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crypto: vmx - ghash: do nosimd fallback manually

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VMX ghash was using a fallback that did not support interleaving simd
and nosimd operations, leading to failures in the extended test suite.

If I understood correctly, Eric's suggestion was to use the same
data format that the generic code uses, allowing us to call into it
with the same contexts. I wasn't able to get that to work - I think
there's a very different key structure and data layout being used.

So instead steal the arm64 approach and perform the fallback
operations directly if required.

Fixes: cc333cd68d ("crypto: vmx - Adding GHASH routines for VMX module")
Cc: stable@vger.kernel.org # v4.1+
Reported-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Daniel Axtens 2019-05-17 01:40:02 +10:00 committed by Herbert Xu
parent 009b30ac74
commit 357d065a44
1 changed files with 86 additions and 125 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

211
drivers/crypto/vmx/ghash.c
View File

@ -1,22 +1,14 @@
// SPDX-License-Identifier: GPL-2.0
/**
* GHASH routines supporting VMX instructions on the Power 8
*
* Copyright (C) 2015 International Business Machines Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 only.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* Copyright (C) 2015, 2019 International Business Machines Inc.
*
* Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
*
* Extended by Daniel Axtens <dja@axtens.net> to replace the fallback
* mechanism. The new approach is based on arm64 code, which is:
* Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
*/
#include <linux/types.h>
@ -38,70 +30,25 @@ void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
const u8 *in, size_t len);
struct p8_ghash_ctx {
/* key used by vector asm */
u128 htable[16];
struct crypto_shash *fallback;
/* key used by software fallback */
be128 key;
};
struct p8_ghash_desc_ctx {
u64 shash[2];
u8 buffer[GHASH_DIGEST_SIZE];
int bytes;
struct shash_desc fallback_desc;
};
static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
{
const char *alg = "ghash-generic";
struct crypto_shash *fallback;
struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
fallback = crypto_alloc_shash(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback)) {
printk(KERN_ERR
"Failed to allocate transformation for '%s': %ld\n",
alg, PTR_ERR(fallback));
return PTR_ERR(fallback);
}
crypto_shash_set_flags(fallback,
crypto_shash_get_flags((struct crypto_shash
*) tfm));
/* Check if the descsize defined in the algorithm is still enough. */
if (shash_tfm->descsize < sizeof(struct p8_ghash_desc_ctx)
+ crypto_shash_descsize(fallback)) {
printk(KERN_ERR
"Desc size of the fallback implementation (%s) does not match the expected value: %lu vs %u\n",
alg,
shash_tfm->descsize - sizeof(struct p8_ghash_desc_ctx),
crypto_shash_descsize(fallback));
return -EINVAL;
}
ctx->fallback = fallback;
return 0;
}
static void p8_ghash_exit_tfm(struct crypto_tfm *tfm)
{
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
if (ctx->fallback) {
crypto_free_shash(ctx->fallback);
ctx->fallback = NULL;
}
}
static int p8_ghash_init(struct shash_desc *desc)
{
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
dctx->bytes = 0;
memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
dctx->fallback_desc.tfm = ctx->fallback;
return crypto_shash_init(&dctx->fallback_desc);
return 0;
}
static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
@ -119,7 +66,51 @@ static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
return crypto_shash_setkey(ctx->fallback, key, keylen);
memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);
return 0;
}
static inline void __ghash_block(struct p8_ghash_ctx *ctx,
struct p8_ghash_desc_ctx *dctx)
{
if (crypto_simd_usable()) {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable,
dctx->buffer, GHASH_DIGEST_SIZE);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
} else {
crypto_xor((u8 *)dctx->shash, dctx->buffer, GHASH_BLOCK_SIZE);
gf128mul_lle((be128 *)dctx->shash, &ctx->key);
}
}
static inline void __ghash_blocks(struct p8_ghash_ctx *ctx,
struct p8_ghash_desc_ctx *dctx,
const u8 *src, unsigned int srclen)
{
if (crypto_simd_usable()) {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable,
src, srclen);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
} else {
while (srclen >= GHASH_BLOCK_SIZE) {
crypto_xor((u8 *)dctx->shash, src, GHASH_BLOCK_SIZE);
gf128mul_lle((be128 *)dctx->shash, &ctx->key);
srclen -= GHASH_BLOCK_SIZE;
src += GHASH_BLOCK_SIZE;
}
}
}
static int p8_ghash_update(struct shash_desc *desc,
@ -129,49 +120,33 @@ static int p8_ghash_update(struct shash_desc *desc,
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
if (!crypto_simd_usable()) {
return crypto_shash_update(&dctx->fallback_desc, src,
srclen);
} else {
if (dctx->bytes) {
if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
memcpy(dctx->buffer + dctx->bytes, src,
srclen);
dctx->bytes += srclen;
return 0;
}
if (dctx->bytes) {
if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
memcpy(dctx->buffer + dctx->bytes, src,
GHASH_DIGEST_SIZE - dctx->bytes);
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable,
dctx->buffer, GHASH_DIGEST_SIZE);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
src += GHASH_DIGEST_SIZE - dctx->bytes;
srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
dctx->bytes = 0;
srclen);
dctx->bytes += srclen;
return 0;
}
len = srclen & ~(GHASH_DIGEST_SIZE - 1);
if (len) {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
src += len;
srclen -= len;
}
if (srclen) {
memcpy(dctx->buffer, src, srclen);
dctx->bytes = srclen;
}
return 0;
memcpy(dctx->buffer + dctx->bytes, src,
GHASH_DIGEST_SIZE - dctx->bytes);
__ghash_block(ctx, dctx);
src += GHASH_DIGEST_SIZE - dctx->bytes;
srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
dctx->bytes = 0;
}
len = srclen & ~(GHASH_DIGEST_SIZE - 1);
if (len) {
__ghash_blocks(ctx, dctx, src, len);
src += len;
srclen -= len;
}
if (srclen) {
memcpy(dctx->buffer, src, srclen);
dctx->bytes = srclen;
}
return 0;
}
static int p8_ghash_final(struct shash_desc *desc, u8 *out)
@ -180,25 +155,14 @@ static int p8_ghash_final(struct shash_desc *desc, u8 *out)
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
if (!crypto_simd_usable()) {
return crypto_shash_final(&dctx->fallback_desc, out);
} else {
if (dctx->bytes) {
for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
dctx->buffer[i] = 0;
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable,
dctx->buffer, GHASH_DIGEST_SIZE);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
dctx->bytes = 0;
}
memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
return 0;
if (dctx->bytes) {
for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
dctx->buffer[i] = 0;
__ghash_block(ctx, dctx);
dctx->bytes = 0;
}
memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
return 0;
}
struct shash_alg p8_ghash_alg = {
@ -213,11 +177,8 @@ struct shash_alg p8_ghash_alg = {
.cra_name = "ghash",
.cra_driver_name = "p8_ghash",
.cra_priority = 1000,
.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = GHASH_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct p8_ghash_ctx),
.cra_module = THIS_MODULE,
.cra_init = p8_ghash_init_tfm,
.cra_exit = p8_ghash_exit_tfm,
},
};