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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright 2019 Google LLC4 */5 6/*7 * Refer to Documentation/block/inline-encryption.rst for detailed explanation.8 */9 10#define pr_fmt(fmt) "blk-crypto-fallback: " fmt11 12#include <crypto/skcipher.h>13#include <linux/blk-crypto.h>14#include <linux/blk-crypto-profile.h>15#include <linux/blkdev.h>16#include <linux/crypto.h>17#include <linux/mempool.h>18#include <linux/module.h>19#include <linux/random.h>20#include <linux/scatterlist.h>21 22#include "blk-cgroup.h"23#include "blk-crypto-internal.h"24 25static unsigned int num_prealloc_bounce_pg = 32;26module_param(num_prealloc_bounce_pg, uint, 0);27MODULE_PARM_DESC(num_prealloc_bounce_pg,28 "Number of preallocated bounce pages for the blk-crypto crypto API fallback");29 30static unsigned int blk_crypto_num_keyslots = 100;31module_param_named(num_keyslots, blk_crypto_num_keyslots, uint, 0);32MODULE_PARM_DESC(num_keyslots,33 "Number of keyslots for the blk-crypto crypto API fallback");34 35static unsigned int num_prealloc_fallback_crypt_ctxs = 128;36module_param(num_prealloc_fallback_crypt_ctxs, uint, 0);37MODULE_PARM_DESC(num_prealloc_crypt_fallback_ctxs,38 "Number of preallocated bio fallback crypto contexts for blk-crypto to use during crypto API fallback");39 40struct bio_fallback_crypt_ctx {41 struct bio_crypt_ctx crypt_ctx;42 /*43 * Copy of the bvec_iter when this bio was submitted.44 * We only want to en/decrypt the part of the bio as described by the45 * bvec_iter upon submission because bio might be split before being46 * resubmitted47 */48 struct bvec_iter crypt_iter;49 union {50 struct {51 struct work_struct work;52 struct bio *bio;53 };54 struct {55 void *bi_private_orig;56 bio_end_io_t *bi_end_io_orig;57 };58 };59};60 61static struct kmem_cache *bio_fallback_crypt_ctx_cache;62static mempool_t *bio_fallback_crypt_ctx_pool;63 64/*65 * Allocating a crypto tfm during I/O can deadlock, so we have to preallocate66 * all of a mode's tfms when that mode starts being used. Since each mode may67 * need all the keyslots at some point, each mode needs its own tfm for each68 * keyslot; thus, a keyslot may contain tfms for multiple modes. However, to69 * match the behavior of real inline encryption hardware (which only supports a70 * single encryption context per keyslot), we only allow one tfm per keyslot to71 * be used at a time - the rest of the unused tfms have their keys cleared.72 */73static DEFINE_MUTEX(tfms_init_lock);74static bool tfms_inited[BLK_ENCRYPTION_MODE_MAX];75 76static struct blk_crypto_fallback_keyslot {77 enum blk_crypto_mode_num crypto_mode;78 struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];79} *blk_crypto_keyslots;80 81static struct blk_crypto_profile *blk_crypto_fallback_profile;82static struct workqueue_struct *blk_crypto_wq;83static mempool_t *blk_crypto_bounce_page_pool;84static struct bio_set crypto_bio_split;85 86/*87 * This is the key we set when evicting a keyslot. This *should* be the all 0's88 * key, but AES-XTS rejects that key, so we use some random bytes instead.89 */90static u8 blank_key[BLK_CRYPTO_MAX_KEY_SIZE];91 92static void blk_crypto_fallback_evict_keyslot(unsigned int slot)93{94 struct blk_crypto_fallback_keyslot *slotp = &blk_crypto_keyslots[slot];95 enum blk_crypto_mode_num crypto_mode = slotp->crypto_mode;96 int err;97 98 WARN_ON(slotp->crypto_mode == BLK_ENCRYPTION_MODE_INVALID);99 100 /* Clear the key in the skcipher */101 err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], blank_key,102 blk_crypto_modes[crypto_mode].keysize);103 WARN_ON(err);104 slotp->crypto_mode = BLK_ENCRYPTION_MODE_INVALID;105}106 107static int108blk_crypto_fallback_keyslot_program(struct blk_crypto_profile *profile,109 const struct blk_crypto_key *key,110 unsigned int slot)111{112 struct blk_crypto_fallback_keyslot *slotp = &blk_crypto_keyslots[slot];113 const enum blk_crypto_mode_num crypto_mode =114 key->crypto_cfg.crypto_mode;115 int err;116 117 if (crypto_mode != slotp->crypto_mode &&118 slotp->crypto_mode != BLK_ENCRYPTION_MODE_INVALID)119 blk_crypto_fallback_evict_keyslot(slot);120 121 slotp->crypto_mode = crypto_mode;122 err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], key->raw,123 key->size);124 if (err) {125 blk_crypto_fallback_evict_keyslot(slot);126 return err;127 }128 return 0;129}130 131static int blk_crypto_fallback_keyslot_evict(struct blk_crypto_profile *profile,132 const struct blk_crypto_key *key,133 unsigned int slot)134{135 blk_crypto_fallback_evict_keyslot(slot);136 return 0;137}138 139static const struct blk_crypto_ll_ops blk_crypto_fallback_ll_ops = {140 .keyslot_program = blk_crypto_fallback_keyslot_program,141 .keyslot_evict = blk_crypto_fallback_keyslot_evict,142};143 144static void blk_crypto_fallback_encrypt_endio(struct bio *enc_bio)145{146 struct bio *src_bio = enc_bio->bi_private;147 int i;148 149 for (i = 0; i < enc_bio->bi_vcnt; i++)150 mempool_free(enc_bio->bi_io_vec[i].bv_page,151 blk_crypto_bounce_page_pool);152 153 src_bio->bi_status = enc_bio->bi_status;154 155 bio_uninit(enc_bio);156 kfree(enc_bio);157 bio_endio(src_bio);158}159 160static struct bio *blk_crypto_fallback_clone_bio(struct bio *bio_src)161{162 unsigned int nr_segs = bio_segments(bio_src);163 struct bvec_iter iter;164 struct bio_vec bv;165 struct bio *bio;166 167 bio = bio_kmalloc(nr_segs, GFP_NOIO);168 if (!bio)169 return NULL;170 bio_init(bio, bio_src->bi_bdev, bio->bi_inline_vecs, nr_segs,171 bio_src->bi_opf);172 if (bio_flagged(bio_src, BIO_REMAPPED))173 bio_set_flag(bio, BIO_REMAPPED);174 bio->bi_ioprio = bio_src->bi_ioprio;175 bio->bi_write_hint = bio_src->bi_write_hint;176 bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;177 bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;178 179 bio_for_each_segment(bv, bio_src, iter)180 bio->bi_io_vec[bio->bi_vcnt++] = bv;181 182 bio_clone_blkg_association(bio, bio_src);183 184 return bio;185}186 187static bool188blk_crypto_fallback_alloc_cipher_req(struct blk_crypto_keyslot *slot,189 struct skcipher_request **ciph_req_ret,190 struct crypto_wait *wait)191{192 struct skcipher_request *ciph_req;193 const struct blk_crypto_fallback_keyslot *slotp;194 int keyslot_idx = blk_crypto_keyslot_index(slot);195 196 slotp = &blk_crypto_keyslots[keyslot_idx];197 ciph_req = skcipher_request_alloc(slotp->tfms[slotp->crypto_mode],198 GFP_NOIO);199 if (!ciph_req)200 return false;201 202 skcipher_request_set_callback(ciph_req,203 CRYPTO_TFM_REQ_MAY_BACKLOG |204 CRYPTO_TFM_REQ_MAY_SLEEP,205 crypto_req_done, wait);206 *ciph_req_ret = ciph_req;207 208 return true;209}210 211static bool blk_crypto_fallback_split_bio_if_needed(struct bio **bio_ptr)212{213 struct bio *bio = *bio_ptr;214 unsigned int i = 0;215 unsigned int num_sectors = 0;216 struct bio_vec bv;217 struct bvec_iter iter;218 219 bio_for_each_segment(bv, bio, iter) {220 num_sectors += bv.bv_len >> SECTOR_SHIFT;221 if (++i == BIO_MAX_VECS)222 break;223 }224 if (num_sectors < bio_sectors(bio)) {225 struct bio *split_bio;226 227 split_bio = bio_split(bio, num_sectors, GFP_NOIO,228 &crypto_bio_split);229 if (!split_bio) {230 bio->bi_status = BLK_STS_RESOURCE;231 return false;232 }233 bio_chain(split_bio, bio);234 submit_bio_noacct(bio);235 *bio_ptr = split_bio;236 }237 238 return true;239}240 241union blk_crypto_iv {242 __le64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE];243 u8 bytes[BLK_CRYPTO_MAX_IV_SIZE];244};245 246static void blk_crypto_dun_to_iv(const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],247 union blk_crypto_iv *iv)248{249 int i;250 251 for (i = 0; i < BLK_CRYPTO_DUN_ARRAY_SIZE; i++)252 iv->dun[i] = cpu_to_le64(dun[i]);253}254 255/*256 * The crypto API fallback's encryption routine.257 * Allocate a bounce bio for encryption, encrypt the input bio using crypto API,258 * and replace *bio_ptr with the bounce bio. May split input bio if it's too259 * large. Returns true on success. Returns false and sets bio->bi_status on260 * error.261 */262static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)263{264 struct bio *src_bio, *enc_bio;265 struct bio_crypt_ctx *bc;266 struct blk_crypto_keyslot *slot;267 int data_unit_size;268 struct skcipher_request *ciph_req = NULL;269 DECLARE_CRYPTO_WAIT(wait);270 u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];271 struct scatterlist src, dst;272 union blk_crypto_iv iv;273 unsigned int i, j;274 bool ret = false;275 blk_status_t blk_st;276 277 /* Split the bio if it's too big for single page bvec */278 if (!blk_crypto_fallback_split_bio_if_needed(bio_ptr))279 return false;280 281 src_bio = *bio_ptr;282 bc = src_bio->bi_crypt_context;283 data_unit_size = bc->bc_key->crypto_cfg.data_unit_size;284 285 /* Allocate bounce bio for encryption */286 enc_bio = blk_crypto_fallback_clone_bio(src_bio);287 if (!enc_bio) {288 src_bio->bi_status = BLK_STS_RESOURCE;289 return false;290 }291 292 /*293 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for294 * this bio's algorithm and key.295 */296 blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,297 bc->bc_key, &slot);298 if (blk_st != BLK_STS_OK) {299 src_bio->bi_status = blk_st;300 goto out_put_enc_bio;301 }302 303 /* and then allocate an skcipher_request for it */304 if (!blk_crypto_fallback_alloc_cipher_req(slot, &ciph_req, &wait)) {305 src_bio->bi_status = BLK_STS_RESOURCE;306 goto out_release_keyslot;307 }308 309 memcpy(curr_dun, bc->bc_dun, sizeof(curr_dun));310 sg_init_table(&src, 1);311 sg_init_table(&dst, 1);312 313 skcipher_request_set_crypt(ciph_req, &src, &dst, data_unit_size,314 iv.bytes);315 316 /* Encrypt each page in the bounce bio */317 for (i = 0; i < enc_bio->bi_vcnt; i++) {318 struct bio_vec *enc_bvec = &enc_bio->bi_io_vec[i];319 struct page *plaintext_page = enc_bvec->bv_page;320 struct page *ciphertext_page =321 mempool_alloc(blk_crypto_bounce_page_pool, GFP_NOIO);322 323 enc_bvec->bv_page = ciphertext_page;324 325 if (!ciphertext_page) {326 src_bio->bi_status = BLK_STS_RESOURCE;327 goto out_free_bounce_pages;328 }329 330 sg_set_page(&src, plaintext_page, data_unit_size,331 enc_bvec->bv_offset);332 sg_set_page(&dst, ciphertext_page, data_unit_size,333 enc_bvec->bv_offset);334 335 /* Encrypt each data unit in this page */336 for (j = 0; j < enc_bvec->bv_len; j += data_unit_size) {337 blk_crypto_dun_to_iv(curr_dun, &iv);338 if (crypto_wait_req(crypto_skcipher_encrypt(ciph_req),339 &wait)) {340 i++;341 src_bio->bi_status = BLK_STS_IOERR;342 goto out_free_bounce_pages;343 }344 bio_crypt_dun_increment(curr_dun, 1);345 src.offset += data_unit_size;346 dst.offset += data_unit_size;347 }348 }349 350 enc_bio->bi_private = src_bio;351 enc_bio->bi_end_io = blk_crypto_fallback_encrypt_endio;352 *bio_ptr = enc_bio;353 ret = true;354 355 enc_bio = NULL;356 goto out_free_ciph_req;357 358out_free_bounce_pages:359 while (i > 0)360 mempool_free(enc_bio->bi_io_vec[--i].bv_page,361 blk_crypto_bounce_page_pool);362out_free_ciph_req:363 skcipher_request_free(ciph_req);364out_release_keyslot:365 blk_crypto_put_keyslot(slot);366out_put_enc_bio:367 if (enc_bio)368 bio_uninit(enc_bio);369 kfree(enc_bio);370 return ret;371}372 373/*374 * The crypto API fallback's main decryption routine.375 * Decrypts input bio in place, and calls bio_endio on the bio.376 */377static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)378{379 struct bio_fallback_crypt_ctx *f_ctx =380 container_of(work, struct bio_fallback_crypt_ctx, work);381 struct bio *bio = f_ctx->bio;382 struct bio_crypt_ctx *bc = &f_ctx->crypt_ctx;383 struct blk_crypto_keyslot *slot;384 struct skcipher_request *ciph_req = NULL;385 DECLARE_CRYPTO_WAIT(wait);386 u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];387 union blk_crypto_iv iv;388 struct scatterlist sg;389 struct bio_vec bv;390 struct bvec_iter iter;391 const int data_unit_size = bc->bc_key->crypto_cfg.data_unit_size;392 unsigned int i;393 blk_status_t blk_st;394 395 /*396 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for397 * this bio's algorithm and key.398 */399 blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,400 bc->bc_key, &slot);401 if (blk_st != BLK_STS_OK) {402 bio->bi_status = blk_st;403 goto out_no_keyslot;404 }405 406 /* and then allocate an skcipher_request for it */407 if (!blk_crypto_fallback_alloc_cipher_req(slot, &ciph_req, &wait)) {408 bio->bi_status = BLK_STS_RESOURCE;409 goto out;410 }411 412 memcpy(curr_dun, bc->bc_dun, sizeof(curr_dun));413 sg_init_table(&sg, 1);414 skcipher_request_set_crypt(ciph_req, &sg, &sg, data_unit_size,415 iv.bytes);416 417 /* Decrypt each segment in the bio */418 __bio_for_each_segment(bv, bio, iter, f_ctx->crypt_iter) {419 struct page *page = bv.bv_page;420 421 sg_set_page(&sg, page, data_unit_size, bv.bv_offset);422 423 /* Decrypt each data unit in the segment */424 for (i = 0; i < bv.bv_len; i += data_unit_size) {425 blk_crypto_dun_to_iv(curr_dun, &iv);426 if (crypto_wait_req(crypto_skcipher_decrypt(ciph_req),427 &wait)) {428 bio->bi_status = BLK_STS_IOERR;429 goto out;430 }431 bio_crypt_dun_increment(curr_dun, 1);432 sg.offset += data_unit_size;433 }434 }435 436out:437 skcipher_request_free(ciph_req);438 blk_crypto_put_keyslot(slot);439out_no_keyslot:440 mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);441 bio_endio(bio);442}443 444/**445 * blk_crypto_fallback_decrypt_endio - queue bio for fallback decryption446 *447 * @bio: the bio to queue448 *449 * Restore bi_private and bi_end_io, and queue the bio for decryption into a450 * workqueue, since this function will be called from an atomic context.451 */452static void blk_crypto_fallback_decrypt_endio(struct bio *bio)453{454 struct bio_fallback_crypt_ctx *f_ctx = bio->bi_private;455 456 bio->bi_private = f_ctx->bi_private_orig;457 bio->bi_end_io = f_ctx->bi_end_io_orig;458 459 /* If there was an IO error, don't queue for decrypt. */460 if (bio->bi_status) {461 mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);462 bio_endio(bio);463 return;464 }465 466 INIT_WORK(&f_ctx->work, blk_crypto_fallback_decrypt_bio);467 f_ctx->bio = bio;468 queue_work(blk_crypto_wq, &f_ctx->work);469}470 471/**472 * blk_crypto_fallback_bio_prep - Prepare a bio to use fallback en/decryption473 *474 * @bio_ptr: pointer to the bio to prepare475 *476 * If bio is doing a WRITE operation, this splits the bio into two parts if it's477 * too big (see blk_crypto_fallback_split_bio_if_needed()). It then allocates a478 * bounce bio for the first part, encrypts it, and updates bio_ptr to point to479 * the bounce bio.480 *481 * For a READ operation, we mark the bio for decryption by using bi_private and482 * bi_end_io.483 *484 * In either case, this function will make the bio look like a regular bio (i.e.485 * as if no encryption context was ever specified) for the purposes of the rest486 * of the stack except for blk-integrity (blk-integrity and blk-crypto are not487 * currently supported together).488 *489 * Return: true on success. Sets bio->bi_status and returns false on error.490 */491bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)492{493 struct bio *bio = *bio_ptr;494 struct bio_crypt_ctx *bc = bio->bi_crypt_context;495 struct bio_fallback_crypt_ctx *f_ctx;496 497 if (WARN_ON_ONCE(!tfms_inited[bc->bc_key->crypto_cfg.crypto_mode])) {498 /* User didn't call blk_crypto_start_using_key() first */499 bio->bi_status = BLK_STS_IOERR;500 return false;501 }502 503 if (!__blk_crypto_cfg_supported(blk_crypto_fallback_profile,504 &bc->bc_key->crypto_cfg)) {505 bio->bi_status = BLK_STS_NOTSUPP;506 return false;507 }508 509 if (bio_data_dir(bio) == WRITE)510 return blk_crypto_fallback_encrypt_bio(bio_ptr);511 512 /*513 * bio READ case: Set up a f_ctx in the bio's bi_private and set the514 * bi_end_io appropriately to trigger decryption when the bio is ended.515 */516 f_ctx = mempool_alloc(bio_fallback_crypt_ctx_pool, GFP_NOIO);517 f_ctx->crypt_ctx = *bc;518 f_ctx->crypt_iter = bio->bi_iter;519 f_ctx->bi_private_orig = bio->bi_private;520 f_ctx->bi_end_io_orig = bio->bi_end_io;521 bio->bi_private = (void *)f_ctx;522 bio->bi_end_io = blk_crypto_fallback_decrypt_endio;523 bio_crypt_free_ctx(bio);524 525 return true;526}527 528int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)529{530 return __blk_crypto_evict_key(blk_crypto_fallback_profile, key);531}532 533static bool blk_crypto_fallback_inited;534static int blk_crypto_fallback_init(void)535{536 int i;537 int err;538 539 if (blk_crypto_fallback_inited)540 return 0;541 542 get_random_bytes(blank_key, BLK_CRYPTO_MAX_KEY_SIZE);543 544 err = bioset_init(&crypto_bio_split, 64, 0, 0);545 if (err)546 goto out;547 548 /* Dynamic allocation is needed because of lockdep_register_key(). */549 blk_crypto_fallback_profile =550 kzalloc(sizeof(*blk_crypto_fallback_profile), GFP_KERNEL);551 if (!blk_crypto_fallback_profile) {552 err = -ENOMEM;553 goto fail_free_bioset;554 }555 556 err = blk_crypto_profile_init(blk_crypto_fallback_profile,557 blk_crypto_num_keyslots);558 if (err)559 goto fail_free_profile;560 err = -ENOMEM;561 562 blk_crypto_fallback_profile->ll_ops = blk_crypto_fallback_ll_ops;563 blk_crypto_fallback_profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;564 565 /* All blk-crypto modes have a crypto API fallback. */566 for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++)567 blk_crypto_fallback_profile->modes_supported[i] = 0xFFFFFFFF;568 blk_crypto_fallback_profile->modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;569 570 blk_crypto_wq = alloc_workqueue("blk_crypto_wq",571 WQ_UNBOUND | WQ_HIGHPRI |572 WQ_MEM_RECLAIM, num_online_cpus());573 if (!blk_crypto_wq)574 goto fail_destroy_profile;575 576 blk_crypto_keyslots = kcalloc(blk_crypto_num_keyslots,577 sizeof(blk_crypto_keyslots[0]),578 GFP_KERNEL);579 if (!blk_crypto_keyslots)580 goto fail_free_wq;581 582 blk_crypto_bounce_page_pool =583 mempool_create_page_pool(num_prealloc_bounce_pg, 0);584 if (!blk_crypto_bounce_page_pool)585 goto fail_free_keyslots;586 587 bio_fallback_crypt_ctx_cache = KMEM_CACHE(bio_fallback_crypt_ctx, 0);588 if (!bio_fallback_crypt_ctx_cache)589 goto fail_free_bounce_page_pool;590 591 bio_fallback_crypt_ctx_pool =592 mempool_create_slab_pool(num_prealloc_fallback_crypt_ctxs,593 bio_fallback_crypt_ctx_cache);594 if (!bio_fallback_crypt_ctx_pool)595 goto fail_free_crypt_ctx_cache;596 597 blk_crypto_fallback_inited = true;598 599 return 0;600fail_free_crypt_ctx_cache:601 kmem_cache_destroy(bio_fallback_crypt_ctx_cache);602fail_free_bounce_page_pool:603 mempool_destroy(blk_crypto_bounce_page_pool);604fail_free_keyslots:605 kfree(blk_crypto_keyslots);606fail_free_wq:607 destroy_workqueue(blk_crypto_wq);608fail_destroy_profile:609 blk_crypto_profile_destroy(blk_crypto_fallback_profile);610fail_free_profile:611 kfree(blk_crypto_fallback_profile);612fail_free_bioset:613 bioset_exit(&crypto_bio_split);614out:615 return err;616}617 618/*619 * Prepare blk-crypto-fallback for the specified crypto mode.620 * Returns -ENOPKG if the needed crypto API support is missing.621 */622int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)623{624 const char *cipher_str = blk_crypto_modes[mode_num].cipher_str;625 struct blk_crypto_fallback_keyslot *slotp;626 unsigned int i;627 int err = 0;628 629 /*630 * Fast path631 * Ensure that updates to blk_crypto_keyslots[i].tfms[mode_num]632 * for each i are visible before we try to access them.633 */634 if (likely(smp_load_acquire(&tfms_inited[mode_num])))635 return 0;636 637 mutex_lock(&tfms_init_lock);638 if (tfms_inited[mode_num])639 goto out;640 641 err = blk_crypto_fallback_init();642 if (err)643 goto out;644 645 for (i = 0; i < blk_crypto_num_keyslots; i++) {646 slotp = &blk_crypto_keyslots[i];647 slotp->tfms[mode_num] = crypto_alloc_skcipher(cipher_str, 0, 0);648 if (IS_ERR(slotp->tfms[mode_num])) {649 err = PTR_ERR(slotp->tfms[mode_num]);650 if (err == -ENOENT) {651 pr_warn_once("Missing crypto API support for \"%s\"\n",652 cipher_str);653 err = -ENOPKG;654 }655 slotp->tfms[mode_num] = NULL;656 goto out_free_tfms;657 }658 659 crypto_skcipher_set_flags(slotp->tfms[mode_num],660 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);661 }662 663 /*664 * Ensure that updates to blk_crypto_keyslots[i].tfms[mode_num]665 * for each i are visible before we set tfms_inited[mode_num].666 */667 smp_store_release(&tfms_inited[mode_num], true);668 goto out;669 670out_free_tfms:671 for (i = 0; i < blk_crypto_num_keyslots; i++) {672 slotp = &blk_crypto_keyslots[i];673 crypto_free_skcipher(slotp->tfms[mode_num]);674 slotp->tfms[mode_num] = NULL;675 }676out:677 mutex_unlock(&tfms_init_lock);678 return err;679}680