |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 480 | continue; |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 481 | else if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 482 | cur_block)) |
Sami Tolvanen | 6dbeda3 | 2015-11-05 02:02:31 +0000 | [diff] [blame] | 483 | return -EIO; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 484 | } |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 485 | |
| 486 | return 0; |
| 487 | } |
| 488 | |
| 489 | /* |
| 490 | * End one "io" structure with a given error. |
| 491 | */ |
| 492 | static void verity_finish_io(struct dm_verity_io *io, int error) |
| 493 | { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 494 | struct dm_verity *v = io->v; |
Mike Snitzer | 30187e1 | 2016-01-31 13:28:26 -0500 | [diff] [blame] | 495 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 496 | |
| 497 | bio->bi_end_io = io->orig_bi_end_io; |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 498 | bio->bi_error = error; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 499 | |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 500 | verity_fec_finish_io(io); |
| 501 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 502 | bio_endio(bio); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 503 | } |
| 504 | |
| 505 | static void verity_work(struct work_struct *w) |
| 506 | { |
| 507 | struct dm_verity_io *io = container_of(w, struct dm_verity_io, work); |
| 508 | |
| 509 | verity_finish_io(io, verity_verify_io(io)); |
| 510 | } |
| 511 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 512 | static void verity_end_io(struct bio *bio) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 513 | { |
| 514 | struct dm_verity_io *io = bio->bi_private; |
| 515 | |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 516 | if (bio->bi_error && !verity_fec_is_enabled(io->v)) { |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 517 | verity_finish_io(io, bio->bi_error); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 518 | return; |
| 519 | } |
| 520 | |
| 521 | INIT_WORK(&io->work, verity_work); |
| 522 | queue_work(io->v->verify_wq, &io->work); |
| 523 | } |
| 524 | |
| 525 | /* |
| 526 | * Prefetch buffers for the specified io. |
| 527 | * The root buffer is not prefetched, it is assumed that it will be cached |
| 528 | * all the time. |
| 529 | */ |
Mikulas Patocka | 3b6b781 | 2013-03-20 17:21:25 +0000 | [diff] [blame] | 530 | static void verity_prefetch_io(struct work_struct *work) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 531 | { |
Mikulas Patocka | 3b6b781 | 2013-03-20 17:21:25 +0000 | [diff] [blame] | 532 | struct dm_verity_prefetch_work *pw = |
| 533 | container_of(work, struct dm_verity_prefetch_work, work); |
| 534 | struct dm_verity *v = pw->v; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 535 | int i; |
| 536 | |
| 537 | for (i = v->levels - 2; i >= 0; i--) { |
| 538 | sector_t hash_block_start; |
| 539 | sector_t hash_block_end; |
Mikulas Patocka | 3b6b781 | 2013-03-20 17:21:25 +0000 | [diff] [blame] | 540 | verity_hash_at_level(v, pw->block, i, &hash_block_start, NULL); |
| 541 | verity_hash_at_level(v, pw->block + pw->n_blocks - 1, i, &hash_block_end, NULL); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 542 | if (!i) { |
Mikulas Patocka | fe5fe90 | 2012-10-12 16:59:46 +0100 | [diff] [blame] | 543 | unsigned cluster = ACCESS_ONCE(dm_verity_prefetch_cluster); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 544 | |
| 545 | cluster >>= v->data_dev_block_bits; |
| 546 | if (unlikely(!cluster)) |
| 547 | goto no_prefetch_cluster; |
| 548 | |
| 549 | if (unlikely(cluster & (cluster - 1))) |
Mikulas Patocka | 553d8fe | 2013-07-10 23:41:17 +0100 | [diff] [blame] | 550 | cluster = 1 << __fls(cluster); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 551 | |
| 552 | hash_block_start &= ~(sector_t)(cluster - 1); |
| 553 | hash_block_end |= cluster - 1; |
| 554 | if (unlikely(hash_block_end >= v->hash_blocks)) |
| 555 | hash_block_end = v->hash_blocks - 1; |
| 556 | } |
| 557 | no_prefetch_cluster: |
| 558 | dm_bufio_prefetch(v->bufio, hash_block_start, |
Sami Tolvanen | a8a3bec | 2019-01-10 16:09:03 -0800 | [diff] [blame] | 559 | hash_block_end - hash_block_start + 1); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 560 | } |
Mikulas Patocka | 3b6b781 | 2013-03-20 17:21:25 +0000 | [diff] [blame] | 561 | |
| 562 | kfree(pw); |
| 563 | } |
| 564 | |
| 565 | static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io) |
| 566 | { |
| 567 | struct dm_verity_prefetch_work *pw; |
| 568 | |
| 569 | pw = kmalloc(sizeof(struct dm_verity_prefetch_work), |
| 570 | GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); |
| 571 | |
| 572 | if (!pw) |
| 573 | return; |
| 574 | |
| 575 | INIT_WORK(&pw->work, verity_prefetch_io); |
| 576 | pw->v = v; |
| 577 | pw->block = io->block; |
| 578 | pw->n_blocks = io->n_blocks; |
| 579 | queue_work(v->verify_wq, &pw->work); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 580 | } |
| 581 | |
| 582 | /* |
| 583 | * Bio map function. It allocates dm_verity_io structure and bio vector and |
| 584 | * fills them. Then it issues prefetches and the I/O. |
| 585 | */ |
Badhri Jagan Sridharan | 8bb45a5 | 2015-12-14 20:09:39 -0800 | [diff] [blame] | 586 | int verity_map(struct dm_target *ti, struct bio *bio) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 587 | { |
| 588 | struct dm_verity *v = ti->private; |
| 589 | struct dm_verity_io *io; |
| 590 | |
| 591 | bio->bi_bdev = v->data_dev->bdev; |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 592 | bio->bi_iter.bi_sector = verity_map_sector(v, bio->bi_iter.bi_sector); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 593 | |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 594 | if (((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 595 | ((1 << (v->data_dev_block_bits - SECTOR_SHIFT)) - 1)) { |
| 596 | DMERR_LIMIT("unaligned io"); |
| 597 | return -EIO; |
| 598 | } |
| 599 | |
Kent Overstreet | f73a1c7 | 2012-09-25 15:05:12 -0700 | [diff] [blame] | 600 | if (bio_end_sector(bio) >> |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 601 | (v->data_dev_block_bits - SECTOR_SHIFT) > v->data_blocks) { |
| 602 | DMERR_LIMIT("io out of range"); |
| 603 | return -EIO; |
| 604 | } |
| 605 | |
| 606 | if (bio_data_dir(bio) == WRITE) |
| 607 | return -EIO; |
| 608 | |
Mike Snitzer | 30187e1 | 2016-01-31 13:28:26 -0500 | [diff] [blame] | 609 | io = dm_per_bio_data(bio, ti->per_io_data_size); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 610 | io->v = v; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 611 | io->orig_bi_end_io = bio->bi_end_io; |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 612 | io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT); |
| 613 | io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 614 | |
| 615 | bio->bi_end_io = verity_end_io; |
| 616 | bio->bi_private = io; |
Kent Overstreet | 003b5c5 | 2013-10-11 15:45:43 -0700 | [diff] [blame] | 617 | io->iter = bio->bi_iter; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 618 | |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 619 | verity_fec_init_io(io); |
| 620 | |
Mikulas Patocka | 3b6b781 | 2013-03-20 17:21:25 +0000 | [diff] [blame] | 621 | verity_submit_prefetch(v, io); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 622 | |
| 623 | generic_make_request(bio); |
| 624 | |
| 625 | return DM_MAPIO_SUBMITTED; |
| 626 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 627 | EXPORT_SYMBOL_GPL(verity_map); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 628 | |
| 629 | /* |
| 630 | * Status: V (valid) or C (corruption found) |
| 631 | */ |
Badhri Jagan Sridharan | 8bb45a5 | 2015-12-14 20:09:39 -0800 | [diff] [blame] | 632 | void verity_status(struct dm_target *ti, status_type_t type, |
Mikulas Patocka | fd7c092 | 2013-03-01 22:45:44 +0000 | [diff] [blame] | 633 | unsigned status_flags, char *result, unsigned maxlen) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 634 | { |
| 635 | struct dm_verity *v = ti->private; |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 636 | unsigned args = 0; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 637 | unsigned sz = 0; |
| 638 | unsigned x; |
| 639 | |
| 640 | switch (type) { |
| 641 | case STATUSTYPE_INFO: |
| 642 | DMEMIT("%c", v->hash_failed ? 'C' : 'V'); |
| 643 | break; |
| 644 | case STATUSTYPE_TABLE: |
| 645 | DMEMIT("%u %s %s %u %u %llu %llu %s ", |
| 646 | v->version, |
| 647 | v->data_dev->name, |
| 648 | v->hash_dev->name, |
| 649 | 1 << v->data_dev_block_bits, |
| 650 | 1 << v->hash_dev_block_bits, |
| 651 | (unsigned long long)v->data_blocks, |
| 652 | (unsigned long long)v->hash_start, |
| 653 | v->alg_name |
| 654 | ); |
| 655 | for (x = 0; x < v->digest_size; x++) |
| 656 | DMEMIT("%02x", v->root_digest[x]); |
| 657 | DMEMIT(" "); |
| 658 | if (!v->salt_size) |
| 659 | DMEMIT("-"); |
| 660 | else |
| 661 | for (x = 0; x < v->salt_size; x++) |
| 662 | DMEMIT("%02x", v->salt[x]); |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 663 | if (v->mode != DM_VERITY_MODE_EIO) |
| 664 | args++; |
| 665 | if (verity_fec_is_enabled(v)) |
| 666 | args += DM_VERITY_OPTS_FEC; |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 667 | if (v->zero_digest) |
| 668 | args++; |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 669 | if (v->validated_blocks) |
| 670 | args++; |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 671 | if (!args) |
| 672 | return; |
| 673 | DMEMIT(" %u", args); |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 674 | if (v->mode != DM_VERITY_MODE_EIO) { |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 675 | DMEMIT(" "); |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 676 | switch (v->mode) { |
| 677 | case DM_VERITY_MODE_LOGGING: |
| 678 | DMEMIT(DM_VERITY_OPT_LOGGING); |
| 679 | break; |
| 680 | case DM_VERITY_MODE_RESTART: |
| 681 | DMEMIT(DM_VERITY_OPT_RESTART); |
| 682 | break; |
| 683 | default: |
| 684 | BUG(); |
| 685 | } |
| 686 | } |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 687 | if (v->zero_digest) |
| 688 | DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES); |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 689 | if (v->validated_blocks) |
| 690 | DMEMIT(" " DM_VERITY_OPT_AT_MOST_ONCE); |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 691 | sz = verity_fec_status_table(v, sz, result, maxlen); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 692 | break; |
| 693 | } |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 694 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 695 | EXPORT_SYMBOL_GPL(verity_status); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 696 | |
Badhri Jagan Sridharan | 424861b | 2016-08-09 12:47:37 -0700 | [diff] [blame] | 697 | int verity_prepare_ioctl(struct dm_target *ti, |
Christoph Hellwig | e56f81e | 2015-10-15 14:10:50 +0200 | [diff] [blame] | 698 | struct block_device **bdev, fmode_t *mode) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 699 | { |
| 700 | struct dm_verity *v = ti->private; |
Christoph Hellwig | e56f81e | 2015-10-15 14:10:50 +0200 | [diff] [blame] | 701 | |
| 702 | *bdev = v->data_dev->bdev; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 703 | |
| 704 | if (v->data_start || |
| 705 | ti->len != i_size_read(v->data_dev->bdev->bd_inode) >> SECTOR_SHIFT) |
Christoph Hellwig | e56f81e | 2015-10-15 14:10:50 +0200 | [diff] [blame] | 706 | return 1; |
| 707 | return 0; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 708 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 709 | EXPORT_SYMBOL_GPL(verity_prepare_ioctl); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 710 | |
Badhri Jagan Sridharan | 8bb45a5 | 2015-12-14 20:09:39 -0800 | [diff] [blame] | 711 | int verity_iterate_devices(struct dm_target *ti, |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 712 | iterate_devices_callout_fn fn, void *data) |
| 713 | { |
| 714 | struct dm_verity *v = ti->private; |
| 715 | |
| 716 | return fn(ti, v->data_dev, v->data_start, ti->len, data); |
| 717 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 718 | EXPORT_SYMBOL_GPL(verity_iterate_devices); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 719 | |
Badhri Jagan Sridharan | 8bb45a5 | 2015-12-14 20:09:39 -0800 | [diff] [blame] | 720 | void verity_io_hints(struct dm_target *ti, struct queue_limits *limits) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 721 | { |
| 722 | struct dm_verity *v = ti->private; |
| 723 | |
| 724 | if (limits->logical_block_size < 1 << v->data_dev_block_bits) |
| 725 | limits->logical_block_size = 1 << v->data_dev_block_bits; |
| 726 | |
| 727 | if (limits->physical_block_size < 1 << v->data_dev_block_bits) |
| 728 | limits->physical_block_size = 1 << v->data_dev_block_bits; |
| 729 | |
| 730 | blk_limits_io_min(limits, limits->logical_block_size); |
| 731 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 732 | EXPORT_SYMBOL_GPL(verity_io_hints); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 733 | |
Badhri Jagan Sridharan | 8bb45a5 | 2015-12-14 20:09:39 -0800 | [diff] [blame] | 734 | void verity_dtr(struct dm_target *ti) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 735 | { |
| 736 | struct dm_verity *v = ti->private; |
| 737 | |
| 738 | if (v->verify_wq) |
| 739 | destroy_workqueue(v->verify_wq); |
| 740 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 741 | if (v->bufio) |
| 742 | dm_bufio_client_destroy(v->bufio); |
| 743 | |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 744 | vfree(v->validated_blocks); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 745 | kfree(v->salt); |
| 746 | kfree(v->root_digest); |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 747 | kfree(v->zero_digest); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 748 | |
| 749 | if (v->tfm) |
| 750 | crypto_free_shash(v->tfm); |
| 751 | |
| 752 | kfree(v->alg_name); |
| 753 | |
| 754 | if (v->hash_dev) |
| 755 | dm_put_device(ti, v->hash_dev); |
| 756 | |
| 757 | if (v->data_dev) |
| 758 | dm_put_device(ti, v->data_dev); |
| 759 | |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 760 | verity_fec_dtr(v); |
| 761 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 762 | kfree(v); |
| 763 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 764 | EXPORT_SYMBOL_GPL(verity_dtr); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 765 | |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 766 | static int verity_alloc_most_once(struct dm_verity *v) |
| 767 | { |
| 768 | struct dm_target *ti = v->ti; |
| 769 | |
| 770 | /* the bitset can only handle INT_MAX blocks */ |
| 771 | if (v->data_blocks > INT_MAX) { |
| 772 | ti->error = "device too large to use check_at_most_once"; |
| 773 | return -E2BIG; |
| 774 | } |
| 775 | |
| 776 | v->validated_blocks = vzalloc(BITS_TO_LONGS(v->data_blocks) * |
| 777 | sizeof(unsigned long)); |
| 778 | if (!v->validated_blocks) { |
| 779 | ti->error = "failed to allocate bitset for check_at_most_once"; |
| 780 | return -ENOMEM; |
| 781 | } |
| 782 | |
| 783 | return 0; |
| 784 | } |
| 785 | |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 786 | static int verity_alloc_zero_digest(struct dm_verity *v) |
| 787 | { |
| 788 | int r = -ENOMEM; |
| 789 | struct shash_desc *desc; |
| 790 | u8 *zero_data; |
| 791 | |
| 792 | v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL); |
| 793 | |
| 794 | if (!v->zero_digest) |
| 795 | return r; |
| 796 | |
| 797 | desc = kmalloc(v->shash_descsize, GFP_KERNEL); |
| 798 | |
| 799 | if (!desc) |
| 800 | return r; /* verity_dtr will free zero_digest */ |
| 801 | |
| 802 | zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL); |
| 803 | |
| 804 | if (!zero_data) |
| 805 | goto out; |
| 806 | |
| 807 | r = verity_hash(v, desc, zero_data, 1 << v->data_dev_block_bits, |
| 808 | v->zero_digest); |
| 809 | |
| 810 | out: |
| 811 | kfree(desc); |
| 812 | kfree(zero_data); |
| 813 | |
| 814 | return r; |
| 815 | } |
| 816 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 817 | static int verity_parse_pre_opt_args(struct dm_arg_set *as, |
| 818 | struct dm_verity *v) |
| 819 | { |
| 820 | int r; |
| 821 | unsigned int argc; |
| 822 | const char *arg_name; |
| 823 | struct dm_target *ti = v->ti; |
| 824 | static struct dm_arg _args[] = { |
| 825 | {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"}, |
| 826 | }; |
| 827 | |
| 828 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
| 829 | if (r) |
| 830 | return -EINVAL; |
| 831 | |
| 832 | if (!argc) |
| 833 | return 0; |
| 834 | |
| 835 | do { |
| 836 | arg_name = dm_shift_arg(as); |
| 837 | argc--; |
| 838 | |
| 839 | if (!strcasecmp(arg_name, DM_VERITY_OPT_DEVICE_WAIT)) { |
| 840 | dm_device_wait = 1; |
| 841 | continue; |
| 842 | } |
| 843 | |
| 844 | } while (argc); |
| 845 | |
| 846 | return 0; |
| 847 | } |
| 848 | |
Sami Tolvanen | 753c1fd | 2015-11-05 02:02:32 +0000 | [diff] [blame] | 849 | static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v) |
| 850 | { |
| 851 | int r; |
| 852 | unsigned argc; |
| 853 | struct dm_target *ti = v->ti; |
| 854 | const char *arg_name; |
| 855 | |
| 856 | static struct dm_arg _args[] = { |
| 857 | {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"}, |
| 858 | }; |
| 859 | |
| 860 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
| 861 | if (r) |
| 862 | return -EINVAL; |
| 863 | |
| 864 | if (!argc) |
| 865 | return 0; |
| 866 | |
| 867 | do { |
| 868 | arg_name = dm_shift_arg(as); |
| 869 | argc--; |
| 870 | |
| 871 | if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) { |
| 872 | v->mode = DM_VERITY_MODE_LOGGING; |
| 873 | continue; |
| 874 | |
| 875 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) { |
| 876 | v->mode = DM_VERITY_MODE_RESTART; |
| 877 | continue; |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 878 | |
Sami Tolvanen | 0cc37c2 | 2015-12-03 14:26:31 +0000 | [diff] [blame] | 879 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) { |
| 880 | r = verity_alloc_zero_digest(v); |
| 881 | if (r) { |
| 882 | ti->error = "Cannot allocate zero digest"; |
| 883 | return r; |
| 884 | } |
| 885 | continue; |
| 886 | |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 887 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_AT_MOST_ONCE)) { |
| 888 | r = verity_alloc_most_once(v); |
| 889 | if (r) |
| 890 | return r; |
| 891 | continue; |
| 892 | |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 893 | } else if (verity_is_fec_opt_arg(arg_name)) { |
| 894 | r = verity_fec_parse_opt_args(as, v, &argc, arg_name); |
| 895 | if (r) |
| 896 | return r; |
| 897 | continue; |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 898 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_DEVICE_WAIT)) { |
| 899 | continue; |
Sami Tolvanen | 753c1fd | 2015-11-05 02:02:32 +0000 | [diff] [blame] | 900 | } |
| 901 | |
| 902 | ti->error = "Unrecognized verity feature request"; |
| 903 | return -EINVAL; |
| 904 | } while (argc && !r); |
| 905 | |
| 906 | return r; |
| 907 | } |
| 908 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 909 | /* |
| 910 | * Target parameters: |
| 911 | * <version> The current format is version 1. |
| 912 | * Vsn 0 is compatible with original Chromium OS releases. |
| 913 | * <data device> |
| 914 | * <hash device> |
| 915 | * <data block size> |
| 916 | * <hash block size> |
| 917 | * <the number of data blocks> |
| 918 | * <hash start block> |
| 919 | * <algorithm> |
| 920 | * <digest> |
| 921 | * <salt> Hex string or "-" if no salt. |
| 922 | */ |
Badhri Jagan Sridharan | 8bb45a5 | 2015-12-14 20:09:39 -0800 | [diff] [blame] | 923 | int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 924 | { |
| 925 | struct dm_verity *v; |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 926 | struct dm_arg_set as; |
Sami Tolvanen | 753c1fd | 2015-11-05 02:02:32 +0000 | [diff] [blame] | 927 | unsigned int num; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 928 | unsigned long long num_ll; |
| 929 | int r; |
| 930 | int i; |
| 931 | sector_t hash_position; |
| 932 | char dummy; |
| 933 | |
| 934 | v = kzalloc(sizeof(struct dm_verity), GFP_KERNEL); |
| 935 | if (!v) { |
| 936 | ti->error = "Cannot allocate verity structure"; |
| 937 | return -ENOMEM; |
| 938 | } |
| 939 | ti->private = v; |
| 940 | v->ti = ti; |
| 941 | |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 942 | r = verity_fec_ctr_alloc(v); |
| 943 | if (r) |
| 944 | goto bad; |
| 945 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 946 | if ((dm_table_get_mode(ti->table) & ~FMODE_READ)) { |
| 947 | ti->error = "Device must be readonly"; |
| 948 | r = -EINVAL; |
| 949 | goto bad; |
| 950 | } |
| 951 | |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 952 | if (argc < 10) { |
| 953 | ti->error = "Not enough arguments"; |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 954 | r = -EINVAL; |
| 955 | goto bad; |
| 956 | } |
| 957 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 958 | /* Optional parameters which are parsed pre required args. */ |
| 959 | if ((argc - 10)) { |
| 960 | as.argc = argc - 10; |
| 961 | as.argv = argv + 10; |
| 962 | r = verity_parse_pre_opt_args(&as, v); |
| 963 | if (r < 0) |
| 964 | goto bad; |
| 965 | } |
| 966 | |
Mikulas Patocka | 5d8be84 | 2013-07-10 23:41:17 +0100 | [diff] [blame] | 967 | if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || |
| 968 | num > 1) { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 969 | ti->error = "Invalid version"; |
| 970 | r = -EINVAL; |
| 971 | goto bad; |
| 972 | } |
| 973 | v->version = num; |
| 974 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 975 | retry_dev1: |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 976 | r = dm_get_device(ti, argv[1], FMODE_READ, &v->data_dev); |
| 977 | if (r) { |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 978 | if (r == -ENODEV && dm_device_wait) { |
| 979 | msleep(100); |
| 980 | goto retry_dev1; |
| 981 | } |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 982 | ti->error = "Data device lookup failed"; |
| 983 | goto bad; |
| 984 | } |
| 985 | |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 986 | retry_dev2: |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 987 | r = dm_get_device(ti, argv[2], FMODE_READ, &v->hash_dev); |
| 988 | if (r) { |
Neeraj Upadhyay | 9677b54 | 2018-09-14 09:20:39 +0530 | [diff] [blame] | 989 | if (r == -ENODEV && dm_device_wait) { |
| 990 | msleep(100); |
| 991 | goto retry_dev2; |
| 992 | } |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 993 | ti->error = "Data device lookup failed"; |
| 994 | goto bad; |
| 995 | } |
| 996 | |
| 997 | if (sscanf(argv[3], "%u%c", &num, &dummy) != 1 || |
| 998 | !num || (num & (num - 1)) || |
| 999 | num < bdev_logical_block_size(v->data_dev->bdev) || |
| 1000 | num > PAGE_SIZE) { |
| 1001 | ti->error = "Invalid data device block size"; |
| 1002 | r = -EINVAL; |
| 1003 | goto bad; |
| 1004 | } |
Mikulas Patocka | 553d8fe | 2013-07-10 23:41:17 +0100 | [diff] [blame] | 1005 | v->data_dev_block_bits = __ffs(num); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1006 | |
| 1007 | if (sscanf(argv[4], "%u%c", &num, &dummy) != 1 || |
| 1008 | !num || (num & (num - 1)) || |
| 1009 | num < bdev_logical_block_size(v->hash_dev->bdev) || |
| 1010 | num > INT_MAX) { |
| 1011 | ti->error = "Invalid hash device block size"; |
| 1012 | r = -EINVAL; |
| 1013 | goto bad; |
| 1014 | } |
Mikulas Patocka | 553d8fe | 2013-07-10 23:41:17 +0100 | [diff] [blame] | 1015 | v->hash_dev_block_bits = __ffs(num); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1016 | |
| 1017 | if (sscanf(argv[5], "%llu%c", &num_ll, &dummy) != 1 || |
Mikulas Patocka | 1d55f6b | 2012-09-26 23:45:48 +0100 | [diff] [blame] | 1018 | (sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) |
| 1019 | >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll) { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1020 | ti->error = "Invalid data blocks"; |
| 1021 | r = -EINVAL; |
| 1022 | goto bad; |
| 1023 | } |
| 1024 | v->data_blocks = num_ll; |
| 1025 | |
| 1026 | if (ti->len > (v->data_blocks << (v->data_dev_block_bits - SECTOR_SHIFT))) { |
| 1027 | ti->error = "Data device is too small"; |
| 1028 | r = -EINVAL; |
| 1029 | goto bad; |
| 1030 | } |
| 1031 | |
| 1032 | if (sscanf(argv[6], "%llu%c", &num_ll, &dummy) != 1 || |
Mikulas Patocka | 1d55f6b | 2012-09-26 23:45:48 +0100 | [diff] [blame] | 1033 | (sector_t)(num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) |
| 1034 | >> (v->hash_dev_block_bits - SECTOR_SHIFT) != num_ll) { |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1035 | ti->error = "Invalid hash start"; |
| 1036 | r = -EINVAL; |
| 1037 | goto bad; |
| 1038 | } |
| 1039 | v->hash_start = num_ll; |
| 1040 | |
| 1041 | v->alg_name = kstrdup(argv[7], GFP_KERNEL); |
| 1042 | if (!v->alg_name) { |
| 1043 | ti->error = "Cannot allocate algorithm name"; |
| 1044 | r = -ENOMEM; |
| 1045 | goto bad; |
| 1046 | } |
| 1047 | |
| 1048 | v->tfm = crypto_alloc_shash(v->alg_name, 0, 0); |
| 1049 | if (IS_ERR(v->tfm)) { |
| 1050 | ti->error = "Cannot initialize hash function"; |
| 1051 | r = PTR_ERR(v->tfm); |
| 1052 | v->tfm = NULL; |
| 1053 | goto bad; |
| 1054 | } |
Eric Biggers | 2ca7ab1 | 2018-12-05 20:54:13 -0800 | [diff] [blame] | 1055 | |
| 1056 | /* |
| 1057 | * dm-verity performance can vary greatly depending on which hash |
| 1058 | * algorithm implementation is used. Help people debug performance |
| 1059 | * problems by logging the ->cra_driver_name. |
| 1060 | */ |
| 1061 | DMINFO("%s using implementation \"%s\"", v->alg_name, |
| 1062 | crypto_shash_alg(v->tfm)->base.cra_driver_name); |
| 1063 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1064 | v->digest_size = crypto_shash_digestsize(v->tfm); |
| 1065 | if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) { |
| 1066 | ti->error = "Digest size too big"; |
| 1067 | r = -EINVAL; |
| 1068 | goto bad; |
| 1069 | } |
| 1070 | v->shash_descsize = |
| 1071 | sizeof(struct shash_desc) + crypto_shash_descsize(v->tfm); |
| 1072 | |
| 1073 | v->root_digest = kmalloc(v->digest_size, GFP_KERNEL); |
| 1074 | if (!v->root_digest) { |
| 1075 | ti->error = "Cannot allocate root digest"; |
| 1076 | r = -ENOMEM; |
| 1077 | goto bad; |
| 1078 | } |
| 1079 | if (strlen(argv[8]) != v->digest_size * 2 || |
| 1080 | hex2bin(v->root_digest, argv[8], v->digest_size)) { |
| 1081 | ti->error = "Invalid root digest"; |
| 1082 | r = -EINVAL; |
| 1083 | goto bad; |
| 1084 | } |
| 1085 | |
| 1086 | if (strcmp(argv[9], "-")) { |
| 1087 | v->salt_size = strlen(argv[9]) / 2; |
| 1088 | v->salt = kmalloc(v->salt_size, GFP_KERNEL); |
| 1089 | if (!v->salt) { |
| 1090 | ti->error = "Cannot allocate salt"; |
| 1091 | r = -ENOMEM; |
| 1092 | goto bad; |
| 1093 | } |
| 1094 | if (strlen(argv[9]) != v->salt_size * 2 || |
| 1095 | hex2bin(v->salt, argv[9], v->salt_size)) { |
| 1096 | ti->error = "Invalid salt"; |
| 1097 | r = -EINVAL; |
| 1098 | goto bad; |
| 1099 | } |
| 1100 | } |
| 1101 | |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 1102 | argv += 10; |
| 1103 | argc -= 10; |
| 1104 | |
| 1105 | /* Optional parameters */ |
| 1106 | if (argc) { |
| 1107 | as.argc = argc; |
| 1108 | as.argv = argv; |
| 1109 | |
Sami Tolvanen | 753c1fd | 2015-11-05 02:02:32 +0000 | [diff] [blame] | 1110 | r = verity_parse_opt_args(&as, v); |
| 1111 | if (r < 0) |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 1112 | goto bad; |
Sami Tolvanen | 65ff5b7 | 2015-03-18 15:52:14 +0000 | [diff] [blame] | 1113 | } |
| 1114 | |
Patrik Torstensson | 7143cbf | 2018-04-13 15:34:48 -0700 | [diff] [blame] | 1115 | #ifdef CONFIG_DM_ANDROID_VERITY_AT_MOST_ONCE_DEFAULT_ENABLED |
| 1116 | if (!v->validated_blocks) { |
| 1117 | r = verity_alloc_most_once(v); |
| 1118 | if (r) |
| 1119 | goto bad; |
| 1120 | } |
| 1121 | #endif |
| 1122 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1123 | v->hash_per_block_bits = |
Mikulas Patocka | 553d8fe | 2013-07-10 23:41:17 +0100 | [diff] [blame] | 1124 | __fls((1 << v->hash_dev_block_bits) / v->digest_size); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1125 | |
| 1126 | v->levels = 0; |
| 1127 | if (v->data_blocks) |
| 1128 | while (v->hash_per_block_bits * v->levels < 64 && |
| 1129 | (unsigned long long)(v->data_blocks - 1) >> |
| 1130 | (v->hash_per_block_bits * v->levels)) |
| 1131 | v->levels++; |
| 1132 | |
| 1133 | if (v->levels > DM_VERITY_MAX_LEVELS) { |
| 1134 | ti->error = "Too many tree levels"; |
| 1135 | r = -E2BIG; |
| 1136 | goto bad; |
| 1137 | } |
| 1138 | |
| 1139 | hash_position = v->hash_start; |
| 1140 | for (i = v->levels - 1; i >= 0; i--) { |
| 1141 | sector_t s; |
| 1142 | v->hash_level_block[i] = hash_position; |
Mikulas Patocka | b1bf2de | 2013-07-10 23:41:16 +0100 | [diff] [blame] | 1143 | s = (v->data_blocks + ((sector_t)1 << ((i + 1) * v->hash_per_block_bits)) - 1) |
| 1144 | >> ((i + 1) * v->hash_per_block_bits); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1145 | if (hash_position + s < hash_position) { |
| 1146 | ti->error = "Hash device offset overflow"; |
| 1147 | r = -E2BIG; |
| 1148 | goto bad; |
| 1149 | } |
| 1150 | hash_position += s; |
| 1151 | } |
| 1152 | v->hash_blocks = hash_position; |
| 1153 | |
| 1154 | v->bufio = dm_bufio_client_create(v->hash_dev->bdev, |
| 1155 | 1 << v->hash_dev_block_bits, 1, sizeof(struct buffer_aux), |
| 1156 | dm_bufio_alloc_callback, NULL); |
| 1157 | if (IS_ERR(v->bufio)) { |
| 1158 | ti->error = "Cannot initialize dm-bufio"; |
| 1159 | r = PTR_ERR(v->bufio); |
| 1160 | v->bufio = NULL; |
| 1161 | goto bad; |
| 1162 | } |
| 1163 | |
| 1164 | if (dm_bufio_get_device_size(v->bufio) < v->hash_blocks) { |
| 1165 | ti->error = "Hash device is too small"; |
| 1166 | r = -E2BIG; |
| 1167 | goto bad; |
| 1168 | } |
| 1169 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1170 | /* WQ_UNBOUND greatly improves performance when running on ramdisk */ |
| 1171 | v->verify_wq = alloc_workqueue("kverityd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, num_online_cpus()); |
| 1172 | if (!v->verify_wq) { |
| 1173 | ti->error = "Cannot allocate workqueue"; |
| 1174 | r = -ENOMEM; |
| 1175 | goto bad; |
| 1176 | } |
| 1177 | |
Mike Snitzer | 30187e1 | 2016-01-31 13:28:26 -0500 | [diff] [blame] | 1178 | ti->per_io_data_size = sizeof(struct dm_verity_io) + |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 1179 | v->shash_descsize + v->digest_size * 2; |
| 1180 | |
| 1181 | r = verity_fec_ctr(v); |
| 1182 | if (r) |
| 1183 | goto bad; |
| 1184 | |
Mike Snitzer | 30187e1 | 2016-01-31 13:28:26 -0500 | [diff] [blame] | 1185 | ti->per_io_data_size = roundup(ti->per_io_data_size, |
| 1186 | __alignof__(struct dm_verity_io)); |
Sami Tolvanen | a739ff3 | 2015-12-03 14:26:30 +0000 | [diff] [blame] | 1187 | |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1188 | return 0; |
| 1189 | |
| 1190 | bad: |
| 1191 | verity_dtr(ti); |
| 1192 | |
| 1193 | return r; |
| 1194 | } |
Badhri Jagan Sridharan | 9219457 | 2016-08-23 11:32:37 -0700 | [diff] [blame] | 1195 | EXPORT_SYMBOL_GPL(verity_ctr); |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1196 | |
| 1197 | static struct target_type verity_target = { |
| 1198 | .name = "verity", |
Patrik Torstensson | 142d4b5 | 2018-03-22 18:18:04 -0700 | [diff] [blame] | 1199 | .version = {1, 4, 0}, |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1200 | .module = THIS_MODULE, |
| 1201 | .ctr = verity_ctr, |
| 1202 | .dtr = verity_dtr, |
| 1203 | .map = verity_map, |
| 1204 | .status = verity_status, |
Christoph Hellwig | e56f81e | 2015-10-15 14:10:50 +0200 | [diff] [blame] | 1205 | .prepare_ioctl = verity_prepare_ioctl, |
Mikulas Patocka | a4ffc15 | 2012-03-28 18:43:38 +0100 | [diff] [blame] | 1206 | .iterate_devices = verity_iterate_devices, |
| 1207 | .io_hints = verity_io_hints, |
| 1208 | }; |
| 1209 | |
| 1210 | static int __init dm_verity_init(void) |
| 1211 | { |
| 1212 | int r; |
| 1213 | |
| 1214 | r = dm_register_target(&verity_target); |
| 1215 | if (r < 0) |
| 1216 | DMERR("register failed %d", r); |
| 1217 | |
| 1218 | return r; |
| 1219 | } |
| 1220 | |
| 1221 | static void __exit dm_verity_exit(void) |
| 1222 | { |
| 1223 | dm_unregister_target(&verity_target); |
| 1224 | } |
| 1225 | |
| 1226 | module_init(dm_verity_init); |
| 1227 | module_exit(dm_verity_exit); |
| 1228 | |
| 1229 | MODULE_AUTHOR("Mikulas Patocka <mpatocka@redhat.com>"); |
| 1230 | MODULE_AUTHOR("Mandeep Baines <msb@chromium.org>"); |
| 1231 | MODULE_AUTHOR("Will Drewry <wad@chromium.org>"); |
| 1232 | MODULE_DESCRIPTION(DM_NAME " target for transparent disk integrity checking"); |
| 1233 | MODULE_LICENSE("GPL"); |