[PATCH] crypto: LLVMLinux: Remove VLAIS from crypto/n2_core.c

[b***@converseincode.com]

=46rom: Behan Webster <***@converseincode.com>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C9=
9
compliant equivalent. This patch allocates the appropriate amount of me=
mory
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 ca=
n
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 <***@converseincode.com>
Signed-off-by: Mark Charlebois <***@gmail.com>
Signed-off-by: Jan-Simon M=C3=B6ller <***@gmx.de>
---
drivers/crypto/n2_core.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c
index 7263c10..ed142d1 100644
--- a/drivers/crypto/n2_core.c
+++ b/drivers/crypto/n2_core.c
@@ -445,10 +445,9 @@ static int n2_hmac_async_setkey(struct crypto_ahas=
h *tfm, const u8 *key,
struct n2_hmac_ctx *ctx =3D crypto_ahash_ctx(tfm);
struct crypto_shash *child_shash =3D ctx->child_shash;
struct crypto_ahash *fallback_tfm;
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(child_shash)];
- } desc;
+ char desc[sizeof(struct shash_desc) +
+ crypto_shash_descsize(child_shash)] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash =3D (struct shash_desc *)desc;
int err, bs, ds;
=20
fallback_tfm =3D ctx->base.fallback_tfm;
@@ -456,15 +455,15 @@ static int n2_hmac_async_setkey(struct crypto_aha=
sh *tfm, const u8 *key,
if (err)
return err;
=20
- desc.shash.tfm =3D child_shash;
- desc.shash.flags =3D crypto_ahash_get_flags(tfm) &
+ shash->tfm =3D child_shash;
+ shash->flags =3D crypto_ahash_get_flags(tfm) &
CRYPTO_TFM_REQ_MAY_SLEEP;
=20
bs =3D crypto_shash_blocksize(child_shash);
ds =3D crypto_shash_digestsize(child_shash);
BUG_ON(ds > N2_HASH_KEY_MAX);
if (keylen > bs) {
- err =3D crypto_shash_digest(&desc.shash, key, keylen,
+ err =3D crypto_shash_digest(shash, key, keylen,
ctx->hash_key);
if (err)
return err;
--=20
1.9.1