https://github.com/torvalds/linux
Revision 12e993b89464707398e4209bd99983e376454985 authored by Linus Torvalds on 16 April 2012, 00:23:00 UTC, committed by Linus Torvalds on 16 April 2012, 00:23:00 UTC
The 'max' range needs to be unsigned, since the size of the user address
space is bigger than 2GB.

We know that 'count' is positive in 'long' (that is checked in the
caller), so we will truncate 'max' down to something that fits in a
signed long, but before we actually do that, that comparison needs to be
done in unsigned.

Bug introduced in commit 92ae03f2ef99 ("x86: merge 32/64-bit versions of
'strncpy_from_user()' and speed it up").  On x86-64 you can't trigger
this, since the user address space is much smaller than 63 bits, and on
x86-32 it works in practice, since you would seldom hit the strncpy
limits anyway.

I had actually tested the corner-cases, I had only tested them on
x86-64.  Besides, I had only worried about the case of a pointer *close*
to the end of the address space, rather than really far away from it ;)

This also changes the "we hit the user-specified maximum" to return
'res', for the trivial reason that gcc seems to generate better code
that way.  'res' and 'count' are the same in that case, so it really
doesn't matter which one we return.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent ebfc5b8
Raw File
Tip revision: 12e993b89464707398e4209bd99983e376454985 authored by Linus Torvalds on 16 April 2012, 00:23:00 UTC
x86-32: fix up strncpy_from_user() sign error
Tip revision: 12e993b
cryptd.c
/*
 * Software async crypto daemon.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * Added AEAD support to cryptd.
 *    Authors: Tadeusz Struk (tadeusz.struk@intel.com)
 *             Adrian Hoban <adrian.hoban@intel.com>
 *             Gabriele Paoloni <gabriele.paoloni@intel.com>
 *             Aidan O'Mahony (aidan.o.mahony@intel.com)
 *    Copyright (c) 2010, Intel Corporation.
 *
 * 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/internal/hash.h>
#include <crypto/internal/aead.h>
#include <crypto/cryptd.h>
#include <crypto/crypto_wq.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>

#define CRYPTD_MAX_CPU_QLEN 100

struct cryptd_cpu_queue {
	struct crypto_queue queue;
	struct work_struct work;
};

struct cryptd_queue {
	struct cryptd_cpu_queue __percpu *cpu_queue;
};

struct cryptd_instance_ctx {
	struct crypto_spawn spawn;
	struct cryptd_queue *queue;
};

struct hashd_instance_ctx {
	struct crypto_shash_spawn spawn;
	struct cryptd_queue *queue;
};

struct aead_instance_ctx {
	struct crypto_aead_spawn aead_spawn;
	struct cryptd_queue *queue;
};

struct cryptd_blkcipher_ctx {
	struct crypto_blkcipher *child;
};

struct cryptd_blkcipher_request_ctx {
	crypto_completion_t complete;
};

struct cryptd_hash_ctx {
	struct crypto_shash *child;
};

struct cryptd_hash_request_ctx {
	crypto_completion_t complete;
	struct shash_desc desc;
};

struct cryptd_aead_ctx {
	struct crypto_aead *child;
};

struct cryptd_aead_request_ctx {
	crypto_completion_t complete;
};

static void cryptd_queue_worker(struct work_struct *work);

static int cryptd_init_queue(struct cryptd_queue *queue,
			     unsigned int max_cpu_qlen)
{
	int cpu;
	struct cryptd_cpu_queue *cpu_queue;

	queue->cpu_queue = alloc_percpu(struct cryptd_cpu_queue);
	if (!queue->cpu_queue)
		return -ENOMEM;
	for_each_possible_cpu(cpu) {
		cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
		crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
		INIT_WORK(&cpu_queue->work, cryptd_queue_worker);
	}
	return 0;
}

static void cryptd_fini_queue(struct cryptd_queue *queue)
{
	int cpu;
	struct cryptd_cpu_queue *cpu_queue;

	for_each_possible_cpu(cpu) {
		cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
		BUG_ON(cpu_queue->queue.qlen);
	}
	free_percpu(queue->cpu_queue);
}

static int cryptd_enqueue_request(struct cryptd_queue *queue,
				  struct crypto_async_request *request)
{
	int cpu, err;
	struct cryptd_cpu_queue *cpu_queue;

	cpu = get_cpu();
	cpu_queue = this_cpu_ptr(queue->cpu_queue);
	err = crypto_enqueue_request(&cpu_queue->queue, request);
	queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);
	put_cpu();

	return err;
}

/* Called in workqueue context, do one real cryption work (via
 * req->complete) and reschedule itself if there are more work to
 * do. */
static void cryptd_queue_worker(struct work_struct *work)
{
	struct cryptd_cpu_queue *cpu_queue;
	struct crypto_async_request *req, *backlog;

	cpu_queue = container_of(work, struct cryptd_cpu_queue, work);
	/* Only handle one request at a time to avoid hogging crypto
	 * workqueue. preempt_disable/enable is used to prevent
	 * being preempted by cryptd_enqueue_request() */
	preempt_disable();
	backlog = crypto_get_backlog(&cpu_queue->queue);
	req = crypto_dequeue_request(&cpu_queue->queue);
	preempt_enable();

	if (!req)
		return;

	if (backlog)
		backlog->complete(backlog, -EINPROGRESS);
	req->complete(req, 0);

	if (cpu_queue->queue.qlen)
		queue_work(kcrypto_wq, &cpu_queue->work);
}

static inline struct cryptd_queue *cryptd_get_queue(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
	return ictx->queue;
}

static int cryptd_blkcipher_setkey(struct crypto_ablkcipher *parent,
				   const u8 *key, unsigned int keylen)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(parent);
	struct crypto_blkcipher *child = ctx->child;
	int err;

	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_blkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
					  CRYPTO_TFM_REQ_MASK);
	err = crypto_blkcipher_setkey(child, key, keylen);
	crypto_ablkcipher_set_flags(parent, crypto_blkcipher_get_flags(child) &
					    CRYPTO_TFM_RES_MASK);
	return err;
}

static void cryptd_blkcipher_crypt(struct ablkcipher_request *req,
				   struct crypto_blkcipher *child,
				   int err,
				   int (*crypt)(struct blkcipher_desc *desc,
						struct scatterlist *dst,
						struct scatterlist *src,
						unsigned int len))
{
	struct cryptd_blkcipher_request_ctx *rctx;
	struct blkcipher_desc desc;

	rctx = ablkcipher_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	desc.tfm = child;
	desc.info = req->info;
	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	err = crypt(&desc, req->dst, req->src, req->nbytes);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static void cryptd_blkcipher_encrypt(struct crypto_async_request *req, int err)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
	struct crypto_blkcipher *child = ctx->child;

	cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
			       crypto_blkcipher_crt(child)->encrypt);
}

static void cryptd_blkcipher_decrypt(struct crypto_async_request *req, int err)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
	struct crypto_blkcipher *child = ctx->child;

	cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
			       crypto_blkcipher_crt(child)->decrypt);
}

static int cryptd_blkcipher_enqueue(struct ablkcipher_request *req,
				    crypto_completion_t complete)
{
	struct cryptd_blkcipher_request_ctx *rctx = ablkcipher_request_ctx(req);
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	struct cryptd_queue *queue;

	queue = cryptd_get_queue(crypto_ablkcipher_tfm(tfm));
	rctx->complete = req->base.complete;
	req->base.complete = complete;

	return cryptd_enqueue_request(queue, &req->base);
}

static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req)
{
	return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt);
}

static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req)
{
	return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt);
}

static int cryptd_blkcipher_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_spawn *spawn = &ictx->spawn;
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_blkcipher *cipher;

	cipher = crypto_spawn_blkcipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->child = cipher;
	tfm->crt_ablkcipher.reqsize =
		sizeof(struct cryptd_blkcipher_request_ctx);
	return 0;
}

static void cryptd_blkcipher_exit_tfm(struct crypto_tfm *tfm)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_blkcipher(ctx->child);
}

static void *cryptd_alloc_instance(struct crypto_alg *alg, unsigned int head,
				   unsigned int tail)
{
	char *p;
	struct crypto_instance *inst;
	int err;

	p = kzalloc(head + sizeof(*inst) + tail, GFP_KERNEL);
	if (!p)
		return ERR_PTR(-ENOMEM);

	inst = (void *)(p + head);

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
		goto out_free_inst;

	memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);

	inst->alg.cra_priority = alg->cra_priority + 50;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;

out:
	return p;

out_free_inst:
	kfree(p);
	p = ERR_PTR(err);
	goto out;
}

static int cryptd_create_blkcipher(struct crypto_template *tmpl,
				   struct rtattr **tb,
				   struct cryptd_queue *queue)
{
	struct cryptd_instance_ctx *ctx;
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	inst = cryptd_alloc_instance(alg, 0, sizeof(*ctx));
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto out_put_alg;

	ctx = crypto_instance_ctx(inst);
	ctx->queue = queue;

	err = crypto_init_spawn(&ctx->spawn, alg, inst,
				CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
	if (err)
		goto out_free_inst;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC;
	inst->alg.cra_type = &crypto_ablkcipher_type;

	inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize;
	inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
	inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize;

	inst->alg.cra_ablkcipher.geniv = alg->cra_blkcipher.geniv;

	inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx);

	inst->alg.cra_init = cryptd_blkcipher_init_tfm;
	inst->alg.cra_exit = cryptd_blkcipher_exit_tfm;

	inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey;
	inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue;
	inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue;

	err = crypto_register_instance(tmpl, inst);
	if (err) {
		crypto_drop_spawn(&ctx->spawn);
out_free_inst:
		kfree(inst);
	}

out_put_alg:
	crypto_mod_put(alg);
	return err;
}

static int cryptd_hash_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct hashd_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_shash_spawn *spawn = &ictx->spawn;
	struct cryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_shash *hash;

	hash = crypto_spawn_shash(spawn);
	if (IS_ERR(hash))
		return PTR_ERR(hash);

	ctx->child = hash;
	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
				 sizeof(struct cryptd_hash_request_ctx) +
				 crypto_shash_descsize(hash));
	return 0;
}

static void cryptd_hash_exit_tfm(struct crypto_tfm *tfm)
{
	struct cryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_shash(ctx->child);
}

static int cryptd_hash_setkey(struct crypto_ahash *parent,
				   const u8 *key, unsigned int keylen)
{
	struct cryptd_hash_ctx *ctx   = crypto_ahash_ctx(parent);
	struct crypto_shash *child = ctx->child;
	int err;

	crypto_shash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_shash_set_flags(child, crypto_ahash_get_flags(parent) &
				      CRYPTO_TFM_REQ_MASK);
	err = crypto_shash_setkey(child, key, keylen);
	crypto_ahash_set_flags(parent, crypto_shash_get_flags(child) &
				       CRYPTO_TFM_RES_MASK);
	return err;
}

static int cryptd_hash_enqueue(struct ahash_request *req,
				crypto_completion_t complete)
{
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
	struct cryptd_queue *queue =
		cryptd_get_queue(crypto_ahash_tfm(tfm));

	rctx->complete = req->base.complete;
	req->base.complete = complete;

	return cryptd_enqueue_request(queue, &req->base);
}

static void cryptd_hash_init(struct crypto_async_request *req_async, int err)
{
	struct cryptd_hash_ctx *ctx = crypto_tfm_ctx(req_async->tfm);
	struct crypto_shash *child = ctx->child;
	struct ahash_request *req = ahash_request_cast(req_async);
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	struct shash_desc *desc = &rctx->desc;

	if (unlikely(err == -EINPROGRESS))
		goto out;

	desc->tfm = child;
	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	err = crypto_shash_init(desc);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int cryptd_hash_init_enqueue(struct ahash_request *req)
{
	return cryptd_hash_enqueue(req, cryptd_hash_init);
}

static void cryptd_hash_update(struct crypto_async_request *req_async, int err)
{
	struct ahash_request *req = ahash_request_cast(req_async);
	struct cryptd_hash_request_ctx *rctx;

	rctx = ahash_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	err = shash_ahash_update(req, &rctx->desc);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int cryptd_hash_update_enqueue(struct ahash_request *req)
{
	return cryptd_hash_enqueue(req, cryptd_hash_update);
}

static void cryptd_hash_final(struct crypto_async_request *req_async, int err)
{
	struct ahash_request *req = ahash_request_cast(req_async);
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	err = crypto_shash_final(&rctx->desc, req->result);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int cryptd_hash_final_enqueue(struct ahash_request *req)
{
	return cryptd_hash_enqueue(req, cryptd_hash_final);
}

static void cryptd_hash_finup(struct crypto_async_request *req_async, int err)
{
	struct ahash_request *req = ahash_request_cast(req_async);
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	err = shash_ahash_finup(req, &rctx->desc);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int cryptd_hash_finup_enqueue(struct ahash_request *req)
{
	return cryptd_hash_enqueue(req, cryptd_hash_finup);
}

static void cryptd_hash_digest(struct crypto_async_request *req_async, int err)
{
	struct cryptd_hash_ctx *ctx = crypto_tfm_ctx(req_async->tfm);
	struct crypto_shash *child = ctx->child;
	struct ahash_request *req = ahash_request_cast(req_async);
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	struct shash_desc *desc = &rctx->desc;

	if (unlikely(err == -EINPROGRESS))
		goto out;

	desc->tfm = child;
	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	err = shash_ahash_digest(req, desc);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int cryptd_hash_digest_enqueue(struct ahash_request *req)
{
	return cryptd_hash_enqueue(req, cryptd_hash_digest);
}

static int cryptd_hash_export(struct ahash_request *req, void *out)
{
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	return crypto_shash_export(&rctx->desc, out);
}

static int cryptd_hash_import(struct ahash_request *req, const void *in)
{
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	return crypto_shash_import(&rctx->desc, in);
}

static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
			      struct cryptd_queue *queue)
{
	struct hashd_instance_ctx *ctx;
	struct ahash_instance *inst;
	struct shash_alg *salg;
	struct crypto_alg *alg;
	int err;

	salg = shash_attr_alg(tb[1], 0, 0);
	if (IS_ERR(salg))
		return PTR_ERR(salg);

	alg = &salg->base;
	inst = cryptd_alloc_instance(alg, ahash_instance_headroom(),
				     sizeof(*ctx));
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto out_put_alg;

	ctx = ahash_instance_ctx(inst);
	ctx->queue = queue;

	err = crypto_init_shash_spawn(&ctx->spawn, salg,
				      ahash_crypto_instance(inst));
	if (err)
		goto out_free_inst;

	inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC;

	inst->alg.halg.digestsize = salg->digestsize;
	inst->alg.halg.base.cra_ctxsize = sizeof(struct cryptd_hash_ctx);

	inst->alg.halg.base.cra_init = cryptd_hash_init_tfm;
	inst->alg.halg.base.cra_exit = cryptd_hash_exit_tfm;

	inst->alg.init   = cryptd_hash_init_enqueue;
	inst->alg.update = cryptd_hash_update_enqueue;
	inst->alg.final  = cryptd_hash_final_enqueue;
	inst->alg.finup  = cryptd_hash_finup_enqueue;
	inst->alg.export = cryptd_hash_export;
	inst->alg.import = cryptd_hash_import;
	inst->alg.setkey = cryptd_hash_setkey;
	inst->alg.digest = cryptd_hash_digest_enqueue;

	err = ahash_register_instance(tmpl, inst);
	if (err) {
		crypto_drop_shash(&ctx->spawn);
out_free_inst:
		kfree(inst);
	}

out_put_alg:
	crypto_mod_put(alg);
	return err;
}

static void cryptd_aead_crypt(struct aead_request *req,
			struct crypto_aead *child,
			int err,
			int (*crypt)(struct aead_request *req))
{
	struct cryptd_aead_request_ctx *rctx;
	rctx = aead_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;
	aead_request_set_tfm(req, child);
	err = crypt( req );
	req->base.complete = rctx->complete;
out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static void cryptd_aead_encrypt(struct crypto_async_request *areq, int err)
{
	struct cryptd_aead_ctx *ctx = crypto_tfm_ctx(areq->tfm);
	struct crypto_aead *child = ctx->child;
	struct aead_request *req;

	req = container_of(areq, struct aead_request, base);
	cryptd_aead_crypt(req, child, err, crypto_aead_crt(child)->encrypt);
}

static void cryptd_aead_decrypt(struct crypto_async_request *areq, int err)
{
	struct cryptd_aead_ctx *ctx = crypto_tfm_ctx(areq->tfm);
	struct crypto_aead *child = ctx->child;
	struct aead_request *req;

	req = container_of(areq, struct aead_request, base);
	cryptd_aead_crypt(req, child, err, crypto_aead_crt(child)->decrypt);
}

static int cryptd_aead_enqueue(struct aead_request *req,
				    crypto_completion_t complete)
{
	struct cryptd_aead_request_ctx *rctx = aead_request_ctx(req);
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	struct cryptd_queue *queue = cryptd_get_queue(crypto_aead_tfm(tfm));

	rctx->complete = req->base.complete;
	req->base.complete = complete;
	return cryptd_enqueue_request(queue, &req->base);
}

static int cryptd_aead_encrypt_enqueue(struct aead_request *req)
{
	return cryptd_aead_enqueue(req, cryptd_aead_encrypt );
}

static int cryptd_aead_decrypt_enqueue(struct aead_request *req)
{
	return cryptd_aead_enqueue(req, cryptd_aead_decrypt );
}

static int cryptd_aead_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct aead_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_aead_spawn *spawn = &ictx->aead_spawn;
	struct cryptd_aead_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_aead *cipher;

	cipher = crypto_spawn_aead(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	crypto_aead_set_flags(cipher, CRYPTO_TFM_REQ_MAY_SLEEP);
	ctx->child = cipher;
	tfm->crt_aead.reqsize = sizeof(struct cryptd_aead_request_ctx);
	return 0;
}

static void cryptd_aead_exit_tfm(struct crypto_tfm *tfm)
{
	struct cryptd_aead_ctx *ctx = crypto_tfm_ctx(tfm);
	crypto_free_aead(ctx->child);
}

static int cryptd_create_aead(struct crypto_template *tmpl,
		              struct rtattr **tb,
			      struct cryptd_queue *queue)
{
	struct aead_instance_ctx *ctx;
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_AEAD,
				CRYPTO_ALG_TYPE_MASK);
        if (IS_ERR(alg))
		return PTR_ERR(alg);

	inst = cryptd_alloc_instance(alg, 0, sizeof(*ctx));
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto out_put_alg;

	ctx = crypto_instance_ctx(inst);
	ctx->queue = queue;

	err = crypto_init_spawn(&ctx->aead_spawn.base, alg, inst,
			CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
	if (err)
		goto out_free_inst;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
	inst->alg.cra_type = alg->cra_type;
	inst->alg.cra_ctxsize = sizeof(struct cryptd_aead_ctx);
	inst->alg.cra_init = cryptd_aead_init_tfm;
	inst->alg.cra_exit = cryptd_aead_exit_tfm;
	inst->alg.cra_aead.setkey      = alg->cra_aead.setkey;
	inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
	inst->alg.cra_aead.geniv       = alg->cra_aead.geniv;
	inst->alg.cra_aead.ivsize      = alg->cra_aead.ivsize;
	inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
	inst->alg.cra_aead.encrypt     = cryptd_aead_encrypt_enqueue;
	inst->alg.cra_aead.decrypt     = cryptd_aead_decrypt_enqueue;
	inst->alg.cra_aead.givencrypt  = alg->cra_aead.givencrypt;
	inst->alg.cra_aead.givdecrypt  = alg->cra_aead.givdecrypt;

	err = crypto_register_instance(tmpl, inst);
	if (err) {
		crypto_drop_spawn(&ctx->aead_spawn.base);
out_free_inst:
		kfree(inst);
	}
out_put_alg:
	crypto_mod_put(alg);
	return err;
}

static struct cryptd_queue queue;

static int cryptd_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct crypto_attr_type *algt;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
	case CRYPTO_ALG_TYPE_BLKCIPHER:
		return cryptd_create_blkcipher(tmpl, tb, &queue);
	case CRYPTO_ALG_TYPE_DIGEST:
		return cryptd_create_hash(tmpl, tb, &queue);
	case CRYPTO_ALG_TYPE_AEAD:
		return cryptd_create_aead(tmpl, tb, &queue);
	}

	return -EINVAL;
}

static void cryptd_free(struct crypto_instance *inst)
{
	struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
	struct hashd_instance_ctx *hctx = crypto_instance_ctx(inst);
	struct aead_instance_ctx *aead_ctx = crypto_instance_ctx(inst);

	switch (inst->alg.cra_flags & CRYPTO_ALG_TYPE_MASK) {
	case CRYPTO_ALG_TYPE_AHASH:
		crypto_drop_shash(&hctx->spawn);
		kfree(ahash_instance(inst));
		return;
	case CRYPTO_ALG_TYPE_AEAD:
		crypto_drop_spawn(&aead_ctx->aead_spawn.base);
		kfree(inst);
		return;
	default:
		crypto_drop_spawn(&ctx->spawn);
		kfree(inst);
	}
}

static struct crypto_template cryptd_tmpl = {
	.name = "cryptd",
	.create = cryptd_create,
	.free = cryptd_free,
	.module = THIS_MODULE,
};

struct cryptd_ablkcipher *cryptd_alloc_ablkcipher(const char *alg_name,
						  u32 type, u32 mask)
{
	char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
	struct crypto_tfm *tfm;

	if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
		     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
		return ERR_PTR(-EINVAL);
	type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	type |= CRYPTO_ALG_TYPE_BLKCIPHER;
	mask &= ~CRYPTO_ALG_TYPE_MASK;
	mask |= (CRYPTO_ALG_GENIV | CRYPTO_ALG_TYPE_BLKCIPHER_MASK);
	tfm = crypto_alloc_base(cryptd_alg_name, type, mask);
	if (IS_ERR(tfm))
		return ERR_CAST(tfm);
	if (tfm->__crt_alg->cra_module != THIS_MODULE) {
		crypto_free_tfm(tfm);
		return ERR_PTR(-EINVAL);
	}

	return __cryptd_ablkcipher_cast(__crypto_ablkcipher_cast(tfm));
}
EXPORT_SYMBOL_GPL(cryptd_alloc_ablkcipher);

struct crypto_blkcipher *cryptd_ablkcipher_child(struct cryptd_ablkcipher *tfm)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(&tfm->base);
	return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_ablkcipher_child);

void cryptd_free_ablkcipher(struct cryptd_ablkcipher *tfm)
{
	crypto_free_ablkcipher(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_ablkcipher);

struct cryptd_ahash *cryptd_alloc_ahash(const char *alg_name,
					u32 type, u32 mask)
{
	char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
	struct crypto_ahash *tfm;

	if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
		     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
		return ERR_PTR(-EINVAL);
	tfm = crypto_alloc_ahash(cryptd_alg_name, type, mask);
	if (IS_ERR(tfm))
		return ERR_CAST(tfm);
	if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
		crypto_free_ahash(tfm);
		return ERR_PTR(-EINVAL);
	}

	return __cryptd_ahash_cast(tfm);
}
EXPORT_SYMBOL_GPL(cryptd_alloc_ahash);

struct crypto_shash *cryptd_ahash_child(struct cryptd_ahash *tfm)
{
	struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);

	return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_ahash_child);

struct shash_desc *cryptd_shash_desc(struct ahash_request *req)
{
	struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	return &rctx->desc;
}
EXPORT_SYMBOL_GPL(cryptd_shash_desc);

void cryptd_free_ahash(struct cryptd_ahash *tfm)
{
	crypto_free_ahash(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_ahash);

struct cryptd_aead *cryptd_alloc_aead(const char *alg_name,
						  u32 type, u32 mask)
{
	char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
	struct crypto_aead *tfm;

	if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
		     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
		return ERR_PTR(-EINVAL);
	tfm = crypto_alloc_aead(cryptd_alg_name, type, mask);
	if (IS_ERR(tfm))
		return ERR_CAST(tfm);
	if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
		crypto_free_aead(tfm);
		return ERR_PTR(-EINVAL);
	}
	return __cryptd_aead_cast(tfm);
}
EXPORT_SYMBOL_GPL(cryptd_alloc_aead);

struct crypto_aead *cryptd_aead_child(struct cryptd_aead *tfm)
{
	struct cryptd_aead_ctx *ctx;
	ctx = crypto_aead_ctx(&tfm->base);
	return ctx->child;
}
EXPORT_SYMBOL_GPL(cryptd_aead_child);

void cryptd_free_aead(struct cryptd_aead *tfm)
{
	crypto_free_aead(&tfm->base);
}
EXPORT_SYMBOL_GPL(cryptd_free_aead);

static int __init cryptd_init(void)
{
	int err;

	err = cryptd_init_queue(&queue, CRYPTD_MAX_CPU_QLEN);
	if (err)
		return err;

	err = crypto_register_template(&cryptd_tmpl);
	if (err)
		cryptd_fini_queue(&queue);

	return err;
}

static void __exit cryptd_exit(void)
{
	cryptd_fini_queue(&queue);
	crypto_unregister_template(&cryptd_tmpl);
}

subsys_initcall(cryptd_init);
module_exit(cryptd_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software async crypto daemon");
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