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: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2023-04-13 14:24:17 +08:00
parent ae131f4970
commit 3c3a24cb0a
2 changed files with 52 additions and 9 deletions

View File

@ -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)

View File

@ -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)