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>