[PATCH AUTOSEL 4.19 29/31] crypto: lrw - simplify error handling in create()

[PATCH AUTOSEL 4.19 29/31] crypto: lrw - simplify error handling in create()

[Sasha Levin]

From: Eric Biggers <ebiggers@google.com>

[ Upstream commit d57063103332b95eac9c118900f35700a491da08 ]

Simplify the error handling in the LRW template's ->create() function by
taking advantage of crypto_drop_skcipher() now accepting (as a no-op) a
spawn that hasn't been grabbed yet.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 crypto/lrw.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/crypto/lrw.c b/crypto/lrw.c
index 5504d1325a56a..11d079c44cafc 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -508,15 +508,15 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 
 	err = -EINVAL;
 	if (alg->base.cra_blocksize != LRW_BLOCK_SIZE)
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	if (crypto_skcipher_alg_ivsize(alg))
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	err = crypto_inst_setname(skcipher_crypto_instance(inst), "lrw",
 				  &alg->base);
 	if (err)
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	err = -EINVAL;
 	cipher_name = alg->base.cra_name;
@@ -529,20 +529,20 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 
 		len = strlcpy(ecb_name, cipher_name + 4, sizeof(ecb_name));
 		if (len < 2 || len >= sizeof(ecb_name))
-			goto err_drop_spawn;
+			goto err_free_inst;
 
 		if (ecb_name[len - 1] != ')')
-			goto err_drop_spawn;
+			goto err_free_inst;
 
 		ecb_name[len - 1] = 0;
 
 		if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 			     "lrw(%s)", ecb_name) >= CRYPTO_MAX_ALG_NAME) {
 			err = -ENAMETOOLONG;
-			goto err_drop_spawn;
+			goto err_free_inst;
 		}
 	} else
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
@@ -568,17 +568,11 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	inst->free = free;
 
 	err = skcipher_register_instance(tmpl, inst);
-	if (err)
-		goto err_drop_spawn;
-
-out:
-	return err;
-
-err_drop_spawn:
-	crypto_drop_skcipher(spawn);
+	if (err) {
 err_free_inst:
-	kfree(inst);
-	goto out;
+		free(inst);
+	}
+	return err;
 }
 
 static struct crypto_template crypto_tmpl = {
-- 
2.20.1

[PATCH AUTOSEL 4.19 30/31] crypto: xts - simplify error handling in ->create()

[Sasha Levin]

From: Eric Biggers <ebiggers@google.com>

[ Upstream commit 732e540953477083082e999ff553622c59cffd5f ]

Simplify the error handling in the XTS template's ->create() function by
taking advantage of crypto_drop_skcipher() now accepting (as a no-op) a
spawn that hasn't been grabbed yet.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 crypto/xts.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/crypto/xts.c b/crypto/xts.c
index ccf55fbb8bc2d..a19965a0fe932 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -449,15 +449,15 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 
 	err = -EINVAL;
 	if (alg->base.cra_blocksize != XTS_BLOCK_SIZE)
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	if (crypto_skcipher_alg_ivsize(alg))
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	err = crypto_inst_setname(skcipher_crypto_instance(inst), "xts",
 				  &alg->base);
 	if (err)
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	err = -EINVAL;
 	cipher_name = alg->base.cra_name;
@@ -470,20 +470,20 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 
 		len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
 		if (len < 2 || len >= sizeof(ctx->name))
-			goto err_drop_spawn;
+			goto err_free_inst;
 
 		if (ctx->name[len - 1] != ')')
-			goto err_drop_spawn;
+			goto err_free_inst;
 
 		ctx->name[len - 1] = 0;
 
 		if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 			     "xts(%s)", ctx->name) >= CRYPTO_MAX_ALG_NAME) {
 			err = -ENAMETOOLONG;
-			goto err_drop_spawn;
+			goto err_free_inst;
 		}
 	} else
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
@@ -507,17 +507,11 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	inst->free = free;
 
 	err = skcipher_register_instance(tmpl, inst);
-	if (err)
-		goto err_drop_spawn;
-
-out:
-	return err;
-
-err_drop_spawn:
-	crypto_drop_skcipher(&ctx->spawn);
+	if (err) {
 err_free_inst:
-	kfree(inst);
-	goto out;
+		free(inst);
+	}
+	return err;
 }
 
 static struct crypto_template crypto_tmpl = {
-- 
2.20.1

[PATCH AUTOSEL 4.19 31/31] gcc-10: avoid shadowing standard library 'free()' in crypto

[Sasha Levin]

From: Linus Torvalds <torvalds@linux-foundation.org>

[ Upstream commit 1a263ae60b04de959d9ce9caea4889385eefcc7b ]

gcc-10 has started warning about conflicting types for a few new
built-in functions, particularly 'free()'.

This results in warnings like:

   crypto/xts.c:325:13: warning: conflicting types for built-in function ‘free’; expected ‘void(void *)’ [-Wbuiltin-declaration-mismatch]

because the crypto layer had its local freeing functions called
'free()'.

Gcc-10 is in the wrong here, since that function is marked 'static', and
thus there is no chance of confusion with any standard library function
namespace.

But the simplest thing to do is to just use a different name here, and
avoid this gcc mis-feature.

[ Side note: gcc knowing about 'free()' is in itself not the
  mis-feature: the semantics of 'free()' are special enough that a
  compiler can validly do special things when seeing it.

  So the mis-feature here is that gcc thinks that 'free()' is some
  restricted name, and you can't shadow it as a local static function.

  Making the special 'free()' semantics be a function attribute rather
  than tied to the name would be the much better model ]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 crypto/lrw.c | 6 +++---
 crypto/xts.c | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/crypto/lrw.c b/crypto/lrw.c
index 11d079c44cafc..871664158c161 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -453,7 +453,7 @@ static void exit_tfm(struct crypto_skcipher *tfm)
 	crypto_free_skcipher(ctx->child);
 }
 
-static void free(struct skcipher_instance *inst)
+static void free_inst(struct skcipher_instance *inst)
 {
 	crypto_drop_skcipher(skcipher_instance_ctx(inst));
 	kfree(inst);
@@ -565,12 +565,12 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	inst->alg.encrypt = encrypt;
 	inst->alg.decrypt = decrypt;
 
-	inst->free = free;
+	inst->free = free_inst;
 
 	err = skcipher_register_instance(tmpl, inst);
 	if (err) {
 err_free_inst:
-		free(inst);
+		free_inst(inst);
 	}
 	return err;
 }
diff --git a/crypto/xts.c b/crypto/xts.c
index a19965a0fe932..6f51052039837 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -393,7 +393,7 @@ static void exit_tfm(struct crypto_skcipher *tfm)
 	crypto_free_cipher(ctx->tweak);
 }
 
-static void free(struct skcipher_instance *inst)
+static void free_inst(struct skcipher_instance *inst)
 {
 	crypto_drop_skcipher(skcipher_instance_ctx(inst));
 	kfree(inst);
@@ -504,12 +504,12 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	inst->alg.encrypt = encrypt;
 	inst->alg.decrypt = decrypt;
 
-	inst->free = free;
+	inst->free = free_inst;
 
 	err = skcipher_register_instance(tmpl, inst);
 	if (err) {
 err_free_inst:
-		free(inst);
+		free_inst(inst);
 	}
 	return err;
 }
-- 
2.20.1