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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" |
a4ffc152 | 35 | |
0cc37c2d | 36 | #define DM_VERITY_OPTS_MAX (2 + DM_VERITY_OPTS_FEC) |
753c1fd0 | 37 | |
a4ffc152 MP |
38 | static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE; |
39 | ||
40 | module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR); | |
41 | ||
3b6b7813 MP |
42 | struct dm_verity_prefetch_work { |
43 | struct work_struct work; | |
44 | struct dm_verity *v; | |
45 | sector_t block; | |
46 | unsigned n_blocks; | |
47 | }; | |
48 | ||
a4ffc152 MP |
49 | /* |
50 | * Auxiliary structure appended to each dm-bufio buffer. If the value | |
51 | * hash_verified is nonzero, hash of the block has been verified. | |
52 | * | |
53 | * The variable hash_verified is set to 0 when allocating the buffer, then | |
54 | * it can be changed to 1 and it is never reset to 0 again. | |
55 | * | |
56 | * There is no lock around this value, a race condition can at worst cause | |
57 | * that multiple processes verify the hash of the same buffer simultaneously | |
58 | * and write 1 to hash_verified simultaneously. | |
59 | * This condition is harmless, so we don't need locking. | |
60 | */ | |
61 | struct buffer_aux { | |
62 | int hash_verified; | |
63 | }; | |
64 | ||
65 | /* | |
66 | * Initialize struct buffer_aux for a freshly created buffer. | |
67 | */ | |
68 | static void dm_bufio_alloc_callback(struct dm_buffer *buf) | |
69 | { | |
70 | struct buffer_aux *aux = dm_bufio_get_aux_data(buf); | |
71 | ||
72 | aux->hash_verified = 0; | |
73 | } | |
74 | ||
75 | /* | |
76 | * Translate input sector number to the sector number on the target device. | |
77 | */ | |
78 | static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector) | |
79 | { | |
80 | return v->data_start + dm_target_offset(v->ti, bi_sector); | |
81 | } | |
82 | ||
83 | /* | |
84 | * Return hash position of a specified block at a specified tree level | |
85 | * (0 is the lowest level). | |
86 | * The lowest "hash_per_block_bits"-bits of the result denote hash position | |
87 | * inside a hash block. The remaining bits denote location of the hash block. | |
88 | */ | |
89 | static sector_t verity_position_at_level(struct dm_verity *v, sector_t block, | |
90 | int level) | |
91 | { | |
92 | return block >> (level * v->hash_per_block_bits); | |
93 | } | |
94 | ||
6dbeda34 | 95 | /* |
d1ac3ff0 | 96 | * Callback function for asynchrnous crypto API completion notification |
6dbeda34 | 97 | */ |
d1ac3ff0 | 98 | static void verity_op_done(struct crypto_async_request *base, int err) |
6dbeda34 | 99 | { |
d1ac3ff0 | 100 | struct verity_result *res = (struct verity_result *)base->data; |
6dbeda34 | 101 | |
d1ac3ff0 GBY |
102 | if (err == -EINPROGRESS) |
103 | return; | |
6dbeda34 | 104 | |
d1ac3ff0 GBY |
105 | res->err = err; |
106 | complete(&res->completion); | |
107 | } | |
6dbeda34 | 108 | |
d1ac3ff0 GBY |
109 | /* |
110 | * Wait for async crypto API callback | |
111 | */ | |
112 | static inline int verity_complete_op(struct verity_result *res, int ret) | |
113 | { | |
114 | switch (ret) { | |
115 | case 0: | |
116 | break; | |
6dbeda34 | 117 | |
d1ac3ff0 GBY |
118 | case -EINPROGRESS: |
119 | case -EBUSY: | |
120 | ret = wait_for_completion_interruptible(&res->completion); | |
121 | if (!ret) | |
122 | ret = res->err; | |
123 | reinit_completion(&res->completion); | |
124 | break; | |
6dbeda34 | 125 | |
d1ac3ff0 GBY |
126 | default: |
127 | DMERR("verity_wait_hash: crypto op submission failed: %d", ret); | |
6dbeda34 ST |
128 | } |
129 | ||
d1ac3ff0 GBY |
130 | if (unlikely(ret < 0)) |
131 | DMERR("verity_wait_hash: crypto op failed: %d", ret); | |
132 | ||
133 | return ret; | |
6dbeda34 ST |
134 | } |
135 | ||
d1ac3ff0 GBY |
136 | static int verity_hash_update(struct dm_verity *v, struct ahash_request *req, |
137 | const u8 *data, size_t len, | |
138 | struct verity_result *res) | |
6dbeda34 | 139 | { |
d1ac3ff0 | 140 | struct scatterlist sg; |
6dbeda34 | 141 | |
d1ac3ff0 GBY |
142 | sg_init_one(&sg, data, len); |
143 | ahash_request_set_crypt(req, &sg, NULL, len); | |
144 | ||
145 | return verity_complete_op(res, crypto_ahash_update(req)); | |
146 | } | |
147 | ||
148 | /* | |
149 | * Wrapper for crypto_ahash_init, which handles verity salting. | |
150 | */ | |
151 | static int verity_hash_init(struct dm_verity *v, struct ahash_request *req, | |
152 | struct verity_result *res) | |
153 | { | |
154 | int r; | |
155 | ||
156 | ahash_request_set_tfm(req, v->tfm); | |
157 | ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | | |
158 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
159 | verity_op_done, (void *)res); | |
160 | init_completion(&res->completion); | |
161 | ||
162 | r = verity_complete_op(res, crypto_ahash_init(req)); | |
163 | ||
164 | if (unlikely(r < 0)) { | |
165 | DMERR("crypto_ahash_init failed: %d", r); | |
166 | return r; | |
167 | } | |
168 | ||
169 | if (likely(v->version >= 1)) | |
170 | r = verity_hash_update(v, req, v->salt, v->salt_size, res); | |
6dbeda34 ST |
171 | |
172 | return r; | |
173 | } | |
174 | ||
d1ac3ff0 GBY |
175 | static int verity_hash_final(struct dm_verity *v, struct ahash_request *req, |
176 | u8 *digest, struct verity_result *res) | |
6dbeda34 ST |
177 | { |
178 | int r; | |
179 | ||
180 | if (unlikely(!v->version)) { | |
d1ac3ff0 | 181 | r = verity_hash_update(v, req, v->salt, v->salt_size, res); |
6dbeda34 ST |
182 | |
183 | if (r < 0) { | |
d1ac3ff0 GBY |
184 | DMERR("verity_hash_final failed updating salt: %d", r); |
185 | goto out; | |
6dbeda34 ST |
186 | } |
187 | } | |
188 | ||
d1ac3ff0 GBY |
189 | ahash_request_set_crypt(req, NULL, digest, 0); |
190 | r = verity_complete_op(res, crypto_ahash_final(req)); | |
191 | out: | |
6dbeda34 ST |
192 | return r; |
193 | } | |
194 | ||
d1ac3ff0 | 195 | int verity_hash(struct dm_verity *v, struct ahash_request *req, |
ffa39380 | 196 | const u8 *data, size_t len, u8 *digest) |
6dbeda34 ST |
197 | { |
198 | int r; | |
d1ac3ff0 | 199 | struct verity_result res; |
6dbeda34 | 200 | |
d1ac3ff0 | 201 | r = verity_hash_init(v, req, &res); |
6dbeda34 | 202 | if (unlikely(r < 0)) |
d1ac3ff0 | 203 | goto out; |
6dbeda34 | 204 | |
d1ac3ff0 | 205 | r = verity_hash_update(v, req, data, len, &res); |
6dbeda34 | 206 | if (unlikely(r < 0)) |
d1ac3ff0 GBY |
207 | goto out; |
208 | ||
209 | r = verity_hash_final(v, req, digest, &res); | |
6dbeda34 | 210 | |
d1ac3ff0 GBY |
211 | out: |
212 | return r; | |
6dbeda34 ST |
213 | } |
214 | ||
a4ffc152 MP |
215 | static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, |
216 | sector_t *hash_block, unsigned *offset) | |
217 | { | |
218 | sector_t position = verity_position_at_level(v, block, level); | |
219 | unsigned idx; | |
220 | ||
221 | *hash_block = v->hash_level_block[level] + (position >> v->hash_per_block_bits); | |
222 | ||
223 | if (!offset) | |
224 | return; | |
225 | ||
226 | idx = position & ((1 << v->hash_per_block_bits) - 1); | |
227 | if (!v->version) | |
228 | *offset = idx * v->digest_size; | |
229 | else | |
230 | *offset = idx << (v->hash_dev_block_bits - v->hash_per_block_bits); | |
231 | } | |
232 | ||
65ff5b7d ST |
233 | /* |
234 | * Handle verification errors. | |
235 | */ | |
236 | static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, | |
237 | unsigned long long block) | |
238 | { | |
239 | char verity_env[DM_VERITY_ENV_LENGTH]; | |
240 | char *envp[] = { verity_env, NULL }; | |
241 | const char *type_str = ""; | |
242 | struct mapped_device *md = dm_table_get_md(v->ti->table); | |
243 | ||
244 | /* Corruption should be visible in device status in all modes */ | |
245 | v->hash_failed = 1; | |
246 | ||
247 | if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) | |
248 | goto out; | |
249 | ||
250 | v->corrupted_errs++; | |
251 | ||
252 | switch (type) { | |
253 | case DM_VERITY_BLOCK_TYPE_DATA: | |
254 | type_str = "data"; | |
255 | break; | |
256 | case DM_VERITY_BLOCK_TYPE_METADATA: | |
257 | type_str = "metadata"; | |
258 | break; | |
259 | default: | |
260 | BUG(); | |
261 | } | |
262 | ||
263 | DMERR("%s: %s block %llu is corrupted", v->data_dev->name, type_str, | |
264 | block); | |
265 | ||
266 | if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS) | |
267 | DMERR("%s: reached maximum errors", v->data_dev->name); | |
268 | ||
269 | snprintf(verity_env, DM_VERITY_ENV_LENGTH, "%s=%d,%llu", | |
270 | DM_VERITY_ENV_VAR_NAME, type, block); | |
271 | ||
272 | kobject_uevent_env(&disk_to_dev(dm_disk(md))->kobj, KOBJ_CHANGE, envp); | |
273 | ||
274 | out: | |
275 | if (v->mode == DM_VERITY_MODE_LOGGING) | |
276 | return 0; | |
277 | ||
278 | if (v->mode == DM_VERITY_MODE_RESTART) | |
279 | kernel_restart("dm-verity device corrupted"); | |
280 | ||
281 | return 1; | |
282 | } | |
283 | ||
a4ffc152 MP |
284 | /* |
285 | * Verify hash of a metadata block pertaining to the specified data block | |
286 | * ("block" argument) at a specified level ("level" argument). | |
287 | * | |
ffa39380 ST |
288 | * On successful return, verity_io_want_digest(v, io) contains the hash value |
289 | * for a lower tree level or for the data block (if we're at the lowest level). | |
a4ffc152 MP |
290 | * |
291 | * If "skip_unverified" is true, unverified buffer is skipped and 1 is returned. | |
292 | * If "skip_unverified" is false, unverified buffer is hashed and verified | |
ffa39380 | 293 | * against current value of verity_io_want_digest(v, io). |
a4ffc152 | 294 | */ |
6dbeda34 ST |
295 | static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io, |
296 | sector_t block, int level, bool skip_unverified, | |
297 | u8 *want_digest) | |
a4ffc152 | 298 | { |
a4ffc152 MP |
299 | struct dm_buffer *buf; |
300 | struct buffer_aux *aux; | |
301 | u8 *data; | |
302 | int r; | |
303 | sector_t hash_block; | |
304 | unsigned offset; | |
305 | ||
306 | verity_hash_at_level(v, block, level, &hash_block, &offset); | |
307 | ||
308 | data = dm_bufio_read(v->bufio, hash_block, &buf); | |
fc0a4461 | 309 | if (IS_ERR(data)) |
a4ffc152 MP |
310 | return PTR_ERR(data); |
311 | ||
312 | aux = dm_bufio_get_aux_data(buf); | |
313 | ||
314 | if (!aux->hash_verified) { | |
a4ffc152 MP |
315 | if (skip_unverified) { |
316 | r = 1; | |
317 | goto release_ret_r; | |
318 | } | |
319 | ||
d1ac3ff0 | 320 | r = verity_hash(v, verity_io_hash_req(v, io), |
6dbeda34 | 321 | data, 1 << v->hash_dev_block_bits, |
ffa39380 | 322 | verity_io_real_digest(v, io)); |
6dbeda34 | 323 | if (unlikely(r < 0)) |
a4ffc152 | 324 | goto release_ret_r; |
a4ffc152 | 325 | |
ffa39380 | 326 | if (likely(memcmp(verity_io_real_digest(v, io), want_digest, |
6dbeda34 ST |
327 | v->digest_size) == 0)) |
328 | aux->hash_verified = 1; | |
a739ff3f ST |
329 | else if (verity_fec_decode(v, io, |
330 | DM_VERITY_BLOCK_TYPE_METADATA, | |
331 | hash_block, data, NULL) == 0) | |
332 | aux->hash_verified = 1; | |
6dbeda34 ST |
333 | else if (verity_handle_err(v, |
334 | DM_VERITY_BLOCK_TYPE_METADATA, | |
335 | hash_block)) { | |
336 | r = -EIO; | |
a4ffc152 MP |
337 | goto release_ret_r; |
338 | } | |
a4ffc152 MP |
339 | } |
340 | ||
341 | data += offset; | |
6dbeda34 ST |
342 | memcpy(want_digest, data, v->digest_size); |
343 | r = 0; | |
a4ffc152 MP |
344 | |
345 | release_ret_r: | |
346 | dm_bufio_release(buf); | |
a4ffc152 MP |
347 | return r; |
348 | } | |
349 | ||
6dbeda34 ST |
350 | /* |
351 | * Find a hash for a given block, write it to digest and verify the integrity | |
352 | * of the hash tree if necessary. | |
353 | */ | |
ffa39380 | 354 | int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, |
0cc37c2d | 355 | sector_t block, u8 *digest, bool *is_zero) |
6dbeda34 | 356 | { |
0cc37c2d | 357 | int r = 0, i; |
6dbeda34 ST |
358 | |
359 | if (likely(v->levels)) { | |
360 | /* | |
361 | * First, we try to get the requested hash for | |
362 | * the current block. If the hash block itself is | |
363 | * verified, zero is returned. If it isn't, this | |
364 | * function returns 1 and we fall back to whole | |
365 | * chain verification. | |
366 | */ | |
367 | r = verity_verify_level(v, io, block, 0, true, digest); | |
368 | if (likely(r <= 0)) | |
0cc37c2d | 369 | goto out; |
6dbeda34 ST |
370 | } |
371 | ||
372 | memcpy(digest, v->root_digest, v->digest_size); | |
373 | ||
374 | for (i = v->levels - 1; i >= 0; i--) { | |
375 | r = verity_verify_level(v, io, block, i, false, digest); | |
376 | if (unlikely(r)) | |
0cc37c2d | 377 | goto out; |
6dbeda34 | 378 | } |
0cc37c2d ST |
379 | out: |
380 | if (!r && v->zero_digest) | |
381 | *is_zero = !memcmp(v->zero_digest, digest, v->digest_size); | |
382 | else | |
383 | *is_zero = false; | |
6dbeda34 | 384 | |
0cc37c2d | 385 | return r; |
6dbeda34 ST |
386 | } |
387 | ||
d1ac3ff0 GBY |
388 | /* |
389 | * Calculates the digest for the given bio | |
390 | */ | |
391 | int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io, | |
392 | struct bvec_iter *iter, struct verity_result *res) | |
393 | { | |
394 | unsigned int todo = 1 << v->data_dev_block_bits; | |
395 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); | |
396 | struct scatterlist sg; | |
397 | struct ahash_request *req = verity_io_hash_req(v, io); | |
398 | ||
399 | do { | |
400 | int r; | |
401 | unsigned int len; | |
402 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
403 | ||
404 | sg_init_table(&sg, 1); | |
405 | ||
406 | len = bv.bv_len; | |
407 | ||
408 | if (likely(len >= todo)) | |
409 | len = todo; | |
410 | /* | |
411 | * Operating on a single page at a time looks suboptimal | |
412 | * until you consider the typical block size is 4,096B. | |
413 | * Going through this loops twice should be very rare. | |
414 | */ | |
415 | sg_set_page(&sg, bv.bv_page, len, bv.bv_offset); | |
416 | ahash_request_set_crypt(req, &sg, NULL, len); | |
417 | r = verity_complete_op(res, crypto_ahash_update(req)); | |
418 | ||
419 | if (unlikely(r < 0)) { | |
420 | DMERR("verity_for_io_block crypto op failed: %d", r); | |
421 | return r; | |
422 | } | |
423 | ||
424 | bio_advance_iter(bio, iter, len); | |
425 | todo -= len; | |
426 | } while (todo); | |
427 | ||
428 | return 0; | |
429 | } | |
430 | ||
bb4d73ac ST |
431 | /* |
432 | * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec | |
433 | * starting from iter. | |
434 | */ | |
435 | int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, | |
436 | struct bvec_iter *iter, | |
437 | int (*process)(struct dm_verity *v, | |
438 | struct dm_verity_io *io, u8 *data, | |
439 | size_t len)) | |
440 | { | |
441 | unsigned todo = 1 << v->data_dev_block_bits; | |
30187e1d | 442 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
bb4d73ac ST |
443 | |
444 | do { | |
445 | int r; | |
446 | u8 *page; | |
447 | unsigned len; | |
448 | struct bio_vec bv = bio_iter_iovec(bio, *iter); | |
449 | ||
450 | page = kmap_atomic(bv.bv_page); | |
451 | len = bv.bv_len; | |
452 | ||
453 | if (likely(len >= todo)) | |
454 | len = todo; | |
455 | ||
456 | r = process(v, io, page + bv.bv_offset, len); | |
457 | kunmap_atomic(page); | |
458 | ||
459 | if (r < 0) | |
460 | return r; | |
461 | ||
462 | bio_advance_iter(bio, iter, len); | |
463 | todo -= len; | |
464 | } while (todo); | |
465 | ||
466 | return 0; | |
467 | } | |
468 | ||
0cc37c2d ST |
469 | static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io, |
470 | u8 *data, size_t len) | |
471 | { | |
472 | memset(data, 0, len); | |
473 | return 0; | |
474 | } | |
475 | ||
a4ffc152 MP |
476 | /* |
477 | * Verify one "dm_verity_io" structure. | |
478 | */ | |
479 | static int verity_verify_io(struct dm_verity_io *io) | |
480 | { | |
0cc37c2d | 481 | bool is_zero; |
a4ffc152 | 482 | struct dm_verity *v = io->v; |
bb4d73ac | 483 | struct bvec_iter start; |
a4ffc152 | 484 | unsigned b; |
d1ac3ff0 | 485 | struct verity_result res; |
a4ffc152 MP |
486 | |
487 | for (b = 0; b < io->n_blocks; b++) { | |
a4ffc152 | 488 | int r; |
d1ac3ff0 | 489 | struct ahash_request *req = verity_io_hash_req(v, io); |
a4ffc152 | 490 | |
6dbeda34 | 491 | r = verity_hash_for_block(v, io, io->block + b, |
0cc37c2d ST |
492 | verity_io_want_digest(v, io), |
493 | &is_zero); | |
6dbeda34 ST |
494 | if (unlikely(r < 0)) |
495 | return r; | |
a4ffc152 | 496 | |
0cc37c2d ST |
497 | if (is_zero) { |
498 | /* | |
499 | * If we expect a zero block, don't validate, just | |
500 | * return zeros. | |
501 | */ | |
502 | r = verity_for_bv_block(v, io, &io->iter, | |
503 | verity_bv_zero); | |
504 | if (unlikely(r < 0)) | |
505 | return r; | |
506 | ||
507 | continue; | |
508 | } | |
509 | ||
d1ac3ff0 | 510 | r = verity_hash_init(v, req, &res); |
6dbeda34 | 511 | if (unlikely(r < 0)) |
a4ffc152 | 512 | return r; |
a4ffc152 | 513 | |
bb4d73ac | 514 | start = io->iter; |
d1ac3ff0 | 515 | r = verity_for_io_block(v, io, &io->iter, &res); |
bb4d73ac ST |
516 | if (unlikely(r < 0)) |
517 | return r; | |
a4ffc152 | 518 | |
d1ac3ff0 GBY |
519 | r = verity_hash_final(v, req, verity_io_real_digest(v, io), |
520 | &res); | |
6dbeda34 | 521 | if (unlikely(r < 0)) |
a4ffc152 | 522 | return r; |
6dbeda34 | 523 | |
ffa39380 ST |
524 | if (likely(memcmp(verity_io_real_digest(v, io), |
525 | verity_io_want_digest(v, io), v->digest_size) == 0)) | |
6dbeda34 | 526 | continue; |
a739ff3f ST |
527 | else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA, |
528 | io->block + b, NULL, &start) == 0) | |
529 | continue; | |
6dbeda34 | 530 | else if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, |
a739ff3f | 531 | io->block + b)) |
6dbeda34 | 532 | return -EIO; |
a4ffc152 | 533 | } |
a4ffc152 MP |
534 | |
535 | return 0; | |
536 | } | |
537 | ||
538 | /* | |
539 | * End one "io" structure with a given error. | |
540 | */ | |
4e4cbee9 | 541 | static void verity_finish_io(struct dm_verity_io *io, blk_status_t status) |
a4ffc152 | 542 | { |
a4ffc152 | 543 | struct dm_verity *v = io->v; |
30187e1d | 544 | struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); |
a4ffc152 MP |
545 | |
546 | bio->bi_end_io = io->orig_bi_end_io; | |
4e4cbee9 | 547 | bio->bi_status = status; |
a4ffc152 | 548 | |
a739ff3f ST |
549 | verity_fec_finish_io(io); |
550 | ||
4246a0b6 | 551 | bio_endio(bio); |
a4ffc152 MP |
552 | } |
553 | ||
554 | static void verity_work(struct work_struct *w) | |
555 | { | |
556 | struct dm_verity_io *io = container_of(w, struct dm_verity_io, work); | |
557 | ||
4e4cbee9 | 558 | verity_finish_io(io, errno_to_blk_status(verity_verify_io(io))); |
a4ffc152 MP |
559 | } |
560 | ||
4246a0b6 | 561 | static void verity_end_io(struct bio *bio) |
a4ffc152 MP |
562 | { |
563 | struct dm_verity_io *io = bio->bi_private; | |
564 | ||
4e4cbee9 CH |
565 | if (bio->bi_status && !verity_fec_is_enabled(io->v)) { |
566 | verity_finish_io(io, bio->bi_status); | |
a4ffc152 MP |
567 | return; |
568 | } | |
569 | ||
570 | INIT_WORK(&io->work, verity_work); | |
571 | queue_work(io->v->verify_wq, &io->work); | |
572 | } | |
573 | ||
574 | /* | |
575 | * Prefetch buffers for the specified io. | |
576 | * The root buffer is not prefetched, it is assumed that it will be cached | |
577 | * all the time. | |
578 | */ | |
3b6b7813 | 579 | static void verity_prefetch_io(struct work_struct *work) |
a4ffc152 | 580 | { |
3b6b7813 MP |
581 | struct dm_verity_prefetch_work *pw = |
582 | container_of(work, struct dm_verity_prefetch_work, work); | |
583 | struct dm_verity *v = pw->v; | |
a4ffc152 MP |
584 | int i; |
585 | ||
586 | for (i = v->levels - 2; i >= 0; i--) { | |
587 | sector_t hash_block_start; | |
588 | sector_t hash_block_end; | |
3b6b7813 MP |
589 | verity_hash_at_level(v, pw->block, i, &hash_block_start, NULL); |
590 | verity_hash_at_level(v, pw->block + pw->n_blocks - 1, i, &hash_block_end, NULL); | |
a4ffc152 | 591 | if (!i) { |
fe5fe906 | 592 | unsigned cluster = ACCESS_ONCE(dm_verity_prefetch_cluster); |
a4ffc152 MP |
593 | |
594 | cluster >>= v->data_dev_block_bits; | |
595 | if (unlikely(!cluster)) | |
596 | goto no_prefetch_cluster; | |
597 | ||
598 | if (unlikely(cluster & (cluster - 1))) | |
553d8fe0 | 599 | cluster = 1 << __fls(cluster); |
a4ffc152 MP |
600 | |
601 | hash_block_start &= ~(sector_t)(cluster - 1); | |
602 | hash_block_end |= cluster - 1; | |
603 | if (unlikely(hash_block_end >= v->hash_blocks)) | |
604 | hash_block_end = v->hash_blocks - 1; | |
605 | } | |
606 | no_prefetch_cluster: | |
607 | dm_bufio_prefetch(v->bufio, hash_block_start, | |
608 | hash_block_end - hash_block_start + 1); | |
609 | } | |
3b6b7813 MP |
610 | |
611 | kfree(pw); | |
612 | } | |
613 | ||
614 | static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io) | |
615 | { | |
616 | struct dm_verity_prefetch_work *pw; | |
617 | ||
618 | pw = kmalloc(sizeof(struct dm_verity_prefetch_work), | |
619 | GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); | |
620 | ||
621 | if (!pw) | |
622 | return; | |
623 | ||
624 | INIT_WORK(&pw->work, verity_prefetch_io); | |
625 | pw->v = v; | |
626 | pw->block = io->block; | |
627 | pw->n_blocks = io->n_blocks; | |
628 | queue_work(v->verify_wq, &pw->work); | |
a4ffc152 MP |
629 | } |
630 | ||
631 | /* | |
632 | * Bio map function. It allocates dm_verity_io structure and bio vector and | |
633 | * fills them. Then it issues prefetches and the I/O. | |
634 | */ | |
7de3ee57 | 635 | static int verity_map(struct dm_target *ti, struct bio *bio) |
a4ffc152 MP |
636 | { |
637 | struct dm_verity *v = ti->private; | |
638 | struct dm_verity_io *io; | |
639 | ||
640 | bio->bi_bdev = v->data_dev->bdev; | |
4f024f37 | 641 | bio->bi_iter.bi_sector = verity_map_sector(v, bio->bi_iter.bi_sector); |
a4ffc152 | 642 | |
4f024f37 | 643 | if (((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
a4ffc152 MP |
644 | ((1 << (v->data_dev_block_bits - SECTOR_SHIFT)) - 1)) { |
645 | DMERR_LIMIT("unaligned io"); | |
846785e6 | 646 | return DM_MAPIO_KILL; |
a4ffc152 MP |
647 | } |
648 | ||
f73a1c7d | 649 | if (bio_end_sector(bio) >> |
a4ffc152 MP |
650 | (v->data_dev_block_bits - SECTOR_SHIFT) > v->data_blocks) { |
651 | DMERR_LIMIT("io out of range"); | |
846785e6 | 652 | return DM_MAPIO_KILL; |
a4ffc152 MP |
653 | } |
654 | ||
655 | if (bio_data_dir(bio) == WRITE) | |
846785e6 | 656 | return DM_MAPIO_KILL; |
a4ffc152 | 657 | |
30187e1d | 658 | io = dm_per_bio_data(bio, ti->per_io_data_size); |
a4ffc152 | 659 | io->v = v; |
a4ffc152 | 660 | io->orig_bi_end_io = bio->bi_end_io; |
4f024f37 KO |
661 | io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT); |
662 | io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits; | |
a4ffc152 MP |
663 | |
664 | bio->bi_end_io = verity_end_io; | |
665 | bio->bi_private = io; | |
003b5c57 | 666 | io->iter = bio->bi_iter; |
a4ffc152 | 667 | |
a739ff3f ST |
668 | verity_fec_init_io(io); |
669 | ||
3b6b7813 | 670 | verity_submit_prefetch(v, io); |
a4ffc152 MP |
671 | |
672 | generic_make_request(bio); | |
673 | ||
674 | return DM_MAPIO_SUBMITTED; | |
675 | } | |
676 | ||
677 | /* | |
678 | * Status: V (valid) or C (corruption found) | |
679 | */ | |
fd7c092e MP |
680 | static void verity_status(struct dm_target *ti, status_type_t type, |
681 | unsigned status_flags, char *result, unsigned maxlen) | |
a4ffc152 MP |
682 | { |
683 | struct dm_verity *v = ti->private; | |
a739ff3f | 684 | unsigned args = 0; |
a4ffc152 MP |
685 | unsigned sz = 0; |
686 | unsigned x; | |
687 | ||
688 | switch (type) { | |
689 | case STATUSTYPE_INFO: | |
690 | DMEMIT("%c", v->hash_failed ? 'C' : 'V'); | |
691 | break; | |
692 | case STATUSTYPE_TABLE: | |
693 | DMEMIT("%u %s %s %u %u %llu %llu %s ", | |
694 | v->version, | |
695 | v->data_dev->name, | |
696 | v->hash_dev->name, | |
697 | 1 << v->data_dev_block_bits, | |
698 | 1 << v->hash_dev_block_bits, | |
699 | (unsigned long long)v->data_blocks, | |
700 | (unsigned long long)v->hash_start, | |
701 | v->alg_name | |
702 | ); | |
703 | for (x = 0; x < v->digest_size; x++) | |
704 | DMEMIT("%02x", v->root_digest[x]); | |
705 | DMEMIT(" "); | |
706 | if (!v->salt_size) | |
707 | DMEMIT("-"); | |
708 | else | |
709 | for (x = 0; x < v->salt_size; x++) | |
710 | DMEMIT("%02x", v->salt[x]); | |
a739ff3f ST |
711 | if (v->mode != DM_VERITY_MODE_EIO) |
712 | args++; | |
713 | if (verity_fec_is_enabled(v)) | |
714 | args += DM_VERITY_OPTS_FEC; | |
0cc37c2d ST |
715 | if (v->zero_digest) |
716 | args++; | |
a739ff3f ST |
717 | if (!args) |
718 | return; | |
719 | DMEMIT(" %u", args); | |
65ff5b7d | 720 | if (v->mode != DM_VERITY_MODE_EIO) { |
a739ff3f | 721 | DMEMIT(" "); |
65ff5b7d ST |
722 | switch (v->mode) { |
723 | case DM_VERITY_MODE_LOGGING: | |
724 | DMEMIT(DM_VERITY_OPT_LOGGING); | |
725 | break; | |
726 | case DM_VERITY_MODE_RESTART: | |
727 | DMEMIT(DM_VERITY_OPT_RESTART); | |
728 | break; | |
729 | default: | |
730 | BUG(); | |
731 | } | |
732 | } | |
0cc37c2d ST |
733 | if (v->zero_digest) |
734 | DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES); | |
a739ff3f | 735 | sz = verity_fec_status_table(v, sz, result, maxlen); |
a4ffc152 MP |
736 | break; |
737 | } | |
a4ffc152 MP |
738 | } |
739 | ||
e56f81e0 CH |
740 | static int verity_prepare_ioctl(struct dm_target *ti, |
741 | struct block_device **bdev, fmode_t *mode) | |
a4ffc152 MP |
742 | { |
743 | struct dm_verity *v = ti->private; | |
e56f81e0 CH |
744 | |
745 | *bdev = v->data_dev->bdev; | |
a4ffc152 MP |
746 | |
747 | if (v->data_start || | |
748 | ti->len != i_size_read(v->data_dev->bdev->bd_inode) >> SECTOR_SHIFT) | |
e56f81e0 CH |
749 | return 1; |
750 | return 0; | |
a4ffc152 MP |
751 | } |
752 | ||
a4ffc152 MP |
753 | static int verity_iterate_devices(struct dm_target *ti, |
754 | iterate_devices_callout_fn fn, void *data) | |
755 | { | |
756 | struct dm_verity *v = ti->private; | |
757 | ||
758 | return fn(ti, v->data_dev, v->data_start, ti->len, data); | |
759 | } | |
760 | ||
761 | static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
762 | { | |
763 | struct dm_verity *v = ti->private; | |
764 | ||
765 | if (limits->logical_block_size < 1 << v->data_dev_block_bits) | |
766 | limits->logical_block_size = 1 << v->data_dev_block_bits; | |
767 | ||
768 | if (limits->physical_block_size < 1 << v->data_dev_block_bits) | |
769 | limits->physical_block_size = 1 << v->data_dev_block_bits; | |
770 | ||
771 | blk_limits_io_min(limits, limits->logical_block_size); | |
772 | } | |
773 | ||
774 | static void verity_dtr(struct dm_target *ti) | |
775 | { | |
776 | struct dm_verity *v = ti->private; | |
777 | ||
778 | if (v->verify_wq) | |
779 | destroy_workqueue(v->verify_wq); | |
780 | ||
a4ffc152 MP |
781 | if (v->bufio) |
782 | dm_bufio_client_destroy(v->bufio); | |
783 | ||
784 | kfree(v->salt); | |
785 | kfree(v->root_digest); | |
0cc37c2d | 786 | kfree(v->zero_digest); |
a4ffc152 MP |
787 | |
788 | if (v->tfm) | |
d1ac3ff0 | 789 | crypto_free_ahash(v->tfm); |
a4ffc152 MP |
790 | |
791 | kfree(v->alg_name); | |
792 | ||
793 | if (v->hash_dev) | |
794 | dm_put_device(ti, v->hash_dev); | |
795 | ||
796 | if (v->data_dev) | |
797 | dm_put_device(ti, v->data_dev); | |
798 | ||
a739ff3f ST |
799 | verity_fec_dtr(v); |
800 | ||
a4ffc152 MP |
801 | kfree(v); |
802 | } | |
803 | ||
0cc37c2d ST |
804 | static int verity_alloc_zero_digest(struct dm_verity *v) |
805 | { | |
806 | int r = -ENOMEM; | |
d1ac3ff0 | 807 | struct ahash_request *req; |
0cc37c2d ST |
808 | u8 *zero_data; |
809 | ||
810 | v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
811 | ||
812 | if (!v->zero_digest) | |
813 | return r; | |
814 | ||
d1ac3ff0 | 815 | req = kmalloc(v->ahash_reqsize, GFP_KERNEL); |
0cc37c2d | 816 | |
d1ac3ff0 | 817 | if (!req) |
0cc37c2d ST |
818 | return r; /* verity_dtr will free zero_digest */ |
819 | ||
820 | zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL); | |
821 | ||
822 | if (!zero_data) | |
823 | goto out; | |
824 | ||
d1ac3ff0 | 825 | r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits, |
0cc37c2d ST |
826 | v->zero_digest); |
827 | ||
828 | out: | |
d1ac3ff0 | 829 | kfree(req); |
0cc37c2d ST |
830 | kfree(zero_data); |
831 | ||
832 | return r; | |
833 | } | |
834 | ||
753c1fd0 ST |
835 | static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v) |
836 | { | |
837 | int r; | |
838 | unsigned argc; | |
839 | struct dm_target *ti = v->ti; | |
840 | const char *arg_name; | |
841 | ||
842 | static struct dm_arg _args[] = { | |
843 | {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"}, | |
844 | }; | |
845 | ||
846 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
847 | if (r) | |
848 | return -EINVAL; | |
849 | ||
850 | if (!argc) | |
851 | return 0; | |
852 | ||
853 | do { | |
854 | arg_name = dm_shift_arg(as); | |
855 | argc--; | |
856 | ||
857 | if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) { | |
858 | v->mode = DM_VERITY_MODE_LOGGING; | |
859 | continue; | |
860 | ||
861 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) { | |
862 | v->mode = DM_VERITY_MODE_RESTART; | |
863 | continue; | |
a739ff3f | 864 | |
0cc37c2d ST |
865 | } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) { |
866 | r = verity_alloc_zero_digest(v); | |
867 | if (r) { | |
868 | ti->error = "Cannot allocate zero digest"; | |
869 | return r; | |
870 | } | |
871 | continue; | |
872 | ||
a739ff3f ST |
873 | } else if (verity_is_fec_opt_arg(arg_name)) { |
874 | r = verity_fec_parse_opt_args(as, v, &argc, arg_name); | |
875 | if (r) | |
876 | return r; | |
877 | continue; | |
753c1fd0 ST |
878 | } |
879 | ||
880 | ti->error = "Unrecognized verity feature request"; | |
881 | return -EINVAL; | |
882 | } while (argc && !r); | |
883 | ||
884 | return r; | |
885 | } | |
886 | ||
a4ffc152 MP |
887 | /* |
888 | * Target parameters: | |
889 | * <version> The current format is version 1. | |
890 | * Vsn 0 is compatible with original Chromium OS releases. | |
891 | * <data device> | |
892 | * <hash device> | |
893 | * <data block size> | |
894 | * <hash block size> | |
895 | * <the number of data blocks> | |
896 | * <hash start block> | |
897 | * <algorithm> | |
898 | * <digest> | |
899 | * <salt> Hex string or "-" if no salt. | |
900 | */ | |
901 | static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
902 | { | |
903 | struct dm_verity *v; | |
65ff5b7d | 904 | struct dm_arg_set as; |
753c1fd0 | 905 | unsigned int num; |
a4ffc152 MP |
906 | unsigned long long num_ll; |
907 | int r; | |
908 | int i; | |
909 | sector_t hash_position; | |
910 | char dummy; | |
911 | ||
912 | v = kzalloc(sizeof(struct dm_verity), GFP_KERNEL); | |
913 | if (!v) { | |
914 | ti->error = "Cannot allocate verity structure"; | |
915 | return -ENOMEM; | |
916 | } | |
917 | ti->private = v; | |
918 | v->ti = ti; | |
919 | ||
a739ff3f ST |
920 | r = verity_fec_ctr_alloc(v); |
921 | if (r) | |
922 | goto bad; | |
923 | ||
a4ffc152 MP |
924 | if ((dm_table_get_mode(ti->table) & ~FMODE_READ)) { |
925 | ti->error = "Device must be readonly"; | |
926 | r = -EINVAL; | |
927 | goto bad; | |
928 | } | |
929 | ||
65ff5b7d ST |
930 | if (argc < 10) { |
931 | ti->error = "Not enough arguments"; | |
a4ffc152 MP |
932 | r = -EINVAL; |
933 | goto bad; | |
934 | } | |
935 | ||
5d8be843 MP |
936 | if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || |
937 | num > 1) { | |
a4ffc152 MP |
938 | ti->error = "Invalid version"; |
939 | r = -EINVAL; | |
940 | goto bad; | |
941 | } | |
942 | v->version = num; | |
943 | ||
944 | r = dm_get_device(ti, argv[1], FMODE_READ, &v->data_dev); | |
945 | if (r) { | |
946 | ti->error = "Data device lookup failed"; | |
947 | goto bad; | |
948 | } | |
949 | ||
950 | r = dm_get_device(ti, argv[2], FMODE_READ, &v->hash_dev); | |
951 | if (r) { | |
21ffe552 | 952 | ti->error = "Hash device lookup failed"; |
a4ffc152 MP |
953 | goto bad; |
954 | } | |
955 | ||
956 | if (sscanf(argv[3], "%u%c", &num, &dummy) != 1 || | |
957 | !num || (num & (num - 1)) || | |
958 | num < bdev_logical_block_size(v->data_dev->bdev) || | |
959 | num > PAGE_SIZE) { | |
960 | ti->error = "Invalid data device block size"; | |
961 | r = -EINVAL; | |
962 | goto bad; | |
963 | } | |
553d8fe0 | 964 | v->data_dev_block_bits = __ffs(num); |
a4ffc152 MP |
965 | |
966 | if (sscanf(argv[4], "%u%c", &num, &dummy) != 1 || | |
967 | !num || (num & (num - 1)) || | |
968 | num < bdev_logical_block_size(v->hash_dev->bdev) || | |
969 | num > INT_MAX) { | |
970 | ti->error = "Invalid hash device block size"; | |
971 | r = -EINVAL; | |
972 | goto bad; | |
973 | } | |
553d8fe0 | 974 | v->hash_dev_block_bits = __ffs(num); |
a4ffc152 MP |
975 | |
976 | if (sscanf(argv[5], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
977 | (sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) |
978 | >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
979 | ti->error = "Invalid data blocks"; |
980 | r = -EINVAL; | |
981 | goto bad; | |
982 | } | |
983 | v->data_blocks = num_ll; | |
984 | ||
985 | if (ti->len > (v->data_blocks << (v->data_dev_block_bits - SECTOR_SHIFT))) { | |
986 | ti->error = "Data device is too small"; | |
987 | r = -EINVAL; | |
988 | goto bad; | |
989 | } | |
990 | ||
991 | if (sscanf(argv[6], "%llu%c", &num_ll, &dummy) != 1 || | |
1d55f6bc MP |
992 | (sector_t)(num_ll << (v->hash_dev_block_bits - SECTOR_SHIFT)) |
993 | >> (v->hash_dev_block_bits - SECTOR_SHIFT) != num_ll) { | |
a4ffc152 MP |
994 | ti->error = "Invalid hash start"; |
995 | r = -EINVAL; | |
996 | goto bad; | |
997 | } | |
998 | v->hash_start = num_ll; | |
999 | ||
1000 | v->alg_name = kstrdup(argv[7], GFP_KERNEL); | |
1001 | if (!v->alg_name) { | |
1002 | ti->error = "Cannot allocate algorithm name"; | |
1003 | r = -ENOMEM; | |
1004 | goto bad; | |
1005 | } | |
1006 | ||
d1ac3ff0 | 1007 | v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0); |
a4ffc152 MP |
1008 | if (IS_ERR(v->tfm)) { |
1009 | ti->error = "Cannot initialize hash function"; | |
1010 | r = PTR_ERR(v->tfm); | |
1011 | v->tfm = NULL; | |
1012 | goto bad; | |
1013 | } | |
d1ac3ff0 | 1014 | v->digest_size = crypto_ahash_digestsize(v->tfm); |
a4ffc152 MP |
1015 | if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) { |
1016 | ti->error = "Digest size too big"; | |
1017 | r = -EINVAL; | |
1018 | goto bad; | |
1019 | } | |
d1ac3ff0 GBY |
1020 | v->ahash_reqsize = sizeof(struct ahash_request) + |
1021 | crypto_ahash_reqsize(v->tfm); | |
a4ffc152 MP |
1022 | |
1023 | v->root_digest = kmalloc(v->digest_size, GFP_KERNEL); | |
1024 | if (!v->root_digest) { | |
1025 | ti->error = "Cannot allocate root digest"; | |
1026 | r = -ENOMEM; | |
1027 | goto bad; | |
1028 | } | |
1029 | if (strlen(argv[8]) != v->digest_size * 2 || | |
1030 | hex2bin(v->root_digest, argv[8], v->digest_size)) { | |
1031 | ti->error = "Invalid root digest"; | |
1032 | r = -EINVAL; | |
1033 | goto bad; | |
1034 | } | |
1035 | ||
1036 | if (strcmp(argv[9], "-")) { | |
1037 | v->salt_size = strlen(argv[9]) / 2; | |
1038 | v->salt = kmalloc(v->salt_size, GFP_KERNEL); | |
1039 | if (!v->salt) { | |
1040 | ti->error = "Cannot allocate salt"; | |
1041 | r = -ENOMEM; | |
1042 | goto bad; | |
1043 | } | |
1044 | if (strlen(argv[9]) != v->salt_size * 2 || | |
1045 | hex2bin(v->salt, argv[9], v->salt_size)) { | |
1046 | ti->error = "Invalid salt"; | |
1047 | r = -EINVAL; | |
1048 | goto bad; | |
1049 | } | |
1050 | } | |
1051 | ||
65ff5b7d ST |
1052 | argv += 10; |
1053 | argc -= 10; | |
1054 | ||
1055 | /* Optional parameters */ | |
1056 | if (argc) { | |
1057 | as.argc = argc; | |
1058 | as.argv = argv; | |
1059 | ||
753c1fd0 ST |
1060 | r = verity_parse_opt_args(&as, v); |
1061 | if (r < 0) | |
65ff5b7d | 1062 | goto bad; |
65ff5b7d ST |
1063 | } |
1064 | ||
a4ffc152 | 1065 | v->hash_per_block_bits = |
553d8fe0 | 1066 | __fls((1 << v->hash_dev_block_bits) / v->digest_size); |
a4ffc152 MP |
1067 | |
1068 | v->levels = 0; | |
1069 | if (v->data_blocks) | |
1070 | while (v->hash_per_block_bits * v->levels < 64 && | |
1071 | (unsigned long long)(v->data_blocks - 1) >> | |
1072 | (v->hash_per_block_bits * v->levels)) | |
1073 | v->levels++; | |
1074 | ||
1075 | if (v->levels > DM_VERITY_MAX_LEVELS) { | |
1076 | ti->error = "Too many tree levels"; | |
1077 | r = -E2BIG; | |
1078 | goto bad; | |
1079 | } | |
1080 | ||
1081 | hash_position = v->hash_start; | |
1082 | for (i = v->levels - 1; i >= 0; i--) { | |
1083 | sector_t s; | |
1084 | v->hash_level_block[i] = hash_position; | |
b1bf2de0 MP |
1085 | s = (v->data_blocks + ((sector_t)1 << ((i + 1) * v->hash_per_block_bits)) - 1) |
1086 | >> ((i + 1) * v->hash_per_block_bits); | |
a4ffc152 MP |
1087 | if (hash_position + s < hash_position) { |
1088 | ti->error = "Hash device offset overflow"; | |
1089 | r = -E2BIG; | |
1090 | goto bad; | |
1091 | } | |
1092 | hash_position += s; | |
1093 | } | |
1094 | v->hash_blocks = hash_position; | |
1095 | ||
1096 | v->bufio = dm_bufio_client_create(v->hash_dev->bdev, | |
1097 | 1 << v->hash_dev_block_bits, 1, sizeof(struct buffer_aux), | |
1098 | dm_bufio_alloc_callback, NULL); | |
1099 | if (IS_ERR(v->bufio)) { | |
1100 | ti->error = "Cannot initialize dm-bufio"; | |
1101 | r = PTR_ERR(v->bufio); | |
1102 | v->bufio = NULL; | |
1103 | goto bad; | |
1104 | } | |
1105 | ||
1106 | if (dm_bufio_get_device_size(v->bufio) < v->hash_blocks) { | |
1107 | ti->error = "Hash device is too small"; | |
1108 | r = -E2BIG; | |
1109 | goto bad; | |
1110 | } | |
1111 | ||
a4ffc152 MP |
1112 | /* WQ_UNBOUND greatly improves performance when running on ramdisk */ |
1113 | v->verify_wq = alloc_workqueue("kverityd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, num_online_cpus()); | |
1114 | if (!v->verify_wq) { | |
1115 | ti->error = "Cannot allocate workqueue"; | |
1116 | r = -ENOMEM; | |
1117 | goto bad; | |
1118 | } | |
1119 | ||
30187e1d | 1120 | ti->per_io_data_size = sizeof(struct dm_verity_io) + |
d1ac3ff0 | 1121 | v->ahash_reqsize + v->digest_size * 2; |
a739ff3f ST |
1122 | |
1123 | r = verity_fec_ctr(v); | |
1124 | if (r) | |
1125 | goto bad; | |
1126 | ||
30187e1d MS |
1127 | ti->per_io_data_size = roundup(ti->per_io_data_size, |
1128 | __alignof__(struct dm_verity_io)); | |
a739ff3f | 1129 | |
a4ffc152 MP |
1130 | return 0; |
1131 | ||
1132 | bad: | |
1133 | verity_dtr(ti); | |
1134 | ||
1135 | return r; | |
1136 | } | |
1137 | ||
1138 | static struct target_type verity_target = { | |
1139 | .name = "verity", | |
a739ff3f | 1140 | .version = {1, 3, 0}, |
a4ffc152 MP |
1141 | .module = THIS_MODULE, |
1142 | .ctr = verity_ctr, | |
1143 | .dtr = verity_dtr, | |
1144 | .map = verity_map, | |
1145 | .status = verity_status, | |
e56f81e0 | 1146 | .prepare_ioctl = verity_prepare_ioctl, |
a4ffc152 MP |
1147 | .iterate_devices = verity_iterate_devices, |
1148 | .io_hints = verity_io_hints, | |
1149 | }; | |
1150 | ||
1151 | static int __init dm_verity_init(void) | |
1152 | { | |
1153 | int r; | |
1154 | ||
1155 | r = dm_register_target(&verity_target); | |
1156 | if (r < 0) | |
1157 | DMERR("register failed %d", r); | |
1158 | ||
1159 | return r; | |
1160 | } | |
1161 | ||
1162 | static void __exit dm_verity_exit(void) | |
1163 | { | |
1164 | dm_unregister_target(&verity_target); | |
1165 | } | |
1166 | ||
1167 | module_init(dm_verity_init); | |
1168 | module_exit(dm_verity_exit); | |
1169 | ||
1170 | MODULE_AUTHOR("Mikulas Patocka <mpatocka@redhat.com>"); | |
1171 | MODULE_AUTHOR("Mandeep Baines <msb@chromium.org>"); | |
1172 | MODULE_AUTHOR("Will Drewry <wad@chromium.org>"); | |
1173 | MODULE_DESCRIPTION(DM_NAME " target for transparent disk integrity checking"); | |
1174 | MODULE_LICENSE("GPL"); |