[CRYPTO] dm-crypt: Make iv_gen_private a union

Rather than stuffing integers into pointers with casts, let's use
a union.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 9 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index facf859b9b87..0d8686505e51 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -86,7 +86,10 @@ struct crypt_config {
          */
         struct crypt_iv_operations *iv_gen_ops;
         char *iv_mode;
-        struct crypto_cipher *iv_gen_private;
+        union {
+                struct crypto_cipher *essiv_tfm;
+                int benbi_shift;
+        } iv_gen_private;
         sector_t iv_offset;
         unsigned int iv_size;
 
@@ -195,21 +198,21 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
         }
         kfree(salt);
 
-        cc->iv_gen_private = essiv_tfm;
+        cc->iv_gen_private.essiv_tfm = essiv_tfm;
         return 0;
 }
 
 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
 {
-        crypto_free_cipher(cc->iv_gen_private);
-        cc->iv_gen_private = NULL;
+        crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
+        cc->iv_gen_private.essiv_tfm = NULL;
 }
 
 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
 {
         memset(iv, 0, cc->iv_size);
         *(u64 *)iv = cpu_to_le64(sector);
-        crypto_cipher_encrypt_one(cc->iv_gen_private, iv, iv);
+        crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
         return 0;
 }
 
@@ -232,21 +235,23 @@ static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
                 return -EINVAL;
         }
 
-        cc->iv_gen_private = (void *)(9 - log);
+        cc->iv_gen_private.benbi_shift = 9 - log;
 
         return 0;
 }
 
 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 {
-        cc->iv_gen_private = NULL;
 }
 
 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
 {
+        __be64 val;
+
         memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
-        put_unaligned(cpu_to_be64(((u64)sector << (u32)cc->iv_gen_private) + 1),
-                      (__be64 *)(iv + cc->iv_size - sizeof(u64)));
+
+        val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
+        put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 
         return 0;
 }