Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
lib/crc32: make crc32c() go directly to lib
Now that the lower level __crc32c_le() library function is optimized for
each architecture, make crc32c() just call that instead of taking an
inefficient and error-prone detour through the shash API.
Note: a future cleanup should make crc32c_le() be the actual library
function instead of __crc32c_le(). That will require updating callers
of __crc32c_le() to use crc32c_le() instead, and updating callers of
crc32c_le() that expect a 'const void *' arg to expect 'const u8 *'
instead. Similarly, a future cleanup should remove LIBCRC32C by making
everyone who is selecting it just select CRC32 directly instead.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20241202010844.144356-16-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
+8
-84
+5
-2
include/linux/crc32c.h
+5
-2
include/linux/crc32c.h
···
2
2
#ifndef _LINUX_CRC32C_H
3
3
#define _LINUX_CRC32C_H
4
4
5
-
#include <linux/types.h>
5
+
#include <linux/crc32.h>
6
6
7
-
extern u32 crc32c(u32 crc, const void *address, unsigned int length);
7
+
static inline u32 crc32c(u32 crc, const void *address, unsigned int length)
8
+
{
9
+
return __crc32c_le(crc, address, length);
10
+
}
8
11
9
12
/* This macro exists for backwards-compatibility. */
10
13
#define crc32c_le crc32c
+3
-7
lib/Kconfig
+3
-7
lib/Kconfig
···
310
310
311
311
config LIBCRC32C
312
312
tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
313
-
select CRYPTO
314
-
select CRYPTO_CRC32C
313
+
select CRC32
315
314
help
316
-
This option is provided for the case where no in-kernel-tree
317
-
modules require CRC32c functions, but a module built outside the
318
-
kernel tree does. Such modules that use library CRC32c functions
319
-
require M here. See Castagnoli93.
320
-
Module will be libcrc32c.
315
+
This option just selects CRC32 and is provided for compatibility
316
+
purposes until the users are updated to select CRC32 directly.
321
317
322
318
config CRC8
323
319
tristate "CRC8 function"
-1
lib/Makefile
-1
lib/Makefile
···
167
167
obj-$(CONFIG_CRC32_SELFTEST) += crc32test.o
168
168
obj-$(CONFIG_CRC4) += crc4.o
169
169
obj-$(CONFIG_CRC7) += crc7.o
170
-
obj-$(CONFIG_LIBCRC32C) += libcrc32c.o
171
170
obj-$(CONFIG_CRC8) += crc8.o
172
171
obj-$(CONFIG_CRC64_ROCKSOFT) += crc64-rocksoft.o
173
172
obj-$(CONFIG_XXHASH) += xxhash.o
-74
lib/libcrc32c.c
-74
lib/libcrc32c.c
···
1
-
// SPDX-License-Identifier: GPL-2.0-or-later
2
-
/*
3
-
* CRC32C
4
-
*@Article{castagnoli-crc,
5
-
* author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
6
-
* title = {{Optimization of Cyclic Redundancy-Check Codes with 24
7
-
* and 32 Parity Bits}},
8
-
* journal = IEEE Transactions on Communication,
9
-
* year = {1993},
10
-
* volume = {41},
11
-
* number = {6},
12
-
* pages = {},
13
-
* month = {June},
14
-
*}
15
-
* Used by the iSCSI driver, possibly others, and derived from
16
-
* the iscsi-crc.c module of the linux-iscsi driver at
17
-
* http://linux-iscsi.sourceforge.net.
18
-
*
19
-
* Following the example of lib/crc32, this function is intended to be
20
-
* flexible and useful for all users. Modules that currently have their
21
-
* own crc32c, but hopefully may be able to use this one are:
22
-
* net/sctp (please add all your doco to here if you change to
23
-
* use this one!)
24
-
* <endoflist>
25
-
*
26
-
* Copyright (c) 2004 Cisco Systems, Inc.
27
-
*/
28
-
29
-
#include <crypto/hash.h>
30
-
#include <linux/err.h>
31
-
#include <linux/init.h>
32
-
#include <linux/kernel.h>
33
-
#include <linux/module.h>
34
-
#include <linux/crc32c.h>
35
-
36
-
static struct crypto_shash *tfm;
37
-
38
-
u32 crc32c(u32 crc, const void *address, unsigned int length)
39
-
{
40
-
SHASH_DESC_ON_STACK(shash, tfm);
41
-
u32 ret, *ctx = (u32 *)shash_desc_ctx(shash);
42
-
int err;
43
-
44
-
shash->tfm = tfm;
45
-
*ctx = crc;
46
-
47
-
err = crypto_shash_update(shash, address, length);
48
-
BUG_ON(err);
49
-
50
-
ret = *ctx;
51
-
barrier_data(ctx);
52
-
return ret;
53
-
}
54
-
55
-
EXPORT_SYMBOL(crc32c);
56
-
57
-
static int __init libcrc32c_mod_init(void)
58
-
{
59
-
tfm = crypto_alloc_shash("crc32c", 0, 0);
60
-
return PTR_ERR_OR_ZERO(tfm);
61
-
}
62
-
63
-
static void __exit libcrc32c_mod_fini(void)
64
-
{
65
-
crypto_free_shash(tfm);
66
-
}
67
-
68
-
module_init(libcrc32c_mod_init);
69
-
module_exit(libcrc32c_mod_fini);
70
-
71
-
MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
72
-
MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
73
-
MODULE_LICENSE("GPL");
74
-
MODULE_SOFTDEP("pre: crc32c");