Revision 231c807a60715312e2a93a001cc9be9b888bc350 authored by Linus Torvalds on 24 March 2019, 18:42:10 UTC, committed by Linus Torvalds on 24 March 2019, 18:42:10 UTC
Pull scheduler updates from Thomas Gleixner: "Third more careful attempt for this set of fixes: - Prevent a 32bit math overflow in the cpufreq code - Fix a buffer overflow when scanning the cgroup2 cpu.max property - A set of fixes for the NOHZ scheduler logic to prevent waking up CPUs even if the capacity of the busy CPUs is sufficient along with other tweaks optimizing the behaviour for asymmetric systems (big/little)" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Skip LLC NOHZ logic for asymmetric systems sched/fair: Tune down misfit NOHZ kicks sched/fair: Comment some nohz_balancer_kick() kick conditions sched/core: Fix buffer overflow in cgroup2 property cpu.max sched/cpufreq: Fix 32-bit math overflow
salsa20_generic.c
/*
* Salsa20: Salsa20 stream cipher algorithm
*
* Copyright (c) 2007 Tan Swee Heng <thesweeheng@gmail.com>
*
* Derived from:
* - salsa20.c: Public domain C code by Daniel J. Bernstein <djb@cr.yp.to>
*
* Salsa20 is a stream cipher candidate in eSTREAM, the ECRYPT Stream
* Cipher Project. It is designed by Daniel J. Bernstein <djb@cr.yp.to>.
* More information about eSTREAM and Salsa20 can be found here:
* http://www.ecrypt.eu.org/stream/
* http://cr.yp.to/snuffle.html
*
* 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; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <asm/unaligned.h>
#include <crypto/internal/skcipher.h>
#include <linux/module.h>
#define SALSA20_IV_SIZE 8
#define SALSA20_MIN_KEY_SIZE 16
#define SALSA20_MAX_KEY_SIZE 32
#define SALSA20_BLOCK_SIZE 64
struct salsa20_ctx {
u32 initial_state[16];
};
static void salsa20_block(u32 *state, __le32 *stream)
{
u32 x[16];
int i;
memcpy(x, state, sizeof(x));
for (i = 0; i < 20; i += 2) {
x[ 4] ^= rol32((x[ 0] + x[12]), 7);
x[ 8] ^= rol32((x[ 4] + x[ 0]), 9);
x[12] ^= rol32((x[ 8] + x[ 4]), 13);
x[ 0] ^= rol32((x[12] + x[ 8]), 18);
x[ 9] ^= rol32((x[ 5] + x[ 1]), 7);
x[13] ^= rol32((x[ 9] + x[ 5]), 9);
x[ 1] ^= rol32((x[13] + x[ 9]), 13);
x[ 5] ^= rol32((x[ 1] + x[13]), 18);
x[14] ^= rol32((x[10] + x[ 6]), 7);
x[ 2] ^= rol32((x[14] + x[10]), 9);
x[ 6] ^= rol32((x[ 2] + x[14]), 13);
x[10] ^= rol32((x[ 6] + x[ 2]), 18);
x[ 3] ^= rol32((x[15] + x[11]), 7);
x[ 7] ^= rol32((x[ 3] + x[15]), 9);
x[11] ^= rol32((x[ 7] + x[ 3]), 13);
x[15] ^= rol32((x[11] + x[ 7]), 18);
x[ 1] ^= rol32((x[ 0] + x[ 3]), 7);
x[ 2] ^= rol32((x[ 1] + x[ 0]), 9);
x[ 3] ^= rol32((x[ 2] + x[ 1]), 13);
x[ 0] ^= rol32((x[ 3] + x[ 2]), 18);
x[ 6] ^= rol32((x[ 5] + x[ 4]), 7);
x[ 7] ^= rol32((x[ 6] + x[ 5]), 9);
x[ 4] ^= rol32((x[ 7] + x[ 6]), 13);
x[ 5] ^= rol32((x[ 4] + x[ 7]), 18);
x[11] ^= rol32((x[10] + x[ 9]), 7);
x[ 8] ^= rol32((x[11] + x[10]), 9);
x[ 9] ^= rol32((x[ 8] + x[11]), 13);
x[10] ^= rol32((x[ 9] + x[ 8]), 18);
x[12] ^= rol32((x[15] + x[14]), 7);
x[13] ^= rol32((x[12] + x[15]), 9);
x[14] ^= rol32((x[13] + x[12]), 13);
x[15] ^= rol32((x[14] + x[13]), 18);
}
for (i = 0; i < 16; i++)
stream[i] = cpu_to_le32(x[i] + state[i]);
if (++state[8] == 0)
state[9]++;
}
static void salsa20_docrypt(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes)
{
__le32 stream[SALSA20_BLOCK_SIZE / sizeof(__le32)];
if (dst != src)
memcpy(dst, src, bytes);
while (bytes >= SALSA20_BLOCK_SIZE) {
salsa20_block(state, stream);
crypto_xor(dst, (const u8 *)stream, SALSA20_BLOCK_SIZE);
bytes -= SALSA20_BLOCK_SIZE;
dst += SALSA20_BLOCK_SIZE;
}
if (bytes) {
salsa20_block(state, stream);
crypto_xor(dst, (const u8 *)stream, bytes);
}
}
static void salsa20_init(u32 *state, const struct salsa20_ctx *ctx,
const u8 *iv)
{
memcpy(state, ctx->initial_state, sizeof(ctx->initial_state));
state[6] = get_unaligned_le32(iv + 0);
state[7] = get_unaligned_le32(iv + 4);
}
static int salsa20_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keysize)
{
static const char sigma[16] = "expand 32-byte k";
static const char tau[16] = "expand 16-byte k";
struct salsa20_ctx *ctx = crypto_skcipher_ctx(tfm);
const char *constants;
if (keysize != SALSA20_MIN_KEY_SIZE &&
keysize != SALSA20_MAX_KEY_SIZE)
return -EINVAL;
ctx->initial_state[1] = get_unaligned_le32(key + 0);
ctx->initial_state[2] = get_unaligned_le32(key + 4);
ctx->initial_state[3] = get_unaligned_le32(key + 8);
ctx->initial_state[4] = get_unaligned_le32(key + 12);
if (keysize == 32) { /* recommended */
key += 16;
constants = sigma;
} else { /* keysize == 16 */
constants = tau;
}
ctx->initial_state[11] = get_unaligned_le32(key + 0);
ctx->initial_state[12] = get_unaligned_le32(key + 4);
ctx->initial_state[13] = get_unaligned_le32(key + 8);
ctx->initial_state[14] = get_unaligned_le32(key + 12);
ctx->initial_state[0] = get_unaligned_le32(constants + 0);
ctx->initial_state[5] = get_unaligned_le32(constants + 4);
ctx->initial_state[10] = get_unaligned_le32(constants + 8);
ctx->initial_state[15] = get_unaligned_le32(constants + 12);
/* space for the nonce; it will be overridden for each request */
ctx->initial_state[6] = 0;
ctx->initial_state[7] = 0;
/* initial block number */
ctx->initial_state[8] = 0;
ctx->initial_state[9] = 0;
return 0;
}
static int salsa20_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const struct salsa20_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
u32 state[16];
int err;
err = skcipher_walk_virt(&walk, req, false);
salsa20_init(state, ctx, walk.iv);
while (walk.nbytes > 0) {
unsigned int nbytes = walk.nbytes;
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
salsa20_docrypt(state, walk.dst.virt.addr, walk.src.virt.addr,
nbytes);
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
return err;
}
static struct skcipher_alg alg = {
.base.cra_name = "salsa20",
.base.cra_driver_name = "salsa20-generic",
.base.cra_priority = 100,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct salsa20_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = SALSA20_MIN_KEY_SIZE,
.max_keysize = SALSA20_MAX_KEY_SIZE,
.ivsize = SALSA20_IV_SIZE,
.chunksize = SALSA20_BLOCK_SIZE,
.setkey = salsa20_setkey,
.encrypt = salsa20_crypt,
.decrypt = salsa20_crypt,
};
static int __init salsa20_generic_mod_init(void)
{
return crypto_register_skcipher(&alg);
}
static void __exit salsa20_generic_mod_fini(void)
{
crypto_unregister_skcipher(&alg);
}
module_init(salsa20_generic_mod_init);
module_exit(salsa20_generic_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION ("Salsa20 stream cipher algorithm");
MODULE_ALIAS_CRYPTO("salsa20");
MODULE_ALIAS_CRYPTO("salsa20-generic");
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