~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/lib/crc-t10dif.c

Version: ~ [ linux-5.16-rc3 ] ~ [ linux-5.15.5 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.82 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.162 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.218 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.256 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.291 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.293 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * T10 Data Integrity Field CRC16 calculation
  4  *
  5  * Copyright (c) 2007 Oracle Corporation.  All rights reserved.
  6  * Written by Martin K. Petersen <martin.petersen@oracle.com>
  7  */
  8 
  9 #include <linux/types.h>
 10 #include <linux/module.h>
 11 #include <linux/crc-t10dif.h>
 12 #include <linux/err.h>
 13 #include <linux/init.h>
 14 #include <crypto/hash.h>
 15 #include <crypto/algapi.h>
 16 #include <linux/static_key.h>
 17 #include <linux/notifier.h>
 18 
 19 static struct crypto_shash __rcu *crct10dif_tfm;
 20 static struct static_key crct10dif_fallback __read_mostly;
 21 static DEFINE_MUTEX(crc_t10dif_mutex);
 22 static struct work_struct crct10dif_rehash_work;
 23 
 24 static int crc_t10dif_notify(struct notifier_block *self, unsigned long val, void *data)
 25 {
 26         struct crypto_alg *alg = data;
 27 
 28         if (val != CRYPTO_MSG_ALG_LOADED ||
 29             static_key_false(&crct10dif_fallback) ||
 30             strncmp(alg->cra_name, CRC_T10DIF_STRING, strlen(CRC_T10DIF_STRING)))
 31                 return 0;
 32 
 33         schedule_work(&crct10dif_rehash_work);
 34         return 0;
 35 }
 36 
 37 static void crc_t10dif_rehash(struct work_struct *work)
 38 {
 39         struct crypto_shash *new, *old;
 40 
 41         mutex_lock(&crc_t10dif_mutex);
 42         old = rcu_dereference_protected(crct10dif_tfm,
 43                                         lockdep_is_held(&crc_t10dif_mutex));
 44         if (!old) {
 45                 mutex_unlock(&crc_t10dif_mutex);
 46                 return;
 47         }
 48         new = crypto_alloc_shash("crct10dif", 0, 0);
 49         if (IS_ERR(new)) {
 50                 mutex_unlock(&crc_t10dif_mutex);
 51                 return;
 52         }
 53         rcu_assign_pointer(crct10dif_tfm, new);
 54         mutex_unlock(&crc_t10dif_mutex);
 55 
 56         synchronize_rcu();
 57         crypto_free_shash(old);
 58 }
 59 
 60 static struct notifier_block crc_t10dif_nb = {
 61         .notifier_call = crc_t10dif_notify,
 62 };
 63 
 64 __u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
 65 {
 66         struct {
 67                 struct shash_desc shash;
 68                 char ctx[2];
 69         } desc;
 70         int err;
 71 
 72         if (static_key_false(&crct10dif_fallback))
 73                 return crc_t10dif_generic(crc, buffer, len);
 74 
 75         rcu_read_lock();
 76         desc.shash.tfm = rcu_dereference(crct10dif_tfm);
 77         *(__u16 *)desc.ctx = crc;
 78 
 79         err = crypto_shash_update(&desc.shash, buffer, len);
 80         rcu_read_unlock();
 81 
 82         BUG_ON(err);
 83 
 84         return *(__u16 *)desc.ctx;
 85 }
 86 EXPORT_SYMBOL(crc_t10dif_update);
 87 
 88 __u16 crc_t10dif(const unsigned char *buffer, size_t len)
 89 {
 90         return crc_t10dif_update(0, buffer, len);
 91 }
 92 EXPORT_SYMBOL(crc_t10dif);
 93 
 94 static int __init crc_t10dif_mod_init(void)
 95 {
 96         struct crypto_shash *tfm;
 97 
 98         INIT_WORK(&crct10dif_rehash_work, crc_t10dif_rehash);
 99         crypto_register_notifier(&crc_t10dif_nb);
100         mutex_lock(&crc_t10dif_mutex);
101         tfm = crypto_alloc_shash("crct10dif", 0, 0);
102         if (IS_ERR(tfm)) {
103                 static_key_slow_inc(&crct10dif_fallback);
104                 tfm = NULL;
105         }
106         RCU_INIT_POINTER(crct10dif_tfm, tfm);
107         mutex_unlock(&crc_t10dif_mutex);
108         return 0;
109 }
110 
111 static void __exit crc_t10dif_mod_fini(void)
112 {
113         crypto_unregister_notifier(&crc_t10dif_nb);
114         cancel_work_sync(&crct10dif_rehash_work);
115         crypto_free_shash(rcu_dereference_protected(crct10dif_tfm, 1));
116 }
117 
118 module_init(crc_t10dif_mod_init);
119 module_exit(crc_t10dif_mod_fini);
120 
121 static int crc_t10dif_transform_show(char *buffer, const struct kernel_param *kp)
122 {
123         struct crypto_shash *tfm;
124         const char *name;
125         int len;
126 
127         if (static_key_false(&crct10dif_fallback))
128                 return sprintf(buffer, "fallback\n");
129 
130         rcu_read_lock();
131         tfm = rcu_dereference(crct10dif_tfm);
132         if (!tfm) {
133                 len = sprintf(buffer, "init\n");
134                 goto unlock;
135         }
136 
137         name = crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
138         len = sprintf(buffer, "%s\n", name);
139 
140 unlock:
141         rcu_read_unlock();
142 
143         return len;
144 }
145 
146 module_param_call(transform, NULL, crc_t10dif_transform_show, NULL, 0644);
147 
148 MODULE_DESCRIPTION("T10 DIF CRC calculation");
149 MODULE_LICENSE("GPL");
150 MODULE_SOFTDEP("pre: crct10dif");
151 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp