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;
 }