From: Behan Webster <beh...@converseincode.com>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using an char array.

The new code can be compiled with both gcc and clang.

struct shash_desc contains a flexible array member member ctx declared with
CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
of the array declared after struct shash_desc with long long.

No trailing padding is required because it is not a struct type that can
be used in an array.

The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
as would be the case for a struct containing a member with
CRYPTO_MINALIGN_ATTR.

Signed-off-by: Behan Webster <beh...@converseincode.com>
Signed-off-by: Mark Charlebois <charl...@gmail.com>
Signed-off-by: Jan-Simon Möller <dl...@gmx.de>
---
 drivers/crypto/mv_cesa.c | 46 +++++++++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/crypto/mv_cesa.c b/drivers/crypto/mv_cesa.c
index 29d0ee5..0d92c85 100644
--- a/drivers/crypto/mv_cesa.c
+++ b/drivers/crypto/mv_cesa.c
@@ -402,26 +402,25 @@ 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;
+       char desc[sizeof(struct shash_desc) +
+               crypto_shash_descsize(tfm_ctx->fallback)] CRYPTO_MINALIGN_ATTR;
+       struct shash_desc *shash = (struct shash_desc *)desc;
        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 +793,24 @@ 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;
+               char desc[sizeof(struct shash_desc) +
+                       crypto_shash_descsize(ctx->base_hash)]
+                       CRYPTO_MINALIGN_ATTR;
+               struct shash_desc *shash = (struct shash_desc *)desc;
+
                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 +826,12 @@ 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);
-- 
1.9.1

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