![Julia Lawall](/assets/img/avatar_default.png)
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>
331 lines
8.2 KiB
C
331 lines
8.2 KiB
C
/*
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* Cryptographic API.
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*
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* Glue code for the SHA512 Secure Hash Algorithm assembler
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* implementation using supplemental SSE3 / AVX / AVX2 instructions.
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*
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* This file is based on sha512_generic.c
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*
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* Copyright (C) 2013 Intel Corporation
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* Author: Tim Chen <tim.c.chen@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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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/byteorder.h>
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#include <asm/i387.h>
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#include <asm/xcr.h>
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#include <asm/xsave.h>
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#include <linux/string.h>
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asmlinkage void sha512_transform_ssse3(const char *data, u64 *digest,
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u64 rounds);
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#ifdef CONFIG_AS_AVX
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asmlinkage void sha512_transform_avx(const char *data, u64 *digest,
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u64 rounds);
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#endif
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#ifdef CONFIG_AS_AVX2
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asmlinkage void sha512_transform_rorx(const char *data, u64 *digest,
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u64 rounds);
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#endif
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static asmlinkage void (*sha512_transform_asm)(const char *, u64 *, u64);
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static int sha512_ssse3_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 __sha512_ssse3_update(struct shash_desc *desc, const u8 *data,
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unsigned int len, unsigned int partial)
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{
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struct sha512_state *sctx = shash_desc_ctx(desc);
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unsigned int done = 0;
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sctx->count[0] += len;
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if (sctx->count[0] < 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_transform_asm(sctx->buf, sctx->state, 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_transform_asm(data + done, sctx->state, (u64) 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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return 0;
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}
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static int sha512_ssse3_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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int res;
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/* Handle the fast case right here */
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if (partial + len < SHA512_BLOCK_SIZE) {
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sctx->count[0] += len;
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if (sctx->count[0] < len)
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sctx->count[1]++;
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memcpy(sctx->buf + partial, data, len);
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return 0;
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}
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if (!irq_fpu_usable()) {
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res = crypto_sha512_update(desc, data, len);
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} else {
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kernel_fpu_begin();
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res = __sha512_ssse3_update(desc, data, len, partial);
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kernel_fpu_end();
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}
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return res;
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}
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/* Add padding and return the message digest. */
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static int sha512_ssse3_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] & 0x7f;
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padlen = (index < 112) ? (112 - index) : ((128+112) - index);
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if (!irq_fpu_usable()) {
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crypto_sha512_update(desc, padding, padlen);
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crypto_sha512_update(desc, (const u8 *)&bits, sizeof(bits));
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} else {
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kernel_fpu_begin();
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/* We need to fill a whole block for __sha512_ssse3_update() */
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if (padlen <= 112) {
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sctx->count[0] += padlen;
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if (sctx->count[0] < 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_ssse3_update(desc, padding, padlen, index);
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}
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__sha512_ssse3_update(desc, (const u8 *)&bits,
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sizeof(bits), 112);
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kernel_fpu_end();
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}
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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 sha512_ssse3_export(struct shash_desc *desc, void *out)
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{
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struct sha512_state *sctx = shash_desc_ctx(desc);
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memcpy(out, sctx, sizeof(*sctx));
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return 0;
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}
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static int sha512_ssse3_import(struct shash_desc *desc, const void *in)
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{
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struct sha512_state *sctx = shash_desc_ctx(desc);
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memcpy(sctx, in, sizeof(*sctx));
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return 0;
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}
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static int sha384_ssse3_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 int sha384_ssse3_final(struct shash_desc *desc, u8 *hash)
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{
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u8 D[SHA512_DIGEST_SIZE];
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sha512_ssse3_final(desc, D);
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memcpy(hash, D, SHA384_DIGEST_SIZE);
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memzero_explicit(D, SHA512_DIGEST_SIZE);
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return 0;
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}
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static struct shash_alg algs[] = { {
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.digestsize = SHA512_DIGEST_SIZE,
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.init = sha512_ssse3_init,
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.update = sha512_ssse3_update,
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.final = sha512_ssse3_final,
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.export = sha512_ssse3_export,
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.import = sha512_ssse3_import,
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.descsize = sizeof(struct sha512_state),
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.statesize = sizeof(struct sha512_state),
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.base = {
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.cra_name = "sha512",
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.cra_driver_name = "sha512-ssse3",
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.cra_priority = 150,
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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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.digestsize = SHA384_DIGEST_SIZE,
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.init = sha384_ssse3_init,
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.update = sha512_ssse3_update,
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.final = sha384_ssse3_final,
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.export = sha512_ssse3_export,
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.import = sha512_ssse3_import,
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.descsize = sizeof(struct sha512_state),
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.statesize = sizeof(struct sha512_state),
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.base = {
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.cra_name = "sha384",
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.cra_driver_name = "sha384-ssse3",
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.cra_priority = 150,
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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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#ifdef CONFIG_AS_AVX
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static bool __init avx_usable(void)
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{
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u64 xcr0;
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if (!cpu_has_avx || !cpu_has_osxsave)
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return false;
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xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
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if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
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pr_info("AVX detected but unusable.\n");
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return false;
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}
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return true;
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}
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#endif
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static int __init sha512_ssse3_mod_init(void)
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{
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/* test for SSSE3 first */
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if (cpu_has_ssse3)
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sha512_transform_asm = sha512_transform_ssse3;
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#ifdef CONFIG_AS_AVX
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/* allow AVX to override SSSE3, it's a little faster */
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if (avx_usable()) {
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#ifdef CONFIG_AS_AVX2
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if (boot_cpu_has(X86_FEATURE_AVX2))
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sha512_transform_asm = sha512_transform_rorx;
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else
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#endif
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sha512_transform_asm = sha512_transform_avx;
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}
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#endif
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if (sha512_transform_asm) {
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#ifdef CONFIG_AS_AVX
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if (sha512_transform_asm == sha512_transform_avx)
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pr_info("Using AVX optimized SHA-512 implementation\n");
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#ifdef CONFIG_AS_AVX2
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else if (sha512_transform_asm == sha512_transform_rorx)
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pr_info("Using AVX2 optimized SHA-512 implementation\n");
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#endif
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else
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#endif
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pr_info("Using SSSE3 optimized SHA-512 implementation\n");
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return crypto_register_shashes(algs, ARRAY_SIZE(algs));
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}
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pr_info("Neither AVX nor SSSE3 is available/usable.\n");
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return -ENODEV;
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}
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static void __exit sha512_ssse3_mod_fini(void)
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{
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crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
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}
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module_init(sha512_ssse3_mod_init);
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module_exit(sha512_ssse3_mod_fini);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("SHA512 Secure Hash Algorithm, Supplemental SSE3 accelerated");
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MODULE_ALIAS_CRYPTO("sha512");
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MODULE_ALIAS_CRYPTO("sha384");
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