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Revision becb2bb72ff906cc0d2bac3ee9574f694364823b authored by Ingo Molnar on 23 September 2017, 12:59:49 UTC, committed by Ingo Molnar on 24 September 2017, 11:04:31 UTC 
x86/fpu: Clean up the parameter definitions of copy_xstate_to_*()
 
Remove pointless 'const' of non-pointer input parameter.

Remove unnecessary parenthesis that shows uncertainty about arithmetic operator precedence.

Clarify copy_xstate_to_user() description.

No change in functionality.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-7-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Raw File
dh_helper.c 
/*
 * Copyright (c) 2016, Intel Corporation
 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
 *
 * 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 <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/string.h>
#include <crypto/dh.h>
#include <crypto/kpp.h>

#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int))

static inline u8 *dh_pack_data(void *dst, const void *src, size_t size)
{
	memcpy(dst, src, size);
	return dst + size;
}

static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
{
	memcpy(dst, src, size);
	return src + size;
}

static inline int dh_data_size(const struct dh *p)
{
	return p->key_size + p->p_size + p->g_size;
}

int crypto_dh_key_len(const struct dh *p)
{
	return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
}
EXPORT_SYMBOL_GPL(crypto_dh_key_len);

int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
{
	u8 *ptr = buf;
	struct kpp_secret secret = {
		.type = CRYPTO_KPP_SECRET_TYPE_DH,
		.len = len
	};

	if (unlikely(!buf))
		return -EINVAL;

	if (len != crypto_dh_key_len(params))
		return -EINVAL;

	ptr = dh_pack_data(ptr, &secret, sizeof(secret));
	ptr = dh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
	ptr = dh_pack_data(ptr, &params->p_size, sizeof(params->p_size));
	ptr = dh_pack_data(ptr, &params->g_size, sizeof(params->g_size));
	ptr = dh_pack_data(ptr, params->key, params->key_size);
	ptr = dh_pack_data(ptr, params->p, params->p_size);
	dh_pack_data(ptr, params->g, params->g_size);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_encode_key);

int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
{
	const u8 *ptr = buf;
	struct kpp_secret secret;

	if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
		return -EINVAL;

	ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
	if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
		return -EINVAL;

	ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
	ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
	ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
	if (secret.len != crypto_dh_key_len(params))
		return -EINVAL;

	/* Don't allocate memory. Set pointers to data within
	 * the given buffer
	 */
	params->key = (void *)ptr;
	params->p = (void *)(ptr + params->key_size);
	params->g = (void *)(ptr + params->key_size + params->p_size);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_decode_key);
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