linux_dsm_epyc7002/arch/powerpc/crypto/crc-vpmsum_test.c
George Spelvin 80d04b7fab powerpc/crypto: Use cheaper random numbers for crc-vpmsum self-test
This code was filling a 64K buffer from /dev/urandom in order to
compute a CRC over (on average half of) it by two different methods,
comparing the CRCs, and repeating.

This is not a remotely security-critical application, so use the far
faster and cheaper prandom_u32() generator.

And, while we're at it, only fill as much of the buffer as we plan to use.

Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-20 22:03:11 +10:00

134 lines
3.1 KiB
C

/*
* CRC vpmsum tester
* Copyright 2017 Daniel Axtens, IBM Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/crc-t10dif.h>
#include <linux/crc32.h>
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/cpufeature.h>
#include <asm/switch_to.h>
static unsigned long iterations = 10000;
#define MAX_CRC_LENGTH 65535
static int __init crc_test_init(void)
{
u16 crc16 = 0, verify16 = 0;
u32 crc32 = 0, verify32 = 0;
__le32 verify32le = 0;
unsigned char *data;
unsigned long i;
int ret;
struct crypto_shash *crct10dif_tfm;
struct crypto_shash *crc32c_tfm;
if (!cpu_has_feature(CPU_FTR_ARCH_207S))
return -ENODEV;
data = kmalloc(MAX_CRC_LENGTH, GFP_KERNEL);
if (!data)
return -ENOMEM;
crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
if (IS_ERR(crct10dif_tfm)) {
pr_err("Error allocating crc-t10dif\n");
goto free_buf;
}
crc32c_tfm = crypto_alloc_shash("crc32c", 0, 0);
if (IS_ERR(crc32c_tfm)) {
pr_err("Error allocating crc32c\n");
goto free_16;
}
do {
SHASH_DESC_ON_STACK(crct10dif_shash, crct10dif_tfm);
SHASH_DESC_ON_STACK(crc32c_shash, crc32c_tfm);
crct10dif_shash->tfm = crct10dif_tfm;
ret = crypto_shash_init(crct10dif_shash);
if (ret) {
pr_err("Error initing crc-t10dif\n");
goto free_32;
}
crc32c_shash->tfm = crc32c_tfm;
ret = crypto_shash_init(crc32c_shash);
if (ret) {
pr_err("Error initing crc32c\n");
goto free_32;
}
pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
for (i=0; i<iterations; i++) {
size_t offset = prandom_u32_max(16);
size_t len = prandom_u32_max(MAX_CRC_LENGTH);
if (len <= offset)
continue;
prandom_bytes(data, len);
len -= offset;
crypto_shash_update(crct10dif_shash, data+offset, len);
crypto_shash_final(crct10dif_shash, (u8 *)(&crc16));
verify16 = crc_t10dif_generic(verify16, data+offset, len);
if (crc16 != verify16) {
pr_err("FAILURE in CRC16: got 0x%04x expected 0x%04x (len %lu)\n",
crc16, verify16, len);
break;
}
crypto_shash_update(crc32c_shash, data+offset, len);
crypto_shash_final(crc32c_shash, (u8 *)(&crc32));
verify32 = le32_to_cpu(verify32le);
verify32le = ~cpu_to_le32(__crc32c_le(~verify32, data+offset, len));
if (crc32 != (u32)verify32le) {
pr_err("FAILURE in CRC32: got 0x%08x expected 0x%08x (len %lu)\n",
crc32, verify32, len);
break;
}
}
pr_info("crc-vpmsum_test done, completed %lu iterations\n", i);
} while (0);
free_32:
crypto_free_shash(crc32c_tfm);
free_16:
crypto_free_shash(crct10dif_tfm);
free_buf:
kfree(data);
return 0;
}
static void __exit crc_test_exit(void) {}
module_init(crc_test_init);
module_exit(crc_test_exit);
module_param(iterations, long, 0400);
MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
MODULE_DESCRIPTION("Vector polynomial multiply-sum CRC tester");
MODULE_LICENSE("GPL");