crypto: shash - remove shash_desc::flags

The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.

With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP.  These would all need to be fixed if any shash algorithm
actually started sleeping.  For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API.  However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.

Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk.  It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.

Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.

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

66 files changed, 8 insertions, 113 deletions

diff --git a/Documentation/crypto/api-samples.rst b/Documentation/crypto/api-samples.rst
index 0f6ca8b7261e..f14afaaf2f32 100644
--- a/Documentation/crypto/api-samples.rst
+++ b/Documentation/crypto/api-samples.rst
@@ -133,7 +133,6 @@ Code Example For Use of Operational State Memory With SHASH
         if (!sdesc)
             return ERR_PTR(-ENOMEM);
         sdesc->shash.tfm = alg;
-        sdesc->shash.flags = 0x0;
         return sdesc;
     }
 
diff --git a/arch/arm/crypto/ghash-ce-glue.c b/arch/arm/crypto/ghash-ce-glue.c
index 60123e9ea9d8..39d1ccec1aab 100644
--- a/arch/arm/crypto/ghash-ce-glue.c
+++ b/arch/arm/crypto/ghash-ce-glue.c
@@ -186,7 +186,6 @@ static int ghash_async_init(struct ahash_request *req)
 	struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 
 	desc->tfm = child;
-	desc->flags = req->base.flags;
 	return crypto_shash_init(desc);
 }
 
@@ -243,7 +242,6 @@ static int ghash_async_digest(struct ahash_request *req)
 		struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 
 		desc->tfm = child;
-		desc->flags = req->base.flags;
 		return shash_ahash_digest(req, desc);
 	}
 }
@@ -256,7 +254,6 @@ static int ghash_async_import(struct ahash_request *req, const void *in)
 	struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 
 	desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
-	desc->flags = req->base.flags;
 
 	return crypto_shash_import(desc, in);
 }
diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c
index 4099a0ae17dd..e3f3e6fd9d65 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_glue.c
+++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c
@@ -172,7 +172,6 @@ static int ghash_async_init(struct ahash_request *req)
 	struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 
 	desc->tfm = child;
-	desc->flags = req->base.flags;
 	return crypto_shash_init(desc);
 }
 
@@ -252,7 +251,6 @@ static int ghash_async_digest(struct ahash_request *req)
 		struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 
 		desc->tfm = child;
-		desc->flags = req->base.flags;
 		return shash_ahash_digest(req, desc);
 	}
 }
diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
index bcddf09b5aa3..4845b8c7be7f 100644
--- a/arch/x86/power/hibernate.c
+++ b/arch/x86/power/hibernate.c
@@ -90,7 +90,6 @@ static int get_e820_md5(struct e820_table *table, void *buf)
 	}
 
 	desc->tfm = tfm;
-	desc->flags = 0;
 
 	size = offsetof(struct e820_table, entries) +
 		sizeof(struct e820_entry) * table->nr_entries;
diff --git a/crypto/adiantum.c b/crypto/adiantum.c
index e6de50f669aa..395a3ddd3707 100644
--- a/crypto/adiantum.c
+++ b/crypto/adiantum.c
@@ -265,7 +265,6 @@ static int adiantum_hash_message(struct skcipher_request *req,
 	int err;
 
 	hash_desc->tfm = tctx->hash;
-	hash_desc->flags = 0;
 
 	err = crypto_shash_init(hash_desc);
 	if (err)
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 97c77f66b20d..f7b0980bf02d 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -56,7 +56,6 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
 		goto error_no_desc;
 
 	desc->tfm   = tfm;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	/* Digest the message [RFC2315 9.3] */
 	ret = crypto_shash_digest(desc, pkcs7->data, pkcs7->data_len,
diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
index d178650fd524..f8e4a932bcfb 100644
--- a/crypto/asymmetric_keys/verify_pefile.c
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -354,7 +354,6 @@ static int pefile_digest_pe(const void *pebuf, unsigned int pelen,
 		goto error_no_desc;
 
 	desc->tfm   = tfm;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 	ret = crypto_shash_init(desc);
 	if (ret < 0)
 		goto error;
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 9338b4558cdc..bd96683d8cde 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -77,7 +77,6 @@ int x509_get_sig_params(struct x509_certificate *cert)
 		goto error;
 
 	desc->tfm = tfm;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	ret = crypto_shash_digest(desc, cert->tbs, cert->tbs_size, sig->digest);
 	if (ret < 0)
diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 42533cf80acc..b3bb99390ae7 100644
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -545,7 +545,6 @@ static void cryptd_hash_init(struct crypto_async_request *req_async, int err)
 		goto out;
 
 	desc->tfm = child;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	err = crypto_shash_init(desc);
 
@@ -637,7 +636,6 @@ static void cryptd_hash_digest(struct crypto_async_request *req_async, int err)
 		goto out;
 
 	desc->tfm = child;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	err = shash_ahash_digest(req, desc);
 
@@ -666,7 +664,6 @@ static int cryptd_hash_import(struct ahash_request *req, const void *in)
 	struct shash_desc *desc = cryptd_shash_desc(req);
 
 	desc->tfm = ctx->child;
-	desc->flags = req->base.flags;
 
 	return crypto_shash_import(desc, in);
 }
diff --git a/crypto/drbg.c b/crypto/drbg.c
index 710b3046a4df..2a5b16bb000c 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1587,7 +1587,6 @@ static int drbg_init_hash_kernel(struct drbg_state *drbg)
 	}
 
 	sdesc->shash.tfm = tfm;
-	sdesc->shash.flags = 0;
 	drbg->priv_data = sdesc;
 
 	return crypto_shash_alignmask(tfm);
diff --git a/crypto/hmac.c b/crypto/hmac.c
index 4ceb3f1f0eb8..a68c1266121f 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -57,8 +57,6 @@ static int hmac_setkey(struct crypto_shash *parent,
 	unsigned int i;
 
 	shash->tfm = hash;
-	shash->flags = crypto_shash_get_flags(parent)
-		& CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	if (keylen > bs) {
 		int err;
@@ -91,8 +89,6 @@ static int hmac_export(struct shash_desc *pdesc, void *out)
 {
 	struct shash_desc *desc = shash_desc_ctx(pdesc);
 
-	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
 	return crypto_shash_export(desc, out);
 }
 
@@ -102,7 +98,6 @@ static int hmac_import(struct shash_desc *pdesc, const void *in)
 	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
 
 	desc->tfm = ctx->hash;
-	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	return crypto_shash_import(desc, in);
 }
@@ -117,8 +112,6 @@ static int hmac_update(struct shash_desc *pdesc,
 {
 	struct shash_desc *desc = shash_desc_ctx(pdesc);
 
-	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
 	return crypto_shash_update(desc, data, nbytes);
 }
 
@@ -130,8 +123,6 @@ static int hmac_final(struct shash_desc *pdesc, u8 *out)
 	char *opad = crypto_shash_ctx_aligned(parent) + ss;
 	struct shash_desc *desc = shash_desc_ctx(pdesc);
 
-	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
 	return crypto_shash_final(desc, out) ?:
 	       crypto_shash_import(desc, opad) ?:
 	       crypto_shash_finup(desc, out, ds, out);
@@ -147,8 +138,6 @@ static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
 	char *opad = crypto_shash_ctx_aligned(parent) + ss;
 	struct shash_desc *desc = shash_desc_ctx(pdesc);
 
-	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
 	return crypto_shash_finup(desc, data, nbytes, out) ?:
 	       crypto_shash_import(desc, opad) ?:
 	       crypto_shash_finup(desc, out, ds, out);
diff --git a/crypto/shash.c b/crypto/shash.c
index 599468478f7b..e55c1f558bc3 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -238,7 +238,6 @@ static int shash_async_init(struct ahash_request *req)
 	struct shash_desc *desc = ahash_request_ctx(req);
 
 	desc->tfm = *ctx;
-	desc->flags = req->base.flags;
 
 	return crypto_shash_init(desc);
 }
@@ -293,7 +292,6 @@ static int shash_async_finup(struct ahash_request *req)
 	struct shash_desc *desc = ahash_request_ctx(req);
 
 	desc->tfm = *ctx;
-	desc->flags = req->base.flags;
 
 	return shash_ahash_finup(req, desc);
 }
@@ -328,7 +326,6 @@ static int shash_async_digest(struct ahash_request *req)
 	struct shash_desc *desc = ahash_request_ctx(req);
 
 	desc->tfm = *ctx;
-	desc->flags = req->base.flags;
 
 	return shash_ahash_digest(req, desc);
 }
@@ -344,7 +341,6 @@ static int shash_async_import(struct ahash_request *req, const void *in)
 	struct shash_desc *desc = ahash_request_ctx(req);
 
 	desc->tfm = *ctx;
-	desc->flags = req->base.flags;
 
 	return crypto_shash_import(desc, in);
 }
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 87abfd1ce232..2bd89a65e9e7 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1328,7 +1328,6 @@ static void generate_random_hash_testvec(struct crypto_shash *tfm,
 
 	/* Digest */
 	desc->tfm = tfm;
-	desc->flags = 0;
 	vec->digest_error = crypto_shash_digest(desc, vec->plaintext,
 						vec->psize, (u8 *)vec->digest);
 done:
@@ -3027,7 +3026,6 @@ static int alg_test_crc32c(const struct alg_test_desc *desc,
 		u32 *ctx = (u32 *)shash_desc_ctx(shash);
 
 		shash->tfm = tfm;
-		shash->flags = 0;
 
 		*ctx = 420553207;
 		err = crypto_shash_final(shash, (u8 *)&val);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index c7ad88d91a09..843a9b9b3d74 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -5443,7 +5443,6 @@ static int drbd_do_auth(struct drbd_connection *connection)
 	rcu_read_unlock();
 
 	desc->tfm = connection->cram_hmac_tfm;
-	desc->flags = 0;
 
 	rv = crypto_shash_setkey(connection->cram_hmac_tfm, (u8 *)secret, key_len);
 	if (rv) {
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 268ef0c5d4ab..6781bcf3ec26 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -304,7 +304,6 @@ void drbd_csum_ee(struct crypto_shash *tfm, struct drbd_peer_request *peer_req,
 	void *src;
 
 	desc->tfm = tfm;
-	desc->flags = 0;
 
 	crypto_shash_init(desc);
 
@@ -332,7 +331,6 @@ void drbd_csum_bio(struct crypto_shash *tfm, struct bio *bio, void *digest)
 	struct bvec_iter iter;
 
 	desc->tfm = tfm;
-	desc->flags = 0;
 
 	crypto_shash_init(desc);
 
diff --git a/drivers/crypto/axis/artpec6_crypto.c b/drivers/crypto/axis/artpec6_crypto.c
index 57e5dca3253f..d2fb72811442 100644
--- a/drivers/crypto/axis/artpec6_crypto.c
+++ b/drivers/crypto/axis/artpec6_crypto.c
@@ -2247,8 +2247,6 @@ artpec6_crypto_hash_set_key(struct crypto_ahash *tfm,
 		SHASH_DESC_ON_STACK(hdesc, tfm_ctx->child_hash);
 
 		hdesc->tfm = tfm_ctx->child_hash;
-		hdesc->flags = crypto_ahash_get_flags(tfm) &
-			       CRYPTO_TFM_REQ_MAY_SLEEP;
 
 		tfm_ctx->hmac_key_length = blocksize;
 		ret = crypto_shash_digest(hdesc, key, keylen,
diff --git a/drivers/crypto/bcm/cipher.c b/drivers/crypto/bcm/cipher.c
index 8862200d4a0b..25f8d3913ceb 100644
--- a/drivers/crypto/bcm/cipher.c
+++ b/drivers/crypto/bcm/cipher.c
@@ -2140,7 +2140,6 @@ static int ahash_init(struct ahash_request *req)
 			goto err_hash;
 		}
 		ctx->shash->tfm = hash;
-		ctx->shash->flags = 0;
 
 		/* Set the key using data we already have from setkey */
 		if (ctx->authkeylen > 0) {
diff --git a/drivers/crypto/bcm/util.c b/drivers/crypto/bcm/util.c
index d8cda5fb75ad..91ec56399d84 100644
--- a/drivers/crypto/bcm/util.c
+++ b/drivers/crypto/bcm/util.c
@@ -242,7 +242,6 @@ int do_shash(unsigned char *name, unsigned char *result,
 		goto do_shash_err;
 	}
 	sdesc->shash.tfm = hash;
-	sdesc->shash.flags = 0x0;
 
 	if (key_len > 0) {
 		rc = crypto_shash_setkey(hash, key, key_len);
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index 10a61cd54fce..3e10573f589e 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -293,8 +293,6 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 	if (key_len > block_size) {
 		/* Must hash the input key */
 		sdesc->tfm = shash;
-		sdesc->flags = crypto_ahash_get_flags(tfm) &
-			CRYPTO_TFM_REQ_MAY_SLEEP;
 
 		ret = crypto_shash_digest(sdesc, key, key_len,
 					  ctx->u.sha.key);
diff --git a/drivers/crypto/chelsio/chcr_algo.c b/drivers/crypto/chelsio/chcr_algo.c
index 8d8cf80b9294..8a76fce22943 100644
--- a/drivers/crypto/chelsio/chcr_algo.c
+++ b/drivers/crypto/chelsio/chcr_algo.c
@@ -2130,7 +2130,6 @@ static int chcr_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 	 * ipad in hmacctx->ipad and opad in hmacctx->opad location
 	 */
 	shash->tfm = hmacctx->base_hash;
-	shash->flags = crypto_shash_get_flags(hmacctx->base_hash);
 	if (keylen > bs) {
 		err = crypto_shash_digest(shash, key, keylen,
 					  hmacctx->ipad);
@@ -3517,7 +3516,6 @@ static int chcr_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
 		SHASH_DESC_ON_STACK(shash, base_hash);
 
 		shash->tfm = base_hash;
-		shash->flags = crypto_shash_get_flags(base_hash);
 		bs = crypto_shash_blocksize(base_hash);
 		align = KEYCTX_ALIGN_PAD(max_authsize);
 		o_ptr =  actx->h_iopad + param.result_size + align;
diff --git a/drivers/crypto/mediatek/mtk-sha.c b/drivers/crypto/mediatek/mtk-sha.c
index 5f4f845adbb8..a0806ba40c68 100644
--- a/drivers/crypto/mediatek/mtk-sha.c
+++ b/drivers/crypto/mediatek/mtk-sha.c
@@ -365,7 +365,6 @@ static int mtk_sha_finish_hmac(struct ahash_request *req)
 	SHASH_DESC_ON_STACK(shash, bctx->shash);
 
 	shash->tfm = bctx->shash;
-	shash->flags = 0; /* not CRYPTO_TFM_REQ_MAY_SLEEP */
 
 	return crypto_shash_init(shash) ?:
 	       crypto_shash_update(shash, bctx->opad, ctx->bs) ?:
@@ -810,8 +809,6 @@ static int mtk_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 	SHASH_DESC_ON_STACK(shash, bctx->shash);
 
 	shash->tfm = bctx->shash;
-	shash->flags = crypto_shash_get_flags(bctx->shash) &
-		       CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	if (keylen > bs) {
 		err = crypto_shash_digest(shash, key, keylen, bctx->ipad);
diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c
index df675aea58f6..0d5d3d8eb680 100644
--- a/drivers/crypto/n2_core.c
+++ b/drivers/crypto/n2_core.c
@@ -469,8 +469,6 @@ static int n2_hmac_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 		return err;
 
 	shash->tfm = child_shash;
-	shash->flags = crypto_ahash_get_flags(tfm) &
-		CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	bs = crypto_shash_blocksize(child_shash);
 	ds = crypto_shash_digestsize(child_shash);
diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 0641185bd82f..51b20abac464 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -1055,7 +1055,6 @@ static int omap_sham_finish_hmac(struct ahash_request *req)
 	SHASH_DESC_ON_STACK(shash, bctx->shash);
 
 	shash->tfm = bctx->shash;
-	shash->flags = 0; /* not CRYPTO_TFM_REQ_MAY_SLEEP */
 
 	return crypto_shash_init(shash) ?:
 	       crypto_shash_update(shash, bctx->opad, bs) ?:
@@ -1226,7 +1225,6 @@ static int omap_sham_shash_digest(struct crypto_shash *tfm, u32 flags,
 	SHASH_DESC_ON_STACK(shash, tfm);
 
 	shash->tfm = tfm;
-	shash->flags = flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	return crypto_shash_digest(shash, data, len, out);
 }
diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
index 21e5cae0a1e0..e641481a3cd9 100644
--- a/drivers/crypto/padlock-sha.c
+++ b/drivers/crypto/padlock-sha.c
@@ -39,7 +39,6 @@ static int padlock_sha_init(struct shash_desc *desc)
 	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
 
 	dctx->fallback.tfm = ctx->fallback;
-	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 	return crypto_shash_init(&dctx->fallback);