crypto: drbg - move to generic async completion

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

The code now also 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>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 9 insertions, 27 deletions

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 70018397e59a..4faa2781c964 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;
@@ -1691,7 +1681,7 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg)
                 return PTR_ERR(sk_tfm);
         }
         drbg->ctr_handle = sk_tfm;
-        init_completion(&drbg->ctr_completion);
+        crypto_init_wait(&drbg->ctr_wait);
 
         req = skcipher_request_alloc(sk_tfm, GFP_KERNEL);
         if (!req) {
@@ -1700,8 +1690,9 @@ 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,
@@ -1762,21 +1753,12 @@ 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:
-                        wait_for_completion(&drbg->ctr_completion);
-                        if (!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);