Memset on a local variable may be removed when it is called just before the variable goes out of scope. Using memzero_explicit defeats this optimization. A simplified version of the semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ identifier x; type T; @@ { ... when any T x[...]; ... when any when exists - memset + memzero_explicit (x, -0, ...) ... when != x when strict } // </smpl> This change was suggested by Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
		
			
				
	
	
		
			228 lines
		
	
	
	
		
			5.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			228 lines
		
	
	
	
		
			5.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/* Glue code for SHA512 hashing optimized for sparc64 crypto opcodes.
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 *
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 * This is based largely upon crypto/sha512_generic.c
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 *
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 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
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 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
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 * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
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 */
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#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
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#include <crypto/internal/hash.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/cryptohash.h>
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#include <linux/types.h>
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#include <crypto/sha.h>
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#include <asm/pstate.h>
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#include <asm/elf.h>
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#include "opcodes.h"
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asmlinkage void sha512_sparc64_transform(u64 *digest, const char *data,
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					 unsigned int rounds);
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static int sha512_sparc64_init(struct shash_desc *desc)
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{
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	struct sha512_state *sctx = shash_desc_ctx(desc);
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	sctx->state[0] = SHA512_H0;
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	sctx->state[1] = SHA512_H1;
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	sctx->state[2] = SHA512_H2;
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	sctx->state[3] = SHA512_H3;
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	sctx->state[4] = SHA512_H4;
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	sctx->state[5] = SHA512_H5;
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	sctx->state[6] = SHA512_H6;
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	sctx->state[7] = SHA512_H7;
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	sctx->count[0] = sctx->count[1] = 0;
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	return 0;
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}
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static int sha384_sparc64_init(struct shash_desc *desc)
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{
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	struct sha512_state *sctx = shash_desc_ctx(desc);
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	sctx->state[0] = SHA384_H0;
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	sctx->state[1] = SHA384_H1;
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	sctx->state[2] = SHA384_H2;
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	sctx->state[3] = SHA384_H3;
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	sctx->state[4] = SHA384_H4;
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	sctx->state[5] = SHA384_H5;
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	sctx->state[6] = SHA384_H6;
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	sctx->state[7] = SHA384_H7;
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	sctx->count[0] = sctx->count[1] = 0;
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	return 0;
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}
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static void __sha512_sparc64_update(struct sha512_state *sctx, const u8 *data,
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				    unsigned int len, unsigned int partial)
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{
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	unsigned int done = 0;
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	if ((sctx->count[0] += len) < len)
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		sctx->count[1]++;
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	if (partial) {
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		done = SHA512_BLOCK_SIZE - partial;
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		memcpy(sctx->buf + partial, data, done);
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		sha512_sparc64_transform(sctx->state, sctx->buf, 1);
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	}
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	if (len - done >= SHA512_BLOCK_SIZE) {
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		const unsigned int rounds = (len - done) / SHA512_BLOCK_SIZE;
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		sha512_sparc64_transform(sctx->state, data + done, rounds);
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		done += rounds * SHA512_BLOCK_SIZE;
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	}
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	memcpy(sctx->buf, data + done, len - done);
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}
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static int sha512_sparc64_update(struct shash_desc *desc, const u8 *data,
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				 unsigned int len)
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{
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	struct sha512_state *sctx = shash_desc_ctx(desc);
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	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
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	/* Handle the fast case right here */
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	if (partial + len < SHA512_BLOCK_SIZE) {
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		if ((sctx->count[0] += len) < len)
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			sctx->count[1]++;
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		memcpy(sctx->buf + partial, data, len);
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	} else
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		__sha512_sparc64_update(sctx, data, len, partial);
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	return 0;
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}
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static int sha512_sparc64_final(struct shash_desc *desc, u8 *out)
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{
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	struct sha512_state *sctx = shash_desc_ctx(desc);
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	unsigned int i, index, padlen;
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	__be64 *dst = (__be64 *)out;
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	__be64 bits[2];
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	static const u8 padding[SHA512_BLOCK_SIZE] = { 0x80, };
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	/* Save number of bits */
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	bits[1] = cpu_to_be64(sctx->count[0] << 3);
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	bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);
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	/* Pad out to 112 mod 128 and append length */
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	index = sctx->count[0] % SHA512_BLOCK_SIZE;
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	padlen = (index < 112) ? (112 - index) : ((SHA512_BLOCK_SIZE+112) - index);
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	/* We need to fill a whole block for __sha512_sparc64_update() */
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	if (padlen <= 112) {
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		if ((sctx->count[0] += padlen) < padlen)
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			sctx->count[1]++;
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		memcpy(sctx->buf + index, padding, padlen);
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	} else {
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		__sha512_sparc64_update(sctx, padding, padlen, index);
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	}
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	__sha512_sparc64_update(sctx, (const u8 *)&bits, sizeof(bits), 112);
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	/* Store state in digest */
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	for (i = 0; i < 8; i++)
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		dst[i] = cpu_to_be64(sctx->state[i]);
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	/* Wipe context */
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	memset(sctx, 0, sizeof(*sctx));
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	return 0;
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}
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static int sha384_sparc64_final(struct shash_desc *desc, u8 *hash)
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{
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	u8 D[64];
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	sha512_sparc64_final(desc, D);
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	memcpy(hash, D, 48);
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	memzero_explicit(D, 64);
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	return 0;
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}
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static struct shash_alg sha512 = {
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	.digestsize	=	SHA512_DIGEST_SIZE,
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	.init		=	sha512_sparc64_init,
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	.update		=	sha512_sparc64_update,
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	.final		=	sha512_sparc64_final,
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	.descsize	=	sizeof(struct sha512_state),
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	.base		=	{
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		.cra_name	=	"sha512",
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		.cra_driver_name=	"sha512-sparc64",
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		.cra_priority	=	SPARC_CR_OPCODE_PRIORITY,
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		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
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		.cra_blocksize	=	SHA512_BLOCK_SIZE,
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		.cra_module	=	THIS_MODULE,
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	}
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};
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static struct shash_alg sha384 = {
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	.digestsize	=	SHA384_DIGEST_SIZE,
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	.init		=	sha384_sparc64_init,
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	.update		=	sha512_sparc64_update,
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	.final		=	sha384_sparc64_final,
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	.descsize	=	sizeof(struct sha512_state),
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	.base		=	{
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		.cra_name	=	"sha384",
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		.cra_driver_name=	"sha384-sparc64",
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		.cra_priority	=	SPARC_CR_OPCODE_PRIORITY,
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		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
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		.cra_blocksize	=	SHA384_BLOCK_SIZE,
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		.cra_module	=	THIS_MODULE,
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	}
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};
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static bool __init sparc64_has_sha512_opcode(void)
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{
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	unsigned long cfr;
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	if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
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		return false;
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	__asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
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	if (!(cfr & CFR_SHA512))
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		return false;
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	return true;
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}
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static int __init sha512_sparc64_mod_init(void)
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{
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	if (sparc64_has_sha512_opcode()) {
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		int ret = crypto_register_shash(&sha384);
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		if (ret < 0)
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			return ret;
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		ret = crypto_register_shash(&sha512);
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		if (ret < 0) {
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			crypto_unregister_shash(&sha384);
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			return ret;
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		}
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		pr_info("Using sparc64 sha512 opcode optimized SHA-512/SHA-384 implementation\n");
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		return 0;
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	}
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	pr_info("sparc64 sha512 opcode not available.\n");
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	return -ENODEV;
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}
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static void __exit sha512_sparc64_mod_fini(void)
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{
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	crypto_unregister_shash(&sha384);
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	crypto_unregister_shash(&sha512);
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}
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module_init(sha512_sparc64_mod_init);
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module_exit(sha512_sparc64_mod_fini);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("SHA-384 and SHA-512 Secure Hash Algorithm, sparc64 sha512 opcode accelerated");
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MODULE_ALIAS_CRYPTO("sha384");
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MODULE_ALIAS_CRYPTO("sha512");
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#include "crop_devid.c"
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