[RFC 00/10] introduce crypto wait for async op function

[RFC 00/10] introduce crypto wait for async op function

[Gilad Ben-Yossef]

Many users of kernel async. crypto services have a pattern of
starting an async. crypto op and than using a completion
to wait for it to end, resulting of the same code repeating
itself in multiple places, sometime with errors.

This patch aims to introduce a generic "wait for async. 
crypto op to complete" functions and move all the users
I could find to use it.  This gets rid of almost 300 
lines of code and fixes at least one bug (hopefully
without adding new ones).

In some cases (indicated in the specific patch description)
the move to the generic function changes the semantics
slightly (such as dropping interruptible when waiting).
I am especially interested in feedback whether people
think this is OK or I should an interruptible variant.

The patch set was boot tested on x86_64 and arm64 which
at the very least tests the crypto users via testmgr
but I am less confident regarding some of the other
users and would love feedback.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>

Gilad Ben-Yossef (10):
  crypto: factor async completion for general use
  crypto: move pub key to generic async completion
  crypto: move drbg to generic async completion
  crypto: move gcm to generic async completion
  crypto: move testmgr to generic async completion
  dm: move dm-verity to generic async completion
  fscrypt: move to generic async completion
  cifs: move to generic async completion
  ima: move to generic async completion
  crypto: adapt api sample to use async. op wait

 Documentation/crypto/api-samples.rst |  52 ++--------
 crypto/af_alg.c                      |  27 -----
 crypto/algif_aead.c                  |  14 +--
 crypto/algif_hash.c                  |  30 +++---
 crypto/algif_skcipher.c              |  10 +-
 crypto/api.c                         |  28 ++++++
 crypto/asymmetric_keys/public_key.c  |  28 +-----
 crypto/drbg.c                        |  35 ++-----
 crypto/gcm.c                         |  34 ++-----
 crypto/testmgr.c                     | 184 +++++++++++------------------------
 drivers/md/dm-verity-target.c        |  81 ++++-----------
 drivers/md/dm-verity.h               |   5 -
 fs/cifs/smb2ops.c                    |  30 +-----
 fs/crypto/crypto.c                   |  28 +-----
 fs/crypto/fname.c                    |  36 ++-----
 fs/crypto/fscrypt_private.h          |  10 --
 fs/crypto/keyinfo.c                  |  21 +---
 include/crypto/drbg.h                |   3 +-
 include/crypto/if_alg.h              |  14 ---
 include/linux/crypto.h               |  28 ++++++
 security/integrity/ima/ima_crypto.c  |  56 ++++-------
 21 files changed, 222 insertions(+), 532 deletions(-)

-- 
2.1.4

[RFC 01/10] crypto: factor async completion for general use

[Gilad Ben-Yossef]

Invoking a possibly async. crypto op and waiting for completion
while correctly handling backlog processing is a common task
in the crypto API implementation and outside users of it.

This patch re-factors one of the in crypto API implementation in
preparation for using it across the board instead of hand
rolled versions.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 crypto/af_alg.c         | 27 ---------------------------
 crypto/algif_aead.c     | 14 +++++++-------
 crypto/algif_hash.c     | 30 +++++++++++++++---------------
 crypto/algif_skcipher.c | 10 +++++-----
 crypto/api.c            | 28 ++++++++++++++++++++++++++++
 include/crypto/if_alg.h | 14 --------------
 include/linux/crypto.h  | 28 ++++++++++++++++++++++++++++
 7 files changed, 83 insertions(+), 68 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 3556d8e..bf4acaf 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -480,33 +480,6 @@ int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 }
 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
 
-int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
-{
-	switch (err) {
-	case -EINPROGRESS:
-	case -EBUSY:
-		wait_for_completion(&completion->completion);
-		reinit_completion(&completion->completion);
-		err = completion->err;
-		break;
-	};
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
-
-void af_alg_complete(struct crypto_async_request *req, int err)
-{
-	struct af_alg_completion *completion = req->data;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	completion->err = err;
-	complete(&completion->completion);
-}
-EXPORT_SYMBOL_GPL(af_alg_complete);
-
 static int __init af_alg_init(void)
 {
 	int err = proto_register(&alg_proto, 0);
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index 8af664f..9543589 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -57,7 +57,7 @@ struct aead_ctx {
 
 	void *iv;
 
-	struct af_alg_completion completion;
+	struct crypto_wait wait;
 
 	unsigned long used;
 
@@ -648,10 +648,10 @@ static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags)
 			       used, ctx->iv);
 	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);
 
-	err = af_alg_wait_for_completion(ctx->enc ?
-					 crypto_aead_encrypt(&ctx->aead_req) :
-					 crypto_aead_decrypt(&ctx->aead_req),
-					 &ctx->completion);
+	err = crypto_wait_req(ctx->enc ?
+				 crypto_aead_encrypt(&ctx->aead_req) :
+				 crypto_aead_decrypt(&ctx->aead_req),
+				 &ctx->wait);
 
 	if (err) {
 		/* EBADMSG implies a valid cipher operation took place */
@@ -912,7 +912,7 @@ static int aead_accept_parent_nokey(void *private, struct sock *sk)
 	ctx->enc = 0;
 	ctx->tsgl.cur = 0;
 	ctx->aead_assoclen = 0;
-	af_alg_init_completion(&ctx->completion);
+	crypto_init_wait(&ctx->wait);
 	sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
 	INIT_LIST_HEAD(&ctx->list);
 
@@ -920,7 +920,7 @@ static int aead_accept_parent_nokey(void *private, struct sock *sk)
 
 	aead_request_set_tfm(&ctx->aead_req, aead);
 	aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				  af_alg_complete, &ctx->completion);
+				  crypto_req_done, &ctx->wait);
 
 	sk->sk_destruct = aead_sock_destruct;
 
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 5e92bd2..fd7a6010 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -26,7 +26,7 @@ struct hash_ctx {
 
 	u8 *result;
 
-	struct af_alg_completion completion;
+	struct crypto_wait wait;
 
 	unsigned int len;
 	bool more;
@@ -88,8 +88,8 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
 		if ((msg->msg_flags & MSG_MORE))
 			hash_free_result(sk, ctx);
 
-		err = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
-						&ctx->completion);
+		err = crypto_wait_req(crypto_ahash_init(&ctx->req),
+						&ctx->wait);
 		if (err)
 			goto unlock;
 	}
@@ -110,8 +110,8 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
 
 		ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
 
-		err = af_alg_wait_for_completion(crypto_ahash_update(&ctx->req),
-						 &ctx->completion);
+		err = crypto_wait_req(crypto_ahash_update(&ctx->req),
+						 &ctx->wait);
 		af_alg_free_sg(&ctx->sgl);
 		if (err)
 			goto unlock;
@@ -129,8 +129,8 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
 			goto unlock;
 
 		ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
-		err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
-						 &ctx->completion);
+		err = crypto_wait_req(crypto_ahash_final(&ctx->req),
+						 &ctx->wait);
 	}
 
 unlock:
@@ -171,7 +171,7 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page,
 	} else {
 		if (!ctx->more) {
 			err = crypto_ahash_init(&ctx->req);
-			err = af_alg_wait_for_completion(err, &ctx->completion);
+			err = crypto_wait_req(err, &ctx->wait);
 			if (err)
 				goto unlock;
 		}
@@ -179,7 +179,7 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page,
 		err = crypto_ahash_update(&ctx->req);
 	}
 
-	err = af_alg_wait_for_completion(err, &ctx->completion);
+	err = crypto_wait_req(err, &ctx->wait);
 	if (err)
 		goto unlock;
 
@@ -215,17 +215,17 @@ static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 	ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
 
 	if (!result && !ctx->more) {
-		err = af_alg_wait_for_completion(
+		err = crypto_wait_req(
 				crypto_ahash_init(&ctx->req),
-				&ctx->completion);
+				&ctx->wait);
 		if (err)
 			goto unlock;
 	}
 
 	if (!result || ctx->more) {
 		ctx->more = 0;
-		err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
-						 &ctx->completion);
+		err = crypto_wait_req(crypto_ahash_final(&ctx->req),
+						 &ctx->wait);
 		if (err)
 			goto unlock;
 	}
@@ -476,13 +476,13 @@ static int hash_accept_parent_nokey(void *private, struct sock *sk)
 	ctx->result = NULL;
 	ctx->len = len;
 	ctx->more = 0;
-	af_alg_init_completion(&ctx->completion);
+	crypto_init_wait(&ctx->wait);
 
 	ask->private = ctx;
 
 	ahash_request_set_tfm(&ctx->req, hash);
 	ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				   af_alg_complete, &ctx->completion);
+				   crypto_req_done, &ctx->wait);
 
 	sk->sk_destruct = hash_sock_destruct;
 
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 43839b0..ec7b40f 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -43,7 +43,7 @@ struct skcipher_ctx {
 
 	void *iv;
 
-	struct af_alg_completion completion;
+	struct crypto_wait wait;
 
 	atomic_t inflight;
 	size_t used;
@@ -684,11 +684,11 @@ static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
 		skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
 					   ctx->iv);
 
-		err = af_alg_wait_for_completion(
+		err = crypto_wait_req(
 				ctx->enc ?
 					crypto_skcipher_encrypt(&ctx->req) :
 					crypto_skcipher_decrypt(&ctx->req),
-				&ctx->completion);
+				&ctx->wait);
 
 free:
 		af_alg_free_sg(&ctx->rsgl);
@@ -948,14 +948,14 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 	ctx->merge = 0;
 	ctx->enc = 0;
 	atomic_set(&ctx->inflight, 0);
-	af_alg_init_completion(&ctx->completion);
+	crypto_init_wait(&ctx->wait);
 
 	ask->private = ctx;
 
 	skcipher_request_set_tfm(&ctx->req, skcipher);
 	skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 						 CRYPTO_TFM_REQ_MAY_BACKLOG,
-				      af_alg_complete, &ctx->completion);
+				      crypto_req_done, &ctx->wait);
 
 	sk->sk_destruct = skcipher_sock_destruct;
 
diff --git a/crypto/api.c b/crypto/api.c
index 941cd4c..1c6e9cd 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -24,6 +24,7 @@
 #include <linux/sched/signal.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/completion.h>
 #include "internal.h"
 
 LIST_HEAD(crypto_alg_list);
@@ -595,5 +596,32 @@ int crypto_has_alg(const char *name, u32 type, u32 mask)
 }
 EXPORT_SYMBOL_GPL(crypto_has_alg);
 
+int crypto_wait_req(int err, struct crypto_wait *wait)
+{
+	switch (err) {
+	case -EINPROGRESS:
+	case -EBUSY:
+		wait_for_completion(&wait->completion);
+		reinit_completion(&wait->completion);
+		err = wait->err;
+		break;
+	};
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(crypto_wait_req);
+
+void crypto_req_done(struct crypto_async_request *req, int err)
+{
+	struct crypto_wait *wait = req->data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	wait->err = err;
+	complete(&wait->completion);
+}
+EXPORT_SYMBOL_GPL(crypto_req_done);
+
 MODULE_DESCRIPTION("Cryptographic core API");
 MODULE_LICENSE("GPL");
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index e2b9c6f..86764fb 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -14,7 +14,6 @@
 #define _CRYPTO_IF_ALG_H
 
 #include <linux/compiler.h>
-#include <linux/completion.h>
 #include <linux/if_alg.h>
 #include <linux/scatterlist.h>
 #include <linux/types.h>
@@ -37,11 +36,6 @@ struct alg_sock {
 	void *private;
 };
 
-struct af_alg_completion {
-	struct completion completion;
-	int err;
-};
-
 struct af_alg_control {
 	struct af_alg_iv *iv;
 	int op;
@@ -81,17 +75,9 @@ void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new);
 
 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con);
 
-int af_alg_wait_for_completion(int err, struct af_alg_completion *completion);
-void af_alg_complete(struct crypto_async_request *req, int err);
-
 static inline struct alg_sock *alg_sk(struct sock *sk)
 {
 	return (struct alg_sock *)sk;
 }
 
-static inline void af_alg_init_completion(struct af_alg_completion *completion)
-{
-	init_completion(&completion->completion);
-}
-
 #endif	/* _CRYPTO_IF_ALG_H */
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 84da997..df2f72f 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>
+#include <linux/completion.h>
 
 /*
  * Autoloaded crypto modules should only use a prefixed name to avoid allowing
@@ -137,6 +138,13 @@
 
 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
 
+/*
+ * Macro for declaring a crypto op async wait object on stack
+ */
+#define DECLARE_CRYPTO_WAIT(_wait) \
+	struct crypto_wait _wait = { \
+		COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 }
+
 struct scatterlist;
 struct crypto_ablkcipher;
 struct crypto_async_request;
@@ -467,6 +475,25 @@ struct crypto_alg {
 	struct module *cra_module;
 } CRYPTO_MINALIGN_ATTR;
 
+/**
+ * A helper struct for waiting for completion of async crypto ops
+ */
+struct crypto_wait {
+	struct completion completion;
+	int err;
+};
+
+/*
+ * Async ops completion helper functioons
+ */
+int crypto_wait_req(int err, struct crypto_wait *wait);
+void crypto_req_done(struct crypto_async_request *req, int err);
+
+static inline void crypto_init_wait(struct crypto_wait *wait)
+{
+	init_completion(&wait->completion);
+}
+
 /*
  * Algorithm registration interface.
  */
@@ -1604,5 +1631,6 @@ static inline int crypto_comp_decompress(struct crypto_comp *tfm,
 						    src, slen, dst, dlen);
 }
 
+
 #endif	/* _LINUX_CRYPTO_H */
 
-- 
2.1.4

Re: [RFC 01/10] crypto: factor async completion for general use

[Eric Biggers]

Hi Gilad,

On Sat, May 06, 2017 at 03:59:50PM +0300, Gilad Ben-Yossef wrote:
> Invoking a possibly async. crypto op and waiting for completion
> while correctly handling backlog processing is a common task
> in the crypto API implementation and outside users of it.
> 
> This patch re-factors one of the in crypto API implementation in
> preparation for using it across the board instead of hand
> rolled versions.

Thanks for doing this!  It annoyed me too that there wasn't a helper function
for this.  Just a few comments below:

> diff --git a/crypto/af_alg.c b/crypto/af_alg.c
> index 3556d8e..bf4acaf 100644
> --- a/crypto/af_alg.c
> +++ b/crypto/af_alg.c
> @@ -480,33 +480,6 @@ int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
>  }
>  EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
>  
> -int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
> -{
> -	switch (err) {
> -	case -EINPROGRESS:
> -	case -EBUSY:
> -		wait_for_completion(&completion->completion);
> -		reinit_completion(&completion->completion);
> -		err = completion->err;
> -		break;
> -	};
> -
> -	return err;
> -}
> -EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
> -
> -void af_alg_complete(struct crypto_async_request *req, int err)
> -{
> -	struct af_alg_completion *completion = req->data;
> -
> -	if (err == -EINPROGRESS)
> -		return;
> -
> -	completion->err = err;
> -	complete(&completion->completion);
> -}
> -EXPORT_SYMBOL_GPL(af_alg_complete);
> -

I think it would be cleaner to switch af_alg and algif_* over to the new
interface in its own patch, rather than in the same patch that introduces the
new interface.

> @@ -88,8 +88,8 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
>  		if ((msg->msg_flags & MSG_MORE))
>  			hash_free_result(sk, ctx);
>  
> -		err = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
> -						&ctx->completion);
> +		err = crypto_wait_req(crypto_ahash_init(&ctx->req),
> +						&ctx->wait);
>  		if (err)
>  			goto unlock;
>  	}

In general can you try to keep the argument lists indented sanely?  (This
applies throughout the patch series.)  e.g. here I'd have expected:

		err = crypto_wait_req(crypto_ahash_init(&ctx->req),
				      &ctx->wait);

>  
> diff --git a/crypto/api.c b/crypto/api.c
> index 941cd4c..1c6e9cd 100644
> --- a/crypto/api.c
> +++ b/crypto/api.c
> @@ -24,6 +24,7 @@
>  #include <linux/sched/signal.h>
>  #include <linux/slab.h>
>  #include <linux/string.h>
> +#include <linux/completion.h>
>  #include "internal.h"
>  
>  LIST_HEAD(crypto_alg_list);
> @@ -595,5 +596,32 @@ int crypto_has_alg(const char *name, u32 type, u32 mask)
>  }
>  EXPORT_SYMBOL_GPL(crypto_has_alg);
>  
> +int crypto_wait_req(int err, struct crypto_wait *wait)
> +{
> +	switch (err) {
> +	case -EINPROGRESS:
> +	case -EBUSY:
> +		wait_for_completion(&wait->completion);
> +		reinit_completion(&wait->completion);
> +		err = wait->err;
> +		break;
> +	};
> +
> +	return err;
> +}
> +EXPORT_SYMBOL_GPL(crypto_wait_req);

crypto_wait_req() maybe should be inlined, since it doesn't do much (note that
reinit_completion is actually just a variable assignment), and the common case
is that 'err' will be 0, so there will be nothing to wait for.

Also drop the unnecessary semicolon at the end of the switch block.

With regards to the wait being uninterruptible, I agree that this should be the
default behavior, because I think users waiting for specific crypto requests are
generally not prepared to handle the wait actually being interrupted.  After
interruption the crypto operation will still proceed in the background, and it
will use buffers which the caller has in many cases already freed.  However, I'd
suggest taking a close look at anything that was actually doing an interruptible
wait before, to see whether it was a bug or intentional (or "doesn't matter").

And yes there could always be a crypto_wait_req_interruptible() introduced if
some users need it.

>  
>  #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
>  
> +/*
> + * Macro for declaring a crypto op async wait object on stack
> + */
> +#define DECLARE_CRYPTO_WAIT(_wait) \
> +	struct crypto_wait _wait = { \
> +		COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 }
> +

Move this definition down below, so it's next to crypto_wait?

>  
>  /*
>   * Algorithm registration interface.
>   */
> @@ -1604,5 +1631,6 @@ static inline int crypto_comp_decompress(struct crypto_comp *tfm,
>  						    src, slen, dst, dlen);
>  }
>  
> +

Don't add unrelated blank lines.

- Eric

Re: [RFC 01/10] crypto: factor async completion for general use

[Gilad Ben-Yossef]

Hi Eric,

On Thu, May 11, 2017 at 6:55 AM, Eric Biggers <ebiggers3@gmail.com> wrote:
> Hi Gilad,
>
> On Sat, May 06, 2017 at 03:59:50PM +0300, Gilad Ben-Yossef wrote:
>> Invoking a possibly async. crypto op and waiting for completion
>> while correctly handling backlog processing is a common task
>> in the crypto API implementation and outside users of it.
>>
>> This patch re-factors one of the in crypto API implementation in
>> preparation for using it across the board instead of hand
>> rolled versions.
>
> Thanks for doing this!  It annoyed me too that there wasn't a helper function
> for this.  Just a few comments below:
>

Thank you for the review.
I will incorporate the feedback into v2.

...

> With regards to the wait being uninterruptible, I agree that this should be the
> default behavior, because I think users waiting for specific crypto requests are
> generally not prepared to handle the wait actually being interrupted.  After
> interruption the crypto operation will still proceed in the background, and it
> will use buffers which the caller has in many cases already freed.  However, I'd
> suggest taking a close look at anything that was actually doing an interruptible
> wait before, to see whether it was a bug or intentional (or "doesn't matter").
>
> And yes there could always be a crypto_wait_req_interruptible() introduced if
> some users need it.

So this one was a bit of a shocker.  I though the  _interruptible use
sites seemed
wrong in the sense of being needless. However, after reading your feedback and
reviewing the code I'm pretty sure every single one of them (including
the one I've
added in dm-verity-target.c this merge window)  are down right dangerous and
can cause random data corruption... so thanks for pointing this out!

I though of this patch set as a "make the code pretty" for 4.13 kind
of patch set.
Looks like it's a bug fix now, maybe even stable material.

Anyway, I'll roll a v2 and we'll see.

Thanks,
Gilad

-- 
Gilad Ben-Yossef
Chief Coffee Drinker

"If you take a class in large-scale robotics, can you end up in a
situation where the homework eats your dog?"
 -- Jean-Baptiste Queru

Re: [RFC 01/10] crypto: factor async completion for general use

[Eric Biggers]

On Thu, May 11, 2017 at 10:29:47AM +0300, Gilad Ben-Yossef wrote:
> > With regards to the wait being uninterruptible, I agree that this should be the
> > default behavior, because I think users waiting for specific crypto requests are
> > generally not prepared to handle the wait actually being interrupted.  After
> > interruption the crypto operation will still proceed in the background, and it
> > will use buffers which the caller has in many cases already freed.  However, I'd
> > suggest taking a close look at anything that was actually doing an interruptible
> > wait before, to see whether it was a bug or intentional (or "doesn't matter").
> >
> > And yes there could always be a crypto_wait_req_interruptible() introduced if
> > some users need it.
> 
> So this one was a bit of a shocker.  I though the  _interruptible use
> sites seemed
> wrong in the sense of being needless. However, after reading your feedback and
> reviewing the code I'm pretty sure every single one of them (including
> the one I've
> added in dm-verity-target.c this merge window)  are down right dangerous and
> can cause random data corruption... so thanks for pointing this out!
> 
> I though of this patch set as a "make the code pretty" for 4.13 kind
> of patch set.
> Looks like it's a bug fix now, maybe even stable material.
> 
> Anyway, I'll roll a v2 and we'll see.
> 

Any that are called only by kernel threads would theoretically be safe since
kernel threads don't ordinarily receive signals.  But I think that at least the
drbg and gcm waits can be reached by user threads, since they can be called via
algif_rng and algif_aead respectively.

I recommend putting any important fixes first, so they can be backported without
depending on crypto_wait_req().

Eric

Re: [RFC 01/10] crypto: factor async completion for general use

[Gilad Ben-Yossef]

On Thu, May 11, 2017 at 11:09 AM, Eric Biggers <ebiggers3@gmail.com> wrote:
> On Thu, May 11, 2017 at 10:29:47AM +0300, Gilad Ben-Yossef wrote:
>> > With regards to the wait being uninterruptible, I agree that this should be the
>> > default behavior, because I think users waiting for specific crypto requests are
>> > generally not prepared to handle the wait actually being interrupted.  After
>> > interruption the crypto operation will still proceed in the background, and it
>> > will use buffers which the caller has in many cases already freed.  However, I'd
>> > suggest taking a close look at anything that was actually doing an interruptible
>> > wait before, to see whether it was a bug or intentional (or "doesn't matter").
>> >
>> > And yes there could always be a crypto_wait_req_interruptible() introduced if
>> > some users need it.
>>
>> So this one was a bit of a shocker.  I though the  _interruptible use
>> sites seemed
>> wrong in the sense of being needless. However, after reading your feedback and
>> reviewing the code I'm pretty sure every single one of them (including
>> the one I've
>> added in dm-verity-target.c this merge window)  are down right dangerous and
>> can cause random data corruption... so thanks for pointing this out!
>>
>> I though of this patch set as a "make the code pretty" for 4.13 kind
>> of patch set.
>> Looks like it's a bug fix now, maybe even stable material.
>>
>> Anyway, I'll roll a v2 and we'll see.
>>
>
> Any that are called only by kernel threads would theoretically be safe since
> kernel threads don't ordinarily receive signals.  But I think that at least the
> drbg and gcm waits can be reached by user threads, since they can be called via
> algif_rng and algif_aead respectively.
>
> I recommend putting any important fixes first, so they can be backported without
> depending on crypto_wait_req().
>

OK, I'll send out a separate bug fix series first and rebase the
crypto_wait one on top
of it then.

Thanks,
Gilad

-- 
Gilad Ben-Yossef
Chief Coffee Drinker

"If you take a class in large-scale robotics, can you end up in a
situation where the homework eats your dog?"
 -- Jean-Baptiste Queru

[RFC 02/10] crypto: move pub key to generic async completion

[Gilad Ben-Yossef]

public_key_verify_signature() is starting an async crypto op and
waiting for it to complete. Move it over to generic code doing
the same.

This also fixes a bug in which the code was passing the
CRYPTO_TFM_REQ_MAY_BACKLOG flag to akcipher_request_set_callback()
but was not correctly testing for -EBUSY return code thus
leading to a possible use-after-free if the crypto backlog
queue was ever used.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 crypto/asymmetric_keys/public_key.c | 28 ++++------------------------
 1 file changed, 4 insertions(+), 24 deletions(-)

diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index d3a989e..d916235 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -57,29 +57,13 @@ static void public_key_destroy(void *payload0, void *payload3)
 	public_key_signature_free(payload3);
 }
 
-struct public_key_completion {
-	struct completion completion;
-	int err;
-};
-
-static void public_key_verify_done(struct crypto_async_request *req, int err)
-{
-	struct public_key_completion *compl = req->data;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	compl->err = err;
-	complete(&compl->completion);
-}
-
 /*
  * Verify a signature using a public key.
  */
 int public_key_verify_signature(const struct public_key *pkey,
 				const struct public_key_signature *sig)
 {
-	struct public_key_completion compl;
+	struct crypto_wait cwait;
 	struct crypto_akcipher *tfm;
 	struct akcipher_request *req;
 	struct scatterlist sig_sg, digest_sg;
@@ -131,20 +115,16 @@ int public_key_verify_signature(const struct public_key *pkey,
 	sg_init_one(&digest_sg, output, outlen);
 	akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
 				   outlen);
-	init_completion(&compl.completion);
+	crypto_init_wait(&cwait);
 	akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
 				      CRYPTO_TFM_REQ_MAY_SLEEP,
-				      public_key_verify_done, &compl);
+				      crypto_req_done, &cwait);
 
 	/* Perform the verification calculation.  This doesn't actually do the
 	 * verification, but rather calculates the hash expected by the
 	 * signature and returns that to us.
 	 */
-	ret = crypto_akcipher_verify(req);
-	if (ret == -EINPROGRESS) {
-		wait_for_completion(&compl.completion);
-		ret = compl.err;
-	}
+	ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
 	if (ret < 0)
 		goto out_free_output;
 
-- 
2.1.4

[RFC 03/10] crypto: move drbg to generic async completion

[Gilad Ben-Yossef]

DRBG is starting an async. crypto op and waiting for it complete.
Move it over to generic code doing the same.

As part of the move the wait for op completion lost its
_interruptible property. However, since each invocation is
supposed to be short and since no other user in the kernel
does the same I believe this is acceptable.

In similar fashion the code now passes CRYPTO_TFM_REQ_MAY_SLEEP
flag indicating crypto request memory  allocation may use GFP_KERNEL
which should be perfectly fine as the code is obviously sleeping
for the completion of the request any way.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 crypto/drbg.c         | 35 ++++++++---------------------------
 include/crypto/drbg.h |  3 +--
 2 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/crypto/drbg.c b/crypto/drbg.c
index fa749f4..101d9f0 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1651,16 +1651,6 @@ static int drbg_fini_sym_kernel(struct drbg_state *drbg)
 	return 0;
 }
 
-static void drbg_skcipher_cb(struct crypto_async_request *req, int error)
-{
-	struct drbg_state *drbg = req->data;
-
-	if (error == -EINPROGRESS)
-		return;
-	drbg->ctr_async_err = error;
-	complete(&drbg->ctr_completion);
-}
-
 static int drbg_init_sym_kernel(struct drbg_state *drbg)
 {
 	struct crypto_cipher *tfm;
@@ -1699,8 +1689,9 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg)
 		return -ENOMEM;
 	}
 	drbg->ctr_req = req;
-	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-					drbg_skcipher_cb, drbg);
+	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+						CRYPTO_TFM_REQ_MAY_SLEEP,
+					crypto_req_done, &drbg->ctr_wait);
 
 	alignmask = crypto_skcipher_alignmask(sk_tfm);
 	drbg->ctr_null_value_buf = kzalloc(DRBG_CTR_NULL_LEN + alignmask,
@@ -1761,22 +1752,12 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
 		/* Output buffer may not be valid for SGL, use scratchpad */
 		skcipher_request_set_crypt(drbg->ctr_req, &sg_in, &sg_out,
 					   cryptlen, drbg->V);
-		ret = crypto_skcipher_encrypt(drbg->ctr_req);
-		switch (ret) {
-		case 0:
-			break;
-		case -EINPROGRESS:
-		case -EBUSY:
-			ret = wait_for_completion_interruptible(
-				&drbg->ctr_completion);
-			if (!ret && !drbg->ctr_async_err) {
-				reinit_completion(&drbg->ctr_completion);
-				break;
-			}
-		default:
+		ret = crypto_wait_req(crypto_skcipher_encrypt(drbg->ctr_req),
+					&drbg->ctr_wait);
+		if (ret)
 			goto out;
-		}
-		init_completion(&drbg->ctr_completion);
+
+		crypto_init_wait(&drbg->ctr_wait);
 
 		memcpy(outbuf, drbg->outscratchpad, cryptlen);
 
diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h
index 22f884c..8f94110 100644
--- a/include/crypto/drbg.h
+++ b/include/crypto/drbg.h
@@ -126,8 +126,7 @@ struct drbg_state {
 	__u8 *ctr_null_value;			/* CTR mode aligned zero buf */
 	__u8 *outscratchpadbuf;			/* CTR mode output scratchpad */
         __u8 *outscratchpad;			/* CTR mode aligned outbuf */
-	struct completion ctr_completion;	/* CTR mode async handler */
-	int ctr_async_err;			/* CTR mode async error */
+	struct crypto_wait ctr_wait;		/* CTR mode async wait obj */
 
 	bool seeded;		/* DRBG fully seeded? */
 	bool pr;		/* Prediction resistance enabled? */
-- 
2.1.4

[RFC 04/10] crypto: move gcm to generic async completion

[Gilad Ben-Yossef]

gcm is starting an async. crypto op and waiting for it complete.
Move it over to generic code doing the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 crypto/gcm.c | 34 ++++++----------------------------
 1 file changed, 6 insertions(+), 28 deletions(-)

diff --git a/crypto/gcm.c b/crypto/gcm.c
index b7ad808..fb923a5 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -16,7 +16,6 @@
 #include <crypto/scatterwalk.h>
 #include <crypto/hash.h>
 #include "internal.h"
-#include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -78,11 +77,6 @@ struct crypto_gcm_req_priv_ctx {
 	} u;
 };
 
-struct crypto_gcm_setkey_result {
-	int err;
-	struct completion completion;
-};
-
 static struct {
 	u8 buf[16];
 	struct scatterlist sg;
@@ -98,17 +92,6 @@ static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
 	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
 }
 
-static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err)
-{
-	struct crypto_gcm_setkey_result *result = req->data;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	result->err = err;
-	complete(&result->completion);
-}
-
 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 			     unsigned int keylen)
 {
@@ -119,7 +102,7 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 		be128 hash;
 		u8 iv[16];
 
-		struct crypto_gcm_setkey_result result;
+		struct crypto_wait wait;
 
 		struct scatterlist sg[1];
 		struct skcipher_request req;
@@ -140,23 +123,18 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 	if (!data)
 		return -ENOMEM;
 
-	init_completion(&data->result.completion);
+	crypto_init_wait(&data->wait);
 	sg_init_one(data->sg, &data->hash, sizeof(data->hash));
 	skcipher_request_set_tfm(&data->req, ctr);
 	skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
 						  CRYPTO_TFM_REQ_MAY_BACKLOG,
-				      crypto_gcm_setkey_done,
-				      &data->result);
+				      crypto_req_done,
+				      &data->wait);
 	skcipher_request_set_crypt(&data->req, data->sg, data->sg,
 				   sizeof(data->hash), data->iv);
 
-	err = crypto_skcipher_encrypt(&data->req);
-	if (err == -EINPROGRESS || err == -EBUSY) {
-		err = wait_for_completion_interruptible(
-			&data->result.completion);
-		if (!err)
-			err = data->result.err;
-	}
+	err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
+							&data->wait);
 
 	if (err)
 		goto out;
-- 
2.1.4

[RFC 05/10] crypto: move testmgr to generic async completion

[Gilad Ben-Yossef]

testmgr is starting async. crypto ops and waiting for them to complete.
Move it over to generic code doing the same.

This also provides a test of the generic crypto async. wait code.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 crypto/testmgr.c | 184 +++++++++++++++++--------------------------------------
 1 file changed, 56 insertions(+), 128 deletions(-)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 6f5f3ed..4b779ca 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -76,11 +76,6 @@ int alg_test(const char *driver, const char *alg, u32 type, u32 mask)
 #define ENCRYPT 1
 #define DECRYPT 0
 
-struct tcrypt_result {
-	struct completion completion;
-	int err;
-};
-
 struct aead_test_suite {
 	struct {
 		const struct aead_testvec *vecs;
@@ -155,17 +150,6 @@ static void hexdump(unsigned char *buf, unsigned int len)
 			buf, len, false);
 }
 
-static void tcrypt_complete(struct crypto_async_request *req, int err)
-{
-	struct tcrypt_result *res = req->data;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	res->err = err;
-	complete(&res->completion);
-}
-
 static int testmgr_alloc_buf(char *buf[XBUFSIZE])
 {
 	int i;
@@ -193,20 +177,10 @@ static void testmgr_free_buf(char *buf[XBUFSIZE])
 		free_page((unsigned long)buf[i]);
 }
 
-static int wait_async_op(struct tcrypt_result *tr, int ret)
-{
-	if (ret == -EINPROGRESS || ret == -EBUSY) {
-		wait_for_completion(&tr->completion);
-		reinit_completion(&tr->completion);
-		ret = tr->err;
-	}
-	return ret;
-}
-
 static int ahash_partial_update(struct ahash_request **preq,
 	struct crypto_ahash *tfm, const struct hash_testvec *template,
 	void *hash_buff, int k, int temp, struct scatterlist *sg,
-	const char *algo, char *result, struct tcrypt_result *tresult)
+	const char *algo, char *result, struct crypto_wait *wait)
 {
 	char *state;
 	struct ahash_request *req;
@@ -236,7 +210,7 @@ static int ahash_partial_update(struct ahash_request **preq,
 	}
 	ahash_request_set_callback(req,
 		CRYPTO_TFM_REQ_MAY_BACKLOG,
-		tcrypt_complete, tresult);
+		crypto_req_done, wait);
 
 	memcpy(hash_buff, template->plaintext + temp,
 		template->tap[k]);
@@ -247,7 +221,7 @@ static int ahash_partial_update(struct ahash_request **preq,
 		pr_err("alg: hash: Failed to import() for %s\n", algo);
 		goto out;
 	}
-	ret = wait_async_op(tresult, crypto_ahash_update(req));
+	ret = crypto_wait_req(crypto_ahash_update(req), wait);
 	if (ret)
 		goto out;
 	*preq = req;
@@ -272,7 +246,7 @@ static int __test_hash(struct crypto_ahash *tfm,
 	char *result;
 	char *key;
 	struct ahash_request *req;
-	struct tcrypt_result tresult;
+	struct crypto_wait wait;
 	void *hash_buff;
 	char *xbuf[XBUFSIZE];
 	int ret = -ENOMEM;
@@ -286,7 +260,7 @@ static int __test_hash(struct crypto_ahash *tfm,
 	if (testmgr_alloc_buf(xbuf))
 		goto out_nobuf;
 
-	init_completion(&tresult.completion);
+	crypto_init_wait(&wait);
 
 	req = ahash_request_alloc(tfm, GFP_KERNEL);
 	if (!req) {
@@ -295,7 +269,7 @@ static int __test_hash(struct crypto_ahash *tfm,
 		goto out_noreq;
 	}
 	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				   tcrypt_complete, &tresult);
+				   crypto_req_done, &wait);
 
 	j = 0;
 	for (i = 0; i < tcount; i++) {
@@ -335,26 +309,26 @@ static int __test_hash(struct crypto_ahash *tfm,
 
 		ahash_request_set_crypt(req, sg, result, template[i].psize);
 		if (use_digest) {
-			ret = wait_async_op(&tresult, crypto_ahash_digest(req));
+			ret = crypto_wait_req(crypto_ahash_digest(req), &wait);
 			if (ret) {
 				pr_err("alg: hash: digest failed on test %d "
 				       "for %s: ret=%d\n", j, algo, -ret);
 				goto out;
 			}
 		} else {
-			ret = wait_async_op(&tresult, crypto_ahash_init(req));
+			ret = crypto_wait_req(crypto_ahash_init(req), &wait);
 			if (ret) {
 				pr_err("alt: hash: init failed on test %d "
 				       "for %s: ret=%d\n", j, algo, -ret);
 				goto out;
 			}
-			ret = wait_async_op(&tresult, crypto_ahash_update(req));
+			ret = crypto_wait_req(crypto_ahash_update(req), &wait);
 			if (ret) {
 				pr_err("alt: hash: update failed on test %d "
 				       "for %s: ret=%d\n", j, algo, -ret);
 				goto out;
 			}
-			ret = wait_async_op(&tresult, crypto_ahash_final(req));
+			ret = crypto_wait_req(crypto_ahash_final(req), &wait);
 			if (ret) {
 				pr_err("alt: hash: final failed on test %d "
 				       "for %s: ret=%d\n", j, algo, -ret);
@@ -420,22 +394,10 @@ static int __test_hash(struct crypto_ahash *tfm,
 		}
 
 		ahash_request_set_crypt(req, sg, result, template[i].psize);
-		ret = crypto_ahash_digest(req);
-		switch (ret) {
-		case 0:
-			break;
-		case -EINPROGRESS:
-		case -EBUSY:
-			wait_for_completion(&tresult.completion);
-			reinit_completion(&tresult.completion);
-			ret = tresult.err;
-			if (!ret)
-				break;
-			/* fall through */
-		default:
-			printk(KERN_ERR "alg: hash: digest failed "
-			       "on chunking test %d for %s: "
-			       "ret=%d\n", j, algo, -ret);
+		ret = crypto_wait_req(crypto_ahash_digest(req), &wait);
+		if (ret) {
+			pr_err("alg: hash: digest failed on chunking test %d for %s: ret=%d\n",
+				j, algo, -ret);
 			goto out;
 		}
 
@@ -486,13 +448,13 @@ static int __test_hash(struct crypto_ahash *tfm,
 		}
 
 		ahash_request_set_crypt(req, sg, result, template[i].tap[0]);
-		ret = wait_async_op(&tresult, crypto_ahash_init(req));
+		ret = crypto_wait_req(crypto_ahash_init(req), &wait);
 		if (ret) {
 			pr_err("alt: hash: init failed on test %d for %s: ret=%d\n",
 				j, algo, -ret);
 			goto out;
 		}
-		ret = wait_async_op(&tresult, crypto_ahash_update(req));
+		ret = crypto_wait_req(crypto_ahash_update(req), &wait);
 		if (ret) {
 			pr_err("alt: hash: update failed on test %d for %s: ret=%d\n",
 				j, algo, -ret);
@@ -503,7 +465,7 @@ static int __test_hash(struct crypto_ahash *tfm,
 		for (k = 1; k < template[i].np; k++) {
 			ret = ahash_partial_update(&req, tfm, &template[i],
 				hash_buff, k, temp, &sg[0], algo, result,
-				&tresult);
+				&wait);
 			if (ret) {
 				pr_err("hash: partial update failed on test %d for %s: ret=%d\n",
 					j, algo, -ret);
@@ -511,7 +473,7 @@ static int __test_hash(struct crypto_ahash *tfm,
 			}
 			temp += template[i].tap[k];
 		}
-		ret = wait_async_op(&tresult, crypto_ahash_final(req));
+		ret = crypto_wait_req(crypto_ahash_final(req), &wait);
 		if (ret) {
 			pr_err("alt: hash: final failed on test %d for %s: ret=%d\n",
 				j, algo, -ret);
@@ -580,7 +542,7 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 	struct scatterlist *sg;
 	struct scatterlist *sgout;
 	const char *e, *d;
-	struct tcrypt_result result;
+	struct crypto_wait wait;
 	unsigned int authsize, iv_len;
 	void *input;
 	void *output;
@@ -619,7 +581,7 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 	else
 		e = "decryption";
 
-	init_completion(&result.completion);
+	crypto_init_wait(&wait);
 
 	req = aead_request_alloc(tfm, GFP_KERNEL);
 	if (!req) {
@@ -629,7 +591,7 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 	}
 
 	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				  tcrypt_complete, &result);
+				  crypto_req_done, &wait);
 
 	iv_len = crypto_aead_ivsize(tfm);
 
@@ -709,7 +671,8 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 
 		aead_request_set_ad(req, template[i].alen);
 
-		ret = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
+		ret = crypto_wait_req(enc ? crypto_aead_encrypt(req)
+					: crypto_aead_decrypt(req), &wait);
 
 		switch (ret) {
 		case 0:
@@ -722,13 +685,6 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 				goto out;
 			}
 			break;
-		case -EINPROGRESS:
-		case -EBUSY:
-			wait_for_completion(&result.completion);
-			reinit_completion(&result.completion);
-			ret = result.err;
-			if (!ret)
-				break;
 		case -EBADMSG:
 			if (template[i].novrfy)
 				/* verification failure was expected */
@@ -866,7 +822,8 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 
 		aead_request_set_ad(req, template[i].alen);
 
-		ret = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
+		ret = crypto_wait_req(enc ? crypto_aead_encrypt(req)
+					: crypto_aead_decrypt(req), &wait);
 
 		switch (ret) {
 		case 0:
@@ -879,13 +836,6 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
 				goto out;
 			}
 			break;
-		case -EINPROGRESS:
-		case -EBUSY:
-			wait_for_completion(&result.completion);
-			reinit_completion(&result.completion);
-			ret = result.err;
-			if (!ret)
-				break;
 		case -EBADMSG:
 			if (template[i].novrfy)
 				/* verification failure was expected */
@@ -1083,7 +1033,7 @@ static int __test_skcipher(struct crypto_skcipher *tfm, int enc,
 	struct scatterlist sg[8];
 	struct scatterlist sgout[8];
 	const char *e, *d;
-	struct tcrypt_result result;
+	struct crypto_wait wait;
 	void *data;
 	char iv[MAX_IVLEN];
 	char *xbuf[XBUFSIZE];
@@ -1107,7 +1057,7 @@ static int __test_skcipher(struct crypto_skcipher *tfm, int enc,
 	else
 		e = "decryption";
 
-	init_completion(&result.completion);
+	crypto_init_wait(&wait);
 
 	req = skcipher_request_alloc(tfm, GFP_KERNEL);
 	if (!req) {
@@ -1117,7 +1067,7 @@ static int __test_skcipher(struct crypto_skcipher *tfm, int enc,
 	}
 
 	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				      tcrypt_complete, &result);
+				      crypto_req_done, &wait);
 
 	j = 0;
 	for (i = 0; i < tcount; i++) {
@@ -1164,23 +1114,12 @@ static int __test_skcipher(struct crypto_skcipher *tfm, int enc,
 
 		skcipher_request_set_crypt(req, sg, (diff_dst) ? sgout : sg,
 					   template[i].ilen, iv);
-		ret = enc ? crypto_skcipher_encrypt(req) :
-			    crypto_skcipher_decrypt(req);
+		ret = crypto_wait_req(enc ? crypto_skcipher_encrypt(req) :
+					crypto_skcipher_decrypt(req), &wait);
 
-		switch (ret) {
-		case 0:
-			break;
-		case -EINPROGRESS:
-		case -EBUSY:
-			wait_for_completion(&result.completion);
-			reinit_completion(&result.completion);
-			ret = result.err;
-			if (!ret)
-				break;
-			/* fall through */
-		default:
+		if (ret) {
 			pr_err("alg: skcipher%s: %s failed on test %d for %s: ret=%d\n",
-			       d, e, j, algo, -ret);
+				d, e, j, algo, -ret);
 			goto out;
 		}
 
@@ -1272,21 +1211,10 @@ static int __test_skcipher(struct crypto_skcipher *tfm, int enc,
 		skcipher_request_set_crypt(req, sg, (diff_dst) ? sgout : sg,
 					   template[i].ilen, iv);
 
-		ret = enc ? crypto_skcipher_encrypt(req) :
-			    crypto_skcipher_decrypt(req);
+		ret = crypto_wait_req(enc ? crypto_skcipher_encrypt(req) :
+					crypto_skcipher_decrypt(req), &wait);
 
-		switch (ret) {
-		case 0:
-			break;
-		case -EINPROGRESS:
-		case -EBUSY:
-			wait_for_completion(&result.completion);
-			reinit_completion(&result.completion);
-			ret = result.err;
-			if (!ret)
-				break;
-			/* fall through */
-		default:
+		if (ret) {
 			pr_err("alg: skcipher%s: %s failed on chunk test %d for %s: ret=%d\n",
 			       d, e, j, algo, -ret);
 			goto out;
@@ -1462,7 +1390,7 @@ static int test_acomp(struct crypto_acomp *tfm,
 	int ret;
 	struct scatterlist src, dst;
 	struct acomp_req *req;
-	struct tcrypt_result result;
+	struct crypto_wait wait;
 
 	output = kmalloc(COMP_BUF_SIZE, GFP_KERNEL);
 	if (!output)
@@ -1486,7 +1414,7 @@ static int test_acomp(struct crypto_acomp *tfm,
 		}
 
 		memset(output, 0, dlen);
-		init_completion(&result.completion);
+		crypto_init_wait(&wait);
 		sg_init_one(&src, input_vec, ilen);
 		sg_init_one(&dst, output, dlen);
 
@@ -1501,9 +1429,9 @@ static int test_acomp(struct crypto_acomp *tfm,
 
 		acomp_request_set_params(req, &src, &dst, ilen, dlen);
 		acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-					   tcrypt_complete, &result);
+					   crypto_req_done, &wait);
 
-		ret = wait_async_op(&result, crypto_acomp_compress(req));
+		ret = crypto_wait_req(crypto_acomp_compress(req), &wait);
 		if (ret) {
 			pr_err("alg: acomp: compression failed on test %d for %s: ret=%d\n",
 			       i + 1, algo, -ret);
@@ -1516,10 +1444,10 @@ static int test_acomp(struct crypto_acomp *tfm,
 		dlen = COMP_BUF_SIZE;
 		sg_init_one(&src, output, ilen);
 		sg_init_one(&dst, decomp_out, dlen);
-		init_completion(&result.completion);
+		crypto_init_wait(&wait);
 		acomp_request_set_params(req, &src, &dst, ilen, dlen);
 
-		ret = wait_async_op(&result, crypto_acomp_decompress(req));
+		ret = crypto_wait_req(crypto_acomp_decompress(req), &wait);
 		if (ret) {
 			pr_err("alg: acomp: compression failed on test %d for %s: ret=%d\n",
 			       i + 1, algo, -ret);
@@ -1563,7 +1491,7 @@ static int test_acomp(struct crypto_acomp *tfm,
 		}
 
 		memset(output, 0, dlen);
-		init_completion(&result.completion);
+		crypto_init_wait(&wait);
 		sg_init_one(&src, input_vec, ilen);
 		sg_init_one(&dst, output, dlen);
 
@@ -1578,9 +1506,9 @@ static int test_acomp(struct crypto_acomp *tfm,
 
 		acomp_request_set_params(req, &src, &dst, ilen, dlen);
 		acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-					   tcrypt_complete, &result);
+					   crypto_req_done, &wait);
 
-		ret = wait_async_op(&result, crypto_acomp_decompress(req));
+		ret = crypto_wait_req(crypto_acomp_decompress(req), &wait);
 		if (ret) {
 			pr_err("alg: acomp: decompression failed on test %d for %s: ret=%d\n",
 			       i + 1, algo, -ret);
@@ -1997,7 +1925,7 @@ static int do_test_kpp(struct crypto_kpp *tfm, const struct kpp_testvec *vec,
 	struct kpp_request *req;
 	void *input_buf = NULL;
 	void *output_buf = NULL;
-	struct tcrypt_result result;
+	struct crypto_wait wait;
 	unsigned int out_len_max;
 	int err = -ENOMEM;
 	struct scatterlist src, dst;
@@ -2006,7 +1934,7 @@ static int do_test_kpp(struct crypto_kpp *tfm, const struct kpp_testvec *vec,
 	if (!req)
 		return err;
 
-	init_completion(&result.completion);
+	crypto_init_wait(&wait);
 
 	err = crypto_kpp_set_secret(tfm, vec->secret, vec->secret_size);
 	if (err < 0)
@@ -2024,10 +1952,10 @@ static int do_test_kpp(struct crypto_kpp *tfm, const struct kpp_testvec *vec,
 	sg_init_one(&dst, output_buf, out_len_max);
 	kpp_request_set_output(req, &dst, out_len_max);
 	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				 tcrypt_complete, &result);
+				 crypto_req_done, &wait);
 
 	/* Compute public key */
-	err = wait_async_op(&result, crypto_kpp_generate_public_key(req));
+	err = crypto_wait_req(crypto_kpp_generate_public_key(req), &wait);
 	if (err) {
 		pr_err("alg: %s: generate public key test failed. err %d\n",
 		       alg, err);
@@ -2055,8 +1983,8 @@ static int do_test_kpp(struct crypto_kpp *tfm, const struct kpp_testvec *vec,
 	kpp_request_set_input(req, &src, vec->b_public_size);
 	kpp_request_set_output(req, &dst, out_len_max);
 	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				 tcrypt_complete, &result);
-	err = wait_async_op(&result, crypto_kpp_compute_shared_secret(req));
+				 crypto_req_done, &wait);
+	err = crypto_wait_req(crypto_kpp_compute_shared_secret(req), &wait);
 	if (err) {
 		pr_err("alg: %s: compute shard secret test failed. err %d\n",
 		       alg, err);
@@ -2125,7 +2053,7 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
 	struct akcipher_request *req;
 	void *outbuf_enc = NULL;
 	void *outbuf_dec = NULL;
-	struct tcrypt_result result;
+	struct crypto_wait wait;
 	unsigned int out_len_max, out_len = 0;
 	int err = -ENOMEM;
 	struct scatterlist src, dst, src_tab[2];
@@ -2137,7 +2065,7 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
 	if (!req)
 		goto free_xbuf;
 
-	init_completion(&result.completion);
+	crypto_init_wait(&wait);
 
 	if (vecs->public_key_vec)
 		err = crypto_akcipher_set_pub_key(tfm, vecs->key,
@@ -2166,10 +2094,10 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
 	akcipher_request_set_crypt(req, src_tab, &dst, vecs->m_size,
 				   out_len_max);
 	akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				      tcrypt_complete, &result);
+				      crypto_req_done, &wait);
 
 	/* Run RSA encrypt - c = m^e mod n;*/
-	err = wait_async_op(&result, crypto_akcipher_encrypt(req));
+	err = crypto_wait_req(crypto_akcipher_encrypt(req), &wait);
 	if (err) {
 		pr_err("alg: akcipher: encrypt test failed. err %d\n", err);
 		goto free_all;
@@ -2204,11 +2132,11 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
 
 	sg_init_one(&src, xbuf[0], vecs->c_size);
 	sg_init_one(&dst, outbuf_dec, out_len_max);
-	init_completion(&result.completion);
+	crypto_init_wait(&wait);
 	akcipher_request_set_crypt(req, &src, &dst, vecs->c_size, out_len_max);
 
 	/* Run RSA decrypt - m = c^d mod n;*/
-	err = wait_async_op(&result, crypto_akcipher_decrypt(req));
+	err = crypto_wait_req(crypto_akcipher_decrypt(req), &wait);
 	if (err) {
 		pr_err("alg: akcipher: decrypt test failed. err %d\n", err);
 		goto free_all;
-- 
2.1.4

[RFC 06/10] dm: move dm-verity to generic async completion

[Gilad Ben-Yossef]

dm-verity is starting async. crypto ops and waiting for them to complete.
Move it over to generic code doing the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 drivers/md/dm-verity-target.c | 81 +++++++++++--------------------------------
 drivers/md/dm-verity.h        |  5 ---
 2 files changed, 20 insertions(+), 66 deletions(-)

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 97de961..56f432d 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -92,74 +92,33 @@ static sector_t verity_position_at_level(struct dm_verity *v, sector_t block,
 	return block >> (level * v->hash_per_block_bits);
 }
 
-/*
- * Callback function for asynchrnous crypto API completion notification
- */
-static void verity_op_done(struct crypto_async_request *base, int err)
-{
-	struct verity_result *res = (struct verity_result *)base->data;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	res->err = err;
-	complete(&res->completion);
-}
-
-/*
- * Wait for async crypto API callback
- */
-static inline int verity_complete_op(struct verity_result *res, int ret)
-{
-	switch (ret) {
-	case 0:
-		break;
-
-	case -EINPROGRESS:
-	case -EBUSY:
-		ret = wait_for_completion_interruptible(&res->completion);
-		if (!ret)
-			ret = res->err;
-		reinit_completion(&res->completion);
-		break;
-
-	default:
-		DMERR("verity_wait_hash: crypto op submission failed: %d", ret);
-	}
-
-	if (unlikely(ret < 0))
-		DMERR("verity_wait_hash: crypto op failed: %d", ret);
-
-	return ret;
-}
-
 static int verity_hash_update(struct dm_verity *v, struct ahash_request *req,
 				const u8 *data, size_t len,
-				struct verity_result *res)
+				struct crypto_wait *wait)
 {
 	struct scatterlist sg;
 
 	sg_init_one(&sg, data, len);
 	ahash_request_set_crypt(req, &sg, NULL, len);
 
-	return verity_complete_op(res, crypto_ahash_update(req));
+	return crypto_wait_req(crypto_ahash_update(req), wait);
 }
 
 /*
  * Wrapper for crypto_ahash_init, which handles verity salting.
  */
 static int verity_hash_init(struct dm_verity *v, struct ahash_request *req,
-				struct verity_result *res)
+				struct crypto_wait *wait)
 {
 	int r;
 
 	ahash_request_set_tfm(req, v->tfm);
 	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP |
 					CRYPTO_TFM_REQ_MAY_BACKLOG,
-					verity_op_done, (void *)res);
-	init_completion(&res->completion);
+					crypto_req_done, (void *)wait);
+	crypto_init_wait(wait);
 
-	r = verity_complete_op(res, crypto_ahash_init(req));
+	r = crypto_wait_req(crypto_ahash_init(req), wait);
 
 	if (unlikely(r < 0)) {
 		DMERR("crypto_ahash_init failed: %d", r);
@@ -167,18 +126,18 @@ static int verity_hash_init(struct dm_verity *v, struct ahash_request *req,
 	}
 
 	if (likely(v->version >= 1))
-		r = verity_hash_update(v, req, v->salt, v->salt_size, res);
+		r = verity_hash_update(v, req, v->salt, v->salt_size, wait);
 
 	return r;
 }
 
 static int verity_hash_final(struct dm_verity *v, struct ahash_request *req,
-			     u8 *digest, struct verity_result *res)
+			     u8 *digest, struct crypto_wait *wait)
 {
 	int r;
 
 	if (unlikely(!v->version)) {
-		r = verity_hash_update(v, req, v->salt, v->salt_size, res);
+		r = verity_hash_update(v, req, v->salt, v->salt_size, wait);
 
 		if (r < 0) {
 			DMERR("verity_hash_final failed updating salt: %d", r);
@@ -187,7 +146,7 @@ static int verity_hash_final(struct dm_verity *v, struct ahash_request *req,
 	}
 
 	ahash_request_set_crypt(req, NULL, digest, 0);
-	r = verity_complete_op(res, crypto_ahash_final(req));
+	r = crypto_wait_req(crypto_ahash_final(req), wait);
 out:
 	return r;
 }
@@ -196,17 +155,17 @@ int verity_hash(struct dm_verity *v, struct ahash_request *req,
 		const u8 *data, size_t len, u8 *digest)
 {
 	int r;
-	struct verity_result res;
+	struct crypto_wait wait;
 
-	r = verity_hash_init(v, req, &res);
+	r = verity_hash_init(v, req, &wait);
 	if (unlikely(r < 0))
 		goto out;
 
-	r = verity_hash_update(v, req, data, len, &res);
+	r = verity_hash_update(v, req, data, len, &wait);
 	if (unlikely(r < 0))
 		goto out;
 
-	r = verity_hash_final(v, req, digest, &res);
+	r = verity_hash_final(v, req, digest, &wait);
 
 out:
 	return r;
@@ -389,7 +348,7 @@ int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,
  * Calculates the digest for the given bio
  */
 int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io,
-			struct bvec_iter *iter, struct verity_result *res)
+			struct bvec_iter *iter, struct crypto_wait *wait)
 {
 	unsigned int todo = 1 << v->data_dev_block_bits;
 	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
@@ -414,7 +373,7 @@ int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io,
 		 */
 		sg_set_page(&sg, bv.bv_page, len, bv.bv_offset);
 		ahash_request_set_crypt(req, &sg, NULL, len);
-		r = verity_complete_op(res, crypto_ahash_update(req));
+		r = crypto_wait_req(crypto_ahash_update(req), wait);
 
 		if (unlikely(r < 0)) {
 			DMERR("verity_for_io_block crypto op failed: %d", r);
@@ -482,7 +441,7 @@ static int verity_verify_io(struct dm_verity_io *io)
 	struct dm_verity *v = io->v;
 	struct bvec_iter start;
 	unsigned b;
-	struct verity_result res;
+	struct crypto_wait wait;
 
 	for (b = 0; b < io->n_blocks; b++) {
 		int r;
@@ -507,17 +466,17 @@ static int verity_verify_io(struct dm_verity_io *io)
 			continue;
 		}
 
-		r = verity_hash_init(v, req, &res);
+		r = verity_hash_init(v, req, &wait);
 		if (unlikely(r < 0))
 			return r;
 
 		start = io->iter;
-		r = verity_for_io_block(v, io, &io->iter, &res);
+		r = verity_for_io_block(v, io, &io->iter, &wait);
 		if (unlikely(r < 0))
 			return r;
 
 		r = verity_hash_final(v, req, verity_io_real_digest(v, io),
-					&res);
+					&wait);
 		if (unlikely(r < 0))
 			return r;
 
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index a59e0ad..b675bc0 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -90,11 +90,6 @@ struct dm_verity_io {
 	 */
 };
 
-struct verity_result {
-	struct completion completion;
-	int err;
-};
-
 static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v,
 						     struct dm_verity_io *io)
 {
-- 
2.1.4

[RFC 07/10] fscrypt: move to generic async completion

[Gilad Ben-Yossef]

fscrypt starts several async. crypto ops and waiting for them to
complete. Move it over to generic code doing the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 fs/crypto/crypto.c          | 28 ++++------------------------
 fs/crypto/fname.c           | 36 ++++++------------------------------
 fs/crypto/fscrypt_private.h | 10 ----------
 fs/crypto/keyinfo.c         | 21 +++------------------
 4 files changed, 13 insertions(+), 82 deletions(-)

diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 6d6eca3..94cac7d 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -125,21 +125,6 @@ struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, gfp_t gfp_flags)
 }
 EXPORT_SYMBOL(fscrypt_get_ctx);
 
-/**
- * page_crypt_complete() - completion callback for page crypto
- * @req: The asynchronous cipher request context
- * @res: The result of the cipher operation
- */
-static void page_crypt_complete(struct crypto_async_request *req, int res)
-{
-	struct fscrypt_completion_result *ecr = req->data;
-
-	if (res == -EINPROGRESS)
-		return;
-	ecr->res = res;
-	complete(&ecr->completion);
-}
-
 int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
 			   u64 lblk_num, struct page *src_page,
 			   struct page *dest_page, unsigned int len,
@@ -150,7 +135,7 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
 		u8 padding[FS_XTS_TWEAK_SIZE - sizeof(__le64)];
 	} xts_tweak;
 	struct skcipher_request *req = NULL;
-	DECLARE_FS_COMPLETION_RESULT(ecr);
+	DECLARE_CRYPTO_WAIT(ecr);
 	struct scatterlist dst, src;
 	struct fscrypt_info *ci = inode->i_crypt_info;
 	struct crypto_skcipher *tfm = ci->ci_ctfm;
@@ -168,7 +153,7 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
 
 	skcipher_request_set_callback(
 		req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		page_crypt_complete, &ecr);
+		crypto_req_done, &ecr);
 
 	BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
 	xts_tweak.index = cpu_to_le64(lblk_num);
@@ -180,14 +165,9 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
 	sg_set_page(&src, src_page, len, offs);
 	skcipher_request_set_crypt(req, &src, &dst, len, &xts_tweak);
 	if (rw == FS_DECRYPT)
-		res = crypto_skcipher_decrypt(req);
+		res = crypto_wait_req(crypto_skcipher_decrypt(req), &ecr);
 	else
-		res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		BUG_ON(req->base.data != &ecr);
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
+		res = crypto_wait_req(crypto_skcipher_encrypt(req), &ecr);
 	skcipher_request_free(req);
 	if (res) {
 		printk_ratelimited(KERN_ERR
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 37b4989..8b4caf3 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -15,21 +15,6 @@
 #include "fscrypt_private.h"
 
 /**
- * fname_crypt_complete() - completion callback for filename crypto
- * @req: The asynchronous cipher request context
- * @res: The result of the cipher operation
- */
-static void fname_crypt_complete(struct crypto_async_request *req, int res)
-{
-	struct fscrypt_completion_result *ecr = req->data;
-
-	if (res == -EINPROGRESS)
-		return;
-	ecr->res = res;
-	complete(&ecr->completion);
-}
-
-/**
  * fname_encrypt() - encrypt a filename
  *
  * The caller must have allocated sufficient memory for the @oname string.
@@ -40,7 +25,7 @@ static int fname_encrypt(struct inode *inode,
 			const struct qstr *iname, struct fscrypt_str *oname)
 {
 	struct skcipher_request *req = NULL;
-	DECLARE_FS_COMPLETION_RESULT(ecr);
+	DECLARE_CRYPTO_WAIT(ecr);
 	struct fscrypt_info *ci = inode->i_crypt_info;
 	struct crypto_skcipher *tfm = ci->ci_ctfm;
 	int res = 0;
@@ -76,17 +61,12 @@ static int fname_encrypt(struct inode *inode,
 	}
 	skcipher_request_set_callback(req,
 			CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-			fname_crypt_complete, &ecr);
+			crypto_req_done, &ecr);
 	sg_init_one(&sg, oname->name, cryptlen);
 	skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
 
 	/* Do the encryption */
-	res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		/* Request is being completed asynchronously; wait for it */
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
+	res = crypto_wait_req(crypto_skcipher_encrypt(req), &ecr);
 	skcipher_request_free(req);
 	if (res < 0) {
 		printk_ratelimited(KERN_ERR
@@ -110,7 +90,7 @@ static int fname_decrypt(struct inode *inode,
 				struct fscrypt_str *oname)
 {
 	struct skcipher_request *req = NULL;
-	DECLARE_FS_COMPLETION_RESULT(ecr);
+	DECLARE_CRYPTO_WAIT(ecr);
 	struct scatterlist src_sg, dst_sg;
 	struct fscrypt_info *ci = inode->i_crypt_info;
 	struct crypto_skcipher *tfm = ci->ci_ctfm;
@@ -131,7 +111,7 @@ static int fname_decrypt(struct inode *inode,
 	}
 	skcipher_request_set_callback(req,
 		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		fname_crypt_complete, &ecr);
+		crypto_req_done, &ecr);
 
 	/* Initialize IV */
 	memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
@@ -140,11 +120,7 @@ static int fname_decrypt(struct inode *inode,
 	sg_init_one(&src_sg, iname->name, iname->len);
 	sg_init_one(&dst_sg, oname->name, oname->len);
 	skcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
-	res = crypto_skcipher_decrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
+	res = crypto_wait_req(crypto_skcipher_decrypt(req), &ecr);
 	skcipher_request_free(req);
 	if (res < 0) {
 		printk_ratelimited(KERN_ERR
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index e39696e..158dadf 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -78,16 +78,6 @@ typedef enum {
 #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL		0x00000001
 #define FS_CTX_HAS_BOUNCE_BUFFER_FL		0x00000002
 
-struct fscrypt_completion_result {
-	struct completion completion;
-	int res;
-};
-
-#define DECLARE_FS_COMPLETION_RESULT(ecr) \
-	struct fscrypt_completion_result ecr = { \
-		COMPLETION_INITIALIZER_ONSTACK((ecr).completion), 0 }
-
-
 /* crypto.c */
 extern int fscrypt_initialize(unsigned int cop_flags);
 extern struct workqueue_struct *fscrypt_read_workqueue;
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 8cdfddc..0ae0426 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -12,17 +12,6 @@
 #include <linux/scatterlist.h>
 #include "fscrypt_private.h"
 
-static void derive_crypt_complete(struct crypto_async_request *req, int rc)
-{
-	struct fscrypt_completion_result *ecr = req->data;
-
-	if (rc == -EINPROGRESS)
-		return;
-
-	ecr->res = rc;
-	complete(&ecr->completion);
-}
-
 /**
  * derive_key_aes() - Derive a key using AES-128-ECB
  * @deriving_key: Encryption key used for derivation.
@@ -37,7 +26,7 @@ static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE],
 {
 	int res = 0;
 	struct skcipher_request *req = NULL;
-	DECLARE_FS_COMPLETION_RESULT(ecr);
+	DECLARE_CRYPTO_WAIT(ecr);
 	struct scatterlist src_sg, dst_sg;
 	struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0);
 
@@ -54,7 +43,7 @@ static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE],
 	}
 	skcipher_request_set_callback(req,
 			CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-			derive_crypt_complete, &ecr);
+			crypto_req_done, &ecr);
 	res = crypto_skcipher_setkey(tfm, deriving_key,
 					FS_AES_128_ECB_KEY_SIZE);
 	if (res < 0)
@@ -64,11 +53,7 @@ static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE],
 	sg_init_one(&dst_sg, derived_key, FS_AES_256_XTS_KEY_SIZE);
 	skcipher_request_set_crypt(req, &src_sg, &dst_sg,
 					FS_AES_256_XTS_KEY_SIZE, NULL);
-	res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
+	res = crypto_wait_req(crypto_skcipher_encrypt(req), &ecr);
 out:
 	skcipher_request_free(req);
 	crypto_free_skcipher(tfm);
-- 
2.1.4

Re: [RFC 07/10] fscrypt: move to generic async completion

[Eric Biggers]

Hi Gilad,

On Sat, May 06, 2017 at 03:59:56PM +0300, Gilad Ben-Yossef wrote:
>  int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
>  			   u64 lblk_num, struct page *src_page,
>  			   struct page *dest_page, unsigned int len,
> @@ -150,7 +135,7 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
>  		u8 padding[FS_XTS_TWEAK_SIZE - sizeof(__le64)];
>  	} xts_tweak;
>  	struct skcipher_request *req = NULL;
> -	DECLARE_FS_COMPLETION_RESULT(ecr);
> +	DECLARE_CRYPTO_WAIT(ecr);
>  	struct scatterlist dst, src;
>  	struct fscrypt_info *ci = inode->i_crypt_info;
>  	struct crypto_skcipher *tfm = ci->ci_ctfm;
> @@ -168,7 +153,7 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
[...]

This patch looks good --- thanks for doing this!  I suggest also renaming 'ecr'
to 'wait' in the places being updated to use crypto_wait, since the name is
obsolete (and was already; it originally stood for "ext4 completion result").

- Eric

[RFC 08/10] cifs: move to generic async completion

[Gilad Ben-Yossef]

cifs starts an async. crypto op and waits for their completion.
Move it over to generic code doing the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 fs/cifs/smb2ops.c | 30 ++++--------------------------
 1 file changed, 4 insertions(+), 26 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 152e37f..cee7bb3 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1706,22 +1706,6 @@ init_sg(struct smb_rqst *rqst, u8 *sign)
 	return sg;
 }
 
-struct cifs_crypt_result {
-	int err;
-	struct completion completion;
-};
-
-static void cifs_crypt_complete(struct crypto_async_request *req, int err)
-{
-	struct cifs_crypt_result *res = req->data;
-
-	if (err == -EINPROGRESS)
-		return;
-
-	res->err = err;
-	complete(&res->completion);
-}
-
 static int
 smb2_get_enc_key(struct TCP_Server_Info *server, __u64 ses_id, int enc, u8 *key)
 {
@@ -1762,12 +1746,10 @@ crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc)
 	struct aead_request *req;
 	char *iv;
 	unsigned int iv_len;
-	struct cifs_crypt_result result = {0, };
+	DECLARE_CRYPTO_WAIT(wait);
 	struct crypto_aead *tfm;
 	unsigned int crypt_len = le32_to_cpu(tr_hdr->OriginalMessageSize);
 
-	init_completion(&result.completion);
-
 	rc = smb2_get_enc_key(server, tr_hdr->SessionId, enc, key);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not get %scryption key\n", __func__,
@@ -1825,14 +1807,10 @@ crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc)
 	aead_request_set_ad(req, assoc_data_len);
 
 	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				  cifs_crypt_complete, &result);
+				  crypto_req_done, &wait);
 
-	rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
-
-	if (rc == -EINPROGRESS || rc == -EBUSY) {
-		wait_for_completion(&result.completion);
-		rc = result.err;
-	}
+	rc = crypto_wait_req(enc ? crypto_aead_encrypt(req)
+				: crypto_aead_decrypt(req), &wait);
 
 	if (!rc && enc)
 		memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE);
-- 
2.1.4

Re: [RFC 08/10] cifs: move to generic async completion

[Pavel Shilovsky]

2017-05-06 5:59 GMT-07:00 Gilad Ben-Yossef <gilad@benyossef.com>:
> cifs starts an async. crypto op and waits for their completion.
> Move it over to generic code doing the same.
>
> Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
> ---
>  fs/cifs/smb2ops.c | 30 ++++--------------------------
>  1 file changed, 4 insertions(+), 26 deletions(-)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 152e37f..cee7bb3 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -1706,22 +1706,6 @@ init_sg(struct smb_rqst *rqst, u8 *sign)
>         return sg;
>  }
>
> -struct cifs_crypt_result {
> -       int err;
> -       struct completion completion;
> -};
> -
> -static void cifs_crypt_complete(struct crypto_async_request *req, int err)
> -{
> -       struct cifs_crypt_result *res = req->data;
> -
> -       if (err == -EINPROGRESS)
> -               return;
> -
> -       res->err = err;
> -       complete(&res->completion);
> -}
> -
>  static int
>  smb2_get_enc_key(struct TCP_Server_Info *server, __u64 ses_id, int enc, u8 *key)
>  {
> @@ -1762,12 +1746,10 @@ crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc)
>         struct aead_request *req;
>         char *iv;
>         unsigned int iv_len;
> -       struct cifs_crypt_result result = {0, };
> +       DECLARE_CRYPTO_WAIT(wait);
>         struct crypto_aead *tfm;
>         unsigned int crypt_len = le32_to_cpu(tr_hdr->OriginalMessageSize);
>
> -       init_completion(&result.completion);
> -
>         rc = smb2_get_enc_key(server, tr_hdr->SessionId, enc, key);
>         if (rc) {
>                 cifs_dbg(VFS, "%s: Could not get %scryption key\n", __func__,
> @@ -1825,14 +1807,10 @@ crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc)
>         aead_request_set_ad(req, assoc_data_len);
>
>         aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
> -                                 cifs_crypt_complete, &result);
> +                                 crypto_req_done, &wait);
>
> -       rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
> -
> -       if (rc == -EINPROGRESS || rc == -EBUSY) {
> -               wait_for_completion(&result.completion);
> -               rc = result.err;
> -       }
> +       rc = crypto_wait_req(enc ? crypto_aead_encrypt(req)
> +                               : crypto_aead_decrypt(req), &wait);
>
>         if (!rc && enc)
>                 memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE);
> --
> 2.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-cifs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Acked-by: Pavel Shilovsky <pshilov@microsoft.com>

Best regards,
Pavel Shilovsky

[RFC 09/10] ima: move to generic async completion

[Gilad Ben-Yossef]

ima starts several async. crypto ops and  waits for their completions.
Move it over to generic code doing the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 security/integrity/ima/ima_crypto.c | 56 +++++++++++--------------------------
 1 file changed, 17 insertions(+), 39 deletions(-)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 802d5d2..0e4db1fe 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -27,11 +27,6 @@
 
 #include "ima.h"
 
-struct ahash_completion {
-	struct completion completion;
-	int err;
-};
-
 /* minimum file size for ahash use */
 static unsigned long ima_ahash_minsize;
 module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
@@ -196,30 +191,13 @@ static void ima_free_atfm(struct crypto_ahash *tfm)
 		crypto_free_ahash(tfm);
 }
 
-static void ahash_complete(struct crypto_async_request *req, int err)
+static inline int ahash_wait(int err, struct crypto_wait *wait)
 {
-	struct ahash_completion *res = req->data;
 
-	if (err == -EINPROGRESS)
-		return;
-	res->err = err;
-	complete(&res->completion);
-}
+	err = crypto_wait_req(err, wait);
 
-static int ahash_wait(int err, struct ahash_completion *res)
-{
-	switch (err) {
-	case 0:
-		break;
-	case -EINPROGRESS:
-	case -EBUSY:
-		wait_for_completion(&res->completion);
-		reinit_completion(&res->completion);
-		err = res->err;
-		/* fall through */
-	default:
+	if (err)
 		pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);
-	}
 
 	return err;
 }
@@ -233,7 +211,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
 	int rc, read = 0, rbuf_len, active = 0, ahash_rc = 0;
 	struct ahash_request *req;
 	struct scatterlist sg[1];
-	struct ahash_completion res;
+	struct crypto_wait wait;
 	size_t rbuf_size[2];
 
 	hash->length = crypto_ahash_digestsize(tfm);
@@ -242,12 +220,12 @@ static int ima_calc_file_hash_atfm(struct file *file,
 	if (!req)
 		return -ENOMEM;
 
-	init_completion(&res.completion);
+	crypto_init_wait(&wait);
 	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
 				   CRYPTO_TFM_REQ_MAY_SLEEP,
-				   ahash_complete, &res);
+				   crypto_req_done, &wait);
 
-	rc = ahash_wait(crypto_ahash_init(req), &res);
+	rc = ahash_wait(crypto_ahash_init(req), &wait);
 	if (rc)
 		goto out1;
 
@@ -288,7 +266,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
 			 * read/request, wait for the completion of the
 			 * previous ahash_update() request.
 			 */
-			rc = ahash_wait(ahash_rc, &res);
+			rc = ahash_wait(ahash_rc, &wait);
 			if (rc)
 				goto out3;
 		}
@@ -304,7 +282,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
 			 * read/request, wait for the completion of the
 			 * previous ahash_update() request.
 			 */
-			rc = ahash_wait(ahash_rc, &res);
+			rc = ahash_wait(ahash_rc, &wait);
 			if (rc)
 				goto out3;
 		}
@@ -318,7 +296,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
 			active = !active; /* swap buffers, if we use two */
 	}
 	/* wait for the last update request to complete */
-	rc = ahash_wait(ahash_rc, &res);
+	rc = ahash_wait(ahash_rc, &wait);
 out3:
 	if (read)
 		file->f_mode &= ~FMODE_READ;
@@ -327,7 +305,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
 out2:
 	if (!rc) {
 		ahash_request_set_crypt(req, NULL, hash->digest, 0);
-		rc = ahash_wait(crypto_ahash_final(req), &res);
+		rc = ahash_wait(crypto_ahash_final(req), &wait);
 	}
 out1:
 	ahash_request_free(req);
@@ -527,7 +505,7 @@ static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
 {
 	struct ahash_request *req;
 	struct scatterlist sg;
-	struct ahash_completion res;
+	struct crypto_wait wait;
 	int rc, ahash_rc = 0;
 
 	hash->length = crypto_ahash_digestsize(tfm);
@@ -536,12 +514,12 @@ static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
 	if (!req)
 		return -ENOMEM;
 
-	init_completion(&res.completion);
+	crypto_init_wait(&wait);
 	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
 				   CRYPTO_TFM_REQ_MAY_SLEEP,
-				   ahash_complete, &res);
+				   crypto_req_done, &wait);
 
-	rc = ahash_wait(crypto_ahash_init(req), &res);
+	rc = ahash_wait(crypto_ahash_init(req), &wait);
 	if (rc)
 		goto out;
 
@@ -551,10 +529,10 @@ static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
 	ahash_rc = crypto_ahash_update(req);
 
 	/* wait for the update request to complete */
-	rc = ahash_wait(ahash_rc, &res);
+	rc = ahash_wait(ahash_rc, &wait);
 	if (!rc) {
 		ahash_request_set_crypt(req, NULL, hash->digest, 0);
-		rc = ahash_wait(crypto_ahash_final(req), &res);
+		rc = ahash_wait(crypto_ahash_final(req), &wait);
 	}
 out:
 	ahash_request_free(req);
-- 
2.1.4

Re: [RFC 09/10] ima: move to generic async completion

[Mimi Zohar]

On Sat, 2017-05-06 at 15:59 +0300, Gilad Ben-Yossef wrote:
> ima starts several async. crypto ops and  waits for their completions.
> Move it over to generic code doing the same.
> 
> Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>

Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

> ---
>  security/integrity/ima/ima_crypto.c | 56 +++++++++++--------------------------
>  1 file changed, 17 insertions(+), 39 deletions(-)
> 
> diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
> index 802d5d2..0e4db1fe 100644
> --- a/security/integrity/ima/ima_crypto.c
> +++ b/security/integrity/ima/ima_crypto.c
> @@ -27,11 +27,6 @@
> 
>  #include "ima.h"
> 
> -struct ahash_completion {
> -	struct completion completion;
> -	int err;
> -};
> -
>  /* minimum file size for ahash use */
>  static unsigned long ima_ahash_minsize;
>  module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
> @@ -196,30 +191,13 @@ static void ima_free_atfm(struct crypto_ahash *tfm)
>  		crypto_free_ahash(tfm);
>  }
> 
> -static void ahash_complete(struct crypto_async_request *req, int err)
> +static inline int ahash_wait(int err, struct crypto_wait *wait)
>  {
> -	struct ahash_completion *res = req->data;
> 
> -	if (err == -EINPROGRESS)
> -		return;
> -	res->err = err;
> -	complete(&res->completion);
> -}
> +	err = crypto_wait_req(err, wait);
> 
> -static int ahash_wait(int err, struct ahash_completion *res)
> -{
> -	switch (err) {
> -	case 0:
> -		break;
> -	case -EINPROGRESS:
> -	case -EBUSY:
> -		wait_for_completion(&res->completion);
> -		reinit_completion(&res->completion);
> -		err = res->err;
> -		/* fall through */
> -	default:
> +	if (err)
>  		pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);
> -	}
> 
>  	return err;
>  }
> @@ -233,7 +211,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
>  	int rc, read = 0, rbuf_len, active = 0, ahash_rc = 0;
>  	struct ahash_request *req;
>  	struct scatterlist sg[1];
> -	struct ahash_completion res;
> +	struct crypto_wait wait;
>  	size_t rbuf_size[2];
> 
>  	hash->length = crypto_ahash_digestsize(tfm);
> @@ -242,12 +220,12 @@ static int ima_calc_file_hash_atfm(struct file *file,
>  	if (!req)
>  		return -ENOMEM;
> 
> -	init_completion(&res.completion);
> +	crypto_init_wait(&wait);
>  	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
>  				   CRYPTO_TFM_REQ_MAY_SLEEP,
> -				   ahash_complete, &res);
> +				   crypto_req_done, &wait);
> 
> -	rc = ahash_wait(crypto_ahash_init(req), &res);
> +	rc = ahash_wait(crypto_ahash_init(req), &wait);
>  	if (rc)
>  		goto out1;
> 
> @@ -288,7 +266,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
>  			 * read/request, wait for the completion of the
>  			 * previous ahash_update() request.
>  			 */
> -			rc = ahash_wait(ahash_rc, &res);
> +			rc = ahash_wait(ahash_rc, &wait);
>  			if (rc)
>  				goto out3;
>  		}
> @@ -304,7 +282,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
>  			 * read/request, wait for the completion of the
>  			 * previous ahash_update() request.
>  			 */
> -			rc = ahash_wait(ahash_rc, &res);
> +			rc = ahash_wait(ahash_rc, &wait);
>  			if (rc)
>  				goto out3;
>  		}
> @@ -318,7 +296,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
>  			active = !active; /* swap buffers, if we use two */
>  	}
>  	/* wait for the last update request to complete */
> -	rc = ahash_wait(ahash_rc, &res);
> +	rc = ahash_wait(ahash_rc, &wait);
>  out3:
>  	if (read)
>  		file->f_mode &= ~FMODE_READ;
> @@ -327,7 +305,7 @@ static int ima_calc_file_hash_atfm(struct file *file,
>  out2:
>  	if (!rc) {
>  		ahash_request_set_crypt(req, NULL, hash->digest, 0);
> -		rc = ahash_wait(crypto_ahash_final(req), &res);
> +		rc = ahash_wait(crypto_ahash_final(req), &wait);
>  	}
>  out1:
>  	ahash_request_free(req);
> @@ -527,7 +505,7 @@ static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
>  {
>  	struct ahash_request *req;
>  	struct scatterlist sg;
> -	struct ahash_completion res;
> +	struct crypto_wait wait;
>  	int rc, ahash_rc = 0;
> 
>  	hash->length = crypto_ahash_digestsize(tfm);
> @@ -536,12 +514,12 @@ static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
>  	if (!req)
>  		return -ENOMEM;
> 
> -	init_completion(&res.completion);
> +	crypto_init_wait(&wait);
>  	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
>  				   CRYPTO_TFM_REQ_MAY_SLEEP,
> -				   ahash_complete, &res);
> +				   crypto_req_done, &wait);
> 
> -	rc = ahash_wait(crypto_ahash_init(req), &res);
> +	rc = ahash_wait(crypto_ahash_init(req), &wait);
>  	if (rc)
>  		goto out;
> 
> @@ -551,10 +529,10 @@ static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
>  	ahash_rc = crypto_ahash_update(req);
> 
>  	/* wait for the update request to complete */
> -	rc = ahash_wait(ahash_rc, &res);
> +	rc = ahash_wait(ahash_rc, &wait);
>  	if (!rc) {
>  		ahash_request_set_crypt(req, NULL, hash->digest, 0);
> -		rc = ahash_wait(crypto_ahash_final(req), &res);
> +		rc = ahash_wait(crypto_ahash_final(req), &wait);
>  	}
>  out:
>  	ahash_request_free(req);

[RFC 10/10] crypto: adapt api sample to use async. op wait

[Gilad Ben-Yossef]

The code sample is waiting for an async. crypto op completion.
Adapt sample to use the new generic infrastructure to do the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
---
 Documentation/crypto/api-samples.rst | 52 +++++++-----------------------------
 1 file changed, 10 insertions(+), 42 deletions(-)

diff --git a/Documentation/crypto/api-samples.rst b/Documentation/crypto/api-samples.rst
index d021fd9..73b466b 100644
--- a/Documentation/crypto/api-samples.rst
+++ b/Documentation/crypto/api-samples.rst
@@ -7,59 +7,27 @@ Code Example For Symmetric Key Cipher Operation
 ::
 
 
-    struct tcrypt_result {
-        struct completion completion;
-        int err;
-    };
-
     /* tie all data structures together */
     struct skcipher_def {
         struct scatterlist sg;
         struct crypto_skcipher *tfm;
         struct skcipher_request *req;
-        struct tcrypt_result result;
+        struct crypto_wait wait;
     };
 
-    /* Callback function */
-    static void test_skcipher_cb(struct crypto_async_request *req, int error)
-    {
-        struct tcrypt_result *result = req->data;
-
-        if (error == -EINPROGRESS)
-            return;
-        result->err = error;
-        complete(&result->completion);
-        pr_info("Encryption finished successfully\n");
-    }
-
     /* Perform cipher operation */
     static unsigned int test_skcipher_encdec(struct skcipher_def *sk,
                          int enc)
     {
-        int rc = 0;
+        int rc;
 
         if (enc)
-            rc = crypto_skcipher_encrypt(sk->req);
+            rc = crypto_wait_req(crypto_skcipher_encrypt(sk->req), &sk->wait);
         else
-            rc = crypto_skcipher_decrypt(sk->req);
-
-        switch (rc) {
-        case 0:
-            break;
-        case -EINPROGRESS:
-        case -EBUSY:
-            rc = wait_for_completion_interruptible(
-                &sk->result.completion);
-            if (!rc && !sk->result.err) {
-                reinit_completion(&sk->result.completion);
-                break;
-            }
-        default:
-            pr_info("skcipher encrypt returned with %d result %d\n",
-                rc, sk->result.err);
-            break;
-        }
-        init_completion(&sk->result.completion);
+            rc = crypto_wait_req(crypto_skcipher_decrypt(sk->req), &sk->wait);
+
+	if (rc)
+		pr_info("skcipher encrypt returned with result %d\n", rc);
 
         return rc;
     }
@@ -89,8 +57,8 @@ Code Example For Symmetric Key Cipher Operation
         }
 
         skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-                          test_skcipher_cb,
-                          &sk.result);
+                          crypto_req_done,
+                          &sk.wait);
 
         /* AES 256 with random key */
         get_random_bytes(&key, 32);
@@ -122,7 +90,7 @@ Code Example For Symmetric Key Cipher Operation
         /* We encrypt one block */
         sg_init_one(&sk.sg, scratchpad, 16);
         skcipher_request_set_crypt(req, &sk.sg, &sk.sg, 16, ivdata);
-        init_completion(&sk.result.completion);
+        crypto_init_wait(&sk.wait);
 
         /* encrypt data */
         ret = test_skcipher_encdec(&sk, 1);
-- 
2.1.4