crypto: gcm - use crypto_grab_ahash() and simplify error paths

Make the gcm and gcm_base templates use the new function
crypto_grab_ahash() to initialize their ahash spawn.

This is needed to make all spawns be initialized in a consistent way.

Also simplify the error handling by taking advantage of crypto_drop_*()
now accepting (as a no-op) spawns that haven't been initialized yet.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/gcm.c b/crypto/gcm.c
index 72649b8cbf2a4523952423bcc3089f3958f539c1..8e5c0ac656611d3e42c91591ea962aa2863b3ce1 100644 (file)
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -13,7 +13,6 @@
 #include <crypto/scatterwalk.h>
 #include <crypto/gcm.h>
 #include <crypto/hash.h>
-#include "internal.h"
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -582,10 +581,9 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl,
        struct crypto_attr_type *algt;
        u32 mask;
        struct aead_instance *inst;
+       struct gcm_instance_ctx *ctx;
        struct skcipher_alg *ctr;
-       struct crypto_alg *ghash_alg;
        struct hash_alg_common *ghash;
-       struct gcm_instance_ctx *ctx;
        int err;
 
        algt = crypto_get_attr_type(tb);
@@ -597,35 +595,26 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl,
 
        mask = crypto_requires_sync(algt->type, algt->mask);
 
-       ghash_alg = crypto_find_alg(ghash_name, &crypto_ahash_type,
-                                   CRYPTO_ALG_TYPE_HASH,
-                                   CRYPTO_ALG_TYPE_AHASH_MASK | mask);
-       if (IS_ERR(ghash_alg))
-               return PTR_ERR(ghash_alg);
-
-       ghash = __crypto_hash_alg_common(ghash_alg);
-
-       err = -ENOMEM;
        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
        if (!inst)
-               goto out_put_ghash;
-
+               return -ENOMEM;
        ctx = aead_instance_ctx(inst);
-       err = crypto_init_ahash_spawn(&ctx->ghash, ghash,
-                                     aead_crypto_instance(inst));
+
+       err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
+                               ghash_name, 0, mask);
        if (err)
                goto err_free_inst;
+       ghash = crypto_spawn_ahash_alg(&ctx->ghash);
 
        err = -EINVAL;
        if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
            ghash->digestsize != 16)
-               goto err_drop_ghash;
+               goto err_free_inst;
 
        err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
                                   ctr_name, 0, mask);
        if (err)
-               goto err_drop_ghash;
-
+               goto err_free_inst;
        ctr = crypto_spawn_skcipher_alg(&ctx->ctr);
 
        /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
@@ -633,18 +622,18 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl,
        if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
            crypto_skcipher_alg_ivsize(ctr) != 16 ||
            ctr->base.cra_blocksize != 1)
-               goto out_put_ctr;
+               goto err_free_inst;
 
        err = -ENAMETOOLONG;
        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
                     "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
-               goto out_put_ctr;
+               goto err_free_inst;
 
        if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "gcm_base(%s,%s)", ctr->base.cra_driver_name,
-                    ghash_alg->cra_driver_name) >=
+                    ghash->base.cra_driver_name) >=
            CRYPTO_MAX_ALG_NAME)
-               goto out_put_ctr;
+               goto err_free_inst;
 
        inst->alg.base.cra_flags = (ghash->base.cra_flags |
                                    ctr->base.cra_flags) & CRYPTO_ALG_ASYNC;
@@ -667,20 +656,11 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl,
        inst->free = crypto_gcm_free;
 
        err = aead_register_instance(tmpl, inst);
-       if (err)
-               goto out_put_ctr;
-
-out_put_ghash:
-       crypto_mod_put(ghash_alg);
-       return err;
-
-out_put_ctr:
-       crypto_drop_skcipher(&ctx->ctr);
-err_drop_ghash:
-       crypto_drop_ahash(&ctx->ghash);
+       if (err) {
 err_free_inst:
-       kfree(inst);
-       goto out_put_ghash;
+               crypto_gcm_free(inst);
+       }
+       return err;
 }
 
 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)