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https://github.com/torvalds/linux
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26052f9b9b
Unfortunately, even with a softdep some distros fail to include the necessary modules in the initrd. Therefore this patch adds a fallback path to restore existing behaviour where we cannot load the new crypto crct10dif algorithm. In order to do this, the underlying crct10dif has been split out from the crypto implementation so that it can be used on the fallback path. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
/*
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* T10 Data Integrity Field CRC16 calculation
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*
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* Copyright (c) 2007 Oracle Corporation. All rights reserved.
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* Written by Martin K. Petersen <martin.petersen@oracle.com>
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/crc-t10dif.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <crypto/hash.h>
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#include <linux/static_key.h>
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static struct crypto_shash *crct10dif_tfm;
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static struct static_key crct10dif_fallback __read_mostly;
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__u16 crc_t10dif(const unsigned char *buffer, size_t len)
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{
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struct {
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struct shash_desc shash;
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char ctx[2];
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} desc;
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int err;
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if (static_key_false(&crct10dif_fallback))
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return crc_t10dif_generic(0, buffer, len);
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desc.shash.tfm = crct10dif_tfm;
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desc.shash.flags = 0;
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*(__u16 *)desc.ctx = 0;
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err = crypto_shash_update(&desc.shash, buffer, len);
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BUG_ON(err);
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return *(__u16 *)desc.ctx;
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}
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EXPORT_SYMBOL(crc_t10dif);
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static int __init crc_t10dif_mod_init(void)
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{
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crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
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if (IS_ERR(crct10dif_tfm)) {
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static_key_slow_inc(&crct10dif_fallback);
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crct10dif_tfm = NULL;
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}
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return 0;
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}
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static void __exit crc_t10dif_mod_fini(void)
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{
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crypto_free_shash(crct10dif_tfm);
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}
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module_init(crc_t10dif_mod_init);
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module_exit(crc_t10dif_mod_fini);
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MODULE_DESCRIPTION("T10 DIF CRC calculation");
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MODULE_LICENSE("GPL");
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MODULE_SOFTDEP("pre: crct10dif");
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