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Commit | Line | Data |
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a4ffc152 MP |
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 | ||
ffa39380 | 17 | #include "dm-verity.h" |
a739ff3f | 18 | #include "dm-verity-fec.h" |
a4ffc152 MP |
19 | |
20 | #include <linux/module.h> | |
65ff5b7d | 21 | #include <linux/reboot.h> |
a4ffc152 MP |
22 | |
23 | #define DM_MSG_PREFIX "verity" | |
24 | ||
65ff5b7d ST |
25 | #define DM_VERITY_ENV_LENGTH 42 |
26 | #define DM_VERITY_ENV_VAR_NAME "DM_VERITY_ERR_BLOCK_NR" | |
27 | ||
a4ffc152 MP |
28 | #define DM_VERITY_DEFAULT_PREFETCH_SIZE 262144 |
29 | ||
65ff5b7d ST |
30 | #define DM_VERITY_MAX_CORRUPTED_ERRS 100 |
31 | ||
32 | #define DM_VERITY_OPT_LOGGING "ignore_corruption" | |
33 | #define DM_VERITY_OPT_RESTART "restart_on_corruption" | |
0cc37c2d | 34 | #define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks" |
843f38d3 | 35 | #define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once" |
a4ffc152 | 36 | |
0cc37c2d | 37 | #define DM_VERITY_OPTS_MAX (2 + DM_VERITY_OPTS_FEC) |
753c1fd0 | 38 | |
a4ffc152 MP |
39 | static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE; |
40 | ||
41 | module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR); | |
42 | ||
3b6b7813 MP |
43 | struct dm_verity_prefetch_work { |
44 | struct work_struct work; | |
45 | struct dm_verity *v; | |
46 | sector_t block; | |
47 | unsigned n_blocks; | |
48 | }; | |
49 | ||
a4ffc152 MP |
50 | /* |
51 | * Auxiliary structure appended to each dm-bufio buffer. If the value | |
52 | * hash_verified is nonzero, hash of the block has been verified. | |
53 | * | |
54 | * The variable hash_verified is set to 0 when allocating the buffer, then | |
55 | * it can be changed to 1 and it is never reset to 0 again. | |
56 | * | |
57 | * There is no lock around this value, a race condition can at worst cause | |
58 | * that multiple processes verify the hash of the same buffer simultaneously | |
59 | * and write 1 to hash_verified simultaneously. | |
60 | * This condition is harmless, so we don't need locking. | |
61 | */ | |
62 | struct buffer_aux { | |
63 | int hash_verified; | |
64 | }; | |
65 | ||
66 | /* | |
67 | * Initialize struct buffer_aux for a freshly created buffer. | |
68 | */ | |
69 | static void dm_bufio_alloc_callback(struct dm_buffer *buf) | |
70 | { | |
71 | struct buffer_aux *aux = dm_bufio_get_aux_data(buf); | |
72 | ||
73 | aux->hash_verified = 0; | |
74 | } | |
75 | ||
76 | /* | |
77 | * Translate input sector number to the sector number on the target device. | |
78 | */ | |
79 | static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector) | |
80 | { | |
81 | return v->data_start + dm_target_offset(v->ti, bi_sector); | |
82 | } | |
83 | ||
84 | /* | |
85 | * Return hash position of a specified block at a specified tree level | |
86 | * (0 is the lowest level). | |
87 | * The lowest "hash_per_block_bits"-bits of the result denote hash position | |
88 | * inside a hash block. The remaining bits denote location of the hash block. | |
89 | */ | |
90 | static sector_t verity_position_at_level(struct dm_verity *v, sector_t block, | |
91 | int level) | |
92 | { | |
93 | return block >> (level * v->hash_per_block_bits); | |
94 | } | |
95 | ||
d1ac3ff0 GBY |
96 | static int verity_hash_update(struct dm_verity *v, struct ahash_request *req, |
97 | const u8 *data, size_t len, | |
12f1ffc4 | 98 | struct crypto_wait *wait) |
6dbeda34 | 99 | { |
d1ac3ff0 | 100 | struct scatterlist sg; |
6dbeda34 | 101 | |
d1ac3ff0 GBY |
102 | sg_init_one(&sg, data, len); |
103 | ahash_request_set_crypt(req, &sg, NULL, len); | |
104 | ||
12f1ffc4 | 105 | return crypto_wait_req(crypto_ahash_update(req), wait); |
d1ac3ff0 GBY |
106 | } |
107 | ||
108 | /* | |
109 | * Wrapper for crypto_ahash_init, which handles verity salting. | |
110 | */ | |
111 | static int verity_hash_init(struct dm_verity *v, struct ahash_request *req, | |
12f1ffc4 | 112 | struct crypto_wait *wait) |
d1ac3ff0 GBY |
113 | { |
114 | int r; | |
115 | ||
116 | ahash_request_set_tfm(req, v->tfm); | |
117 | ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | | |
118 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
12f1ffc4 GBY |
119 | crypto_req_done, (void *)wait); |
120 | crypto_init_wait(wait); | |
d1ac3ff0 | 121 | |
12f1ffc4 | 122 | r = crypto_wait_req(crypto_ahash_init(req), wait); |
d1ac3ff0 GBY |
123 | |
124 | if (unlikely(r < 0)) { | |
125 | DMERR("crypto_ahash_init failed: %d", r); | |
126 | return r; | |
127 | } | |
128 | ||
f52236e0 | 129 | if (likely(v->salt_size && (v->version >= 1))) |
12f1ffc4 | 130 | r = verity_hash_update(v, req, v->salt, v->salt_size, wait); |
6dbeda34 ST |
131 | |
132 | return r; | |
133 | } | |
134 | ||
d1ac3ff0 | 135 | static int verity_hash_final(struct dm_verity *v, struct ahash_request *req, |
12f1ffc4 | 136 | u8 *digest, struct crypto_wait *wait) |
6dbeda34 ST |
137 | { |
138 | int r; | |
139 | ||
f52236e0 | 140 | if (unlikely(v->salt_size && (!v->version))) { |
12f1ffc4 | 141 | r = verity_hash_update(v, req, v->salt, v->salt_size, wait); |
6dbeda34 ST |
142 | |
143 | if (r < 0) { | |
d1ac3ff0 GBY |
144 | DMERR("verity_hash_final failed updating salt: %d", r); |
145 | goto out; | |
6dbeda34 ST |
146 | } |
147 | } | |
148 | ||
d1ac3ff0 | 149 | ahash_request_set_crypt(req, NULL, digest, 0); |
12f1ffc4 | 150 | r = crypto_wait_req(crypto_ahash_final(req), wait); |
d1ac3ff0 | 151 | out: |
6dbeda34 ST |
152 | return r; |
153 | } | |
154 | ||
d1ac3ff0 | 155 | int verity_hash(struct dm_verity *v, struct ahash_request *req, |
ffa39380 | 156 | const u8 *data, size_t len, u8 *digest) |
6dbeda34 ST |
157 | { |
158 | int r; | |
12f1ffc4 | 159 | struct crypto_wait wait; |
6dbeda34 | 160 | |
12f1ffc4 | 161 | r = verity_hash_init(v, req, &wait); |
6dbeda34 | 162 | if (unlikely(r < 0)) |
d1ac3ff0 | 163 | goto out; |
6dbeda34 | 164 | |
12f1ffc4 | 165 | r = verity_hash_update(v, req, data, len, &wait); |
6dbeda34 | 166 | if (unlikely(r < 0)) |
d1ac3ff0 GBY |
167 | goto out; |
168 | ||
12f1ffc4 | 169 | r = verity_hash_final(v, req, digest, &wait); |
6dbeda34 | 170 | |
d1ac3ff0 GBY |
171 | out: |
172 | return r; | |
6dbeda34 ST |
173 | } |
174 | ||
a4ffc152 MP |
175 | static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, |
176 | sector_t *hash_block, unsigned *offset) | |
177 | { | |
178 | sector_t position = verity_position_at_level(v, block, level); | |
179 | unsigned idx; | |
180 | ||
181 | *hash_block = v->hash_level_block[level] + (position >> v->hash_per_block_bits); | |
182 | ||
183 | if (!offset) | |
184 | return; | |
185 | ||
186 | idx = position & ((1 << v->hash_per_block_bits) - 1); | |
187 | if (!v->version) | |
188 | *offset = idx * v->digest_size; | |
189 | else | |
190 | *offset = idx << (v->hash_dev_block_bits - v->hash_per_block_bits); | |
191 | } | |
192 | ||
65ff5b7d ST |
193 | /* |
194 | * Handle verification errors. | |
195 | */ | |
196 | static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, | |
197 | unsigned long long block) | |
198 | { | |
199 | char verity_env[DM_VERITY_ENV_LENGTH]; | |
200 | char *envp[] = { verity_env, NULL }; | |
201 | const char *type_str = ""; | |
202 | struct mapped_device *md = dm_table_get_md(v->ti->table); | |
203 | ||
204 | /* Corruption should be visible in device status in all modes */ | |
205 | v->hash_failed = 1; | |
206 | ||
207 | if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) | |
208 | goto out; | |
209 | ||
210 | v->corrupted_errs++; | |
211 | ||
212 | switch (type) { | |
213 | case DM_VERITY_BLOCK_TYPE_DATA: | |
214 | type_str = "data"; | |
215 | break; | |
216 | case DM_VERITY_BLOCK_TYPE_METADATA: | |
217 | type_str = "metadata"; | |
218 | break; | |
219 | default: | |
220 | BUG(); | |
221 | } | |
222 | ||
223 | DMERR("%s: %s block %llu is corrupted", v->data_dev->name, type_str, | |
224 | block); | |
225 | ||
226 | if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS) | |
227 | DMERR("%s: reached maximum errors", v->data_dev->name); | |
228 | ||
229 | snprintf(verity_env, DM_VERITY_ENV_LENGTH, "%s=%d,%llu", | |
230 | DM_VERITY_ENV_VAR_NAME, type, block); | |
231 | ||
232 | kobject_uevent_env(&disk_to_dev(dm_disk(md))->kobj, KOBJ_CHANGE, envp); | |
233 | ||
234 | out: | |
235 | if (v->mode == DM_VERITY_MODE_LOGGING) | |
236 | return 0; | |
237 | ||
238 | if (v->mode == DM_VERITY_MODE_RESTART) | |
239 | kernel_restart("dm-verity device corrupted"); | |
240 | ||
241 | return 1; | |
242 | } | |
243 | ||
a4ffc152 MP |
244 | /* |
245 | * Verify hash of a metadata block pertaining to the specified data block | |
246 | * ("block" argument) at a specified level ("level" argument). | |
247 | * | |
ffa39380 ST |
248 | * On successful return, verity_io_want_digest(v, io) contains the hash value |
249 | * for a lower tree level or for the data block (if we're at the lowest level). | |
a4ffc152 MP |
250 | * |
251 | * If "skip_unverified" is true, unverified buffer is skipped and 1 is returned. | |
252 | * If "skip_unverified" is false, unverified buffer is hashed and verified | |
ffa39380 | 253 | * against current value of verity_io_want_digest(v, io). |
a4ffc152 | 254 | */ |
6dbeda34 ST |
255 | static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io, |
256 | sector_t block, int level, bool skip_unverified, | |
257 | u8 *want_digest) | |
a4ffc152 | 258 | { |
a4ffc152 MP |
259 | struct dm_buffer *buf; |
260 | struct buffer_aux *aux; | |
261 | u8 *data; | |
262 | int r; | |
263 | sector_t hash_block; | |
264 | unsigned offset; | |
265 | ||
266 | verity_hash_at_level(v, block, level, &hash_block, &offset); | |
267 | ||
268 | data = dm_bufio_read(v->bufio, hash_block, &buf); | |
fc0a4461 | 269 | if (IS_ERR(data)) |
a4ffc152 MP |
270 | return PTR_ERR(data); |
271 | ||
272 | aux = dm_bufio_get_aux_data(buf); | |
273 | ||
274 | if (!aux->hash_verified) { | |
a4ffc152 MP |
275 | if (skip_unverified) { |
276 | r = 1; | |
277 | goto release_ret_r; | |
278 | } | |
279 | ||
d1ac3ff0 | 280 | r = verity_hash(v, verity_io_hash_req(v, io), |
6dbeda34 | 281 | data, 1 << v->hash_dev_block_bits, |
ffa39380 | 282 | verity_io_real_digest(v, io)); |
6dbeda34 | 283 | if (unlikely(r < 0)) |
a4ffc152 | 284 | goto release_ret_r; |
a4ffc152 | 285 | |
ffa39380 | 286 | if (likely(memcmp(verity_io_real_digest(v, io), want_digest, |
6dbeda34 ST |
287 | v->digest_size) == 0)) |
288 | aux->hash_verified = 1; | |
a739ff3f ST |
289 | else if (verity_fec_decode(v, io, |
290 | DM_VERITY_BLOCK_TYPE_METADATA, | |
291 | hash_block, data, NULL) == 0) | |
292 | aux->hash_verified = 1; | |
6dbeda34 ST |
293 | else if (verity_handle_err(v, |
294 | DM_VERITY_BLOCK_TYPE_METADATA, | |
295 | hash_block)) { | |
296 | r = -EIO; | |
a4ffc152 MP |
297 | goto release_ret_r; |
298 | } | |
a4ffc152 MP |
299 | } |
300 | ||
301 | data += offset; | |
6dbeda34 ST |
302 | memcpy(want_digest, data, v->digest_size); |
303 | r = 0; | |
a4ffc152 MP |
304 | |
305 | release_ret_r: | |
306 | dm_bufio_release(buf); | |
a4ffc152 MP |
307 | return r; |
308 | } | |
309 | ||
6dbeda34 ST |
310 | /* |
311 | * Find a hash for a given block, write it to digest and verify the integrity | |
312 | * of the hash tree if necessary. | |
313 | */ | |
ffa39380 | 314 | int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, |
0cc37c2d | 315 | sector_t block, u8 *digest, bool *is_zero) |
6dbeda34 | 316 | { |
0cc37c2d | 317 | int r = 0, i; |
6dbeda34 ST |
318 | |
319 | if (likely(v->levels)) { | |
320 | /* | |
321 | * First, we try to get the requested hash for | |
322 | * the current block. If the hash block itself is | |
323 | * verified, zero is returned. If it isn't, this | |
324 | * function returns 1 and we fall back to whole | |
325 | * chain verification. | |
326 | */ | |
327 | r = verity_verify_level(v, io, block, 0, true, digest); | |
328 | if (likely(r <= 0)) | |
0cc37c2d | 329 | goto out; |
6dbeda34 ST |
330 | } |
331 | ||
332 | memcpy(digest, v->root_digest, v->digest_size); | |
333 | ||
334 | for (i = v->levels - 1; i >= 0; i--) { | |
335 | r = verity_verify_level(v, io, block, i, false, digest); | |
336 | if (unlikely(r)) | |
0cc37c2d | 337 | goto out; |
6dbeda34 | 338 | } |
0cc37c2d ST |
339 | out: |
340 | if (!r && v->zero_digest) | |
341 | *is_zero = !memcmp(v->zero_digest, digest, v->digest_size); | |
342 | else | |
343 | *is_zero = false; | |
6dbeda34 | 344 | |
0cc37c2d | 345 | return r; |
6dbeda34 ST |
346 | } |
347 | ||
d1ac3ff0 GBY |
348 | /* |
349 | * Calculates the digest for the given bio | |
350 | */ | |
d4b1aaf5 | 351 | static int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io, |
352 | struct bvec_iter *iter, struct crypto_wait *wait) | |
d1ac3ff0 GBY |
353 | { |
354 | unsigned int todo = 1 << v->data_dev_block_bits; | |
355 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
356 | struct scatterlist sg; | |
357 | struct ahash_request *req = verity_io_hash_req(v, io); | |
358 | ||
359 | do { | |
360 | int r; | |
361 | unsigned int len; | |
362 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
363 | ||
364 | sg_init_table(&sg, 1); | |
365 | ||
366 | len = bv.bv_len; | |
367 | ||
368 | if (likely(len >= todo)) | |
369 | len = todo; | |
370 | /* | |
371 | * Operating on a single page at a time looks suboptimal | |
372 | * until you consider the typical block size is 4,096B. | |
373 | * Going through this loops twice should be very rare. | |
374 | */ | |
375 | sg_set_page(&sg, bv.bv_page, len, bv.bv_offset); | |
376 | ahash_request_set_crypt(req, &sg, NULL, len); | |
12f1ffc4 | 377 | r = crypto_wait_req(crypto_ahash_update(req), wait); |
d1ac3ff0 GBY |
378 | |
379 | if (unlikely(r < 0)) { | |
380 | DMERR("verity_for_io_block crypto op failed: %d", r); | |
381 | return r; | |
382 | } | |
383 | ||
384 | bio_advance_iter(bio, iter, len); | |
385 | todo -= len; | |
386 | } while (todo); | |
387 | ||
388 | return 0; | |
389 | } | |
390 | ||
bb4d73ac ST |
391 | /* |
392 | * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec | |
393 | * starting from iter. | |
394 | */ | |
395 | int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, | |
396 | struct bvec_iter *iter, | |
397 | int (*process)(struct dm_verity *v, | |
398 | struct dm_verity_io *io, u8 *data, | |
399 | size_t len)) | |
400 | { | |
401 | unsigned todo = 1 << v->data_dev_block_bits; | |
30187e1d | 402 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
bb4d73ac ST |
403 | |
404 | do { | |
405 | int r; | |
406 | u8 *page; | |
407 | unsigned len; | |
408 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
409 | ||
410 | page = kmap_atomic(bv.bv_page); | |
411 | len = bv.bv_len; | |
412 | ||
413 | if (likely(len >= todo)) | |
414 | len = todo; | |
415 | ||
416 | r = process(v, io, page + bv.bv_offset, len); | |
417 | kunmap_atomic(page); | |
418 | ||
419 | if (r < 0) | |
420 | return r; | |
421 | ||
422 | bio_advance_iter(bio, iter, len); | |
423 | todo -= len; | |
424 | } while (todo); | |
425 | ||
426 | return 0; | |
427 | } | |
428 | ||
0cc37c2d ST |
429 | static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io, |
430 | u8 *data, size_t len) | |
431 | { | |
432 | memset(data, 0, len); | |
433 | return 0; | |
434 | } | |
435 | ||
843f38d3 PT |
436 | /* |
437 | * Moves the bio iter one data block forward. | |
438 | */ | |
439 | static inline void verity_bv_skip_block(struct dm_verity *v, | |
440 | struct dm_verity_io *io, | |
441 | struct bvec_iter *iter) | |
442 | { | |
443 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
444 | ||
445 | bio_advance_iter(bio, iter, 1 << v->data_dev_block_bits); | |
446 | } | |
447 | ||
a4ffc152 MP |
448 | /* |
449 | * Verify one "dm_verity_io" structure. | |
450 | */ | |
451 | static int verity_verify_io(struct dm_verity_io *io) | |
452 | { | |
0cc37c2d | 453 | bool is_zero; |
a4ffc152 | 454 | struct dm_verity *v = io->v; |
bb4d73ac | 455 | struct bvec_iter start; |
a4ffc152 | 456 | unsigned b; |
12f1ffc4 | 457 | struct crypto_wait wait; |
a4ffc152 MP |
458 | |
459 | for (b = 0; b < io->n_blocks; b++) { | |
a4ffc152 | 460 | int r; |
843f38d3 | 461 | sector_t cur_block = io->block + b; |
d1ac3ff0 | 462 | struct ahash_request *req = verity_io_hash_req(v, io); |
a4ffc152 | 463 | |
843f38d3 PT |
464 | if (v->validated_blocks && |
465 | likely(test_bit(cur_block, v->validated_blocks))) { | |
466 | verity_bv_skip_block(v, io, &io->iter); | |
467 | continue; | |
468 | } | |
469 | ||
470 | r = verity_hash_for_block(v, io, cur_block, | |
0cc37c2d ST |
471 | verity_io_want_digest(v, io), |
472 | &is_zero); | |
6dbeda34 ST |
473 | if (unlikely(r < 0)) |
474 | return r; | |
a4ffc152 | 475 | |
0cc37c2d ST |
476 | if (is_zero) { |
477 | /* | |
478 | * If we expect a zero block, don't validate, just | |
479 | * return zeros. | |
480 | */ | |
481 | r = verity_for_bv_block(v, io, &io->iter, | |
482 | verity_bv_zero); | |
483 | if (unlikely(r < 0)) | |
484 | return r; | |
485 | ||
486 | continue; | |
487 | } | |
488 | ||
12f1ffc4 | 489 | r = verity_hash_init(v, req, &wait); |
6dbeda34 | 490 | if (unlikely(r < 0)) |
a4ffc152 | 491 | return r; |
a4ffc152 | 492 | |
bb4d73ac | 493 | start = io->iter; |
12f1ffc4 | 494 | r = verity_for_io_block(v, io, &io->iter, &wait); |
bb4d73ac ST |
495 | if (unlikely(r < 0)) |
496 | return r; | |
a4ffc152 | 497 | |
d1ac3ff0 | 498 | r = verity_hash_final(v, req, verity_io_real_digest(v, io), |
12f1ffc4 | 499 | &wait); |
6dbeda34 | 500 | if (unlikely(r < 0)) |
a4ffc152 | 501 | return r; |
6dbeda34 | 502 | |
ffa39380 | 503 | if (likely(memcmp(verity_io_real_digest(v, io), |
843f38d3 PT |
504 | verity_io_want_digest(v, io), v->digest_size) == 0)) { |
505 | if (v->validated_blocks) | |
506 | set_bit(cur_block, v->validated_blocks); | |
6dbeda34 | 507 | continue; |
843f38d3 | 508 | } |
a739ff3f | 509 | else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA, |
843f38d3 | 510 | cur_block, NULL, &start) == 0) |
a739ff3f | 511 | continue; |
6dbeda34 | 512 | else if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, |
843f38d3 | 513 | cur_block)) |
6dbeda34 | 514 | return -EIO; |
a4ffc152 | 515 | } |
a4ffc152 MP |
516 | |
517 | return 0; | |
518 | } | |
519 | ||
520 | /* | |
521 | * End one "io" structure with a given error. | |
522 | */ | |
4e4cbee9 | 523 | static void verity_finish_io(struct dm_verity_io *io, blk_status_t status) |
a4ffc152 | 524 | { |
a4ffc152 | 525 | struct dm_verity *v = io->v; |
30187e1d | 526 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
a4ffc152 MP |
527 | |
528 | bio->bi_end_io = io->orig_bi_end_io; | |
4e4cbee9 | 529 | bio->bi_status = status; |
a4ffc152 | 530 | |
a739ff3f ST |
531 | verity_fec_finish_io(io); |
532 | ||
4246a0b6 | 533 | bio_endio(bio); |
a4ffc152 MP |
534 | } |
535 | ||
536 | static void verity_work(struct work_struct *w) | |
537 | { | |
538 | struct dm_verity_io *io = container_of(w, struct dm_verity_io, work); | |
539 | ||
4e4cbee9 | 540 | verity_finish_io(io, errno_to_blk_status(verity_verify_io(io))); |
a4ffc152 MP |
541 | } |
542 | ||
4246a0b6 | 543 | static void verity_end_io(struct bio *bio) |
a4ffc152 MP |
544 | { |
545 | struct dm_verity_io *io = bio->bi_private; | |
546 | ||
4e4cbee9 CH |
547 | if (bio->bi_status && !verity_fec_is_enabled(io->v)) { |
548 | verity_finish_io(io, bio->bi_status); | |
a4ffc152 MP |
549 | return; |
550 | } | |
551 | ||
552 | INIT_WORK(&io->work, verity_work); | |
553 | queue_work(io->v->verify_wq, &io->work); | |
554 | } | |
555 | ||
556 | /* | |
557 | * Prefetch buffers for the specified io. | |
558 | * The root buffer is not prefetched, it is assumed that it will be cached | |
559 | * all the time. | |
560 | */ | |
3b6b7813 | 561 | static void verity_prefetch_io(struct work_struct *work) |
a4ffc152 | 562 | { |
3b6b7813 MP |
563 | struct dm_verity_prefetch_work *pw = |
564 | container_of(work, struct dm_verity_prefetch_work, work); | |
565 | struct dm_verity *v = pw->v; | |
a4ffc152 MP |
566 | int i; |
567 | ||
568 | for (i = v->levels - 2; i >= 0; i--) { | |
569 | sector_t hash_block_start; | |
570 | sector_t hash_block_end; | |
3b6b7813 MP |
571 | verity_hash_at_level(v, pw->block, i, &hash_block_start, NULL); |
572 | verity_hash_at_level(v, pw->block + pw->n_blocks - 1, i, &hash_block_end, NULL); | |
a4ffc152 | 573 | if (!i) { |
6aa7de05 | 574 | unsigned cluster = READ_ONCE(dm_verity_prefetch_cluster); |
a4ffc152 MP |
575 | |
576 | cluster >>= v->data_dev_block_bits; | |
577 | if (unlikely(!cluster)) | |
578 | goto no_prefetch_cluster; | |
579 | ||
580 | if (unlikely(cluster & (cluster - 1))) | |
553d8fe0 | 581 | cluster = 1 << __fls(cluster); |
a4ffc152 MP |
582 | |
583 | hash_block_start &= ~(sector_t)(cluster - 1); | |
584 | hash_block_end |= cluster - 1; | |
585 | if (unlikely(hash_block_end >= v->hash_blocks)) | |
586 | hash_block_end = v->hash_blocks - 1; | |
587 | } | |
588 | no_prefetch_cluster: | |
589 | dm_bufio_prefetch(v->bufio, hash_block_start, | |
590 | hash_block_end - hash_block_start + 1); | |
591 | } | |
3b6b7813 MP |
592 | |
593 | kfree(pw); | |
594 | } | |
595 | ||
596 | static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io) | |
597 | { | |
598 | struct dm_verity_prefetch_work *pw; | |
599 | ||
600 | pw = kmalloc(sizeof(struct dm_verity_prefetch_work), | |
601 | GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); | |
602 | ||
603 | if (!pw) | |
604 | return; | |
605 | ||
606 | INIT_WORK(&pw->work, verity_prefetch_io); | |
607 | pw->v = v; | |
608 | pw->block = io->block; | |
609 | pw->n_blocks = io->n_blocks; | |
610 | queue_work(v->verify_wq, &pw->work); | |
a4ffc152 MP |
611 | } |
612 | ||
613 | /* | |
614 | * Bio map function. It allocates dm_verity_io structure and bio vector and | |
615 | * fills them. Then it issues prefetches and the I/O. | |
616 | */ | |
7de3ee57 | 617 | static int verity_map(struct dm_target *ti, struct bio *bio) |
a4ffc152 MP |
618 | { |
619 | struct dm_verity *v = ti->private; | |
620 | struct dm_verity_io *io; | |
621 | ||
74d46992 | 622 | bio_set_dev(bio, v->data_dev->bdev); |
4f024f37 | 623 | bio->bi_iter.bi_sector = verity_map_sector(v, bio->bi_iter.bi_sector); |
a4ffc152 | 624 | |
4f024f37 | 625 | if (((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
a4ffc152 MP |
626 | ((1 << (v->data_dev_block_bits - SECTOR_SHIFT)) - 1)) { |
627 | DMERR_LIMIT("unaligned io"); | |
846785e6 | 628 | return DM_MAPIO_KILL; |
a4ffc152 MP |
629 | } |
630 | ||
f73a1c7d | 631 | if (bio_end_sector(bio) >> |
a4ffc152 MP |
632 | (v->data_dev_block_bits - SECTOR_SHIFT) > v->data_blocks) { |
633 | DMERR_LIMIT("io out of range"); | |
846785e6 | 634 | return DM_MAPIO_KILL; |
a4ffc152 MP |
635 | } |
636 | ||
637 | if (bio_data_dir(bio) == WRITE) | |
846785e6 | 638 | return DM_MAPIO_KILL; |
a4ffc152 | 639 | |
30187e1d | 640 | io = dm_per_bio_data(bio, ti->per_io_data_size); |
a4ffc152 | 641 | io->v = v; |
a4ffc152 | 642 | io->orig_bi_end_io = bio->bi_end_io; |
4f024f37 KO |
643 | io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT); |
644 | io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits; | |
a4ffc152 MP |
645 | |
646 | bio->bi_end_io = verity_end_io; | |
647 | bio->bi_private = io; | |
003b5c57 | 648 | io->iter = bio->bi_iter; |
a4ffc152 | 649 | |
a739ff3f ST |
650 | verity_fec_init_io(io); |
651 | ||
3b6b7813 | 652 | verity_submit_prefetch(v, io); |
a4ffc152 MP |
653 | |
654 | generic_make_request(bio); | |
655 | ||
656 | return DM_MAPIO_SUBMITTED; | |
657 | } | |
658 | ||
659 | /* | |
660 | * Status: V (valid) or C (corruption found) | |
661 | */ | |
fd7c092e MP |
662 | static void verity_status(struct dm_target *ti, status_type_t type, |
663 | unsigned status_flags, char *result, unsigned maxlen) | |
a4ffc152 MP |
664 | { |
665 | struct dm_verity *v = ti->private; | |
a739ff3f | 666 | unsigned args = 0; |
a4ffc152 MP |
667 | unsigned sz = 0; |
668 | unsigned x; | |
669 | ||
670 | switch (type) { | |
671 | case STATUSTYPE_INFO: | |
672 | DMEMIT("%c", v->hash_failed ? 'C' : 'V'); | |
673 | break; | |
674 | case STATUSTYPE_TABLE: | |
675 | DMEMIT("%u %s %s %u %u %llu %llu %s ", | |
676 | v->version, | |
677 | v->data_dev->name, | |
678 | v->hash_dev->name, | |
679 | 1 << v->data_dev_block_bits, | |
680 | 1 << v->hash_dev_block_bits, | |
681 | (unsigned long long)v->data_blocks, | |
682 | (unsigned long long)v->hash_start, | |
683 | v->alg_name | |
684 | ); | |
685 | for (x = 0; x < v->digest_size; x++) | |
686 | DMEMIT("%02x", v->root_digest[x]); | |
687 | DMEMIT(" "); | |
688 | if (!v->salt_size) | |
689 | DMEMIT("-"); | |
690 | else | |
691 | for (x = 0; x < v->salt_size; x++) | |
692 | DMEMIT("%02x", v->salt[x]); | |
a739ff3f ST |
693 | if (v->mode != DM_VERITY_MODE_EIO) |
694 | args++; | |
695 | if (verity_fec_is_enabled(v)) | |
696 | args += DM_VERITY_OPTS_FEC; | |
0cc37c2d ST |
697 | if (v->zero_digest) |
698 | args++; | |
843f38d3 PT |
699 | if (v->validated_blocks) |
700 | args++; | |
a739ff3f ST |
701 | if (!args) |
702 | return; | |
703 | DMEMIT(" %u", args); | |
65ff5b7d | 704 | if (v->mode != DM_VERITY_MODE_EIO) { |
a739ff3f | 705 | DMEMIT(" "); |
65ff5b7d ST |
706 | switch (v->mode) { |
707 | case DM_VERITY_MODE_LOGGING: | |
708 | DMEMIT(DM_VERITY_OPT_LOGGING); | |
709 | break; | |
710 | case DM_VERITY_MODE_RESTART: | |
711 | DMEMIT(DM_VERITY_OPT_RESTART); | |
712 | break; | |
713 | default: | |
714 | BUG(); | |
715 | } | |
716 | } | |
0cc37c2d ST |
717 | if (v->zero_digest) |
718 | DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES); | |
843f38d3 PT |
719 | if (v->validated_blocks) |
720 | DMEMIT(" " DM_VERITY_OPT_AT_MOST_ONCE); | |
a739ff3f | 721 | sz = verity_fec_status_table(v, sz, result, maxlen); |
a4ffc152 MP |
722 | break; |
723 | } | |
a4ffc152 MP |
724 | } |
725 | ||
5bd5e8d8 | 726 | static int verity_prepare_ioctl(struct dm_target *ti, struct block_device **bdev) |
a4ffc152 MP |
727 | { |
728 | struct dm_verity *v = ti->private; | |
e56f81e0 CH |
729 | |
730 | *bdev = v->data_dev->bdev; | |
a4ffc152 MP |
731 | |
732 | if (v->data_start || | |
733 | ti->len != i_size_read(v->data_dev->bdev->bd_inode) >> SECTOR_SHIFT) | |
e56f81e0 CH |
734 | return 1; |
735 | return 0; | |
a4ffc152 MP |
736 | } |
737 | ||
a4ffc152 MP |
738 | static int verity_iterate_devices(struct dm_target *ti, |
739 | iterate_devices_callout_fn fn, void *data) | |
740 | { | |
741 | struct dm_verity *v = ti->private; | |
742 | ||
743 | return fn(ti, v->data_dev, v->data_start, ti->len, data); | |
744 | } | |
745 | ||
746 | static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
747 | { | |
748 | struct dm_verity *v = ti->private; | |
749 | ||
750 | if (limits->logical_block_size < 1 << v->data_dev_block_bits) | |
751 | limits->logical_block_size = 1 << v->data_dev_block_bits; | |
752 | ||
753 | if (limits->physical_block_size < 1 << v->data_dev_block_bits) | |
754 | limits->physical_block_size = 1 << v->data_dev_block_bits; | |
755 | ||
756 | blk_limits_io_min(limits, limits->logical_block_size); | |
757 | } | |
758 | ||
759 | static void verity_dtr(struct dm_target *ti) | |
760 | { | |
761 | struct dm_verity *v = ti->private; | |
762 | ||
763 | if (v->verify_wq) | |
764 | destroy_workqueue(v->verify_wq); | |
765 | ||
a4ffc152 MP |
766 | if (v->bufio) |
767 | dm_bufio_client_destroy(v->bufio); | |
768 | ||
843f38d3 | 769 | kvfree(v->validated_blocks); |
a4ffc152 MP |
770 | kfree(v->salt); |
771 | kfree(v->root_digest); | |
0cc37c2d | 772 | kfree(v->zero_digest); |
a4ffc152 MP |
773 | |
774 | if (v->tfm) | |
d1ac3ff0 | 775 | crypto_free_ahash(v->tfm); |
a4ffc152 MP |
776 | |
777 | kfree(v->alg_name); | |
778 | ||
779 | if (v->hash_dev) | |
780 | dm_put_device(ti, v->hash_dev); | |
781 | ||
782 | if (v->data_dev) | |
783 | dm_put_device(ti, v->data_dev); | |
784 | ||
a739ff3f ST |
785 | verity_fec_dtr(v); |
786 | ||
a4ffc152 MP |
787 | kfree(v); |
788 | } | |
789 | ||
843f38d3 PT |
790 | static int verity_alloc_most_once(struct dm_verity *v) |
791 | { | |
792 | struct dm_target *ti = v->ti; | |
793 | ||
794 | /* the bitset can only handle INT_MAX blocks */ | |
795 | if (v->data_blocks > INT_MAX) { | |
796 | ti->error = "device too large to use check_at_most_once"; | |
797 | return -E2BIG; | |
798 | } | |
799 | ||
778e1cdd KC |
800 | v->validated_blocks = kvcalloc(BITS_TO_LONGS(v->data_blocks), |
801 | sizeof(unsigned long), | |
802 | GFP_KERNEL); | |
843f38d3 PT |
803 | if (!v->validated_blocks) { |
804 | ti->error = "failed to allocate bitset for check_at_most_once"; | |
805 | return -ENOMEM; | |
806 | } | |
807 | ||
808 | return 0; | |
809 | } | |
810 | ||
0cc37c2d ST |
811 | static int verity_alloc_zero_digest(struct dm_verity *v) |
812 | { | |
813 | int r = -ENOMEM; | |
d1ac3ff0 | 814 | struct ahash_request *req; |
0cc37c2d ST |
815 | u8 *zero_data; |
816 | ||
817 | v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
818 | ||
819 | if (!v->zero_digest) | |
820 | return r; | |
821 | ||
d1ac3ff0 | 822 | req = kmalloc(v->ahash_reqsize, GFP_KERNEL); |
0cc37c2d | 823 | |
d1ac3ff0 | 824 | if (!req) |
0cc37c2d ST |
825 | return r; /* verity_dtr will free zero_digest */ |
826 | ||
827 | zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL); | |
828 | ||
829 | if (!zero_data) | |
830 | goto out; | |
831 | ||
d1ac3ff0 | 832 | r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits, |
0cc37c2d ST |
833 | v->zero_digest); |
834 | ||
835 | out: | |
d1ac3ff0 | 836 | kfree(req); |
0cc37c2d ST |
837 | kfree(zero_data); |
838 | ||
839 | return r; | |
840 | } | |
841 | ||
753c1fd0 ST |
842 | static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v) |
843 | { | |
844 | int r; | |
845 | unsigned argc; | |
846 | struct dm_target *ti = v->ti; | |
847 | const char *arg_name; | |
848 | ||
5916a22b | 849 | static const struct dm_arg _args[] = { |
753c1fd0 ST |
850 | {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"}, |
851 | }; | |
852 | ||
853 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
854 | if (r) | |
855 | return -EINVAL; | |
856 | ||
857 | if (!argc) | |
858 | return 0; | |
859 | ||
860 | do { | |
861 | arg_name = dm_shift_arg(as); | |
862 | argc--; | |
863 | ||
864 | if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) { | |
865 | v->mode = DM_VERITY_MODE_LOGGING; | |
866 | continue; | |
867 | ||
868 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) { | |
869 | v->mode = DM_VERITY_MODE_RESTART; | |
870 | continue; | |
a739ff3f | 871 | |
0cc37c2d ST |
872 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) { |
873 | r = verity_alloc_zero_digest(v); | |
874 | if (r) { | |
875 | ti->error = "Cannot allocate zero digest"; | |
876 | return r; | |
877 | } | |
878 | continue; | |
879 | ||
843f38d3 PT |
880 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_AT_MOST_ONCE)) { |
881 | r = verity_alloc_most_once(v); | |
882 | if (r) | |
883 | return r; | |
884 | continue; | |
885 | ||
a739ff3f ST |
886 | } else if (verity_is_fec_opt_arg(arg_name)) { |
887 | r = verity_fec_parse_opt_args(as, v, &argc, arg_name); | |
888 | if (r) | |
889 | return r; | |
890 | continue; | |
753c1fd0 ST |
891 | } |
892 | ||
893 | ti->error = "Unrecognized verity feature request"; | |
894 | return -EINVAL; | |
895 | } while (argc && !r); | |
896 | ||
897 | return r; | |
898 | } | |
899 | ||
a4ffc152 MP |
900 | /* |
901 | * Target parameters: | |
902 | * <version> The current format is version 1. | |
903 | * Vsn 0 is compatible with original Chromium OS releases. | |
904 | * <data device> | |
905 | * <hash device> | |
906 | * <data block size> | |
907 | * <hash block size> | |
908 | * <the number of data blocks> | |
909 | * <hash start block> | |
910 | * <algorithm> | |
911 | * <digest> | |
912 | * <salt> Hex string or "-" if no salt. | |
913 | */ | |
914 | static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
915 | { | |
916 | struct dm_verity *v; | |
65ff5b7d | 917 | struct dm_arg_set as; |
753c1fd0 | 918 | unsigned int num; |
a4ffc152 MP |
919 | unsigned long long num_ll; |
920 | int r; | |
921 | int i; | |
922 | sector_t hash_position; | |
923 | char dummy; | |
924 | ||
925 | v = kzalloc(sizeof(struct dm_verity), GFP_KERNEL); | |
926 | if (!v) { | |
927 | ti->error = "Cannot allocate verity structure"; | |
928 | return -ENOMEM; | |
929 | } | |
930 | ti->private = v; | |
931 | v->ti = ti; | |
932 | ||
a739ff3f ST |
933 | r = verity_fec_ctr_alloc(v); |
934 | if (r) | |
935 | goto bad; | |
936 | ||
a4ffc152 MP |
937 | if ((dm_table_get_mode(ti->table) & ~FMODE_READ)) { |
938 | ti->error = "Device must be readonly"; | |
939 | r = -EINVAL; | |
940 | goto bad; | |
941 | } | |
942 | ||
65ff5b7d ST |
943 | if (argc < 10) { |
944 | ti->error = "Not enough arguments"; | |
a4ffc152 MP |
945 | r = -EINVAL; |
946 | goto bad; | |
947 | } | |
948 | ||
5d8be843 MP |
949 | if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || |
950 | num > 1) { | |
a4ffc152 MP |
951 | ti->error = "Invalid version"; |
952 | r = -EINVAL; | |
953 | goto bad; | |
954 | } | |
955 | v->version = num; | |
956 | ||
957 | r = dm_get_device(ti, argv[1], FMODE_READ, &v->data_dev); | |
958 | if (r) { | |
959 | ti->error = "Data device lookup failed"; | |
960 | goto bad; | |
961 | } | |
962 | ||
963 | r = dm_get_device(ti, argv[2], FMODE_READ, &v->hash_dev); | |
964 | if (r) { | |
21ffe552 | 965 | ti->error = "Hash device lookup failed"; |
a4ffc152 MP |
966 | goto bad; |
967 | } | |
968 | ||
969 | if (sscanf(argv[3], "%u%c", &num, &dummy) != 1 || | |
970 | !num || (num & (num - 1)) || | |
971 | num < bdev_logical_block_size(v->data_dev->bdev) || | |
972 | num > PAGE_SIZE) { | |
973 | ti->error = "Invalid data device block size"; | |
974 | r = -EINVAL; | |
975 | goto bad; | |
976 | } | |
553d8fe0 | 977 | v->data_dev_block_bits = __ffs(num); |
a4ffc152 MP |
978 | |
979 | if (sscanf(argv[4], "%u%c", &num, &dummy) != 1 || | |
980 | !num || (num & (num - 1)) || | |
981 | num < bdev_logical_block_size(v->hash_dev->bdev) || | |
982 | num > INT_MAX) { | |
983 | ti->error = "Invalid hash device block size"; | |
984 | r = -EINVAL; | |
985 | goto bad; | |
986 | } | |
553d8fe0 | 987 | v->hash_dev_block_bits = __ffs(num); |
a4ffc152 MP |
988 | |
989 | if (sscanf(argv[5], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
990 | (sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) |
991 | >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
992 | ti->error = "Invalid data blocks"; |
993 | r = -EINVAL; | |
994 | goto bad; | |
995 | } | |
996 | v->data_blocks = num_ll; | |
997 | ||
998 | if (ti->len > (v->data_blocks << (v->data_dev_block_bits - SECTOR_SHIFT))) { | |
999 | ti->error = "Data device is too small"; | |
1000 | r = -EINVAL; | |
1001 | goto bad; | |
1002 | } | |
1003 | ||
1004 | if (sscanf(argv[6], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
1005 | (sector_t)(num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) |
1006 | >> (v->hash_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
1007 | ti->error = "Invalid hash start"; |
1008 | r = -EINVAL; | |
1009 | goto bad; | |
1010 | } | |
1011 | v->hash_start = num_ll; | |
1012 | ||
1013 | v->alg_name = kstrdup(argv[7], GFP_KERNEL); | |
1014 | if (!v->alg_name) { | |
1015 | ti->error = "Cannot allocate algorithm name"; | |
1016 | r = -ENOMEM; | |
1017 | goto bad; | |
1018 | } | |
1019 | ||
d1ac3ff0 | 1020 | v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0); |
a4ffc152 MP |
1021 | if (IS_ERR(v->tfm)) { |
1022 | ti->error = "Cannot initialize hash function"; | |
1023 | r = PTR_ERR(v->tfm); | |
1024 | v->tfm = NULL; | |
1025 | goto bad; | |
1026 | } | |
d1ac3ff0 | 1027 | v->digest_size = crypto_ahash_digestsize(v->tfm); |
a4ffc152 MP |
1028 | if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) { |
1029 | ti->error = "Digest size too big"; | |
1030 | r = -EINVAL; | |
1031 | goto bad; | |
1032 | } | |
d1ac3ff0 GBY |
1033 | v->ahash_reqsize = sizeof(struct ahash_request) + |
1034 | crypto_ahash_reqsize(v->tfm); | |
a4ffc152 MP |
1035 | |
1036 | v->root_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
1037 | if (!v->root_digest) { | |
1038 | ti->error = "Cannot allocate root digest"; | |
1039 | r = -ENOMEM; | |
1040 | goto bad; | |
1041 | } | |
1042 | if (strlen(argv[8]) != v->digest_size * 2 || | |
1043 | hex2bin(v->root_digest, argv[8], v->digest_size)) { | |
1044 | ti->error = "Invalid root digest"; | |
1045 | r = -EINVAL; | |
1046 | goto bad; | |
1047 | } | |
1048 | ||
1049 | if (strcmp(argv[9], "-")) { | |
1050 | v->salt_size = strlen(argv[9]) / 2; | |
1051 | v->salt = kmalloc(v->salt_size, GFP_KERNEL); | |
1052 | if (!v->salt) { | |
1053 | ti->error = "Cannot allocate salt"; | |
1054 | r = -ENOMEM; | |
1055 | goto bad; | |
1056 | } | |
1057 | if (strlen(argv[9]) != v->salt_size * 2 || | |
1058 | hex2bin(v->salt, argv[9], v->salt_size)) { | |
1059 | ti->error = "Invalid salt"; | |
1060 | r = -EINVAL; | |
1061 | goto bad; | |
1062 | } | |
1063 | } | |
1064 | ||
65ff5b7d ST |
1065 | argv += 10; |
1066 | argc -= 10; | |
1067 | ||
1068 | /* Optional parameters */ | |
1069 | if (argc) { | |
1070 | as.argc = argc; | |
1071 | as.argv = argv; | |
1072 | ||
753c1fd0 ST |
1073 | r = verity_parse_opt_args(&as, v); |
1074 | if (r < 0) | |
65ff5b7d | 1075 | goto bad; |
65ff5b7d ST |
1076 | } |
1077 | ||
a4ffc152 | 1078 | v->hash_per_block_bits = |
553d8fe0 | 1079 | __fls((1 << v->hash_dev_block_bits) / v->digest_size); |
a4ffc152 MP |
1080 | |
1081 | v->levels = 0; | |
1082 | if (v->data_blocks) | |
1083 | while (v->hash_per_block_bits * v->levels < 64 && | |
1084 | (unsigned long long)(v->data_blocks - 1) >> | |
1085 | (v->hash_per_block_bits * v->levels)) | |
1086 | v->levels++; | |
1087 | ||
1088 | if (v->levels > DM_VERITY_MAX_LEVELS) { | |
1089 | ti->error = "Too many tree levels"; | |
1090 | r = -E2BIG; | |
1091 | goto bad; | |
1092 | } | |
1093 | ||
1094 | hash_position = v->hash_start; | |
1095 | for (i = v->levels - 1; i >= 0; i--) { | |
1096 | sector_t s; | |
1097 | v->hash_level_block[i] = hash_position; | |
b1bf2de0 MP |
1098 | s = (v->data_blocks + ((sector_t)1 << ((i + 1) * v->hash_per_block_bits)) - 1) |
1099 | >> ((i + 1) * v->hash_per_block_bits); | |
a4ffc152 MP |
1100 | if (hash_position + s < hash_position) { |
1101 | ti->error = "Hash device offset overflow"; | |
1102 | r = -E2BIG; | |
1103 | goto bad; | |
1104 | } | |
1105 | hash_position += s; | |
1106 | } | |
1107 | v->hash_blocks = hash_position; | |
1108 | ||
1109 | v->bufio = dm_bufio_client_create(v->hash_dev->bdev, | |
1110 | 1 << v->hash_dev_block_bits, 1, sizeof(struct buffer_aux), | |
1111 | dm_bufio_alloc_callback, NULL); | |
1112 | if (IS_ERR(v->bufio)) { | |
1113 | ti->error = "Cannot initialize dm-bufio"; | |
1114 | r = PTR_ERR(v->bufio); | |
1115 | v->bufio = NULL; | |
1116 | goto bad; | |
1117 | } | |
1118 | ||
1119 | if (dm_bufio_get_device_size(v->bufio) < v->hash_blocks) { | |
1120 | ti->error = "Hash device is too small"; | |
1121 | r = -E2BIG; | |
1122 | goto bad; | |
1123 | } | |
1124 | ||
a4ffc152 MP |
1125 | /* WQ_UNBOUND greatly improves performance when running on ramdisk */ |
1126 | v->verify_wq = alloc_workqueue("kverityd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, num_online_cpus()); | |
1127 | if (!v->verify_wq) { | |
1128 | ti->error = "Cannot allocate workqueue"; | |
1129 | r = -ENOMEM; | |
1130 | goto bad; | |
1131 | } | |
1132 | ||
30187e1d | 1133 | ti->per_io_data_size = sizeof(struct dm_verity_io) + |
d1ac3ff0 | 1134 | v->ahash_reqsize + v->digest_size * 2; |
a739ff3f ST |
1135 | |
1136 | r = verity_fec_ctr(v); | |
1137 | if (r) | |
1138 | goto bad; | |
1139 | ||
30187e1d MS |
1140 | ti->per_io_data_size = roundup(ti->per_io_data_size, |
1141 | __alignof__(struct dm_verity_io)); | |
a739ff3f | 1142 | |
a4ffc152 MP |
1143 | return 0; |
1144 | ||
1145 | bad: | |
1146 | verity_dtr(ti); | |
1147 | ||
1148 | return r; | |
1149 | } | |
1150 | ||
1151 | static struct target_type verity_target = { | |
1152 | .name = "verity", | |
843f38d3 | 1153 | .version = {1, 4, 0}, |
a4ffc152 MP |
1154 | .module = THIS_MODULE, |
1155 | .ctr = verity_ctr, | |
1156 | .dtr = verity_dtr, | |
1157 | .map = verity_map, | |
1158 | .status = verity_status, | |
e56f81e0 | 1159 | .prepare_ioctl = verity_prepare_ioctl, |
a4ffc152 MP |
1160 | .iterate_devices = verity_iterate_devices, |
1161 | .io_hints = verity_io_hints, | |
1162 | }; | |
1163 | ||
1164 | static int __init dm_verity_init(void) | |
1165 | { | |
1166 | int r; | |
1167 | ||
1168 | r = dm_register_target(&verity_target); | |
1169 | if (r < 0) | |
1170 | DMERR("register failed %d", r); | |
1171 | ||
1172 | return r; | |
1173 | } | |
1174 | ||
1175 | static void __exit dm_verity_exit(void) | |
1176 | { | |
1177 | dm_unregister_target(&verity_target); | |
1178 | } | |
1179 | ||
1180 | module_init(dm_verity_init); | |
1181 | module_exit(dm_verity_exit); | |
1182 | ||
1183 | MODULE_AUTHOR("Mikulas Patocka <mpatocka@redhat.com>"); | |
1184 | MODULE_AUTHOR("Mandeep Baines <msb@chromium.org>"); | |
1185 | MODULE_AUTHOR("Will Drewry <wad@chromium.org>"); | |
1186 | MODULE_DESCRIPTION(DM_NAME " target for transparent disk integrity checking"); | |
1187 | MODULE_LICENSE("GPL"); |