android_kernel_xiaomi_sm8350/drivers/crypto/padlock-sha.c
Herbert Xu a760a6656e crypto: api - Fix module load deadlock with fallback algorithms
With the mandatory algorithm testing at registration, we have
now created a deadlock with algorithms requiring fallbacks.
This can happen if the module containing the algorithm requiring
fallback is loaded first, without the fallback module being loaded
first.  The system will then try to test the new algorithm, find
that it needs to load a fallback, and then try to load that.

As both algorithms share the same module alias, it can attempt
to load the original algorithm again and block indefinitely.

As algorithms requiring fallbacks are a special case, we can fix
this by giving them a different module alias than the rest.  Then
it's just a matter of using the right aliases according to what
algorithms we're trying to find.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-26 14:06:31 +08:00

311 lines
7.8 KiB
C

/*
* Cryptographic API.
*
* Support for VIA PadLock hardware crypto engine.
*
* Copyright (c) 2006 Michal Ludvig <michal@logix.cz>
*
* 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 <crypto/algapi.h>
#include <crypto/sha.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/cryptohash.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <asm/i387.h>
#include "padlock.h"
#define SHA1_DEFAULT_FALLBACK "sha1-generic"
#define SHA256_DEFAULT_FALLBACK "sha256-generic"
struct padlock_sha_ctx {
char *data;
size_t used;
int bypass;
void (*f_sha_padlock)(const char *in, char *out, int count);
struct hash_desc fallback;
};
static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
{
return crypto_tfm_ctx(tfm);
}
/* We'll need aligned address on the stack */
#define NEAREST_ALIGNED(ptr) \
((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
static struct crypto_alg sha1_alg, sha256_alg;
static void padlock_sha_bypass(struct crypto_tfm *tfm)
{
if (ctx(tfm)->bypass)
return;
crypto_hash_init(&ctx(tfm)->fallback);
if (ctx(tfm)->data && ctx(tfm)->used) {
struct scatterlist sg;
sg_init_one(&sg, ctx(tfm)->data, ctx(tfm)->used);
crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
}
ctx(tfm)->used = 0;
ctx(tfm)->bypass = 1;
}
static void padlock_sha_init(struct crypto_tfm *tfm)
{
ctx(tfm)->used = 0;
ctx(tfm)->bypass = 0;
}
static void padlock_sha_update(struct crypto_tfm *tfm,
const uint8_t *data, unsigned int length)
{
/* Our buffer is always one page. */
if (unlikely(!ctx(tfm)->bypass &&
(ctx(tfm)->used + length > PAGE_SIZE)))
padlock_sha_bypass(tfm);
if (unlikely(ctx(tfm)->bypass)) {
struct scatterlist sg;
sg_init_one(&sg, (uint8_t *)data, length);
crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
return;
}
memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
ctx(tfm)->used += length;
}
static inline void padlock_output_block(uint32_t *src,
uint32_t *dst, size_t count)
{
while (count--)
*dst++ = swab32(*src++);
}
static void padlock_do_sha1(const char *in, char *out, int count)
{
/* We can't store directly to *out as it may be unaligned. */
/* BTW Don't reduce the buffer size below 128 Bytes!
* PadLock microcode needs it that big. */
char buf[128+16];
char *result = NEAREST_ALIGNED(buf);
int ts_state;
((uint32_t *)result)[0] = SHA1_H0;
((uint32_t *)result)[1] = SHA1_H1;
((uint32_t *)result)[2] = SHA1_H2;
((uint32_t *)result)[3] = SHA1_H3;
((uint32_t *)result)[4] = SHA1_H4;
/* prevent taking the spurious DNA fault with padlock. */
ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
: "+S"(in), "+D"(result)
: "c"(count), "a"(0));
irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
}
static void padlock_do_sha256(const char *in, char *out, int count)
{
/* We can't store directly to *out as it may be unaligned. */
/* BTW Don't reduce the buffer size below 128 Bytes!
* PadLock microcode needs it that big. */
char buf[128+16];
char *result = NEAREST_ALIGNED(buf);
int ts_state;
((uint32_t *)result)[0] = SHA256_H0;
((uint32_t *)result)[1] = SHA256_H1;
((uint32_t *)result)[2] = SHA256_H2;
((uint32_t *)result)[3] = SHA256_H3;
((uint32_t *)result)[4] = SHA256_H4;
((uint32_t *)result)[5] = SHA256_H5;
((uint32_t *)result)[6] = SHA256_H6;
((uint32_t *)result)[7] = SHA256_H7;
/* prevent taking the spurious DNA fault with padlock. */
ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
: "+S"(in), "+D"(result)
: "c"(count), "a"(0));
irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
}
static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
{
if (unlikely(ctx(tfm)->bypass)) {
crypto_hash_final(&ctx(tfm)->fallback, out);
ctx(tfm)->bypass = 0;
return;
}
/* Pass the input buffer to PadLock microcode... */
ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
ctx(tfm)->used = 0;
}
static int padlock_cra_init(struct crypto_tfm *tfm)
{
const char *fallback_driver_name = tfm->__crt_alg->cra_name;
struct crypto_hash *fallback_tfm;
/* For now we'll allocate one page. This
* could eventually be configurable one day. */
ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
if (!ctx(tfm)->data)
return -ENOMEM;
/* Allocate a fallback and abort if it failed. */
fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback_tfm)) {
printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
fallback_driver_name);
free_page((unsigned long)(ctx(tfm)->data));
return PTR_ERR(fallback_tfm);
}
ctx(tfm)->fallback.tfm = fallback_tfm;
return 0;
}
static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
{
ctx(tfm)->f_sha_padlock = padlock_do_sha1;
return padlock_cra_init(tfm);
}
static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
{
ctx(tfm)->f_sha_padlock = padlock_do_sha256;
return padlock_cra_init(tfm);
}
static void padlock_cra_exit(struct crypto_tfm *tfm)
{
if (ctx(tfm)->data) {
free_page((unsigned long)(ctx(tfm)->data));
ctx(tfm)->data = NULL;
}
crypto_free_hash(ctx(tfm)->fallback.tfm);
ctx(tfm)->fallback.tfm = NULL;
}
static struct crypto_alg sha1_alg = {
.cra_name = "sha1",
.cra_driver_name = "sha1-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_DIGEST |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA1_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct padlock_sha_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(sha1_alg.cra_list),
.cra_init = padlock_sha1_cra_init,
.cra_exit = padlock_cra_exit,
.cra_u = {
.digest = {
.dia_digestsize = SHA1_DIGEST_SIZE,
.dia_init = padlock_sha_init,
.dia_update = padlock_sha_update,
.dia_final = padlock_sha_final,
}
}
};
static struct crypto_alg sha256_alg = {
.cra_name = "sha256",
.cra_driver_name = "sha256-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_DIGEST |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA256_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct padlock_sha_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(sha256_alg.cra_list),
.cra_init = padlock_sha256_cra_init,
.cra_exit = padlock_cra_exit,
.cra_u = {
.digest = {
.dia_digestsize = SHA256_DIGEST_SIZE,
.dia_init = padlock_sha_init,
.dia_update = padlock_sha_update,
.dia_final = padlock_sha_final,
}
}
};
static int __init padlock_init(void)
{
int rc = -ENODEV;
if (!cpu_has_phe) {
printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
return -ENODEV;
}
if (!cpu_has_phe_enabled) {
printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
return -ENODEV;
}
rc = crypto_register_alg(&sha1_alg);
if (rc)
goto out;
rc = crypto_register_alg(&sha256_alg);
if (rc)
goto out_unreg1;
printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
return 0;
out_unreg1:
crypto_unregister_alg(&sha1_alg);
out:
printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
return rc;
}
static void __exit padlock_fini(void)
{
crypto_unregister_alg(&sha1_alg);
crypto_unregister_alg(&sha256_alg);
}
module_init(padlock_init);
module_exit(padlock_fini);
MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Ludvig");
MODULE_ALIAS("sha1-all");
MODULE_ALIAS("sha256-all");
MODULE_ALIAS("sha1-padlock");
MODULE_ALIAS("sha256-padlock");