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Revision 9a40ac86152c9cffd3dca482a15ddf9a8c5716b3 authored by Khem Raj on 04 June 2010, 03:05:15 UTC, committed by Russell King on 08 June 2010, 18:42:18 UTC 
ARM: 6164/1: Add kto and kfrom to input operands list.
 
When functions incoming parameters are not in input operands list gcc
4.5 does not load the parameters into registers before calling this
function but the inline assembly assumes valid addresses inside this
function. This breaks the code because r0 and r1 are invalid when
execution enters v4wb_copy_user_page ()

Also the constant needs to be used as third input operand so account
for that as well.

Tested on qemu arm.

CC: <stable@kernel.org>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1 parent 76962be
Raw File
arc4.c 
/* 
 * Cryptographic API
 *
 * ARC4 Cipher Algorithm
 *
 * Jon Oberheide <jon@oberheide.org>
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/crypto.h>

#define ARC4_MIN_KEY_SIZE	1
#define ARC4_MAX_KEY_SIZE	256
#define ARC4_BLOCK_SIZE		1

struct arc4_ctx {
	u8 S[256];
	u8 x, y;
};

static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
			unsigned int key_len)
{
	struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
	int i, j = 0, k = 0;

	ctx->x = 1;
	ctx->y = 0;

	for(i = 0; i < 256; i++)
		ctx->S[i] = i;

	for(i = 0; i < 256; i++)
	{
		u8 a = ctx->S[i];
		j = (j + in_key[k] + a) & 0xff;
		ctx->S[i] = ctx->S[j];
		ctx->S[j] = a;
		if(++k >= key_len)
			k = 0;
	}

	return 0;
}

static void arc4_crypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);

	u8 *const S = ctx->S;
	u8 x = ctx->x;
	u8 y = ctx->y;
	u8 a, b;

	a = S[x];
	y = (y + a) & 0xff;
	b = S[y];
	S[x] = b;
	S[y] = a;
	x = (x + 1) & 0xff;
	*out++ = *in ^ S[(a + b) & 0xff];

	ctx->x = x;
	ctx->y = y;
}

static struct crypto_alg arc4_alg = {
	.cra_name		=	"arc4",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	ARC4_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct arc4_ctx),
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(arc4_alg.cra_list),
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	ARC4_MIN_KEY_SIZE,
	.cia_max_keysize	=	ARC4_MAX_KEY_SIZE,
	.cia_setkey	   	= 	arc4_set_key,
	.cia_encrypt	 	=	arc4_crypt,
	.cia_decrypt	  	=	arc4_crypt } }
};

static int __init arc4_init(void)
{
	return crypto_register_alg(&arc4_alg);
}


static void __exit arc4_exit(void)
{
	crypto_unregister_alg(&arc4_alg);
}

module_init(arc4_init);
module_exit(arc4_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
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