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![Christoph Hellwig](/assets/img/avatar_default.png)
Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been horribly confusingly misnamed. Rename it to BIO_MAX_VECS to stop confusing users of the bio API. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
667 lines
18 KiB
C
667 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2019 Google LLC
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*/
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/*
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* Refer to Documentation/block/inline-encryption.rst for detailed explanation.
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*/
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#define pr_fmt(fmt) "blk-crypto-fallback: " fmt
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#include <crypto/skcipher.h>
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#include <linux/blk-cgroup.h>
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#include <linux/blk-crypto.h>
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#include <linux/blkdev.h>
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#include <linux/crypto.h>
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#include <linux/keyslot-manager.h>
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#include <linux/mempool.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include "blk-crypto-internal.h"
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static unsigned int num_prealloc_bounce_pg = 32;
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module_param(num_prealloc_bounce_pg, uint, 0);
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MODULE_PARM_DESC(num_prealloc_bounce_pg,
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"Number of preallocated bounce pages for the blk-crypto crypto API fallback");
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static unsigned int blk_crypto_num_keyslots = 100;
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module_param_named(num_keyslots, blk_crypto_num_keyslots, uint, 0);
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MODULE_PARM_DESC(num_keyslots,
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"Number of keyslots for the blk-crypto crypto API fallback");
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static unsigned int num_prealloc_fallback_crypt_ctxs = 128;
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module_param(num_prealloc_fallback_crypt_ctxs, uint, 0);
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MODULE_PARM_DESC(num_prealloc_crypt_fallback_ctxs,
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"Number of preallocated bio fallback crypto contexts for blk-crypto to use during crypto API fallback");
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struct bio_fallback_crypt_ctx {
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struct bio_crypt_ctx crypt_ctx;
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/*
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* Copy of the bvec_iter when this bio was submitted.
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* We only want to en/decrypt the part of the bio as described by the
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* bvec_iter upon submission because bio might be split before being
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* resubmitted
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*/
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struct bvec_iter crypt_iter;
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union {
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struct {
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struct work_struct work;
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struct bio *bio;
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};
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struct {
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void *bi_private_orig;
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bio_end_io_t *bi_end_io_orig;
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};
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};
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};
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static struct kmem_cache *bio_fallback_crypt_ctx_cache;
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static mempool_t *bio_fallback_crypt_ctx_pool;
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/*
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* Allocating a crypto tfm during I/O can deadlock, so we have to preallocate
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* all of a mode's tfms when that mode starts being used. Since each mode may
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* need all the keyslots at some point, each mode needs its own tfm for each
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* keyslot; thus, a keyslot may contain tfms for multiple modes. However, to
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* match the behavior of real inline encryption hardware (which only supports a
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* single encryption context per keyslot), we only allow one tfm per keyslot to
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* be used at a time - the rest of the unused tfms have their keys cleared.
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*/
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static DEFINE_MUTEX(tfms_init_lock);
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static bool tfms_inited[BLK_ENCRYPTION_MODE_MAX];
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static struct blk_crypto_keyslot {
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enum blk_crypto_mode_num crypto_mode;
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struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
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} *blk_crypto_keyslots;
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static struct blk_keyslot_manager blk_crypto_ksm;
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static struct workqueue_struct *blk_crypto_wq;
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static mempool_t *blk_crypto_bounce_page_pool;
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static struct bio_set crypto_bio_split;
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/*
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* This is the key we set when evicting a keyslot. This *should* be the all 0's
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* key, but AES-XTS rejects that key, so we use some random bytes instead.
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*/
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static u8 blank_key[BLK_CRYPTO_MAX_KEY_SIZE];
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static void blk_crypto_evict_keyslot(unsigned int slot)
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{
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struct blk_crypto_keyslot *slotp = &blk_crypto_keyslots[slot];
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enum blk_crypto_mode_num crypto_mode = slotp->crypto_mode;
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int err;
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WARN_ON(slotp->crypto_mode == BLK_ENCRYPTION_MODE_INVALID);
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/* Clear the key in the skcipher */
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err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], blank_key,
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blk_crypto_modes[crypto_mode].keysize);
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WARN_ON(err);
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slotp->crypto_mode = BLK_ENCRYPTION_MODE_INVALID;
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}
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static int blk_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
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const struct blk_crypto_key *key,
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unsigned int slot)
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{
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struct blk_crypto_keyslot *slotp = &blk_crypto_keyslots[slot];
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const enum blk_crypto_mode_num crypto_mode =
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key->crypto_cfg.crypto_mode;
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int err;
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if (crypto_mode != slotp->crypto_mode &&
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slotp->crypto_mode != BLK_ENCRYPTION_MODE_INVALID)
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blk_crypto_evict_keyslot(slot);
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slotp->crypto_mode = crypto_mode;
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err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], key->raw,
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key->size);
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if (err) {
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blk_crypto_evict_keyslot(slot);
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return err;
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}
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return 0;
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}
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static int blk_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
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const struct blk_crypto_key *key,
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unsigned int slot)
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{
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blk_crypto_evict_keyslot(slot);
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return 0;
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}
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/*
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* The crypto API fallback KSM ops - only used for a bio when it specifies a
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* blk_crypto_key that was not supported by the device's inline encryption
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* hardware.
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*/
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static const struct blk_ksm_ll_ops blk_crypto_ksm_ll_ops = {
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.keyslot_program = blk_crypto_keyslot_program,
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.keyslot_evict = blk_crypto_keyslot_evict,
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};
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static void blk_crypto_fallback_encrypt_endio(struct bio *enc_bio)
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{
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struct bio *src_bio = enc_bio->bi_private;
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int i;
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for (i = 0; i < enc_bio->bi_vcnt; i++)
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mempool_free(enc_bio->bi_io_vec[i].bv_page,
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blk_crypto_bounce_page_pool);
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src_bio->bi_status = enc_bio->bi_status;
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bio_put(enc_bio);
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bio_endio(src_bio);
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}
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static struct bio *blk_crypto_clone_bio(struct bio *bio_src)
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{
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struct bvec_iter iter;
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struct bio_vec bv;
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struct bio *bio;
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bio = bio_kmalloc(GFP_NOIO, bio_segments(bio_src));
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if (!bio)
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return NULL;
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bio->bi_bdev = bio_src->bi_bdev;
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if (bio_flagged(bio_src, BIO_REMAPPED))
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bio_set_flag(bio, BIO_REMAPPED);
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bio->bi_opf = bio_src->bi_opf;
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bio->bi_ioprio = bio_src->bi_ioprio;
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bio->bi_write_hint = bio_src->bi_write_hint;
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bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
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bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
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bio_for_each_segment(bv, bio_src, iter)
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bio->bi_io_vec[bio->bi_vcnt++] = bv;
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bio_clone_blkg_association(bio, bio_src);
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blkcg_bio_issue_init(bio);
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return bio;
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}
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static bool blk_crypto_alloc_cipher_req(struct blk_ksm_keyslot *slot,
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struct skcipher_request **ciph_req_ret,
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struct crypto_wait *wait)
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{
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struct skcipher_request *ciph_req;
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const struct blk_crypto_keyslot *slotp;
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int keyslot_idx = blk_ksm_get_slot_idx(slot);
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slotp = &blk_crypto_keyslots[keyslot_idx];
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ciph_req = skcipher_request_alloc(slotp->tfms[slotp->crypto_mode],
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GFP_NOIO);
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if (!ciph_req)
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return false;
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skcipher_request_set_callback(ciph_req,
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CRYPTO_TFM_REQ_MAY_BACKLOG |
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CRYPTO_TFM_REQ_MAY_SLEEP,
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crypto_req_done, wait);
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*ciph_req_ret = ciph_req;
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return true;
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}
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static bool blk_crypto_split_bio_if_needed(struct bio **bio_ptr)
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{
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struct bio *bio = *bio_ptr;
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unsigned int i = 0;
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unsigned int num_sectors = 0;
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struct bio_vec bv;
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struct bvec_iter iter;
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bio_for_each_segment(bv, bio, iter) {
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num_sectors += bv.bv_len >> SECTOR_SHIFT;
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if (++i == BIO_MAX_VECS)
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break;
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}
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if (num_sectors < bio_sectors(bio)) {
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struct bio *split_bio;
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split_bio = bio_split(bio, num_sectors, GFP_NOIO,
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&crypto_bio_split);
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if (!split_bio) {
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bio->bi_status = BLK_STS_RESOURCE;
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return false;
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}
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bio_chain(split_bio, bio);
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submit_bio_noacct(bio);
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*bio_ptr = split_bio;
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}
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return true;
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}
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union blk_crypto_iv {
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__le64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
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u8 bytes[BLK_CRYPTO_MAX_IV_SIZE];
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};
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static void blk_crypto_dun_to_iv(const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
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union blk_crypto_iv *iv)
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{
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int i;
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for (i = 0; i < BLK_CRYPTO_DUN_ARRAY_SIZE; i++)
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iv->dun[i] = cpu_to_le64(dun[i]);
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}
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/*
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* The crypto API fallback's encryption routine.
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* Allocate a bounce bio for encryption, encrypt the input bio using crypto API,
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* and replace *bio_ptr with the bounce bio. May split input bio if it's too
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* large. Returns true on success. Returns false and sets bio->bi_status on
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* error.
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*/
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static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
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{
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struct bio *src_bio, *enc_bio;
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struct bio_crypt_ctx *bc;
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struct blk_ksm_keyslot *slot;
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int data_unit_size;
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struct skcipher_request *ciph_req = NULL;
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DECLARE_CRYPTO_WAIT(wait);
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u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
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struct scatterlist src, dst;
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union blk_crypto_iv iv;
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unsigned int i, j;
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bool ret = false;
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blk_status_t blk_st;
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/* Split the bio if it's too big for single page bvec */
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if (!blk_crypto_split_bio_if_needed(bio_ptr))
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return false;
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src_bio = *bio_ptr;
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bc = src_bio->bi_crypt_context;
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data_unit_size = bc->bc_key->crypto_cfg.data_unit_size;
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/* Allocate bounce bio for encryption */
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enc_bio = blk_crypto_clone_bio(src_bio);
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if (!enc_bio) {
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src_bio->bi_status = BLK_STS_RESOURCE;
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return false;
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}
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/*
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* Use the crypto API fallback keyslot manager to get a crypto_skcipher
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* for the algorithm and key specified for this bio.
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*/
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blk_st = blk_ksm_get_slot_for_key(&blk_crypto_ksm, bc->bc_key, &slot);
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if (blk_st != BLK_STS_OK) {
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src_bio->bi_status = blk_st;
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goto out_put_enc_bio;
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}
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/* and then allocate an skcipher_request for it */
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if (!blk_crypto_alloc_cipher_req(slot, &ciph_req, &wait)) {
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src_bio->bi_status = BLK_STS_RESOURCE;
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goto out_release_keyslot;
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}
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memcpy(curr_dun, bc->bc_dun, sizeof(curr_dun));
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sg_init_table(&src, 1);
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sg_init_table(&dst, 1);
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skcipher_request_set_crypt(ciph_req, &src, &dst, data_unit_size,
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iv.bytes);
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/* Encrypt each page in the bounce bio */
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for (i = 0; i < enc_bio->bi_vcnt; i++) {
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struct bio_vec *enc_bvec = &enc_bio->bi_io_vec[i];
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struct page *plaintext_page = enc_bvec->bv_page;
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struct page *ciphertext_page =
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mempool_alloc(blk_crypto_bounce_page_pool, GFP_NOIO);
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enc_bvec->bv_page = ciphertext_page;
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if (!ciphertext_page) {
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src_bio->bi_status = BLK_STS_RESOURCE;
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goto out_free_bounce_pages;
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}
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sg_set_page(&src, plaintext_page, data_unit_size,
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enc_bvec->bv_offset);
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sg_set_page(&dst, ciphertext_page, data_unit_size,
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enc_bvec->bv_offset);
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/* Encrypt each data unit in this page */
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for (j = 0; j < enc_bvec->bv_len; j += data_unit_size) {
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blk_crypto_dun_to_iv(curr_dun, &iv);
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if (crypto_wait_req(crypto_skcipher_encrypt(ciph_req),
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&wait)) {
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i++;
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src_bio->bi_status = BLK_STS_IOERR;
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goto out_free_bounce_pages;
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}
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bio_crypt_dun_increment(curr_dun, 1);
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src.offset += data_unit_size;
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dst.offset += data_unit_size;
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}
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}
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enc_bio->bi_private = src_bio;
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enc_bio->bi_end_io = blk_crypto_fallback_encrypt_endio;
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*bio_ptr = enc_bio;
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ret = true;
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enc_bio = NULL;
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goto out_free_ciph_req;
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out_free_bounce_pages:
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while (i > 0)
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mempool_free(enc_bio->bi_io_vec[--i].bv_page,
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blk_crypto_bounce_page_pool);
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out_free_ciph_req:
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skcipher_request_free(ciph_req);
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out_release_keyslot:
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blk_ksm_put_slot(slot);
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out_put_enc_bio:
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if (enc_bio)
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bio_put(enc_bio);
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return ret;
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}
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/*
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* The crypto API fallback's main decryption routine.
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* Decrypts input bio in place, and calls bio_endio on the bio.
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*/
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static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
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{
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struct bio_fallback_crypt_ctx *f_ctx =
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container_of(work, struct bio_fallback_crypt_ctx, work);
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struct bio *bio = f_ctx->bio;
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struct bio_crypt_ctx *bc = &f_ctx->crypt_ctx;
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struct blk_ksm_keyslot *slot;
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struct skcipher_request *ciph_req = NULL;
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DECLARE_CRYPTO_WAIT(wait);
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u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
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union blk_crypto_iv iv;
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struct scatterlist sg;
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struct bio_vec bv;
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struct bvec_iter iter;
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const int data_unit_size = bc->bc_key->crypto_cfg.data_unit_size;
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unsigned int i;
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blk_status_t blk_st;
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/*
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* Use the crypto API fallback keyslot manager to get a crypto_skcipher
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* for the algorithm and key specified for this bio.
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*/
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blk_st = blk_ksm_get_slot_for_key(&blk_crypto_ksm, bc->bc_key, &slot);
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if (blk_st != BLK_STS_OK) {
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bio->bi_status = blk_st;
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goto out_no_keyslot;
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}
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/* and then allocate an skcipher_request for it */
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if (!blk_crypto_alloc_cipher_req(slot, &ciph_req, &wait)) {
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bio->bi_status = BLK_STS_RESOURCE;
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goto out;
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}
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memcpy(curr_dun, bc->bc_dun, sizeof(curr_dun));
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sg_init_table(&sg, 1);
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skcipher_request_set_crypt(ciph_req, &sg, &sg, data_unit_size,
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iv.bytes);
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/* Decrypt each segment in the bio */
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__bio_for_each_segment(bv, bio, iter, f_ctx->crypt_iter) {
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struct page *page = bv.bv_page;
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sg_set_page(&sg, page, data_unit_size, bv.bv_offset);
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/* Decrypt each data unit in the segment */
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for (i = 0; i < bv.bv_len; i += data_unit_size) {
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blk_crypto_dun_to_iv(curr_dun, &iv);
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if (crypto_wait_req(crypto_skcipher_decrypt(ciph_req),
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&wait)) {
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bio->bi_status = BLK_STS_IOERR;
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goto out;
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}
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bio_crypt_dun_increment(curr_dun, 1);
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sg.offset += data_unit_size;
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}
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}
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out:
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skcipher_request_free(ciph_req);
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blk_ksm_put_slot(slot);
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out_no_keyslot:
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mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);
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bio_endio(bio);
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}
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/**
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* blk_crypto_fallback_decrypt_endio - queue bio for fallback decryption
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*
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* @bio: the bio to queue
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*
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* Restore bi_private and bi_end_io, and queue the bio for decryption into a
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* workqueue, since this function will be called from an atomic context.
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*/
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static void blk_crypto_fallback_decrypt_endio(struct bio *bio)
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{
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struct bio_fallback_crypt_ctx *f_ctx = bio->bi_private;
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bio->bi_private = f_ctx->bi_private_orig;
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bio->bi_end_io = f_ctx->bi_end_io_orig;
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/* If there was an IO error, don't queue for decrypt. */
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if (bio->bi_status) {
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mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);
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|
bio_endio(bio);
|
|
return;
|
|
}
|
|
|
|
INIT_WORK(&f_ctx->work, blk_crypto_fallback_decrypt_bio);
|
|
f_ctx->bio = bio;
|
|
queue_work(blk_crypto_wq, &f_ctx->work);
|
|
}
|
|
|
|
/**
|
|
* blk_crypto_fallback_bio_prep - Prepare a bio to use fallback en/decryption
|
|
*
|
|
* @bio_ptr: pointer to the bio to prepare
|
|
*
|
|
* If bio is doing a WRITE operation, this splits the bio into two parts if it's
|
|
* too big (see blk_crypto_split_bio_if_needed). It then allocates a bounce bio
|
|
* for the first part, encrypts it, and update bio_ptr to point to the bounce
|
|
* bio.
|
|
*
|
|
* For a READ operation, we mark the bio for decryption by using bi_private and
|
|
* bi_end_io.
|
|
*
|
|
* In either case, this function will make the bio look like a regular bio (i.e.
|
|
* as if no encryption context was ever specified) for the purposes of the rest
|
|
* of the stack except for blk-integrity (blk-integrity and blk-crypto are not
|
|
* currently supported together).
|
|
*
|
|
* Return: true on success. Sets bio->bi_status and returns false on error.
|
|
*/
|
|
bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
|
|
{
|
|
struct bio *bio = *bio_ptr;
|
|
struct bio_crypt_ctx *bc = bio->bi_crypt_context;
|
|
struct bio_fallback_crypt_ctx *f_ctx;
|
|
|
|
if (WARN_ON_ONCE(!tfms_inited[bc->bc_key->crypto_cfg.crypto_mode])) {
|
|
/* User didn't call blk_crypto_start_using_key() first */
|
|
bio->bi_status = BLK_STS_IOERR;
|
|
return false;
|
|
}
|
|
|
|
if (!blk_ksm_crypto_cfg_supported(&blk_crypto_ksm,
|
|
&bc->bc_key->crypto_cfg)) {
|
|
bio->bi_status = BLK_STS_NOTSUPP;
|
|
return false;
|
|
}
|
|
|
|
if (bio_data_dir(bio) == WRITE)
|
|
return blk_crypto_fallback_encrypt_bio(bio_ptr);
|
|
|
|
/*
|
|
* bio READ case: Set up a f_ctx in the bio's bi_private and set the
|
|
* bi_end_io appropriately to trigger decryption when the bio is ended.
|
|
*/
|
|
f_ctx = mempool_alloc(bio_fallback_crypt_ctx_pool, GFP_NOIO);
|
|
f_ctx->crypt_ctx = *bc;
|
|
f_ctx->crypt_iter = bio->bi_iter;
|
|
f_ctx->bi_private_orig = bio->bi_private;
|
|
f_ctx->bi_end_io_orig = bio->bi_end_io;
|
|
bio->bi_private = (void *)f_ctx;
|
|
bio->bi_end_io = blk_crypto_fallback_decrypt_endio;
|
|
bio_crypt_free_ctx(bio);
|
|
|
|
return true;
|
|
}
|
|
|
|
int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
|
|
{
|
|
return blk_ksm_evict_key(&blk_crypto_ksm, key);
|
|
}
|
|
|
|
static bool blk_crypto_fallback_inited;
|
|
static int blk_crypto_fallback_init(void)
|
|
{
|
|
int i;
|
|
int err;
|
|
|
|
if (blk_crypto_fallback_inited)
|
|
return 0;
|
|
|
|
prandom_bytes(blank_key, BLK_CRYPTO_MAX_KEY_SIZE);
|
|
|
|
err = bioset_init(&crypto_bio_split, 64, 0, 0);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = blk_ksm_init(&blk_crypto_ksm, blk_crypto_num_keyslots);
|
|
if (err)
|
|
goto fail_free_bioset;
|
|
err = -ENOMEM;
|
|
|
|
blk_crypto_ksm.ksm_ll_ops = blk_crypto_ksm_ll_ops;
|
|
blk_crypto_ksm.max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
|
|
|
|
/* All blk-crypto modes have a crypto API fallback. */
|
|
for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++)
|
|
blk_crypto_ksm.crypto_modes_supported[i] = 0xFFFFFFFF;
|
|
blk_crypto_ksm.crypto_modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;
|
|
|
|
blk_crypto_wq = alloc_workqueue("blk_crypto_wq",
|
|
WQ_UNBOUND | WQ_HIGHPRI |
|
|
WQ_MEM_RECLAIM, num_online_cpus());
|
|
if (!blk_crypto_wq)
|
|
goto fail_free_ksm;
|
|
|
|
blk_crypto_keyslots = kcalloc(blk_crypto_num_keyslots,
|
|
sizeof(blk_crypto_keyslots[0]),
|
|
GFP_KERNEL);
|
|
if (!blk_crypto_keyslots)
|
|
goto fail_free_wq;
|
|
|
|
blk_crypto_bounce_page_pool =
|
|
mempool_create_page_pool(num_prealloc_bounce_pg, 0);
|
|
if (!blk_crypto_bounce_page_pool)
|
|
goto fail_free_keyslots;
|
|
|
|
bio_fallback_crypt_ctx_cache = KMEM_CACHE(bio_fallback_crypt_ctx, 0);
|
|
if (!bio_fallback_crypt_ctx_cache)
|
|
goto fail_free_bounce_page_pool;
|
|
|
|
bio_fallback_crypt_ctx_pool =
|
|
mempool_create_slab_pool(num_prealloc_fallback_crypt_ctxs,
|
|
bio_fallback_crypt_ctx_cache);
|
|
if (!bio_fallback_crypt_ctx_pool)
|
|
goto fail_free_crypt_ctx_cache;
|
|
|
|
blk_crypto_fallback_inited = true;
|
|
|
|
return 0;
|
|
fail_free_crypt_ctx_cache:
|
|
kmem_cache_destroy(bio_fallback_crypt_ctx_cache);
|
|
fail_free_bounce_page_pool:
|
|
mempool_destroy(blk_crypto_bounce_page_pool);
|
|
fail_free_keyslots:
|
|
kfree(blk_crypto_keyslots);
|
|
fail_free_wq:
|
|
destroy_workqueue(blk_crypto_wq);
|
|
fail_free_ksm:
|
|
blk_ksm_destroy(&blk_crypto_ksm);
|
|
fail_free_bioset:
|
|
bioset_exit(&crypto_bio_split);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Prepare blk-crypto-fallback for the specified crypto mode.
|
|
* Returns -ENOPKG if the needed crypto API support is missing.
|
|
*/
|
|
int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
|
|
{
|
|
const char *cipher_str = blk_crypto_modes[mode_num].cipher_str;
|
|
struct blk_crypto_keyslot *slotp;
|
|
unsigned int i;
|
|
int err = 0;
|
|
|
|
/*
|
|
* Fast path
|
|
* Ensure that updates to blk_crypto_keyslots[i].tfms[mode_num]
|
|
* for each i are visible before we try to access them.
|
|
*/
|
|
if (likely(smp_load_acquire(&tfms_inited[mode_num])))
|
|
return 0;
|
|
|
|
mutex_lock(&tfms_init_lock);
|
|
if (tfms_inited[mode_num])
|
|
goto out;
|
|
|
|
err = blk_crypto_fallback_init();
|
|
if (err)
|
|
goto out;
|
|
|
|
for (i = 0; i < blk_crypto_num_keyslots; i++) {
|
|
slotp = &blk_crypto_keyslots[i];
|
|
slotp->tfms[mode_num] = crypto_alloc_skcipher(cipher_str, 0, 0);
|
|
if (IS_ERR(slotp->tfms[mode_num])) {
|
|
err = PTR_ERR(slotp->tfms[mode_num]);
|
|
if (err == -ENOENT) {
|
|
pr_warn_once("Missing crypto API support for \"%s\"\n",
|
|
cipher_str);
|
|
err = -ENOPKG;
|
|
}
|
|
slotp->tfms[mode_num] = NULL;
|
|
goto out_free_tfms;
|
|
}
|
|
|
|
crypto_skcipher_set_flags(slotp->tfms[mode_num],
|
|
CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
|
|
}
|
|
|
|
/*
|
|
* Ensure that updates to blk_crypto_keyslots[i].tfms[mode_num]
|
|
* for each i are visible before we set tfms_inited[mode_num].
|
|
*/
|
|
smp_store_release(&tfms_inited[mode_num], true);
|
|
goto out;
|
|
|
|
out_free_tfms:
|
|
for (i = 0; i < blk_crypto_num_keyslots; i++) {
|
|
slotp = &blk_crypto_keyslots[i];
|
|
crypto_free_skcipher(slotp->tfms[mode_num]);
|
|
slotp->tfms[mode_num] = NULL;
|
|
}
|
|
out:
|
|
mutex_unlock(&tfms_init_lock);
|
|
return err;
|
|
}
|