crypto: api - Move type exit function into crypto_tfm

The type exit function needs to undo any allocations done by the type
init function.  However, the type init function may differ depending
on the upper-level type of the transform (e.g., a crypto_blkcipher
instantiated as a crypto_ablkcipher).

So we need to move the exit function out of the lower-level
structure and into crypto_tfm itself.

As it stands this is a no-op since nobody uses exit functions at
all.  However, all cases where a lower-level type is instantiated
as a different upper-level type (such as blkcipher as ablkcipher)
will be converted such that they allocate the underlying transform
and use that instead of casting (e.g., crypto_ablkcipher casted
into crypto_blkcipher).  That will need to use a different exit
function depending on the upper-level type.

This patch also allows the type init/exit functions to call (or not)
cra_init/cra_exit instead of always calling them from the top level.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 3d2317e4af2e..ea52cd944fd9 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -480,6 +480,8 @@ struct crypto_tfm {
                 struct compress_tfm compress;
                 struct rng_tfm rng;
         } crt_u;
+
+        void (*exit)(struct crypto_tfm *tfm);
         
         struct crypto_alg *__crt_alg;