Commit 3c3a24cb authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: api - Add crypto_clone_tfm 



This patch adds the helper crypto_clone_tfm.  The purpose is to
allocate a tfm object with GFP_ATOMIC.  As we cannot sleep, the
object has to be cloned from an existing tfm object.

This allows code paths that cannot otherwise allocate a crypto_tfm
object to do so.  Once a new tfm has been obtained its key could
then be changed without impacting other users.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ae131f49

crypto/api.c

+50 −9
Original line number Diff line number Diff line
@@ -488,28 +488,44 @@ struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask) 
}

EXPORT_SYMBOL_GPL(crypto_alloc_base);



void *crypto_create_tfm_node(struct crypto_alg *alg,

			const struct crypto_type *frontend,

			int node)

static void *crypto_alloc_tfmmem(struct crypto_alg *alg,

				 const struct crypto_type *frontend, int node,

				 gfp_t gfp)

{

	char *mem;

	struct crypto_tfm *tfm = NULL;

	struct crypto_tfm *tfm;

	unsigned int tfmsize;

	unsigned int total;

	int err = -ENOMEM;

	char *mem;



	tfmsize = frontend->tfmsize;

	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);



	mem = kzalloc_node(total, GFP_KERNEL, node);

	mem = kzalloc_node(total, gfp, node);

	if (mem == NULL)

		goto out_err;

		return ERR_PTR(-ENOMEM);



	tfm = (struct crypto_tfm *)(mem + tfmsize);

	tfm->__crt_alg = alg;

	tfm->node = node;

	refcount_set(&tfm->refcnt, 1);



	return mem;

}



void *crypto_create_tfm_node(struct crypto_alg *alg,

			     const struct crypto_type *frontend,

			     int node)

{

	struct crypto_tfm *tfm;

	char *mem;

	int err;



	mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL);

	if (IS_ERR(mem))

		goto out;



	tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);



	err = frontend->init_tfm(tfm);

	if (err)

		goto out_free_tfm;
@@ -525,13 +541,38 @@ void *crypto_create_tfm_node(struct crypto_alg *alg, 
	if (err == -EAGAIN)

		crypto_shoot_alg(alg);

	kfree(mem);

out_err:

	mem = ERR_PTR(err);

out:

	return mem;

}

EXPORT_SYMBOL_GPL(crypto_create_tfm_node);



void *crypto_clone_tfm(const struct crypto_type *frontend,

		       struct crypto_tfm *otfm)

{

	struct crypto_alg *alg = otfm->__crt_alg;

	struct crypto_tfm *tfm;

	char *mem;



	mem = ERR_PTR(-ESTALE);

	if (unlikely(!crypto_mod_get(alg)))

		goto out;



	mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC);

	if (IS_ERR(mem)) {

		crypto_mod_put(alg);

		goto out;

	}



	tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);

	tfm->crt_flags = otfm->crt_flags;

	tfm->exit = otfm->exit;



out:

	return mem;

}

EXPORT_SYMBOL_GPL(crypto_clone_tfm);



struct crypto_alg *crypto_find_alg(const char *alg_name,

				   const struct crypto_type *frontend,

				   u32 type, u32 mask)

crypto/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -106,6 +106,8 @@ struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type, 
				      u32 mask);

void *crypto_create_tfm_node(struct crypto_alg *alg,

			const struct crypto_type *frontend, int node);

void *crypto_clone_tfm(const struct crypto_type *frontend,

		       struct crypto_tfm *otfm);



static inline void *crypto_create_tfm(struct crypto_alg *alg,

			const struct crypto_type *frontend)