crypto: cryptd - use crypto_grab_shash() and simplify error paths

Make the cryptd template (in the hash case) use the new function
crypto_grab_shash() to initialize its shash spawn.

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

This required making cryptd_create_hash() allocate the instance directly
rather than use cryptd_alloc_instance().

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

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

diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index a03ac28..fb03aca 100644 (file)
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -221,32 +221,6 @@ static int cryptd_init_instance(struct crypto_instance *inst,
        return 0;
 }
 
-static void *cryptd_alloc_instance(struct crypto_alg *alg, unsigned int head,
-                                  unsigned int tail)
-{
-       char *p;
-       struct crypto_instance *inst;
-       int err;
-
-       p = kzalloc(head + sizeof(*inst) + tail, GFP_KERNEL);
-       if (!p)
-               return ERR_PTR(-ENOMEM);
-
-       inst = (void *)(p + head);
-
-       err = cryptd_init_instance(inst, alg);
-       if (err)
-               goto out_free_inst;
-
-out:
-       return p;
-
-out_free_inst:
-       kfree(p);
-       p = ERR_PTR(err);
-       goto out;
-}
-
 static int cryptd_skcipher_setkey(struct crypto_skcipher *parent,
                                  const u8 *key, unsigned int keylen)
 {
@@ -662,39 +636,36 @@ static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
 {
        struct hashd_instance_ctx *ctx;
        struct ahash_instance *inst;
-       struct shash_alg *salg;
-       struct crypto_alg *alg;
+       struct shash_alg *alg;
        u32 type = 0;
        u32 mask = 0;
        int err;
 
        cryptd_check_internal(tb, &type, &mask);
 
-       salg = shash_attr_alg(tb[1], type, mask);
-       if (IS_ERR(salg))
-               return PTR_ERR(salg);
-
-       alg = &salg->base;
-       inst = cryptd_alloc_instance(alg, ahash_instance_headroom(),
-                                    sizeof(*ctx));
-       err = PTR_ERR(inst);
-       if (IS_ERR(inst))
-               goto out_put_alg;
+       inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+       if (!inst)
+               return -ENOMEM;
 
        ctx = ahash_instance_ctx(inst);
        ctx->queue = queue;
 
-       err = crypto_init_shash_spawn(&ctx->spawn, salg,
-                                     ahash_crypto_instance(inst));
+       err = crypto_grab_shash(&ctx->spawn, ahash_crypto_instance(inst),
+                               crypto_attr_alg_name(tb[1]), type, mask);
        if (err)
-               goto out_free_inst;
+               goto err_free_inst;
+       alg = crypto_spawn_shash_alg(&ctx->spawn);
+
+       err = cryptd_init_instance(ahash_crypto_instance(inst), &alg->base);
+       if (err)
+               goto err_free_inst;
 
        inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC |
-               (alg->cra_flags & (CRYPTO_ALG_INTERNAL |
-                                  CRYPTO_ALG_OPTIONAL_KEY));
+               (alg->base.cra_flags & (CRYPTO_ALG_INTERNAL |
+                                       CRYPTO_ALG_OPTIONAL_KEY));
 
-       inst->alg.halg.digestsize = salg->digestsize;
-       inst->alg.halg.statesize = salg->statesize;
+       inst->alg.halg.digestsize = alg->digestsize;
+       inst->alg.halg.statesize = alg->statesize;
        inst->alg.halg.base.cra_ctxsize = sizeof(struct cryptd_hash_ctx);
 
        inst->alg.halg.base.cra_init = cryptd_hash_init_tfm;
@@ -706,19 +677,16 @@ static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
        inst->alg.finup  = cryptd_hash_finup_enqueue;
        inst->alg.export = cryptd_hash_export;
        inst->alg.import = cryptd_hash_import;
-       if (crypto_shash_alg_has_setkey(salg))
+       if (crypto_shash_alg_has_setkey(alg))
                inst->alg.setkey = cryptd_hash_setkey;
        inst->alg.digest = cryptd_hash_digest_enqueue;
 
        err = ahash_register_instance(tmpl, inst);
        if (err) {
+err_free_inst:
                crypto_drop_shash(&ctx->spawn);
-out_free_inst:
                kfree(inst);
        }
-
-out_put_alg:
-       crypto_mod_put(alg);
        return err;
 }