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

[Mimi Zohar <zohar@linux.vnet.ibm.com>]

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);