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>

12 files changed, 0 insertions, 23 deletions

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);
 }
 
@@ -48,7 +47,6 @@ static int padlock_sha_update(struct shash_desc *desc,
 {
 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 
-	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 	return crypto_shash_update(&dctx->fallback, data, length);
 }
 
@@ -65,7 +63,6 @@ static int padlock_sha_import(struct shash_desc *desc, const void *in)
 	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_import(&dctx->fallback, in);
 }
 
@@ -91,7 +88,6 @@ static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
 	unsigned int leftover;
 	int err;
 
-	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 	err = crypto_shash_export(&dctx->fallback, &state);
 	if (err)
 		goto out;
@@ -153,7 +149,6 @@ static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
 	unsigned int leftover;
 	int err;
 
-	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 	err = crypto_shash_export(&dctx->fallback, &state);
 	if (err)
 		goto out;
diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c
index 975c75198f56..c8d401646902 100644
--- a/drivers/crypto/qat/qat_common/qat_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_algs.c
@@ -164,7 +164,6 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 	memset(ctx->ipad, 0, block_size);
 	memset(ctx->opad, 0, block_size);
 	shash->tfm = ctx->hash_tfm;
-	shash->flags = 0x0;
 
 	if (auth_keylen > block_size) {
 		int ret = crypto_shash_digest(shash, auth_key,
diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c
index 1afdcb81d8ed..9ef25230c199 100644
--- a/drivers/crypto/s5p-sss.c
+++ b/drivers/crypto/s5p-sss.c
@@ -1534,7 +1534,6 @@ static int s5p_hash_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/vmx/ghash.c b/drivers/crypto/vmx/ghash.c
index 611ff591410e..b5a6883bb09e 100644
--- a/drivers/crypto/vmx/ghash.c
+++ b/drivers/crypto/vmx/ghash.c
@@ -101,7 +101,6 @@ static int p8_ghash_init(struct shash_desc *desc)
 	dctx->bytes = 0;
 	memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
 	dctx->fallback_desc.tfm = ctx->fallback;
-	dctx->fallback_desc.flags = desc->flags;
 	return crypto_shash_init(&dctx->fallback_desc);
 }