Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c
index 1ad33e5..8cc01a6 100644
--- a/lib/crc-t10dif.c
+++ b/lib/crc-t10dif.c
@@ -1,11 +1,9 @@
+// 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 <martin.petersen@oracle.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2. See the file COPYING for more details.
*/
#include <linux/types.h>
@@ -14,10 +12,47 @@
#include <linux/err.h>
#include <linux/init.h>
#include <crypto/hash.h>
+#include <crypto/algapi.h>
#include <linux/static_key.h>
+#include <linux/notifier.h>
-static struct crypto_shash *crct10dif_tfm;
+static struct crypto_shash __rcu *crct10dif_tfm;
static struct static_key crct10dif_fallback __read_mostly;
+static DEFINE_MUTEX(crc_t10dif_mutex);
+
+static int crc_t10dif_rehash(struct notifier_block *self, unsigned long val, void *data)
+{
+ struct crypto_alg *alg = data;
+ struct crypto_shash *new, *old;
+
+ if (val != CRYPTO_MSG_ALG_LOADED ||
+ static_key_false(&crct10dif_fallback) ||
+ strncmp(alg->cra_name, CRC_T10DIF_STRING, strlen(CRC_T10DIF_STRING)))
+ return 0;
+
+ mutex_lock(&crc_t10dif_mutex);
+ old = rcu_dereference_protected(crct10dif_tfm,
+ lockdep_is_held(&crc_t10dif_mutex));
+ if (!old) {
+ mutex_unlock(&crc_t10dif_mutex);
+ return 0;
+ }
+ new = crypto_alloc_shash("crct10dif", 0, 0);
+ if (IS_ERR(new)) {
+ mutex_unlock(&crc_t10dif_mutex);
+ return 0;
+ }
+ rcu_assign_pointer(crct10dif_tfm, new);
+ mutex_unlock(&crc_t10dif_mutex);
+
+ synchronize_rcu();
+ crypto_free_shash(old);
+ return 0;
+}
+
+static struct notifier_block crc_t10dif_nb = {
+ .notifier_call = crc_t10dif_rehash,
+};
__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
{
@@ -30,11 +65,13 @@
if (static_key_false(&crct10dif_fallback))
return crc_t10dif_generic(crc, buffer, len);
- desc.shash.tfm = crct10dif_tfm;
- desc.shash.flags = 0;
+ rcu_read_lock();
+ desc.shash.tfm = rcu_dereference(crct10dif_tfm);
*(__u16 *)desc.ctx = crc;
err = crypto_shash_update(&desc.shash, buffer, len);
+ rcu_read_unlock();
+
BUG_ON(err);
return *(__u16 *)desc.ctx;
@@ -49,6 +86,7 @@
static int __init crc_t10dif_mod_init(void)
{
+ crypto_register_notifier(&crc_t10dif_nb);
crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
if (IS_ERR(crct10dif_tfm)) {
static_key_slow_inc(&crct10dif_fallback);
@@ -59,12 +97,24 @@
static void __exit crc_t10dif_mod_fini(void)
{
+ crypto_unregister_notifier(&crc_t10dif_nb);
crypto_free_shash(crct10dif_tfm);
}
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)
+{
+ if (static_key_false(&crct10dif_fallback))
+ return sprintf(buffer, "fallback\n");
+
+ return sprintf(buffer, "%s\n",
+ crypto_tfm_alg_driver_name(crypto_shash_tfm(crct10dif_tfm)));
+}
+
+module_param_call(transform, NULL, crc_t10dif_transform_show, NULL, 0644);
+
MODULE_DESCRIPTION("T10 DIF CRC calculation");
MODULE_LICENSE("GPL");
MODULE_SOFTDEP("pre: crct10dif");