Merge tag 'llvmlinux-for-v3.18' of git://git.linuxfoundation.org/llvmlinux/kernel

Pull LLVM updates from Behan Webster:
 "These patches remove the use of VLAIS using a new SHASH_DESC_ON_STACK
  macro.

  Some of the previously accepted VLAIS removal patches haven't used
  this macro.  I will push new patches to consistently use this macro in
  all those older cases for 3.19"

[ More LLVM patches coming in through subsystem trees, and LLVM itself
  needs some fixes that are already in many distributions but not in
  released versions of LLVM.  Some day this will all "just work"  - Linus ]

* tag 'llvmlinux-for-v3.18' of git://git.linuxfoundation.org/llvmlinux/kernel:
  crypto: LLVMLinux: Remove VLAIS usage from crypto/testmgr.c
  security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c
  crypto: LLVMLinux: Remove VLAIS usage from libcrc32c.c
  crypto: LLVMLinux: Remove VLAIS usage from crypto/hmac.c
  crypto, dm: LLVMLinux: Remove VLAIS usage from dm-crypt
  crypto: LLVMLinux: Remove VLAIS from crypto/.../qat_algs.c
  crypto: LLVMLinux: Remove VLAIS from crypto/omap_sham.c
  crypto: LLVMLinux: Remove VLAIS from crypto/n2_core.c
  crypto: LLVMLinux: Remove VLAIS from crypto/mv_cesa.c
  crypto: LLVMLinux: Remove VLAIS from crypto/ccp/ccp-crypto-sha.c
  btrfs: LLVMLinux: Remove VLAIS
  crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

12 files changed, 122 insertions, 159 deletions

diff --git a/crypto/hmac.c b/crypto/hmac.c
index 8d9544cf8169..e392219ddc61 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -52,20 +52,17 @@ static int hmac_setkey(struct crypto_shash *parent,
 	struct hmac_ctx *ctx = align_ptr(opad + ss,
 					 crypto_tfm_ctx_alignment());
 	struct crypto_shash *hash = ctx->hash;
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(hash)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, hash);
 	unsigned int i;
 
-	desc.shash.tfm = hash;
-	desc.shash.flags = crypto_shash_get_flags(parent) &
-			    CRYPTO_TFM_REQ_MAY_SLEEP;
+	shash->tfm = hash;
+	shash->flags = crypto_shash_get_flags(parent)
+		& CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	if (keylen > bs) {
 		int err;
 
-		err = crypto_shash_digest(&desc.shash, inkey, keylen, ipad);
+		err = crypto_shash_digest(shash, inkey, keylen, ipad);
 		if (err)
 			return err;
 
@@ -81,12 +78,12 @@ static int hmac_setkey(struct crypto_shash *parent,
 		opad[i] ^= 0x5c;
 	}
 
-	return crypto_shash_init(&desc.shash) ?:
-	       crypto_shash_update(&desc.shash, ipad, bs) ?:
-	       crypto_shash_export(&desc.shash, ipad) ?:
-	       crypto_shash_init(&desc.shash) ?:
-	       crypto_shash_update(&desc.shash, opad, bs) ?:
-	       crypto_shash_export(&desc.shash, opad);
+	return crypto_shash_init(shash) ?:
+	       crypto_shash_update(shash, ipad, bs) ?:
+	       crypto_shash_export(shash, ipad) ?:
+	       crypto_shash_init(shash) ?:
+	       crypto_shash_update(shash, opad, bs) ?:
+	       crypto_shash_export(shash, opad);
 }
 
 static int hmac_export(struct shash_desc *pdesc, void *out)
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 9459dfd7357f..29a0cbdd0d19 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1678,16 +1678,14 @@ static int alg_test_crc32c(const struct alg_test_desc *desc,
 	}
 
 	do {
-		struct {
-			struct shash_desc shash;
-			char ctx[crypto_shash_descsize(tfm)];
-		} sdesc;
+		SHASH_DESC_ON_STACK(shash, tfm);
+		u32 *ctx = (u32 *)shash_desc_ctx(shash);
 
-		sdesc.shash.tfm = tfm;
-		sdesc.shash.flags = 0;
+		shash->tfm = tfm;
+		shash->flags = 0;
 
-		*(u32 *)sdesc.ctx = le32_to_cpu(420553207);
-		err = crypto_shash_final(&sdesc.shash, (u8 *)&val);
+		*ctx = le32_to_cpu(420553207);
+		err = crypto_shash_final(shash, (u8 *)&val);
 		if (err) {
 			printk(KERN_ERR "alg: crc32c: Operation failed for "
 			       "%s: %d\n", driver, err);
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index 873f23425245..96531571f7cf 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -198,10 +198,9 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 {
 	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
 	struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
-	struct {
-		struct shash_desc sdesc;
-		char ctx[crypto_shash_descsize(shash)];
-	} desc;
+
+	SHASH_DESC_ON_STACK(sdesc, shash);
+
 	unsigned int block_size = crypto_shash_blocksize(shash);
 	unsigned int digest_size = crypto_shash_digestsize(shash);
 	int i, ret;
@@ -216,11 +215,11 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 
 	if (key_len > block_size) {
 		/* Must hash the input key */
-		desc.sdesc.tfm = shash;
-		desc.sdesc.flags = crypto_ahash_get_flags(tfm) &
+		sdesc->tfm = shash;
+		sdesc->flags = crypto_ahash_get_flags(tfm) &
 			CRYPTO_TFM_REQ_MAY_SLEEP;
 
-		ret = crypto_shash_digest(&desc.sdesc, key, key_len,
+		ret = crypto_shash_digest(sdesc, key, key_len,
 					  ctx->u.sha.key);
 		if (ret) {
 			crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
diff --git a/drivers/crypto/mv_cesa.c b/drivers/crypto/mv_cesa.c
index 29d0ee504907..032c72c1f953 100644
--- a/drivers/crypto/mv_cesa.c
+++ b/drivers/crypto/mv_cesa.c
@@ -402,26 +402,23 @@ static int mv_hash_final_fallback(struct ahash_request *req)
 {
 	const struct mv_tfm_hash_ctx *tfm_ctx = crypto_tfm_ctx(req->base.tfm);
 	struct mv_req_hash_ctx *req_ctx = ahash_request_ctx(req);
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm_ctx->fallback)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm_ctx->fallback);
 	int rc;
 
-	desc.shash.tfm = tfm_ctx->fallback;
-	desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+	shash->tfm = tfm_ctx->fallback;
+	shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 	if (unlikely(req_ctx->first_hash)) {
-		crypto_shash_init(&desc.shash);
-		crypto_shash_update(&desc.shash, req_ctx->buffer,
+		crypto_shash_init(shash);
+		crypto_shash_update(shash, req_ctx->buffer,
 				    req_ctx->extra_bytes);
 	} else {
 		/* only SHA1 for now....
 		 */
-		rc = mv_hash_import_sha1_ctx(req_ctx, &desc.shash);
+		rc = mv_hash_import_sha1_ctx(req_ctx, shash);
 		if (rc)
 			goto out;
 	}
-	rc = crypto_shash_final(&desc.shash, req->result);
+	rc = crypto_shash_final(shash, req->result);
 out:
 	return rc;
 }
@@ -794,23 +791,21 @@ static int mv_hash_setkey(struct crypto_ahash *tfm, const u8 * key,
 	ss = crypto_shash_statesize(ctx->base_hash);
 
 	{
-		struct {
-			struct shash_desc shash;
-			char ctx[crypto_shash_descsize(ctx->base_hash)];
-		} desc;
+		SHASH_DESC_ON_STACK(shash, ctx->base_hash);
+
 		unsigned int i;
 		char ipad[ss];
 		char opad[ss];
 
-		desc.shash.tfm = ctx->base_hash;
-		desc.shash.flags = crypto_shash_get_flags(ctx->base_hash) &
+		shash->tfm = ctx->base_hash;
+		shash->flags = crypto_shash_get_flags(ctx->base_hash) &
 		    CRYPTO_TFM_REQ_MAY_SLEEP;
 
 		if (keylen > bs) {
 			int err;
 
 			err =
-			    crypto_shash_digest(&desc.shash, key, keylen, ipad);
+			    crypto_shash_digest(shash, key, keylen, ipad);
 			if (err)
 				return err;
 
@@ -826,12 +821,12 @@ static int mv_hash_setkey(struct crypto_ahash *tfm, const u8 * key,
 			opad[i] ^= 0x5c;
 		}
 
-		rc = crypto_shash_init(&desc.shash) ? :
-		    crypto_shash_update(&desc.shash, ipad, bs) ? :
-		    crypto_shash_export(&desc.shash, ipad) ? :
-		    crypto_shash_init(&desc.shash) ? :
-		    crypto_shash_update(&desc.shash, opad, bs) ? :
-		    crypto_shash_export(&desc.shash, opad);
+		rc = crypto_shash_init(shash) ? :
+		    crypto_shash_update(shash, ipad, bs) ? :
+		    crypto_shash_export(shash, ipad) ? :
+		    crypto_shash_init(shash) ? :
+		    crypto_shash_update(shash, opad, bs) ? :
+		    crypto_shash_export(shash, opad);
 
 		if (rc == 0)
 			mv_hash_init_ivs(ctx, ipad, opad);
diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c
index 7263c10a56ee..f8e3207fecb1 100644
--- a/drivers/crypto/n2_core.c
+++ b/drivers/crypto/n2_core.c
@@ -445,10 +445,7 @@ static int n2_hmac_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 	struct n2_hmac_ctx *ctx = crypto_ahash_ctx(tfm);
 	struct crypto_shash *child_shash = ctx->child_shash;
 	struct crypto_ahash *fallback_tfm;
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(child_shash)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, child_shash);
 	int err, bs, ds;
 
 	fallback_tfm = ctx->base.fallback_tfm;
@@ -456,15 +453,15 @@ static int n2_hmac_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 	if (err)
 		return err;
 
-	desc.shash.tfm = child_shash;
-	desc.shash.flags = crypto_ahash_get_flags(tfm) &
+	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);
 	BUG_ON(ds > N2_HASH_KEY_MAX);
 	if (keylen > bs) {
-		err = crypto_shash_digest(&desc.shash, key, keylen,
+		err = crypto_shash_digest(shash, key, keylen,
 					  ctx->hash_key);
 		if (err)
 			return err;
diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 710d86386965..24ef48965e45 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -949,17 +949,14 @@ static int omap_sham_finish_hmac(struct ahash_request *req)
 	struct omap_sham_hmac_ctx *bctx = tctx->base;
 	int bs = crypto_shash_blocksize(bctx->shash);
 	int ds = crypto_shash_digestsize(bctx->shash);
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(bctx->shash)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, bctx->shash);
 
-	desc.shash.tfm = bctx->shash;
-	desc.shash.flags = 0; /* not CRYPTO_TFM_REQ_MAY_SLEEP */
+	shash->tfm = bctx->shash;
+	shash->flags = 0; /* not CRYPTO_TFM_REQ_MAY_SLEEP */
 
-	return crypto_shash_init(&desc.shash) ?:
-	       crypto_shash_update(&desc.shash, bctx->opad, bs) ?:
-	       crypto_shash_finup(&desc.shash, req->result, ds, req->result);
+	return crypto_shash_init(shash) ?:
+	       crypto_shash_update(shash, bctx->opad, bs) ?:
+	       crypto_shash_finup(shash, req->result, ds, req->result);
 }
 
 static int omap_sham_finish(struct ahash_request *req)
@@ -1118,18 +1115,15 @@ static int omap_sham_update(struct ahash_request *req)
 	return omap_sham_enqueue(req, OP_UPDATE);
 }
 
-static int omap_sham_shash_digest(struct crypto_shash *shash, u32 flags,
+static int omap_sham_shash_digest(struct crypto_shash *tfm, u32 flags,
 				  const u8 *data, unsigned int len, u8 *out)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(shash)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
 
-	desc.shash.tfm = shash;
-	desc.shash.flags = flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+	shash->tfm = tfm;
+	shash->flags = flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	return crypto_shash_digest(&desc.shash, data, len, out);
+	return crypto_shash_digest(shash, data, len, out);
 }
 
 static int omap_sham_final_shash(struct ahash_request *req)
diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c
index 3e26fa2b293f..f2e2f158cfbe 100644
--- a/drivers/crypto/qat/qat_common/qat_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_algs.c
@@ -149,10 +149,7 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 				  unsigned int auth_keylen)
 {
 	struct qat_auth_state auth_state;
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(ctx->hash_tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, ctx->hash_tfm);
 	struct sha1_state sha1;
 	struct sha256_state sha256;
 	struct sha512_state sha512;
@@ -165,12 +162,12 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 	int i, offset;
 
 	memset(auth_state.data, '\0', MAX_AUTH_STATE_SIZE + 64);
-	desc.shash.tfm = ctx->hash_tfm;
-	desc.shash.flags = 0x0;
+	shash->tfm = ctx->hash_tfm;
+	shash->flags = 0x0;
 
 	if (auth_keylen > block_size) {
 		char buff[SHA512_BLOCK_SIZE];
-		int ret = crypto_shash_digest(&desc.shash, auth_key,
+		int ret = crypto_shash_digest(shash, auth_key,
 					      auth_keylen, buff);
 		if (ret)
 			return ret;
@@ -193,10 +190,10 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 		*opad_ptr ^= 0x5C;
 	}
 
-	if (crypto_shash_init(&desc.shash))
+	if (crypto_shash_init(shash))
 		return -EFAULT;
 
-	if (crypto_shash_update(&desc.shash, ipad, block_size))
+	if (crypto_shash_update(shash, ipad, block_size))
 		return -EFAULT;
 
 	hash_state_out = (__be32 *)hash->sha.state1;
@@ -204,19 +201,19 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 
 	switch (ctx->qat_hash_alg) {
 	case ICP_QAT_HW_AUTH_ALGO_SHA1:
-		if (crypto_shash_export(&desc.shash, &sha1))
+		if (crypto_shash_export(shash, &sha1))
 			return -EFAULT;
 		for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
 			*hash_state_out = cpu_to_be32(*(sha1.state + i));
 		break;
 	case ICP_QAT_HW_AUTH_ALGO_SHA256:
-		if (crypto_shash_export(&desc.shash, &sha256))
+		if (crypto_shash_export(shash, &sha256))
 			return -EFAULT;
 		for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
 			*hash_state_out = cpu_to_be32(*(sha256.state + i));
 		break;
 	case ICP_QAT_HW_AUTH_ALGO_SHA512:
-		if (crypto_shash_export(&desc.shash, &sha512))
+		if (crypto_shash_export(shash, &sha512))
 			return -EFAULT;
 		for (i = 0; i < digest_size >> 3; i++, hash512_state_out++)
 			*hash512_state_out = cpu_to_be64(*(sha512.state + i));
@@ -225,10 +222,10 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 		return -EFAULT;
 	}
 
-	if (crypto_shash_init(&desc.shash))
+	if (crypto_shash_init(shash))
 		return -EFAULT;
 
-	if (crypto_shash_update(&desc.shash, opad, block_size))
+	if (crypto_shash_update(shash, opad, block_size))
 		return -EFAULT;
 
 	offset = round_up(qat_get_inter_state_size(ctx->qat_hash_alg), 8);
@@ -237,19 +234,19 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 
 	switch (ctx->qat_hash_alg) {
 	case ICP_QAT_HW_AUTH_ALGO_SHA1:
-		if (crypto_shash_export(&desc.shash, &sha1))
+		if (crypto_shash_export(shash, &sha1))
 			return -EFAULT;
 		for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
 			*hash_state_out = cpu_to_be32(*(sha1.state + i));
 		break;
 	case ICP_QAT_HW_AUTH_ALGO_SHA256:
-		if (crypto_shash_export(&desc.shash, &sha256))
+		if (crypto_shash_export(shash, &sha256))
 			return -EFAULT;
 		for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
 			*hash_state_out = cpu_to_be32(*(sha256.state + i));
 		break;
 	case ICP_QAT_HW_AUTH_ALGO_SHA512:
-		if (crypto_shash_export(&desc.shash, &sha512))
+		if (crypto_shash_export(shash, &sha512))
 			return -EFAULT;
 		for (i = 0; i < digest_size >> 3; i++, hash512_state_out++)
 			*hash512_state_out = cpu_to_be64(*(sha512.state + i));
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index cd15e0801228..fc93b9330af4 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -526,29 +526,26 @@ static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 			    u8 *data)
 {
 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
-	struct {
-		struct shash_desc desc;
-		char ctx[crypto_shash_descsize(lmk->hash_tfm)];
-	} sdesc;
+	SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
 	struct md5_state md5state;
 	__le32 buf[4];
 	int i, r;
 
-	sdesc.desc.tfm = lmk->hash_tfm;
-	sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+	desc->tfm = lmk->hash_tfm;
+	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	r = crypto_shash_init(&sdesc.desc);
+	r = crypto_shash_init(desc);
 	if (r)
 		return r;
 
 	if (lmk->seed) {
-		r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
+		r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
 		if (r)
 			return r;
 	}
 
 	/* Sector is always 512B, block size 16, add data of blocks 1-31 */
-	r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
+	r = crypto_shash_update(desc, data + 16, 16 * 31);
 	if (r)
 		return r;
 
@@ -557,12 +554,12 @@ static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 	buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
 	buf[2] = cpu_to_le32(4024);
 	buf[3] = 0;
-	r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
+	r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
 	if (r)
 		return r;
 
 	/* No MD5 padding here */
-	r = crypto_shash_export(&sdesc.desc, &md5state);
+	r = crypto_shash_export(desc, &md5state);
 	if (r)
 		return r;
 
@@ -679,10 +676,7 @@ static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 	u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
 	u8 buf[TCW_WHITENING_SIZE];
-	struct {
-		struct shash_desc desc;
-		char ctx[crypto_shash_descsize(tcw->crc32_tfm)];
-	} sdesc;
+	SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
 	int i, r;
 
 	/* xor whitening with sector number */
@@ -691,16 +685,16 @@ static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 	crypto_xor(&buf[8], (u8 *)&sector, 8);
 
 	/* calculate crc32 for every 32bit part and xor it */
-	sdesc.desc.tfm = tcw->crc32_tfm;
-	sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+	desc->tfm = tcw->crc32_tfm;
+	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 	for (i = 0; i < 4; i++) {
-		r = crypto_shash_init(&sdesc.desc);
+		r = crypto_shash_init(desc);
 		if (r)
 			goto out;
-		r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4);
+		r = crypto_shash_update(desc, &buf[i * 4], 4);
 		if (r)
 			goto out;
-		r = crypto_shash_final(&sdesc.desc, &buf[i * 4]);
+		r = crypto_shash_final(desc, &buf[i * 4]);
 		if (r)
 			goto out;
 	}
diff --git a/fs/btrfs/hash.c b/fs/btrfs/hash.c
index 64f15bb30a81..aae520b2aee5 100644
--- a/fs/btrfs/hash.c
+++ b/fs/btrfs/hash.c
@@ -31,18 +31,16 @@ void btrfs_hash_exit(void)
 
 u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
+	u32 *ctx = (u32 *)shash_desc_ctx(shash);
 	int err;
 
-	desc.shash.tfm = tfm;
-	desc.shash.flags = 0;
-	*(u32 *)desc.ctx = crc;
+	shash->tfm = tfm;
+	shash->flags = 0;
+	*ctx = crc;
 
-	err = crypto_shash_update(&desc.shash, address, length);
+	err = crypto_shash_update(shash, address, length);
 	BUG_ON(err);
 
-	return *(u32 *)desc.ctx;
+	return *ctx;
 }
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index a39195539601..74b13ec1ebd4 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -58,6 +58,11 @@ struct shash_desc {
 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 };
 
+#define SHASH_DESC_ON_STACK(shash, ctx)				  \
+	char __##shash##_desc[sizeof(struct shash_desc) +	  \
+		crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \
+	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
+
 struct shash_alg {
 	int (*init)(struct shash_desc *desc);
 	int (*update)(struct shash_desc *desc, const u8 *data,
diff --git a/lib/libcrc32c.c b/lib/libcrc32c.c
index b3131f5cf8a2..6a08ce7d6adc 100644
--- a/lib/libcrc32c.c
+++ b/lib/libcrc32c.c
@@ -41,20 +41,18 @@ static struct crypto_shash *tfm;
 
 u32 crc32c(u32 crc, const void *address, unsigned int length)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
+	u32 *ctx = (u32 *)shash_desc_ctx(shash);
 	int err;
 
-	desc.shash.tfm = tfm;
-	desc.shash.flags = 0;
-	*(u32 *)desc.ctx = crc;
+	shash->tfm = tfm;
+	shash->flags = 0;
+	*ctx = crc;
 
-	err = crypto_shash_update(&desc.shash, address, length);
+	err = crypto_shash_update(shash, address, length);
 	BUG_ON(err);
 
-	return *(u32 *)desc.ctx;
+	return *ctx;
 }
 
 EXPORT_SYMBOL(crc32c);
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index d34e7dfc1118..78d66dae15f4 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -386,17 +386,14 @@ static int ima_calc_file_hash_tfm(struct file *file,
 	loff_t i_size, offset = 0;
 	char *rbuf;
 	int rc, read = 0;
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
 
-	desc.shash.tfm = tfm;
-	desc.shash.flags = 0;
+	shash->tfm = tfm;
+	shash->flags = 0;
 
 	hash->length = crypto_shash_digestsize(tfm);
 
-	rc = crypto_shash_init(&desc.shash);
+	rc = crypto_shash_init(shash);
 	if (rc != 0)
 		return rc;
 
@@ -426,7 +423,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
 			break;
 		offset += rbuf_len;
 
-		rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len);
+		rc = crypto_shash_update(shash, rbuf, rbuf_len);
 		if (rc)
 			break;
 	}
@@ -435,7 +432,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
 	kfree(rbuf);
 out:
 	if (!rc)
-		rc = crypto_shash_final(&desc.shash, hash->digest);
+		rc = crypto_shash_final(shash, hash->digest);
 	return rc;
 }
 
@@ -493,18 +490,15 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
 					 struct ima_digest_data *hash,
 					 struct crypto_shash *tfm)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
 	int rc, i;
 
-	desc.shash.tfm = tfm;
-	desc.shash.flags = 0;
+	shash->tfm = tfm;
+	shash->flags = 0;
 
 	hash->length = crypto_shash_digestsize(tfm);
 
-	rc = crypto_shash_init(&desc.shash);
+	rc = crypto_shash_init(shash);
 	if (rc != 0)
 		return rc;
 
@@ -514,7 +508,7 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
 		u32 datalen = field_data[i].len;
 
 		if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
-			rc = crypto_shash_update(&desc.shash,
+			rc = crypto_shash_update(shash,
 						(const u8 *) &field_data[i].len,
 						sizeof(field_data[i].len));
 			if (rc)
@@ -524,13 +518,13 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
 			data_to_hash = buffer;
 			datalen = IMA_EVENT_NAME_LEN_MAX + 1;
 		}
-		rc = crypto_shash_update(&desc.shash, data_to_hash, datalen);
+		rc = crypto_shash_update(shash, data_to_hash, datalen);
 		if (rc)
 			break;
 	}
 
 	if (!rc)
-		rc = crypto_shash_final(&desc.shash, hash->digest);
+		rc = crypto_shash_final(shash, hash->digest);
 
 	return rc;
 }
@@ -571,15 +565,12 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
 {
 	u8 pcr_i[TPM_DIGEST_SIZE];
 	int rc, i;
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(tfm)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
 
-	desc.shash.tfm = tfm;
-	desc.shash.flags = 0;
+	shash->tfm = tfm;
+	shash->flags = 0;
 
-	rc = crypto_shash_init(&desc.shash);
+	rc = crypto_shash_init(shash);
 	if (rc != 0)
 		return rc;
 
@@ -587,10 +578,10 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
 	for (i = TPM_PCR0; i < TPM_PCR8; i++) {
 		ima_pcrread(i, pcr_i);
 		/* now accumulate with current aggregate */
-		rc = crypto_shash_update(&desc.shash, pcr_i, TPM_DIGEST_SIZE);
+		rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
 	}
 	if (!rc)
-		crypto_shash_final(&desc.shash, digest);
+		crypto_shash_final(shash, digest);
 	return rc;
 }