https://github.com/torvalds/linux
Revision 3a7e02c040b130b5545e4b115aada7bacd80a2b6 authored by Linus Torvalds on 26 July 2024, 22:32:27 UTC, committed by Linus Torvalds on 26 July 2024, 22:32:27 UTC
The minmax infrastructure is overkill for simple constants, and can
cause huge expansions because those simple constants are then used by
other things.

For example, 'pageblock_order' is a core VM constant, but because it was
implemented using 'min_t()' and all the type-checking that involves, it
actually expanded to something like 2.5kB of preprocessor noise.

And when that simple constant was then used inside other expansions:

  #define pageblock_nr_pages      (1UL << pageblock_order)
  #define pageblock_start_pfn(pfn)  ALIGN_DOWN((pfn), pageblock_nr_pages)

and we then use that inside a 'max()' macro:

	case ISOLATE_SUCCESS:
		update_cached = false;
		last_migrated_pfn = max(cc->zone->zone_start_pfn,
			pageblock_start_pfn(cc->migrate_pfn - 1));

the end result was that one statement expanding to 253kB in size.

There are probably other cases of this, but this one case certainly
stood out.

I've added 'MIN_T()' and 'MAX_T()' macros for this kind of "core simple
constant with specific type" use.  These macros skip the type checking,
and as such need to be very sparingly used only for obvious cases that
have active issues like this.

Reported-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/all/36aa2cad-1db1-4abf-8dd2-fb20484aabc3@lucifer.local/
Cc: David Laight <David.Laight@aculab.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent e8432ac
Raw File
Tip revision: 3a7e02c040b130b5545e4b115aada7bacd80a2b6 authored by Linus Torvalds on 26 July 2024, 22:32:27 UTC
minmax: avoid overly complicated constant expressions in VM code
Tip revision: 3a7e02c
fcrypt.c
/* FCrypt encryption algorithm
 *
 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.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.
 *
 * Based on code:
 *
 * Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <asm/byteorder.h>
#include <crypto/algapi.h>
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/module.h>

#define ROUNDS 16

struct fcrypt_ctx {
	__be32 sched[ROUNDS];
};

/* Rotate right two 32 bit numbers as a 56 bit number */
#define ror56(hi, lo, n)					\
do {								\
	u32 t = lo & ((1 << n) - 1);				\
	lo = (lo >> n) | ((hi & ((1 << n) - 1)) << (32 - n));	\
	hi = (hi >> n) | (t << (24-n));				\
} while (0)

/* Rotate right one 64 bit number as a 56 bit number */
#define ror56_64(k, n) (k = (k >> n) | ((k & ((1 << n) - 1)) << (56 - n)))

/*
 * Sboxes for Feistel network derived from
 * /afs/transarc.com/public/afsps/afs.rel31b.export-src/rxkad/sboxes.h
 */
#undef Z
#define Z(x) cpu_to_be32(x << 3)
static const __be32 sbox0[256] = {
	Z(0xea), Z(0x7f), Z(0xb2), Z(0x64), Z(0x9d), Z(0xb0), Z(0xd9), Z(0x11),
	Z(0xcd), Z(0x86), Z(0x86), Z(0x91), Z(0x0a), Z(0xb2), Z(0x93), Z(0x06),
	Z(0x0e), Z(0x06), Z(0xd2), Z(0x65), Z(0x73), Z(0xc5), Z(0x28), Z(0x60),
	Z(0xf2), Z(0x20), Z(0xb5), Z(0x38), Z(0x7e), Z(0xda), Z(0x9f), Z(0xe3),
	Z(0xd2), Z(0xcf), Z(0xc4), Z(0x3c), Z(0x61), Z(0xff), Z(0x4a), Z(0x4a),
	Z(0x35), Z(0xac), Z(0xaa), Z(0x5f), Z(0x2b), Z(0xbb), Z(0xbc), Z(0x53),
	Z(0x4e), Z(0x9d), Z(0x78), Z(0xa3), Z(0xdc), Z(0x09), Z(0x32), Z(0x10),
	Z(0xc6), Z(0x6f), Z(0x66), Z(0xd6), Z(0xab), Z(0xa9), Z(0xaf), Z(0xfd),
	Z(0x3b), Z(0x95), Z(0xe8), Z(0x34), Z(0x9a), Z(0x81), Z(0x72), Z(0x80),
	Z(0x9c), Z(0xf3), Z(0xec), Z(0xda), Z(0x9f), Z(0x26), Z(0x76), Z(0x15),
	Z(0x3e), Z(0x55), Z(0x4d), Z(0xde), Z(0x84), Z(0xee), Z(0xad), Z(0xc7),
	Z(0xf1), Z(0x6b), Z(0x3d), Z(0xd3), Z(0x04), Z(0x49), Z(0xaa), Z(0x24),
	Z(0x0b), Z(0x8a), Z(0x83), Z(0xba), Z(0xfa), Z(0x85), Z(0xa0), Z(0xa8),
	Z(0xb1), Z(0xd4), Z(0x01), Z(0xd8), Z(0x70), Z(0x64), Z(0xf0), Z(0x51),
	Z(0xd2), Z(0xc3), Z(0xa7), Z(0x75), Z(0x8c), Z(0xa5), Z(0x64), Z(0xef),
	Z(0x10), Z(0x4e), Z(0xb7), Z(0xc6), Z(0x61), Z(0x03), Z(0xeb), Z(0x44),
	Z(0x3d), Z(0xe5), Z(0xb3), Z(0x5b), Z(0xae), Z(0xd5), Z(0xad), Z(0x1d),
	Z(0xfa), Z(0x5a), Z(0x1e), Z(0x33), Z(0xab), Z(0x93), Z(0xa2), Z(0xb7),
	Z(0xe7), Z(0xa8), Z(0x45), Z(0xa4), Z(0xcd), Z(0x29), Z(0x63), Z(0x44),
	Z(0xb6), Z(0x69), Z(0x7e), Z(0x2e), Z(0x62), Z(0x03), Z(0xc8), Z(0xe0),
	Z(0x17), Z(0xbb), Z(0xc7), Z(0xf3), Z(0x3f), Z(0x36), Z(0xba), Z(0x71),
	Z(0x8e), Z(0x97), Z(0x65), Z(0x60), Z(0x69), Z(0xb6), Z(0xf6), Z(0xe6),
	Z(0x6e), Z(0xe0), Z(0x81), Z(0x59), Z(0xe8), Z(0xaf), Z(0xdd), Z(0x95),
	Z(0x22), Z(0x99), Z(0xfd), Z(0x63), Z(0x19), Z(0x74), Z(0x61), Z(0xb1),
	Z(0xb6), Z(0x5b), Z(0xae), Z(0x54), Z(0xb3), Z(0x70), Z(0xff), Z(0xc6),
	Z(0x3b), Z(0x3e), Z(0xc1), Z(0xd7), Z(0xe1), Z(0x0e), Z(0x76), Z(0xe5),
	Z(0x36), Z(0x4f), Z(0x59), Z(0xc7), Z(0x08), Z(0x6e), Z(0x82), Z(0xa6),
	Z(0x93), Z(0xc4), Z(0xaa), Z(0x26), Z(0x49), Z(0xe0), Z(0x21), Z(0x64),
	Z(0x07), Z(0x9f), Z(0x64), Z(0x81), Z(0x9c), Z(0xbf), Z(0xf9), Z(0xd1),
	Z(0x43), Z(0xf8), Z(0xb6), Z(0xb9), Z(0xf1), Z(0x24), Z(0x75), Z(0x03),
	Z(0xe4), Z(0xb0), Z(0x99), Z(0x46), Z(0x3d), Z(0xf5), Z(0xd1), Z(0x39),
	Z(0x72), Z(0x12), Z(0xf6), Z(0xba), Z(0x0c), Z(0x0d), Z(0x42), Z(0x2e)
};

#undef Z
#define Z(x) cpu_to_be32(((x & 0x1f) << 27) | (x >> 5))
static const __be32 sbox1[256] = {
	Z(0x77), Z(0x14), Z(0xa6), Z(0xfe), Z(0xb2), Z(0x5e), Z(0x8c), Z(0x3e),
	Z(0x67), Z(0x6c), Z(0xa1), Z(0x0d), Z(0xc2), Z(0xa2), Z(0xc1), Z(0x85),
	Z(0x6c), Z(0x7b), Z(0x67), Z(0xc6), Z(0x23), Z(0xe3), Z(0xf2), Z(0x89),
	Z(0x50), Z(0x9c), Z(0x03), Z(0xb7), Z(0x73), Z(0xe6), Z(0xe1), Z(0x39),
	Z(0x31), Z(0x2c), Z(0x27), Z(0x9f), Z(0xa5), Z(0x69), Z(0x44), Z(0xd6),
	Z(0x23), Z(0x83), Z(0x98), Z(0x7d), Z(0x3c), Z(0xb4), Z(0x2d), Z(0x99),
	Z(0x1c), Z(0x1f), Z(0x8c), Z(0x20), Z(0x03), Z(0x7c), Z(0x5f), Z(0xad),
	Z(0xf4), Z(0xfa), Z(0x95), Z(0xca), Z(0x76), Z(0x44), Z(0xcd), Z(0xb6),
	Z(0xb8), Z(0xa1), Z(0xa1), Z(0xbe), Z(0x9e), Z(0x54), Z(0x8f), Z(0x0b),
	Z(0x16), Z(0x74), Z(0x31), Z(0x8a), Z(0x23), Z(0x17), Z(0x04), Z(0xfa),
	Z(0x79), Z(0x84), Z(0xb1), Z(0xf5), Z(0x13), Z(0xab), Z(0xb5), Z(0x2e),
	Z(0xaa), Z(0x0c), Z(0x60), Z(0x6b), Z(0x5b), Z(0xc4), Z(0x4b), Z(0xbc),
	Z(0xe2), Z(0xaf), Z(0x45), Z(0x73), Z(0xfa), Z(0xc9), Z(0x49), Z(0xcd),
	Z(0x00), Z(0x92), Z(0x7d), Z(0x97), Z(0x7a), Z(0x18), Z(0x60), Z(0x3d),
	Z(0xcf), Z(0x5b), Z(0xde), Z(0xc6), Z(0xe2), Z(0xe6), Z(0xbb), Z(0x8b),
	Z(0x06), Z(0xda), Z(0x08), Z(0x15), Z(0x1b), Z(0x88), Z(0x6a), Z(0x17),
	Z(0x89), Z(0xd0), Z(0xa9), Z(0xc1), Z(0xc9), Z(0x70), Z(0x6b), Z(0xe5),
	Z(0x43), Z(0xf4), Z(0x68), Z(0xc8), Z(0xd3), Z(0x84), Z(0x28), Z(0x0a),
	Z(0x52), Z(0x66), Z(0xa3), Z(0xca), Z(0xf2), Z(0xe3), Z(0x7f), Z(0x7a),
	Z(0x31), Z(0xf7), Z(0x88), Z(0x94), Z(0x5e), Z(0x9c), Z(0x63), Z(0xd5),
	Z(0x24), Z(0x66), Z(0xfc), Z(0xb3), Z(0x57), Z(0x25), Z(0xbe), Z(0x89),
	Z(0x44), Z(0xc4), Z(0xe0), Z(0x8f), Z(0x23), Z(0x3c), Z(0x12), Z(0x52),
	Z(0xf5), Z(0x1e), Z(0xf4), Z(0xcb), Z(0x18), Z(0x33), Z(0x1f), Z(0xf8),
	Z(0x69), Z(0x10), Z(0x9d), Z(0xd3), Z(0xf7), Z(0x28), Z(0xf8), Z(0x30),
	Z(0x05), Z(0x5e), Z(0x32), Z(0xc0), Z(0xd5), Z(0x19), Z(0xbd), Z(0x45),
	Z(0x8b), Z(0x5b), Z(0xfd), Z(0xbc), Z(0xe2), Z(0x5c), Z(0xa9), Z(0x96),
	Z(0xef), Z(0x70), Z(0xcf), Z(0xc2), Z(0x2a), Z(0xb3), Z(0x61), Z(0xad),
	Z(0x80), Z(0x48), Z(0x81), Z(0xb7), Z(0x1d), Z(0x43), Z(0xd9), Z(0xd7),
	Z(0x45), Z(0xf0), Z(0xd8), Z(0x8a), Z(0x59), Z(0x7c), Z(0x57), Z(0xc1),
	Z(0x79), Z(0xc7), Z(0x34), Z(0xd6), Z(0x43), Z(0xdf), Z(0xe4), Z(0x78),
	Z(0x16), Z(0x06), Z(0xda), Z(0x92), Z(0x76), Z(0x51), Z(0xe1), Z(0xd4),
	Z(0x70), Z(0x03), Z(0xe0), Z(0x2f), Z(0x96), Z(0x91), Z(0x82), Z(0x80)
};

#undef Z
#define Z(x) cpu_to_be32(x << 11)
static const __be32 sbox2[256] = {
	Z(0xf0), Z(0x37), Z(0x24), Z(0x53), Z(0x2a), Z(0x03), Z(0x83), Z(0x86),
	Z(0xd1), Z(0xec), Z(0x50), Z(0xf0), Z(0x42), Z(0x78), Z(0x2f), Z(0x6d),
	Z(0xbf), Z(0x80), Z(0x87), Z(0x27), Z(0x95), Z(0xe2), Z(0xc5), Z(0x5d),
	Z(0xf9), Z(0x6f), Z(0xdb), Z(0xb4), Z(0x65), Z(0x6e), Z(0xe7), Z(0x24),
	Z(0xc8), Z(0x1a), Z(0xbb), Z(0x49), Z(0xb5), Z(0x0a), Z(0x7d), Z(0xb9),
	Z(0xe8), Z(0xdc), Z(0xb7), Z(0xd9), Z(0x45), Z(0x20), Z(0x1b), Z(0xce),
	Z(0x59), Z(0x9d), Z(0x6b), Z(0xbd), Z(0x0e), Z(0x8f), Z(0xa3), Z(0xa9),
	Z(0xbc), Z(0x74), Z(0xa6), Z(0xf6), Z(0x7f), Z(0x5f), Z(0xb1), Z(0x68),
	Z(0x84), Z(0xbc), Z(0xa9), Z(0xfd), Z(0x55), Z(0x50), Z(0xe9), Z(0xb6),
	Z(0x13), Z(0x5e), Z(0x07), Z(0xb8), Z(0x95), Z(0x02), Z(0xc0), Z(0xd0),
	Z(0x6a), Z(0x1a), Z(0x85), Z(0xbd), Z(0xb6), Z(0xfd), Z(0xfe), Z(0x17),
	Z(0x3f), Z(0x09), Z(0xa3), Z(0x8d), Z(0xfb), Z(0xed), Z(0xda), Z(0x1d),
	Z(0x6d), Z(0x1c), Z(0x6c), Z(0x01), Z(0x5a), Z(0xe5), Z(0x71), Z(0x3e),
	Z(0x8b), Z(0x6b), Z(0xbe), Z(0x29), Z(0xeb), Z(0x12), Z(0x19), Z(0x34),
	Z(0xcd), Z(0xb3), Z(0xbd), Z(0x35), Z(0xea), Z(0x4b), Z(0xd5), Z(0xae),
	Z(0x2a), Z(0x79), Z(0x5a), Z(0xa5), Z(0x32), Z(0x12), Z(0x7b), Z(0xdc),
	Z(0x2c), Z(0xd0), Z(0x22), Z(0x4b), Z(0xb1), Z(0x85), Z(0x59), Z(0x80),
	Z(0xc0), Z(0x30), Z(0x9f), Z(0x73), Z(0xd3), Z(0x14), Z(0x48), Z(0x40),
	Z(0x07), Z(0x2d), Z(0x8f), Z(0x80), Z(0x0f), Z(0xce), Z(0x0b), Z(0x5e),
	Z(0xb7), Z(0x5e), Z(0xac), Z(0x24), Z(0x94), Z(0x4a), Z(0x18), Z(0x15),
	Z(0x05), Z(0xe8), Z(0x02), Z(0x77), Z(0xa9), Z(0xc7), Z(0x40), Z(0x45),
	Z(0x89), Z(0xd1), Z(0xea), Z(0xde), Z(0x0c), Z(0x79), Z(0x2a), Z(0x99),
	Z(0x6c), Z(0x3e), Z(0x95), Z(0xdd), Z(0x8c), Z(0x7d), Z(0xad), Z(0x6f),
	Z(0xdc), Z(0xff), Z(0xfd), Z(0x62), Z(0x47), Z(0xb3), Z(0x21), Z(0x8a),
	Z(0xec), Z(0x8e), Z(0x19), Z(0x18), Z(0xb4), Z(0x6e), Z(0x3d), Z(0xfd),
	Z(0x74), Z(0x54), Z(0x1e), Z(0x04), Z(0x85), Z(0xd8), Z(0xbc), Z(0x1f),
	Z(0x56), Z(0xe7), Z(0x3a), Z(0x56), Z(0x67), Z(0xd6), Z(0xc8), Z(0xa5),
	Z(0xf3), Z(0x8e), Z(0xde), Z(0xae), Z(0x37), Z(0x49), Z(0xb7), Z(0xfa),
	Z(0xc8), Z(0xf4), Z(0x1f), Z(0xe0), Z(0x2a), Z(0x9b), Z(0x15), Z(0xd1),
	Z(0x34), Z(0x0e), Z(0xb5), Z(0xe0), Z(0x44), Z(0x78), Z(0x84), Z(0x59),
	Z(0x56), Z(0x68), Z(0x77), Z(0xa5), Z(0x14), Z(0x06), Z(0xf5), Z(0x2f),
	Z(0x8c), Z(0x8a), Z(0x73), Z(0x80), Z(0x76), Z(0xb4), Z(0x10), Z(0x86)
};

#undef Z
#define Z(x) cpu_to_be32(x << 19)
static const __be32 sbox3[256] = {
	Z(0xa9), Z(0x2a), Z(0x48), Z(0x51), Z(0x84), Z(0x7e), Z(0x49), Z(0xe2),
	Z(0xb5), Z(0xb7), Z(0x42), Z(0x33), Z(0x7d), Z(0x5d), Z(0xa6), Z(0x12),
	Z(0x44), Z(0x48), Z(0x6d), Z(0x28), Z(0xaa), Z(0x20), Z(0x6d), Z(0x57),
	Z(0xd6), Z(0x6b), Z(0x5d), Z(0x72), Z(0xf0), Z(0x92), Z(0x5a), Z(0x1b),
	Z(0x53), Z(0x80), Z(0x24), Z(0x70), Z(0x9a), Z(0xcc), Z(0xa7), Z(0x66),
	Z(0xa1), Z(0x01), Z(0xa5), Z(0x41), Z(0x97), Z(0x41), Z(0x31), Z(0x82),
	Z(0xf1), Z(0x14), Z(0xcf), Z(0x53), Z(0x0d), Z(0xa0), Z(0x10), Z(0xcc),
	Z(0x2a), Z(0x7d), Z(0xd2), Z(0xbf), Z(0x4b), Z(0x1a), Z(0xdb), Z(0x16),
	Z(0x47), Z(0xf6), Z(0x51), Z(0x36), Z(0xed), Z(0xf3), Z(0xb9), Z(0x1a),
	Z(0xa7), Z(0xdf), Z(0x29), Z(0x43), Z(0x01), Z(0x54), Z(0x70), Z(0xa4),
	Z(0xbf), Z(0xd4), Z(0x0b), Z(0x53), Z(0x44), Z(0x60), Z(0x9e), Z(0x23),
	Z(0xa1), Z(0x18), Z(0x68), Z(0x4f), Z(0xf0), Z(0x2f), Z(0x82), Z(0xc2),
	Z(0x2a), Z(0x41), Z(0xb2), Z(0x42), Z(0x0c), Z(0xed), Z(0x0c), Z(0x1d),
	Z(0x13), Z(0x3a), Z(0x3c), Z(0x6e), Z(0x35), Z(0xdc), Z(0x60), Z(0x65),
	Z(0x85), Z(0xe9), Z(0x64), Z(0x02), Z(0x9a), Z(0x3f), Z(0x9f), Z(0x87),
	Z(0x96), Z(0xdf), Z(0xbe), Z(0xf2), Z(0xcb), Z(0xe5), Z(0x6c), Z(0xd4),
	Z(0x5a), Z(0x83), Z(0xbf), Z(0x92), Z(0x1b), Z(0x94), Z(0x00), Z(0x42),
	Z(0xcf), Z(0x4b), Z(0x00), Z(0x75), Z(0xba), Z(0x8f), Z(0x76), Z(0x5f),
	Z(0x5d), Z(0x3a), Z(0x4d), Z(0x09), Z(0x12), Z(0x08), Z(0x38), Z(0x95),
	Z(0x17), Z(0xe4), Z(0x01), Z(0x1d), Z(0x4c), Z(0xa9), Z(0xcc), Z(0x85),
	Z(0x82), Z(0x4c), Z(0x9d), Z(0x2f), Z(0x3b), Z(0x66), Z(0xa1), Z(0x34),
	Z(0x10), Z(0xcd), Z(0x59), Z(0x89), Z(0xa5), Z(0x31), Z(0xcf), Z(0x05),
	Z(0xc8), Z(0x84), Z(0xfa), Z(0xc7), Z(0xba), Z(0x4e), Z(0x8b), Z(0x1a),
	Z(0x19), Z(0xf1), Z(0xa1), Z(0x3b), Z(0x18), Z(0x12), Z(0x17), Z(0xb0),
	Z(0x98), Z(0x8d), Z(0x0b), Z(0x23), Z(0xc3), Z(0x3a), Z(0x2d), Z(0x20),
	Z(0xdf), Z(0x13), Z(0xa0), Z(0xa8), Z(0x4c), Z(0x0d), Z(0x6c), Z(0x2f),
	Z(0x47), Z(0x13), Z(0x13), Z(0x52), Z(0x1f), Z(0x2d), Z(0xf5), Z(0x79),
	Z(0x3d), Z(0xa2), Z(0x54), Z(0xbd), Z(0x69), Z(0xc8), Z(0x6b), Z(0xf3),
	Z(0x05), Z(0x28), Z(0xf1), Z(0x16), Z(0x46), Z(0x40), Z(0xb0), Z(0x11),
	Z(0xd3), Z(0xb7), Z(0x95), Z(0x49), Z(0xcf), Z(0xc3), Z(0x1d), Z(0x8f),
	Z(0xd8), Z(0xe1), Z(0x73), Z(0xdb), Z(0xad), Z(0xc8), Z(0xc9), Z(0xa9),
	Z(0xa1), Z(0xc2), Z(0xc5), Z(0xe3), Z(0xba), Z(0xfc), Z(0x0e), Z(0x25)
};

/*
 * This is a 16 round Feistel network with permutation F_ENCRYPT
 */
#define F_ENCRYPT(R, L, sched)						\
do {									\
	union lc4 { __be32 l; u8 c[4]; } u;				\
	u.l = sched ^ R;						\
	L ^= sbox0[u.c[0]] ^ sbox1[u.c[1]] ^ sbox2[u.c[2]] ^ sbox3[u.c[3]]; \
} while (0)

/*
 * encryptor
 */
static void fcrypt_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	const struct fcrypt_ctx *ctx = crypto_tfm_ctx(tfm);
	struct {
		__be32 l, r;
	} X;

	memcpy(&X, src, sizeof(X));

	F_ENCRYPT(X.r, X.l, ctx->sched[0x0]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x1]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x2]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x3]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x4]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x5]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x6]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x7]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x8]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x9]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0xa]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0xb]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0xc]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0xd]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0xe]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0xf]);

	memcpy(dst, &X, sizeof(X));
}

/*
 * decryptor
 */
static void fcrypt_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	const struct fcrypt_ctx *ctx = crypto_tfm_ctx(tfm);
	struct {
		__be32 l, r;
	} X;

	memcpy(&X, src, sizeof(X));

	F_ENCRYPT(X.l, X.r, ctx->sched[0xf]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0xe]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0xd]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0xc]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0xb]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0xa]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x9]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x8]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x7]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x6]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x5]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x4]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x3]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x2]);
	F_ENCRYPT(X.l, X.r, ctx->sched[0x1]);
	F_ENCRYPT(X.r, X.l, ctx->sched[0x0]);

	memcpy(dst, &X, sizeof(X));
}

/*
 * Generate a key schedule from key, the least significant bit in each key byte
 * is parity and shall be ignored. This leaves 56 significant bits in the key
 * to scatter over the 16 key schedules. For each schedule extract the low
 * order 32 bits and use as schedule, then rotate right by 11 bits.
 */
static int fcrypt_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
	struct fcrypt_ctx *ctx = crypto_tfm_ctx(tfm);

#if BITS_PER_LONG == 64  /* the 64-bit version can also be used for 32-bit
			  * kernels - it seems to be faster but the code is
			  * larger */

	u64 k;	/* k holds all 56 non-parity bits */

	/* discard the parity bits */
	k = (*key++) >> 1;
	k <<= 7;
	k |= (*key++) >> 1;
	k <<= 7;
	k |= (*key++) >> 1;
	k <<= 7;
	k |= (*key++) >> 1;
	k <<= 7;
	k |= (*key++) >> 1;
	k <<= 7;
	k |= (*key++) >> 1;
	k <<= 7;
	k |= (*key++) >> 1;
	k <<= 7;
	k |= (*key) >> 1;

	/* Use lower 32 bits for schedule, rotate by 11 each round (16 times) */
	ctx->sched[0x0] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x1] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x2] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x3] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x4] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x5] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x6] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x7] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x8] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0x9] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0xa] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0xb] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0xc] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0xd] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0xe] = cpu_to_be32(k); ror56_64(k, 11);
	ctx->sched[0xf] = cpu_to_be32(k);

	return 0;
#else
	u32 hi, lo;		/* hi is upper 24 bits and lo lower 32, total 56 */

	/* discard the parity bits */
	lo = (*key++) >> 1;
	lo <<= 7;
	lo |= (*key++) >> 1;
	lo <<= 7;
	lo |= (*key++) >> 1;
	lo <<= 7;
	lo |= (*key++) >> 1;
	hi = lo >> 4;
	lo &= 0xf;
	lo <<= 7;
	lo |= (*key++) >> 1;
	lo <<= 7;
	lo |= (*key++) >> 1;
	lo <<= 7;
	lo |= (*key++) >> 1;
	lo <<= 7;
	lo |= (*key) >> 1;

	/* Use lower 32 bits for schedule, rotate by 11 each round (16 times) */
	ctx->sched[0x0] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x1] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x2] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x3] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x4] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x5] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x6] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x7] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x8] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0x9] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0xa] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0xb] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0xc] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0xd] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0xe] = cpu_to_be32(lo); ror56(hi, lo, 11);
	ctx->sched[0xf] = cpu_to_be32(lo);
	return 0;
#endif
}

static struct crypto_alg fcrypt_alg = {
	.cra_name		=	"fcrypt",
	.cra_driver_name	=	"fcrypt-generic",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	8,
	.cra_ctxsize		=	sizeof(struct fcrypt_ctx),
	.cra_module		=	THIS_MODULE,
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	8,
	.cia_max_keysize	=	8,
	.cia_setkey		=	fcrypt_setkey,
	.cia_encrypt		=	fcrypt_encrypt,
	.cia_decrypt		=	fcrypt_decrypt } }
};

static int __init fcrypt_mod_init(void)
{
	return crypto_register_alg(&fcrypt_alg);
}

static void __exit fcrypt_mod_fini(void)
{
	crypto_unregister_alg(&fcrypt_alg);
}

subsys_initcall(fcrypt_mod_init);
module_exit(fcrypt_mod_fini);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("FCrypt Cipher Algorithm");
MODULE_AUTHOR("David Howells <dhowells@redhat.com>");
MODULE_ALIAS_CRYPTO("fcrypt");
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