From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- lib/crc-t10dif.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 lib/crc-t10dif.c (limited to 'lib/crc-t10dif.c') diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c new file mode 100644 index 0000000000..1ed2ed4870 --- /dev/null +++ b/lib/crc-t10dif.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * T10 Data Integrity Field CRC16 calculation + * + * Copyright (c) 2007 Oracle Corporation. All rights reserved. + * Written by Martin K. Petersen + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static struct crypto_shash __rcu *crct10dif_tfm; +static DEFINE_STATIC_KEY_TRUE(crct10dif_fallback); +static DEFINE_MUTEX(crc_t10dif_mutex); +static struct work_struct crct10dif_rehash_work; + +static int crc_t10dif_notify(struct notifier_block *self, unsigned long val, void *data) +{ + struct crypto_alg *alg = data; + + if (val != CRYPTO_MSG_ALG_LOADED || + strcmp(alg->cra_name, CRC_T10DIF_STRING)) + return NOTIFY_DONE; + + schedule_work(&crct10dif_rehash_work); + return NOTIFY_OK; +} + +static void crc_t10dif_rehash(struct work_struct *work) +{ + struct crypto_shash *new, *old; + + mutex_lock(&crc_t10dif_mutex); + old = rcu_dereference_protected(crct10dif_tfm, + lockdep_is_held(&crc_t10dif_mutex)); + new = crypto_alloc_shash(CRC_T10DIF_STRING, 0, 0); + if (IS_ERR(new)) { + mutex_unlock(&crc_t10dif_mutex); + return; + } + rcu_assign_pointer(crct10dif_tfm, new); + mutex_unlock(&crc_t10dif_mutex); + + if (old) { + synchronize_rcu(); + crypto_free_shash(old); + } else { + static_branch_disable(&crct10dif_fallback); + } +} + +static struct notifier_block crc_t10dif_nb = { + .notifier_call = crc_t10dif_notify, +}; + +__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len) +{ + struct { + struct shash_desc shash; + __u16 crc; + } desc; + int err; + + if (static_branch_unlikely(&crct10dif_fallback)) + return crc_t10dif_generic(crc, buffer, len); + + rcu_read_lock(); + desc.shash.tfm = rcu_dereference(crct10dif_tfm); + desc.crc = crc; + err = crypto_shash_update(&desc.shash, buffer, len); + rcu_read_unlock(); + + BUG_ON(err); + + return desc.crc; +} +EXPORT_SYMBOL(crc_t10dif_update); + +__u16 crc_t10dif(const unsigned char *buffer, size_t len) +{ + return crc_t10dif_update(0, buffer, len); +} +EXPORT_SYMBOL(crc_t10dif); + +static int __init crc_t10dif_mod_init(void) +{ + INIT_WORK(&crct10dif_rehash_work, crc_t10dif_rehash); + crypto_register_notifier(&crc_t10dif_nb); + crc_t10dif_rehash(&crct10dif_rehash_work); + return 0; +} + +static void __exit crc_t10dif_mod_fini(void) +{ + crypto_unregister_notifier(&crc_t10dif_nb); + cancel_work_sync(&crct10dif_rehash_work); + crypto_free_shash(rcu_dereference_protected(crct10dif_tfm, 1)); +} + +module_init(crc_t10dif_mod_init); +module_exit(crc_t10dif_mod_fini); + +static int crc_t10dif_transform_show(char *buffer, const struct kernel_param *kp) +{ + struct crypto_shash *tfm; + int len; + + if (static_branch_unlikely(&crct10dif_fallback)) + return sprintf(buffer, "fallback\n"); + + rcu_read_lock(); + tfm = rcu_dereference(crct10dif_tfm); + len = snprintf(buffer, PAGE_SIZE, "%s\n", + crypto_shash_driver_name(tfm)); + rcu_read_unlock(); + + return len; +} + +module_param_call(transform, NULL, crc_t10dif_transform_show, NULL, 0444); + +MODULE_DESCRIPTION("T10 DIF CRC calculation (library API)"); +MODULE_LICENSE("GPL"); +MODULE_SOFTDEP("pre: crct10dif"); -- cgit v1.2.3