linux_dsm_epyc7002/include/crypto/algapi.h
Eric Biggers fbb6cda441 crypto: algapi - introduce the flag CRYPTO_ALG_ALLOCATES_MEMORY
Introduce a new algorithm flag CRYPTO_ALG_ALLOCATES_MEMORY.  If this
flag is set, then the driver allocates memory in its request routine.
Such drivers are not suitable for disk encryption because GFP_ATOMIC
allocation can fail anytime (causing random I/O errors) and GFP_KERNEL
allocation can recurse into the block layer, causing a deadlock.

For now, this flag is only implemented for some algorithm types.  We
also assume some usage constraints for it to be meaningful, since there
are lots of edge cases the crypto API allows (e.g., misaligned or
fragmented scatterlists) that mean that nearly any crypto algorithm can
allocate memory in some case.  See the comment for details.

Also add this flag to CRYPTO_ALG_INHERITED_FLAGS so that when a template
is instantiated, this flag is set on the template instance if it is set
on any algorithm the instance uses.

Based on a patch by Mikulas Patocka <mpatocka@redhat.com>
(https://lore.kernel.org/r/alpine.LRH.2.02.2006301414580.30526@file01.intranet.prod.int.rdu2.redhat.com).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-16 21:49:09 +10:00

297 lines
8.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Cryptographic API for algorithms (i.e., low-level API).
*
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*/
#ifndef _CRYPTO_ALGAPI_H
#define _CRYPTO_ALGAPI_H
#include <linux/crypto.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
/*
* Maximum values for blocksize and alignmask, used to allocate
* static buffers that are big enough for any combination of
* algs and architectures. Ciphers have a lower maximum size.
*/
#define MAX_ALGAPI_BLOCKSIZE 160
#define MAX_ALGAPI_ALIGNMASK 63
#define MAX_CIPHER_BLOCKSIZE 16
#define MAX_CIPHER_ALIGNMASK 15
struct crypto_aead;
struct crypto_instance;
struct module;
struct rtattr;
struct seq_file;
struct crypto_type {
unsigned int (*ctxsize)(struct crypto_alg *alg, u32 type, u32 mask);
unsigned int (*extsize)(struct crypto_alg *alg);
int (*init)(struct crypto_tfm *tfm, u32 type, u32 mask);
int (*init_tfm)(struct crypto_tfm *tfm);
void (*show)(struct seq_file *m, struct crypto_alg *alg);
int (*report)(struct sk_buff *skb, struct crypto_alg *alg);
void (*free)(struct crypto_instance *inst);
unsigned int type;
unsigned int maskclear;
unsigned int maskset;
unsigned int tfmsize;
};
struct crypto_instance {
struct crypto_alg alg;
struct crypto_template *tmpl;
union {
/* Node in list of instances after registration. */
struct hlist_node list;
/* List of attached spawns before registration. */
struct crypto_spawn *spawns;
};
void *__ctx[] CRYPTO_MINALIGN_ATTR;
};
struct crypto_template {
struct list_head list;
struct hlist_head instances;
struct module *module;
int (*create)(struct crypto_template *tmpl, struct rtattr **tb);
char name[CRYPTO_MAX_ALG_NAME];
};
struct crypto_spawn {
struct list_head list;
struct crypto_alg *alg;
union {
/* Back pointer to instance after registration.*/
struct crypto_instance *inst;
/* Spawn list pointer prior to registration. */
struct crypto_spawn *next;
};
const struct crypto_type *frontend;
u32 mask;
bool dead;
bool registered;
};
struct crypto_queue {
struct list_head list;
struct list_head *backlog;
unsigned int qlen;
unsigned int max_qlen;
};
struct scatter_walk {
struct scatterlist *sg;
unsigned int offset;
};
void crypto_mod_put(struct crypto_alg *alg);
int crypto_register_template(struct crypto_template *tmpl);
int crypto_register_templates(struct crypto_template *tmpls, int count);
void crypto_unregister_template(struct crypto_template *tmpl);
void crypto_unregister_templates(struct crypto_template *tmpls, int count);
struct crypto_template *crypto_lookup_template(const char *name);
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst);
void crypto_unregister_instance(struct crypto_instance *inst);
int crypto_grab_spawn(struct crypto_spawn *spawn, struct crypto_instance *inst,
const char *name, u32 type, u32 mask);
void crypto_drop_spawn(struct crypto_spawn *spawn);
struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
u32 mask);
void *crypto_spawn_tfm2(struct crypto_spawn *spawn);
struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb);
int crypto_check_attr_type(struct rtattr **tb, u32 type, u32 *mask_ret);
const char *crypto_attr_alg_name(struct rtattr *rta);
int crypto_attr_u32(struct rtattr *rta, u32 *num);
int crypto_inst_setname(struct crypto_instance *inst, const char *name,
struct crypto_alg *alg);
void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen);
int crypto_enqueue_request(struct crypto_queue *queue,
struct crypto_async_request *request);
void crypto_enqueue_request_head(struct crypto_queue *queue,
struct crypto_async_request *request);
struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue);
static inline unsigned int crypto_queue_len(struct crypto_queue *queue)
{
return queue->qlen;
}
void crypto_inc(u8 *a, unsigned int size);
void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int size);
static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
{
if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
__builtin_constant_p(size) &&
(size % sizeof(unsigned long)) == 0) {
unsigned long *d = (unsigned long *)dst;
unsigned long *s = (unsigned long *)src;
while (size > 0) {
*d++ ^= *s++;
size -= sizeof(unsigned long);
}
} else {
__crypto_xor(dst, dst, src, size);
}
}
static inline void crypto_xor_cpy(u8 *dst, const u8 *src1, const u8 *src2,
unsigned int size)
{
if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
__builtin_constant_p(size) &&
(size % sizeof(unsigned long)) == 0) {
unsigned long *d = (unsigned long *)dst;
unsigned long *s1 = (unsigned long *)src1;
unsigned long *s2 = (unsigned long *)src2;
while (size > 0) {
*d++ = *s1++ ^ *s2++;
size -= sizeof(unsigned long);
}
} else {
__crypto_xor(dst, src1, src2, size);
}
}
static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
{
return PTR_ALIGN(crypto_tfm_ctx(tfm),
crypto_tfm_alg_alignmask(tfm) + 1);
}
static inline struct crypto_instance *crypto_tfm_alg_instance(
struct crypto_tfm *tfm)
{
return container_of(tfm->__crt_alg, struct crypto_instance, alg);
}
static inline void *crypto_instance_ctx(struct crypto_instance *inst)
{
return inst->__ctx;
}
struct crypto_cipher_spawn {
struct crypto_spawn base;
};
static inline int crypto_grab_cipher(struct crypto_cipher_spawn *spawn,
struct crypto_instance *inst,
const char *name, u32 type, u32 mask)
{
type &= ~CRYPTO_ALG_TYPE_MASK;
type |= CRYPTO_ALG_TYPE_CIPHER;
mask |= CRYPTO_ALG_TYPE_MASK;
return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
}
static inline void crypto_drop_cipher(struct crypto_cipher_spawn *spawn)
{
crypto_drop_spawn(&spawn->base);
}
static inline struct crypto_alg *crypto_spawn_cipher_alg(
struct crypto_cipher_spawn *spawn)
{
return spawn->base.alg;
}
static inline struct crypto_cipher *crypto_spawn_cipher(
struct crypto_cipher_spawn *spawn)
{
u32 type = CRYPTO_ALG_TYPE_CIPHER;
u32 mask = CRYPTO_ALG_TYPE_MASK;
return __crypto_cipher_cast(crypto_spawn_tfm(&spawn->base, type, mask));
}
static inline struct cipher_alg *crypto_cipher_alg(struct crypto_cipher *tfm)
{
return &crypto_cipher_tfm(tfm)->__crt_alg->cra_cipher;
}
static inline struct crypto_async_request *crypto_get_backlog(
struct crypto_queue *queue)
{
return queue->backlog == &queue->list ? NULL :
container_of(queue->backlog, struct crypto_async_request, list);
}
static inline u32 crypto_requires_off(struct crypto_attr_type *algt, u32 off)
{
return (algt->type ^ off) & algt->mask & off;
}
/*
* When an algorithm uses another algorithm (e.g., if it's an instance of a
* template), these are the flags that should always be set on the "outer"
* algorithm if any "inner" algorithm has them set.
*/
#define CRYPTO_ALG_INHERITED_FLAGS \
(CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK | \
CRYPTO_ALG_ALLOCATES_MEMORY)
/*
* Given the type and mask that specify the flags restrictions on a template
* instance being created, return the mask that should be passed to
* crypto_grab_*() (along with type=0) to honor any request the user made to
* have any of the CRYPTO_ALG_INHERITED_FLAGS clear.
*/
static inline u32 crypto_algt_inherited_mask(struct crypto_attr_type *algt)
{
return crypto_requires_off(algt, CRYPTO_ALG_INHERITED_FLAGS);
}
noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size);
/**
* crypto_memneq - Compare two areas of memory without leaking
* timing information.
*
* @a: One area of memory
* @b: Another area of memory
* @size: The size of the area.
*
* Returns 0 when data is equal, 1 otherwise.
*/
static inline int crypto_memneq(const void *a, const void *b, size_t size)
{
return __crypto_memneq(a, b, size) != 0UL ? 1 : 0;
}
static inline void crypto_yield(u32 flags)
{
if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
cond_resched();
}
int crypto_register_notifier(struct notifier_block *nb);
int crypto_unregister_notifier(struct notifier_block *nb);
/* Crypto notification events. */
enum {
CRYPTO_MSG_ALG_REQUEST,
CRYPTO_MSG_ALG_REGISTER,
CRYPTO_MSG_ALG_LOADED,
};
#endif /* _CRYPTO_ALGAPI_H */